DE1573737B2 - Device for vacuum testing of closed containers - Google Patents

Description

40

The invention relates to a device for vacuum testing of closed containers Scanning the shape deviation of the lid surface to be tested compared to the lid edge one pressed by spring force on the edge of the lid of the containers conveyed past one after the other Support member in which a contact-free responding electronic to the distance from the ..... cover surface Proximity switch is arranged, which acts on an ejector.

It is known (US Pat. No. 3,064,807), for vacuum testing of sealed containers To scan the lid surface by means of an electronic proximity switch, which is in a transverse to Direction of conveyance of the container pivotable against spring force arranged arm between two parallel to the conveying direction attached to the arm on the arm and sliding out of the lid surface Baking is arranged. The jaws fall between two consecutive containers because of their Shaping in the space between two container lids and being used by the next one Container lifted up again. This results in a restless operating sequence and leads to vibrations, which have an unfavorable influence on the measurement results. Furthermore, since the arm is only about a fixed axis

nits.

It is also known (USA. Patent 2 936071), the scanning of container lids by means of make rotatably driven scanning bars, which are transverse to the direction of flow of the container place on the lid and are resilient on both sides. This resilient arrangement of several The scanning bar leads to vibrations, which also do not allow a reliable display. It is also known (U.S. Patent 2924093), each individual container provided with a lid on a lifting ram to arrange, whereupon by the lifting ram the container from below against one in the test head arranged seal is pressed, whereupon the lid space enclosed by the seal is connected to a vacuum source and then the measurement is carried out by means of a pin-operated switch. This arrangement works relatively slowly.

In contrast, the invention is based on the object of the device described above To be designed in such a way that the speed at which the containers are scanned is significantly increased, with a reliable display and with height deviations of the containers within the manufacturing tolerances, which is proportionate in relation to the shape deviation of the lid surface to be tested are large, are automatically balanced.

This object is achieved in that the support member is plate-shaped with a downwardly protruding ring-shaped approach seated on the edge of the lid is formed and on all sides is tiltable and resiliently suspended.

This has the advantage that the conveying speed and thus the number of scanned Container per unit of time can be increased significantly. One just leaving the support member This is because the container keeps the support member in the previous position during the next container can already get under the front of the plate-shaped support member without that Altitude is changed significantly. Furthermore, the spring suspension, which can be tilted in all directions the advantage provides that the plate-shaped support member sit securely on the lid edge can, even if the cover is screwed on at an angle or otherwise tilted. Because in this state of the lid, a vacuum inside the container is certain not to have come about, the inner one Part of the cover is therefore curved outwards, can with the support member adapting on all sides in such faulty containers can be identified in a simple manner. This allows in the bottling plant other devices that detect tilting or incorrect screwing on of lids should be omitted. The device according to the invention also works with height deviations of the container, which can be a total of 1.66 mm in containers for children's food, for example. These height deviations are relatively large, as the change in position of the cover surface to be scanned is about 1.3 mm, depending on whether a proper vacuum has been created in the container is or not.

Advantageous further developments of the invention are

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described in the subclaims. In Ausgestal- see 42 arranged with the side walls 28 device of the device according to claim 2 one and 30 are firmly connected and achieved in a certain construction for the resilient suspension of the th position transversely to the conveyor belt by screws 44 support member. The formation of the established by longitudinal slots and the device according to claim 3 ensures that 5 angle brackets 38 are pushed through and can only take place in the feeine vacuum display when most of the tabs 42 are screwed,
the container lid actually centered under the in A fixed angle piece 46 is provided with a vertical support member arranged proximity switch th arm 48, which has arrived at the side wall 28. is and is attached to her by means of screws 50, the

In the description below, the invention is inserted through longitudinal slots 52 in arm 48

Exercise on the basis of the drawing are explained, for example, in order to adjust the angle piece 46 in

tert. It shows perpendicular direction to allow. A locking

F i g. 1 is a side view of the device for screw 54 extending through bore 56 in FIG

Vacuum test, horizontal arm 58 of elbow 46 and is in

F i g. 2 is a plan view of part of the front 15 of a nut 60 welded to the arm 48 according to Fig. 1, screws. The lower end 62 of the screw 54

F i g. 3 is a section along the line 3-3 in FIG. 3 presses against the surface of the side wall 28, see above

F i g. 2 that by turning the screws 54 the elbow

4 shows a section along the line 4-4 which 46 can be adjusted with respect to the fixed part 28,

Fig. 2, 20 when the screws 50 are loose.

F i g. Figure 5 is a section along line 5-5 in the support plate 64 is on the horizontal arm

F i g. 2, 58 of the elbow 46 attached so that by means of

F i g. 6 shows a section through a container cover of the screws 66, which are inserted through longitudinal slots 68 in FIG

for use in the device plate 64 shown in FIG. 1 and in the arm 58

device, 25 are screwed, a setting in the transverse direction

7 shows a side view of a can for children to the conveyor belt 20 is possible.

Kost with the cover in section, At the free end of the support plate 64 is on their

F i g. 8 shows a side view, partially in section, of the underside of the test head 70 suspended in a floating manner;

Another embodiment of the device The test head 70 consists of a plate-shaped

measured Fig. 1, 30 support head 72 with a flange 74, which

F i g. 8 a a further embodiment of the cover upwards through the hole 76 in the plate 64

kels, partly in section, stretches. The support head 72 is on the plate 64

9 shows a section along the line 9-9 through four symmetrically arranged support bolts78

F i g. 8, hung. The bolts 78 extend loosely through

F i g. Figure 10 is a schematic representation of Figure 35 showing the holes 80, with the forward ends of the bolts

Control device for the embodiment according to 78, for example, fixed in the support head 72

F i g. 1 and are screwed. Each bolt 78 is provided with a compression spring

11 is a schematic representation of a portion of the 82 provided between the lower upper of the Control device for the embodiment of the surface of the support plate 64 and the surface of the Abgem 8 and 9, the omitted parts 40 supporting head 72 being arranged.

with the corresponding parts of FIG. 10 identical. The holes 76 and 80 have opposite the

are. Flange shoulder 74 and the bolt 80 such a large one

According to Fig. 1 to 5, an endless conveyor belt is radial play on that the head 72 is provided from its 20, which the container C on its upper lowest position, which is caused by the contact of the bolt strand 22 from right to left in Fig. 1 promotes. The 45 heads 78 on the surface of the support plates 70 loading conveyor belt 20 is driven by the motor 24. is true, can move freely upwards. Furthermore, the closed containers C are supported by a limited inclined device, not shown, on the right constriction of the head 72, which, as described below, is placed on the upper run 22 and are also necessary on the lower run is.

removed from the upper run 22 on the left end. Since 50 in FIGS. 6 and 7 is a frequent closure the delivery rate is very large and in the size of glasses for children's food used lid order of about 1000 containers per minute shows. The lid according to Fig. 6 consists of the push-button the surface on the conveyor belt 20 in a line, the one with an upwardly protruding surface Containers together. the, annular section 84 and with a central

The test station 26 is provided opposite the upper 55 Irish snap part 86, the strand of the conveyor belt 20 is arranged and normally consists of the convex one shown in FIG. 6 in consisting of two side walls 28 and 30 in Figure 2, the solid lines shown, position. As soon as one part of the frame of the conveyor belt 20 forms lids on the glass according to FIG. 7 are arranged in a seal or fixed on this. The side was applied, with a walls 28 and 30 in the glass with two guide rails 32 60 reaching vacuum, is due to the and 34 provided to the container C during the vacuum, the snap part 86 in the concave position, passing at the test station 26 in such a way that is shown in Figure 7 with solid lines. that the containers crosswise to the conveyor belt. If the lid is not sufficiently aligned with the glass. The attachment of the guide has been sealed, if a vacuum does not come about, rails 32 and 34 on the side walls 28 and 30 65 so that the snap part 86 is back up into its position by means of angle brackets 38, which snaps onto the guide's original convex position are fastened in sub-rails by screws 40. The broken lines in FIG. 7 is shown.
Angle brackets 38 are slidable on the fixed La- With the device shown are now intended

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In this design, the lid is checked to ensure that there is no vacuum in the container, the inside of the container has been sufficiently evacuated, so that the head is raised to the highest point of the indicated by whether a sufficient sealing beveled edge of the lid is raised, if it was achieved properly. A sufficient Va- can not be slanted. As a result, the button 88 kuum is indicated by the snap part 86, which is then at a distance from the center of the lid in its concave position, while the convex position is set, which is larger than normal. Thus, the position of the snap part 86 does not indicate that a sufficient guarantee that an insufficiently sealed cup of the vacuum could not be created. halter is eliminated. The radial play in the. To scan the position of the snap part 86, holes 76 and 80 allow the inclination of a probe head 88 in the flange attachment of the head 72 io head, so that a contact of 360 ° between firmly arranged. An approaching rim 90 and head 72 and the ring-shaped switch are used as the sensing device. The probe head is also connected to the approach 84 of the cover, and an oscillator is connected, which is inclined to the control passage through the test station via a connection when the cover or container is thrown with a monostable flip-flop. ;, .._ .. '. tion of a relay is connected. The probe head is a 15 To sort out the waste container is part of the oscillator stage, so that if an electro-pneumatic differential motor 92 is arranged on the plate trically conductive object in the probe area of the probe 94, the object is arranged in the longitudinal direction as shown in FIGS. 2 and 5 is, this object oscillator energy device of the conveyor belt 20 is absorbed by screws 96, which can be seen in a change in amplitude, which is shown by Lähgsschlitze 98 in. The change in amplitude controls the switching to 20 plate 94 are inserted through and with a two-part of the monostable flip-flop, which in turn is screwed to a th plate 100. The plate 100 can control relays. Basically, the scanning head generates a signal in the transverse direction to the conveyor belt 20 through the head and actuates a switch when a dovetail groove 102, in which a third metallic object plate 104 engages in the scanning area, is set. The plate will. 25 104 is an elbow, its horizontal arm

Such devices can slide on the plate 100 with the utmost sensitivity and lower it.

'can be set. With the right arm in question, adjustable for a vertical change in position

Cover is the entire deflection range of the change of the entire arrangement on the plate 28

Cover is arranged between the convex and concave position by means of screws 106 , which through

about 1.3 mm, whereby the probe heads are set in a longitudinal slot 108 in the vertical arm of the part

that they can put the concave or convex position les 104 through them. The screw 110

of the snap part securely on the lid extends upward through the longitudinal slot 112 in

can ask. F i g. 5 and is screwed to the plate 100.

In the case of the lids shown in the drawing, it is thus illustrated that the motor 92: There is, however, one difficulty in that the permissible vertical direction as well as transverse and longitudinal manufacturing tolerances of such liners can be adjusted . These adjustment deviations of ± 0.8 mm allow, or a result, the purpose of the motor 92 being in an exact height deviation of 1.6 mm, which is brought opposite the position in which the piston rod is in the lead-out area of the lid snap-in part 114 of the motor 92 touches the tank; the Kol is proportionally large. 40 be'nstange 114 is normally in the retracted

In order to compensate for this height deviation, go into position and open the path of the container and at the same time free the button 88 in a certain conveyor belt 20 . After the push button 88 detects that the height of the rejector should be set against the top surface of the cover, the lower side of the head 72 is actuated with a motor 92 and extends the piston rod, as shown in the ring-shaped projection 90 protruding below that the tip 116 contacts the waste container; the when introducing the container under the table to push it from the conveyor belt onto a non-ge-head on the circular extension 84 of the container; which comes to sit on the deck of the motor 92. The springs 82 and opposite side of the Förderbärides .aufgeb, the floating arrangement of the head 72 is on the. The vertical position adjustment of the motor support plate 64 allows an upward or downward movement of the head to allow the tip 116 of the piston-oriented movement of the head to compensate rod 114 to allow the container to be at different container heights. The normal rest position rizontal plane- which contains the center of gravity of the container of the head 72, which is established by adjustment of the bolts 78; to toast. :: ν ^ r, · -: - ,; ■ - .. -; c ^ and the. Is height adjustment of the angle piece 46 designate the timing of the engine 92 in the longitudinal direction is right, is selected so; that the lower 55 to the conveyor belt is for the purpose of having the tip surface of the head 72 at such a distance 116 the container in line with the vertical mit above the conveyor belt 20 which touches less than the tell line of the cylindrical container. As a result, the smallest container height is. ... ·. the inevitable delay between; your

For the exact checking of the container it is ndtwen- Umschalt'signäl the button and the extension of the dig that the head 72 furthermore an oblique movement 60 piston rod 114 , it is necessary that the longitudinal axis of the piston rod 114 can perform something outside of a horizontal plane further to the end of the presence or absence of a conveyor belt, seen in the direction of conveyance, against sufficient vacuum in the container to be precisely determined above the center line of the button 88, even if the container lid is jammed; Of course, this distance must correspond to the deterioration of the lid, for example, with the screw delay time between the changeover of the length of the day on the container and the extension of the piston rod 114 . If the lid is not properly screwed onto the container and the conveying speed of the container, it is almost impossible to set it to For derbarid 20:

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The setting of the motor 92 in the transverse direction is connected to the high-pressure line 132 and thereby to the conveyor belt is also dependent on the conveyance of the high pressure of 4 atmospheres in the cylinder of the speed of the container. Usually tors 92 is brought. As a result of the small inner distance, the conveying speed is so great that the container measurements of the motor 92 result in a differential at the test station in quantities of about 1000 5 pressure of 3.66 atmospheres, which the piston rod moves past containers per minute. The momentarily brings them into the fully extended position, holders are located on the conveyor belt in a line. The air in front of the piston comes out of the cylinder and collides with each other, so that when it is ejected through the line 138 into the chamber 140 if a container pushes the piston rod shut again. By adjusting the volume of the chamber 140 must be returned before the next successive io, a pressure is built up which, for example, 0.36 atmospheres container past the piston rod. For this purpose, and thus above 0.34 and below 4 atmospheres, the motor 92 is relatively smaller.

pneumatic drive with a bore of 19 mm. The piston stroke is very fast, so that

and has a stroke of 1.2 to 13 mm. To the scrap container almost instantly from the

Simplification of the motor actuation takes place the full 15 conveyor line on the opposite side of the conveyor

Stroke of the motor use. As a result of the position fastener the strap is ejected.

position of the motor 92 transversely to the conveyor belt protrudes The actuation time of the solenoid valve 124 is

the piston rod in the conveying path of the container only through the working properties of the button 88 and

with a distance determined by the position of the cylinder of the amplifier 122 . The actuation time

of the motor 92 opposite the conveyor track of the For- 20 of the button 88 and subsequent actuation of the

derbandes is determined. In order to avoid further interference Coil 124 , the pushbutton amplifier used

To decrease the possibilities, the tip 116 has a ker-unit dependent, the delay times

conical shape on · and is made of rubber or fluctuate approximately between 5 and 40 ms. The return

another elastic material to achieve a gentle response time or the time between switching on and

To achieve bumping of the tip against the container. 25 Turning off the coil 124 is of the properties

The container is ejected by hitting the arrangements and the sensing distance

and ejection of the container and less through and fluctuates between 8 and 120 ms. Another

Pushing the container on one side. Time delay occurs due to the switching movement

In Fig. 10 a circuit diagram is shown. The date valve 126 between the actuation position and ster 88 is via the line 120 with the amplifier 30 of the venting position. The time for change 122 connected. The button 88 and the amplifier switch the valve between its two end positions 122 work as a switch to connect the coil 124 to the lungs as well as the time for the response of the button mains supply L 1 and L 2, if this is due to the setting of the Motor 92 in longitudinal button detects a reject container. The coil direction to the conveyor belt is compensated.
124 belongs to the 3-way solenoid valve 126. This 3-way valve connecting the motor 92, which is normally closed due to the small dimensions of the cylinder, the valve 126 with the Zydet needs the line 128 optionally with an atmospheric chamber of the motor 92 Only for an extremely brief vent 130 or to be connected to the high pressure line period of time since the piston stroke 132, which in turn is connected to a pressure source 134 via a pressure regulator 136 in the extended position, is almost instantaneously connected. It is followed by nor- 40. In accordance with the full piston stroke, for example via the valve 126, the line 128 with the rod 114 , the response time is therefore connected to the vent 130 according to FIG. 10 as short as possible, if possible. After actuation, the solenoid valve is not energized. Therefore, the coil 124 is almost instantly switched off the coil 124 voltage, so switch tet so that the valve returns to its normal, in Fig. 10, the valve connections and connect the position shown 45 in which the cylinder chamber high pressure line 132 with the Line 128 of the motor 92 is ventilated. The pressure from the

The other cylinder chamber of the engine 92 is immediately conveyed by the pressure collector 140 the return

the line 138 with the pressure collector 140 connection of the piston.

that in turn with the pressure source 134 via the A further embodiment is in the

Line 142 with a second pressure regulator 144 shown in 50 FIGS. 8, 8 a, 9 and 11. In some cases it is

Connection. The pressure collector 140, also in the formation of the cover surface such that the

Fig. 1 shown consists of a simple Luftkam- sensitivity of the button not to be set

mer, the volume of which can be set between the cover plate on the edge by pressing the adjustment

screw 146 can be adjusted. The pressure of the lid and the snap part in the middle of the lid

controls 136 and 144 are set in such a way that one can distinguish between behavior. Accordingly, in the case of

moderately high pressure, such as 4 atmospheres using a single button in the above

of the line 132 occurs, while a relativelymä- written embodiment the shape of the

Toughly low pressure of about 0.34 atmospheres normally cover such that the button would be actuated when

in the collector 140 and in the line 138 in front the front and the rear end of the cover below

prevails. 60 is conveyed past the button. Such a lid

The one cylinder chamber of the engine 92 is thus shown in FIG. 8 a shown. This lid has a

under a pressure of about 0.34 atü, causing the surface 200 to be completely flat, besides that

Piston rod 114 pressed into its retracted position snap part 202 in the middle of the cover,

is brought and where the other cylinder space of the When using such a cover is still a

Motor 92 is vented. When detecting an off 65 second button 204 in addition to the one described

shot container by the button 88 receives the Ma- arrangement on a tab 206 , which is on

Magnet coil 124 of the valve 126 voltage, so that that of the support plate 64 is fixed. The long axis of the

Valve switches over so that the line 128 with the button 204 lies in the same vertical plane

like the button 88 and is actuated by the sheet metal of the lid edge when the lid is under the button 88 is precisely aligned centrically. The two buttons are connected in series so that the amplifier 122 only switches if both buttons 88 and 204 have responded at the same time. The button 204 is actuated every time a container lid is arranged centrally under the button 88 is. At this time, however, the button 88 is not actuated, except in the event that the lid is insufficient Can recognize vacuum in the container.

10

The button 88 is actuated twice during the passage of each container, namely once when the leading edge of the lid and the other when the trailing edge of the lid is conveyed past will. In both cases, however, the distance between the button 204 and the cover is set so that that the button 204 is not actuated.

Fig. 11 shows the circuit connections for the embodiment of Fig. 8 and 9, wherein'die ίο valve circuit was omitted, but with the valve circuit according to Fi g. 10 is identical. :;

_; For this purpose 2 sheets of drawings

Claims (3)

Patent claims: 1. Device for vacuum testing of closed containers by scanning the form deviation the lid surface to be tested opposite the lid edge with a spring force on the lid edge of the one after the other past container pressed support member, in which a on the distance from the lid surface contactless responsive electronic proximity switch is arranged, which acts on an ejection device, characterized in that the support member (72) plate-shaped with a downwardly protruding ring-shaped, onto the edge of the lid seated approach (90) is formed and is resiliently suspended tiltable on all sides. 2. Apparatus according to claim 1, characterized in that the support member (72) by means of vertically extending screws (78) is suspended from a support plate (64), the screws are screwed either into the support member (72) or into the support plate and with a large Play through holes (80) of the other component, and that between the support plate and support member Compression springs (82) are arranged. 3. Apparatus according to claim 1, characterized by a further proximity switch (204) which is arranged on one side of the container in such a way that it only generates a signal when a container approaches if the container lid is centered below the one in the support member (72 ) arranged proximity switch (88) is located. can be swiveled, the scanning of lids placed at an angle leads to false displays and incorrect results.