Abstract: A shock shutoff valve, especially for earthquake zones, has a valve body with a normally vertical flow bore therein controlled by a plug rotatable within the valve body. A portion of the flow bore in the plug is so movable between an open position and a closed position. A pedestal in the flow bore is adjacent a seat around the plug portion of the flow bore. A ball resting on the pedestal can be dislodged by shock to move from the pedestal and roll into the seat and so block the flow bore. The seat and the ball are of mutually attracting magnetic materials effective to urge the ball and the seat together not under normal conditions but when the valve body has been displaced and the flow bore is inclined to the vertical.

Abstract: In an aircraft multiple disc brake assembly, an excessive total brake torque can be experienced during favorable, dry, conditions. To limit the brake torque to a predetermined maximum, the plurality of conventional brake piston assemblies are modified to provide a pressure responsive surface area which is in an opposing relationship to the braking force. When a predetermined amount of braking torque is experienced, conventional electronics employing strain gauge sensors control a solenoid valve to vent pressurized brake fluid to the opposing surface area thereby reducing the braking force and limiting the total braking torque experienced by the brake assembly to a predetermined maximum amount. The brake pressure is not affected by this system.

Abstract: For use in an earthquake-prone environment, and especially as a gas valve, there is provided a valve body approximately symmetrical about a longitudinal axis and having a transverse intersecting plug bore through the body. A plug is rotatable in the bore to turn a passage through the plug from a position communicating with inlet and outlet ports into a position out of communication therewith. The plug bore merges with a valve seat in one position of the plug substantially coinciding with a plane forming a boundary of a chamber in the plug and normal to the usually vertical longitudinal axis. In one position of the plug, that plane is also coincident with a table forming part of the chamber boundary. There is a chamber wall upstanding from the table and having a distance from a pedestal upstanding from the table that increases as the wall approaches the plug. Also on the plug is a plug wall that extends around much of the valve seat and is in effect a continuation of the chamber wall.