GB315406A - Improvements in or relating to grinding machines - Google Patents

Abstract

315,406. Cincinnati Grinders, Inc., (Assignees of Booth, C.). July 13, 1928, [Convention date]. Centreless grinding ; guides and rests ; wheels.-A centreless grinding machine for grinding seatings on poppet valves &c. consists of a bed 20 on which is mounted, on slides 22, 24, a head 25 carrying a regulating- wheel 27, adjustable by a screw 29 and also movable to and from the work by a sleeve 31 operable by a handle 33. The work, consisting of a stem 34 previously ground in a centreless grinding machine, and a head 35 is supported with the stem on a rest 37 carried bv a bracket 38 on the slide 22 and is retained in position by rollers 39 carried by arms 42 pivotally carried by the bracket. 38 and normally pressed up to the work by springs 43. The valve is positioned during grinding with the stem pressed up to a stop consisting of an ejector rod 45, by means of a roller 52 carried by an arm 53, which is pivoted at 58 in a block 54 pivotally mounted on the bracket 38 by a screw 55, and normally pressed up to the valve head by springs. The seating is ground by a cup grinding-wheel 65 mounted on a spindle 63 by clamps 64, the spindly being carried by a slide 62 on diagonal ways on the bed, and reciprocated thereon to equalize wear of the wheel. When the seating is ground the regulating-wheel is retracted, the rollers are removed from the work, and the work is ejected, by operation of the lever 33, which moves a bar 69 carrying at cam actuating a bar 76 to move the levers 42, 53 outwardly, a cam 77 also engaging a stud 78 on the arm 53 to move this about the pivot 55. After movement of the rollers, the ejector rod 45 is moved through ratchet mechanism 83 - - 85, a shaft 51, rockarm 50, and a lever 47. In a modification, Fig. 11, the valve. stem is carried by a bearing 88 on an arm 87 movable by a cam on a rod 95, which also carries means for moving the head-engaging roller 103 and the ejector 101. The work-rest 37 may be provided or its working face with a concave portion to receive the valve stem.