Patent GB-289793-A (GB)
Title: Power scraper
IPC: B23D79/00
Filed: 1928-04-30
Abstract: 289,793. Anderson, S. F. April 30, 1927, [Convention date]. Scraping; filing-machines, reciprocating. - A portable power scraper for reducing metal or other surfaces and stated to be applicable by suitable modification of the tool, to polishing, abrading, sawing, filing, and like operations, is provided with a gear-driven tool-ram having universal movement for application to the work. The base 16 carries a column 17 surmounted by a hallbearing turntable 18 having rods 19 on which the ram carriage 20 is guided for vertical adjustment. The base 16 encloses a wheeled truck 24 and for transporting the apparatus the base and other parts may be raised away from the truck to the dotted position in Fig. 12 by lever mechanism actuated from a hand lever 30. The upper ends of the rods 19 are connected by a strap 39 to which a crane hook may be attached. The ram carriage 20 comprises brackets 40 connected by a shaft 43 on which a yoke 44 is mounted, the yoke being provided with rollers 46 for guiding the ram 21. The movement of the yoke about the shaft 43 allows the movement of the ram in a vertical plane. The ram is provided with rack teeth 48 on its under side engaged by a driving gear 49 which is rotated alternately in opposite directions. The ram is also grooved to receive a controlling rack 51 which engages at 53 with a groove in a sleeve 22 which is reciprocated by the operator to control the direction of the tool movement. The end of the ram is fitted with a scraper 55 clamped in a holder 56 threaded on to a sleeve 58 which has rotary movement between collars 59, 60 on the part 47 of the ram. The control sleeve has a portion 61 extending through a slot in the tool holder and having limited axial movement therein. The end 64 of the ram is weighted so that when not in use the ram assumes the vertical dotted position in Fig. 1, with an abutment 63 on the control rack engaging the yoke 44. In this position the weight of the ram is carried by a spring 65, the gearing being held in a neutral position. The ram mechanism is operated from an electric motor 68 driving through a coupling 71 and worm gearing 73, 74 a pair of shafts 77, 78 respectively these shafts being mounted in the head 18, and arranged to drive in opposite directions a pair of bevel gears 82, 83, loose on the shaft 43. The gears 82, 83 are respectively connected to a pair of clutch housings 84, 85. A sleeve 86 rotates freely between the gears 82, 83. and is keyed to the gear 49 operating the tool ram. A gear 54 engaging the control rack 51 carries a pin 88 and is connected to split rings 89 and 91 which fit within the clutch members. Rollers 92, 93 mounted on the pin 88 are respectively located within the slotways of the split rings. In operation, when the control rack 51 is moved to the left the split ring 91 is moved so that the roller 93 is forced against the driving member 85, and the members 85, 86 thus rotate together. This movement of the member 86 drives the gear 49 in the same direction and actuates the ram for the return stroke. To reverse the direction o:' the ram, the control rack is moved in the opposite direction, this movement disengaging the roller 93 and engaging the roller 92 to reverse the sleeve 86 and gear 49 for the forward stroke. By manual operation of the sleeve 22 the operator causes the tool to reciprocate with any desired length of stroke. The ram carriage 20 is raised and lowered by means of a screw 98 driven from either of a pair of wheels 100, 101 in the head 18. Intermeshing gears 102. 103 are mounted on the arm 104 and the former gear carries a pinion engaging a. nut 99 to .operate the screw 98. The arm 101 may be operated from a lever 23 to bring either of the gears 102, 103 into frictional engagement with its grooved wheel to raise or lower the carriage 20. Specification 146,372 is referred to.