This section is from the book "Spons' Mechanics' Own Book: A Manual For Handicraftsmen And Amateurs", by Edward Spon. Also available from Amazon: Spons' Mechanics' Own Book.
This is another method of securing more rapid and continuous rotation of the tool. A quick-speed hand-drill sold by Churchills, Finsbury, for 7s. 6cl. is shown in Fig. 397. It has a continuous revolving movement in one direction at a speed of 500-1000 turns per minute. It is operated by holding the handle in the left hand, and quickly drawing out the cord with the right hand; on relieving the tension, the cord is re-wound on the spindle by a spring concealed in the spool. The momentum given to the fly-wheel is sufficient to maintain the speed while the cord is re-wound and the operation repeated. It may bo worked in any position. It carries an adjustable self-centreing chuck for holding the drill-points; 6 of these, from 1/32 to 1/8 in., are sent with each drill. It will be found a rapid working tool for light work in wood or metal.
Fig. 398 shows the Miller's Falls breast-drill mounted in a steel frame. Most work can better be done with the drill mounted in the frame. When used against the breast, it often requires a heavy pressure, which is very fatiguing to the workman. In this arrangement, there is a leverage of 5 to 1, which makes the feeding an easy matter. When work is required, which cannot be done in the frame, the drill can be taken out and used in the ordinary way. The upright rods of the frame are 5/8-in. round steel, 16 in. high, and 8 in. apart. As seen in the cut, the drill is held true by the frame, and the work held firmly in place by the clamp. The lever feed is operated by hand, or a weight may be used. The drillstock is of 5/8-in. round steel, heavily nickel-plated. The gears are cut, and are changeable from even to a speed of 3 to 1, as may be desired. The handles are rosewood. The jaws of the chuck are forged steel, and will hold any size or shape shank - round, square, or flat. An extra set of steel jaws is supplied for small round drills only.
The drillstock can be put in or out of the frame by the half-turn of a thumb-nut. The machine weighs only 15 lb., and costs 30s. It is sold by Churchills.