265,977. Fraigneux E., (Assignees of Laviolette, .4. F.). Feb. 9, 1926, [Convention date]. Wire and like compensators for double-wire transmission for operating railway signals &c. comprises two pulleys J<1> carried by a nut E slidable along a rotatable screw B mounted between centres C. The nut is prevanted from rotafion by trunnions G working between guides H. The pulleys have bearings K engaging in the slotted branches of a bifurcated lever L embracing the supporting frame A, one end of the lever having a counterpoise weight, not shown, and the other being connected by cardan joint to a support. Each wire passes over a pair of pulleys J and under the corresponding intermediately pulley J<1>. Normally the nut E and pulleys J<1> are movable under the action of the counterpoise, but when a pull is exerted the unequal tension in the two wires tends to tilt the nut and locks it on the screw so that the pull is transmitted without lost motion. The screw may be vertical or horizontal and may have a brake, not shown.