JPH0145932B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention relates to snap action electrothermally operated circuit breakers. More particularly, the present invention relates to an improved circuit breaker mechanism for use in a compact snap action circuit breaker that combines switch and circuit breaker functions.

Description of the Prior Art For compact snap-action circuit breakers,
U.S. Pat. No. 2,911,503, issued November 3, 1959, describes a safety switch that in its on, or closed, state forms a circuit through a bimetallic element, a pair of contacts, and a lever. ing. In this case, when the bimetal element is heated by an overcurrent, it deflects the lever beyond the center line of the over-center spring. This causes the switch to open with a snapping sound.

However, bimetallic elements in circuit breakers such as those described in the aforementioned US patents are generally suspended in air. This tends to cause the recoil element to bend the bimetallic element downward in a direction opposite to that required to trip the circuit breaker. Additionally, circuit breakers such as those described in the above-referenced US patents use separate heaters and heating elements to heat the bimetallic elements. Finally, in conventional circuit breakers, adjustment of the circuit breaker is typically accomplished by calibration screws that lack precision.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new and improved electrothermally operated circuit breaker mechanism.

It is a further object of the present invention to provide a thermal circuit breaker having a low mass thermal element that heats and cools quickly without the need for auxiliary heaters and thus has a faster trip time than conventional circuit breakers. It is in.

In the present invention, the thermal element is supported by the insulating housing of the circuit breaker. In the circuit breaker of the present invention, the bimetal element as a thermal element is directly heated by passing the current to be monitored. The current rating of the circuit breaker according to the invention can be precisely adjusted by inserting a pin through an opening in the circuit breaker housing.

The circuit breaker according to the invention is particularly suitable for low current applications. Since the electric power is related to the thickness of the bimetal element, the bimetal element of the circuit breaker of the present invention is made thin,
It is advantageous to operate circuit breaker application devices accurately and sharply at very low currents.

The thin bimetal element in the circuit breaker of the present invention is
It also acts like a spring that bends against the starting friction. That is, such bimetallic elements store mechanical energy that assists the temperature-related bending forces in the bimetallic material during tripping of the circuit breaker. Once the starting friction forces are overcome, the circuit breaker opens as if a spring were released.

The small circuit breaker of the present invention together with a semiconductor element
Better than traditional circuit breakers for mounting on PC boards. The compact design of the present invention saves space and makes circuit component selection less critical for space demanding PC boards.

A second example of the present invention provides a multipole circuit breaker that opens two or more circuits in response to an overcurrent flowing through any one of the circuits.

A third embodiment of the invention provides a dual contact circuit breaker mechanism.

Other characteristics and advantages of the invention are also apparent from the description of the examples below.

Description of examples The invention will be explained with reference to the drawings.

1 to 5 show a first embodiment of a snap-acting thermal circuit breaker according to the present invention. As shown in FIG. 1, the thermal circuit breaker includes a housing 2 made of an insulating material, such as molded plastic. A line terminal 4 and a load terminal 6 are installed within the housing 2. In the illustrated example, the line terminal 4 is a U-shaped conductor. This terminal 4 has a short leg 8, a long leg 10 and a bridge 12. The long leg 10 has a portion 10a located within the housing 2 and extends outwardly from the housing 2;
Part 1 for connecting to the external electrical circuit to be protected
0b. As shown in FIG. 2, the line terminal 4 has an elongated slotted opening 14 extending from the long leg 10 across the bridge 12 to the short leg 8. As shown in FIG. The line terminal 4 also has a pair of notches 16 located halfway between the two parallel portions forming the leg portions 10a.

Advantageously, the load terminals 6 are straight conductors. In this example, a portion 6a of the load terminal 6 inside the housing 2 is wider than a portion 6b protruding from the housing. Approximately in the center of the wide portion 6a of the load terminal 6 is a tab 1 as shown in FIG.
form 8.

The circuit breaker of the present invention also includes a movable contact blade member 20. As shown in FIGS. 1 and 4, the contact blade member 20 has a pair of (preferably chamfered) tips 2 that seat in the notches 16 of the line terminals 4.
It has 2. Contact blade 20 is positioned for rotation about tip 22 thereof. As can be seen in FIG. 4, the contact blade 20 also has an opening 24 on its axis. One end 26a of the bias spring 26 is attached to this opening 24. The other end 26b of the spring 26 is attached to the short leg 8 of the line terminal 4. The spring 26 is connected to the long leg 10 of the line terminal 4.
extending through a grooved opening 14 at. Spring 2
6 is the engagement point (indicated by A) between the one spring end 26b and the short leg 8, and the tip 2 of the contact blade.
2 biases the contact blades 20 in opposite directions as a function of the position of the spring end 26a relative to a line connecting the contact point (indicated at B) with the notch 16. Contact blade 20 is rotationally biased downward when the thermal circuit breaker is in the contact closed position due to spring 26 being beyond the center position. The contact blade 20 has a preferably circular contact pad 28 mounted at its end opposite the pivoting tip 22.

The circuit breaker also includes a bimetallic element 30. As shown in FIG. 1, bimetallic element 30 is L-shaped and has a first portion 32 that is attached to load terminal 6. As shown in FIG. Bimetal element 30
also has an elongated second part or leg 34 which rests on an insulating serrated surface 36 on the inside of the housing 2. Sawtooth surface 36 is formed to support bimetallic element 30 with a minimum contact area. In this way, the housing 2 no longer acts as a heat sink for the bimetal element 30.

The bimetal element 30 is composed of an upper layer and a lower layer. The lower layer is made of a metal having a larger coefficient of expansion than the metal of the upper layer. Therefore, bimetal element 3
When 0 is heated, it bends upwards as shown in FIG.

The bimetal element 30 also has its elongated second portion 3
It has a (preferably circular) contact pad 38 attached to the free end of 4. When the circuit breaker is in the contact closed position as shown in FIG.
is in electrical contact with pad 28 of blade member 20.

The circuit breaker of the present invention may optionally be provided with additional contact pads 40 on the contact blades 20 and additional terminals 42. The auxiliary terminal 42 has a somewhat hook-shaped conductor portion 43 at one end thereof, as shown in FIG. This terminal 42 can be externally connected to, for example, an alarm device or another circuit that can activate an alarm.

The auxiliary terminal 42 also acts as a stopper to prevent the contact blade 20 from moving too much. Accordingly, if an alarm or warning circuit is not required, the housing 2 may be configured to include a stop protrusion or the equivalent in place of the terminal 42.

The circuit breaker of the present invention is suitable for mounting on a printer circuit board (referred to as a "PCB"). Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM)
The PCB has a terminal post opening of 0.025 inch (1
Inches are standardized to be spaced many times apart (approximately 2.54 cm). Typical CAD/CAM PCB post holes are spaced 0.100 inches on center in a row. Adjacent rows are also 0.100 inches apart on centers and 0.050 inches eccentric from each other.

Terminals 4, 6 and 42 of the circuit breaker shown in FIG.
are preferably and advantageously spaced apart from each other by many times the 0.025 inch CAD/CAM PCB standard. In the example of the circuit breaker shown in Figures 1 to 5, for example, terminals 4 and 6 are separated by a distance of 0.400 inch (16 times 0.025 inch), and terminals 4 and 42 are separated by a distance of 0.325 inch (0.025 inch).
13 times the PCB standard).

The housing 2 is also provided with a reset button 44,
The upper portion of the reset button extends outwardly from the top of the housing 2. Reset button 44
The lower portion 48 of extends into the housing 2.
This lower portion 48 has a generally cylindrical shifter 50;
Legs 5 extending from the end of this shaft 50
2. The shift 50 extends through the grooved opening 14 of the line terminal 4. An opening 54 is provided in the leg portion 52 . The circuit breaker is assembled so that spring 26 passes through opening 54 as shown in FIG.

In a preferred embodiment of the invention, one end of the housing 2 is provided with an opening 56 that provides access to the bending tabs 18 of the load terminals 6. The current rating of the circuit breaker, which indicates the current carrying capacity of the circuit breaker, can be adjusted by inserting a pin through the opening 56 and bending the tab 18 inward. Bending tab 18 in this manner causes bimetallic element 30 to rotate counterclockwise.

When the circuit breaker is activated, current flows through the contact blades 20,
Contact pads 28 and 38, bimetal element 30
and flows between terminals 4 and 6. When an overcurrent flows through the circuit breaker, the bimetal element 30 heats up and bends upward, causing the blade member 20 to release the spring 26.
rotate counterclockwise against the bias force of. The bimetal element 30 rotates the blade member 20 upwards enough to separate the spring end 26a and the blade member 20.
When the connecting point (indicated by C) is moved above the line connecting points A and B, the bias direction of the spring 26 is reversed and the blade member 20 rapidly rotates counterclockwise. The circuit breaker opens as shown in FIG. 5 by the snap action. In this case, by providing an optionally constructed attachment as shown, the contact pad 40 of the blade member 20 will come into contact with the terminal 42 in the open contact position, thereby activating an alarm circuit or the like.

Once the circuit breaker trips and becomes open,
Current no longer flows through the bimetal 30. When the bimetal 30 subsequently cools, it returns to its original position on the sawtooth surface 36. However, since the spring 26 remains biasing the blade member 20 in a counterclockwise direction, the circuit breaker will remain open until manually reset. The circuit breaker is reset by moving the reset button 44 downward. At this time, the spring 26 has engagement points A and B.
leg 52 until it moves to a level lower than the line connecting the
is pushed downward. This causes spring 2
The direction of the biasing force at 6 is reversed again so that the blade member 20 is forced downwardly into contact with the bimetal 30. The circuit breaker is thus returned to the contact closed position.

The circuit breaker can be manually opened by moving the reset button 44 upwardly, forcing the spring 26 upwardly from its central position.

FIG. 6 shows the mechanism of a multi-pole circuit breaker which is a second embodiment of the present invention. As shown in the figure, this example includes two thermal circuit breakers having substantially the same construction as that of the first embodiment in a single housing 2'. In the example of FIGS. 6 and 7, the first
Corresponding parts to those in the example are indicated with a single prime (') or double prime (''), respectively.The poles (balls) of a thermal circuit breaker are both marked with a single It is controlled by a single reset button 44' consisting of a cross arm 48' and a single cylindrical shaft 50'. The cross arm 48' is provided with two circular openings 54' and 54''. The circuit breaker has springs 26' and 26'' connected to the opening 5, respectively.
4' and 54''.

Upon actuation of this second example circuit breaker, the cross arm 48' is pushed up when either pole of the circuit breaker opens (either due to overcurrent or by manually moving the reset button 44' upwardly). This opens both poles at the same time. Similarly, moving the reset button 44' downward lowers the cross arm 48', which closes both poles of the circuit breaker simultaneously. It is clear that the example is not limited to two-pole circuit breaker arrangements.

FIG. 8 shows the mechanism of a double contact circuit breaker which is a third embodiment of the present invention. The circuit breaker in this example includes a housing 58 made of an insulating material,
Inside this housing are one line terminal 60 and two
Attach the load terminals 62 and 64. Line terminal 60 may be located in the central portion of the dual contact thermal circuit breaker.

In this third example, the line terminal 60 is connected to the housing 5.
8, which has an elongated grooved opening 66 as shown by dotted lines in FIG. As in the case of the first example, the line terminal 60 also has a pair of notches 68 on the opposite side of the grooved opening 66.
It is equipped with

Load terminals 62 and 64 are straight conductors. Load terminals 62 and 64 have tabs 1 of the first example.
Tabs 70 and 72 of similar shape to 8 are provided for circuit breaker adjustment.

As with the first embodiment, this third embodiment dual contact thermal circuit breaker also includes a movable contact blade member 74. The contact blade 74 has a pair of (preferably beveled) tips 76 that seat in the notch 16 of the line terminal 60. Contact blade 74 is positioned for rotation about tip 76 thereof. The contact blade 74 also has an opening 78 on its axis in which one end 80a of a biasing spring 80 is mounted.
The other end 80b of the spring 80 is attached to an extension 82 of the housing 52 as shown in FIG. Spring 80 extends through slotted opening 66 in line terminal 60. The spring 80 connects the point where one spring end 26b engages with the extension 82 (indicated by A) and the point where the tip 76 of the contact blade contacts the notch 68 (indicated by B). Biasing contact blades 74 in opposite directions as a function of the position of spring end 80a relative to the line. Contact blade 74 has two contact pads 84 and 86 mounted on each side of the contact blade 74 at its end opposite pivot tip 76 .

The circuit breaker of this example also includes a pair of bimetallic elements 88 and 90 whose profile is in the shape of the housing 58 as shown in FIG. As in the first example, bimetallic elements 88 and 90 have first portions 92 and 94 that are attached to load terminals 62 and 64, respectively. Additionally, contact pads 96 and 98 are attached to each end of elongated portions 100 and 102 of bimetallic elements 88 and 90.

Housing 58 has a pair of serrated surfaces 104 and 106 on its interior surface. If there is no overcurrent, the bimetal element 88 as shown in FIG.
and 90 sit on sawtooth surfaces 104 and 106. As previously discussed, the serrated surfaces 104 and 106 support their respective bimetallic elements with minimal contact area.

Openings 108 and 110 are provided in the housing portion adjacent load terminals 62 and 64. The current rating of a double contact circuit breaker is
Insert a pin-like object through 08 or 110,
Adjustment can be made by bending tabs 70 or 72. In this manner, the corresponding bimetallic element 88 or 90 is rotated to achieve the desired calibration.

In operation, contact blade 74 seats on either one of the two contacts 96 or 98 to form a closed circuit to the corresponding load terminal. When an overcurrent flows through this closed circuit, the bimetallic element in this circuit deforms sufficiently to force contact blade 74 into spring 80.
The contact blade 74 is then snapped into contact with the other bimetal element.

As is clear from the foregoing, the present invention is an improved mechanism for snap-acting thermal circuit breakers. The thermal circuit breaker according to the present invention has a predetermined set of notches in the housing to speed up the heating and cooling of the bimetallic element, resulting in faster trip times than conventional thermal circuit breakers. Furthermore, since the thermal circuit breaker of the present invention can be made compact in size,
It is better than conventional ones for mounting on PC boards together with semiconductor elements. A second embodiment of the invention is a multipole circuit breaker, which opens all circuits in response to an overcurrent flowing through any one of the circuits. Third aspect of the present invention
The embodiment uses two bimetallic elements to switch between two individual circuits.

In a variant of the invention shown in FIGS. 9-11, the stub member 3 extends inwardly from the inner wall of the housing 2 such that its end 3a lies over a portion of the biasing spring 26. As shown in Figure 11,
The stub member 3 has a bottom surface portion 3b that is chamfered or sloped upward, and a top surface portion 3c that is chamfered or sloped downward. The stub member 3 is preferably formed integrally with the housing 2,
Moreover, it is advantageous.

When testing a prototype PC board-mounted circuit breaker according to the present invention, contact pads 28 and 3 were tested.
It was confirmed that there is a sliding action between the two. Contact pads 28 and 38 cannot be made perfectly smooth, and as these contacts slide over each other, the irregularities in the contact surfaces will cause the current flowing through them to vary. Such problems are particularly noticeable during the early stages of an overcurrent condition, when the bimetallic element begins to heat up and bends upwards relatively slowly. These current fluctuations can adversely affect the operation of the circuit to which the circuit breaker is connected. Since the inventive circuit breaker is designed to operate in the extremely low current range associated with computer circuits (5A to 0.5A or on the order of lower), contact pad surface mismatch may result in Even small current fluctuations result in relatively large disturbances in the current flowing to the associated printed circuit. The stub member 3 provides a simple, low cost and effective solution to the sliding contact problem.

During operation (at the contact closed position shown in Figure 1)
When an overcurrent condition occurs, bimetallic element 30 begins to heat up and the elongated portion or leg 34 of the bimetallic element begins to bend upwardly along its length. The upward force exerted by the bending of the leg 34 is transferred by the spring 26 to the contact blade 2.
increases until it exceeds the downward force applied to 0. Without the stub member 3, the leg 34 of the bimetallic element would then begin to push the contact blade 20 upwards. This creates relative sliding movement between pads 28 and 38. If the overcurrent is not as great as it is, the movement of the legs 34 and blades 20 will occur relatively slowly, resulting in undesirable current fluctuations as described above.

However, it is preferred and advantageous to insert the end portion 3a of the stub member 3 into the upward movement path of the spring 26, as in the preferred embodiment of the invention shown in FIGS. 9-11. In this way, the upward force exerted by the heated bimetallic element leg 34 becomes sufficiently large that it exceeds the frictional force exerted on the spring 26 by the end portion 3a of the stub member. is temporarily suppressed against upward movement. When the upward bending force applied by the legs 34 exceeds the combined force of the downward bias force applied by the spring 26 and the friction suppressing force applied by the stub member 3, the stub member 3 Chamfered or sloped surface portion 3a
This allows the spring 26 to slide relatively easily over and around the stub end portion 3a.

When the upward bending force exceeds the combined downward restraining force, the legs 34 immediately move upwardly, quickly forcing the contact blade 20 upwardly past the aforementioned over-center position. The direct restraining action of stub end 3a on spring 26 effectively prevents upward movement of leg 34 and prevents relative sliding movement of contact pads 28 and 38. Legs 3
The rapid movement of the leg 34 when the bending force of the spring 26 exceeds the combined force of the downward biasing force of the spring 26 and the restraining force of the stub causes the contact pad 28 to
The length of time during which the sliding action occurs between and 38 is significantly reduced. This minimizes variations in the current flowing through the contacts due to differences in contact pad surfaces, and such variations are effectively negligible.

The chamfered upper portion 3c of the stub member 3 is connected to the spring 26 when the reset button 44 is pressed down to close the contacts and reset the circuit breaker as described above.
can easily slide over and around the stub end 3a.

Regarding the stub member 3, the first embodiment (first to
5), it is clear that the embodiments shown in FIGS. 6 to 8 can also use one or more spring restraining stub members. Stub member 3
can also be positioned so that it provides a direct deterrent force to the legs 34 of the bimetallic element or to the contact blades 20.

In short, it is desirable to provide means for temporarily suppressing the bending action of the bimetallic elements and therefore the relative sliding action between the contact pads, thereby minimizing the effects of fluctuations in the current flowing through the circuit breaker contacts. confirmed that it is desirable. In the present invention, this is accomplished by means of requiring a bimetallic element that provides a substantial contact opening force until a point is reached where the inhibiting force is quickly removed and the contact opens quickly.

The chamfered or inclined surfaces 3b and 3c of the stub member 3 face upwardly at the leg portion 34;
Alternatively, when the downward bending force exceeds the restraining force provided by the stub member 3, the legs 34 can slide relatively easily over and around the stub end 3a.

It goes without saying that the present invention is not limited to the above-mentioned examples, but can be modified in many ways.

[Brief explanation of drawings]

FIG. 1 is a cutaway side view showing a first example of a snap-acting thermal circuit breaker for mounting on a PC board according to the present invention in a contact closed state; FIG. 2 is a front view showing a line terminal in the circuit breaker of FIG. 1; FIG. 3 is a front view showing the load terminal of the circuit breaker of FIG. 1; FIG. 4 is a top view of FIG. 1; FIG. FIG. 6 is a top view of the second example of the present invention as a multi-pole breaker mechanism; FIG. 7 is a side view of FIG. 6; FIG. A cutaway top view of the third embodiment of the invention; FIG. 9 is a side view showing the internal structure of the housing of the circuit breaker of the invention with additional restraining means; FIG.
-10 line; Figure 11 is 11 of Figure 9.
It is a sectional view on line -11. 2...Housing, 3...Stub member, 4...
Line terminal, 6... Load terminal, 14... Grooved opening, 16... Notch, 18... Tab, 20... Contact blade member, 24... Opening, 26... Bias spring, 28... Contact pad, 30... Bimetal element, 36... Sawtooth surface, 38, 40... Contact pad, 42... Attachment terminal, 44... Reset button, 50... Shaft, 52... Leg, 54,
56... Opening, 58... Housing, 60... Line terminal, 62, 64... Load terminal, 66... Grooved opening, 68... Notch, 70, 72... Tab,
74... Contact blade member, 78... Opening, 80
... Bias spring, 84, 86 ... Contact pad,
88,90...bimetal element, 96,98...
Contact pad, 104, 106...Sawtooth surface, 10
8,110...opening.

Claims (1)

Claims: 1. an electrically insulating housing having a serrated surface on a lower portion; first and second terminal means extending through the housing for connecting the circuit breaker to an electrical circuit; and is electrically connected to the first terminal and is not in a deformed state;
a bimetal element disposed on the serrated surface; a first contact member coupled to the bimetal element; a second contact member disposed within the housing and electrically coupled to the second terminal. and; mounting means for mounting the second contact member such that it comes into contact with and separates from the first contact member; and a mounting means for coupling the second contact member to the first contact member; and a second position, biasing the second contact member into electrical contact with the first contact member in the first position and biasing the second contact member in electrical contact with the first contact member in the second position. bias means for biasing the second contact member so that it is out of electrical contact with the first contact member; and the bimetal element is deformed when a sufficient overcurrent flows through the bimetal element. hand,
A circuit breaker, characterized in that the second contact member is configured to move from the first position toward the second position against the action of the biasing means. 2. The circuit breaker according to claim 1, wherein the electrically insulating housing has a sawtooth surface on a lower portion of the housing, and the bimetallic metal is not in a deformed state on the sawtooth surface. A circuit breaker characterized by an element that remains in place. 3. The circuit breaker according to claim 1, wherein the circuit breaker includes a reset means operable to return the second contact member from the second position to the first position. A circuit breaker characterized by: 4. The circuit breaker according to claim 1, wherein the housing includes access means that allow access to the first terminal in order to adjust the trip rating of the first contact member. A circuit breaker characterized by: 5. The circuit breaker of claim 4, wherein the first terminal includes a bendable tab in a portion within its housing. 6. The circuit breaker according to claim 5, wherein the bimetal element has an L-shape including a first part and a second part, and the first part is connected to the first part of the first terminal. A circuit breaker characterized by having bendable tabs abutted against each other. 7. The circuit breaker according to claim 1, wherein the mounting means is constituted by a blade member, and an opening is provided along the longitudinal axis of the blade member. 8. The circuit breaker according to claim 7, wherein the biasing means comprises an over-center spring, one end of which is connected to the second terminal,
A circuit breaker characterized in that the other end of the spring is connected to the mounting means through the opening. 9. The circuit breaker according to claim 8, wherein the circuit breaker is provided with a reset means that can be operated to return the second contact member from the second position to the first position, The reset means includes a reset member extending within the housing and movable within the housing, the reset member and the biasing means engaging each other to place the second contact member in the first position. and a second position. 10. The circuit breaker according to claim 9, wherein the reset member has an opening therein, and the biasing means is passed through the opening. 11. The circuit breaker according to claim 1, further comprising a reset means capable of returning the second contact member to the first position when the second contact member is in the second position; the electrically insulating housing has a serrated surface on a lower portion of the housing on which the bimetallic element rests when not in a deformed state; access means for providing access to the first terminal for adjusting the trip rating of the member; a bendable tab in a portion of the housing of the first terminal adjacent the access means; the bimetallic element comprising a first portion and a second portion, the first portion abutting the bendable tab of the first terminal; and the attachment means comprising a blade member; has an opening along its longitudinal axis; said biasing means comprises an over-center spring, one end of said spring being connected to said second terminal, and the other end of said spring being connected to said attachment means through said opening; A circuit breaker characterized by being connected. 12. The circuit breaker of claim 11, wherein said reset means includes a reset member extending within said housing and movable within said housing, said reset member defining an opening through which said biasing means passes. A circuit breaker, wherein the reset member and the biasing means engage with each other to move the second contact member between the first position and the second position. 13. In the circuit breaker according to claim 1, means is provided for applying a deformation inhibiting force to the bimetal element, and when the deforming force of the bimetal element exceeds the inhibiting force, the bimetal element is released and the second A circuit breaker characterized in that the bimetal element is not deformed until the contact member is moved toward the second position. 14. The circuit breaker according to claim 13, wherein the bimetal restraining means is constituted by a stub member, and the stub member extends from the inner wall of the housing to the movement path of the biasing means inside the housing. A circuit breaker characterized in that the movement of the biasing means is suppressed. 15. The circuit breaker of claim 1, wherein the first and second terminal means are spaced apart from each other by an integral multiple of 0.025 inches, and the circuit breaker is constructed by computer-aided design techniques. A circuit breaker characterized in that it can be attached to a manufactured printed circuit board. 16. The circuit breaker according to claim 1, further comprising: a third terminal means extending through the housing for connection to an electrical circuit; a third contact member coupled to; when the second contact member is in the second position;
A circuit breaker characterized in that the second contact member is biased into electrical contact with the third contact member. 17. The circuit breaker of claim 1, wherein the first, second, and third means are spaced apart from each other by a distance that is an integral multiple of 0.025 inches, and wherein the circuit breaker is printed using computer-aided design techniques. A circuit breaker characterized in that it can be mounted on a circuit board. 18 an electrically insulating housing; extending through the housing, the first terminal means being connected to the first electrical circuit, and the second terminal means being connected to the second electrical circuit;
first and second terminal means connected to an electrical circuit; third terminal means; a first bimetal element located within the housing and electrically coupled to the first terminal; the first bimetal element a first contact member coupled to the element; a second bimetal element located within the housing and electrically coupled to the second terminal; a second contact member coupled to the second bimetal element; a third contact member located at and electrically connected to the third terminal;
a third contact member mounting means that is attached to the contact member so as to alternately come into contact with and separate from the contact member;
The means for sufficiently biasing the contact member includes alternately biasing the third contact member in opposite rotational directions between a first position and a second position, and in the first position, the third contact member biasing means for biasing a member such that it is in electrical contact with the first contact member and in the second position biasing the third contact member such that it is in electrical contact with the second contact member; ; when a sufficient overcurrent is applied to the first bimetal element, the first bimetal element deforms against the action of the bias means, causing the third contact member to from the first position towards the second position; when a sufficient overcurrent is applied to the second bimetal element, the second bimetal element deforms against the action of the biasing means, and the second bimetal element deforms against the action of the biasing means; A circuit breaker, characterized in that the three contact members are configured to move from the second position to the first position. 19. The circuit breaker of claim 18, wherein the electrically insulating housing has a serrated surface around an inner periphery of the housing, and the circuit breaker is in the first and second positions, respectively. In case,
A circuit breaker characterized in that the first and second bimetal elements are arranged to alternately rest on the sawtooth surface. 20. The circuit breaker of claim 18, wherein the housing has access to the first and second terminals for adjusting the trip ratings of the first and second contact members, respectively. A circuit breaker characterized by comprising a means. 21. A multipole circuit breaker comprising: an electrically insulating housing; and a plurality of pole units disposed within the housing, each having substantially the same circuit breaker mechanism, each circuit breaker mechanism having: first and second terminal means extending through the housing for connecting the circuit breaker to an electrical circuit; a bimetallic element located within the housing and electrically coupled to the first terminal; the bimetallic element a first contact member coupled to; a second contact member located within the housing and electrically coupled to the second terminal; the second contact member being in contact with the first contact member; a second contact member attachment means for attaching the second contact member so as to separate the second contact member;
The means for sufficiently biasing the contact member includes biasing the second contact member alternately in opposite directions between a first position and a second position, in the first position the second contact member biasing means biased into electrical contact with a first contact member such that in the second position the second contact member is biased into electrical contact with the first contact member; and when a sufficient overcurrent is applied to the bimetal element, the bimetal element deforms and moves the second contact member from the first position to the second position against the action of the biasing means. all of the second contact members when the multi-pole circuit breaker is coupled to each of the plurality of circuit breaker mechanisms and the second contact member is in the second position; A multi-pole circuit breaker, characterized in that it also includes a reset means capable of returning the circuit breaker to the first position. 22 In the multi-pole circuit breaker according to claim 21, the reset means is commonly connected to all of the circuit breaker mechanisms, and when a sufficient overcurrent is applied to any of the circuit breaker mechanisms, . A multi-pole circuit breaker, comprising means for moving all of the second contact members from the first position to the second position. 23. The multi-pole circuit breaker according to claim 21, wherein the circuit breaker moves from the second position to the first position.
comprising reset means operable to return the second contact member to the position;
the reset means extends within the housing;
and a reset member movable within the housing, the reset member having a plurality of openings through which each of the biasing means is passed;
A multi-pole circuit breaker characterized in that the reset member and the biasing means engage each other to move each of the second contact members between the first position and the second position substantially simultaneously.