Patent GB-798113-A (GB)
Title: Improvements in apparatus and method for making ribbed bands
IPC: B29D29/08
Filed: 1956-04-30
Abstract: 798,113. Laminates. UNITED STATES RUBBER CO. April 30, 1956 [July 5, 1955], No. 13178/56. Class 140. [Also in Group XXIV] A band having opposite parallel edges and uniformly spaced parallel ribs, such as rubber teeth, extending perpendicular to the edges, is made by securing a sheet of material to the surface of the drum, winding a strip of rib material, such as rubber tooth stock, on to the sheet in a helical path at a pitch equal to the pitch required for the ribs of the band, securing the strip to the sheet material and cutting the composite material along a line perpendicular to the helical path of the rib material. The sheet material may be surfaced with natural or synthetic rubber and may have a tacky surface or it may be a weftless, rubberized fabric with warp threads extending parallel to the axis of the drum. It may be wound on to the drum with a helical pitch equal to that required for the ribs. The drum may have several grooves out in it at right-angles to the various pitches of helix, which grooves form guides for the cutting tools used for cutting the material perpendicular to the ribs. As shown in Fig. 5, grooves A<SP>1</SP>, A<SP>2</SP> and A<SP>3</SP> are parallel to each other and are such that when the sheet material is wrapped as shown cutting along these grooves cuts out the overlapped portion and divides the material into two equal strips. B and C represent grooves perpendicular to other pitches of helix. The band may be formed into a positive drive belt by wrapping it round a mould having axially extending grooves, causing the ends to overlap and be adhered together and vulcanizing. A sheet of rubber-faced material 12 (Figs. 1-3) is wound with its rubber face outward on to cylinder 11 (C<SP>1</SP> Fig. 5) rotatably mounted through stub shafts 30 and 31 in bearings 32 and 33 in frames 34 and 34<SP>1</SP>. The cylinder is driven by motor 35 through sprocket 36, chain 38, sprocket 37 and stub shaft 30. Strip 13 is fed to the drum from reel 39, supported on turntable 40 which is carried by carriage 41 and is movable along the axis of the drum at a rate proportional to the speed of revolution of the drum. On frame 50 on carriage 41, are mounted four upper rollers 51 and a lower roller 52 all provided with flanges 53. The rear and front upper rollers run on rails 42<SP>1</SP> and 42, respectively, and lower roller 52 makes contact with the bottom of rail 42<SP>1</SP>. Threaded split nut clutch 54 on carriage 41, operated by a handle engages and disengages the carriage from the feed-screw 43 and enables the carriage to be moved manually. The feed-screw 43 is geared to the drum 11 by a train of gears 44-49. The strip material is fed from reel 39 on turntable 40, rotatably mounted on frame 41, over guide roll 58, mounted in spindle 59, through stationary guide 60 and over roll 61 rotatably mounted in a pan 62 containing solvent for the rubber. The strip then passes over stationary guides 63 under guide roll 64 and then through guide 65 on to the sheet material where a roll 66 rotatably mounted on one end of arm 67 presses the tacky strip on to the sheet material. To the other end of the arm 67 is affixed a rock-shaft 68, pivotally mounted in bracket 69, the other end of the rock-shaft being provided with an arm 70 disengagably attached to a spring whose other end is attached to bracket 69. An arrest 72 on bracket 68 supports arm 67 away from the drum. Through pivotal joint 73 the end of the arm 67 is movable in an arc along the axis of the drum to permit the roller to take up any helical angle. A revolution counter is geared to the drum. The pitch of the teeth on the band may be varied by changing gears 44 and 49 for gears with a greater or lesser number of teeth. Motor 35 is controlled by a master switch 117, a hand switch 118 and a foot switch 119, both the master switch and one or other of the foot or hand switches being necessary for use.