US120712A - Improvement in screw-die presses - Google Patents

Description

V l Jamesj Cla/a No. 120,712. SOHW-m@ pfefawmd Nov. 7,1811..

UNITED STATES JAMES H. OLAPP, OF PROVIDENCE, RHODE ISLAND.

IMPROVEMENT IN SCREW-DIE PRESSES.

Specification forming part of Letters Patent No. 120,712, dated November 7, 1871.

To all 'whom it may concern:

Be it known that I, JAMES H; GLAPP, of th city and county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Screw-Die Presses.

My invention consists in a novel mode of attaching the spindle to the crosshead of the plunger and also in combining therewith a means for compensating for the wear of the screw-spindle from time to time 5 and I do hereby declare that the following specification, taken in connection with the drawing furnished and forming a part of the same, is a true, clear, and exact description thereof.

Refering to the drawing, Figure l represents one of my improved pressesin perspective. Fig. 2 represents the same in cross-vertical section.

A is the bed-plate, on which the die-plate a is secured in a manner well knowntopersons skilled in the art. B is a standard mounted upon the bed-plate. O is a screw-spindle mounted in a threaded housing, D, which is supported by the standard. This screw is immediately over the center of the die-plate holder, and on atrue vertical line. In this instance a four-threaded screw is employed. E is a crosshead attached to the lower end of the screw-spindle. It is provided on each side with slides, to which adjustable gibs e are fitted. The lower end of the crosshead is provided with asocket for receiving either an auxiliary socket, f, which in turn receives the male die g, or it may be iitted to receive the latter direct. F is an operative lever, rigidly attached to the upper end of the spindle. Attached to one of its ends is a pendent arm, h, the lower end of which is grasped by the operator and swung from and toward himself for the purpose of raising and depressing the die-plun ger. Die-presses constructed and operating substantially as thus far described have long been in use. As heretofore constructed, if the threads of the screw-spindle and housing become worn, there is more or less play between the threads, necessitating a corresponding greater movement of the lever by the workman than would otherwise be requisite for operating the dies. A part of my present improvement, which I will now particularlyl explain, is intended to correct this diiculty. H is a check-nut, iitted to the screwspindle. It occupies a recess in the top of the housing D, and may be securely held in any desired position by set-screws t', which pass through the housing and engage with the outside of the nut. It will be readily understood that, during the mere upward and downward movement of the spindle, its specific gravity will keep the lower sides of its several threads and the upper sides of the corresponding threads in the housing in constant frictional contact, and that those surfaces will therefore be subject to wear. When, however, the male die or plunger g comes in contact with the sheet metal to be cut, and the work of cutting commences, the weight of the spindle Vis overcome and the bearing or frictional contact is transferred from the surfaces before mentioned, to the upper sides of the screw-threads on the spindle and the lower sides of the corresponding threads in the housing. It is obvious, although when new there isno play between the screw and the housing, that this continual wear will soon cause intervening spaces between the up per sides of the threads on the spindle and the lower sides of the threads in the housing. With such spaces there must be, at the moment the plunger-die g comes in contact with the metal to be out, a certain semi-rotary movement of the screw, which is unaccompanied with any corresponding downward movement of the plunger; and that this useless movement must be made before any cutting action can possibly occur. As the strain on the screw during the cutting action ranges from a few hundred pounds to several tons, it is essential that the real working portions of the screw be always held in close working relation with each other-that is, the upper sides of the screw-threads on the spindle and the lower sides of the threads in the housing. The holding-nut H is provided with threads especially intended to bear upward against the under sides of the threads on the spindle, and thus sustain the weight of the spindle during all of its mere upward and downward movement, and thus hold the working portions of the screw and its housing in close contact with eachother. By an occasional renewing of the check-nut, as it loses its threads by wearing, it is practicable to use up a screw-spindle entirely, and have its operation at the last as true, smooth, and perfect as when it was first built. The other portion of my present invention consists in a novel mode of connecting the cross-head and screw-spindle. It is obvious-that, rwhile the latter is subjected constantly to a semi-rotary movement, the former is capable of a vertical movement only; and that, therefore, there will be more or less wear of the parts adjacent to the point of connection; and that this wear would result in a constantly-increasing intervening vertical space between the screw-spindle and the plunger, of the same character as that already described as occurring` between the spindle and its housing; and, therefore, the same necessity exists for taking up this space in both cases. As before stated, the strain on the screw sometimes amounts to several tons. It is therefore essential that there be a continuous and solid metallic connection between the lower end ofthe screw-spindle and the cross-head. This has been partially accomplished heretofore by the use of slotted wedges, which embraced the lower end of the screw-spindle. My improvement therein is thus described. I is a cross-head screw, which consists, in this instance, of a threaded sleeve ttedto the lower end of the spindle, and arranged to allow the spindle to turn freely therein. It is held vertically to the spindle by a collar, m, secured to the lower end of the spindle, which should project below the collar. The cross-head is provided with a screw-socket, to which the threaded sleeve I is fitted; and the two are connected by inserting' the end of the screw-spindle (with its threaded sleeve, which becomes a part thereof,) into the screw-socket of the cross-head, and then turning the sleeve until the lower end of the spindle and the bottom of the socket in the cross-head, or a bearing-plate inserted therein, are in close contact.

A holdin g-nut, fn, fitted to the screw ofthe sleeve is then turned down to bear upon the cross-head and thus prevent any possible rotary movement of the sleeve. As the end of the spindle wears away the screw is turned from time to time, and the bearing-surfaces are thus kept in 'continuous contact. lt will be observed, as between the crosshead and the spindle, that the weight ofthe former is supported entirely by the screw on the sleeve, and that a small screw-thread on the end of the spindle, which should freely pass through a fixed collar attached to the cross-head, would support it in precisely the same manner with the assistance of a main nut and an auxiliary holding device corresponding with the nut u, both being fitted to the small screw-thread on the endl of the spindle.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. The combination, with the screw-spindle and cross-head, of the sustaining-screw connecting` the cross-head to the spindle, and holdingnut n, substantially as described.

2. The combination of the scrcw-spind1e,crosshead, sustaining-screw for connecting the crosshead to the spindle, and holding-nut fn with the check-nut H fitted to the screw-spindle and capable of an independent vertical adjustment, as and for the purposes specified.

JAMES H. GLAPP.

Witnesses:

WM. C. Woon,

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