US3625384A

US3625384A - Article-handling apparatus

Info

Publication number: US3625384A
Application number: US762896A
Authority: US
Inventors: Frank E Boerger; Carlo Nuccio; Charles A Rosboschil
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1968-09-26
Filing date: 1968-09-26
Publication date: 1971-12-07
Anticipated expiration: 1988-12-07
Also published as: DE1948425C3; CA951341A; FR2018893A1; DE1948425A1; GB1265345A; JPS4936151B1; DE1948425B2

Abstract

Articles are transported from one position to another by being disposed in trays, which are carried within a portable magazine. The trays are automatically unloaded in sequence from the magazine and transported to a position in which the articles in the tray may be removed therefrom. The unloaded tray is then returned to the magazine and the next of the trays is removed from the magazine. The apparatus includes coding means on the magazine to indicate the status of the articles within each of the trays in the magazine.

Description

United States Patent [72] Inventors Frank E. Boerger Poughkeepsie; Carlo Nuccio, Poughkeepsie; Charles A.

Rosboschil, Wappingers Falls, all of N.Y.

[2]] Appl. No. 762,896

[22] Filed Sept. 26, 1968 [45] Patented Dec. 7, 1 971 [73] Assignee International Business Machines Corporation Armonk, N .Y.

[54] ARTICLE-HANDLING APPARATUS 12 Claims, 17 Drawing Figs.

214/85 A, 214/310, 214/152 [51 Int. Cl 865g 59/00 [50] Field of Search... 214/301,

[56] References Cited UNITED STATES PATENTS 1,940,867 12/1933 .lameset a1. 214/16.l2BX

2,617,700 11/1952 Christieetal ..2l4/16.12BX

2,762,489 9/1956 OSullivan 214/1612 B X 3,308,977 3/1967 Cochran et al. 214/301 3,332,560 7/1967 Niepmann 214/302 3,420,392 1/1969 Flint 214/301 2,333,097 11/1943 Duboc et al. 214/164 3,038,078 6/1962 Kern 214/164 UX 3,447,697 6/1969 Morey et al. 214/16 B X 2,701,065 2/1955 Bertel 214/1614 E FOREIGN PATENTS 1,179,866 10/1964 Germany 214/85 Primary E.raminerGerald M. Forlenza Assistant Examiner-George F. Abraham An0rneysHanifin and Clark and Frank C. Leach, Jr.

ABSTRACT: Articles are transported from one position to another by being disposed in trays, which are carried within a portable magazine. The trays are automatically unloaded in sequence from the magazine and transported to a position in which the articles in the tray may be removed therefrom. The unloaded tray is then returned to the magazine and the next of the trays is removed from the magazine. The apparatus includes coding means on the magazine to indicate the status of the articles within each of the trays in the magazine.

PATENTEDUEC mu 3.625384 sum 1 0r 7 FIG.1

INVENTORS FRANK E. BOERGER CARLO NUCCIO CHARLES A. ROSBOSCHIL BY 'M 6. M 9

ATTORNEY PATENTEDHEB 719m 3,625,384

I sum 2 0r 7 PATENTEU DEC 7 l9?) SHEET @1551 OF T PATENTEDHEC Han 3, 25,384

I SHEET 4 BF 7 ARTICLE-HANDLING APPARATUS In the automatic production of many similar-shaped articles of relatively small size such as electronic modular circuits, for example, the wafers, which have the electronic modular circuits formed thereon as integrated circuits, must be transported from one work station or area to another. During this transportation of the wafers, they must not become contaminated so that the wafers will have uniform characteristics when the various processing steps for forming the circuits on the wafer are carried out.

Even after the wafers have been transported to the work station or area, it is necessary to remove the wafers from the containing means without any contamination of the wafers. If the production of the electronic modular circuits is to be performed at a reasonable cost, it is necessary that these operations be performed as rapidly as possible.

The present invention satisfactorily meets the foregoing problem by providing a magazine in which trays, which contain a plurality of wafers in each, may be readily transported from one work station to another without any contamination of the wafers. When the magazine is positioned at a work station or area, the present invention utilizes an apparatus in which each of the trays is individually unloaded from the magazine and the wafers, which are within the tray, are removed from the tray and positioned for transport by other apparatus through the processing apparatus in which at least one of the steps in forming the circuit on the wafer is performed.

When transferring the wafers from one work station or area to another, it also is necessary that they do not become damaged during transit. The present invention satisfactorily solves the foregoing problem by protecting the wafers during transit by mounting them in individual trays with each tray having a plurality of receptacles with each receptacle receiving one of the wafers.

Depending on the sequence of operations in forming circuits on the wafers, it may be necessary to store the wafers at one or more of the work stations. The present invention satisfactorily meets this problem since the magazine, which contains the trays having the wafers therein, also can satisfactorily function as a storage container for the wafers until they are ready to be processed at a work station. Since the trays within a specific magazine may contain wafers that have been subjected to different parts of the process in which the circuit is formed on the wafer, it is necessary to prevent trays, which contain wafers that have already been subjected to a specific processing step, from being removed from the magazine. Accordingly, the magazine of the present invention utilizes coded means to regulate or control the trays that are withdrawn from the magazine for unloading of the wafers therefrom at a specific work station.

An object of this invention is to provide an apparatus for automatically loading and unloading trays from a magazine and articles from each of the trays.

Another object of this invention is to provide coding means to control which trays are removed from the magazine in which they are carried when the magazine is at a specific work station.

A further object of this invention is to provide a magazine, which transports trays, that also functions as a storage container.

Still another object of this invention is to provide an apparatus for transporting articles and removing the articles from the transport means without any manual handling thereof.

The foregoing and other objects, features, and advantages of the invention will be more apparent from the following more particular description of the preferred embodiment of the invention as illustrated in the accompanying drawings.

In the drawings FIG. 1 is an elevational view, partly in section, showing a magazine of the present invention for supporting the trays and a portion of the mechanism of the present invention utilized for removing the trays from the magazine.

FIG. 2 is a perspective view of one of the trays for supporting the articles with an article supported therein.

FIG. 3 is a top plan view of a mechanism for moving each of the trays out of the magazine to a position in which the articles may be removed from the tray and returning each of the trays into the magazine.

FIG. 4 is a side elevational view of a portion of the mechanism of FIG. 3.

FIG. 5 is a top plan view, taken substantially along line 55 of FIG. 1, of a portion of the apparatus of the present invention in which the magazine is supported when the trays are removed therefrom and returned thereto.

FIG. 6 is a side elevational view of the support structure of FIG. 5.

FIG. 7 is an elevational view, partly in section, showing the mounting arrangement of a microswitch that is actuated when one of the trays is moved downwardly within the magazine.

FIG. 8 is a top plan view of a lifter for lifting the articles from the tray when the tray is disposed above the lifter and taken substantially along line 8 -8 of FIG. 9.

FIG. 9 is a sectional view, partly in elevation, of the lifter of FIG. 8 and a handler for removing the articles from the lifter after the lifter has removed the articles from the tray with the portion of the view showing the lifter taken substantially along line 99 of FIG. 8.

FIG. 10 is a schematic view illustrating the movement of articles from the magazine to another system in which the articles are transported to a processing station.

FIG. 11 is a side elevational view of the handler of FIG. 9 but showing the movable part of the handler in its uppermost position.

FIG. 12 is a fragmentary plan view showing one set of fingers of the handler of FIG. 9 for retaining an article therein for support thereby and taken substantially along line l2-l2 of FIG. I 1.

FIGS. 13-16 are schematic views showing the relationship of trays within a magazine during positioning of one of the trays for removal from the magazine and return thereto.

FIG. 17 is a perspective view showing a device for indicating the condition of the articles in the trays within the magazine.

Referring to the drawings and particularly FIG. I, there is shown a magazine 10 having a plurality of trays 11 supported therein in vertically stacked relation. As shown in FIG. 2, each of the trays 11 has four receptacles or pockets 12 to receive articles 14, which may be wafers on which an integrated circuit is to be formed, for example, thereon.

The magazine 10 is substantially rectangular shaped in cross section and is formed by a pair of substantially parallel sidewalls 15, which are joined at their upper ends to each other by an upper plate 16 and at their lower ends by a baseplate 17. The magazine 10 has sliding doors l8 and 19 on opposite sides thereof with each of the sliding

doors

18 and 19 being slidably mounted in tracks, which are formed in the sidewalls 15. Thus, the doors l8 and 19 may be raised to permit access to the interior of the magazine 10.

Locking means 20 locks each of the sliding doors I8 and 19 in its lowermost position in which the openings into the magazine 10 are completely closed. Each of the locking means 20 includes a pin 21, which is resiliently urged into an aligned recess 22 in the upper plate 16 by a spring 23. The force of the spring 23 is overcome when a handle 24, which is fixed to the pin 21, withdraws the pin 21 from the recess 22. The pin 21 has a collar 25 thereon to limit movement of the pin 21 into the recess 22 in the upper plate 16 and to act against the spring 23 when the handle 24 withdraws the pin 21 from the recess 22 in the upper plate 16.

When the handle 24 is grasped to withdraw the pin 21 from the recess 22 in the upper plate 16, the sliding

door

18 or 19 may be lifted to permit access to the interior of the magazine 10. However, when the locking means 20 is disposed as shown for the sliding door 18 in FIG. 1, the interior of the magazine 10 is completely closed and no dust or light may enter the magazine 10. Thus, the articles 14, which are supported within the trays 11 in the magazine 10, are protected from contamination.

The locking means 20 for the door 19 is shown with the handle 24 in the position in which the pin 21 is withdrawn from the recess 22 so that there may be relative movement between the magazine 10 and the door 19. The handle 24 is retained in a notch 25' in an outwardly extending flange of the door. The notch 25' is shown in the flange of the door 18.

The upper plate 16 of the magazine 10 supports means for compressing the trays 11 within the magazine 10 when the magazine 10 is substantially loaded with the trays 11. This compression of the trays 11 relative to each other prevents any inadvertent removal of any of the articles 14 from the receptacle or pocket 12 in which each is disposed.

The compression means includes a plate 26 on the lower end of a rod 27, which is threadedly connected to the upper plate 16. Accordingly, turning of a handle 28, which is fixedly secured to the upper end of the rod 27, moves the bottom surface of the plate 26 into engagement with the top surface of the uppermost of the trays 11 disposed in vertically stacked relation within the interior of the magazine 10. This causes the trays 11 to be compressed within the magazine 10.

When the magazine 10 is disposed within an opening in a retention frame 29 (see FIG. the lower surface of the bottom plate 17 of the magazine rests on the upper surface of an elevator 30. The elevator 30 is slidably mounted on a pair of

rods

31 and 32, which are fixedly secured at their upper ends to the top of a table 33. The table 33 has an opening 34 through which the elevator 30 may slide.

The lower end of each of the

rods

31 and 32 is fixedly secured to a frame 35, which is fixedly supported by the table 33. Thus, the elevator 30 may be moved from the solid line position of FIG. 1 to the phantom line position of FIG. 1 by sliding along the

rods

31 and 32.

The elevator 30 has a feed screw 36 connected thereto and driven from a stepping motor 37 by a ball nut 38, which is supported by the frame 35. Since the elevator 30 cannot rotate because of its sliding cooperation with the

rods

31 and 32, the feed screw 36 causes sliding movement of the elevator 30 along the

rods

31 and 32.

When the magazine 10 is disposed within the retention frame 29, a vertically disposed orientation tang 39 (see FIGS. 1 and 17) on each of the sliding doors l8 and 19 is disposed within a cooperating slot 40 (see FIGS. 5 and 6) of the magazine retention frame 29. When the tangs 39 are properly seated in the slots 40, the bottom surface of the baseplate 17 rests on the upper surface of the elevator 30, as shown in FIG. 1, when the elevator 30 is in its uppermost position.

One of the tangs 39 is notched to rest on a pin 40 (see FIG. 6) in one of the slots 40. This insures that the magazine 10 is positioned in the desired relation to the magazine retention frame 29 since the other of the tangs 39 does not have the notched portion and the other of the slots 40 does not have one of the pins 40.

Each of the sliding

doors

18 and 19 has a horizontally disposed plate 41 extending across the top of the tang 39. When the magazine 10 is in the position shown in FIG. 1, the plate 41 of each of the sliding

doors

18 and 19 rests against an upper surface 42 of the magazine retention frame 29.

Each of the plates 41 has screws 43 (see FIG. 17) extending downwardly therefrom for cooperation with arms 44 of microswitches 45 (see FIGS. 6 and 17), which are mounted in the magazine retention frame 29. The magazine retention frame 29 has four of the microswitches 45 adjacent each of the slots 40 with two of the microswitches 45 disposed on one side of the slot 40 and the other two of the microswitches 45 disposed on the other side of the slot 40. Thus, four of the microswitches 45 are available for cooperation with the screws 43 on the plate 41 of the sliding door 18 while the other four of the microswitches 45 are available for cooperation with the screws 43 on the plate 41 of the sliding door 19. Accordingly, eight of the microswitches are adapted to be actuated when the magazine 10 is disposed within the magazine retention frame 29.

By selecting the number of the screws 43 on each of the sliding

doors

18 and 19 and their positions on the horizontal plates 41, a desired coded signal is provided by the magazine 10 when it is supported by the magazine retention frame 29. That is, the number of switches 45 actuated and which of the switches 45 is actuated determines the signal to a logic circuit (not shown) to which the microswitches 45 are connected. This enables the logic circuit to determine which of the trays 11 are to be removed from the magazine 10 and returned thereto.

After the tangs 39 have been properly seated within the slots 40 in the magazine retention frame 29, it is necessary to remove the pins 21 of the locking means 20 from the aligned recesses 22 in the upper plate 16. This is accomplished by rotating the handles out of the locking means 20 for disposition within the notches 25'. Then, when the elevator 30 is lowered, the magazine 10 follows the movement of the elevator 30 but the sliding doors l8 and 19 remain fixed and are not moved with the magazine 10.

Since the magazine 10 follows the movement of the elevator 30, it is necessary for the baseplate 17 of the magazine 10 to have a pair of openings 46 therein for cooperation with the

rods

31 and 32 to permit the

rods

31 and 32 to pass through the plate 17. It also is necessary for the baseplate 17 to have slots 47 formed therein and communicating with each of the openings 46. The slots 47 accommodate the support structure connecting the upper end of each of the

rods

31 and 32 to the top of the table 33.

As shown in FIG. 2, each of the trays 11 also has openings 48 on each side thereof to accommodate the

rods

31 and 32 when the tray 11 moves downwardly with the magazine 10. Each of the openings 48 communicates with a slot 49, which accommodates the support structure for one of the upper ends of the

rods

31 and 32 to the top of the table 33.

Since the baseplate 17 of the magazine 10 has the openings 46 and the slots 47 therein, it is necessary to close the openings 46 and the slots 47 in the baseplate 17 when the magazine 10 is employed to transport the trays 11. This closing is necessary to seal out any dust or light from the interior of the magazine 10.

Accordingly, each of the sliding doors l8 and 19 has a cylindrical-shaped member 50 (see FIG. 1) for disposition within the openings 46 in the baseplate 17. The cylindrical-shaped members 50 are supported in spaced relation to the interior surfaces of the sliding

doors

18 and 19 by members 51. The size of the openings 48 in the trays 11 and the slots 49 in the trays 11 are such that they pass over the cylindrical-shaped members 50 and the connecting members 51 when the trays 11 move upwardly or downwardly within the magazine 10.

When the magazine 10 is disposed in the magazine retention frame 29 with the baseplate 17 on the magazine 10 resting on the upper surface of the elevator 30 and the tangs 39 properly seated in the slots 40 in the magazine retention frame 29, it is then necessary to lower each of the trays 11 to a position in which they may be moved from the magazine 10 and then returned to the magazine 10. When one of the trays 11 is being removed from the magazine 10 and then returned to the magazine 10, it is necessary to support the remainder of the stacked trays 11 above the tray 11, which is being removed from the magazine 10 and returned thereto, with the lowermost of the stacked trays 11 being spaced from the tray 11 that is being removed and returned.

Accordingly, a pair of retaining

arms

52 and 53 is pivotally mounted on the magazine retention frame 29. The retaining

arms

52 and 53 have their pivotally mounted

support rods

54 and 55, respectively, pivoted by the

rotary solenoids

56 and 57, which are supported on the retention frame 29. Accordingly, when the

solenoids

56 and 57 are energized, the retaining

arms

52 and 53 are moved to a position in which they will engage inclined lower edges 57 of one of the trays 11 within the stacked relation in the magazine 10. The anns 52 and 53 engage the tray 11, which is above the tray 11 that is to be removed from and returned to the magazine 10. It should be understood that the retaining

arms

52 and 53 are continuously biased by the springs to the position in which they do not engage any of the trays 11 so that deenergization of the

solenoids

56 and 57 results in the retaining

arms

52 and 53 being returned to the position in which they do not retain any of the trays 11.

The movement of each of the trays 11 from the magazine and back to the magazine 10 is performed by a push-pull means including an arm 58 having a circular shaped end 59 that is adapted to be disposed within one of the openings 48 in the tray 11. When one of the trays 11 is moved into the plane containing the arm 58, one of the openings 48 in the tray 11, which is to be removed from the magazine 10, will encompass the end 59 while the slot 49, which is communicating with the opening 48 in the tray 11 encompassing the end 59, will have a portion of the am 58 extending therethrough. Accordingly, movement of the arm 58 controls movement of the tray 11 provided that the tray 11 is not frictionally restrained.

The arm 58 is connected to a carrier 60 (see FIG. 3), which is slidably mounted on a frame 61 by being slidable along rods 61' fixed to the frame 61; the frame 61 is fixedly secured to the top of the table 33. The carrier 60 is connected to a piston rod 62 (see FIG. 4) of a fluid cylinder 63. The fluid cylinder 63, which is preferably an air cylinder, is supported by the top of the table 33. Accordingly, when fluid is' supplied to one end of the cylinder 63, the arm 58 is extended from the frame 61 and when fluid is supplied to the opposite end of the cylinder 63, the arm 58 is retracted.

Movement of the arm 58 is stopped by engagement of the carrier 60 with

stop pins

63a and 63b on the frame 61. Retraction of the arm 58 is stopped by engagement of the carrier 60 with the stop pin 6311 while extension of the arm 58 is stopped by the carrier 60 engaging the stop pin 63b.

The frame 61 has a pair of microswitches 64 and 65 (see FIG. 3) mounted thereon to indicate that movement of the arm 58 in each direction has stopped. The microswitch 64 has an arm 66, which is moved by a cam surface on the carrier 60, to deenergize the microswitch 64 to indicate retraction of the arm 58 into the frame 61 has been completed and to stop fluid flow to the cylinder 63. The retraction of the arm 58 is stopped in the position in which the end 59 is aligned with one group of the vertically aligned openings 48 in the trays 11.

When an arm 67 of the microswitch 65 engages a cam surface on the carrier 60, the extension of the arm 58 from the frame 61 has been completed and fluid flow to the cylinder 63 is stopped. This is the position to which the tray 11 is moved to have the articles 14 removed therefrom.

As previously mentioned, there must be clearance between each of the trays 11, which is to be moved by the arm 58, and the tray 11 thereabove and adjacent thereto when the arm 58 moves the tray 11 from the magazine 10. Accordingly, with the magazine 10 positioned as shown in FIG. 1, it is first necessary to energize the stepping motor 37 to lower the elevator 30.

When the stepping motor 37 ceases to lower the elevator 30 after the predetermined number of steps required to position the lowermost of the trays 11 so that the retaining

arms

52 and 53 would not engage the lowermost of the trays 11 but the tray 11 above the lowermost tray 11, the

rotary solenoids

56 and 57 are energized by the logic circuits to move the

arms

52 and 53 into their retaining positions. Then, the stepping motor 37 continues to be energized to move the elevator 30 downwardly. As a result, the lowermost of the trays 11 continues to move downwardly as will all of the other of the trays l I.

As the elevator 30 moves downwardly, a pair of microswitches 68 (one shown for the arm 53), which are carried by the

arms

52 and 53, will be energized. This occurs due to the inclined edges 57 of the tray 11, which is next to the lowermost of the trays ll, engaging a bracket 70 (see FIGS. 6 and 7), which is pivotally mounted on each of the

arms

52 and 53 for actuating the microswitches 68. When the microswitches 68 are energized, the logic circuit receives a signal and allows the stepping motor 37 to step only a predetermined number of steps. This will precisely position the lower tray 11 for actuation by the arm 58 with the desired clearance between the upper surface of the lowermost tray 11 and the bottom surface of the next adjacent of the trays 11 thereabove in the magazine 10.

When the stepping motor 37 stops after the predetemiined number of steps after the microswitches 68 are energized, the logic circuit permits flow of fluid to the fluid cylinder 63 to move the arm 58 away from the frame 61. Thus, the microswitches 68 insure that there is a clearance between the tray 11, which is to be removed from the magazine 10 by the arm 58, and the remainder of the trays 11 within the magazine 10 above the tray 11, which is to be removed.

It should be understood that the lower surface of the tray 11, which is to be removed from the magazine 10, will always be positioned in the desired horizontal plane when the microswitches 68 have been actuated since this indicates a certain clearance from the next adjacent of the trays 11 in the magazine 10. The positions of the brackets of the microswitches 68 are such that this clearance insures that the lower surface of the tray 11, which is to be removed from the magazine 10 by the arm 58, is in the desired horizontal plane.

When the arm 58 is moved its maximum distance from the frame 61, the tray 11, which the arm 58 is disposed within and moving, is positioned above an article lifter 71 (see FIG. 8), which is supported by the table 33. The tray 11 is disposed above the lifter 71 so that each of the receptacles or pockets 12 in the tray 11 is positioned above a corresponding piston 72 of the article lifter 71.

When the tray 11 is positioned above the lifter 71, it is supported by a plate 71' (see FIG. 9), which is fixedly supported by the table 33, and properly oriented by a push-pull mechanism 72 (see FIG. 10). The push-pull mechanism 72' is actuated by the logic circuit when the

rotary solenoids

56 and 57 are energized.

The pistons 72 are adapted to enter each of the receptacles 12 in the tray 11 through an opening 73 (see FIG. 2) in the center of each of the receptacles 12. Accordingly, when the pistons 72 are moved upwardly through the openings 73 in the tray 11, the articles 14 are removed from the tray 11 and supported by the lifter 71.

The pistons 72 are supported on a movable support 74 (see FIG. 9), which is attached to piston rod 75 on a fluid cylinder 76; the fluid cylinder 76 is secured to the table 33 and is preferably an air cylinder. The movable support 74 is slidably mounted on a pair of rods 77, which extend between upper portion 78 and lower portion 79 of a frame 80. The frame 80 is supported on a plate 81, which is secured to the cylinder 76 for support from the table 33 through the cylinder 76. Accordingly, when fluid is supplied to the cylinder 76, the support 74 is moved upwardly to cause the pistons 72 to engage the bottoms of the articles 14 in the tray 11.

In order to retain each of the articles 14 on the upper surface of the aligned piston 72 after the articles 14 are removed from the tray ill, each of the pistons 72 has a passage 82 extending therethrough and communicating with a recess 83 in the top surface of the plate 72. The passages 82 are connected to a suitable vacuum pump (not shown) whereby a vacuum is applied through the passage 82 and the recess 83 in each of the pistons 72 to retain the article 14 on the piston 72. This prevents any accidental dislodging of the article 14 from the piston 72.

Simultaneous upward movement of the pistons 72 occurs when the arm 58 has completed its movement to position the tray 11 above the lifter 71 with the openings 73 in the tray 11 aligned with the pistons 72. Thus, when the microswitch 65 (see FIG. 3) has its arm 67 actuated by the cam surface on the carrier 60, this indicates to the logic circuit that movement of the arm 58 has stopped. When the logic circuit receives this signal, it allows fluid to be supplied to the cylinder 76 to cause upward movement of the movable support 74. It also simultaneously allows the vacuum to be applied through the passages 82 in the pistons 72.

Upward movement of the movable support 74 is stopped when a pin 84, which extends downwardly from the upper portion 78 of the frame 80, is engaged by a microswitch 85, which is carried on one end of the movable support 74. When this occurs, the vacuum to the passages 82 is stopped and fluid to the cylinder 76 is reversed whereby the movable support 74 starts downward. When the pistons 72 are moved to their uppermost positions, which are when the microswitch 85 engages the pin 84, fingers 86 of an article handler 87 (see FIG. 9) are moved to grasp the articles 14, which are supported on the upper surfaces of the four pistons 72. The article handler 87 has four groups of the fingers 86 with each group of the fingers 86 adapted to cooperate with the article 14 on one of the pistons 72.

The article handler 87 includes a main support plate 88, which is supported in spaced relation to the top of the table 33 by support legs 89. The support plate 88 has a support 90 extending downwardly therefrom. The support 90 has four cylindrical-shaped members 91 supported thereby and extending downwardly therefrom. Each of the cylindrical-shaped members 91 has one of the sets of the fingers 86 attached thereto.

Each of the fingers 86 has a brace 92 extending through an aperture 93 in a cam plate 94. The cam plate 94 is supported at the lower end of a glide housing 95, which is carried by a rod 96. The rod 96 is connected to a piston rod of a fluid cylinder 97, which is supported by the main plate 88 and is preferably an air cylinder, whereby movement of the glide housing 95 is controlled. Thus, when fluid is supplied to one end of the fluid cylinder 97, the glide housing 95 is moved downwardly to the position of FIG. 9 whereby the cam plate 94 moves the fingers 86 of each of the sets toward each other so as to grasp the article 14, which is supported on the piston 72. When fluid is supplied to the other end of the cylinder 97, the glide housing 95 is moved upwardly from the position of FIG. 9.

The vertical movement of the glide housing 95 is accomplished by utilizing vertically disposed guide rods 98, which are supported from the main support plate 88. Two of the rods 98 extend through horizontally spaced openings in an upper flange 99 and horizontally spaced openings, which are vertically aligned with the openings in the upper flange 99, in a lower flange 100 on one side of the glide housing 95 while two more of the rods 98 extend through horizontally spaced openings in an upper flange 101 (see FIG. 11) and horizontally spaced openings, which are vertically aligned with the openings in the upper flange 101, in a lower flange 102 on the other side of the glide housing 95. Thus, when the fluid cylinder 97 has fluid supplied thereto to move the glide housing 95, the housing 95 can only move in a vertical direction.

Downward movement of the glide housing 95 is stopped by a mechanical stop, which includes a screw stop 103 (see FIG. 11) on each of the

flanges

99 and 101. Each of the screw stops 103 cooperates with the head of a bolt 104, which is carried on each of L-shaped supports 105 and 106 that extend downwardly from the support plate 88 and are supported thereby. This insures that the fingers 86 are properly positioned to retain the article 14 therein.

At the same time that the movable support 74 of the lifter 71 starts to move downwardly, the push-pull mechanism 72 is returned to the position shown in FIG. by a signal from the logic circuit. When the mechanism 72 returns to the position of FIG. 10, a switch is actuated to supply a signal to the logic circuit to start a return conveyor 112.

When the movable support 74 of the lifter 71 reaches its lowermost position, a microswitch 113 (see FIG. 9), which is carried by the movable support 74 on the opposite side from the microswitch 85, engages a stop pin 114 on the frame 80. This provides a signal to the logic circuit to stop the flow of fluid to the cylinder 76.

When the logic circuit receives the signal that the pistons 72 have been retracted from the tray 11, fluid is supplied to the cylinder 63 to cause retraction of the arm 58. This pulls the tray 11 back into the magazine 10.

Retraction of the arm 58 ceases when the carrier 60 engages the stop pin 63a (see FIGS. 3 and 4). This is when the tray 11 is again properly positioned within the magazine 10 so that the openings 48 (see FIG. 2) in the tray 11 are aligned with the elevator support rods 31 and 32 (see FIG. 1) to permit the tray 11 to move downwardly when the elevator 30 is next actuated.

When the microswitch 64 (see FIG. 3) is actuated by the cam surface on the carrier 60 to indicate that retraction of the arm 58 has been completed, it supplies a signal to the logic circuit to cause deenergization of the rotary solenoids 56 and 57 (see FIG. 1). This causes the retaining

arms

52 and 53 to be moved away from engagement with the tray 11, which they have been engaging to support the stack of the trays 11 as schematically shown in FIG. 13, to the position of FIG. 14. As a result, the stack of the trays 11 drops to close the clearance between the trays 11, which have been supported by the retaining

arms

52 and 53, and the tray 11, which was removed from and then returned to the magazine 10. This is schematically shown in FIG. 14.

When the retaining

arms

52 and 53 are removed from engagement with the tray 11, the microswitches 68 (see FIG. 7) are no longer closed since the brackets 70 are moved away from the tray 11 with the retaining

arms

52 and 53. As a result, the opening of the microswitches 68 provides a signal to the logic circuit to indicate that the retaining

arms

52 and 53 are no longer holding the trays 11.

When the logic circuit receives this signal, the stepping motor 37 is again energized to lower the elevator 30 a predetermined number of steps whereby the magazine 10 is moved further downwardly to cause another of the trays 11 to be moved toward the position for movement out of and then return into the magazine 10 by means of the arm 58. After the elevator 30 is moved downwardly the predetermined number of steps to position the trays 11 as shown in FIG. 15, the

rotary solenoids

56 and 57 are again energized by the logic circuit to return the retaining

arms

52 and 53 to the position of FIG. 16 in which they will again engage the next of the trays 11 without engaging the prior tray 11, which the

arms

52 and 53 had previously engaged.

The stepping motor 37 continues to move the elevator 30 downwardly until the tray 11, which the retaining

arms

52 and 53 are to support, has the lower edges 57' engage the brackets 70 of the microswitches 68. When this occurs, the logic circuit receives a signal and allows the stepping motor 37 to step only a predetermined number of steps. This precisely positions the tray 11, which is above the lowermost tray 11, for the actuation by the arm 58 with the desired clearance provided between the tray 11, which is to be moved out of the magazine 10 by the arm 58, and the adjacent tray 11 thereabove in the same manner as shown in FIG. 13. When the stepping motor 37 stops after the predetermined number of steps after energization of the microswitches 68, the logic circuit again permits the arm 58 to again move the tray 11, which is disposed for movement out of the magazine 10, since the clearance between the upper surface of the tray 11 and the tray 11, which is held by the retaining

arms

52 and 53, exists. Of

course, there also must be a signal to the logic circuit that the article lifter 71 and the article handler 87 are ready to receive another of the trays 11 before the logic circuit allows fluid to flow to the cylinder 63.

While the article lifter 71 is ready to receive another of the trays 11 when the tray 11 is removed from the article lifter 71 by the actuator arm 58, the articles 14, which are carried by the fingers 86 of the article handler 87, must be removed therefrom before the article handler 87 is ready to receive another of the trays 11.

Accordingly, when the return conveyor 112 starts due to th push-pull mechanism 72' returning to the position of FIG. 10, it advances a carrier 115 (see FIG. 10), which transports the articles 14 from the article handler 87, to a position in which a photocell is picked. Through the logic circuit, this stops the return conveyor 112 and raises positioner pins from the table 33 to properly position the carrier 115 beneath the sets of the fingers 86.

At the same time that the positioner pins are moved to their active positions, the push-pull mechanism 72' is actuated to dispose the carrier I beneath the sets of fingers 86 to receive the articles 14, which are held by the fingers 86. Guide plates 115' and 116 (see FIG. 9), which are mounted on opposite sides of the glide housing 95, cooperate to align the carrier 115, which is wider than the tray 11. When the carrier 115 is appropriately positioned beneath the sets of the fingers 86, a signal is supplied to the logic circuit to cause the cylinder 97 to retract or lift upwardly the glide housing 95. As a result, the fingers 86 in each of the sets are moved away from each other by the cam plate 94 to cease to hold the article 14 therein.

As shown in FIG. 9, a blowoff tube 117 extends through the center of each set of the fingers 86' and supplies nitrogen against the article 14, which is held by the fingers 86. The supply of nitrogen through the blowoff tube 117 cleans the articles 14, which are wafers, before they are moved to a processing station by the carrier 115. The supply of nitrogen to the blowoff tube 117 occurs when the photocell is picked by the carrier 115.

After the carrier 115 has received the articles 14 from the article handler 87, the positioner pins are retracted into the table 33 and the push-pull mechanism 72 is retracted to the position of FIG. 10. When the push-pull mechanism 72 is returned to the position of FIG. 10, a signal is supplied to the logic circuit to indicate this. Then, a push-pull mechanism 118 (see FIG. 10) is activated to remove the carrier 115 from beneath the article handler 87 to a continuously moving conveyor 119, which will transport the articles 14 in the carrier 115 to a processing station.

After the carrier 115, which receives the articles 14 from the article handler 87, has been removed from beneath the article handler 87 by the push-pull mechanism 118, the pushpull mechanism 118 is returned to the position of FIG. 10. Then, a signal is supplied to the logic circuit to indicate this. Accordingly, the cylinder 63 may then have fluid supplied thereto to move another of the trays 11 from the magazine 10.

When the glide housing 95 is moved upwardly, upward movement is stopped by engagement of the

upper flanges

99 and 101 with limit screws 120 (one shown in FIG. II), which are carried by the main support plate 88 of the article handler 87.

While upward movement of the glide housing 95 is stopped by the mechanical stop, flow of fluid to the cylinder 97 is stopped when a cam roller 121 (see FIG. 9) on an arm 122 of a microswitch 123, which is carried by a bracket 124 extending downwardly from the main support plate 88, engages a surface 125 of the guide plate 115. Thus, when the microswitch 123 is actuated by the cam roller I21 engaging the surface 125 of the guide plate 115', a signal is supplied to the logic circuit to stop flow of fluid to the cylinder 97.

At this time, another cycle is ready. Thus, the tray 11 can now be removed from the magazine 10 by the arm 58 and the entire cycle repeated.

Considering the operation of the present invention, the magazine 10 is loaded in the magazine retention frame 29 with the tangs 39 in the slots 40 and the screws 43, which are sup ported on the horizontally disposed plate 41 on each of the

doors

18 and 19 of the magazine 10, engaging the microswitches 45. This produces a signal to the logic circuit to indicate which of the trays 11 are to be removed therefrom. After the magazine 10 is properly positioned in the magazine retention frame 29, both of the locking means are released so that the magazine 10 may be moved downwardly by the elevator while the sliding

doors

18 and 19 remain fixed in the magazine retention frame 29.

With the magazine 10 properly loaded in the magazine retention frame 29, the stepping motor 37 is energized by a pushbutton on the control panel. Accordingly, the stepping motor 37 moves the elevator 30 and the magazine 10 with the trays 11 therein downwardly for a predetermined number of steps. The stepping motor 37 is stopped after the elevator 30 has been lowered a predetermined number of steps.

Then, the

rotary solenoids

56 and 57 are energized to move the retaining

arms

52 and 53 along the microswitches 68 into the positions in which the

arms

52 and 53 will engage the next of the trays 11 above the lowermost of the trays II. It is assumed that the logic circuit receives a signal from the microswitches 45 to indicate that the first of the trays 11 is to be removed from the magazine 10. If this were not the situation, then the elevator 30 would have been moved downwardly by the stepping motor 37 for the number of steps that would have positioned the tray 11, which was initially desired to be removed from the magazine 10, for removal from the magazine 10.

When the

rotary solenoids

56 and 57 are picked to move the retaining

arms

52 and 53 along with the microswitches 68 into positions in which they will be engaged by one of the trays II in the magazine 10, the stepping motor 37 also is energized at this same time. Thus, the elevator 30 begins to move downwardly in stepped increments.

As the elevator 30 moves downwardly, the inclined surfaces 57' of the tray 11, which is above the lowermost tray 11, initially engage the brackets 70 on the

arms

52 and 53. This activates the microswitches 68 to supply a signal to the logic circuit.

When the logic circuit receives a signal due to both of the microswitches 68 being energized, the stepping motor 37 may then continue to step the elevator 30 downwardly for a predetermined number of steps until the lower most tray 11 is disposed with the clearance from the next of the trays II. This is shown in FIG. 13.

After the stepping motor 37 has been stepped the desired number of steps after the microswitches 68 have been activated, the logic circuit stops the stepping motor 37. At this time, the elevator 30 has positioned the lowermost tray 11 so that the end 59 of the arm 58 is disposed within the opening 48 in the tray 11. Accordingly, fluid is supplied to the cylinder 63 to move the carrier 60 to position the tray 11 above the article lifter 71 (see FIGS. 8 and 9). It should be understood that the push-pull mechanism 72' (see Flg. 10) is activated at the same time that the

rotary solenoids

56 and 57 are picked. Thus, the push-pull mechanism 72 is positioned beneath the article handler 87 and above the article lifter 71 when the tray 11 is moved between the article lifter 71 and the wafer handler 87. It should be understood that the complete movement of the push-pull mechanism 72' is not completed until after movement of the carrier 60 has started.

When the carrier 60 completes its movement to position the tray 11 above the article lifter 71 by disposing the tray on the plate 71 for support thereby, the microswitch 65 (see FIG. 3) is activated by the arm 67 being engaged by a cam surface on the carrier 60. This not only stops flow of fluid to the cylinder 63 but also provides a signal to the logic circuit to cause fluid to be supplied to the cylinder 76 (see FIG. 9) to move the movable support 74 upwardly and vacuum to be applied to the passages 82 in the pistons 72. The vacuum retains the articles 14 on the tops of the piston 72 as the movable support 74 is moved upwardly.

When the movable support 74 completes its upward movement, the microswitch 85 is activated to provide a signal to the logic circuit. This reverses the supply of fluid to the cylinder 76 to cause downward movement of the movable support 74 of the article lifter 71 and activates the supply of fluid to the cylinder 97 to start downward movement of the cam plate 94. At the same time, the push-pull mechanism 72 is retracted from the position in which it aided in positioning the tray 11.

The downward movement of the cam plate 94 moves the fingers 86 toward each other to grasp the articles 14 therebetween. When the fingers 86 grasp the articles 14 for supporting the articles, they remove the articles I4 from the pistons 72 on which the articles 14 have been supported. While the cylinder 76 for moving the movable support 74 downwardly has the fluid supply reversed at the same time that the fluid is supplied to the cylinder 97 to move the cam plate 94 downwardly, the relative inertia of the two structures is such that the fingers 86 will grasp the articles 14 before the pistons 72 have moved downwardly.

The downward movement of the article lifter 71 is stopped when the microswitch 113 is activated. As a result, this supplies a signal to the logic circuit to stop fluid flow to the cylinder 76 and to supply fluid to the cylinder 63 to retract the arm 58 so as to return the tray 11 to the magazine 10.

When the carrier 60 has been retracted into the frame 61 so that the microswitch 64 (see FIG. 3) is actuated by a cam surface on the carrier 60 engaging the roller on the arm 66 of the microswitch 64, a signal is supplied to the logic circuit to stop flow of fluid to the cylinder 63. The logic circuit also deenergizes the

rotary solenoids

56 and 57 to return the

arms

52 and 53 to the position of FIG. 14 whereby the trays 11 may fall downwardly so that there is no longer any clearance between the tray 11, which has been removed from the magazine and returned thereto, and the trays 11 thereabove. The logic circuit then supplies a signal to the stepping motor 37 to lower the elevator a predetermined number of steps so that the retaining anns 52 and 53 will be able to move into engagement with the inclined surface 57 of the third of the trays l 1 above the baseplate 17 in the manner shown in FIG. 16 when the

rotary solenoids

56 and 57 are next energized.

At the same time that the movable support 74 (see FIG. 9) of the article lifter 71 returned to the position in which the microswitch 113 was activated, the push-pull mechanism 72 (see FIG. 10) returned to the position in which it activated a microswitch to supply a signal to the logic circuit. This resulted in the logic circuit activating the return conveyor 112 to move one of the carriers 115 to a position in which a photocell was activated through sensing the carrier 115 at this position. When this occurs, the return conveyor 112 is inactivated by the logic circuit.

At this time, the positioner pins are advanced upwardly from the table 33 into a position to limit the amount of movement of the carrier 115 beneath the article handler 87. The movement of the carrier 11S underneath the article handler 87 by the push-pull mechanism 72 being activated occurs at the same time that the positioner pins are moved upwardly from the table 33.

At this time, the logic circuit also supplies a signal to cause the blowoff tubes 117 to supply nitrogen to the articles 14 to clean them. Thus, the blowoff tubes 117 apply nitrogen before the fingers 86 of the article handler 87 release the articles 14 therefrom.

When the push-pull mechanism 72' completes its inward movement whereby the carrier 115 is properly positioned beneath the fingers 86 of the article handler 87, a switch is activated to provide a signal to the logic circuit whereby fluid is supplied to the cylinder 97 to move the camp plate 94 upwardly and cause the fingers 86 to cease to retain the articles 14 therein. As a result, the articles 14 fall into the carrier 115.

After fluid flow to the cylinder 97 has returned the cam plate 94 to the uppermost position, the microswitch 123 is deenergized to provide a signal to the logic circuit to indicate this. This stops flow of fluid to the cylinder 97.

At the same time that the fluid is supplied to the cylinder 97 to move the cam plate 94 upwardly to cause the articles 14 to be released from the fingers 86, the push-pull mechanism 72 is retracted. When the push-pull mechanism 72' completes its retraction, a switch is activated to indicate this to a logic circuit. At this time, the positioner pins are retracted into the table 33 and the push-pull mechanism 118 is activated to move the carrier 115 onto the conveyor 119. The conveyor 119 is a continuously moving conveyor so that the carrier 115 is rapidly moved away from the article handler 87 as soon as the carrier 115 is disposed on the conveyor 119.

Upon the push-pull mechanism 118 completing its push cycle whereby the carrier 115 is pushed onto the conveyor 119, a switch is actuated to provide a signal to the logic circuit. As a result, the logic circuit supplies a signal to retract the push-pull mechanism 118 to the position of FIG. 10. When the push-pull mechanism 118 returns to the position of FIG.

10, it actuates a switch to indicate to the logic circuit that it is no longer disposed beneath the article handler 87.

Then, the logic circuit not only supplies a signal to stop movement of the push-pull mechanism 118 but also supplies a signal to pick the

rotary solenoids

56 and 57 and to start downward movement of the elevator 30 by energizing the stepping motor 37. This moves the retaining

arms

52 and 53 into the position shown in Flg. 15. As the downward movement of the elevator continues, the microswitches 68 are activated, as previously described, and the remainder of the cycle continues in the same manner. Of course, the signal from the logic circuit, which picks the

rotary solenoids

56 and 57, activates the push-pull mechanism 72 to dispose it beneath the article handler 87.

If desired, one or more of the trays 11 may be skipped and not removed from the magazine 10. This would be accomplished through the signals supplied to the logic circuit from the microswitches 45, which are actuated by the screws 43 carried on the horizontal disposed plates 41 on the

doors

18 and 19. In this arrangement, the stepping motor 37 would lower the elevator 30 a much greater distance than merely the thickness of one of the trays 11 when the tray 11, which has been removed from the magazine 10, is returned thereto.

When all of the trays 11 which are carried by the magazine 10 and are to be removed therefrom, have been removed and returned thereto, the logic circuit supplies a signal to the stepping motor 37 to lower the elevator 30 until a microswitch 126 (see FIG. 1), which is carried by the frame 35, is actuated by the elevator 30 being in its lowermost position as indicated in phantom lines.

When the elevator 30 is in its lowermost position, the signal to the logic circuit from the microswitch 126 causes the stepping motor 37 to be reversed in direction and the speed to be increased to move the elevator 30 upwardly until the elevator 30 is stopped by a microswitch (not shown).

When the microswitch is engaged by the elevator 30 in its upward movement, the signal to the logic circuit causes the logic circuit to reverse the stepping motor 37 and lower the elevator 30 at the lower speed, which is used in lowering the elevator to remove the traps 11 from the magazine 10. The stepping motor 37 is energized for a predetermined number of steps and then stopped. This disposes the elevator 30 in the solid line position of FIG. 1.

Then, the magazine 10 is removed from the magazine retention frame 29. Prior to removal of the magazine 10 from the magazine retention frame 29, the handles 24 of the locking means 20 are removed from the notches or slots 25' in the

doors

18 and 19 and rotated so that the locking means 20 may again lock the

doors

18 and 19 to the upper plate 16 of the magazine 10. This provides a storage container for the tray 11 into which neither dust nor light may penetrate. Furthermore, the trays 11 are secured by the compression plate 26 through the handle 28.

After the magazine 10 is removed from the magazine retention frame 29, it may be transported to another station or stored. It also may be necessary to vary the number of the screws 43 in one or both of the horizontally disposed plates 41 on the doors l8 and 19 at this time.

Instead of utilizing the magazine 10 for transporting articles to a work station and then removing the articles therefrom for processing at the work station, it should be understood that the present invention may be readily utilized for receiving articles from a work station for transport therefrom. In such an arrangement, each of the trays 11 would be removed from the magazine 10 by the actuating arm 58 and disposed in a position in which the articles 14 could be deposited within the receptacles 12 in the trays 11. After the articles 14 were placed in the receptacles 12 in the tray 11, the tray 11 would be returned to the magan'ne 10. The elevator 30 would have to be lowered after each of the trays 11 was returned to the magazine 10 in the same manner as previously described so that another of the trays 11 could be removed from the magazine 10 for receiving the articles 14.

The sliding doors l8 and 19 on the magazine 1 would have the screws 43 on the plates 41 to indicate which of the trays 11 was empty and available to receive the articles 14. Thus, only a portion of the trays 11 within the magazine might be available to receive the articles 14.

The articles 14 are dropped into the receptacles 12 in the tray 111 from a vacuum article pickup. The vacuum article pickup removed the articles 14 from one of the carriers 115 into which the articles l4l have been disposed after the articles 14 have been treated at the processing station.

While the retaining

arms

52 and 53 have been shown as actuated by the

rotary solenoids

56 and 57, it should be understood that any other suitable means for moving the retaining

arms

52 and 53 may be employed. For example, an air cylinder with a gear drive arrangement could be utilized.

An advantage of this invention is that wafers may be automatically transferred in sets from a storage area to a processing station. Another advantage of this invention is that the articles are protected during transit or storage from breakage, dust, or light. A further advantage of this invention is that the magazine may be utilized for both transporting the articles and storing the articles.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in the form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. An apparatus for handling articles including:

a plurality of container means, each of said container means adapted to support at least one article;

first means to support a plurality of said container means in vertically stacked relation in engagement with each other; second means to removably support said first support means; transport means to remove any of said container means from said first support means separately to a position external of said first support means and return said removed container means from the external position to said first support means in the same stacked relation before another of said container means is removed therefrom by said transport means; means to lower the stacked relation of said container means a predetermined distance;

third means to support all of said container means above said container means that is to be removed from said first support means by said transport means, said third means being effective after said lowering means has lowered the stacked relation of said container means the predetermined distance;

and means to cause said lowering means to lower said container means that is to be removed from said first support means by said transport means and any of said container means therebeneath until said container means that is to be removed is at the position at which said container means is removed from said first support means by said transport means, said causing means being effective after said third means is effective whereby a clearance is provided between the lowermost of said container means supported by said third means and said container means that is to be removed from said first support means by said transport means.

2. The apparatus according to claim 1 in which:

each of said container means removed from and returned to said first support means by said transport means has at least one article supported thereby;

and means to automatically remove the article from said container means after said container means is removed from said first support means and before start of return of said container means to said first support means.

3. The apparatus according to claim l including means to selectively render said third support means inefiective at various times during movement of said container means by said lowering means.

4. An apparatus for handling articles including:

first means to support a plurality of said container means in vertically stacked relation in engagement with each other; second means to removably support said first support means;

transport means to remove any of said container means from said first support means separately to a position external of said first support means and return said removed container means from the external position to said first support means in the same stacked relation before another of said container means is removed therefrom by said transport means;

third means, separate from said first support means, being selectively efi'ective to support all of said container means stacked above said container means being removed from said first support means by said transport means in spaced relation to said container means being removed from said first support means by said transport means to provide a clearance therebetween;

and said first support means having means supported thereby to select which of said container means is removed from and returned to said first support means by said transport means when said first support means is supported by said second support means.

5. The apparatus according to claim 4 in which said second support means has means supported thereby cooperating with said selecting means of said first means to control which of said container means is removed from said first support means and returned thereto by said transport means.

6. An apparatus for handling articles including:

first means to support a plurality of said container means in stacked relation;

said first support means includes:

a body supporting said container means; and said body having sliding access means on opposite sides thereof;

second means to support said first support means;

said second support means includes:

means to fixedly support said sliding access means when said first support means is supported on said second support means;

and means to movably support said body when said first support means is supported on said second support means;

and transport means adapted to move each of said container means from said first support means separately and return each of said container means to said first support means before another of said container means is removed therefrom.

7. The apparatus according to claim 6 including means to lock each of said sliding access means to said body when said first support means is removed from said second support means to form a closed housing for said container means.

8. A method of handling articles including:

arranging a plurality of containers in vertically stacked relation with each of the containers adapted to support at least one article;

disposing the stacked containers so that a container may be moved horizontally therefrom by lowering the stacked containers for a predetermined distance, preventing further lowering of the containers above the container to be horizontally moved from the stacked containers, and lowering the horizontally movable container and any containers therebeneath until the horizontally movable container is at the position at which it is to be horizontally moved;

supporting the containers above the horizontally movable container in vertically spaced relation to the horizontally movable container while the horizontally movable container is removed from the stacked relation and then returned to the stacked relation;

removing the horizontally movable container from the stacked relation to a position external of the stacked relation and returning the horizontally movable container from the external position to the stacked relation before tainer means after said container means is removed from said first support means;

and means to indicate that said container means is removed from said first support means by said transport means,

another of the containers can be removed from the 5 said indicating means insuring that said automatic stacked relation; removal means is not actuated until said container means stopping support of the containers above the horizontally is removed from said first support means by said transport movable container after it has returned to the stacked means. I relation; 12. An apparatus for handling articles including; and lowering the stacked relation of the containers to posia plurality of container means, each of said container means tion another of the containers for horizontal movement adapted to support at least one article; from the stack after the horizontally movable container is first means to support a plurality of said container means in returned to the stacked relation and the support of the stacked relation; containers above the horizontally movable container is second means to support said first support means; ended. l5 transport means adapted to move each of said container 9. The method according to claim 8 in which: means from said first support means separately and return each of the containers supports at least one article therein; each of said container means to said first support means and selecting the containers to be removed is in accordance f r n her f i ontainer means iS removed with an indicating signal. therefrom;

10. The method according to laim 9 including removing third means to support all of said container means stacked the articles from any container that is removed from the above said container means being removed from said first stacked containers during the time that the ontain r i support means in spaced relation to said container means removed from the stacked containers. being removed from said first support means to provide a 11. An apparatus for handling articles including: cleal'ance lhel'ebetween;

a plurality of container means, each of said container means mflans l0 vertically move Said Container means r h adapted to support at least one article; position in which said container means may be moved first means to support a plurality of said container means in from Said first pp means y Said transport means stacked relation; after said container means has been returned to said first second means to removably support said first support pp means y Said transport means;

means; said third support means including signal means actuated by transport means to remove any of said container means the lowermost of said container means supported by said from said first support means separately to a position exthird PP means; ternal of said first support means and return said removed and 531d movable means mfmng Said conmmer container means from the external position to said first mean? that to be removed from Sam fi suPpon means support means in the Same stacked relation before 3 5 by said transport means a predetermined distance after another of said container means is removed therefrom by actuation of said signal means to produce the clearance Said transport means; between the lowermost of said container means supeach of said container means removed from and returned to Ported by Sam suppon means and Sand comamer said first support means by said transport means having at mfians to be removed from Sam first suppon means by least one article supported thereby; 40 Send transport means means to automatically remove the article from said con-

Claims

1. An apparatus for handling articles including: a plurality of container means, each of said container means adapted to support at least one article; first means to support a plurality of said container means in vertically stacked relation in engagement with each other; second means to removably support said first support means; transport means to remove any of said container means from said first support means separately to a position external of said first support means and return said removed container means from the external position to said first support means in the same stacked relation before another of said container means is removed therefrom by said transport means; means to lower the stacked relation of said container means a predetermined distance; third means to support all of said container means above said container means that is to be removed from said first support means by said transport means, said third means being effective after said lowering means has lowered the stacked relation of said container means the predetermined distance; and means to cause said lowering means to lower said container means that is to be removed from said first support means by said transport means and any of said container means therebeneath until said container means that is to be removed is at the position at which said container means is removed from said first support means by said transport means, said causing means being effective after said third means is effective whereby a clearance is provided between the lowermost of said container means supported by said third means and said container means that is to be removed from said first support means by said transport means.

2. The apparatus according to claim 1 in which: each of said container means removed from and returned to said first support means by said transport means has at least one article supported thereby; and means to automatically remove the article from said container means after said container means is removed from said first support means and before start of return Of said container means to said first support means.

3. The apparatus according to claim 1 including means to selectively render said third support means ineffective at various times during movement of said container means by said lowering means.

4. An apparatus for handling articles including: a plurality of container means, each of said container means adapted to support at least one article; first means to support a plurality of said container means in vertically stacked relation in engagement with each other; second means to removably support said first support means; transport means to remove any of said container means from said first support means separately to a position external of said first support means and return said removed container means from the external position to said first support means in the same stacked relation before another of said container means is removed therefrom by said transport means; third means, separate from said first support means, being selectively effective to support all of said container means stacked above said container means being removed from said first support means by said transport means in spaced relation to said container means being removed from said first support means by said transport means to provide a clearance therebetween; and said first support means having means supported thereby to select which of said container means is removed from and returned to said first support means by said transport means when said first support means is supported by said second support means.

6. An apparatus for handling articles including: a plurality of container means, each of said container means adapted to support at least one article; first means to support a plurality of said container means in stacked relation; said first support means includes: a body supporting said container means; and said body having sliding access means on opposite sides thereof; second means to support said first support means; said second support means includes: means to fixedly support said sliding access means when said first support means is supported on said second support means; and means to movably support said body when said first support means is supported on said second support means; and transport means adapted to move each of said container means from said first support means separately and return each of said container means to said first support means before another of said container means is removed therefrom.

8. A method of handling articles including: arranging a plurality of containers in vertically stacked relation with each of the containers adapted to support at least one article; disposing the stacked containers so that a container may be moved horizontally therefrom by lowering the stacked containers for a predetermined distance, preventing further lowering of the containers above the container to be horizontally moved from the stacked containers, and lowering the horizontally movable container and any containers therebeneath until the horizontally movable container is at the position at which it is to be horizontally moved; supporting the containers above the horizontally movable container in vertically spaced relation to the horizontally movable container while the horizontally movable container is removed from the stacked relation and then returned to the stacked relation; removing the horIzontally movable container from the stacked relation to a position external of the stacked relation and returning the horizontally movable container from the external position to the stacked relation before another of the containers can be removed from the stacked relation; stopping support of the containers above the horizontally movable container after it has returned to the stacked relation; and lowering the stacked relation of the containers to position another of the containers for horizontal movement from the stack after the horizontally movable container is returned to the stacked relation and the support of the containers above the horizontally movable container is ended.

9. The method according to claim 8 in which: each of the containers supports at least one article therein; and selecting the containers to be removed is in accordance with an indicating signal.

10. The method according to claim 9 including removing the articles from any container that is removed from the stacked containers during the time that the container is removed from the stacked containers.

11. An apparatus for handling articles including: a plurality of container means, each of said container means adapted to support at least one article; first means to support a plurality of said container means in stacked relation; second means to removably support said first support means; transport means to remove any of said container means from said first support means separately to a position external of said first support means and return said removed container means from the external position to said first support means in the same stacked relation before another of said container means is removed therefrom by said transport means; each of said container means removed from and returned to said first support means by said transport means having at least one article supported thereby; means to automatically remove the article from said container means after said container means is removed from said first support means; and means to indicate that said container means is removed from said first support means by said transport means, said indicating means insuring that said automatic removal means is not actuated until said container means is removed from said first support means by said transport means.

12. An apparatus for handling articles including: a plurality of container means, each of said container means adapted to support at least one article; first means to support a plurality of said container means in stacked relation; second means to support said first support means; transport means adapted to move each of said container means from said first support means separately and return each of said container means to said first support means before another of said container means is removed therefrom; third means to support all of said container means stacked above said container means being removed from said first support means in spaced relation to said container means being removed from said first support means to provide a clearance therebetween; means to vertically move said container means from the position in which said container means may be moved from said first support means by said transport means after said container means has been returned to said first support means by said transport means; said third support means including signal means actuated by the lowermost of said container means supported by said third support means; and said vertically movable means moving said container means that is to be removed from said first support means by said transport means a predetermined distance after actuation of said signal means to produce the clearance between the lowermost of said container means supported by said third support means and said container means to be removed from said first support means by said transport means.