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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    — ■- .... —■ ■ ■—— ■ ■■ —■ * ■ 1 ■ — — .1 — .i — ■■■ ■ ■ ■■■». Bramah's Improvements in the Construction of Steam Engines and Boilers. thither, as in all other steam engines, and by the return of the stroke the cone is again driven into its former station, and thus a reciprocal action is kept up, the same as in other engines where valves are used. This cone applied at the bottom of a cylinder, with an open top, completes this part of an atmospheric engine ready for the working geer, which consists of nothing more than one 5 handle, as above mentioned, fixed on a bar or axis in the usual way, and two wooden pulleys properly proportioned, with a leather strap so joined to each as to cause these pulleys (one of which is fixed on the handle bar, and the other on the spindle which turns the cone) to move each other when the handle is carried up or down for the purpose of turning the cone in the way and for 10 the ends already described. This cone, with the same working geer, also answers for a single acting engine, where the elastic force of steam is used, and the atmosphere excluded. In the construction of a double acting engine, one of these cones is stationed at the top and another at the bottom of the steam cylinder, just in the manner already described, with this difference only, that the 15 steam pipe must form a junction with both the cones on one side and the con- . densing pipe the same on the other side of the outer cases, as above. When this is completed, the same handle, &c. as already mentioned, will completely answer in this instance also, only it will be necessary to adopt such a connecting movement between the external spindles of each cone as will cause them to 20 revolve in opposite directions when the plug tree strikes the handle. This may be accomplished by means of line or strap connected with two wooden pullies in a diagonal direction, or by sundry other common and simple means, particular attention being always paid to the placing the cones previous to their union by this connecting means so that the apertures cut in each, as above directed, may 25 fall exactly opposite to each other when in their active station. It is further necessary to remark that the application of these cones will in every case pre¬ vent the engine from being blowed clear of air or water in the usual manner before she starts, and that it will be necessary for the engine builder to contrive a separate communication between the cylinder and the steam pipe in the best 30 manner the situation and local circumstances of the engine will admit, and in no case whatever can this be attended with any difficulty. The double cone is applicable only to engines on the double acting principle, and by which they are rendered exactly the same in the working geer and in the operation of all the external parts as the single acting ones, and are more simple and compact, and 35 expose less quantity of joint or union of parts where air leaks may be appre¬ hended than such as are constructed with two separate single cones stationed as above described ; only it must be considered that in applying a double cone instead of the latter, there will be unavoidably a trifling loss of steam propoi>
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