Mechanical locking device for electrical equipment

Claim 1

A mechanical locking device including a rotatable stem-shaped locking member for latching together a first part having a locking opening therein and a second part, by cooperation of said locking member with said opening during a rotation of said locking member, wherein said locking member is shaped so as to be able to be pushed axially through a resilient locking hole in said second part and so as to be thereafter unable to move axially either in a forward or rearward direction, wherein said first part is a rack for mounting electrical equipment and provided with said opening and with guiding means and that said second part comprises a printed circuit board with parallel edges slidably mounted in said guiding means and a supporting element and is provided with said locking hole, said supporting element carrying said locking member, and wherein said resilient hole in said supporting element is delimited by an annular recess prolonged by a resilient split frusto-conical sleeve comprising a plurality of resilient lips and that said locking member has a first collar fitting in said annular recess and a frusto-conical second collar, said split sleeve and said second collar being so shaped that when said locking member is inserted into said hole until said first collar is engaged in said annular recess, said second collar spreads out said resilient lips of said split sleeve until these lips snap behind said second collar.