Patent Application
20140097932
The invention relates to a safety fuse for use in a motor vehicle. Such safety fuses are used to protect an electrical circuit from overloading. The invention furthermore relates to a bus bar and an arrangement with one or more such fuses.
So-called MIDI fuses are known in the prior art, as shown in
The fuse shown in
If fastening fuse 10, shown in
An object of the invention is to provide a fuse, in which a mechanical load of the melting temperature range is avoided.
This object is achieved by the fuse according to claim 1. Advantageous further developments are provided in the dependent claims.
The invention is based on a fuse, especially for use in a motor vehicle according to the preamble of claim 1, e.g., a MIDI fuse, as described at the beginning.
The invention provides that a preferably form-locking securing element, in particular an anti-rotation element, is arranged on an area or a portion protruding from a housing of a first contact blade of the fuse. The securing element preferably extends approximately vertically to the direction, in which the portion of the first contact blade protrudes from the housing, and/or approximately vertically or perpendicularly to a plane defined by the portion protruding from the housing of the first contact blade. The securing element is used to secure the fuse on a device, in particular a fastening element and/or a connecting element, e.g., a base or a cable lug, thereby diverting a lateral force acting on the fastening or connecting element and/or the fuse on the fastening or connecting element, due to the preferably rail- and/or flank-like securing element, in particular a guide rail, thereby preventing the application of a force on the fusion section and/or the housing. Specifically, the securing element prevents rotation of the fuse or the first contact blade, particularly in a plane defined by the portion of the first contact blade protruding from the housing, relative to the device, especially the base on which the first contact blade may be fastened.
The first contact blade and the fusion section, and optionally a second contact blade, may be arranged in a common plane or in planes arranged parallel to one another.
One embodiment according to the invention provides that at least one bend is arranged on at least one lateral edge of the portion of the first contact blade protruding from the housing. In the preferred embodiment with two lateral edges, the opposing lateral edges extend in the direction in which the portion of the first contact blade protrude from the housing. For example, the two lateral edges laterally define the first contact blade.
In an arrangement in which the fuse is mounted on a base, the base is enclosed between the bends of the first contact blade. The bends thus encompass the base at least partially, and preferably on its shoulders. These bends advantageously provides rotation prevention between the base and the first contact blade. This rotation prevention prevents rotation of the fuse of, in particular, the first contact blade, in the plane of the first contact blade relative to the base. The base may be made of plastic.
Preferably, the first contact blade is fastened to the base by a screw connection. If a torque is applied to establish the screw connection in the first contact blade, this torque is transmitted to the base via the bends encompassing the base in order not to subject the fusion section to the said torque.
Preferred embodiments of the invention are described below with reference to the figures. The features disclosed there, separately and in any combination, represent an advantageous further development of the object of the invention.
In the following figures, similar elements are each denoted by the same reference numerals.
Fuse 10 of
The first contact blade 11, the second contact blade 12, and the fusion section are made of an electrically conductive material, e.g., metal. Preferred metals are copper or zinc, or copper- or zinc-based alloys. Contact tongues 11, 12, and the fusion section are preferably punched from a plate-shaped semifinished product, e.g., a metal sheet, particularly a copper or zinc plate, or a tin-coated copper plate. Contact tongues 11, 12 and the fusion section are thus integral.
The first contact blade 11 and the fusion section, and in this example, also the second contact blade 12, are arranged in a common plane. In principle, it would be possible also to arrange the first contact blade 11, the fusing section, and in particular the second contact blade 12 in parallel and spaced-apart planes.
Moreover, fuse 10 has a housing that encloses fusion section 13, from which at least a portion of the first contact blade 11, and at least a portion of the second contact blade 12 protrude freely. The first contact blade 11 and the second contact blade 12 protrude in opposite directions from housing 13. The portion protruding from housing 13 of the first contact blade 11 has an opening 14 with a closed, more specifically a circular cross-section. Opening 14 serves to fasten fuse 10 to a base 31, as described below. The second contact blade 12 in the shown embodiment has no opening. Advantageously, the opening is punched during the punching of contact blades 11, 12 and the fusion section.
Whereas the lateral edges 11a, 11b in the fuse shown in
As the bends 15a, 15b are formed on lateral edges 11a, 11b, they can be relatively easily produced during or after punching by reshaping, e.g., by bending. Thus, the first contact blade 11, the second contact blade 12, the fusing section, and the bends 15a, 15b may be made by punching and bending the plate-shaped semifinished product.
The first contact blade 11, may have, e.g., a portion enclosed by housing 13 (not shown). This is likewise the case for the second contact blade 12. The lateral edges of the portion protruding from housing 13 of the first contact blade 11 may have bends 15a, 15b, whereas the lateral edges of the portion enclosed by housing 13 of the first contact blade 11 have no bends.
The fusion portion preferably joins the first contact blade 11 and the second contact blade 12, in particular the portion enclosed by housing 13 of the first contact blade 11 and the portion enclosed by housing 13 of the second contact blade 12. Housing 13 is fastened to the enclosed portion of the first contact blade 11 and/or encompasses snugly the first contact blade 11, in the area where the portion of contact blade 11 is arranged in housing 13. The same applies to the second contact blade 12. Housing 13 forms a slit-shaped opening for the first contact blade 11, as well as the second contact blade 12.
Housing 13 protrudes relative to the common plane, in which the first contact blade 11 and the second contact blade, as well as the fusing section, are arranged, on either side of the plane at about the same distance away from the plane. This result in a compact design for fuse 10.
As can be best seen in
If changes are made in the fusion sections, the punching tool for the fusion sections formed integrally with bus bar 20 needs changing, whereas if fuses 10 are attached separately to bus bar 20, changes can very easily be done by replacing the fuses 10 to be added to bus bar 20 resulting in tooling cost savings.
The second contact blade 12 is preferably placed against bus bar 20, in particular flat against bus bar 20. Bus bar 20 and contact blade 12 are preferably connected with a non-detachable joint 21, i.e., separation of the second contact blade 12 from bus bar 20 is only possible by causing irreversible destruction of joint 21. Alternatively, detachable joints, such as screw connections may be provided in order to connect the second contact blade 12 with bus bar 20.
In the example shown, the second contact blade 12 is connected to bus bar 20 by a press joint 21, which joint 21 is of the non-detachable kind. Press joints are known in the art as TOX® joints.
Base 31 is formed of a plastic material, and preferably integrally with a carrier 30. Base 31 comprises a screw bolt 32 or a screw-like device with a threaded section, a supporting area and a clamping area. Screw bolt 32 may be clamped by pressing or inserting screw bolt 32 into the plastics material, or preferably by extrusion coating of screw bolt 32 with plastic during the manufacturing of base 31. Besides supporting fuse 10 at the base 31 (i.e., inside), enclosure of fuse 10 may also take place from the outside. In this case, outer abutment surfaces are guided along the contour of fuse 10. The tuning of the width of base 31 relative to the width of the fuse is optimized in terms of dimensional clearance.
Base 31 is enclosed between the bends 15a, 15b of the first contact blade 11, in particular with no or only very slight clearance. Thus, the distance between bends 15a, 15b of the first contact blade 11 is approximately the width of base 13 arranged between these bends 15a, 15b. This prevents rotation of the first contact blade 11 relative to base 31 in the plane of the first contact blade 11. A torque applied to the first contact blade 11 due to friction by the screw connection, with which the first contact blade 11 is fastened to base 31, is transferred to based 31 via bends 15a, 15b enclosing base 31, such that the fusion section is unaffected by the torque.
The portion of the first contact blade 11 protruding from housing 13 is enclosed, in particular clamped, between base 31 and a threaded means 33, which in the shown embodiment is a nut. Base 31 of plastic has a threaded insert in the form of a screw bolt 32. Screw bolt 32 is connected to an electrical conductor leading to one or more appliances. Screw bolt 32 extends through opening 14 of the first contact blade 11, whereby nut 33 is screwed onto the screw bolt 32.
Alternatively, the threaded insert inserted in base 31 may be a nut, into which the threaded means in the shape of a screw is fastened, whereby the first contact blade 11 is enclosed, in particular clamped, between the screw head and base 31.
The bends 15a, 15b thus prevent rotation of the first contact blade 11 relative to base 31 about the screw axis of the threaded means and/or the threaded insert.
The shape of fuse 10 may be designed asymmetrically relative to its contact blades 11, 12, i.e., the first contact blade 11 provided with the opening is longer than the second contact blade 12. Thus, a sufficient clearance, e.g., for mounting large lugs or other connection devices, is created between the fastened cable lug and the fuse housing 13, which is preferably made of plastic.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20 2011 050 310.0 | May 2011 | DE | national |
This is a U.S. National Phase of PCT/EP2012/059493, filed May 22, 2012, which claims the benefit of priority to German Patent Application No. 20 2011 050 310.0, filed May 31, 2011, the contents of both of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2012/059493 | 5/22/2012 | WO | 00 | 11/27/2013 |
