GB331719A - Improvements in telescopic guards for rotating elements such as rotary shafts - Google Patents

Abstract

331,719. Cincinnati Bickford Tool Co., and Klausmeyer, D. C. July 31, 1929. Guards. - An adjustable guard for rotating members, such as shafts, comprises a strip of spring steel or other resilient material 20 in volute form with the turns overlapping, as shown at 21, the larger end being surrounded by a tubular member 22, which houses some or all of the convolutions when the guard is collapsed. The guard is particularly, but not exclusively, applicable to machines in which frame members, between which the shaft &c. runs, mutually approach and recede. As applied to a radial drill, Fig. 2, the guard 20 surrounds the vertical driving-shaft 12, to which is slidably keyed a bevel wheel 17 driving the horizontal shaft 7 on the radial arm 4, the arm 4 being raised and lowered by a feed screw (not shown). The volute strip 20, which is initially in flat spiral form, is extended as the arm 4 rises and is secured by hooked ends 20b, 20a and screws to sleeves 23, 22 respectively on the arm 4 and on a bearing 13, which is integral with the usual sleeve 3 rotatable on the fixed vertical pillar (not shown). Alternatively, the guard may be initially volute and merely bear at its ends on the parts 4, 13. The sleeve 22 may contain oil or oil-soaked packing, the oil being picked up by the guard when collapsed, distributed over the contacting surfaces during expansion, and returned by gravity down the edges of the convolutions. In a modification, where the parts 4, 13 do not approach so closely, the sleeves 22, 23 are extended, as shown at 22b, 23<b>, Fig. 7, and the guard 20 is shortened so that it is reversely extended, as shown in broken lines, when the radial arm is at its lowest point.