US3776421A

US3776421A - Mechanism for separating a container closure from a stack of closures

Info

Publication number: US3776421A
Application number: US00229212A
Authority: US
Inventors: W Harrison; E Keene
Original assignee: WR Grace and Co
Current assignee: WR Grace and Co Conn
Priority date: 1972-02-16
Filing date: 1972-02-16
Publication date: 1973-12-04
Anticipated expiration: 1990-12-04

Abstract

A closure feed mechanism for reciprocating slide-type container closure lining machines. It is provided with cut-off knives which separate the lowermost closure from the closure in the feed stack by causing the knives to advance transverse to the motion of the slide rather than advance longitudinally at the speed of the slide. As a result, knives approach the closures with one-half of their prior velocities, and denting or bending the closures is substantially eliminated.

Description

United States Patent 1 Harrison et a].

[4 1 Dec. 4, 1973 1 MECHANISM FOR SEPARATINC A CONTAINER CLOSURE FROM A STACK OF CLOSURES [75] Inventors: William B. Harrison, Dedham;

Edwin E. Keene, Roslindale, both of Mass.

[73] Assignee: W. R. Grace & Co., Cambridge,

Mass.

[22] Filed: Feb. 16, 1972 [21] Appl. No.: 229,212

Related US. Application Data [63] Continuation of Ser. No. 1,209, Jan. 7, 1970.

52 US. Cl. 221/251, 133/5 51 Int. Cl. 865g 59/00 58 Field of Search 221/238, 251, 297;

[56] References Cited UNITED STATES PATENTS 1,787,085 12/1930 Nelson 133/513 2,384,052 9/1945 Stewart et al 221 /251 3,180,523 4/1965 Wahl 221/251 X 3,419,186 12/1968 Cease 221/297 X FOREIGN PATENTS OR APPLICATIONS 401,404 5/1966 Switzerland 221/251 1,014,491 12/1965 Great Britain 221/251 Primary Examiner-Samuel F. Coleman Attorney-William L. Baker et al.

[57] ABSTRACT A closure feed mechanism for reciprocating slide-type container closure lining machines. It is provided with cut-off knives which separate the lowermost closure from the closure in the feed stack by causing the knives to advance transverse to the motion of the slide rather than advance longitudinally at the speed of the slide. As a result, knives approach the closures with one-half of their priorvelocities, and denting or bending the closures is substantially eliminated.

2 Claims, 3 Drawing Figures PATENTEU 4 I975 INVENTORS WILLIAM B. HARRISON EDWIN E. KEENE BY 7? I ATTORNEY I I Q\U MECHANISM FOR SEPARATING A CONTAINER CLOSURE FROM A STACK OF CLOSURES This is a continuation of application Ser. No. 1,209, filed January 7, 1970.

This invention relates to feed mechanisms for container closure lining machines, and particularly to an improved device for separating the lowermost closure from a feed stack and transporting it to the lining position.

Container closure lining machinery roughly falls into two types: rotary and reciprocating. Reciprocating machines are largely used because they are easily and simply adapted to handle the various sizes of container closures. Simple change parts fit the machine to closures of numerous types. It is characteristic of the reciprocating machine that a stack of unlined closures is supported above a reciprocating slide which moves back and forth across the work table through a distance which is somewhat more than twice the diameter of the closure. As the slide advances, knives on the slide pass just above the lowermost closure, cut if off, and drop it onto the work surface while the closure just above is retained in its supported position.

As the slide advances across the work surface, the closure is carried to the lining station where a rotary chuck which is constantly spinning receives the closure and rotates it beneath a nozzle through which an exactly measured quantity of sealing composition is ejected onto the sealing area. During the lining interval, the slide retracts and picks up another unlined closure, such as a can end, and as the slide again begins its advance, stacking fingers on the forward part of the slide engage the lined closure, move it off the chuck, and tuck it under a rising stack of lined closures at the delivery end of the machine.

Some of these machines operate at outputs as high as 500 closures per minute. Since the complete stroke of the slide is more than twice the diameter of a closure, using a 211 can end as an example, the total travel of the slide across the work surface is 5,500 inches per minute. The reciprocating motion has high linear acceleration and deacceleration. Therefore, if the closure is but slightly burred or distorted, collisions with knives moving at'such high velocities will cause considerable binding and buckling, and jamming will ensue. Infrequently as this happens, for can manufacturing machinery is dependable and precise, a burr or a slightly bent or warped closure will bring about a jam. Because of the high production rates, jams are costly and their causes must be eliminated wherever possible.

According to the present invention a mechanism is provided which engages the closures at very much lower speeds but retains the same lined closure output which is achieved by a normal slide mechanism. The present invention reduces the speed of the knives which advance against the closure to approximately one-twelfth of the velocities in the prior feed mechanism. As a result, there is small tendency for the knives to dent or distort the closure. There is much less stack bounce, and if an inverted closure exists in the stack, that closure will not feed through to cause a jam.

Moreover,.the cut-off knives will not operate when a closure in an inverted position is present in the feed stack of closures, thus interrupting the lining operation. The presence of an inverted closure is detectable visually and this permits the operator to discontinue the operation and remove the closure. Such correction can be effected in a matter of seconds.

A further important advantage is that due to the location of the knives, the lining nozzle may be placed on the lateral diameter, i.e., at the 3-oclock and 9-oclock positions. The prior placement of the nozzles at 8- oclock or 2-oclock may drag some compound across the face of the can end.

These and other objects and advantages will become apparent as the description proceeds, and from the drawings in which FIG. 1 is a top plan view of the improved knife mechanism.

the figure is split along the center line YY so that a single figure may show the feed bars in both extended and retracted positions. In the figure, the left-hand slide feed bar is in the advanced position and the right-hand slide feed bar is in the retracted or back position.

FIG. 2 is a sectional elevation along the line AA of FIG. 1.

FIG. 3 is a sectional elevation along the line BB of FIG. 1.

In the usual reciprocating machine, two feed bars, spaced apart slightly more than the diameter of the closure, are attached to a cross-head which is not shown. In the improved cutoff and feed mechanism, the knives which strip the closure from the stack 19 and drop it onto the work surface move transversely to the motion of the slide as the feed bars retract. Their inward motion is controlled by a curved cam track which is cut in the upper face of each feed bar.

Also, in the normal reciprocating machine the feed bars work in ways which are formed in a part called a hopper. This not only supports the stack of ends and allows them to pass through an opening to the work surface, but forms a'rigid guide for the quickly reciprocating bars.

The knives of this invention are mounted on cam levers which are pivoted on the hopper casting. Accordingly, instead of approaching the end at the velocity of the feed bar motion, which is what happens when the knives are attached to the feed bar, the knives move inwardly but at a velocity determined by the cam track. Although the whole operation is rapid, the efiect of these inwardly moving knives is much more a wedging operation than a headlong blow, and small defects in the can end such as a burr or a warp can be made to feed rather than bend up and jam when struck by the higher velocity. This is especially useful when aluminum ends are lined.

This is accomplished by the following arrangements: as the figure shows, the slide feed bars 10 carry curved cam trackways 11 and 12 cut in the upper surface of the bars. Trackway 11 is cut in the left-hand feed bar. Both trackways are so angled that as the slide bars are pulled backwards in the fully retracted position, the knives are forced transversely inwardly and cut off the lowermost closure from the feed stack 19. This occurs because cam levers 13 pivoted on the hopper 14 by the pivot pins l515 are controlled by the cam roller 16 which is fastened near the ends of the cam levers l3-13. The pivot or hinge pins 15 are drilled to provide passage ways for lubricant.

The closure which is cut off from the stack drops to the work surface and is pushed by edge 20 of the feed bar to the rotary chuck 21. There it is lined with sealing compound which is metered through a nozzle (not shown) which is positioned above the chuck.

The height of the knives above the working surface is set by the design of the closure, and adjustment is made by a series of shims 17 which may be placed between the lever 13 and the knife 18. The knife is shaped as shown.

The radius of the knife may change to accomodate the closures, but ordinarily a knife ground to a radius of 1 9% inch and sloping upwardly at an angle of 15 from an edge thickness of approximately 0.010 inch will separate the closures effectively.

The knives are made as left-hand and right-hand pairs. In machines adjusted for lining number 21 1 can ends, the length of the stroke of the slide feed bars in 5.500 inches. The over-all length of the cam track cut in the feed bars in 6.505 inches. The track as shown in the dotted portion on the drawing is formed in three sections: a 2.250 inch length of slot parallel to the axis of the bar, a 2.379 inch length of slot cut at an angle of 6 to the axis of the bar, and a 1.876 inch length of slot cut parallel to the axis of the bar, but continuing from the angular portion. This small movement advances the knives sufficiently to free the can ends or closures, but the speed of the inward motion of the knives is but one-twelfth of what it would be were the knives directly connected to the feed bars.

As a result, the ends sufi'er very little damage, and feed becomes much more possible. Nevertheless, the output of the machine remains the same.

In the specification and claims, the word hopper has been used, and since it is the name by which the part overlying the slide bars in known on commonly used machines, it should be understood that this part does not necessarily have to be a hopper through which the closures are fed, but may be any bridge working overlying the feed bars which will support the pivoted knife cam levers.

We claim:

1. A container closure lining machine including a feed stack member for storing unlined closure elements; a rotary chuck member upon which unlined closure elements are deposited for receiving lining compositions; a hopper member beneath said stack of closure elements supporting a pair of spaced, reciprocating feed slide bar members for engaging opposite sides of said closures and delivering said closures in a reciprocating motion from said stack member to said chuck; arms pivoted on said hopper member and overlying each of the said feed slide bar members; cam tracks formed in each of the said feed bars; a pair of cutoff knives, each attached near one end of each of said arms and directed inwardly; and, a cam roller attached to each of the other ends of said arms and working in each of said cam tracks; said cam tracks in said feed bars being curved in a direction which is at an angle to the reciprocating direction of said bars causing said knives to move transversely to the reciprocating motion of the bars whereby closures will be cut from the said feed stack by said knives and the velocity of contact of the said cutoff knives with said closures is thereby reduced.

2. The lining machine of claim 1 wherein the vertical position of said knives is adjusted by shims interposed between the arms and the said knives.