Patent GB-1337272-A (GB)
Title: Honing tool arrangements
IPC: B24B33/02
Filed: 1970-01-13
Abstract: 1337272 Grinding DEREK HARTLE Ltd 12 Jan 1971 [13 Jan 1970] 1572/70 Heading B3D [Also in Division F2] A honing tool arrangement 10 for a machine for honing the bore of a tube or cylinder comprises a rotatable and axially reciprocatable tubular shaft means 46, 48, 52 attached to a honing tool, a tool diameter control means having a control rod movable longitudinally within and relative to the tubular shaft means to alter the diameter of the tool and including fast and slow feed means, the slow feed means being effected by a screw 136 and nut member 138, the nut member being movable to be disengaged from the screw to permit fast longitudinal feed movement of the control rod, and brake means 86, 88 operative to cause relative rotation between the screw and nut member when engaged and when the tubular shaft means is rotated to cause slow feed longitudinal movement of the control rod. As described, two identical tool arrangements 10, 12 are mounted on an overarm 14 of a pillar 16 for simultaneous operation on a pair of workpieces mounted on a bed 18. The arrangements may be mounted in a horizontal or vertical honing machine. Each arrangement consists of a head assembly 20 connected by a bayonet joint 22 to a lower assembly 24 which, in turn, is connected by a bayonet joint 26 to a honing tool 28. The tool has a body 30 which is formed with a spigot 32 carrying the bayonet pegs 34 and has honing stones 44 radially adjustable by conical cams 40 on a push-rod 36, a spring 38 urging the rod to a position wherein garter springs 170 retract the stones. The head assembly has a portion 46 of the tubular shaft means mounted in radial and thrust bearings 64 in a crosshead 66 and splined to receive a bevel gear 54 meshing with a bevel gear 56 rotatable by an electric motor 60 to effect rotation of the honing tool. The crosshead 66 is provided with bushes 68 slidable on vertical guide rods 70 on the overarm and is reciprocatable by piston-and-cylinder devices 72, 74 to effect reciprocation of the tool. The gears 54, 56 are located in a fixed gear-box 62 from which extend a pair of posts 75 slidably receiving a slide 80 in which the upper end of shaft portion 25 is mounted by bearings 78. A body 82 on the slide houses the brake means 84 consisting of a rotatable disc 88 and a non- rotatable disc 86 axially adjustable by a nut 90 to control the drag caused by a viscous fluid between the discs. The rotatable disc is connectable by an electromagnetic clutch 94 to a rod 98 having a squared end 100 received in a squared socket 102 in a portion 104 of the control rod. The portion 104 has a flange 106 mounted in bearings in a thrust-plate 108 which is axially movable to effect longitudinal movement of the control rod and a fast expansion of the honing stones by piston-and-cylinder devices 110, 112 in the body 82. The lower end of the portion 104 of the control rod has a blind square socket 120 receiving the squared end 122 of an intermediate portion 126 of the control rod, the socket being adjacent a universal joint 124 between the portions 46, 48 of the tubular shaft. A spring 128 urges the end 122 into the socket 120. The lower end of the intermediate portion 126 has a blind squared socket 130 receiving the squared end 132 of the lower portion 134 of the control rod adjacent a universal joint 50 between the intermediate and lower portions 48, 52 of the tubular shaft. The screw 136 is formed on the lower portion 134 and is engaged by a pair of nut members 138 which are engageable and disengageable with the screw upon axial movement of inclined members 148 carried by an annular piston 152 in a cylinder 154. The lower end of the lower portions 136 of the control rod is engaged by the push-rod 36 of the tool. With the nut members 138 disengaged from the screw 136 and the clutch 94 disengaged, operation of the piston-and-cylinder devices 110, 112 effects a fast expansion of the tool. When the nut members engage the screw and the clutch is engaged, the drag caused by the viscous brake 84 causes relative rotation to occur between the screw 136 and nut members to a slow expansion of the tool. Honing is effected under the control of a sizing device, timing mechanism or stroke counting device. Expansion of the tool may be continuous or intermittent. In other embodiments, the screw 136 is formed on the push-rod of the tool, or the nut members may be movable about pivots parallel to the axis of the tool by lever means. Instead of a viscous brake, an eddy current or servo-motor type brake may be used.