US2310730A - Circuit controller - Google Patents

Description

Feb. 9, 1943; w. L BUTLER Erm.

CIRCUIT CONTROLLER Filed June 18, '1941 a4A Inventors: 49 l/l/llemfwl Lawrence Butler` George l\/l. llaLJSle Tlfweir` Attorney.

armatures cooperate motor starter which Patented F el.v 9, 19-4-3 2,310,730 CIRCUIT CONTROLLER William Lawrence Butler,

Schenectady, and

George M. Hausler, Ballston Lake, N. Y., asslgnors to General Electric Company, a corporation of New York Application June 18, 1941, Serial No. 398,608 (ci. irs-336) 8 Claims.

Our invention relatesto circuit controllers and particularly to multi-point motor starters of the type disclosed in Patent 2,223,278, issued on November 26, 1940, to Fred H. Winter.

The motor starter disclosed in the above Winter patent comprises a contactor having a plurality of armatures which are arranged for sequential drop-out to control a plurality oi normally closed resistance shunting switches. The

with magnetically independent cores whichl are arranged for simultaneous eriergizationv by a single actuating coil. The starter also includes certain interlock switches which have a particular utility in connection with systems similar to those disclosed Vin the s patent.

An object oi our invention generally stated is to provide a motor starter of the above type which shall have improved emciency'of operation and which shall be inexepensive and easy to manufacture in large quantities.

The principal object of our invention is to pro.. vide, in a motor starter of the above type, an armature suspension and contact arrangement which shall prevent undesirable vibration and chattering of the contacts in their closing operation.

and assembly, inexpensive to manufacture, and eicient in operation.

It is a still further object of our invention to provide contact adjusting means for such a shall be lsimple and efllcient and which shall insure a predetermined minimum Contact pressure at all times.

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Accordingly, the invention preferably com-` prisesa circuit controller composed of a frame carrying an electromagnet having a plurality of independently operable armatures and a contact carrying head portion mounted above said electromagnet and having contacts sequentially operable by said armatures. The movable motor controlling contacts are carried by light canti-` lever springs which are adjustably attached to the head portion of the controller to insure a minimum contact pressure at all times. For fastening each armature to its associated core and simultaneously biasing the armatures to deenergzed positions spaced from the cores, we provide each armature with a channel shaped hinge member of spring metal stamped to provide a plurality of spring lingers engageable with a pro- `iection on one leg of the core. As will become more evident hereinafter, this form of armature hinge is extremely simple in construction, consists of a minimum number of parts, is efficient in operation and is inexpensive to manufacture and assemble. In addition to the foregoing advantages, the hinge also performs the dual function oi. both pivotally connecting the armature to the frame and biasing it to its normal position.

To the attainment of the foregoing and other objects and advantages, our invention in one form is preferably embodied in the detailed construction to be hereinafter more fully described and claimed, and is illustrated in the accompanying drawing in which Fig. 1 is a side elevation, partly in section, of our circuit controller snowing the armatures in their normal deenerglzed positions; Fig. 2 is an end view of the controller with the parts in the same positions as in Fig. 1; Fig. 3 is a plan View of the controller showing particularly the interlock switch assembly on the controller head; Fig. 4 is a fragmentary View similar. to Fig. 1 showing the movable parts of the controller in their actuated positions; and Fig. 5 is an enlarged perspective View of an armature hinge construction embodying our invention.

Referring now to the drawing, our circuit controller in one form comprises a frame including a base plate I i! upon which are mounted three U-shaped magnetic cores II, I2 and I3 and four perpendicular mounting studs I4, I5, I6 and Il, and a contact head assembly generally designated by the numeral I8 supported upon the studs I4, I5, I6 and I1. The three U-shaped cores II, I2` and I3 are disposed in alignment with their side legs extending perpendicularly from the base I0 to facilitate the mounting of a common actuating coil I9 upon the forward legs of all the cores.

As best shown at Figs. 1 and 4, each of the U- shaped cores is provided with a magnetic armature 2Il arranged across the end faces of the core legs in transverse abutting relation thereby to bridge the gap between the legs at their outer ends. Since the three electromagnets are of similar construction, only one need be described by way of example. The armature 20 of Fig. 1 is pivotally mounted adjacent the end face of the rear leg of the corevII and biased. to a normal position in spaced relation to the end face of the forward core leg by means of a resilient hinge member 2l. Referring now particularly to Fig. 5, it will be observed that the resilient hinge member 2| is channel shaped in cross section and is stamped to provide a pair of connected bowed spring fingers 25 and 23 extending upwardly from the lower end ofthe hinge. Adjacent the armature 20 the hinge member 2| is bent inwardly to provide a shoulder 21 positioned to engage the outside of the back leg of the core I I. Preferably the hinge member 2| is'placed against an end surface of the armature 20` in a plane perpendicular to the sides of the amature and is fastened to the amature in this position by any suitable means such as welding at 23. Adjacent its upper end facethe rear leg of the core member is provided with a generally T-shaped projection .23 forming upon its side nearest the base I a transverse notch 30 adapted to receive the free ends of the spring ilngers\25 and 26. The notch 30 is preferably slightly oifset laterally from the leg of the corey Il. as is best shown at Fig. 5. 'Ihe other side of the T-shaped projec= tion 29 forms with the rear leg ofA the core II a transverse groove 3l within which the shoulder 21 is seated in the assembled position. As may now be seen by examination of Figs. 1 and 4, the rear face of the armature 20 slightly overhangs the rear leg of the core Il due to the presence of the inwardly turned shoulder 21. Because of this slight overhang the longitudinally extending hinge 2i lies in paralleispaced relation to the rear leg of the core when the armature 20 is in its attracted position. The drop-out movement ofthe armature 20 is limited by engagement of the lower end of the hinge 2| with the core leg.

In operation the armature 2li pivots about the knife edge formed by the inwardly projecting shoulder 21 in moving from its deenergized position in Fig. 1 to its attracted position of Fig. 4. In pivoting about the knife edge 21 to the position of Fig. 4 th'e lower end of the hinge 2i moves through an are which brings it closer to thenotch 30 against the bias of the spring fingers 25 and 26. The tendency of the spring fingers 25 and 26 to assume a straight position normally forces the lower end of the hinge member 2l to the position shown in Fig. 1 and thus biases the armature 2li to its deenergized position spaced from the front leg of the core I I.

The movable ends of the armatures 20 are arranged to engage the end faces of the front legs of the cores II, I2 and I3 in their actuated positions. Since it is essential to the operation of this device that the drop-out voltage of each .of the armatures be accurately predetermined,` it

is necessary to provide means for preventing the armatures from'sticking to their associated cores due to th'e residual magnetism of the cores. For this purpose we have shown shims 32 of suitable non-magnetic material fastened to the lower sides of the armatures 20 in the region of their engagement with the cores II, I2 and I3.

To provide for operating the various motor controlling and interlock contacts associated with our circuit controller the movable end of the armature 20 has attached thereto a block of insulating material 33 formed to provide a contact operating pin 34 and a damping buier 35.

Th'e contact carrying controller head I8 comprises a at base 40 formed of a molded insulating compound and mounted upon the outer ends of the studs I4, I5, I and I1. The base 40 has mounted upon the inner side thereof a plurality of movable motor controlling contacts 4I and carries upon its outer surface a number of interlock contacts which preferably are connected in circuit as shown in the above-mentioned Winter Patent No. 2,223,218 and will be described in greater detail hereinafter. As best shown at Figs. 1 and 4, each of the movable motor controlling contacts 4I is mounted upon the free end of a relatively light cantilever spring 42 which' is biased toward the base 40 to hold the contacts ,4I

5 in engagement with cooperating fixed contact strips 43 mounted upon insulating base 40. Each of the iixed contact strips 43 is formed to provide at the opposite end l the insulating base 40.

Each cantilever spring 42 is connected in spaced relation to the inner side of the base 4D by means of a bolt 45 extending through the base 4@ 'and threaded into'a plate 4% below the spring. The contact carrying cantilever springsf42 are thin and of relativelysmall mass so that their inertia and hence their tendency to rebound after engaging the stationary contacts 43 are minimized. To further assist in preventing rebound of the movable contacts 4i and to increase the contact pressure when the contacts are in their normal closed positions, a second `relatively heavy cantilever spring 41 is also mounted upon each' bolt 45 adjacent and parallel to the spring 42. As shown in Winter Patent 2,223,278, all the movable contacts of this type of circuit controller are'connected together to a common external terminal. VIn our improved controller this connection is effected and the cantilever springs 42' and 41 are spaced from the base 40 by a T-shaped co'ntact i plate 42 which extends across the rear side of the base 4B and is pierced by each of the spring securing bolts 45 (Fig. 3). The contact plate 48 also extends `beyond the rear side of th'e base 40 to provide a common external terminal connector. The heavy springs 41 are biased toward the base and into engagement with the relatively light springs 42 along substantially their entire length.

To provide for operative connection of the conv 4Q tacts 4I to the movable ends of the armatures 2B, the relatively heavy springs 41 are slit and bent toward the armatures to form slotted hangers 49 to receive the pins 34 and to leave central for- Wardly extending pins 50. 'I'h'e free ends of the light cantilever springs 42 are similarly slotted and bent toward the armatures in parallel spaced relation to the hangers 49 to form hooks 55 for engaging the pins 50. Since the springs 4 1are biased toward the controller head I8, the hangers 50 49 assist the spring hinges 2l in moving the armatures to their deenergized positions.

In order to insure a constant preadjusted minimum pressure at the contacts 4I, 43 the cantilever springs 42 and 41 are provided with' an adjusting bolt 60 which passes through the insulating base 40 slightly forward of the spacer 48 and is threaded into the plate 46 to draw the cantilever springs 42 and 41 toward the base 40. Each bolt 50 comprises a lower externally threaded shank portion extending from the bottom of the base 40 and a cylindrical head 6I positioned withl a cylindrical recess Bla in the base 40 and seated upon a shoulder formed at the bottom of thev recess.

6 To provide for application of additional tension to the cantilever springs whereby the separate armature 20 may be independently adjusted to drop out in sequential timed relation as the energization of the actuating coil I9 decays, the cylindrical bolt heads 6I are threaded longitudinally to receive second adjusting bolts 62. 'I'he heads of the bolts 62 are seated upon removable plates or washers 63 which rest upon shoulders formed by the top of the recesses Bla. thereby to raise the the inner side of the.

thereof a terminal conductor extending beyond justments is preferably assured by soldering the lower bolt 80 to the threaded plate 43 as indicated at 84. With the minimum contact pressure adjustment completed for each of the motor controlling contacts, the plate 83 and the bolts '82 may be replaced. The bolts 62 may now be adjusted to determine the drop-out voltages of the various armatures thereby to provide a timing adjustment for the various motor controlling contacts to insure the desired sequential closure of the contacts as the energization of the coil I9 decays. If desired the permanence of the timing adjustment when obtained may be insured by soldering the bolts 82 to the non-rotatably seated plates 83.

Mounted on the outer surface of the insulating base 40 we have shown a pair of interlock contacts 85 and 88 carried at opposite ends of a strip 81 of electrically conducting material. The interlock contacts 85 and 88 may, of course, be used in any desired circuit relation, but when our circuit controller is used in connection with the motor controlling system of Winter Patent 2,223,278 we prefer t connect the contacts 65 and 68 in series in a manner similar to the interlock contacts 29a and 29h of the patent. The conducting strip 81 is slotted and slidably mounted upon a pair of studs 88 and 89 projecting from the base 4,0. To bias the contact stripv 81 toward the base 4|! and into contact engaging position a pair of compression springs 10, 1| are mounted between the strip 61 and a pair of stops 12, 13 upon the studs 88, 69 respectively. As shown in Figs. 1 and 2, when the three armatures 20 are in their deenergized positions the contact strip 81 is forced to contact disengaging position against the bias of the springs and 1| by a plurality of slidable pusher rods 15, 18 and 11. Each of the rods 15, 16 and 11 passes through the insulating base 40 and engages one of the relatively stiff contact springs 41. The upper ends of the pusher rods 15, 15, 11 are provided with shoulders engaging the under side of the contact strip 61 and with extending tongue portions passing through the contact strip.

|I'he extending tongue portions of the pusher rods are provided on all the rods only for the purpose of uniformity, since in our preferred form of contactar only one of these extending tongue portions is used. It will be understood, however, that, if desired, additional interlock switches may be added in connection with the extending tongues of the other pusher rods. By way of example we have shown a normally closed interlock contact 80 connected to one end of a pivoted lever 8|, the other end of which engages the extending tongue .of the pusher rod 11. 'I'he lever 8| is pivoted to a projecting stud 82 mounted upon the base 40 and is biased to contact opening position by a compression spring 83. However, with the circuit controller in its deenergized condition the pusher rod 11 is raised and holds the interlock contact 80 in its closed position. When our circuit controller is used in the system disclosed in the above mentioned Winter patent we prefer to connect the interlock contact 80 in a manner similar to the interlock contact 28 of the patent.

In operation, when the actuating coil I8 is energized the three cores I2 and I3 are simulteneously magnetized and the three armatures 20 are simultaneously drawn to their attracted positions. As each armature 20 begins to move toward its attracted position it draws with it the relatively heavy spring 41. After a certain amount of lost motion the forwardly extending pin 50 on the free end of the spring 41 engages the hook 55 on the relatively light spring 42 and draws the spring 42 away from the base 40 to open the motor controlling contacts 4|, 43. -As the armatures 20 move toward their attracted positions the consequent movement of the free ends of the springs 41 permits the springs 10 and 1| to depress the contact strip 81 and the pusher rods 15, 18 and 11 thereby to close the contacts 65 and 88. This movement of the pusher rod 11 also permits the spring 83 to rotate the lever 8| in a clockwise direction, as viewed in Fig. l, to open the interlock contact 8U as at Fig. 4.

As shown in the Winter patent, release of a manually operated start switch removes the actuating coil from the line and permits the charge of a timing condenser gradually to decay through the coil |9. As the energization of the coil diminishes the armatures 20 are released in sequential time relation as determined by the thickness of the shims 32 and by the adjustment of the various bolts 82 previously described. As each armature 2li is released it moves away from the core along with both of the springs 42 and 41. When the contact 4| engages the fixed contact 43 the relatively light spring 43 ceases its movement and the heavy spring 41 and the armature 2|) continue to move to take up the lost motion. As has been previously pointed out, the inertia of the relatively light spring 42 is so small that no appreciable rebound of the contact occurs upon its initial engagement. kAs the heavy spring 41 continues to take up the lost motion after engagement of the contacts 4| and 43 it gradually engages the light spring 42 along an ever increasing length thereby gradually to increase the contact pressure and to assist in preventing rebound of the contact 4|. The armature 2U follows the heavy cantilever spring 41 so that the butler 35 of the armature, which is closely adjacent the spring 41, tends to prevent oscillation of the heavy spring.

Regardless of which of the armatures 20 is first released. the release of the ilrst armature raises the associated pusher rod to open either the contact 65 or the contact B6 and thus break the series interlock circuit through these contacts. If our circuit controller is used in either of the control systems disclosed in the Winter patent. the last armature to be released is that associated with the core I3 and the pusher rod 11. When this last armature is released the pusher rod 11 engages the lever 8| and rotates it in a counterclockwise direction, as viewed in Fig. 1, thereby to reclose the interlock contact 80.

While we have shown but one preferred embodiment of our invention by way of illustration` many modifications will occur to those skilled in the arts, and we therefore Wish to have it understood that we intend by the appended claims to cover all such modiiications as fall within the true spirit and scope' of our invention.

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

1. In an electromagnetic circuit controller, a magnetic core having an extending leg defining an end face, one side of said leg being lprovided with a projection adjacent said end face, a magnetic armature extending transversely of said leg in abutting relation thereto, and spring means fastened to said armature and engaging said leg on one side of said projection, said means extending longitudinally of said leg resiliently to engage the other side of said projection thereby to connect said armature to said leg and to bias said armature for pivotal movement about said one side of said leg away from said end face.

2. In an electromagnetic circuit controller, a magnetic core having an extending leg deiining an end face, said leg beingprovided with a projection on one side thereof adjacent said end face, a magnetic armaturev extending transversely of said leg in abutting relation thereto, and a resilient channel shaped hinge member connected to said armature and engaging said one side of said leg on one side of said projection,- said hingemember extending longitudinally ot said leg beyong said projection, and resiliently engaging the other side of said projection to connect said armature to said leg and to bias said armature for pivotal movement about said one side of said leg away from said end face.

3. In an electromagnetic circuit*l controller, a magnetic core having an extending leg deiining an end face, said leg being provided with a projectionA on one side thereof adjacent said face, said projection being formed to provide a transverse groove on the side adjacent said end face, a magnetic armature having one end positioned against said end face in abutting relation thereto and extending transversely of said leg, and a channel shaped hinge member connected to said one end of said armature and interlockingly engaging said transverse groove, said hinge member having a longitudinally extending portion lying along said leg and supporting a plurality oi.' cantilever spring lingers, the free ends of said spring iirgers engaging said projection opposite said transverse groove thereby to connect said armature to said core and to bias said armature for pivotal movement away from said end face.

4. In an electromagnetic circuit controller. a magnetic core having an extending leg deiining an end face, one side of said leg being provided with a transverse T-shaped projection adjacent said end face, a magnetic armature having one end positioned in transverse abutting relation to said leg, said armature having an end surface extending substantially parallel to but slightly .overhanging-said one side of said leg, and a chan'- nel shaped hinge member of resilient metal connected to the end surface of said armature and extending longitudinally of said leg, said hinge member being provided with an inwardly turned shoulder interlockingly engaging the near side of said T-shaped projection and having at its extending end a pair of integrally formed spring lingers, said spring lingers being bowed outwardly thereby to engage the other side of said T-shap'ed projection at their free ends.

5. In an electromagnetic circuit controller, a base, a U-shaped magnetic core member having a pair of legs extending perpendicular to said base in substantially parallel spaced relation, an :actuating winding mounted upon a iirst of said legs,

the outer side of a second of said legs being proarmature overhangingsaid to accommodate said shoulder within said groove,

vided with a transverse T-shaped projection near the end thereof, the over-hanging head portion oi said projection providing an odset transverse notch on the side nearest said base and forming with said second leg a transverse groove at the other side thereof, a magnetic armature extending across the ends of said legs in bridging relation thereto, and a channel shaped hinge member composed o! resilient metal ii'xedly connected to one end of said armature and extending longitudinally of said second leg, said hinge member having an inwardly turned shoulder interlockingly engaging said transverse groove thereby to form a knife edge pivot for said armature, said second leg suiiiciently the extending end oi said hinge member having integrally formed therewith a pair of connected spring fingers bowed outwardly to engage said transverse notch at their free ends thereby pivotally to connect said armature to said second leg and to bias said armature to a normal position spaced from the end of said first leg.

6. In combination, an extending irame member of substantially rectangular cross section dening an end face, one side of said frame member being provided with a transverse projection adjacent said end face, a pivoted member extending transversely of said frame member in abutting relation to said end face,and a resilient channel shaped hinge member connected to said pivoted member and engaging said one side of said leg on the near side of said projection, said hinge member extending longitudinally of said frame member beyond said projection and resiliently engaging the other side of said projection thereby to connect said pivoted member to said frame member and to bias said pivoted member for movement about said one side of said frame member away from said end face.

7. In combination, a frame member comprising an extending leg of substantially rectangular cross section deiining an end face, said leg being provided with a transverse projection on one side thereof adjacent said end face, said projection being formed to provide a transverse groove on the side adjacent said end face, a pivotally mounted movable member of substantially rectangular cross section having one end positioned against said end face in abutting relation thereto and extending transversely of said leg, and a channel shaped hinge member connected to said one end of said pivoted member and interlockingly engaging said-transverse groove, said hinge member having a longitudinally extending. portion lying along said one side of said leg and supporting a plurality of cantilever spring iingers, the free ends of said spring iingers engaging said projection opposite said transverse groove thereby to c'onnect said pivoted member to said leg and to bias said pivoted member for movement away from said end face.

8. In combination, a frame comprising an extending xed leg of substantially rectangular cross section defining an end face, one side of said leg being provided with a transverse T- shaped projection adjacent said end face, a substantially rectangular movable leg having one end positioned in transverse abutting relation of said fixed leg, said movable leg having an end surface extending substantially parallel to but slightly overhanging said one side of said xed leg, and a channel shaped hinge member of resilient metal connected to the end surface of said movable leg and extending longitudinally of said fixed leg, said hinge member being provided with an inwardly turned shoulder interlockingly engaging the near side of said T-shaped projection and having at its extending end a. pair of integrally formed spring fingers, said spring ngers being bowed outwardly thereby to engage the other side of said T-shaped projection at their free ends for connecting said legs together in pivotal relation and biasing said movable leg for rotation about said shoulder away from said end face.

WILLIAM LAWRENCE BUTLER. GEORGE M. HAUSLER.

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