US2929904A - Circuit breaker - Google Patents

Description

6 Sheets-Sheet 1 Original Filed Jan. 19, 1954 Rum INVE/VTOP DA W0 A" M0 YEA? ATTORNEY March 22, 1960 D. F. MOYER CIRCUIT BREAKER .6 Sheets-Sheet 2 Original Filed Jan. 19, 1954 1] Q A w 1.. Q w? R Q I l I m .m Q m m M & w 3 Q 3% & E m mm w a C & SvN

um w w w lMVE/VTOE 0/! W0 E 440 1 52 A TTOE/VE'Y March 22, 1960 D. FQMOYER 2,929,904

' CIRCUIT BREAKER Original Filed Jan. 19, 1954 s Sheets-$heet s 6 Sheets-Sheet 4 IN VEN TOR. DA V/D MOYEE aw-M ATTORNEY March 22, 1960 D. F. MOYER cmcun BREAKER Original Filed Jan. 19, 1954 m @EVVWEEE "I March 22, 1960 D. F. MOYER 2,929,904

' CIRCUIT BREAKER Original Filed Jan. 19, 1954 6 Sheets-Sheet 5 ATTORNEY March 22, 1960 D. F. MOYER CIRCUITBREAKER Original Filed Jan. 19, 1954 6 Sheets-Sheet 6 hum IN VEN TOR. v DA v/D F Mo YER ATTORNEY CIRCUIT BREAKER David F. Meyer, Dayton,

-lviotors Corporation,

Delaware Ohio, assignor to General Detroit, Mich, a corporation of 3 (Ilaims. (Cl. 200-168) This invention relates to a motor starting controller. An object of the invention is to provide an improved structural arrangement of a motor starting controller that is more compact and which provides for quick and easy disassembly of the several parts of the structure for replacement and repair when necessary.

Another object of the invention is to provide a motor starting controller wherein all of the main electric lines are connected ot the controller on one side thereof on in-going line terminals and the correspondnig out-going main lines are connected on the opposite side of the controller so that in-line or straight line connections areprovided for each primary electric line extending to and from the controller. This arrangement provides for ease of hook-up by an electrician since any one line entering the controller leaves the controller on the directly opposite side. 7

A further object of the invention is to provide for connection of an auxiliary current overload control that is connected to the line terminals of the main contactor without in any way disturbing the in-line connection of the electric lines to and from the controller.

A further object of the invention is to provide a magnetic motor starting controller wherein the movements of the armature of the electro-magnet and of the movable contact carrier of the contactor are linear movements linearly aligned to eliminate angularly directed forces on the contact carrier and thereby increase its freedom of movement.

Still another object of the invention is to provide a magnetic motor starting controller in accordance with the foregoing object wherein an auxiliary control switch is actuated by the contact carrier of the main starting contactor, the actuator for the auxiliary control switch being linearly aligned with the linear movement of the contact carrier of the main contactor and provided with linear movement for actuation of the auxiliary control switch whereby to maintain all movements of the contactor linearly aligned with the contact carrier of the main contactor to eliminate angularly directed forces that may create friction in movement of the contact carrier.

Still another object of the invention is to provide a magnetic motor starting controller wherein the starting contactor may be used alone or in conjunction with auxiliary controls that may be assembled onto the contactor without in any way affecting the operating functions or characteristics of the main contactor.

Another object of the invention is to provide a motor starting controller wherein the contact carrier for the movable contacts of the controller is demountably attached to the armature of the electro-magnet in a manner to provide for disconnection of the contact carrier from the armature without in any way affecting the position of the armature relative to the electro-magnet coil, and to provide for removal of the armature from the electro-magnet only after the contact carrier has been disengaged from the armature. Removal of the armatrue from the electro-magnet will also provide for disassembly of the magnet coil from the core of the electromagnet.

It is also an object of the invention to provide a motor starting controller wherein the movable contacts on the contact carrier as well as the stationary contacts and the line terminals are all removable from their supporting structures for easy replacement, the disassembly provided for these elements as well as the disassembly of the armature and magnet coil of the electro-magnetproviding for replacement of any part of the contactor in-a relatively free and easy manner.

Another object of the invention is to arrange cooperating stationary contacts and in-going and out-going line terminals with the cooperating movable contact means for conducting current within walled chambers or compartments to separate the electrical connections and contacts for each line phase from every other line phase as well as from the neutral line.

It is another object of the invention to provide a contactor in accordance with the foregoing object wherein the partition walls extend between the terminal base and the cover provided for the contactor to thereby completely separate the cooperating contact sets one from the other and to also utilize the contact carrier as a parti-v tion wall to separate adjacent stationary contacts of any one contact set from each other with the cooperating movable contacts on the carrier positioned on opposite sides of the partition wall thus formed by the carrier.

Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accompanying drawings wherein a preferred form of the invention is clearly shown.

In the drawings:

Fig. 1 is a plan view of a motor controller incorporating features of this invention.

Fig. 2 is a side elevational view of the controller illustrated in Fig. 1 as viewed from the left hand side of the device of Fig. 1.

Fig. 3 is a vertical longitudinal cross sectional view of i the controller taken along line 3-3 of Fig. 1.

Fig. 4 is a vertical transverse cross sectional view of Patented Mar. 2 2, 196d between the stationary contacts- Fig. 6 is a horizontal transverse cross sectional view taken along line 6-6 of Fig. 1.

Fig. 7 is a vertical longitudinal cross sectional view taken along line 7-7 of Fig. 1.

Fig. 8 is a plan view of the terminal and contact block of the controller.

Fig. 9 is a bottom view of the contact and terminal block as viewed from the reverse'side illustrated in Fig. 8. Fig. 10 is a horizontal transverse cross sectional view of along line 10-10 of Fig. 7.

Fig. 11 is a plan view of the controller similar to Fig. 1

the auxiliary control switch for the controller taken but illustrating the attachment of two auxiliary overload controls to the line terminals of the controller.

In this invention the controller comprises a mounting plate 10 that supports the main lower end of the contactor 15 there is provided an electromagnet 20 for operating the contactor.

For protection of the electric motor that is supplied contactor 15. At the with current through the contactor, a current responsive overload device 25 is positioned atone side of the contactor and is connected into the line circuit in a manner hereinafter referred to.

The contactor may also be provided with a second need be electrically synchronized with the operation of the main motor starting control.

The mounting plate has a plurality of screw slots 11, 12 and 13 provided for receiving screw heads by which the plate 10, can be mounted on any suitable support. A sheet 14 of electrical insulating material is placed upon the upper face of the mounting plate 10 on which the terminal and contact base 16 is mounted.

The terminal base 16 has a pair of lugs 17 and 18 extending from the rear face of the base 16 that project into holes 19 and 21 respectively provided in the mounting plate 10 whereby to accurately position the terminal base 16 upon the mounting plate 10. The lug 17 is of smaller diameter than the lug 18 to insure correct positioning of the terminal base 16. upon the mounting plate 10.

The terminal base 16 has a platform portion 22 on which the stationary contacts 23a to 23] inclusive are mounted. Each of the stationary contacts engages one of the line terminals 24a to 24 respectively. Since each of the cooperating pairs of stationary contacts and line terminals are mounted in the terminal base 16 in the same manner, only one of the terminal and contact mounting structures will be referred to.

Having reference to the stationary contact 23a and its cooperating line terminal 24a, the stationary contact 23a is mounted in a recess 26 that extends part way through the terminal base 16. The recess 26 is positioned longitudinally of the terminal base 16. The opposite face of the terminal base 16 has a recess 27 that is angular to the recess 26 and extends partially through the base 16. The bottom wall of the recess 26 is in exactly the same plane as the bottom wall of the recess 27. Thus, at the cross over juncture between the angularly disposed recesses 26 and 27 an opening 28 is formed the plane of which is in the plane of the bottom wall of the recess 26 and of the bottom wall of the recess 27.

The stationary contact 23a has a right angle leg 29 that is placed in the recess 26 of the terminal base with the bottom face 31 of the contact leg 29 engaging the bottom wall of the recess 26.

The line terminal 24a has a leg portion 32 that rests within the recess 27 so that the surface 33 of the leg 32 is in the plane of the bottom wall of the recess 27. Thus, the face 31 of the stationary contact 23a engages directly the face 33 of the line terminal 24a for direct conduction of electric current from the line terminal to the contact. A machine screw 34 extends through the leg 29 of the stationary contact into threaded engagement with the leg 32 of the terminal 24a whereby to retain the two elements together.

It will be apparent that the stationary contact 23a can be removed from the line terminal 24a merely by removing the screw 34, and thiscan be done without in any way affecting the position of the line terminal 24a with reference to the terminal base 16.

The terminal base 16 has an opening 35 that is linearly aligned with the recess 27 so that the fiat line terminal 24a can extend through the edge of the base 16 with the leg 32 resting in the recess 27. Each of the line terminals 24a has the leg 32 thereof formed with a hook 36 that engages a wall 37 when the terminal is moved linearly relative to the recess 27. This prevents the line terminal 24a from being pulled from the terminal block 16 when the contact 23a is removed from the line terminal. The contact 23a normally locks the line terminal 24a in position in the terminal base 16 since the recess 26 in which the leg 29 of the contact is positioned provides a wall 38 that prevents transverse movement of the line terminal and attached contact relative to the base 16.

The opening 35 in the edge of the terminal base 16 is coextensive with an opening 39 adjacent the edge so that a substantially L-shaped opening is formed in the edge of the terminal base 16 adjacent the recesses 26 and 27.

Removal of the line terminal24a can be occasioned vby first moving it linearly relative to the recess 27 and then moving it normal thereto so that the book 36 then passes through the L-shaped opening 35-39.

The line terminals 24a, 24c and 24e are adapted to be connected with the three wires of a three-phase wiring system. The line terminals 24b, 24d and 24 are linearly aligned with the line terminals 24a, 24c and 24e whereby the wires of the three-phase wiring system may be connected straight through the terminal base for simplification of wiring.

The terminal base 16 has partition wall sections 40 and 41 that separate the line terminal set 24c24d from the line terminal sets 24a24b and 24e24f thereby compartmenting the line terminal sets and their cooperating stationary contacts one from the other. The end walls 42 and 43 provide closure walls for confining the terminal sets 24a--24b and 24e-24f. The partition walls 40 and 41 extend substantially above the level of the contacts 23a to 23 and substantially above the level of the contacts 23a to 23f to make it more difficult to di rectly engage the live contacts and terminals by an operator when replacing one of the contacts or disassembling the contactor.

The cover 45 for the terminal base 16 has recessed portions 44 and 46 that receive the upper ends of the partition walls 40 and 41 whereby to totally compartment the terminal and contact sets one from the other. The side walls 47 and 48 of the cover 45 complete the enclosure of the stationary contacts 2311-23 inclusive.

The stationary contact sets 23a23b, 23c--23d and 23e-23f are bridged by the movable contacts 49a, 49b and 490 respectively whereby to conduct current between the respective line terminals on opposite sides of the terminal base 16.

The movable contact bars 49a, 49b and 49c are supported in a contact carrier 50 that has linear movement only to move the movable contacts into and out of engagement with the cooperating stationary contacts.

The contact carrier 50 is made of an electrical insulating material and extends through the partition walls 40 and 41. The upper end of the carrier 50 engages the guide surface 51 on the terminal base 16. The lower end of the carrier 50 engages corresponding guide surfaces 52 at the opposite end of the base 16. The base 16 has the slightly relieved areas 53 and 54 between the aforementioned guide surfaces whereby to form the same.

The cover 45 is provided with the relieved areas 55 and 56 that correspond to the relieved areas 53 and 54 on the terminal base 16 whereby to provide guide surfaces 57 and 58 on opposite sides of the relieved areas 55 and 56 engaged by the opposite ends of the carrier 50.

The contact carrier 50 has longitudinally extending ridges 59 and 60 on opposite sides thereof that engage the guide walls 64 and 65 provided on the terminal base 16. The guide arrangement for the contact carrier 50 just described provides for minimum of frictional contact of the carrier with the guide surfaces and thereby aids freedom of movement of the carrier.

The contact bars 49a, 49b, and 49c are each removably supported in the carrier 50 in openings 66a, 66b, and 666 respectively. Each of the contact bars is retained in its respective opening by means of a light compression spring 67 that has one end thereof resting upon a projection 68 at one end of the respective opening. The opposite end of the spring 67 engages a recessed portion 69 on the respective contact bars whereby to hold the contacts in position in the carrier 50. Each of the contact barsengage shoulders 70 provided on the carrier to position the contact bars substantially normal to the carrier when out of engagement with the cooperating stationary contacts. The spring 67 allows for engagement of the contact bars with both of its co.- operating stationary contacts with like pressure even though they may not be at exactly the same planar level.

T e l e a d o he i r s sv dsd w th e T head fitting 71 for connection to the armature of the electr c-magnet in a manner-hereinafter described;

Theelectro-magnet 20 for operating the'contactcarrier 50 comprises a substantially C-shaped core 75 there case assembly is normal to the axis of the opening 76' in the core 75. This provides an opening through the electro-rnagnet assembly that receives the armature 90. Electric current is conducted to the operating coil 87 through the terminals 91.

The armature 90 comprises a body 92 that has an extension member 93 projecting from the upper end thereof. The member 93 extends through a slot 94 in the core 75 and through a slot 95 in the nylon guide plate 96 mounted on the core 75 by means of the tabs 97 extending from the outer frame members 98 of the core 75.

The free end of the extension 93 on the armature 92 has a T slot 99 that engages the T head 71 on the contact carrier 50 whereby the a rmature 92 is suspended from the "carrier 50 when the controller is in its normal vertical position. 'The lowerj wall. ltltl'of the T slot 99 in the armature extension 93 has a convex curvature whereby to provide for point contact of the armature extension 93 with the lower end of the T head 71 to maintain as nearly as possible linear actuation of the armature relative to the carrier.

The armature 92 passing through the core slot 101 engages the nylon rollers 82 which maintain accurate spacing of the walls of the armature relative to the walls of the core slot. This establishes and maintains throughout the life of the controller a positively dimensioned air gap between the armature and the core that does not vary during the life of the controller.

The auxiliary control 25, which is the current overload control device, is provided with a line terminal 105 extending from one side thereof and a line terminal 106 extending linearly aligned therefrom on the opposite side of the control 25. With the terminals 105 and 106 being linearly aligned, the terminal 105 can be attached to the line terminal 24b of the contactor and still maintain in-line connection for the electric lines to and from the controller. In the event overload protection is required on both lines of a three-phase circuit, a similar controller can be attached to contact terminal 24 At the upper end of the contactor there is provided the auxiliary control switch 30 that has a contact carrier 110 provided with an actuating lug 111 that engages the upper end of the contact carrier 50 of the controller. The carrier 110 has linear movement with the actuating lug 111 being linearly aligned with the carrier 50 and operated thereby in linear alignment with the carrier 50.

The auxiliary switch 30 has the contact bars 112 supported on the carrier 110, the bars being floated between cooperating springs 113114 and 115116 so that satisfactory contact can be made with either the upper set of stationary contacts 120 or the lower set of contacts 121. The upper set of stationary contacts are locked within the casing by means of a retaining bar 122.

Each of the contact sets which includes aligned terminals and stationary contacts with a bridging movable contact is so arranged that induced electrical forces are created to cause the are normally effected between cooperating movable and stationary contact upon opening of the same to be blown to the forward outside corner of the cooperating stationary and movable contact. The result is that the contact engaging faces remain clean direction will be from the left to the right between the,

for good electrical contact and only the forward outside corners of the-contacts are affected by the'arcing oc casioned by the high current fiow through the contacts when contact engagement is broken.

These electrical forces are created as a result of partial loops formed by the arrangement of the contacts with respect to one another.

Referring to Figs. *1 and 4, the terminal 24a with its stationary contact 23a together with the left hand end; of the contact bar 49a provides a partial loop, or part of, an ampere turn.

Assuming currnet flow to be from the left to the right of the device of Figs. 1 and 4, the current fiow will be through the terminal 24a upwardly through the station-j ary contact 23a and to the left hand end of'the movable contact 49a. Utilizing Flemings right hand rule, with the middle finger representing the direction of current1 flow, the forefinger will represent the direction offiuxj and the thumb the direction of the force. Applying this 1 rule to the contact arrangement just referred to, the fiuxf contacts 23a and 49a with the force vertically upward.

Since the controller can deal with both direct as well 1 as alternating current, when the alternating current reverses its flow, the flux will be from the right to the left between the aforementioned contacts with the force still remaining vertical outwardly of the controller.

There is a second partial loop, orampere turn, pro duced between the top of the stationary contact 23a, the" contact bar 49a and the top of the stationary contact 1; 23b. Againassuming current flow from left to right. of the device Of Figs. 1 and 4, the flux will be vert cal to the contact bar 49a, that is'along the axis of the car rier 50, with the force normal to the line of flux, that is vertically outward relative to the carrier 50. Even when the alternating current reverses itself, the force remains in the same vertical direction while the flux changes its direction. With both vertical forces operating simultaneously within the chamber containing contacts 23a and 49a, the resultant force is outwardly toward the outer left hand corner of the contacts 23a and 49a.

It will therefore be apparent that the currentflow through the contact sets effect electrical forces that blow the arc outwardly from the engaging faces of the contacts and thereby minimizes pitting damage to the contacts.

The cover 45 can be provided with metallic inserts enclosing the gap between the stationary and movable contacts to effect are quenching, if desired. This application is a division of my copending application S.N. 404,843, filed January 19, 1954, now Patent No. 2,874,- 245, issued February 17, 1959.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted as may come within the scope of the claims which follow.

What is claimed is as follows:

1. A terminal base for a motor starting controller comprising, a platform of electrical insulating material, a first recess in one face of said platform extending partially through the platform, a second recess in the opposite face of the platform angular to the first recess and extending partially through the platform, said recess having its bottom surface in the plane of the bottom surface ofthe second recess whereby to provide an opening in the platform only at the cross-over juncture of the common plane of the said recesses, a contact member in one of said recesses having a surface bridging said opening in the plane of the opening and a terminal member in the other of said recesses having a surface bridging said opening in the plane of the opening with the said surfaces thereby being in surface contact with each other in the said plane of said opening, and means between said contact member and said terminal member in the area of their surface contact securing the same ne he th reb warns he ame is he r select ve a ses es: r

Z. A terminal base {or a motor". starting controller comprising, a platform of electrical insulating material, a first recess in one face of said platform extending partially through the platform, a second recess in the opposite face of the platform angular to the first recess and extending partially throngh the platform, said recess having its bottom surface in the plane of the bottom surface of the second recess whereby to provide an opening in the platform only at-the cross-over juncture of the common plane of the said recesses, said base having an opening in the edge thereof linearly aligned with said recess, a contact member in the first of said recesses having a Su -{ace bridging said opening in the plane of the opening and a terminal member in the second of said recesses having a suriace bridging said opening in the plane of the opening with the said surfaces thereby being in surface contact with each other in the said plane of said opening with said terminal member projecting through said edge opening, and means between said contact member and said terminal member in the area of their surface contact securing the same together thereby retaining the same in their respective recesses.

3. A terminal base for a motor starting controller comprising, a platform of electrical insulating material, a first recess in one iaceot said platform extending par tially through the platform, a second recess in the opposite face of the platform angular to the first recess and extending partially through the platform, said recess having its bottom surface in the plane of the bottom surface oi'the second recess whereby to provide an opening in the platform only at the cross-over juncture of the com-. mon plane oi the said recesses, said base having an opening in the edge thereqf linearly aligned with said recess and coentensive with an opening through the platform normal thereto immediately adjacent the edge of the platform having said edge opening whereby to provide a substantially l -shaped opening adjacent said second recess, a contact member in the first of said recesses having a surface bridging said opening in the plane of the opening and a terminal member in the second of said recesses having a surface bridging said opening in the plane of the opening with the said surfaces thereby being in surface contact with each other in the said plane of said opening with said terminal member projecting through said 'L-shaped opening, said terminal member having a hook on the inner end thereof to engage the edge of said platform to prevent removal of said terminal member from the second recess by movement of the terminal member linearly relative'to said second recess, said L-shaped opening providing for removal of said terminal member upon movement thereof linearly relative to said second recess and normal thereto and means between said contact member and said terminal member in the area of their surface contact securing the same together thereby retaining the same in their respective recesses.

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