Patent GB-578463-A (GB)
Title: A grinding or abrading machine
IPC: B24B5/01
Filed: 1944-05-24
Abstract: 578,463. Grinding- machines ; trueing. NORTON CO. May 24, 1944, No. 10048. Convention date, Sept. 23, 1943. [Class 60] A grinding-machine is provided with a dial gauge to indicate when the work has been ground to finished size, the gauge also serving to indicate reduction in diameter of the grinding- wheel due to wear or trueing whereby the additional feed to be given to the wheel may be indicated. The machine, described as for grinding a series of race ways in the hub of an aeroplane propeller blade 10, Fig. 1, has the blade mounted on a vertical axis for rotation during grinding by the wheel 11, which is carried by a vertical shaft 13 on slide 15 adjustable on horizontal ways on a base 17 by a screw 19 engaging a nut 18 on the slide, the screw is rotatable, through gearing 21-24, by a hand wheel 25 having micrometer mechanism 26. The work is carried by a support 30 having a shaft 32 carried by a slide 34 and driven by a belt and pulley 37 from a motor 40 mounted on the base 17, and the slide 34 is adjustable vertically in guide ways on the base by means of a screw 50 engaging a nut 48 in a part of the casing 34, and rotated, through gearing 52-55 by a hand-wheel 57. The grinding-wheel 11 is trued by a diamond 60, Fig. 3, mounted in a holder 61, Fig. 5 slidable in a swinging cradle 62 and urged away from the wheel to contact with a form bar 65 by a spring 64 so that as the cradle is swung the diamond gives the required shape to the periphery of the wheel 11. The cradle 62 and bar 55 are carried by a slide 70 movable in a casing 87 on the slide 15 towards and from the wheel 11, the slide having arms 72 with journals'73 for the cradle pivots 80, 81 and the pivot 80 carrying a handle 83 for, rocking the cradle. The slide is mounted on the underside .of a cover 86 pivotally mounted at 89 on the casing 87 and is adjustable by a screw 101 carried in a housing 103 on the cover and engaging a nut 100 on the slide, the screw being rotatable through gearing 104, 105 by a micrometer dial. On the base 17 is mounted a dial gauge 110 the plunger 114 of which is operated by a bar 112 slidably mounted in supports 113 on the slide 15 ; the bar carries a pin engaging a yoke on the lower end of a lever 116 pivoted at 117 on the slide 15, and a yoke at the upper end of the lever engages a pin 122 carried by -the support 76 for the form bar 65. The lever arms are of the same length so that when the slide 15 is fed by the wheel 25 to effect a grinding operation, the lever moves parallel to itself the gauge plunger 114 moving accordingly; feed is continued until the gauge registers zero, that is, the grinding is completed. When the wheel 11 is to be trued, the slide 70 is advanced to feed the diamond the required amount, this movement causing the lower end of the lever . 116 to move back an equal amount, which is indicated by the gauge 110 ; the micrometer 26 then is used to feed the wheel 11 by the indicated amount in addition to the normal feed, thus allowing for the reduction in diameter of the wheel. Normal wear of the wheel is compensated similarly, the diamond being advanced until it just touches the wheel 11, the advance being indicated by the, gauge. Specification 550,601 is referred to.