. Railway mechanical engineer . he forces of release. The force has been ob-tained by calculating the forces required to produce the re-corded changes of velocity over a given period of time. Itis unquestionable that in many of the gears, probably inevery case, the sticking and irregularity of gear closure wasaccompanied by high forces which, because of their very lim-ited duration, could not manifest themselves in the time-displacement curves. The mean or average forces and the ul-timate peak forces as deduced in these curves, however, aresubstantially correct and it is questionable whether a
. Railway mechanical engineer . he forces of release. The force has been ob-tained by calculating the forces required to produce the re-corded changes of velocity over a given period of time. Itis unquestionable that in many of the gears, probably inevery case, the sticking and irregularity of gear closure wasaccompanied by high forces which, because of their very lim-ited duration, could not manifest themselves in the time-displacement curves. The mean or average forces and the ul-timate peak forces as deduced in these curves, however, aresubstantially correct and it is questionable whether after allthe mean force as depicted, or in other words the force sup-plied over long enough period of time to produce penetrationor to do the work of rupture, is not the real damaging factor. The time-force curves will assist in an understanding ofthe fact that the force between colliding cars is not governedor in any manner reduced by the action of a friction gear Solid Butter in Car ATest Gear No/2 in Car B•YeLQcity»S*8n\RH. \ Compression k —---+—- j, Sec Draff Oear Cycle Fig. 4—Time-Closure Curves, Westinghouse D-3 Gears over a spring gear of the same characteristics. Energy ab-sorption has in itself no effect whatever upon the compres-sion line. But its influence is immediately apparent in theforces of release. For while it requires high forces to over- come the frictional resistance and to compress a friction gear,the force immediately disappears when the gear starts torelease. This action is clearly shown in the time-force curves. Time-Closure Curves Time-closure curves are developed for each of the runs,Fig. 4 showing such a curve for the single gear run for theWestinghouse D-3 gear. Curve D in this figure has beenderived and erected from the superimposed car-movementcurves and shows the full yield that took place between thecars, including draft gear compression, center sill compres-sion, and side sill movement. Curve C is
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
