Patent GB-664570-A (GB)
Title: Improvements in or relating to grinding machines
IPC: B24B7/08
Filed: 1949-10-13
Abstract: 664,570. Grinding. PAPAGEORGES, D. Oct. 13, 1949 [Oct. 13, 1948], No. 26279/49. Class 60 A grinding wheel comprises a plurality of grinding units clamped around and projecting above the periphery of a driven wheel, the lower part of each grinding unit being enclosed by a U-shaped casing having diverging sides the edges of which are reinforced and lipped, a locking plate located between adjacent casings being held in abutment with the corresponding lips by bolts extending through the plate and between the lips into engagement with the wheel. The grinding wheel, Figs. 6 and 7, consists of grinding units 43 of trapezoidal section bearing against flat faces 53 of the rim of the driven wheel 42. Each unit is enclosed at its lower end by a U-shaped cover 54 having diverging side portions 55 the longitudinal edges 56 of which are reinforced and lipped on their outside by extra layers of material. Against these lipped reinforcements bear locking plates 57 formed externally with grooves 58 through which locking screws 59 pass into engagement with tapped holes in the rim of the wheel 42; nuts 61 bear on the plates 57 through a plate lock washer 60. The units are individually adjusted to compensate for wear. A surface grinder has a frame 1 the head 2 of which comprises a work table 3 having a central well in the mouth of which is located a central platform 4 secured, by set screws 6, to the underside of an arm 5 forming the work guide. The ends of the arm 5 are secured by screws 8 to the table 3 and screws 7 carried by the ends of the arm 5 bear on the table 3. The central portion of the arm 5 carries a screw 15 with a graduated head 16, engaging tapped holes in the table 3 and in a cover plate 13 seating upon the upper surface of the table; the upper work-receiving surfaces of the cover plate 13 and of the central platform 4 are hardened by electrolytic chromium plating or otherwise. Cylindrical plugs 5<SP>1</SP>, located one on each side of the graduated head 16 of the screw 15, are accommodated wholly within corresponding holes in the arm 5 and are secured by bolts 12 passing through the table 3 and cover plate 13; the plugs 5<SP>1</SP> are engaged by grub screws 5<SP>11</SP> carried by the arm 5 after vertical adjustment of the arm 5 has been effected. The centre of the platform 4 is screwed on to the threaded upper end portion of a support spindle 10; bolts 63 pass through the platform 4 and through a tapped collar 62 on the end portion of the spindle to lock the platform 4 against rotation relative to the spindle. The lower end of the supporting spindle 10 rests, through thrust bearing 17, against the splined shaft 44 of the electric motor 21, the splined shaft 44 engaging the interior of a hollow driving shaft 20 to the upper end of which is keyed a carrier disc 39 having on its underside fins 40 and a spigot 45. The wheel 42 of the grinding wheel is secured by screws 41 to the top face of the disc 39. The lower annular face of the disc 39 bears upon a central support 27 which forms a roller bearing housing. The upper part of the support 27 is screw-threaded at 35 to engage the topped bore of a sleeve 36 secured to the machine head 2. The interior portion of the support 27 at its lower annular face is provided with two pins 24 each having an extension 25 engaging longitudinal grooves 26 in a co-axial sleeve 28 formed at its upper part as a worm wheel 29 meshing with a worm 30 keyed on to control shaft 31 having hand wheel 32. The upper end of the sleeve 28 is, by way of its upper and lower annular surfaces 33, 46 engaged in and held by the corresponding faces 47, 48 of a cross slide 49, one end of which engages the control shaft 31 while the other end is fitted with a tapped bush engaged by the screw threaded portion 50 of a shaft 51 having a handwheel 52 which when operated locks the collar 28 and thus fixes the angular position of the support 27. Lubrication passages 37, 38 for the upper and lower bearings of the driving shaft 20 are provided.