US2389913A - Feed pusher - Google Patents

Description

Nox r. 27, 1945. c. s. KASPER 2,389,913

FEED .PUSHER Filed Sept. 22, 1943 INVENTOR A TTORNE Y5.

Patented Nov. 27, 1945 UNITED STATES PATENT OFFICE FEED PUSHER Cass S. Kasper, Grosse Pointe, Mich.

Application September 22, 1943, Serial No. 503,385

2 Claims.

The invention relates generally to automatic screw machines and it has particular relation to: a stock pusher for feeding bar stock into the machine.

As will be readily understood by those skilled in the art, stock pushing devices are used in automatic screw machines for the purpose of intermittently feeding the bar stock. Ordinarily, the bar stock used is either round or hexagonal in shape and often it is substantially large in dimensions so that considerable force is required to move it, especially when the stock is long. While perhaps different types of stock pushing devices have been employed in machines of this character, a rather well known type includes spring-like gripping fingers which have constant and strong friction engagement with the side surfaces of the stock. These devices will frictionally slide over the stock in one direction without moving it owing to the fact that the stock is held against movement and when the devices are reversely moved, the maintained frictional contact will advance the stock into the machine. Due to the fact that the frictional engagement is maintained on the stock during movement of the devices in both directions, it is apparent that considerable wear must occur on the spring-like fingers and that their efiiciency will decrease accordingly.

One object of the invention is to provide an improved stock pushing device which will be more efiicient, more durable, and more practical in operation, so that the cost of operation of the machine will be decreased and its efliciency increased.

Another object of the invention is to provide a stock pushing device which may be manufactured and assembled easily and inexpensively.

Another object of the invention is to provide an improved stock pushing device wherein in the idling movement of the device, wear thereon through engagement of the device with the stock, is minimized.

Another object of the invention is to provide an improved stock pushing device of the foregoing character, wherein immediate gripping of the stock by the device occurs upon reversing the movement when the stock is to be fed into the machine.

Other objects of the invention will become apparent from the following specification, from the drawings relating thereto, and from the claims hereinafter set forth.

For a better understanding of the invention, reference may be had to the drawing wherein:

Figure 1 is a longitudinal, cross-sectional View, illustrating a stock pushing device constructed according to one form of the invention;

Fig. 2 is an end elevational View taken substantially along the line 2--2 of Fig. 1;

Fig. 3 is a cross-sectional view on the order of Fig. 1 illustrating another form of the invention;

Fig. 4 is an end elevational view taken substantially along the line 4-4 of Fig. 3. I

Referring to Figs. 1 and 2, a stock pushing sleeve forming part of the stock pushing device' is indicated at H) and one end of this sleeve has threaded engagement, as indicated at H, with a reciprocatory member 12 forming part of an automatic screw machine and which is adapted to be moved during operation of the latter. On its inner periphery, the sleeve I0 is provided with a tapered secondary sleeve element M which is adapted to serve as a piloting element when a bar of stock is introduced. For the purpose of moving the stock, rings l6 and I! are provided within the sleeve and each of these at the top of the sleeve extends between a pair of projections it] and I 9 which are riveted to the sleeve wall. These projections axially anchor the rings on the sleeve so that when the latter is moved to the right in the stock pushing operation, the rings necessarily must move with the sleeve.

Each ring is biased toward a tilted position by a spring element 2! having a small loop or eye.

22 intermediate its ends which is anchored on the sleeve by means of a riveted projection 23 located substantially opposite the projections l8 and I9. Circumferentially, at each side of the projection 23, the spring wire first extends in a circumferential direction along the inner surface of the sleeve, as indicated at 25, and then it is reversely turned, as indicated at 25, so that the two portions 25 and 26 are disposed in normally diverging relation. The free end of the portion 25 is turned toward the center of the sleeve, as indicated at 21, so as to provide a part adapted to contact the side of the ring 16. Fromv this it will be apparent that the spring element includes two parts, each comprising the sections 25, 25, and 21,- with the spring anchored between the two parts 25 by means of the loop ZZ and with the two ends 2'! contacting the side spring so as to move it towards a radial position and permit the bar to easily pass through. The spring urges the ring to a position such that upper and lower portions of the ring contact upper and lower sides of the bar and, since the bar in this instance is shown as of hexagonal shape, the corners of the bar will normally be in contact with the upper and lower sides of the ring. Any slight movement of the stock to the right tends to shift the ring to permit the stock to move through, but any tendency of the stock to move to the left naturally tends to increase force of contact between the rings and the upper and lower corners of the stock. This tendency of the ring to obtain positive, binding engagement is accentuated by the springs which normally are acting to urge them into binding relation with the stock. Rings such as shown, which are circular in cross section, are suitable for hexagonal bars in particular since the corners of the latter will enable obtaining sufficient binding action between the rings and the stock.

From the foregoing, it should be understood that when the stock is first inserted, it may freely be moved through the rings to its approximate position and then the stock may be moved in the same direction by moving the sleeve If! to the right. Since the rings are instantly able to grip the stock through forceful binding engagement, any advancing movement of the sleeve will instantly effect corresponding movement of the stock. Idling movement of the sleeve to the left allows the rings to slide over the stock freely, but immediately upon reversed movement of the sleeve, the rings bind against the stock and move it.

The relative dimensions of the rings and sleeve are such that the rings may be moved into radial positions if necessary and they will have suflicient clearance in the sleeve that no interference between the rings and the surface of the sleeve will occur during any tilting of the rings required or, if the rings should contact the sleeve surface during tilting, such rings may shift radially at least enough to avoid interference. While some shifting of the rings radially may occur, the portion 21 on the springs and the projections l8 and I9 will permit this without permitting any disassembly. Different dimensions of stock may be handled by the device since it will be apparent that the rings may have binding engagement with different sizes of the stock merely by tilting to different positions. When the sleeve is free from the stock, the left hand ring may abut against the larger end of the secondary sleeve l4 and the other ring against parts of the left spring so as to hold the parts assembled with the sleeve. Disassembly may be accomplished by removing the springs and, if necessary, removing one or more of the riveted projections. Finally, it might be said that the rings will be made of hardened metal so as to avoid unnecessary wear and, in view of the fact that they may rotate or turn, this Wear will be distributed eircumferentially.

The device shown by Figs. 3 and 4 is adapted particularly for handling round stock, indicated at 30, and, in order to obtain stronger binding engagement with the stock, rings 3| are employed which have a cylindrical surface 32 bored at an angle to the plane of the ring. In other words, the axis of the outer periphery of the ring is at a slight angle to the axis of the surface 32. Projections 33 and 34 at the upper side of the ring hold it in axial position and these are riveted to the sleeve in the manner previously indicated. For preventing rotation of the ring,

its upper portion has a radial slot 35 at one side which receives the projection 34, and it should be understood that this slot will be of such character that tilting of the ring will be permitted, while still obtaining axial anchoring, so that movement of the sleeve will effect axial movement of the ring.

At the left side of the ring, a tapered su face 36 is provided so that the stock may be guided into the ring and into the cylindrical portion 32. Itshould be understood that the diameter of the cylindrical portion 32 may be varied and that normally the diameter will be at least slightly greater than the stock diameter so as to obtain binding engagement at the left hand lower edge of the surface and at the right hand upper edge thereof. The variation in diameter should be such as to allow variations in stock dimensions, while still enabling the rings to bind securely against the stock. Spring elements 2|, which are the same as already described, may be -em ployed for biasing the rings to tilted positions. In this case, as in the previous design, the rings will immediately bind against the stock when the sleeve is moved to the right, while they will tilt into non-binding positions upon moving the sleeve to the left. Finally, it might be said that the axis of the cylindrical surface 32 and the axis of the outer periphery of the ring will lie in a vertical plane or in the plane of the paper. as seen in Fig. 3. In other words, if the ring is in the position shown in Fig. 3, a boring tool to form the surface 32 must be tilted vertically from a position axially coinciding with the axis of the ring, This is mentioned particularly so that it will be understood how the cylindrical surface is related to the ring with the latter held against rotation.

Each device may be manufactured inexpensively and assembled easily. With the rings constructed of hardened metal, it will be apparent that each device will have long life and, in view of the repeated use of these devices in the operation of automatic screw machines, long life and efficient operation are definitely desirable.

Although more than one form of the invention has been described and illustrated in detail, it will be apparent to thos skilled in the art that various modifications may be made without departing from the spirit of the invention.

What is claimed is:

1. A stock pusher for an automatic screw ma- V chine or the like comprising a sleeve adapted to be shifted axially in on direction to move the stock and to be shifted idly in the other direction, a ring disposed transversely in the sleeve and through which the stock is to extend. the inner periphery of the ring being adapted to have binding engagement with the stock when the latter is tilted, means anchoring the ring on the sleeve at one point so that it may tilt and bindingly engage the stock while being axially moved by the sleeve, and a generally V shape wire spring element having the ends of its legs respectively anchored on the sleeve and engaging the ring at a location generally opposite said anchoring means, the intermediate portion of the spring being bowed circumferentially of the sleeve so that the wire extends circumferentially of the sleeve first in one direction along the inner surface of the latter and then reversely in the other air cumf'erential direction.

2. A stock pusher for an automatic screw maanchored to the sleeve inner surface at one point and having side portions extending circumferentially in opposit directions, each side portion terminating in a circumferentially reversed portion to define a, loop disposed in a cylindrical segment adjacent the sleeve surface, the ends of such loop portions remote to th wire anchoring point, engaging the ring at a point generally opposite the ring anchoring means.

CASS S. KASPER.

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