Circuit breakers with secondary displacement springs
09613763 ยท 2017-04-04
Assignee
Inventors
Cpc classification
H01R12/714
ELECTRICITY
H01H1/50
ELECTRICITY
H01H71/0207
ELECTRICITY
International classification
H01H1/50
ELECTRICITY
Abstract
Circuit breakers with a first bus energizing spring held in the housing that electrically connects the circuit board to an external electrical connection. The bus primary energizing spring is configured to deflect toward the circuit board with a first linear displacement. The circuit breakers also include a second bus energizing spring held in the housing that is configured to deflect toward the circuit board with a second linear displacement that supplements the first linear displacement.
Claims
1. A circuit breaker, comprising: a housing; a circuit board in the housing; a first bus energizing spring held in the housing that electrically connects the circuit board to an external electrical connection, the first bus energizing spring is configured to deflect toward the circuit board with a first linear displacement; and a second bus energizing spring held in the housing with at least a portion extending over and in cooperating alignment with the first bus energizing spring and is configured to deflect toward the circuit board with a second linear displacement to thereby provide a linear displacement capability as a summation of the first and second linear displacements, wherein the second bus energizing spring has an unloaded configuration and a fully compressed configuration, and wherein, when in the fully compressed configuration, the second bus energizing spring has a substantially flat configuration.
2. The circuit breaker of claim 1, wherein the second linear displacement is a controlled displacement so that the second energizing spring ceases deflection at a flat state to provide the substantially flat configuration whereby the second energizing spring cannot be over stressed.
3. The circuit breaker of claim 1, wherein the second bus energizing spring is integral to the first bus energizing spring.
4. The circuit breaker of claim 1, wherein the second bus energizing spring is a discrete component separate from the first bus energizing spring.
5. The circuit breaker of claim 1, wherein the first bus energizing spring has an elongate segment that resides adjacent and spaced apart from an arm, wherein the elongate segment has a first planar segment that merges into a second planar segment, the second planar segment defining a circuit board contact surface that contacts the circuit board, and wherein the first planar segment comprises, holds, and/or is in aligned contact with the second bus energizing spring.
6. The circuit breaker of claim 1, wherein the housing comprises a first housing member and a second housing member that attach together, wherein the second housing member holds the circuit board, and wherein the second bus energizing spring resides adjacent the first housing member and is integral to the first bus energizing spring.
7. A circuit breaker, comprising: a housing; a circuit board in the housing; a first bus energizing spring held in the housing that electrically connects the circuit board to an external electrical connection, the first bus energizing spring is configured to deflect toward the circuit board with a first linear displacement; and a second bus energizing spring held in the housing in cooperating alignment with the first bus energizing spring and is configured to deflect toward the circuit board with a second linear displacement to thereby provide a linear displacement capability as a summation of the first and second linear displacements, wherein the second linear displacement is less than the first linear displacement.
8. A circuit breaker, comprising: a housing; a circuit board in the housing; a first bus energizing spring held in the housing that electrically connects the circuit board to an external electrical connection, the first bus energizing spring is configured to deflect toward the circuit board with a first linear displacement; and a second bus energizing spring held in the housing in cooperating alignment with the first bus energizing spring and is configured to deflect toward the circuit board with a second linear displacement to thereby provide a linear displacement capability as a summation of the first and second linear displacements, wherein the first bus energizing spring has an elongate segment and an arm that resides adjacent and spaced apart from the elongate segment, wherein the elongate segment has a first planar segment that merges into a second planar segment, the second planar segment defining a circuit board contact surface that contacts the circuit board, wherein the second bus energizing spring has at least one tab that extends above the first planar segment in an unloaded configuration and is substantially flat and coplanar with the first planar segment in a fully compressed configuration.
9. The circuit breaker of claim 8, wherein the second energizing spring comprises a sleeve with a plurality of spaced apart tabs that deflect into respective receiving apertures, and wherein the sleeve is held on the first planar segment.
10. The circuit breaker of claim 8, wherein the first planar segment comprises a single tab with a free end surrounded on three sides by a gap space that defines the bus secondary energizing spring.
11. A circuit breaker, comprising: a housing; a circuit board in the housing; a first bus energizing spring held in the housing that electrically connects the circuit board to an external electrical connection, the first bus energizing spring is configured to deflect toward the circuit board with a first linear displacement; and a second bus energizing spring held in the housing in cooperating alignment with the first bus energizing spring and is configured to deflect toward the circuit board with a second linear displacement to thereby provide a linear displacement capability as a summation of the first and second linear displacements, wherein the housing comprises a first housing member and a second housing member that attach together, wherein the second housing member holds the circuit board, and wherein the second bus energizing spring resides adjacent the first housing member in abutting contact with the first bus energizing spring and electrically connects the first bus energizing spring to the external electrical connection.
12. A circuit breaker, comprising: a housing; a circuit board in the housing; a first bus energizing spring held in the housing that electrically connects the circuit board to an external electrical connection, the first bus energizing spring is configured to deflect toward the circuit board with a first linear displacement; and a second bus energizing spring held in the housing with at least a portion extending over and in cooperating alignment with the first bus energizing spring and is configured to deflect toward the circuit board with a second linear displacement to thereby provide a linear displacement capability as a summation of the first and second linear displacements, wherein the housing comprises a first housing member and a second housing member that attach together, wherein the second housing member holds the circuit board, and wherein the second bus energizing spring resides adjacent the first housing member and can compress to a flat configuration at full loading due to contact with the first housing member when the first and second housing members are attached.
13. A circuit breaker, comprising: a housing; a circuit board in the housing; a first bus energizing spring held in the housing that electrically connects the circuit board to an external electrical connection, the first bus energizing spring is configured to deflect toward the circuit board with a first linear displacement; and a second bus energizing spring held in the housing with at least a portion extending over and in cooperating alignment with the first bus energizing spring and is configured to deflect toward the circuit board with a second linear displacement to thereby provide a linear displacement capability as a summation of the first and second linear displacements, wherein the second bus energizing spring is in abutting contact with the first bus energizing spring and electrically connects the first bus energizing spring to the external electrical connection.
14. A device with a circuit, comprising: a housing comprising a first housing member attached to a second housing member; a circuit board in the housing; a first energizing spring held in the housing that electrically connects the circuit board to an external electrical connection, the first energizing spring is configured to deflect toward the circuit board, wherein the first energizing spring has an elongate segment and an arm that resides adjacent and spaced apart from the elongate segment, wherein the elongate segment has a first planar segment that merges into a second planar segment, the second planar segment residing against the circuit board; and a second energizing spring held in the housing, wherein the second energizing spring extends above the first planar segment in an unloaded configuration and is substantially flat and coplanar with the first planar segment in a fully compressed configuration.
15. The device of claim 14, wherein the first energizing spring is configured to deflect toward the circuit board with a first linear displacement, and wherein the second energizing spring is configured to deflect toward the circuit board with a second linear displacement that is less than the first linear displacement.
16. An energizing spring for a device with a circuit, comprising: a first conductive energizing spring comprising an elongate segment and an arm, wherein the elongate segment and the arm reside adjacent and spaced apart from each other, wherein the elongate segment has an upper planar segment that merges into a lower planar segment; and a second conductive energizing spring that contacts the planar upper surface of or that resides over an aperture in the planar upper surface and that is configured to deflect downward to a substantially flat configuration upon full compression.
17. The energizing spring of claim 16, wherein the first conductive energizing spring comprises a back segment holding the arm and elongate segment and the arm, and wherein the elongate segment and the arm extend orthogonally outward from the back segment.
18. The energizing spring of claim 16, wherein the first conductive energizing spring is a monolithic shaped metallic body and the second conductive energizing spring comprises at least one projecting tab that can deflect down to the substantially flat configuration to be coplanar with the planar upper segment.
19. The energizing spring of claim 16, wherein the second conductive energizing spring is attached to the planar upper segment.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
(19) The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. Like numbers refer to like elements and different embodiments of like elements can be designated using a different number of superscript indicator apostrophes (e.g., 10, 10, 10, 10).
(20) In the drawings, the relative sizes of regions or features may be exaggerated for clarity. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
(21) It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
(22) Spatially relative terms, such as beneath, below, lower, above, upper and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as below or beneath other elements or features would then be oriented above the other elements or features. Thus, the exemplary term below can encompass both an orientation of above and below. The term upper can encompass both an orientation of above and below a component or feature described relative thereto as lower. The device may be otherwise oriented (rotated 90 or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. The term about refers to numbers in a range of +/20% of the noted value.
(23) As used herein, the singular forms a, an and the are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms includes, comprises, including and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being connected or coupled to another element, it can be directly connected or coupled to the other element or intervening elements may be present. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.
(24) The term printed circuit board refers to a substrate with electrical paths and components thereon, typically a rigid or semi-rigid substrate. The term semi-rigid refers to substrates that flex upon normal loading.
(25) Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
(26) Turning now to the figures,
(27) Although D.sub.2 is shown as less than D.sub.1 with the first energizing spring 10 being a primary energizing spring and the second energizing spring 20 being a secondary energizing spring, other configurations may be used. For example, the second energizing spring 20 may be configured to have a linear displacement D.sub.2 that is about the same as the linear displacement D.sub.1 of the first energizing spring 10.
(28) To ensure proper electrical engagement, there is a lower displacement limit which is determined by a minimum force that is acceptable. There is also an upper displacement limit which is determined by spring stress levels that is acceptable. A varying amount of displacement can be dictated or consumed by component and assembly variation. Therefore, different circuit breakers with the same layout and components can have different displacements. It is desirable to have sufficient displacement after assembly to prevent fatigue set-in over a defined life span/endurance test.
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(30) The use of at least one second energizing spring 20 that cooperates with the first (e.g., primary) energizing spring 10, which together can be described as a compound spring, can provide additional displacement for ensuring a desired contact force and each spring 10, 20 can be configured to operate within its stress levels to avoid set/fatigue.
(31) By way of example only, and not limiting to embodiments of the claimed invention, in the past, in some particular designs, the spring arm 14 was configured to have deflection limits with a contact force with tolerances of a minimum of 0.020 inches and a maximum of 0.059 inches. Because of this, the piece part component tolerance limits were tight/small, which can result in higher component costs and lower yields. Using the second energizing spring 20, the lower limit on the arm 14 can be dropped to a lower value, such as to about 0.010 inches (half of the current requirement) or even lower, typically to about 0.005 inches, because contact force pressure can be maintained by the supplemental or second energizing spring 20. Again, different designs, materials, environments and the like (stress level, material composition, hardness, thermal, cycle, steady state operation) can vary the dimensions and the above is provided by way of example only.
(32) The supplemental linear displacement provided by the secondary spring 20 may increase spring failures limits and/or desensitize loading variations during assembly due to component variability.
(33) The contact surface 12 of the body 10b of the first spring 10/10 can have a larger surface area A.sub.1 than the surface area A.sub.2 of the upper surface 19 and/or the upper surface of the body of the secondary spring 20b. A.sub.1 can be greater than A.sub.2 by between about 1.5-10, for example. However, in some embodiments, the reverse configuration can be used where A.sub.2 is >A.sub.1.
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(35) The second energizing spring 20 can be configured to deflect with a maximum linear displacement that is less than the maximum linear displacement provided by D.sub.1 with D.sub.2 typically being between about 5%-40%, more typically between 10-20%, of D.sub.1, for example. In some embodiments, D.sub.1 added to D.sub.2 can provide an increase in total displacement of between about 5% to about 40%, more typically between about 10% to about 20%. These values are thought to be typical, but are provided by way of example and are not limiting to embodiments of the invention.
(36) The second energizing spring 20 can be configured to have a controlled displacement so that the second energizing spring 20 deflects from an unloaded projecting state (
(37) Again, by way of example only, in some particular embodiments, the deflections can be between about 0.50 inches to about 0.001 inches, but the designs can be configured to provide other deflection values. The full compression/flat state can be configured to occur when fully compressed, loaded, e.g., which may be associated with when the at least one second energizing spring 20 is assembled inside the housing 100h, e.g., when the cover 101 of the housing is attached to the other housing member 102 (
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(40) The first energizing spring 10 can have an elongate segment 18 and the arm 14. The arm and elongate segment 14, 18 can reside adjacent and spaced apart and both can extend side-by-side in a common direction, e.g., each can extend outward toward a corner of the housing. The elongate segment 18 can have the first planar segment 19 that merges into the second planar segment 12. The second planar segment 12 can define the circuit board contact surface that contacts the circuit board 50, The second energizing spring 20 can have at least one tab 21t, 22t (for example), that extends above the first planar segment 19 in an unloaded configuration and can, in some embodiments, be substantially flat and coplanar with the first planar segment 19 in a fully compressed configuration.
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(42) The housing 100h can be held in any suitable orientation. In some use environments, it can be held with a front surface F (
(43) The circuit breakers 100 may be held in starter units for supplying power controlling electrical motors and pumps or held in general feeder units for supplying feeder circuits. The term unit refers to a structure (typically having sides of a protective metal shell) that contains a circuit breaker for turning power ON and OFF to a motor, or feeder circuit. The unit can include other components such as a power transformer, a motor starter to control a single motor and PLCs (programmable logic controllers), drives and the like. As is well known, the unit can have a bus grid with power stabs in the back that connect to bus bars that carry power (current) to the compartments of a vertical section in a cabinet. The bus bars can be horizontal and can be connected to larger (typically horizontal) bus bars that bring power to vertical sections. The horizontal bus bars are usually in the top, but some MCC designs may have them in the center or bottom.
(44) As is well known, the circuit breaker 100 can have a load side (designated as Load in
(45) The circuit breaker 100 can be configured as a molded case circuit breaker or MCCB which is a device designed to open and close a circuit, typically allowing both manual open and close operation and automatic circuit interruption, the latter to open a circuit under certain conditions, e.g., an over-current. The circuit breaker 100 may be particularly suitable for residential purposes but may also be suitable for commercial and industrial uses.
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(49) It is also contemplated that a conductive polymeric semi-rigid or flexible plug, O-ring or other structure may be used as the second energizing spring 20. Combinations of these and embodiments such as those discussed above and/or other spring configurations may be used.
(50) In some embodiments, the second energizing spring 20 can be held apart from the first energizing spring 10 and held on the surface 19 upon assembly of the housing members 101, 102.
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(53) The first energizing spring 10, 10 and the at least one second energizing spring 20 can be electrically conductive and may be metallic, electrically conductive polymeric or other suitable electrically conductive material, or combinations of electrically conductive materials.
(54) The at least one second energizing spring 20 can have a flexible non-conductive substrate with a conductive outer coating or film. The second energizing spring 20 can comprise a resilient conductive polymeric material (e.g., electro active polymeric materials). See, e.g., U.S. Pat. No. 7,466,154, entitled Conductive Particle Filled Polymer Electrical Contact and Shirakawa et al., Synthesis of Electrically Conducting Organic Polymers: Halogen Derivatives of Polacetylene, (CH)x, J. C. S. Chem. Comm. 1977, 578-580, the contents of which are hereby incorporated by reference as if recited in full herein.
(55) In some embodiments, the first energizing spring body 10b and the second energizing spring 20 are formed of a conductive metal such as, but not limited to brass, for example, and are typically formed of the same metal, and the metal can be a non-ferromagnetic metal.
(56) Where the second energizing springs 20 are separate components 20S they can comprise the same or different electrically conductive material as the primary energizing spring 10.
(57) Although described for use with circuit breakers, the energizing springs 10/10 may also be suitable for other circuits and devices with circuits.
(58) The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the invention.