Forfatter: A.-M.Inst.C E., George Frederick Zimmer
År: 1916
Forlag: Crosby Lockwood and Son
Sted: London
Sider: 752
UDK: 621.87 Zim, 621.86 Zim
Being a Treatise on the Handling and Storing of Material such as Grain, Coal, Ore, Timber, Etc., by Automatic or Semi-Automatic Machinery, together with the Various Accessories used in the Manipulation of such Plant
COAL FACE CONVEYORS
167
various forms of valves and slides. The cut-off is always so arranged as to utilise the
expansion of the air, whilst a few are on the compound system.
The Korfmann Conveyor is one of the latest types. It is supported on wedge-shaped
runners which can be placed in a variety of positions to suit level or inclined seams.
The engine is noteworthy for its comparative simplicity. Figs. 221 to 223 show
this in section, also a separate section of the slide box in the second position, and an
end view. The first position of the slide valve (shown in the upper section) rests, owing
to its own weight, in the lowest position. As the compressed air is admitted it passes
round the annular channels in the gear box and cylindrical slide valve and through
radial openings, the central passage and port behind the piston pushing it forward.
The cylindrical portion or piston of the slide gear is compounded, and consists of the
lower main portion fitted with an upper wing, and has in addition a small plunger in its