US 3104542 A
Description (OCR text may contain errors)
Sept. 24, 1963 M. F. scoeems REMOTELY CONTROLLED DUST SAMPLER INVENTOR. flay FScc g qz'fzs BY Filed July 14, 1961 lfqcu urr dz Source Vacuum- Source 7/ United States Patent 3,104,542 REMOTELY CONTROLLED DUST SAMPLER Max F. Scoggins, Richland, Wash, assignor to the United States of America as represented by the United States Atomic Energy Commission Filed July 14, 1961, Ser. No. 124,240 3 Claims. (Cl. 73-28) The invention relates to a novel remotely controlled dust sampler, more particularly to such a sampler for radioactive atmospheric dust, remotely controlled without the use of a system of wires and electrical relays.
Dust samplers prior to a test must be covered from the atmosphere both to protect the dust-entrapping membrane from damage by moisture and to prevent stray particles of dust from becoming entrapped in the membrane prior to the measured period of exposure of :the test.
In order for a test to be accurate the rate of flow of the atmosphere through the dust-entrapping membrane must be steady. This is provided for by shielding the membrane from the Wind and drawing the atmosphere and its dust content through the membrane at a constant rate by means of a partial vacuum. This is usually done by having a single vacuum source serve quite a number of samplers, being connected to them by a plurality of suction lines over a considerable distance. Accurate sampling requires several hundred, or even more, samplers to be used in a field test; they must be dispersed in all directions over the area being tested and at different levels from the ground level to the tops of buildings or towers such as those used for radio and television broadcasting. In areas near installations which handle radioactive materials towers are sometimes built especially for this purpose.
The time when a test for radioactive dust is to be commenced cannot always be foreseen. Even tests of a routine nature have to await favorable conditions of wind, rain, and the like, while those not of a routine nature, as, for example, when an accident occurs at an installation of the kind mentioned, public safety may demand that a test be made immediately. For these reasons manual removal of the covers on dust samplers is unsatisfactory; the cost in dispatching a large number of men over the area to remove the covers is unreasonable, and even if cost were not a consideration, manual removal cannot be as prompt and dependable as is desirable.
Proposals have been made for removing dust sampler covers by an arrangement of electrically actuated remotely controlled relays; this would perhaps be satisfactory were it not for the cost of installing and maintaining a network of wires running to each of the dust samplers. If the same result could be attained without such a network, a worthwhile economy would be achieved.
It is, accordingly, an object of the invention to provide a dust sampler which may be remotely controlled Without an electrical relay or a wire system.
Other objects of the invention will appear as the description proceeds.
All such objects are attained by my invention of a remotely controlled dust sampler, which will now be described in detail with reference to the drawings, in which FIG. 1 is a sectional view, partially diagrammatic, of the dust sampler with the cover in place;
FIG. 2 is a view similar to FIG. 1, with the cover released; and
FIG. 3 is a sectional view taken on the line 3-3 of FIG. 1.
4 is a base member made of plastic such as polyethylene, polypropylene, or the like. The base member 4 has a collar portion 4a, preferably of circular cylindrical shape, projecting in one direction. The base member 4 also has a nipple 5, which projects in the opposite direction and is provided with raised annuli 6 .and 7 for receiving and 3,104,542 Patented Sept. 24, 1963 "ice,
holding a suction line 7a leading to a vacuum-producing means or source 7b. 8 is a body, preferably of circular cross-section, made of metal, plastic, or other suitable material, metal being preferred.
A flanged ring 9, preferably of a plastic material such as polyethylene, is tightly fitted within the body 8 and tightly embraces the collar portion 4a of base member 4.
A filter 10, which comprises a filter membrane 10a, a
mass 10b of backing material, and a frame 10c, is tightly fitted Within collar portion 4a of base member 4 and is retained therein by the flanged ring 9. The filter frame may be of metal or plastic. Membrane 10a is made of paper, cloth, laminated material or any porous membrane material capable of permitting air to flow through it while entrapping and retaining dust from the atmosphere. The mass 10b of backing material may be of glass Wool, asbestos, or any similar material which will support membrane 1G6: and permit air to pass through.
Body 8 has a hinge appendage 11 at one side and a notch 12 at the other side. Near the notch 12 the body 8 holds a spring-urged plunger 13, which is normally biased against an annular rim 1-4 of a cover 15. The cover 15 also comprises an inwardly yieldable portion, or diaphragm 15a and a clamping ring 15b, which holds the peripheral portions of the diaphragm 15a against the rim 14 with the help of screws 150, which extend through the diaphragm 15a and the clamping ring 15b and are threaded into the rim 14. The rim 14 and ring 15b may be of brass, and the diaphragm 15a, of rubber.
The cover 15 is supported on the hinge appendage 11 of the body 8 by a pair of closely spaced hinge projections 16 on the cover 15 and a pin 17 passing through the hinge appendage and the hinge projections. The cover 15 is tightly held against the body 8 by a hook portion 18 formed on one end of a lever 19 and entering the notch 12 formed in the body 8. The lever 19 is pivoted at an intermediate region near the hook portion 18 on a pin 20 carried on spaced cars 21 formed on the rim 14. The end of the lever 19 remote from the hook portion 18 is pivotally connected by a pin 22 .to one end of a post 23, the other end of which is attached to the central portion of the diaphragm 15a by a screw 26 and a washer 27. The pins 17, 20, and 22, the lever 19, and the post 23 may be formed of steel.
When a sutficient vacuum is applied through the suc tion line 7a and vacuum source 7b, the diaphragm 15a will yield inwardly to the pressure of the atmosphere and assume a deformed shape as shown in dash-dot lines in FIG. 1. Consequently, the post 23 moves downward and leftward as shown in FIG. 1, causing the lever 19 to pivot on pin 20 and move its hook portion 18 out of the notch 12 in the body 8. Now the plunger 13 moves the cover 15 to the full-line position of FIG. 2, Whereupon it swings by gravity about the pin 17 to the dashdot position of FIG. 2.
In carrying out the invention the samplers are placed I in the various locations necessary to make a reliable sampling and connected by lines to the vacuum-producing means; then, when it is desired to begin a test all that is necessary to do is to apply suificient vacuum and the diaphragms 15a of all the samplers will yield inwardly at the same instant due to atmospheric pressure, and the covers 15 will fall away permitting the atmosphere to flow rearwards through the membranes 10a which will entrap and hold the atmospheric dust. When it is desired to terminate the tests, the vacuum is discontinued, the bodies 8 are removed from the rings 9, and the rings are removed from base members 4. Now the filters 10 are taken out of the base members, or the filter membranes 10a alone are removed from the frames 10c and backing masses 1%, depending on the construction of the filters It). When new samples are taken, new filters active incident.
or new filter membranes 19a are put in place, and
covers returned to the closed position shown in FIG. 1.
There will be, of course, a slight variation of time of exposure of the filter membranes 19:: after the partial vacuum has been discontinued and until the filters or filter membranes are removed; this, however, is negligible and not to be compared to the variation in time of exposure if the samplers were uncovered manually prior to a test, especially in the case of an unexpected radio- In such a case a sudden increase in radioactive dust in the atmosphere makes it necessary to begin a test immediately, whereas when the radioactivity subsides toward the normal level it is not nearly so critical to withdraw the membranes at any exact time.
It will be understood that this invention is not to be limited to the details given herein, but that it may be modified within the scope of the appended claims.
What is claimed is:
1. A dust sampler comprising a base member, a suction line connected therewith, a body having a notch, means for applying the base member to one end of the body in a gas-tight manner, a filter positioned in the base member, a cover withdrawably attached to the body at the end opposite the base member and having an inwardly yieldable portion, a hook pivotally mounted on the cover and engageable in the notch, and means for communicating motion of the inwardly yieldable portion of the front cover to the hook, whereby the hook escapes from the notch and the cover withdraws from the body.
2. An atmospheric dust sampler comprising a base member having a collar portion and a nipple portion, a suction line applied to the nipple portion, a body having a notch, means for holding the collar portion of the base member in gas'tigbt engagement with one end of the ment of the hook from the notch, and means for communicating to the hook motion of the diaphragm toward the base member.
3. An atmospheric dust sampler comprising a base member having a cylindrical collar portion and a nipple portion adapted to be connected with a suction line, a hollow body having a notch at its top, a cylindrical re-' taining ring tightly fitting between the body and the collar portion of the base member, a filter fitted within the collar portion in a gas-tight manner and held therein by the retaining ring, a cover hinged to the bottom of the I body and having an inwardly yieldable concentric dia-.
phragm, a spring-urged plunger mounted in the body so as to be biased against the cover, a lever pivoted on the cover and having at one end a hook engageable with the notch in the body, and a post pivotally connected to the other end of the lever and attached to the diaphragm, whereby inward motion of the diaphragm withdraws the hook from the notch.
References Cited in the file of this patent- UNITED STATES PATENTS 1,517,144 Anderson Nov. 25,1924
2,235,308 Banker Mar. 18, 1941 2,703,153 Revoir et a1. Mar. 1, 1955 FOREIGN PATENTS 666,550 France Jan. 2, 1 929