US233707A - staee - Google Patents

Description

(Model) E. Tl STARR. 2Sheets-Sheet 1. Dental Engine Hand Piece.

No. 233,707. Patented Oct. 26, 1880.

(Model.) 2 Sheetssneet 2.

E. T. STARR.

.Dental Engine Hand Piece. v No. 233,707. Patented Oct. 26,1880.

N. PETERS, FI-lDTQ-LlrrloaimnmA WASHINGTON. D c.

Y ELIT. STARR, OFPHILADELPHIA, PA., ASSIGNOR TO JAS. W. WHITE, J.

'CLARENCE VHITE, AND H. M. LEWIS, AS TRUSTEES, OF SAME PLACE.

DENTAL-ENGINE HAN D-PIEC E.

SPECIFICATION forming part of Letters Patent No. 233,707, dated October 26, 1880.

Application filed August 16, 1880. (Model.)

To all whom t may concern:

Be it known that I, ELI T. STARR, ot the city and county of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Dental-Engine Hand-Pieces, (Case H,) of which the following is a specification.

Myinvention relates to dental-engine handpieces which arecapable of being grasped by the hand to guide and direct the operatingtool driven by a rotary spindle-chuck mounted in the hand-piece casing.

The objects of my invention are to improve the construction and organization of such hand-pieces, to the end that wear of the chuck and its bearings may be compensated; that the tool-locking devices may be readily manipulated by the same hand that grasps the hand-piece in order to release a tool from or lock it in Ithe chuck-socket, and that loose motion or rattling of the, tools in the chuck may be avoided.

The subject-matter claimed is particularly pointed ont at the close of the specification.

In the accompanying drawings, Figure l is a longitudinal central section through the hand-piece. Fig. 2 is a cross-section therethrough on the line 2 2 of Fig. l; and Figs. 3 to l0, inclusive, are views of toolshanks adapted for use with a hand-piece embodying my improvements.

The casing A of the hand-piece is a sec- -tional one, as usual, consisting, in the present example, of four tubular sections, a a a2 a3. The section a is the handle-section, and it affords bearing for the front end of the rotary spindle tool-holder or chuck B. Said handlesection surrounds the tool-holder and forms a sheath for it, and is ordinarily held centrally of the fingers and thumb of the operator (somewhat after the fashion of holding a pen or pencil) in directing, guiding, and holding the operating-tooljo its work. Said handlesection is connected with the tubular section a by screw-threads, so as to be detachable for oiling, 85o., and said section a constitutes the rear axial bearing of the spindle tool-holder, said tool-holder being connected at its buttend with aflexible power-conveyer, as usual,

tion on its longitudinal axis in the said bearings in the hand-piece casing. Casing-section ais connected with section a2 by screw-threads, so as to be readily separable, while the shanksection a4 is connected with said section a3 by a swivel-joint ot' well-known construction, so that the handle-section, which is grasped by the operator, ina-y turn or swivel around the tool-holder relatively to said shank-section to conform to the turning movements ofthe hand, and this without interfering with the free rotation oi' said tool-holder in its bearings. The said shank-section is connected with a iiexible tubular sleeve or cover, which envelops the iiexible power-conveyer, so as to form a sheath for said conveyer, within which it may freely rotate. The said iiexible shaft and sheath may be substantiallylike those shown in Stows reissued Letters Patent No. 8,607, of March 4, 1879.

An annular collar, b, is formed upon the tool-holder, and this collar bears upon a loose hard-metal friction-ring, c, (of which there may be two or 1nore,) interposed between said collar and the annular shoulder formed by the front end of the casing-section a', whereby said collar constitutes the thrust or push bearing of the tool-holder, and prevents inward endwise movement of said holder in the casing when a push orthrust cut is being made with the operating-tool.

In order to prevent endwise outward movement of the tool-holder in the casing when a pulling or draw cut is being made with the operating-tool, I preferably form the front end ot' the tool-holder with a tapering bearing-surface fitting the correspondingly-shaped bearingin the handle-section of the casing. Such a tapering bearing also compels the chuck to run smoothly, and affords means for readily compensating for wear of the chuck and bearings by adjusting or screwing up the sections a a ofthe casing.

I also provide the tool-holder at its rear end with an adjustable collar, d, of hard metal, and this collar may constitute the pull-bearing by abutting against the annular shoulder formed by the rear end of the casing-section c', and thus save the effect of wear on the front tapering bearing of the tool-holder at the nose of the hand-piece.

I do not claim herein, however, any of the devices so far described, nor do I claim the annular space c at the front end ofthe casing in advance ofthe front end of the tool-holder B, which is for the purpose of preventing the escape of lubricating-oil to the outside of the hand-piece, and also to prevent access of saliva, &c., taken up by the operating-tool, to the bearings ofthe tool-holder, as such is the invention of one Phillips, heretofore patented.

The front end of the tool-holder is socketed, as usual, for the reception of the driving-ends ofthe operating-tools; but this socket in this example is a peculiar one, in that it tapers from its largest part at the mouth inwardly, while the shank of the operating-tool is correspondingly tapered, so as to t snugly in the said socket. The said tool-shank is provided with a driving-surface,f, which engages with an actuating surface or pin, h, extending into or across the tool-socket, whereby the tool is positively driven with the tool-holder, and is also provided with a notch or groove, f', for the engagement of the tool-locking device, which prevents endwise movement or disengagement of the tool. Said tool-lock consists, preferably, of a stiff or rigid sliding latch or tumbler, G, fitted in a longitudinal groove in the tool-holder, and connected with a ring or annulus, H, encircling said holder, and capable of sliding thereon while compelled to rotate therewith. A spiral spring, I, encircling the tool-holder, is compressed between said sliding ring H and a iixed collar or annular shoulder, i, of the tool-holder, and the force or tension of this spring is always exerted to force the ring H, and with it the latch G, backward, so as to depress the beak or hook g of the front goose-necked end of said latch G, which rides under the fixed collar i, into engagement with the locking-notch f of the toolshank, thereby locking said shank in the socket and exerting a drawing action thereon, so as to keep said shank in the tapering socket with a close fit, thus preventing lateral motion or rattling of the tool in the socket.

In order to disengage the locking end of the latch from the locking-notch of the tool-shank, (should one bein the socket ofthe holder,) to permit of the withdrawal of the tool, or to permit the insertion of a different tool in the holder, I provide the front edge of the hooked end g of the locking-latch with an inclined or wedged surface, gso that when the latch is moved forward said inclined surface g' will ride upon a similar surface, g2, in the toolholder, and be forced or wedged upward, the upward movement of the latch being permitted by cutting away a portion of its upper edge, as at g3, under the fixed collar t' of the tool-holder. The latch is also provided with an abrupt shoulder, g4, so that the latch when forced forward not only rides its hooked end g out of contact with the tool-shank, but forces said tool outward or loosens it by its shoulder g4 coming against the end of the tool. By this mode of construction I overcome the objection heretofore existing to the use ot' tapering shanked tools with dentalengine hand-pieces-that is, I prevent the wedging or sticking of the tool in the socket of the holder by forcing it positively out or looseningit.

In order to place the latch under the control ot the hand that holds and guides the hand-piece in operation, so that but one hand is required to hold the hand-piece and operate the tool-lock, I pivot a lever, J, externally upon the casing, the rear end of which lever is provided with a hook or nose,j, adapted, when the lever is raised from its position parallel with the casing, to entera slot, a4, in said casing, and engage the rear side of the sliding ring H, so as to move said ring forward and carry with it the slidinglatch, to.

move said latch from its locking position, as before explained. n

It will be understood, of course, that as the lever is rocked from front to rear the hook j will travel around the pivot or fulcrum of the lever to carry the latch forward.

A light plate-spring, k, acts upon the lower edge of the lever to hold it down closely to the casing when not rocked by the finger, while the spiral spring I throws thelatch into its locking position to draw the tool rmly in the socket and lock it from endwise movement as soon as the pressure upon the lever is removed and said lever allowed to assume its normal position, as shown in Fig. 1.

I have shown inFigs. 3 to l0, inclusive, several forms of tool-shanks for hand-pieces embodying my improvements.

In Figs. 5 and 8, instead of shanks having a tapering surface to fit a corresponding socket, I have shown shanks having straight cylindrical portions of different diameters. For such shaped shanks the toolholder socket will be correspondingly formed.

In Fig. l, I have also shown the operatingtool as formed in sections, the portion carrying the operating-point tting in a socket of the shank proper, the two sections being united by a through-pin or some such fastening.

I disclaim herein in favor of my application filed July 29, 1880, any patentable subjectmatter common to the two cases.

I claim as my inventionl. The combination, substantially as hereinbefore set forth, of the hand-piece casing, the spindle tool-holder turning in bearings therein, the rigid sliding tool-locking latch, the spring to move said latch in one direction to exert a drawing action upon the tool-shank and lock said shank in the tool-holder socket, and the lever pivoted upon the casing so as to lie parallel therewith and be capable of a rockin gmotion fromfront to rear, and the hand- IOO IOS

piece to move the latch and release it from engagement with the tool-shank.

2. The combination, substantially as hereinbefore set forth, of the hand-piece casing, the spindle tool-holder turning in bearings therein, the fixed collar or shoulder on said holder, and the sliding latch movable in a recess in the tool-holder beneath said collar, and having a portion of its upper edge cut away to permit the front end of the latch, when forced forward, to rise laterally in the recess to disen gage it from the tool-shank.

3. The combination, substantially as hereinbefore set forth, of4 the hand-piece casing, the spindle tool-holder turning in bearings in said casing, the sliding tool-lookin g latch provided with a beak at its front end to engage a ELI T. STARR.

Vitnesses:

WM. J. PEY'roN, J AMES YOUNG.

It is hereby certified that in Letters Patent No. 233,707, dated October 26, 1880, to Eli T. Starr, for Dental Engine Hand Piece, iu line 132 page 2 of the specification forming part of said Letters Patent, after the word rear 2o comme and the word and were erroneously inserted, and the word of was erroneously omitted; that the proper corrections have been made in the records of this Oee, and

thaty said correction is hereby iliade in the Letters Patent.

Signed, conntersigned, and sealed this 30th day of October, A. D. 1880.

[SEAL] C. SCHURZ,

Secretary of the Inter/01. Countersigned E. M. MARBLE, Commissioner of Patents.

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