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Publication numberUS3889215 A
Publication typeGrant
Publication dateJun 10, 1975
Filing dateApr 3, 1974
Priority dateApr 5, 1973
Also published asDE2416152A1, DE2416152B2, DE2416152C3
Publication numberUS 3889215 A, US 3889215A, US-A-3889215, US3889215 A, US3889215A
InventorsImanishi Hitoshi, Yoshino Akira
Original AssigneeMatsushita Electric Works Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Circuit breaker
US 3889215 A
Abstract
A circuit breaker wherein electrical arrangement for detecting excess current in and switching or breaking power supply contacts for associated circuit and mechanical arrangement for transmitting ON-OFF operation or contact switching operation to the contacts are separately disposed as electrically insulated by a separation wall in a chassis for integrally housing the both arrangements. The separation wall has only two narrow apertures for allowing the motion responsive to detected excess current transmitted to the mechanical arrangement and therethrough back to the contacts.
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Description  (OCR text may contain errors)

United States Patent [191 Yoshino et al.

CIRCUIT BREAKER Inventors: Akira Yoshino; Hitoshi Imanishi,

both of Seto, Japan Matsushita Electric Works, Ltd., Osaka, Japan Filed: Apr. 3, 1974 Appl. No.: 457,423

Assignee:

Foreign Application Priority Data Apr. 5, 1973 Japan 48-38934 Apr. 6, 1973 Japan 48-39932 US. Cl. 335/6; 335/201; 335/202; 337/46 Int. Cl. H0lh 9/34 Field of Search 335/6, 202, 201, 190, 143; 337/46, 53, 23, 143

References Cited UNITED STATES PATENTS 6/1948 Wise 335/143 June 10, 1975 2,540,491 2/1951 Rowe et al. 335/23 2,660,642 11/1953 Warren 337/53 2,703,350 3/1955 Rosing 337/46 2,989,604 6/1961 Wegh 335/6 3,240,904 3/1966 Dowdle et al 337/46 Primary Examiner-J-larold Broome Attorney, Agent, or F irm-Wolfe, Hubbard, Leydig, Voit & Osann, Ltd.

[ 5 7 ABSTRACT A circuit breaker wherein electrical arrangement for detecting excess current in and switching or breaking power supply contacts for associated circuit and mechanical arrangement for transmitting ON-OFF operation or contact switching operation to the contacts are separately disposed as electrically insulated by a separation wall in a chassis for integrally housing the both arrangements. The separation wall has only two narrow apertures for allowing the motion responsive to detected excess current transmitted to the mechanical arrangement and therethrough back to the contacts.

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IZQ lh ,9\ 1 Fig. 24C 22a 22 [2a Ih CIRCUIT BREAKER This invention relates to a circuit breaker for protecting a load by breaking a circuit in case such excess current as a short-circuiting current or overload current flows through the circuit.

Generally a circuit breaker is formed largely of three parts of an operating part, switching contact part and excess current detecting part so that, in case an excess current flows through a circuit, this excess current will be detected by the excess current detecting part and the switching contact part will be operated, through the operating part, by this detection to switch off the circuit. The above mentioned three parts have been arranged and fixed on the same surface (for example, the upper surface) of a chassis made of a synthetic resin. However, the operating part is mostly of a mechanical formation while the switching contact part and excess current operated element are mostly of electric formations. Therefore, there have been defects that, when they are fixed as arranged on the same surface of the chassis, the assembling work specifically in the mechanical field must be carried out with a larger attention than is required to the electric parts outside the mechanical field and is, therefore, inefficient and that, in the case of the maintenance and inspection, the mechanical part and electrical part can not be checked separately from each other and the whole parts must be checked.

Further, many of metal parts are used for the operating part and, therefore, it must be considered to insulate this operating part from both of the switching contact part and excess current detecting part which are electrical parts.

In the present invention, in view of the above mentioned points, a partition wall is integrally formed in the middle on the inside surface of the side wall of a case made of a synthetic resin to separately form upper and lower space parts which are open respectively outward, a handle operating part is arranged in the upper space part, a switching contact part and excess current detecting part are arranged in the lower space part, holes are made vertically through both sides of the partition wall, a moving plate for operatively connecting the handle operating part and switching contact part with each other is arranged in the hole on one side and an operatively connecting plate for operatively connecting the excess current detecting part and handle operating part with each other is arranged in the hole on the other side so that such defects as referred to before will be successfully solved.

An object of the present invention is, therefore, to provide a mold case circuit breaker wherein each of the said parts which are respectively made to be a unit can be arranged in an optimum state and the assembling work and maintenance service can be carried out efficiently.

Other objects and advantages of the present invention will be made clear by the following description of the invention detailed with reference to a preferred embodiment in conjunction with accompanying drawings, in which:

FIG. I is an explanatory view showing schematically the arrangement of a circuit breaker of the present invention;

FIG. 2 is an upper surface view of the apparatus of the present invention;

FIG. 3 is a lower surface view of the same with a back lid removed;

FIG. 4 is a side view of the same;

FIG. 5 is a view showing the interior with a part of a cover cut off;

FIG. 6 is an upper surface view shown with the cover removed;

FIG. 7 is an upper surface view in FIG. 6 shown with an upper lid removed;

FIG. 8 is a lower surface view in FIG. 3 with a lower lid removed;

FIG. 9 is a sectioned view shown along an input terminal and output terminal in FIG. 6;

FIGS. 10A through 10C are upper surface view, lower surface view and vertical sectioned view substantially at the centre of a chassis;

FIG. 11 is a cross sectional view along a carrier of the chassis;

FIG. 12 is a perspective view of an operating part;

FIG. 13A is a perspective view of the operating part as disassembled, and FIG. 138 shows main elements in the operating part;

FIG. 14A is a front view of the operating part as assembled;

FIG. 14B is a rear view of the same;

FIG. 14C is a side view of the same;

FIG. 15 is a perspective view of an electromagnet employed in the device;

FIGS. 16A through 16C show a coil in the above;

FIG. 17 is a perspective view of a switching contact unit;

FIG. 18 is a perspective view of a carrier;

FIG. 19 is a perspective view of an armature;

FIG. 20 is an elevation of a handle;

FIGS. 21 and 22 are fragmentary sectioned views for explaining the operating part as fitted;

FIGS. 23A, B and C are views for explaining the operation of the operating part;

FIGS. 24A through 24C are view for explaining the operation of the contact plate;

FIGS. 24A through 24C are fragmentary sectioned views showing operations of contacting plate; and

FIGS. 25A and 25B are explanatory views showing operative relation between certain main elements in the operating part.

FIG. 1 shall be explained in the following.

FIG. 1 shows a unit arrangement of a circuit breaker of the present invention. In the drawing, INPUT is an input terminal, OUTPUT is an output terminal and these terminals are arranged on both sides of a case A. B is a switching terminal. C is an excess current detecting part. D is an operating part. An upper space and lower space are formed by a partition wall E in the case A. The operating part D is arranged in the upper space. The switching contact part B and excess current detecting part C are arranged in the lower space. F is an operatively connecting plate integrally having an armature for transmitting the operation of the excess current detecting part C to the operating part D. F is a carrier for transmitting the operation of the operating part to the switching contact .part. The electric current path is from the input terminal through the switching contact part B and excess current detecting part C to the output terminal OUTPUT. The operation sequence is from the excess current detecting part C through the operatively connecting plate F, operating part D and carrier F to the switching contact part B. G is a handle. The operat- 3 ing part D is manually operated by the handle G so as to make ON and OFF.

FIG. 2 shows an upper surface view, in which 57 is a handle to be rotated so as to have three positions of U, V and W within a fan-shaped concave part 68 provided on a cover 65. The trip is indicated by a red mark appearing in an indicating window hole 62 made on the upper surface of the case. 70 is a set screw used to fit the cover 65 to the chassis.

FIG. 3 is a lower surface view showing the circuit breaker of the present invention with the bottom plate removed. Thin parts 69 are provided on the side wall 65a of the cover 65 so that electric wires 66 may be inserted and fitted within the unit by removing said parts. I is a chassis, and 64 is its lower lid.

FIG. 4 shows a side view of the circuit breaker. A handle 57 is rotatably provided on the cover 65. 69 is a thin part.

FIG. 5 shows a vertically sectioned view of the above. The electric wires 66 are fitted to the chassis 1.

FIG. 6 is an upper surface view of the device in FIG. 1 shown with the cover 65 removed. 5 and 6 are respectively an input terminal and output terminal. A fanshaped indicating plate 63 is fixed integrally with the handle 57 to the lower part of the handle 57. A trip indicating part 63a is provided on this indicating plate so that, with the rotation of the handle 57, the trip indicating part 63a will move and that, when the indicating part 63a is positioned below the indicating window hole 62 of the lid 59, the trip state will be indicated. 59b is a concave part made on the upper lid 59. 59C is an edge of the lid.

FIG. 7 is a view showing the interior of the device shown in FIG. 6 with the upper lid 59 removed.

In the drawing, the operating part D is secured between both side walls 2 of the chassis I. There are shown a carrier F (indicated by 22 in the drawing) operated by said operating part D and an operatively connecting plate F (indicated by 25 in the drawing) operated by the excess current detecting part C.

FIG. 8 is a view shown in FIG. 3 with the lower lid 64 removed. There are shown the excess current detecting part C, switching contact part B and operatively connecting plate F (25) operated by the excess current detecting part C.

FIG. 9 is a vertically sectioned view of the device of the present invention and is a detailed view corresponding to FIG. 1. There are shown the input terminal a 5, switching contact part B, excess current detecting part C, operatively connecting plate F, operating part D, carrier F and output terminal b 6. The excess current detecting part C and operating part D are arranged as separated above and below the partition wall E(3) of the case.

FIGS. 10A through 10C show a chassis A(1), wherein FIG. 10A is an upper surface view thereof. The operating part D (not illustrated here) is fitted in the space between the side walls 2. 71 is a hole for fitting the operating part D. The space is sectioned into an upper space and lower space by a partition wall 3. 72

and 73 are communicating windows made in the.partition wall for housing the elements forming the excess current detecting part C as described later. FIG. 10C shows a vertically sectioned view of the chassis. There are shown the partition wall 3 and communicating windows 72 and 73.

FIG. 11 is a sectioned view of the device along the communicating window 72, wherein the carrier 22 (or F) is shown here.

Now the formation of each part shall be detailed.

FIG. 12 shows an operating part unit. FIG. 13A shows the respective elements thereof as disassembled in a perspective view. The above described operating part D is held between two ground plates 33 and 33'. 39 is an arcuate groove made in the ground plates. is a hole made in each ground plate, in which the long leg 37a of a later described U-shaped shaft 37 is pivoted. Said U-shaped shaft 37 has a long leg 37a and short leg 37b. In an operating plate 38 formed to be U- shaped by bending two plates, there are formed two holed 38a and 38b and a calked pin 38c inside. The long leg 37a of the shaft 37 is inserted through the hole 38a of the operating piece 38 and is inserted into the hole 75 of the ground plate 33. The short leg 37b is inserted into the hole 38b of the operating piece through a roller 76 contained inside the operating piece 38 (see FIG. 12). That is, the operating piece 38 is fitted to the ground plates 33 and 33 so as to be rotatable with the shaft 37a as a center. 40 is a turning arm provided with a tip part 40a as somewhat inclined at one end, with a hole 400 at the other end and with a projection 40b in the substantially intermediate part. A shaft 41 is in serted in the hole 40c of the turning arm 40. Further, the turning arm 40 is inserted in the intermediate part (between the hole 406 and projection 40b) into the intermediate part (between the hole 38b and pin 38c) of the operating plate 38 (see FIG. 12B). 42 is a hanging frame bent to be a U-shaped. 42a is its connecting part. 42b is a pivoting hole. The hanging frame 42 has at its tip engaging parts 44 with which the shaft 41 of the turning arm 40 is to be engaged and inclined parts 45. The ground plates 33 and 33 are combined with each other with a fixed space between them by inserting the projections at both ends of calked rivets 34 into the holes 33a and 33 'a. The operating plate 38 is rotatably supported between both ground plates with the long leg 37a of the U-shaped shaft 37 inserted in the holes 75 of the ground plates 33 and 33'. The hanging frame 42 is rotatably supported by the ground plates with a shaft 43 inserted in the hole 42b of the hanging frame and the holes 33b and 33'b of the ground plates. 49 is a responding piece formed to be substantially L-shaped and having a bent part 49b formed at one end, a pivoting hole 49c formed at the other end a projection 52 formed on the sideopposite the bent part 49b. The responding piece 49 is rotatably supported between the ground plates 33 and 33 by inserting a shaft 50 in the hole 490 of the responding piece 49 and the respective holes 330 and 33 'c of the ground plates 33 and 33.

The above mentioned responding piece, hanging frame and turning arm are so arranged that, as shown in FIG. 13B, the tip parts 49a and 52 of the responding piece 49 will be engageable with the bent part 42a of the hanging frame 42 and the shaft 41 inserted in the hole 40c of the turning arm 40 will be contactable with the engaging part 44 and inclined part 45 of the hanging frame 42. A spring 51 is inserted between the projection 54 of the responding piece 49 and the bent projection 53 of the ground plate 33 so as to give a counter-clockwise pressing force to the responding piece 49. A spring 56 is engaged at one end with the short leg 37b of the U-shaped shaft 37 and at the other end with the hole 33d of the ground plate 33 so as to give a clockwise torque to the operating plate 38. 46 is a U- shaped spring inserted at the open end 46b in the holes 48 of the ground plates 33 and 33', engaged in the intermediate part 46a with the cut and raised parts 47 of the ground plates 33 and 33 and contacted at the other end 46c with the sides 44d of the engaging parts 44 so as to give a clockwise torque to the engaging parts 44. The thus formed state is shown in FIGS. 14A through 14C, in which FIG. 14A shows a front view of the operating part, FIG. 148 shows its rear view and FIG. 14C shows its side view.

FIGS. 15 and 16A through 16C show an oil dash pot type electromagnetic device employed as an excess current detecting part. It is formed of a coil 17, coil frame 18, L-shaped yoke and oil dash pot 20.

FIG. 17 shows a switching contact unit, in which a movable contact 13 is provided at the tip of a contact plate 12, a hole 12a is provided in the intermediate part, a middle leg 10a of an E-shaped supporting metal piece 10 is inserted in the hole 12a, the contact plate 12 is embraced on the sides by hooked parts provided at the tips of both legs 10b and 100 and the contact plate 12 is supported rotatably on the supporting metal piece 10 by a coil spring 77 fitted on the middle leg 10a. 78 is a terminal metal piece connected with the contact plate 12 through a lead wire 15.

FIG. 18 shows the carrier 22 (or F) in which grooves 22a for inserting the contact plate 12 are made on the lower side and a stepped part 24 to contact the turning arm 40 is made on the upper side as described later.

FIG. 19 is of an operatively connecting plate to which is fixed an armature 25 formed of a turning plate 27, to the lower side of which is fixed an iron piece 26 with a pin 29 and in a part of which is provided a projection 25 to push the bent part 49b of the responding piece 49. 30 is a supporting shaft provided to project at each end of the operatively connecting plate so as to rotatably fit the plate to the chassis l as described later.

FIGS. 20 and 22 show the handle 57 made of a synthetic resin. 57a is a hole in which the long leg 37a of the U-shaped shaft 37 is to be inserted and which is made through the handle 57. 57b is a hole in which the short leg 37b is to be inserted and which does not pass through the surface.

Now the assembly of the device of the present invention shall be explained.

The respective leg parts 5b and 6b of the L-shaped input terminal metal piece 5 and output terminal metal piece 6 are inserted respectively in the concave parts la and 1b of the chassis I (see FIGS. 7, 8, 9 and 10) made of an insulator. Wire fastening screws 7 are fitted to the respective upper pieces 50 and 6a of the terminal metal pieces 5 and 6 and a fixed contact 9 is provided on the leg part 5b of the input terminal metal piece 5.

Then, the opening on the back surface of the chassis (FIG. 10B) is directed upward andthe stepped part.24 of the carrier 22 (FIG. 18) is inserted in the communicating window 72 of the chassis I, then the supporting metal piece 10 (FIG. 17) of the contact plate 12 is inserted in the concave part 1d (FIG. 10B) of the chassis and the metal piece 78 is inserted in the groove 1c of the chassis to fit the contact plate. Then the coil frame 6 18 of the electromagnet (FIGS. 15 and 16) is inserted between the wall parts 1 f and lg of the chassis to fit the electromagnet, and the coil 17 is soldered in the end part 17a to the metal pieces 78 and 66. Then the back lid 64 is secured to the bottom surface of the chassis.

Thus the assembly of the electric parts through the opening on the back surface of the chassis is completed. Then the opening on the front surface of the chassis is (FIG. 10A) is directed upward. First, the hole 71 is aligned with the hole 33 of the ground plate of the completed operating part (FIGS. 12 and 14) and the operating part is fixed to the chassis with the rivet 36 (FIG. 21). Then the operatively connecting plate 25 is fitted. The indicating plate 63 indicating the trip is fitted to the U-shaped shaft 37, then the upper lid 59 is secured to the upper surface of the chassis l, the long legs 37a and 37b of the U-shaped shaft 37 are inserted respectively in the holes 57a and 57b (FIG. 20) of the handle 57, a lock washer 57b is fitted to the upper part of the long leg'37a, a lid 79 is fixed above the long leg 37a (FIG. 22) and a case 65 is applied (FIGS. 3 and 4).

Now the operation of the device according to the present invention shall be described in the following.

i. FIG. 23A shows the contact in the OFF-state in which the contact plate 12 is separated from the fixed contact 9 (see FIG. 24A). In this case, the handle 57 is in the position of W in FIG. 2 and the indicating plate 63 is in the position of W in FIG. 6. In this case, the projection 52 of the responding piece 49 is engaged with the end part 42b of the hanging frame 42 and the shaft 41 of the turning arm 40 is positioned at the left end of the arcuate groove 39 of the ground plates 33 and 33' and is engaged with the inclined part 44b of the hanging frame 42.

ii. When the handle 57 is rotated counterclockwise so as to be in the state shown in FIG. 233 (the handle position is in the state of U in FIG. 2), the handle will rotate with the shaft 37a as a center, the operating plate 38 will also rotate together with the handle, and the upper end part 40a of the turning arm 40 will rotate clockwise with the shaft 41 as a center. Therefore, the carrier 22 will move rightward against the resiliency of the spring 14 and, at the same time, the contact will move toward ON against the resiliency of the spring. At this time, in case the roller (of the roller bearing) slides while under the reaction on the projection provided on the turning arm and passes the apex of the projection, the displacement of the operating plate will become maximum. When the U-shaped arm 37 further rotates and the roller lowers down the slope of the projection, the carrier 22 will somewhat return to the OFF side. In this state, the spring 56 to return the handle will give a force to move the turning arm to the OFF side but, by overcoming it, a stable state will be made and the ON state will be obtained, because a dead point is formed at the projection 4b of the turning arm.

iii. If an excess current flows in this state (see FIG. 9), the attracting iron core 19 of the electromagnet will attract the armature 25 and the contact will be OFF so as to be in the trip state. Its details are as follows.

Now, by the resiliency of the spring 14, the. carrier 22 will be pushed toward OFF side and this force will give a clockwise torque component to the slope 44b of the hanging frame 42 through the turning arm and to the hanging frame 42 through the shaft 41 of the turning arm and will give a torque. When the responding piece 49 and the frame are disengaged from each other, the

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2443090 *Aug 4, 1945Jun 8, 1948Wise Donald RCircuit breaker
US2540491 *Sep 17, 1946Feb 6, 1951Trumbull Electric Mfg CoElectric circuit breaker
US2660642 *Aug 2, 1951Nov 24, 1953Gen ElectricElectrical circuit breaker
US2703350 *Oct 18, 1952Mar 1, 1955Cutler Hammer IncManually operated switch with trip-free overload
US2989604 *Apr 4, 1957Jun 20, 1961Gen ElectricCircuit breaker
US3240904 *Aug 12, 1963Mar 15, 1966Gen ElectricCircuit breaker assembly
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4222019 *Jul 31, 1978Sep 9, 1980Weber Ag, Fabrik Elektrotechnischer Artikel Und ApparateCircuit breaker with manual release
US5168545 *Mar 9, 1992Dec 1, 1992Robertshaw Controls CompanyTemperature operated control system, control device therefor, and methods of making the same
US6417749 *Sep 30, 1998Jul 9, 2002Rockwell Automation Technologies, Inc.Electric contactor housing
Classifications
U.S. Classification335/6, 337/46, 335/202, 335/201
International ClassificationH01H73/00, H01H73/02, H01H73/42, H01H71/02, H01H73/04
Cooperative ClassificationH01H71/0207, H01H73/42, H01H73/04, H01H73/02
European ClassificationH01H73/42, H01H71/02B, H01H73/04, H01H73/02