Patent GB-529391-A (GB)
Title: Improvements in or relating to flights of steps produced from mouldable building materials
IPC: E04F11/18
Filed: 1939-05-16
Abstract: 529,391. Stairs or steps. PFEIFER, L. H. May 16, 1939, No. 14643. Convention date, May 16, 1938. [Class 20 (iv)] [Also in Group V] A flight of steps is built up of step bodies each consisting of integral tread and riser portions 1. 3 moulded from "artificial stone" and provided with two reinforcing bars 4, 5 cast in the riser and a third reinforcing bar 6 in the rear end of the tread, the arrangement being such that the riser of one step body is supported above the rear end of the tread of the step body next below it, and a clamping bar 7 is secured over the projecting ends of the vertically-aligned bars 4, 5, 6 of the two bodies and pressed against the end faces thereof by nuts screwed on to the ends of the bars. A mortar joint may be provided between the adjacent step bodies to fill any gap therebetween. The bars 7 may serve as balaster-rail posts. The underside of the treads may be lined, the lining being fixed in position by loops 6<SP>1</SP> which are looped around the bars 6 during moulding of the bodies. The bodies may be of a mixture of pumice, wood dust, quartz, and cement or gypsum, and a steel-netting reinforcement may be provided. The risers may be provided with apertures 3<SP>1</SP>, and a nosing bar 2' may be embedded at the edge of the tread. For winding staircases, the bodies may be wedgeshaped in plan. The Specification as open to inspection under Sect. 91 describes also a mould for moulding the bodies, comprising an inverted channel-member 8 forming the underside of the bodies, as shown in Fig. 2 (Cancelled), and walls 10, together with channel irons 11, for forming the outer portions of the risers and nosings. Front and rear walls 12 are mounted on rods 13 welded to the walls 10 and the underside of the channel-member 8. To enable two bodies to be cast in the mould, one or a pair of division pieces 14 is supported between the front and rear walls 12 in notches 16 thereof ; if desired, the notches 16 may be formed in separate centreplates in, and adjustable relatively to, the main portions of the walls 12. The rods 4, 5 6 are supported in holes in the front and rear walls, and, to provide for adjusting the positions of the rods 6, a series of holes for supporting such rods may be provided in the adjustable centre-plates. The mould may be pivoted on a horizontal axis mounted in a travelling carriage so that, after casting. it may be inverted into such a position that it is. supported on trestles ; the mould may then be removed by moving it either vertically upwards or downwards. The mould shown in Fig. 8 (Cancelled) comprises a base-frame 24, which may be in the form of a travelling carriage, a detachable frame 25, mounted thereon, and a mould box 26. The frame 25 and mould box 26 are supported on walls 27 which are firmly connected with the frame 24 and reinforced by angle-pieces 28 and ribs 29. At each end of the mould box is pivotally mounted an outer wall 30, which is adapted to mould the nosing and riser portions of the stair bodies. Reinforcing rods 33 for the stair body are supported in openings 34 in the front and rear walls 32, and are clamped in position by nuts screwed on to the projecting ends thereof. The rear face of the riser is moulded by means of a detachable wall 40 which is supported in notches 41 in the front and rear walls 32; the lower end of the wall 40 is connected with a tube 42 which engages the notches 41. Apertures may be cast in the risers, and the form of the riser may be modified by means of cores 39 provided adjacent the wall 30 of the mould. Displaceable filler members 44 are provided for moulding the end edge of the tread of the body. The thickness of the tread may be altered by the insertion of intermediate pieces. After casting, the walls 40 are drawn upwards, the walls 30 are swivelled outwardly, and the box 26, together with the moulded bodies, are then lifted from the base. This subject-matter does not appear. in the Specification as accepted.