Patent GB-134676-A (GB)
IPC: B24B27/00
Abstract: 134,676. Rivett, E. Dec. 17, 1918: Disk &c. apparatus; driving-devices; protecting parts of machines.-Relates to grinding-machines of the type comprising rotatable tool and work spindles in vertical alinement and having means for moving the work or the tool relatively to each other, and consists in means for imparting, automatically or otherwise, vertical feeding movements to the work spindle and a transverse feeding motion to the tool spindle; also in arranging a series or bank of work and tool spindles in such a manner that each unit is under separate control; also in means for protecting the spindle bearings against water &c. used in the grinding operation. The machine comprises a series of grinding. disks 76 mounted on vertical spindles 75 capable of being swung about an axis 71 towards or from the work, the work being held on a series of chucks 20 mounted on vertical spindles 11. to which an axial movement is imparted. The whole series of spindles is mounted in one frame, all being driven from a single main shaft 7 by belt gearing, but the traversing motion of the chucks and the swinging movement of the tools are under separate control for each unit. The machine is described as applied to the internal grinding of cylinders. The chuck spindles 11 are mounted in a frame 2, the base 3 and walls 4, 5 of which form a chamber to receive oil and water used in grinding and lubrication. A petticoat 19, and other guards 16, 18, protect the spindle bearings. The spindles are driven by belt gearing 28, 22 from the main shaft 7 through cone pulleys 27, 23, which permit the speed of each spindle to be separately adjusted; or, by means of a connecting-rod 29, the pivoted arms 25 may be locked so as to loosen the belt 22 and stop the spindle. The vertical traverse of the spindle 11 is imparted by means of a slide-bar 30, Fig. 2, reciprocated laterally through a roller 34 which is spring-held against a heart-shaped cam 33 driven from the main shaft. A shaped lever 46 pivoted to the slide-bar at 47 engages with a stud 51 on a vertical rod 48, and lifts it during each traverse to an extent determined by an adjustable cam 45, the position of which is manually controlled by gearing 57, 61, 62, 67, 68, Figs. 1, 2, and 3. The spindle 11 is supported on a bracket 50 carried by the rod 48 and therefore shares the vertical movement of the latter. The grinding-spindles are belt-driven from a vertical shaft 96 driven bv belt-gearing from the main shaft 7. The bracket 99, Figs. 1 and 3, supporting the shaft 96 is adjustable in a slot in the stud 71 to tension the belt. The swinging arm 72 supporting the spindle 75 is also adjustable by means of a set-screw 103 to vary the initial vertical position of the grinding-tool relatively to the work-holder 20. The disk 76 is fed laterally towards the work during grinding by means of an arm 77, Fig. 3, rigid on the swinging head 72 and spring-pressed into contact with an eccentric 83, mounted on a vertical shaft 82. This shaft 82 is rotated by means of a wheel 90 and a screwed rod 87 engaging an arm 85 at the foot of the shaft to vary the eccentricity of the cam 83, and therefore the extent to which the arm 77 is forced outwards, and consequently the lateral feed of the grinding-disk towards the work. This lateral feed may be accomplished automatically by means of pawls 92, 91 mounted adjustably on a reciprocating rod 31 actuated from the slide-bar 30 and engaging with and rotating the wheel 90. The grinding- spindles 75 are fitted with idler pulleys 110, 111, 112, 113, Fig. 2, so as to equalize the pull of the driving-belt upon the spindle. A similar arrangement of balanced belt gearing is also employed in driving the series of spindles 96 from the main shaft.