Model: 138 Gravity Drop Ore Stamp
In this model, sharp falls of the vertical rod are derived from the mutilated rotating wheel or pinion. This pinion acts upon the teeth in the rod and raises it until all teeth have meshed; then the rod falls. These [devices] are used for crushing rock to extract the ore and are generally mounted in gangs, having a large number in line.
[Virginia Downward & William M. Clark, 1930]

[Editor’s Note: This device is similar to the Clark model 137 in that the motion of the hammer depends on the physics of gravity and not on geometry alone. Therefore, it is not a pure kinematic mechanism. The constrained motion of the partial pinion and the hammer is similar to a rack and pinion mechanism. This device is described in the mechanical movements catalog of Henry T. Brown, 1868, in Figure 351. FCM]

Francis Moon 2005-00-00