Patent Application
20180350547
The present invention relates to a fuse panel module to allow access to one or more fuses. More particularly, the invention is directed to a fuse panel module having a movable fuse holder.
Fuses are a common component found in many electrical devices. In general, fuses are electrical safety components consisting of a wire or strip that melts and interrupts a circuit when the current passing through the fuse exceeds a particular amperage. Once a fuse is blown, i.e., the wire or strip melts, the fuse must be replaced to re-establish the circuit.
Replacing blown fuses in fused electrical devices often requires disassembly of the electrical device and/or use of one or more hand-tools to access and retrieve a blown fuse. Accordingly, accessing and replacing a blown fuse can often be a difficult, cumbersome and time-consuming process.
In addition, although current panel fuse holders connect the fuses while insolating them from the user, they compromise either panel space, contact stability or fuse current capability. A fuse holder must tolerate high fuse temperature, conduct heat away from the fuse and fit in a housing. Metal contacts survive high temperatures while conducting heat away from the fuse. Axial fuse holders, which minimize panel space by presenting the smallest profile of the fuses to the user, must make contact with the proximal end of the fuse after the housing accepts the distal end. This is presently done either by a movable proximal fuse contact, actuated by a part of the dielectric cover, or a fuse contact mounted on the cover that connects through an additional, separable contact to the housing circuit. Such axial fuse holders cannot tolerate much heat. In the first case, the dielectric cover that actuates the fuse contact cannot tolerate high fuse temperatures, and its movable fuse contact cannot conduct much heat. In the second case, the separable contact generates heat and restricts heat transmission from the fuse. Radial fuse holders present both ends of a fuse to fixed metal fuse contacts but occupy more panel space.
It would, therefore, be beneficial to provide a fuse panel module in which the fuses could be inserted and removed without damage to the fuse or the fuse contacts. In addition, it would be beneficial to provide a fuse panel module which combines the compact advantage of axial fuse holders with the thermal advantages of radial fuse holders.
An object is to provide a fixed proximal fuse contact that is mounted in a housing of a fuse panel module and which is opened by a camming member while a distal end of the fuse passes through the proximal contact. As the proximal end of the fuse enters the proximal fuse contact, the camming member releases the proximal fuse contact onto the proximal fuse head. Meanwhile, a distal fuse contact mounted in the housing receives the distal fuse head. Both fuse contacts are permanently connected to the housing circuit, are metal and provide preload to maintain a stable fuse contact. This creates less heat and provides superior transmission of heat away from the fuses, with the minimal panel footprint of an axial fuse holder.
An embodiment is directed to a panel fuse module for use with one or more fuses. The panel fuse module includes a housing with a first fuse contact and a second fuse contact. The first fuse contact is resiliently deformable and is mounted on a post of the housing. The second fuse contact is mounted on the post of the housing and spaced from the first fuse contact. A movable fuse holder is provided which is moveable relative to the housing and relative to the first fuse contact. The movable holder is movable from a first position in which a portion of the movable fuse holder extends from the housing and one or more fuses may be inserted into the movable fuse holder without engaging the first fuse contact or the second fuse contact to a second position in which the movable fuse holder is inserted into the housing. A cam member is provided on the movable fuse holder. As the movable fuse holder is moved from the first position toward the second position, the cam member cooperates with the first fuse contact to move the first fuse contact from a less-stressed first position to a more-stressed second position to allow the respective fuse of the one or more fuses to be inserted into the housing without engaging the first fuse contact. As the movable fuse holder is moved into the second position, the cam member disengages the first fuse contact to allow the first fuse contact to move toward the less-stressed first position to allow the first fuse contact to be provided in mechanical and electrical engagement with the respective fuse of the one or more fuses.
An embodiment is directed to a panel fuse module for use with one or more fuses. The panel fuse module includes a housing having a fixed post, a fixed rail and a fuse holder. The fuse holder is movable relative to the fixed post, and the fixed rail from a first position in which a respective fuse of the one or more fuses is positioned in the fuse holder to a second position in which the respective fuse and the fuse holder are inserted into the housing. A first fuse contact is mounted on the fixed post proximate the front of the housing. A second fuse is mounted on the fixed post spaced from the first fuse contact toward the rear of the housing. A cam member is provided on the movable fuse holder. As the fuse holder is moved from the first position toward the second position, the cam member cooperates with the first fuse contact to move the first fuse contact from a less-stressed first position to a more-stressed second position to allow the respective fuse to be inserted into the housing without engaging the first fuse contact. As the fuse holder is moved into the second position, the cam member disengages the first fuse contact to allow the first fuse contact to move toward the less-stressed first position to allow the first fuse contact to be provided in mechanical and electrical engagement with the respective fuse of the one or more fuses.
An embodiment is directed to a method of terminating a fuse in a fuse panel module, the fuse module having a first fuse contact and a second fuse contact. The method includes: inserting the fuse into a movable fuse holder of the fuse panel module; moving the movable fuse holder from a first position in which the fuse does not engage the first or second fuse contact to a second position in which the fuse is provided in mechanical and electrical engagement with the first and second fuse contacts; camming the first fuse contact to an open or resiliently deformed position as the movable portion is moved between the first position and the second position, the open position allowing the fuse to move relative first fuse contact without engaging the first fuse contact; and disengaging the first fuse contact from a cam of the movable fuse holder when the movable portion is moved to the second position, allowing the first fuse contact to resiliently move toward a less-stressed position, allowing the first fuse contact to be moved and retained in electrical and mechanical engagement with the fuse when the movable fuse holder is in the second position.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the preferred embodiments. Accordingly, the invention expressly should not be limited to such preferred embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features, the scope of the invention being defined by the claims appended hereto.
As best shown in
The housing 12 has a front wall 16 with an outwardly facing surface 18 and an inwardly facing surface 20. A switch 22 extends through the front wall 16 and has a rocker 24 which extends proximate the outward facing surface 18. A plug-receiving cavity 26 extends from the outwardly facing surface 18. The plug-receiving cavity 26 has contacts 28 which extend therein for making a mechanical and electrical connection with a mating plug (not shown). A fuse holder-receiving opening 29 extends through the front wall 16 and is dimensioned to receive a movable fuse holder 70 therein, as will be more fully described.
Two posts 30 extend from the inwardly facing surface 20 of the front wall 16 in a direction away from the outwardly facing surface 18. The posts 30 are essentially mirror images of each other and are positioned on either side of the movable fuse holder-receiving opening 29. Each post 30 has an outer surface 32 (
A first fuse contact 40 and a second fuse contact 42 are positioned on each post 30. The first fuse contacts 40 are fixed to the posts 30 proximate to the inwardly facing surface 20 of the front wall 16. The second fuse contacts 42 are spaced from the first fuse contacts 40 and are positioned proximate a distal end 44 of the posts 30.
As best shown in
The plate portions 48, 49 are optional and are used if the fuse contacts 40, 42 are not bypassed by the wires 66, 68 from the switch 22 and contacts 28. When present, the plate portions 48, 49 are symmetrical to provide double-fusing.
Positioned proximate the resilient fuse engagement contact arms 50 of each fuse contact 40 is a wire termination portion 56. The wire termination portion 56 has wire termination arms 58 which extend from a top and bottom (as viewed in
The plate portions 48 have securing members 62 which are formed therein. The securing members 62 cooperate with the posts 30 to help retain and maintain the fuse contacts 40, 42 in position on the posts 30. The plate portions 48 have a relatively large surface area which allows for superior transmission of heat away from the fuses 15. The transmission of heat is also facilitated by the location of the plate portions 48 on the outer surface 32 of the posts 30, directly adjacent to the wall of the outer cover 14, where more air circulation is available to cool the plate portions 48.
The plate portions 48 extends over the outer surface 32. The resilient fuse engagement contact arms 50 and the wire termination arms 58 extend from the plate portions over the posts 30 past the contoured inner surface 34 and into a movable fuse holder receiving passage which aligns with the movable fuse holder-receiving opening 29.
As best shown in
Positioned proximate the resilient fuse engagement contact arms 51 of each fuse contact 42 is a wire termination portion 57. The wire termination portion 57 has wire termination arms 59 which extend from a top and bottom (as viewed in
The plate portions 49 have securing members 63 which are formed therein. The securing members 63 cooperate with the posts 30 to help retain and maintain the fuse contacts 42 in position on the posts 30. The plate portions 49 have a relatively large surface area which allows for superior transmission of heat away from the fuses 15. The transmission of heat is also facilitated by the location of the plate portions 49 on the outer surface 32 of the posts 30, directly adjacent to the wall of the outer cover 14, where more air circulation is available to cool the plate portions 49.
The plate portions 49 extends over the outer surface 32. The resilient fuse engagement contact arms 51 and the wire termination arms 59 extend from the plate portions over the posts 30 past the contoured inner surface 34 and into a movable fuse holder receiving passage which aligns with the movable fuse holder-receiving opening 29.
Wires 66 extend from the switch 22 to the first fuse contacts 40. Wires 68 extend from the contacts 28 to the second fuse contacts 42. Although wires are shown, other methods and devices for making the electrical connection between the switch 22 and the first fuse contacts 40 and between the contacts 28 and the second fuse contacts 42 can be used, such as, for example, using stamped and formed metal leads.
As best shown in
Camming members 74 are provided on the movable fuse holder 70 and extend proximate to and are essentially parallel to a longitudinal axis of the movable fuse holder 70. As best shown in
The height of the raised section 78 is greater than the height of the tip section 76 or the release section 80. A ramp 82 is provided between the raised section 78 and the tip section 76. The raised section 78 engages the cam engagement portions 54 of a first fuse contact 40 when the movable fuse holder 70 is moved from the first position toward the second position, as shown in
The height of the release section 80 is less than the height of the tip section 76 or the raised section 80. A ramp 84 is provided between the release section 80 and the raised section 78. The release section 80 is dimensioned such that the cam engagement portions 54 of the first fuse contact 40 do not engage when the release section 80 of the movable fuse holder 70 when the movable fuse holder 70 is in the second position or proximate to the second position, as shown in
In various embodiments, the release section 80 may be positioned to allow the resilient fuse engagement contact arms 50 to be released from the raised section 80 just prior to the movable fuse holder 70 reaching the second position. This allows the arcuate shaped sections 52 of the resilient fuse engagement contact arms 50 to provide a wiping action to the fuse 15 to eliminate and oxides or contaminants on the surface of the fuse 15.
The second fuse contacts 42 are maintained in a fixed position on the posts 30. The second fuse contacts 42 do not engage the camming members 74 of the movable fuse holder 70. Consequently, as the movable fuse holder 70 is moved to the second position, the end of each fuse 15 enters the resilient fuse engagement contact arms 51, causing the arcuate shaped sections 53 of the resilient fuse engagement contact arms 51 to move to a slightly more-stressed position, thereby ensuring that the arcuate shaped sections 53 of the resilient fuse engagement contact arms 51 of the second fuse contacts 42 exert a force on the fuse 15 to maintain a mechanical and electrical connection between the second fuse contact 42 and the fuse 15. This also allows the arcuate shaped sections 53 of the resilient fuse engagement contact arms 51 of the second fuse contacts 42 to provide a wiping action to the fuse 15 to eliminate any oxides or contaminants on the surface of the fuse 15. The positioning of the fuse 15 between the arcuate shaped sections 53 of the resilient fuse engagement contact arms 51 is guided by the lead-in portions 65
Fuse retention sections 86 are provided on the movable fuse holder 70 proximate the camming members 74. The fuse retention sections 86 have spring clips 88 which cooperate with the fuses 15 to maintain the fuses 15 in position on the movable fuse holder 70. Positioning shoulders 90 are provided and cooperate with the fuses 15 to allow the fuses 15 to be properly positioned in the fuse retention sections 68.
A guide rail receiving slot 92 extends through the movable fuse holder 70. The guide rail receiving slot 92 cooperates with the guide rail 38 to maintain the movable fuse holder 70 in proper position in the movable fuse holder receiving passage as the movable fuse holder 70 moves between the first and the second position. Stabilization members 94 also are provided on the movable fuse holder 70. The stabilization members 94 prevent unwanted movement of the movable fuse holder 70 when the movable fuse holder 70 is in the second position.
The fuse holder 70 includes a foot 99 that prevents connection of the input terminals to power by a mating plug until the protective plate 72 blocks access through the fuse holder-receiving opening 29 to live metal parts by the end user. The fuse holder 70 does not cause connection of the fuses 15 to potentially live parts until the protective plate 72 blocks access by the end user.
A detent 97 on the fuse retention sections 86 of the moveable fuse holder 70 cooperates with a detent 96 on the housing 12 to secure the moveable fuse holder 70 in the fully or completely installed position in the housing 12, whereby a tool is required for the removal of the moveable fuse holder 70 from the housing 12.
In operation, the fuses 15 are positioned in the fuse retention sections 86 and are maintained in position by the spring clips 88. With the fuses 15 properly positioned, the movable fuse holder 70 is moved from the first or open position, shown in
As the movable fuse holder 70 approaches the second position, the leading ends of the fuses are inserted between the arcuate shaped sections 51 of the second fuse contacts 42, as previously described. As this occurs, the cam engagement portions 54 move from the raised portions 78 of the camming members 74 allowing the resilient fuse engagement contact arms 50 to return toward the less-stressed position to make electrical and mechanical engagement with the trailing end of the fuses 15, as previously described.
When the movable fuse holder 70 is in the second position, the first fuse contacts 40 and the second fuse contacts 42 are provided in electrical and mechanical engagement with the fuses 15. In this position, fuses 15 behave in a manner known in the art, allowing the electrical current to flow form the mating plug through the fuses 15 to the switch 22.
When the fuses are to be removed or replaced, fuse holder 70 is moved from the second or closed position, shown in
The configuration of the panel fuse module 10 and the fuse contacts 40, 42 allows for proper insulation, contact stability and large current capability. Both the first fuse contacts and the second fuse contacts are permanently connected to the housing circuit, are metal and are preloaded to maintain a stable fuse contact. Consequently, the fuse contacts 40, 42 provide a good electrical connection with the fuses. In addition, the configuration of the plate portions 48, 49 of the contacts 40, 42 and their positioning on posts 30 provides for superior transmission of heat away from the fuses, with the minimal panel footprint of an axial fuse holder. Consequently, the panel fuse module 10 combines the compact advantage of axial fuse holders with the thermal advantages of radial fuse holders.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention of the invention as defined in the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other specific forms, structures, arrangements, proportions, sizes, and with other elements, materials and components, without departing from the spirit or essential characteristics thereof. One skilled in the art will appreciate that the invention may be used with many modifications of structure, arrangement, proportions, sizes, materials and components and otherwise used in the practice of the invention, which are particularly adapted to specific environments and operative requirements without departing from the principles of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being defined by the appended claims, and not limited to the foregoing description or embodiments.
