US2362970A - Cold forging machine - Google Patents

Description

Nov. 21, 1944. w. E. BOLLAND CbLD FORGING MA CHINE Filed Dec. 20 1945 v 4 Sheets-Sheet l 20 wawz Nov. 21, 1944:

W. E. BOLLAND COLD FORGING MACHINE Filed Dec. 20, 1 943 4-Sheets-Sheet 2 Nov. 21, 1944. wisoLLANn 2,362,970, r

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' Nov. 21, 1944.

.' E. BOLI AND ,362,970

Patented Nov. 21 1944 i U I 2,362,970 co n FORGINGMACHINE' ,swiuiam Edmundi'Bolland, Ne'ohells, Birmingham,

.-Birmingham, England ApplicationfDecembei 20; 1943, Serial No. 515,073

- "In Great Britain March 5, 1943 7 2 Claims. fc1.1c-12') Y vj invention relates to 'niultiblow cold forg} ing machines of thekind adapted to form hexagonal or other heads onlengths of steel or other metal rod or wire intended" to serve as bolts, rivets or the like. At the present time there is used for, this purpose awell; known two-blow automatic machine consisting of a-die,'a pair of punches which operate successively 'on one end each work. piece, a crank-actuated toggle ine'chanismfor imparting the operative movements to the punches, and means for intermittently'feeding to the die the'metal to be headed. Ordinarily the metal stock is in theform of a coil, "and the free end of the coil which is fed into the die serves to eject from-' the die the England, assignorto H. Newton & Co -Ltd 'quired lengthcan be fed and removed succes sively by handga slide carrying punches which are movable relatively to thedie, a rotary memher for actuating the slide, and a clutch for transmitting m'otionfrom a source to the said -member,"the-clutch being under the control of the attendant and being'ad apted' to disconnect the 7 said member from the source automatically at th end of each work cycle. a

In the accompanying sheets of explanatory drawings: 1

Figure 1 is a part sectional side elevation, and

I Figure 2 a part sectional plan, of a two-blow cold the line '3-3 of Figure 2..

previously headed piece which has beensevered 4 i'roxn the stock byacutting means forming apart I "of th machine. The'mo'de. of :action of themachine isbriefly as follows; Afters work piece hastbeen fedinto'the diegitzisgrip-ped by the latter, and then the first punch comes into action for forming a swelling on the adjacent end of the work piece, this movement'of the slide which car.-

forging machine embodying the invention.

Figure 3 is a sectional side elevation taken on 'Figure4 is a fragmentary sectional view taken on the line 4-4 of Figure 2.,

Ties both punches being efiectedduring one-half of arevolution of the crank which actuates'the toggle mechanism. Then the punches'are, moved relatively to the slide to bring the other punch into position, and during the next half revolution of the crank the second punch causes the final shape to be imparted to the head on the work piece; ,On releaseof the work piece bythe die it is ejected by the next feed movement of the stock. This machine operates continuously, in that each cyclefollows its predecessor without intermission. v

Adisadvantage of theabove described machine is that-there is=a limit to the length of the work pieces which can be dealt with, this being due. to the fact that the finished work pieceis ejected. automatically by the incoming work piece,

and that suflicient space must be allowed between the adjacent ends'of the die and punch slide to permit this action. The amount of space permissible sets a limit to the. length of the work piece that can be dealt with, and consequently it is impossible with such. a machine tul forge headsonwork pieces exceeding a certain. length. The machine, however, possesses great advantages over other forms of heading machines, and'thc problem to which our present invention is directed is that of construci'ng a machine which whilst retaining the main advantages of a machine, such as that above described; enables work piecesof any length to be dealt with.

The'invention consists of a multi-blo'w'heading machine havingin combination adie to and mm which work pieces previously cut to the re- Figures 5, :6 and 7 aresimilar fragmentary sectionalviews drawn-to a larger scale than, Figures 1to 4,.and illustrating the manner in which the v punches act on the work piece.

,In-carrying the invention into effect as shown, I employ a machinercomprising a main frame a,

a transverse driving shaft b carried by bearings c on the frame, a horizontally movable slide 6 supported between longitudinal guides f on the ;frame, toggle mechanism g through which the slide=is operable by a crank i on the driving shaft 'andwhich serves to impart two operative strokes to the slide in each rotation of the driving shaft,

a verticallymovable slide. 7 mounted onthe front ,end'of the horizontally movable slide and carry- .ing a pair. of punches k, k situated one above the other, link and lever mechanism m through which the vertically movable slide is actuated from a cam n on the driving shaft to bring the punches successively .into an operative position during "each rotation of the driving shaft, a die 0 supported by the front end of theirame and having fixed and movable parts 0 0 between which the work piece as (indicated by broken lines in Figure 1), is gripped whilst being subjected to the action of the punches, and a second toggle device q operable through a slidable member r and a lever s from a second cam t on the driving shaft to .actuatethe movable part of the die.

The machine so far described is of conventional form'wi'th the exceptionthat the worksevering means usually employed are dispensed with, and that work pieces (in the form of pieces I of metal rod or wire cut to the required length) can be successively inserted into and removed from the die o by hand. Thus, in'the example shown the workpieces as p can be inserted into upper side of the die and allowed to fall out through the underside of .the die.

It will be understood that the cavity 2) in the die is shaped in the usual manner to enable a hexagonal or other head to be formed on one end of each work piece as p under the successive action of the punches k, 70

Figures 5 to 7 illustrate the manner in which the punches k, k act on the work piece 12 in the die 0. In Figure 5 the first punch k is shown in the operative position which it occupies immediately prior to acting on the work piece 13.. In this position the punch k is coaxial with the work piece p, the latter having been gripped between the die parts 0 o with the end to be headed projecting to the required extent from the rear of the die. The operative stroke of the first punch It causes the projecting end of the work piece :1 to receive a bulbous form. as shown in Figure 6, whereupon this punch is withdrawn and the second punch k caused to assume the operative position previously occupied by the first punch. The operative stroke of the second punch k causes the bulbous end of the work piece 10 to fill the die cavity 1) and form the required hexagonal or other head on the work piece,.this condition being shown in Figure '7.

For determining the extent to which the work piece 10 projects from the rear of the die 0 prior to the heading operation, I employ a stop in the form of an arm w on one end of a rod :11, the latter being rotatably supported by bearings 1: s0 arranged on the frame a at one side of the horizontally movable slide a that by appropriate oscillatory movements of the rod the arm can be moved into and out of an operative position in which its outer end lies opposite to the rear end of the die cavity. Near the end remote from the arm w the rod :0 is cranked (as shown in Figures 1 and'2) so that this end of the rod can co-operate with a third cam 11 on the driving shaft 1). This cam y serves to move the rod a: in the direction for moving the arm into its operative position, the opposite movement of the rod being effected under the control of the cam by a torsion spring 2 on the rod. When the machine is at rest the arm 10 occupies its operative position in which it serves as a stop for the work piece being inserted into the die o. At the commencement of each rotation of the driving shaft 1) the arm w is moved under the action of the spring 2 to an inoperative position clear of the punches k, Id, and at the end of each such rotation the arm is returned by the cam to its operative position against the action of the spring.

For imparting the required motion to the driving shaft 17 I employ a fly-wheel 2 adapted to be driven continuously by a belt (not shown) from an electric motor or other power source. The fly-wheel 2 is carried by a hollow boss 3 on one side of an annular member 4 which is rotatably mounted on the driving shaft b. If desired the fly-wheel may be rigidly secured to the annular member 4 by a nut 5, on the outer end of the boss, but preferably annular friction discs 6 are arranged between the sides of the fly-wheel and the adjacent surfaces of the nut and annular member to permit relative rotational movement between the fly-wheel and annular member in the event of the machine being over loaded. At the side remote from the boss 3 the annular member 4 is formed with a recess 1 for accommodating the adjacent side of a second annular member 8 secured on the driving shaft b. The two annular members 4, 8, form coaxial parts of a clutch which enables the continuously rotating fly-wheel 2 to be connected to the driving shaft h under the control of the attendant, and which automatically disconnects the shaft from the fly-wheel at the end of each rotation of the shaft. The two clutch members 4, 8 are interconnectible by a spring-loaded key 9 which is mounted in a radial hole in the member 8 and is adapted to engage either of a pair of recesses l 0 in the inner peripheryof the member 4. The key 9 is controlled by a catch lever ll pivoted to a bracket l2 on the frame a, and is adapted to act on a shoulder l3 on the key. The catch lever H is operable by a cam-shaped lever l4 also pivoted to the bracket l2, this latter lever being connected by link and lever mechanism I5 to a pedal I6. Moreover, the camshaped lever I4 is loaded by a spring I! which is stronger than the spring l8 employed for loading the key 9, and which serves normally to hold this lever in the position (shown in full lines in -Figure 3) in which the catch lever II holds the key 9 clear of the inner periphery of the clutch member 8 on the driving shaft b. When the key 9 is in this condition the fly-wheel 2 and the associated clutch member 4 can rotate freely on the driving shaft b.

Depression of the pedal 16 by the attendant serves to move the cam-shaped lever I4 against the action of its loading spring I1. to a position shown in broken lines in Figure 3. The effect of this is to release the key 9 which under the action of its loading spring l8 enters one of the recesses ill in the rotating clutch member 4, when the latter assumes an appropriate position, and serves by contact with a hard metal abutment piece is in this recess to transmit motion to the other clutch member 8 and the driving shaft b. When the driving shaft b commences to rotate the pedal I6 is released by the attendant, and the ensuing movement of the cam-shaped lever l4 under the action of its loading spring [1 causes the catch lever II to assume a position in which it serves automatically to return the key 9 to its initial operative position at the end of a complete revolution of the driving shaft 1), thus bringing the machine to rest. During this revolution of the driving shaft b a work piece is headed as previously described, and when the machine is brought to rest the headed workpiece is removed from the die 0 and another work piece is inserted preparatory to the pedal l6 being again depressed to cause a repetition of the above described operations.

Whilst the rate of output of the machine forming the subject of my invention is less than that of an ordinary two-blow cold forging machine adapted to operate on short work pieces, it is nevertheless much greater than that of other means or methods at present used for heading long work pieces, and moreover it enables the same high quality of performance to. be obtained as is produced by the usual two-blow machines. The invention is not, however, limited to twoblow cold forging machines, but may be applied to three-blow or other multi-blow cold forging machines.

Having thus described my invention what I claim'as new and desire to secure by Letters Patent is: v

1. A multi-blow cold forging machine of the kind specified, having in combination a die to and from which work pieces previously cut to the required length can be fed and removed suc cessively by hand, a slide carrying punches which ,are movable relatively to the die, a rotary member for actuating the slide, and a clutch for .transmitting motion from a source to the said memberfithe clutch comprising a pair of coaxial parts,

2. A multi-blow cold forging machine of the kind specified, having in combination a die to and from which work pieces previously cut to o the required length can be fed and removed successively by hand, a slide movable relatively to the die, punches carried by the slide and movable relatively thereto so as toact in succession on each work piece fed to-the die, a rotary member for actuating'the slide, and a clutch adapted to I be brought into action under the control of the attendant for transmitting motion from a source to the said member, and to be put out of action automatically after the punches have performed their function on a'work piece.

WILLIAM EDMUND BOLLAND.

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