GB602178A - Improvements in or relating to circular saw benches - Google Patents

Abstract

602,178. Circular saw benches. GREEN. G. .Tune 25, 1945, No. 16166. [Class 145 (ii)] A circular-saw bench comprises a slotted plane table with extension rods supported beside two opposite edges thereof, parallel to the plane of the saw, and rotatable about one end through 180 degrees to carry a crosssupport such as a roller, at a distance beyond the table approximating to its length. The table 1, Fig. 1, is carried on a frame 2, and through its slot 1<SP>1</SP>, Fig. 8, projects the saw 18, which is carried on a sub-frame 8 and driven through a pulley 16 by a motor 14 carried on the sub-frame. The sub-frame is pivoted on a transverse rod 5, and the amount of projection of the saw is controlled by a hand wheel 22 or by a pedal 23. Pivoted on a rod 29 secured to the frame are parallel rods 31 which in the position shown are held in alignment with the saw blade plane by screws 32 and are utilized to carry work guides and other attachments carried on sleeves threaded on to them. The rods 31 can be pivoted about the rod 29 into an extended position in which they are supported by slats 34 which then rest on projections 36 in the frame, and in which they can receive slidable blocks acting as bearings for the spindle of a transverse roller which acts as a support for long workpieces. Also attached to the frame are bearings for a threaded rod 42 rotatable by a hand wheel 43 and carrying a tapped sleeve 44, having a vertical socket 45 which is constructed to receive the pivot pin of a fence, the other end of which is secured to a saddle which rests on a sleeve 49 slidable on the rod 29 and clamped thereto by a screw 51 ; by loosening the screw 51 and rotating the wheel 43 the distance of the fence from the saw is adjustable, and the fence can be set if desired at a small angle to the saw blade by turning on its pivot pin. The frame carries a socket into which may be fitted the pivot pin 58 of a radius arm 56 carrying a vertical spindle 57 to which a workpiece of wood or metal may be secured as by a screw. By rotating the workpiece around the pivot 57, a circular disc may be cut from it, the radius of which is predetermined by the adjustment of the spindle along a slot 56<SP>1</SP> and the pivoting of the arm 56 about the pin 58 by means of a link 61 secured to the sleeve 44. On one of the rods 31 may be carried a block 63 supporting a vertical spindle 65 on which is pivoted an arm 67, the movement of which is limited by pins 72 on the block sliding in arcuate slots 72<SP>1</SP> in the arm and carrying a pointer 73. A vertical spindle 68 on the arm 67 carries a workpiece and an indexing head 69 engaging a detent 71. By this apparatus, arcuate grooves can be cut in the workpiece, their extent, radius and position being controlled by the pivoting of the arm 67, the adjustment of the spindle 68 along a slot 67', and the rotation of the indexing head 69. The rods 31 may also carry mitre guides or straight angle bar guides to square the end of a straight workpiece. An attachment for cutting gear teeth comprises sleeves 75, Fig. 13, sliding on the rods 31 and carrying slotted uprights 76 carrying a transverse rod 77 to which is secured a block 78 supporting a work spindle 79. The spindle 79 carries an indexing wheel 81 engaged by a spring pawl 82 and a wheel 83 having a slightly different number of teeth engaged by a spring pawl 84. The workpiece can be fed along the saw blade axis by means of a yoke 91, screwed rod 92 and hand wheel 95. For cutting rack teeth and dovetailing, the sleeves 75 may carry a cross-bar 97, Fig. 14, and a rack 98 beside it. On the bar 97 is slidably carried a work carriage 99 to which is pivoted a face plate 101 to which the workpiece is secured by clamps 102. The carriage 99 supports a spindle rotatable therein by a crank handle 105 and carrying a pinion engaging the rack 98, whence by rotating the handle 105 the carriage 99 is moved along the bar 97. To the carriage 99 is secured a disc 107 on which is rotatable a ring 106, the relative movement of the disc and ring being limited to a small angle by a pin 108 carried on the ring and sliding in a short arcuate slot in the disc. The handle 105 engages notches in the ring 106. To cut rack teeth, the plane 101 is set at right angles to the saw 18 and the handle moved one step after each cut. For dovetailing, the plane 101 is set at an angle, and after the first cut is swung to the opposite incline. Before the second cut, the spindle is turned through the angle allowed by the pin 108 to compensate for the lateral movement of the work due to its swing. After the next cut, the work is moved one step by first moving the ring back to its original position and then moving the handle 105 to the next notch in the ring. The rods 31 may be used to support sleeves carrying transverse rods of the same diameter and distance apart as the rods 31, on which may be carried attachments which are desired to be slidable transversely. A sanding disc may be secured to the pulley 16 by means of set-screws entering the holes 16<SP>1</SP> therein.