Fire fighting system

• US 3,924,688 A
• Filed: 04/05/1974
• Issued: 12/09/1975
• Est. Priority Date: 04/05/1974
• Status: Expired due to Term

• Current Assignee: G&H Techniology Incorporated
• Original Assignee: Earl A. Cooper, Roger C. Stephenson
• Inventors: Cooper, Earl A., Stephenson, Roger C.
• Primary Examiner(s): King, Lloyd L.
• Assistant Examiner(s): Mar, Michael
• Application Number:
  US05/458,221
• Time in Patent Office: 613 Days
• Field of Search: 169/19,56,59,60,61,11 337/1 74/2
• US Class Current: 169/61
• CPC Class Codes: A62C 37/40 with electric connection between sensor and actuator

Abstract

A fire control system is disclosed herein having a plurality of hot wire electromechanical activators for non-explosive initiation of a corresponding plurality of fire extinguishers. The activators may be connected either in parallel for increased reliability or in series for increased ease in testing for continuity. Each activator has a split collet formed of two spool halves with a restraining wire wrapped around it having a hook at one end attached to a hot wire which is connected to electrical leads mounted on one of the spool halves. A shaft contacts the split collet in such a manner so as to cause the spool halves to separate when not restrained by the restraining wire. Displacement of the shaft is obtained by applying an actuation current to the leads which reduces the tensile strength of the hot wire until it falls below the tensile stress applied by the restraining wire. When the hot wire fails in tension, the restraining wire is released to thereby permit the spool halves to separate to permit the shaft to be displaced by an internal spring or external force. The shaft is connected either directly to a utilization device such as a fire extinguisher for displacement thereof in a direction parallel to the centerline of the shaft or through a cylinder having fingers for displacement at an angle to the centerline of the shaft.

Claims

1. An electromechanical mechanism for a non-explosive initiation of an actuator, said mechanism including:

a plurality of separable spool sections secured together and formed to have a recess therebetween, a pair of electrical terminals on one of said sections, wrapping means wrapped around said plurality of spool sections for applying circumferential tension thereto to maintain said sections together, a securing portion formed on said wrapping means, an electrically conductive element engaged by said securing portion, said electrically conductive element being connected to said terminal, a movable member disposed at one end in said recess, a utilization device coupled to said movable member whereby the movement of said utilization device and said movable member are restrained by the application of circumferential tension by said wrapping means to said plurality of separable spool sections, and a source of electrical current coupled to said electrically conductive element, said electrically conductive element having a tension greater than said circumferential tension applied by said securing means to said plurality of separable members at ambient temperatures, said tension of said electrically conductive element being less than said circumferential tension when said tension element is heated up by current applied by said source of electrical current, whereby the application of current by said source of electrical current disengages said securing means from said electrically conductive tension element to enable said movable member to initiate actuation of Said utilization device.

2. An electromechanical mechanism for a non-explosive initiation of an actuator, said mechanism including:

a plurality of separable spool sections secured together and formed to have a recess therebetween, wrapping means wrapped around said plurality of spool sections for applying circumferential tension thereto to maintain said sections together, a securing portion formed on said wrapping means, an electrically conductive element engaged by said securing portion, a movable member disposed at one end in said recess, a utilization device coupled to said movable member whereby the movement of said utilization device and said movable member are restrained by the application of circumferential tension by said wrapping means to said plurality of separable spool sections, a source of electrical current coupled to said electrically conductive element, said electrically conductive element having a tension greater than said circumferential tension applied by said securing means to said plurality of separable members at ambient temperatures, said tension of said electrically conductive element being less than said circumferential tension when said tension element is heated up by current applied by said source of electrical current, whereby the application of current by said source of electrical current disengages said securing means from said electrically conductive tension element to enable said movable member to initiate actuation of said utilization device, and a cylinder having fingers for engaging said movable member at the end opposite to the end movably disposed in said recess for displacement of said cylinder at an angle to the centerline of said movable member when said movable member is displaced.

3. The mechanism of claim 2 wherein said securing portion is a bent portion which is secured to said tension element and is hooked thereon.

4. The mechanism as described in claim 2 including a housing for enclosing said actuator mechanism, a spring mounted in said housing, a shaft in said housing, and a shoulder on said shaft for engaging said spring to effect displacement of said shaft when said electrically conductive tension element disengages said securing portion.

5. The mechanism as described in claim 2 wherein at least one of said plurality of separable spool sections has a tapered surface and said movable member has at least one tapered surface for mating with said tapered surface of said one of said plurality of separable spool sections.

6. A non-explosive fire extinguisher actuator comprising:

a sensing element for sensing a fire, a pair of members, a tapered surface on the first of said members, a movable element, a tapered surface on said element for engaging the tapered surface on said first member, a wire wrapped around said pair of members for applying circumferential tension stress to said members to retain them together, a securing portion on said wire, a hot wire responsive to said sensing element and engaged by said securing portion, said hot wire having a tensile strength greater than the tensile stress of said wrapped wire at ambient temperatures, said hot wire having a tensile strength less than the tensile stress of said wrapped wire at an elevated temperature, a source of fire extinguishing substance responsive to the displacement of said movable element, whereby the sensing by said sensing element of a fire activates the actuator by elevating the temperature of said hot wire to reduce the tensile strength thereof below the tensile stress of said wrapping wire to enable displacement of said shaft to initiate operation of said source of fire extinguishing substance, and said source of fire extinguishing substance includes a throat through which said substance is transferred and a butterfly valve mounted in said throat for engaging said shaft.

7. The actuator of claim 6 and including a pair of terminals mounted on one of said pair of members, said hot wire is coupled to said terminals, and an electrical current source coupled to said terminals by a pair of electrical leads.

8. The actuator of claim 6 wherein said securing portion is a hooked portion which is hooked on to said hot wire.

9. The actuator of claim 6 wherein said means for applying axial force is a spring and said shaft is formed with a shoulder for engaging said spring.

10. An actuator including the combination of sensing means, a plurality of members, securing means for retaining said members together and having a latching extension thereon, wire means responsive to said sensing means and secured to said latching extension, said wire means having a tensile strength greater than the tensile stress exerted thereon by said latching extension at ambient temperature, said wire means having a tensile strength less than the tension stress exerted thereon by said latching extension at an elevated temperature, said securing means including a wire wrapped around said plurality of members and having a thickness greater than the thickness of said wire means, and a utilization device positioned to engage said plurality of members and operative to be displaced when the temperature of said wire means is elevated by said sensing means.

11. The actuator of claim 10 wherein said plurality of members includes a split collet having a pair of spool members at least one of which has a relieved portion for engaging said utilization device.

12. The actuator of claim 10 wherein said utilization device includes a movable member having a tapered surface for engaging said relieved portion of said one of said spool members.

13. The actuator of claim 10 wherein one of said spool members includes a pair of electrical terminals and said wire means is connected between said pair of electrical terminals.

14. An actuator system comprising:

a plurality of hot-wire actuators, control means to which each of said plurality of hot-wires is responsive, a second plurality of sensors for sensing a predetermined condition and each connected to said control means, whereby the sensing by at least one of said sensors of said predetermined condition initiates actuation of at least one of said plurality of hot-wire actuators, and testing means in said control means for testing said plurality of hot-wire actuators simultaneously.

15. The system as described in claim 14 including lamp means in said testing means for signaling continuity of each of said hot-wire actuators,

16. The system as described in claim 14 including means connecting said plurality of hot wires in series, and means in said testing means for applying an electrical current to said plurality of hot wire actuators.

17. The system as described in claim 14 including a lamp in said testing means for signaling continuity of each of said hot-wire actuators.