Patent GB-719233-A (GB)
Title: Improvements in or relating to beams and like structural elements for use in connection with scaffolding and other temporary supporting structures
Inventor: HAWES ALBERT HENRY
IPC: E04G11/50
Filed: 1951-12-24
Abstract: 719,233. Flexible beams for supporting shutter ing In the construction of curved concretestructurcs; structural beams. KWIKFORM, Ltd. Dec. 22, 1952 [Dec. 24, 1951; March 25, 1952; Sept. 11, 1952], Nos. 30093/51, 7598/52 and 22780/52. Class 20 (2) A flexible beam for use in supporting shuttering for curved concrete structures, e.g. roofs, floors, walls, towers, or for use in supporting temporary structures, e.g. temporary roofs for buildings or in the construction of false work in the building of aircraft and ships, comprises a pair of elongated flexible metal members connected together in spaced opposed relationship, e.g. by channel or V-shaped metal strips, such as to permit relative longitudinal movement between the two members when the beam is bent to different degrees of curvature, means being provided to secure the beam at the particular curvature required. In one form for supporting flexible shuttering plates as described in Specification 668,379; the beam comprises two metal members 30, 31, Fig. 2, each formed of flexible metal strip, the member 30 comprising relatively few sections 32 rigidiy secured end to end and having welded thereto metal strip members 35 of diverging channel form. The extremities 36, Fig. 3, of the members 35 are bent outwardly to overlap each other and are formed with elongated slots. The member 31 is built up from a large number of separate overlapping strips 37 formed with elongated slots adapted to receive bolts 39 to permit relative movement between the strips 37 and each bolt 39 passes through a slot in the base 41 of one of a number of further channel strip members 42, their slotted overlapping extremities 43 overlapping the extremities 36 and each four mutually overlapping extremities are secured by a bolt 45. These slotted connections between the member 31 and the channel strips 42 and between the channel strips 35 and 42 allow the beam to be bent to curved configuration when the bolts 39, 45 are slackened and allow relative movement between the members 30, 31. Tightening of the bolts 39 when the beam is curved, retains the beam in its curved form. For effecting the bending of the beam and for local adjustments in the curvature of the beam. turn buckle struts 71 are pivotally connected end to end by means of lugs 75 secured to the member 31 so that by tightening all the bolts 39, 45 except those adjacent one particular strut and operating on this strut, a local variation in curvature is effected. The beam may be stiffened by a longitudinal member, built up similarly to the member 31 and located medially of the beam by the bolts 45 between the two sets of channel strip members 35, 42. Each end of the beam is rigidly connected to a bracket 51 comprising a pair of spaced metal plates 52 having aligned holes adapted to receive a short tube 50 on which the bracket can pivot and to which a pair of supporting uprights 46 are connected as shown m Fig. 3. To permit the beam to be supported at one or both ends from the top of a wall instead of from a scaffolding structure, each bracket 51 has mounted between its plates 52 a lip carrying member 60 of elongated box form having slotted sides adapted to receive bolts 62, 63, the bolt 62 having a single set of holes 64 in the plates 52 while a number of holes 65, arranged in an arc, are provided for the bolt 63. This arrangement permits a bolt 63 to be inserted through selected holes 65 so that the lip carrying member 60 can be maintained in an approximate horizontal position irrespective of variations in the position of the bracket 51 arising from changes in curvature of the beam. The member 60 can be displaced horizontally relative to the bracket 51 to provide any adjustment in the overall span of the beam. Two beams may be connected end to end in mutually inclined positions of carrying shuttering plates to form a gutter by means of a slotted,member 84, Fig. 9 (not shown) similar to the lip carrying member 60 but without a lip portion'secured to its end. Staging 79, Fig. 1, may be supported from a number of parallelly arranged beams by means of scaffold tubes inserted horizontally through holes 77 in the lugs 75 on the member 31. Shuttering plates 25, Fig. 3, are secured to the member 30 by means of clamps 82 as described in Specification 668,379. Alternatively timber shuttering may be used and secured to the beams by bolts or the beams may support canvas or hessian sheets on which cement or plaster-like material is sprayed to form a curved structure. An alternative form of end bracket for the beam is shown in Fig. 13, the upper end of the bracket carrying a box-like part 90 to which may be pivotally connected a lip member 94. Two beams may be connected end to end by fish plates secured to adjacent parts 90 of the end brackets, the bottoms of the two beams being connected by a short turn-buckle strut. Fig. 15 shows an alternative form of the beam in which the flexible members 30, 31 are connected by a single row of V-shaped metal strips 100, the ends of the beam being closed by apertured channel members 105 to enable beams to be joined end to end by slotted fish plates 109. One end of a connected series of beams is supported by means of a pair of plates 113 carrying a cross tube P16 to which a supporting upright is clamped. No bracing struts are provided, the beam being bent manually to the curvature required and the bolts 104 then tightened to retain the curvature. The beam may also be bent in the opposite direction to that shown in Fig. 15, as is shown in Fig. 18 in the formation of a concrete exterior of a circular tower, the beams in this case being secured to uprights 118 by clamps, 119 and the shuttering plates 25 secured by clamps 124. In further modifications two rows of V-shaped strip members 100, Figs. 20, 21 are provided, all the apices being we'ded to the members 30, 31, the upper half of the beam being relatively movable to the lower half and the lower member 31 comprising overlapping relative movable plates 37, Fig. 20, or a single continuous strip, Fig. 21.