. Railway mechanical engineer . vided with a new attachment by means of which straight andtaper shank drills can be readily ground without any time-consuming adjustments. The operation of the grinder isshown in the illustrations. Figs. 1 and 2 illustrate how long,straight and taper, collared shank drills, respectively, are po-sitioned. When the body of taper and collared shank drillsbecomes too short to be supported by the sliding V block,Fig. 2, this part is thrown out and the shank of the drill issupported by a center detail in the elevating tailstock. Fig. 3shows how a short, straight shank
. Railway mechanical engineer . vided with a new attachment by means of which straight andtaper shank drills can be readily ground without any time-consuming adjustments. The operation of the grinder isshown in the illustrations. Figs. 1 and 2 illustrate how long,straight and taper, collared shank drills, respectively, are po-sitioned. When the body of taper and collared shank drillsbecomes too short to be supported by the sliding V block,Fig. 2, this part is thrown out and the shank of the drill issupported by a center detail in the elevating tailstock. Fig. 3shows how a short, straight shank drill is positioned in theholder for grinding. Nine belt and eight motor-driven styles of twist drill grind-er are offered. These are made up in different combinationsfrom four holders having the following capacities: No. 52to % in., 3/32 to l/ in., ]/A to 2l/2 in., and y2 io 4 machine is equipped with means for obtaining differentclearance angles and includes a built-in wheel truing Fig. 2—Grinding a Taper, Collared Shank Drill Fig. 3—Grinding a Short Straight Shank Drill On account of the voluminous amount of drilling work inrailway shops, twist drill grinders are an essential part ofthe toolroom equipment. The shop managements should notbe content, however, to operate old style grinders whengrinders with improved attachments are available. Espe-cially when these attachments make possible a more accurategrinding of drills or when they allow for the grinding ofshort taper, or collared shank drills which would otherwisehave to be ground by hand they should be installed. Theaggregate saving due to their use will in the long run pay bigdividends on the money invested. It is obvious that a shop or roundhouse so small as to re-quire only the occasional use of twist drills could not affordthe installation of a twist drill grinder, but in most cases thedrilling requirements are large. Many drills of all differentkinds and sizes have to be maintained in good work
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
