US3393108A - Expired air collector and method of making the same - Google Patents

Description

W. C. JONES July 16, 1968 EXPIRED AIR COLLECTOR AND METHOD OF MAKING THE SAME 5 Sheets-Sheet 1 Original Filed Aug. 17, 1964 E m E V m WILLIAM C. JONES BY AT T Y s July 16, 1968 w. c. JONES 3,393,108

EXPIRED AIR COLLECTOR AND METHOD OF MAKING THE SAME Original Filed Aug. 17, 1964 3 Sheets-Sheet 2 FIG.4

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ATT'YS W. C. JONES July 16, 1968 EXPIRED AIR COLLECTOR AND METHOD OF MAKING THE SAME 3 Sheets-Sheet 5 Original Filed Aug. 17, 1964 ATT'YS United States Patent 01 fice 3,393,108 Patented July 16, 1968 3,393,108 EXPIRED AIR COLLECTOR AND METHOD OF MAKING THE SAME William C. Jones, 16 W. 328 Walnut Lane, Timber Trails, Elmhurst, Ill. 60126 Original application Aug. 17, 1964, Ser. No. 390,132, now

Patent No. 3,321,976, dated May 30, 1967. Divided and this application Aug. 16, 1966, Ser. No. 572,784

3 Claims. (Cl. 156-253) ABSTRACT OF THE DISCLOSURE A method of perforating an uninflated plastic bag intended for use as a component of equipment for collecting and analyzing expired air. Selective perforation of one wall of the bag without perforating or damaging the other wall lying directly therebeneath is achieved by first affixing a plastic patch to the top wall, the patch having a pre-formed opening and being secured to the top wall in a narrow zone about that opening. Thereafter, the patch is lifted by its peripheral tab portion to pull the top wall of the bag away from the wall lying directly therebeneath while, at the same time, a tool is brought into engagement with the portion of the top wall within the limits of the patch opening to restrain and thereby perforate the top wall portion disposed within such opening.

This application is a division of my co-pending application Ser. No. 390,132, filed Aug. 17, 1964, now US. Patent 3,321,976.

This invention relates to the method of fabricating components of a device for collecting a quantity of exhaled air from a subject for the purpose of analyzing the carbon dioxide content thereof, or for any other suitable test purposes.

The equipment commonly used for collecting exhaled or expired air from a subject normally consists of a mouthpiece, an air-control valve connected to the mouthpiece, and a container for collecting the air passing through the valve. In the past, the containers have been bulky and expensive, the connections between such containers and the valve assemblies have been fairly complex, in order to insure a leak-proof seal between the parts, and the valve units have been expensive to manufacture and purchase, and have frequently presented problems of manipulation and cleaning for the user. The valve assemblies customarily used with such breathing equipment ordinarily employ tapered valve members which are rotatably received in casings having tapered valve seats, the combinations therefor being in the nature of standard stopcock constructions to insure an airtight fit between the parts. Such parts are normally ground or lapped together, with the result that the assemblies are expensive to manufacture and are composed of parts which cannot be interchanged with the components of other similar assemblies.

Cleaning of the parts therefore presents problems for a user since care must be taken to avoid co-mingling of the components of similar assemblies. Furthermore, even when properly matched parts are assembled together, sticking of such parts frequently occurs and such sticking often requires interruption and re-running of the tests.

It is a principal object of the present invention to provide an expired air collector which is relatively inexpensive and trouble-free in construction and operation and, specifically, to provide a method for fabricating a basic component or components of such a device. In particular, it is an object to provide a disposable air-collection bag, and its method of manufacture, which includes a highlyeffective connecting means for sealing the coupling of the bag with a valve unit.

Other objects will appear from the specification and drawings in which:

FIGURE 1 is a perspective view of a collector assembly including a disposable bag formed by the method of the present invention;

FIGURE 2 is an exploded perspective view of the parts illustrated in FIGURE 1;

FIGURE 3 is a vertical sectional view of the valve unit;

FIGURE 4 is a rear elevational view taken along line 44 of FIGURE 3;

FIGURE 5 is an elevational view similar to FIG- URE 4 but illustrating the parts in a different position of adjustment;

FIGURE 6 is a perspective view, taken partly in section, illustrating the disposable bag component of the collector assembly prior to perforation of that bag;

FIGURE 7 illustrates the step of perforating the bag;

FIGURE 8 is a broken sectional view illustrating the perforating action; and

FIGURE 9 is a fragmentary elevational view of the complete assembly showing the collector bag in section to reveal the sealing relationship between the parts.

Referring to the drawings, the air collector assembly essentially comprises a valve unit A, a mouthpiece tube assembly B mounted on the valve unit, and an air collection bag C. In use, all three components are assembled in the relationship illustrated in FIGURE 1.

The valve unit A comprises a pair of valve members 10 and 11 having fiat opposing surfaces 12 and 13 in contiguous relation. The parts are joined for relative rotation about an axis normal to the plane of these contiguous surfaces by means of a connecting assembly 14 as shown in FIGURE 2.

The connecting assembly comprises a bolt or threaded stud 15, an adjustment nut 16, and a spring member 17. Bolt 15 extends through the aligned apertures 18 and 19 of valve members 10 and 11, and spring 17, which is interposed between the knurled adjustment nut 16 and the rear face of valve member 11, urges the opposing faces of the two valve members into snug sealing contact. When disassembly of the parts is desired, nut 16 is simply unthreaded from bolt 15, permitting separation of the major components 10 and 11 as illustrated in FIGURE 2.

Valve member 10 is preferably formed from a suitable molding plastic such as polystyrene or an acrylic resin and has a cylindrical-shaped body portion 10a and an integrally-formed depending handle portion 10b. Opening 18 extends along the axis of cylindrical portion 10a.

Valve member 11 is similarly formed of plastic material and also includes a cylindrical body portion 11a and radially-extending handle 11b. In the illustration given, handle 11b is in the form of a stepped metal shaft having one end thereof cemented or otherwise anchored in a radial bore 20 provided in the valve member.

Mouthpiece B is composed of two parts: a metal tube 21 which is connected at one end to valve member 10 and which projects rearwardly therefrom, and a plastic sleeve 22 which is fitted over the free end of the metal breathing tube. Referring to FIGURES 2 and 3, it will be seen that the cylindrical body of valve member 10 is provided with a passage 23 extending longitudinally therethrough along a line spaced between the central axis of the body and the cylindrical periphery thereof. The rear end portion of the passage or bore is enlarged and tightly receives the forward end of breathing tube 21. While a tight frictional interfit between the parts is adequate to maintain them in operative relationship, the forward end of the breathing tube may, if desired, be cemented or otherwise permanently secured within the enlargement of the bore.

The rear end of the breathing tube is flattened slightly so that when viewed in transverse section it defines a horizontally-extending ellipse. The mouthpiece sleeve 22 is composed of a deformable plastic material such as polyvinyl chloride and readily conforms to the shape of the tubes rear end portion when the sleeve is slipped in place (FIGURE 1). In use, the clear plastic sleeve projects rearwardly a short distance beyond the free end of the breathing tube. The sleeve thereby forms a protective covering for that portion of the breathing tube to be placed into a subjects mouth. After use of the air-collecting device, the disposable plastic sleeve is simply removed and discarded and a new sleeve is slipped in place.

Cylindrical valve member 11 is provided with a passage 24 extending in an axial direction therethrough, the passage being disposed between the rotational axis of the member and the periphery thereof. As shown in FIGURE 3, passage 24 is in register with passage 23 of valve member 10 when the valve is in an open condition. As valve member 11 is rotated with respect to member 10, their respective passages 24 and 23 are moved out of alignment and opening 25 is brought into register with passage 23 (FIGURE As shown most clearly in FIGURE 2, opening 25 extends in an axial direction through valve member 11 and is spaced circumferentially from flow passage 24. Opening 25 and passage 24 are of equal radial distances from the rotational axis of the valve member so that rotation of the valve member 11 over an arc of approximately 90 degrees will place either opening 25 or flow passage 24 in direct communication with passage 23 and mouthpiece B. To limit the extent of rotation of the valve member 11 with respect to valve member 10, the handle portion a is provided with a forwardly-projecting stop pin 26 (FIGURES 4 and 5). When passage 24 communicates with the mouthpiece, the stop pin is engaged by handle 11b (FIGURE 4). A radially-extending stop member 27 projects outwardly from the periphery of valve member 11 from a point spaced circumferentially approximately 90 degrees from handle 1111. Therefore, when the valve member 11 has been rotated approximately 90 degrees from the position illustrated in FIGURE 4, the radial stop member 27 engages pin 26 and prevents further rotation of the valve member 11 in the same direction. When stop pin 26 is engaged by member 27, the opening of the valve member is in communication with mouthpiece B through the passage 23 of valve member 10. In this manner a gas to be rebreathed can be introduced in the bag, saved gas-tight until rebreathed, then saved again until time is convenient for analysis.

A generally cylindrical probe tube 28 projects forwardly from valve member 11 and has its rear end portion received and secured within passage 24. As shown in FIG- URE 3, the probe tube is provided with an axial opening 29 at its free end as well as with lateral openings 30. It will also be observed that the free end portion of the probe tube 28 is rounded to facilitate insertion of the probe into the opening of bag C.

Because of its length, handle 11b is the principal means for gripping valve member 11 and rotating it with respect to valve member 10. However, to the extent that stop member 27 projects radially from valve member 11, it may be used as an auxiliary or alternate handle for operating the valve.

Handle 11]) functions not only as an operating lever but also as a fitting for coupling the valve to a spirometer or to some other device for analyzing the air collected in bag C. For this purpose, the stepped handle has a flow passage 31 extending axially therethrough and this passage communicates with passage 24 of the valve member 11 by means of radial bore 20. Thus, when the valve is adjusted into the position illustrated in FIGURES 3 and 4, both the probe 28 and the tubular handle 11b communicate with the mouthpiece B through passages 24 and 23 of the valve members. To facilitate connection of the tubular handle to a spirometer or other measuring device,

4 the distal portion of the stepped handle is tapered slightly (FIGURE 3). This portion of the handle may therefore be readily inserted or plugged into the socket of the analytical device (not shown).

Bag C is formed from a polyester film and is completely sealed except for a single reinforced opening 32 in the side wall thereof. The polyester film, used because of its gas-impermeable properties, is relatively hard and non-stretchable. To reinforce opening 32 and to provide an effective means for sealingly attaching the bag to probe 28, I therefore laminate a patch 33 on the bags surface. The patch is formed from a resilient and slightly elastic plastic material such as polyvinyl chloride and is provided with an opening 34 of a diameter slightly smaller than the outside diameter of probe 28. The patch is sealed to the bag by heat-sealing or by suitable adhesives in the zone immediately adjacent the periphery of opening 34. As shown in FIGURE 9, the outermost portions of the patch remain unsealed to the bag and thereby define tab portions 33a.

Insertion of the probe 28 into the bag through opening 34 of the patch causes a stretching of the patch about-the surface of the probe. In FIGURE 9 it will be seen that the patch stretches inwardly about the probe to define a tensioned collar 33b. It has been found that the formation of such a collar results in an effective air-tight seal between the bag and the inserted probe.

FIGURES 6-8 illustrate certain steps in the formation of the opening in bag C. As indicated by the sectioning of the bag, the bag may be formed as a segment of a continuous tube, each individual bag being cut from the tube and heat-sealed along spaced heat-sealing zones 35 to form a completely imperforate bag structure. Thereafter, patch 33 with its preformed opening 34 is cemented or otherwise sealed to the outer surface of the bag. A tab portion 33a of the patch is then lifted either manually (as shown) or mechanically, the lifting action serving to separate opposite walls of the bag so that only one wall will be perforated by the flat spatula-like tool 36. The wall of the bag to which the tab is afiixed is lifted into contact with the end of the tool, or the tool may be lowered into contact with the bag, or both, until the end of the tool bears against the unperforated wall of the bag within the opening 34 of the patch. Then, by continuing the downward movement of the tool and/or the upward movement of the bags upper wall, the end of the tool tears the Wall of the bag to form opening 32 and flap 37 (FIGURE 8). Since the film from which the bag is formed is thin (preferably 0.0005 of an inch in thickness), flap 37 is of no consequence and does not in any way interfere with the cooperative action of patch 33 and probe 28 when the bag and valve unit are connected together.

In operation of the air-collecting assembly, an operator first inserts probe 28 through opening 34 of the patch until the lateral apertures 30 of the probe are well within the bag. Valve member 11 is rotated into the position illustrated in FIGURE 5 so that mouthpiece B communicates with passage 25 which in turn communicates with the atmosphere. A subject, holding the apparatus by means of handle 10b, breathes several times through mouthpiece B until he becomes accustomed to the device and his breathing pattern reaches a normal level. Handle lever 11b is then swung clockwise (when viewed in FIG- URE 4) to bring the mouthpiece into direct communication with probe 28 and bag C. The exhaled air flows directly into the bag and is collected therein. Since the passage of the probe 28 is substantially larger in crosssectional dimensions than that of handle-fitting 11b, and since no significant back pressure is exerted by the walls of the bag C, there is no significant leakage of air through handle 11b at the time the bag is being filled.

As soon as a sufficient quantity of air has been collected in the bag, valve member 11 is rotated in the position illustrated in FIGURE 5, thereby blocking the flow of gas between the mouthpiece and the bag. Handlefitting 11b, which remains in constant communication with passage 24 and probe 28, is simply inserted into the socket of the gas analysis equipment (not shown) and the air collected in the bag is expelled through the handle by applying a slight pressure to the bags side walls. The configuration of collar 33b permits substantial pressure with no significant leakage of air as its inward shape increasingly tightens in a check valve action.

After the air collected in the bag has been analyzed, the bag is disconnected from the probe and is discarded. Similarly, the plastic sleeve 22 is removed from mouthpiece tube 21 and is also discarded.

Since the pressures involved in the operation of the apparatus are relatively low, and since the valve members 10 and 11 have large surface areas in mutual contact, there is no leakage of air between the flat opposing surfaces of such members. If desired, a small amount of a lubricant may be smeared upon the opposing surfaces of the valve members to insure further against any possibility of leakage as well as to lubricate the parts for relative movement.

Interchangeability of the valve members is readily achieved because of the fact that the contacting surfaces of such parts are fiat. Thus, valve member 10 may be operatively connected to a valve member 11 which is either a replacement part or which is taken from another valve assembly, without encountering problems of mismatching and without danger that leakage will occur because of the substitution.

While in the foregoing I have disclosed an embodi ment of the invention in considerable detail for purposes of illustration, it will be understood by those skilled in the art that many of these details may be varied without departing from the spirit and scope of the invention.

I claim:

1. In a method of perforating a wall of a completely sealed plastic bag, the steps of securing a plastic patch having a pre-formed opening therein upon a wall of said bag, said patch having a tab portion overlying said wall and projecting laterally beyond the zone of securement between said patch and wall, and thereafter lifting said patch by said tab portion while at the same time urging a perforating tool into contact with the wall of said bag within the limits of said patch opening.

2. In a method of perforating a wall of a fiat and completely sealed plastic bag, the steps of positioning a flat patch having a pre-formed opening therein upon a wall portion of said bag, securing said patch to said wall portion in a narrow zone extending about said opening while at the same time leaving a peripheral portion of said patch unsecured to said bag, and thereafter lifting said patch by the peripheral portion thereof while at the same time urging a perforating tool into contact with the wall portion of said bag within the limits of said patch opening.

3. In a method for selectively perforating one wall of a plastic bag disposed in superimposed engagement with a second wall thereof without also perforating said second Wall, the steps of positioning a patch having a pre-formed opening therein upon the outer surface of said one wall, securing said patch to said one wall in a narrow zone extending about said opening, urging a tool into contact with a portion of said one wall in the area defined by said patch opening to restrain movement of said portion away from engagement with said second wall, and thereafter drawing said one wall by said patch away from said second wall while said tool is in engagement with said portion to perforate said one wall in the area defined by the opening of said patch.

DOUGLAS 1. DRUMMOND, Primary Examiner.

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