Tham khảo tài liệu 'five hundred and seven mechanical movements part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Mechanical Movements. 113 Steam being alternately admitted below piston and allowed to escape raises and lets fall the . hammer. 471. Hotchkiss s atmospheric hammer de- rives the force of its blow from compressed airHammer head c is attached to a piston fitted to a cylinder B which is connected by a rod D with a crank A on the rotary driving-shaft As the cylinder ascends air entering hole r is compressed below piston and lifts hammer. As cylinder descends air entering hole e is compressed above and is stored up to produce the blow by its instant expansion after the crank and connecting-rod turn bottom center. ị 472. Grimshaw s compressed air hammer. At the bottom of The head of this hammer is attached to a piston A which works in a cylinder B into which air is admitted like steam to a steam engine above and below the piston bv a slide-valve on top. The air is received from a reservoir c in the framing supplied by an air pump D driven by a crank on the rotary driving-shaft E. 1 473. Air-pump of simple construction. Smaller tub inverted in larger one. The latter contains water to upper dotted line and the pipe from I shaft or space to be exhausted passes through it j to a few inches above water terminating with ị valve opening upward. Upper tub has short ị pipe and upwardly-opening valve at top and is I suspended by ropes from levers. When upper tub descends great part of air within is expelled through upper valve so that when afterward raised rarefaction within causes gas or air to ascend through the lower valve. This pump was successfully used for drawing off carbonic . acid from a large and deep shaft. r 474. zEolipile or Hero s steam toy described by Hero of Alexandria 130 years . and now-regarded as the first steam engine the rotary form of which it may be considered to represent. 466. Hydrostatic press. Water forced by the pump through the small pipe into the ram cylinder and under the solid ram presses up the ram. The amount of force obtained is in .
