Gripping device utilizing a shape memory alloy
AssigneeThe Boeing Company
InventorJoseph T. Bloch
Life of this patent
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Abstract
A gripping device for gripping or grasping an object within a set of jaws utilizing a shape memory alloy material that is both simple of construction and suitable for use in space as well as on Earth. The shape memory alloy contracts when heated and operates to move the jaw bears in a given direction. When no heat is applied to the shape memory alloy, a returning mechanism moves the jaw bars in the opposite direction. The shape memory alloy material may be in the form of a strap or wire which is easily heated and provides for a fast closing and opening action of the jaws of the gripping device.
Claims29
A gripping device comprising:
- (a) a plurality of jaw bars;
- (b) a first and second electrical terminal;
- (c) a first shape memory alloy wire having a characteristic of contracting when heated, said shape memory alloy wire being attached at a first end thereof to said first electrical terminal, a second end of said wire being electrically connected to a second terminal;
- (d) movement transmitting means, separate and distinct from said first shape memory alloy wire, connected to the second end of said wire for transmitting the contracting movement of said first shape memory alloy wire to said jaw bars so as to bias said jaw bars in a given direction being one of (1) toward one another and (2) away from one another when said shape memory alloy wire is heated;
- and
- (e) means for biasing said jaw bars in a direction opposite to said given direction.
A method for opening and closing the jaws of a gripping device comprising:
- (a) supplying a first electrical current to a first shape memory alloy wire to cause said first shape memory alloy wire to contract;
- (b) transmitting movement caused by said contraction to said jaw bars and to a second shape memory alloy wire;
- (c) utilizing said transmitted movement to bias said jaw bars away from one another and to stretch said second shape memory alloy wire;
- (d) removing said first current from said first shape memory alloy wire;
- (e) supplying a second electrical current to said second shape memory alloy wire to cause said second shape memory alloy wire to contract;
- (f) transmitting movement caused by said contraction to said jaw bars and said first shape memory alloy wire;
- and
- (g) utilizing said transmitted movement to bias said jaw bars toward one another and to stretch said first shape memory alloy wire.
A gripping device comprising:
- (a) a housing;
- (b) a plurality of jaw bars movably secured to said housing;
- (c) a first shape memory alloy wire having a characteristic of contracting when heated, said shape memory alloy wire being attached at a first end thereof to said housing;
- (d) movement transmitting means, separate and distinct from said first shape memory alloy wire, connected to a second end of said wire for transmitting the contracting movement of said first shape memory alloy wire to said jaw bars so as to bias said jaw bars in a given direction being one of (1) toward one another and (2) away from one another when said shape memory alloy wire is heated;
- and
- (e) means for biasing said jaw bars in a direction opposite to said given direction.
A method for opening and closing the jaws of a gripping device comprising:
- (a) heating a first shape memory alloy wire to cause said first shape memory alloy wire to contract;
- (b) transmitting movement caused by said contraction to said jaw bars and to a second shape memory alloy wire;
- (c) utilizing said transmitted movement to bias said jaw bars away from one another and to stretch said second shape memory alloy wire;
- (d) terminating heating of said first shape memory alloy wire;
- (e) heating said second shape memory alloy wire to cause said second shape memory alloy wire to contract;
- (f) transmitting movement caused by said contraction to said jaw bars and said first shape memory alloy wire;
- and
- (g) utilizing said transmitted movement to bias said jaw bars toward one another and to stretch said first shape memory alloy wire.
Dependencies are inferred from the claim text.