Abstract: A circular plate with a plurality of apertures therein surrounds a vertical upright member used in constructing a scaffolding. An end of either a horizontal or diagonal spacer member is joined to the upright by a tapered wedge which is passed through the aperture. A wedge support member is secured to the end of the spacer and comprises a pair of parallel legs which straddle the plate. Each of the legs has a slot therein to allow passage of the wedge. A U-shaped tooth depends from the upper leg and is shaped to conform to the perimeter of the aperture in the plate. Both the tooth and the aperture are tapered so that as the wedge is driven into the aperture, the tooth is forced into engagement with the perimeter of the aperture. Engagement between the tooth and the aperture prevents lateral movement of the spacer relative to the upright.

Abstract: A method for the in situ repair of heat exchanger tubes in major heat exchanger equipment is disclosed in which supercooled sleeves are inserted into cracked heat exchanger tubes and are expansion-fitted firmly against the inner walls of the cracked tubes. In order to prevent premature expansion of the relatively long, small diameter sleeves during insertion, the tubes may be filled with a heat sink material which is removed following insertion. The insertion is also preferably accomplished very rapidly by means of a power-actuated ram which maintains the sleeve at its low temperature until the very last moment before insertion. Various guide means and plug means for the sleeve are described. The technology is also indicated as being applicable to the temporary sealing of defective tubes by using a removable plug in the form of a closed-end sleeve into whose interior a cryogenic agent can be selectively introduced during insertion and removal.

Abstract: A connector for use in builder's scaffolding systems for connecting crossmembers to upright members where the upright members have sockets provided thereon and each of the sockets has an internal clamping face. The connector is coupled to one end of the crossmember. It has an upper and a lower limb spaced apart for receiving the socket therebetween. A generally trapezoidal opening having four sides, two of which are non-parallel, is provided in the two limbs. In engaging the connector, two of the four sides form first and second clamping sides. A wedge coupling member is received within the trapezoidal opening and mounted for clamping engagement with the internal clamping face of the socket and selected portions of the first and second clamping sides. The trapezoidal opening permits connection of the crossmember at a plurality of angles to the upright within the range permitted by the first and second clamping sides.