US3073031A - Dental instrument - Google Patents

Description

Jan. l5, 1963 H.,s. BRENMAN ETAL 3,073,03'1

DENTAL INSTRUMENT Filed March 29, 1960 w .p M .b M 4 6 w 5 4 1 /IB ///////,`l 3 m 2 5 2 Fig.

IN V EN TOR. HENRY S. BRENMAN SEMOND LEVITT ATTORNEY V3,073,031y Patented Jan. 15, 1963 United States Patent Office 3,073,031 Y DENTAL INSTRUMENT Henry' S. Brenmau, 1913 Walnut St., Philadelphia, Pa., and Semond Levitt, 1835 Lippincott Road, Huntington Valley, Pa. Filed Mar. 29, 1960, Ser. No. 18,386

6 Claims. (Cl. 32-46) This invention comprises a dental instrument, and more particularly a dental instrument for effecting a wide variety of cutting actions.

. This invention has as an object the provision of a novel dental instrument.

v This invention has as another object the provision of an oscillating cutter which may be adapted during the course of the cutting operation to conform with different angles of the surface being worked on, with little or no change in the'position of the handpiece,whereby the extent of pain and discomfort experienced by the patient is minimized.

This invention has as yet another object the provision of a dental instrument in which an oscillating movement of a cutting tool is achieved without any appreciable internal olf balance displacement of the rotating portion of the instrument, such as is commonly referred toV as hum, whereby the operator of such instrument mayY employ the same with the maximum amount ofl digital sensitivity orffeel. v

.Other objects will appear hereinafter.

r` For the purpose of illustrating the invention there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

`Referring to the drawings wherein like reference characters refer to like parts: A

FIGURE 1l is a vertical sectional view through the dental instrument of the present invention, with the cutting tip being disposed in its outermost disposition.

, FIGURE 2 is a view similar tothat of FIGURE l, but with the cutting tip being disposed in its innermost disposition. I

FIGURE 3 is a cross-sectional view taken o-nyline '3l- 3V ofFIGURE l. 1 'f l n FIGURE 4 is a fragmentary perspective view revealing the outer and inner `throws at the end of the drive shaft. FIGURE' Slis. a fragmentary-.view revealing the vaccommodationof. the cutting tip toa surface being worked u on.

pThe dental instrument of the present invention is designated generally as and comprises the drive shaft 12 disposed within the handle :14.

The drive shaft 12 may be operatively engaged with the spindle (not shown) of a conventional dental unit by conventional means. A wide variety of such means for operatively engaging the drive shaft of a dental instrument with a dental unit are known, and accordingly the same need not be illustrated herein.

The drive shaft 12, which has a true circular crosssection, is guided by the bearing surface 16 on the interior of the handle 14, so that the drive shaft 12 may rotate at high speed about its center line designated 18.

The handle 14 of dental instrument 10 is provided with a bored T-shaped head 20 at its outer end. The T- shaped head 20 comprises the bore 22 which is perpendicularly disposed in respect to and `in communication with the bore 24 of the remainder of the handle 14. The outer surface of the T-shaped head 20 on either side of the remainder of the handle 14 is provided with male threads onto which are threadably secured the caps 26 and 2S. The cap 26 is imperforate, but the cap 28 is provided with an opening which serves as a bearing, as will be more fully explained below.

A balance bushing 30 is provided within the bore 22 of T-shaped head 20. The balance bushing 30 is machined to a high degree of polish so that it may be smoothly reciprocated within the bore 22 of T-shaped head 20.

The wall of the balance bushing 30 is slotted for an arcuate length of approximately one hundred and eighty degrees or somewhat less than one hundred and eighty degrees to form the slot 32. The axial height of the slot 32 is suicient to receive the inner throw 34 on the outer end of the drive shaft 12. The axial height of the slot 32 is sulcient to permit the entry of the outer throw 36 of the drive shaft 12 through the wall of the balance bushing 30 and into the slot 38 of the tool holder 40.

The tool holder 40 comprises a cylindrical rod having a highly polished surface which is smoothly received within the balance bushing 30 and smoothly guided by the bearing surface 42 at the end of the balance bushing '30 adjacent the cap 26 and by the bearing surface 44 which forms the wall of the aperture of the cap 28. The bearing surfaces 42 and 44 enable the tool holder 40 to be smoothly reciprocated upon the rotation of the drive shaft 12 as will be explained below.

vThe center line 46 of the inner throw 34 and the center line 48 of the outer throw 36 are oppositely disposed in respect to the center line 18 of the drive shaft 12 and are equidistant therefrom. Thus, the rotation of the drive shaft 12 is balanced notwithstanding the opposite throws 34 and 36.

The tool holder 40 is provided with a threaded socket 50 at its end which is received within the bearing surface 44. The matingly threaded end 52 of the cutting tip 54 is threadably received within the threaded socket 50. The cutting tip 54 may be secured in position by the knurled lock nut 56. Alternatively, a collet or other clamping means may be used to hold the cutting tip in position. p

A wide variety of cutting tips may be utilized in the dental instrument 10 of the present invention. In the illustrated embodiment the cutting tip comprises a corrugated file-like surface 58, but it is to be understood that' a wide variety-of cutting surfaces may be utilized. More-y over, while in the illustrated embodimentthe cutting tip 54'comprises a straight member, it is to be understood that offset or angular cutting tips `may be utilized. l

- The operation of the dental instrument 10 of ent invention is as follows:

'I Upon rotation of the drive shaft 12, thel innerl throw 34 urges the balance bushing 30 in a direction opposite to the direction which the outer throw 36 urges the tool holder 40. As heretofore noted, the center lines 46 and 48 of the inner and outer throws 34 and 36 are oppositely equidistant from the center line 18 of the drive shaft 12. The rotation of the drive shaft 12 is balanced, and moreover the reciprocation of the cutting tip 54 is smooth and balanced because while the balance bushing 30 is being urged in one direction the tool holder 40 and the cutting tip 54 are being urged in the opposite direction. This may be ascertained from a comparison of FIG- URES l and 2 which disclose the cutting tip 54 in its outermost disposition and its innermost disposition respectively. It will be seen that when the cutting tip 54 is in its outermost disposition, the balance bushing 30 is in its disposition in which it is most closely adjacent to the cap 26. On the other hand, when the cutting tip 54 is in its innermost disposition, the balance bushing 30 is in its disposition where it is most closely adjacent to the cap 28. In this manner, balancing of the masses being moved is achieved.

The smooth facile operation of the dental instrument 10 permits close digital control and feel to be achieved the pres- A bythe operator of the instrument, since the same is not interferedV with by the hum which normally arises from unbalanced vibrations when an eccentric changes its rotational movement to oscillating or reciprocating movement.

The presence ofthejslots 32 and 38 in the balance bushing 30faud1tool holder 40 respectively permit the cutting tip tobernoved during operation so as' to conform with different angles of thesurface being worked upon. This is shown'in FIGURE 5 wherein it is seen th-at when the cutting,` tip 54`` is utilized on an arcuatesurface, the cutting tip 54 may change itsV disposition from that shown in its center dispositionto that shown in the phantom line dispositions. This permits` the operator of the dental instrument to follow` a/c'urved or irregular surface without theneces'sity'for shutting off the dental instrument 10 and makingY vrepeatedV adjustments. Moreover, this enables the operato-r toA eiectworking on surfaces whose irregularity is such that preset adjustment would prove difcultor impossible.

While thee/instrument of the present invention has been described as -a dental instrument, it is of course to be understood that itrnay be utilized for a wide variety of other precision Workingmanipulations, such as on jewelry, detail work in models, etc.

`'The present invention may be embodied in'other speciic forms without departing. fromthe spirit or essential attributes thereof and, accordingly, reference should be made to thexappended claims, rather than tothe foregoing specification as indicating fthe scope of the invention.

, l.. dental instrument including al tubular handle, a bored'head disposed at the end of said handle, a drive shaft rotatablyA received within` said handle, aninner throw and an outer throw at the outer en d of s aid drive shaft projecting into said bored head, a balance bushing reciprocally mounted within said bored head, and a tool holderY reciprocally mounted Within` and guided by said balance bushing, with said inner throw being operatively engaged with saidbalance, bushing andlsaid outer throw being operatively erigaged with said tool holder.

v 2. Adental instrument inaccordance with claim l in which the'center lines of Ythe inner and outerv throws are oppositely equidistantly. disposed from the center line of the drivershaft.

's'. A dental instrument including a tubular handle,v a bored head disposed at theend of said handle,.a drive shaft rotatably received within said handle, an eccentric at the outer end of said ,drive shaft projecting intosaid bored head, atool holderreciprocally mounted in said bored head, a wall of said tool holderbeing slotted by an arcuate lslot which extends for an appreciable portion of the periphery of said tool holder, -said eccentric being opera tively engaged with -said tool holder by communicating with walls of said slot in said tool holder, with the lateral dimensions of said slot being appreciably greater than the lateral dimensions of said eccentric, whereby upon rotation of said drive shaft said toolV holder is reciprocat'ed in respect to said boredhead and may simultaneously be partially rotated in respect ,to saidfboredV head.

4. A dental instrument includinga tubular handle, a bored head disposed at the end of` said handle, a drive shaft rotatably received within said handle, oppositely disposed throws at the outer end of said drive shaft projectl ing into said bored head, a balance bushing reciprocally mounted within said bored head, a wall of said balance bushing beingslotted by an arcuate slot which extendsy for an appreciable portion of the periphery of said balance bushing and whose lateral dimensions are appreciably greater than v.the lateral dimensions of either of the oppositely disposed throws, oneof saidoppositely'disposed throws beingoperatively engaged with said balance bushing by communicating with walls of said slot in said bal ance bushing, a'tool holder reciprocally mounted in said bored head to reciprocate in an opposite direction in respect. to the direction of reciprocation of said balance bushing, a wall of said tool holderv being slotted by an arcuate slot which extends for an appreciable portion of the periphery of said tool holder, with the lateral dimensions of lsaid arcuate slot in the wall of said tool holder being appreciablyfgr'leater than the lateral Adimensions' of eitherof said oppositely disposed throws, the other of said `oppositely disposed Vthrows 'being operatively engagedv with` said tool holder by communicating with walls of said slot vinY said tool holder, lwhereby upon rotation of said drive shaft said tool holder .is reciproated in respect to said bored heady and may simultaneously be partially rotated in re spect to said bored head.

.5. A dental'instrument in accordance with claim 4 in which the center lines of the oppositely disposed throws are oppositely equidistant fromthe center line of the drive shaft.

6.l A Vdental instrument in accordance with claim 5 in which the oppositely disposed throws comprise yinner andouterthrows, and in which the inner'throw is operatively engagediwith Walls of'the slot 'ofthe balance bushing and in lwhich fthe outer lthrow'is operatively engaged with walls of the slot of the tool holder.

Fleury et al. Aug. 26, 1890 Eberly Dec. 6, 1938

Claims (1)

1. A DENTAL INSTRUMENT INCLUDING A TUBULAR HANDLE, A BORED HEAD DISPOSED AT THE END OF SAID HANDLE, A DRIVE SHAFT ROTATABLY RECEIVED WITHIN SAID HANDLE, AN INNER THROW AND AN OUTER THROW AT THE OUTER END OF SAID DRIVE SHAFT PROJECTING INTO SAID BORED HEAD, A BALANCE BUSHING RECIPROCALLY MOUNTED WITHIN SAID BORED HEAD, AND A TOOL HOLDER RECIPROCALLY MOUNTED WITHIN AND GUIDED BY SAID BALANCE BUSHING, WITH SAID INNER THROW BEING OPERATIVELY ENGAGED WITH SAID BALANCE BUSHING AND SAID OUTER THROW BEING OPERATIVELY ENGAGED WITH SAID TOOL HOLDER.

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