Fusible member connection apparatus and method

• US 5,695,306 A
• Filed: 05/08/1996
• Issued: 12/09/1997
• Est. Priority Date: 05/08/1996
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Nygren, William D. Jr.
• Primary Examiner(s): Wilson, Neill R.
• Application Number:
  US08/646,588
• Time in Patent Office: 580 Days
• Field of Search: 411/19, 411/267, 411/270, 411/432, 411/433, 411/434, 411/909, 29/426.4
• US Class Current: 411/433
• CPC Class Codes: B64G 1/641 Interstage or payload connectors docking systems B64G1/646
• CPC Class Codes: B64G 1/645 Separators
• CPC Class Codes: B64G 1/6459 Fluid-actuated
• CPC Class Codes: F15B 15/19 Pyrotechnical actuators
• CPC Class Codes: F15B 15/261 using positive interengagement, e.g. balls and grooves, for locking in the end positions
• CPC Class Codes: F16B 31/007 Break-bolts loosening at high temperature
• CPC Class Codes: Y10T 29/49821 by altering or destroying work part or connector

Abstract

A connection apparatus utilizes a structural element made of fusible material supported directly in the connection load path of the device. A carrier mechanism is axially translatably supported in the device and utilizes a connecting member to connect two desired structures. The connection mechanism engages and holds the connecting member in a first axial position. In one embodiment, the connection mechanism releases the connecting member when translated to a second axial position. In another embodiment the connection mechanism tensions the connection when translated to the a second axial position. The fusible member is heated to transition from solid to liquid. In the liquid state, the fusible member no longer opposed axial load on the carrier mechanism. The fusible alloy comprises a low melting temperature alloy, such as bismuth-lead or bismuth-tin.

Claims

1. A connection apparatus comprising:

a housing;

a carrier mechanism translatably supported by said housing between an original axial position and a subsequent axial position relative to said housing responsive to an axial load on said carrier mechanism;

means for latching a connecting member to said carrier mechanism;

means for applying an axial load to said carrier mechanism;

a fusible material member capable of transitioning between solid to liquid responsive to thermal change, said fusible material member in said solid state supported in said housing in a manner to oppose said axial load thereby maintaining said carrier mechanism is said original axial position; and

heating means for transitioning said fusible material from solid to liquid;

whereby, when said fusible member is transitioned to liquid, said carrier mechanism is free to translate from said original axial position to said subsequent axial position responsive to said axial load.

2. An apparatus, as claimed in claim 1, wherein said latch means releases said connecting member from said carrier mechanism in said subsequent axial position of said carrier mechanism.

3. An apparatus, as claimed in claim 1, wherein said fusible material comprises an alloy having a melting temperature below 200 degrees centigrade.

4. An apparatus, as claimed in claim 1, wherein said fusible material comprises an alloy of bismuth and lead.

5. An apparatus, as claimed in claim 1, wherein said fusible material comprises an alloy of bismuth and tin.

6. An apparatus, as claimed in claim 1, wherein said carrier mechanism includes:

a piston seated in a piston cylinder; and

a positive stop to limit the stroke of said piston.

7. An apparatus, as claimed in claim 6, further including a chamber for receiving the liquid fusible material, and wherein said positive stop defines a plurality of narrow through passages in fluid communication with said chamber.

8. An apparatus, as claimed in claim 6, further including spring means cooperating with said piston for urging said piston stroke.

9. An apparatus, as claimed in claim 8, wherein said spring means urges the piston to stroke in a direction opposite to the structure to which the apparatus is connected.

10. An apparatus, as claimed in claim 6, wherein:

said piston comprises a material having a first selected coefficient of thermal expansion;

said piston cylinder comprises a material having a second selected coefficient of thermal expansion greater than said first selected coefficient of thermal expansion;

whereby

said piston cylinder, when heated, radially expands relative to said piston providing an annular gap between said piston and said piston cylinder.

11. An apparatus, as claimed in claim 10, wherein said piston is sized to interference fit with said piston cylinder prior to said radial expansion of said piston cylinder.

12. An apparatus, as claimed in claim 1, further including:

a control gate supported by said housing in a first orientation obstructing disengagement between said connecting member and said latch means with said carrier mechanism in said original axial position.

13. An apparatus, as claimed in claim 12, wherein:

said control gate is moveable to a second orientation not obstructing disengagement between said connecting member and said latch means with said carrier mechanism is said original axial position.

14. A connection apparatus comprising:

a connecting member;

a piston cylinder;

a piston translatably seated within said piston cylinder responsive to an axial force;

a structural member comprised of an alloy capable of transitioning from solid to a liquid when heated and transitioning back to solid when cooled, said structural member in said solid state supported in piston cylinder to oppose said axial force and maintain said piston in an original axial position relative to said piston cylinder;

latch means for engaging said connecting member to said piston cylinder; and

heating means for heating and transitioning said structural member.

15. An apparatus, as claimed in claim 14, wherein:

said piston cylinder and said piston have two dissimilar thermal coefficients of expansion so that said piston cylinder when heated radially expands relative to said piston to form at least one radial gap therebetween through which said liquid alloy may flow.

16. An apparatus, as claimed in claim 14, further comprising a chamber for receiving the liquid alloy of said structural member when transitioned, wherein said piston cylinder includes a ledge providing a positive stop to limit the stroke of said piston and said ledge defines a plurality of narrow channels in fluid communication with said chamber through which said liquid alloy may flow.

17. An apparatus, as claimed in claim 14, wherein said connecting member includes a ball shaped end and said latch means includes a ball socket adapted to seat said ball shaped end.

18. An apparatus, as claimed in claim 14, wherein said connecting member includes a threaded end and said latch means includes a plurality of threaded jaws retained by a radial spring and transversely translatable into and out of engagement with the threaded connecting member.

19. A method of connecting comprising the steps of:

translatably supporting a carrier mechanism to a housing between an original axial position relative to the housing and a subsequent axial position spaced from the odginal axial position;

engaging a connecting member to the carrier mechanism;

providing a fusible material member capable of transitioning from solid to liquid in response to thermal change;

supporting the fusible material member in the housing in its solid state to oppose axial load on the carrier mechanism to maintain the carrier mechanism in the original axial position;

applying an axial load to the carrier mechanism to translate the carrier mechanism to the subsequent axial position;

heating the fusible material to transition it from solid to liquid; and

providing at least one chamber to receive said liquid material forced to flow in response to the axial load;

the carrier mechanism thus becoming free to translate from the original axial position to the subsequent axial position responsive to the axial load.

20. A method of connecting, as claimed in claim 19, comprising the further step of:

releasing the engagement of the connecting member with the carrier mechanism during the translation of the carrier mechanism from the original axial position to the subsequent axial position.

21. A method of connecting, as claimed in claim 19, comprising the further step of:

tensioning the engagement of the connecting member with the apparatus during the translation of the carrier mechanism from the original axial position to the subsequent axial position.