ON THE AUTOMATIC BALANCE OF RECIPROCATING MECHANISM. 667 



flexible or articulated connection or hooked rod, motion is communicated 

 to the rotating weight. In figs. 2 and 3 a simple mode of connection is 



Fig. 1. 



shown. When the pulley in the bracket, A, is driven from some source 

 of power, rotation at the same speed is given to the weight, W. Being 



Fig. 2. 



an unbalanced weight it sets up vibration in the thing to which it is 

 attached, namely, in this case the screen, and the whole of the work done 

 is absorbed in vibrating or gyrating the screen through a range which is 

 proportional to the relations as to dimensions and weights already 

 referred to. In fig. 6 is shown in plan an alternative method on the same 

 principle, by means of which a rotating eccentric weight, "W, running 

 in bearings in a bracket, B, and driven by a flexible connection, C, 

 imparts to the screen a reciprocating motion. In this case the range 

 of reciprocation is limited by the mode of suspension of the screen 

 weight, of the screen and its load when it is undesirable that the 

 screen should be lifted by the inertia of motion of the weight, W, in the 

 downward part of its rotating path. The movements described with 

 reference to these diagrams are illustrated by three of the models 

 exhibited. 



