GB597523A - Improvements in and relating to brush contact devices for rotatable radio aerials - Google Patents

Abstract

597,523. Collectors. SJOSTRAND, H. E. April 26, 1945, No. 10545. [A Specification was laid open to inspection under Sect. 91 of the Acts, Oct. 13; 1945.] [Class 38 (i)] The brush of a slip-ring brush contact, suitable for rotatable aerials, is freely mounted so that the angular position of the brush relatively to the slip-ring is wholly determined by the contact surfaces. The brush or slipring is made of a precious metal, e.g, silver, or an alloy of precious metal. In the form shown in Fig. 1, a disc-shaped brush 2 held in a metal holder 3 is mounted universally on the cupshaped end of a spring support 5 which maintains the brush in contact with a plane slip-ring 1. The contact surface of the brush has a central recess so that a steady brush pressure is maintained. In a modification, Fig. 4 (not shown), the brush is of annular shape and the holder has a cup-shaped depression extending into the brush in which the end of the support 5 rests. In a further modification, Fig. 5, the brush 15 is urged into contact with a cylindrical slip-ring 14 by a spring plunger 18 engaging a ball-shaped projection 17 on the brush holder. Alternatively, a rectangular brush may be used which is slidable in a rectangular hole in a stationary support. The brush may be made of soft graphite. Where a graphite brush and metal holder are employed, the two may be joined by a suitable amalgam or the holder may be silvered on the interior and pressed and crimped on to the brush. The brush may be fixed to the holder galvanically.