Grinding machines

1,180,276. Grinding. AMERICAN CYANAMID CO. 2 March, 1967 [12 May, 1966], No. 10006/67. Heading B3D. A centreless grinding machine for grinding long soft strands, e.g. sutures, comprises a regulating wheel 40 which is inclined relative to a grinding-wheel 22 to provide an infeed throat for receiving a part to be ground, the diameter of the regulating wheel diminishing progressively towards an outfeed position of the throat to compensate for changes in the peripheral speed of the part as its diameter is reduced by grinding. The grinding wheel 22 is carried by a shaft 18 which is driven by a belt 21 and mounted in a bracket 13 adjustable along guides 14 by a hand wheel 16. The regulating wheel is mounted on a belt-driven shaft 35 carried by a bracket 31 which is supported, at one end, by a pivot 28 on a post 27 and, at the other end by a bolt 32 engaging an arcuate slot in an upright 29 whereby the bracket can be adjusted about the pivot 28. The post 27 and upright 29 are mounted on a frame 23 adjustable about a pivot 24 whose axis is tangential to the discharge end of the grinding wheel. The regulating wheel is dressed to have a conical or hyperbolic configuration. A worksupport blade is disposed between the wheels and is adjustable by a hand wheel 45. A nozzle 46 delivers a spray of coolant, such as kerosene, to the grinding wheel to wash debris therefrom and a further nozzle delivers coolant to the suture during grinding. A scraper 48 removes portions of the suture which adhere to the regulating wheel. The sutures are fed through a funnel 49 to a tube 50 connected to an infeed injector which rotates and axially feeds the suture to the grinding throat. After grinding, the suture passes to a take-off and drying ejector 52 connected by a tube 53 to a braking ejector 54. The infeed injector has a housing 55, Fig. 4, containing an insert 56 which is formed with an axial bore 63 for the suture and a helical thread communicating with a chamber 61 connected to an air supply pipe 62, the air passing along the thread and imparting rotation and axial movement to the suture. The take-off and drying ejector has a housing 69, Fig. 5, containing an insert 70 which is connected by a pipe 73 to a relatively low pressure air supply which passes in the opposite direction to the feed of the suture 17 to effect drying. A space 71 between the insert and housing is connected to an air supply pipe 72 and produces an annular air jet for carrying the suture from the grinding throat