The Practical mechanic's journal . the bar, «, which is the moving power of the whole,is as follows:—As the hammer descends, every portion of it acquiresmomentum, and when the shock of the blow puts a sudden check upon itsmovement, the bar, », having its momentum stored principally at its freeweighted end, overcomes the resistance of the spring below it, and, movingon its centre, the bent extremity shifts the bar, t, laterally, and releases the detent, o. This action may take place at any portion of the bar, t, for,as it always moves in a parallel direction, it is immaterial at what pointthe f
The Practical mechanic's journal . the bar, «, which is the moving power of the whole,is as follows:—As the hammer descends, every portion of it acquiresmomentum, and when the shock of the blow puts a sudden check upon itsmovement, the bar, », having its momentum stored principally at its freeweighted end, overcomes the resistance of the spring below it, and, movingon its centre, the bent extremity shifts the bar, t, laterally, and releases the detent, o. This action may take place at any portion of the bar, t, for,as it always moves in a parallel direction, it is immaterial at what pointthe force is applied; and thus, at whatever portion of its fall the hammermay be stopped, the momentum of the bar, u, brings the latter down;the bar, t, is moved laterally, and the detent, o, being thus removed, thereaction of the helical spring in the box, h, assisted by the weight of thescrew, e, opens the steam-valve to admit steam under the piston; and thehammer consequently rises until the guard, n, meets the end of the lever. carried by the nuts, m, of the screws, d and e (see fig. 1). This move-ment then changes the position of the slide valve, as mentioned in thedescription of fig. 1 ; the steam escapes from below the piston, and thedetent, o, falls again beneath the collar of the screw, e, ready for the suc-ceeding blow. A handle on the short lever of the detent, o, brings the latter withinreach of the attendant on the platform, who has thus the whole machineunder easy control, and is in a suitable position for directing the motionof the forged mass, whilst he can exactly apportion the power to thework to be done, and the state of the heat. When it is desired tolessen the force of the blow, the steam is admitted beneath the piston, justbefore the hammer reaches the mass upon which it acts, so that acushion of steam is interposed to partially sustain the force of the blow,and modify it for any particular purpose; and so exactly does this answerthe end, that the hammer ma
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Keywords: ., bookcentury1800, bookdecade1840, bookidpra, booksubjecttechnology
