Delayed restraint release device for inflatable escape slides

• US 4,567,977 A
• Filed: 05/14/1984
• Issued: 02/04/1986
• Est. Priority Date: 05/14/1984
• Status: Expired due to Term

• Current Assignee: Goodrich Corporation (Rtx Corporation)
• Original Assignee: Goodrich Corporation (Rtx Corporation)
• Inventors: Fisher, John M.
• Primary Examiner(s): Nase, Jeffrey V.
• Application Number:
  US06/610,055
• Time in Patent Office: 631 Days
• Field of Search: 193/25 B, 182/48, 403/341, 403/340, 403/31, 188/317, 188/272, 92/29
• US Class Current: 193/25.00B
• CPC Class Codes: A62B 1/20 by making use of sliding-ropes, sliding-poles or chutes, e.g. hoses, pipes, sliding-grooves, sliding-sheets
• CPC Class Codes: B64D 25/14 Inflatable escape chutes
• CPC Class Codes: Y10T 403/66 Interfitted members with external bridging piece

Abstract

A delayed restraint releaseable device utilized to restrain and controllably release the lower end of an inflating escape slide at a predetermined pressure, orientation and time. The device combines two distinct restraint mechanisms into one combination unit. The primary release is accomplished by means of shear pin or pins located at the first end of the device. Under normal conditions, the release is accomplished by shearing of the pin or pins under the load provided by the tied back inflating slide. The back-up release, in series with the primary release, occurs when the pressure of the reduced load causes a piston within the restraint to move against both a spring and captive fluid. As the piston moves, the fluid transfers through a precise sized orifice in the piston, from one side of the piston to the other. The piston moves eventually to a point at which the interlocking leg of the piston support shaft is released, thus allowing the ends of the mechanism to separate.

Claims

1. In an inflatable emergency evacuation slide having an inboard end and an outboard end, a delayed restraint release device comprising:

strap means having a pair of spaced ends, one of said ends connected to a portion of said slide remote from said inboard end and the other of said ends adapted to be connected to an aircraft from which said evacuation slide is to be deployed,

a separable mechanism coupling said strap means together at a location intermediate said spaced ends to temporarily preclude deployment of said slide,

means to retard separation of said separable mechanism including a housing, a piston within said housing, an aperture in said piston, and a fluid within said housing moveable from one side of said piston to the other side of said piston through said aperture in said piston.

2. The device as set forth in claim 1 wherein said piston includes a piston rod formed of two parts retained together within said housing prior to deployment of the slide but separable upon movement caused by deployment of the slide as said two parts move out of said housing.

3. The device as set forth in claim 1 and further including a coil spring within the housing coupling said housing and said piston to provide further resistance to the movement of said piston within said housing.

4. The device as set forth in claim 1 and further including an additional separable mechanism in series with the first mentioned separable mechanism.

5. The device as set forth in claim 4 wherein said additional separable mechanism includes a bored cylinder and mating lug, said cylinder and said lug being apertured, and a shear pin extending through said apertures in said lug and said cylinder for separation upon receiving a predetermined pressure.

6. The device as set forth in claim 5 and further including a third separable mechanism in parallel with said additional separable mechanism.

7. In an inflatable emergency evacuation slide, a delayed restraint release device comprising:

strap means with spaced ends for coupling a remote portion of evacuation slide to an aircraft to temporarily preclude full deployment of the slide,

a separable mechanism coupling said strap means together at a location intermediate said spaced ends,

means to retard separation of said separable mechanism including a housing, a piston within said housing, an aperture in said piston, said piston including a piston rod formed of two parts retained together by said housing prior to deployment of the slide but separable upon movement caused by deployment of the slide as said two parts move to the exterior of said housing, and a fluid within said housing moveable from one side of piston to the other side through said aperture in said piston, and further including an additional separable mechanism in series with the first mentioned separable mechanism.