| 摘要 |
A device for dispensing molten thermoplastic material comprising a barrel member (14) having an internal melting chamber communicating with an outlet opening through a nozzle (16), and a sleeve (18) having one end secured at the barrel member (14) and a through opening communicating with the end of the melting chamber opposite the outlet opening. The sleeve (18) is adapted to receive a rod (20) of solid thermoplastic material with one end portion of the rod (20) in the melting chamber and the rod (20) projecting through the sleeve (18) along a predetermined path. the barrel member (14) is heated to melt the end portion of the rod (20) therein, and a drive (22) adapted to be switched between a deactivated state and an activated state is provided for driving the rod (20) of solid thermoplastic material into the melting chamber at a predetermined rate to expel molten thermoplastic material through the nozzle (16). Upon switching of the drive (22) from the activated state to the deactivated state the drive (22) moves the rod (20) of solid thermoplastic material a small distance out of the melting chamber to cause molten thermoplastic material in the nozzle (16) to flow toward the melting chamber and restrict movement (i.e., dripping or stringing) of that molten thermoplastic material out of the nozzle (16). |
