Patent GB-117611-A (GB)
Title: Improvements in and relating to Cross Feed Mechanism for Grinding Machines.
IPC: B24B47/04
Filed: 1918-06-17
Abstract: 117,611. Norton Grinding Co., (Assignees of Norton, C. H., Turner, A., and Willcox, J. S.). June 27, 1917, [Convention date]. Disk apparatus; feed-devices.-Relates to cross. feed mechanism for cylindrical grinding machines and consists of a continuous automatic feed providing three forward speeds and a reverse, any one of which may be selected by the operator. A stop-motion also is provided to arrest the movement of the feed shaft at a predetermined point. The carriage 16 of the grinding-wheel W is moved towards and from the work K by a nut engaging a screw on a shaft 22, which is driven from a set of cone pulleys. The pulley shaft is co-axial with a shaft 53 and is coupled thereto, by a set of clutches and back gearing, in such a manner that the shaft 53 may be driven direct or at a reduced speed through the gearing. The shaft 53 drives, through a bevel-wheel reversing-train, a shaft 42 on which is a loose pinion 40 geared through an idle wheel 36 to a wheel 27 on the feed shaft 22. The loose pinion has clutch teeth at both ends, and it may be move endways to engage a clutch 45 fixed on the shaft or to engage a clutch 90 on an epicyclic reducing-train 91, 92. The clutches on tho shafts 42, 53 are controlled by cams on a vertical shaft 78 provided with a hand-lever at its upper end. The cams are so disposed that both the shafts 42, 53 may be driven directly; or one, 53, may be driven directly and the other through its gear; or both may be driven through the gears, giving respectively high, intermediate, and low speeds to the feed shaft. The clutch for the reversing-train is controlled by a cam on a sleeve surrounding the vertical shaft and likewise provided with a hand-lever, at its upper end, whereby it may be placed for forward or reverse movement of the feed shaft, or in a neutral position. The wheel 27 drives the shaft 22 by means of a friction coupling and means are provided to arrest the motion of the shaft at a predetermined point in the feed. For this purpose, the shaft carries a wheel 120 in gear with a pinion 140 having fixed to it a wheel 142, which engages a pinion carried by an arm 144 rotatable upon the supporting-stud of the wheel 142. The pinion is capable of movement axially, but not of rotation, in a sleeve mounted in the end of the arm and carrying a spring plunger 154, which may be engaged in any one of a ring of holes in the arm. The pitch of the holes corresponds, to a definite small advance of the grinding-wheel carriage. The arm also carries an abutment piece 145 adapted to engage a fixed stop 146. By disengaging the spring plunger, the sleeve, and with it the pinion, may be turned, the pinion then rolls upon the wheel 142, and the arm is moved back from the fixed stop to any determined amount; the spring plunger is then engaged in one of the holes. When then, in consequence of the rotation of the feed shaft, the wheel 142 is turned carrying with it the arm 144 until its abutment piece meets the fixed stop, the movement of the feed shaft is arrested, the friction coupling allowing the wheel 27 to turn upon it. Normally the wheel 120 is loose on the shaft 22; it is coupled thereto when the work is approaching the finished size by means of a clutch 129, 130. A spring surrounding the end of the shaft tends to move the wheel to the right to throw the clutch into engagement; this action is prevented by a set of pivoted dogs in the eye of the wheel ; the dogs are liberated by a sleeve 135, which is moved by a forked lever engaging the end of a sliding rod moved by gearing from the feed screw. In order to adapt the device for work of different diameters, the sliding rod may be set endways by hand, its gearing being provided with friction connexions to permit this. The clutch may be disengaged upon reversal of the feed motion by providing an arm on the sleeve of the reversing-gear control to engage an arm connected to the forked lever embracing the sleeve 135.