Patent Application
20060164192
This invention relates generally to electrical power distribution blocks, and more specifically, to electrical power distribution utilizing feed through junction blocks.
Feed through junction blocks are utilized, in one example, in the routing of electrical power from one side of a barrier to another. Utilization of such feed through junction blocks provides for a neat, clean, and electrically sound interconnection between circuits on each side of such a barrier. An example of such a barrier is the firewall between the engine compartment and passenger compartment of a vehicle. Such feed through junction blocks often incorporate threaded studs which allows one or more ring terminals to be secured to the stud utilizing, for example, a washer and a nut.
While it is possible to simply run a wire through a firewall, problems exist with such a configuration. One problem is that it is difficult to secure a wire that passes through a hole in the firewall. Such an installation also tends to compromise the barrier between the two compartments. Also, vibration may cause a hole to be worn through the insulation of such a wire passing through a hole in a firewall, leading to electrical shorts and other electrical system malfunctions.
Known feed through junction blocks partially address the difficulties associated with running electrical circuits through barriers as they include a mounting plate. Such junction blocks are typically fastened to the barrier with a plurality of fasteners that extend through the barrier and the mounting plate. While known feed through junction blocks provide a securely mounted electrical connection between circuits on opposite sides of a barrier, such feed through junction blocks are typically utilized with circuit protection devices discretely wired to the junction block, for example, circuit breakers and fuses. The location of connecting terminals in known circuit protection devices, particularly circuit breakers, which are panel (or firewall) mountable makes it difficult to wire the device to the junction block and the circuit to be protected. This problem is particularly acute in installations where access is restricted, such as vehicle firewall installations.
In one aspect, an electrical feed through junction block is provided that comprises a mountable housing comprising a front and a back, a first conductive terminal extending from the front of the housing, a second conductive terminal extending from the housing in a direction opposite the first conductive terminal, and an overcurrent protection device located within the housing. The overcurrent protection device is configured to provide a conductive path between the first conductive terminal and the second conductive terminal when in a non-overcurrent position.
In another aspect, a circuit breaker is provided that comprises a bimetallic element comprising a contact thereon, a first conductive terminal in electrical contact with the bimetallic element, a second conductive terminal comprising an electrical contact formed on an end thereof, the electrical contact configured to the electrical contact on the bimetallic element, and a mountable housing. The first conductive terminal extends from the housing, and the second conductive terminal extends from the housing in a direction opposite the first conductive terminal.
In the embodiment illustrated, the insulating extension 14 is configured to engage a hole formed in, for example, an automotive firewall, to which the junction block 10 is to be mounted. Therefore, the insulating extension 14 insulates the conducting member 16 from the firewall. The plate engaging unit 18 includes a first end 24 and a second end 26 each of which is a substantially flat surface that provides for adequate electrical connection between the junction block 10 and a conductor attached to the junction block 10, for example, a ring terminal (not shown) that has been secured against one of the ends 24 and 26 by the engagement of a nut (or a washer and a nut) onto a respective one of the first threaded stud 20 and the second threaded stud 22.
As described, the feed through junction block 10 provides an efficient mechanism for the transfer of electrical power from one side of, for example, a firewall to the other side of the firewall with a minimal effect on the integrity of such a firewall. Circuit protection devices, however, must be discretely or individually wired between the feed through junction block 10 and the circuits which receive power via feed through junction block 10. Wiring of the circuit protection devices to such junction blocks is difficult due to space restrictions in the vicinity of the firewall, leading to increased time and labor costs to establish electrical connections to the electrical system. Additionally, installation difficulties may present reliability issues if electrical connections are not properly established.
In an exemplary embodiment, the feed through junction block 50 includes a mountable chassis 52, and a first conductive stud 54 extending from the mountable chassis 52 which is operable as a first circuit breaker contact. In one embodiment, the first conductive stud 54 is a threaded stud configured to be engaged by a washer and nut. In one embodiment, the first conductive stud 54 extends from a conductive base plate 55 which has a diameter larger than a diameter of the first conductive stud 54. The conductive base plate 55 is substantially flat and its surface is raised slightly from that of the mountable chassis. The conductive base plate 55 is particularly useful for providing an adequate electrical connection to conductors that are attached to the first conductive stud 54. One example of such a conductor is a ring terminal (not shown), having a surface that comes into substantial contact with the conductive base plate 55.
A tripping element housing 56 is formed as a portion of the mountable chassis 52 and partially provides an area for internal components relating to operation of a reset handle 58 and a protective member 60 or guard for reset handle 58 which extend through a tripping element housing cover 62. The tripping element housing cover 62 is secured to the tripping element housing 56 utilizing multiple fastening devices, for example, rivets 64. In another embodiment (not shown), the feed through junction block 50 and tripping element housing 56 may be configured with a manual tripping element and a protective member similar to protective member 60 to provide protection for the manual tripping element.
As described above, the bistable element 100 is manufactured to have a predetermined overcurrent snap action. Upon an overcurrent condition, the bistable element 100 heats up and deflects to a second position (not shown) to separate the contact between the bistable element 100 and internal portion 106 of the first conductive stud 54, thereby interrupting the flow of current through the feed through junction block 50. A manual reset shaft 120 extends through mountable chassis 52 for use by an operator at a first end 122 where reset handle 58 is attached. A second end 126 of manual reset shaft 120 is configured to return the bistable element 100 to the non-overcurrent position. In one embodiment, operation of the bistable element 100 causes the reset handle 58 to rotate to indicate the circuit breaker has tripped upon an overcurrent condition. In another embodiment, a spring 130 is attached to shaft 120 and moves to an extended position when the reset handle 58 is moved back to the untripped position. The bistable element 100 is configured to cool quickly after tripping, and utilization of the reset handle 58 causes a force to be applied to a portion of the bistable element 100 causing it to return to a first relatively straight position.
It should be understood that the scope of the feed through junction blocks are not limited in scope to the embodiments described herein. Other embodiments which incorporate other circuit breaker configurations, including, but not limited to other manual reset circuit breakers, push-to-trip circuit breakers (which include components within the mountable chassis to move the bistable element), automatic reset circuit breakers, and modified reset circuit breakers (which utilize a resistor to keep the bistable element in the open state after a trip) are considered to be within the scope of the invention. In addition, those skilled in the art will recognize that fuse configurations may also be employed.
More specifically,
The feed through junction blocks 50 and 150 provide an efficient mechanism for the transfer of electrical power from one side of a firewall to the other side of the firewall with a minimal effect on the integrity of such a firewall. In addition, the feed through junction blocks 50 and 150 provides overcurrent protection for circuits that receive power through the feed through junction blocks. Utilizing the feed through junction blocks 50 and 150 allow for the protection of circuits without having to individually wire discrete components (i.e., fuses or circuit breakers) between the feed through junction block and the circuits being powered via the feed through junction block.
As described, the feed through junction blocks 50 and 150 provide an efficient mechanism for the transfer of electrical power while incorporating a circuit protection device. Incorporation of such a device overcomes the above described problems associated with discretely wired circuit protection devices, including, but not limited to, space restrictions and increased time and labor costs to establish electrical connections to an electrical system. As such, the compact package of feed through junction blocks 50 and 150 saves space in comparison to separate junction blocks and overcurrent protection devices which are wired together in an electrical system.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
