Apparatus for welding a blown tubular film

摘要

A linear drive system(8) with a moving part(11) acting along a line(9) moves two rods(15,16) operating welding plate supports(6,7) and hence welding plates(2,3). Each rod is connected via a joint(17) to the moving part of the linear drive which acts in a direction(9) transverse to the movement(20) of the welding tool plates. Each rod is also connected with a joint(13,14) on the welding plate tool carriers(6,7). The line of movement(9) of the linear drive unit(8) divides the distance(18) between the two joints(13,14) in half. Rods may be symmetrical with the linear line of movement and rods can be either of equal or different lengths. A control unit(21) governs movements of the linear drive which comprises a linear motor acting on the principle of a suspended railway. The linear line of movement is at 90[deg] to the movement direction(20) of the welding plates(2,3). Both rods may be connected to the moving part(11) of the linear drive via a common joint(17) or via separate joints.