US1421157A - Control system and apparatus - Google Patents

Description

E. M. BOUTON.

CONTROL SYSTEM AND APPARATUS.

APPLICATION FILED MAY I2, 1919.

Patented June 27, 1922.

, INVENTOR 'l'c fyarflfioufon. BY

TORINEY WITNESSES:

UNITED STATES PATENT OFFICE.

EDGAR M. IBOUTON. OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR 'IO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

CONTROL SYSTEM AND APPARATUS.

To all whom it may concern:

Be it known that I, EDGAR M. BOUTON, a citizen of the United States, and a resident of VVilkinsbur in the county of Allegheny and State of ennsylvania, have invented a new and useful Improvement in Control Systems and Apparatus, of which the following is a specification.

My invention relates to motor-control systems and apparatus and it has for its object the provision of a novel system and novel apparatus for controlling an electric motor through a predetermined cycle of operation.

According to my invention, the motor 011'- cuit is adapted to be closed by a contactor, the actuating coil of which may be energized by a rela that is freely movable in one direction but is retarded during its return to its initial position. The relay is of special construction and forms part of my invention. Upon the return of the rela to its initial position, the contactor coil ecomes short-circuited, permitting the opening of the contactor and the stopping of the motor.

In the accompanying drawings, Figure 1 is a side elevational view of a relay constructed in accordance with my invention; Fig. 2 is a front elevational view thereof, with parts in section, and Pi 3 is a diagrammatic view of a contro system embodying my invention.

Referring to Figs. 1 and 2, my improve relay comprises a contact member 1 having two positions in one of which it is adapte to bridge contact members 2- and, in the other, contact members 3. The contact member 1 is mounted upon a supporting rod 4 that is biased downwardly by a weight 5 and is provided with a rack member 6 for engaging a pinion 7 that is mounted upon a shaft 8 upon which is also mounted a ratchet wheel 9 that is adapted to be engaged by a spring-pressed awi 10 carried upon a loosely mounte gear wheel 11. The gear wheel 11 meshes with a pinion 12 that is mounted u on the same shaft as a gear wheel 13, w ich, in turn, meshes with a pinion 14 that is rigidly rotatable with a disk 15 of conducting material, such as aluminum, and is adapted to be rotated, when the weight 5 is allowed to drop by gravity, in the magnetic field of a permanent or a coil magnet 16. The

magnet 16 is adjustable, to vary the force Specification of Letters Patent. Patented J une 27 1922 Application filed May 12,

1919. Serial No. 296,814.

exerted by its field upon the disk 15, by means of slots 17 and bolts or similar members 18. The contact member 1 is adapted. to be raised, in opposition to the force exerted by the weight 5, by a core member 19 that is adapted to be energized by a coil 20. The core member 19 is adapted also to engage a loosely mounted member 21 which, in turn, is adapted to engage a switch member 22 in order to effect the disenga ement of said member 22 with contact mem ers 23 when thecore member 19 occupies its uppermost position.

The actuation of the contact member 1 from engagement with the contact members 3 into engagement with the contact members 2 is efi'ected without hindrance upon the energization of the coil 20, as the ratchet wheel 9 does not effectively engage the pawl 10 durin such operation. During the return of t e contact member 1 from engagement with the contact members 2 into engagement with the contact members 3, however, the ratchet wheel 9 engages the pawl 10 whereby the return movement of the contact member 1 is retarded through the mechanism above described by the influence of the magnetic field of the magnet 16 upon the conducting disk 15.

My relay is of particular use in, and is desi ed for, a system of the kind diagrammatlcally illustrated in Fig. 3, in which a motor 24, having an armature 25 and a series field-magnet winding 26 is connected between line conductors 27 and 28b a contactor 29, having an energizin coi 30'the circuit of which is adapted to e closed by the contact members 1 and 2 of my relay. The contact members 1 and 3 are adapted to short-circuit the coil 30. Inserted into circuit with the coil 30 at various times, as will appear hereinafter, are a plurality of resistors 31, 32 and 33, the resistor 31 be ing normally short-circuited by the contact members 22 and 23. A double-throw knife switch 31 is adapted, in one of its positions, to permit the control of the mo tor 24 by the contactor 29 and, in its other position, to connect the motor 24 directly to the line conductors 27 and 28. A plurality of push-botton switches 35 serve initially to close the circuit of the coil 20.

Assuming that the switch 34 has been actuated to the ri ht and that one of the pushbuttons 35 has con closed, a circuit will be established from the line conductor 28, through the switch 34, the contact members 22 and 23, the coil 20 and a push-button switch 35, to the line conductor 27 The coil 20, becoming thus energized, will eifect the free, unrestrained upward movement of the core member 19, whereuponthe contact member 1 will be actuated into engagement with the contact members 2 to effect the closing of the circuit of the coil 30 from the conductor 28, through the switch 34, the contact members 22 and 23, the contact members 1 and 2, the coil 30, the resistor 33 and the switch 34, to the conductor 27. The

contactor 29 will thereupon become closed by its actuating coil 30, whereupon the circuit of the motor will become established from the conductor 28 through the switch 34, the contactor 29, the armature 25, the series field-magnet winding 26 and the switch 34, to the conductor 27.

The system of Fig. 3 is particularly adapted for use in pneumatic-tube systems, the push-button switches 35 being adapted to be closed by the packages which are adapted to be transported by the tube systems. Immediately following the removal of the package from engagement with the push-button switches 35, this switch becomes released, thereb effecting the opening of the circuit of the coil 20. The core member 19 begins thereupon to fall by gravity, in response to the force exerted by the weight 5. Engagement between the contact members 1 and 2 is therefore but temporary. A holding circuit for the coil 30 becomes immediately established, however, from the conductor 28, through the switch 34, the contactor 29, the resistor 32, the coil 30, the resistor 33 and the switch 34, to the conduc tor 27.

The contact members 1 and 3 do not engage immediately following the disengagement of the contact members 1 and 2, there being a time interval between the disengagement of the one and the engagement of the other because of the retarding influence of the magnetic field of the magnet 16 upon the conducting disk 15. -During this tlme interval, the motor 24 continues to operate. Upon the return of .the relay to its initial position, however, wherein the contact memer 1 engages the contact members 3, the

coil 30 is shunted effecting the opening of the contactor 29 by gravity. The motor 24 thereupon stops.

It sometimes happens, however, that the push-button switches 35 fail to become released, so that the coil 20 remains energized for a considerable period of time. To prevent the overheating of' this coil, the member 21 is adapted to break the engagement of the contact members 22 and 23, thereby insertin into series with the coil 20,.as also into series with the coil 30, the resistor 31.

The release of the contact members 22 and 23 is indeed preferably effected upon every. actuation of the relay, for the current which is necessary to maintain the core member'19 in actuated position is small and the coil 20 need, therefore, not be highly energized except for a comparatively small period of time.

It is not necessary that the relay be returned to its initial position before it may again be actuated by its coil 20, for actuation of a push-button switch 35 will effect the energization of the coil 20 at any time, irrespectlve of the position in space which the relay may then occupy.

I have found that the relay illustrated in Figs. 1 and 2 is of particular advantage when used in connection with the system of Fig. 3, for ordinary time-element relays, like dash-pots, are unreliable and their operation is not uniform. All that is necessary, in the case of the relay described above, is initially to adjust the position of the magnet 16. Once so adjusted, the relay will continue to operate, through successive operations vof the motor, uniformly and reliably.

I claim as my invention:

1. The combination with a motor and a switch for closing the circuit of said motor and havin an actuating coil, of a switch for contro ling said coil, means operable upon temporary actuation thereof to effect the closing of said second-named switch, means for maintaining said coil energized, means for delaying the return of said second-named switch to its initial position, and means for short-circuiting said coil upon the return of said second named switch to said initial position.

2. The'combination with a motor and a switch for closing the circuit of said motor, of a switch biased to open position and having an actuating coil for actuating said second-named switch to closed positlon to effect the closing of said first-named switch,

and means operable upon temporary actuation thereof, to close the circuit of said coil and thereby effect the actuation of said second-named switch to closed position irrespective of the position which said secondnamed switch may occupy.

3. The combination with a motor, a switch for closing the circuit of said motor and having an actuating coil, and a relay for closing the circuit of said coil and having an actuating coil, of a normally short-circuited resistor, and means for inserting said resistor into circuit with each of said coils upon the actuation of said relay.

4. The combination with an electric motor, of controlling means therefor comprisin a member biased in one direction and a swltch carried thereby, a second switch having a lost-motion connection to said memher, and means comprising a rotating contor, of controllin means therefor comprisducting member and a magnet for retarding in a main switc a relay for controlling the movement of saidmember in one direcsaid switch that is freely responsive when 15 tion. actuated to effect the closing of said switch 5. The combination with an electric moand means for retarding said relay in its tor, of controlling means therefor compris-\ operation to effect the opening of said ing a switch mechanism that is freely reswitch.-- sponsive in its operation. to efiect the clos- In testimony whereof, I have hereunto 20 ing of the motor circuit and means for resubscribed my name this 29th day of April, tarding said mechanism in its operation to 1919. efiect the opening of the motor circuit.

6. The combination with an electric mo- EDGAR M. BOUTON.

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