US1201363A - Self-contained engine hand-tool. - Google Patents

Description

W. G. SHELTON.

SELF CONTAINED EN GINE HAND TOOL. APPLICATION FILED mm. 11, 1913.

1,201,363., Patented Oct. 17,1916.

INVENTOR WITN'ESSES: w

30 I By Aftorneyx,

UNITED sTA rEs WILLIAM GENTRY SHELTON, OF NEW YORK, N. Y.

SELF-CON'.l'.AI1\l'11D ENGINE HAND-TOOL.

Specification of Letters Patent.

Application filed March 17, 1913. Serial No. 754,918.

To all whom it may concern:

Be it known that 1, WILLIAM GENTRY S nL'roN, a citizen of the United States, residing in the borough of Manhattan, city, county, and State of New York, have invented, certain new and useful Improvements in Self- Contained Engine Hand- Tools, of which the following is a specification.

Among the objects of the invention is the provision of a drill stock or hand-piece carrying a self-contained engine, the handpiece and engine being in the form of and constituting a hand-tool. The invention also comprises controlling means carried by the hand tool for the transmission mechanism 4 between the engine shaft and the driven spindle, and for the motor.

The rotary parts of a motor which is carried by a hand tool requiring the most delicate and precise manipulations must be small for lightness and rotated at a high speed for power, too high indeed for direct application to certain tools, for instance a dental drill or allied tool. The ability to effectively reduce the speed and increase the power at the point of utilization was a problem the solving of which made the use of this form of tool feasible. x

In the drawings accompanying this specification one practicable embodiment of a form of the invention is illustrated, where-- Figure 1 is a view partly in cent'ral, longitudinal or axial section and partly in elevation; Fig. 2 is a section taken on the plane at about the line 2-2 of Fig. 1 looking down. (The section upon which Fig. 1 is taken is illustrated in this view by the line 1-1). Fig. 3 is a view partly in elevation and partly in section substantially transverse to the section of.Fig. 1. The plane of this section is illustrated at the line 3-3 in Fig. 2. .Fig. 4 is a transverse section taken on a plane at about the line 4-4 of Fig. 1 looking up. Fig. 5 is a detail of the switch and contact mechanism. Fig. 6 is a diagram of the wiring.

The drill stock or part 7 carrying the driven shaft 13 in the illustration is a commercial form of dental hand piece and car-,

ries a dental engine, the-whole comprising a hand tool having a self-contained engine. The hand tool illustrated has the usual coupling screw 8 to which is attached the casing of the engine. In the present illustration the coupling 8 is connected with a coupling member 9. The coupling member 9 has a flange. 10 for engaging the member 11 of the hand-piece for holding this in position relatively to the coupling 8. In this form of handpiece the chuck 12 of the drivenshaft 13 is closed by moving the hand-piece away from the coupling 8 and is opened by moving it toward the same.

The main portion 14 of the engine casing is shown having a screw-threaded connection with the coupling 9. This main portion constitutes a frame as well as the housing of the engine. The engine in the present instance is driven by means of an electric motor. The motor which is employed is a single bearing motor which has been found most eflicient for steadiness as well as'lightness. The field magnets 15 together with their coils 16 are mounted on this member 14. A bearing 17 in the form of a tube or Patented 001.47, 1916. I

hollow cylinder is secured at one end, the

18 which has a spindle or shaft 19 extend-- ing through the bearing 17 and also a bearing 20 for engaging the outer surface of the bearing 17. A motor of suflicient lightness for use in a hand tool to get the requisite power will have to run at a too high rate of speed for driving certain tools. It is therefore necessary to gear the speed down between the motor or engine shaft 19 and the driven shaft 13. The transmission connection for effecting this reduction "in the present illustration comprises a roller gearing. A member 21 having an external bearing surface is shown mounted upon the engine shaft 19. Outside this is a member 22 having an internal bearing surface, and between these members is a race of balls 23 carried by a ball cage 24. The ball cage carries a series of pins 25, three in the present illustration, and the driven shaft 13 carries a coupling for such pins, in the present instance a disk 26 having a series of notches 27 for receiving and engaging the pins 25. When the member 21 is rotated, and the member 22 is free .to rotate, it will rotate tation of the member 21, and the ball cage remains substantially stationary. Upon ina reverse direction to the direction of roeither slowing down or stopping the rotation of the member 22 the ball cage will be rotatedv in the direction of rotation of the member 21 but at a reduced speed, the reduction being about 2% to 1 in the present showing. A brake or friction member 28 is provided for this purpose, and is carried by a resilient arm 29 which is mounted upon the hand piece, in such position that the operator may readily engage it by his fingers when he desires to rotate the driven shaft 13 and whatever tool 30 .he may be employing in the chuck;

The engine casing not only comprises the members above referred to but a cover member 31 for the main frame member 14. This cover member is oscillatorily mounted upon the bolts 32 which extend from the frame member 14 through the field magnets and through slots 33 in the cover member 31. These slots are for the purpose of limiting the amount of oscillation of the member 31. This member is also provided with a flange 34 surrounding the-free end of the frame member 14 for making a secure joint between these parts and guiding the oscillation of the member 31. The purpose of such oscillation is for changing the position of the brushes and switches for effecting a re ersal of rotation. of the armature.

The circuit is substantially as follows: The lead line 35 comes into the casing with the lead line 36 in the form ofa cable, the lead line 35 passes around the field coils 37 and 38, and then has two contact buttons 39, 40; the lead line 36 has two contact buttons 41 and 42. A pair of buttons 43 and 44 are associated with the brushes 45 and 46 respectively, which run upon the armature 47.

When it is desired to drive the armature in one direction the cap member 31 of the engine casing will be moved to the position to bring the parts as illustrated in Figs. 5 and 6, wherein the contact button 43 is in engagement with the contactbutton 41 and the contact button 44 will be in engagement with the contact button 40. When, however, it is desired to reverse the direction of the armature and thereby reverse the direction of the tool, the operator may, while still holding the tool in operative position, move the cover member 31 to its other limit of ture and also of the tool 3.0. The buttons J movement and bring the button 43 into engagement with the button 39, and the button 44 into engagement with the button 42, thereby changing the direction of current and the direction of rotation of the armaconnected with the lead lines are shown mounted upon insulation bridges 48, which are held in position upon the bolts 32.

From the foregoing description it will be apparent that drills and other tools may be readily inserted in and removed from the chuck upon the driven shaft, as occasion may demand, and that the reduction transmission gearing will reduce the speed transmitted to these tools to a safe working speed, and this without undue vibration. It will also be apparent that the tool may be stopped and started without stopping and starting the motor, and that the tool may be 1 ing the use of the tool and While the transmission connection is in efficient or working position or when these are at rest as oocasion may demand,

- The reduction transmission in the illustration is connected to the driven shaft and located at one end of the hand piece and the chuck on such shaft is located at the opposite end of the hand piece. This is of particular advantage. in a mechanically controlled clutch. V

In the illustration the power is shown applied to the inner of the three members of the clutch and taken from the intermediate member, although the power may be applied to any one ofthe three members andtaken from either of. the others. I

- In the construction described the use of the particular form of transmission gearing is of importance for several, reasons. In .order to bring the tool within the compass of weight which is permissible, an extremely small and rapidly rotating motor must be provided, and in such constructions toothed reduction gearing is unsuitable for the purpose. Furthermore, the gearing herein provided is subject to quick and easy control by the finger of the usergmoved in a normal direction. It will be'understood, however, that the gearing set forth is capable of other usesthan that to which it is shown as applied, and is adapted to be located at other points than that disclosed. v

While but one embodiment of'the invention has been shown for the purpose of illustrating the same, yet it will be apparent that motor, an electric switch carried by the cas-- mg for controlling the'current to the motor,

and a controlling member for said coupling means carried by the hand-piece whereby the motor and shaft may be instantaneously uncoupled at will for coupling the shaft to the moto-r'and uncouplingthe same therefrom.

2. In a self-contained engine hand-tool,

the combination with a casing, of a hand .piece carried thereby,a driven shaft in the rotation of the driven shaft.

i. In a self-contained engine hand-tool, the combination with a casing, of a hand piece carried thereby, a driven shaft in the hand'piece, an electric motor in the casing, transmission mechanism between the motor shaft and the driven shaft, and a finger piece fast with the hand piece and extending into the casing for controlling the trans mission mechanism, and means for controlling the current to the motor.

5. The combination with a hand piece anda driven shaft mounted therein, of a motor, a casing forthe motor having one part carried by the hand piece and carrying the motor, and another part oscillator-ii) mounted on the other part, and means controlled by the oscillation of such part for controlling the direction of rotation of the mot-or, and

a controlling member carried by the hand piece for coupling the shaft to the motor and uncoupling the same therefrom 6. The combination with a hand piece and a driven shaft mounted therein, of a motor,

a casing for the motor having one part carried by the hand piece and carrying the motor, and another part-'oscillatorily mounted on the other part and carrying the brushes for the motor, the oscillation of such part serving to control the direction of rotation of the motor, and a controlling member carried by the hand piece for coupling the shaft to the motor and uncoupling the same therefrom.

7. The combination with a hand piece, of a driven shaft carried thereby, a chuck on the shaft at one end of the hand piece and a reduction transmission and clutch on the shaft at the other end of the hand piece, and an actuator for the clutch carriedby the said I hand piece.

8. The combination with a hand piece, of a driven shaft carried thereby, a chuck carried by the shaft at one end of the hand piece and a member of a transmission mech anism connected to the shaft at the other end of the hand piece, and an actuator for the transmission mechanism carried by the hand piece.

In witness whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

WVILLIAM GENTRY SHELTON. W'itnesses CHAS. LYON RUssELL. Ti-imms F. TVALLAGI-I.

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