Handpiece holder including automatically releasable power lockout means

[57] ABSTRACT

A holder for a powered handpiece such as a dental drill or the like is disclosed which holder includes means for interrupting the power to the handpiece that not only interrupts the power when the handpiece is received in the holder but also includes a lockout feature for selectively maintaining the interruption of power while the handpiece is removed from the holder. According to this invention the lockout feature is automatically released by replacement of the handpiece in the holder or by tapping the holder.

Claims, 6 Drawing Figures

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PATENTElW 91975

3,904,841

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3,904,841 fabricate and in which the number of moving parts is reduced toward a minimum.

HANDPIECE HOLDER INCLUDING AUTOMATICALLY RELEASABLE POWER LOCKOUT MEANS

BACKGROUND OF THE INVENTION

SUMMARY OF THE INVENTION

Briefly, a holder for a powered handpiece according to this invention comprises an elongated rigid body having a first surface extending transversely of the axis of elongation at one end thereof and a second surface extending along the axis of elongation. The body is supported by support means for rotation in a generally vertical plane about an axis located at one end of the first surface and extending transversely of the axis of elongation of the body. Switch means are rigidly mounted with respect to the support means and engage the first surface toward the other end thereof from the axis of rotation, which switch means is adapted to resist rotation of the body downwardly in the vertical plane from a position in which the axis of elongation is generally horizontal and to urge rotation of the body in an upward arc from the horizontal with the switch means interrupting the power to the handpiece only when the axis of elongation of the body is in the generally horizontal position. A quiver means is mounted on the other end of the body from the axis of rotation for re²⁵ movably supporting the handpiece and lock means are provided for selectively locking the body with its axis of elongation in the generally horizontal position. The lock means comprises a first elongated member rigidly mounted with respect to the support means and extending in a generally horizontal direction transversely of the axis of elongation of the body and adjacent the second surface of the body when the axis of elongation of the body is in the generally horizontal position, and a second elongated member mounted on the body and selectively extendible from the second surface in a generally vertical direction, when the axis of elongation of the body is in the generally horizontal position, into frictionally binding engagement with the first elongated member to prevent rotation of the body upwardly through the arc in the vertical plane as urged by the switch means.

This invention relates to a holder for a powered handpiece such as a dental drill or the like including means for interrupting the power to the handpiece and more particularly to such a device including a lockout feature for selectively maintaining the interruption of power while the handpiece is removed from the holder which lockout feature is automatically released by the application of mechanical forces to the holder as by replacement of the handpiece in the holder.

Tools or handpieces of various kinds powered by the flow of fluids such as air or water or electrical energy are well known. For example, in the practice of dentistry air powered turbine type drills have recently become quite common in addition to the hand held syringes which have been used for some time for the selective application of air, water or spray to the oral cavity.

In fact it has become common to operate a number of air powered dental drills adapted to perform different operations from a common source of high pressure air through a common master control valve. Thus, it is necessary to interrupt the connection between the master control valve and all of such drills, except for the one selected for use. Heretofore, this has been accom- 30 · plished by providing a dental unit, including a plurality of holders, one for each handpiece, which holders have included a means for interrupting the connection to the master control valve of the handpiece associated therewith when such handpiece is received in the holder (see 35 for example U.S. Pat. Nos. 3,049,805 and 3,514,171)

Other examples of handpiece holders used in the prior art are disclosed in U.S. Pat. Nos. 3,638,310 and 3,672,059. According to the teaching of these patents each handpiece holder includes a mechanism compris- 40 ing a complicated arrangement of springs and valves in order to disconnect the37valve. In addition, according to the teaching of these patents, a locking means is included in each holder to selectively maintain the mechanism in the position thereof which disconnects the handpiece from the master control valve even though the handpiece is removed from the holder.

This additional “lockout” feature is useful where it is desired to remove one handpiece from its holder for maintenance, for example, while another handpiece is in actual use. Thus, the locking button is manually moved to its locking position by the dentist or dental assistant prior to removing the handpiece from the holder for maintenance. When the handpiece is returned to its holder or it is desired to place the handpiece in use the dentist or dental assistant must remember to manually move the locking button to its unlocked position

It is an object of this invention to provide a handpiece holder including the lockout feature described hereinabove but in which the lockout feature will be automatically released upon replacement of the handpiece in the holder or the application of impact to any part of the holder.

It is another object of this invention to provide a hand-piece holder including the lockout feature described hereinabove which is simple and inexpensive to

BRIEF DESCRIPTION OF THE DRAWING

The foregoing and other objects and features of this invention will be more fully understood from a reading of the following detailed description in conjunction with the appended drawing wherein:

FIG. 1 is a perspective view of a powered handpiece holder in accordance with a preferred embodiment of this invention including a fragmentary representation of a dental unit and with the handpiece indicated in supported position by dotted lines.

FIG. 2 is a top view in elevation of the holder of FIG. 1.

FIG. 3 is a bottom view in elevation of the holder of FIG. 1.

FIG. 4 is a fragmentary cross-sectional view taken along lines 4—4 in FIG. 2 with the parts of the holder shown in the positions they assume when the handpiece is supported by the holder.

FIG. 5 is a view identical to FIG. 4 but with the parts of the holder shown in the positions they would normally assume when the handpiece is removed from the holder.

FIG. 6 is a view identical to FIGS. 4 and 5 but with the parts of the holder shown in their locked position when the hand-piece is removed from the holder.

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DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 a handpiece holder 10 according to a preferred embodiment of this invention is shown mounted on apparatus 11 such as the tray of a dental treatment unit. The grip portion of a powered handpiece 12, which may be an air turbine dental drill connected through an appropriate valve (not shown) to the master control valve (not shown) of a source of high pressure air (not shown) by means of a first hose 13 and through similar valves (not shown) to a source of water under pressure (not shown) through a second hose 14, for example, is shown in dotted lines as supported in the holder 10.

The holder 10 comprises a “quiver” member 15 in the form of a short longitudinally slotted tube mounted on the end of an elongated main body member 16. The body member 16 is mounted on a bracket type support member 17 for rotation about an axis provided by pin 18 and the bracket member 17 is mounted on the apparatus 11.

Referring to FIGS. 2 and 3, in addition to FIG. 1, it will be seen that the quiver member 15 preferably has a tapered inner bore and that the holder is mounted so that the axis of the quiver is generally vertical with its restricted end at the bottom and the longitudinal slot toward the front. Thus, the hoses 13 and 14 may be conveniently threaded into and out of the quiver 15 through the slot in order to insert the normally conical outer surface of the grip portion 12 of a dental handpiece into mating supported relation with the inner bore of the quiver 15 or remove it from supported relation for use.

It will be understood that when the handpiece grip 12 is supported by the quiver 15 its weight will tend to rotate the elongated body member 16 downwardly through an arc in a vertical plane within the bracket 17 about the axis established by the pin 18 which passes through the sides of the bracket 17 and the body 16 therebetween. According to this invention the body 16 is provided with a first surface 21 extending in a generally vertical plane at the opposite end thereof from the quiver 15 and a second surface 22 extending in a generally horizontal direction along the axis of elongation of the body 16 on the underside thereof.

The pin 18 passes through the body 16 adjacent the upper end of the first surface 21 and, as best shown in FIGS. 3 through 6 the downward rotation of the body 16 about the pin 18 is resisted by the plunger 25 of a switch means 26 which engages the first surface 21 toward the lower end thereof. It will be understood that the plunger 25 of the switch means 26 is biased to resiliently project therefrom as by spring means or air pressure, for example. It will also be understood that the switch means 26 is of the type which is actuated when the plunger 25 projects therefrom and is deactuated by forcing the plunger 25 into the switch 26.

For example, in the specific embodiment shown in the drawing the switch 26 may be an air valve interposed between a pressurized air inlet hose 27 and an air outlet hose 28 (see FIGS. 4-6). Thus, when the handpiece grip 12 is supported in the quiver 15, its weight will rotate the body 16 downwardly about the pin 18 causing the first surface 21 to force the plunger 25 into the switch 26 to close the valve against the pressure of the air supplied by the hose 27. When the handpiece is removed from the holder 10, the air pressure supplied by the hose 27 will force the plunger 25 out of the switch 26 and the engagement of the plunger 25 with the first surface 21 will rotate the body 16 upwardly about the pin 18.

The outlet hose 28 may be connected to operate appropriate valves interposed between the handpiece and the master control valves for the air and water sources respectively to isolate the handpiece therefrom when the hose 28 is not pressurized. It will be understood that the switch 26 could also be an electrical switch with wires substituted for the hoses 27 and 28 and in which the plunger 25 is spring biased to project from the switch 26. Or the switch 26 could be a water valve similar to the air valve described above. It will also be understood that the connections to and from the valve or switch 26 could be arranged in a wide variety of ways to operate appropriate means for isolating the handpiece from sources of power when supported by the holder.

According to this invention a locking means is provided to lock the body 16 in its downward position. Such locking means comprises a first member, which may take the form of a further pin 31, mounted on the bracket support means 17 and extending adjacent the second surface 22 of the body 16 transversely of the axis of elongation thereof and a second member, which may take the form of a rod 32 which is mounted on the body 16 and adapted to be selectively extended from the second surface of the body 16 by means of a button 33 to engage the first member or pin 31 when the body 16 is in its downward position. It will be understood that when the rod 32 is extended from the lower surface 22 of the body 16, the tendency of the body 16 to rotate in an upward direction as urged by the plunger 25 of the switch 26 will produce a frictionally binding engagement between the rod 32 and pin 31, thus restraining the plunger 25 and maintaining the switch 26 in its deactuated condition.

However, as shown in FIGS. 4-6, the rod 32 is spring biased to its retracted position as by means of a compression spring 34 which may be of the helical type. Thus, any lessening of the frictionally binding engagement of the rod 32 with the pin 31 will tend to allow the spring 34 to retract the rod 32 from its extended position with respect to the surface 22 thereby releasing the body 16 for upward rotation as urged by the plunger 25 of switch 26.

According to this embodiment of the invention, the upward rotation of the body 16 is limited by a further rod 35 rigidly mounted to project from the second surface 22 of the body 16 in spaced relation to the pin 31 when the body 16 is in its downward position. Thus, upward rotation of the body 16 will bring the rod 35 into engagement with the pin 31 thereby limiting such upward rotation.

Also according to this embodiment of the invention, the downward rotation of the body 16 is limited by the pin 31 rather than entirely by the plunger 25 of the switch 26. Thus, according to this embodiment of the invention, the second surface 22 of the body 16 includes a notch 36 adapted to receive the pin 31 in contact with its sides when the body is in its downward position. This arrangement provides greater stability in the frictionally binding engagement between the pin 31 and the rod 32 when the rod 32 is extended within the notch 36.

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It will be understood that even a momentary downward impact on the body 16 including the quiver 15 will be sufficient to release the frictionally binding engagement between the pin 31 and rod 32 allowing the spring 34 to retract the rod . 32 and thus freeing the body for upward rotation. Thus, the body 16 may be locked in its downward position by simultaneously removing the handpiece from the quiver 15 and pressing down on the button 33. The handpiece will thus be disconnected from the power source and may be serviced without interfering with the use of another handpiece of the apparatus. When the handpiece is replaced in the quiver 15 the locking means will be automatically released and the handpiece will be available for use as required. Alternatively, a tap or momentary downward impact on the quiver 15 or body 16, including button 33, will release the locking means and place the handpiece in operation without returning it to the holder 10.

According to the embodiment of this invention shown in the drawing, this automatic release feature of 20 this invention is enhanced by providing a short taper on the free end of the rod 32. Thus, when the rod 32 is fully extended, the cylindrical side thereof engages the pin 31, but as soon as the rod 32 begins to retract the taper on the free end thereof will engage the pin 31 25 tending to assist in the retraction of the rod 32 by the spring 34.

According to this embodiment of the invention the quiver 15 and body 16 may both be made of a suitable plastic material. As shown in the drawing the end of the ³⁰body 16 to which the quiver 15 is attached, as by means of a screw 38, may be concave and slightly inclined to thereby rigidly support the quiver 15 with its axis at an angle to the vertical for ease of inserting or removing the handpiece. ³⁵

The body may otherwise be a simple block although the notch 36 in the second surface 22 thereof is preferred for the reasons given above. Similarly, the first surface 21 of the body 16 may be other than a simple flat surface as desired. ⁴θ

For example, according to the embodiment shown in the drawing, the mounting bracket 17 is a U-shape metal member and is mounted on the apparatus 11 by means of an aperture through the closed end thereof to accommodate the switch 26. As shown in the drawing, ⁴⁵the switch 26 is provided with a threaded flange which passes through an aperture in the apparatus 11 as well as the aperture in the bracket 17 thus allowing the bracket 17 to be fixed to the apparatus by means of a nut 39 applied to the threaded flange of the switch as ³is well known in the art. A mounting post 40 may also be included in the bottom wall of the bracket 17 projecting therefrom to engage a cooperating aperture in the apparatus 11 to provide additional mounting rigid- ₅₅ity.

The mechanical simplicity of the holder 10 according to the teaching of this invention and its ease of fabrication is clearly shown in the drawing. For example, the rod 32, button 33 and spring 34 are mounted in a countersumk passageway through the body 16, with an intersecting passageway (indicated in dotted lines in FIGS. 4—6) providing access for interconnecting the button 33 and pin 32 as by means of a connecting pin with the spring 34 captured between the button 33 and the bottom of the countersunk portion of the passageway. The intersecting passageway may also cooperate with the connecting pin to limit the movement of the rod 32 and button 33 as will be seen from a comparison of FIGS. 5 and 6.

Thus, the holder of this invention is simple and inexpensive to fabricate and yet provides features of advan5 tage not found in the prior art. The moving parts of the holder according to this invention are reduced to a minimum while maintaining efficient operation and the holder may be readily mounted and maintained on existing apparatus.

It is believed that those skilled in the art will make obvioiis modifications, some of which are suggested hereinabove, in the holder as shown and described to adapt it for specific uses. In particular, the holder of this invention may be readily adapted for handpieces powered by various sources of energy and for handpieces of various sizes and shapes.