System, method and apparatus for reducing frictional forces and for compensating shape memory alloy-actuated valves and valve systems at high temperatures
First Claim
1. A three-way, three-position valve system including two shape memory alloy (“
- SMA”
)-actuated valves for controlling the flow of fluids, the valve system comprising;
a housing having a substantially closed cavity for maintaining a pressurized fluid, said cavity including a first inlet port, a first outlet port connected to a user device actuatable by the pressurized fluid, and a second outlet port connected to a vent;
a first SMA-actuated valve including a first seal for closing and opening said first inlet port to selectively provide pressurized fluid to the cavity, a first SMA actuator configured to control the position of said first seal to vary fluid flow through said first inlet port, and a first temperature compensator for negating contraction forces generated by said first SMA actuator due to temperature;
a second SMA-actuated valve including a second seal for closing and opening said second outlet port to selectively vent the cavity of pressurized fluid to depressurize the user device, either a bidirectional SMA actuator or a unidirectional SMA actuator configured to control the position of said second seal to vary fluid flow through said second outlet port, and a second temperature compensator negating contraction forces generated by said second SMA actuator due to temperature;
the second outlet port being located along the cavity closer to the first outlet port than to the first inlet port thereby defining a direct pressurized fluid vent path from the user device to the vent.
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Accused Products
Abstract
A valve system including a number of shape memory alloy (“SMA”)-actuated valves for controlling the flow of fluids is disclosed as is a variety of types of SMA-actuated valves and methods of operation. In one embodiment, a valve system includes a housing having a substantially closed cavity as well as a second port for communicating a fluid. Further, the valve system includes a first SMA actuator configured to control the position of the first seal to vary fluid flow through the firs port, and a first temperature compensator for adjusting the position of the seal by an amount proportional to temperature. A second SMA-actuated valve, driven by either a unidirectional or a bidirectional SMA actuator, controls the position of the second seal to vary fluid flow through the second port, and a second temperature compensator for adjusting the position of the second seal by another amount proportional to temperature.
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Citations
18 Claims
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1. A three-way, three-position valve system including two shape memory alloy (“
- SMA”
)-actuated valves for controlling the flow of fluids, the valve system comprising;a housing having a substantially closed cavity for maintaining a pressurized fluid, said cavity including a first inlet port, a first outlet port connected to a user device actuatable by the pressurized fluid, and a second outlet port connected to a vent; a first SMA-actuated valve including a first seal for closing and opening said first inlet port to selectively provide pressurized fluid to the cavity, a first SMA actuator configured to control the position of said first seal to vary fluid flow through said first inlet port, and a first temperature compensator for negating contraction forces generated by said first SMA actuator due to temperature; a second SMA-actuated valve including a second seal for closing and opening said second outlet port to selectively vent the cavity of pressurized fluid to depressurize the user device, either a bidirectional SMA actuator or a unidirectional SMA actuator configured to control the position of said second seal to vary fluid flow through said second outlet port, and a second temperature compensator negating contraction forces generated by said second SMA actuator due to temperature; the second outlet port being located along the cavity closer to the first outlet port than to the first inlet port thereby defining a direct pressurized fluid vent path from the user device to the vent. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
- SMA”
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18. A three-way, three-position valve system including a number of shape memory alloy (“
- SMA”
)-actuated valves for controlling the flow of fluids, the valve system comprising;a housing defining a substantially closed cavity; means for maintaining a pressurized fluid in said cavity, said means including a first port for admitting pressurized fluid into the cavity and a second port for transferring pressurized fluid to a user device, and a vent port for venting pressuring fluid from the user device via the cavity, the second port being closer to the vent port than to the first port; a first SMA-actuated valve including first sealing means for closing and opening said first port, first SMA actuation means for controlling the position of said first seal to vary fluid flow into the cavity through said first port, and first temperature compensation means for negating contraction forces generated by said first SMA actuator due to temperature; and a second SMA-actuated valve including second sealing means for closing and opening said second port, bidirectional SMA actuation means for controlling the position of said second seal to vary fluid flow from the user device through said second port and into the vent, and second temperature compensation means for negating contraction forces generated by said second SMA actuator due to temperature.
- SMA”
Specification