Patent GB-859381-A (GB)
Title: Method and apparatus for butt splicing
IPC: B29D30/46
Filed: 1957-07-05
Abstract: A method of butt splicing the edges of two lengths of self adhering sheet material e.g. unvulcanised rubber covered fabric comprises positively clamping one edge along spaced segments, positively clamping the other edge along spaced segments and bringing the two edges, while thus clamped, forcibly together with the positively clamped segments of one edge engaging the unclamped segments of the other edge.  How a splice is made (see Figs. 1, 2 and 6a).  A butt splicing mechanism 10 (the splicer) is positioned between a delivery conveyer 12 and a take off conveyer 14.  Bias-cut adhesive sheet material 15 cut at its bias angle is fed by the conveyer 12 to a receiving apron 16, which, cooperating with a longitudinal guide rail 23, positions the leading edge 17 close to the trailing edge 18 of an adjacent piece of sheet material so that the splicer can operate to join the edges.  The spicer includes a number of splicing heads 25 supported by a frame 27 which slides on column 28 and is controlled by pneumatic pressure cylinders 38 disposed between the table 31 on which the splicer is made and the lower rail 34 of the frame. Pinions 42 engage rack <PICT:0859381/IV(a)/1> <PICT:0859381/IV(a)/2> <PICT:0859381/IV(a)/3> <PICT:0859381/IV(a)/4> <PICT:0859381/IV(a)/5> <PICT:0859381/IV(a)/6> <PICT:0859381/IV(a)/7> teeth 43 to maintain the vertical alignment of the frame and the operating angle of the splicer may be adjusted by rotating the base plate 30 supporting the columns 28 about the pivot 45.  Details and operation of the splicing of heads 25 (see Figs. 4, 7).  A U-shaped member 51 supports by a parallel linkage 58, 59 vertical bars 55 to which are secured transverse anchor bars 63 extending parallel to the splicing axis "X" and carrying splicing shoes 65 which comprise a number of interengaging teeth 68 the bottoms of which engage and confine substantially all the margins of the pieces 15 and 15s of sheet material to be joined when the frame 27 and hence the member 51 is lowered.  Springs 70 hold the parts 55 apart in the inoperative position and adjusting screws 72 are provided.  As the frame member 51 is lowered, the splicing shoes 65 engage the fabric margins and subject them to pressure whilst forcibly butting them together.  To help the fabric move under the action of the shoes movable spring loaded rods 80a and 80b are incorporated in the supporting table 31. Each rod 80 corresponds to a tooth 68 of the shoes with which it co-operates first to hold the margin and then it moves with the shoe whilst the margins are butted.  The full movement of the shoes 64 is arranged to be slightly more than the initial distance between the edges 17 and 18 so that towards the end of the splicing movement the teeth 68 forcibly move over the butted joint and in so doing scrape a narrow strip of rubber from one margin to the other, the shoes being serrated for this purpose.  Feeding fabric to and from the splicer (see Figs 1 and 2).  The feed conveyer 12 passes fabric to the apron 16 which consists of a number of belts 114 disposed about a common spool at their rearward end but separate spools 116 at the splicer end which are pivotally connected to the table 31.  Each belt has a weighted take up spool to automatically adjust the tension therein when the angle of the splicer is altered.  The take off apron 19 comprises rollers which are rotated about an axis parallel to the longitudinal axis of the machine so that the fabric is continually pressed against the guide rail 23.  To position the stock edge for splicing (see Figs 16b and 16d) the fabric is moved quickly by conveyers 12 and 14 past a photo electric arrangement 183, 184 until this operates to show conveyer 14 whereupon the next piece of fabric starts to approach the first piece until it cuts off the lights to the cell which then slows conveyer 12.  Fingers 180a and 180b trail along the first piece of fabric until finger 180b makes contact with the table 31 whereby conveyer 14 is stopped.  The second piece of fabric moves towards the first piece again until finger 180a is lifted to stop conveyer 12.  The pieces are then positioned for splicing.