US2979004A

US2979004A - Stock lifter for use with dies

Info

Publication number: US2979004A
Application number: US750717A
Authority: US
Inventors: Roy H Kenville; Max K Kenville
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-07-24
Filing date: 1958-07-24
Publication date: 1961-04-11
Anticipated expiration: 1978-04-11

Description

April 11, 1961 R. H. KENVILLE ETAL 2,979,004

STOCK LIFTER FOR USE WITH DIES Filed July 24, 1958 2 Sheets-Sheet 1 23 l 30 2/ 2/ 3) 5o SIJ Q 4l 4/ g 29 29 k 20 1%- 25 25 47\ i// 13 27 1 27 /3 l I INVENTORS RogH. Kenvzlle and Max KKenvLZZe 26 25 644 26 ATTORNEY April 11, 1961 R. H. KENVILLE EIAL 2,979,004

STOCK LIFTER FOR USE WITH DIES Filed July 24, 1958 2 Sheets-Sheet 2 H KINVEIYIGQRS R0 envL e and Y MgxKKenvLZLe A TTOR N 57 STOCK LIFTER FOR USE WITH DIES Roy H. Kenviile, 1802 Penbrook Lane, and Max K. Kenviile, 1929 Bayberry Lane, both of Flint, Mich.

Filed July 24, 1958, Ser. No. 750,717

Claims. (Cl. 113-42) The present invention relates to stock lifters used on, and controlled in their operation by stamping and drawing dies for slidably supporting strip stock in a slightly elevated position upon the separation of the die members so as to permit the advancement of the stock between the open die members.

Generally, there is provided a plurality of lifters. arranged in pairs and spaced from one another along a row of progressive dies with lifters of each pair located at opposite side edges of a strip of sheet stock upon which die operations are to be performed. There are transverse grooves near the upper ends and in adjacent side of the lifters of each pair into which the opposite edge portions of the strip stock extend for slidably supporting and guiding the stock as it is intermittently advanced to and from the different dies. The lifters which usually have their lower end portions slidably mounted in the lower die members for limited vertical movement in an upward direction are engaged by the upper die members and are depressed into the lower die members during downward movement of said upper die members for lowering the strip stock on to the lower die members. Springs which are under the lifters and which are compressed by lowering of the upper die members on the lifters, elevate the lifters and the strip stock carried thereby to the upward limited positions of said lifters upon return of said upper die members to their upward inactive positions. This raising of the strip stock disengages the same from the lower die members and positions said stock and all depressed portions formed thereon horizontally above all parts of the lower die members so as to provide clearance for advancement of the stock along the row of progressive dies.

It is an object of the invention to provide a stock lifter 0f the above indicated character having the body thereof constructed of a short section of cylindrical tubing cut and formed for rigid securement of a head on one end thereof.

Another object of the invention is to provide in a lifter of the character set forth, a novel and improved manner of constructing a transverse stock-supporting groove at the head end, and in a side of the cylindrical tubular body.

A further object of the invention is to provide in a lifter of the above character, a longitudinally extending recess of novel and simple construction in a side of the cylindrical tubular body, and a fixed guiding and stopping element projecting into the recess for controlling longitudinal movement of the lifter.

It is also an object of the invention to provide a stock lifter of the above indicated character which is extremely simple and substantial in construction, economical to manufacture, and thoroughly efiicient and practical in use.

These, together with various auxiliary features and ob jects of the invention which will later become apparent as the following description proceeds, are attained by the present invention, a preferred embodiment of which ice has been illustrated by way of example only, in the accompanying drawings, wherein:

Figure l is a top plan of a plurality of lower stationary die members for progressive operations on a strip of sheet stock shown supported by the improved stock lifters;

Figure 2 is an enlarged vertical cross section taken on line 2-2 of Figure 1, showing a pair of stock lifters in elevation and showing an upper die member in section and in raised position;

Figure 3 is a cross sectional view similar to Figure 2, but differing in that it shows thepair of stock lifters in section and the various parts in their relative positions when the upper die member is lowered to perform a die operation;

Figures 4 and 5 are further enlarged fragmentary sectional views of the upper ends of a stock litter in the process of manufacture and prior to securement of the head to the tubular body and the provision of the stock supporting groove, Figure 4 being a vertical section, while Figure 5 is a horizontal cross section taken on line 5-5 of Figure 4; and Figures 6 and 7 are sectional views similar to Figures 4 and 5, respectively, showing the construction of the parts after the attachment of the head to the tubular body, and the provision of the stock supporting groove.

Referring now more specifically to the accompanying drawings, wherein like numerals designate similar parts throughout the various views, attention is directed first, to Figure 1 wherein it will be seen that there is indicated at 10 a plurality of lower die members arranged in a row upon a spacer plate 11 and bolted, as at 12, to a die shoe 13, which in turn is rigidly supported on the bed of a press (not shown). Directly above the lower die members 10, and adapted for cooperation therewith in performing die operations on a strip of sheet metal stock 14, there is shown in Figures 2 and 3 one of a plurality of upper die members 15 mounted on a die plate 16, which in turn is carried by a reciprocal press head (not shown). There is an upper movable die member 15 for mating with each stationary die member, and as the strip of sheet stock 14 dwells between feeding operations thereto the press head is lowered and all sets of dies perform operations on the strip stock simultaneously; it being understood that the centers of all sets of dies are evenly spaced, and that all feed strokes to the stock are identical so as to advance the stock from center to center.

Any number of sets of dies may be employed and they may consist of a combination of stamping, forming, and punching dies for performing progressive operations on the stock material. Articles while being produced with an assortment of dies of this character remain a part of the strip stock material until they have arrived at the final stage or due operation, where they are then separated from each other and the remainder or waste stock material, it being necessary to keep the partially completed articles connected together so as to control their movements, and positions relative to the different sets of dies with a single feeding operation to the stock material. This manner of die operation requires the raising and lowering of the strip stock between each operation of the dies on the strip stock because of the necessity of having all depressed portions formed on said strip stock by said dies horizontally above all parts of the lower die members while effecting feeding operations. It is mainly for the purpose of raising and lowering the strip stock that a plurality of stock lifters positioned at opposite side edges of the strip stock are employed. Stock lifters also function as guides in slidably supporting the strip stock against lateral movement, as well as strippers for disengaging the stock material from the dies. g

The improved stock lifters, generally indicated by the numeral 20, and forming the subject of this invention are of a unique construction that is especially adapted for both economical and quantity production. As all of the stock lifters are of identical construction, the following'desription of one should suflice for all. The body 21 of the lifter is constructed of either seamless or welded cylindrical tubing cut and formed for securement of a head 22 on its upper end, and has a longitudinal extending recess 23 in the upper portion of its side, and a transverse groove 24 at its upper end and extending inwardly in its side diametrically opposite the recess 23.

The cylindrical body 21 is slidably supported in a bore 25 extending vertically through the lower die member 10, and can have its lower end portion forced downward-' ly against tension of a spiral compression spring 26 and into aligned

holes

27 and 28 extending through the spacer plate 11 and in the die shoe 13, respectively. A guiding and stopping element 29 for the body 21 and in the form of a socket head cap screw is threaded into a relatively deep counterbored hole 3%) slightly spaced outwardly of and parallel with the bore 25. The head 31 of the cap screw is of an abnormally large diameter and its brim portion projects into the longitudinal recess 23 in the body for preventing rotation as well as limiting outward movement of said body in the bore 25 during vertical sliding movement of said body. The transverse groove 24 receives a longitudinal edge portion of the strip stock 14 and its rounded bottom 32 is closely fitted to the edge of the stock for slidable engagement therewith, while upper and lower

flat surfaces

33 and 34, respectively, forming the sides of said groove are loosely fitted to opposite sides of said edge portion and are moved into and out of engagement with same for raising and lowering the strip stock upon vertical movement of the stock lifter.

The upper portion 35 of the head 22 is circular in plan and of a like diameter as that of the outer diameter of the tubular body 21 and its under surface rests upon the upper end of said tubular body, while the lower portion 36 of said head is of a reduced size and is snugly received within the upper end portion of said tubular body. Between said upper and

lower portions

35 and 36 of said head there is a further reduced neck portion 37 of an arcuate shape in horizontal cross section and slightly off set to one side of the vertical center of said head, as clearly shown in Figures and 7. Spaced downwardly from the upper end of the tubular body a distance equal to the height of the reduced neck portions 37, said body is slit parallel to its upper end and substantially one half therearound, as indicated by the numeral 38 in Figure 4, and the part 39 of said tubular body above said slit is swaged inwardly and into contact with the convex surface 40 of the arcuate shaped neck 37, thus providing therewith the rounded bottom 32 for the stock engaging groove 24 and the means for securing the head 22 on the tubular body.

The longitudinally extending recess 23 in the tubular body 21, which is also constructed by cutting and reforming the tubular body, is provided by slitting the wall of said body as at 41, on a plan similar to the slit 38, but substantially midway of the length and one quarter the distance therearound, and then bending as at 42, the entire portion of said body directly above said slit inwardly on a curve whereby the inner surface of the tubular wall conforms to the cocaved surface 43 of the arcuate shaped neck 37 of the head 22, which engages the upper end portion of this inwardly bent portion with said concaved surface of said neck. In Figure 2 it can be seen that the upper end of the undisturbed lower portion of the tubular body at the slit 40 provides a shoulder that engages the under side of the head 31 of the cap screw 29 for limiting upward movement of the stock lifter when the head of the press is elevated.

The spiral compression spring 26, previously mentioned, has its lower end seated on the bottom of a reduced extension 44 of the opening 28 in the die shoe 13, while its upper end bears against the bottom 45 of an inverted cup 46 inserted in the lower end of the tubular body 21, there being an annular flange 47 on the lower end of said inverted cup that engages the lower end of said tubular body to prevent upward movement of said inverted cup relative to said body. In the upper die member, as shown in Figures 2 and 3, there is a shallow cavity 48 in the under side thereof, into which the upper portion of the head 22 is received and against the bottom of which said head abuts when said die member is lowered on the stock lifter. To prevent the creation of air pressure or a vacuum in the hollow stock lifter and the openings into which it is arranged, there are provided breather openings 49 and 50 through the bottom wall 45 of the inverted cup 46 and the recessed portion 23 of the tubular body, respectively, as also shown in Figure 3.

From the foregoing, it can be seen that a plurality of the improved stock lifters 20 arranged in pairs at spaced intervals throughout the length of a row of progressive dies slightly elevate a strip of stock 14, upon which the dies are performing operations, to the limit of upward movement of the stock lifters upon the raising of the head of a press and disengagement of the upper die members 15 from the strip stock. It can further be observed that during descent of the press head, the upper die members 15 engage the head 22 of all stock lifters 20 simultaneously, and depress said stock lifters into the lower die members 10, thus lowering the strip stock onto said lower die members, it being understood that while the strip stock is in its elevated position and slidably supported by the stock lifters it is advanced a distance equal to the common distance between the centers of the different die sets.

While a considerable portion of the above description has been devoted to a specific type of die operation, namely, a plurality of dies for performing progressive operations on strip stock, with which the present invention on improved stock lifters is especially adapted for use, it is to be understood that said improved stock lifters may also be employed with other types of die operations or even may be used solely for the purpose of stripping the work from the dies.

In view of the foregoing description taken in conjunction with the accompanying drawings, it is believed that a clear understanding of the construction, operation, and advantages of the invention will be quite apparent to those skilled in the art.

It is to be understood, however, that even though there is herein shown and described a preferred embodiment of the invention, various changes may be made without departing from the spirit and full intendment of the invention.

What is claimed is:

1. A stock lifter for use in pairs and at opposite edge portions of strip stock for separating and supporting the strip stock out of engagement with a pair of relatively movable die members during separation of said die members while performing die operations upon said stock, said stock lifter comprising a tubular body slidably supported by one of said die members for endwise movement parallel with the relative movement of the die members, spring means yieldably projecting an end portion of said slidable tubular body outwardly of the above mentioned die member and in a direction towards the other die member, and a head seated on the projected end of said tubular body and having a reduced neck portion thereon within said tubular body, said head being engaged by the second mentioned die member so as to depress said tubular body relative to said first mentioned die member upon closing of said die members, said reduced neck of said head having in the side thereof a transverse groove, said tubular body having a deformed end portion Within said transverse groove so as to retain said head on said tubular body and provide therewith the bottom of said groove, said groove having an edge portion of the strip stock extending therethrough so as to raise and lower the strip stock upon opening and closing of said die members.

2. A stock lifter for use in pairs and at opposite edge portions of strip stock for separating and supporting the strip stock out of engagement with a lower stationary die member and an upper movable die member during separation of said die members while performing die operations upon the stock, said stock lifter comprising a tubular body slidably supported by the lower stationary die member for endwise movement parallel with the movement of the upper movable die member, spring means yieldably projecting an end portion of said slidable tubular body upwardly and outwardly of the stationary die member and in a direction towards the upper movable die member, and a head seated on the upper projected end of said tubular body and having a reduced neck portion thereon within said tubular body, said head being engaged by said movable die member so as to depress said tubular body upon closing of said movable die member on said stationary die member, said reduced neck of said head having in the side thereof a transverse groove, said tubular body having a convex deformed upper end portion within said transverse groove so as to retain said head on said tubular body and provide therewith a horizontally rounded bottom of said groove, said groove having an edge portion of the strip stock extending therethrough so as to raise and lower the strip stock upon opening and closing of said die members.

3. A stock lifter for use in pairs and at opposite edge portions of strip stock for separating and supporting the strip stock out of engagement with a pair of relatively movable die members during separation of said die members while performong die operations upon said stock, said stock lifter comprising a tubular body slidably supported by one of said die members for endwise movement parallel with the relative movement of the die members, spring means yieldably projecting an end portion of said slidable tubular body outwardly of the above mentioned die member and in a direction towards the other die member, a head rigidly fixed on the projected end of said tubular body and being engaged by the second mentioned die member so as to depress said tubular body relative to said first mentioned die member upon closing of said die members, said head having in the side thereof a transverse groove through which an edge portion of the strip stock extends so as to raise and lower the strip stock upon opening and closing of said die members, said tubular body having a side thereof inwardly and arcuately deformed for a distance short of its length so as to provide a longitudinally extending recess in its side, and a headed screw threaded into said first mentioned die member and having a portion of the head thereof within said recess for guiding sliding movement of said tubular body.

4. A stock lifter for use in pairs and at opposite edge portions of strip stock for separating and supporting the strip stock out of engagement with a pair of relatively movable die members during separation of said die members while performing die operations upon said stock, said stock lifter comprising a tubular body slidably supported by one of said die members for endwise movement parallel with the relative movement of the die members,

spring means yieldably projecting an end portion of said slidable tubular body outwardly of the above mentioned die member and in a direction towards the other die member, a head rigidly fixed on the projected end of said tubular body and being engaged by the second mentioned die member so as to depress said tubular body relative to said first mentioned die member upon closing of said die members, said head having in the side thereof a transverse groove through which an edge portion of the strip stock extends so as to raise and lower the strip stock upon opening and closing of said die members, said tubular body having a side thereof inwardly and arcuately deformed for a distance short of its length and terminating in a shoulder, said deformation providing a longitudinally extending recess in the side of said tubular body, and a headed cap screw threaded into said first mentioned die member and parallel with the direction of movement of said tubular body, the head of said screw being of enlarged diameter and having a peripheral portion thereof projecting into said recess so as to guide sliding movement and limit with said shoulder endwise movement of said tubular body.

5. A stock lifter for use in pairs and at opposite edge portions of strip stock for separating and supporting the strip stock out of engagement with a pair of relatively movable die members during separation of said die members while performing die operations upon said stock, said stock lifter comprising a tubular body slidably supported by one of said die members for endwise movement parallel with the relative movement of the die members, spring means yieldably projecting an end portion of said slidable tubular body outwardly of the above mentioned die member and in a direction towards the other die member, a head rigidly fixed on the projected end of said tubular body and being engaged by the second mentioned die member so as to depress the said tubular body inwardly and relative to said first mentioned die member upon closing of said die members, said head having in the side thereof a transverse groove through which an edge portion of the strip stock extends so as to raise and lower the strip stock upon opening and closing of said die members, said tubular body having a side thereof inwardly and arcuately deformed for a distance short of its length so as to provide a longitudinally extending recess at its projected end portion, a guiding and limiting element secured to said first mentioned die member and having a portion thereof projecting into said recess for controlling sliding movement of said tubular body, said spring means for yieldably projecting said tubular body outwardly of said first mentioned die member consisting of an inverted cup-shaped member within the inner end portion of said tubular body and having a flared flange on the brim portion thereof in engagement with the inner end of said tubular body, and a spiral compression spring partially in said cup-shaped member and seated at its opposite ends, on the bottom of said cup-shaped member and on said first mentioned die member.

References Cited in the file of this patent UNITED STATES PATENTS 316,082 Tyler et al. Apr. 21, 1885 1,147,273 Sherbondy July 20, 1915 1,768,294 Reid June 24, 1930