US2246530A

US2246530A - Dental engine

Info

Publication number: US2246530A
Application number: US318825A
Authority: US
Inventors: William H Nitschke
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-02-14
Filing date: 1940-02-14
Publication date: 1941-06-24
Anticipated expiration: 1958-06-24

Description

June 24, 1941 w. H. NITSCHKE DENTAL ENGINE Filed Feb. 14, 1940 ATTORNEYS Patented June 24, 1941 UNITED STATES PATENT orrlce 2,246,530 DENTAL ENGINE Wiiliam H. Nitschke, New York, N. Y. Ap eas ment, 14,1940,SerialNo. 318,825

2- Claims.

, This invention relates to a novel and improved form. of dental engine, the novel features ,of which will be best understood from the following description and the annexed drawing, in which I have shown a selected embodiment of the in.- vention and in which:

Fig. 1 is an elevation of so much of the dental engine as is necessary to an understanding of the invention; Fig. 2 is a view on the same plane asFig. 1,,but showing only parts of the engine and on an enlarged scale;

I Fig, 3 is, a fragmentary view showing a different arrangement of a spring than oneof the springs shown in Figs. 1 and 2.

The invention will be described and defined, for convenience, as embodied in what is usually called a dental engine, but by that expression I intend to include all similar apparatus, for example that sometimes referred to as a surgical engine.

The engine comprises the usual motor I having a shaft 2 over which runs a belt 3 which engages various pulleys and finally runs over a pulley 5 on a hand piece 6 which carries the tool I. The motor I is carried on a standard 8 of any usual or suitable construction and upon which is carried a support 9 which may be pivoted as at II], to an arm I0 secured to the casing of the motor I and extending upwardly therefrom. However, the

support 9 is sometimes secured in fixed position and may be considered as relatively fixed, although it may be adjusted on its pivot III, or may be balanced thereon with a counterweight.

At the forward end of the support 9, there is provided a pivot I I on which is pivoted an arm I2 which, for the sake of convenience, I shall refer to as the upper arm. This arm depends from the pivot I I about which it may swing freely, and at its lower end is provided with a pivot I3 on which freely swings the fore arm I4 of the engine. The hand piece 6 may be secured to the front end of the fore arm I4 by a suitable wrist piece I5, the details of which are not necessary to an understanding of the invention and consequently will not be described.

The structure described above is more or less conventional and, as known, the engine is operated by the dentist holding the hand piece in one hand, somewhat in the way that a pencil is held, usually the hand piece resting upon the crotch between the thumb and the fore finger, and the front part of the hand piece being engaged by the tips of the thumb and fore finger, in the same manner that a pencil is engaged when writing. Usually, the weight supported by the hand of the dentist is on the order of seven ounces, although this weight may vary somewhat with differentengines. However, there is always a constant weight to be supported by the hand of the dentist, and this weight is enough to tire the hand of the dentist and thus possibly interfere with the accuracy of the work which he is doing With the tool in his. hands.

The weight is felt on the rear end of the hand piece 6 and thus tends to pivot the hand piece about the point where it is supported on the hand of the dentist. If the hand piece is not carefully held at all times, the weight of the engine thus may cause a movement of the hand piece and consequently of the tool, which may cause inaccurate work.

I have found that I can overcome the above difficulties and can practically balance the engine in such a way that there is practically no weight applied at the rear of the hand piece, and the pull drag is greatly diminished. For example, in one test made by me, I found that I had reduced the weight at that point from seven ounces to one ounce and, by careful adjustment,

it can be entirely eliminated. This result I have achieved by the following construction:

Connected to the support 9 and the upper arm I2 is a spring, here shown as a tension spring I6,

which may be secured at one end to a clamp I'I on the support 9 and at the other end to a rod I8 which may be secured by a clamp I9 to the upper arm I2, this rod forming an extension of the arm I2 extending past the pivot II as shown. The tension of the spring may be adjusted by securing one end of it to an eye-bolt 2'0 threaded into engagement with the clamp II.

Preferably I also use another spring 2| which may be secured at one end to a clamp 22 on the upper arm I2 and at the other end to a clamp 23 on the fore arm I4. The tension of the spring may be adjusted by a turn buckle 24.

By the above arrangement, the weight of the fore arm, wrist piece, and hand piece may be taken up by the spring 2| and transferred in large measure to the upper part of the upper arm I2, particularly when the upper arm I2 is approximately vertical. However, when the engine is in use, this arm is often pulled out of the vertical so that the lower end is not directly under the pivot II and the more this arm departs from the vertical, the greater is the proportion of its weight which has to be supported by the hand of the dentist, and more specifically the greater is the weight which tends to tip the hand piece in the dentist's hand. However, by using the spring I6 and arranging it in such a Way that a great part of the weight of the upper arm I2 is transferred to the support 9, it will be seen that even when the upper arm is not vertical, its weight or at least the component thereof, which otherwise would be felt on the dentists hand, is instead transferred to the support. Thus no matter what may be the position of the upper arm or for that matter of the fore arm, the balanced condition is maintained so that there is no appreciable weight felt at the rear end of the hand piece 6. Therefore, no matter What may be the position of the engine, or rather of the arms I2 and I4, the hand piece is balanced so that the dentist does not have to overcome any weight or tendency to tip the hand piece in his hand.

In Fig. 3, I have shown the pivoted connection between the arms I2 and M and have shown a spring 25 coiled about the pivot I3 connecting those arms and transferring some of the weight of the arm I4 to the arm I2. In this form, as in the form shown in Figs. 1 and 2, it will be seen that the spring It will create a tendency for the arm I2 to rotate in a counterclockwise direction about the pivot I I, whereas the spring 2| or 25, as the case may he, would tend to cause a similar rotation of the arm It about the pivot I3.

This invention may be made an integral part of the dental engine and is applicable to all engines of this type, such as the surgical engine.

While I have shown the invention as embodied in a. specific form, it is to be understood that various changes in details may be made without departing from the scope of the invention as de fined by the appended claims.

I claim:

1. In a motor driven tool of the class described, a support and an upper arm hanging from said support, a fore-arm hanging from said upper arm on a horizontal pivot upon which it is movable to any angular position with respect to the upper arm Without bodily displacement of said pivot, a hand piece secured at its rear end on the free end of said fore-arm, and a spring acting between said upper arm and fore-arm and tending to rotate the fore-arm on its pivot to raise said fore-arm and thus balance the hand piece in the hand of the operator by relieving the downward pull of the fore-arm on the rear end of the hand piece.

2. In a motor driven tool of the class described, a support and an upper arm hanging from said support on a horizontal pivot upon which it is movable to any angular position with respect to the support without bodily displacement of the pivot, a fore-arm hanging from said upper arm on a horizontal pivot upon which it is movable to any angular position with respect to the upper arm without bodily displacement of said lastnamed pivot, a hand piece secured at its rear end on the free end of said fore-arm, a spring acting between said upper arm and fore-arm and tending to rotate the fore-arm on its pivot to raise said fore-arm and thus balance the hand piece in the hand of the operator by relieving the downward pull of the fore-arm on the rear end of the hand piece, and a second spring acting between said support and said upper arm and tending to rotate the upper arm on said pivot on the support, to move the lower end of said upper arm forwardly.

WILLIAM H. NITSCHKE.