Abstract: This invention provides an improvement in a no-back device having a ball screw connected to a variable load of reversible polarity (±L) and having a portion penetrating a housing. The device includes a braking mechanism acting between the housing and the ball screw for producing a force that resists movement of the ball screw in the direction of an “aiding” load, but does not substantially resist movement of the ball screw in the direction of an “opposing” load. The improvement broadly includes: a first spring acting between the housing and the braking mechanism for exerting a first preload force (F1) on the braking mechanism for simulating the application of an external load on the ball screw in one of the directions; whereby the apparent operational integrity of the no-back device may be checked when no external load is applied to the ball screw.

Abstract: An apparatus for axial support and shock suppression of a pipe includes a walking beam having an inner portion secured to the pipe and an outer portion. The inner and outer portions of the walking beam are pivotally interconnected above an axis extending through the centerline of the pipe. A pair of support members are pivotally connected to the outer portion of the walking beam on opposite sides of the pipe so that longitudinal loads to the pipe are reacted without effecting a bending moment in the pipe. In the preferred embodiment, a rigid strut and a yieldable snubber device comprise the support members.