Roller brake system

Claim 1

A roller brake system including at least one roller brake assembly mounted to structure, said roller brake assembly being comprised of: a roller; a roller shaft connected to said roller; means for retaining said roller shaft at a predetermined orientation and distance from structure including means allowing limited movement of said roller shaft in a direction generally perpendicular to said shaft; a brake pad member between said roller and structure, said member having a surface for frictionally engaging said roller on a first side thereof, said member being sealably attached to structure on a second side opposite said first side thereof to define a chamber therebetween, said member biasing said roller away from said chamber; a source of pressurized medium; means to communicate the pressurized medium into said chamber whereby the flow of pressurized medium into said chamber deforms said brake pad member into frictional engagement with said roller, said communication means including valve means for controlling flow of medium into said chamber, said valve means having a portion positioned to contact said second side to allow flow through said valve means into said chamber when a load on said roller is overcoming said brake pad member bias and release valve means to allow flow of pressurized medium from said chamber when the pressure of said medium is higher on the chamber side thereof than on the opposite side thereof; means for controllably communicating said source of pressurized medium to said valve means including an electrically actuated pressure regulator valve, said regulator valve communicating medium to said valve means at a predetermined pressure when activated, a tank for storing pressurized medium, and a check valve for preventing flow of pressurized medium from said tank toward said source.