514 Report hn the Trials of Implements at Wolverhampton. 
■wheel, E, actuated by a pinion upon an npper shaft, which receives motion 
from the steam-engine eitlier by rigcjcr and strap (as during the trial in Class 
III.), or by a coupling-shaft with universal joints. The spur-wheel is con- 
Fig. 22.— Section of Messrs. Tuxford and Sons' DetacTicd Patent Windlass. 
nected or disconnected with either drum by " adjustable expanding friction- 
couplings," which may be thus described. Carried in guides or cheeks cast 
upon the arms of the spur-wheel, are " toggle-blocks," F F and G G (Figs. 
21 and 22), three upon one side of the wheel and three on the other ; tiic 
stems by which the blocks are supported sliding in the guides, so that they 
can be thrust outwards against the inner part of the rim of each drum or 
withdrawn from contact. For effecting this movement each sot of three blocks 
is connected with a loose boss or ring surrounding the shaft and sliding upon 
a feather, by means of three " toggle-bars " jointed and made with right and 
left hand adjusting screws for altering their length. Thus, when the ring H 
is drawn toward the spur-wheel, the bars J J press the blocks F F against the 
flange of the drum C, the pressure being exactly equal upon all three blocks, 
while the amount of thrust from this triple knee-joint action can be regulated 
by lengthening or shortening the toggle-bars J J. In this position the spur- 
wheel E is in gear with and drives the drum C. By sliding the boss along 
the shaft away from the spur-wheel, the toggle-blocks are withdrawn from 
contact with the drum, as represented in Fig. 21, where the ring or boss K, 
drawn aside, causes the blocks G G to approach the centre, thus leaving the 
drum B released from connection with the spur-wheel. It will be understood 
that as both the rings or bosses H and K are secured by keys through lateral 
slots to a spindle, L, passing up the centre of the shaft D, the disconnection of 
one drum and gearing of the other are simultaneously effected by simply 
(sliding the spindle L further in or out of the shaft. The outer end of the 
spindle has a screw cut oa it, and carries a light bevel-wheel, M, in the boss of 
