US3376590A

US3376590A - Socketing machine

Info

Publication number: US3376590A
Application number: US536740A
Authority: US
Inventors: Orville H Landreth
Original assignee: Orville H. Landreth
Current assignee: ORVILLE H LANDRETH
Priority date: 1966-03-23
Filing date: 1966-03-23
Publication date: 1968-04-09
Anticipated expiration: 1985-04-09

Description

April 9, 1968 .0. H. LANDRETH SOCKET ING MACHINE 2 Sheets-Sheet 1 Filed March 23, 1966 mm W i T1 F.\ k V T & {n Q Q \M Q R Lw\ Q April 1968 o. H. LANDRETH I 3,376,590

SOCKETING MACHINE Filed March 23, 1966 2 Sheets-Sheet 2 0/ w //e Zane re f5 INVENTOR.

ATTORNEY United States Patent 3,376,590 SOCKETING MACHINE Orville H. Landreth, 7902 Glen Prairie, Houston, Tex. 77017 Filed Mar. 23, 1966, Ser. No. 536,740 8 Claims. (Cl. 10-15) ABSTRAQT OF THE DISCLOSURE Apparatus for forming socketed rivets and the like including a plain, cylindrical punch and a collet chuck received thereabout, the punch and collet having engaging wedging surfaces whereby when these parts are advanced to push the formed rivet out of the machine, the punch will be securely gripped by the collet so that the work piece can be disengaged from the punch as by retracting the collet and the gripped punch into the machine.

This invention relates to socketing machines for use, for instance, in the making of semi-tubular rivets.

Machines now on the market for manufacturing semitubular rivets utilize appropriate die and header combinations for forming the head, shank, and socket. In the latter operation, the partially-formed blank is introduced into the axial bore of a die and then, with the head properly backed up, an extruding punch or knockout pin with a suitably reduced extremity is driven into the end of the blank causing cold flow of the blank metal to form the socket by extrusion. The socketing punch and blank are then driven forwardly to permit a stripper to be inserted between the rivet head and the die, whereupon the socketing punch is forcibly retracted to separate the same from the formed blank. This retracting and stripping operation necessitates the provision on the punch of a radial shoulder which may be engaged by the pull-back mechanism. Such special configuration of the punch materially increases the cost of this part. Furthermore, in order to remove the punch, as is frequently necessary for inspection and/or replacement, it is necessary first to withdraw the extruding dies and to further disassemble the machine. This requires many hours of costly labor and down time.

Accordingly, an object of the present invention is to provide a socketing machine having a simple cylindrical socketing punch and means for gripping the punch in stripping the workpiece therefrom.

Another object is to provide a socketing machine, as for making extruded, semi-tubular rivets, in which the socketing punch can be easily expelled from the machine for inspection and/or replacement without substantial disassembly of the machine.

These objects and others hereafter appearing are attained in my invention herein disclosed which, in general, consists in the provision of a simple cylindrical socketing punch in combination with a collet chuck received about the punch in such a way that during expression of the formed workpiece blank from the machine, the extruding punch is securely gripped so that, upon retraction of the collet chuck, with a stripper inserted between the rivet head and the die, the punch and formed blank will be separated.

In the accompanying drawings which illustrate the invention,

FIG. 1 is a longitudinal central section through a portion of a machine for manufacturing semi-tubular rivets;

FIG. 2 is a view of parts of the structure in FIG. 1 in different operative position;

FIGS. 3, 4, and 5 are views of the parts in FIG. 2 in other operative relationships; and

FIG. 6 is a disassembled view of the collet chuck device for gripping the extruding punch.

3,3755% Patented Apr. 9, 1968 FIG. 1 shows a bed portion 8 of a rivet-making machine body having a longitudinal chamber 9 therethrough. At the left end of chamber 9 there is received a die case 10 normally secured in position by a pin 11 and itself receiving front and

rear die inserts

12 and 13. At the rear of bed chamber 9 there is provided guide structure 14 and 15 for a plunger 16 which is actuated by suitable means not shown. Projecting longitudinally from plunger 16 is an intermediate pin 17, in effect forming part of the plunger means and with its left end slidably received in a bushing 18 within a collet chuck device, generally designated 19'. The left end of pin 17 abuts the socketing or knockout pin 20 which is generally cylindrical, except for the left-hand end 21 which is reduced for socketing the end of a workpiece blank 22, as will be explained.

The portion of the rivet-making apparatus disclosed in FIGS. 1-5 is designed for the purpose of performing the last or socketing operation upon the workpiece blank. For this purpose, -a back-up head 25 is provided with a backup insert 26 having a concave face for closely fitting against the previously formed head 27 of the rivet to secure the blank in position.

The collet-chuck device 19, as better shown in FIG. 6, includes an outer sleeve portion 29 having an intermediate annular collar 30 and a nose portion 32 at its left-hand end with inwardly tapered wall 32a. Slidably received within outer sleeve 29' is the inner sleeve 33 which is generally tubular and cylindrical except for longitudinal cuts 34 in the left portion thereof and an externally tapered nose portion 35 at the left end. Tapered nose 35 is complementary to internal taper 32a at the end of the outer sleeve 29. Internally of the inner sleeve approximately at the beginning of the tapered nose thereof, there is provided an internal shoulder 36 for a purpose to be described. In the assembly, collar 30 is urged rightwardly against an internal shoulder 31 in chamber 9 by means of a heavy coiled spring 37. A somewhat lighter coiled spring 38 is compressed between the right-hand side of collar 30 and a spring seat collar 39 on plunger 16. FIG. 3 shows a stripper member 40 interposed between the head 27 of the expressed rivet and face 41 of the die structure to permit separation of the formed rivet and socketing punch 20.

In operation,

parts

29 and 33 of the collet chuck will be loosely nested so that punch 20 may slide freely therethrough. With the back-up head 25 in the position of FIG. 1 abutting a rivet head in the die, plunger 16 and intermediate pin 17 will be driven leftwardly to cause socketing punch 20 to pierce the right-hand end of the rivet blank causing extrusion of the rivet metal and formation of the socket in the shank end, as shown. Plunger 16 then continues its leftward movement, first compressing coiled spring 38 and ultimately causing the left-hand end of intermediate pin 17 to seat against internal shoulder 36 in inner collet member 33, as shown in FIG. 2. Since pin 17 is slightly longer than the linear distance between shoulder 36 and the right-hand ends of

sleeves

29 and 33, pin 17 will remain projected slightly beyond the right end of the collet chuck. Thus, continued leftward pressure exerted by the plunger will be applied to inner collet sleeve 29 tending to drive the same leftwardly with respect to outer collet sleeve 33, sufficient clearance being provided between nose 35 and rear die insert 13 to permit this. The complementary wedging noses of the collet parts will cause inner nose 35 to firmly grip the right-hand end of socketing punch 20. The entire collet chuck device may be moved a slight additional distance leftwardly to permit stripper block 40 to be inserted between rivet head 27 and die means face 41. At the same time, collar 30 will move leftwardly from annular stop shoulder 31 compressing heavy spring 37. Consequently, upon retraction of plunger 16, heavy spring 37 will expand to retract the collet chuck device rightwardly, carrying with it socketing punch 20 so as to separate the punch from the formed rivet. Collar 30 will again seat upon stop shoulder 31 (FIG. 4) and the rivet can drop into a collecting receptacle. Plunger 16 will be fully retracted to the position of FIG. 1 for the insertion of another partially-formed blank into die

means

10, 12, 13.

An important advantage of the novel cylindrical socketing pin 20 is that it can be readily ejected from the machine without the necessity of disassembling either the die or collet chuck means. For instance, the portion of chamber 9 between collar 31 and plunger collar 39 may be charged with compressed air which will be directed past suitable clearance provided in the surface of intermediate pin 17, as by a small flat thereon, to the rear end of punch 20. With the head 25 and other machine parts cleared from the die means face, the socketing punch will be forced leftwardly out of the machine, as indicated in FIG. 5. This removal operation can be performed in ten or fifteen minutes at a saving of at least five or six dollars in production time. Furthermore, very material saving can be made in the cost of production of the socketing punch due to the decreased number of operations neces sary because of elimination of the external shoulder heretofore necessary in holding the punch during the stripping operation.

The form of rivet-making machine as shown herein is, in general, well-known, and its general features may be modified in various respects as will occur to those skilled in the art. The exclusive within the scope of the appended claims is contemplated.

I claim:

1. Apparatus for making socketed articles comprising a body having a chamber, die means in said chamber having an opening therein for receiving a workpiece blank, a socketing punch movably carried in said chamber, plunger means aligned with said punch in said chamber and movable in one direction to a first position for causing blank socketing movement of said punch and to a second position for ejecting the socketed blank from said die means, collet chuck means in said chamber about said punch, stop means in said chamber for opposing movement of said chuck means in said direction, said chuck means having a shoulder engageable by said plunger means in said second position thereof for causing said chuck use of all modifications as come 4. means to grip said punch, and means for stripping the socket blank from said punch.

2. Apparatus as described in claim 1 in which said stop means comprises a spring and said stripping means includes said spring and means for preventing retraction of said blank upon retraction of said plunger means and result-ant shifting of said chuck means by said spring.

3. Apparatus as described in claim 2 in which the body of said punch is uniformly cylindrical and shaped to pass through said chuck and die means when said chuck means is relaxed.

4. Apparatus as described in claim 3 in which said chuck means comprises an inner sleeve with a longitudinally split, exteriorly tapered nose portion and an outer sleeve with a complementary internally tapered nose portion, said portions being capable of relative axial shifting to cause said inner nose portion to grip the punch therein.

5. Apparatus as described in claim 4 further including a collar projecting radially from said outer sleeve, said spring being compressed between said die means and said collar.

6. Apparatus as described in claim 5 in which said shoulder engageable' by said plunger means is formed by an internal shoulder within said inner sleeve for applying the force of said plunger means through said complementary tapered noses to said spring.

7. Apparatus as described in claim 6 in which said plunger means includes a main plunger part and an inter mediate plunger part connecting said main part and said socketing punch, said internal shoulder being spaced from the opposite end of said inner sleeve a distance less than the length of said intermediate part whereby said intermediate part, when resting against said internal shoulder, projects beyond said inner sleeve for actuation by said plunger main part.

8. Apparatus as described in claim 3 further including means for applying fluid pressure to the inner end of said punch for driving the same outwardly through said chuck and die means.

References Cited UNITED STATES PATENTS LEONIDAS VLACHOS, Primmy Examiner.