Thermostat having a movable backstop

A thermostat, comprising:

• a frame;
• a setting wheel rotatably attached to said frame having an outer edge and a central region, said setting wheel having a first ramp formed on said outer edge and a second ramp formed in said central region;
• a first lever having first and second ends and movable between first and second positions pivotally attached to said frame at said first end of said first lever, said first lever being in contact with said ramp at said second end of said first lever and being adapted to move between said first and second positions upon rotation of said setting wheel;
• a deformable element connected to said second lever, said deformable element expanding and contracting has a function of temperature;
• a fixed contact attached to said frame adapted to connect to an electrical circuit;
• a movable contact in contact with said second lever, said movable contact being movable in response to rotation of said setting wheel, and being adapted to physically contact said fixed contact when a preselected criteria has been achieved;
• a backstop means movable between first and second extreme positions, said backstop means being physically in contact with said first lever, said first lever when moved from said first to said second position causing said backstop means to move from said first two a second of said extreme positions, said backstop means further being positioned so that said movable contact lies between said backstop means and said fixed contact;
• second lever having first and second ends and movable between first and second positions pivotally attached to said frame at said first end of said second lever, said second end of said second lever being in contact with said second ramp and adapted to move said movable contact between said fixed contact and said backstop.

An improved thermostat of the type including a frame, a setting wheel, a movable contact, a fixed contact, and a backstop, said movable contact being positioned so that it can move between said fixed contact and said backstop in response to rotation of said setting wheel, wherein the improvement comprises a means for moving the backstop between two extreme positions, said means for moving being comprised of:

• a ramp positioned on said setting wheel;
• a lever having first and second ends, said first end being attached to said frame, said second end being adapted to contact said ramp, said second end being movable pivotally between first and second positions;
• a plunger having first and second ends, said second end being in contact with said backstop, said first end being in contact with said lever, said plunger being able to move said backstop form one of said extreme positions to the other, when said lever moves from said first to said second position;
• and
• a spring having first and second ends, said first end being attached to said frame, said second end being attached to said backstop, said spring being adapted to cause said backstop to be at the position of two extreme positions which is nearer to said fixed contact.