Specification of Joseph Bramah : steam engines and boilers.

  • Bramah, Joseph.
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: Specification of Joseph Bramah : steam engines and boilers. Source: Wellcome Collection.

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    jBramah's Improvements in the Construction of Steam Engines and Boilers. ■ ————————-■ ■ ■ ■———■——————— cones are sometimes made open at both ends, and sometimes one end is shut and only one open, as the nature of the engine may require. They are likewise made sometimes single and sometimes double, as circumstances or fancy may direct; when single and applied to a single acting engine, the open end of the 5 cone is presented with its mouth to that part of the steam cylinder where the steam is to enter for the purpose of acting on the piston, and provided this open end be that of the larger diameter of the cone, then the lesser diameter will be the exterior end to which the moving cause must be affixed, and when both the ends of the cone is open there must be a flaunch on the outer case to 10 receive a cap and air-tight stuffing box through which the motion of the cone is to be communicated as before observed ; on the contrary, when the external end of the cone is not open, but left solid, the cap and stuffing box may be dispensed with at the discretion of the maker; but I would in all cases recommend the cap and stuffing-box as a guarantee to keep out the surrounding atmosphere should 15 the cone through use become imperfect. On opposite sides of the outer case of this cone is united two pipes similar to a stop-cock, one of which leads from said cone to the condensor and the other from it to the boiler, both communi¬ cating with the hollow part into which the cone is fitted, so that one pipe conducts the steam from the boiler to the cone, and the other from the cone 20 to the condensor. Now on one side of this cone is cut an aperture of equal dimensions with the pipes just mentioned, or may be less if necessary, but it must be so cut as to come in exact congruity with the opening or mouth of both the above pipes in the rotation of the cone, when turned about from without, and the distance between the two apertures formed in the outer case 25 by the mouths of the pipes must equal at least the diameter of the aperture in the cone, in order that as the cone is turned these openings may one of them be shut by the blank or solid side before the other begins to open; the whole being thus equipped, and supposing the aperture of the cone to be turned so as to become coincident with the end of the steam pipe, the steam 30 will then pass into the cavity of the cone on that side, and of course be carried into the steam cylinder through the open end of the cone, which is at all times presented to it. At the same time the steam, while acting on the piston, cannot escape to the condensor, because the aperture leading thither is kept shut by the blank or solid side of the cone, as above stated, till the engine has 35 made her stroke, and at which juncture the handle by the stroke of the plug tree or other contrivance, and a proper connection between the handle bar and the axis or spindle by which the cone is moved, suddenly turns the cone so as to first shut the steam pipe, and then station its aperture in exact congruity with the mouth of the condensing pipe, which instantly conveys the steam