332 APPLIED MECHANICS 
284. The Simple Conical Pendulum Governor.—One of the earliest 
forms of the simple conical pendulum governor, as ‘applied to a steam- 
engine, is shown in Fig. 518, ABC and A’B’C’ are the arms, jointed 
together and to the vertical spindle HK at BB’. Links CD and C’D’ 
connect the arms to the sleeve E, which, while it rotates with the spindle 
HK, can slide up or down on it when the balls A and A’ fall and rise 
with changes of speed. The sleeve E has a groove turned on it to receive 
the forked end of a lever, through which, and through other levers and 
links if necessary, the sliding motion of the sleeve is transmitted and 
converted into the motion of the throttle valve. The vertical spindle HK 
is driven by the engine which the governor has to control. To reduce the 
strain on the joint at BB’, caused by the inertia of the balls when the 
Fie. 518. Fig. 519. Fia. 520. 
angular velocity of the spindle changes, the arms AB and A’B’ work in 
slots in the curved arms ML and MN, which are fixed to the spindle at M. 
A later and more common form of the simple governor is that shown 
in Fig. 519, and to this the description just given will apply, except that 
the arms ML and MN are dispensed with, but the sleeve E is driven by 
a key on the spindle HK, which, however, does not interfere with the 
vertical sliding of the sleeve on the spindle. 
A modification of the design shown in Fig. 519, which makes the 
governor more sensitive, is that in which the axes of the joints at B and 
B’ are made to coincide and intersect the axis of the vertical spindle, as 
in Fig. 518. A still more sensitive form is that shown in Fig. 520, 
which is known as a crossed arm governor. The three designs shown in 
Figs. 518, 519, and 520 correspond to the three forms of the simple 
conical pendulum shown in Figs. 511, 512, and 513, p. 329. 
Neglecting friction and the effects of the mass of the arms and sleeve, 
the formulz connecting the speed with the height h for the governors 
described in this Article are the same as for the simple conical pendulum, 
namely, _g_ 9g _ 60% 
wt darn? 42 N2° 
The following results are useful in connection with calculations on 
governors :— 
g=32°2. —/g = 56745. 7 —0°8156. 
4a? 
