US2323889A - Stock pusher - Google Patents

Description

STOCK PUSHER Filed Sept. 18, 1942 INVENTOR 6505 652220212 ATTORNEY Patented July 13, 1943 UNITED STATES PATENT OFFICE STOCK PUSHER George F. Zezula, Commerce, Mich. Application September 18, 1942, Serial No. 459,066

2 Claims.

My invention is used in conjunction with automatic screw machines in their various forms, such as modern multiple spindle machines, in which the stock to be worked upon, in the form of long rods, is fed into the respective machine by means of a suitable mechanism through the head stock spindle. The usual arrangement calls for a tube ending in a spring collet, which is located at the operative end of the spindle and through which a length of stock is pushed outwardly towards and to a stop aligned with the mouth of the collet.

Positioned within the tube ending with a collet, is a pusher tube, being a part of the mechanism serving to advance the stock through the collet, said pusher tube, terminating at its end, adjacent the collet, with a pusher or push finger, to which my invention pertains.

Several kinds of said pushers are known in the industry, my improvement relating especially to one of them, known as master pusher which consists of a cylindrical shell, made of high grade of spring temper steel, split by long slots, extending in the direction of the axis of the shell, and removable pads, fitting into one end of said pusher and held there firmly by keys, flanges or other means.

It will be understood that the bar stock, that is rods fed into the respective machine, are engaged by said pads, and as the pads are made of a metal which is softer than the rods they soon wear out to a point where their grip upon said rods is loose and ineiiective. When this stage of wear was reached, it was necessary to remove the pushers as a whole, or the pads alone where this could be done, and to substitute other pads in their place. The operation was slow, diificult and expensive as it often resulted in breakage of the cylindrical shells holding the pads.

In order, therefore, to eliminat the above difiiculties, to prolong the life of the pushers and to secure certain other advantages, I have improved the pushers, especially the master pushers in the manner which will be presently described, the specific purpose of my invention being:

To eliminate the necessity of removing the pads from the pushers, by providing an easily removable and replaceable insert of split construction, within the grip of said pads;

To provide an insert which upon wear may be easily adjusted and restored to its initial degree of efiiciency without being removed from the pusher or the pads, respectively.

My further purpose is to provide an insert of simple construction which may be made of an easily available material such as brass, and which therefore, will cost comparatively little.

Having thus outlined the purposes of my invention, I shall now describe my improvement with reference to the accompanying drawing, in which:

Fig. l is an exploded perspective view of a pusher, including my removable insert;

Fig. 2 is an exploded perspective view, magnified, of another species of a pusher;

Fig. 3 is a longitudinal sectional view of the pusher shown in Fig. 1;

Fig. 4 is a longitudinal sectional view of the pusher shown in Fig. 21.

Similar numerals refer to throughout the several views.

The pusher shown in Fig. 1 comprises a cylindrical shell lfi, made of high grade spring steel, said shell tapering towards what may b considered, its operative end, which will be presently described. At its opposite end, the shell is provided with an external thread, this serving as a means of afiixing the pusher to the end of the pusher tube, which is not shown here. The threaded part l2 extends from the end of the shell to an annular shoulder l l. The body of the shell is split longitudinally, parallel to its longitudinal axis, by means of diametrically disposed slots, which are marked iii, the outer ends of the parts separated by said slots, forming jaws M, opposed to each other. Owing to the fact that the shell is made of spring steel, and owing to said slots I3, the jaws may be spread apart and are similar parts capable of exerting considerable pressure upon an object held between them. Numeral l8 indicates an insert which is threaded externally and which may be screwed into said jaws, the latter being equipped with an internal thread indicated by numeral l5.

As a rule, the insert is made of brass and is of a somewhat larger diameter than the internal diameter of the shell at the end encompassed by said jaws I 4. The insert is provided witha diametrical slot I I on its outer surface for the application of a screw driver, and contains a centrally located hole of a size suited to the diameter of the stock which is to be fed through the pusher.

The pusher shown in Figs. 2 and l, is substantially the same as that in Figs. 1 and 3, with the exception of its operative end, which includes additional elements, known as pads. The shell 20 comprising an externally threaded section 22; adjoining a shoulder 2!, is split by means of slots 23 to form two resilient members opposed to each other and terminating in jaws 24. Each jaw contains an inner flange 35 and is lined with a pad 26, extending between said flange and the shoulder 25. Both pads, when in place, form a cylinder or a sleeve split longitudinally, as shown, the split between the pads coinciding with slots 23. An inner shoulder 32 restricts the diameter of the opening between the pads at one end thereof, adjoining said shoulders 25. In order to secure the pads in place against rotary movement within jaws 24, an integrally formed key 28 on one of the pads, fits into a slot 29 within said flange 35 at the end of the respective jaw. I wish to add here that the pads are Provided with an internal thread 33.

The operative member of the pusher which immediately engages the stock to be advanced thereby is an insert 30. The insert which is threaded on the outside, is provided with a diametrical screw driver slot 3|, and a central hole 36. Like in the case of the pusher shown in Figs. 1 and 3, the insert is of a somewhat larger diameter than the diameter of the opening between the pads, so that when the insert is screwed into its place between pads 26, it is held there tightly under the tension of the opposed sections of shell 20, split by means of slots 23.

I shall now describe the operation of my pushers. The pushers as now used, are, as a rule, equipped with pads alone which after a period of use, become worn on the inner surfaces which come in contact with the stock passingbetween them. With the wear their usefulness is A terminated and they have to be replaced by other pads. In the case of my improved pushers, it is the insert which engages the stock to be fed. As the insert is made of substantially the same material as the pads, it too will wear out in about the same time. This, however, does not call for its replacement. On the contrary the insert is left in place but its useful life may be prolonged by the simple expedient of sawing the insert in half, in the plane of its longitudinal axis, along its screw driver slot. After a while, when the wear of the inner surface of the insert, now sawn in two, demands it, the operation may be repeated, and the insert may be re-sawn in the same plane as before. This is possible as the cut surfaces of the insert tightly abut each other under the tension of the jaws formed by the outer ends of the shell as above described. When desirable, the insert may be easily removed from between the pads, by means of a screw driver, and a new one may be substituted in its place.

It will be seen from the above description that my inserts not only take the place of pads, which may be even omitted from pushers, but that they render a new service and furnish a new utility of which the pads are not capable. This results from the feature which makes it possible first to use an uncut insert as a whole, and then to cut it in two, a number of times in succession and by bringing the cut parts close together to reduce the distance between the opposed inner surfaces of the passage left therein for the moving stock. This is not feasible when pads are used.

I wish to point out that my improved pusher has already proved its usefulness, practicability, and economy in actual use in an industrial establishment.

I realize that further changes may be made in the construction of my pusher without departing from the inventive principle disclosed herein. What I, therefore, wish to claim, is as follows:

1. A stock pusher of the kind described, comprising a cylindrical shell of resilient metal, said shell being provided, at one end, with an external thread as a means of connecting it operatively to a pusher tube, and being split, at the other end, into opposing members by a plurality of slots extending a part of the length of said shell, separate pads threaded on the inner surface for the inner side of each end of said opposing members, and a removable cylindrical insert, held between said pads under the tension of said members, said insert being provided with a central hole for admission of stock.

2. A stock pusher as described, comprising a cylindrical shell of resilient material, said shell being provided, at one end, with an external thread, and being split 'at the other end, into opposing members by a plurality of slots, extending a part of length of said shell, separate pads, threaded on the inner surface and being held on the inner side at the end of each of the opposing members, and an externally threaded cylindrical insert, held between said pads under the tension of said members, said insert being provided with a central hole for admission of stock and a diametrical slot on its face for application of a screw driver.

GEORGE F. ZEZULA.

Images