Method and means for isolating equipment from shock loads

• US 5,402,317 A
• Filed: 12/29/1993
• Issued: 03/28/1995
• Est. Priority Date: 12/29/1993
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Rydberg, Allan
• Primary Examiner(s): LEDYNH, BOT L
• Application Number:
  US08/174,926
• Time in Patent Office: 454 Days
• Field of Search: 361/785-789, 361/613, 361/676, 361/677, 361/687, 361/688, 361/689, 361/699, 174/17 LF, 439/59, 439/60-62
• US Class Current: 361/785
• CPC Class Codes: F16F 15/023 using fluid means

Abstract

The current invention is a method and apparatus for shock mounting an obj in a container. A container is provided having side walls to accommodate movement of the object. The container is filled with a fluid having substantially the same density as the object to be shock mounted. The object is mounted in the container by a plurality of shock mounts. In accordance with the apparatus, a container is provided with an incompressible fluid therein. The object to be shock mounted is immersed in the fluid and suspended at an equilibrium position in the fluid filled container. The object can be a circuit board or some other similarly delicate device.

Claims

1. An apparatus for providing shock load isolation comprising:

a circuit board of predetermined overall volume and weight having a predetermined density;

a container for said circuit board having inside dimensions which accommodate limited movement of said circuit board;

an incompressible liquid inside said container, said liquid having substantially the same density as that of said circuit board;

a means for mounting said circuit board in an equilibrium position suspended in said liquid filled container, said means for mounting exerting restoring forces on said circuit board which are very small in comparison to the weight of said circuit board; and

an electrical connection means on the exterior of said container electrically connected to said circuit board.

2. Apparatus according to claim 1 wherein said container is completely sealed to prevent leakage of said liquid.

3. Apparatus according to claim 1 wherein said connection means is connected to said circuit board by a cable extending from the circuit board to a connector.

4. Apparatus according to claim 1 wherein said incompressible liquid is a dielectric fluid.

5. A method of shock mounting a circuit board comprising the steps of:

providing a container structure for the circuit board;

providing said container structure with side walls that define an internal space to accommodate limited movement of said circuit board within said container structure;

filling said defined internal space with a liquid having a density such that buoyant forces on said circuit board balance the weight forces, thereby minimizing inertial forces caused by acceleration of said circuit board; and

mounting said circuit board in said container structure by means that exerts restoring forces on said circuit board within said container structure, said restoring forces being very small compared to the weight of the circuit board;

said mounting step serving primarily to locate said circuit board in an equilibrium position where said circuit board is spaced from the side walls of said container structure in the absence of inertial forces;

providing a connector on the exterior of said container structure; and

connecting said connector to said circuit board electrically.

6. The method of claim 5 wherein said liquid is a dielectric.