Temperature sensing apparatus

An apparatus comprising:

• a body, said body enclosing a chamber, said chamber bounded by a frangible transparent portion and a case wall, said case wall having an opening therethrough, said case wall having an outer case wall surface extending in surrounding relation of said opening;
• an indicator housed in said chamber and visible through said frangible portion;
• a closure member disposed outwardly of said chamber from said opening, said closure member having a closure wall surface in opposed facing relation of said case wall surface;
• a member extending in abutting relation between said closure wall surface and said case wall surface, said member having a resilient lip portion extending in surrounding relation of said opening and in abutting relation with one of said wall surfaces, wherein said lip portion is deformable to disengage said abutting surface responsive to pressure in said chamber, whereby pressure in said chamber is relieved.

An apparatus for indicating a condition in an environment comprising:

• a body enclosing a chamber;
• a indicator in said chamber indicating a condition in the environment;
• a wall bounding said chamber having an outer case wall surface, said wall having an opening therethrough;
• a closure member overlying said opening, said closure member having a closure wall surface disposed outwardly from said chamber and in opposed facing relation of said case wall surface;
• a member comprised of resilient material extending between said wall surfaces and in abutting relation therewith, wherein pressure in said chamber deforms said resilient member to disengage one of said surfaces to relieve pressure from said chamber.

An apparatus for indicating a condition in an environment comprising:

• a body enclosing a chamber;
• an indicator in said chamber indicating a condition in the environment;
• a case wall bounding said chamber, said wall having an opening therethrough;
• a closure wall surface extending externally of said chamber and in overlying relation with said opening;
• a member extending in closing relation of said opening, said member including a deformable lip portion engaging said closure wall surface and wherein pressure in said chamber deforms said lip portion to disengage said wall surface to relieve pressure from said chamber.