US95113A - Improved machine for forming screw-threads on sheet-metal caps - Google Patents

Description

fvnesses f N-IPUERS. PROM-LITHOGRAPHER WASHINGTON D G i .i i wir.,

TllOMAS HOUGHTON, OF PHlLADELPHIA, DENNSYLVANIA, ASSIGNOR TO S. B. ROWLEY.

IMPROVED MACHINE FOR FOR-MING SCREW-THREADS 0N SHEET-METAL CAPS.

Specification forming part of Letters Patent No. 95, l l 3, dated September 21, 1869.

To all ,whom 'it may concern:`

Beit known that I, THoMAs HoUGHroN, of the cityand count-yof Philadelphia, andState of Pennsylvania, have invented a new and useful Device for Swaging Screw-Threads on Articles of Malleable Metal; and I do hereby declarethe following to be aclear and exact description of the nature thereof', sufficient to enable others skilled in the art to which my invention appertains to fully understand and use the same, reference being had to the accompanying drawings, making part of this specification, in which- Figur'e 1 is a top view of the device illustrating myiinvention. Figs. 2 and 3 are side views thereof. Fig. 4 is an end View thereof. Figs. 5,6, 7,8, and 9 are views of detached parts thereof.

Similar letters of reference indicate corresponding parts in the several gures.

My invention is a novel device for swaging screw-threads on sheet metal cylinders, caps or rings, and other articles; and it consists in i means for advancing the threading-rollers against the blank resting-in the dies and the automatic returnrthereof, the blank being meanwhile held and released by a peculiar holder and then readily withdrawn in a complete and perfect state. These results are accomplished by an ingenious mode of throwing the proper pulleys in and out of gear in a manner as will be hereinafter more fully described. v

In the drawings, A represents atable or bed, supported upon suitable legs or feet a, and from which arise standards A', supporting a hollow shaft or mandrel, B, having a longitudinal groove, b. B is a toothed wheel mounted on the mandrel and provided with a` key tting into the groove b, whereby the mandrel may be longitudinally moved, yet always be rotated by the wheel B'.

To one end of the hollow mandrel B, I secure a swaging head or chuck, C, consisting of a suitable disk of metal carrying grooved rollers D, which are mounted on screw-rods a', placed within eccentric bushings in suitable openin gs in the head C. The heads of the screw rods are flush with the outer face of the rollers D, and the screw ends receive tightening-nuts d, whose inner faces are concave, so as to clear the bushing-yet have their edges to come in contact with the head, and thereby hold tightly the screw-rods without disturbing the bushing. rlhe rollers 'D are arranged on sides opposite to each other at the outer face of the head C and are let into the same so that one face of each will project farther than the other, yet the peripheries of both extend beyond the periphery of the head C. When the rollers D become worn from use, or it is desired to move them nearer to or farther away from the center of the head, and thus increase or decrease the depth of the thread intended to be cut, it is only necessary to turn the eccentric bushing of the screw-rods a', and thereby cause the rollers to assume a corresponding position.

A standard, C', arises from the table or bed A, and forms a bearing for the mandrel B, which, at the point where it passes through the bearing, has upon it a screw-thread, b.

The journal is provided with a pin or key, c, passing through an opening therein, so as to extend -into the grooves comprising the screwthread b. It is -now evident that if the Amandrel B is rotated it will advance or recede relative to the direction of rotation, and thereby carry the swaging head C correspondingly.

D isa standard arising from one end of the bed and provided with a tongue in its lower side fitting into a longitudinal opening, o', in the bed, so as to allow the standard to be readily moved. A small block is secured beneath the tongue and extends beyond the side of the opening o', and is provided with a setscrew, so as to steady and hold standard in place. This standard forms a holder for the sectional female die E, which is let into the upper edge of the standard so as to be flush with the top and the inner side thereof. This die is of semi'cylindrical form, and has its internal face cut with screw-threads f, whose `pitch and dimensions shall be in accordance with the thread intended to be out in the metal.

A corresponding die, D, is secured to a block, E', which is hinged to theV standard D so as to swing thereon',and the two dies meet and form a perfect die of cylindrical shape, and v of size a little larger than the head or chuck O,

with the groove of the rollers D almost in contact with the threads f of the dies.

. It will be perceived that when the die is.A closed its inner end is open to receive the chuck C; butthe outer end is entirely' closed and forms a bed against which the blank is to bc placed and rests while being threaded.

The sectional die is prevented from untimely or accidental swinging upward by means of a lock, in the form of an inverted T, passing through a transverse slot in an extension-piece of the standard D', and catching thereunder when turned, so as to be at right angles with the slot. By again turning thelock to register with the slot the block E' is easily raised and the dies opened. This operation is assisted by a lever, d', which is secured to the top of the vertical part of the lock above the block E', in which said part is journaled. A pin, e', may pass through lthe two parts and thus prevent lateral and longitudinal displacement of the dies. The sectional dies are retained in place by set-screws and are readily removable, as also is the chuck C; but both must be firmly held in place during operation.

F represents the blank-holder,consisting of a flat disk of metal secured to a sliding rod F', which passes entirely through the hollow mandrelB. This rod has its free end cut with screwthreads f', on which are placed two nuts, f between which are secured one end of a conncctingbar, G, whose other end is attached to a horizontal rod or shaft G', having its bearings under the bed or table A or otherwise.

The free end of the shaft G' has connected to it a cord or chain, g, which passes over a pulley, g',at one end ofthe table and is united to a treadle resting on the iioor of the room or workshop. A coil-spring, h,encircles the shaft G' and bears against the the connecting-bar G and thereby draws the sliding rod F' and the blank-holderFin adirection away from the dies E D".

By means of the cord g the bar Gr is drawn toward the dies and thereby forces the blankholder against the bed or closed endof the dies. In order that this holder may tit snugly against the chuck C when advanced into the dies, I construct it in diameter alittle smaller than the chuck C, and form the latter with a ange, so that the holder will iit within it. A portion of the holder is also cut away and allows the roller D, which projects the farthest, to protrude through the cut-away portion and be flush with the face of the holder.

To the side of the standard A' is secured a bent arm, H, one part of which is slotted, through which passes freely a lever, H', whose lower end is hinged to a spring or weighted bar or strip, H", attached to the bed or table A.

Near thc upper end of the lever H' is formed a slot, 7L', receiving a tappet, I, which projects inwardly, and has the end which enters the slot of smaller size, and provided with a screw and washer, whereby the tappet may be readily adjusted. rl"he free end of the tappet has its upper inner edge beveled, but its lower side is at to thejunctiou of the bevel.

The strip H" is secured to the table by a set-screw, whereby it can be adjusted as desired. The opposite end has on its under side a pin or lug, i, and is prevented from moving or sliding transversely by an arm or guide, j.

J is a rod or arm projecting from the side of the standard A', and has pivoted to it a lever, K, whose upper end is bifurcated or forked, so as to partly straddle a collar, h'. secured to the hollow mandrel B at or near the end opposite to the chuck C. The collar K' is retained in place by a set-screw, and is thereby adjustable. 0n this collar is secured a sleeve or ring, L, and is provided on its outer periphery with a tripping pin or lug, L'.

It will be perceived that if the mandrel D is revolved and advanced it will carry the collar with it, and thus cause it to approach the tappet I, and when it reaches said tappet, pin L' catches under it, and as it revolves with the collar it raises the lever H' and strip H", thereby connecting the pulleys. When the pin has entirely cleared the tappet, the strip H" immediately draws the lever H' in its first position, ready for the next operation.

M represents a lever pivoted to an arm projecting from the side of the table beneath the mandrel, or in any other suitable place, and this lever passes under the pin i of the springstrip H", and is turned into a handle, 7c.

At a point between the handle of the lever and its pivot I secure two arms, k', one being on each side of the lever and projecting upwardly, and in the space thus formed the lower end ot' the forked lever c has a certain play, which islimited by set-screws on the arms k.

The end of the lever M opposite to its handle has pivoted to it one end of a sliding bar, M', which has its guides in the sides of the table A and projects on both sides of the table. lts other end receives a thumb-screw, l, between which land the table is a coiled spring, m, encircling the bar M.

It is evident that if the handle of the lever be moved in the direction of the dies it will clear the pin t' and the spring-strip H", and immediately descends, thereby holding the lever and preventing its return.

The coil-spring m, bearin g against the screw l of the sliding bar M', causes the handle end of the lever to press against the pin fi, which is prevented from releasing it by the spring or weighted strip H" holding it down to its work.

Now, from what has been previously described, it will be seen that if the pin L of the collar K' raises the tappet and lever H', the spring H" is likewise raised, and thereby clears the pin i, and at once releases the lever M.

As the collar K advances with the mandrel B and reaches the inner fork ot' the lever K it moves it and causes the lower end ot' the lever to press against the outer arm k' on the lever, and assists in the operation of throwing out the lever at the moment it is tripped; but when the collar returns and bears against the outer fork of the lever K the lower end of this lever presses against the inner arm k', and gradually draws the lever toward the die,

but not past the pint'. These movements are the means by which, after the mandrel is advanced, it is automatically returned and then prevented from again advancing until the lever M is moved by the hand, and thereby cause powerto becommunicatedto the `toothed wheel B' on the mandrel B. In order to accomplish these results I employ an ingenious gearing arrangement, which operates with the parts hitherto described.

At the point where the lever M is pivoted to the sliding bar M',` Ipivot to the {lever'or bar, or secure to the pintle of the joint, an arm, N, which extends upwardly and is connected to a sliding rod,`N', which passes through ahollow shaft,`0 mounted on standards, 0', arising from the bed or table A. rIhis shaft is prevented from lateral or longitudinal play` by suitable shoulders or collars.

The upper end ofthe arm Nhas'an opening through which passes one end of the rod N', which end is cut with suitable threads. and receives nuts n, one of which is on each side of the top of arm N. When the lever M is operated the arm N will receive motion therefrom7 and bearingagainst the nuts n will move the rod N' in and out of the hollow shaft O.

On thehollow shaft 0, I secure a collar, P, having a longitudinal slot, o, registering with a similar slot'on the hollow shaft 0. In these slots a pin, o', is allowed to play, having one end secured to the sliding rod N and the other end connected to a pulley, Q, which is slipped over the collar P and slides freely thereon to the extent of the play of the pin p in the slots.

When the sliding rod N is drawn in or out of the hollow shaft it will carry the pulley Q with it. This pulley is constructed of two truncated cones joined at their bases, or a pulley having its periphery beveled from the center to its sides.

On the shaft O, I place two loose pulleys, R R', which are of ordinary construction, except ing that their inner faces are cut away so as to leave a bevel-flange, r, to correspond with the bevel periphery ot the cone-pulley Q. One pulley, R, is prevented from lon gitndinal play in the direction ofthe dies by its hub ittin g against t the standard O'. The other pulley, It', has no play in the direction of the lever M, by reason of a toothed wheel, S, iirmly secured on the shaft and arranged close to the hub of said pulley, with an interposed washer, q, to overcome friction. The toothed wheel S meshes with the toothed wheel B on the hollow mandrel B, and communicates motion thereto through the medium of the pulleys It R'. These pulleys receive their motion from belts, or otherwise, and rotate in opposite directions, so that if the cone-pulley is brought against one of the said drivin g-pulleys it'will be turned in one direction, and if brought against the opposite pulley will be rotated in the opposite direction, the hollow mandrel (which is ro` tated through the medium of the wheels S and B') being caused, byits screw-thread bearing on the pin c, to advance or recede according as the cone bears against one or other of the driving-jgiulleys.`

As the wheel B' has a feather fitting a longitudinal groove, b, in the shaft, the latter can slide through the wheel, which is retained in itslateral positionlby the standards A'. Should the cone not bear sufciently againstthe loose pulleys, the nuts n mustbe moved accordingly, so as to regulate the play of the rod N' in the proper direction.

When the lower end of `the forked lever K draws the lever M in the direction of the die, the cone-pulley@ will brought at a point between the two loose pulleys, and thereby the latter will rotate freely without communicating power to any other parts of the device.

'This free rotation occurs so soon as the chuck C is entirely withdrawn from the die.

The means for accomplishing the above results may be differently constructed and arranged, but it is necessary that they possess all the features described.

The operation is as follows: Power being communicated to the pulleys R R', so as to rotate in opposite directions, the block, E is swung olf of the standard D and the blank placed in the die E against its closed side.

The foot is now applied to the treadle, so as to draw the horizontal shaft G', and, through the medium of the connecting-bar G and sliding rod F', to force the blank-holderF against the blank in the die against the rest therefor,

where the blank will be held irmly so long as the foot is on the treadle. The block is swung `back in place and locked as described. rlhe lever M is then pushedclear of the pin li on the spring or weighted strip H". This carries the sliding rod N' in the direction opposite to the die, and causes the cone-pulley to come in contact with the pulley B', and thereby communicates power to it in the same direction. The shaft 0 and toothed wheels S and B' are thus rotated and advance the mandrel, running the chuck C into the die. The grooved rollers D now force the metal into the threads of the die and cause a corresponding thread to be swaged on the blank. So soon as the chuck has advanced to the extent desired, the collar K' on the mandrel, having followed it, brings the pin 4 L' against the tappet I, raises it andthe lever H' and the spring-strip H", thereby tripping the lever M and allowing it to y away fromv the pin. The spring m on the shaft N' causes the sliding rod N' to move in the direction of the die, and thereby force the conepulley against the pulley B, which immediately communicates its motion to said cone-pulley and forces the shaft O to rotate in a correspond-v ing direction, and, through the medium of the wheels S B', to rotate the mandrel B, so as to nnserew itself or to recede from the die, and thereby bring the chuck or head Cout of said die. The bevel-edge of the tappet allows the tripping-pin to pass over the tappet, and so soon as the collar reaches the outer arm of the fork of the lever the lower end of said lever moves toward the inner arm k' on the lever M, and gradually moves the lever M in the direction from whence it has just been tripped,

and brings the colle-pulley at a point between tivo pulleys, R R', thereby throwing them out ofgear and stopping therotation of mandrel B. The block E is now unlocked and swung off from the die-holder or standard D', when the blank, as completely threaded, is withdrawn, ready for the introduction ot' another blank, after which the block is closed and locked, and the lever M moved to catch under the pin when the device is in gear to continue the threading opera-tion. /Vhen larger or smaller articles are to be threaded the dies and chuck must correspond in size thereto.

Should a deep or shallow thread be desired the eccentric bushings ofthe screw-rods of the rollers must be moved or turned accordingly.

It will be found that the device is practical and simple in detail and sure in execution.

Having thus described my invention, what l claim as new, and desire to secure by Letters Patent, is-

1. The mode of swaging threads on sheetnielal ware from the inside thereof', substantiall y as described.

2. The rollers D, chuck G, and sectional die E D", combined and operating substantially as described.

3. The blank-holder F, in combination with the die, substantially as described.

4. The hollow mandrel B, with screw-threads b' and groove I), andthe Wheel B', operating together, substantially as described.

5. The tripping mechanism for the lever M, consisting' ofthe collar K', pin L',lever H', and spring H", or equivalent, substantially as described.

6. The forked lever K, in combination with the collar K' and lever M, substantially as and for the purposedescribed.

7. The means for throwing` the pulleys R lt' in and out of gea-r, consisting of the conical pulley or clutch Q, the hollow shaftO, and the sliding rod N', substantially as described.

8. rlhe eccentric bushings for the rods bearing the sWaging-rollers D, substantially as and for the purpose described.

l). The sectional die, consisting ot the stationary part D' and the hinged part E', in conlbination With tlieadvancing and receding chuck C, substantially as described.

l0. The combination of the various parts, substantially as described, for the purpose specified.

To the above I have signed my naine this 3d day of December, 1867.

THOMAS HOUGHTON.

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