Temperature sensing, indicating and recording means

Claim 1

A TEMPERATURE INDICATING DEVICE COMPRISING A CASING INCLUDING PLURAL INTERNAL DIVIDER WALLS FORMING PLURAL SUBSTANTIALLY PARALLEL ELONGATED COMPARTMENTS WITHIN THE CASING, CORRESPONDING ENDS OF THE COMPARTMENTS HAVING OPENINGS LEADING TO THE EXTERIOR OF THE CASING, SAID OPENINGS BEING OF REDUCED CROSS SECTION, WHEREBY EACH COMPARTMENT HAS STOP SHOULDERS FORMED AT ITS LEADING END, AN INDICATOR PLUNGER WITHIN EACH COMPARTMENT OF THE CASING AND MOVABLE LONGITUDINALL THEREIN FROM A RETRACTED NON-INDICATING POSITION TO AN EXTENDED TEMPERATURE INDICATING POSITION, EACH PLUNGER HAVING A REDUCED LEADING EXTREMITY PROJECTABLE THROUGH THE ADJACENT OPENING AND SHOULDERS ENGAGEABLE WITH SAID COMPARTMENT STOP SHOULDERS TO LIMIT FORWARD MOVEMENT OF THE PLUNGER, AN EXPANSIBLE SPRING MOUNTED WITHIN EACH COMPARTMENT BEHIND THE PLUNGER THEREIN AND BEARING UPON THE REAR END OF THE PLUNGER, AND A FUSIBLE DETENT PIN FOR EACH PLUNGER WITHIN THE CASING HAVING MECHANICAL INTERLOCKING ENGAGEMENT THEREWITH PRIOR TO FUSION OF THE DETENT PIN AND RELEASABLY SECURING EACH PLUNGER IN SAID RETRACTED NON-INDICATING POSITION, EACH FUSIBLE DETENT PIN UPON FUSION RELEASING ITS PLUNGER FOR MOVEMENT TO THE INDICATING POSITION, AND EACH DETENT PIN HAVING A SPECIFIC PRECISE FUSION TEMPERATURE DIFFERENT FROM THE FUSION TEMPERATURES OF THE OTHER DETENT PINS OF THE DEVICE, WHEREBY THE DEVICE MAY BE USED TO MONITOR A RANGE OF TEMPERATURES.