SET-114 TATE 'atNT BOARD December 1937
United States Department of Agriculture
Bureau of Entomology and Plant Quarantine
A MOTOR-DRIVEN TELESCOPING STIRRER FOR USE WITH
AN INSECTICIDE SPRAYING APPARATUS
By L. D. Goodhue, Division of Insecticide Investigations,
and E. H. Siegler, Division of Fruit Insect Investigations
In connection with laboratory tests of insecticides it is desirable to
standardize the procedure and maintain all conditions as constant as possible.
In tests where foliage, or in this case where apple plugs are sprayed, it is
necessary for the spray gun to deliver the spray material at a constant rate.
The commonly used atomizer type of gun with a suction feed can not be expected
to deliver at a constant rate unless the level of the liquid in the supply
vessel is maintained constant. Since considerable agitation is usually neces-
sary to maintain a uniform suspension of the insecticide, stirring with one
hand and keeping the liquid at the correct level with the other becomes a
difficult task. The inconvenience in this method prompted the development
of this improved stirrer.
The spray apparatus for which this stirrer was developed has been de-
scribed by E. H. Siegler and F. Munger (A Laboratory Spray Apparatus, Jour. "-
Econ. Ent. 28: 704-706, 1935). The spray gun employed is of the atomizer
type with a suction feed.
The telescoping stirrer is shown diagramatically in figure 1. It con- '
sists essentially of a 4-inch brass rod 12 inches long fitting inside of a 6- A,1
inch piece of brass tubing which holds the propeller. Pressure from the beaker
on the bearing point causes the two parts of the stirrer to telescope, thus
making it possible to obtain vigorous agitation at the bottom of the beaker and
at the same time to keep the level of the suspension constant with respect to ,
the spray gun. The brass tube is provided with a brass collar and screw. The -
screw slides in the milled groove in the rod and causes the two parts of the -
stirrer to turn together. The groove begins about 2 inches from the bottom of -
the rod, thus keeping the two pieces of the stirrer together when the beaker is
removed. The lower end of the stirrer is closed and is provided with a blunt r.
point which acts as a bearing on the bottom of the beaker. The use of a rubber
propeller, which is easily made from a rubber stopper, eliminates the possi-
bility of breaking the beaker.
The glass tube which conducts the spray material to the gun is made
from i-inch tubing bent as indicated in the diagram. This form allows the '--...
level of the liquid to be kept constant with respect to the spray gun by raising,.
the beaker as the spray material is withdrawn.
To spray 6un
600 cc. Beaker,
r-l3' 1 = I'
g3<-Collar and screw
- Liquid level
- Brass tube
Figure l.--Diagrbm of the telescoping stirrer and associated parts.
UNIVERSITY OF FLORIDA
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