GB1367167A - Electrochemical seal - Google Patents

Abstract

1367167 Battery lead-in seals GATES RUBBER CO 5 Oct 1971 [7 Oct 1970] 46267/71 Heading H1B [Also in Division H2] A method of making a liquid-tight electrical connection through a wall of an electric device in particular, a maintenance-free lead-acid battery, comprises making part of the connector in the form of a socket 30 of deformable conductive material, e.g. lead, and positioning the socket against the internal surfaces of a boss 40 formed in a top wall 16 of plastics material. The plastics material has a degree of resilience and a hardness such that it may deform the material of the socket 30, a preferred material being polypropylene. A seal between the wall and the socket is made by radially expanding the socket and in Figs. 2, 3 this is performed by a blind or Pop rivet 32 (Registered Trade Mark) having a mandrel 44 which is pulled and severed to collapse the rivet as shown in Fig. 3. Electrical connection with the rivet is made by a terminal tag 42 integral therewith, the rivet being made of tin-plated steel. Figure 1 shows two such connections extending through an inner top 16 of a maintenance-free lead-acid battery 10, one tag 42 being welded to the battery top 14 and the tag (not shown) of the other connection being connected to the container 12 having a polypropylene liner 20, the sockets 30 being connected, respectively, to the positive and negative electrode plates. The battery has a vent 18 closed by a re-sealing rubber valve 24 and a carbonate pill for neutralizing electrolyte which escapes through the valve. In a modified connection, the radial expansion of the socket is obtained by a selftapping screw inserted in the socket (Figs. 4, 5, not shown). In another modification (Figs. 6, 7, not shown) the socket 30 is replaced by an annular member of lead and an O-ring is placed between the tag 42 and the upper surface of the wall 16.