THE DESIGN OF AN OIL ENGINE. 37 
sets of cylinders. It has been stated that the fuel and the admission valves must be 
subject to regulation as to timing, etc. The starting and exhaust valves do not need 
this regulation. For this reason the fuel and exhaust valves are placed on the front 
side of the engine and the starting and admission valves on the back side. It is prac- 
tical to vary but one set of valves from one cam shaft, therefore the proposed ar- 
rangement. The cam shaft as designed is composed of a shaft and a sleeve. The 
drive is on the sleeve and the fixed valve is driven from the sleeve. The shaft which 
is within the sleeve can be varied in its position relative to the sleeve. The cams for 
the variable acting valves are operated from the shaft within the sleeve. This means 
that at one side the fuel valve is operated from the shaft and the exhaust valve from 
the sleeve, while on the other side the starting valve is operated from the sleeve and 
the admission valve from the shaft. This is shown in the plan of the cam gear. No 
defense will be offered for this mechanical arrangement. It was worked out after 
years of scheming and perhaps a better arrangement can be produced to get the same 
result. This result must be obtained, however. The drive from the sleeve to the 
shaft is composed of a spiral key and keyway similar to that used in the side-shaft 
steam engine for reversing. The timing of these valves is regulated by the levers 
shown at the end of the cam boxes. It is claimed that this device is a working and 
practical arrangement. Nothing more is claimed for it. 
REVERSING. 
The motor ships run by four-cycle engines are for the most part reversed by 
swinging the cams clear of the cam shafts while the cams are being moved along the 
cam shafts. This is needed for a multi-cylinder engine, because otherwise one or- 
another set of cams would always be prevented from moving by coming in contact 
with its roller. This difficulty is remedied in the motor ship, as has been stated, by 
swinging all rollers clear of the cams during a change of cycle. For a compact en- 
gine this arrangement is rather clumsy. The same result obtained by this swinging 
movement must be obtained. In this engine it is obtained by a modification of the 
roller and roller fork. The rollers are carried on a long pin with considerable play 
on each side of the rollers. The rollers are held in a central position by means of 
balanced springs. With this design, in changing from one cycle to another, those 
cams which interfere with a roller will simply push the interfering roller to one 
side and the other cams are not prevented from attaining their new position. The 
displaced rollers take their normal position as soon as the cams have rotated enough 
to allow this action. In making the change from one cycle to another in a 6-cylinder 
engine there will be normally 24 cams bearing on the cam surfaces. These cam roll- 
ers must be held down by strong springs in order to assure prompt action of the 
valves at high speeds. To move the cams along the cam shaft would naturally call 
for the expenditure of considerable effort. In order to make this action easier and 
the maneuvering of the engine more prompt a provision is made on the cam boxes 
whereby all cam rollers may be simultaneously lifted about 1/32 inch. This will be 
