US287683A - And eli t - Google Patents

Description

(Model.)

"W. A. JOHNSTON,

A, W. BROWNB, E. Vfr.Y STARR, AA,

W. GILBERT.

J. DENTAL ENGINE HAN D PIECE.

No. 287,683. Patented 00A. 30, 188s.

VIV/V".

N. PETERS. Phum-Lhngmphnr. Washngian. D. C.

` 'UNITED t STATES PATENT OFFICE. e

WILLIAM A. JOHNSTON, OF OLIFTON, AND ARTHUR W. RROWNE, OF WEST- FIELD, NEW YORR, AND ELI T. STARR AND JOHN W. GILBERT, OF PHILA- YDELPHIA, PENNSYLVANIA, -AssIeNORs TO THE S. S. WHITE DENTAL MANUFACTURING COMPANY, OF PHILADELPHIA, PENNSYLVANIA.

DENTAL-ENGINE HAND-PIECE.

SPECIFICATION forming part of Letters Patent No. 287,683, dated OctoberV SO, 1583. Application filed February 12, 1883. (Model.)

0 all whom t may concern: Be it known that we, WILLIAM A. JOHN- STON, of the village of Clifton, county of Richmond, and State of New York, ARTHUR W. Y BROWNR, of the village of Westfield, in said county and State, and EDIT. STARR and JOHN NV. GILBERT, both of the city and county of Philadelphia, in the State of Pennsylvania, have r4jointly invented certain new and useful Improvements in Hand-Pieces or Tool-Carriers, more especially adapted for use with dental and surgical engines and electromotors, of whichthe following is a speciiication.

Our invention relates more especially to the hand-pieces or tool-carriers of the powerdriven engines used by dentists and surgeons in their operations 5 and it constitutes moreparticularly an improvement upon the hand-piecesV shown in the patents of Johnston and Browne,

' V20 No. 213,662, of March 25, 1879, and in the patents of E. T. Starr, Nos. 233,707, 233,708, and 233,709, of October 26, 1880.

` The prime objects of our invention are,

first, to provide an absolutely secure and true tool-fastening, whereby the tool shall at all times be firinly seated in the socket of its rotary spindle without liability to either lateral or end playtherein; second, to providefor readily exposing the working parts of the hand-piece for oiling, cleaning, or inspection Without disturbing the adjustment of the bearings of the` rotary spindle of the hand-piece, third, to permitthe bit to be changed while the engine v is in motion, and enable the rotary spindle to f run as freely with the tool-fastening released as when a tool is clamped inthe socket of the rotary spindle; fourth, to facilitate the substitution of one bit or tool for another without changing the position of the hand-piece in the 4o hand 5 fifth, to provide a nose-cap covering the end of the spindle, the ready removal of which facilitates the oiling and cleaning of the front end ofthe spindle; sixth, to retain the feature of drawing the shank of the tool firmly into place in the spindle-socket when inserted therein, as shown in the Johnston and Browne patent above mentionedhwhile providing against the accidental removal of the'bit or tool when a pull cut is being made; seventh, to preventthe liability of the lubricating-oil used about the hand-piece from soiling the fingers of the operator or the face of the patient; eighth, to prevent the several screws used in the construction of the hand-piece from being lost or mislaid in taking apart the hand-piece; ninth, to so construct the various parts that any of them can be renewedwithout sacrificing the other parts of the organization; tenth, to improve the arrangement of the journals and bearings of thehand-piece; eleventh, to provide an improved connectionbetween the rotary power-driven shaft ,of the engine and therear or butt end of the rotary spindle; and,

twelfth, to improve the construction of the front or socket end of the spindle, so that its tapered j ournal may be readily removed, when worn, and replaced without sacrificing the rest of the spindle.

The subject-matter claimed herein as of our invention is particularly pointed out at the close of the specification.

In the accompanying drawings we have shown all our improvements as embodied in the best way now known to us.

It is to be understood that some of these improvements maybe used without the others, andk in hand-pieces diering in their details of constructionfrom that particularly shown.

In said drawings, Figure 1 is a longitudinal section through a hand-piece embodying our improvements; and Fig. 2,A a similar view .through a portion thereof, the tool-locking mechanism of the hand-piece and its operating devices being shown in a position different from that shown in Fig. 1. Figs. 3, 4, and 5 Y are transverse sectional views on the lines x x,

Fig. 6 is a-perspecy y, and z z, respectively. tive view of the rear or driving end of an operating-tool adapted to the socket of the rotary spindle of the hand-piece, aud Fig. 7 is a view of the split or squeeze nut which locks the pull-collar of the spindle in place.

The hand-piece casing in the example shown consists of a handle-section, a, a second secof the casing, said shank-section being connected with the section a by means of a swiveljoint, as in the well-known hand-piece of the S. S. White dental engine, whereby the handle-section may turn freely to conform to the movements of the hand of the operator relatively to the shank-section. Said shank-section is permanently connected with the outer or free end of the iiexible sheath of the engine which envelopes the flexible driving-shaft, as usual. Neither said sheath nor said shaft is shown in the drawings, as to depict them therein would be unnecessary. The outer or free end of the flexible driving-shaft is connected to the rear or butt end of the rotary spindle B of the hand-piece in this .organization by means of a socket-connection, b. This socket piece or connection is connected at its rear end, preferably by soldering, as usual, with the front end of the flexible shaft, so as to form a permanent connection therewith. The front end of the connection b is'also socketed, and the socket is provided with a female thread at its inner termination, so as to permit the connection to be firmly screwed upon the malethreaded end of the spindle B, so as to form a firm but detachable connection therewith. rlhe spindle B has a tapering shoulder, b', formed thereon, corresponding with the tapering or conical mouth of the socket of the connection b, whereby upon firmly screwing up said connection a 'firm driving-connection is formed, even as against back rotation of the engine. The enlarged frictional surfaces afforded by the cone shoulder and the conesocket very materially aid in making the connection a secure driving one, in whichever direction the driving-sh aft may turn. The spindle B has its bearings in the hand-piece casin g. The front end of the spindle is socketed for the reception of the tool-shanks, as usual, and has a taper or cone journal which fits a corresponding bearing formed by the front end of the handle-section of the casing. The advantages of a cone-journal for the rotary spindle at the front or nose end of a hand-piece arer well established, and need not be reiterated here by us.

The handle-section a of the casing is usually made of brass. In order to afford a durable bearing for the tapered end of the spindle, we preferably construct the bearing therefor at the nose of the hand-piece of a hardened-steel thimble, a3, soldered or otherwise suitably connected to the front end of the handle-section proper. By this means, when the said thimble is worn too much for the successful operation of the hand-piece, it may readily be removed and a new one substituted for it. ln order, likewise, to provide for the renewal of the cone-journal of the spindle when worn, so as not to sacrifice the entire spindle, we construct the cone of the spindle of an externally-tapering tube, b2, of hardened steel, so connected to the reduced end of the spindle as to be removed by a machinist when worn and a new one placed thereon. rlhe preferred construction is to reduce the front end of the spindle B, as clearly shown in Fig. 1. The hardened cone-journal b2 is then `forced on the reduced socketed end of the spindle and firmly soldered in place. It is then centered by the socket in the end of the spindle, and the cone ground to shape and trued exactly with the center of the socket. The socket in the front end of the spindle B for the reception ofthe tool-shank has atapered mouth, as in the Johnston and Browne patent before mentioned, for the reception of the cone-shoulder formed on the shank of the operating-tool. It will be noticed that the end of the spindle B projects a little beyond the end of the hard-metal thimble-piece a, before described. This projecture of the front end of the spindle beyond the casing proper is more especially for the purpose of exposing the end of the spindle for the purpose of cleaning and lubricating the front journal thereof. If this spindle, however, was not inclosed, saliva, grit from the teeth, and other impurities would find ready access to the front bearing of the hand-piece, while the lubricatingoil would also escape and soil the fingers of the operator and face of the patient. To avoid these objections we provide the front or nose of the hand-piece with a tapered cap, (3,' internally threaded at its inner end, so as to fit the threads a4, formed on the exterior hardmetal thimble-piece, a. The cap C, when screwed in place, as shown in Fig. l, fully covers the protruding end of the spindle and overlaps the cone-shoulder formed on the toolshank, whereby there is formed, as clearly shown in. said figure, a space, a5, which most effectually prevents the entrance of saliva and other deleterious matter to the front. bearing of the hand-piece, while the exudation or escape of the lubricant is also prevented. This screw-cap C is readily screwed on or taken off from the front end of the hand-piece as occasion requires.

The rear axial bearing of the spindle B is provided in the union-piece or collet D. The spindle B is prevented from inward endwise movement in the hand-piece casing by means of a thrust-bearing formed by a collar, E, fitted upon the spindle, and held thereon by means of a set-screw, c. This thrust-collar is readily removable from the spindle by loosening the set-screw c. When in place upon the spindle, however, its position is determined by means of the shoulder b, formed on the spindle, the collar being forced up against said shoulder. The set-screw c, which has a tapered end fitting a longitudinal groove, b, of the spindle, is then tightened up, causing its pointed or cone end to bear against au inclined shoulder formed by a slot, c, in the spindle, whereby the collar E will be forced firmly up against its shoulder l3 on the spindle, and be securely locked, so axs to rotate therewith.

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The rear face of the thrust-collar E is smooth or fiat, and interposed between said end and the front end of the union-piece or collet D is a hard-metal anti-friction ring, d, such as is shown in the Johnstonand Browne patent. This ringtakes the wear of the thrust of the spindle and effectually protects the front end of the union-piece or collet D from wear. Both the thrust-collar E and the anti-friction -ring d are preferably of hardened steel fordura bility, and when too much worn they may be replaced by new ones. The pull-bearing ofthe spindle is formed by. a hard-metal collar, F,

which is fitted to the spindle, and locked thereon from turning by means of the cone end yof a screw or pin, f, which fits in the. longitudinal groove b* of thespindle before mentioned. The said pullbearing fis forced firmly up against the rear end of the union-piece or collet D by means of a squeeze-nut, G, which is'` screwed upon the threaded end of the spindle B, as clearly shown inFig. 1. From this description it willbe seen that, while the spindle B is capable of freely rotating axially in .the union-piece or collet D, still they spindle cannot move endwise in either direction, while all wear of the thrust and pull collars may be taken up by the adjustment and the parts readily renewed when desired. The unionpiece or collet D at its rear end'isk screwthreaded for the reception of the internallythreaded front end of the casing-section a. Said casing-section, when screwed in place upon the union-sleeve or collet, is firmly fastened in place by means of a set-screw, g. Projecting upward from the union-piece D is a lug, d', having an opening therethrough extending longitudinally ofthe hand-piece, and screw-threaded for the reception of an adj usting-screw, H. The front portion of said unionpiece is smooth, so as to enable the rear end of the handle-section c of thecasing to be readily slipped thereon. Said handle-section u of the casing is provided with a longitudinal slot,

a, which permits the rear end of said section to be slipped on the front end of ythe unionpiece, past the setting device H, and be brought up against the end ofthe easing-sections a', so as to form a nice joint. The extent, however, to which the handle-section of the casing is slipped upon the union-piece D" is determined Y'by vthe set-screw H, before mentioned, inasmuch as when the said handle-section is slipped upon the union-piece its inward movement is limited by the shoulder formed at the end of the slot as coming against the front end of said screw H. When the handle-section has been slipped upon the union-piece to its fullest eX- tent as determined by the adjusting device H, it is held in such position by means of thesetscrew I, having a tapering inner end, which bearsagainst an inclined or wedge surface, d2, formed in the periphery of the union-piece, as clearly shown in Fig. l. As the said screw-is tightened up,.it will `be obvious that the handle-section of the casing is wedged backward to its greatest extent as allowed by the setscrew H, before mentioned. This provision of screws Hand I with the inclined surface d2 of the union-piece is for the purpose'of enabling the handle-section to be adjusted so as to compensate for any wear of the journal or bearing at the front end of the hand-piece, and is a simple and very desirable method of compensating for wear and securing the proper action of the spindle in the easing.` It will be noticed that the screws e, g, and I are constructed with reduced upper or driving ends, and that the openings in which they move terminatein reduced diameters, whereby-while the screws may be readily turned to perform their functions, still they cannot be entirely removed, so as to be mislaid'or lost. This is also a'verydesirable feature. v

It will be noticed, also, that the thrust and pull collars E and F are locked tothe grooved spindle B by means of pins or pointed screws,

whereby they are locked to the spindle and compelled to rotate therewith, while movable endwise thereon for purposes of adjustment, removal, or replacement. This-is also a desirable feature, because the circumferential positions of the collars when placed on the spindle must always be the same, the collars having the same positions circumferentially when taken oft' and replaced as before existed.

inasmuch as wear takes place between the coltherein against endwise movement, but the cone-shoulder on the yshank is also drawn or forced by the action of a spring firmly in its corresponding seat in the mouth of the toolsocket. This avoids endwise movement of the ICO IIO

tool in thesocket and prevents any `wabbling or rattling movement of the tool. Under some circumstances, however, when a pull cut is being made with a hand-piece like that of Johnston and Brownes, the pull upon the tool wedges the tool-fastening'outward, and the tool pulls out of the socket. To avoid this difficulty, and to improve the class of tool-locks shown in the Johnston and Browne and Starr patents, we havedevisedy the locking mechanismwhich'we will now describe.

A longitudinal groove or recess, B', is made in the spindle, and fitted in the front end thereof is a spring-latch, J. The rear end of this latch is provided with a depending lug, j, sliding in its groove, and the latch at its front end is provided with a tapering or arrow-shaped head, j', the lower portion of which forms a hook to engage a shoulder on the tool-shank to lock the tool in the tool-socket, the front end of the groove B opening into or communicating with said socket. The tool-shank is preferably socket and enable it to be readily removed.

provided with two transverse lockiiiggrooves, t' i, and with a reduced end having a drivinglng, i', as usual. Back of the hook end of the locking-latch is a depending lug, ji, the function of which will presently be described.

Surrounding the spindle and overlappin g the locking end of the latch J is an endwisenmovable sleeeve, K, the upper portion of' which is slotted or cut away, as clearly shown in Figs. 1, 2, and 3. The rear end of this sliding sleeve is connected by a link, L, with a ring, M, also fitted upon the spindle so as to move cndwise thereon.

Intcrposed between the frontend of the ring M and a rigid pin or shoulder on the spindle is a coiled spring, N, the tension or stress of which acts to throw and keep the ring M back against the front end of the thrust-collar E. This action of the spring consequently, by means of the link L, normally retains the slotted sleeve K in the position shown in Fig. 1, with its front end over the front end of the locking-lateh,whereby said locking-latch cannot rise under any pulling-strain upon the tool.

Vhen it is desired to release the lockinglatch from the tool-shank, so as to permit the tool to be removed, or a new tool to be inserted in its place, the ring M is forced forward, carrying with it the link L, which has depending lug Z. The first portion of this movement carries the frontend of the sleeve K forward, and brings its slot above the end of the lockinglateh J. As soon as the front end-of the sleeve K has passed from above the head of the locking-latch, the lug lof the link L comes against the end of the locking-latch and forces it for* ward, causing its inclined or beveled end to ride up the inclined surface b5, formed upon the spindle B, and spring down into a crossnotch, b, in advance of the incline b5, above mentioned. The tool-locking latch is then in the position shownin Fig. 2, and the toolshank is released and may be removed.

In order to lock the tool-shank in the socket,y the ring M is moved backward upon the spindle, carrying the sleeve K with it, and as this sleeve comes in contact with the locking end ofthe spring-latch it trips orforces it over the inclined wedging-shoulder b5, and permits it to spring down into engagement with one of the cross-notches t' of the tool-shank, the head of the locking-latch in its descending movements drawing the tool firmly into the toolsocket, with its cone-shoulder firmly centered in the cone-mouth of said socket of the spindle. As the head or locking end of the springlatch springs down into engagement with the tool-shank, to lock itin the socket, the front end of the sleeve K again rides over the upper surface of said head, and prevents it from rising until the said sleeve K is again forced forward. During the unlocking operation the shoulder j2 of the lockingdatch J comes against an annular shoulder, i, on the tool, formed by reducing the end of the tool-shank, and forces the said tool outward, so as to loosen it in its This feature is to overcome the difficulty of withdrawing the tools by reason of their tendency to stick in the socket.

In order to cause the movements of the toolloek which have been described, we preferably employ a gripping pawl or hook, O, acting through a slot in the handle-section of the casing, and pivoted at its forward end to a rocking lever, I), pivoted externally upon the casing at one end, and affording at its other a handle or surface by which to rock the lever backward and forward longitudinally of the casing. The upper surface Aof' the hook or pawl at the point o is rounded or inclined, and the front end of the plate-spring Q, bears upon said surface of the latch, so as to keep the rear end of thelatch pressed downward, with a tendency, during the rocking movements of the lever, to enter the opening in the easing and engage the ring M by means of a projecting point or tooth, o. The extreme rear end of the pawl is provided with an inclined surface, which, when the lever is in the position shown in Fig. l, rides up the incline r, so as to carry the pawl out of the recess inthe casing. When the lever I? is rocked in the forward direction, it carries the pawl with it, and this pawl, being acted upon by the spring before mentioned, is forced down through the slot in the casing, while its tooth o engages the annular shoulder m of the ring M, carrying that ring forward, to manipulate the tool-lock and release the tool, as before described. y

By reason of the engagement of the end of the locking-latch with the cross-notch b, before described, the tool-locking devices are held in their unlocked position without frictional contact between the ring M and the pawl O. This avoidance of friction is a desirable feature, especially when the handpiece is used with motors which it might not be desirable to stop while changing the bits or tools. W'hen the lever is rocked from front to rear, the tooth o comes in contact with the rear annular shoulder, m', ofthe ring M, and carries the ring backward to lock the tool in the socket, as before descrbed, the pawl at the end of the movement of the lever I riding up out of the slot in the casing, as before described, thus leaving the spindle free and unretarded in its rotation.

Any suitable means may be employed to afford a driving-connection between the toolshank and the spindle. In this present i11- stanee we provide the inner end of the toolsocket witha driving-surface formed by means of a tube having its wall at one or more sides slotted for the passage of the driving-lug i of the tool-shank, as is clearly shown in Figs. l and 2.

Without elaborating the advantages of a handpicce constructed according to our invention, and the facilities it affords for accurate adjustment, durability, and efficiency of work, nor of its adaptability for repairs and cleaning of its parts, we state our claim as fol- IOO IIO

lows, first premising that any'and all matter not specically claimed herein is reserved for a future application or applications, and` that this reservation of the right to claim any patentable matter disclosed herein, but not now claimed, is not affected or lessened by the making and cancellation of any claim or claims in the prosecution of this present application.

We claim herein-` 1. The combination, with the handle-section of a hand-piece casing, of an external detachable screw-threaded cap fitted to external threads on the nose of said handle-section, substantially as described.

2. A tubular sectional hand-piece casing,

the sections of which are united by a unionpiece carrying an adjustable screw or device which determines the approach of one section relatively to Vthe other, substantially as described.'

3. A hand-piece casing the handle-section of which is united to `another section by a union-piece the front end of which is fitted `Vto receive said handle-section and enable it to be slipped freely endwise thereon, said casing4 ing w'edging device carried by said last-mentioned section, substantially as described.

casing fitted to slide upon the smooth front end of a union-piece or collet, substantially as described.

6. The combination, with thehand-piece cas-A ing and union-piece thereof, of a spindle fitted to turn in said union-piece, and be locked from endwise movement therein by a thrust-collar on said spindle at the front of the union-piece, a pull-collar on said spindle at the rear of said union-piece, and alocking device to hold said pull-collar against the rear face of said unionpiece, said thrust and pull collars having projecting portions fitting a longitudinal groove in the spindle, so as to be incapable of turning on the spindle, while movable endwise thereon, substantially as described.

7. The combination of the longitudinallygrooved spindle, the vpull-collar fitted to move endwise on said spindle, andV provided with a projection tting the groove thereof, and a locking device to retain said collar in position.

8. The combination, with the longitudinallygrooved spindle having a shoulder thereon,

of thev thrust-collar fitted to said spindle, and

having a projection tting its groove, whereby the collar may be moved endwise to abut an incline or wedgesuriacetherein, of thethrustcollar fitted to said spindle, and provided with 1 a set-screw the wedge end of which fits the groove of said spindle, and when tightened acts upon the incline thereof, whereby the collar is firmly forced against the shoulder on the spindle and locked securely thereto.

10. The spindleprovided at its forward socketed end with a rigid but detachable tubular journal, so as to be replaced when worn, substantially as described.

1l. The socketed spindle reduced at its forward end, and having rigidly soldered. thereto a hardened tubular journal vhaving a tapered or cone'd periphery to fit a correspondingly-Vv shaped bearing, substantially as described.

12. The internally-threaded and conicallysocketed driving shaft connection, substantially as described.

18. The endwise-movable tool-locking latch, in combination with the spindle, and the slotted sleeve movable endwise on said spindle over the locking end of said latch.

14. The combination, substantially as hereinbefore set forth, of the spindle, the endwisemovable tool-locking latch, a ring mounted on said spindle and fitted to slide thereon to operate said latch, and a link-connection between the latch and ring.

15. The combination of the spindle, the locking-latch, the slottedV sleeve movable on the spindle over the lockingV end of said latch, a

' ring fitted on the spindle to control the movements of Ysaid latch, a link-connection between said ring and said sleeve, whereby the two 5. In a hand-piece, a'tubular section of theV move together, a projection on said link which, at the end of its forward movement, forces the latch forward torelease the tool, and a spring to retract said ring and sleeve to bring the parts of the tool-lock to their locking position, substantially as described. f

16. The combination, substantially as hereinbefore set forth, of a spindle, a spring-operated toolllocking latch carried thereby, and a shoulder or equivalent detent to"` retain the latch in' its unlocked position, when movedto release the tool, until positively tripped to `move the tool-lock to its locking position.

17. The combination, substantially as hereinbefore set forth, of a spindle fitted to turn in a hand-piece casing, a spring-operated tool.-

- lock carried by saidspindle, a shoulder or equivalent detent to 4retain the tool-lock in its unlocked position when moved to release the tool, and a device mounted on the casing .and

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operating therethrough to manipulate said tool-lock, whereby the tool-lock may be operated, while the spindle is in motion, to release a tool, andbe held open as long as desired without frictional conta/ct with the external operating device. 18. The combination, substantially as hereinbefore set forth, with the tool-locking meehanism of a dental-engine hand-piece7 of a piv- Oted device carrying an indep enden tly-pivoted pawl or hook to operate said tool-locking mechanism from the outside of the casing.

19. The combination, substantially as hereinbefore set forth, of the hand-piece easing, the spindle tted to turn therein, the ring M, fitted to move 011 the spindle, and the lever carrying` a pivoted pawl or hook to move said ring in operating` a tool-locking mechanism.

20. A tool-lock operating apparatus for hand-pieces, consisting of a lever, a pawl or hook connected therewith, and a spring acting upon said pawl, substantially as described.

21. The combination of the hand-piece casing, the spindle fitted to turn therein, the toollocking,` mechanism, the ring fitted to move WM. A. JOHNSTON. A. W. BROWNE. ELI T. STARR. JOHN V. GILBERT. Witnesses:

E. M. WHITE, W M. J. PnY'roN.

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