. American engineer and railroad journal . readies nearlyto the top. The diameters of both are greatlyincreased at the lower end. A third bearinghas been introduced, which adds strength andrigidity. A place for a large roller bearing torest and swing on is provided by the rein-forced portions as well as means for clamp-ing the column easily and firmly. The clamping handle is alw-ays within easyreach of the operator since it follows the arm,and no pressure is exerted on the rollers ofthe bearing when the arm is clamped in po-sition. These rollers are tapered, of largediameter, and thoroughly pr
. American engineer and railroad journal . readies nearlyto the top. The diameters of both are greatlyincreased at the lower end. A third bearinghas been introduced, which adds strength andrigidity. A place for a large roller bearing torest and swing on is provided by the rein-forced portions as well as means for clamp-ing the column easily and firmly. The clamping handle is alw-ays within easyreach of the operator since it follows the arm,and no pressure is exerted on the rollers ofthe bearing when the arm is clamped in po-sition. These rollers are tapered, of largediameter, and thoroughly protected from chipsand dirt. In the design of the spindle driving gear an important im-provement has been made to reduce the friction to which thisgear is subjected by the pull exerted upon it when the spindlefeeds down. This has been accomplished by making the spindledriving gear rest and revolve on a ball bearing. The mechanism for the feed, which is of the all-geared type,is enclosed in a small case. Eight changes in all are available;. ^^^sr W0^^^ ^ M^iu.:*M ^^^^^^^H IT .\DDITI0.\.\L \RING FOR HEAD. THE DRESES IMPROVED DRILL. four of these ranging from to in. per revolution ofthe spindle are secured by the little handle on the feed shaftat the right of the head and are increased from to by the small crank above, both being within easy reach ofthe operator. The use of a ratchet clutch enables the hand feedto work ahead of the power feed. .\ swinging dog attachedto an extension on the spindle sleeve is brought into contactwith an adjustable dog on the feed bar, and there is a graduatedscale by which the depth of a hole can be gauged from of these dogs can be put on the feed bar and the swing-ing dog brought into contact with them successively for differ-ent depths of holes. A safety release for the end of the feedis provided. The quick advance and return device has fourlevers, any one of which engages and disengages the feed i
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroadengineering
