SrATE U ptANT Y BOARD 
 
 United States Department of Agriculture 
 Bureau of Entomology and Plant Quarantine 
 
 A MECHANICAL TIMING DEVICE 
 FOR LABORATORY SPRAYING TESTS * 
 
 By F. W. Carlson and M. A. Yothers, 
 Division of Fruit Insect Investigations 
 
 In laboratory tests of various sprays against overwintering 
 codling moth larvae cocooned in grooved wooden pupation sticks 
 (1-3/8" x 5/16" x 6-3/4"), it was necessary to regulate the length 
 of time and the position of each lot of sticks while being sprayed. 
 In order to make all lots as nearly uniform as possible the follow- 
 ing device was developed as illustrated and described. 
 
 On the base (fig. 1, A), measuring 7-5/8" x 31-1/2", two 
 uprights (C) were built 37" high. Two rollers, 2-1/2" x 6-1/2", 
 were placed between these two uprights to carry a canvas belt (F) . 
 On this belt, at intervals of approximately 1 foot, were riveted 
 6 heavy tin cleats (G) to hold the pupation sticks. These cleats 
 were bent in such a way as to clasp the lower ends of the sticks 
 and hold them against the belt. 
 
 Attached to the main base (A) was another base (B) for the 
 motor (E), for which an electric fan motor was used, with the fan 
 removed. Over this motor a cover (H) was built to protect it from 
 the sprays. On the base (A) a worm gear (D) , formerly a reduction 
 gear in a "Jersey" centrifuge, ratio 10 to 1, was connected by 
 belt with the motor (E) and with the large 10" V pulley (I) on a 
 shaft to turn the rollers and revolve the belt (F) . On the fan 
 motor is a 1-1/2" V pulley, on the worm gear shaft with which it 
 operates is a 2" V pulley, and on the worm gear shaft carrying 
 the belt to the 10" pulley is a 1-1/2" V pulley. 
 
 This set-up, with the fan motor running at low speed, re- 
 volves the belt carrying the sticks at a rate of about 30 seconds 
 for a revolution, or 5 seconds for each cleat of sticks to pass 
 through the spray. 
 
 * This machine was developed at the Yakima, Wash. , laboratory in 
 the course of control experiments against the overwintering stage 
 of the codling moth. The writers are indebted to C. W. Murray 
 and John F. Cassidy, now of the Bureau of Agricultural Chemistry 
 and Engineering, for helpful suggestions. 
 
- 2 - 
 
 This machine was used with a spraying set-up composed of a 
 1/4-hp. electric motor (fig. 2, A), a compressor (B), and a 1-pint 
 capacity paint gun (C) . The paint gun was set or held on the 
 stand (D) at the same distance each time from the moving objects 
 being sprayed. 
 
 The speed of the belt carrying the objects to be sprayed 
 can, of course, be readily regulated by changing the speed of the 
 fan motor and by using a different ratio of pulleys. 
 
 List of Materials 
 
 1 piece 25/32" x 7-5/8" x 31-1/2" S4S1/ — Base 
 
 1 piece 25/32" x 7-5/8" x 19" S4S — Motor base 
 
 2 pieces 25/32" x 1-5/8" x 37" S4S -- Uprights 
 2 pieces 25/32" x 1-5/8" x 7" S4S — Brace 
 
 1 piece 25/32" x 1-5/8" x 10" S4S cut 45° — Brace 
 
 2 pieces 25/32" x 1-5/8" x 2-3/4" S4S cut 45° — Corner braces 
 
 1 piece 25/32" x 1-5/8" x 8-1/2" S4S — Base plate 
 
 2 pieces 25/32" x 1-5/8" x 27-1/2" S4S — Braces 
 
 3 pieces 25/32" x 1-5/8" x 5-1/2" S4S — Worm gear mounting 
 1 piece 25/32" x 1-5/8" x 1-3/4" S4S — Worm gear brace 
 
 1 piece 25/32" x 1-5/8" x 4" S4S — Brace 
 
 2 wood rollers 2-1/2" x 6-1/2" 
 
 3 lag screws 3/8" x 3" 
 1 lag screw 1/2" x 4" 
 
 1 piece canvas — Belt 6" x 72" 
 
 5 metal pupation-stick holders — attached to belt 
 
 1 reduction gear 10 to 1 
 
 1 10" V pulley 
 
 1 2" V pulley 
 
 2 1-1/2" V pulleys 
 1 V belt 1/2" x 58" 
 1 V belt 1/2" x 38" 
 
 1 5-gal . oil can cut out to cover motor 
 
 2 belt guards 
 
 1/ Surfaced 4 sides. 
 
TTIec/iaTiica) Tim ma Device. For Laboratory 
 Spray my Tests. 
 
 Figure 1. — A, Base; B, motor base; C, uprights; D, worm 
 gear; E, motor; F, canvas belt; G, metal pupation-stick 
 holders; H, motor cover; I, large pullej. 
 
Digitized by the Internet Archive 
 in 2013 
 
 http://archive.org/details/mechanicaltimingOOunit 
 

 Figure 2. — Complete timing device (as diagrammed in figure 1) 
 and spraying set-up. A, Electric motor; B, compressor; 
 C, paint gun; D, paint-gun stand. 
 
Figure 3» — Mechanical timing device from a different angle 
 from that shown in figures 1 and 2. 
 
UNIVERSITY OF FLORIDA 
 
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 3 1262 09240 9340