Cable connection system for battery connectors

Abstract

 The cable connection system is used for battery connectors (10) both ends of which are to be coupled by means of a bolt (20) to a battery cell such that a cable connection element (28) makes an electric contact to said bolt (20) and/or said connector (10), wherein said bolt (20) is made up of a head (22) and a threaded stud (18) of conductive material to be screwed to a battery terminal (54). An electric tap cable (38) is connected with the head (22) of said bolt (20) in a fixed manner or in a removable sealed manner.

Description

[0001] A present invention relates to a cable connection system for battery connectors as set forth in the preamble of claim 1.

[0002] In order to connect battery cells with each other, battery connectors are used having a core of conductive material, e. g. copper, encapsulated in a plastic sheath. Both ends of such connector are provided with a bore through which a bolt is inserted to be screwed into the threaded bore of a battery terminal. In such battery connectors it is most important to provide for a hermitical seal of the critical points at both ends of the connector in order to prevent corrosion and premature wear phenomena caused by liquids, humidity or fluids which may enter the battery cell or penetrate from it. For this purpose, battery connectors used up to now are provided with sealing elements and narrow fitting tolerances.

[0003] During the application of batteries it its often useful and necessary to provide cable connection elements in order to obtain information on important values like electric current or tension which is particularly requested for the so-called battery management of accumulators in industrial trucks or the like. To this end, up to now it was common use to slip on the stud of the bolt a metallic loop element with a radial arm to which the stripped end of the electric cable is fixed by crimp connection. However, this has the drawback that the hermetic seal at the critical points of the battery connectors was interrupted with the consequence that corrosive fluids could enter the cell or leave it. Thus, the battery cell was subjected to quick wear and decay such that the cell had to be replaced by a new one.

[0004] It is an object of the present invention to provide for a cable connection system that avoids the above mentioned drawbacks. It should preferably be made up of prefabricated structural elements having an integrated electric cable such that it may be used as a unit to be assembled with a battery connector in an air and liquid tight manner.

[0005] According to the invention, this problem is resolved by a cable connection system of the type described in the preamble of claim 1 and characterized in that an electric tap cable is connected with the head of the bolt in a fixed manner or in a removable sealed manner.

[0006] In the first mentioned alternative, the electric cable is firmly connected with the head of conductive material of the bolt providing a prefabricated integrated unit which has the advantage that the fixed connection between the bolt and the cable is free of transition current which was always present in traditional cable connection systems made up of two or more different pieces.

[0007] In this new configuration, the stripped end of the electric cable may be fastened in a radial bore provided in the head to which it is fixed by soldering, welding, glueing, pressing, clamping, screwing or the like.

[0008] According to a further feature of the invention, the head of the bolt may be encapsulated in an insulating plastic capsule.

[0009] In an alternative solution of the invention, the stripped end of the electric cable is firmly fastened to a ring of conductive material to be slipped on the stud of the bolt, said ring being inserted in a bore of a sealing ring of rubber or plastic.

[0010] This solution has the advantage that the direction of the electric cable does not depend on the angular position of the bolt and can be freely choosen without any risk of interrupting the tight sealing properties.

[0011] According to a further characteristic of the invention, the sealing ring is provided with a radial extension encapsulating the end of the electric cable fastened to said ring of conductive material.

[0012] Preferably, said ring of conductive material has an axially protruding shoulder with a preferably conical section abutting the corresponding uncovered end of the connector. By screwing the threaded stud of the bolt into a battery terminal or the like, the protruding shoulder will firmly contact the uncovered end of the connector, and simultaneously a protruding end of the sealing ring will overlap an annular ring of a plastic sheath enclosing the battery conductor. In this way the critical point between the battery connector end the bolt is hermetically sealed.

[0013] Further characteristics and advantages of the invention will become apparent in detail in the following description of two embodiments illustrated in the drawing in which:

Figure 1 is a longitudinal section of a first embodiment of the cable connection system,

Figure 2 shows the bolt and the cable connection element from below,

Figure 3 is an exploded lateral view of the cable connection element of figure 2,

Figure 4 is the exploded lateral view of the cable connection element of figure 2 rotated by 90°,

Figure 5 shows a simplified solution of the bolt and the cable connection system according to the invention,

Figure 6 is a lateral view of the embodiment of figure 5 and

Figure 7 shows a longitudinal section in plane VII-VII of figure 6.

[0014] Figure 1 illustrates schematically one end of a traditional battery connector 10 used to interconnect two battery cells. The battery connector 10 is made up of a core 12 of conductive material, e. g. copper, which is embedded in a plastic sheath 14. The illustrated end of the battery connector 10 is provided with a bore 16 through which the threaded stud 18 of a bolt 20 passes such that its threaded end may be screwed into the threaded bore of a battery terminal 54.

[0015] The bolt 20 of conductive material, e. g. metal, has an hexagon head 22 with an integrated lower annular collar 24. Between the annular collar 24 and the threaded stud 18 an annular shoulder 26 is provided which is an integral part of the whole bolt 20. Both, the head 22 and the annular collar 24 of the bolt 20, may be encapsulated in an insulating plastic capsule 56.

[0016] As, according to this preferred feature, the head 22 and the annular collar 24 of the bolt 20 are covered - with the exception of the annular shoulder 26 - by an insulating plastic material, this capsule 56 insulates completely the whole bolt 20 against corrosion and acts as a means of electrical insulation. As will be described later on, the uncovered annular shoulder 26 of the bolt 20 will provide for the electrical connection making a contact with the other parts such as the battery terminal 54.

[0017] As further illustrated in figure 1, a cable connection element 28 is slipped on the stud 18 of the bolt 20. Said cable connection element 28 comprises a ring 30 of conductive material, e. g. brass or copper, and a sealing ring 32 of rubber or plastics. As may be seen in figures 1 and 4, the ring 30 of conductive material is provided with a radial bore 34. Into said bore 34 the stripped end 36 of an electric cable 38 is inserted where it is fastened by soldering, welding, glueing, pressing, clamping, screwing or the like.

[0018] The ring 30 of conductive material is inserted in a bore 40 of said sealing ring 32 of rubber or plastic. In the radial position corresponding to the radial bore 34, the sealing ring 32 is provided with a radial extension 42 encapsulating the end 36 of the electric cable 38 which is fastened in the mentioned radial bore 34. In order to provide for the tight seal, the sheathed end 36 of the electric cable 38 is press fit in the radial extension 42 of the sealing ring 32.

[0019] The ring 30 of ring of conductive material has an axially protruding shoulder 44 with a preferably conical section abutting in the mounted position the opposed uncovered end of the metallic core 12 of the battery conductor 10.

[0020] As illustrated in figure 1, a protruding end 48 of the sealing ring 32 and the shoulder 44 of the ring 30 define an annular cavity 46 overlapping an annular ring 50 of the plastic sheath 14 when the bolt 20 is firmly fixed in the battery terminal 54. In this way, the critical end of the battery connector 10 engaged by the bolt 20 and the cable connection element 28 is hermetically sealed without compromising the electric contact between the conductive annular shoulder 26, the ring 30 and the battery connector 10.

[0021] In order to ensure a good electric contact, the ring 30 of conductive material, together with the sealing ring 32, is provided with a cylindrical seat 52 for the annular shoulder 26 of conductive material provided between the head 22 and the stud 18 of said bolt 20.

[0022] In the mounted position, the bolt 20 will be screwed with its threaded stud 18 in the threaded bore of the battery terminal 54 such that its head 22 presses the conical shoulder 44 of the ring 30 of conductive material against the core 12 of the battery connector 10. Simultaneously, the annular ring 50 provided around the bore 16 of the connector 10 will be pressed into the annular cavity 46 thus providing hermitical seal.

[0023] In figures 5 to 7 a simplified embodiment of the invention is illustrated according to which the stripped end 36 of the electric cable 38 is directly connected with the head 22. As may be seen from figure 7, the head 20 is made up of a ring shaped core 60 of conductive material into which the radial bore 34 is machined. The ring shaped core 60 is an integral part of the annular shoulder 26 and the threaded stud 18.

[0024] As in the above mentioned embodiment, the stripped end 36 of the electric cable 38 is fastened in the radial bore 34 by soldering, welding, glueing, pressing, clamping, screwing or the like.

[0025] As already mentioned, the core 60 of the head 22 is encapsulated in an insulating capsule 56 comprising also the annular collar 24 engaged by the cable 38 which is embedded in a cable covering 58.

[0026] The bolt 20 illustrated in figures 5 to 7 has such a form that, in the mounted position, its annular shoulder 26 directly engages the annular cavity 62 surrounded by the annular ring 50 of the plastic sheath 14 (see figure 1). As the shape and dimensions of said conductive annular shoulder 26 are also such to fit perfectly into the annular cavity 62, a perfect electric contact is ensured, while the plastic capsule 56 of the head 22, together with the annular ring 50 of the plastic sheath 14, ensure a perfect tight seal.

Claims

1. Cable connection system for battery connectors (10) both ends of which are to be coupled by means of a bolt (20) to a battery cell such that a cable connection element (28) makes an electric contact to said bolt (20) and/or said connector (10), wherein said bolt (20) is made up of a head (22) and a threaded stud (18) of conductive material to be screwed to a battery terminal (54), characterized in that an electric tap cable (38) is connected with the head (22) of said bolt (20) in a fixed manner or in a removable sealed manner.

2. Cable connection system according to claim 1, wherein the stripped end (36) of the electric cable (38) is firmly fastened to a ring (30) of conductive material to be slipped on the stud (18) of the bolt (20), said ring (30) being inserted in a bore (40) of a sealing ring (32) of rubber or plastic.

3. Cable connection system according to claim 2, wherein said sealing ring (32) is provided with a radial extension (42) encapsulating the end (36) of the electric cable (38) fastened to said ring (30) of conductive material.

4. Cable connection system according to claim 3, wherein the stripped end (36) of the electric cable (38) is fastened in a radial bore (34) of said ring (30) by soldering, welding, glueing, pressing, clamping, screwing or the like.

5. Cable connection system according to any of the preceding claims, wherein said ring (30) of conductive material has an axially protruding shoulder (44) with a preferably conical section abutting the corresponding uncovered end of the connector (10).

6. Cable connection system according to any of the preceding claims, wherein said sealing ring (32) axially protrudes beyond the ring (30) of conductive material such that its protruding end (48) overlaps an annular ring (50) of a plastic sheath (14) enclosing said battery conductor (10), said annular ring (50) being provided around a bore (16) of the conductor (10) crossed by said bolt (20).

7. Cable connection system according to any of the preceding claims, wherein said ring (30) of conductive material and said sealing ring (32) are provided with a cylindrical seat (52) for an annular shoulder (26) of conductive material provided between head (22) and stud (18) of said bolt (20).

8. Cable connection system according to any of the preceding claims, wherein the sheathed end (36) of said electric cable (38) is press fit in the radial extension (42) of the sealing ring (32).

9. Cable connection system according to claim 1, wherein the stripped end (36) of the electric cable (38) is firmly connected with the head (22) of conductive material of said bolt (20).

10. Cable connection system according to claim 9, wherein the stripped end (36) of the electric cable (38) is fastened through a moulded insulating annular collar (24) and through a radial bore (34) in the conductive head (22) to which it is fixed by soldering, welding, glueing, pressing, clamping, screwing or the like.

11. Cable connection system according to any of the preceding claims, wherein the head (22) of the bolt (20) is made up of a nut screwed on the threaded stud (18) of the bolt (20) in a way that it forms part of said stud (18).

12. Cable connection system according to any of the preceding claims, wherein the head (22) of the bolt (20) and its integrated annular collar (24) are encapsulated in an insulating plastic capsule (56).

13. Cable connection system according to claim 12, wherein the capsule (56) is moulded over the head (22) and the end (36) of the cable (38) to form an integral sealing and insulating element around the head (20) and the cable (38).

Drawing