Multi-stage fin deployment assembly

• US 8,324,544 B2
• Filed: 06/02/2010
• Issued: 12/04/2012
• Est. Priority Date: 06/02/2010
• Status: Expired due to Fees

• Current Assignee: Woodward HRT Incorporated (Woodward Incorporated)
• Original Assignee: Woodward HRT Incorporated (Woodward Incorporated)
• Inventors: Palani, Kumaraguru Poonamalli, Burt, Raymond Lee
• Primary Examiner(s): Collins, Timothy D
• Assistant Examiner(s): Stehle, Jamie S
• Application Number:
  US12/792,159
• Publication Number:
  US 20120175460A1
• Time in Patent Office: 916 Days
• Field of Search: 244/3.24, 244/3.27, 244/3.28, 244/3.29, 244/49
• US Class Current: 244/3.24
• CPC Class Codes: F42B 10/14 using fins spread or deployed after launch, e.g. after leaving the barrel

Abstract

A multi-stage fin deployment assembly includes a rotary actuator configured to release a first spring-loaded stage that, when deployed, releases a second spring-loaded stage to deploy a set of deployable member or fins. By chaining these spring-loaded stages together, a relatively small input force, as provided by the rotary actuator, causes the second spring-loaded stage to generate a relatively large output force on the fins. This multistage force magnification makes it possible for the deployment assembly to utilize smaller actuators that require less power and take up less space, compared to conventional locking mechanisms.

Claims

1. A guidable projectile, comprising:

a guidable projectile frame having a support structure;

a set of fins, each fin being pivotally attached to the guidable projectile frame; and

a deployment assembly to deploy a set of fins relative to the guidable projectile frame, the deployment assembly including;

an actuator supported by the support structure, the actuator being constructed and arranged to provide an actuator force;

a first spring-loaded stage supported by the support structure and in operative communication with the actuator, the first spring-loaded stage being constructed and arranged to provide a first spring-loaded output force to a fin restraining element in response to the actuator force from the actuator to move the fin restraining element from a locked position to an unlocked position relative to the set of fins; and

a second spring-loaded stage supported by the support structure and in operative communication with the first spring-loaded stage, the second spring-loaded stage being constructed and arranged to provide a second spring-loaded output force in response to the first spring-loaded output force from the first spring-loaded stage, the second spring-loaded output force being applied to the set of fins to move the set of fins from an initial non-deployed configuration relative to the support structure to a subsequent deployed configuration relative to the support structure.

2. A guidable projectile as in claim 1, wherein the first spring-loaded stage includes:

a drive element in operative communication with the fin restraining element and with the second spring-loaded stage,

a lock/release spring in contact with a base portion and with the drive element, and

a ball lock/release mechanism coupled to the drive element, the ball lock/release mechanism being constructed and arranged to (i) initially reside in a locked state in which the lock/release spring is compressed along a common axis between the base portion and the fin restraining element, and (ii) transition from the locked state to an unlocked state in which the lock/release spring decompresses along the common axis to move the drive element linearly relative to the base portion.

3. A guidable projectile as in claim 2, wherein the actuator includes a rotary solenoid having a stator supported by the guidable projectile frame, and a rotor in operative communication with the ball lock/release mechanism of the first spring-loaded stage;

wherein the rotary solenoid is constructed and arranged to rotate the rotor about the common axis when the actuator provides the actuator force to transition the ball lock/release mechanism from the locked state to the unlocked state.

4. A guidable projectile as in claim 3, wherein the second spring-loaded stage includes:

a deployment element,

a deployment spring in contact with a load bearing portion and the deployment element, and

a deployment shuttle carried by the deployment element and in operative communication with the set of fins, the deployment shuttle being constructed and arranged to (i) initially reside in a first state in which the deployment spring is compressed along the common axis between the load bearing portion and the deployment element, and (ii) transition from the first state to a second state in which the deployment spring decompresses along the common axis to move the deployment element linearly relative to the load bearing portion.

5. A guidable projectile as in claim 4, wherein the drive element of the first spring-loaded stage is constructed and arranged to linearly displace the fin restraining element along the common axis when the first spring-loaded stage provides the first spring-loaded output force in response to the actuator force from the actuator, displacement of the fin restraining element along the common axis transitioning the deployment shuttle from the first state to the second state.

6. A guidable projectile as in claim 5, wherein each fin is pivotally attached to the guidable projectile frame;

and

wherein decompression of the deployment spring and movement of the deployment shuttle along the common axis pivots each fin from a non-deployed position to a deployed position relative to the guidable projectile frame.

7. A guidable projectile as in claim 5, wherein the lock/release spring of the first spring-loaded stage has a first spring constant (k1);

wherein the deployment spring of the second spring-loaded stage has a second spring constant (k2); and

wherein second spring constant (k2) exceeds the first spring constant (k1) by at least a factor of ten (10) to provide a multi-stage force magnification effect on the set of fins during deployment.

8. A guidable projectile as in claim 5, wherein the set of fins includes at least two fins;

and

wherein, during deployment, movement of the deployment shuttle along the common axis pivots each fin in a respective radially outward direction relative to the common axis.

9. A guidable projectile as in claim 5, wherein the guidable projectile frame defines a hollow core to contain and protect the lock/release spring of the first spring-loaded stage and the deployment spring of the second spring-loaded stage.

21. The guidable projectile as in claim 1, wherein the fin restraining element includes a set of fingers, each finger of the set of fingers configured to engage a corresponding groove in each fin of the set of fins.

10. A deployment assembly to deploy a set of deployable members relative to a support structure, comprising:

an actuator supported by the support structure, the actuator being constructed and arranged to provide an actuator force;

a first spring-loaded stage supported by the support structure and in operative communication with the actuator, the first spring-loaded stage being constructed and arranged to provide a first spring-loaded output force to a deployable member restraining element in response to the actuator force from the actuator to move the deployable member restraining element from a locked position to an unlocked position relative to the set of deployable members; and

a second spring-loaded stage supported by the support structure and in operative communication with the first spring-loaded stage, the second spring-loaded stage being constructed and arranged to provide a second spring-loaded output force in response to the first spring-loaded output force from the first spring-loaded stage, the second spring-loaded output force being applied to the set of deployable members to move the set of deployable members from an initial non-deployed configuration relative to the support structure to a subsequent deployed configuration relative to the support structure.

11. A deployment assembly as in claim 10, wherein the first spring-loaded stage includes:

a drive element in operative communication with the deployable member restraining element and with the second spring-loaded stage,

a lock/release spring in contact with a base portion and with the drive element, and

a ball lock/release mechanism coupled to the drive element, the ball lock/release mechanism being constructed and arranged to (i) initially reside in a locked state in which the lock/release spring is compressed along a common axis between the base portion and the fin restraining element, and (ii) transition from the locked state to an unlocked state in which the lock/release spring decompresses along the common axis to move the drive element linearly relative to the base portion.

12. A deployment assembly as in claim 11, wherein the actuator includes a rotary solenoid having a stator supported by the support structure, and a rotor in operative communication with the ball lock/release mechanism of the first spring-loaded stage;

wherein the rotary solenoid is constructed and arranged to rotate the rotor about the common axis when the actuator provides the actuator force to transition the ball lock/release mechanism from the locked state to the unlocked state.

13. A deployment assembly as in claim 12, wherein the second spring-loaded stage includes:

a deployment element,

a deployment spring in contact with a load bearing portion and the deployment element, and

a deployment shuttle carried by the deployment element and in operative communication with the set of deployable members, the deployment shuttle being constructed and arranged to (i) initially reside in a first state in which the deployment spring is compressed along the common axis between the load bearing portion and the deployment element, and (ii) transition from the first state to a second state in which the deployment spring decompresses along the common axis to move the deployment element linearly relative to the load bearing portion.

14. A deployment assembly as in claim 13, wherein the drive element of the first spring-loaded stage is constructed and arranged to linearly displace the deployable member restraining element along the common axis when the first spring-loaded stage provides the first spring-loaded output force in response to the actuator force from the actuator, displacement of the deployable member restraining element along the common axis transitioning the deployment shuttle from the first state to the second state.

15. A deployment assembly as in claim 14, wherein the support structure is a guidable projectile frame;

wherein the set of deployable members includes a set of fins, each fin being pivotally attached to the guidable projectile frame; and

wherein decompression of the deployment spring and movement of the deployment shuttle along the common axis pivots each fin from a non-deployed position to a deployed position relative to the guidable projectile frame.

16. A deployment assembly as in claim 14, wherein the lock/release spring of the first spring-loaded stage has a first spring constant (k1);

wherein the deployment spring of the second spring-loaded stage has a second spring constant (k2); and

wherein second spring constant (k2) exceeds the first spring constant (k1) by at least a factor of ten (10) to provide a multi-stage force magnification effect on the set of deployable members during deployment.

17. A deployment assembly as in claim 14, wherein the set of deployable members includes at least two fins;

and

wherein, during deployment, movement of the deployment shuttle along the common axis pivots each fin in a respective radially outward direction relative to the common axis.

18. A deployment assembly as in claim 14, wherein the support structure defines a hollow core to contain and protect the lock/release spring of the first spring-loaded stage and the deployment spring of the second spring-loaded stage.

22. The deployment assembly as in claim 10, wherein the deployable member restraining element includes a set of fingers, each finger of the set of fingers configured to engage a groove in each member of the set of deployable members.

19. A method of deploying a set of fins relative to a guidable projectile frame, the method comprising:

placing a first spring-loaded stage in a locked state in which a lock/release spring of the first spring-loaded stage is compressed along a common axis defined by the guidable projectile frame, the first spring-loaded stage being in operative communication with an actuator supported by the guidable projectile frame;

placing a second spring-loaded stage in a locked state in which a deployment spring of the second spring-loaded stage is compressed along the common axis, the second spring-loaded stage being in operative communication with the first spring-loaded stage and the set of fins; and

providing an actuator force from the actuator to the first spring-loaded stage to transition the first spring-loaded stage including a deployable member restraining element from the locked state to an unlocked state relative to the set of fins in which the lock/release spring decompresses along the common axis, transitioning of the first spring loaded stage from the locked state to the unlocked state moving the second spring-loaded stage from the locked state to an unlocked state in which the deployment spring decompresses along the common axis to move the set of fins from an initial non-deployed configuration relative to the guidable projectile frame to a subsequent deployed configuration relative to the guidable projectile frame.

20. A method as in claim 19, wherein the lock/release spring of the first spring-loaded stage has a first spring constant (k1);

wherein the deployment spring of the second spring-loaded stage has a second spring constant (k2); and

wherein second spring constant (k2) exceeds the first spring constant (k1) by at least a factor of ten (10) to provide a multi-stage force magnification effect on the set of fins during deployment.

23. The method as in claim 19, wherein transitioning of the first spring-loaded stage from the locked state to the unlocked state, further includes:

disengaging a finger of a set of fingers of the first spring-loaded stage from a corresponding groove in each fin of the set of fins.