“…The positioning assembly shaft structure consists of a body (9) made of insulating brown bakerite material and a roller assembly (8) used to position the pipe edge (Figure 5). The structure of the roller assembly consists of a V groove roller (13), an M5 bolt (12) used as the roller shaft, a push handle (14), nut (15), support cover ( 16), and spring (17). The bolt M5 (18) links the support cover to the push handle.…”