This invention relates generally to fuses and to wiring lugs used in fuse modules. More particularly, the invention relates to an improvement of the wiring lugs used by fuse modules to provide a connection between a terminal element and an electrical lead.
Fuse modules provide a means for fuses to be incorporated into an electrical circuit. Typically, a fuse module has two terminals for electrical leads and two terminals for a fuse connection. The mechanism that has typically been used to connect electrical leads to fuse connections has been the wiring lug, which contains electrical lead terminals and fuse clip terminals. A load side electrical lead is attached to a first lead terminal. A line side electrical lead is attached to a second lead terminal. The circuit through the fuse module then may be completed by the installation of the fuse in the fuse terminal, which electrically connects the line side and load side lead terminals through the fuse element.
Previous wiring lugs have used screw terminals where the electrical leads couple to the lead terminals via the use of screws. The electrical leads are brought into contact with the screws while in a first position. The screws are then placed in a second position, creating an electrical and mechanical connection between the electrical leads and the screw by arresting the leads between the screw and a surface. These connections may be formed by placing the lead under the head of the screw and the screw head coming in contact with a surface. Alternatively, these screw terminals may involve the electrical lead being wound around the screw terminals and the screw rotating to the surface. Alternatively, the screw could press the electrical lead to the terminal by directly applying physical pressure at the base of the screw. These previous methods led to problems with heat transfer and electrical resistance. Additionally, high torque is needed to secure the electrical leads to the screw terminals, which is a problem in itself and which may damage the leads. Additional features of previous embodiments included securing devices that have congruent teeth flanking either side of the electrical lead, leading to the possibility of damaging the leads during installation.
An additional problem with conventional lugs relates to the conductive materials used in wiring lugs. Clips used in such applications have been made of conductive materials that have inherent spring properties to them, such as C19025, C7025, or C7026, to provide the necessary physical properties to secure the fuses to the wiring lugs. In addition to the expense associated with such conductive materials, there is usually an amount of ‘scrap’ conductive material that is unused. This excess material has been undesirable as these devices used special copper alloys that are expensive. The use of these copper alloys also leads to the additional problem of requiring a hydraulic press because the conductive material is too strong to be manipulated with hand tools, thereby further increasing manufacturing costs.
Therefore, a need exists in the art for a wiring lug that can securely couple to both an electrical lead and a fuse terminal while making use of minimal conductive materials and labor.
The invention relates generally to a wiring lug that can connect electrical leads and fuse terminals. This connection is facilitated by an improved fastening mechanism that couples the electrical lead to the wiring lug as will be described below.
The wiring lug according to the invention comprises a fuse clip that receives a fuse contact and a pressure plate that couples to an electrical conductor. A box lug moves with respect to the pressure plate to crimp the conductor between an interior of the box lug and the pressure plate. The crimping in this fashion can provide an increased area of electrical contact between the conductor and the pressure plate. One or more projections formed in the pressure plate can increase a holding strength of the wiring lug on the conductor. The projections also can maintain alignment of the pressure plate and the box lug by mating with corresponding apertures in the box lug. This wiring lug may be used in fuse holders as described below.
According to one aspect of the invention, a wiring lug can include a fuse clip member and a box lug. The fuse clip member comprises a fuse clip for receiving a contact of a fuse and a first pressure plate for contacting an electrical conductor. The box lug includes an opening into which the pressure plate of the fuse clip member is disposed, where the interior bottom surface of the box lug comprises a second pressure plate. A securing member determines movement of the box lug with respect to the fuse clip member. When the securing member that is operably coupled to the box lug is in a first position, the first pressure plate of the fuse clip member and the second pressure plate of the box lug are disposed in a non-clamping relationship and do not claim the conductor therebetween. When the securing member is in a second position, the first pressure plate and the second pressure plate are coupled by moving the box lug from a first position to a second position, thereby securing the conductor between them.
In accordance with another aspect of the invention, the wiring lug may be incorporated into a fuse module. Two wiring lug may be installed into a fuse module where a fuse may be installed into the wiring lugs to complete an electrical circuit. The wiring lugs used in the fuse module may receive an electrical conductor from either the line side or the load side, respectively, of an electrical circuit. The electrical conductors may then be separately coupled between the first pressure plate and the second pressure plate in one of the wiring lugs. A fuse may then be installed in the fuse module providing an electrical connection between the two fuse clips of the separate wiring lugs.
In accordance with yet another aspect of the invention, the fuse clip member may be formed from a single piece of conductive material. The fuse clip member formation beings with a primary member. A piece of the primary member that is substantially rectangular and located in the center of the primary member is split away on all but one side, forming a secondary member. The distal end of the secondary member is rotated such that at least a portion of the secondary member is substantially perpendicular to the primary member. The secondary member is configured to become the pressure plate. The primary member is then bent to form a fuse clip by disposing two ends of the primary member adjacent to each other. A spring is disposed around the two ends of the primary member to bias the two ends towards each other. This method of creating a fuse clip member allows for minimal generation of waste, while creating a single member that can receive a fuse contact and can act as a pressure plate used as an electrical conductor contact.
These and other aspects, objects, and features of the invention will become apparent to those having ordinary skill in the art upon consideration of the following detailed description of exemplary embodiments exemplifying the best mode for carrying out the invention as presently perceived.
For a complete understanding of the invention and the advantages thereof, reference is now made to the following description in conjunction with accompanying figures in which:
The appended drawings illustrate only exemplary embodiments of the invention and therefore do not limit its scope, as the invention may admit other equally effective embodiments.
The invention may be better understood by reading the following description of non-limitative, exemplary embodiments with reference to the attached drawings wherein like parts of each of the figures are identified by the same reference characters.
With reference to
Referring to
Each of the wiring lugs 102 further comprises a box lug 108. Each box lug 108 comprises a pressure plate 108a. A screw-type fastener 110 is threadably coupled to the box lug 108 for moving the box lug 108 with respect to the pressure plate 104a of the fuse clip member 104. The fastener 110 is accessible via an aperture 111 in the fuse module 100. The aperture 111 is configured to hold the fastener 110 in a substantially fixed position with regard to the fuse clip member 104. As illustrated in
As illustrated in
In the exemplary embodiment illustrated in
For each wiring lug 102, the box lug 108 is moved from the first, open position to the second, closed position by turning the fastener 110. The fastener 110 mates with the box lug 108 such that turning the fastener 110 causes the box lug 108 to move up or down on the fastener 110. Since the fastener 110 and the pressure plate 104a of the fuse clip member 104 are substantially maintained in a fixed position with regard to each other, movement of the box lug 108 along the fastener 110 moves the box lug 108 with respect to the pressure plate 104a of the fuse clip member 104. Accordingly, the box lug 108 can move from the open position (illustrated with wiring lug 102a in
The fuse module 100 illustrated in
In this exemplary embodiment, the pressure plate 104a of the fuse clip member 104 comprises a projection 302 extending toward the pressure plate 108b of the box lug 108. As illustrated, the projection 302 comprises a v-shape. However, a semi-circular, square, or other suitable shape of the projection 302 is within the scope of the invention. Although not illustrated in
The box lug 108 further comprises an aperture 304 disposed in a position corresponding to the projection 302 of the pressure plate 104a of the fuse clip member 104. As illustrated, the aperture 304 is disposed in a side wall 306 of the box lug 108. The aperture 304 also is disposed in the pressure plate 108a of the box lug 108. While illustrated as semi-circular in shape, a v-shape, square, or other suitable shape of the aperture 304 is within the scope of the invention. Accordingly, the projection 302 of the fuse clip member 104 is visible and extends through the aperture 304 of the box lug 108. In an exemplary embodiment, the box lug 108 can comprise a second aperture on an opposite side of the pox lug 108 for receiving the second projection discussed previously.
In the exemplary embodiment illustrated in
In an alternative exemplary embodiment, the projection 302 can be a continuous projection extending across the pressure plate 104a of the fuse clip member 104. In this embodiment, a conductor may deform around the projection 302 when crimped between the pressure plates 104a, 108a, thereby providing additional holding strength to retain the conductor within the wiring lug 102.
The exemplary embodiment in
With reference to
A front area and back area of the box lug 108 are open, allowing access to an interior of the box lug 108. These openings allow the fuse clip member 104 to be inserted and allow the box lug 108 to move up or down relative to the fuse clip member 104. In an alternative exemplary embodiment (not shown), the front area and back area can have partial walls that restrict the movement of the fuse clip member 104 with respect to the box lug 108.
Although the pressure plate 108a is depicted in
The operation of a wiring lug being operated from the open position to the closed position will now be described with reference to
In the exemplary embodiment previously described, the rotation of the fastener 110 from a first position to a second position causes the pressure plate 108a from the box lug 108 to move closer to the pressure plate 104a, which is in a fixed position. In an alternative exemplary embodiment (not shown), the rotation of the fastener 110 from a first position to a second position may cause the pressure plate 104a to move toward the pressure plate 108a of the box lug 108, which can be in a fixed position.
As previously discussed, the fuse clip member 104 comprises at least one projection 302. Each projection can correspond to an aperture 304 in the box lug 108. In an exemplary embodiment, the projection 302 may be smaller than the aperture 304 in the base of the box lug 108. This projection 302 and aperture 304 may act to further restrict the movement of the electrical lead 802 installed in the wiring lug 102 by introducing a roughness that aids in restricting the electrical lead 802 in the wiring lug 102. The projections 302 can allow for a more secure connection of the electrical lead 802 to the wiring lug 102 with lower torque applied to the screw fastener 110 to secure the electrical lead 802.
By use of the pressure plates 104a, 108a, the electrical lead 802 is in contact with the fuse clip member 104 for substantially the length of the pressure plate 104a where the electrical lead 802 is in contact with the pressure plate 104a. This contact allows more of the electrical lead 802 to be in contact with the terminal and removes the single physical point of contact between the electrical lead 802 and the pressure plate 104a. The pressure plate 104a acts as the entire contact surface. In addition, with more surface area in contact, the electrical connection is more secure. Furthermore, the distribution of the contact between the electrical lead 802 and the pressure plate 104a reduces generated heat.
With reference to
The method 700 includes providing a primary member of electrically conductive material as shown in step 780. The primary member then has a secondary member formed therein as shown at step 785. The secondary member is then molded to receive an electrical contact at step 790, and the primary member is molded to receive the fuse contact at step 795. The method 700 described in
Any spatial references herein, such as, for example, “upper,” “lower,” “above,” “below,” “rear,” “between,” “vertical,” “angular,” “beneath,” “top,” “bottom,” “side,” etc., are for the purpose of illustration only and do not limit the specific orientation or location of the described structure.
Therefore, the invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those having ordinary skill in the art and having the benefit of the teachings herein. While numerous changes may be made by those having ordinary skill in the art, such changes are encompassed within the spirit and scope of this invention as defined by the appended claims. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention as defined by the claims below. The terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.
This application is a divisional application of U.S. patent application Ser. No. 12/179,829 filed Jul. 25, 2008 now U.S. Pat. No. 8,026,786, the disclosure of which is hereby incorporated by reference in its entirety.
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Entry |
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European Search Report of 09166300.5; Nov. 4, 2009; 6 pages. |
Number | Date | Country | |
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20110314671 A1 | Dec 2011 | US |
Number | Date | Country | |
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Parent | 12179829 | Jul 2008 | US |
Child | 13215571 | US |