Crane.| Prospecting, Mining and Milling Machinery. 265 
hand nut, K, the block, J, is raised, which forces out the tog- 
gle seat, I. 
A heavy casting, L, furnished with a movable plate, M, is 
supported by and hangs upon the shaft, NV. The toggle seat, 
O, is set into the lower back side, and a few inches below it 
is attached an eye bolt, R. From the eye bolt a long rod, S, 
runs backward, passing through a heavy helical spring, Q. 
By tightening the nut, P, the jaw, L, is forced back upon the 
toggles, which are thus securely set and held in their seats. 
When the casting, F, is raised by the eccentric, the inner ends 
of the toggles, H, are raised and approach parallelism, but as 
the seat, J, is set in the frame of the crusher, it is stationary 
and cannot move, so that the jaw, L, will be forced forward. 
When the bumper, F, falls, after a semirevolution of the shaft, 
A, the spring, Q, draws back the jaw, L. The toggles are thus 
held tightly in their seats, and the jaw, JL, is given an oscil- 
lating movement, the rapidity of which is regulated by the 
movement of bumper, /, and that in turn by the rotation of 
the shaft, A. 
A movable jaw piece, 7’, fits into the front of the crusher 
frame, while on either side of the same and resting against 
the sides of the crusher frame, in specially formed seats, are 
cast-iron plates, U, which are fastened by bolts, V. The heavy 
stationary jaw piece, 7’, with the two lighter hand plates, U, 
and the plate, M, on the movable jaw, L, form a hopper into 
which the material to be crushed is thrown. The movable 
jaw, L, with its plate, W, works between the hand plates, U, 
which protect the sides of the crusher frame from wear and 
are readily removed when worn or broken. In figure 65, 7, 
and 2 show two different forms of hand plates. 
The space between the fixed jaw, 7, and the plate, M, in 
the movable jaw, L, is varied by the tightener, J. The stroke 
given by this crusher is comparatively short, but quick and 
powerful, 
The maximum size of material that can be fed to this form 
of crusher is that which can fall sufficiently far down be- 
tween the jaws of the crusher to be caught by them and so 
reduced. The maximum and minimum sizes of crushed 
