and raise pieces of the plate 1 34 3 is an substantially upper opened channel bar type sleeve like member both side plates 3 39 3 39 of which are formed respectively into a wedge like plate after the fashion of the plates 1 39 1 39 and have respectively a slightly inturned upper edge 4 when in use the member 1 may as well known in fig1 be assembled with member 3 in such a manner as held in the latter from below in the use of the inturned edges 4 4 in longitudinally relatively movable and vertically spaced relation for clamping a cable a between the bottom plates of the two members 5 is a shim of an oblong thin plate formed with a slit 5 39 along one side of the longitudinal eges thereof this slit 5 39 has a rather larger size than the contour of the cross section of the lower portion of the side plate 3 39 so that the shim may be in a loose fit to the plate 3 39 in a little spaced relation to fit in the side plate 3 39 to the shim it may be fitted in from.