GB935033A - Improvements in or relating to methods of manufacturing rubber-to-metal bonded components - Google Patents

Abstract

935,033. Universal joints. METALASTIK Ltd. July 20, 1961 [Aug. 9, 1960], No. 27625/60. Class 80 (2). [Also in Group XXXII] A method of making a rubber-to-metal bonded article comprises using a fusible metal member to form a core defining a working space for the rubber and/or to space apart metal or rubber or metal and rubber parts of the article during the rubber-to-metal bonding operation and then melting out the fusible metal member, the melting-point of the fusible member being higher than the temperature reached by the article during the moulding operation and not sufficiently high as to cause damage to the rubber, or to the rubber-to-metal bond, when it is melted out. In making a universal coupling the two plates, Fig. 2, forming an annular disc 10 are brought together with a gasket-like fusible metal ring 18 interposed between each pair of corresponding part-spherical, cup-like portions 15, 16 and rod-like inner members 12, with part-spherical protuberances 13, are located centrally within the assembled cup-like portions. Unvulcanized rubber, forced into the space between each protuberance 13 and its enclosing cup-like portions 15, 16, is then cured causing the moulded rubber to bond to the protuberances 13 and the cup-like portions 15, 16. The rings 18 are then melted out and the two annular plates are forced together to pre-compress the rubber, the plates being secured, e.g. by welding, around their inner and outer edges. Instead of having separate rings 18 a single gasket-like insert of fusible metal may be used having four apertures corresponding with the openings of the rings 18. Precompression may be accomplished partly by the take-up of space previously occupied by the fusible member 18 and partly by expanding the inner members 12. In making a flexible coupling, Fig. 3, two frustoconical rings 30, 31 of rubber are moulded between a metal interleafing 32 carried by a driving, or driven, flange 33 of the coupling, an outer cup-like portion 34 of a coupling sleeve 35, and an inner cup-like portion 36 which can be bolted to the sleeve 35, an annular fusible metal member 40 spacing the parts 34, 36. After the fusible member 40 has been melted out the part 36 is drawn up to-the part 39 and is secured by studs introduced into tapped holes 38, the rubber rings 30, 31 being compressed. To define the outer face 44 of the ring 30 a core of fusible metal 40 may be used. In a modification the cup-like portions 32, 34, 36 may be convergent away from the coupling sleeve 35, a thinner fusible member being used and the portions 34, 36 being finally forced apart to compress the rings 30, 31 and to enlarge the working space for the rubber. The fusible member is advantageously made of an alloy of lead and tin.