Patent GB-1271089-A (GB)
Title: Electric storage batteries
Inventor: HARRIS JOHN DEREK
IPC: H01M50/169
Filed: 1968-07-04
Abstract: 1,271,089. Seaming non-metallic sheet material. JOSEPH LUCAS (INDUSTRIES) Ltd. 24 Sept., 1969 [4 July, 1968], No. 31880/68. Heading B5K. [Also in Division H5] A heater 43, Figs. 6 and 7, for melting the surface of an internal shoulder 27, Fig. 4, in a recessed battery box lid 25 to facilitate welding of the lid 25 to a battery box 11, Fig. 3, is formed with a portion 48a, 48b, 48c which is inserted into the open end of the lid 25 to engage the shoulder 27 and which is undercut at 49 to the rear of the surface of the portion 48a, 48b, 48c so that the wall 26 of the lid 25 adjacent the shoulder 27 is not melted. As shown in Fig. 3, the polypropylene box 11 is partitioned by walls 12 into six compartments each receiving a pre-formed pack 13 of positive and negative battery plates and separators. The two sets of plates in each of the central four packs are connected to lugs 15, 16, the latter having spigots 16a extending through holes in the walls 12. The lugs 15, 16 are welded together by a tool 18 comprising electrodes 21, 22. The packs 13 in the end compartments each have one set of plates connected to a lug 15 or 16 and the other set connected to a terminal post 17. The polypropylene lid 25, Fig. 4, is formed with walls 28 to engage the free edges of the walls 12, the walls 28 being thicker than the walls 12. The lid 25 is formed with six filling tubes 29 having associated vent passages 31, spigots 33 for lead inserts for the terminal posts 17 and tapered pegs 30 to guide the lid 25 into correct longitudinal position on the box 11. The heater 43, Figs. 6 and 7, carries rollers 45 to run in guideways 42, Fig. 5, and has passages 46 to receive electrical heating elements. Secured to the lower face of the heater is a plain aluminium plate 47 and secured to the upper face is a pair of aluminium plates 48a, 48b which are mirror images of each other and spaced by an aluminium piece 48c which is replaceable by a different dimension piece to alter the overall dimensions of the portion 48a, 48b, 48c. The tubes 29 and the spigots 33 of the lid 25 are received in holes 51 in the plates 48a, 48b. To effect welding, the boxes 11 having their lids 25 placed thereon are carried by a conveyer between guide rails 53 singly over a platform 41. As a box reaches the platform 41, it engages a stop 52 to operate a micro-switch which starts a cam-control system. The platform 41 is raised and a die part 37 is lowered by a pneumatic ram 39 to engage and grip the lid 25. Mechanical means (not shown) is actuated to hold the box 11 firmly on the platform 41. The part 37 with the lid 25 is raised to its original position and the platform 41 is lowered to a position slightly above the moving conveyer. The heater 43 is moved along the guideways 42 to lie between the box 11 and the lid 25. The part 37 is lowered so that the portion 48a, 48b, 48c engages the shoulder 27 and the free edges of the walls 28. One second later, the platform 41 is raised so that the free edges of the box 11 and the walls 12 engage the plate 47. After maintaining the box and lid in contact with the heater for a further three seconds, the part 37 and the platform 41 are returned to their previous position and the heater 43 is retracted. The lid is pressed firmly into contact with the box 11 so that a weld is formed, molten polypropylene flowing into a wedge-shaped gap defined between a tapered upper wall of the box 11 and the wall 26 of the lid 25. The lid 25 is released from the part 37 and the platform 41 is lowered so that the conveyer removes the welded box.