Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures

Definitions

• the invention relates to a device for checking the straightness, possibly also the height and / or deformations, of containers made of transparent material, preferably bottles, with a conveyor belt on which the containers stand and that the containers are illuminated ⁇ barrier transported to a test zone in which a light beam arrangement is formed, which encloses a test surface with a predetermined geometry in a plane which runs essentially parallel to the plane of the conveyor belt and which cooperates with a detector arrangement for the light beam arrangement which generates output signals according to the test result.
• the light beam arrangement consists of a total of eight light sources, the four light beams crossing at right angles send out, which are received by a total of eight detectors. If the light rays are not disturbed by any object (bottle), the detectors receive the undisturbed light rays. However, as soon as a bottle enters the test zone, the marginal light beams are deflected from the wall of the bottle and the associated detectors receive disturbed signals.
• the test area formed for the edge light rays is somewhat smaller than 10 corresponding to the outer limits of the bottle.
• a light beam is directed from above through the bottle neck to the bottle bottom and from
• the diameter of the light beam must be adapted quite precisely to the inside diameter of the bottle neck and it is also not readily possible to use bottles
• the invention avoids these disadvantages. It is based on the object, preferably a device for checking the straightness, possibly also the height and / or deformations, of containers made of transparent material
• the invention is characterized in that the light beam arrangement is formed by a single light beam which is deflected via mirrors in such a way that it encloses the test area, the edges of which in the measuring position do not meet the outer limits of the relevant container to be checked touch if this container is currently formed within a predetermined tolerance, but touch these limits if the container is crooked within the predetermined tolerance, the light beam falling onto a single detector at the exit of the test zone.
• the device Via the light barrier and the known conveying speed of the conveyor belt, the device according to the invention knows at what instant the relevant container to be tested is located within the test area in such a way that the light beam defining and limiting the test area is outside the outer limits of the container in question. If the container in question is straight, the light beam is not disturbed by the container and the output signal of the detector is also undisturbed. However, if it is an oblique container, the container interferes with the light beam and the output signal of the detector is also disturbed. The light beam defining the test area will thus be directed such that the edges of the test area take a small distance from the outer boundaries of the containers to be checked at the time of the test.
• the device according to the invention can also be used without further checking the height of the containers. In this case it is only necessary to ensure that the light beam in the test zone is at a predetermined height above the conveyor belt. If the container in question does not have this height, for example a bottle with a broken neck, then the light beam is not disturbed at all and this is an indication that the container does not reach the predetermined height and is therefore also sorted out must become.
• test area is adjustable, so that an adjustment to containers with different geometries can then take place.
• This adjustment can be achieved in a structurally simple manner in that the mirrors are displaced via a corresponding mechanism.
• the light source producing the single light beam and the height of the mirrors can be adjusted above the conveyor belt. This allows the device to be set to different heights to be measured.
• the light source generating the only light beam is a laser light source.
• laser light is distinguished by an opening angle of the light beam close to zero, so that the accuracy of the test of the device according to the invention continues due to this feature is improved.
• a device for checking a transparent container using a laser light source is known per se from US Pat. No. 4,283,145.
• At least four of the mirrors are preferably provided.
• the geometry of the test surface can be adapted better and better to the geometry of the outer boundary of the containers to be tested.
• This important embodiment of the invention is characterized in that at least one illuminated gap extending in the longitudinal direction is provided, the light beam of which, after passing through one of the containers to be checked, falls on a detector with an evaluation unit which does this Compares the output signal of the detector with a stored reference signal. If the container in question is not deformed, for example if it has no deflection, thickening, thinning or the like on its wall, then the detector generates an output signal at the time of measurement, which - within predetermined tolerances - matches the stored reference signal.
• the container in question has deformations, there are deviations between the stored reference signal and the measurement signal, and these deviations then indicate that the container in question is deformed. It should be recalled that there can be containers which are straight and nevertheless deformed, so that this important embodiment of the invention provides additional information when checking the containers.
• the light beam advantageously penetrates the
• the accuracy of the checking of the containers for deformations is further improved if a plurality of gaps offset with respect to one another are provided with associated detectors and evaluation circuits, the light rays of which penetrate the container to be checked in different directions. Through these measures, the container in question is opened in different directions
• the length of the column is adjustable so that a different height of the containers to be checked can then be taken into account.
• the containers do not necessarily have to keep a distance from one another on the conveyor belt if these containers are checked for straightness and height.
• the containers are additionally checked for deformations, it is preferred if a device is provided which ensures a predetermined distance between the containers to be tested on the conveyor belt, so that adjacent containers do not interfere with the measurement result during the check.
• Fig. 1 - an embodiment of the device according to the invention in plan view:
• FIG. 2 shows the measuring field of the device shown in FIG. 1 in section perpendicular to the conveying device
• FIG 3 shows a typical signal curve of the deformation channel during a container pass.
• the light beam 2 decoupled from a laser 1 is guided such that it defines a diamond-shaped test surface 3 in the measuring field.
• mirrors 4, 5, 6 and 7 are provided, which deflect the light beam accordingly.
• the mirrors 4, 5, 6 and 7 are arranged on two mutually displaceable plates 8 and 9.
• the height of the test zone formed in this way with respect to a conveyor belt 10 should preferably be only slightly smaller than the height of the object to be examined, if this is a bottle 22.
• the laser beam 2 is received by means of a diode 11.
• the laser light source 1 is attached to one of the plates 9.
• both plates 8 and 9 and thus the laser light source 1, the deflecting mirrors 4, 5, 6 and 7 and the detector 11 can be displaced horizontally in their plane in order to achieve a different centering of the diamond-shaped test surface 3 or also in the Height can be adjusted in order to enable the test zone to be adapted to the height of the mouth region of the container 22 in the case of different container heights.
• the height of the laser light beam 2 can be adjusted by an adjustment mechanism 25.
• the mutually displaceable plates 8 and 9 and the deflecting mirrors 4, 5, 6 and 7 are moved together.
• the laser light beam 2 only detects the mouth of the bottle 22.
• a light box 12 in which three linear gaps 13, 14 and 15 are provided, is provided for precise checking of the longitudinal axis position of the containers.
• the light box 12 is shaped such that an angle of approximately 45 ° is formed between the radiation directions of the rays emerging from the columns.
• the beams in columns 13, 14 and 15 are imaged on opaque, opaque masks via imaging lenses 16, 17 and 18 if there is no object in the beam path.
• a detector 19, 20 and 21 designed as a diode is arranged directly behind the masks.
• the beam of the middle gap 14 passes directly through the measuring field and thus through the container 22 to be tested.
• the light beams in the column must be deflected mirrors 23 and 24 are deflected accordingly.
• HF fluorescent tubes 26 are arranged behind the columns 13, 14, 15.
• the test process is started by a one-way light barrier 27.
• Clock pulses are derived from a drive motor (not shown here), the conveyor belt 10 moving at a uniform speed of e.g. approx. 1/10 mm / cycle.
• the pulses are fed to the evaluation unit.
• the signal sequence of the detector 11 is evaluated. If there is no interruption of the light beam 2 during the run-in, it can be assumed that the container mouth, e.g. the bottle neck has broken off. However, if the light beam 2 is interrupted when the container is in the middle of the test surface 3, the longitudinal axis of the container is crooked, because otherwise an interruption would not be possible.
• the device shown in FIG. 4 manages with only three mirrors 4, 5, 6, which enclose a test area 3.
• the time at which a just formed container 22 is located in the center of the test area 3 enclosed by the light beam 2 is known via a signal emitted by the light barrier 27. If the container 22 is straight, the detector 11 receives a signal not disturbed by the container 22 at this moment. If, on the other hand, the container - within predetermined tolerances - is skewed, it deflects the light beam 2 at this test time, so that the detector 11 receives a faulty or no signal at all.
• the wall of the container is checked for deformations by comparing the output signals of the detectors 19, 20, 21 with stored standard values of reference objects. In the event of a deviation from the desired signal curve, the container is classified as deformed. This is shown in FIG. 3.
• the course of the light intensity measured via one of the detectors 19, 20, 21 is shown as a function of time.
• the uninterrupted line shows the signal course of reference bottles. If an increased intensity occurs at time t, as drawn with dashed lines, this means a deformation of the container.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Length Measuring Devices By Optical Means (AREA)
• Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

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Citations (3)

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• 1986
  • 1986-04-05 DE DE19863611535 patent/DE3611535A1/de active Granted
• 1987
  • 1987-03-27 WO PCT/EP1987/000173 patent/WO1987006001A1/de not_active Application Discontinuation
  • 1987-03-27 JP JP62502607A patent/JPH01500056A/ja active Pending
  • 1987-03-27 EP EP19870902476 patent/EP0263858A1/de not_active Withdrawn

Patent Citations (3)

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