Patent GB-783711-A (GB)
Title: Improvements in or relating to friction linings for clutches, brakes, bearing journals and the like
IPC: F16D69/02
Filed: 1954-11-26
Abstract: A method of improving linings subjected to friction to obtain a virtually constant coefficient of friction, for use in clutches, brakes and bearings, comprises incorporating cupric oxide in the friction surface of the linings.  One or more of the following may also be added: zinc, copper, iron, lead, nickel, cobalt, molybdenum, tungsten, the oxides of iron, lead, zinc, chromium, nickel, cobalt, molybdenum and tungsten, calcined alumina, titanium oxide, brass, carbon black and powdered graphite.  To render the coefficient of friction more independent of temperature changes, a substance having a high coefficient of thermal conductivity, such as calcium fluoride, may be added. The linings, which are of asbestos or like material, may be impregnated or coated with the above substances, or pellets formed of these substances may be embedded in the friction surfaces. To coat the linings, varnishes or glues are employed having, e.g., phenolaldehyde, urea-formaldehyde, cresol or silicone resin bases. One such composition comprises the following constituents in the proportions by weight of:-black cupric oxide, 40-50 per cent; powdered zinc, 5-15 per cent; calcined alumina, 1-6 per cent; phenoplast, to make up to 100 per cent.  Another such composition comprises: black cupric oxide 32-40 per cent; iron oxide, 8-10 per cent; zinc powder, 5-15 per cent; calcined alumina, 1-6 per cent; phenoplast, to make up to 100 per cent.  A third such composition comprises cupric oxide, litharge, powdered chlorinated rubber, benzene and isobutyl alcohol.  Preparations containing the substances for treating the linings by the method of the invention may be sold in two packages of which (a) the first packing contains synthetic resin with a part of the mixture; and (b) the second packing contains the rest of the mixture and an "accelerator" which, when combined with the contents of the first package, causes a hardening of the agglomerated mass by chemical action or polymerization.ALSO:A method of improving linings subjected to friction to obtain a virtually constant coefficient of friction, for use in clutches, brakes and bearings, comprises incorporating cupric oxide in the friction surface of the linings.  One or more of the following may also be added; zinc, copper, iron, lead, nickel, cobalt, molybdenum, tungsten, the oxides of iron, lead, zinc, chromium, nickel, cobalt, molybdenum and tungsten, calcined alumina, titanium oxide, brass, carbon black and powdered graphite.  To render the coefficient of friction more independent of temperature changes, a substance having a high coefficient of thermal conductivity such as calcium fluoride, may be added.  The linings, which are of asbestos or like material, may be impregnated or coated with the above substances, or pellets formed of these substances may be embedded in the friction surfaces. To coat the linings, varnishes or glues are employed having, e.g., phenol-aldehyde, urea-formaldehyde cresol or silicone resin bases. One such composition comprises the following constituents in the proportions by weight of : black cupric oxide, 40-50 per cent; powdered zinc, 5-15 per cent; calcined alumina, 1-6 per cent; phenoplast, to make up to 100 per cent.  Another such composition comprises: black cupric oxide, 32-40 per cent; iron oxide, 8-10 per cent; zinc powder, 5-15 per cent; calcined alumina, 1-6 per cent; phenoplast, to make up to 100 per cent.  A third such composition comprises cupric oxide, litharge, powdered chlorinated rubber, benzene and isobutyl alcohol.  Preparations containing the substances for treating the linings by the method of the invention may be sold in two packages of which (a) the first packing contains synthetic resin with a part of the mixture and (b) the second packing contains the rest of the mixture and an "accelerator" which, when combined with the contents of the first package, causes a hardening of the agglomerated mass by chemical action or polymerization.