US 5,326,948 AGranted

Apparatus for equipment unit protection switching

AssigneeAT&T Bell Laboratories

InventorsRobert C. Brockway, Philip S. Dietz, Lo C. Nguyen

Life of this patent

Estimating the term…

Loading patent…

Abstract

An equipment unit protection switch from an in-service equipment unit to a standby equipment unit is realized prior to any movement of the active equipment unit about to be removed from an equipment frame in which it is inserted. This is achieved by advantageously incorporating apparatus for generating an equipment unit removal indication signal that enables a controller to anticipate the removal of the equipment unit from the equipment frame. To this end, the equipment units employ an equipment unit latch and an associated switch to generate the equipment removal indication signal. Initial movement of the latch causes the equipment unit removal indication signal to be generated prior to any movement of the equipment unit in the frame in which it is inserted.

Claims22

Dependent claims

Apparatus for use in effecting an equipment unit protection switch from an equipment unit being removed from an equipment frame in which it is intended to be inserted to a standby equipment unit, the equipment unit including a circuit board intended to be inserted in a connector in the equipment frame and a latch pivotally mounted on said circuit board at a pivot point for securing the equipment unit in the equipment frame, the apparatus being CHARACTERIZED BY,

said latch having a first lever arm and a second lever arm, the first lever arm extending from the pivot point in a first direction and the second lever arm extending from the pivot point in a second direction, the first lever arm being used for application of a first force for causing rotational movement of the latch about the pivot point, the second lever arm having a cam out surface for applying a force toward removal of the circuit board from the connector in the equipment frame when the circuit board is fully inserted in the connector and when the first force is applied to the first lever arm in a direction toward removing the circuit board from the connector, the cam out surface being arranged such as to allow initial movement of the first lever arm from a closed position prior to applying the second force toward removing the circuit board from the equipment frame so that the first lever arm of the latch is allowed to move freely prior to the cam out surface applying the second force toward removing the circuit board from the connector in the equipment frame,
light responsive switch means associated with said latch and being responsive to said initial movement of said latch for generating an equipment unit removal indicated signal for initiating the equipment unit protection switch prior to any movement of said circuit board in its connector, and
means responsive to said equipment unit removal indication signal for effecting the protection switch.

A system for effecting an equipment unit protection switch including at least a first equipment unit intended to be an active equipment unit and at least a second equipment unit intended to be a standby equipment unit, each of said equipment units intended to be inserted in an equipment frame, and each of said equipment units including a circuit board intended to be inserted in a connector in the equipment frame and a latch pivotally mounted on said circuit board at a pivot point for securing the equipment unit in the equipment frame, the system being CHARACTERIZED BY,

said latch in each of said equipment units having a first lever arm and a second lever arm, the first lever arm extending from the pivot point in a first direction and the second lever arm extending from the pivot point in a second direction, the first lever arm being used for application of a first force for causing rotational movement of the latch about the pivot point, the second lever arm having a cam out surface for applying a force toward removal of the circuit board from the connector in the equipment frame when the circuit board is fully inserted in the connector and when the first force is applied to the first lever arm in a direction toward removing the circuit board from the connector, the cam out surface being arranged such as to allow initial movement of the first lever arm from a closed position prior to applying the second force toward removing the circuit board from the equipment frame so that the first lever arm of the latch is allowed to move freely prior to the cam out surface applying the second force toward removing the corresponding circuit board from the connector in the equipment frame,
light responsive switch means in each of said equipment units associated with said latch and being responsive to initial movement of said latch for generating an equipment unit removal indication signal for initiating the equipment unit protection switch prior to any movement of said circuit board in the corresponding equipment unit in its connector, and
means responsive to said equipment unit removal indication signal for effecting a protection switch from the active equipment unit being removed to said standby equipment unit.

Dependencies are inferred from the claim text.