194 DETAILS OP (PADDLE-WHEEL)
both as to design and proportion. The reliefvalves openings are shown, with the facings indotted lines in the sectional elevation, at thebottom steam passages. To enable a just appre-ciation of the merits of the details under notice,
/ / // / /
MESSES, watt’s OSCILLATING CYLINDER AND VALVES.
the following dimensions of the same are quotedfrom the working drawings, from which thoseherein alluded to were reduced :—
Ft. In.
Diameter of Cylinder ....
0
64
Length of Stroke .....
5
0
Diameter of Cylinder Cover
6
0
Thickness of Cylinder Body
0
14
Vertical Distance of centre of Trunnion from
the base of the bored portion of the
Cylinder ......
3
2
Vertical distance between centre of Trunnion
and centre of Exhaust port .
0
64
Total depth of Belt .....
3
0
0
0
4
Diameter of Trunnion bearing .
2
4
Length of ditto ....
0
81
Internal diameter of Trunnion tubing
0
174
Thickness of metal of Cylinder Cover and
Steam Passages ....
0
li
Diameter of Piston Bod ....
0
9
Diameter of Stuffing Box ....
0
12
Depth of Stuffing Box ....
0
13
Depth of Bottom Bush ....
0
7
0
6
Stroke of Slide Valve ....
0
7
Outside Lap do. .
0
Inside Lap do.
0
0i
Lead do.
0
0|
Travel of the Piston during the admission of
the steam by the slide valve, up-stroke .
0 40f
Ditto, down-stroke .....
0 32 i
Width of Supply Ports in Cylinder
0
2
Width of Exhaust Ports in Cylinder .
0
6
Width of Largo Bars in Cylinder
0
8
Width of Small Bars in Cylinder
0
24
Width of Supply Opening caused by the
0
If
Length of Steam Ports ....
2
6
Diameter of Slide Valve Bod
0
li
Diameter of Belief Openings in Cylinder
0
34
The depth of the bottom bush in the st uffin gbox for the piston rod being of importance,another example of the same is represented byFig. 40—page 195—shown half in section andhalf complete. In this case, the lower bush ismuch deeper in proportion to the diameter ofthe rod than the other, although the diameterof the cylinder is 61 inches, and the strokeonly 4 feet 6 inches. The diameter of thepiston rod is 7i inches, and the stuffing box