US2752161A

US2752161A - Pushers

Info

Publication number: US2752161A
Application number: US370094A
Authority: US
Inventors: Larry F Smrekar
Original assignee: ALFRED A ABRAMOSKA; JOHN R COX
Current assignee: ALFRED A ABRAMOSKA; JOHN R COX
Priority date: 1953-07-24
Filing date: 1953-07-24
Publication date: 1956-06-26
Anticipated expiration: 1973-06-26

Description

June 26, 1956 L. F. SMREKAR PUSHERS Filed July 24, 1953 IN VEN TOR. LARRY E SMREKAR United States Patent 6 PUSHERS Larry F. Smrekar, Solon, Ohio, assignor of one-half to John R. Cox and one-half to Alfred A. Abramoska Application July 24, 1953, Serial No. 370,094

6 Claims. 01. 279-46) My invention relates to pushers for feeding stock through a machine tool, such as an automatic screw machine and the like.

An object of my invention is the provision of improved means in a pusher of this general type for holding the pads held by the pusher against circumferential movement relative to the pusher.

Another object is the provision in a pusher for holding pusher pads against circumferential movement and at the same time to permit the ready insertion and withdrawal of the pads from the pusher.

Another object is the provision for forming and locating stop means in a pusher in a manner to protect the stop means against breakage or distortion.

Another object is the provision of pad-engaging means in a pusher arranged to maintain the forward end of the pusher in advance of the stop means in a normal arcuate form.

A further object is the provision for maintaining the forward end of the pusher in circular form while providing a tongue extending radially inwardly of the pusher to engage a pad.

A further object is the provision of an improved combination of pusher and pads constructed and arranged to provide results heretofore not obtainable.

A still further object is the provision of a new construction in a pusher having parts arranged to provide operating characteristics both novel and useful.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a side view of a pusher embodying my invention;

Figure 2 is a longitudinal sectional view taken through the line 22 of Figure 1;

Figure 3 is an end view looking rearwardly at the forward end of my pusher in the direction of the arrows 3-3 of Figure 2; and

Figure 4 is an enlarged sectional view taken in the' direction of the arrows 44 of Figure 2.

My pusher has a hollow, generally cylindrical body 11 having a threaded rearward end 12 adapted to be threadably engaged to a reciprocating tube or member through which stock or longitudinal work pieces are advanced and fed forwardly in a machine, such as an automatic screw machine, by the pusher. The forward end 13 of the pusher is open and it is through this forward end 13 through which the' stock is advanced by' thep'usher'.

To provide

resilient fingers

15, 16 and'17 from the wall of the pusher 11, there'are three slots 14 extending longitudinally of the pusher from the forward end thereof. The slots 14 are relatively narrow at the forward end and of greater width at a location'intermediate the ends of the pusher, as seen in the drawing. The arrangement of the slots 14 is such that the walls of the pusher intermediate the slots form fingers and the steel material thereof, being heat-treated, are of a resilient nature" to ice resiliently and firmly provide a grasping force upon the stock being advanced by the pusher.

Within the bore of the pusher and adjacent the forward end thereof are three

pads

18, 19 and 20. Each pad is of arcuate form and coincides in general shape and dimension with the inner wall surface of each of the

corresponding fingers

15, 16 and 17. There is thus a hardened steel pad disposed on the inward wall surface of each of the fingers at the forward end of the pusher and arranged to engage the stock, such as a rod, being advanced by the pusher. A shoulder located rearwardly of the forward end of the pusher limits the rearward movement of the pads in the pusher as seen in Figure 2.

The forward end of the pusher has an inwardly disposed flange in the plane of the forward end 13 and around the circumferential extent of the pusher to hold the pads Within the pusher when the fingers are in a compressed condition.

The finger 15 has a tongue 21 formed therein on the wall of the pusher. This tongue 21 is formed by severing the metal around three sides of a rectangular area and displacing the severed metal radially inward as seen in the drawing. The inward displacement is limited, however, so that the amount of radial intrusion or extension of the tongue within the bore of the pusher is less than the wall thickness of the pusher. Thus, as seen in Figure 2, the forward end of the tongue 21, while displaced inwardly, is also within the confines of the wall from which it was cut and is thus embraced on all sides by the wall remaining in the'cyiindrical plane of the pusher.

The pad 18 corresponding with the finger 15 has a slot or recess 22 cut therein so as to accommodate the inwardly disposed tongue 21. The tongue 21 thus is pushed within the slot or recess 22 of the pad 18. By the arrangement described and illustrated, the pad 13 is held against circumferential movement within the pusher by means of the interfitting of the tongue 21 in the member for limiting revolving or turning of the pads within the pusher. It is understood that separate pins have sometimes been mounted in a finger to extend radially inward and engage the pad. However, the construction of the push'ers to accommodate such pins and mounting of the pins is not economical and the pins, being relatively rigid, tend to fracture and wear. It is also understood that tongues have also been cut in the forward ends of pushers, but in these cases the pusher was slit from the forward end thereof to leave the tongue free at the forward end of the pusher. Such tongues extending from the extreme forward end of the pusher do not have the support and bracing. action that is sometimes necessary and they tend to break or become distorted.

Another disadvantage of having tongues extending from the extreme forward end of the pusher, instead of being spaced therefrom as above shown and described, is that in the heat-treating of the forward end of the pusher, a distortion is produced. Because of the interruption of the tongue in the forward end of the pusher in such other and previous pushers, the extreme forward end of the pusher, upon being heat-treated, tends to distort and become warped from a true circle. By the invention herein disclosed, the forward end is not interrupted in a circumf erential direction by a slit tongue and is retained in a true and undistorted circular form during heat treatment and thereafter.

Other advantages and benefits from the construction herein disclosedwill be apparent to those acquainted with the construction and use of pushers of this general type.

To mount the

pads

18, 19 and 20 within the pusher 11, the

fingers

15, 16 and 17 are slightly spread apart to open up somewhat the forward end of the pusher. While in this expanded position, the

pads

18, 19 and 20 are inserted through the forward end of the pusher and placed against the inner wall of the pusher adjacent its forward end to the position shown in the drawing. Pad 18, having the slot or recess 22, is positioned under the tongue 21 formed from the finger the pad 19 is positioned adjacent the finger 16 and the pad is positioned adjacent the finger 17. Upon release of the fingers, the resilient force thereof presses the pads toward each other and they are thereafter held in position by the resiliency of the fingers. The stock being fed by the pusher moves through the cylindrical open space between the pads and in each operation of the pusher, the pads grasp the stock to advance the same, as is well understood in the operation of pushers of this general type.

The present disclosure includes the description contained in the appended claims as well as that set forth above.

Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

I claim as my invention:

1. In combination, a pusher for use in a machine tool, a plurality of stock-receiving pads, said pusher being adapted to hold said stock-engaging pads within its bore adjacent the forward end thereof, one of said pads having a recess formed at its forward end, said recess having a bottom wall extending forwardly and radially in a slope and having spaced side walls extending radially of the pad, said pusher being split at its forward end to provide a plurality of resilient fingers, each having an arcuate transverse shape at the forward end of the pusher, a pad-engaging stop member carried by one of said fingers to limit circumferential movement of said pads in said bore relative to the pusher, said stop member being formed of a portion of said one finger being partially cut from said one finger longitudinally thereof and displaced radially inward at a location spaced from said forward end of the pusher, said portion extending in a slope forwardly and radially inward of said pusher and having longitudinally extending and radially disposed side edges protruding in said bore to oppose in a circumferential direction said side walls of said recess to provide abutments to said pad moved in either circumferential direction, the said finger forwardly of said displaced portion being conformed to said arcuate shape of the finger at said forward end, said stop member being positioned to interengage said one pad in said bore and to hold the same against circumferential movement.

2. In combination, a pusher for use in a machine tool, a plurality of stock-receiving pads, said pusher being adapted to hold said stock-engaging pads within its bore adjacent the forward end thereof, one of said pads having a longitudinally extending recess at its forward end and said recess having opposed and radially disposed sides, said pusher being split at its forward end to provide a plurality of resilient fingers each having an arcuate transverse shape at the forward end of the pusher, a pad-engaging stop member earried by one of said fingers to limit circumferential movement of said pads in said bore relative to the pusher, said stop member being a portion of the wall of said one finger partially severed from said finger by a U-shaped cut with the side arms of the U directed rearwardly of the U base to form a tongue dependent on said finger at the rear of the severed portion, said portion being pressed radially inward to protrude into said bore for engagement with said one pad, said portion extending forwardly of the pusher and being spaced from the forward end of the pusher, the said finger forwardly of said portion extending uninterruptedly in the said arcuate transverse shape at said forward end, the sides of said severed portion extending in said bore in a longitudinal direction and being radially disposed to provide abrupt stops opposing the sides of said recess to limit circumferential movement of said one pad in both circumferential directions.

3. In combination, a pusher for use in a machine tool, a plurality of stock-engaging pads, said pusher being adapted to hold said stock-engaging pads within its bore adjacent the forward end thereof, one of said pads having a forwardly extending recess at its forward end, said recess having opposed substantially parallel side walls, said pusher being split at its forward end to provide a plurality of resilient fingers each having an arcuate transverse shape at the forward end of the pusher, a pad-eugaging stop member carried by one of said fingers to limit circumferential movement of said one pad in said bore relative to said pusher, said stop member being a portion of the wall of said one finger partially severed from said finger to form a forwardly directed tongue dependent on said finger at the rearward end of the tongue, said portion being pressed radially inward to protrude into said bore for interengagement with said one pad, the said portion having longitudinally extending and radially disposed side edges presenting abutments to the said side Walls of said recess to limit movement of said one pad in both circumferential directions, the said portion being spaced from the forward end of said pusher, the said finger forwardly of said portion extending uninterruptedly in the said arcuate transverse shape at said forward end, the said portion protruding inwardly of said bore a radial distance less than the thickness of said wall to provide a bracing support for said portion along its said side edges.

4. In combination, a pusher for use in a machine tool, a plurality of stock-engaging pads, said pusher being adapted to hold said stock-engaging pads within its bore adjacent the forward end thereof, one of said pads having a recess at its forward end, said recess having radially extending and substantially parallel side walls, said pusher being split at its forward end to provide a plurality of resilient fingers each having an arcuate transverse shape at the forward end of the pusher, a pad-engaging stop member carried by one of said fingers to limit circurn ferential movement of said pads in said bore relative to the pusher, said stop member being a portion of the wall of said one finger partially severed from said finger to form a forwardly directed tongue dependent on said finger at the rearward end of the tongue, said portion being displaced radially inward into said bore to extend within the recess of said pad to oppose the side walls of said recess, said portion being located rearwardly of the forward end of the pusher to leave an uninterrupted wall of said arcuate transverse shape forwardly of said portion at said forward end, the edge of said portion where severed from the wall of the pusher being substantially confined around its periphery by the said wall to brace the portion against circumferential displacement.

5. A pusher having a tongue extending into the bore thereof to hold pads in said bore adjacent the forward end of the pusher against circumferential movement, one of said pads having radially disposed and axially extending walls opposed to each other to define a recess therebetween at the forward end of said pad, said tongue being positioned in said bore to engage one of said pads, said tongue being cut from the wall of the pusher along a line leaving the tongue dependent on said wall at the rearward end of said tongue and the tongue extended toward the forward end of the pusher, the forward end of the tongue being spaced rearwardly of the forward end of the pusher, said tongue being displaced radially ward a distance less than the thickness of the wall of the pusher from which cut to partially confine the tongue within the said wall, said tongue having substantially parallel side walls disposed radially of the pusher and forming abutments opposed to the side walls of said recess to stop circumferential movement of said pad relative to said pusher.

6. The combination of a pusher having a plurality of resilient fingers formed in the forward end portion thereof and a corresponding number of stock-engaging pads carried in the pusher adjacent a respective finger, one of said fingers having a tongue cut therefrom at a location rearwardly of the forward end of the pusher and displaced radially inward of the pusher to incline inwardly and forwardly of the pusher, said tongue being defined 6 by a U-shaped cut in which the base of the U is circumferential of the pusher and spaced from the forward end thereof and in which the side-arms of the U extend in a rearward direction longitudinally of the pusher, the side edges of the tongue formed by the side-arms of the U providing longitudinally disposed and oppositely faced abutments Within said pusher, one of said pads corresponding with said finger having a recess formed therein at its forward end for accommodating said tongue, said recess having radially disposed and opposed side walls spaced to complementarily receive therebetween the said tongue, the tongue in said recess holding the said one pad against circumferential movement in the said pusher.

References Cited in the file of this patent UNITED STATES PATENTS 2,187,170 OConnell Jan. 16, 1940 2,351,220 Martin June 13, 1944 Martin Jan. 3, 1950