Entering and securing of plug-in circuit module - using entry guide and captive pull-up and clamping screw

摘要

A typical application is to mounting circuit modules in telecommunications equipment. In such installations the space available for mounting plug in components is usually very limited, which can make insertion and withdrawal difficult. The module (1) is initially entered by hand into the stationary receptacle (2) by constructing the latter to give a lead in. The module is pushed in until the fastending screw (4) makes contact with the end (3) of the corresponding tapped hole. The screw has a head which is in a slot in the module This slot makes the screw captive and at the same time allows some axial movement. The axial movement is such that when the screw first engages with the threads in the hole several turns have to be completed before the under side of the head bears against the face of the slot. Further turning then pulls the module home and makes the electrical connections (5,6,7,8). To disengage the module the process is reversed.