Patent GB-784976-A (GB)
Title: Improvements in or relating to cylinder surfacing tools
IPC: B24B33/08
Filed: 1956-03-23
Abstract: 784,976. Honing. AMMCO TOOLS, Inc. March 23, 1956 [April 12, 1955], No. 9194/56. Class 60. A rotatable cylinder surfacing tool comprises surfacing units 19 each mounted by links 32, 34 on a body 12 so as to move radially while remaining parallel to the axis of the tool, the units being interconnected for movement in unison and being yieldingly biased in an expanding direction by resilient means 40 exerting a substantially constant force. The body 12 has a central bore 13 therethrough threaded at its upper end 14 for reception of a driving element, e.g., a flexible shaft. The body 12 has wings 18 with ears 20 to which the inner ends of the links 32 are secured by pins 22 ; the inner ends of the links 34 are secured by pins 29 to lugs 28 on the body 12. Each link 32 comprises a channel from arm 31 and a short lever 36 formed as an extension of one flange of the channel of arm 31 ; the lever 36 extends through an opening 25 in the body 12 into the bore 13. A compression spring 40 surrounds a rod 42 mounted for reciprocation in the bore 13, the spring being confined -between the under surface of the body 12 and a spring retainer 44 fitted on the lower end of the rod 42 ; the upper end of the rod 42 has a pair of flanges 46, 48 guided in the bore 13 and receiving between them the inner ends of the levers 36, so that the surfacing units 19 are biased outwardly. A rubber washer 49 below the flange 46 provides a resilient limit stop for the units in their outward movement. Each surfacing unit 19 includes a carrier 50 in the form of a channel having a web 54 with straight transverse end edges 56 and side flanges 58; the flanges have apertures 33a for a pin 33 passing through the outer end of a link 32 ; one flange has an extension 39 connected by a pin 37 to the outer end of a link 34. Mounted on each carrier 50 is an abrasive unit 52 including a channel-shaped mounting member 71 and an abrasive element or stone 72. The channel is formed of spring material, e.g. steel, and includes a web 68 and side flanges 70, the ends of the web having extensions 74 bent out of the plane of the web in the direction of the flanges and turned under, forming yieldable gripping elements or hooks. The abrasive unit 52 is attached to the carrier 50 by engaging the gripping elements 74 over the end edges 56 of the carrier web 54, the flanges 70 engaging the carrier flanges 58 to prevent displacement in transverse directions. The abrasive element or stone 72 is mounted on the outer surface of the mounting channel 71, e.g., by cement. The links 34 are arranged so as to be in tension having regard to the intended direction of rotation of the tool. The angular relation between each arm 31 and the corresponding lever 36, their location relative to the axis of the tool, and the spring rate and initial loading of the spring 40 are so chosen as to produce substantially uniform surfacing pressure throughout the range of expansion of the tool. Preferably the angle between arm 31 and lever 36 is 90 degrees plus ¢ the angle through which the link swings between minimum and maximum diameter positions ; the latter angle is 30-60 degrees, preferably 47 degrees. For that angle the spring 40 is compressed to such an extent that approximately 32 per cent of the compression of the spring is utilized in expanding the units from minimum to maximum diameter position. Other values are given.