Patent GB-696959-A (GB)
Title: Device for producing a high finish on cylindrical surfaces
IPC: B24B5/38
Filed: 1950-10-17
Abstract: 696,959. Grinding and polishing. BERSTECHER, K. Oct. 17, 1950 [Oct. 17, 1949], No. 25326/50. Class 60. In a device for producing a high finish on cylindrical surfaces of work pieces by means of adjustable working tools rotating about their own axes, the stationary work piece extends through the device and the device is held by adjustable centering rollers with the working tools disposed between the centering rollers, the working tools and centering rollers being mounted on a rotary part of the device rotating about the axis of the work piece, so that the centering rollers and thus the entire device are centered by the surface of the work piece itself. The device may be used for fine-grinding or honing the rolls used in the paper and sheet metal arts; grinding wheels, buffing wheels or sanding discs are employed. In one embodiment, Figs. 1 and 2, the device comprises a housing 8 having lower and upper halves secured together by screws 87. On each side of the housing 8 is an annular member 11 having a peripheral groove embracing the side wall of the housing; a cylindrical extension 211 of the member 11 is engaged by rolls 24 mounted, by eccentric bushings 240 permitting adjustment, on a shaft 76 carried by the housing 8. The annular members 11 are rotated by a flexible shaft 9 which drives through coupling 23<SP>1</SP> a shaft 78 mounted in an extension 108 of the lower half of the housing 8, the shaft 78 carrying a gear 10 meshing with a toothed ring 411 on one member 11. Grinding wheels 1 are mounted on shafts 2 mounted in casings 20, the other end of each casing being supported on bushings carried by the ends of links 19; the casing 20 and links 19 constitute a bell-crank lever, the arms of which are held in desired angular relationship by tightening a bolt 21 passing through the bushings. The other ends of the links 19 are connected by pins 83 to lugs 82 on pistons 18 working in cylinders 80 carried by the members 11, the lugs 82 projecting through slots 81 in the cylinder walls; the pistons are urged inwardly, to move the grinding wheels outwardly, by springs (not shown), and the pistons 18 are moved outwardly, to move the grinding wheels inwardly into contact with the work 25, by fluid pressure admitted through supply line 22, carried by the housing 8, annular groove II, passage 88 in the cylinder 80 and groove 89 in the piston 18 to the inner end of the cylinder 80. The grinding wheels are rotated by pulleys 3 on the shafts 2, belts 79 and pulleys 4 mounted by ball bearings 77 on the bushings supporting the casings 20; the pulleys 4 project through openings in the casings 20 into contact with the inner surface of an annular pulley 5 rotatably mounted between the side walls of the annular members 11. The pulley 5 is driven by a belt 74 from a pulley 6 on a shaft 73 mounted in the extension 108 of the lower half of the housing 8 and driven through coupling 23 by flexible shaft 7. To support the device on the work, three pairs of centering rolls 12 are provided, freely rotatable on pins 84 mounted in carriers 13 radially adjustable in links 14 which are connected by screw 85 to links 17; the latter are pin-connected to a ring 16 located on the outside of the members 11. The links 14 have an extension on the inside to which are secured pistons 15 slidable in a cylindrical hole open on both sides and arranged on each side of the hollow extension 80 of member 11. The annular spaces I, which are connected with each other by external means (not shown) are adapted to be filled with oil through a supply line 22<SP>1</SP> ; by controlling the pressure, the movement of the pistons 15 may be regulated so as to move inwardly against the pressure of a spring (not shown). The ring 16 ensures equal movement of the rolls 12 under the action of the pistons 15. The rolls 12 may be set at an angle other than 90 degrees to the axis of the work 25 so as to impart a longitudinal travel of the device along the work; the direction of travel can be reversed by reversing the direction of rotation of shaft 9. In a modification, Figs. 3 and 4, an annular member 311 is rotated in casing 308 by toothed ring 91, gears 440, 40 and electric motor 31. The grinding wheels 301 are mounted on shafts 302 carried by housings 34 which form with links 50 bell-crank levers pivotally mounted in member 311 ; the angular relationship of the arms of the bell-crank is adjustable as in the first embodiment. The grinding wheel shaft 302 is driven by a belt 26 from a pulley combined with a gear wheel 27 which meshes with internal teeth on an annular pulley 33 driven by a belt 32 from a pulley 35 driven by an electric motor 30. Ring gears 41, 60 mounted in annular grooves of member 311 have external ratchet teeth engageable by pawls 55, 59 and internal teeth meshing with gears 42, 57 on a shaft 93. The shaft 93 carries a worm 43 meshing with a worm wheel 44 slidable on a shaft 46; a friction disc 45 secured to the inner end of the shaft engages an annular member 47 screwed in a partly tapped cavity in member 311. The member 47 acts as a stop for a piston 48 connected to the link 50 by pin 49. By causing the pawl to engage the ratchet, the stop 47 is adjusted. Rolls 61 carried by the pawls are engaged by the rotating parts so as to disengage the pawls after a short interval Rolls 312 support the device on the work 25.