The Mechanical Engineering of Collieries, الجزء 1،المجلد 1"Colliery Guardian" Office, 1886 |
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عبارات ومصطلحات مألوفة
air-compressing engines appliances applied arrangement atmospheric attached average axles beam boiler bolts bottom Brinsop bucket Burnley cage cast iron cent chapter clack Clay Cross clip pulley coal colliery column compressed air condenser connection Cornish engine Cornish pumping engine crank cubic curve degs delivery diameter double-acting driving driving wheel drum effective efficiency Elevation exhaust Fahr feet fixed fly-wheel friction Hadfield's hauling engines hauling rope heat horizontal horse-power hydraulic injector lever lift load machine machinery miles mining minute motion Patent pipe piston rod placed plunger pressure of steam pump rods pumping engine quantity raised Ram Pumping revolutions per minute round screen Section shaft shown in fig side slide square inch steam cylinder steam pressure Steam Pump stroke surface tail rope temperature tons tubs underground vacuum valve gear velocity vertical wear weight wheel whilst Wigan winding engines writer wrought iron yards
مقاطع مشهورة
الصفحة 85 - The means of accomplishing these points did not immediately present themselves ; but early in 1765 it occurred to me, that if a communication were opened between a cylinder containing steam, and another vessel which was exhausted of air and other fluids, the steam, as an elastic fluid, would immediately rush into the empty vessel, and continue to do so until it had established an equilibrium ; and if that vessel were kept very cool by an injection or otherwise, more steam would continue to enter...
الصفحة 65 - I have seen the water run like a constant fountain stream forty feet high ; one vessel of water rarefied by fire driveth up forty of cold water. And a man that tends the work is but to turn two cocks, that one vessel of water being consumed, another begins to force and re-fill with cold water, and so successively, the fire being tended and kept constant, which the self-same person may likewise abundantly perform in the interim between the necessity of turning the said cocks.
الصفحة 298 - ... equal in amount to the versed sine of the arc described by the lower end of the lever E, thus correcting the above error, and giving an equal travel to the centre, F, of the lever above and below the centre of the slot. At the same time, the error introduced by the movement of the end of the valve link, G, is corrected by curving the slot, J, to a radius equal to the length of G.
الصفحة 130 - The action of the differential valve gear is so sensitive and perfect that the load on the engine may be greatly varied whilst in full work without requiring hand control by the stop valve. Engines on this plan may accordingly be employed to pump direct into town mains without the use of stand pipes or balance valves.
الصفحة 126 - From the foregoing description of the valve gear, it will be understood that every erratic motion of the engine alters the relative position of the valves with respect to the main piston, and in that way the engine checks itself. So perfect is the action of this gear, that when properly adjusted, the full load may be thrown suddenly off the engine without any injury resulting. The effect of a sudden loss of load is to reverse the action of the valves, and to throw the steam against the motion of...
الصفحة 297 - M, thereby causing the curved path traversed by the centre, F, of the lever, E, to cross the vertical centre line, and diverge from it on either side at will. The forward or backward motion of the engine is governed by giving the slot this inclined position on one or other side of the vertical centre line ; and the amount of expansion depends on the amount of the inclination, the exactly central or vertical position being
الصفحة 65 - An admirable and most forcible way to drive up water by fire, not by drawing or sucking it upwards, for that must be as the philosopher calleth it, infra spheeram activitatis, which is but at such a distance. But this way hath no bounder, if the vessels be strong enough ; for I have taken a piece of a whole cannon, whereof the end was burst, and filled it...
الصفحة 126 - ... made to cut off steam by its motion, whilst the uniformly moving subsidiary piston is employed in admitting it. As long as the resistance to the engine is sufficient to prevent its motion becoming relatively equal to that of the subsidiary piston, steam is admitted up to the fixed point of cut off; but should a loss of resistance, or a superior pressure of steam, cause the engine to acquire a speed relatively greater than the speed of the subsidiary piston, then the motion of the steam valve...
الصفحة 67 - ' that in a little water, changed into steam by means of fire, we can have an elastic power like air $ but that it totally disappears when chilled, and changes into water, by which means he perceived, that he could contrive a machine in such a manner that with a small fire he could be able, at a trifling expense, to have a perfect vacuum.
الصفحة 129 - Fig. 12, is actuated by the piston rod through a lever H, working on a fixed centre, -which reduces the motion to the required extent and reverses its direction. The valve spindle is not coupled direct to this lever, but to an intermediate lever L, which is jointed to the first lever H, at one end; the other end M, is jointed to the...