Patent GB-1198823-A (GB)
Title: Improvements relating to Universal Spindles
IPC: B24B41/04
Filed: 1967-10-16
Abstract: 1,198,823. Grinding; machine tool details. HALL-TOLEDO CORP. 16 Oct., 1967 [28 Oct., 1966], No. 47007/67. Headings B3B, B3C and B3D. A universal spindle comprises an outer rotatable sleeve having driving and driven sections, an inner rotatable shaft also having driving and driven sections, a pair of double universal joints relatively spaced along the spindle and coupling together the sections in the sleeve and the sections in the shaft, the sleeve and the shaft being relatively rotatable. A multiple spindle automatic machine for simultaneously grinding a pair of valve seats 21 in the cylinder head 20 of an I.C.E., each valve seat having associated therewith a valve guide 22 in which a pilot 25 may be fitted, comprises a base 31 and a vertical support 32. Above base 31 is a table 33 to which is attached a fixture for the cylinder head 20.  A saddle 35 supported on vertical slideways 37 on support 32 has mounted thereon a first motor 41 driving, through a gear-box 43 and chain 48, a cross-shaft 50 journalled in the saddle. A second, high-speed motor 52 drives a pulley 53. Spindles 55, 55 depending from saddle 35 carry grinding-wheels 59, 59. Saddle 35 is moved vertically by an air cylinder 65 mounted by a bracket 68 on support 32 and having a piston-rod 67 connected to a plate 70 secured to saddle 35. For coarse adjustment, pre-set stop means 69 engages the central part of an arm 73 pivoted at 74 to saddle 35 and carrying a pin 75 co-operating with a variable feed plunger 78 mounted on and movable relative to saddle 35 under control of an adjustable air cylinder motor, rack, pinion and screw mechanism 79 mounted on saddle 35. Each spindle 55 comprises upper and lower shafts 71, 72 and upper and lower sleeves 76, 77. Sleeve 76 is mounted on shaft 71 by ball-bearings 90, 92. Sleeve 77 is mounted on shaft 72 by ball - bearings 104, 105, and is threaded at 107 to receive the threaded end of an enlargement 109 of the hub 110 of grinding-wheel 59. Shaft 72 has a bore 85 the lower end of which receives a socket 60 having its axis eccentric to that of shaft 72, the socket 60 receiving a pilot 25. Shaft 71 is mounted in bearings (80), 81 in a gear-box 62 within which a gear (83) on spindle 71 meshes with a gear (84) on cross-shaft 50 driven by motor 41. Sleeve 76 has a pulley 112, and a belt 54 passes round the pulleys 112 of both spindles and the pulley 53 driven by motor 52. Shafts 71, 72 are connected by a double Cardan type universal joint 88. Sleeves 76, 77 are connected by a double universal joint of the constant velocity type. To prevent undue erratic motion when the spindles are retracted and disengaged from pilots 25 guide means in the form of sleeves or shields 115 are provided, these being fixed by brackets 116 to saddle 35. An air-oil mist is supplied to the interior of each spindle 55 from an atomizer 195 including a pair of oil supply bowls 196 connected to an air control valve 198. The mist is passed to the upper end (202) of shaft 71 which has an axial duct 205, radial bores (206), (207) within gearbox 62 and radial bores 208, 209. The mist passes through a space 215 between the inner and outer double universal joints to bearing 104 and through space 216 to bearing 105. A coupling 87 has an axial duct 211 and radial bores 214. Cams (225), (226), (227), (228) on saddle 35 actuate control switches (230), (231), (232), (233) to give the following cycle:- (1) Start button pushed: saddle descends rapidly, (2) switch 232 operated: lubrication started, (3) switch 233 operated: motors 41, 52 energized, (4) switch 231 operated: fine feeding mechanism 79 started, (5) time delay switch 230 operated: feed stopped, and after delay motors 41, 52 stopped and saddle raised. The grinding-wheels 59 may be replaced by other types of tools such as cutting, boring or milling tools.