in engagement with second catch 9 as will be explained the assembly further comprises a bias mechanism 20 see fig7 for biasing drawer 1 to move at least partially out of housing 3 upon a press of push button 5 under a condition that the drawer is not blocked from moving outwardly as seen in fig7 bias mechanism 20 may comprise a compression spring 21 mounted upon a cylindrical guide rod 23 positioned in housing 3 behind inserted drawer 1 guide rod 23 is mounted so as to allow limited axial movement of the rod forwardly and rearwardly a rearward end of spring 21 abuts against an oppositely facing seat 24 provided at an upper rearward part of housing 3 the forward end of spring 21 is seated on a forward enlarged diameter portion of rod 23 such that spring 21 biases rod 23 axially outwardly to a position that places a forward end of guide rod 23 in contact with a rear push surface 25 of drawer 1 when the drawer is fully advanced within the housing this contact upon full advancement of the drawer into the housing also displaces rod 23 rearwardly against the bias of compression spring 21 so as to preload the spring to bias rod 23 and hence drawer 1 outwardly as a.