Pencil delivering glue and similar material

摘要

The pencil comprises a sleeve (2) with closed bottom (4), in which a rotary spindle (3) works by means of a bearing (7). A screw-thread (9) in the spindle at one side of the bearing runs for the whole sleeve length, while on the other side of the bearing is an external hand-operated knurled nut (10). The screw-thread engages in a tapped bore (16) in the base (13) of a piston (11), which also incorporates a cladding (12) guiding it inside the sleeve. The cladding of the piston is joined to the base via a fracture point, at which breakage occurs on relative movement in the lengthwise direction between the two. There can be an internal stop (26) at the top end of the sleeve, preventing the cladding emerging from it, while the base continues to move forwards under the action of the nut.