Cam activated circuit card clamp

Abstract

A cam activated circuit card clamp is provided. The circuit card clamp is comprised of a base member (204), a leverage arm (412), and a cam activation shaft (422). The circuit card clamp is also comprised of one or more cams (410-1, 410-2, 410-3, 410-4), one or more ramp members (308-1, 308-2, 308-3, 308-4), and one or more wedge members (418-1, 418-2, 418-3, 418-4). The cam activation shaft is coupled to the leverage arm. The cams are in contact with the cam activation shaft which has one or more compression springs disposed thereon. The cams are adapted to pivot about a pivot shaft when actuated. The cams also have a surface adapted to engage an adjacent wedge member when actuated. Each ramp member has an inclined surface adapted to deflect an adjacent wedge member when the adjacent wedge member is compressed against the ramp member. Each wedge member has a surface adapted to engage an adjacent cam. Each wedge member also has an inclined surface adapted to slidingly engage an adjacent ramp member when compressed together. A method for applying a clamping force to a circuit card is also provided.

Description

BACKGROUND OF THE INVENTION [0001] 1. Statement of the Technical Field [0002] The invention concerns clamping mechanisms, and more particularly, clamping mechanisms for fastening printed circuit boards or printed circuit cards to chassis. [0003] 2. Description of the Related Art [0004] Traditionally, circuit card clamps have been used for fastening circuit cards within a slot of a chassis such as a heat exchanger, heat sink, or cold plate. For example, U.S. Pat. No. 4,775,260 to Kecmer and U.S. Pat. No. 5,071,013 to Peterson describe circuit card clamps consisting of a threaded rod with wedge-shaped bodies disposed thereon. A circuit card clamp coupled to a circuit card can be inserted into a chassis slot. Subsequently, the threaded rod can be rotated with a tool (i.e., torque wrench) in order to shorten the length of the circuit card clamp. By shortening the circuit card clamp, the wedge-shaped bodies are compressed thereby creating an increase in the circuit card clamp's width. As...

AI Technical Summary

Benefits of technology

[0009] The invention concerns a method for applying a clamping force to a circuit card for purposes of securing the circuit card to a chassis. The method includes rotatably mounting one or more cams to a base member. The cams are linearly spaced apart along the base member in a direction parallel to a first direction. A first end of each cam rotates about a pivot point by applying a force to a second end of the cams. The force is aligned with the first direction and is applied to the second end of the cam using an elongated cam activation shaft having one or more compression springs disposed thereon. The compression springs are positioned along the cam activat

Problems solved by technology

Ultimately, the clamping device and the thermal performance of the circuit card clamp's architecture are limited by the size of the threaded rod.

This circuit card clamp assembly similarly suffers from drawbacks.

For example, the clamping device is limited by the quantities and the strength of the beveled washers which create the clamping force.

This limitation typically results in an insufficient clamping force exerted by the circuit card clamp for adequately fastening a circuit card to a chassis to prevent loosening of a circuit card.

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