with screw, worm, or the like, not self-locking but normally prevented from rotation by friction members which slip upon excessive pressure

Props; Chocks > Telescopic props > with parts held together by positive means, with or without relative sliding movement when the prop is subject to excessive pressure > with axial screw-and-nut, rack-and-worm, or like mechanism > with screw, worm, or the like not self-locking but normally prevented from rotation by friction members which slip upon excessive pressure

Props (in the building art E04G25/00); Chocks > Telescopic props (general means for fixing telescopic parts together ) > with parts held together by positive means, with or without relative sliding movement when the prop is subject to excessive pressure > with axial screw-and-nut, rack-and-worm, or like mechanism > with screw, worm, or the like, not self-locking but normally prevented from rotation by friction members which slip upon excessive pressure