DK175986B1 - Automatic gas cylinder neck detector - Google Patents

Description

The invention relates to an automatic wear detecting apparatus for gas cylinder necks of the type 1 having an external thread on which a protective cap can be screwed.

5 The interest here is particularly directed at the wear of the external thread on the necks of the gas cylinders, such as e.g. liquefied gas gas cylinders. Such wear is especially evident by repeating and unscrewing the protective cap on the neck of the gas bottle each time this bottle is filled with gas.

10 The wear of the thread on the neck of the bottles has been markedly enhanced by the use of electric unscrewing and screwing machines which allow the caps to be quickly screwed off and on the necks of the bottles, but which also increase the frictional contact between the thread in the cap and the external thread of the bottle. neck.

15 The wear of the external thread on the neck of the gas bottles presents a safety problem during the various handling steps of bottles with worn neck, such as. loading and unloading on delivery. In fact, at the time of unloading and unloading a bottle, the supplier holds the bottle in a handle attached to the cap.

If the external thread on the bottle necks is worn, the cap can slide on the neck and release, causing the bottle to accidentally be dropped.

Under these conditions, it is recommended to inspect the gas bottle neck for wear to prevent the risk of accident while handling the bottles. Furthermore, increasing efforts are being made to automate the various inspection operations carried out on the gas cylinders and thus to eliminate wear inspection of the necks visually performed by an operator before which the gas cylinders pass placed on a conveyor.

In known installations, the inspection of the gas bottle neck wear is performed by the cap applicator each time caps are attached to the gas bottle necks. This inspection simply consists of checking whether the cap is locked or loosely attached to the neck. If the cap on the neck is loose, the cap / neck attachment is considered to be defective and the corresponding gas bottle is temporarily removed from the circulation for repair. Only later is a more accurate inspection of the throat in the i in i in i in 2 DK 175986 B1 1 by an inspector by means of a template, which makes it possible to assess the degree of wear of the external thread on the neck to be checked.

This quick inspection to check if the cap on the neck is loose is not accurate as it does not allow a quantitative assessment of the degree of wear of the external thread on the neck to be checked and the risk of throat wear errors. is reasonably large, which means the risk of accidents as a result. of handling a bottle with a poorly inspected, worn neck, cannot be eliminated. In order to eliminate the risk of accidents when handling bottles with worn necks, the invention proposes a new apparatus for automatic inspection of wear of the external thread on a gas cylinder neck, which allows the dimensions of the external thread concerned to be accurately measured, and comparing these measurements with a reference measurement which thus constitutes an allowable tolerance threshold in order to remove all bottles outside this tolerance. The invention also proposes an automatic inspection apparatus which allows the inspection of gas bottles of different heights.

More particularly, the invention relates to an automatic wear inspection apparatus for the neck of a used gas cylinder and of the type comprising an external thread, characterized in that it comprises: - an inspection head mounted movably on a fixed support, under which the gas cylinder, to be inspected, put in place, the reference means (22, 24) disposed on the inspection head (20) to rest on the dome of the gas cylinder (100), to two jaws disposed on the inspection head and movable on a horizontal translational in relation to a vertical median plane in such a way that each of the jaws from the side may engage the outer thread of the neck of the gas bottle to be inspected in order to make a measurement of the outside diameter of the neck, an inductive transducer connected to one of the two jaws and arranged to record and transmit to the electronic control unit information about the jaw displacement ing.

3 DK 175986 B1

Thus, the apparatus of the invention conveniently allows a precise assessment of the wear rate of the diameter of the external thread on the throats of the gas cylinders in a clear position on a conveyor belt of various sizes. The measurement of the external thread on the neck is carried out by means of the inspection head of the apparatus according to the origin transmitted directly by means of the inductive transducer to an electronic control unit which compares this measurement to a value which constitutes the predetermined permitted tolerance threshold.

If the measurement is greater than the permissible tolerance threshold, the bottle is considered suitable for use. If not, it is deducted from revenue for repair. A 10 bottle so inspected no longer poses any risk of accident.

According to a preferred embodiment of the apparatus according to the invention, each jaw is in the form of a right angle with a horizontal support part and a vertical part with a contact part on the side, with the reference support means comprising a set of two side pads, adapted to rest on the dome of the for inspection, position the bottle for pre-positioning the inspection head over the neck of the bottle prior to measuring the external thread of the neck in such a way that each of the horizontal support members of the opposing jaws rests on the upper side of the neck.

The apparatus of the invention further comprises a displacement member which is attached to the jaw opposite the inductive transducer and is adapted to, when the bottle inspection head is positioned above the neck, from the side push the vertical portions of the jaws to side contact on both sides of the neck. threads to perform the measurement of the external thread on the neck.

25 Once the pads rest on the bottle dome, the shape of the jaws allows the jaws to be positioned correctly on the neck of the bottle, regardless of the size of the gas cylinders to be measured before the inspection measurement is performed. It also makes it possible to always measure the neck diameter at the second or third thread of the external thread counted from the upper part of the neck. Since the wear on the outer thread is of the tapered wear type, the very first thread turns at the upper part of the neck are always more worn and are not representative of the actual wear of the thread. Therefore, it is sufficient if the second or third threading of the threading mechanism is correct for the latter to be considered suitable for use.

4 DK 175986 B1

Other features and advantages of the present invention will become more apparent in the light of the detailed description below of a preferred embodiment of the invention with reference to the accompanying drawings, in which: - FIG. 1 shows a general perspective view of the apparatus according to the invention; FIG. 2 is a detailed perspective view of the inspection head of the apparatus of FIG. 1, 10! FIG. 3 shows a set of four diagrams illustrating the various stages of the positioning of the inspection head on the apparatus of FIG. 1 on the gas cylinder to be inspected; FIG. 4 is a front view of the inspection head of the apparatus according to the invention as shown in FIG. 2 together with a reproduction of the electronic control unit.

Figures 1 and 2 show an apparatus according to the invention suitable for automatically inspecting the wear of the external thread on the neck 101 of a gas bottle 100.

As shown in FIG. 1, the apparatus of a fixed support 10 in the form of an inverted U is fixed with each side arm 11, 12 to the vertical sides of a U-profile rail 60 arranged to guide the gas cylinders arranged vertically on a conveyor belt which lies between the vertical sides 61.62.

The apparatus of FIG. 1 further comprises, as FIG. 2 more clearly shows an inspection head 20 which is movably mounted by means of an articulated system 30, here a pulley / cable and counterweight system on the support 10. This inspection head must be able to inspect the external thread on the neck, regardless of the bottle height. on a gas bottle in clear position on a conveyor belt, while measuring the outer diameter of the neck as the bottle gets in place between the side arms 11, 12 of the support 10 just below the inspection head 20.

in DK 175986 B1 5

In the embodiment of the apparatus shown in FIG. In and 2, the inspection head 20 consists of a set of two side pads 23, 24, preferably made of plastic, which constitute a reference resting on the bottle dome 100, and two opposing jaws 21, 22.

5

It can be seen more clearly in FIG. 2 and 4, that each jaw 21, 22 is formed at a right angle with a horizontal support part 25, 26 and perpendicular thereto a vertical part 27, 28 with side cone stroke. In addition, the two jaws are movable in a horizontal translational manner with respect to a vertical median plane P1 by means of a displacement member 50, in the present case a pneumatic actuator 50 which is secured to one of the two jaws 21, 22 on such a Each jaw 21, 22 is capable of laterally contacting the outer thread of the neck 101 of the gas bottle 100 to perform the measurement of the outer diameter of the neck 101.

15 The diagrams 1, 2, 3 and 4 of FIG. 3 shows more precisely the various stages for positioning the inspection head 20 on the neck 101 of the bottle 100 to be inspected.

Diagram 1 shows that when the inspection head 20 is in its ready position, e.g.

! 20 between two consecutive inspections, the side pads 23,24 are placed slightly! under the dome of the gas cylinder 100 intended for inspection. The positioning of the pads 23, 24 in the ready position is controlled by an actuator 400 shown in FIG. I and 2, in such a way that the pads are then placed lower than the dome on the smallest gas bottle of each type. For butane gas bottles, the actuator 25 400 is in the retracted position, while the actuator 400 in the propane gas bottles is in an extended position.

Diagram 2 shows that when a gas bottle 100 gets into position below the inspection head 20, the latter gradually moves upwardly by the articulated system 30 until the two side pads 23, 24 rest on the dome of the bottle 100 which slowly continues to move. move forward. In this position, the inspection head 20 is provisionally placed over the neck 101 of the bottle 100.

Thereafter, as the diagram 3 shows, the inspection head 20 gradually moves downward again before carrying out the measurement of the outside diameter of the neck 100 in the bottle 100 in such a way that each horizontal support member 25, 26 on the opposite jaws 21, 22 rest on the surface 102 of neck 101.

Finally, diagram 4 shows that the pneumatic actuator 50 is activated as soon as the 5 jaws are in place on the surface 102 of the neck 101 in order to displace the jaws 21, 22 in such a way that the vertical portions 27, 28 from the side comes into contact with both sides of the neck 101 on its external thread, to perform the measurement of the outer diameter of neck 101 by the second / third threading of the thread. In fact, since the wear on the outer thread of a gas-bottle neck is of the tapered type, the first threads at the upper part j of the neck are almost always more worn, which means that they are not typical of the actual wear state of the external threads on the neck. In this case, it is assumed that the wear condition of the neck is represented by the condition of the external thread at the second or third thread count from the upper part of the neck.

15 If the thread at this level is correct, the cap will be screwed correctly on the neck without risk of loosening.

It should further be noted that the inspection head 20 appropriately allows inspection of the external thread on a neck regardless of the height of the 20 gas cylinder designated for inspection and regardless of whether the bottle in question is equipped with a valve or not.

Regardless of the height of the gas bottle to be inspected, the pads 23, 24 of the inspection head 20 fit into the dome of the bottle in question and themselves act as a reference for positioning the jaws 21, 22. The gas cylinders 100 for inspection shown in FIG. . 1, 2, 3 and 4, are gas cylinders for liquid petroleum gas, which contain approx. 26 liters of gas, but the apparatus according to the invention shown in these figures can also inspect bottles with larger contents, such as e.g. a volume of about 70 liters of gas. Furthermore, it can be seen in FIG. 1, 2 and 3, that the right-angled shape of the jaws 21, 22 allows the neck 101 to be inspected on a gas bottle 100 with the valve 200 in place. This feature is particularly advantageous since it is not necessary for the operating personnel to remove the valve from the gas bottle to check the wear on its throat by the apparatus of the invention.

7 DK 175986 B1

It can be seen more clearly in FIG. 2, the inspection head 20 is further mounted on plastic pins 21 ', 20 ", which are connected to each jaw 21, 22. If a bottleneck is deformed, the inspection head 20 can thus be tilted slightly to measure it, the jaws 21 then remaining completely Recovery of the inspection head 20 to the clear position relative to the median plane PI is accomplished by springs 51.

In the embodiment of the apparatus shown in FIG. 1, 2, 3 and 4, and as can be seen more clearly in FIG. 4, the apparatus comprises an inductive shear transducer 40 10 for a differential transformer attached to the jaw 22 opposite the jaw containing the pneumatic actuator 50 and in line with the actuator 50. This inductive shear transducer 40 is intended, in part, to capture the information about the shear of the jaws 21, 22, more precisely the distance between the two jaws 21, 22, and partly to transmit a signal S related to the distance to an electronic control unit 41. The displacement of the jaws 21, 22 is symmetrical with respect to the Piplane if the bottleneck is straight but it can be asymmetrical if the neck is deformed and, more specifically, does not align with the PI plane.

It is interesting to note that inductive transducer 40 is disposed on the same line as actuator 50. Thus, when actuator 50 displaces jaws 21, 22, no tilting occurs with respect to the vertical axis Z of jaw driven by actuator.

The signal S emitted by the inductive transducer 40 is proportional to the value Φ0 + ΔΦ, where Φ0 is the distance between the jaws in the neutral position and ΔΦ corresponds to the registration of the diameter of the neck 101 for the second / third thread recovery of the external thread. This signal S is processed by a measurement processing unit 42 which compares this signal S with a threshold signal S threshold »which is proportional to the value +0 + A® threshold / where A® threshold equals 30 to the tolerance limit acceptable for external thread wear on a bottleneck 101. The A® threshold value must of course be predetermined. If the value Φ0 + ΔΦ is less than the threshold value Φ0 + A® threshold, i.e., if ΔΦ <ΔΦ156 ^ βΙ, this bottleneck 101 is considered to be worn, and the processing unit 42 then activates an electronic sequence unit 43 adapted for this case 8 DK 175986 B1 while ejecting the bottle which does not meet the specifications, to mark the useless bottle by means of a marking device 500.

If, on the other hand, the value +0 + ΔΦ is greater than ®0 + A® threshold, the processing unit 42 activates the same electronic sequence unit 43, which in this case is adapted to release the inspected gas bottle ready for reuse.

The electronic sequence unit 43 is further arranged to control the diameter measurement sequence of the necks of the gas cylinders as they pass below the inspection head 20.

According to the embodiment of the apparatus shown in FIG. 1, it is finally interesting to note that the U-profile rail has two fixed-stop restriction stop devices 63, 64 located on each of the vertical sides 61, 62 of the opposite 15 U-shape on the level of the fixed support. Each restriction stop device comprises, in part, a stop pin located in front of the inspection apparatus and arranged to stop a gas bottle passing on the conveyor belt and to hold it in the ready position until the previous bottle has been inspected, and and, secondly, a second stop pin provided by the inspection apparatus to stop the gas cylinder destined for inspection and which is disposed after the inspection head 20. It is in fact appropriate to carry out the inspection measurement on a stationary bottle in order to avoid vibrations from moving bottles, since these vibrations may impair the inspection measurement. Once the measurement has taken place, the stoppered inspected bottle is further moved along the rail 60 to exhaust 25 and / or marking.

Claims (8)

An automatic wear inspection apparatus for the neck (101) of a used gas bottle (100) and of the type comprising an external thread, characterized in that it comprises: - an inspection head (20) mounted movably on a fixed support ( 10), under which the gas bottle to be inspected comes in 35 place. 9 DK 175986 B1 on the inspection head (20) is placed on the reference means (22, 24) to rest on the dome of the gas bottle (100), to opposite jaws (21, 229), which are arranged on the inspection head (20) and are movable on a horizontal translational manner with respect to a vertical center plane (PI) in such a way that each of the jaws (21, 22) can engage laterally with the external thread on the neck (101) of the gas bottle (100), to be inspected to measure the outside diameter of the neck (101), an inductive transducer (40) connected to one of the two jaws 10 (21, 22) and arranged to record and to a electronic control unit (41) to transmit information about the displacement of the jaws (21, 22). Apparatus according to claim 1, characterized in that each of the jaws (21, 22) is in the form of a right angle with a horizontal support part (25, 26) and a vertical side contact part (27, 15 28), and that the reference support means (23 , 24) is a set of two side pads (23, 24) arranged to rest on the dome of the bottle (100) to be inspected so as to position the inspection head (20) over the neck (100) of the bottle (100). 101) before measuring the outer diameter of the neck (101) and in such a way that each of the horizontal support members (25, 26) on the opposing jaws (21, 22) will rest on the surface (102) of the neck (101) . Apparatus according to claim 1 or 2, characterized in that it comprises a displacement member (50) arranged on the jaw (21, 22) opposite the inductive transducer (40) and arranged when the inspection head (20) for first, the bottle (100) is positioned above the neck (101) to push the vertical side contact portions (27, 28. of the jaws (21, 22) laterally on both sides of the neck (101) towards the external thread to make the measurement of outer diameter of neck (101). Apparatus according to claim 3, characterized in that the displacement means (50) is an actuator (50). Apparatus according to any one of claims 1 to 3, characterized in that the fixed support (10) is in the form of an inverted U with two side arms (11, 12) between which the bottles to be inspected pass. 35 10 DK 175986 B1 Apparatus according to any one of claims 1-5, characterized in that it comprises a U-profile rail (60) having two opposite vertical sides to which the fixed support (10) is connected, said rail (60) is arranged to guide the gas cylinders arranged vertically on a conveyor between the 5 vertical sides (61, 62) to transport them at least to the fixed support (10) and place them under the inspection head (20). Apparatus according to claim 6, characterized in that the U-profile rail comprises two fixed-pin restriction stop devices (63, 64), one on each of the vertical faces (61, 62) facing each other and at the level of the fixed support (10), and arranged to stop each of the gas bottles (100) passing on the conveyor along the entire rail (60), and in particular to place them under the inspection head (20). Apparatus according to any one of claims 1 to 7, characterized in that the electronic control unit (41) comprises: - a measurement processing unit (42) arranged to process the information generated in the form of a signal from the inductive transducer (40). ), an electronic sequencing unit (43) intended to control the measurement, marking or ejection of sequences of the gas cylinders (100), the measuring processing unit (42) directly activating the electronic sequencing unit (43) after comparing, inter alia, the neck diameter measurement (101) of the gas cylinders (100) at a predetermined reference threshold.