Thermal element and parts therefor and methods of making the same

In an assembly of a seal means and a plunger movable relative to said seal means with said seal means comprising a washer-like resilient seal member having an opening therethrough and press-fittingly receiving said plunger therethrough in such a manner that an inner peripheral portion of said washer-like member is turned into substantially parallel sealing and wiping engagement with said plunger while being substantially transverse to the remainder of said washer-like member, the improvement wherein said washer-like member contains abrasive means therein to provide a scraping action of said inner peripheral portion thereof against said plunger to clean the same as said plunger is moved relative thereto.

In a method of making a thermal element having a cylinder member carrying a piston member that projects out of an opening of an end of said cylinder member to be extended and retracted relative thereto upon changes of sensed temperature, the improvement comprising the steps of forming a washer-like resilient seal member to be carried by said end of said cylinder member and have an opening therethrough, press-fitting said piston member through said opening in such a manner that an inner peripheral portion of said washer-like member is turned into substantially parallel sealing and wiping engagement with said piston member while being substantially transverse to the remainder of said washer-like member, and forming said washer-like member to contain abrasive means therein so as to provide a scraping action of said inner peripheral portion thereof against said piston member to clean the same as said piston member is moved relative thereto.

In a method of making an assembly of a seal means and a plunger movable relative to said seal means with said seal means comprising a washer-like resilient seal member having an opening therethrough and press-fittingly receiving said plunger therethrough in such a manner that an inner peripheral portion of said washer-like member is turned into substantially parallel sealing and wiping engagement with said plunger while being substantially transverse to the remainder of said washer-like member, the improvement comprising the step of forming said washer-like member to contain abrasive means therein to provide a scraping action of said inner peripheral portion thereof against said plunger to clean the same as said plunger is moved relative thereto.