US3201994A

US3201994A - Fluid sampling device

Info

Publication number: US3201994A
Application number: US256729A
Authority: US
Inventors: Clarence W Adams
Original assignee: Beckman Instruments Inc
Current assignee: Beckman Coulter Inc
Priority date: 1963-02-06
Filing date: 1963-02-06
Publication date: 1965-08-24
Anticipated expiration: 1982-08-24

Description

Aug. 24, 1965 c. w. ADAMS FLUID SAMPLING DEVICE Filed Feb. 6, 1963 FIG. I

FIG. 2

INVENTOR CLARENCE W. ADAMS ATTORNEY United States Patent M 3,2tll,994 FLUID SAMPLHNG DEVHCIE Clarence W. Adams, Grange, Calif assigner to Beeliman instruments, line a corporation of California Filed Feb. 6, 1963., fier. No. 256,729 2 Claims. (til. 73-4215) This invention relates generally to a device for obtaining substantially uncontaminated fluid samples from flexible, puncturable containers of plastic or other materials and, in particular, to an improved sealing means for isolating the sample chamber of the sampling device from the atmosphere.

The present invention is an improvement upon the fluid sampling device disclosed in copending patent application Serial No. 245,609, filed December 18, 1962, entitled Fluid Sampling Device and Method and assigned to the same assignee as the present invention. As stated in the copending patent application, the necessity occasionally arises for withdrawing a gas sample from a flexible plastic bag for analysis of the gas. In doing this, there is a problem in establishing communication between the interior of such plastic bag and the sampling device without the occurrence of contamination of the sample by leakage of the atmosphere to the sample.

In the copending patent application, there is disclosed a fluid sampling device in which a housing is provided having a surface engageable with a wall of a flexible bag. The housing is provided with a sample chamber having an open side in the bag-engaging surface and closeable by the wall of the bag. An annular evacuable means is provided in the housing and encircles the open side of the sample chamber. Means are provided for evacuating the annular evacuable means to hold the wall of the bag against the bag-engaging surface of the housing. The housing carries a needle for puncturing the wall of the bag through the open side of the sample chamber to establish communication between the interior of the bag and the sample chamber so as to enable a sample of the gas in the bag to flow into the sample chamber. The

, sample may be analyzed by an analyzing instrument incorporated in the sampling device. In order to prevent contaminants from passing into the sample chamber between the bag and the bag-engaging surface of the housing, there is provided a pair of O-rings which surround the sample chamber and annular evacuable means. For most purposes, this sealing means has proved to be adequate. However, in some circumstances as, when the flexible bag is made of Mylar or certain other plastic materials, some leakage has occurred with the abovedescribed sealing means. This has been due to the failure of the O-rings to conform to wrinkles which are present in the flexible bag when the bag is urged against the bag-engaging surface of the sampling device by the annular evacuable means. Thus, leakages have occurred causing a break in the vacuum used to secure the flexible bag to the sampling device and, accordingly, permitting the passage of contaminants into the gas sample chamber.

It is, therefore, the principal object of the present invention to provide a simple and effective means for obtaining a substantially uncontaminated sample from a flexible bag.

Another object of the invention is to provide a novel sealing means on an element having means for attaching a flexible bag thereto and effective to isolate the central portion of the element from the atmosphere.

A further object of the invention is to provide a sampling device having vacuum means for attaching a flexible bag thereto with a novel sealing arrangement between the bag and the bag-engaging surface of the sampling device 3,Z@l,994 Patented Aug. 24, 3365 so that a substantially uncontaminated sample can be Withdrawn from the bag and admitted into the sample chamber of the sampling device.

Still a further object of the invention is to provide a sampling device having a detachable head element car-rying a vacuum means for attaching a flexible bag to the head portion and a sealing means for permitting the obtaining of a substantially uncontaminated sample from the bag.

According to a principal aspect of the present invention, the pair of O-rings used as the sealing means between the fluid sampling device and the flexible bag are replaced by a resilient lip which encircles the bag-engaging portion of the sampling device. When the sampling device is opera-ted to attach a flexible bag thereto, the flexible lip will conform, due to its resiliency, to any wrinkles occurring in the flexible bag. Thus, flexible bags made of Mylar or certain other plastic materials which tend to wrinkle easily can be secured to a sampling device in close sealing relationship and without the problem of having contaminants reach the sample chamber of the sampling device.

Another aspect of the invention is to provide a detachable head element for the sampling device which engages the flexible bag and secures it to the device. This head element carries the novel resilient lip of this invention. This arrangement is advantageous in that, if the resilient lip becomes damaged, only the separate head element of the sampling device need be replaced.

These and other objects and advantages will become apparent from the following description taken in connection with the accompanying drawing wherein:

FlGURE l is a partial sectional view of a gas sampling device of the invention without a gas filled flexible bag attached thereto; and

FIGURE 2 is a fragmentary, partial sectional view of the gas sampling device of the invention showing in particular the detachable head element of the sampling device with a gas filled flexible bag secured thereto.

Referring now to the drawing in detail, the gas sampling device of the invention is designated generally by the numeral 10 and is adapted to obtain a sample from a flexible, puncturable bag 12, shown in FIG. 2. This bag may be termed of a suitable plastic material or any other flexible material, but the present invention has its greatest advantage when the bag is of a plastic material such as Mylar which tends to Wrinkle readily.

The sampling device includes a housing generally designated by numeral 14 which includes a main body element 16 and a detachable head element 13. On one side of the body element 16 is a handle 29 of any suitable construction. The head element 18, which will be described in greater detail below, is provided with a bore 22. in its upper surface and with an annular groove 24 Within the bore. An extension 2-6 depending from the bottom of the body element 16 has an annular protuberance 25 which frictionally engages the annular groove 24. The head element may be made of any suitable resilient material such as ordinary rubber, neoprene, or silicone rubber. Due to the resiliency of the head ele ment, it may be readily attached and detached to the extension 26 of the body element of the gas sampling device.

The housing 14 is provided with an evacuable sample chamber, generally designated by numeral 36, and includes a bore 32 extending through the body element 16 and a bore 34 extending through the resilient head element 18. The head element 18 has a bag-engaging surface 36 and the sample chamber 22 has an open side or end 38 in said surface 36 and is closeable by a Wall 40 of the flexible bag T2.

The bore 32 of the sample chamber slideably receives a shank 42 of a needle 44 for puncturing the bag wall 20. The point 46 of the needle is formed 'on a reduceddiameter stem 48 which renders the sample-receiving space annular. The shank 42 of the needle projects out wardly from the housing l adjacent the handle '20, and is provided at its outer end with a buttonstl for depressther prevents' contaminants from, the atmosphere from reaching the sample chamber 30.

Ithas been found in practice that the sealing means of a this invention very effectively permits the attachment of ing the needle to puncture the bag wall 20.: A fluid type seal around the needle shank 42 is provided by Q-rings by the body element 16and engaging:

52 and .54 carried theshanlcp Surrounding thebore 34' adjacent its open end 38 in the head element 18 is anannular recess ,56 which reflexible bags, which readily wrinkle, to the gas sampling devicelt) andpermits samples from theegas filled bags to bewithdrawn and supplied to the samplechamber without being subjected to any contaminants. A factor which increases the sealing ability of the lip 70 is that atmos-' pheric pressure acts upon the upper portion 78 of the lip i and helps maintainv the lip in its sealing relationship with ceives an annular evacuable. means shown as comprising a porous ring 58. The ring may be formed of 'a sintered metalor plastic material, it having been found that sintered brass performs quite satisfactorily, The ring 58 has an annular face 69 which forms a part of the bag-engage ing surface 56 of they head element '18. Communicating with the annular recess 56'are passages 62-and 64, the latter receiving a vacuum line 66 controlled by a valve 68. The vacuum line 66 may be'connected to a suitable vacuum pump or the like, not shown As will be apparent,

when the bag-engaging surface '56 is placed against the bag wall 46 and the porous ring 58 is evacuated, the bag wall will be held firmly against the annular face 60 0f the porous ring, Preferably, the area of the annularface'etl is relatively large to provide a large area vacuum engagethe flexible bag '12. r Inforder to permit purging-of thesample chamberfiti i by evacuation, the body element 16 is provided with a passage 80 which communicateswiththe sample chamber and which is adapted to be placed in communication with v a passage'82 connected to avacuum line 84having a control valve 86. The vacuum line is connected tov a vacuum 1 source such as a. vacuum pump'or the like, not shown.

A needle valve 88 carried-by the body element 16 is provided to control the flow of gas'from the sample chamber 3-0 to thevacuunrline 84. -After purging of the sample a chamber 30 when the needle'valve 88 is open, the valve isclosed-and the bag wall 40 is then punctured by means V to the samplechamber.

ment between the surface 36 and the bag wall 40 so as to j securely attach the bag wall to the'sampling device 10.

It is the most important feature of the inventionto provide a sealing means on the head element 18 which will prevent contaminants from reaching the sample chamber when a vacuum is drawn therein, by means which will be described-below; As explained before, since "many flexible bags are formed of certain plastics which readily wrinkle when deformed, it is necessary t'ojprovide a sealing means which will readily conform to such wrinkles.

of theneedle 44 to admit a gas sample from the bag 12 i The sample thus introduced into the sample chamber 30 maybe analyzed in any suitable manner by any'suitable analyzing means which preferably include an element 90 carried by the body element 16 in communication with the f sample chamber 30 through a passage 92. The elementfii) may be agas sensor, or any other'suitable analyzer.

Such a sealing means would prevent any breaks in the vacuum ofthevacuum holding means of the sampling device 10 and permit the passage 'of-uncontaminated sample from the bag to the sample chamber'StL; T 0 this end, there is provided a lip 70 which is formed offthe same resilientmaterial as the detachable head element 18;

However, if the head element were made of some other i material and integral with orattachedfto body element 16 by means other than the groove and protuberance arrange: ment disclosed herein, it would be possible that a separate resilient lip 70 could be provided and be detachably conneeted to the head element 18,

As seen in FIG. 1 of the drawing, the lip extends outwardly from the bag-engaging surface. 36 of the head element and the bag-engaging, portion 72 of I the lip is In operatiomthe surface 36 of the sampling device 10 is placed against the bag wall 40 and the-valve 68 is opened, the valve normally being closed. The foregoing has the efieet'of evacuating the porous ring 58 so as to press the 'bag wall 40 tightly against the annular base of the ring. Normally, the, control valve '86 in vacuum line 84 is open and :valve 88 closed. Once 'thesampling device hasbeen attached to the bagwall 40 in the-manner described, the

I needle valve 88 is opened to evacuate'the sample chamber 30 and all sp'aces,'-passages, and the like communicating-therewith- 'After the sample chamber 30 has been Jpurged by evacuating it in this'fashion, the-valve88 is closed and the needle 44isactuated to puncture the bag wall-40 so as to admit a; sample into the sample chamber.

This-sample is the analyzed, either by the element 60 directly orby equipment connected to such element.

Although several embodiments of the invention have been disclosed herein for' purposes of illustration, it will 7 be understood that various changes can be made in the disposed atsubstantially a 30 anglecwith respect to the plane of the surface 36., Although this angle has been '55 shown to be 30, and has been found to be the optimum .-angle, it is possible for the lip to .adequately'provide its sealing function when the angle is between 10 and 45 7 The lip is also shaped so that it is tapered toward'its outer periphery-to a point 74.,v At this point along the periphery, the lip has its greatest resiliency. With the surface 36 of the head element 18 placed against the bagwallAO and when the porous ring 58 and sample chamber 30 are evacuated, the "bag wall will be; firmly attached to the underside of the head'element 18'. The position of the resilient lip, 70, once thegvacuum is] created in the gas samplingdevice 10, is shown in 'FIG.'2." ,The resilient lip becomes generally flattened-out and coplanar with the bag-engaging surface 36'and, due to its configuration and original angular position, thelip readily'eonforms to l. {any wrinkles which occur in the flexible bag.;12; =T,hus,

the bag-engaging portion 72 of the lip 70 provides; a first sealing area between the bag andjthe head element '18.

Also, that portion of the'surface 36 disposed between'the recess 56 provides a second sealing area 76'; which fur open side 38 of the samplechamber 30 and the annular V form, details, arrangement" and proportions of the variousparts 'without departingfrom the spirit and scope of {the invention as defined'by the claims which follow.

1 'What is claimedisz 1. In asarnpling'device uncontaminated-sample from a flexible, puncturable container of fluid the combinationf:

a bodyelement and afsepara-ble'head element frictiona lipformed of resilient material carried bysaid head element and encircling said surface, said holding rne'ans andsaid open sidefof said sample chamber; 5 said'resilient'lip extending outwardly from the periphcry of said 'surface and at an acute angle with respect tosaid surface, said lip tapering to a point at its forobtaining a substantially 5 6 outer periphery and being engageable by said wall said head element is formed of the same resilient material of the container to isolate said simple chamber and as said lip.

said holding means from the atmosphere; and

means carried by said housing for puncturing said wall References Cited y the Examiner Of the container ihlOllgh said OPCII side Of said sam- 5 UNITED STATES PATENTS pie chamber to establish communication between 2 198 765 4/40 Featherstone et a1. 248363 X h i t h l t e in mm of t e container and said samp e cham 2,786,355 3/57 y et a1 73 421.5

her through said wall, whereby to enable a sample of the fluid in the container to flow into said sample Y chamber 10 RIChARD C. QUEISSER, Pnmary Examzner. 2. A sampling device as set forth in claim 1 wherein ROBERT L. EVANS, Examiner.

Claims

1. IN A SAMPLING DEVICE FOR OBTAING A SUBSTANTIALLY UNCONTAMINATED SAMPLE FROM A FLEXIBLE, PUNCTURABLE CONTAINER OF FLUID, THE COMBINATION OF: A BODY ELEMENT AND A SEPARABLE HEAD ELEMENT FRICTIONALLY SECURED TO SAID BODY ELEMENT; SAID HEAD ELEMENT HAVING A SURFACE ENGAGEABLE WITH A WALL OF THE CONTAINER; SAID BODY ELEMENT AND SAID HEAD ELEMENT BEING PROVIDED WITH A SAMPLE CHAMBER HAVING AN OPEN SIDE IN SAID SURFACE AND CLOSEABLY SAID WALL; EVACUABLE MEANS IN SAID HEAD ELEMENT FOR HOLDING SAID WALL AGAINST SAID SURFACE; MEANS FOR EVACUATING SAID SAMPLE CHAMBER AND SAID EVACUABLE MEANS; A LIP FORMED OF RESILIENT METERIAL CARRIED BY SAID HEAD ELEMENT AND ENCIRCLING SAID SURFACE, SAID HOLDING MEANS AND SAID OPEN SIDE OF SAID SAMPLE CHAMBER; SAID RESILIENT LIP EXTENDING OUTWARDLY FROM THE PERIPHERY OF SAID SURFACE AND AT AN ACUTE ANGEL WITH RESPECT TO SAID SURFACE, SAID LIP TAPERING TO A POING AT ITS OUTER PERIPHERY AND BEING ENGAGEABLE BY SAID WALL OF THE CONTAINER TO ISOLATE SAID SIMPLE CHAMBER AND SAID HOLDING MEANS FROM THE ATMOSPHERE; AND MEANS CARRIED BY SAID HOUSING FOR PUNCTURING SAID WALL OF THE CONTAINER THROUGH SAID OPEN SIDE OF SAID SAMPLE CHAMBER TO ESTABLISH COMMUNICATION BETWEEN THE INTERIOR OF THE CCONTAINER AND SAID SAMPLE CHAMBER THROUGH SAID WALL, WHEREBY TO ENABLE A SAMPLE OF THE FLUID IN THE CONTAINER TO FLOW INTO SAID SAMPLE CHAMBER.