Constant rate deployment device
View Patent ↗A spring-based deployment system deploys a mass at a limited velocity. Using techniques common to the art of timepieces, the motion of a gear, like the rotation of a clock's second hand, is controlled to occur at a substantially constant rate. In a preferred embodiment, an escapement is used to limit the amount of motion per unit time, thereby limiting the velocity. During the period of motion, a high-force can be applied to overcome friction and other adverse affects. Because the amount of motion is limited by the escapement, the amount of kinetic energy produced by this high-force is limited, and thus the shock effects introduced when the deployed mass is stopped at its deployed state are limited. An optimized design can by achieved via an appropriate tradeoff between total deployment time and controlled deployment rate.
1. A spacecraft comprising:
at least one object that occupies:
a first space relative to the spacecraft when the spacecraft is launched, and
a second space relative to the spacecraft when the spacecraft is in its operational orbit, and
a deployment system that is configured to effect movement of the at least one object from the first space to the second space;
the deployment system comprising:
a spring that is configured to apply a force to effect the movement of the object from the first space to the second space, and
a regulator that is configured to limit the movement of the object to an average velocity that is substantially independent of the force applied by the spring.
2. The spacecraft system claim 1 , wherein
the regulator includes an escapement that is configured to apply the force to the object as a scries of energy-transfer pulses.
3. The spacecraft system of claim 2 , wherein
the escapement includes a balance that is configured to periodically limit application of the force to the object, thereby providing the series of energy-transfer pulses.
4. The spacecraft system of claim 2 , wherein
the escapenlent includes a pallet that is configured to periodically engage teeth in a gear that is operably coupled to the object, thereby periodically restraining movement of the gear.
5. The spacecraft system of claim 1 , further including
a hinge, operably coupled to the spring and the regulator, that is configured to effect an angular deployment of the object from the first state to the second state.
6. The spacecraft system of claim 1 , further including
a piston, operably coupled to the spring and the regulator, that is configured to effect a linear deployment of the object from the first state to the second state.
7. A method of deploying an object on a spacecraft from a first space relative to the spacecraft to a second space relative to the spacecraft, comprising:
preloading a spring so as store potential energy that can be used to apply a force to the object to effect a movement of the object, and
regulating the movement of the object to an average velocity that is substantially independent of the force applied to the object.
8. The method of claim 7 , wherein
regulating the movement of the object includes
applying the force to the object as a series of energy-transfer pulses.
9. The method of claim 7 , wherein
regulating the movement of the object includes
periodically limiting application of the force to the object to control the average velocity.
10. The method of claim 7 , wherein
regulating the movement of the object includes
engaging teeth in a gear that is operably coupled to the object, thereby restraining movement of the gear.
11. The method of claim 7 , further including
effecting an angular deployment of the object from the first state to the second state.
12. The method of claim 7 , further including
effecting a linear deployment of the object from the first state to the second state.