US2272763A - Circuit controller - Google Patents

Description

Feb. 10, 1942. AYERS 2,272,763

CIRCUITCONTROLLER Filed Nov 28, 1940 Fig.

g y INSULATION Fig.2. 4o

INSULATION i v F g 42 40 l5 INSULATION Irwventor: Edgar H. Ayers,

His Attorney.

Patented Feb. 10, 1942 CIRCUIT CONTROLLER Edgar H. Ayers, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application November 28, 1940, Serial No. 367,560

11 Claims.

My invention relates to circuit controllers and more particularly toseries rtype circuit controllers adapted to be used as starting relays in connection with split-phase alternating current motors.

In starting circuits for split-phase motors it is known to use a series relay having an operating coil in the running circuit and control contacts in the starting circuit of the motor. The motor starting relay of this type most common-ly used heretofore comprises an operating Winding connected in series with the running circuit of the motor and a pair of normally open contacts connected in series with the starting circuit of the motor. In operation, the high starting current traversing the motor running winding energizes the relay, causing it to complete the motor starting winding circuit through the relay control contacts. As the motor comes up to speed and the current diminishes in value the relay is unable to maintain its armature picked up. When the armature drops out it opens the starting circuit of the motor and the motor continues to run on its running winding only.

It will be observed that, in the type of starting relay described above, the relay contacts are designed to be closed when the relay coil is energized; thus ordinary mechanical design therefore indicates that the relay contacts would be open when the relay coil is deenergized. With such an arrangement it is necessary that the relay contacts, in closing, make a starting current which may be many times the normal operating current of the motor. The presence of such a high current upon closing of the contacts tends to cause the contacts to weld together and produces numerous other undesirable and deleterious results, as will be evident to those skilled in the art.

While these difficulties may be overcome by the use of a shunt-connected or voltage responsive relay having normally closed starting contacts, the use of a shunt relay is undesirable from a cost standpoint. It will 'be readily understood that the expense necessarily incurred in the Winding of a shunt coil having many turns of very fine wire is far greater than that incurred in the winding of a series coil formed of relatively large wire and having only a small number of turns. Furthermore, the voltage type relay in its present form is basically noiser than the current responsive type of relay.

Accordingly, it is an object of my invention to provide a series type circuit controller having normally closed control contacts.

It is a further object of my invention to provide a series type circuit controller having normally closed control contacts arranged to remain closed upon full energization of the controller and to I tudinal wall ll.

open upon subsequent partial deenergization of the controller.

Further objects and advantages of my invention will be apparent, and the invention itself will be better understood, from the following description taken in conjunction with the accompanying drawing; and the features which I be lieve to be novel and patentable will be pointed out with particularity in the appended claims. In the drawing Fig. 1 represents a top view of a controller embodying my invention; Fig. 2 is a front elevational View of Fig. 1 showing the controller in its deenergized position; Fig. 3 is a front elevational view of the controller in its partially energized position; and Fig. 4 is a circuit diagram of connections for a controller embodying my invention applied to a typical splitphase motor starting circuit.

Referring now to the drawing, I have shown my invention in one form as applied to a starting controller for a split-phase motor of the type frequently employed in a refrigeration system. However, it will be obvious that my invention has broad application to motors requiring special starting means. The controller is mounted on a base i0 formed of suitable insulating material and having a vertically projecting longi- The upper edge of the Wall ll serves as a support for a substantially U-shaped magnetizable frame l2 fixed to the wall H by rivets in and it!) or other suitable fastening means. The frame I2 is bent edgewise and has a core portion extending through the center of a current responsive operating Winding l3 and terminating in a pole piece it. Electrically connected to the frame l2 by a lead Wire [6 is a terminal l5 fixed in the base it. Positioned in spaced attractive relationship to the pole piece it is an armature ll of magnetizable material mounted upon a cantilever spring l9 and carrying a resilient contact member 20. In order to dampen oscillations of the armature H which might be produced by the alternating character of the electromotive force supplied to the coil [3, I have provided short circuited windings 2! attached to the upper end of the armature I'l. As is well understood in the art, the damping effect of the short circuited windings H is due mainly to the out-of-phase flux produced by the circulating current induced in the windings by the changing flux in the core member I2. The cantilever'spring i9 is fixedly attached at one end to the magnetizable frame l2 by any suitable means such as a rivet 22. The resilient member 23 carries a control contact 23 and, together with the armature I1 and the cantilever spring l9, constitutes a pivotally mounted movable member operative in response to energization of the pole piece M.

Biased into engagement with the control contact 23 is a contact 24 mounted upon one end of a cantilever spring 25. The opposite end of the cantilever spring 25 is fixedly attached to a portion of the insulating base I!) by any suitable means such as an internally threaded rivet 2G. The rivet 26, together with the bolt 21 cooperating therewith, constitutes another terminal of my controller. Referring now to the operating winding I3, this winding is connected at one end to the magnetizable frame [2 by any suitable means such as a welded connection 28; and the other end of the winding 13 is connected by a lead 29 to a terminal 30 fixed in the base For engaging the resilient movably mounted contact member 25 I have shown a latch member 35 pivoted on a pin 33 and including at its lower extremity a latch 31. Though the pin 36 may be attached to any convenient support, it is shown in the drawing as welded to the magnetizable frame l2. The latch member 35 is biased into engagement with the contact member 25. As clearly shown in Figs. 2 and 3, the latch member 35 is biased by the location of its own center of gravity to rotate in a clockwise direction. It will be understood, of course, that if desired the bias of the latch member toward the contact member 25 may be obtained by any other suitable means, such as a spring. As clearly shown in Figs. 2

and 3, the latch 31 is provided with two notches 1- 3B and 39, the notch 38 engaging the contact member 25 when the armature I1 is in its deenergized position, and the notch 39 engaging the contact member 25 when the armature I1 is in its fully energized position or its partially en- 2 ergized position as shown in Fig. 3. Mounted upon the armature I! I have shown a tripping member 40 carrying a tripping pin 4!. The tripping pin M is adapted to engage the substantially horizontal portion 42 of the latch member 35 when the armature I1 is in its deenergized position.

Referring now to Fig. 4, I have shown a schematic diagram of a split-phase alternating current motor comprising a running winding 45 and a starting winding 46 connected to alternating current line conductors 4'! and 48 through the winding 13 and the contacts 23 and 24 of my circuit controller. The electrical circuit through my circuit controller, schematically indicated in Fig. 4, may now be followed on Figs. 1, 2, and 3. The line conductor 41 is connected to the terminal 15; and the running circuit for the motor may be followed from the terminal I through the lead wire it, the magnetizable frame l2, the connection 28, the series winding I3, the lead 29 and the terminal 30 to the running winding 45 of the motor, and from the running winding 45 to the line conductor 48. From the terminal I5 of the controller the starting circuit may be traced through the lead wire IS, the magnetizable frame l2, the cantilever spring IS, the contact member 20, the contacts 23 and 24, the contact member 25 and the terminal connection 26 to the starting winding 45 of the motor, and from the starting winding 45 to the line can ductor 48.

In operation, when the line switch ii! of Fig. 4 is closed a high starting current traverses both the running winding 45 and the starting winding 46 of the motor and passes through the series winding [3 of the circuit controller. The high current flowing through the winding [3 attracts the armature I! from its deenergized position shown in Fig. 2 to its fully energized position (not shown) in which the armature H is directly opposite the pole face M. In the fully energized position of the controller the contact member 25 and the contact 24 have been deflected by the movable contact member to a position in which the movably mounted resilient contact member engages the notch 39 of the latch 31. It will be borne in mind that in this position the contacts 23 and 24 are still in engagement. As the motor, thus set into operation, begins to come up to speed the motor current diminishes in value until it is insufiicient to hold the armature ll of the controller in its fully energized position. The armature I"! then falls back to some intermediate position, such as that shown in Fig. 3. In the intermediate position shown in Fig. 3 the tripping pin 41 has not yet engaged the portion 42 of the tripping member 35, but the contact 23 has been sufliciently retracted to separate it from the latched contact 2%. In this position the starting winding 45 of the motor i opened at the contacts 23 and 24 and the motor is operating on its running winding 45 alone.

If new the line switch 43 of Fig. i is opened, the motor running circuit, including the series winding it will be completely deenergized and the armature ii will drop out and assume its initial position shown in Fig. 2. In falling back to its deenergizcd position the tripping pin 4! attached to the tripping member 4 engages the portion 13 of the latch member causing the latch member to rotate in a counter-clockwise direction and release the resilient contact member from the notch 39. Upon release the resilient contact member 25 springs upward, bringing the contact 24 again into engagement with the movable contact and engaging the notch 38 of the latch 37. In the deenergized position shown in Fig. 2 the latch member 35 determines the position of both the armature H carrying the contact member 2b and the position of the resilient contact member 25. It will be observed that engagement of the resilient member 25 with the notch 38 of the latch 31 tends to rotate the latch member 35 in a clockwise direction, while engagement of the tripping pin 4! with the latch member 35 tends to rotate the latch member 35 cotmterclockwise. Thus, the contact member 25, biasing the latch member 35 clockwise, holds the arm 42 of the latch member against the tripping pin 4! attached to the armature IT and thereby positions the armature. The contact member 223 is of suflicient resilience to maintain the contacts 23 and 24 in engagement in the deenergized position shown.

While I have illustrated and described only one preferred embodiment of my invention, many modifications will occur to those skilled in the art; and I, therefore, wish to have it understood that I intend by the appended claims to cover all 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 a circuit controller, a movable member carrying a first contact and having two spaced limiting positions, a movably mounted contact member resiliently biased into engagement with said first contact, latching means engaging said movably mounted contact member when said movable member is in one of said limiting positions, and tripping means mounted on said movable member and engaging said latching means when said movable member is in said other limiting position.

2. In a circuit controller, a movable member carrying a first contact and having two limiting positions, a movably mounted contact member resiliently biased into engagement with said first contact, latching means biased into engagement with said movably mounted contact member and engageable therewith when said movable member is in one of said limiting positions to hold said contacts out of engagement while said movable member is in any intermediate position, and tripping means carried by said movable member and engaging said latching member when said movable member is in said other limiting position.

3. In a circuit controller, a movable mem er carrying a contact and having two spaced limiting positions, a movably mounted contact member resiliently biased into following engagement with said contact, latching means engaging said movably mounted contact member when said movable member is in one of said limiting positions, and tripping means carried by said movable member and engaging said latching means when said movable member is in said other limiting position.

4. In a circuit controller, a pivotally mounted movable member carrying a first contact and having two spaced limiting positions, a fixedly mounted cantilever spring carrying at its free end a second contact, said cantilever spring biasing said second contact into following engagement with said first contact, a pivotally mounted latch member engaging said cantilever spring when said movable member is in one of said limiting positions, and a tripping finger mounted on said movabl member and engaging said latching member when said movable member is in said other limiting position.

5. In a circuit controller, a magnetic frame, a magnetic armature carrying a first contact and movable with respect to said frame from a deenergized to an energized position, a coil for magnetizing said frame and said armature, a contact member carrying a second contact biased into following engagement with said first contact, latch means engaging said contact member when said armature is in its energized position, and tripping means engaging said latching means when said armature is in its deenergized position.

6. In a circuit controller, a magnetic frame, a magnetic armature carrying a first contact and movable with respect to said frame from a deenergized to an energized position, a coil for magnetizing said frame and said armature, a resiliently mounted contact member carrying a second contact biased into following engagement with said first contact, latch means engaging said resiliently mounted contact member when said armature is in its energized position, and tripping means mounted upon said armature engaging said latching means when said armature is in its deenergized position.

7. In a circuit controller, a magnetic frame, a pivotally mounted magnetic armature carrying a first contact and movable with respect to said frame from a deenergized to an energized position, a coil for magnetizing said frame and said armature, a resiliently mounted contact member carrying a second contact biased into following engagement with said first contact, a pivotally mounted latch member biased into engagement with said contact member and engaging said contact member when said armature is in said energized position, and tripping means mounted upon said armature and engaging said latching member when said armature is in said deenergized position.

8. In a circuit controller, a magnetic frame, a pivotally mounted magnetic armature carrying a first contact and movable with respect to said frame from a deenergized to an energized position, a current carrying coil embracing said frame in magnetizing relation with said frame and said armature, a fixedly mounted resilient cantilever spring carrying at its free end a second contact biased into following engagement with said first contact, a pivotally mounted latching member biased into engagement with said cantilever spring and engaging said cantilever spring when said armature is in said energized position, and a tripping finger carried by said armature and engaging said latching member when said armature is in said deenergized position.

9. In a circuit controller, a resiliently mounted armature biased to a first limiting position, a first contact mounted upon said armature, a movably mounted contact member biased into engagement with said first contact, means for moving said armature and said contact member to a second limiting position spaced from said first position, and latch means for retaining said contact member in said second position until said armature returns to said first position.

10. In a circuit controller, an insulating support, a magnetic frame mounted upon said support, a first cantilever spring having one end mounted upon said frame, a magnetic armature mounted upon the free end of said first spring and having an end movable with respect to said frame from a deenergized to an energized position, a first contact resiliently mounted upon said armature, a current carrying coil embracing said frame in magnetizing relation to said frame and armature, a second cantilever spring carrying at its free end a second contact biased into following engagement with said first contact, a pivotally mounted latching member biased into engagement with said second cantilever spring and engaging said spring when said armature is in said energized position, and a tripping finger carried by said armature and engaging said latching member when said armature is in said deenergized position.

11. In a circuit controller, a movable member carrying a movable contact and having a predetermined normal position, a second contact resiliently biased into following engagement with said movable contact and arranged to control a first circuit, latch means for retaining said second contact out of engagement with said movable contact, means responsive to a predetermined high current in a second circuit to actuate said movable member to move said second contact to latching position while said contacts remain engaged, said means being arranged to return said movable contact to an intermediate position upon a diminution of said current thereby to disengage said contacts, and trip means actuated by said movable member upon return of said member to said normal position for releasing said latch means thereby to permit said second contact to reengage said movable contact.

EDGAR H. AYERS.

Images