Apparatus for continuously unwinding a plurality of rolled-up tapes

An apparatus for continuously unwinding a plurality of rolled-up tapes made of a fusible material wherein the tapes are successively unwound, one at a time, from at least two reminders for supporting the tape thereon, with a tail end of a preceding tape joined to a leading end of a following tape, the apparatus comprising:

• transport means for transporting the preceding tape via a joining station;
• and
• joining means at said joining station for
• holding the following tape with its leading end folded into a fold and with the tail end of the preceding tape within the fold of the leading end of the following tape,
• thermally bonding the tail end of the preceding tape to the leading end of the following tape which has been folded over itself so as to produce a joint, and
• cutting off a portion of the joint with a length thereof left uncut:
• the joining means comprising:
• a joining block provided with a pair of vertical pressure-receiving faces opposed to each other and about which the folded-over leading end of the following tape engages from below the joining block,
• a pair of movable members arranged on opposite sides of the joining block and respectively movable toward and away from the pressure-receiving faces of the joining block,
• a pair of heaters, a heater fixedly positioned on each of the movable members and each having a heating face facing toward a pressure-receiving face of the joining block, the heating face of each heater being formed with a horizontal cutting ridge,
• a pair of rods being horizontally and axially movable, each of which is slidable supported by one of the movable members so as to be positioned below the heater and movable in the direction of movement of the movable member,
• a pair of holding members, each of which is fixed to an end of one of the rods and provided with a holding face facing toward a pressure-receiving face of the joining block, the end facing toward an end of the other rod,
• a pair of springs, each of which biases each of the holding members toward the joining block so that the holding member projects beyond the heater, and
• a hydraulic cylinder for each rod having a piston movable at a two-step stroke of a first step stroke and a second step stroke, the cylinder being operable such that after the first step stroke of the piston, the heating face of the heater on the rod is positioned away from the pressure-receiving face of the joining block while the pressure-receiving face of the holding member is pressed against the pressure-receiving face, and after the second-step stroke of the piston, both the heating face and the holding face are pressured against the pressure-receiving face.