Scientific American Supplement, No. 415, December 15, 1883 by Various
page 49 of 126 (38%)
page 49 of 126 (38%)
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each of precisely this same length. Further, the axis about which the
reversing lever, T, vibrates is so situated that when that lever, as in Fig 11, is thrown full to the left, the pin in its upper end is exactly in line with the rock-shaft, O. When the parts are in this position, the suspension-rod, S, the arm, G, and the lever, M, will be as one piece, and their motions will be identical, consisting simply of vibration about the axis of the rock-shaft, O. The motion of the lever, M, is then due solely to the pin, B, which is in this case exactly in line with the journal, J, so that the result is the same as though this eccentric rod were connected directly to the lever; and the pin, P, being also in line with B and J, and kept so by the suspension-rod, S, it will be seen that the bridle-rod, R, will move with the link, L, as though the two were rigidly fastened together. When the reversing lever, T, is thrown full to the right, as in Fig. 12, the pin, P, is drawn to the inner end of the slot in the arm, G, and is thus exactly in line with the rock-shaft, O. The suspension-rod, S, will, therefore, be at rest; but the pin, A, will have been drawn, by the bridle-rod, R, into line with the journal, J, and the bridle-rod itself will now vibrate with the lever, M, whose sole motion will be derived from the pin, A. There is, then, no block slip whatever when the link thus suspended and operated is run in "full gear," either forward or backward. If this arrangement be used in cases where the link is used as an expansion device, there will be, of course, some block slip while running in the intermediate gears. But even then, it is to be observed |
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