CA2392579A1 - Container inspection and sorting system - Google Patents

Abstract

There is provided a device and method for detecting low fills in a bottling line wherein a single pulse of light in a narrow beam is used to determine that the level of liquid in the container meets a predetermined level, said level being the central base portion of the liquid meniscus. This mode of evaluation is more accurate and reduces the number of false low-fills.

Description

CONTAINER INSPECTION AND SORTING SYSTEM
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention relates to the inspection of containers and, in particular, containers such as bottles, which are transparent or translucent and allows the passage of light therethrough. More particularly, the present invention provides for the non-contact examination of an individual bottle in a line or stream of similar bottles travelling along a moving conveyor, the bottles being filled with an aqueous liquid such as a potable water-based beverage such as beer or a soft drink.
The required inspection is effected and any cansequential action such as sorting or rejecting the bottles taken without the movement of the bottles being affected.
DESCRIPTION OF PRIOR ART
Various inspection systems have been proposed for examining a stream of containers such as glass bottles moving along a conveyor and these systems may be used to sort the containers based upon one or more of the bottle characteristics disclosed by the examination. Many previous systems of this type employ apparatus that are regularly disruptive of smooth flow.

Examples of such disruptions may be, for example, devices that remove containers from a straight conveying path for inspection; kickers; separators and diversion elements that are prone to knock containers down; and inspection stations that require some or all of the containers to be slowed, spun or even stopped in place.
Reference may be made to various arrangements by which bottle rim or side wall inspection are carried out for example, U.S. Patent 4,454,542 discloses a video rim inspection technique; U.S.
Patent 4,391,373 discloses rim inspection using photocell pairs and US Patent 3,932,042 teaches sidewall inspection techniques. U.5. Patent 4,121,103 teaches absorption in the visible and infrared regions and base analysis devices. U.S. Patent 5,903,006 teaches using the absorption of light in the infrared region to detect and evaluate the concentration of water in an aqueous solution. The light source used is a light-emitting laser diode emitting light having a wavelength within the range 1.3 to 1.9 Vim.
U.S. Patent 6,043,504 also teaches the use of a semiconductor light-emitting device to "inter alia" detect the presence of water and, in Col. 1 et seq. discusses the issues with conventional photoelectric switches and the available semi-conductor light-emitting devices, particularly lasers which can provide light of the desired wavelength to the significant exclusion of light of other wavelengths. This means that the amount of the projected light, which is absorbed upon contact with water, is very high and a significant percentage of that initially projected.
Consequently, it is possible to detect the large decrease from a beam which is attributed to water absorption of the light and hence to evaluate the presence or absence of water. This patent also teaches the general use of the photoelectric switch to detect the level of a liquid composed mostly of water. However, the method as taught leaves something to be desired when applied to the problem of determining whether a bottle containing a water-based beverage is filled to the correct level as the bottle is rapidly moving on a conveyor subsequent to it being filled. The problem arises not only because the meniscus of the beverage liquid is not a planer surface but it is exaggerated since the neck of a beer or soft drink bottle usually has a small cross-sectional area: Also because the filled bottle may be subjected to significant sway or wobble because of the high speed of the conveyors transporting the filled bottles to the next stage in the process and bottle contact with adjacent bottles and conveyor guide rails. This bottle wobbling results in the beverage liquid in the bottle becoming subject to agitation or oscillation.
More importantly, these systems scan the full width of the bottle or bottle neck and hence the light beam encounters all the material "creeping" up the bottle wall which, as discussed, can be agitated and oscillate making locating the actual fill height difficult and inexact. The result is that it becomes most difficult to locate the level of the beverage in the bottle. Consequently, in the prior art devices when the light beam scans the whole neck of the bottle it can encounter several situations which can result in an invalid evaluation of the liquid level resulting in, for example, the rejection of a bottle when the liquid level may actually meet the required level. To explain more fully when the liquid in a bottle is subject to oscillation such that, when the bottle is at the evaluation station, the liquid surface meniscus is momentarily at an angle such that the light beam does not encounter sufficient liquid to be absorbed to the degree necessary register as meeting the required standard level, it will register that bottle non-compliant with a set standard. This results in rejection when that should not have been the case.
U.S. Patent 3,784,827 describes a sealed radioisotope source for use in a container inspection system. This system involves passing y-radiation through a liquid containing-container at a position just below the desired light fill level. If the liquid is filled to the correct height, the radiation is absorbed by the liquid. Alternatively, if the liquid is not at the desired height, the radiation passes through the container without absorption. The amount of radiation passing through the container indicates whether or not the container has been filled to the desired height.
However, the x-radiation beam has a fan-like profile, which is less focussed, and it is difficult to provide reasonable assurance that no - or only an acceptably small number - of low fills are cleared. The system needs to be set in a conservative manner resulting in an unacceptable number of bottles being incorrectly designated as low fills and rejected.
In order to reduce the possibility of an incorrect evaluation of the liquid level in the usually neck region, of the container it is preferred that steps are taken to stabilize the meniscus in each container when it is in the inspection stations i.e. at the point of evaluation. This can be accomplished in a number of ways; for example; the bottle may be stopped for a time sufficient to allow the liquid to settle or the liquid contents of the bottle can be rotated. This latter proposal to some extent stabilizes movement of the meniscus, at least sufficiently to hope that the critical central area remains at a constant level. However, this is a complex and costly operation.
Another method uses mechanical means such as a feed screw arranged to contact and engage the container when in the inspection station and prevent it from as wobbling or swaying. This method however has obvious speed restrictions. This can be compared with prior art devices which provide continuous scanning across the full width of the container when the detector can be confronted with an aggregated signal from a wide beam of radiation, parts of which may have encountered liquid of various "thickness" and others no liquid at all. The net result at best is that the light received by the photo receiver must be subjected to processing activities involving initially an evaluation of the total radiation it receives and a comparison thereof with a value which has previously be determined to constitute a "low fill" or acceptable level situation.
Once obtained, this information may be used to accomplish a number of objectives, for example, a container diversion device located downstream of the detection device of the present invention could be supplied with the information as to which containers are "low fills"
resulting in such containers being diverted from the moving stream or line to be further processed.
It is an object of the present invention to provide an inspection device for more accurately determining the fill height of aqueous contents in a bottle thereby reducing the number of false rej ects.
It is another object of the invention to provide such a device which is relatively inexpensive, easy to maintain operating and which requires little space for installation.
BRIEF DESCRIPTION OF INVENTION
It has now been found that many disadvantages associated with prior art contents level inspection devices can be avoided and, more specifically, a more consistent exact measurement of the desired fill level can be obtained by effecting a single point evaluation of the fill level. This evaluation is made according to the invention essentially at the intersection of the desired fill height and the vertical axis of the bottle or more correctly, the bottle neck portion. This location which is arranged to be the central portion of the meniscus of the bottle content liquid has been found to be relatively insensitive to the oscillations and like movements of the liquid content of the travelling bottles caused by motions of the latter, such as wobbling. This single evaluation is effected by projecting a single pulse of light in the form of a narrow or fine beam of light at the neck of the bottle to be inspected, the beam being arranged to contact the bottle substantially at the intersection of the plane of the desired fill level and the central vertical axis of the bottle or more specifically, the neck portion. The center portion of the meniscus is arranged to be at or immediately below the desired fill height. As a consequence, the pulse of light either:
(i) contacts the body of liquid right up to the surface of that central region of the meniscus and is blocked or absorbed by the liquid, and (ii) if above that central region of the meniscus, "sees" only glass (or another light transmitting bottle material) and is detected by the associated light receptor.
With respect to (i) the receptor is not activated and does not generate a signal. This signifies that the filled bottle neck liquid level specifications are met and the bottle is acceptable.
In the case of (ii), the beam is transmitted to the light receptor which then generates a signal that the bottle under test is a low-fill. i.e. unacceptable.
It may be noted that some bottling operation, such as the filler can impact a small amount of rotational movement to the bottle and its contents, this assisting stabilization of the meniscus to some extent.
In contrast to prior art devises, the use of a fine beam means that only a relatively small amount of liquid is needed to obtain a definite measurement which results in a simple "yes" for acceptable or "no" for an unacceptable. To enhance this sensitivity, it is very preferable that a significant percentage of the light beam used be readily absorbed by the liquid being detected. In the present case, a beam tuned to the water molecule is preferred since the beverage with which the present invention is advantageously used has significant water content.
There are various commercially available lasers which provide the desired characteristics and, since these can be relatively physically small, they can be installed in a plant without too much difficulty.
Consequently, it is very preferred that the light source used according to the present invention be a laser tuned to the water molecule. It should be noted that these lasers provide light having a wavelength predominantly in the range of from about 1.40 to 1.55 microns. One supplier of such lasers and associated light guides etc. is IDEC Corporation of Japan.
This generated signal is arranged to activate a bottle rejection system such as a hopper; slat rejecter or the like. However, it is preferred that the novel rejecter device as taught in Assignees' Pending U.S. Application Serial No. 09/891,616, (F. Linton), the contents of which application are incorporated herein in their totality be used and this combination constitutes another aspect of the present invention.

It is further preferred that the combination of detector and deflector combination of the present invention be used in combination with a container tracking device which delays the signal from the detector to the defector.
It will be appreciated that any located low-fill is not generally rejected at the inspection station.
The action point of rejection, is usually downstream but it is then necessary to track the progress of any found low-fill so that the rejection device is activated to reject it, and only it, when the low-fill reaches the rejection station. Such tracking systems axe readily commercially available and routinely used the art, one such system is a shift register system, an example of which is the "Checkmate" software system of Krones Inc., 9600 South 5$t" Street, Franklin, WI 53132-0100.
Further and detailed description thereof is felt unnecessary.
DESCRIPTION OF INVENTION
In one aspect, the present invention provides an inspection device for determining if the level of an aqueous liquid in a container having a neck portion is at a predetermined level, at least a zone in the neck portion containing at the predetermined level being adapted to transmit light, said device comprising a first means adopted to emit a single pulse of light in a narrow beam toward a second and opposing means adapted to detect said light, the space between the first and second means defining a container inspection station, means to transport containers to be inspected through said station and means to initiate projection of said pulse of light when a container to be inspected is at a position in said station such that said pulse contacts said bottle neck portion at a location representing the intersection of the predetermined level and a central vertical axis of said neck.
In another aspect, the present invention provides a sorting device for separating from a stream of bottles containing an aqueous liquid travelling along a pathway, which bottles have a neck portion which is able to transmit light, those bottles whose liquid content meets a predetermined level, which level is located in said neck portion, from those containers whose content does not meet said predetermined level, said device comprising:
a first means adopted to emit a single pulse of light in a narrow beam toward a second and opposing means adapted to detect said light if the Ievel of liquid in said container fails to meet the predetermined level, the space between the first and second means defining a container inspection station, means to transport bottles to be inspected through said station and means to II
It is furt initiate projection of said pulse of light when a container to be inspected is at a position in said station such that said pulse contacts said container neck portion at a location representing the intersection of said predetermined level and a central vertical axis of said neck, and container deflector means which, in response to a signal initiated by said second means, is adopted to remove said stream of containers.
In another embodiment, the present embodiment provides a method for detecting in a stream of aqueous liquid filled containers travelling along a pathway, which containers have a neck portion which is able to transmit light, those containers whose liquid content meets a predetermined level, which level is located in said neck portion, from those containers whose content does not meet said predetermined level, said method comprising: passing said bottles to a station where a pulse of light in a narrow beam is projected at a portion of the neck of each bottle which includes the intersection of the said predetermined level and a central vertical axis of the container and where the container contents do not meet the predetermined level detect such beam which passes through the container neck of the bottle under inspection.
In yet another embodiment, the present invention provides a container sorting method for separating from a stream of liquid filled containers travelling along a pathway, which have a neck portion which is able to transmit light, those bottles whose liquid content meets a predetermined level which is located in said neck portion from those whose content does not meet said predetermined level, said method comprising: passing said bottles to a station where a pulse of light in a narrow beam is projected at a portion of the neck of each container which includes the intersection of the said predetermined level and a central vertical axis of the container neck detecting any such beam which passes through the bottle neck and using same to activate a container deflector which removes the container in question from the stream of containers without affecting the motion of the other containers in the stream of bottles.
It will be appreciated that the present invention may be used with advantage to handle different types containers which meet the light transmittance requirements but it is especially useful in the processing of containers especially bottles and specifically glass bottles containing soft drinks but especially alcoholic beverages such as beer.
The present invention will be further described, but not limited by, reference to the drawings in which:
FIG. 1 is a diagrammatic cross-section through an inspection station showing the adjustable support which carnes the optical detector system according to the present invention.
FIG. 2 is a perspective view from upstream of part of the inspection station of FIG. 1 along the conveyor and showing the inspection station with an associated bottle infeed worm arrangement.
FIG. 3 shows in detail the adjusting mechanism for adjustion of the deflector system according to the present invention.
FIG. 4 is a detail of the connections of the trigger device and the emitter head of the inspection station; and FIG. 5 is a cross-section of a bottle neck showing the substantially consistent meniscus level despite movement of a bottle at the inspection station.
FIG. 6 is a cross-sectional view of a deflector device used according to the present invention.
FIG. 7A is angled perspective of the paddle unit shown in FIG. 6 and 7B is an end elevation in the direction of arrow A in FIG. 6A of the paddle unit.
FIG. 8 comprises diagrammatic cross sectional views showing a bottle on a conveyor, in FIG.

8A at the point the paddle plate is initially contacting the bottle, (the angle of the paddle plate to the vertical being exaggerated) and in FiG. 8B secondary contact occurring slightly later in the rej ection stroke.
FIG. 9 is an angled perspective view of the deflector installed on a bottle conveyor.
FIG.10 is a diagrammatic plan view of a divertor system used according to the present invention this showing a main conveyor, associated secondary bottle take-off conveyor and bottle rejection table showing in solid a deflector plate of a divertor of the present invention in its rest position and, in phantom, at the end of its diverting position extending across the pathway of the conveyor for a stream of travelling bottles.
As best seen in FIG. 1 and FIG. 2, a bottle inspection station, generally designated 10, comprises a mounting assembly generally designated 12 and an associated conveyor 14. The assembly 12 has a main arm consisting of an L beam 1$ having a horizontal member 20 and a vertical member 22. Bolted, via bolts 21, to horizontal member 20 are two L-shaped brackets 24 and 26. As will be discussed in detail below, the vertical arms 25 and 27 thereof carry the components of the light emitting and receiving elements of the inspection system.

Horizontal member 20 also has provision at 28 for a bottle cap detector 30 which is connected via line 32 to power and signal transmitting means (not shown).
The previously described assembly is attached to and carried by adjusting mechanism 34. This comprises a base plate 36 which is carried by a pedestal 38 which, in turn, is firmly secured by bolts (not shown) to the floor 40. It may be noted that only a small area is required to seat the pedestal foot 39. Turning to FIG. 3 secured to the edges of base plate 36 via bolts 42 are vertically upstanding side plates 44 and 46, the latter being provided with slot 48. A top plate 50 is secured to the upper edges of side plates 44 and 46 via welds 52 thereby completing a rigid box-like housing which is securely affixed to the floor 40 via pedestal 38.
Top plate 50 contains a hole (not shown) and, concentric therewith, a journal bearing 54 secured by bolts 55.
Extending through the hole and bearing 54 is a shaft 56, the lower portion of which 57 is threaded as shown. To the uppermost extremity of shaft 56 is filled a crank 58 having a handle 59, rotation of which rotates shaft 56. Located horizontally in the box-like housing is a moveable plate 60 which has a centrally located hole 61 to accommodate the threaded portion 57 of shaft 56. Affixed to plate 40 and extending upwardly and parallel to shaft 56 are three guide rods 62 (only one shown) which are adapted to move vertically through a guide bore (not shown) in moving plate 60. The 'three guide rods 62 are spaced apart and form an isosceles triangle and provide stability and reduce any possibility for moving plate 60 to quaver.
Moving plate 60 carnes at an edge, a bar (not visible) which is arranged to extend thmugh slot 48 in end plate 46.
The portion of the bar which extends through slot 48 is tapp~ and a washer 64 and a locking crank 66 are located thereon. Finally, secured to moving plate 40 via bolts 70 is member 20 of support arm 18.
To adjust the height of moveable plate 60, and thereby arm 18 and items secured thereto, and in particular the light detector components, such as emitter 70, photoreceptor 71, their guards 73 locking crank 66 is rotated so as to release moveable plate 60. Subsequently, rotation of crank 58 results in rotation of shaft 56 whereby moveable plate 60 through rotation of threaded bar 57 is raised or lowered as desired. Guide rods 62 ensure that moveable plate 60 remains and is maintained horizontal and that movement is smooth and exact. It may also be noted that cap detector 30 is also carried by support arm 18.
Also shown in FIG. 1 is conveyor 14 which carries a line of bottles from a bottle filler (not shown) to a bottle labeller (not shown) at high speed - 920 bottles/minute in this case. However, only one bottle 80 is shown located at the inspection station. The location of the inspection station is close so that there are no labels especially neck labels, or the bottles which could interfere with the light beam. Note that the inspection station assembly, the combination of adjusting mechanism 34 and support arm 18 and its attachments are not connected to the conveyor assembly but directly to the floor. This ensures that normal movement or shaking etc.
of the conveyor does not result in movement of the detection device which could result in the calibration settings of the beam and receive system being inadvertently changed.
Refernng again to FIG. 2, there is also shown a fiber optic assembly 70 (IDEC
SA9WTS31) which is connected via light guides 72 to a laser assembly (IDEC SA1 W-FW2) not shown. As a practical matter, the alignment of the laser beam is effected prior to installing the mounting brackets and support arm 18 into position in the insp~tion station. In brief, the fiber optic cable 72 is connected to the laser assembly {not shown) and a voltage of 12-24 volts DC is applied to the laser. The emitter end of the cable 72 is then mounted into its associate bracket member 27 and the amplifier lens is then attached. In fact, the laser beam is essentially invisible and a led is used to achieve the alignment, the laser beam being located in the center of the led circle. Once aligned, the fiber optic cable plus amplifying lens can be removed and readily re-installed when the bracket assembly has to be installed in the inspection station location at associated conveyor 14.
SYSTEM OPERATION
The operation of the system may be stated briefly as follows. The arrival of a bottle 80 at the inspection station breaks the light beam of trigger 86. The centre of the trigger is positioned some three eighths (3/8) of an inch upstream from the centre of the laser light emitter. This ensures that the light strikes the centre area of the neck of the bottle as required by the present invention. The trigger is also programmed to detect the "back wall" of each bottle i.e. when the bottle has left the station and it will not activate the laser assembly again until it has made that detection. This ensures that the photodetector can only receive one pulse of light her bottle and its decision is based solely on its receiving or not receiving that one measured pulse of Light.
Breaking of the beam results in a command or prompt being sent to the laser assembly which is activated to send a pulse of light to the emitter. As stated the system is arranged so that the time between the break in the trigger beam and the light pulse being emitted results in the light pulse striking the bottle along its vertical axis C-C, refer FIG. 5. Previously the position of the emitter 70 and the light sensor 71 had been set so that the laser beam would be located at a height above the conveyor which equates to the desired fill level when a bottle is at the inspection station. In other words, on line with or just below the base of the meniscus - line B-B in FIG. 5. This equates to the intersection of the desired fill height and the central axis C-C of the bottle neck and, in this case, also the bottle. The laser used (an IDEC SAIW-FN2 laser assembly, obtainable for IDEC) Corporation of Japan produces a light which is able to travel through the glass from which the bottle is made but is absorbed to a significant extent by water molecules. The sensitivity of the system is preset so that the beam which passes above the meniscus - even if it travels through the liquid film at the edges of the meniscus i.e. the central base portion thereof is below the desired level - is not absorbed or "blocked" but is picked up by receiver 71 and which counts it as a "no hit". This equates to a determination that the bottle in question is a low-fill. A
signal is then generated which passes to a bottle rejecter system using a divertor device (see below) and the bottle is removed from the stream or line of bottles at the appropriate location. If, on the other hand, the laser beam encounters the base of the meniscus or therebelow, the light is absorbed, in effect blocked, does not pass to the receiver 71, which, consequently, is not activated. No signal is generated and the bottle in question simply continues along the conveyor to the next series of operations e.g. a labeller etc. It may be noted that, from a practical view point a found low-fill may not be removed from the line of bottles immediately.
The following description relates in detail to the preferred bottle deflector device which in combination with the detection unit described above, constitutes a separate aspect of the present invention. For convenience, the deflector or divertor device is located downstream of the labeller. Consequently, this system utilizes a known tracking system, the Krones "Checkmate"
software, to trace the progress of a found no-fill bottle through the labeller to the deflector device downstream of the labeller.
Turning to FIG. 6, this shows a vertical cross-section through a divertor device of the present invention secured to an associated bracket assembly. The divertor unit generally designated 110 comprises an electric synchronous motor 112 (model BLX234A2E000 from Thompson Industries Inc., Thompson Control Division, 2 Channel Drive, Port Washington, NY 11058) and secured thereto an article deflector member or paddle unit 114, the latter consisting of a mount 116 carrying a rectangular bottle-contacting plate 118. Note this Plate 118 has a length of about the diameter of a bottle. Secured to the upper portion of mount 116 by two bolts (not shown), which extend up through the base 120, is a clamping collar 122. Collar 122 has a grub bolt 124 located in internal bore 126, which bolt 124 extends through the collar 122 across slot 128 to enter and engage its associated nut (not shown) tapped internally in collar 122. Collar 122 is also provided with a bore 130. The mount 116 is made of a rigid plastic material namely polyamide as is the contact plate 118 which has a relatively smooth surface. Plate 118 is secured to mount 116 by friction via joints 119 and 121 (refer FIG. 2B). Mount 116 is, to some extent, cut-away to reduce weight. It will be appreciated that the plate material is very rigid and hard wearing requiring essentially no maintenance. It needs to be replaced only after a prolonged period of use especially compared with the softer pads used in prior out devices. The length of plate 118 is about or just less than the diameter of the bottles travelling on the conveyor 148, namely about 69 mm and its height is about 55 mm. It is angled to the vertical - refer FIG.
8A - about 5°, that angle being exaggerated for clarity.

As shown especially in FIG. 7A, the paddle unit 114 is adapted to be secured to the shaft 132 via bore 130 which is located toward one longitudinal end of the unit 114. This is for convenience in this specific embodiment. In other embodiments, it may be preferable to locate the bore i.e.
the vertical axis about which plate 118 would rotate, in the center part of unit 114. The design is chosen to best suit the specific application requirements.
The paddle unit 114 is secured to the drive shaft 132 of motor 112 by locking collar 122 and specifically, by tightening grub bolt 134 when motor drive shaft 132 has been located within bore 130. Motor 112 is supplied with power and signals from a detection unit through connection 134 via power and information transmission lines 135 - refer FIG.
9.
The divertor unit 110 is supported and carried by a bracket assembly generally designated 136.
This comprises three separate brackets numbered 138, 140 and 142 respectively.
Bracket 138 consists of a plate 144 which is secured to a support member 145 of the conveyor 148 via bolts 150. Extending from plate 144 are bolts 152 which are adapted to extend through slots 154 vertical limb 155 of L-shaped bracket 138 and be, secured by nuts 156. These allow bracket 138 to be vertically adjustable and then locked into place via bolts 152. Bracket 138 also has a metal gusset 158 welded to and joining both limbs of the bracket to provide structural rigidity. Turning to bracket 140 this is similar to bracket 138 but smaller. One limb 160 is secured to limb 155 of bracket 138 via bolts 162 which extend through slots 164 - refer FIG. 9. This arrangement allows bracket 140 to move horizontally for adjustment toward and away from the conveyor 148 and then be locked in the desired location by the tightening of screws 162.
Turning to bracket 142, this is secured to bracket 140 via first bolts 166, their associated holes through vertical limb 168 of bracket 140 being adapted to receive bolts 166 and allow for some movement in a vertical plane. Adjustment bolt 170 is tapped into vertical limb 168 of bracket 140.
These in combination with bolts 170 provide an adjusting system where limb 143 can rotate to a limited extent in a vertical plane and be secured at any position within that range of rotation. Finally, motor 112 is secured via bolts 172 to the upper limb 143 of bracket 142. The divertor unit 110 can be seen attached via bracket assembly 136 to a conveyor 148 in FIG. 9. It should also be noted that a section has been omitted from conveyor sidewall 180, and the plate 118 is located in that opening 181, approximately in line with the two sections of wall 180 adjacent to and defining opening 181.

In summary, bracket assembly 136 via the combination of the three individual brackets 138, 140 and 142 provides for vertical adjustment; horizontal adjustment; and angle adjustment in a vertical plant. Since paddle unit 114 is secured directly to motor 112 via shaft 132, adjustment of the location and angle of the motor 112 relative to the conveyor 148 also adjusts the location and angle of the paddle 114 and in particular, the bottle contacting-plate 118. It has been found that a small deviation from the vertical of plate 118 assists in maintaining diverted bottles in an upright condition as they leave the deflector and move across the conveyor 148. In this embodiment of the present invention, - refer FIG. 8A - a deviation of about 3° - S° anti-clockwise from the vertical i.e. the upper corner 119 of plate 118 is closer to the conveyor path and hence the line of bottles 174 than the lower corner 121, has been found preferable. Also shown in FIG. 8B is the point or edge 117 of the bottle, this being radically opposite the point where plate 118 contacts and acts on the bottle 174.
Initially, the bottle when resting on and being carried by the conveyor because of lubricant located on the conveyor has a tendency to adhere to the conveyor surface.
Consequently, the initial contact between corner 119 and the bottle can still result in the bottle tending to rotate about bottle edge 117 and become unstable and under the influence of the moving conveyor leave the deflector unit in an uncontrolled condition. Consequently, in the shown preferred embodiment, the plate 118 is angled to the vertical about 5°. It is believed that this small angle is sufficient to allow the bottle to rotate in a vertical plane a small amount which is sufficient to break the "seal" between the bottle base and the conveyor. Immediately thereafter, the lower portion of plate 118 contacts the bottle also and allows the bottle to righten to maintain control of the movement of the bottle so that when it leaves the paddle plate 118, it is in a stable equilibrium and exits the line and successfully moves to the desired location be it a receptacle or another conveyor.
Turning to FIG. 10, this is a diagrammatic plan view of a conveyor system incorporating the present invention. A bottle input conveyor 170 is provided with a bottle inspection device 172 adapted to inspect bottles travelling in a stream on conveyor 170 in the direction of the arrow. A
deflector device 176 of the present invention is located downstream of inspection station 172 and adjacent conveyor sidewall or rail 180. Of deflector device 176, only the paddle unit 182 is actually shown (in plan) with bottle contact plate 184 being shown (in solia~
in its base or rest position generally adjacent, and parallel to conveyor sidewall 180. The vertical position of paddle unit 182 relative to the conveyor 170 is set so that upon rotation, bottle contact plate 184 can swing across the conveyor and make contact with a selected bottle at the desired position on the bottle wall - refer FIG. 8A - travelling thereon in the direction of the arrow. The conveyor wall 180 at the location of the deflector 176 and, more specifically, adjacent bottle contact plate 184, is cut away to provide a gap to allow for the rotation of the plate 186 of the paddle unit 182 across the conveyor 170.
Located adjacent and parallel to, conveyor 170, but on the opposite side thereof to deflector 176, is a bottle take-off, conveyor 188. On the other side of conveyor 188 is a bottle receiving table 190 this being located to receive totally unrecoverable rejects. Rotation of the paddle 182 in an anti-clockwise direction results in the bottle contact plate 184 moving across conveyor 180 - the new position thereof being shown in phantom at 192 contacting bottle 174a.
Also shown in phantom are previously deflected or rejected bottles 174b and 174c.
As indicated earlier, in the case of the specific synchronous motor BLX234, the full count is 8000. Since the paddle is mounted on the motor shaft 132, this means that the paddle member would rotate 360° an a full count. In this specific case, a 21°
rotation of the paddle which is required to provide the thrust necessary to move the bottles out of the line on to the take-off conveyor is achieved by programming the motor with a count of 525 (525/8000 x 360=21°). The count of 525 represents the distance from the base or rest position of the paddle 118 adjacent a conveyor to its full extension over the conveyor required to effect the desired rejection of the bottles. Following completion of the initial rotation, the programmed reverse rotation immediately occurs returning the paddle to its original and rest position outside the pathways this completing the cycle. The motor cannot respand to another signal, and hence the paddle cannot move to reject another bottle, until that cycle is complete. However, the characteristics of the motor are such that it is able to complete that cycle extremely rapidly and sufficient to handle the high-speed rejection of bottles required by modern facilities. It should be noted that even with the high rates involved, the device is able to reject a single bottle even when the bottles in the rapidly moving line are in contact with each other. Further, it should also be noted that even when adjacent bottles are required to be rejected, the present invention completes a full cycle in respect of each bottle. Consequently, each bottle is smoothly removed by the same sweeping action and the second and subsequent adjacent bottles in a line to be rejected do not encounter a paddle resting in the in pathway. This is important since the synchronous motor can be programmed to provide a different rejection action, and thereby controllably direct even adjacent bottles to different destinations, in response to it receiving different signals from a sensing station. The above calculation is given only for bottles to be moved to the adjacent conveyor.
The motor parameters required to mane bottles to the 190 or other destinations can readily be calculated. Such calculations might require taking into account a different deflector plate design, weight etc. but this is readily achieved by simple system tests. Consequently, say 50 adjacent bottles are to be rejected - some for absence of crowns; some far being low fills etc., each can be dispatched to the correct area for that defect. Articles to be simply sorted are handled in the same manner.
Moreover, the two rotational movements in a cycle can be effected at the same or different rates of acceleration but in any event, are preferably at a maximum relative to the motor characteristics to ensure the cycle is completed as soon as possible and the paddle is in its rest position outside of the pathway. For example, in the situation described above for movement to conveyor 188, the initial acceleration is at about 38,000 rps and deceleration toward the stop at about 11,000 rps for a velocity of b700 rps.
The devices of the present invention have significant advantages over prior art devices, namely:
(i) simple in construction;
(ii) easily installed requiring minimal scarce space and utilities;
(iii) require little maintenance (iv) have rapid response times;
(v) the detector device reduces false low-fill calls (vi) is able to reject or sort articles moving at high speeds for prolonged periods with no reduction in efficiency (vii) is inexpensive (viii) the detection and sorting device can operate with available deflection devices but is advantageously used with the deflection device of the present invention.

Claims

I Claim:

(1) An inspection device for determining if the level of an aqueous liquid in a container having a neck portion is at a predetermined level, at least the neck portion in a zone containing the predetermined level being adapted to transmit light, said device comprising a first means adopted to emit a single pulse of light in a narrow beam toward a second and opposing means adapted to detect said light, the space between the first and second means defining a container inspection station, means to transport containers to be inspected through said station and means to initiate projection of said pulse of light when a container to be inspected is at a position in said station such that said pulse contacts said bottle neck portion at a location representing the intersection of the predetermined level and a central vertical axis of said neck.

(2) A sorting device for separating from a stream of bottles containing an aqueous liquid travelling along a pathway, which bottles have a neck portion which is able to transmit light, those bottles whose liquid content meets a predetermined level, which level is located in said neck portion, from those containers whose content does not meet said predetermined level, said device comprising: a first means adopted to emit a single pulse of light in a narrow beam toward a second and opposing means adapted to eject said light if the level of liquid in said container fails to meet the predetermined level, the space between the first and second means defining a container inspection station, means to transport bottles to be inspected through said station and means to initiate projection of said pulse of light when a container to be inspected is at a position in I
said station such that said pulse contacts said container neck portion at a location representing the intersection of said predetermined level and a central vertical axis of said neck, and container deflector means which, in response to a signal initiated by said second means, is adopted to remove said container from said stream of containers.

(3) A device according to Claim 1 or 2 wherein the light is provided by a laser.

(4) A device according to Claim 1 or 2 wherein the light has a wavelength of from about 1.40 to about 1.55 microns.

(5) The device according to Claim 1 wherein the station includes means adopted to engage each container when in the station and substantially maintain the container in a plane which includes the said longitudinal axis and the direction of travel of the container and prevents the container from moving other than to travel through the station thereby minimizing movement of the centre portion of the meniscus out of a horizontal orientation.

(6) A device according to Claim 1 wherein the inspection station is provided with means to reduce bottle movement except in the direction of travel of the container which means is a worm screw.

(7) A device according to Claim 2 wherein the deflector means comprises in combination a synchronous electric motor and a bottle deflector member, the latter being adapted to be:

(i) located adjacent said pathway;
(ii) rotatable by said motor into said pathway to contact and controllably sweep a selected bottle from said stream; and (iii) rotatable by said motor out of said pathway to allow subsequent unselected bottles to continue travelling along said pathway without contacting said deflector member. The device according to Claim 2 wherein said deflector member is elongate, is mounted directly onto a shaft of said motor and is adapted to rotate in a substantially horizontal manner about a generally vertical axis.

(8) A container detection method for detecting in a stream of aqueous liquid filled containers travelling along a pathway, which containers have a neck portion which is able to transmit light, those containers whose liquid content meets a predetermined level, which level is located in said neck portion, from those containers whose content does not meet said predetermined level, said method comprising: passing said bottles to a station where a pulse of light in a narrow beam is projected at a portion of the neck of each bottle which includes the intersection of the said predetermined level and a central vertical axis of the container neck and where the container contents do not meet the predetermined level detect such beam which passes through the bottle neck of the container under inspection which denotes a container whose liquid content does.

(9) A bottle sorting method for separating from a stream of liquid filled containers travelling along a pathway, which have a neck portion which is able to transmit light, those bottles whose liquid content meets a predetermined level which is located in said neck portion from those whose content does not meet said predetermined level, said method comprising: passing said bottles to a station where a pulse of light in a narrow beam is projected at a portion of the neck of each container which includes the intersection of said predetermined level and a central vertical axis of the container neck detecting any such beam which passes through the bottle neck and using same to activate a container deflector which removes the container in question from the stream of containers without affecting the motion of the other containers in the stream of bottles.