US 5,964,322 AGranted

Elevator safety brake having a plasma sprayed friction coating

AssigneeOtis Elevator Company

InventorsMark S. Thompson, Raymond Zatorski, James T. Beals, Philip H. McCluskey, David W. McKee, Michael C. Lang, Fred J. Lussier, Dat T. Nguyen, Paul Bennett

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Abstract

An elevator safety brake for stopping an elevator car is provided with a brake shoe having a fused sprayed friction coating for contacting an elevator guide rail surface to provide a stopping force. In a preferred embodiment, the coating is obtained by plasma spraying an admixture of 85 weight percent nickel-chromium alloy particles and 15 weight percent tungsten carbide particles on a substrate. The plasma sprayed admixture is fused. The fused sprayed friction surface of the brake exhibits a consistent high friction and low wear suitably accommodating high speed, high load elevators installed in very tall buildings.

Claims12

Dependent claims

An elevator safety brake for stopping an elevator car, the brake comprising:

a brake shoe having a base and further having a rail contacting friction surface attached to the base for contacting an elevator guide rail surface, wherein at least a portion of the rail contacting friction surface comprises a coating obtained by providing an admixture of nickel alloy particles and particles containing a hard, inert material selected from the group consisting of metal oxides, metal carbides and metal nitrides, spraying the admixture onto the base and fusing the sprayed admixture;
and
means for pressing the rail contacting friction material of the brake shoe against the guide rail surface to stop the elevator car.

Dependencies are inferred from the claim text.