US2064657A - Control device - Google Patents

Description

Dec. 15 1936. R. w. GOFF 2,064,657

CONTROL DEVICE Filed Feb. 28, 1935 Inventor.-

His Attovneg- Patented Dec. 15', 1936 PATENT OFFICE CONTROL DEVICE Robert W. Gofi, Schenectady, N. Y., assignor'to General Electric Company, a corporation of New York Application February 28, 1935, Serial No. 8,653

10 Claims.

My invention relates to control devices, more particularly to control devices of the type which are operable to close an electric circuit and which are incapable of maintaining the circuit closed beyond a predetermined period of time, and hasfor an object the provision of a simple and reliable device of this type.

In various electrical circuits, it is desirable to close an initial energizing circuit to an electroresponsive device for a predetermined time only. For example, where an electroresponsive device is employed to protect a circuit against voltage failure, the device is usually provided with means for establishing an initial energizing circuit and with means for establishing a holding circuit'to' maintain the device energized in accordance with the voltage of the circuit to be protected. In order that the initial energizing circuit may not be manually held closedupon a failure or a dip in the voltage, it is desirable that the control device for establishing the initial energizing circuit shall be incapable of maintaining this energizing circuit closed regardless of the position in which the control device is held. Much is yet to be desired in a foolproof device of this type which is simple and reliable and which cannot be held in a circuit-closing position. Accord-' ingly, it is a further object of my invention to provide a foolproof control device sequentially operable to a plurality of positions to establish an energizing circuit, which device includes time delay means for maintaining the circuit closed for a predetermined time, the device being incapable of maintaining a closed circuit after the time delay means has operated.

In carrying out my invention in one form, I provide a control switch comprising a member sequentially movable to a plurality of positions to close a plurality of pairs of contacts which are connected in series circuit relation in an electrical circuit. One pair of contacts is normally biased to open circuit position and is released for movement to that position under the influence of suitable time delay means when the mov able member is moved to close another pair of contactswhereby the movable member is incapable of being so operated as positively to retain all of the contacts in closed circuit position.

For a more complete understanding of my invention, reference may now be had to the drawing, in which Fig. 1 illustrates diagrammatically an undervoltage protective system provided with a control switch embodying my invention, and Fig. 2 illustrates diagrammatically the applica tion of a control switch embodying my invention to a different type of undervoltage protective systern.

Referring now to the drawing, I have shown in Fig. 1 an undervoltage protective system comprising an electroresponsive device In arranged to be initially energized through a control switch H embodying my invention, to establish a holding circuit for the electroresponsive device l0 whereby after my improved control switch has completed its cycle of operation, the electroresponsive device l0 remains energized in accordance with the voltage of the circuit to be protected. As shown, the electroresponsive device l0 comprises an energizing winding l2 and. a movable core I3 which is connected by means of alink l4 and an arml5 to a rotatable shaft IS on which are resiliently mounted a pair of bridging members I! and [8 for respectively completing a circuit through a plurality of pairs of stationary contacts I9, 20, and 2|; 22 from a pair of supply lines 23 and 24 to a load circuit such, for example, as an electric motor which may be connected to the conductors 25 and 26.

The control switch H for initially energizing the winding l2 of the electroresponsive device l0 comprises an operating arm 21 secured to a rotatable shaft 28 on which is mounted an insulated control member 29 provided with a pair of laterally extending flanges 30 and 3|. It will be apparent that the operating arm- 21 may be moved by anysuitable means. In certain applications of my invention, for example, in the control of manufacturing machinery; it is desirable to operate the control switch H from a distance and in such a case the arm 21 may be operated by means of a suitable operating lever or shipper rod.

As shown, a portion of the flange 3| is cut away to provide a notch therein which is bounded by the portions 32 and 33 of the flange. Ex-

tending into the notch in the flange 3| is an arm 34 of a bifurcated operating member which is secured to a rotatable shaft 35, the other arm 36 of the bifurcated member being connected to a link 37 upon which is mounted a wiping spring 38 for resiliently supporting a bridging member 39 in co-operating relation with a pair of stationary contacts '40.

Mounted on the rotatable shaft 35 is atiming device indicated generally by the reference numeral 4 i. This timing device 4 I, which I have illustrated somewhat diagrammatically, is preferably of the type described and claimed in Patent No. 1,967,880, issued July 24,' 1934, to William J. Fleming and me, and comprises an oscillating weight 42 arranged to be driven by an escapement gear 43 connected to a shaft 44 which operates a driving member 45 adjustably secured to a pin 48, one end of which nests within a slot 4! in the oscillating weight 42. The rotatable shaft 35 supports a second escapment gear 48 and in order that the shaft 35 may be rotated in one direction without interference from the timing device 45, the escapement gear 48 is provided with a one-way clutch which is effective to connect the escapement gear 48 to the shaft 35 only when the shaft 35 rotates in a counterclockwise direction, as viewed in the drawing, relative to the gear 48. As shown, the escapement gear 48 is cylindrical and the inner surface thereof is provided with a plurality of serrations or very fine gear teeth 49 arranged to be engaged by a plurality of pivoted fingers, one of which is indicated by the reference numeral 50, supported on a spider 5| secured to the shaft 35. It will be apparent that when the shaft 35 is rotated in a clockwise direction, the fingers 50 will move over the teeth 45 without establishing a driving connection between the shaft 35 and the escapement gear 48, and that when the shaft 35 is rotated in a counterclockwise direction, the pivoted fingers 50 will engage the teeth 49 to drive the escapement gear 48 with the shaft 35.

Supported between the flanges 30 and 3| of the rotatable insulating member 29 is a bridging member 52 of conducting material arranged to co-operate with a pair of stationary contacts 53 which are connected in series circuit relation with the stationary contacts 40.

Having in mind the construction and arrangemetit of the principal elements thereof, it is believed that a complete understanding of my invention may now be had from a description of the operation. In the drawing the control switch H is shown in a neutral position with the contacts 40 and 53 in open circuit relation, and the electroresponsive device In is in its deenergized position with the load circuit represented by the conductors 25 and 26, disconnected from the supply lines 23 and 24. In order initiallyto energize the electroresponsive device Hi, the arm 21 is rotated in a counterclockwise direction as viewed in the drawing to its first position and it will be.

apparent that the portion 32 of the flange 3| engages the arm 34 to rotate the shaft 35 in a clockwise direction and to operate the bridging .member 39 into engagement with the contacts 40. Closing the contacts 40, however, has no immediate effect since the circuit therethrough is open at the contacts 53. The arm 21 may now be operated in a clockwise direction to its second position in which the bridging member 52 engages the contacts 53 to complete an initial -energizing circuit for the energizing winding I2 of the electroresponsive device III. This circuit may be traced from the supply line 24 through the conductor 54, by way of the contacts 40 and the bridging member 39 to the conductor 55, by way of the contacts 53 and the bridging member 52 to the conductor 58, through the energizing windin. l2 and the conductor 51 to the supply line 23.

The operating mechanism for the bridging member 39 which comprises the arms 34 and 36 and the shaft 35 is normally biased to the position shown in the drawing either by gravity or by a spring 55, and as soon as the operating arm 2? is moved i a clockwise direction to operate the insulating member 23 from its first position to its second position, the portion 32 of the flange 3| moves away from the arm 34, and the operating mechanism for the bridging member 39 will be released for movement in accordance with its bias within the notch in the flange 3|. Movement of the arms 34 and 36 in this direction, however, is retarded by the time delay mechanism 4|, and the spring 38 provides suflicient lost motion between the link 31 and the bridging member 39 to prevent opening of the circuit through the contacts 40 until after the circuit has been completed through the contacts 53.

Upon initial energization of the device ID, the bridging members I! and i8 are operated to connect the load circuit represented by the conductors 25 and 25 to the supply lines 23 and 24 through the contacts I!) to 24 inclusive, and a holding circuit for the device |0 is thereby established which may be traced from the supply line 24 through the contact 22, the bridging member l8, the contact 2|, the conductors 28 and 56, the energizing winding l2, and by way of the conductor 5'! to the supply line 23. Subsequent operation of the bridging member 39 to open the initial energizing circuit through the contacts 40 is therefore ineffective to deenergize the device H), which remains energized in accordance with the voltage applied to the load circuit represented by the conductors 25 and 26.

It will be apparent now. that the control device cannot be held in a position to maintain closed the initial energizing circuit through the contacts 40 and 52 after the time delay mechanism 4| has operated and that the load circuit is protected against undcrvoltage conditions by the device H) which operates to interrupt the circuit through the bridging members I! and 8 upon a dip in voltage, thereby interrupting the holding circuit for the winding 2.

In the embodiment of my invention shown in Fig. 2, I have illustrated an undervoltage protective system comprising an electroresponsive device 60 and a control device 6| embodying my 61 whichis connected by means of a link 68 and an arm 69 to a rotatable shaft 10 on which are resiliently mounted a pair of bridging members 1| and 12 in co-operating relation with a plurality of pairs of stationary contacts 13- and I4.

In this embodiment of my invention, the control device 6| comprises an operating arm 15 secured to a rotatable shaft 16 on which is mounted an insulated control member 11 provided with a pair of laterally extending flanges l8 and 19. The control member 11 is similar to the control member 29 shown in Fig. 1 and accordingly, the flange 19 is provided with a notch and a conducting bridging member 8| is supported between the flanges I8 and 19 for co operation with a pair of stationary contacts 82.

Arranged adjacent the control member 11, I provide an electromagnet 83 comprising a magnetic frame 84, an energizing winding 85 and the movable magnetic element 86 normally biased by gravity to its unattracted position. Extendin from the magnetic frame 84 is a pin 81' on which is pivotally mounted a bifurcated member having an arm 88 extending into the notch 80, the other arm 89 of the bifurcated member being connected by means of a link 90 and a pin 9| to the movable magnetic element 86. As shown,

the movable magnetic element 86 is connected to suitable time delay mechanism indicated generally at 92 in order to control a movable switch member 93 pivoted at 94 and biased by spring 95 in a direction to close the circuit to a pair of contacts 66 connected in series circuit relation with the contacts 82, the time delay mechanism being arranged normally to hold the switch member 93 in its open circuit position when the magnetic element 86 is in its normal unattracted position.

Although any suitable time delay mechanism may be provided which is operable in one direction with a time delay and operable substan- .-tially instantaneously in another direction, I

h ve shown for purposes of illustration a time delay mechanism of the type described and claimed in my copending application Serial No. 8,652, filed February 28, 1935, which application is assigned to the same assignee as the present invention. As shown, the time delay mechanism 92 comprises a segmental gear 91 connected to the magnetic element 86 by a link 98 and provided with an end portion 89 for operating the switch member 93. Thesegmental gear 91 is pivoted on a pin I and is operable upon movement of the magnetic element 86 to drive a toothed element or pinion IOI which in turn, drives a timing device similar to the device 49 shown in Fig. 1. In this embodiment of my invention, the timing device comprises an escapement gear I02 connected to a shaft I03 which operates a driving member I04 adjustably secured to a pin I05, one end of which nests within the slot I06 in an oscillating weight IN. The oscillating weight I0! is rotatably supported on a shaft I08 to which the pinion IN is secured ,for driving a second escapement gear I09 through a one-way clutch (not shown).

For purposes fully described in my copending application, the pivot pin I00 for the segmental "description of the operation. When it is desired to energize the load circuit represented by the conductors 64 and 65 from the supply lines 62 and 63, the operating handle I is first moved by any suitable means to rotate the control member IT in a counterclockwise direction as viewed in the drawing, and the flange I9 will thereupon operate the arm 88 to raise the magnetic element 86 to its attracted position. As the magnetic element 86 is raised, the segmental gear 61 1s rotatedto release the switch member 83 for movement to bridge the contacts 96 in accordance with the bias exerted by the spring 95, the segmental gear 91' rotating the pinion IOI independently of the timing mechanism due to the one-way clutch within the 'escapement gear I08.

The operating handle I5 may now be rotated from its first position in a clockwise direction to its second position, in which position the bridging member 8| engages the fixed contacts 82 and the magnetic element 86 will begin to move to its normal position, the arm 88 being released for movement within the notch 80.

However, the time delay mechanism isnow effective'to retard movement of the magnetic element 86 and the segmental'gear 9'I and-accordingly, these members will not move sufiiciently to actuate the switch member 93 until after the bridging member 8| has completed an energizing circuit for the electroresponsive device 66. This circuit may be traced from the supply lead 63 through the conductor II2, the contacts 82 and the bridging member 8i. the conductor 3, the contacts 66 and the bridging member carried by the switch member 93, the conductor H4, the energizingwinding 66 and. the conductor II5 to the supply lead 62. Upon energization of the winding 66, the movable member 6! of the. electroresponsive device 60 will be operated and the bridging members II and I2 will respectively engage the contacts I3 and I4, thereby connecting the load circuit to the supply lines and establishing an energizing circuit for the winding 85 of the electromagnet 83, which energizing circuit may be traced from the supply line 63 through the contacts I4 and the bridging member I2, the conductors 65 and II 6, the energizing winding 85 and the conductor II I to the supply line 62. The movable magnetic element 86 will now be magnetically operated to its attracted position and accordingly, the switch member 93 is permitted to maintain a,.closed circuit through the contacts 96.

It will be apparent now that the electroresponsive device 60 and the electromagnet 83 will remain-energized so long as the voltage across the supply lines 62 and 63 is maintained at a normal value. Upon the occurrence of a dip in voltage of sufficient magnitude to release the movable member 61 of the device 60, the bridging members II and 12 will be operated to disconnect the load circuit from the supply lines and to deenergize the winding 85 of the electromagnet 83, the movable element 86 of which will then begin to move towards its unattracted position under the influence of the timing mechanism. In the event that normal voltage is restored to the supply lines 62 and 63 before the segmental gear 91 has moved sufiiciently to operate the switch member 93, the winding 66 will be energized through the previously traced circuit to reclose the bridging members II and I2 and reenergize the winding 85. However, if the dip in voltage continues for an interval of time greater than that [or which the timing device is set, the segmental gear 91 will operate the switch member 93 to open the circuit through the contacts 96. cuit may then be reconnected to the supply lines only by operating the control device 6I in the manner described above.

It will be apparent that when the device 6| has been so operated as to establish energizing circuits for the electroresponsive device.60 and the electromagnet 83, the control member 11 of the control device 6| cannot be held in such a position as to maintain a closed circuit during the occurrence of undervoltage conditions.

The load circuit may be disconnected from the supply lines at any time by moving the operating handle I5 of the control device H in a counterclockwise direction from its second position to open the energizing circuit for the winding 66 through the contacts 82.

While I have shown a particular embodiment of my invention, it will be understood, of course,

The load cirthat I do not wish to be limited thereto since many modifications may be made and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

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

1. In combination, a control member movable between a plurality of positions, means responsive to movement of said control member to onev position for partially completing an electric circuit, means responsive to movement of said control member to a second position for completingv said partially complete circuit, said first-mentioned means being normally biased to open circuit position and being released for movement in accordance with its bias when said control member is moved from said one position to said second position, and time delay means for preventing said first-mentioned means from moving tosaid open circuit position for a predetermined time after said control member moved from said one position.

2. In combination, a control member movable between a plurality of positions, a first pair of contacts, means responsive to movement of said control member to one position for controlling said first pair of contacts, a second pair 01' contacts, means responsive to movement or said control member to a second position for controlling said second pair of contacts, said first pair of contacts being immediately released for movement to normal position upon movement of said control member from said one position, and time delay means for preventing said first pair of contacts from returning to normal position for a predetermined time after said control member is moved from said one position.

3. In combination, a control member movable between a plurality of positions, a first pair of contacts normally biased to open circuit position, means responsive to movement or said control member to one position for operating said contacts to closed circuit position, a second pair of contacts, means responsive to movement of said control member to a second position for closing said second pair of contacts, said first pair of contacts being immediately released for movement to said biased position upon movement of said control member from said one position, and time delay means for preventing said first pair of contacts from moving to said biased position for a predetermined time after said control member is moved from said one position.

i. In combination, a control member rotatable between a plurality of positions, said member including a flange provided with a notch, means including an arm extending into said notch for partially completing a circuit upon movement of said control member to one position, means including a bridging member carried by said flange for completing said partially complete circuit upon movement of said control member to a second position, said notch and said arm having sufiicient lost motion to permit said arm to remain in its circuit completing position when said control member is moved from said one position, said arm being biased to open circuit position, and time delay means for preventing said arm from moving to open circuit position for a predetermined time after said control member is moved from said one position.

5. In combination, a control member rotatable between a plurality of positions, said control member including a fiange provided with a notch,

a first pair of contacts normally biased to open circuit position, means including an arm extending within said notch for operating said contacts to closed circuit position upon movement of said control member to one position, a second pair of contactsfimeans including a bridging member carried by said flange for closing a circuit through said second pair of contacts upon movement of said control member to a second position, said notch and said arm having sufiicient lost motion to permit said arm to remain in circuit closing position when said control member is moved to said second position, and time delay means for preventing said first pair of contacts from returning to open circuit position in accordance with the bias thereon for a predetermined time after said control member is moved to said second position.

6. In combination, a control member movable between a plurality 01' positions, an electromagnet having a movable magnetic element normally biased to unattracted position, means responsive to movement of said control member to one position for operating said magnetic element to attracted position, means responsive to operation or said magnetic element to said attracted position for partially completing a circuit, means responsive to movement of said control member to a second position for completing said partially complete circuit, said magnetic element being releasable for movement to said unattracted position when said control member is moved from said one position to said second position, time delay means for preventing said magnetic element from returning to said unattracted position to open said circuit for a predetermined time, and means responsive to completion of said circuit for energizing said'electromagnet to maintain said magnetic element in its attracted position.

*7. In combination, a control member movable between a plurality of positions, a first pair of contacts, an electromagnet having a movable magnetic element normally biased to unattracted position, means responsive to movement of said control member to one position for operating said magnetic element to attracted position, means responsive to operation oi! said magnetic element to said attracted position for closing said first contacts, a second pair of contacts, means responsive to movement of said control member to a second position for closing said second contacts, said magnetic element being releasable for movement to its biased position to open said first contacts when said control member is moved from said one position to said second position, time delay meansfor' preventing said magnetic element from returning to said unattracted position for a predetermined time, and means responsive to closure of a circuit through both of said pairs 01' contacts for energizing said electromagnet to maintain said magnetic element in said attracted position.

8. In combination, an electroresponsive device including means for establishing a holding circuit therefor when said, device is energized, control means for sequentially establishing and interrupting an initial energizing circuit for said electroresponsive device, whereby said device is maintainedin its energized condition solely by said holding circuit, said sequential means comprising a control member movable between a plurality of positions to close a plurality of pairs oi contacts, lost motion means for preventing one pair of contacts from being held in closed circuit position by said control member when said control member is in position to close a second pair of said contacts, and time delay means for preventing said one pair of contacts from opening before said second pair of contacts is closed by said control member.

9. In combination, an electroresponsive device having means for establishing a holding circuit therefor when said device is energized, control means for sequentially establishing and interrupting an initial energizing circuit for said electroresponsive device, whereby said device is maintained in its energized condition solely by said holding circuit, said sequentialmeans comprising a control member movable between a plurality of positions, means responsive to movement of said control member to one position for partially completing said energizing circuit, said circuit completing means being normally biased to open circuit position and being immediately released for movement in accordance with its bias when said control member is moved from said one position, means responsive to movement of said control member to a second position for completing said energizing circuit, and time delay means for preventing said first circuit completing means for moving to open circuit position for a predetermined time after said control member is moved from said one to said second position.

10. In combination, an electroresponsive device including means for establishing a holding circuit therefor when said device is energized, means for sequentially establishing and interrupting an initial energizing circuit for said device, whereby said device is maintained in its energized condition solely by said holding circuit, said sequential means comprising a control member movable between a plurality of positions, a first pair of contacts connected in circuit with said electroresponsive device and normally biased to open circuit position, means responsive to movement of said control member to one position for operating said contacts to closed circuit position, asecond pair of contacts connected in series circuit relation with said first pair of con- ROBERT W. GOFF.

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