US2052061A - Molding press - Google Patents

Description

Aug. 25, 1936. A. F. TOELKE 2,052,061

MOLDING PRESS Filed June 21, 1933 2 Sheets-Sheet 1 J4 I W /9 :J

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A. F. TOELKE MOLDING PRESS Aug. 25, 1936.

Filed June 21, 1953 2 Sheets-Sheet 2 ATTORNEY Patented Aug. 25, 1936 UNITED STATES PATENT OFFICE 11 Claims.

This invention relates to molding presses primarily for use in the production of bricks and other ceramic articles, although the use thereof in compacting and molding other plastic or like 5 materials into variousshapes is also contemplated.

In presses for such purposes heretofore used, a rather gradual application of the compacting and molding pressures is ordinarily required to produce perfect blanks free from objectionable fissures or fractures which would otherwise be developed therein. This condition imposes a serious limitation upon the speed at which such presses may be economically operated and correspondingly curbs the production capacity thereof.

An objectof the present invention is to provide an improved press for this purpose which will reliably produce perfect blanks at high speed operation. This I have accomplished by the pro- ZQ; duction of a press in which the compacting and molding pressures are pneumatically applied in such manner as to utilize in full measure the characteristic resiliency of air or other gaseous me dium under pressure.

25 Another object is to provide animproved automatic control for such presses especially suited for high speed press operation.

Presses for these purposes not infrequently include a rotary mold carrier, which requires peri- 9 odic indexing, and a cooperating pressure plunger. Another object is to provide an improved means for automatically controlling and coordinating the indexing of the carrier and the reciprocation.

of the plunger, so as to reliably effect proper sequential operation thereof.

Other objects and advantages will appear, either expressed orimplied, from the following description of a molding press embodying the 40 present invention.

In the accompanying drawings:- Figure 1 is a vertical sectional View, taken substantiallyalongthe line l-l of Fig.2, of a molding press constructed in accordance with the pres 45 ent invention.

" Fig. 2 is a vertical sectional view taken at right angles to the plane of the section of Fig. 1.

Fig. 3 is a fragmentary sectional view illustrating on a somewhat larger scale a part of the 0 control mechanism shown in Fig. 1.

Fig. 4 is a sectional view,.also on a larger scale, of another portion of the control mechanism shown inFig. 1.

Fig.5 is a fragmentary sectional view on the a -151. q :Fi 2- Fig.6 is a top elevation of a metering plate and itsactuating mechanism.

The molding press selected for illustration in; cludes a main cylinder H1, supporting a smaller pull-back cylinder H aligned therewith, the main 5 cylinder being mounted upon a plate l2, anchored to an appropriate supporting frame l3. A relatively large single-acting piston M in the cylinder l0 serves to drive a plunger l5 downwardly on a pressure stroke, the plunger being returned by a to relatively small single-acting piston I6, working in the cylinder II and connected to the piston H by a rod H.

The pistons l4 and I6 .are actuated by air or other resilient pressure fluid, supplied through a pipe or conduit l 8 under the control of an appropriatevalve l9.

The control valve shown is of a well known type involving a double-headed piston 2|], which in its upper position admits pressure fluid from the pipe 2 I8 to a passage 2|, leading to the main cylinder l0, and which in its lower position admits pressure fluid from the pipe 18 to a passage 22 leading to the pull-back cylinder I I. In either position of the piston 2|] the pressure fluid passes between the 25 end heads thereof so that the same is always .bal- L anced as to pressure and its .position is not disturbed thereby. When the piston 20 is in upper position the passage 22 fromthe .pull-back cylinder is open to an exhaust port 23, and when in lower 39 position the passage 2| from the main cylinder is free to exhaust through the upper open end 24 of the valve casing.

In this instance the valve I9 is controlled by a stop element 25 which coacts with a stem 26 depending from the valve piston 20. The valve piston is urged downwardly by gravity or otherwise. The element, shown at 25, is in the form of a plate mounted for lengthwise movement crosswise of the valve stem 26, and is provided 40 with an openingZ'l through which the stem 26 instantly projects whenever the opening 21 is caused to register therewith ,by a longitudinal shifting of the plate. This of 'coursere'sults in a prompt shifting of the valve piston 20' into its lower position.

The plate 25 is also mounted for movement in a direction longitudinally of the valve stem 26, and serves, by such movement, to lift the valve piston 20 into its upper position. so

These two distinct movements of the .plate 25 are made possiblelin this'instance preferably by a mounting means which will now be described. One end of the plate 25 is supported by a rod 28, through .a ball-and-socket joint 29, and at its 5s other end the plate is hingedly connected, as at 30, to the depending arm 3| of a bellcrank rockably supported upon a fixed horizontal pivot 32. The bellcrank 3| is actuated and controlled, in a manner to be later explained, by a pull rod 33, extending loosely through the other horizontal arm 34 of the bellcrank, and provided with a stop nut 35, adjustable thereon.

An appropriate spring 35 urges the arm 3|, and consequently the plate 25, toward the left from the position of Fig. 1, so that the opening Z'l is normally out of register with the valve stem 26, in

which position the valve piston 28 is retained in the elevated position shown and the main cylinder I is exposed to fluid pressure.

Whenever the arm 3| is swung toward the right,

- against the spring 35, so as to shift the plate 25 into the Fig. 1 position, the valve stem 25 is free to pass through the opening 21, and the valve piston 20 shifts instantaneously into its lower position, so that the pull-back cylinder I is then exposed to fluid pressure and the plunger l executes a return stroke.

Thereafter, by a pull on the rod 28, the outer end of the plate 25 is lowered until the opening 21 therein clears the end of the stem 26, whereupon the plate 25 and arm 3| are shifted toward the left, by the spring 36, so as to reposition the outer end of the plate 25 beneath the stem 25. Then by an upward thrust on the rod 28, the plate 25 and consequently the stem 25, are lifted and return the valve piston to its upper position. The main cylinder H) is thus again exposed to fluid pressure and the plunger l5 starts down on its next working stroke.

Movement of the arm 3| toward the left is preferably limited by suitable coacting stops 31 and 38 on the bellcrank and its support, respectively, the arm 3| assuming this limiting position substantially throughout the working stroke of the plunger l5, and reassuming that position when, during the up stroke, the plate 25 is lowered to clear the stem 26.

Appropriate means for operating and controlling the rods 28 and 33 will be fully described hereinafter.

The plunger l5 carries a die 39 which cooperates successively with a circular series of split dies 40 carried by a rotary mold drum 4 l. The halves of each die 40 are hinged to individual die. carriers 42, each guided for lengthwise reciprocation radially of the drum in appropriate sockets 43 formed in the periphery of the drum. Each carrier 42 is slotted to accommodate the curved tails 44 of the die halves, the tails cooperating with the individual sockets 43 to spread the die halves and thereby release the contained molded blank, whenever the carrier is projected outwardly, as indicated in Fig. 2.

The die carriers 42 are controlled by individual cross-heads 45, attached to the lower ends thereof and projecting through and guided by radial slots 45 provided in the web 4ll of the mold drum. In their inner retracted positions the several carriers 42 rest against appropriate individual abutments 48 provided on the hub 49 of the drum.

The drum 4! is mounted for intermittent rotation about a horizontal axis beneath the plunger l5 and, in this instance, is supported by a shaft 50 which extends through the hub 49 and through appropriate hangers 5| depending rigidly from the supporting frame l3. Indexing of the drum is effected by suitable means, such as a dog 52,

. carried by a reciprocable rod 53, and cooperating with successive notches 54 formed in the periphery of the drum to actuate the same. The rod 53 is fluid actuated by a piston 55 working in a cylinder 55 fixed to and depending from the plate l2.

Each indexing movement of the drum 4| is controlled and accurately limited by an index pin 51, mounted in a block 58 fixed to an auxiliary support 59, and cooperating with a series of holes 60 suitably arranged in the end of the drum. A spring 6| urges the pin 51 toward the drum, the pin being retractable by an appropriate lever 62, herein shown as a hand lever. The arrangement is such that when the pin 51 is retracted, by actuation of the lever 62, and the cylinder 56 energized, the drum is rotated by the dog 52, until the next hole 53 of the series registers with the pin 51, whereupon the pin snaps into that hole so as to prevent further rotation of the drum and to accurately position the same.

By each indexing movement of the drum a new die 45 in the upper part of the drum is brought into accurate alignment beneath the plunger die 39, and also a new die 40 in the lower part of the drum is brought into the blank ejecting position of Fig. 1.

In the machine shown the several dies 40 and their carriers 42 are actuated and controlled in their movements radially of the drum by mechanism carried by and movable with the plunger l5. This mechanism includes a pair of bars 63 hingedly mounted, as at 64, on the opposite ends of a cross-head 65 secured to and movable with the plunger H3. The bars 63 extend downwardly from the ends of cross-head 65 adjacent the ends of the drum 4|, and each is provided intermediate its ends with a cam lug 65 for coaction with continuous cam surfaces 6! formed internally of the drum ends. Each bar 63 is also shaped at its lower end to form a catch 68 adapted to engage beneath an end of a carrier cross-head 45 and to provide a cam surface 69. Springs 10 yieldably draw the bars 53 toward each other.

The arrangement is such that, during each up stroke of the plunger l5, the aligned carrier 42 and its cross-head 45 are lifted by the catches 68 until the bars 63 are forced outwardly by the spreading action of the cam lugs 66 against the cam surfaces 61, the bars being retained in this spread condition until, during the next down stroke, the lugs 66 pass the cam surfaces 6'! and permit the catches 68 to engage beneath the ends of the cross-head 45 of the next carrier 42 which has, in the meantime, been brought into alignment with the plunger l5.

The carrier actuating mechanism shown also includes a second pair of bars 1|, fixed at their upper ends to the plunger cross-head 55, and extending downwardly into the vicinity of those carriers 42 in the bottom side of the drum 4|. Each of the bars H is forked, as at 12, at its upper end to accommodate the intermediate bar 63, and yoke shaped, as at 13, intermediate its ends to accommodate the hub ends 14 of the drum. The lower end of each bar 1| is shaped to provide an oppositely tapered notched head 75 for interlocking engagement with an end of an adjacent carrier cross-head 45.

The arrangement is such that during each up stroke of plunger l5 the bars 1| lift and thus retract the engaged carrier cross-head 45 substantially into contact with its cooperating abutment 48, and then after the drum 4| is indexed and during the next down stroke of the plunger I5, the heads 75 engage the cross-head 45 of the newly positioned carrier 42 and force the same downwardly into the projected blank ejecting position shown in Figl. The ,b-ars ,II are .suificiently resilient to permit thelheads I5 to snap over and into interlockingengagement ,with the ends of the aligned carrier cross-head .45 duringfthis downward movement thereof with the plunger I5. During the intermittent'rotation or indexing of the drum 4! clockwise (Fig. l)",the several dies 40, having been projected into blankejecting position and having been thereafter retracted, are I carried upwardly by the drum so as to position them successively beneath theplunger die 39, and duringthis upward travel, eachdie .40 receives a fresh supply ofmaterial from an appropriate reservoir or hopper I6. I

The reservoir shown is in the form of an open bottomed cylinder whichrests upon a metering disk I! rotatablysecured to the plate I 2 by means of a center stud I8 screwed into the plate. Arms 19 dependingfrom the reservoir I6 engage the plate I2 and frame I3 to position the reservoir and to retainthe same against rotation with the disk I1. The disk I! is provided with a circular series of holes 80, open to the contents of the reservoir, and each of a size to contain a properly measured supply of material for one of thedies 40. These holes 80 are arranged to pass successively over a discharge opening 8 I, formed in the plate I2, and beneath a stationary plate 82 in the bottom of the reservoirs As the disk 'I'I rotates, the plate 82.ser,ves to severthe charge of material in the adjacent hole 80' from .the contents of the reservoir, so as. to permit that charge to discharge through theopening .8I into a chute 8.3 through which it is conducted to one of the dies 1 40 in the drum.

, The meteringdisk TI is intermittently rotated or indexed by appropriate means, such-as a ratchet pawl 84, cooperating with notches 85 in the periphery of the disk, and supported'and actuated by an oscillating lever 86. The lever 86 is intermittently actuated preferably from a tail rod 81 on the piston I6 through appropriate connections (not'shown) including the link 88.-

Provision is made. in the machine shown for automatically actuating and controlling the index pin 51, the indexing cylinder 56, and the rods 2 8 and 33 which control the actuation of the plunger I5, so as to assure operation of the severalparts of the machine in, proper sequence. This control mechanism will now be described.

The index pin actuating lever 62 is fixed to a rock shaft 89, journalled in the block 50, and carrying acrank arm' 90 and a crank arm 9| at the opposite ends thereof. Arm 9I is connected to the rod 28. Arm 90 is connected, through a link.92, with a piston 93, working in a cylinder 94, supported by the plate I2. .The cylinder 94 is energized through a pipe 95, under the control of an auxiliary valve 96, which in turn is controlled by the plungerv I5 in a manner to be later explained.

The indexing cylinder 56 is energized through a pipe 91 under control of asecond auxiliary valve 98, which in turn .is controlled by the lever .62. The auxiliary valves 96 and. 98 are similarly constructed. Each includesa poppet valve 99, which controls communication between, a pressure chamber I and a feed chamber ml, the valve element99 having a stem l 02 loosely en- .gaged within an actuating member I03, which functions to control an exhaust port I64 and also to displace the valve element 99 from its seat when said member I03 is forced inwardly, thereby to open communication between the chambers 0 and W..- h e er rmri e ith an actuating stem I which projects outwardly from the end of the ,valve housing. The chamber I 00 .is alwaysexposedto fluid pressure through a pipe, I 06.

The valve 96 is mounted uponan auxiliary sup.

port I01 in such position that its stem I05 projects into the .path -of a trip element I08, car-, ried Jayme-plunger cross-head 65. The trip element I08 is rockably mounted, as at I 09, and so arranged as to force the stem I05 inwardly'ata' predetermined point in the upward travel of the plunger I5, but it is freeto rock upwardly so as to pass the stem I 05, without disturbing the same during the down stroke of the plunger. The pipe 95, leading to the cylinder 94, communicates with the chamber IOI. I

The valve 98 is mounted upon an auxiliary support I, I0 in such position that its stem I05 is actuated by an enlargement III on the lever 62, whenever the lever 62 is actuated to withdraw vthe index pin 51. The pipe 91, leading to the indexing cylinder 56, communicates with the chamber IOI of this valve.

The rod 33 is connected at its lower end to an arm II2 rigidly connected with one ofthe bars 63, so that when the cam lug .66 thereon clears the cam surface 67 of the drum, during the down stroke of the plunger I5, permitting the bar 63 to swing inwardly, the arm H2 is actuated to pull the rod 33 and thereby reverse the valve I9 in the manner above explained.

The. several parts of the control mechani sm coact to effect operation of the machine in the following manner. of the parts, the plunger I5 has completedits downward working stroke. The plunger die 39 has,

completed the compacting and molding of the charge of material in the aligned die 46, and the carrier 42 of the opposite lower die 40 has been projected by the bars II so as to discharge a molded blank onto an appropriate conveyor I55 disposed therebeneath. Also the bars 53 have swung inwardly intoengagement withthe crosshead 45 of the upper aligned .die carrier 62.,and the rod 33 has been actuated so that the plate has been shifted to registerthe hole 21 with the stem 26 of the main valve I9. Instantly thereafter the valve piston 26 moves. downwardly, projecting the valve stem 26 through the hole 21 and the press plunger I5 begins an upward or return stroke.

During this return stroke, the projected lower die carrier 42 is lifted and thus retracted by the bars II; and the upper die carrier 42, containing the freshly molded blank, is lifted by the bars63, so that it travels upwardly with'the plunger die 39 until that die has cleared the co-' acting socket Y43, and thereafter the bars '63, spread by the action of lug 66 against the cams 61, release the carrier and permit the plunger die 39 to complete its upward travel alone. By this arrangement the plunger die 39 is not separated from the die 40 until they have cleared the socket 43, thereby avoiding a vacuum efiect which would spoil the blank if it were attempted to, separate those dies while in the socket 4 3.

At a predetermined point in the return stroke of the plunger I5, the trip element I68 strikes the stem I65 of valve 96 and forces the member I63 thereof inwardly, to close the exhaust port I04, and to unseat the element 99 so as to connect pipe 95 with the pressure pipe I06. The cylinder 9:3 is thus energized to actuate the lever 62 and thereby withdraw-the index pin 51 from engagement with the drum 4I.

In the illustrated positions The lever 62, thus actuated, strikes the stem I05 of valve 98 and forces the member I03 thereof inwardly, to close the exhaust port I04, and to unseat the element 99, so as to connect pipe 91 with the pressure pipe I06. The indexing cylinder 56 is thus energized to thereby rotate and index the drum 4|. In the meantime the trip element I08 has cleared the stem I05 of valve 96, and the member I03 has again moved outwardly, thereby permitting the element 99 to reseat and reopening the exhaust port I 04, and thereby deenergizing the cylinder 94. The index pin 51 is thus free to enter the next hole 60 in the drum and to thereby stop and accurately position the next die 40 beneath the plunger die 39.

At the time that the index pin 51 was withdrawn by the actuation of lever 62, this movement of the lever, transmitted through the crank arm 90, actuated the rod 28 and swung the plate 25 downwardly so that the hole 21 therein cleared the end of the valve stem 26. When this occurred, the plate 25 and arm 3I shifted to the left, under the action of the spring 36, thereby positioning the solid end of the plate 25 beneath the projected valve stem 26.

Thereafter, as the index pin 51 advances into the new hole 60 in the drum, the lever 62 is thereby actuated in such direction as to lift the crank arm 90 and thereby force the rod 28 and plate 25 upwardly. This action returns the valve piston 20 into the upper position shown, so as to energize the main cylinder I and thereby force the plunger I downwardly on its next working stroke.

During the down stroke of the plunger I5, the bars II, carried by it, engage the cross-head 45 of the lowermost die carrier 42 and force it into the projected blank-ejecting position shown; and the plunger die 39 enters the aligned socket 43 and coacts with the uppermost die 40 to compact and mold the charge of material previously applied thereto. As the plunger I5 approaches the end of its down stroke, the lugs 66 clear the cams 61, so as to permit the bars 63 to swing inwardly, and finally the latches 68 thereon swing into engagement beneath the ends of the carrier crosshead 45. The valve control plate 25 is shifted, through the arm H2 and rod 33 toward the Fig. 1 position by this inward swinging action of one of the bars 63, but it is not until this swinging action is completed by actually engaging the catches 68 beneath the cross-head 45, that the plate 25 is shifted sufficiently to permit shifting of the valve piston 20 into its lower position.

Due to this arrangement, the control mechanism is inefiective to automatically reverse the motion of the plunger I5, to begin an upward return strok'e, until the catches 66 are actually engaged beneath the crosshead 65, so that the engaged die 40 always moves with the plunger die 39 for a short distance on each stroke of the plunger.

Various changes may be made in the embodiment of the invention hereinabove specifically described without departing from or sacrificing the advantages of the invention as defined in the appended claims.

I claim:

1. In a molding press the combination of coacting molding dies, means for reciprocating one of said dies to effect a working stroke and a return stroke, separate means movable with said first named die for holding said dies against separation during an initial part of the return stroke thereof, and means for releasing said holding means to permit said dies to separate before completion of the return stroke.

2. In a molding press the combination of coacting molding dies, means for reciprocating one of said dies to effect a working stroke and a return stroke, a movable carrier for another of said dies, means movable with said first named die and engageable with said carrier to move the same with said first named die during a return stroke thereof, and means responsive to the engagement of said last named means with said carrier for automatically reversing the motion of said first named die at the end of a working stroke thereof.

3. In a molding press the combination of coacting molding dies, fluid means for reciprocating one of said dies to effect a working stroke and a return stroke, a movable carrier for another of said dies, means movable with said first named die and engageable with said carrier to actuate the same, and means responsive to engagement of said last named means with said carrier for controlling said fiuid means.

4. In a molding press the combination of coacting molding dies, fluid means for reciprocating one of said dies to effect a working stroke and a return stroke, valve mechanism for controlling said means, a movable carrier for another of said dies, means movable with said first named die and rockable into engagement with said carrier to actuate the same during a part of the return stroke of said first named die, and means responsive to the rocking action of said last named means for controlling said valve mechanism to initiate a return stroke.

5. In a molding press theoombination of coacting molding dies, fluid actuated reciprocating means for one of said dies effective to produce a working stroke and a return stroke, valve mechanism for controlling said means, a movable carrier for another of said dies, carrier actuating means movable with said first named die and rockable into engagementwith said carrier at the end of each working stroke, means responsive to the rocking action of said last named means for shifting said valve mechanism to thereby initiate a return stroke, and means for disengaging said carrier actuating means at a predetermined point in said return stroke.

6. In a molding press the combination of coacting molding dies, resilient fluid pressure means for directly operating one of said dies to produce a working stroke and a return stroke and thereby efiect compacting pressure therebetween, separate means for holding said dies against separation at the end of a working stroke, and means for releasing said last named means to permit separation of said dies at a predetermined point in said return stroke.

7. In a molding press the combination of a fluid actuated rotary carrier, a series of molding dies carried thereby and movable therein, a reciprocating molding die for coaction with said series of dies successively, fluid actuated means for actuating said reciprocating die, means actuated by and movablewith said last named means for moving said dies in said carrier, and control means for effecting actuation of both of said fiuid actuated means in predetermined sequence.

8. In a molding press the combination of a fluid actuated rotary carrier, a reciprocable index pin for intermittently locking said carrier, a series of molding dies carried thereby, a fluid actuated reciprocating molding die coacting with said first named dies successively, means for automatically supplying a charge of material to said series of dies successively, and control means responsive toactuation of said index pin for cating said last named die, means for intermitv tently rotating said carrier, an index pin movable to intermittently lock said carrier and withdrawable to release the latter, means responsive to withdrawal movement of said pin for effecting actuation of said carrier rotating means, and means responsive tolocking movement of said pin for efiecting actuation of said last named die.

10. In a molding press the combination of a carrier rotatable about a substantially horizontal axis, a series of molding dies carried thereby about said axis, each of said dies comprising separable coacting elements, a reciprocable molding die for coaction with said first named dies successively, and means automatically operable when said first named dies are below said axis to separate the elements thereof to thereby release and discharge the molded blanks by gravity therefrom.

11. In a molding press the combination of coacting molding dies, means for reciprocating one of said dies to effect a working stroke and a return stroke, a movable carrier for the other of said dies, means laterally movable into engagement with said carrier at a predetermined point in the working stroke for holding said dies against separation during a portion of the return stroke, and means responsive to lateral movement of said last named means for terminating the working stroke.

AUGUST F. TOELKE.

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