Patent GB-599157-A (GB)
Title: Resilient joints or mountings and method of making same
IPC: B25B27/28
Filed: 1945-07-09
Abstract: In the assembly of a resilient mounting (see Group XXXII) of the kind comprising inner and outer rigid tubular members separated by a separately vulcanized annulus of rubber like material under radial compression and longitudinal extension, the engaging surfaces of the rigid element and annulus are treated to reduce friction and then after assembly to cause adhesion without removing strain in the annulus.  Friction is reduced by any suitable hardening treatment of the rubber such as by immersion into sulphur chloride, anhydrous hydrochloric acid, a solution of sulphuric acid, a solution of a halogen such as chorine, as described in U.S.A. Specification 1,928,988, a solution of an oxidising agent or by a coating of a hard drying composition such as a solution or dispersion of a thermoplastic or thermosetting resin.  A suitable lubricant may also be used, but should be completely absorbed in the rubber annulus.  If the annulus is composed of a natural rubber compound or of a copolymer of butadiene and styrene rubber compound, petrolatum or mineral oil may be used as lubricant.  For copolymers of butadiene acrylonitride types of rubber compounds suitable plasticizers such as oleic acid or other higher fatty acids may be used.  Other generally suitable lubricants include high boiling esters or oily plasticizers rubber cements, solutions of rubbery polymer &c. Treatment for adhesion comprises the application of a resinous film to the engaging surfaces of the rubber annulus and rigid elements and may comprise as a basic constituent one or more natural or synthetic resins such as the hard setting organo-silicones, thermoplastic and thermosetting resins including vinyl esters such as polyvinyl chloride, copolymer of vinyl chloride and vinyl acetate, the polyacrylate resins including polymethyl methacrylate, and esters and amides of acrylic and chloracrylic acids, rubber addition products such as rubber chloride, polyvinyl acetal resins including polyvinyl butyral, phenol aldehyde and modified aldehyde resins including polyvinyl butyral, modified phenol formaldehyde resins, rubber modified phenolic resins, the condensation products such as the polyhydric alcohol esters of unsaturated esters of unsaturated acids and copolymers of these materials with esters of polybasic saturated or unsaturated acids with unsaturated alcohols such as diallyl maleate &c.  The resin may be an organic rubber to metal adhesive which may include cyclized rubber derivatives of rubber conversion products such as the reaction products of rubber and amphoteric metal halides, isomerization products of rubber prepared by heating rubber in the presence of sulphuric or organic sulphonic acids, such as phenol sulfonic acids, including paratoluene sulphonic acid and various salts of strong acids, modified rubber hydrochloride, rubber chloride &c.  Preferred rubber to metal adhesives are those described in Specification 595,009 and prepared by heating a mixture of rubber and a salt of a strong acid and a salt of a weak acid in a form having thin section to obtain an exothermic reaction product.  After assembly of the mounting the engaging surfaces are subjected to heat by the passage of an electric current, high frequency electric field, of magnetic flux.  Specification 461,478 also is referred to.