Low shock anti-friction release device

A tension release device for retaining a pin subject to a tension force and for selectively releasing the pin, the tension release device comprising:

• an actuator that develops a force at a selected time, based on a phase change of a metal alloy contained in said actuator;
• an anti-friction release mechanism that retains the pin until the selected time, whereupon the anti-friction release mechanism releases the pin in response to the force developed by said actuator;
• and
• a housing in which said anti-friction release mechanism is disposed;
• wherein said anti-friction release mechanism comprises:
• a pawl that is rotatably connected to said housing;
• and
• a shuttle, moveable with respect to said housing and said pawl in response to the force developed by said actuator;
• wherein the pin is retained by said pawl when said pawl is oriented in an initial position, said pawl being engaged with the pin so that the tension force on the pin tends to prevent the pawl from rotating in a first direction, and said pawl being engaged with said shuttle so that said pawl is prevented from rotating in a second direction opposite said first direction.

A spacecraft comprising:

• a main body;
• an appendage attached to a periphery of said main body;
• and
• a tension release device attached to a periphery of said main body, said tension release device initially maintaining said appendage in a folded configuration and releasing said appendage to unfold at a selected time after the spacecraft has been placed into space;
• wherein said tension release device comprises:
• an actuator that develops a force at a selected time, based on a phase change of a metal alloy contained in said actuator, and
• an anti-friction release mechanism that retains the appendage via a pin until the selected time, whereupon the anti-friction release mechanism releases the pin in response to the force developed by said actuator.

A spacecraft comprising:

• a main body;
• an appendage attached to a periphery of said main body;
• and
• a tension release device attached to a periphery of said main body, said tension release device initially maintaining said appendage in a folded configuration and releasing said appendage to unfold at a selected time after the spacecraft has been placed into space;
• wherein said tension release device comprises:
• an actuator that develops a force at a selected time, based on a phase change of a metal alloy contained in said actuator,
• an anti-friction release mechanism that retains the appendage via a pin until the selected time, whereupon the anti-friction release mechanism releases the pin in response to the force developed by said actuator, and
• a housing in which said anti-friction release mechanism is disposed;
• wherein said anti-friction release mechanism comprises:
• a pawl that is rotatably connected to said housing;
• and
• a shuttle, moveable with respect to said housing and said housing and said pawl in response to the force developed by said actuator;
• wherein the pin is retained by said pawl when said pall is oriented in an initial position, said pawl being engaged with the pin so that the tension force on the pin tends to prevent the pawl from rotating in a first direction, and said pawl being engaged with said shuttle so that said pawl is prevented from rotating in a second direction opposite said first direction.

An actuator for providing a linear actuation motion at a selected time, the actuator comprising:

• a cylinder having an end wall,
• a piston disposed inside said cylinder,
• a spring disposed so as to bias said piston to move toward said end wall,
• a mass of metal alloy disposed between said piston and said end wall, and
• a heat source, disposed adjacent said cylinder, for generating heat when energized at the selected time so as to melt said mass of metal alloy and thereby release energy stored in said spring;
• wherein the release of energy stored in said spring moves said piston and provides the linear actuation motion, the linear actuation motion being caused solely by said spring.

A tension release device for retaining a pin subject to a tension force and for selectively releasing the pin, the tension release device comprising:

• an actuator that develops a force at a selected time, based on a phase change of a metal alloy contained in said actuator;
• an anti-friction release mechanism that retains the pin until the selected time, whereupon the anti-friction release mechanism releases the pin in response to the force developed by said actuator;
• and
• a housing in which said anti-friction release mechanism is disposed;
• wherein said anti-friction release mechanism comprises:
• a pawl that is rotatably connected to said housing and engaged with the pin in an initial position;
• and
• a shuttle, moveable with respect to said housing and said pawl in response to the force developed by said actuator.

A tension release device for retaining a pin subject to a tension force and for selectively releasing the pin, the tension release device comprising:

• an actuator that develops a force at a selected time, based on a phase change of a metal alloy contained in said actuator;
• and
• an anti-friction release mechanism that retains the pin until the selected time, whereupon the anti-friction release mechanism releases the pin in response to the force developed by said actuator;
• wherein said anti-friction release mechanism comprises:
• a pawl that is engaged with the pin in an initial position;
• and
• a shuttle, in rolling engagement with said pawl and being moveable with respect to said pawl in response to the force developed by said actuator.

A tension release device for retaining a pin subject to a tension force and for selectively releasing the pin, the tension release device comprising:

• an actuator that develops a force at a selected time, based on a phase change of a metal alloy contained in said actuator;
• an anti-friction release mechanism that retains the pin until the selected time, whereupon the anti-friction release mechanism releases the pin in response to the force developed by said actuator;
• and
• a housing in which said anti-friction release mechanism is disposed;
• wherein said anti-friction release mechanism comprises:
• a pawl that is engaged with the pin in an initial position;
• and
• a shuttle, in rolling engagement with both said pawl and said housing, the shuttle being moveable with respect to said housing and said pawl in response to the force developed by said actuator.

A spacecraft comprising:

• a main body;
• an appendage attached to a periphery of said main body;
• and
• a tension release device attached to a periphery of said main body, said tension release device initially maintaining said appendage in a folded configuration and releasing said appendage to unfold at a selected time after the spacecraft has been placed into space;
• wherein said tension release device comprises:
• an actuator that develops a force at a selected time, based on a phase change of a metal alloy contained in said actuator;
• and
• an anti-friction release mechanism that retains the pin until the selected time, whereupon the anti-friction release mechanism releases the pin in response to the force developed by said actuator;
• wherein said anti-friction release mechanism comprises:
• a pawl that is engaged with the pin in an initial position;
• and
• a shuttle, in rolling engagement with said pawl and being moveable with respect to said pawl in response to the force developed by said actuator.