Patent GB-978167-A (GB)
Title: Improvements in or relating to cable spacers for multiconductor, electrical, overhead transmission lines
Inventor: HOROVITZ MARCUS
IPC: H02G7/12
Filed: 1962-05-18
Abstract: 978,167. Cable spacers. METALASTIK Ltd May 1, 1963 [May 18, 1962], No. 19352/62. Heading H2C. A cable spacer for at least three conductors of a multi-conductor overhead transmission line comprises a clamp for each conductor with spacing members, struts and ties connected to one another and to the clamps to maintain the geometrical shape of the spacer whilst permitting limited relative longitudinal movement between the conductors in a direction normal to the plane of the spacer. As shown in Fig. 1, spacing members 115 are arranged in a square with the clamps 117 at each corner carrying conductors 110, 111, 112, 113, two of the clamps being attached to a diagonal link 141. Each clamp comprises parts 118, 119 hinged at 122 and having an eye bolt 123 to draw the clamp jaws together and grip a conductor. The parts 118 of the clamp have perpendicular lugs 120 connected to forked arms of the spacing members 115 by hinge joints 128 comprising cylindrical rubber bushes 129 tight-fitted between the bores in the lugs 120 and inner metal sleeves 130 which are tight-fitted on bolts 127 and are non- rotatable. These bushes damp low amplitude vibrations and wind movements. The bushes 129 may be bonded to the lugs 120 or to the sleeves 130 and are disposed with their cylindrical axes normal to the direction of the conductors so as to permit angular movement of the clamps relative to the links 115 by torsional deformation in the bushes. Link 141 is connected to lugs 140 by similar hinge joints 145 and acts as both a strut and a tie. In a further embodiment (Fig. 2, not shown) instead of the single diagonal link 141, the spacer is crossbraced in both diagonal directions by a pair of flexible wire ties connected to a central connecting block. For five conductors the spacing members each form a side of a pentagon and five ties radiate from a central block, or a pair of ties are connected at one end to a common clamp and at the other end each to one of the pair of clamps opposite. As shown in Fig. 3, a central cross-piece 160 is provided having four lugs 161, the outer ends of the radiating arms 164 being rigidly connected to the clamps 117. Alternatively, the arms 164 may be connected to the clamps 117 by further hinge joints and also either (1) the spacing members 115 may be replaced by wire or other flexible ties or (11) two opposite spacing members 115 may be removed (Fig. 5, not shown). To provide more universal movement the bolt 127 may carry a spherical member enclosed in a rubber layer which is compressed by three axially separated members carried in a bore in the lug, or by the lug itself, which is then formed in two cupshaped ports. Instead of hinge joints of rubber the following may be used: (1) metal ball joints, (ii) plain metal hinges, (iii) flexible spacing members, i.e. composed of wire cable directly connected to the clamps, or (iv) metal spring elements connected to the spacing members and to the clamps. Alternatively, the clamps may be lined with rubber sleeves which grip the conductors and provide the necessary limited longitudinal movement. Specification 944,522 is referred to. Reference has been directed by the Comptroller to Specification 788,076.