Improvements in or relating to transistor mounting arrangements

895,558. Transistors. STANDARD TELEPHONES & CABLES Ltd. Oct. 2, 1959 [Oct. 9, 1958], No. 32212/58. Class 37. A transistor casing flanged at one end is inserted into a hole smaller than the flange in a support-member until the flange is adjacent one side of the hole, and is then retained in position by a spring member of good heat conductivity with an outer diameter greater than that of the hole placed to grip the part of the casing projecting on the other side of the hole. In one embodiment (Fig. 3) the transistor casing 8 is pushed through a compressed helical spring 7 which when released firmly grips the casing. As an alternative the casing 11 is mounted within a spiral spring 10 (Fig. 4) of slightly smaller internal diameter. In Fig. 6 is shown a composite arrangement comprising a printed circuit applied to the back of a cover-plate 13 through which project split tubes 17 mounted on a common heat sink plate 16. Transistors 20 are inserted into the split tubes the closed ends of which are pressed against the heat sink plate by helical springs 18.