US231734A

US231734A - stake

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Publication number: US231734A
Authority: US
Publication date: 1880-08-31
Anticipated expiration: 1897-08-31

Description

(Model.)

E. T. STARR. Dent-a1 Engine Hand Piece.

No. 231,734 Patented Ag. 31,1880.

WITNESSES UNITED 'STATES l PATENT Ormea.

ELI T. STARR, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR T()Y JAMES W. WHITE, J. CLARENCE WHITE, AND H. M. LEVIS, ALL OF SAME PLAGE, AS TRUSTEES UNDER THE VILL OF SAMUEL S. WHITE, DEGEASED.

DENTAL-ENGINE HAND-PIECE.

SPECIFICATION forming part of Letters Patent No. 231,734, dated August 31, 1880.

` Appncmion filed July 10,1880. (Model.)

To all whom t may concer-n:

Be it known that I, ELI T. STARR, a citizen of the United States, residing in the city and county of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Dental-Engine Hand- Pieces, of which the following is a specification.

My invention relates to the class of hand- Io pieces for dental engines in which the operating-tool is secured in the socket of they spindle tool-holder or chuck by means of aspring-jaw or split tool-fastening carried by the chuck in its revolutions.

The best hantl'pieces of this type known to me are those exemplied in the Letters Patent granted to Re Qua, January 22, 1878, as i No. 199,469; Cushing, August 5, 1879, as No. 218,239, and Phillips, September 23, 1879, as No. 219,873.

My invention constitutes an improvement more especially upon the hand-pieces of Gushing and of Phillips, and has for its object the production of a superior instrument.

My invention consists in certain new coinbinations and organizations of devices, which are recited at the end of the specication.

In the accompanying drawings, whichillustrate the best way now known to me of embodying my improvements, Figure 1 is a longitudinal central section through the handpiece. Fig. 2 is a similar.- section through a portionof the hand-piece with some ot' the parts in positions different from that depicted in Fig. 1. Fig. 3 is a transverse section through the device on the line 3 3 of Fig. 2, and Figs. 4 and 5 are similar transverse sections on the lines 4 4 and 5 5, respectively, of Fig. 1.

The casing A of the hai'id-piece is preferably composed of four tubular sectionsthat is, of a nose or end section, c, preferably of hardened steel 5 of a handle-section, a', which surrounds the tool-holder or chuck B and forms a sheath for it., said section being grasped usu- 4 5 ally between the fm gers and thumb somewhat in the manner of holding a pen or pencil, to guide the operatin g-tool and hold it toits work of a section, a2, preferably of hard metal, to which the handle section is connected by screw-threads, so as to permit said handle-scc- 5o tion to be readily detached to uncover the toolholder or chuck for oilin g, e., and of a shank,- section, a3, connected with the said section a2 by screw-threads, so as to permit ready separation of said sections in order to obtain ac- 55 cess to the interior of the hand-piece.

The t0ol-holder or chuck B has its bearin gs at front in the nose or section a of the casing and in rea-r of the hard-metal section c2, and is given a rapid revolving motion upon its lon- 6o gitudinal axis in said tubular bearings by a flexible power-conveyer or shaft of the usual or any approved construction.

The shank-section a3 of the casing is preferably connected with the outer or free end of' 65 a flexible sheath or tube, which envelops the flexible power-conveyer to protect it-for eX- ainple, as in the well-known. S.. S. White dental engine, and as shown in the reissued Letters Patent granted to N. Stow, March 4, 1879. 7o

I have deemed it unnecessary to show either 'the flexible driving-shaft `or its exibleenveloping-sheath, as they frm no part of the subject-matter herein'claimed.

The tool-holder is locked from endwise move- 7 5 1n ent in the casing by annular shoulders, which abut against corresponding shoulders formed on the interior of the casing. The annular shoulder I) at the front end of the tool-holder constitutes the pull-bearing, preventing end- 8o wise movement of said tool-holder in an outward direction when a pulling or draw cut is being made with the operating-tool; and the annular shoulder b', formed by the milled collar b2, near the rear end of the tool-holder, 5 constitutes the push or thrust bearing, preventing endwise movement of the tool-holder in an inward direction when a pressure or thrust cut is being made with the tool. l

The tool-holder or chuck is tubular. A 9o shaft, C, is passed through the chuck from end to end, the front end of which shaft is lon gitudinally split, so as to` form spring clampingjaws, and is socketed for the insertion of the shanks of the operatingtools, which are clamped or fastened in the socket by the compression of the clamping-jaws.

The ends of the members of the split or spring-jawed tool-fastening protrude a short distance in front of the end of the chuck and terminate in a sli ghtly-enlarged tapering head, so that when drawn within the mouth ofthe toolholder the said members will be closed together or compressed, while when moved out from said mouth they will spring apart, eX- pand, or move laterally, as is common in this form of tool-fastening, and as fully described in the patents hereinbefore referred to.

In order to positively move the said shaft C endwisc within the tool-holder or chuck to compress or release the clamping-jaws, (the toolholder being locked from endwise movement, as before described,) the said shaft at its rear end, which is extended through and beyond the rear end of the chuck, is provided wit-l1 a cl;1p-piece,D,itted upon the shaft and locked from endwise movement thereon by two collars, d d', fixed to the shaft, thefrontenlarged end ofsaid cup-piece being internally threaded to receive the externally or male threaded buttend of the chuck, so that by turning said chuck on its axis to screw it in or out of said cup, said cup, and with it the shaft C, will be caused to move endwise to clamp or release the tool-fastening, according to the direction of rotation of the chuck.

In order to prevent the said cup-piece from turning when it is desired to operate the toolfastening, while permitting ,it to move end wise with said fastening as the chuck is turned by the milled collar b2, which is grasped by the fingers through openings c c in the opposite sides of the casing when the thimble or sleeve E is drawn back to expose said openings and collar, a pin or screw, j', is passed through said sleeve, and its end engages with one ot a series of i longitudinal peripheral grooves, d2, formed on the cup-piece l). (Clearly shown in Figs. l, 2, and 3.)

The sleeve E is permitted to be moved backward and forward on the casing to en gage and disengage its screw ffrom the cup-piece by means of a longitudinal slot, g, in the easingseetions a2 a3, while it is prevented from turning relatively to said easing by said screw, wherebyit is obvious that it'the sleeve is drawn back to engage its screw with one of the grooves ot' the cup-piece D said cup-piece will be locked from rotation independently of the casing, while the chuck may be turned by its milled collar in order to reciprocate the cuppiece and shaft C in the chuck.

In operation, ofcourse the sleeve will be in its forward position, as shown in Fig. 1, to cover the openings c o', and so as not to in# terfere with the rotation of the shaft and chuck in the casing in driving the operating-tool.

Fig. 2 shows the sleeve E as drawn back, with its screw locking the cup-piece D from turning, to permit the milled collar b2 to be turned to screw the cup-piece and shaft forward to release the tool-fastenin g.

The socket of the tool-fastenin g is preferably provided with a tangential pin, h, or with a suitable lug to engage a notch in the toolshank, so as to lock said tool firmly in the socket and enable it to be driven firmly and positively without relying upon the tool-clamping devices alone for the purpose.

It will be noticed that a chamber, z', is formed at the nose of the hand-piece forward of the front end of the tool-holder, and this is for the purpose of arrestin g the entrance of extraneous matter to the bearing ot' the chuck, and for preventin g the escape of lubricating-oil to the outside ofthe hand-piece. This featureis the invention of Phillips, whose patent has been above referred to.

I claim as my inventionl. The combination, substantially as hereinbefore set forth, of the oasin g, the tubular toolholder turning in bearings therein, the shaft passing through said tool-holder and having its front end split to form tool-locking jaws, the cup-piece itted on said shaft so as to be incapable of endwise movement thereon and connected with the tool-holder by a screw-connect-ion, and the sliding thimble to look said cup-piece from turning without preventing its endwise movement while exposing the cluck for operation to enable theJ toollocking shaft 1 to be reciproeated.

2. The combination, substantially as hereinbefore set forth, ot' the casing having openings ill its side, the tubular chuck mounted in said casing and having a collar to turn it opposite said openin gs, the shaft extended through said chuck having a socket and clamping-jaws at its front end, the pin or lug in the socket of said chuck to enga-ge the locking-notch of a tool-shank, the cup-piece on said shaft connected with the chuck by a screw-connection, and the sliding thimble which locks said cuppiece from turning while exposing the collar by which the'ehuck is turned to reciproca-te the In testimony whereof I have hereunto subscribed lny name.

ELI T. STARR. Witnessesz GEORGE P. MORGAN, WILLIAM H. GILBERT.

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