Assuming that all the parts mentioned have been prepared, the cylinder
should be arranged in its proper place on the bed, the piston rod centrally
over its centre line. Mark and drill the screw holes in the bed.
The Valve Gear.--We may now attend to the valve gear. A fork must be made
for the end of the valve rod, and soldered to it with its slot at right
angles to the slots which engage with the valve lugs. Slip the rod into the
steam chest, put the valve on the rod, and attach the chest (without the
cover) to the valve plate by a bolt at each corner. Pull the valve forward
till the rear port is just uncovered, and turn the eccentric full forward.
You will now be able to measure off exactly the distance between the
centres of the valve-rod fork pin and the rear screw of the eccentric. The
valve connecting rod (Fig. 53, VCR) should now be made and placed in
position. If the two forward holes are filed somewhat slot-shaped, any
necessary adjustment of the valve is made easier. If the adjustment of VCR
and the throw of the eccentric are correct, the valve will just expose both
end ports alternately when the crank is revolved.
Pages:
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133