Patent GB-190800610-A (GB)
Title: Improvements in Appliances for use in Building Chimneys and the like.
Inventor: WEIGHTMAN WILLIAM THOMAS
Filed: 1908-01-10
Granted: 1908-07-30
Abstract: 610. Weightman, W. T. Jan. 10. [Application for Patent of Addition to No. 3185, A.D. 1904.] No Patent granted (Sealing fee not paid). Scafolding.-Relates to the chimney scaffolding described in Specification No. 3185, A.D. 1904. In this scaffolding, the upper and lower frames are alternately clamped to and unclamped from the chimney, and are alternately raised and lowered so that the scaffolding is made to move step by step up or down the chimney. The object of this invention is to arrange the clamps and lifting-apparatus so that the scaffolding can be worked by two men instead of four. The upper and lower frames each comprise two oppositely-arranged girders a, and two beams b at right-angles to the girders. The girders and beams are connected together at the four corners by shoes c. Parallel with each girder a is a shaft d, Figs. 2, 3, and 4, which has right and left handed screw-threads. Each threaded end of the shaft works in a nut e formed on the shoe. A toothed wheel d' on the shaft d meshes with another wheel f<1> slidingly mounted on the shaft f, which has at each end a bevel-wheel g meshing with another bevel-wheel i, which for the lower frame is fixed on a sleeve h<4>, Fig. 3. The ends of the shaft h work in nuts h<1> mounted in the shoes c. The nut h' has an extended portion h', over which the sleeve h<4> is placed. The bevel-wheel i is held in gear with the wheel g by the engagement of a spring catch i<1> on the sleeve h<4> with grooves h<3> in the nut extension h<2>, the catch itself being held in engagement by a slip-ring i<3>. By throwing the bevel-wheels i, g into gear and rotating the sleeve, the nut h' and shaft f are rotated. The shaft h being unable to rotate, the nut h<1> and shoe c move along the shaft h, and at the same time the shoe also moves along the shaft f, so that the shoes become released from the chimney sides. For the upper frame, the bevel-wheel i is mounted as a rotating nut on the screwed shaft h, the sleeve h<4> and nut h' being dispensed with, and by rotating either the shaft d or shaft f, the corner shoes are moved to unclamp or clamp against the chimney sides, as desired. The upper frame is connected to the lower frame by rods k, pivoted on the shoes of the lower frame and working through sockets l supported in bearings pivotally mounted on the upper shoes c. Each socket l is threaded to mesh with screw-threads on the corresponding rod k, and carries a bevel-wheel n, which meshes with a pinion o on a shaft actuated by a rope-wheel q. A rope q<1> passes over two of these wheels on the same side of the chimney, and thence by intermediate guidepulleys r to the lower platform, or to the ground. When the scaffolding is to be raised, the lower frame is first loosened about the chimney, and the rope-wheels q are rotated to raise the lower frame, which is then clamped about the chimney. The upper frame is then loosened and the pulleys q are rotated in the opposite direction, whereby the upper frame is raised and is then clamped about the chimney. When the appliance is used for circular or polygonal chimneys, brackets are employed, each comprising two arms u, v, Fig. 6, between which are secured the shoes c. A third arm w serves to support the bracket. The arms are connected to a member s bearing against the chimney by ball-and-socket joints, and a roller x serves to facilitate the upward movement of each bracket when raising the frames.