US738871A - Speed-regulating device. - Google Patents

Description

PATENTED SEPT. 15, 1903.

M. W. ALEXANDER. SPEED REGULATING DEVICE.

APPLICATION FILED JUNE 5, 1903.

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No. 738,871. PAIENTED SEPT. 15, 1903. M. W. ALEXANDER. SPEED REGULATING DEVICE.

APPLICATION FILED JUNE 5, 1903.

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n4: NORRIS PETERS cofPmo-u no. wnswmsrou n c UNITED STATES Patented September 15, 1903.

PATENT OFFICE.

MAGNUS W. ALEXANDER, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SPEED-REGULATING DEVICE.

SPECIFICATION forming part of Letters Patent No. 738,871, dated September 15, 1903. Application filed June 5,1903. Serial No. 160,165. (No model.)

To all whom it may concern:

Be it known that I, MAGNUS W. ALEXAN- DER, a citizen of the United States, residing at Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Speed-Regulating Devices, ofwhich the following is a s pecification. I

My invention relates to speed-regulating devices, and in its broadest aspect is capable of use in many relations. It is herein described and shown as embodied in a governor for limiting the speed of an electric motor.

Itsobject and nature will be best understood from the following detailed description, taken in connection with the accompanying drawings, and what I regard as rny'invention will be particularly pointed out in the appended claims.

In the drawings, Figure l is a perspective View of a motor provided with a governor constructed in accordance with my invention. Fig. 2 is a vertical section of said governor, taken on the line 2 2 of Fig. 3. Fig. 3 is a vertical section taken on the line 3 3 of Fig. 2. Fig. 4 is a horizontal section taken on the line 4 4 of Fig. 3. Fig. 5is a perspective view of a portion of the governor-casing having parts broken away to illustrate the rheostat-contacts, and Fig. 6 is a diagram illustratin g the electrical connections of the parts.

Referring in detail to the accompanying drawings, in which like characters refer to like parts throughout the several views, 10 designates the aforesaid governor, which is secured to the motor whose speed is to be governed bysuitable arms 11, which connect its casing 12 to the motor-casing 13.

The governor 10 consists, essentially, of a,

controlling-rheostat 14, connected in circuit with the motor-armature 15 and f eld-winding 16, a pump 17, comprising two intermeshing toothed wheels 18 and 19, geared to the armature-shaft 20 and adapted to pump a fluid, such as oil, into a storage-chamber 21, having an outlet 22 by which the fluid may escape, a valve 23 for varying the size of the outlet 22, and a spring-pressed piston 24:,

forming a yielding wall for the chamber 21 and connected to the rheostat 14:,- so as to operate it to cut resistance into or out of the motor-circuit when said piston is moved by its spring 25 or the pressure of the fluid in the chamber 21.

The upper portion of the casing 12 is provided with a chamber 26, in which are located the rheostat-contacts, which comprise a contact-strip 27, a range of oppositely-disposed contacts 28, and a movable contact 29, adapted to bridge the space between them. The contacts 28, which are insulated from each other and the chamber-wall upon which they are supported, are connected to suitably-interposed resistance-coils 30, and the contactstrip 27, similarly insulated from its supporting-wall, is connected to the supply-lead 31. The rheostat 14, motor-armature 15, and fieldwinding 16 are connected in series by the supply-leads 31 32 and the wires 33 and 34, I as clearly illustrated in Fig. 6. The resist- 7o ance-coils 30 are suitably protected by an inclosing casing 35, secured to the casing 11, and the contact-strip 27 is provided with a suitable binding-post 36 for the attachment of the lead 31.

In line with the chamber 26 and extending from the opposite side of the casing 12 into the chamber 21 is a cylinder 37, in which the piston 24 reciprocates. The stem 38 of said piston extends through the partition 39, sep- 8\ arating the chambers 21 and 26, and is provided with a head 40, which fits within a cylindrical portion of said chamber 26 so as to reciprocate therein. A coiled spring 25, surrounding the piston-stem 38 and abutting against the head 40 and the partition 39, normally holds the pisto in the position illustrated in Fig. 2.

The movable rheostat contact 29, previously referred to, is supported upon and insulated from the head 40 on the piston-stem 38, and the piston and the rheostat-contacts are so positioned that when the piston is in the position illustrated in Fig. 2 the contact 29 is in the position illustrated in Fig. 6 and 5 all the resistance-coils 30 are short-circuited;

The intermeshing toothed wheels 18 and 19 of the pump 17 are located in a pumpingchamber 42 directly beneath the chamber 21, and the wheel 19 is mounted directly upon toothe armature-shaft 20 in the manner illustrated in Fig. 3, so that when saidv armature to the outer wall of the casing rotates said wheels are driven in the direction indicated by the arrows in Fig. 2 to carry the fluid, with which the interior of the casing is filled, from the lower side of the pumping-chamber 42 around the outside of said wheels to the chamber 21.

A vertical partition 43, extending parallel l2, separates the chamber 21 from a chamber 44, which is in unrestricted communication with the lower portion of the pumping-chamber 42 and which, together with the opening 22 through said wall 43,constitutes a communicating passage connecting opposite sides of the pump 17.

Fluid may be supplied to the chambers 21, 42, and 44 through an opening at the top of the casing 12, which is closed bya screw-cap 45. A cook 46 communicates with the pumping-chamber 42 at its lowest point and serves to drain olf the fluid.

From the above description it will be apparent that the piston 24 is held by the spring 25 normally in its innermost position, as illustrated in Fig. 2, and when in such position the resistance 30 will be short-circuited. As soon, however, as the motor is thrown in the circuit the armature will begin to rotate and drive the pump 17, which will pump the oil contained in the lower part of the pumping-chamber 42 into the chamber 21, from which it will escape by the outlet 22 to the chamber 44 and thence again to the lower part of the pumping-chamber 42 to be again pumped into the chamber 21. This pumping action will continue while the armature rotates, and the oil will continue to follow the same course over and over again. If, however, the motor speeds up so that the fluid cannot escape through the outlet 22 as fast as it is pumped into the chamber 21, it will be compressed therein, and when its pressure has increased sufficiently it will force the piston 24 outward against the tension of its spring 25 and maintain it there as long as the pumping action is sufficient to maintain the necessary pressure in the chamber 21. This outward movement of the piston 24 will move the rheostat-contact 29 to include in the motor-circuit more or less of the resistance 30,

. which will decrease the motor and pump speed, so that the pressure in the chamber 21 will fall 0% and allow the piston to be partially or wholly returned to its normal position.

Itis apparent that the pump speed, and consequently the motor speed necessary to compress the fluid in the chamber 21 sufficiently to operate the piston 24, depends upon the rate at which the fluid escapes through the outlet 22 and that if this rate be low a low motor speed will be sufficient, while if the rate be high a correspondingly high motor speed will be necessary. The valve 23 by which this rate of flow may be varied therefore constitutes a means for adjusting the maximum speed of the motor.

I do not wish to be limited to the specific arrangement and structure herein disclosed, since it is apparent my invention may be used in other connectionsas-, for example, in controlling the throttle-valve of the steamengine; but I aim to cover in the appended claims all modifications and alterations which may fall within the spirit and scope of my invention.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. The combination of a power-driven machine, means for controlling the supply of power to said machine, a chamber having one of its walls consisting of a movable member connected and arranged to operate said controlling means, a pump geared to said machine so as to be driven thereby and connected and arranged to pump a fluid into said chamber, and a contracted passage between said chamber and the inlet side of said pump.

2. The combination of a power-driven machine, means for controlling the supply of power to said machine, a chamber having one of its walls consisting of a movable member connected and arranged to operate said controlling means, a pump geared to said machine so as to be driven thereby and connected and arranged to pump a fluid into said chamber, a passage between said chamber and the inlet side of said pump, and means for varying the size of said passage.

3. The combination of an electric motor, a controlling-rheostat therefor comprising a range of resistance-varying contacts and a movable contact for progressively engaging the same, a chamber having one of its walls consisting of a movable member connected and arranged to move said movable contact, a pump geared to said motor so as to be driven thereby and connected and arranged to pump a fluid into said chamber, a passage between said chamber and the inlet side of said pump, and means for varying the size of said passage.

4. The combination of an electric motor, a rheostat connected in series with the motorarmature comprising a range of resistancevarying contacts and a movable contact for progressively engaging the same, a piston connected and arranged to move said movable contact, a cylinder in which said piston reciprocates, a chamber in constant communication with said cylinder, a rotary pump geared to said motor so as to be driven thereby and connected and arranged to pump a fluid into said chamber, a passage between said chamber and the inlet side of said pump, and a valve by which the sizeof said passage may be varied.

In witness whereof I have hereunto set hand this 3d day of June, 1903.

MAGNUS W. ALEXANDER.

Witnesses:

DUGALD MoK. MOKILLOP, J OHN J. WALKER.

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