US918154A

US918154A - Metal-tube machine.

Info

Publication number: US918154A
Application number: US42759108A
Authority: US
Inventors: Leslie E Hooker
Original assignee: Individual
Current assignee: Individual
Priority date: 1908-04-17
Filing date: 1908-04-17
Publication date: 1909-04-13
Anticipated expiration: 1926-04-13

Description

L. E. HOOKER.

METAL TUBE MACHINE.

APPLICATION rum) APB.17, 1908.

Patentfad Apr. 1;3, 1909. I

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Witnesses ggg; w %W (L. E. HOOKER.

METAL TUBE MACHINE.

APPLICATION FILED APR. 17,1908.

918,154. Patented 13, 1909.

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amnntoz LESLIE E. HOOKER, OF PAWTUGKET, RHODE ISLAND.

METAL-TUBE MACHINE.

Application filed April i7, 1908. Serial No. 427,591.

To all whom it may concern:

Be it known that I, LESLIE E. HooKnR, acitizen of the United States, residing at Pawtucket, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Metal-Tube Machines, of which the following is a specification.

My invention relates to the manufacture of tubes by the method disclosed in the patent to G. W. Lee issued Julie 5th, 1906, No. 822,285, and consists in certain improvements which I have made in the construc tion of the apparatus by which said method is carried out. 1 I have found by experiment that much stronger tubes can be made by starting the extrusion with a cup-shaped blank formed by folding up the edges of a disk around a punch or mandrel than when starting with a disk, 'as described in the above mentioned patent, but, when working with a hard metal, such as brass, the strains upon the dies and punches, are so great as to cause frequent breakage.

The improved construction of these, hereinafter described, removes practically all danger of breakage, and enables tubes to be made suitable for cartridge shells, which are v stronger and lighter than those made by the present process of drawing. So that, my present invention consists in certain im rovements in the construction of the dies in which the blanks are placed to be extruded into tubes, in the provision of mechanism for detaching and removing the flange scrap from the tubes and dies; in improvements in the construction of the forming and extruding punch, and, finally, in the combination and arrangement of the arts going to make up a practical and e cient machine for carrying out the, process.

In the accompanying drawings, Figure 1 is a central longitudinal section througl'f'the dies and the punch-carrying slide of a press equipped with my improvements, Fig. 2 is a plan view of the tube-retaining means to prevent their withdrawal from the dies with the forming unch, Fig. 3 is an enlarged section of a b ank to be operated upon, Fig. .1: is a cross-section ofFig. 1, taken on the line of said figure, and Fig. 5 is a. sectional view of a modified form of the punch holder. I

Any suitable form of press maybe used, that illustrated being by way of example Specification of Letters Patent.

Patented April 13, 1909.

. only. On top of the apertured bed-plate 1 of the press is bolted a plate 2, in which are inserted two hardened plugs 3, 3, which are centrally bored and lie directly beneath the dies 4, 1. The'dies are held in aplate 5, which is shrunk onto them, thus constituting a sustaining jacket for the same, said plate 5 being bolted down onto the plate 2. The dies have each a central aperture, of substantially equal diameter with the blanks, in which is placed a hardened bushing 6, the upper end of which slopes slightly inwardly toward the central aperture 7, as shown. This bushing constitutes one of the most essential features which renders,the present a paratus so cilicient and practical. Hereto ore, in carrying out the process of the said patent thc'die was made integral and it would not last when working on hard metal, such as cop er, for example In the present construction, the bushing has merely a driving fit in the die and rests on thehardened plug 3, which takes the downward strain-instead of the die,

which is subjected to a radially outward strain only. It is essential that the bushing 6 should pass entirely through the die 4 and rest upon the hardened plug 3, as practice has demonstrated that when the bushing is sustained by a shoulder within the die, breakage always occurs at that oint. In this connection I may say that t e construction of die just described is useful wherever a drawing operation is used and I therefore do not wish to be understood as limitin my invention in this respect to use in extru ing presses.

In the machine herein illustrated, I have shown two dies, with which cooperate, at each stroke of the press, one forming and extruding punch 8 and one of two trimming punches 9, all three of which tools are carried in the slide 10, mounted in a transverse guide of the reciprocating press-head 12.

The slide 10 is moved from one extreme position to the other by the hand of the operator, or by any ordinary slide-moving mechanism, between each stroke of-the press, adjustable stops 11 for said'slide being provided. Each trimming-punch is adjustablv threaded into a stem 13, set in the slide, and a similar stem 14 carriesthe forming and extruding punch. In the head 12 of the press are set two hardened plugs 15,.similar to the plugs 3- and directly above the same, pressure being exerted'through them to the punches. Obviously a rotary turret could be used instead of the slide.

die above described. The stem 14 has a countersunk central bore, as shown, in the lower end of which is fitted an anvil 16, above which, in the smaller portion of the bore, is slidably mounted a nut 17. Into this latter is adjustably threaded the central portion of the punch 18, which I will designate as the former, a set-screw 19 being provided, if desired, to lock said former in adjusted position. To keep the nut 17 from rotating when the former is adjusted, a setscrew 20 is, or may be provided in the stem, the same engaging in a lateral slot in said nut.

Surrounding the lower part of the former 18, and clamped against the anvil 16 by the chuck 21, is the extruding plunger 22. It will thus be seen that the former can move relatively to the extruding plunger, by which construction important results are obtained. While the above is the preferred construction, it is not absolutely essential that the former should be capable of sliding longitudinally relatively to the lunger, although it is essential, for a practically eflicient machine, that it should be made separate therefrom. In other words, the former may be threaded directly into the stem 14, as shown in Fig. 5. Either construction enables'me to make these punches of the requisite hardness without incurrin danger of their breaking at the point of unction which they very soon did when made integral, owing to the tremendous strain, tending to pull the ,former .downwardlyand to force the plunger upwardly While the tube was bein extruded, and the inelasticity of theintegra construction. The new constructions give elasticity to. the tool which enables them to yield under the, strain and thus avoid breakage.

In, practice, it is usually necessary to pass the tubes through a strai htened die or through a shaping die, as w en they are to,

be finished hexagonal in cross-sectlon, for lnstance. There is, of course, a

of the en shaped blank are increased'in height. T e former 18 is accordingly adjusted downward in the stem, so that it will contact with the bottom of the blank just be- As will be obvious, the amount of movement of the block ornut 17 in the stemmay be adjusted by increasing'or diminish-- ing the length of said nut.

racticallimit to the diameter of the blanks -w ich can be extruded,under present conditions I find There remains to be described the construction and operation of the trimmingpunches. The action of these is to push the tube away from the flange left on the top of .the bushing, and the only essential feature of their construction is that their diameter where they enter the dies must be intermediate the inside diameter oi the bushing and the inside diameter of the tube. Thus they tear the walls of the tube away from the liange, and as they go up again, the'fiange is car ried with them, by reason 01 the contraction. of the metal onto the punch and also of the dish-shaped form of the'lianges which, when the upward movement of the punch tends to straighten them out, causes them to bind on the punch. As shown, the punches are formed with heads 25, having shoulders at both ends, the smaller front end of the punches serving as guides to center them in at the tubes, and the shoulders to act on the metal of the tube, one to sever and push away the wall from the flange and the other to engage the flange and with-draw it on the upward stroke, but this construction is not essential, it being only necessary that the diameter of. the trimming punch bear the relation stated to those of the bushing and tube, and that it be suiiiciently solid or resistant to sever the metal. The scrap flanges may be stripped from the trimming punches, or allowed to collect thereon and be subsequently removed by unscrewing the punches from the stems 13. I

To prevent the tube from sticking to the former 18 as the latter rises from the die, 1 provide a spring clam 27 adjustably located below the plate 2, so as to grip the'end of the tube as it is extruded. Any form of clamp or catch may beused, that shown consisting of two semi-circular plates 27 having a conical. aperture .28 atjtheir center and with their meeting edges beveled. Screws 29 loosely and adjustablyfsecure the plates to the; platev 2 and screwsf30 in connection with a wire 3ljpassing' around theperiphery of the clamp,i7 hold'fthe' plates together.

Their action wiltybejjfobvious; they yield apart as the tubepassesdown but are caused to bite the same when it starts to go up, thusreleasing it from the former.

Y The operation is as ,follows: A blank beingplaced in one ofthe dies, resting on the top of the bushing, the slide is moved so as to bring-the punch 8 over said die and the press is started. The former 18 first strikes 65 fore the extruding punch commences to actuplunger were integral, as previously eo'nent construction, the former is carried downward intov the throat of the *die by the metal as it is extruded at the commencement of the operation, until the lower end of the nut 17 strikes against the anvil 16, which also takes the upward pressure exerted by the plunnor-"22.

The threaded connection of the former with the nut provides a certain elasticity, and all danger of breakage of the former is obviated. Furthermore, another important result is obtained by permitting the former to move downwardly at first into the die, which'is that the interior of the closed end of the tube is perfectly finished in this operation, that is to say, a square vcorner is formed, whereas, when the former was rigidly attached to the plunger, the metal would flow in around the" end of the former leaving a round corner at the inside end of the tube, which had to be removed in the finishing operation or else a greater length of the tube had to be sawed ofl". In the manufacture of cartridgeshells, when the closed end of the tube forms the head of the shell, it is difiicult to square up the said round corner Without causing cold-shuts'in the metal, fora great deal of pressure has to be exerted in the operation of shaping the head of the shell to get rid of said round cornerywhereas all such difficulty is avoided when the corner is left square, as it is with the apparatus constructed as above described. 1

Having thus described my invention, what I claim is: a,

1.' Ina machine of the class described, the combination with the bed plate, of a perforated hardened plug held therein, a jacketed die secured on said bed-plate and a bushing inserted in said die and resting on said' 2. In a press of the class described, the combination with the die plate and the reciprocating head, of a punch carrier movable in said head, a forming and extruding punch and a trimming punch carriedin said carrier, whereby they are alternately brought into alinement with said die.

3. In a machine forforming tubes by extrusion, the combination with a die containing a bushin of less length than the thick- I ness of said die, of a support for said bushing underneath the die, a punch comprising an extruding plun er of a diameter to fit the aperture in said fie and a former of a diameter less than the inside diameter of sa bushing, means to adjust said former relatively to said plunger and means to reciprocate said punc 4. In a machine for forming tubes by extrusion, the combination with the bed-plate and reciprocating head of the press, a plate secured to said bed-plate and containing a pair of dies,oa carrier movably mounted in said head, and containing a forming and extruding punch and two trimming punches,

the diiferent positions of said carrier being adapted to cause said forming'and extruding punch to, coact with one of said dies and to cause one of said trimming punches to coact with the other of said dies, whereby, at each reciprocation of said head, one tube is extruded from a blank another tube is separated from its scrap flange and'the latter removed.

5. In a machine for forming tubes by extrusion, adie having'a central aperture and a bushing therein, of a punch, comprising a former adapted to enter said bushing and an extruding plunger of a diameter to fit the aperture in said die, and a trimming punch, the diameter of which is less than the internal diameter of said bushing and greater than the diameter of said former.

ing an internal shoulder, a punch having a central former of less diameter than the reduced portion of said aperture and an annular plunger fittingthe upper portion of said aperture, and a trimming punch the diameter of which is intermediate that of said reduced portion and that of said former.

7, A. machine for the purpose described, comprising in combination a supporting plate containing an apertured hardened plug, a die secured on said supporting plate and containing a bushing, the lower end of which rests on said hardened plug, a reciprocating head containing a hardened plug, a slide, containing a forming and extruding punch and a trimming punch, movable transversely in said head to bring said punches alternately beneath said last mentionedplug and over said die, said formingand extrudin punch comprising a central former of less iameter plate containing an apertured hardened plug,

a die secured on said supporting plate and containing a bushing, the lower end. of which rests on said hardened plug, a reciprocating head containing a hardened plug, a slide containing a forming and extruding punch and a trimming punch, movable transversely in said head to bring said punches alternately beneath said last mentioned plug and over said die, said forming and extruding punch comprising a central former of less diameter than the aperture in said bushing and said trimming punch being of a diameter intermediate that of said former and that of the aperture in said bushing and diameter less than that of the aperture in the die but greater than the internal diameter of the tube formed, and means to reciprocate said punch into said die.

10. In a. machine of the class described, the combination with the die, and the reciprocating press-head, of a stem carried by said head, and an anvil secured in the lower portion of said stem, a block slidably mounted in said stem above said anvil, a former adjustably secured in said block, an extruding plunger surrounding the lower end of said.

former, and means to clamp said plunger against said anvil.

11. In a machine of the class described, the

combination with a die, of a reciprocatory head, a hollow stem secured therein, an annular, plunger bearing against the end of said stem, means to secure said plunger in position, and a central forming-punch passin throu h said plunger and adjustably secured to sai stem.

12. In a machine of the class described, the combination with a. die containing a hardened bushing of less length than the thickness of said die, and an apertured hardened plug beneath said die and bushing to support the latter in place independently of the die, of a reciprocating head having rigidly secured thereto a hollow extendingfplunger of a diameter to fit said die, and a central forming punch of a diameter less than that of said bushing. and movably secured in said head.

13. In machine of the class described, the combination with a die containing a bushing of less length than the thickness of, said die,

'and a support for said bushing independent of said die, of a reciprocatory head carrying an apertured extruding plunger, of a diameter to fit the aperture in said die, and a formin punch of a diameter less than the inside iameter of said bushing, and projecting centrally through said plunger, but secured to said head independently of the same, and means to reciprocate said head.

In'testimony, whereof I have affixed my signature, in presence of two witnesses.

LESLIE E; HOOKER.