Glue gun heat housing

A device for heating a substantially solid heat softenable glue stick comprising, a heating chamber housing having a heating chamber formed therein and a separate elongated passage located parallel to said chamber and including a first open end for receiving a substantially solid glue stick and a second opposed open end defining an exit opening for melted glue, said heating chamber having an open side located generally parallel to said passage, a positive temperature coefficient resistance cartridge means positioned in said chamber for heating the housing adjacent said passage to a temperature sufficient to soften a glue stick therein;

• said cartridge being generally circular in cross section and including at least one PTC resistor and at least two pressure bodies located on opposite sides of said at least one PTC resistor, said chamber having a generally arcuate semi-circular wall portion formed therein adjacent to but spaced from said passage which is generally complementary to the circular periphery of the cartridge and at least a pair of side walls extending therefrom leading to an opening in the housing which defines one side of the chamber;
• cam means in said chamber having at least one surface engaged with said cartridge and being complementary in shape thereto and two additional surfaces engaged with said side walls of the chamber and movable with respect thereto;
• and spring means mounted on said housing and engaged with said cam means for urging the cam means into engagement with the cartridge to accommodate expansion and contraction thereof.