Patent GB-190907868-A (GB)
Title: Improved Safety Automatic Feed for Wood Sawing Machines.
Inventor: PICKLES GEORGE
IPC: B27B25/00
Filed: 1909-04-02
Granted: 1910-03-31
Abstract: 7868. Pickles, G. April 2. Circular-saw machines; tables and fences.- Machines for sawing box boards are provided with (1) an automatic longitudinal feed or travel with a quick return, and (2) means for feeding the block transversely a predetermined distance after each cut through the medium of friction disks and for releasing the pressure during the back stroke. (1) The block is engaged by adjustable pushers 7, 8 mounted on a reciprocating bar 6. The bar 6 is provided with a rack which is engaged by a spur-wheel 12 of a two-speed reverse gear. The wheel 12 is mounted on a shaft 13, which carries another wheel 15 and gears directly with a wheel 22 loosely mounted on a shaft 16. The wheel 15 gears through an intermediate wheel 24 with a wheel 23, also loosely mounted on the shaft 16. A clutch member 25, which rotates with the shaft 16, is mounted between the wheels 22, 23, and may be engaged with either wheel or disengaged from both by means of a rod 26, lever 27, link 28, and lever 29 mounted on a shaft 30 having a projection 32. The projection 32 is engaged by stops 33, 34 at either end of the stroke to reverse the feed. A hand-lever 35 enables the clutch to be thrown out of gear at any time, and a pivoted rocking lever 36, provided with a pin 37 adapted to enter an opening in the hand-lever 35, enables the lever to be locked to hold the movable clutch member in an inoperative position. Other means may be provided for operating the clutch. The pusher 7 is extended at the outer side as an arm 7<1>, which rides on a bar 9 at the base of the fence 10 for engaging the board that is being sawn off. A vertical extension or plate 7<2> is provided on the arm 7<1> and, in order to keep this plate from coming into contact with the saw, its upper edge is provided with an adjustable guide-piece 7<3> adapted to slide in a groove 11<1>. (2) On the top of the casing 14 containing the two-speed gear is mounted a transverse main slide 38 which carries a secondary slide 39. The secondary slide is provided with a rack which is engaged by a pawl 40 adjustably mounted on a link 41. The link 41 is pivoted to the main slide 38 and is connected to the casing 14 by a link 42. A mutilated pinion 45 is mounted on the upper end of the shaft 13 and is frictionally gripped between two spring-pressed disks 46, 47, which are secured to the shaft. The pinion 45 gears with a rack 38<2> on the slide 38. When the bar 6 commences to feed the block to the saw, the friction disks cause the quadrant to move the main and secondary slides until the block abuts against the fence, after which the disks slip on the pinion. On the reverse motion of the shaft 13, the pressure on the block is relieved. The backward movement of the slide is limited by a stop on the main slide engaging a fixed projection on the casing 14. In order to control the amount of feed, the slide 35 is provided with a set-screw 53 which engages a fixed stop 54 on the casing 14. As the main slide is moved back, the pawl 40 rides over one, two, or more teeth on the rack 39<1>, according to the extent of the previous forward movement of the main slide as determined by the set-screw 53. On the next forward movement of the main slide, the lever 41 causes the pawl 40 to move the secondary slide 39 an additional distance beyond the main slide equivalent to the tcoth or teeth passed over by the pawl on the previous backward movement of the main slide. The secondary slide is thus intermittently advanced until the pawl 40 rides clear of the teeth of the rack on the secondary slide.