US3452438A - Dental handpiece - Google Patents

Description

July 1, 1969 L 3,452,438

DENTAL HANDPIECE Filed Sept. 6. 1966 Sheet /7 I I l/ m Mum me MAM/c5 A 04 y July 1, 1969 LORY 3,452,438

DENTAL HANDPIECE Filed Sept. 6, 1966 Sheet 3 of 2 hwavro:

MAl/P/CE Lazy United States Patent 3,452,438 DENTAL HANDPIECE Maurice Lory, Paris, France, assignor to Etablissements E. Quetin, Paris, France, a corporation of France Filed Sept. 6, 1966, Ser. No. 577,266 Claims priority, applicaotiog France, Sept. 7, 1965, 3 7 0 Int. Cl. Am 1/00 US. C]. 32-28 1 Claim ABSTRACT OF THE DISCLOSURE The present invention refers to portable dentist drills of the kind comprising a motor incorporated within a portable casing for cooperating at the choice of the practitioner with any one of a plurality of toolholders.

Portable drills are usually fitted with a spray equip ment adapted to produce on the operating field a jet or spray of atomized cooling fluid, normally constituted by a mixture of water and air, but which also may include other fluids as disinfectants, anesthetics or others.

One of the problems encountered in such apparatuses is to heat the spray to an appropriate temperature, generally 37 C. To this effect one already proposed a heating system comprising a self-heating tube inserted on the flowpath of each of the fluids to be atomized, said tube consisting of an electrically resistant tubular section.

Such a heating equipment is usually disposed upstream of the drilling apparatus, with the resulting disadvantage of placing it in a remote position from the operating field and increasing thereby the thermic inertia of the system. According to another more recent proposal the heating is arranged within the toolholder, but this arrangement involves an alteration of all the toolholders, requiring the electric current to be supplied within the toolholder itself, which may cause difiiculties in certain types of toolholders.

The present invention has for object to avoid all these difliculties and essentially consists in arranging the conditioning means of the spray within the portable casing of the driving motor.

According to the invention there is provided an arrangement whereby the spray conditioning means are arranged within the motor casing and include a mixing chamber having one outlet and at least two inlets, each of said inlets being connected to a source of fluid by a self-heating tube incorporated into said casing.

This arrangement provides several advantages such as:

Low thermic inertia;

Regularity of the mixture realized in the mixing chamber;

Utilizing of heat eventually generated in the driving motor particularly when this one is an electric motor;

Possibility of working with any existing toolholders.

According to a preferred embodiment of the invention the self-heating tubes are grouped under an insulating 3,452,438 Patented July 1, 1969 sheathing in a cable wound around a support member of the driving motor. This arrangement offers the additional advantage of a particularly compact construction, the whole heating system being integrated within the motor unit without increasing the overall dimension thereof.

One form of embodiment of the invention will be described hereafter with reference to the attached drawings wherein:

FIG. 1 shows a portable drilling apparatus according to the invention, partly in section;

FIG. 2 is a diagram of an electric control equipment.

Referring to FIG. 1, there is shown, in its portable casing, an electric motor 1, and interchangeable toolholder 2 and the tool 3, as well as spraying nozzle 4, connected by a flexible piping 4A to the outlet of a mixing chamber 5, this latter itself having two inlets respectively connected to heating tubes 6 and 7, which are arranged in this particular case to warm up flows of air and water, arriving as in 6a and 7a together with the electric current wiring (not shown in FIG. 1).

These electrically resistant tubes are covered with a heat resistant insulating sheath 8, and the assembly is wound around support member 9 which is also used for supporting motor 1.

This particular arrangement made possible by the very small volume taken by the tubes and their sheath allows for leading the fluids to mixing chamber 5, bringing them to the suitable temperature in a very short time owing to the very low thermic inertia of the system.

The self-heating tubes 6 and 7 are constituted for example each by a section of a length of about twenty centimeters of a tubular resistance with an inner diameter of millimeter and an external diameter of A millimeter.

FIG. 2 shows an associated electric control equipment. Motor 1 is fed by its own source of energy through a relay 10, in case of an electric motor, or through an electrovalve in case of a hydraulic or pneumatic motor.

This relay 10 (or this electrovalve) is controlled by the operator by means of switch 11.

The heating tubes 6 and 7 form two resistances connected in parallel across secondary winding of a reducing transformer 17 with multiple tappings at the primary.

By means of switches 12 and 13 and of the relay 14 the operator can at will cut olf simultaneously the spray system (switch 12) and the heating system (switch 13) the electrovalves 15 and 16, respectively controlling the admission of the fluids in heating tubes 6 and 7.

The regulation of the temperature is effected either by the selection of the transforming ratio of the transformer, or by any other equivalent means.

The voltage provided by the secondary of the transformer being only of a few volts and the circuit of the tubes 6 and 7 of course being connected to earth, all risk of incident or accident by electric shock for the patient or the operator is eliminated.

What I claim is: 1. Dentist drill apparatus comprising: a portable casing, a driving motor incorporated within said casing, a toolholder interchangeably adaptable to said casing, a spray nozzle on said toolholder, a mixing chamber for mixing air and water within said casing having an outlet and at least two inlets, one for air and the other for water,

3 4 an external conduit connecting said nozzle to said outfluid and of a reducing transformer feeding the heatlet for supplying mixed air and water to said outlet, ing resistances constituted by said self-heating confor each of said inlets, a self-heating conduit consisting duits.

of an electrically resistant tube sectionmcorporated References Cited within said casing and connecting said inlet to a 5 Source f fl id UNITED STATES PATENTS and an electric control equipment comprising, from an 3,254,646 6/1966 Staunt et a1. 128173.1 electric source, a motor control circuit and a spray 3 346,958 10/1967 Sinatra et a1, 32-28 control circuit, a common switch for both circuits, the second of which comprising the grouping in 10 ROBERT PESHOCK, Primary Examiner. parallel of electrovalves each controlling a flow of

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