US2218402A - Pusher - Google Patents

Description

Oct. 15, 1 940.

S. B. MARTIN IUSHER Filed July 21, 1938 IN VENTOR. Q

Swan/m0 AR7/N f/u n-z *r 1113 ATTORNEYS Patented Oct. 15, 1940 UNITED STATES PATENT. OFFICE PUSHER I Stoddard B. Martin, Lakewood, Ohio Application July 21, 1938, Serial No. 220,469

.. My invention is an improvement in stock gripping means and relates more particularly to pushers for automatic screw machines or the like.

One of the objects of the present invention is to provide stock gripping means which is not only positive in operation and simple of construction, but which is designed for a long, useful life.

Another object of my invention is to provide means within the device to trap particles of metal and other foreign matter and to thereby assist in preventing accumulation of these particles at places where they may bind or obstruct the proper functioning of the gripping members.

A further object of the invention consists in an arrangement of parts by which certain elements carried by the device may be interchanged with one another as they become worn in use, thereby prolonging the useful life of. the entire assembly.

A still further object of the invention is to enable the operator to more easily remove the constituent parts of the device through one end of the pusher tube without removing the tube from the machine.

Another object of the invention is to increase the capacity of the tube to a maximum, that is, to permit the tube to receive bar. stock of a diameter very closely approaching the inside diameter of the tube. For thispurpose I have provided removable and replaceable bearing members and gripping members; i

A still further object is to provide means whereby the gripping member may easily be released from its gripping position should it become accidentally bound. Such release may be effected bythe insertion of a length of wire into the stock receiving end of the tube and pushing the Wire forward to tilt the gripping ring out of gripping position.

Other objects and advantages of my invention will become more apparent from the following descriptions'of several embodiments thereof, reference being'made to the accompanying drawing in which like reference characters are employed to designate like parts throughout the same.

In the drawing:

Figure 1 is a longitudinal section through one embodiment of my invention;

Figure 2 is a transverse section taken on line 2-2 of Figure 1;

Figure 3 is a section taken on line 33 of Figure 1;

Figure i is a longitudinal sectionthrough a second embodiment of my invention;

Figure 5 is a transverse section taken on line 55 of Figure l;v

Figure 6 is a longitudinal section through a third embodiment of the invention, and

Figure 7 is a detail of a modified form of gripping ring, illustrated in transverse section.

Referring now first to Figures 1 to 3 inclusive,

8 Claims. (CI. 29-61) illustrating the first embodiment of my invention, the pusher tube is shown at l. The outer wall of the tube is threaded at Z to themain pusher tube section 3, while the opposite end of the tube l is threaded at 4 to' receive the end,

cap 5. This end cap lies flush with the outer wall of the tube l and is provided with an inwardly extending annular flange 6 defining the opening 1. The flange functions as an abutment for the gripping rings 8 although it is to be understood that while the gripping rings 8 and 9 are substantially identical, the ring 8 when located as in Figure 1, that is, in abutment with the flange 6 of the cap, does not there function as a gripping ring. In this location the ring 8 functions as a bearing ring to support the adjacent end of the bar stock Ill axially in the tube I.

The ring 9, in the position shown, is adjacent the bearing member H and is spaced from the ring 8 by means of a compression spring l2. In this position the ring 9 functions as a stock gripping ring as indicatedand, as such, is capable of being tilted by the spring toward the adjacent face l3 of the bearing member ll.

As the bar stock is fed through the tube from the left in Figure 1 the end of the stock is guided into the opening I4 of the bearing member by means of the rounded annular wall 15. i A bearing member ll having an axial opening corresponding to the diameter of the stock is selected so that the stock may be properly supported axially in the tube I.-

This bearing member II is interchangeable with others having axial openings corresponding to different diameters of bar stock ranging from the smallest to a diameter closely approaching the internal diameter of the tube I. Likewise the rings 8 and 9 are interchangeable with others of suitable internal diameter for the same purpose. Thus it will be seen that by my invention it is possible to feed bar stock'of different diameters through the tube l without removing the tube from the machine, it being only necessary to select a bearing member II and rings 8 and 9 having internal diameters corresponding to the diameter of the stock fed into the tube. This is an important advantage since it saves considerable time in changing over to accommodate different sizes of stock, and necessitates only a series of bearing members and rings as additional equipment, thus eliminating the cost of maintaining a large number of pusher tubes and the labor and time involved in substituting one size for another.

In further carrying out my invention I provide a bearing member as at l l, which is provided with one or more traps or cut away portions I6. In the illustration I have shown a pair of these traps located diametrically opposite and formed inwardly of the member from the inclined face l3 to provide receptacles for receiving scale and other particles of metal and foreign matter which accumulates in the tube.

The bearing member H is provided with a slot or opening I! longitudinally thereof and extending through the same at the narrowest portion of the bearing member. This slot affords access to the tilted ring 9 from the rear of the tube by means of a wire or rod 18 as illustrated in Figure 1. In this manner the ring 9 may be manually moved out of gripping relation with the stock at any time against the compression of the spring I2 as indicated by the broken lines in Figure 1.

The bearing member is inserted within the tubefrom the cap end and seats against an annular shoulder l9 formed in the tube.

Each of the interchangeable rings 8 and 9 is provided with transverse teeth or ridges 20 along itsinner circumference for engagement with the bar stock.

When the ring 9 is. tilted by the spring i2 as shown, diametrically opposite teeth of the ring will be moved into contact with the bar stock as at 2| and 22. In this position relative movement between the bar stock and the pusher tube will be permitted when the tube is retracted to the left in Figure 1, but movement of the tube to the right will cause the lower portion of the inclined face [3 of the bearing H to press against the lower portion of the ring. In so doing the forward edge of the tooth 20 at 2! will bite or grip the surface: of the bar stock to hold. it securely against relative movement with the tube. Movement of the tube to the right will feed the bar stock forwardly with the tube toward the usual collet (not shown).

Since the ring 8 is maintained in the vertical position by abutment with the end cap under pressure from the spring l2, the same merely serves in this position as a bearing member to support the forward portion of the bar stock in the tube.

When the feeding stroke is complete and as the tube is withdrawn to the left again, the point 2| of the tooth 20 in contact with the bar stock will merely slide along the same to permit relative movement between the bar stock and the tube. During the return movement ,of the tube a collet is actuated in the manner to hold the bar stock against movement to the left.

If, after long use, the ring 9 becomes worn or the teeth grip the stock less effectively, the ring 8 may be substituted therefore and the ring 9 shifted to the position now occupied by ring 8. Thus the useful life of the assembly is greatly prolonged. Furthermore, when bar stock of a greater or less diameter is to be fed by the tube, it is only necessary to substitute a bearing member and rings having an internal diameter suitable to receive the selected stock. By this invention, the device is capable of handling a wide range of bar stock sizes without removing the pusher tube assembly. The bearing members and rings are readily changed by merely removing the cap 6 and withdrawing these parts from the right hand end of the tube.

In Figures 4 and 5 I have illustrated a pusher tube embodying a modification of my invention, in which the principle of operation is substantially the same as that described above.

However, in the present form I have provided three interchangeable rings 25, 26, and 21 which are identical in construction. Each of the rings is provided with transverse teeth or ridges 28 for gripping engagement with the bar stock or for supporting the same, depending upon the position of the respective rings.

The tube l is provided with an internal annular shoulder 29 against which one of the rings, 25, rests in a vertical plane. The ring 25 in the position shown serves to support and guide the bar stock as it is fed into the tube from the left. Adjacent the ring 25 I provide an annulus 33 which abuts against the ring 25 and which is relatively thin walled to provide a space 3| between its inner diameter and the bar stock. In this way there is provided a space for receiving and trapping scale, chips or other particles of metal or foreign matter.

The side circumferential wall 32 of the annulus lies in a plane inclined to the vertical as is illustrated in Figure 4 and is thus adapted to engage the ring 26 to tilt the same against the compression of the spring 33.

It will be noted, due to the inclination of the side 32 of the annulus, that the lower portion thereof in Figure 4 extends to the right and overlies an annular recess 34 formed in the tube. The recess 39 is of sufficient depth and width to freely accommodate the ring 26 vertically therein whereby the ring may readily be urged to tilted position by the lower portion of the annulus protruding into the recess.

The coiled spring 33, which in this embodiment is preferably of polygonal cross-section, abuts the ring 2'! at one side and exerts its force of compression against the ring 26 at its opposite side as illustrated to tilt the said ring.

The ring 21 in the position shown serves as a support for the bar stock and abuts the flange B of the end cap, as shown.

Each of the rings 25, 26, and. 21 is identical and as such, these rings are interchangeable, one with another. Each ring is slotted transversely, as at 35, so that, a wire or rod 36 may be inserted through the left hand end of the pusher tube and the slot 35 of the left hand ring to engage the side wall of the next or gripping ring to release its grip on the bar stock by urging it toward its vertical position against the compression of the spring 33. This is indicated by the broken lines in Figure 4.

Each of the rings 25, 26, and 21 is provided with a series of transverse teeth or ridges 31 around its inner circumference, and when the respective rings are used in the position of ring 26 or as a stock gripping ring, these teeth bitingly engage the bar stock when the ring is tilted.

In Figure 4, the ring 26 is illustrated as functioning as the gripping ring. As shown, the bottom portion of the ring abuts the. overlying portion 38 of the annulus while the spring 33 exerts its force of compression upon the upper part of the ring to tilt it to the left. When the ring is thus tilted, the point 39 of the lower teeth bitingly engage the bar stock material and movement of the tube 1 to the right will feed the bar stock with it.

In Figure 6 I have illustrated another modification of my invention which is similar to the forms already illustrated and described in connection with Figures 1 to 5 inclusive, and particularly Figures 4 and 5, but which differs therefrom in the following particulars.

I have found that the springs l2 and 33- which are of the coiled type and which are highly satisfactory in use, require a tube section I of greater length than that contemplated in Figure 6.

In Figure 6 the tube 49 may be shortened by employing a resilient, bowed annulus 4|, inter- Cir posed between the rings 26 and 21 and exerting a tilting pressure upon the gripping ring 26. While the spring annulus is shown as having its convex side abutting the ring 26, it may be reversed. so that its convex side abuts the ring 2? if desired.

The operation of this form of the invention is similar to the forms described heretofore and in all the forms I have provided simple and positive means for gripping the bar stock when the tube is moved. to feed the stock to a collet, yet which permits relative movement between the tube and bar stock to return the pusher tube to its original position in preparation for the next feeding operation.

In Figure 7 I have illustrated a slightly modified form of gripping ring which is indicated at Ell. In this form the inner annular surface of the ring is concave in cross section as at 5! to provide sharp stock gripping annular edges 52.

When a ring of this construction is substituted for the rings 9 or 26 and is tilted as heretofore described, the edges 52 will positively grip the bar stock to feed it to a collet when the pusher tube is moved to the right in the drawing.

In each of the modifications of Figures 1 to 3, Figures 4, 5, and 6, the parts Within the pusher tube end may readily be removed by first removing the. end cap 5. This may be accomplished with a minimum of labor and time and eliminates replacement of entire pusher tube assemblies and the consequent tearing down of the machine.

Various changes in the details of construction and arrangement of parts may be made without departing from the spirit of my invention or the scope of the appended claims.

I claim:

1. In a device of the class described, a stock feeding tube, means for slidably supporting bar stock axially within. the tube, and stock gripping means in the tube to positively feed the stock with the tube in one direction only, said gripping means including a ring loosely encircling the stock, an abutment in the tube engageable with a relatively small section of the ring to tilt the same on the stock, and a spring engageable with an opposite face of the ring and exerting a force of compression on said ring to maintain in tilted stock gripping position when the tube is moved in said one direction, and a trap associated with said abutment to receive and retain foreign matter'deposited within the tube.

2. In a device of the class described, a stock feeding tube, means for slidably supporting bar stock axially within. the tube, and stock gripping means in the tube to positively feed the stock with the tube in one direction only, said gripping means including a ring loosely encircling the stock, an abutment in the tube engageable with a relatively small section of the ring to tilt the same on the stock, and a spring engageable with an opposite face-of the ring and exerting a force of compression on said ring to maintain in tilted stock ripping position when the tube is moved in said one direction, said supporting means having an opening therein communicating one end of the tube with said ring whereby a tool may be inserted through the tube and opening to release said ring from its stock gripping position.

3. In a pusher tube for feeding bar stock there.- through to a collet or the like, spaced stock supporting members in the tube, a trap for foreign matter adjacent one of said supporting members, and stock gripping means located between said trap and said other supporting member.

4. In a pusher tube for feeding bar stock therethrough to a collet or the like, spaced stock supporting members in the tube, a trap for foreign matter adjacent one of said supporting members, and stock gripping means located between said trap and said other supporting member, said supporting members and said gripping means. being interchangeable with one another.

5. In a pusher tube for feeding bar stock therethrough to a collet or the like, spaced stock sup porting members in the tube, a trap for foreign matter adjacent one of said supporting members, and stock gripping means located between said trap and said other supporting member, said supporting members and said gripping means being interchangeable with one another, and a retaining cap on said tube to retain the parts in operative relation. in the tube, but permitting removal thereof from the end of the tube upon removal of the retainer.

6. In a pusher tube for feeding bar stock therethrough to a collet or the like, spaced stock supporting members in the tube, a trap for foreign matter adjacent one of said supporting members, and stock gripping means located between said trap and said other supporting member, said trap being in the form of an annulus having one side wall lying in a plane intersecting the vertical to provide an abutment, said stock gripping means including a tiltable ring encircling said stock and having substantially parallel sides one of which is engageable with said abutment, and a spring engageable with the other side of the ring and exerting a pressure thereagainst to tilt the ring to stock gripping position.

7. In a pusher tube for feeding bar stock therethrou'gh to a collet or the like, spaced stock supporting members in the tube, a trap for foreign matter adjacent one of said supporting members, and stock gripping means located between said trap and said other supporting member, said trap being in the form of an annulus having one side wall lying in a plane intersecting the vertical to provide an abutment, said stock gripping means including a tiltable ring encircling said stock and. having substantially parallel sides one of which is engageable with said abutment, and a spring engageable with the other side of the ring and exerting a pressure thereagainst to tilt the ring to stock gripping position, said spring comprising a bowed annulus of resilient material.

8. A stock gripping ring comprising an annulus having an internal diameter at its side walls slightly larger than that of the stock passing therethrough whereby to permit tilting of the annulus out of a plane normal to the axis of the stock, the inner wall defining the annulus opening being concave in cross section in a plane parallel to the ring axis to form sharp annular edges with the side walls of the annulus.

STODDARD B. MARTIN.

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