US 3516161 A
Description (OCR text may contain errors)
I. A. ELLMAN 3,516,161
AMALGAM PACKER ATTACHMENT FOR DENTAL HANDPIECE June 23, 1970 Filed Aug. 28, 1967 25 nexus-ii m} Flg 3 F19 4 INVENTOR. I. A. ELLMAN ATTORNEY United States Patent 3,516,161 AMALGAM PACKER ATTACHMENT FOR DENTAL HANDPIECE lfrving A. Ellman, Auerbach Lane, Lawrence, N.Y. 11559 Filed Aug. 28, 1967, Ser. No. 663,611 Int. Cl. A61c 3/08 US. CI. 32-53 Claims ABSTRACT OF THE DISCLOSURE An amalgam packer attachment for use in a normal contra angle dental handpiece. The packer is constructed as a single tool piece with an offset tapered end adapted to be reciprocated by the inner rotating sleeve of the handpiece. An arm is coupled to the tool and is shaped to engage the handpiece to prevent rotation of the tool and also to prevent the tool from falling out of the handpiece.
This invention relates to an amalgam packer attachment for a dental handpiece.
It is known that amalgam restorations are improved by mechanically compacting or condensingthe amalgam. Many reconstructions of the handpiece have been proposed for converting the rotary motion thereof to a re ciprocating action useful for vibrating or tamping the amalgam to provide homogeneous dense fillings of tooth cavities. The prior art constructions have been unsatisfactory for one or more of the following reasons. Alteration of the handpiece was necessary, which is time wasting and cumbersome. A mechanically complicated tool was involved, which is expensive to manufacture and subject to breakdown. Mounting of the tool was cumbersome.
One object of the invention is a simplified packing tool which when attached to a standard handpiece is capable of carrying out a tamping function. 7
Another object of the invention is a novel packing tool attachment for a contra angle for converting its rotary motion into a reciprocating motion.
Still another object of the invention is a novel, inex pensive packing tool interchangeable with the ordinary bur and sterilizable like the ordinary bur yet capable when inserted into a standard contra angle of performing a reciprocating motion without a rotary motion effective for mechanically packing or tamping amalgam tooth fillings.
These and other objects of the invention as will appear hereinafter are attained by my novel tool construction which involves a modification of the conventional bur shank end to form an offset tapered end adapted to cooperate directly with the standard inner rotating sleeve of the handpiece now acting as a cam to cause the tool to be axially reciprocated. Associated with the tool is means for stopping its rotation to enable the offset end to act as a follower and also means to prevent the tool from falling out of the sleeve. Thus, with no change what ever in the handpiece itself, the tool can be caused to reciprocate to perform a packing or tamping function especially useful for condensing an amalgam filling while in a tooth cavity.
One exemplary embodiment of my invention will now be described in greater detail with reference to the accompanying drawing, wherein: FIG. 1 is an elevational view of a conventional contra angle handpiece with my new packing tool inserted therein; FIG. 2 is a cross-sectional view of the handpiece showing more clearly its relationship to the packing tool; FIGS. 3 and 4 are detail views in two different rotary positions of the handpiece rotating sleeve and the tool shank; FIG. 5 is an eleva- 3,516,161 Patented June 23, 1970 tional view of my novel packing tool alone; FIG. 6 is an elevational view of a standard bur.
My new packing tool is illustrated in FIG. 5. It comprises a cylindrical shank 1 of the same diameter as a conventional bur so that it can be inserted in a conventional contra angle handpiece. The bottom part 2 of the tool referred to as the working end can be shaped in various known ways to enable it to perform the packing, tamping or plugging function. Thus, it may be shaped as shown in FIG. 1 as a simple cylinder with a flat bottom. Alternatively, the sides of the cylinder may be recessed as shown in FIG. 5 to improve visual observation of the filling while it is being compacted. If desired, an overpad of rubber could be fitted over the working end.
The upper end of the shank 1 is shaped 3 to be driven by the handpiece. In particular, the driving end of the shank is provided with an end 4 of reduced cross-section compared with that of the shank and which is offset from the longitudinal axis 5 of the shank 1 about which axis the tool would rotate if it were permitted to do so. In the specific form illustrated, the offset region 4 of reduced cross-section is formed by simply grinding a flat 6 inclined at an angle to the axis 5 in the end of the shank. The angle is not critical. I have obtained satisfactory results with an angle of about 45.
At a middle portion of the shank 1 is secured an arm 7 in the form of a bent stiff wire. The wire is secured at one end 8 to the shank as for example by soldering or brazing and then extends 9 transversely to the shank axis 5 to clear the handpiece, and then extends upwardly 10 for another distance to clear the top of the handpiece, and then has its end 11 bent toward the shank fora short distance to form a loose holding portion on, the handpiece.
The function of the arm 7 will be better understood from FIG; 1 where the tool is seen inserted in a conventional contra angle handpiece 12. As will be observed, the point of attachment 8 of the arm 7 is located below the handpiece, and the remaining portions of the arm 7 are shaped so that the vertical wire portion 10 abuts the side of the handpiece 12, and the bent end 11 extends with a small clearance over the top of the handpieceand thus in that position prevents the tool from falling out of the handpiece. That position can be attained either by rotating the tool, or by bending the wire while inserting the tool into the desired position. The standard latch 13 present in the handpiece 12 is not used to hold the tool in place. That function is performed by the wire 7 with its bent end 11.
The operation of the tool will be clearer from FIG. 2. The standard contra angle handpiece 12 has a drive shaft 14 terminating in a pinion 15 which engages a gear 16 on an inner rotatable sleeve 17. The upper end of the sleeve 17 is closed off by a stop partition 18 having a semi-circular opening 19 offset from the central axis of rotation of the sleeve 17 for receiving the shank end of the standard bur 20 as illustrated in FIG. 6. The shank 20 end has a shoulder 21 which engages the partition 18, and an offset, semi-circular projection 22 which fits through the opening 19 and at the top of which is provided an annular groove 23 for engagement by the latch 13 to prevent the bur from falling out of the sleeve 17. When the sleeve 17 is rotated, the bur rotates also, being fixed to the sleeve by the semicircular projection which engages the semi-circular opening 19 in the sleeve.
The inventive tool has an offset pointed end 4 with a tapered side 6 only a small part of which passes through the offset opening 19 and only when the latter is aligned with the end 4 and the working end of the tool is pressed against the work, which is illustrated in FIG. 3. If the tool is kept stationary, and the sleeve 17 is now rotated one-half a revolution, as will be observed in FIG. 4, since the offset opening 19 and projection 4 are no longer aligned, and in fact the partition 18 abuts the pointedend 4, the tool is pushed downwardly a short distance 25. Similarly, when the sleeve 17 is rotated back to the position illustrated in FIG. 3, the tool when pressed by the dentist against the work will be moved upwardly a short distance. In effect, the partition 18 edge bordering the opening 19 during rotation of the sleeve 17 acts as a cam surface coacting with the offset pointed end 4 of the tool as a follower surface and the pressure applied by the dentist causing the tool to be reciprocated axially as the sleeve 17 is rotated in the usual way within the handpiece 12. The tool is prevented from rotating within the sleeve 17, which would prevent the desired camming action, by the arm 7 which abuts the side of the handpiece and which also prevents the tool from falling out of the sleeve 17.
It will be observed that the standard handpiece 12 remains completely undisturbed. No alterations or modifications are required of it to convert the usual rotary bur motion into a reciprocating hammer action. The desired conversion is obtained by a simple reconstruction of the driving end of the tool to enable it to act as a follower cammed by the stop partition of the inner rotating sleeve, together with the addition of means for stopping the tool from rotating to obtain the desired cam action. An additional feature is the means associated with the rotation stopping means to keep the tool in position within the rotary sleeve, which latter means are combined with the stopping means in the single wire 7. In the preferred form shown in FIG. 5, a one-piece tool construction results which is inexpensive to manufacture yet performs quite satisfactorily the packing or tamping action desired.
While I have described my invention in connection with specific embodiments and applications, other modifications thereof will be readily apparent to those skilled in this art without departing from the spirit and scope of the invention.
What is claimed is:
1. A reciprocable packer for use in dentistry comprising a dental handpiece having a rotatable member with its upper end closed off by a stop partition having an opening offset from the central axis of rotation thereof, a packing tool comprising a shank portion having a longitudinal axis and having a working end and a driving end, said working end being shaped to compact material when reciprocated in contact therewith, said driving end having a tapered portion of reduced size offset from the longitudinal axis for mounting in the handpiece in camming relationship with the stop partition of the rotatable member of the handpiece when the offset end of the tool is in the opening, and means for stopping said shank from rotating when contacted by the rotatable member of the handpiece, .said stopping means including an arm member connected in antirotation relationship with a shank portion intermediate the working and driving ends and extending therefrom to a position to abut the handpiece to prevent rotation of the tool.
2. A reciprocable packer as set forth in claim 1 and including means for preventing said tool from falling out of the handpiece.
3. A reciprocable packer as set forth in claim 2 wherein the rotation-stopping means comprises a wire having one end affixed to the shank and having a portion extending transversely to the shank and then generally parallel thereto toward the driving end spaced in such manner from the shank that the wire comes into contact with the side of the handpiece, the free end of said Wire being bent toward the shank forming a portion fitting over the top of the handpiece to prevent the tool from falling out.
4. A reciprocable packer as set forth in claim 3 wherein the driving end includes a single flat surface inclined at an oblique angle to the longitudinal axis of the shank.
5. A reciprocable packer as set forth in claim 4 wherein the handpiece comprises a contra angle handpiece having an inner rotatable drive sleeve receiving the driving end of the shank, said sleeve having on its interior a partition defining an offset semi-circular opening large enough to receive a part only of the inclined surface of the tool end but small enough to prevent entry of the whole tool shank, and means for rotating the drive sleeve whereby the non-rotating shank is reciprocated as the driving end falls into and is then cammed out of the offset opening in the rotating drive sleeve.
References Cited UNITED STATES PATENTS 2,327,203 8/1943 McKenzie 32-54 ROBERT PESHOCK, Primary Examiner US. Cl. X.R.