US1760814A

US1760814A - Circuit controller

Info

Publication number: US1760814A
Application number: US215228A
Authority: US
Inventors: Frank E Case
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1927-08-24
Filing date: 1927-08-24
Publication date: 1930-05-27
Anticipated expiration: 1947-05-27
Also published as: GB296058A; FR659289A

Description

May 27, 193% F. E. (:ASE

CIRCUIT CONTROLLER Filed Aug. 24, 1927 wc {o o t m5 t m A 5 mm F Patented May 27, 1930 UNITED STATES PATENT OFFICE FRANK E. CASE, OF ERIE, PENNSYLVANIA, ASSIGNOR TO GENERAL ELECTRIC CO]!!- PANY, A CORPORATION OF NEW YORK CIRCUIT CONTROLLER Application filed August 24, 1927. Serial No. 215,228.

This invention relates to the control of electric circuits and more particularly to circuit controllers having one or more circuit controlling contacts arranged to be operated by means of rotatable cams,-and the princi-- pal object of the invention is to provide for operation of the contacts independently of the rotation of the operating cams.

While not necessarily limited thereto, the present invention is particularly advantagoons in cam operated circuit controllers having a plurality of circuit controlling con tacts arranged to be operated in a predetermined sequence for controlling the circuit of an electric motor or other translating device. By means of the present invention, automatic simultaneous operation of the several circuit controlling contacts of the controller to their circuit opening positions may be produced upon the occurrence of overload or other abnormal conditions in the circuit of the motor, or other translating device, irrespective of the angular position of the operating cams.

With the present invention embodied in a controller having a plurality of circuit controlling contacts arranged to be operated in sequence through the agency of a rotatable cam shaft, the cam shaft is movably mountcd so that it may be shifted bodily out of normal operating relation with the switch contacts under the control of an electroresponsive device, such as an electromagnet or the like. In this way all of the switch members may be moved simultaneously to a predetermined circuit controlling position with the cam shaft in any angular position. The controlling electromagnet preferably is energized in accordance with the current in the motor circuit controlled by the controller so as to permit the cam shaft to move out ofoperating relation with the switch member and thereby effect operation of the controller contacts in the circuit opening position upon the occurrence of overload conditions in the motor circuit.

In the accompanying drawing, the single figure diagrammatically illustrates a motor controller embodying a preferred form of the present invention arranged to provide automatic overload protection for the motor.

The motor controller illustrated in the.

22, 23, with which the

respective members

10, 11, 12, 13, are provided.

The

cams

14, 15, 16, 17, are angularly displaced on the cam shaft 18, as indicated in the drawing, so as to operate the

switch mem bers

10, 11, 12, 13, in a predetermined sequence. Thus, the switch member 10 is first operated to the circuit closing position upon rotation of the operating handle 19 in the direction indicated by the arrow in the drawand the switch members 11, 12 and 13 are successively closed upon continued rotation of the cam shaft 18.

In accordance with the present invention the cam shaft 18 is so mounted that the operating cams 1-1, 15, 16, 17, may be moved out of operating relation with the switch members. As shown diagrammatically in the drawing, the cam shaft '18 is rotatably mounted in suitable bearings at the/ends of the arms 21 extending in spaced relation from the pivot bearing 25, which it will be understood is supported in suitable bearings. This mounting permits the cam shaft 18 to swing bodily around the pivot bearing 25 and also rotate in the bearings in the ends of the arms 21. The cam shaft 18 normally is maintained in cooperating relation with the rollers on the switch members by means of the toggle mechanism 26. The toggle mechanism comprises the-lever 27 and the link 28. The lever 27 is provided with an operating handle and is mounted upon the pivot 29 and connected through the link 28 with the cam shaft 18. p

\Vhcn the toggle mechanism 26 is extended as illustrated in the drawing, the engagement of the link 28 with the pin 30 serves to lock the toggle mechanism over center so as to hold the cam shaft 18 in the position shown. The toggle mechanism 26 may be collapsed either by operating the lever 27 or by means of the electroresponsive tripping mechanism 31. As shown in the drawing, the tripping mechanism 31 comprises the electromagnet 32 having its armature 33 connected to operate the bell crank arm 34 about the pivot Upon energization of the electromagnet to attract the armature 33, the free end of the bell crank 31 engages with the toggle mechanism 26 to collapse the same and therebypermit the cam shaft 18 to swing downward about the pivot 25 out of the position in which it is shown in the drawing.

The controller, constructed as just described, is particularly adapted to control the energizing circuit of an electric motor, although the controller may be used in other service. As shown diagrammatically in the drawing the controller is connected to control the energization and operation of the motor 36 which is arranged to be energized from the supply line T with the speed regulating resistors R R R in the motor circuit. The switch member 10 is connected to open and close the energizing circuit for the motor 36, while the switches, 11, 12, 13 are connected respectively to short circuit the regulating resistors R R R The electromagnet 32 is connected directly in the eneri gizing circuit of the motor to be energized in accordance with the current therein.

The operation of the controller is as follows: Upon rotation of the operating handle 19 in the direction indicated by the arrow in the drawing the cam 14 cooperates with the roller 20 to move the switch member 10 from its biased position in which it is shown to the circuit closing position. This completes a circuit extending from the supply line T through the operating winding of the electromagnet 32, the switch member' 10, the speed regulating resistors R R R and the field and armature windings of the motor 36, as indicated in the drawing. Upon continued movement of the operating handle 19, the switch 10 is maintained in the closed position and the switches 11, 12, 13, are operated successively by the

cams

15, 16, 17 to short circuit the regulating resistors R R R step by step. This results in full speed operation of the motor 36. Upon the return movement of the operating handle 19, the switches 13, 12, 11, are successively opened to reinsert the resistors R R R in the motor circuit and the switch 10 is finally operated to the circuit opening position to interrupt the motor circuit.

The electromagnet 32 is so designed that during normal conditions of current flow in the motor circuit the armature 33 remains in the unattracted position. In case, however, motor 36 should become overloaded with a resulting abnormal flow of current through the operating winding of the electromagnet 32, the armature 33 is attracted. As previously described, this results in tripping the toggle mechanism 26 to permit the release of the cam shaft 18. \Vith the toggle mechanism 26 collapsed the axis of rotation of the shaft 18 is moved so as to simultaneously effect operation of any of the

switches

10, 11, 12, 13 that may be in the circuit closing position to the circuit opening position irrespective of the angular position in which the cam shaft 18 may be. The cam shaft 18 is readily returned into the normal operative position by means of the resetting lever 27.

In this way overload protection for the motor 36 is provided without requiring any contacts in the circuit other than those necessary for the normal control of the motor.

It will be understood that the apparatus shown is illustrative and that various changes and modifications therein may be' made without departing from the-spirit and scope of the invention.

\Vhat I claim as new and desire to secure by Letters Patent of the United States is 1. The combination of a plurality of movable switch members, a movable operating member therefor, means for movably mounting the operating member in a spaced relation with the switch members to effect operation of the switch members in sequence between a plurality of circuit controlling positions upon corresponding movement of the switch operating member, and automatic means associated with the mounting means for automatically eifecting movement of the operating member from said spaced relation with the switch members in accordance with certain conditions to effect operation of the switch members to a predetermined circuit controlling position.

2. The combination of a movable switch member, a rotatable cam operating member therefor, means for mounting the cam member with the axis of rotation thereof in a position to effect operation of the switch member between a plurality of positions upon rotation of the cam member, and means sociated with the mounting means for shifting the axis of rotation of the cam member to effect operation of the switch member to a predetermined position.

3. The combination of a movable switch member operable between the circuit closing and the circuit opening positions, a cam operating member therefor, means for mounting the cam operating member with the axis of rotation thereof in a position to effect operation of the switch member between said positions upon rotation of the cam member, and means associated with the mounting means for shifting the axis of rotation of the cam member to effect operation of the switch member to the circuit opening position independently of the angular position of the cam.

4:. The combination of a movable switch member, operating means therefor including a rotatable cam, means for mounting the cam in a predetermined spaced relation with the switch member to effect operation of the switch member between a plurality of positions upon angular movement of the cam, and automatic means associated with the mounting means for effecting movement of the cam out of operating relation with the switch member to effect operation of the switch member to a predetermined position independently of the angular position of the cam in response to predetermined conditions. 7

5. The combination of a plurality of movable switch members, a relatively movable manual operating member therefor, means for movably mounting the said relatively movable member ina spaced relation with the switch members to effect operation of the switch members in sequence between a plurality of circuit controlling positions upon corresponding m-ovement of the relatively movable member, electroresponsive means associated with the mounting means for automatically effecting movement of the relatively movable member from said spaced relation with the switch members in accordance with predetermined electrical conditions to thereby automatically effect operation of the switch members to a predetermined circuit controlling position.

6. The combination of a switch member movable between a plurality of positions and biased to one of said positions, means for operating the switch member between said positions, including a rotatable cam movable means for mountin the cam with the axis of rotation thereof? in a plurality of positions with respect to the switch member, one of said positions permitting movement of the switch member between a plurality of circuit controlling positions upon corresponding angular movement of the cam, and automatic means associated with said monnting means for efiecting movement of the axis of rotation of the cam to another position to permit movement of the switch memher in accordance with its bias irrespective of the angular position of the cam in response to predetermined conditions.

7. A circuit controlling device comprising a switch member biased to the circuit opening. position, operating means for the switch member including a rotatable cam, means for mounting the cam with the axis of rotation thereof movable between a plurality of positions, one of said positions permitting the cam to effect movement of the switch member to and from the circuit closing position upon corresponding angular movement of the cam, and electroresponsive with said mounting means for effecting movement of the axis of rotation of the cam to another position to insure operation of the switch member to the circuit opening position in accordance with its bias irrespective of the angular position of the cam upon the occurrence of predetermined electrical conditions in the circuit controlled by the switc member.

8. The combination of a plurality of movable switch members, each operable between a plurality of circuit controlling positions, a common manual operating means for operating the said switch members each way between-said positions in a predetermined sequence upon predetermined movements of the operating means, and automatic means for effecting a different movement of the said operating means to insure simultaneous operation of the switch members to predetermined positions in response to predetermined conditions.

9. The combination of a plurality of movable switch members, each operable between a plurality of circuit controlling positions, operating means including a movable member operable between a plurality of positions for effecting successive operation of the movable switch members between said circuit controlling positions, said movable member being mounted for movement to a different position to effect simultaneous movement of the switch members to predetermined circuit controlling positions and electroresponsive means for controlling the movement of said operating member to said different position in accordance with predetermined electrical conditions.

10. The combination of a plurality of mov able switch members, operating means therefor including a rotatable cam shaft having cams for effecting operation of the switch members in a predetermined sequence upon rotation of the cam shaft about its axis, and means for effecting movement of the axis of rotation of the cam shaft to permit simultaneous movement of the switch members to a predetermined circuit controlling position independently of the angular position of the cam shaft.

11. A circuit controlling device comprising a plurality of movably mounted switch members each having a plurality of circuit controlling positions and biased to one of said positions, operating means therefor including a cam shaft provided with a plurality of cams for effecting operation of the switch members between said circuit controlling positions in a predetermined sequence, means for rotatably mounting the cam shaft with the axis of rotation thereof in a plu.-

rality of positions one of said positions insuring sequential operation of the switch members upon angular movement of the cam shaft, and electroresponsive means for effecting movement of the axis of rotation of the cam shaft to a difierent position to permit simultaneous operation of the switch members in accordance with their bias independently of the angular position of the cam shaft in response to predetermined electrical conditions.

12. A circuit controlling device comprising a plurality of switch members each mounted for movement between the circuit closing and the circuit opening position and biased to the circuit opening position, operating means therefor including a rotatable cam shaft having a plurality of cams arranged to effect successive operation of the switch members from the circuit opening po sition to the circuit closing position, means for movably mounting the cam shaft in operative relation with the switch members with the cam shaft biased out of said operative relation to permit the simultaneous op eration of the switc members to the circuit opening position in accordance with their bias, and electroresponsive means energized in accordance with the current in the circuit controlled by the switch members forcontrolling the movement of the cam shaft in accordance with its bias.

In witness whereof, I have hereunto set my hand this 20th day of August, 1927.

FRANK E. CASE.