US2635194A - Method of and apparatus for ampoule inspection - Google Patents

Description

Apri] 14, 1953 E. w. KELLOGG E1 AL 2,635,194

METHOD OF AND APPARATUS F OR AMPOULE INSPECTION Filed May 27, 1949 ATTOR'NY Patented Apr. 14,- 1953 Edward W. Keuogg and Lawrence T. sachnebenf d Haddonield, and James Price, Erlton, N. 3.,; assignors to Radio Corporation, of America,a

corporation of Delaware Applicationll/Iay, 1949, Serial N0.V95,818

l Thisinvention relates to a method of V74and apparatus for inspecting'the contentsof light transmitting cyclindrically shaped bodies, such as medic'al-ampules. More particularly, the invention relates to a method of and apparatus for inspecting the contents of individual ampules for the presence of contaminating particles.

Serums and other liquids intended for therapeutic use are frequently packaged in small, hermetically sealed, substantially cylindrical containers made yof-glass or other transparent malteri'als. It is usually necessary that the contents be of a high degree of purity and free of anysuspended particles large enough to be visible to the unaided eye. However, in the processes of manufacturing many of these medicinals, many mechanical handling steps, such as filtration, are utilized. Tiny particles or slivers of the ltering medium, 'for example, may be introduced into the liquid, and containers which iny clude such particles or slivers must be discarded.

This necessitates very careful inspection by many operators in order to detect and remove from each batch those ampules containing contaminating substances.

'Heretofora this inspection had to be conducted visually and the ampules separated into passed and rejected categories entirely by hand. Furthermore, an inspector who had to minutely examine many `units in the course of a day was subject to great eyestrain and eyefatigue so that there was always present the danger `of vpassing ampules which should'have been Vrejected because of the presence of contaminating matter.

The present invention,` although not designed for completely automatic handling of the ampules, eliminates the necessity for the visual rinspection and provides a rapid means for electronically inspecting each unit for particles which maybe either more or less dense than lthe liquid in which they are present.

Briefly, the essential feature of the invention is Athefemployment of a novel apparatus and method for spinning an ampule just prior to inspection :and for holding the ampule in position duringthe 'inspection period without interfering with the passage of a beam of light therethrough. This is accomplished by Aproviding a pair `of driven rollers with an opening therebetween, and adapted to impart rotational motion to the ampule when the ampule is in frictional Vcontact with the rollers. A beam .of light is kpassed through the .opening and thence through the ampule, and light leaving the ampule is directed 4 Claims. (Cl. Z50- 218) to a photocell. A dierential in air'pressure is created on either side of the opening between the rollers, and this servesto increase the -frictional contact between the ampule and thehrollers so that the ampule, even though in an upright position, can be rotated rapidly, abrupt: ly halted, and inspected without'utilizing any further means for holding the ampule in position. Withv some ampules, however,` an additional meansto hold theampules while spinning is desirable, and a mechanical ejector may be used to free the ampule from the holding eiect of the air pressure after the inspection-period is over.

Gne object of the present invention is to provide an improved apparatus for electronically inspecting the contents of individual, lighttransmitting, liquid-filled containers, having a generally cylindrical shape.

Another object of the invention is to provide an improved method of electronically inspecting the contents of individual, light-transmitting, liquid-filled containers for the presence of contaminating particles.

Another object of the invention is to provide an improved apparatus especially adapted to inspect electronically the contents of relatively small containers filled with liquid.

Another object of the invention is to provide an improved-apparatus for inspecting the contents of relatively small, liquid-filled medical ampules while the contents are rapidly whirling within the container.

Another 'object of the invention is to provide an improved apparatus for imparting a whirling motion to the contents of Va liquid-lled ampule and `inspecting the whirling contents electronically, without interfering with the passage of a beam of light passing through the ampule.

Another object of the invention is to provide a means of substituting electronic inspection for visual inspection of relatively small medical ampules. n 1

A further object of the invention is to provide an improved' means and method for holdings. small cylindrical body during a spinning operation, and means for releasing the body at the end of an operational period.

Still another object ofthe invention is to -provide Yan improved method and apparatus for spinning a relatively fragile glass body and holding it during an inspection process.

These land other objects will be more :apparent and the invention will be `better understoodw-ith reference to the following description and the accompanying drawings, of which:

Figure 1 is a plan view, partially in section and partly diagrammatic, of the essential parts of an apparatus which may be utilized to carry out the objects of the present invention,

Figure 2 is an elevation view of part of the apparatus of Figure 1,

Figure 3 is a plan view, partially in section, of a' .a liquid which is Within a bottle, the method including holding the bottle between rotatable chucks, rapidly spinning the bottle between rotatable chucks, rapidly spinning the bottle and its contents, suddenly stopping the rotation o! the bottle, and, immediately thereafter, photoelectrically inspecting the contents of the bottle -While the liquid is still rotating but while the bottle is stationary. A beam of light is focussed at a plane cutting through the bottle and the light is ldirected through the bottle to a photoelectric cell on the other side. Any particle of contami- Ynating matter suspended in the liquid moves rapidly back and forth through the light beam due to the whirling motion of the liquid and a signal is produced in the output circuit of the photocell due to intermittent interruption of the passage of part of the light. The characteristics of the bottle, itself, do not influence the results oi the inspection since the bottle is stationary during the inspection period and since the inspection apparatus responds only to intermittent interruption of the light beam.

The previously used apparatus, which has been designed to utilize the above described method, operates very well when the liquid containers are relatively large and have considerable structural strength. However, the apparatus disclosed in the said Stout patent and in those patents directed to improvements thereon is not adapted to handle relatively small objects such as medical ampules, which may have a volume of only 1 t 10 cc. and which may be only 1 to 3 inches in length and about 1A; to 3A of an inch in diameter. Moreover, medical ampules are usually quite fragile with relatively thin walls. Accordingly, the present invention has been developed to utilize the basic inspection method described above but to apply it to the inspection of the contents of relatively small containers of a fragile nature.

Referring, now, to Figure 1, there has been provided a vacuum chest 2 which may be made of any suitable material, such as sheet metal. This chest has a box-like portion 4, having side, back, bottom, and top walls 6 generally square or rectangular in outline. The front wall 8, of the chest, is provided with a protruding bay l0. The front wall I i of the bay is provided with an opening l2 in the form of a narrow slit and may also b eprovided with additional openings I4 and I6, spaced adjacent the central slit.

One of the sidewalls is provided with an openingl' leading to a conduit 20, which is connected to means 22 for creating a reduced pressure within the chest. The means for creating the reduced pressure may be any device, such as a suction fan, which is adapted to produce a low vacuum.

Two cylindrically shaped rollers 24 and 26, having surfaces 28 of a resilient material, such as rubber, are mounted on the front of the bay Ill such that one is positioned on either side of the slit I2. An opening 30 is provided between the rollers which are spaced apart a distance approximately equal to the width of the slit. The rollers are rotatably mounted between a top bracket 32 and a bottom bracket 34 and are spaced just far enough from the front wall Il of the bay such that they are free to rotate. Each roller is provided with an axle 36 which rotates within top and bottom ball-bearings 38 and 4U, carried by the top and bottom mounting brackets 32 and 34, respectively.

Means, now to be further described with reference to Figure 2, is also provided for driving both of the rollers in the same direction. Each of the axles 36 of the rollers extends downward through the bottom bearings 40 andhas a downwardly protruding portion 42 extending beyond the lower mounting bracket. Each of the protruding portions is provided with a thickened sleeve 44. Bearing against both sleeves is a rubber tired driving Wheel 4B, which is rotated by means of a shaft 48 driven by motor 50. The motor is connected to a power source (not shown) and may be turned on and off by means of a key, or switch, 52. The motor is preferably a universal type having brushes and commutator. Since the driven partsV are relatively light in weight andiit tightly, their motion can be started and stopped relatively abruptly.

A light source and optical systems are provided within the vacuum chest. 'I'he light source may be a lamp 54 mounted adjacent the end oi the chest opposite the bay I0.. Between the light source and the central slit l 2, which serves to dene the light beam, is an optical system cornprising a set of condensing lenses 56, another optical slit 5.8, and a cylindrical lens '60, which system is for the purpose of focussing the beam from .the light source at a plane just beyond the opening between the rollers.

The remainder of the complete optical system comprises another set of lenses 62, positioned beyond the rollers outside the vacuum chest, while the inspection device is a photoelectric cell 64 having a conventional output circuit 66, which is connected t0 an indicating device 68, such as a signal light or buzzer. It is preferable, of course, to shield the photocell from the effects of stray light and spurious reflections.

The operation of the device is as follows. An ampule 10, containing liquid, is placed over the opening 30 in frictional contact with the resilient outer walls 28 of the rollers 24 and'26. At the same time, the suction means is placed in operation such that there is a suction of about 0.5 to 1 ounce per square inch at the opening between the rollers. Since there is a lowered airpressure just within the opening between the rollers, the ampule is held in position against the rollers by the relatively higher outside atmospheric pressure pressing against the ampule. The slits `|4 and-i6.' positioned on either side of the optical slit l2 enable a larger volume of air to be drawn throughA the vacuum chest. The differential in air pressure may also be said to increase Vthe frictional contactgbetween the ampule and the rollersso that the ampule is held rmly against the'rollers'." Therollers are then spun rapidly for a short `.:pe'rioizi:of time. tflhis icausesxthefampuleiandiits contentsftowrotaterapidly; also. lThe rotation `of the rollers iis athen abruptlyxstopped by .stoppingr rlthesmotor. 50. The rotation; ofat-heampule is, also, `rof course, suddenly "halted, .but ftheliquid continues-itc `:whirl fior-a, time due itoaitsiownlinertia.

During'this period, the inspection system :is in :operation fand, ir #a :particle lof' `suiii'cient-size ris ate a*suitable i mechanism to. "indicate `that the ampule should be'rejected. "Thisfmaybefa signal {light or buzzer or may "be an Vani-,climatic sepl"grating 4dev-ice of conventional design -which di- 'greets Aall massed tampules to one receptacle-.and

-After the end of the inspection period'jthe-suc- "tion'may be releasedeither bystopping the Opelation of the suction device or by `closing a lvalve l2 inthe'suction conduit 20. The 'ampule will 4then 'drop laway from the Arollers intofany receptacl'e AI3provi'ded tov receive it.

' The "above 4described 'apparatus functions" well with Asmall ampules having -`a diameter `which is jsubstantielly-uni'form. Because ofthe means'employed for holding the ampule 4while spinning andinspecting it,'there `is nothing to interfere with'thepassage of the 'light "beam through the center of the ampule. lInaddition, the apparatus is adapted-to hold the fragile ampule without applying any "heavyforoe to its wallswhich would result in a` largepercentageof breakage- Chucks for holding the ampules had previously been tried buto necessity produced some obstruction of the light close-to the bottom of the ampule, the very place where foreign particles are Vmost likely t bepresent. Also, the widely varying sizes of the xampules and their peculiar shape, due to the presence of "a sealing-oi protuberance, makes it extremely cdifiicult to designa practicalehuck.

'Whenthe `ampules are not of substantiallyuni- Viforxn diameter, and are ofthe larger sizes'.` a modi- ;doationof the apparatus, such asfshownxin Fignure 3, :has been found advantageous. As Nillustrated in the figure, a movable arm 14 carrying three small idler rollers 16, 18, and 80 may be swung into position during the spinning Operation such that the idler rollers bear against the wall of the ampule and assist the suction device in holding the ampule against the surfaces of the driving rollers. At the conclusion of the spinning cycle, the idler rollers are swung out of the Way by the arm 14 so as not to interfere with the inspection step. This may be accomplished either manually or automatically in the embodiment which is now to be described. The arm 14, carrying the idler rollers, is pivoted on a pin 82 located at one side of one of the driving rollers 24 such that the arm and the rollers can be swung out of the path of the light beam passing through the center of the ampule. The arm is provided with a short branch 84 integrally joined thereto at right angles. The branch is pivotally connected to a link 86 which, in turn, is pivotally joined to a plunger 8B extending through a solenoid 90. The end of the plunger is provided with a button 92y to which a spring 94 is connected. The other end of the spring is fastened to a fixed plate 96 through which the solenoid plunger also passes. When the solenoid has no current passing through it, the spring pulls the plunger forward and this motion is translated to the arm "M, movn.ing'itfaroundinia;swingingmotionsuch-thatlthe (from :a power r'source tnotJshown), ,fas by pressing fa key 9 8,` and `this i pullsnthe i plunger whack '.into

the solenoid, ,which faction, in turn, swings "the `.arm l lia-ndzthe idlerrollers :outfofthepath/ofthe light beam passing 4:through 'the centerV of v`the ampule to the position,shown'sinligurei6. The solenoid maybe actuated 'by vany conventional means such asa' manual contact. switch, as'shown, or automatically 'operated 'byarelay'tnot shown) The difference inpressure onfeither "sidefoffthe opening-between theirollersl 30 may-'also'becreated in a diierent"'manner. Instead fof fapplyingfsuction'through the: openingfa'streamof compressed air may be directed vtoward-s the *opening from the outside. An object placedacrosslthe opening will thus be held on vthe rollers bythe increased airV pressure directed against its-'exposed walls. This is not as satisfactoryyhowever,fasthepreviously describ'edembodiment. j

Although the ampule may be released'fromthe rollers at the end of the inspectioniperiodbyfcutting off the suction in themanner previously'described, it is possible-to release the fampulewithout cutting oli lthe suction,ina `manner-"which 'is now to beV described.

Referring now to Figure- 5, "ther'e is 'show-n an ampule l0, being held against rollers `2li` 'and'26 by means of a diierential in air pressure which may be maintained Vby'meansfsuch aspreviously described. Idler rollers 16,"18andnimay'also'be swung into-position against the ampule to aid in holding it against the rollers duringfthe timethe ampule is being spun. `When larger diameter ampules are being spun, thetwoouter idler rollers 16 and 80 make `contactwiththe wallsof the ampule. When l'ampules ofthe smallest diameters are spun, only the vcenteridler "18 makes Contact with the ampule. 'The ampuleejectin'g apparatus comprises an ejectorarm |100, positioned between and immediately behind vzthe ampule spinning rollers'24 4and V26,"th'e lowerfend of the arm being provided with a toe `portion-'102 extending forwardly through the opening 30 between the rollers.

The ejector arm is provided with means for lmparting reciprocating vertical motion thereto. This means may comprise a horizontal lever arm |04, plvoted about a centrally positioned fulcrum |06, with one end of the lever arm being pivotally connected to the top end of the ejector arm and the other end being pivotally connected to the lower end of a plunger |08, which is adapted t0 be drawn upwards against the biasing action of a springr H0, by a solenoid H2, which may be energized by closing a key switch I I4, using a conventional power source (not shown). The spring is adjusted to normally hold the plunger at the downward extremity of its stroke when the solenoid is not energized.

During the period in which the ampule is being spun and the following .period in which the ampule is stationary but the contents are still spinning, the ejector arm is held at the upward extremity of its stroke so that it does not interfere with the passage of the inspection beam through the ampule. This position is illustrated in Figure 5.

Immediately after the rollers 24 and 26 have stopped spinning and just prior to the start of the inspection period, the idler solenoid is deenergized, whereupon the idler rollers are swung away fro-m the 'ampule as previously described. The inspection period then follows.

vImmediately following the inspection period,

.the solenoid is actuated, drawing the plunger 108 upward and moving the ejector arm downward Y(as shown in Figure 6), whereupon'the forwardly extending toe I 02 pushes against the ampule and -kicks it forward, away from the ampule-spinning .against a pair 'of rollers by a force created by a differential in air pressure between two dierent points on its external surface and the object is then spun by driving the rollers. At the end of the operational period, the object may be released from its contact with the rollers by producing a sufficient force in opposition to the force which is due to the differential in air pressure or else byshuttingl oli?v the means which produced the pressure differential. The opposing force v.may be either an ejector arm or any other mechanical-equivalent such as a reverse air blast. Various other modifications in the apparatus may also be made within the spirit of the invention, which has a particular application to the method of inspection described.

We claim as our invention:

1. Apparatus for inspecting the contents of a transparent container having substantially cylindrical side walls, including a pair of driven rollers having an opening therebetween and adapted to impart rotational motion to said container when said walls are in frictional Contact with said rollers, means for passing a beam of light through said opening and through said container, means for creating a dilerential in air pressure on either side of said opening whereby the frictional contact of said walls with said rollers is increased, and auxiliary means for holding said container against said rollers while said container is rotating.

48 2. Apparatus according to claim 1 including means for moving said auxiliary'holding lmean out of the path of said beam of light.

3. A method of inspecting the iiuid contents of a transparent container having substantially cylindricallyV shaped side walls. said method comprising holding said walls in frictional contact with a pair of-rotatable rollers by means of a differential in air pressure between different points on said walls, rotating saidv container and its contents' by rotation of said rollers, 4stopping the rotation of said container while the contents remain in rotation, and photoelectricallyinspectring said rotating contents. l

n 4. A method of inspecting the iiuid contents of a transparent containerhaving substantially cylindrically shaped side walls, said method comprising holding said walls in frictional contact with a pair of rotatable rollers by means of a force created by the differential in air pressure between different points on said walls, rotating said container and its contents by rotation of said rollers, stopping the rotation of said conr tainer while the contents remain in rotation, photoelectrically inspecting said rotating contents, and releasing said container from said contact with a force in opposition to the force caused by said dilerential in air pressure. EDWARD W. KELLOGG.. LAWRENCE T. SACI-ITLEBEN. JAMES F. PRICE.

References cited m the me of this patent i UNITED STATES PATENTS Number Name f' Date A 1,003,786 Pecht Sept, 19, 1911 1,333,006 Welser Mar. 9, 1920 1,553,760 Ellis Sept. 15, 1925 1,836,690 Talbot Dec. 15. 1931 1,871,430 Snow Aug. 9, 1932 1,926,466 Twohy Sept. 12, 1933 2,021,696 Millerv Nov. 19, 1935 2,079,833 Bennett May 11, 1937 2,192,580 Sachtleben Mar. 5, 1940 2,255,034` Bauer Sept. 2, 1941 2,436,082 Stout Feb. 17', 1948

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