Abstract: An apparatus for testing the operation of a mechanical snubber having first and second engaged sections, the first section including linear motion input means and the second section including drive means coupled to motion limiting means. A tester housing is coupled to the snubber and has actuator means rotatably supported by the tester housing for engaging the drive means. The actuator means is adapted for engagement by test means for driving the actuator means to drive the drive means for testing the operation of the motion limiting means.

Abstract: A dual mode valve actuator for automatically controlling the operation of a valve comprises a first reversible drive motor and a first planetary drive assembly which operate to move the valve stem axially during a first mode of operation. The actuator further comprises a second drive motor and a second planetary drive assembly which cooperate with the first planetary drive assembly to rotate the valve stem without axial movement during a second mode of operation. A control means is provided to control the operational mode of the actuator.

Abstract: A method and apparatus for testing seismic shock absorbing snubbers in situ. Such snubbers are used in power plants in association with piping that is yieldably attached by way of pipe hangers or supports to the plant building structure. Typically, snubbers are operatively connected between the pipe and the building or other support structure. Such snubbers permit free motion of the pipe in response to slow thermal expansion or contraction of the pipe, but resist or damp rapid motion of the pipe induced by seismic shock or vibration.

Abstract: A mechanical, seismic-shock-absorbing snubber adapted to accept extremely high impact loads that may be imposed upon it by reason of its interposition between heavy, relatively moveable structures. While permitting essentially unrestricted, slow, relative motion between the structures, such as may be caused by thermal effects (e.g., the expansion or contraction of a high pressure steam pipe yieldably attached by way of hangers or supports to a building structure as in a nuclear power plant), the snubber limits both the velocity and acceleration of relative motion between the structures such as might result from violent seismic shock or vibration. The snubber employs, as its damping mechanism, an escapement wheel, which rotates in response to relative movement of the structures between which the snubber is interposed and employs a cooperating, pivoted, pallet member of predetermined effective mass driven by the escapement wheel into oscillation.

Abstract: A valve actuator which is operable alternatively by a motor and manually. The motor is coupled into the drive train for the actuator through a planetary gear device so as to enable rapid actuation of the valve by the motor. The motor is coupled through a special one-way coupling to the sun-gear drive of the planetary assembly which permits the motor to drive the sun gear in either direction upon rotation of the motor but prevents rotation of the sun gear when the motor is arrested. A handwheel is coupled to the ring-gear drive of the planetary assembly through a worm and pinion so that the handwheel may then drive the ring gear under manual operation, but the ring gear is retained against rotation by the worm pinion when the handwheel is idle. The planet-gear drive serves as the normal output of the planetary assembly and is coupled to the valve spindle through a torque-limiting device.

Abstract: A highly effective, multi-purpose mechanical snubber is achieved by providing an elongated, centrally disposed, axially movable rack member controllably engaged with at least one worm, having an axis of rotation substantially parallel to the central axis of the rack member and mounted for rotation about said axis in response to axial translation of the rack member. In one embodiment, the mechanical snubber also incorporates an inertial mass which is rotationally responsive to the rotational movement of the worm. By employing one or two worms and rotationally driving the inertial mass in similar or opposed directions, various alternative vibratory control systems are achieved with the single mechanical snubber construction of this invention.

Abstract: A highly effective, multi-purpose mechanical snubber is achieved by providing an elongated, centrally disposed, axially moveable rack member controllably engaged with at least one worm gear, having an axis of rotation substantially parallel to the central axis of the rack member and mounted for rotation about said axis in response to axial translation of the rack member. In one embodiment, the mechanical snubber also incorporates an inertial mass which is rotationally responsive to the rotational movement of the worm gear. By employing one or two worm gears and rotationally driving the inertial mass in similar or opposed directions, various alternative vibratory control systems are achieved with the single mechanical snubber construction of this invention.