. American engineer . y for drilling andcounter-sinking will require IS minutes. They are drilled andcounter-sunk in 21 minutes. .A. speed of 350 r. p. m. is usedon the hand feed for drilling 15/32 in. holes and a speed of300 r. p. m. is used for countersinking. Detailed times of theoperation are as follows: Prepare machine and set work 3 min Drill 28 15/32 in. holes 8 min. Change tool and speed and countersink 28 holes 8 min. Remove work and clear machine 2 min. The liners are then returned to the fitter and applied to tlie sideplate and crosshead. They are held by i/^ in. copper f
. American engineer . y for drilling andcounter-sinking will require IS minutes. They are drilled andcounter-sunk in 21 minutes. .A. speed of 350 r. p. m. is usedon the hand feed for drilling 15/32 in. holes and a speed of300 r. p. m. is used for countersinking. Detailed times of theoperation are as follows: Prepare machine and set work 3 min Drill 28 15/32 in. holes 8 min. Change tool and speed and countersink 28 holes 8 min. Remove work and clear machine 2 min. The liners are then returned to the fitter and applied to tlie sideplate and crosshead. They are held by i/^ in. copper fitting, riveting and finishing of the job complete will re-quire 60 minutes for the four liners. The sectional liners are also carried in stock, machined tosize and the fitting and applying of six of them requires 30minutes. After they are in place the side plates and bolts areapplied, nuts put on and split keys inserted. This work willconsume 60 minutes more. The complete operation of repairing this type of crosshead. View Showing the Clamp for Holding Piston Heads, and the Lathefor Finishing Rods. as described will thus consume a total of 386 minutes as fol-lows : Removing side plates and side liners * 60 min. Reclaiming shoes 140 min. Fitting and drilling four side liners 36 min. Applying side liners 60 min. Fitting and applying six sectional liners 30 rain. Assembling and bolting up 60 min. Total 386 min. BORING THE CYLINDER. If the cylinder needs reboring, a three year erecting shopapprentice removes the back cylinder head, cleans the counter- 559 560 AMERICAN ENGINEER. VuL. 80. Xd. 11 bore and sets up the boring bar. The boring bar used at theseshops is the Underwood, manufactured by H. B. Underwood& Co., Philadelphia. The machinist checks the setting of thebar and the apprentice then proceeds to lake the necessarycuts, being careful to leave a witness mark. An air motordrives the boring bar at a speed of 4 r. p. m., and the rough-ing cut will carry a feed of Z/2>2 in.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroa, bookyear1912
