US2982286A - Blood collection apparatus - Google Patents

Description

May 2, 1961 E. s. WELCH, JR 2,982,286

BLOOD COLLECTION APPARATUS Filed Aug. 5. 1956 2 Sheets-Sheet 1 lzweiziofl: lkizvaflddowuemfi flifiys May 2, 1961 E. s. WELCH, JR 2,982,286

BLOOD COLLECTION APPARATUS Filed Aug. 3. 1956 2 Sheets-Sheet 2 lwvaadsoaieawwda n shown with a container installed in the chamber wall; andia clamp as .in Fig; 4;

blood cells.jYI t,'is desirablel'als'ojtoobtain and sto Yblo'od in determined or measured jyolurnes, A furth quirement is that theblo odbe agitated in thecollect1on-,-j asf'for mixing with previously introduced anti-coagulant solution, in minimum space, "with minimum eltortjand without injuryito: the blood components. i

2,982,286 7 BLOOD COLLECTION APPARATUS 7 Edward Sohier Welch, Jr., Framingham, Mass., assignor,

by mesne assignments, to Baxter Laboratories, Inc., Morton Grove, 11]., a corporation of Delaware Filed Aug. 3, 1956, Ser. N0. 602,006

25 Claims. or. 128-276) This invention relates to blood handling and more it particularly to the controlled collection of blood in collapsible containers. The invention aims at controlling the blood collection for minimum discomfort to the donor and for no damage to the blood cells. The invenntion provides new and improved method and apparatus tor applying reduced pressure or partial vacuum to and through the collapsible containers in the blood collection,

and for controlling the partial vacuum for optimum rate and also uniformity of flow of the blood. The invention contemplates and provides additionally for mixing the blood with a preservative during collection; for detecting and measuring the volume of the collected blood; and for stopping the collection'automatically upon the filling of the collapsible containers with desired, determined blood volumes. from a consideration of the following specification taken The invention will be better understood in conjunction with the accompanying drawings in which: Fig. 1 is a front end view of the invention apparatus chamber for blood collection;

Fig. 2 is a side view of the apparatus illustrating the agitation of the chamber;

Fig. Sis a partly schematic view of the blood collection controllingapparatus of the invention, illustrating a "the relation and coupling of the chamber evacuating and agitating means;

ig. tisa fragmentary, larger scale Fig; 7 is a horizontal section, on a scale still further enlarged, taken through the containerinlet tube,;and illustrating the reception of the tube and als'o the leakage openingthrough thecharnber wall; and Fig. 8 isa n blood collection controlling apparatus of the nyention.

schematic view of aymodified ormofthe In the collection ofgblogd and more particu *rly, human whole blood, it is desired first tnat he bl i llect at a uniform rate, afiording minimal physiologicldisturbance' to theldonor'," and'so as tolprecludeidamage'to the The collecto'n 'of t blood, asflfor, "storage; or,

hais g nerally been accomplished heretofore with rigid ntainers such as glassb'ottles. This collectioniof f blood allow the escape 'lof "air no United States Patent O I v the. required mixing of'the blood with a preservative, has

I 2,982,286 "R m dv ay 2 1951 in by donor venous pressure andgravity. This method has the disadvantage of not being a completely closed system and furthermore provides no way of increasing the rate of blood-flow. V

' It is common practice also to use a closed bottle that has been nearly completely evacuated initially. It is found, however, that introducing fresh whole blood into a nearly complete vacuum is damaging to the red cells.

In other cases, the required vacuum is established by arranging a vacuum system for opening and continuously evacuating through'the bottle'closure. But the hazard of contamination from the piercing of the bottle closure, and the inconvenience, otherwise, of the use of a vacuum system with glass-bottles have made this method relatively unacceptable in practice.

The shaking or agitation of'the rigid containers, for

also proven difficult. More particularly, rotating or oscillating a reasonable size or heavy glass bottle consumes space, introduces mechanical. problems, and, due to the inevitable air-blood interface, results in a cell-damaging sloshing or even a water hammer action between the blood and the bottle Walls and between colliding portions of the blood, all as'well known to thoseskilled in the art. 7

While the desired detecting or measuring of the col- 1 lected blood volume may be'accomplished with these rigid glass containers by optical or weighing rneans, it

may not be convenientlycarried out coincident withthe aforementioned agitation. .But this container shaking is continuously. necessary to. the adequate. mixing of the fbloodwiththe anti-coagulant or the like preservative solution during collection.

glass or other rigid containers',fdetermination of the volume necessitates the unwanted interruption tation.

It follows that with those of theagi- The..more recently introduced collapsible containers,

which are nowalso generally employed inblood banking practice, have been found better suited to andrnore (readily manipulated for desired control of the blood col- .lcction. With such collapsible containers, including' 'the j plastic" bagwherein shown byway of example,.,"the .re-

duced'pre'ssure or partial vacuum required'fordesiredto finduce or increase the rateof flowof the bloodfromthe 3 donors veins can be established withougnand transmitted undimin'ished'fthrou gh; the flexible. container iIt will be apparent that apartiahvacuum which carithus' be established inside by a system wholly outside'theQcontainers ,can be' controlled also tor desired uniformitybf grate .of collection. Moreover, andjin viewpjf the col- ;Q lapsibility and: light ,weightof .th'esej plastic or the like containers,v ltheir' agitation may be accomplished .{with much lighter; devices," in smaller space; and' withqut deleterious efiect 1 on; the, blood; the air blood' intertace 'fjbein'g'eliminated'by'the initial collapse off the conta jers.

Furthergdetec ting or. measuring theq volum'e' tithe collected bloodmay lee-carried out, automatically a in "conjunction ,withthe, continuouslagitation of th ible containerspFor it isfound that the exterri fc'ontainedvolume, so that'the' expansion in fillingo containersflprovides a -oontinu'ous and measured non interife rently; "ag tati n eiar du ng elletie "M impo wfi lv; I nuojus dete *ofblo'od volpme b stopping the flow of the blood, and optionally the container agitation, upon the completion of the blood collection.

.My present invention provides a convenient, accurate and fast method and apparatus for controlling the collection of the blood in these collapsible containers. It affords more particularly improved method and apparatus mp ying and applying these several features and charac- 1 teristicS, of the handling and use of such containers. My ention is distinguished also by the ease and simplicity of handling of the containers; by the directness and accuracy of the blood volume measuring, and compatibility of such measuring with the agitation of the blood in col- I lection; and by the application of the blood volume measuring to the control and automatic stopping of the container filling and agitating. In the form here concerned, the invention apparatus provides a chamber adapted easily and simply to be loaded with a collapsible blood container, and which may be evacuated to induce the flow of the blood into the container, and also agitated for the required mixing of the incoming blood with the previously introduced preservative. The apparatus chamber will be seen further to be sufliciently confining of the containers to mount means adapted for engaging the container wall, upon its expansion in collection. Pursuant still further to the invention, such means is employed for controlling, ordering, and signalling the stoppage of the collection of the blood, and, optionally, the agitation of the container.

Referring now more particularly to the drawings, there is shown in Figs. 1 and 2 the housing or panel such as may mount or support various of the apparatus components, and which may in turn rest on a larger or wider base or stand 11, as may be fitted with feet or the like 12.

The housing or stand 10, 11 may be fashioned of metal or other material of a strength, weight and durability appropriate to the support and protection of the apparatus components, and it may mount the usual carrying handle and name plate or other identification means, not shown;

In accordance with the invention, there is supported from the housing 10 a plastic or other transparent light weight rigid chamber 20 for receiving and enclosing a blood container, and herein comprising the cylinder 21 closed at its one end 22 and fitted at its other with anaccess lid or door 23 which may be freely swung, as on the pivots or hinges 24, from the open or Figs. 1, 2 position through the Fig. 4 position to the fully closed position of Figs. 5 and 7. The container receiving chamber 20 is provided further with a tray or shelf26 on which the blood container is placed and supported. The bag or pack herein illustrating the collapsible container is indimay be substantially free of air, as for elimination of air-blood interface. Further, it is fashioned of a plastic or other material susceptible of sterilization, and characterized also by hemorepellence. The container C may be It has sealed to or through one said 'closed, sealed, blood handling system of flexible, transparent, light weight, and durable construction, and which fashioned for a contained fluid volume of say, 500 cc.,

and it may be supplied with a suitable quantity, in such instance 75 cc. of an anti-coagulant or preservative solution such as desired to be continuously mixed with the blood in its collection, all as.,conventional in theart.

The closed, sealed, hemorepellent blood collecting and storing system C, T will be understood to be installed in the apparatus with the.container.C restedon chamber slot extending between and normal to said hole 27 and the cylinder open end, and proportioned to permit the ready insertion of the tube T into the annular, close fitting opening 27, and to provide also a small leakage path for passage or bleed of air into the chamber 20 when the door 23 is closed.

My novel blood collection controlling apparatus comprises fur'ther means for continuously agitating the cylinder 21, for the desired mixing of the blood with the preservative. The agitating means herein illustrating the invention is seen to comprise a reciprocating or oscillating motor 30 having a rotating arm or shaft 31 which may be joined to the chamber 20 by a surrounding strap or sleeve 32 having a clamp fastening 32a, Fig. 1. The motor 30, which may be of the vacuum operated type such as commonly employed for automotive windshield wipers, is provided with a manual on-otf control switch or valve 33 and a manual speed control or throttling valve 34. The motor 30 will be understood to drive shaft 31 so as to oscillate or reciprocate the chamber 20 about a diametrical axis at or near the center of the chamber length, and through a small horizontally centered are, as indicated by the solid and dotted line chamber positions, Fig. 2. The rate of this chamber oscillation is regulated by adjustment of throttling valve 34.

Further in accordance with the invention, means are provided for evacuating the cylinder 21 for and during the collection of the blood, and comprising a vaccum source or pump such as indicated at 40, Fig. 3, and which may be coupled to and communicate with the chamber 20 through vacuum line 41, Figs. 1 and 3. The degree of vacuum applied through line 41 may be controlled or regulated by a regulating type valve 42 such as mounts a screw adjustment 42a. The vacuum system and line 40, 41 is seen to terminate and communicate with the chamber 20 at a nipple 43 entering or threaded through the cylinder 21 at a point centered above the collapsible bag or container C, Figs. 1, 2.

In accordance with the invention, the vacuum line 41 comprises further a series valve herein formed as a block 44 mounted on chamber 20 and having parallel passages 45a, 45b coupled to the hoses 41a, 41b which connect it with the vacuum valve 42 and port 43 respectively. The block passages 45a, 45b are seen as cross-connected by a passage 46 in which slides stem valve 47 having the annular peripheral recess 47a connecting the passages 45a, 45b in the open position, Fig. 5. The valve stem 47 is resiliently biased from its open or Fig. 5 position by coil or the like spring means 48 confined in slide passage enlargement 46a. The. resilient biasing means 48 urges the slide 47 toward the seated position of Fig. 4, wherein it valves or closes, by the shift of the peripheral recess 47a out of alignment and communication, with the passages 45a, 45b, the vacuum passage 41. The release of the energy stored in spring 48, to seat valve 47 and close 'line 41, is related to and more particularly follows automatically upon completion of the container filling, as hereinafter explained. a

'Means are provided by the invention'for automatically detecting andmeasu'ring the presence of a desired or determined fluid volume in the container C. As heretofore pointed out, under certain conditions the external dimensions of the collapsible container are closely proportioned to its contained volume,,and so that when the container is on a flat surface the elevation of its upper wall above said surface, and for any volume, may be'accurately predicted. Accordingly the container upper wall may be employed for operating a continuous volume ,indicator, or, as herein,.it may be used for actuating a control or signal device when the contained volume has risen to a predetermined valve. In the presentlembodiment,

the invention apparatus is seento regulate, measure, or

'elevatiorr "oi- "the container upper wall to l the. predicted I height is then detected by its engagement withsa'id'nipple 43. This engagement of'thejsnrodthplastic' surface of thefcout-ain'er C against the polished end of nipple 43 will *behndrstcjdd to occlude the port and seal ofi'the .chamber 20 fromfli'ne 4 1. ltwillbe apparent that the partial 3 vacuum established in-chamber ztl by'pumpl m will then -bediss'ipa'ted by the bleedthrough passage 27a.

Further 'in' a'ccordancewith theinvention, this measurung' or' detecting of the desired containerbloodlvolume occlusion of the nipple 43 -is employed to close and *seal'the'container inlet or donor tube-'T against further bloo'dflow 'automatic'ally, 'and without interference With t the agitation of the container. Referring now more particularly to Figs. 4 and' 5, therefisprovided on cylinder J QtatesJclampbIO k "50 clockwise to the 'open position of "Fig. 5. *Seating of the valve 47, as 'by 'the thrust of spring .48, will drive the block 50 counterclockwise to the left, "to the closed position of Fig. 4, in which the clamp is seen to close on and seal the container inlet tube'T. 'iSpringj ds is selected or conditioned for a thrust lessthan thatfpposnew k'erted on' block 50 by the TpinZS; when the normal partial vacuum obtains in chamber 20 and generates the intended negative or closing pressure at .door .23, so that clamp 50 is normally urged and'con- 'finedto the right or open position of Fig. 5. 3

f In the operation 'ofthe invention" apparatus 1 vacuum pump it) may be-started'with'motor valve 33 closed,- so fas to drive arm 31 toone limit of its excursion and thus "elevate'the entrance endof chamber '20 for more convenient' access through door 23. The closed collapsible, blood storing system C, T is then installed by laying the container C onshelf 26 holding open clamp 49; 50 forin- ,fSertion of tube T into the cylinder opening 27,- andthen ffjr eleasing the block so to dam the'tubeT. With'the {container C thus 'closed the sterile sealed bloodcollecting fassembly jrnay be opened, as by rfemoval of the, usualprojtective' fsheath f rom' the tube seated collection need-le.

' I .Ehlebotomy is then perfiormed, with application -fof 'therieedle "to the arm 'offthe donor D, Figi l. The collection .Loftheblood and filling of the container C is commenced 'lbyfclos ing the door"23, which again opensi'inlet clamp 149,150,andalsoshiftsvalve 47 to open vacuum line 41.

girlie evacuation of {the chamberlt) is thuscommenced g automatically ,up'o n andlsimultaneously with the initiating sof1E the.-ilow of the bloodll As .earlier noted, the pres'sure diiference across door 23resultingfrom the evacuating of chamber 20 is such as'to hold the clds edagaiiist I the force ofgsiaring 48. The chamber "oscillatingf niotor r30-m3Y: Q be a e pl by. m l t ng v v to woscillate. chamber lzti. fortheidesired agitation of the) jcontainer C, and continuous 1 mixing of the incoming bloodiwithlthe previouslyintroducedanti-coagulant;

{physiologically determined, ;is controlled in furtheupart by adjustment of vacuum regulator valve 42., Thus dur-" d'majntained'atlalevel of vacuum as determined'by he rate of pumping uec e'ss a ryto rnaintain the desired ightqof which is. Serena alibrated flhen'trate of blood.flow'intothecontainer, in part ettingof; the scre 4241. It will beunderstood that run is' determined bythe-size of lea a i b q P prior to collection. The evacuation of chamber 21 is thus halted, 'with the result that, with the continuing :air influx through bleed 27a, the chamber pressure is caused to rise rapidly to atmospheric.

This, of course, equalizes the pressure across the door 23. The energy stored in spring -48 is :thus' again released'to drive valve '47 to open the door andclose clamp 49, 50 and tube T againstfurther blood'flow:into thecontainer C. The vacuum motor '40 -may then beturned oil manually,'the tube T clamped by other-and conventional means, andthe container .C removed from the evacuating chamber 20, which is then andthereby ready for another container filling cycle.

Inthe modification shown in Fig. 8, which will be understood toduplicate the Fig. 3 form in all other respects-the blood collecting apparatus is provided in addition withmeans forautomatically starting and stopping the oscillation of evacuating chamber 20. -More particularly, "a flexible hose 60 is arranged for communication at its one-end withthe chamber 20 and mounts at its other end 'a 'flexi-ble bellows 61. The hose and bellows 60, 61,

T and saidchamber 20 will be understood to be constructed and arrangedsuch that the pressure withineach is always, forpr'actical purposes at least, identical. The-belevacuation of chamber 20'which initiates the blood flow serves also to'collapse bellows 61 and hence automatically to shift "valve 33 to start oscillating the motor 30. Similarly,-at the end of collection the return of the chamber to atmospheric pressure reverses thisprocessing and more particularly expands bellows 61 automatically to reposition valve 33 and stopmotor 30. Itwill bereadily apprecia-ted that this automatic agitation control serves as an additional visual indication of the completion of the blood collection;

Inithe colleetion of the blood the flow through. donor tube T with its attached needle may sometimes be impeded, as by occasional blood clots. In accordance/with the invention; thedonor .tube maybe cleared 'by'overriding I the regulated vacuum and subjecting the container c tofull pumpvacuum. Thus-in boththe Figs. 3 and 8 embodiments the vacuum line41 may comprise. also a passage paralleling or bypassingregulating valve and normally closed, as by a spring valve 62; At the discretion of the operator, line 41,..maylbeppened and; chamber g ti vgided to'the f ull vacuuniofpunipl 4 0merely iby: finger I f pressure against valve 62. IT

1 It will be understood thatfmyiiiventionis 'nptguniaed a to the, particular embodiments, thereof illustrated], and a described herein, and I set forlth'its scope-in my vfollowing iiiliiigbr thebontainercto the bjl ood volume s; sig nalleidiby th'erisinglor elevating.

' ealing'or port-closingqengagementf r ;Apparatusfor controlling I a collapsible containercomprising a; chamber for enclos- 'ing 1 the containenomeans for agitating .said chamber,v e5 ting the: collection the-cylinder :21 is continuously pumped V 'il'l a. collapsible conta closing. the container,

1. Apparatus for controllinguhescollection of blood ina collapsible container,having anginlet comprising a 7 chamber; forenclosing the containen means for agitating said chamber means for evacuating the-charnber means operable during agitating for detecting the container blood volume, and means governed; by, said detecting means for, closing the container inlet. K i

the tan-mania aided in .means .for evacuating, the chamber, and means for detectmined container volu 3-: App r u o c n" omprising a chambenforienrolling ffthe collec tiion' of blood Q nsfor evacuating",sai d charn ,ber, lrneans for' autornaticall y regulating said evacuatihg means toimaintainaiflpredetermined level of vacuum'in the chjarnbenmeans v for agitating theehar'nber', and means ,controlling'?saidjagitating'imeans. to startfstop automatically upon the starting and stopping of the evacuating means.

4. Apparatus for controlling the collection of blood in a collapsible container having an inlet comprising a chamber for enclosing the container, means for evacuating the chamber, means for signalling the collection of a predetermined blood volume, and means responsive to the operation of said signalling means for occluding said evacuating means and said container inlet.

Apparatus for controlling the collection of blood in a collapsible container having an inlet comprising a chamber for enclosing the container, means for agitating said chamber, means within said chamber and operable during said agitating for detecting the container blood volume, and means governed by said detecting means for closing the container inlet upon the collection of thedetected blood volume.

' 6. Apparatus for controlling the collection of blood in a collapsible container comprising a chamber for enclosing 'and supporting the container, means for agitating said chamber, and means operable during said agitating for detecting the container expansion to a predetermined height and thereby the blood collection to a predetermined volume.

7. Apparatus for controlling the collection of blood in a collapsible container comprising a chamber for enclosing the container, means for agitating the chamber, and

' adjustable means within said chamber for detecting any predetermined container volume, said means operable during said agitating to stop and thereby signal the collection of the blood in any such predetermined volume.

8. Apparatus for controlling the collection of blood in a collapsible container comprising a chamber for enclosing the container, means for evacuating the chamber, chamber carried means for measuring and signalling the collection in said container of a predetermined blood volume, and means for occluding said evacuating means, said occluding means operable responsive to said signalling by said measuring means.

9. Apparatus for controlling the collection of blood in a collapsible container comprising a chamber for enclosing the container, evacuating means for said chamber, said means automatically valved by filling of said container to a determined blood volume, and means actuated automatically by the valving of said means for closing the container inlet. e

1 0. Apparatus for'controlling the collection of blood in a'collapsible container comprising a chamber for enclosing the container, chamber evacuating means ported within said chamber and for valving by determined expansion of said container, and clamp means for engaging thecontainer inletand operable automatically upon and by said valving to close said inlet.

11,. Apparatus for controlling; the collection of blood, in a collapsible container comprising achamber for enclosing the container, a bleed opening to said chamber, means for establishing a regulated vacuum in the chamber, said means rendered inoperative by determined expansion of said container, a door for sealing said chamber, said door held closedby the operation of said vacuum establishing means,- a clamp for closing the container inlet, said clamp engaged and held open by the closing of saiddoor, and means" biasing said clamp oppositely of said doorand operable to close said clamp and open said door automaticallyupon the rendering inoperative of said vacuum establishing means.

12. Apparatus for controlling the collection of blood closing means automatically upon said valving of said evacuating means.

13. Apparatus for controlling the collection of blood in a collapsible container comprising a chamber forenclosing the container, a vacuum-closed door on the chamber, evacuating means including a vacuum line opening into said chamber and sealed by determined expansion of said container, a clamp for the container inlet, said clamp held open by said door, a valve in said vacuum line, said valve held open by said clamp, spring means for closing said valve and clamp and opening said door, and a container bleed whereby said spring means is operable to close said valve and clamp upon the sealing of said evacuating means.

14. Apparatus for controlling the collection of blood in a collapsible container having an inlet comprising a chamber for enclosing the container, means for developing a controlled degree of vacuum in the chamber, means affording an air bleed to the chamber, means for detecting the collection of a predetermined blood volume and for thereupon stopping said vacuum developing means, a clamp engaging and conditioned to close the container inlet, and means for holding open said clamp subject to said controlled degree of vacuum, said holding open means permitting said clamp to close upon the dissipation of said vacuum by said bleed means following the stopping of said developing means. v

15. Apparatus for controlling the collection of blood in a collapsible container comprising a chamber for enclosing the container, a chamber oscillating motor, a control for said motor, means for evacuating said chamber, and a variable volume member communicating with said chamber and having a movable wall positioning said control.

16. Apparatus for controlling the collection of blood in a collapsible container having an inlet comprising a chamber for enclosing the container, means for maintaining a vacuum in said chamber, means operable upon the collection of a predetermined blood volume to dis- 'clamp, means for seating said valve and closingv said clamp, and vacuum operated means opposing and overcoming said seating and closing means during said collection.

, 18. Apparatus for controlling the collection of blood in a collapsible container comprising a chamber for enclos- V in the means associated with I said evacuating'for measuring the blood volume collected ,ing the container, means for evacuating the chamber,

means automatically regulating said evacuating'me'ans for a determinedlevel of vacuum in the chamber, and said chamber and operable durmg in said container.

19. Apparatus for controlling the collectionof blood in a collapsible container comprising a chamber for enclosing-the: container, means for developing a vacuum chamber, means automatically regulating said developing means for a determined lower level of vacuum in the chamber, and means for by-passing said regulating means to subject said chamber to the full vacuum of said developing means.

20; For controlling the collection of. blood in acollapsible container, a chamber for enclosing the container,

' a dooron said chamber, a vacuum line to said chamber,

andmeans operative upon the opening andelosing of said door to close and open said line.

21. For controlling the collection of blood in a collapsible container having "an inlet, a chamber for enclosingathe container, a door on said chamber, a vacuum hne to saidchamber, and means operative upon the opening and closing of said door to close and open said line and said inlet.

22. For controlling the collection of blood in a collapsible container, a chamber for enclosing the container, at door on said chamber, means for evacuating the chamber, means for agitating the chamber, and means operative upon the closing and opening of said door to start and stop said evacuating and agitating means.

23. For controlling the collection of blood in a collapsible container having an inlet, a chamber for enclosing the container, means for closing and opening the container inlet, means for evacuating the chamber, means for agitating the chamber, and means for starting and stopping said evacuating and agitating means dependent upon the closing and opening of said inlet.

24. Apparatus for controlling the collection of blood in a collapsible container having an inlet comprising a chamber, means in the chamber for detecting the collected'blood, and means controlled by said detecting means for closing said inlet upon the collection of a predetermined blood volume.

25. Apparatus for controlling the collection of blood 10 in a collapsible container having an inlet comprising a chamber, means in the chamber for detecting the collected blood, means for evacuating the chamber, means for agitating the chamber, and means operable to close said inlet and stop said evacuating and agitating responsive to the detecting of a predetermined blood volume.

References Cited in the file of this patent UNITED STATES PATENTS 1,855,658 Whipple et al. Apr. 26, 1932 2,169,088 Carter Aug. 8, 1939 2,597,715 Erikson May 20, 1952 2,757,375 Rieutord et a1 July 31, 1956 2,757,669 Gewecke et al. Aug. 7, 1956 2,761,445 Cherkin Sept. 4, 1956 2,784,932. Poitras Mar. 12, 1957 2,842,123 Rundhaub July 8, 1958 2,845,929 Strumia Aug. 5, 1958 FOREIGN PATENTS 1,124,356 France June 25, 1956

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