US2280823A - Feeding device - Google Patents

Description

prl 28, 1942. HANSEN 2,280,823

FEEDING DEVICE Filed May 8, 1940 2 Sheets-Sheet 2 INVENTOR "La B La.

i ATTNEY Patented Apr. 28, 1942 UNITED STATES PATENT OFFICE FEEDING DEVICE John Hansen, Seattle, Wash., assignor to American Can Company, New York, N. Y., a corporation of New Jersey 4 Claims.

The present invention relatesto a feeding device for a container or can making machine and has particular reference to feeding sheets or strips in a continuous step-by-step fashion through a working station in the machine in a manner which compensates for increased spacing between sheets or strips so that no working movements are lost between the feeding of the end of one sheet or strip and the beginning of the next in line.

In some can making machines such as for eX- ample, strip feed presses or the like in which can parts are cut from sheet metal strips by suitable die mechanism, considerable lost motion is often encountered in idle or non-productive die movement between the feeding of strips. In most cases these strips are formed in short lengths and usually at least one or two strokes of the die mechanism are lost between each strip as. they are fed one after the other into the die.

The greatest difficulty is encountered when feeding the so called scroll shear strips which are usually cut from a stagger row layout sheet which gives the strips undulated side edges. such strips the stagger layout leaves a greater amount of scrap stock at one end of the strip than at its opposite end. Hence when such strips are fed endwise into the die mechanism in a continuous procession a longer feeding stroke is required to bring the strip into proper position in the die on the rst stroke than is required for the remainder of the feeding strokes.

The instant invention contemplates overcoming this difculty by providing a feeding device which will compensate for this extra feeding distance at the beginning of a strip feeding operation so that the strips may be fed successively into the die mechanism without permitting any idle strokes of the mechanism.

An object therefore of the invention is the provision of a strip feeding device for a can making machine wherein the strips may be fed successively into a working station of the machine while preventing any lost operations of the devices at the working station between the end of one strip and the beginning of a suce ceeding strip.

Another object is the provision of such a feeding device wherein a predetermined feeding stroke in advancing a strip in a step-b-y-step manner will be greater than the following strokes for each strip so that compensation may be effected for strips of various lengths.

Numerous other objects and advantages of thc invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Figure 1 is a top plan view of a feeding device embodying the instant invention, the View showing principal parts of a can making machine and showing a strip in place for feeding, with parts broken away and shown in section;

Fig. 2 is a longitudinal sectional view taken substantially along the line 2-2 in Fig. 1;

Fig. 3 is an end view of the device as viewed from the left in Fig. 1;

Fig. 4 is an enlarged View of one of the feed lingers used in the device, with parts broken away;

Figs. 5 and 6 are transverse sections taken substantially along the line 5 5 and 5 6 in Fig. l, with parts broken away, Fig. 6 being drawn on an enlarged scale; and

Fig. 7 is a schematic plan View of two adjacent strips in feeding positions and showing the difference in stroke requirement in feeding such strips.

As a preferred embodiment of the invention the drawings illustrate principal parts of a strip feed press of the character disclosed in United States Patent 1,443,751, issued January 30, 1923, to H. Schoendelen. In such a machine can parts, such as can ends, drawn can bodies, friction rings and many other such articles are cut and formed from strips A of sheet metal well known in can making practice as scroll shear strips.

These strips are preferably cut from large sheets in which the can parts to be formed are laid out in stagger row fashion. The strips are cut out along lines of severance which extend between the stagger rows and hence result in undulated side edges B. The potential can parts (marked C) are equally spaced throughout the length of the strip and the center distance between such parts is marked X in Fig. 7.

However, due to the stagger layout the center of the first can part C in some strips is spaced a greater distance from the front yend of the strip than the distance the last can ypart in the strip is spaced from the back end thereof. Hence when two adjacent strips are fed end to end and space between them is allowed for the feeding elements the center distance between the last can part C in one strip and the first can part in a succeeding strip is greater than the center distance between can parts in the strip itself. This greater distance is marked Y in Fig. 7 and it is to compensate for this difference in center distance that the invention is particularly directed as will now be described and explained.

The strips A are supported on top of a table I I which is secured to a bed I2 which may be a part of the main frame of the machine. Side guides I3 formed along the edges of the table retain the strip in longitudinal position while a top plate I4 secured to the side guides prevents vertical displacement of the strip. The strips are placed upon the table in any suitable manner in time with the moving parts of the machine, such as disclosed in the above mentioned patent.

Adjacent one end of the table I! (at the right as viewed in Figs. 1 and 2) there is disposed a conventional die mechanism which is adapted to cut and form the can parts C from thestrips A as the latter are fed into proper position thereto. This die mechanism is shown by way of eX- ample, ,as consisting of a die member i6 and a cooperating punch member I'I. 'The die member is preferably secured to a bed plate I8 which may be supported on the main frame of the machine. The punch member I'I is vertically movable relative to the die member and may be actuated in Iany suitable manner in time with the other moving parts of the machine.

The strips are fed along the table I! and are positioned between the die members for the can part cutting and forming operation, in a stepby-step or intermittent movement. For this purpose there is provided a feeding device which includes a longitudinally reciprocable feed bar 2| which slides in a groove 22 formed in the bed I2 longitudinally thereof. The feed bar carries a @plurality of relatively fixed ngers or feed dogs 23 which are spaced apart at equal intervals along the bar and these intervals are equal to the distance X between the potential can parts C in the strips A to be fed. These lingers are disposed in the groove 22 alongside of the bar and move with it within the groove.

Each finger 23 is mounted on a pivot pin 24 (Figs. l and 4) which is riveted into an adjust- L which is formed on the clamping block 28 so that the finger may engage and feed the strips A on a forward stroke of the feed bar. The finger is also yieldably backed up adjacent its lower end by a compression spring 32 (Fig. 4) so that it may be depressed below the strip as when the feed bar moves through a backward or return stroke. The spring is disposed in a recess 33 formed in the lower portion of the clamping block 28. A setscrew 34 in the block and engaging the end of the spring is provided for adjusting the amount of pressure on the finger.

The feed bar 2i is reciprocated by way of a link 36 (Figs. l, 2 and 3) which is connected to a coupling 31 carried on the outer end of the feed bar and held in place by loeknuts 33 threaded onto the bar. The link is actuated in any suitable manner in time with the other moving parts of the machine.

When a strip A1 to be fed is placed upon the table II it depresses all of the fingers 23 which it engages. It is placed in front of the first 1inger, i. e., the one at the extreme left as viewed in Fig. 2 and hence when the feed bar moves forward on a feeding stroke the first nriger engages behind the back edge of the strip and 4pushes the strip through one step.

On the return stroke of the feed bar the strip remains stationary and the fingers drag along the bottom of the strip. On this return stroke the second finger on the bar as it comes adjacent the back edge of the strip snaps up into feeding position ready to -feed the strip through a second advancing step upon the next forward stroke of the bar. In this manner each finger along the bar is brought into play for advancing the strip along the table II and into the die mech- `anism `at the end thereof and at each such step the die mechanism cuts out and forms a can part from the strip.

There are preferably one or more fingers 23 at the left of the feed bar 2| as viewed in Fig, 2 which advance the strip through one or more idle steps before the forward end of the strip enters the die mechanism. This is done to provide the proper space for placing the strips on the table. However, after the rst strip is fed, subsequent strips follow close onto the tail of each other so that the die mechanism will always have a strip in place for every stroke thereof.

As the last finger 23 pushes the tail end of a strip into the die mechanism the next strip in line is in position to have its forward end advanced into the die. It is on this next step that the longer stroke of the feed bar 2l, as hereinbefore explained, is required to bring the first potential can part C in the strip in proper position under the die. This long stroke is brought about by a movable finger or feed dog 45 which is carried on the feed bar ZI in the same yieldable manner as and along with the other fingers 23 but is located in the proper position relative to the die mechanism for engaging behind the back edge of the strip on the stroke which moves the forward end of the strip into the die.

The movable finger 45 (Figs. 1, 2 and 5) is mounted on a pivot pin 46 held in a slide block 4l which is similar to the adjusting blocks 25, The block ll is freely movable and slides in the slot 2G in the feed bar 2l so that the movement of the feed bar is not modified by the long stroke movement of the dog 55, as explained above. The slide block is clamped by a clamping block Lili and a screw le toan auxiliary slide bar 5I which slides in a groove 52 formed in the bed i2 adjacent the path of travel of the feed bar.

The auxiliary slide bar 5I extends back beyond the bed I2 and is secured to the lower end of an upright lever 55. The lever intermediate its ends is mounted on a pivot stud 5S threaded into a bracket 5l secured to feed bar coupling 31. The bracket thus moves with theV feed bar. The upper end of the lever 55 carries a cam roller 58 which operates against a sloping cam surface 59 of a stationary cam E@ adjustably secured by bolts 6I to a bracket t2 fastened to the stationary top plate Id. Adjusting setscrews 63 threaded in the bracket 32 engage against the cam for adjusting it in a desired position.

The cam roller 53 is pressed against the cam surface 59 by a compression spring E5 which surrounds a rod 66. The outer end of the rod extends through the lever 55 adjacent the cam roller. The other end of the rod is formed with a bearing 61 carried on a pivot screw t8 secured in the movable bracket 51. The spring is interposed between the lever 55 and the bearing 61.

Hence when the feed bar ZI moves forward on,

a feeding stroke the movable bracket l, the lever 55, the auxiliary slide bar 5| and the movable linger or feed dog i5 all move forward with the feed bar, the finger 45 operating in the same manner and for the saine purpose as lall the other feed fingers it. During this forward feeding stroke the cam roller 58 on the lever 55 traverses the sloping cam surface 59 ofcam i and this depresses the roller.

Depression of the cam roller 58 rocks the lever $5 on its pivot stud 55 against the resistance of the spring 55 and this rocking action shifts the auxiliary slide bar 5i forward relative to the feed bar. This action pushes the movable feed nger 45 forward at a faster rate than the fingers 23 which are secured to the feed bar and hence the movable finger 45 traverses a greater distance than the fingers 23. The distance so traversed is equal to the distance Y in Fig. 7. On the return stroke of the feed bar 2l the reverse of this action takes place and hence the movable finger returns to its original feeding position.

This movement of the movable finger or dog 45 takes place on each stroke of the feed bar `2l but it is only effective when the finger is in feeding engagement with the back edge of strip. This, as explained hereinbefore, is only when the forward end of the strip is about to enter the die mechanism. Since during this stroke a distance equal to the distance Y hereinbefore mentioned is to be traversed in order to properly locate the forward end of the strip under the die, the caml 60 may be adjusted to give this stroke.

In this manner strips ymay be readily fed one right after the other without skipping any strokes of the die mechanism. Hence greater production and a more uniform operation results.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacricing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

l. In a device for feeding strips of sheet material in a continuous procession along a predetermined path of travel to position successive portions of the strip at a working station, the combination of a feed bar reciprocable through a feeding stroke and a return stroke, a plurality of feed dogs spaced at equal intervals along said feed bar for successively engaging behind the feeding edge of the strip to advance the strip in a step-by-step manner, and elements operable with and freely mounted on said feed bar when it moves through a feeding stroke for moving a greater distance than said feed dogs for engaging the rear of and advancing said strip through a greater distance than the stroke of the feed bar as the strip initially enters the working station, whereby to compensate for the difference in the positions of the end portions of succeeding adjacent strips.

2. In a device for feeding strips of sheet material in a continuous procession along a predetermined path of travel to position successive portions of the strip at a working station, the

combination of a feed bar reciprocable through a feeding stroke and a return stroke, a plurality of feed dogs spaced at equal intervals along said feed bar for successively engaging behind the feeding edge of the strip to advance the strip in a step-by-step manner, one of said feed dogs being freely mounted on and movable with said feed bar, and means for shifting said freely mounted dog with and for a greater distance than said feed bar during a feeding stroke thereof for engaging the rear edge of succeeding strips so that each strip will be advanced a greater distance on the first stroke than on the succeeding strokes, whereby to compensate for the difference in the positions of the end portions of succeeding adjacent strips.

3. In a device for feeding strips of sheet material in a continuous procession along `a predetermined path of travel to position successive portions of the strip at a working station, the combination of a main feed bar reciprocable through a feeding stroke and a return stroke, a plurality of feed dogs secured to said main feed bar at equally spaced intervals therealong for successively engaging behind the feeding edge of the strip to advance the strip in a step-bystep manner, an auxiliary feed bar freely slidable on and relative to said main feed bar and operable independently thereof, a feed dog secured to said auxiliary feed bar and serving as one of the feed dogs on said main feed bar for initially advancing each strip into said working station, and cam actuated means for shifting said auxiliary feed bar and the dog carried thereon relative to said main feed bar when the latter moves through a feeding stroke to move said auxiliary feed dog a greater distance than the distance traversed by said main feed dogs, said auxiliary feed bar dog engaging the rear edge of and advancing successive strips through a greater distance than the stroke of the main feed bar for the first feeding step of each successive strip as said strip initially enters the working station, whereby to compensate for the difference in the positions of the end portions of succeeding adjacent strips.

4. In a device for feeding strips of sheet material in a continuous procession along a predetermined path of travel to position successive portions of the strip at a working station, the combination of a main feed bar reciprocable through a feeding stroke and a return stroke, a plurality of feed dogs secured to said feed bar at equally spaced intervals therealong for successively engaging behind the feeding edge of the strip to advance the strip in a step-by-step manner, an auxiliary feed bar disposed adjacent said main feed bar, a feed dog secured to said auxiliary feed bar and serving as one of the feed dogs on said main feed bar for initially advancing each strip into said working station, a bracket on said main feed bar, a lever on said bracket and connecting with said auxiliary feed bar, and a stationary cam traversed by said lever for shifting said auxiliary feed bar and the dog carried thereon relative to said main feed bar when the latter moves through a feeding stroke, said auxiliary feed bar dog advancing said strip through a greater distance than the stroke o-f the main feed bar as the strip initially enters the working station to compensate for the difference in the positions of the end portions of succeeding adjacent strips.

JOHN HANSEN.

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