GB190915229A - Improvements in Sleeper Sawing Machinery. - Google Patents

Abstract

15,229. Christie, A. C. June 29. Band saw machines; tables and fences.-Relates to a machine for sawing logs of timber, more especially to form sleepers. An endless chain 2, sliding in a groove 4 in the table 1, feeds the logs 52 through a centring-device to the band saw 30, which is mounted on a bed-plate 31 also supporting the driving-motor 33. The bed-plate 30 is adjusted by means of a screw 35 so as to bring the saw-blade 6 in position to divide the block equally, or to cut off pieces of the required thickness. The centring- device consists of two pairs of rollers 8, 9 and 26, 27 mounted on arms 10, 11 and 12, 13 pivoted to brackets 5, 5<A> carried by slides 22, 23 on the table 1. When the blocks are to be sawn into two equal parts, the arms 10, 11 and 12, 13 are secured to interengaging toothed quadrants 14, 15 and 28, 29, from which weights 18, 19 are hung so as to cause the rollers 8, 9 and 26, 27 to tend always to approach each other. When the blocks are to be sawn into unequal parts, the band saw is displaced by means of the screw 35 or the arms 11, 12, and in some cases the a.rm 10, are disconnected from their respective quadrants and swung out of the way while an adjustable fence is arranged opposite the roller 27. A second endless chain 53, also sliding in a groove in the table, is provided for conveying the sawn piece 62 from the saw, a series of vertically adjustable rollers 55, 56, 57 being arranged to feed forward the pieces 62 until engaged by the dogs on the chain. The endless chains 2, 53 pass over pulleys 63, 64 on a shaft 65 driven from an electric motor 73, the pulley 63 being adjustable on the shaft 65 to bring the dogs on the chains opposite one another by means of a worm 67, Fig. F. The electric motor 73 drives the shaft 65 and also a shaft 37 and worm gearing 51 for operating the screw 35, by means of gearing similar to that shown in Specification 7159/03, consisting of oppositely rotating friction pulleys 69, 70 driven by the motor and friction rollers 77, 76 mounted on pivoted frames 80, 81 so as to be operable by levers 94, 95. The friction pulley 77 is connected through spur gearing 84, 86, adjustable friction gearing 88, 89, and spur gearing 92, 93 to the shaft 65, the friction gearing 88, 89 being operable by means of a lever 96 arranged adjacent to the levers 94, 95. The friction pulley 76 is connected through spur gearing 85 to the shaft 37, which is arranged to operate, through chain and worm gearing, an indicating-dial 46 showing the displacement of the band saw 30. A hand-wheel 45 may be fitted to the worm spindle 42 to allow the screw 35 to be operated by hand. Instead of using electricity as a motive power, the machine may be driven by belts from overhead shafting.