GB806043A - Improved tool for grinding annular seats - Google Patents

Abstract

806,043. Grinding valve-seats. YULE, I. M. Feb. 26, 1957 [March 9, 1956], No. 7381/56. Class 60. A tool for grinding an annular valve seat having an axially-aligned guide comprises a spindle 17, Fig. 2, which is rotatably mounted within an outer body 10 and carries a grinding wheel 24, a locating sleeve 28 formed with a frustro-conical portion 29 to engage the annular seat and an opening 34 in its wall through which the periphery of the grinding wheel projects to engage the seat being ground, and a pilot shaft 32 which engages the axially-aligned guide and is coaxial with the locating sleeve and offset from the grinding wheel spindle. The spindle 17 is driven by an electric motor 15 disposed within the body 10 and is axially-adjustable to displace the grinding wheel relative to the locating sleeve 28 by a screw 22 rotatable by a grooved cap 23 ; a spring-pressed ball 25 engages the cap to provide a non-positive lock. The spindle is upwardly-urged against a thrust race 19 by a spring 18 and is located in a rotatable externallythreaded sleeve 26 in screw-threaded engagement with the eccentrically-mounted locating sleeve 28. The sleeve 26 is upwardly urged by a spring washer 61 against a shoulder 63 on the body 10, and is rotated by a plate 48 connected to an internally-geared ring 46 which is rotated by planet gears 42 in engagement with a fixed internally-geared ring 44 located in a cupshaped member 35. The planet gears are rotatably mounted on a carrier 41 disposed on a journal bearing 40 carried on a downwardlyprojecting portion of the member 35. The spindle 17 is rotated at high speed by the motor 15 and an impeller 54, keyed to the spindle and provided on its periphery with a plurality of serrations, imparts centrifugal force to fluid maintained within a recess 51 by an end-plate 52. The fluid passes to the rear of vanes 58, Fig. 6, which are disposed within slots 57 in the carrier 41, and displaces them radially inwards to project into the oil space and provide abutment surfaces for the oil to drive the planet carrier. As the rotational speed of the carrier increases, the vanes are urged radially outwards and the drive maintained by viscous drag. Oil seals are provided at various positions around the spindle 17, and the oil in the recess 51 may be used for lubrication purposes, axial passages being provided in the sleeve 26 and spindle 17. In a modification, the locating sleeve may be fixed to the outer body which is driven through reduction gearing housed within itself, and in other embodiments, the spindle may be driven by a fluid-pressure motor or a flexible shaft. Specification 806,044 [Group XXIX] is referred to.