Patent GB-524139-A (GB)
Title: Improvements in wooden frame trusses of buildings
IPC: E04C3/42
Filed: 1938-10-03
Abstract: 524,139. Building trusses. CHRISTOPH & UNMACK AKT.-GES., and SAHLBERG, W. Oct. 3, 1938, No. 28643. [Class 20 (iv)] A frame truss for buildings comprises upright and cross-members each built up to a box or I- cross-section from continuous webs in the form of plywood plates and " flanges " of rectangular timber members, and the joint between the upright and cross-members is formed by glueing a plywood joint-plate in recesses provided in the flanges of the said members. The various parts are glued together. The truss frame shown in Figs. 2, 5 and 8 is of box cross-section throughout. The upright comprises two timber flanges 20, 21 with a plywood plate 42 glued on each side ; the cross-member comprises timber flanges 29, 30 with a plywood plate 43 glued on each side. At the intersection between the upright and crossmember, the flanges 20, 29 are tenon-jointed, the flange 21 is tenon-jointed at its upper end to the flange 29, and the flange 30 is extended to the inner side of the flange 20. The space at the corner is filled in with timber pieces 33 ... 36 which are glued together and to the flanges, bolts 37 also being used. Prior to the application of the plywood plates 42, 43, the sides of the flanges 20, 21 from their upper ends to the line 39, Fig. 8, and the corresponding surfaces at the ends of the flanges 29, are recessed to receive plywood joint-plates 41 which are secured by glue. The outer flanges 20, 29 of the upright and cross-members project beyond the web plates 42, 43 and are provided with two longitudinal grooves for securing the wall and roof plates. Wood sill and cornice members 27, 28 are also provided. The flanges 20, 21 are connected at their lower ends by glued wedges 22 and dowels 23 and are secured to a bearer 26 by a cranked metal member 24. A timber member 28 is glued between the flanges 20, 21 intermediate their ends. The truss shown in Figs. 9 and 11 is of I-shape. the upright consisting of timber flanges 96, 97 glued on the edges of a plywood web 95, and the cross-member consists of timber flanges 102, 103 glued on to a plywood web 112. The web plate 95 extends up to the line 98 and the flanges 96, 97 extend up to the diagonal joint line where they meet timber members 100, 101 which constitute extensions of the flanges 102, 103 and are glued on to a plywood web 99 which abuts at its lower end portion the web plate 95. A plywood joint-plate 105 is provided at the corner on each side of the abutting web plates 95, 99, being glued in position and extending beyond the inner corner which is reinforced by timbers 107, 108. The corner is stiffened at each side by a diagonal clamp 109 which extends beyond the outer edge of the corner and is bolted to an upright 110. At the joint line 104 between the cross-member and the extension, the timbers 100 ... 103 have tapered ends to provide wedgeshaped spaces where they meet to receive gluedin wedges 111, and the joint between the two web plates 99, 112 is bridged over on each side by wood plates 113, 114 which are bolted in position. The truss shown in Figs. 14, 16 and 17 is of box form comprising plywood webs and flanges of spaced rectangular timbers. The flanges 200, 210 of the upright truss extend up to the upper flanges 240 of the cross-member, and the lower flanges 250 of the cross-member extend towards the upright flanges 200. Plywood plates 270, 280, 290 are glued on the outside of the flanges and plywood web plates 220, 260 are glued between the flanges to form the boxsection. At the corner, stiffening members 200a are glued on to the inner faces at the outer flanges 200 and filling members 200b are glued between adjacent flanges 200 and adjacent stiffening members 200a; similarly stiffening and filling members 210a are glued on the inner flange 210. The upper and lower flanges 240, 250 of the cross-member are also provided at the corner with glued-on stiffening and filling members 240a, 250a. Inclined supporting flanges 310 are provided between the flanges 210, 250 and provided with a glued-on covering plate 320. The web plates 220. 260 end respectively at the lines 230, 300 and between these lines a plywood web plate 330 is glued on at the both sides of the flanges of the upright and cross-member, the joints at the lines 230, 300 being strengthened by filling timbers 340 and recessed cover-plates. In. the interior of the corner one or more plywood joint-plates 370 are glued into recesses in the inner surfaces of the timbers of the upright and cross-member.