US2874245A

US2874245A - Circuit breaker

Info

Publication number: US2874245A
Application number: US404843A
Authority: US
Inventors: David F Moyer
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1954-01-19
Filing date: 1954-01-19
Publication date: 1959-02-17
Anticipated expiration: 1976-02-17

Description

6 Sheets-Sheet 1 Filed Jan. 19, 1954 9+ Q 8% uvw JNVENTOR. DAVID E Move/E ATTOE/VEY D. F. MOYER CIRCUIT BREAKER Feb. 17, 1959 Filed Jan. 19. 1954 6 Sheets-Sheet 2 3w ill. uww L 9% awn w WWW N n 1 1| MN QM a RN. nN Ldd uvvzwz'on. DA v10 F No YER ATTORNEY 6 Sheets-Sheet 3 Filed Jan. 19, 1954 R mm QM mm JNVEIW'OR. DAVID 1? Mo YER ATTORNEY Feb. 17, 1959 D. F. MOYER CIRCUIT BREAKER 6 Sheets-Sheet 4 Filed Jan. 19, 1954 INVENTOR. DAVID FMQYEE BY ATTORNEY 1 D. F. MOYER CIRCUIT BREAKER Feb. 17, 1959 Filed Jan. 1.9, 1954 mo N MN M MW w G m M u Feb. 17, 1959 D. F. MOYER CIRCUIT BREAKER 6 Sheets-Sheet 6 Filed Jan. 19, 1954 RR OQW QAU oo W R m Y WM Ma F ilnited States Patent CIRCUIT BREAKER David F. Moyer, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application January 19, 1954, Serial No. 404,843

3 Claims. (Cl. 200-104) 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 to the controller on one side thereof on in-going line terminals and the corresponding out-going main lines are connected on the opposite side of the controller so that in-line or straight-line connections are provided 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.

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 effecting 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 effecting 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 armature from the 2,874,245 Patented Feb. 17, 1959 electro-magnet will also provide for disassembly of the magnet coil from the core of the electro-magnet.

' 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-magnet providing for replacement of any part of the contactor in a relatively free and easy manner. 7

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 between the stationary contacts 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 partition 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 had to the accompanying drawings wherein a preferred form of the invention is clearly shown.

In the drawings:

Figure l is a plan view of a motor corporating features of this invention.

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

Figure 3 is a vertical longitudinal cross sectional view of the controller taken along line 33 of Figure 1.

Figure 4 is a vertical transverse cross sectional view of the controller taken along line 4-4 of Figure 2.

Figure 5 is a horizontal transverse cross sectional view taken along line 5'5 of Figure 1.

Figure 6 is a horizontal transverse cross sectional view taken along line 6-6 of Figure 1.

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

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

Figure 9 is a bottom view of the contact and terminal block as viewed from the reverse side illustrated in Figure 8.

Figure 10 is a horizontal transverse cross sectional view of the auxiliary control switch for the controller taken along line 1010 of Figure 7.

Figure 11 is a plan view of the controller similar to Figure 1 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 contactor 15. At the 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 with current through the contactor, a current responsive overload device 25 is positioned at one 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 auxiliary control which is the control switch 30 adapted controller infor making and breaking circuit to auxiliary devices that need be electrically synchronized with the operation of the main motor starting control.

The mounting plate 16 has a plurality of screw '

slots

11, 12 and 13 provided for receiving screw heads by which the plate 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 It The lug 17 is of smaller diameter than the lug 18 to insure correct positlignin'g of the terminal base 16 upon the mounting plate 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 2311 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 this can 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 flat 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

nal 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 'thata substantially L shaped opening is formed in the edge of the terminal base 16 adjacent the recesses 26 and 27. Removal of the line terminal 24a can be occasioned by first moving it linearly relative to the recess 27 and then moving it normal thereto so that the hook 36 then passes through the L shaped opening 3539.

The line terminals 24a, 24c and 24a are adapted to be connected with the threewires 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 24c--24d from the line terminal sets 24a--.-24b 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 23 to make it more diflicult to directly 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 23a-23f inclusive.

The stationary contact sets 23a23b, 23c23d and 23e23f are bridged by the

movable contacts

49a, 49b and 49c 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 490 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 660 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 inthe carrier 50. Each of the contact bars engage 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 cooperatingstationary contacts with like pressure even though they may not be at exactly the same planar level. i

The lower end of the carrier 50 is provided with a T head fitting 71 for connection to the armature of the electro-magnet in a manner hereinafter described.

The electro-magnet 20 for operating the contact carrier 50 comprises a substantially C shaped core 75 thereby providing an opening 76 within the core. The core 75 is secured to the plate by means of rivets 77. The C shaped core 75 has the opposing legs 78 and 79 provided with recesses 80 and '81 that receive the nylon rollers 82.

A magnet coil 85 that comprises the electrical insulating shell 86 and a magnet coil 87 is placed within the opening 76 of the core 75 in a manner that the axis of the armature opening 88 through the coil and case assembly is normal to the axis of the opening 76 in the core 75. This provides an opening through the electro-magnet 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 armature 92 is suspended from the carrier 50 when the controller is in its normal vertical position. The lower wall 100 of the T slot 99 in the armatureextension 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 inline 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 113-114 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 for good electrical contact and only the forward outside 6 corners of the contacts are affected by the arcing occasioned by the high current flow 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 Figures 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 current flow to be from the left to the right of the device of Figures 1 and 4, the current flow will be through the terminal 24a upwardly through the stationary 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 current flow, the forefinger will represent the direction of flux and the thumb the direction of the force. Applying this rule to the contact arrangement just referred to, the flux direction will be from the left to the right between the

contacts

23a and 49a with the force vertically upward.

Since the controller can deal with both direct as well 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, or ampere turn, produced between the top of the stationary contact 23a, the contact bar 49a and the top of the stationary contact 23b. Again assuming current flow from left to right of the device of Figures 1 and 4, the flux will be vertical to the contact bar 490, that is along the axis of the carrier 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 current fiow 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 arc quenching, if desired.

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. In an electric motor starting controller, the combination of, a flat platform terminal base containing a plurality of current in-going and out-going terminal connectors disposed in a common plane on one side of said platform with each iii-going terminal paired with an outgoing terminal and linearly aligned with the same, a plurality of stationary contacts all projecting from the said one side of the said platform, one of said stationary contacts engaging respectively one of said connectors and all arranged generally at a common level above the said platform, said platform having partition walls projecting upwardly from said one side and disposed between each set of linearly aligned terminal connectors and cooperating stationary contacts and coextensive linearly with said connectors and projecting upwardly from the said platform to at least the uppermost projecting portions of the said connectors and said stationary contacts thereby electrically isolating paired contacts and connectors, a movable contact carrier supporting a plurality of contact bars transversely of the carrier each engageable with stationary contacts of paired in-going and out-going terminal connectors, said carrier being disposed at the level of the stationary contacts and projecting through openings in said partition walls and movable on its longitudinalaxis linearly normal to said partition walls and the linear alignment of said terminals, said carrier having transverse recesses in opposite sides thereof which align with said walls when the contact bars of the carrier engage cooperable stationary contacts, wall means projecting upwardly from said one side of said platform at opposite ends of said carrier to at least the level of the uppermost side of said carrier and having linearly aligned slots therein forming guide slots for said carrier for linear movement thereof therein, other wall means extending upwardly from said platform to support one side of said carrier and having longitudinally extending recesses therein covered by the said one side of said carrier, and a cover member enclosing said carrier and said movable and stationary contacts having a wall adjacent the upper edges of said partition walls and said wall means at opposite ends of said carrier and having longitudinally extending recesses therein aligned with said carrier and covered thereby and having other wall means depending from said first wall means adjacent said partition walls and end walls into close proximity with said one side of said platform to fully enclose thereby each stationary contact in an electrically isolating chamber having the walls between the chambers provided with closed recesses providing arc quenching chambers.

2. An electric motor starting controller in accordance with the structure of claim 1 wherein, said carrier is linearly slidable in the said guide means and which includes, an electromagnet having an armature movable linearly of its longitudinal axis and linearly aligned axially with the longitudinal axis of said carrier to effect linear movement of the carrier by linear "movement only of said armature, and means forming a free swinging connection between one end of said carrier and one end of said armature for transmission of linear movement of the armature to the carrier without effecting angular deflection forces.

3. An electric motor starting controller in accordance with the structure of claim 2 that includes an anti-friction guide plate on said electromagnet adjacent the said free swingingconnection and through which an armature part extends for longitudinal linear alignment of the longitudinal axis of the armature with the longitudinal axis of said carrier.

References Cited in the file of this patent UNITED STATES PATENTS 2,049,747 Parsons Aug. 4, 1936 2,266,536 Cooper Dec. 16, 1941 2,304,972 Van Valkenburg et al. Dec. 15, 1942 2,339,675 Bucklen et al Jan. 18, 1944 2,344,654 Stong Mar. 21, 1944 2,348,556 Matthias May 9, 1944 2,390,344 Ayers et a1 Dec. 4, 1945 2,397,102 Graham Mar. 29, 1946 2,433,710 Schleicher Dec. 30, 1947 2,448,650 Aitken Sept. 7, 1948 2,449,221 Hammerly Sept. 14, 1948 2,514,913 Tyrner July 11, 1950 2,561,450 Russell July 24, 1951 2,658,962 Bourne Nov. 10, 1953 2,672,536 Rosing et al. Mar. 16, 1954 2,735,994 Obszarny Feb. 21, 1956 FOREIGN PATENTS 688,207 Germany Feb. 16, 1940