US 3286506 A
Description (OCR text may contain errors)
Nov. 22, 1966 R. LLOYD SAMPLING PUMP Filed May 2o, 1964 INVENTOR.
ATTORNEYS we E623 wr ,EMS om k Q mm 32E O m 4 kumlu UnitedStates Patent O 3,286,506 SAMPLING PUMP Richard L. Lloyd, Salt Lalke City, Utah, assignor to the United States of America as represented by the Secretary of the Army Filed May 20, 1964, Ser. No. 369,046 1 Claim. (Cl. 73--23) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.
The present invention relates to a pump to take a sample of air or other gas and test it to determine how much of a certain contaminant it contains. The sampling pump is of l-ow-cost construction and simple to operate for quick on-the-spot testing.
In the drawings:
FIG. l is a side view of the pump with parts in cross section.
FIG. 2 is a view of the hollow piston rod.
FIG. 3 is a View of the hollow piston rod taken at right angles to the view of FIG. 2; and
FIG. 4 is a view of the glass tube containing an indicating compound and adapted to be inserted in the hollow piston rod.
Sampling pump casing has a plunger 12 mounted on plunger rod 14 for manual reciprocation by the hand piece 16. The pump is closed at one end by cap 18 with a vent hole 20 therein. The pump is closed at the other end by cap 22 having a tube connector 24 and check valve 26 therein. Plunger 12 has sealing O rings 28 and check valve 30 mounted thereon. Plunger rod 14 has a resilient seat 32 and a stop member 34 mounted therein to limit movement of glass tube 36. The glass tube is calibrated along its length with visible indicia 37 and is further secured against movement in the opposite direction by threaded screw 38 and wing nut 40 which may be adjusted to press tube 36 gently against resilient seat 32.
Plunger rod 14 has a slot 42 and an oval shaped hole 44 through which glass tube 36 with its indicating compound 46 may be viewed. The compound 46 may be secured in glass tube 36 by any means desired. Exhaust hole 48 is drilled near the end of plunger rod 14.
OPERATION The sampling pump is preferably transported to the site where it is to be used with the glass tube cartridge 36 removed from the pump casing 10 and sealed against contamination of the indicating compound 46. At the site where the air is to be tested the plunger is reciprocated repeatedly to draw in the air to be sampled at 24 and to exhaust the air through exhaust hole 48 (and slot 42). When the pump is fully charged with air to be sampled, with the plunger 12 pulled all of the way toward cap 18, the calibrated glass tube 36 with indicating cornpound 46 is inserted in plunger rod 14. Hand piece 16 is attached to rod 14 and screw 38 is adjusted to prevent end movement of tube 36. Plunger 12 is then pushed to its limit toward cap 22. With this movement, the predetermined volume of sample air in pump casing 10 ahead of plunger 12 is forced thru check valve 30 into plunger rod 14, thru glass tube 36 and indicating compound 46 and out thru exhaust hole 48. Plunger rod 14 may then be pulled back. The extent of discoloration or other change in compound 46 may then be observed thru viewing slot 42 and hole 44. With the aid of calibrations 37 on the side of glass tube 36 the operator may determine the relative amount of contaminating or other types of impurities in the air.
A pump for testing a sample of a gas comprising:
a pump casing;
a plunger reciprocably mounted in the casing;
a hollow plunger rod having a cut-.away area attached to the plunger and reciprocably mounted in the casing;
a glass tube with graduated indicia thereon viewable through said cut-away area and mounted in the hollow plunger rod;
a removable closure for the plunger rod that may be removed so that the glass tube may be inserted in the plunger;
a color-changeable indicating compound in the glass tube;
a valve means for the pump operative to admit a sarnple of air to be tested to the pump as the plunger is reciprocated in one direction;
and valve means for the plunger to admit the sample to the glass tube and the indicating compound as the plunger is reciprocated in a second direction to change the color of the compound in accordance with the characteristics of the air sample.
References Cited bythe Examiner UNITED STATES PATENTS JAMES I. GILL, Acting Primary Examiner. RICHARD C. QUEISSER, Examiner. J. FISHER, Assistant Examiner.