05-03-2013, 01:13 PM
Grinding Attachments For Lathe
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INTRODUCTION
In the absence of a grinding machine many repair shops complete repairs by boring and turning, when a fine degree of accuracy would be advisable. Many owners of small shops do not care to go to the expense of installing grinding machines although desiringtheir use. In accompanying illustration, Fig. 336, a grinding attachment is shown, that the designer states may be attached to anyengine latheof sufficient center capacity.
The grinder itself is carried by a slab and studshaft, the arm of which is about 1.75 inches in diameter, so as to insure the necessary rigidity. The slab is attached to the face plate of the lathe by means of two .75 inch bolts, of which the top one is arranged in a radial slot, to facilitate adjustment of the work in hand. Upon the arm of the studshaft is mounted a length of solid drawn hydraulic tubing, which revolves on two brass bushings forced and sweated into the ends of it, thus leaving an annular space for the lubricant.
The tube carries a driving pulley on its inner end, the grinding wheel being attached to the outer end. The driving pulley is secured to the tube by means of two set screws. This pulley is fitted with a sufficiently convex face, in order to eliminate lateral slip of the belt. The outer end of the tube is threaded to receive a thimble which is screwed and sweated into place.
Owing to the path which the wheelspindlefollows the use of a floating countershaft is necessary. The connecting rod to the latter is shown broken off in the lower illustration and the arrangement of the floating countershaft is depicted in the upper drawing. As previously mentioned thefeedof the grinding wheel is adjusted by the bolt situated in the radial slot while the travel is supplied by the lathe slide rest.
Some machinists display considerable ingenuity in building grinding attachments for the lathe and such a device is shown at Fig. 337. It will be noted that the design does not employ a floating countershaft. With it the inventor claims he is able to grind hardened steel spindles, camshafts, crankpins, valves, cylinders, etc., and states that in planning the attachment considerable thought was given to have the equipment as rigid as possible and that all parts operated on with it should be ground quite circular. The maker states that the attachment can be used either for grinding internal or external work and that it can be fitted easily to the ordinary lathe. The left hand figure shows the end elevation and that at the right the grinding spindle and method of attaching it to the tool clamp of the top portion of a compound slide rest. The smaller figure shows a plan of the grinding arm itself, which is somewhat after the style of a Land is grinder. The attachment can be made fairly easily, but if desired can be purchased. For internal work it is provided with a long arm but for external work, the latter is only about 3 inches in length.