Fail-open locking element and thermostat incorporation same

A locking element for a thermostat having a displaceable valve supported by upper and lower bridges, said locking element comprising:

• (a) an end portion for attaching said locking element to said displaceable valve;
• (b) at least one body portion connected to said end portion;
• and
• (c) a locking means located on said body portion, said locking means being adapted to engage said lower bridge to lock said displaceable valve in an open position when said displaceable valve has been displaced a pre-determined amount, said pre-determined amount being located in the range that said displaceable valve is displaced when subjected to temperatures between the maximum normal working temperature of said thermostat and the failure temperature of said thermostat;
• wherein said locking element is resiliently flexible relative to said displaceable valve in order to flex as said displaceable valve is being displaced by said pre-determined amount.

A thermostat for liquid-cooling systems, comprising:

• (a) a flange having an opening;
• (b) a valve for sealing said opening, said valve being displaceable from said opening for allowing the passage of liquid through said opening;
• (c) an upper bridge and a lower bridge spanning said opening on opposed sides of said flange for supporting said valve in said opening;
• (d) means for displacing said valve from said opening in response to a temperature variation, said displacing means including a pin contacting the underside of one of said bridges, at one end, and being extendibly housed within a body at the other end, said body containing a temperature sensitive means for extending said pin, and said body being rigidly attached to said valve for sealing said opening in said flange when said pin is retracted relative to said body;
• (e) a spring located between said valve and the other of said bridges for urging said valve into sealing engagement with said opening;
• and
• (f) at least one locking element having
• (i) an end portion for attaching said locking element to said thermostat, said locking element being positioned to act between said displaceable valve and the remainder of said thermostat,
• (ii) at least one body portion positioned generally parallel to a path of displacement of said valve, and
• (iii) a tab rigidly connected to said body portion, said tab protruding into said path of displacement for locking said displaceable valve in an open position when said displaceable valve has been displaced a pre-determined amount, said pre-determined amount being located in the range that said displaceable valve is displaced when subjected to temperatures between the maximum normal working temperature of said thermostat and the failure temperature of said thermostat.