| 摘要 |
468,009. Drilling - machinea. ARCHDALE & CO., Ltd., J., and FEATHER, G. May 13, 1936, No. 13518. [Class 83 (iii)] In a drilling - machine the spindle b is fed by a rack and pinion e, f, rotated through bevel gearing d from a shaft a which is rotatable by means of a hand lever i, and a clutch h. A collar g keyed to the shaft a is surrounded by a portion of the clutch h which is split longitudinally at j, and the lever i is pivoted to a lug t on one side of the split and carries an adjustable screw k engaging an inclined stop pin l on the other side. Rotation of the lever in the feeding direction causes the screw k to close the split j and contracts the clutch for feeding the spindle b, whereas release of the lever allows the clutch to expand and be returned, together with the lever, by means of a spring n attached to the clutch h and a stationary sleeve o. A stop q in the clutch engages the end r of a recess in a stationary sleeve p to limit rotation of the shaft a in the feeding direction. The friction surfaces of the clutch may be engaged by relative axial movement, or may be replaced by a pawl and ratchet, the pawl being put into operation by pivotal movement of the lever and the ratchet teeth being provided on the periphery or face of a collar secured to the shaft a. |
