GB390951A - Improvements in frames for cycles and motorcycles - Google Patents

Abstract

390,951. Cycle frames. FRANCIS & BARNETT, Ltd., Lower Ford Street, and FRANCIS, G. I., Inglesby, Gibbet Hill Road, both in Coventry. April 13, 1932, No. 10537. [Class 136 (iii).] In a frame for motor and other cycles of the type comprising a steering-head and front down member formed as a single unit in which the former is supported throughout its entire length by the latter, such unit is made either in two parts divided longitudinally in the plane of the steering axis and permanently connected together, or in solid form, as a casting, stamping, or forging ; the upper rail and upper rear stays, and also the lower rail and lower rear stays may also be made as single units. The head 2 and front down member 3 are made as a single unit, either from one or more sheetmetal blanks or as a solid casting, stamping, or forging. For example, two sheet-metal pressings may be arranged side by side and welded together along their meeting edges, a tubular liner being inserted in the head part and riveted or welded in place. The liner may be rolled from sheet metal, the edges being flanged outwards for welding between the front edges of the pressings. Alternatively, the head and front down member may be made from a single sheet-metal blank folded into a box-like form about a longitudinal centre line, the abutting edges being welded together. When a solid casting, stamping, or forging is employed, the front down member may be of girder section, and the head is made hollow by the use of a core, or is first made solid and then bored. The upper rail 7 and upper back stays 8 are formed as an integral structure, as are also the lower rail 9 and lower rear stays 10, these structures being bolted to the member 3 and braced by a pair of inclined members 12.