Temperature compensated snap-beam actuator

Claim 2

A temperature compensated thermal actuator comprising: two substantially parallel thermo responsive bimetal beams, one beam a thermal operator and the other a temperature compensator for the thermal operator oppositely arranged, each beam having a central portion movable in a first direction upon heating and in the opposite direction upon cooling; said beams being mechanically linked at a position intermediate said ends so that the beams move together as a unit, said beams being subject to longitudinal buckle upon the application of a compressive loading thereto which exceeds a critical value; first loading means to provide a compressive loading throughout a first of said bimetal beams in excess of said critical value whereby said beam snaps from one to the other of two positions dependent upon the temperature of said beam; second loading means to provide a compressive loading throughout the second of said bimetal beams to approximately said critical value at which loading said second beam can assume changes in displacement with no change in force whereby said second beam operates as a temperature compensator for said first snap beam without changing the loading on said first beam; and electric heating means associated with said first snap beam for operating said first beam in said first direction when heated and thereby operating both of said beams from said one position to said other position.

Claim 3

The invention according to claim 1 and further comprising: contact means operated in accordance with the position of said beams.

Claim 4

The invention according to claim 1 wherein said first and second loading means comprise resilient means.

Claim 5

The invention according to claim 1 and further comprising: stop means positioned to constrain the movement of said beam.

Claim 6

A temperature compensated thermal actuator comprising: a first and second thermally responsive beam, said beams having their end positions relatively fixed and having a central portion movable in a first direction upon heating and in a second direction when heating ceases, said first beam being provided with a snap action throughout a certain range of its movement; first support means mechanically interconnecting and positioning one end of said first and second beams; second support means interconnecting and posItioning the other end of said first and second beams so that said beams are positioned relatively parallel to one another, said beams being oppositely arranged to provide temperature compensation; first spring means associated with said support means and positioned to apply compressive end loading to said first beam, said loading exceeding in magnitude that necessary to cause buckling of said beam to cause said snap action; second spring means associated with said support means and positioned to apply a lesser magnitude of compressive end loading to said second beam which loading is approximately that necessary to cause buckling of said second beam; heating means associated with said first beam to actuate said first beam when heated; mechanical link means connecting the central portions of said first and second beams so that they move as a unit; and electrical contact means operated in accordance with the position of said beams.

Claim 7

A temperature compensated thermal actuator comprising: a first and second thermally responsive beam, said beams having their end positions relatively fixed and having a central portion movable in a first direction upon heating and in a second direction when heating ceases, said first beam being provided with a snap action throughout a certain range of its movement; first support means mechanically interconnecting and positioning one end of said first and second beams; second support means interconnecting and posItioning the other end of said first and second beams so that said beams are positioned relatively parallel to one another, said beams being oppositely arranged to provide temperature compensation; first spring means associated with said support means and positioned to apply compressive end loading to said first beam, said loading exceeding in magnitude that necessary to cause buckling of said beam to cause said snap action; second spring means associated with said support means and positioned to apply a lesser magnitude of compressive end loading to said second beam which loading is approximately that necessary to cause buckling of said second beam; heating means associated with said first beam to actuate said first beam when heated; mechanical link means connecting the central portions of said first and second beams so that they move as a unit; and electrical contact means operated in accordance with the position of said beams.

Claim 8

The invention according to claim 5 in which said snap beams are made with an initial longitudinal curvature to cause return in said second direction upon cessation of heating.

Claim 9

The invention according to claim 5 and further comprising stop means positioned to constrain the movement of said beam within said snap acting range.

Claim 10

The invention according to claim 5 and further comprising: adjustable means associated with at least one of said first and second beams for adjusting the magnitude of said compressive end loading.

Claim 11

The invention according to claim 8 wherein said adjusting means comprises screw means.

Claim 12

The invention according to claim 8 wherein said adjustable means, said spring means and said beam are longitudinally aligned.

Claim 13

A snap beam type thermal sequencer comprising: a plurality of thermally responsive bimetal snap beams; loading means applying a compressive longitudinal loading on each of said plurality of thermally responsive snap beams, said means loading each said beam in excess of its buckling load so that said beams are biased to either of two positions, said snap beams having a central portion which snaps in a first direction upon heating and in a second direction when heating ceases and the beam cools; electrical heating means positioned in heat transfer relation with said snap beams whereby said beams can be simultaneously heated, said means comprising an electrical heating chamber having first and second end member means and having longitudinal connecting member means extending between said end member means, the end member and connecting member means defining said chamber, said first and second end member means receiving and positioning said plurality of snap beams within said chamber, said chamber including power input terminals for connection to a controlled supply of power whereby said chamber can be heated to simultaneously heat said beams; and means coupling the position of said snap beams to switching means.

Claim 14

A snap beam type thermal sequencer comprising: a plurality of thermally responsive bimetal snap beams; loading means applying a compressive longitudinal loading on each of said plurality of thermally responsive snap beams, said means loading each said beam in excess of its buckling load so that said beams are biased to either of two positions, said snap beams having a central portion which snaps in a first direction upon heating and in a second direction when heating ceases and the beam cools; electrical heating means positioned in heat transfer relation with said snap beams whereby said beams can be simultaneously heated, said means comprising an electrical heating chamber having first and second end member means and having longitudinal connecting member means extending between said end member means, the end member and connecting member means defining said chamber, said first and second end member means receiving and positioning said plurality of snap beams within said chamber, said chamber including power input terminals for connection to a controlled supply of power whereby said chamber can be heated to simultaneously heat said beams; and means coupling the position of said snap beams to switching means.

Claim 15

The sequencer of claim 11 wherein each of said beams is compressively loaded to a slightly different value to cause a sequential operation of said beams.

Claim 16

The sequencer of claim 11 in which said loading means comprises individual spring means for end loading each of said beams.

Claim 17

The sequencer of claim 13 in which said individual spring means each applies a spring load to its respective beam which differs from the others.

Claim 18

The sequencer of claim 13 in which said individual spring means further comprise adjusting means to individually adjust the end loading applied to the beams.

Claim 19

The sequencer of claim 11 and further comprising: a plurality of thermally responsive compensator beams, one for each of said snap beams; said first and second end member means also being adapted for receiving and positioning said plurality of compensator beams such that one compensator beam is substantially parallel to each snap beam.

Claim 20

The sequencer of claim 11 and further comprising: stop means positioned to conStrain the movements of said beams to define said two positions of each of said beams.