US1941195A - Can closing machine - Google Patents

Description

CAN CLOSING MACHINE Filed Jan. 51,1931 2 Sheets-Sheet, l

Dec. 26, 1933. c. A. ANDERSON 1,941,195

CAN CLOSING MACHINE Filed Jan. :51, 1931 2 Sheets-Sheet 2 2 Mill" imilii'iilll" Z9 57 A6 2y A ii'li;

Patented Dec. 26, 1933 1,941,195 CAN CLOSING momma Chicago, 111., assignor to Company,

a corporation of Application January 31, 1931. Serial No. 512,529

Carl A. Anderson,

General Can Maine 8 Claims.

This invention relates to improvements in can closing machines.

In the use of so called friction top cans for the vacuum packing of food or other products, the covers have in some instances become loose, either because of rough handling of the cans or because of internal pressure due to the formation of gas, the result being that the vacuum is destroyed and the asserted advantages of that mode of packing thereby lost.

The principal object of the invention therefore is to provide can closing mechanism having means for securing the friction covers in place against accidental displacement during handling or by internal pressure, but without appreciably increasing the effort required to remove said covers in the conventional manner by any suitable prying tool.

Another object of the invention is to provide a can closing machine having means for holding a cover in its initial position on a can, to prevent displacement thereof by the outrush of air during the extraction of the air from the can.

Other objects relate to various features of construction and arrangement of parts which will be apparent from a consideration of the following specification and accompanying drawings, wherein:

Fig. 1 is a broken vertical sectional view of a machine embodying the present-invention.

Fig. 2 is an enlarged broken vertical sectional view taken on line 2-2 of Fig. 3.

Fig. 3 is a bottom plan view of the cover positioning and lug forming member partly in section.

Fig. 4 is a broken side elevation of the hood and actuating mechanism therefor.

In my Patent 1,855,786 which issued April 26, 1932, based on application, Serial No. 499,840, filed December 3, 1930, of which this application is a continuation in part, 1 have disclosed a machine for extracting air from friction top cans and thereafter pressing the covers into sealing position thereon. The present improvements are shown in connection with the mechanism illustrated in said prior application, but it will be understood that said improvements may be employed in other relations.

Said patent discloses a support 10 carrying a housing 11 which is recessed to accommodate the hood closing member 12 which is supported by suitable springs 12a, two of which are shown in Fig. 1. The member 12 has a vertical rim 13 within which is a can support or plate 14 secured to the stationary rod or shaft 15 which is threaded at its lower end to the housing 11. The shaft 15 has a smooth upper portion 15a. on which slides the member 12 which is provided with packing 1'7 and a packing gland 18. The shaft 15 is stationary and is provided with a passage 15b communicating with which is a pipe 19 which is connected to a vacuum or suction device shown in the application above mentioned.

The support 10 carries a pair of standards 20 on which a hood or upper chamber member 21 is vertically reciprocal by means of an arm or pitman 21a. When the hood 21 descends, its lower edge, which is provided with rubber or like sealing material 22, engages the upper edge of the flange 13 and provides an air tight chamber for a can 23, and its friction top cover 24, previously positioned on the plate 14. Upon the closing of the chamber as just described, the air in the chamber and in the can 23 is removed through the passage 15b and pipe 19. The con- 7 tinued downward movement of the hood 21 and member 12, which is possible because of the springs 13 which support the latter member, brings a die 25 which is secured to the upper inner end of the hood, into contact with the cover 24 and presses it into airtight contact with the can 23. The hood then ascends, and the sealed can may be placed on a conveyor 26 and an additional can removed from the conveyor 27 and placed on the plate 14 for similar operation. The features above mentioned are more fully described in my prior application above identified to which reference is made for a complete understanding of the details of structure and the automatic functioning of the parts.

It sometimes happens that the cover 24 of the can 23 is slightly displaced by the outrush of air from the can when the vacuum is applied, with the result that the descending hood and die crush or deform the can. The present improvements remedy this defect by the application of pressure to the cover prior to the removal of the air, which pressure is sufiicient to hold the cover in position against displacement, but insuflicient to press it into position on the can and thus prevent the removal of the air therefrom.

In the present improvements the die 25 is provided with radial slots 28 in its lower surface in which reciprocate plungers 29 having lugs 30 on their outer ends. The plungers 29 are held in position in the die 25 by means of screws 31 which operate in slots 32 in the die. Above each plunger 29 a passage 33 is formed in the die in which springs 34 are positioned and which press the screws 31, and therefore the plungers 29, in-

wardly. Screw plugs 35 confine the springs 34 in the passages 33 and enable the tension of the springs to be varied. The die 25 and hood are centrally recessed and through this recess extends a shaft 36 having its lower end provided with inclines 37, oneeach for the complementally inclined ends 29a of the plungers 29. By suitable relative movement between the inclines 3'7 and 29a, the plungers 29 will be wedged outwardly, thus forcing the lugs 30 against the vertical walls 38 of the cover 24 and pressing lugs 39 therein which engage the lower edge of the bead 40 of the can top 41, as shown most clearly in Fig. 2.

Suitable packing 42 and gland 43 are provided for the shaft 36 to prevent leakage of air into the hood chamber during the removal of air from the can. I find it desirable to provide a pressure lubricating nipple 44'for the gland, the lubricant assisting in the exclusion of air between the packing and the shaft as well as reducing friction. The shaft passes through a bracket 45 which may be supported by the standards 20, and is provided with a nut 46 near its upper end. The shaft 36 is provided with a central recess 47 in its lower portion in which is provided a cover presser member 48 actuated downwardly by a spring 49. The presser 48 has a key way 48a in its outer surface into which projects a threaded key 50 which prevents the presser from dropping from the recess when the hood 21 is in the raised position shown in Fig. 1.

During the downward stroke of the hood 21 and before the vacuum is applied, the presser '48 will engage the cover 24 of the can and will hold it in position against displacement during the subsequent extraction of the air. As the hood 20 continues its descent, the die 25 will engage the cover and press it into position on the can. The shaft 36 moves downwardly with the hood until the nut 44 reaches the stop bracket 45. The nut 44 is adjusted preferably so that the steppage of the shaft 36 occurs just prior to the completion of the downward stroke of the hood, for instance while the hood, and consequently the die 25, have about one-sixteenth of an inch yet to travel before the cover 24 is fully seated. The stoppage of the shaft 36 results in the wedge or inclines 29a acting on the inclines 37, and forcing the plungers 29 outwardly during the completion of the downward stroke of the hood, whereby the lugs 30 press lugs 39 in the vertical wall 38 of the cover. The lugs 39 are formed immediately below the lower edge of the rib 40 of the can top and thus supplement the engagement of the can and cover.

The covers seated by the mechanism described are seldom loosened accidentally or by the gas pressure that sometimes develops in freshly packed coffee, for instance, although they can be removed without great difliculty by any suitable prying tool inserted beneath the edge of the covers in the manner by which friction top cans are conventionally opened.

After the plungers 29 have been pressed outwardly and the hood 21 starts to move upwardly, the springs 33 force the plungers inwardly and release the lugs from engagement with the can. A collar 51, which has a pin 52 passing through a slot 53 in the shaft 36, is engaged by the gland 43 on the upward movement of the hood and thus elevates the shaft 36 sufficiently so as to avoid interference with the manipulation of the cans to and from the plate 14. The slotted connection between the collar 51 and the shaft 36 permits a slight upward movement of the hood and die relative to the shaft at the beginning of the upward stroke of the hood. This relative movement permits the springs 34 to force the plungers 29 inwardly to free them from engagement with the cover.

Although I have shown and described one embodiment of the invention for the purpose of illustration, I do not wish to be restricted specifically thereto except as so limited by the appended claims.

I claim:

1. In an air extracting and can closing machine, the combination of a pair of relatively movable chamber forming members, a cover holding device actuated by one of said members into contact with the cover of the can prior to the extraction of the air therefrom, and means carried by one of said-members for subsequently moving said cover bodily into closing position on said can.

2. In an air extracting and can closing machine, the combination of upper and lower chamber forming members, means for moving one of said members into air tight contact with the other, a stationary support for a can within said chamber, a spring actuated cover presser member carried by said upper chamber forming member for holding said cover in position on said can during the extraction of air therefrom, and means for subsequently moving said cover bodily into closing position on said can.

3. A can closing machine comprising a support for a can and a cover resting loosely on the latter, a reciprocal hood member open at the bottom, a hood closing member, means for reciprocating said hood member into contact with said closing member to form an airtight chamber enclosing said can and cover, means for extracting air from said chamber and can, means for holding said cover against displacement during the extraction of the air from said chamber and can, and means carried by said hood for subsequently pressing said cover into sealing position on said can.

4. Mechanism comprising a support for a can having a cover resting loosely thereon, a reciprocal open bottom hood movable downwardly over said can and support, a closing member for said hood for forming therewith an airtight chamber, means for extracting air from said chamber and can during the downward stroke of said hood, means operable by said hood during the extraction of the air to prevent the displacement of said cover from said can, and a cover seating member operable by said hood for pressing said cover into sealing position on said can during the latter portion of the downward stroke of said hood.

5. A machine of the class described comprising a recessed housing, a movable chamber base positioned in said housing, means for resiliently urging said base upwardly, a support for a can associated with said base, a hood movable into contact with said base for forming an airtight chamber for said can, means comprising an air extraction duct communicating with said chamber for removing air from the same and said can, a cover seating member carried by said hood, an upwardly yielding presser member depending from said cover seating member and means for moving said hood and base downwardly against the action of said resilient means for effecting initial engagement of said presser member with a cover on said can, followed by engagement of said seating member with said cover to seat the same.

6. A machine of the class described comprising a stationary housing having a recess in the 1 upper side thereof, a stationary support for a can with its cover loosely resting thereon, said support being positioned concentrically with respect to said recess, a hood closing member resiliently mounted in said recess, a hood having an open bottom movable downwardly over said can and cover into contact with said closing member to form an air-tight chamber enclosing said can and cover, said hood closing member being movable into said recess upon contact of the same by said hood, means for extracting air from said chamber during the downward movement of said closing member, a cover seating member carried by said hood for pressing said cover into sealing position on said can during the final portion of the downward stroke of said hood and an upwardly yielding presser member depending from said cover seating member to engage said cover prior to its final movement into sealing position.

7. A can closing machine comprising upper and lower members relatively movable to engage each other and form a chamber enclosing a can with a cover loosely resting thereon, means carried by said upper member for pressing said cover against its seat on said can and a downwardly projecting member yieldingly mounted in said means to engage said cover and prevent upward displacement thereof prior to said seating operation.

8. A can closing machine comprising a support for a can with a cover loosely resting thereon, a vertically movable hood, means to lower said hood and enclose said can and cover, a shaft arranged vertically in an opening in said hood, a die in the top of said hood to engage said cover and seat it during said lowering movement and a presser member mounted in a recess in said shaft and depending therefrom to engage said cover lightly prior to its engagement by said die, said presser member being moved inwardly by its engagement with said cover.

CARL A. ANDERSON.

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