Improvements in or relating to leads for interconnecting electrical batteries

Abstract

 A pair of electrically conducting leads (11,12) for removable attachment to two electrical batteries in order to form a temporary interconnection between the two batteries when spaced apart from each other is provided. Each od the leads includes an elongated electrical conductor surrounded by an insulating cover (13), and each lead (11) has at both outer ends an attachment (14) for releasable attachment to a battery terminal in order to form an electrical connection between the table end of the lead (11) and the battery terminal. At least one of the leads (11) is formed with a releasable connection (15) in at its central region which releasable connection (15) permits the lead (11) to be split into two separated parts (11a, 11b) each for connection to respective battery terminals before completing the connection in the central region of the lead (11) to form the electrical interconnection between the two batteries. The releasable connection (15) may be in the form of a plug or socket connector (16, 21). One of the leads (12) may be continuous without a connection at its central region.

Description

[0001] The invention relates to leads for interconnecting electrical batteries. More particularly the invention is applicable to leads known as "jump leads" for forming a temporary interconnection between two secondary batteries such as lead acid batteries used in motor vehicles. Such leads are frequently used to form a temporary connection between a dischargedbattery in one vehicle and a charged battery in a further vehicle in order to form a temporary interconnection enabling the vehicle having the discharged battery to be started by current supplied from the battery of the other vehicle.

[0002] When using such leads to form temporary interconnection there is a danger as an explosive gas mixture may exist in the vicinity of-either battery and this can be ignited by any spark generated during the conn- ection or disconnection of the jump leads. Safe connecting procedures have been developed but they are not always carried out as the users of such jump leads may be unaware of the hazard involved.

[0003] It is an object of the present invention to provide improved connecting leads or so-called "jump leads" which are constructed so as to facilitate safe interconnection of batteries.

[0004] The present invention provides a pair of electrically conducting leads for removable attachment to two electrical batteries in order to form a temporary interconnection between the two batteries when spaced apart from each other, each of said leads comprising an elongated electrical conductor surrounded by an insulating cover, and each lead having at both outer ends attachment means for releasable attachment to a battery terminal in order to form an electrical connection between the end of the lead and the battery terminal, at least one of the leads being formed with a releasable connection in a central region of the lead remote from either of said outer ends, said releasable connection permitting the lead to be split into two separated parts each for connection to respective battery terminals before completing the connection in the central region of the lead to form the electrical interconnection between the two batteries.

[0005] The invention is particularly applicable to leads as aforesaid for the interconnection of secondary electrical batteries su:: as for example lead acid batteries used in motor vehicles.

[0006] Preferably said releasable connection comprises mating electrically conducting members connected to respective parts of the lead and housed within electrically insulating shield means arranged to conceal the conducting members when the two parts of the lead are separated.

[0007] Preferably said releasable connection comprises a plug and socket connector. Preferably said plug and socket connector comprises a bayonet connection to permit ready connection and disconnection.

[0008] Preferably said plug and socket connection comprises two separate parts each having electrically insulating shield means and each comprising a flange arranged to abut face to face with the corresponding flange on the other part of the connection when the connection is completed, said flanges being provided with centrally located apertures through which the electrical connection is made. In this way said flanges provide a flash quard reducing the possibility of any spark escaping from the connection when the connection is made or broken.

[0009] Preferably said plug and socket connector comprises two separate parts each having electrically insulating shield means, the shield means of one part closely surrounding the socket and the shield means of the second part surrounding but being so spaced from the second part as to closely surround the shield means of the first pert when the connection is completed by insertion of the plug in the socket.

[0010] Preferably said releasable connection is located substantially midway along said one of the leads.

[0011] Preferably one of the leads is formed in one piece with no connection in its central region, said lead comprising a continuous electrical conductor surrounded by a continuous electrically insulating sleeve extending along its entire length. Preferably said continuous lead is of substantially the same length as the other lead when the two parts are connected together.

[0012] Also according to the present invention there is provided a set of electrically conducting leads for removable attachment to two electrical batteries in order to form a temporary interconnection between the two batteries when spaced apart from each other, said set comprising at least three lead portions each portion having electrical connector means at its opposite ends, two of said portions being held together by tie means, such as a flexible cord, so that the lead portions adjacent the tie means are prevented from extensive separation.

[0013] Also according to the present invention there is provided a pair of electrically conducting leads for removable attachment to two electrical batteries in order to form a temporary interconnection between _he two batteries when spaced apart from each other each of.said leads comprising an elongated electrical conductor surrounded by an insulating cover, and each lead having at both outer ends attachment means for releasable attachment to a battery terminal in order to form an electrical connection between the end of the lead and the battery terminal, at least one of the leads being provided with switch means in a central region of the lead remote from either of said outer ends, said switch means beirgoperable to electrically disconnect the leads at each side of the seitch means from each other while the outer ends are connected to respective battery terminals and to reconnect the leads in the central region of the lead to form the electrical interconnection between the two batteries.

[0014] Use of electrically conducting leads as aforesaid reduces the likelihood of sparks causing any explosion. In use, the one piece lead with no central connection is first connected at its opposite end to terminals of the same polarity on the two batteries to be interconnected. The lead with the central releasable connection is first separated into two parts and the respective ends are then connected to the other terminals of matching polarity on the two batteries.

[0015] The last connection is made by connecting the releasable connector in the central region of the said one jump lead. This last connection can then be made at a safe distance from the ends of the leads so that any sparking during making or breaking the connection would not ignite gases in the vicinity of the battery. Preferably the connection is shrouded so that no inadvertent connections can be made to the vehicle body and any spark formed within the connection itself is shrouded so as to reduce the risk of passing into the surrounding atmosphere.

[0016] Preferably the releasable connection may be readily disconnected as the first connection is broken when removing the jump leads after use.

[0017] Three embodiments of this invention will now be described by way of example and with reference to the accompanying drawings in which:

Figure 1 shows a pair of jump leads for connecting between a discharged battery and another battery to enable a vehicle containing the discharged battery to be started by the current from the other battery which may be at a spaced position such as in a nearby vehicle, and

Figure 2 shows a pair of jump leads in which one lead is provided with a switch device at its central region,

Figure 3 shows a plug and socket connection for use in a pair of jump leads according to the present invention.

[0018] In Figure 1 two leads 11 and 12 each comprise generally an alongated electrically conducting cable housed within an electrically insulating sleeve 13 surrounding the cable. At the outer ends of each lead are releasable bulldog clips 14 electrically connected to the cable within the leads and arranged for simple connection and disconnection to battery terminals when in use.

[0019] Lead 11 is provided with a releasable connector 15 in its central region so that the lead may be separated into two separated parts 11a and 11b. The releasable connection 15 comprises a plug and socket connection of the quick release bayonet type. Lead 11a is electrically connected to a conducting pin 16 housed within an electrically insulating shield member 17 provided with a flat annular flange 18. The shield 17 and flange 18 are retractable against a spring 19 surrounding the pin 16 so that when connection is made, the pin 16 may project through an aperture 20 in the centre of the flange 18 in order to connect with the other half of the plug and socket connection. The lead 11b is electrically connected to a conducting member 21 formed with a cylindrical recess 22 adapted to receive the pin 16 in electrically conducting engagement therewith. The recess -22 is aligned with a central aperture 23 in an annular flange 24 arranged to match and abut the flange 18 when the connection is made. The flange 24 forms part of an insulating shield 25 which surrounds the socket 22. The wall of the socket 22 is formed with a cutaway portion 26 arranged to form the releasable bayonet connection with a projecting peg 27 on the pin 16.

[0020] When the connection is broken as shown in the drawing, the shields 17 and 25 together with the flanges 18 and 24 completely surround the electrical conducting parts of the plug and socket connection so that no electrically conducting member is readily accessible from an external position. To complete the connection, the two flanges 18 and 24 are pressed together in alignment with each other and further movement towards each other causes the pin 16 to pass through the apertures 20 and 23 so as to engage the socket 22 when relative rotation of the two connecting parts permits engagement of the bayonet connection. The coupling may be broken by a reverse operation.

[0021] As is shown in the drawing, the releasable connection 15 is located in the central region of the lead 11 and in this particular example is located substantially midway along the length of the lead 11. When connected together in its central region, the lead 11 is of substantially the same length as the lead 12 although for the sake of clarity in the drawing the lengths are not accurately represented.

[0022] In use as jump leads to enable one vehicle to be started by use of the battery in an adjacent vehicle, the lead 12 is first connected by the bulldog clips 14 at its opposite ends to the positive terminals of the two batteries in the respective vehicles. The releas-' able connection 15 in the lead 11 is separated and the clips 14 on the respective parts 11a and 11b of the separated lead are then connected to the respective negative terminals of the two batteries. The connection 15 is then held at a position well away from both batteries and the two flanges 18 and 24 are pushed together so as to complete the connection 15 as previously described. This completes the last electrical connection between the two batteries and then enables the vehicle to be started by means of current passed through the jump leads. After the vehicle has started, the connection is first broken by releasing the connection 15 while it is still located remote from the two batteries. After the connection has been separated, the clips 14 on the leads 11 are then removed from the battery terminals and then the lead 12 is similarly removed by release of the bulldog clips 14.

[0023] The electrical insulation surrounding the releasable connection 15 prevents any inadvertent electrical connections being made between the jump leads and the vehicle bodies. Furthermore, the quick release nature of the baonet coupling in the releasable connection 15 simplifies disconnection of the coupling 15 as the first electrical connection to be broken after use of the jump leads.

[0024] The invention is not limited to the details of the foregoing example.

[0025] In the drawing, the lead 12 is shown as a single unitary lead extending between the clips 14 at its remote ends. It is however possible for the lead 12 to be formed in more than one part with suitable interconnecting means intermediate its ends.

[0026] Although the particular example described has showed a preferred construction for a releasable connector 15 intermediate the ends of one of the leads, it will be understood that other forms of releasable connector may be used. For example, each part 11a and 11b of the lead may be formed with releasable clips such as bulldog clips at its opposite ends so that the two parts are then interconnected by electrically coupling the two bulldog clips in the central region. Preferably some interconnecting cord or other like tie means is provided to link together the two parts 11a and 11b in their central region so that even when the cable is electrically separated at its central connection, the two interconnecting parts are retained in close proximity with each other so that they are readily at hand to be connected together to form the electrical connection after the clops 14 at the outer ends have been connected to the appropriate battery terminals.

[0027] Figure 2 shows a second embodiment of a pair of jump leads in which parts similar to those shown in Figure 1 are given like reference numerals. Instead of providing lead 11 with the releasable connection 15, the lead 11 is provided with a switch device 30 having a toggle 31 which can be manually operated to electrically connect or disconnect the two lead parts 11a and 11b. When the lead 12 has been connected to the positive terminals of the two batteries the lead 11 is connected to the negative terminals of the batteries whilst the toggle 31 of the seitch device 30 is at a position which causes the two lead parts 11a and 11b to be electrically disconnected. Thereafter the toggle 31 is moved to a position in which the two lead parts 11a and 11b become electrically connected. When the vehicle has started the toggle is again moved to a position at which the two lead parts become electrically disconnected and the clips 14 on lead 11 are removed from-the battery and then the lead 12 is similarly removed by release of its clips 14.

[0028] Figure 3 shows a plug and socket connection 30 of a pair of jump leads. Lead parts 30a and 30b are similarl to leads 11a and 11b shown in Figures 1 and 2 and may be provided at their ends with clips similar to clips 14. Lead 30a is electrically connected to a tubular socket 31 by being gripped by the reduced portion 33 of the socket 31. The socket 31 is provided with a longitudinally extending slotted opening 34 which allows the socket 31 to spread radially to a limited extent. The socket 31 and the adjacent end portion of the lead 30a are closely surrounded by an electrically insulating shield member 35 in the form of a resilient plastics sheath. The shield member 35 has a periphal step 36 intermediate its end. Lead 30b is electrically connected to tubular plug 37 by being gripped by the reduced portion 38cf the plug 37. The plug 37 and the adjacent end portion of the lead 30b are surrounded by and electrically insulating shield member 39 in the form of a resilient plastics sheath. The forward end portion of the shield member 39 is spaced from the plug 37 to provide a recess 40 having a depth equal to the distance from the forward end of the shield member 36 of the socket 31 to the step 36. The width of the recess 40 and of the plug 37 is such that the plug 37 can be inserted in the socket 31 with the shield member 39 of the plug 37 closely surrounding the shield member 35 of the socket 31 up to the step 36. The overall width of the shield members 35 and 39 is the same so that when the two parts are connected a continuous surface is presented along both shield members. The slot 34 of the socket 31 resilience of the shield member 35 and 39 enable the connection between the plug 37 and the socket 31 and between the two shield members 35 and 39 to be sufficiently tight to prevent the two parts becoming accidently separated during use but not so tight as to render connection or disconnection difficult. Also a tight connection between the plug 37 and socket 31 provides good electrical contact.

Claims

1. A pair of electrically conducting leads (11, 12) for removable attachment to two electrical batteries in order to form a temporary interconnection between the two batteries when spaced apart from each other, each of said leads (11, 12) comprising an elongated electrical conductor surrounded by an insulating cover (13), and each lead (11, 12) having at both outer ends attachment means (14) for releasable attachment to a battery terminal in order to form an electrical connection between the end of the lead (11, 12) and the battery terminal, characterised by at least one of the leads (11) being formed with a releasable connection (15) in a central region of the lead (11) remote from either of said outer ends, said releasable connection (15) permitting the lead (11) to be split into two separated parts (11a, 11b) each ior connection to respective battery terminals before completing the connection in the central region of the lead to form the electrical interconnection between the two batteries.

2. A pair of electrically conducting leads as claimed in Claim 1, characterised in that said releasable connection (15) comprises mating electrically conducting members (18, 21) connected to respective parts of the lead (11) and housed within electrically insulating shield means (17, 25) arranged to conceal the conducting members (16, 21) when the two parts (11a, 11b) of the lead (13) are separated.

3. A pair of electrically conducting leads as claimed in Claim 1 or Claim 2, characterised in that said releasable connection (15) comprises a plug and socket connector (16, 26).

4. A pair of electrically conducting leads as claimed in Claim 3, characterised in that said plug and socket connector comprises a bayonet connection (16, 26) to permit ready connection and disconnection.

5. A pair of electrically conducting leads as claimed in Claim 3, or Claim 4, characterised in that said plug and socket connector (16, 26) comprises two separate parts each having electrically insulating shield means (17, 25) and each comprising a flange (18, 24) arranged to abut face to face with the corresponding flange (18, 24) on the other part of the connection (15) when the correction (15) is completed, said flanges (18, 24) being provided with centrally located apertures (20, 23) through which the electrical connection (15) is made.

6. A pair of electrically conducting leads as claimed in Claim 5, characterised in that said plug and socket connector (30) comprises two separate parts each having electrically insulating shield means (35, 39), the shield means (35) of one part closely surrounding the socket (31) and the shield means (39) of the second part surrounding but being so spaced from the plug (37) as to closely surround the shield means (35) of the first part when the connection is completed by insertion of the plug (37) in the socket (31).

7. A pair of electrically conducting leads as claimed in any one of the preceding claims, characterised in that one of the leads (12) is formed in one piece with no connection in its central region, said lead (12) comprising a continuous electrical conductor surrounded by a continuous electrically insulating sleeve (13) extending along its entire length.

8. A pair of electrically conducting leads as claimed in Claim 7, characterised in that said continuous lead (12) is substantially the same length as the other lead (11) when the two parts (11a, 11b) are connected together.

9. A set of electrically conducting leads (11, 12) for removable attachment to two electrical batteries in order to form a temporary interconnection between the two batteries when spaced apart from each other, characterised by said set comprising at least three lead portions (11a, 11b, 12) each portion having electrical connector means (14) at its opposite ends, two of said portions (11a, 11b) being held together by tie means, such as a flexible cord, so that the lead portions (11a, 11b) adjacent the tie means are prevented from extensive separation.

10. A pair of electrically conducting leads (11, 12) for removable attachment to two electrical batteries in order to form a temporary interconnection between-the two batteries when spaced apart from each other each of said leads (11, 12) comprising an elongated electrical conductor surrounded by an insulating cover (13), and each lead (11, 12) having at both outer ends attachment means (14) for releasable attachment to a battery terminal in order to form an electrical connection between the end of the lead (11, 12) and the battery terminal, characterised by at least one of the leads (11) being provided with switch means (30) in a central region of the lead (11) remote from either of said outer ends, said switch means (30) being operable to electrically disconnect the lead (11) at each side of the switch means from each other while the outer ends are connected to respective battery terminals and to reconnect the lead (11) in the central region of the lead (11) to form the electrical interconnection between the two batteries.

Drawing