US773120A

US773120A - Electric-motor sysyem.

Info

Publication number: US773120A
Application number: US18351803A
Authority: US
Inventors: Adolph F Christmas
Original assignee: FRANK R MCFEATTERS
Current assignee: FRANK R MCFEATTERS
Priority date: 1903-12-02
Filing date: 1903-12-02
Publication date: 1904-10-25
Anticipated expiration: 1921-10-25

Description

No. 773,120. PATENTED OCT. 25, 1.904.

' A. F. CHRISTMAS.

ELECTRIC MOTOR SYSTEM.

APPLICATION FILED DEC. 2, 1903 NO MODEL.

WITNESSES. INVENTOR. 9 6Q- MC/ [ll m mm UNITED STATES Patented October 25, 1904.

PATENT OFFICE.

ADOLPH F. CHRISTMAS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF TVVO-THIRDS TO FRANK R. M FEATTERS, OF WILKINSBURG, PENN- SYLVANIA.

ELECTRIC-MOTOR SYSTEM.

SPECIFICATION forming part of Letters Patent No. 773,120, dated October 25, 1904.

' Application filed December 2, 1903. Serial No. 188,518. (No model.) i

To all whom it 777/(LZ/ concern.-

Be it known that I, ADoLPH F. CHRISTMAS, a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electric-Motor Systems; and I do hereby declare the following to be a full,clear, and exact description thereof.

My invention relates to electric-motor systems, and more especially to a system for operating reciprocating electric motors provided with a plurality of coils.

One object of my invention is to provide such a system wherein a reciprocating motor having two coils and of simple design may be employed and whereby the circuit Will be broken and made momentarily and alternately through the two coils, so that heating of the motor is avoided and a high efiiciency developed.

A further object of the invention is to provide such amotor system wherein the making of the circuit alternately through the two coils of the motor will be in synchronism with the period of oscillation of the armature of the motor.

Afurther object of my invention is to provide such a system wherein the motor is cushioned and aided by the expansive forces of air which is automatically compressed in the operation of the motor.

The accompanying drawingshows a diagram of the system, the motor and the circuit maker and breaker being shown in section.

My invention is intended to operate With reciprocating motors provided with two coils. Such a motor is shown in the drawing and has been illustrated as a reciprocating hammer. This motor is provided with a suitable frame or casing 1, having therein the

coils

2 and 3. In these coils is the sleeve or bobbin 4:, in which reciprocates the core or armature 5, which latter performs the desired work-- such, for instance, as operating a tool 6. The active or Working stroke of the core 5 is secured by the energization of the coil 2, and its idle or rearward stroke is secured by the energization of the coil 3. The inner end of the sleeve 4 is tightly closed, as by means of a head 7, and the core fits said sleeve closely, so that in its idle or backward movement it will compress air between its inner end and the head 7 which air not only acts as a cushion, but also by its expansive force starts the core on its outward or active stroke, thus aiding the coil 2 and increasing the strength of the blow. In order that this air-space may not act by suction to retard the core 5 in its outward movement, a suitable air-vent is provided in such relation that it will be uncovered by the inner end of the core 5 when the latter approaches the limit of its outward move ment. This duct is shown at 8 as passing through the partition 9 between the two

coils

2 and 3 and communicating with a groove 10 in the inner face of the sleeve 1, which extends to the required distance to be uncovered by the core at the proper time.

The

coils

2 and 3 are energized alternately and only momentarily, thus gettinga strong magnetic pull on the core and at the same time preventing the heating of the coils and motor, as would be the case if the current were switched directly from one coil to the other without any appreciable interval of time between the same.

For breaking the circuit and making it alternately through the two coils I make use of a circuit-interrupting device, which is specifically described and claimed in my application, Serial No. 183,519, filed December 2,

1903, and which comprises a rotary body 12, preferably a cylindrical metallic tube having heads 13 of suitable insulating material and suitably mounted to rotate in standards or bearings let. In the chamber 15 is a body of mercury 16, which, however, only partially fills the same. Projecting through the heads 13 are circuit terminals or fingers l7 and 18, which for simplicity of construction are extended to form the trunnions on which the body is rotated. Secured to each of these terminals outside of the insulated heads are metallic plates 19, against which bear brushes and 21, respectively. Bearing against the outer face of the cylindrical body 12 is another brush 22. The two

fingers

17 and 18 are oppositely arranged, as shown, and in the rotation of the body the mercury will remain stationary, and these fingers will alternately sweep through or come in contact with said mercury, thus establishing an electric path from the brush 22 through the mercury and alternately to the finger 17 and brush 20 and to the finger 18 and brush 21. The

brushes

20 and 21 are connected electrically to binding-

posts

23 and 2 The motor and circuit-interrupter described are connected in a suitable system having a generator 25 and a positive main 26 and negative main 27. The positive main is connected to the brush 22, and therefore is always in electric connection with the mer cury in the chamber of the circuit-breaker. The negative main 27 is connected to the two

coils

2 and 3 of the motor, being common to said coils. The coil 2 of the motor is connected by awire 28 to, the brush 20 of the circuit-breaker, while the coil 3 of the motor is connected by a wire 29 to the brush 21 of the circuit-breaker.

The circuit-breaker may be rotated in any suitable way--such, for instance, as by attaching a handle or crank to one of the trunnions thereof. Preferably, however, one of the trunnions will be provided with a pulley 30, which will be driven by means of a belt 31 from any suitable source of power, such as a counter-shaft in a factory or other convenient source. Preferably, however, said circuit-breaker will be driven from an electric motor 32, bridged across the

mains

26 and 27 and having its shaft provided with a pulley 33 for receiving the belt 31.

A suitable starting and stoppingdevice will be provided on or in proximity to the motor, and when the latter is used for a reciprocat ing hammer, such as shown, this starting and stopping device can conveniently take the form of a switch-blade 35, cooperating with terminals 36, a suitable lever 37 being provided for closing the switch when the tool is grasped by the operator and a spring 38 being provided for opening said switch as soon as the tool is released, all as described and claimed in my application, Serial No. 183,520, filed December 2, 1903.

In the operation of this motor system the current coming from the positive brush of the generator will pass to the brush 22 and through the metallic casing 12 to the mercury contained therein, the circuit interrupter will be rotated, and the

fingers

17 and 18 will alternately come in contact with the mercury, thus alternately directing the current from the mercury to the brush 20 and coil 2 of the motor or to the brush 21 and coil 3 of the motor, thus causing alternate energizations of these coils. Inasmuch as the

fingers

17 and 18 are comparatively narrow, they will be in contact with the mercury only a short interval of time compared to the period elapsing between the time when one of said lingers leaves the mercury and the other comes in contact therewith. As a consequence the

coils

2 and 3 of the motor are only momentarily energized, getting thereby a strong magnetic pull on the core and at the same time preventing the coils and motor from heating, as would be the case if the current were continued through each coil until it was switched into the next coil. The rotation of the circuit-breaker will be timed so as to be in synchronism with the period of oscillation of the core 5 of the motor. Furthermore, the core of the motor fitting closely, as it does, in the sleeve 4 will in its backward or idle stroke compress air between itself and the head 7, which compressed air by its expansive force starts the core on its forward or active stroke and reinforces the magnetic pull caused by the energization of the coil 2, thus increasing the strength of the blow.

It will thus be seen that in my improved motor system the magnetic pull of the coil is reinforced by the compressed air stored on the idle movement of the core. Furthermore, by reason of maintaining the current through the motor-coils for only a short period of time the expenditure of energy for the work obtained is very small. The circuit-interrupter is such that it can be made to act in exact synchronism with the motor, and it is not detrin'ientally affected by the arcs which occur when the current is interrupted, as such arcs will merely expend themselves in volatilizing a portion of the mercury; but as the latter is contained in a tight casing it will again condense and seek the main body of mercury. This rotating circuit-breaker will automatically make and break the circuit to the motor-coils as long as the circuit is closed at the motor. hen this circuit, however, is open, the circuit-breaker will still continue to rotate, but only idly, and as it requires practically no power to rotate it no appreciable loss of energy occurs.

My motor system will operate with either a direct or alternating current.

hat I claim is 1. In an electric-motor system, the combination with a reciprocating motor having a plurality of coils, circuits thereto, and a circuitinterrupter and changer arranged to break the circuits and make them alternately through said coils, said circuit interrupter and changer being arranged to allow a long time interval between the breaking of the circuit and the succeeding making thereof.

2. In an electric-motor system, the combination with a reciprocating motor having a plurality of coils, circuits thereto, and a circuit interrupter and changer arranged to break the circuits and make them momentarily and alternately through said coils.

3. In an electric-motor system, the combination with a reciprocating motor, a plurality of coils therefor, a reciprocating armature cooperating with said coils, circuits to said coils, and a circuit interrupter and changer arranged to break said circuits and make the same alternately through said coils and in synchronism with the period of oscillation of the armature, said circuit interrupter and changer being arranged to allow a long time interval between the breaking of the circuit and the succeeding making thereof.

4. In an electric-motor system, the combination with a reciprocating motor, a plurality of coils therefor, a reciprocating armature cooperating with said coils, circuits for said coils, and a circuit interrupter and changer arranged to break the circuits and make them momentarily and alternately through said coils and insynchronism with the period of oscillation of the armature.

5. In an electric-motor system, the combination with a plurality of coils, a sleeve'therefor closed at one end, a reciprocating core in said sleeve and closely fitting the same and acting with the closed end of the sleeve to form an. air-cylinder, circuits to said coils, and a circuit interrupter and changer arranged to break the circuits and make them momentarily and alternately through said coils.

6. In an electric-motor system, the combination With a plurality of coils, a sleeve therein closed at one end, a reciprocating core in said sleeve and closely fitting the same and acting with the closed end of the sleeve to form an air-cylinder, circuits to said coils, and a time-interval circuit interrupter and changer arranged to break said circuits and make them alternately and momentarily through said coils and in synchronis'm with the period of oscillation of the armature.

7. In an electric-motor system, the combination with a reciprocating motor having a plurality of coils, circuits therefor, and a rotary mercury circuit maker and breaker in said circuits arranged to break said circuits and make them alternately through said coils 8. In an electric-motor system, the combination with a plurality of coils, of circuits therefor, a rotary circuit-interrupter having a chamber partially filled with mercury, a positive terminal in constant connection with said mercury, and oppositely-arranged terminals projecting into said chamber and arranged to alternately and momentarily dip into the mercury in the rotation of the body, and independent connections from said terminals to the coils of the motor. 7

9. In an electric-motor system, the combination with a reciprocating motor provided with two coils, a source of energy, a rotary circuit breaker comprising a chamber partially filled with mercury, a main connecting the positive brush of the source of energy with said mercury, two oppositely-arranged contacts cooperating With the mercury and arranged in the rotation of the body to, alternately contact With said mercury, connections between each of said contacts and one of the coils of the motor, a main from said coils to the negative pole of the source of energy, a motor bridged across the mains, and connections between said motor and the rotary circuit-breaker.

In testimony whereof L the said ADoLrH F. CHRISTMAS, have hereunto set my hand.

ADOLPH F. CHRISTMAS.

Witnesses:

F. W. WINTER, ROBERT (J. TOTTEN.