| 摘要 |
1,164,299. Moulding ring members; thermosetting laminate. HENRY CROSSLEY (PACKINGS) Ltd. 12 Oct., 1967 [25 Oct., 1966], No. 47844/66. Headings B5A and B5N. [Also in Division F3] A projectile driving band which fragments and is discarded from a projectile as the projectile leaves the muzzle of a gun is made by impregnating a length of fibrous material with a thermosetting resin, dipping the impregnated material in an inert filler, cutting the impregnated and dipped material into strips, superposing the strips in a mould and bonding them together by pressure, e.g., of 1 ton per square inch without complete curing of the thermosetting resin, forming the laminated structure into narrow wedges by punching or cutting, loading the wedges in a circular die so that the planes of the laminates are radially disposed, and applying heat and pressure, the temperature preferably being 320‹ F. and the pressure 3 tons per square inch, so as to bond the wedges together to form a rigid moulding. The fibrous material may be woven asbestos cloth, jute, woven cotton cloth, hessian or glass cloth and may incorporate small amounts of metallic strands, e.g., of copper. The resin may be a phenol resin such as cresol formaldehyde or phenol formaldehyde. The inert filler may be P.T.F.E. which is coated on to the strips before the partial bonding or an ebonite solution consisting of "Hycar" (Registered Trade Mark), butyraldehyde/aniline complex, zinc oxide, light calcined magnesia, red iron oxide, dibutyl phthalate and carbon black made up as a solution in toluol and ethylene dichloride. The solution may incorporate P.T.F.E. powder. To increase the fragmentation effect of the band the wedges may be warmed and dipped into P.T.F.E. powder prior to moulding and bonding. |
