SPKAYING APPARATUS. 



153 



Fig. 3 represents a side view of the nozzle and a cross 

 section of the piston abo at three-fourths natural size. The 

 cylinder u projects at right angles from the top of the tube 

 w. This cylinder is closed at the end by a bevelled block. 

 The orifice v is closed by a sliding piston which is composed 

 of one or two pieces. The cross section of the piston shown 

 in Fig. 7 represents the form having two parts, an inner 

 piston which can be screwed out, as represented by the dot- 

 ted line e, and an outer part or sleeve c. By turning the 

 screw s the spray can be changed instantly from a long- 

 range spray suitable for orchards to a spray fine and mist- 

 like. However the opening may be adjusted, it so remains, 

 except when obstructions become lodged in the nozzle. The 

 spring X is designed to hold the sliding valve in position 

 except when obstructions are forced into the nozzle. As 

 such obstructions prevent the passage of the fluid, the pres- 

 sure upon the walls of the opening in the nozzle instantly 

 increases. This forces the piston back from the outlet orifice 

 so that the opening will admit the passage of any object not 

 larger than one-fifth by three- sixteenths inch. When the 

 obstruction passes out, the force of the spring sets the valve 

 back into position and the nozzle works again as desired. 

 The tension of the spring x can be varied by moving the ring 

 z up or down. Figs. 4 and 5 represent two pistons, each 

 composed of one piece. No. 4 is adapted for long-distance 

 work; No. 5 is adapted for short-distance work, as it 

 throws a very fine spray which cannot be forced to a dis- 

 tance. These parts are made to be used where a change of 

 spray is not desirable. All the pistons are interchangeable. 

 Fig. 6, Plate XXYIL, represents a lighter nozzle, designed 

 for knapsack pumps. The spray is fan shaped. The advan- 

 tages of such a nozzle are evident. When the spraying is 

 done by means of a pole extension, such small particles as 

 clog some other nozzles are quickly released without any 

 delay or stopping of the pump or lowering the pole to clear 

 the nozzle. 



The extension nozzle consists of a metal pipe, sometimes 

 inclosed in a bamboo pole. It is made to enable the opera- 

 tor to raise the nozzle to a height of twelve feet or more 

 from the ground, so that orchard trees may be sprayed with- 



