Bellows temperature bulb sensor

Claim 1

A temperature sensing device comprising: a mounting base; a first body having two ends with a bellows-like surface therebetween and with one end mounted to said base; a hollow cylinder body having one end closed and one end open and the closed end projecting into said first body with clearance from said bellows-like surfaces and the mounting base, said hollow body extending to the second end of said first body; an annular member sealed between said cylinder body and said first body to form a sensing bulb between said bodies, said base and said annular member and to permit free communication of a fluid with the inner surface of said hollow body; at least one stiffening bar means mechanically affixed to a point on each of the convolutions of said sensing bulb to substantially eliminate expansion or contraction of said sensing bulb from a difference in internal and external pressures; a temperature expansive fluid filling and sensing bulb and in contact with the inside walls of said bellows-like surface and said cylinder body; means for communicating, externally to said sensing bulb, the reaction of said temperature expansive fluid to any temperature to which the outside surface of said sensing bulb is subjected; and indicating means associated with said communicating means and responsive to the reaction of said temperature expansive fluid for registering said temperature being sensed.