Plural set point pressure responsive switching apparatus utilizing a single pressure sensing driver element

A dual set point pressure switch comprising:

• a pressure responsive driving element;
• an actuator driven by said driving element;
• first an second electric switches operated by said actuator;
• first force responsive means blocking movement of said actuator and unblocking said actuator for driven movement at a first predetermined pressure value;
• first stop means arresting said driven movement of said actuator at a first increment of travel wherein said actuator operates said first switch, said first stop means thereafter being driven coincidentally with said actuator by said driving element;
• said first force responsive means being disposed between said actuator and said first stop means, said first stop means comprising means for adjustibly applying an initial force to said first force responsive means;
• second force responsive means blocking movement of said first stop means and said actuator and unblocking said first stop means and said actuator for driven movement at a second predetermined pressure value;
• second stop means arresting said driven movement of said first stop means and said actuator at a second increment of travel wherein said actuator operates said second switch;
• said second force responsive means being disposed between said first stop means and said second stop means, said second stop means comprising means for adjustibly applying an initial force to said second force responsive means independently of said initial force applied to said first force responsive means.

Dual set point pressure responsive electric switching apparatus comprising:

• first and second electric switches;
• a pressure responsive driver;
• a two-stage lost motion actuator directly driven by said driver sequentially operating said first and second switches;
• a fixed end stop and an intermediate stop movable relative to said end stop;
• and
• first and second force breakover devices respectively abruptly changing from an initial condition to a secondary condition when force applied thereto attains a respective predetermined value, said first breakover device being disposed between said intermediate stop and said actuator and said second breakover device being disposed between said intermediate stop and said end stop;
• said intermediate stop limiting movement of said actuator and said driver upon condition change of said first breakover device, thereby defining a first increment of travel of said actuator wherein said first switch is operated, said driver thereafter applying force to and moving said intermediate stop and said actuator coincidentally, said end stop limiting movement of said actuator and said intermediate stop over condition change of said second breakover device, thereby defining a second increment of travel of said actuator wherein said second switch is operated;
• said intermediate stop comprising an adjustable seat against which said first breakover device bears, adjustment of said second applying initial force on said first breakover device for varying the force value at which said first breakover device changes conditions;
• and
• said end stop being adjustible toward and away from said intermediate stop for applying initial force on said second breakover device separately and independently of said initial force on said first breakover device for varying the force value at which said second breakover device changes conditions.