DE2521943A1 - METHOD AND DEVICE FOR MANUFACTURING CAN LIDS - Google Patents

Description

• AT I = NTA NVA ir F

DR. E. WIEGAND DIPL-ING. W. NIEMANN 2 5 2 I ΰ 4 O

DR. M. KÖHLER DIPL-ING. C GERNHARDT

MÖNCHEN HAMBURG TELEPHONE: 55547ί 8000 MÖ N CH E N 2, TELEGRAMS: KA R PATENT MATH I LD E N STRASS E 12 TELEX: 529068 KARF D

16th quay 1975

W 4 2 323/75 Si / az

Toyo Seikan Kaisha Limited Chiyoda-ku, Tokyo (Japan)

Method and apparatus for manufacturing can ends

The invention relates to a method and a Device for the division of can lids with a flanged one Section for folding and sections or spots to open, the inner circumferential edges with a sealing ring are coaters,

Can lids with such sections or locations for. Openings are well known and many can bodies with such lids have found use in practice. the Opening points can easily be opened by, for example be pressed in with a fingertip * so that the contents can be removed. Verden such can lids before folding or before connecting to the can body

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treated in the following way. Most of the opening points is cut and a sealant is applied to the inner circumference of the opening points, to reinforce the cut areas. When using a sealant with suitable components. is, the opening point can withstand the external and internal pressures acting on the can in a certain way and prevent the contents from leaking. The experiences made in the past fully confirm that Usefulness of can lids with such opening parts. The conventional process of applying a sealant to the interior surfaces of the openings in can lids however, suffers from a low level of efficiency, The throughput that can be achieved with conventional technology is low and amounts to around 75 pieces per minute. The cause this is because it is time consuming and difficult due to the very high viscosity of the sealant, Administer the sealant in small drops.

In recent years, there has been a greater need for an increase in productivity. The desirable The target was assumed to be 300 pieces per minute. This goal cannot be achieved with the conventional method. The method according to the invention and the device according to the invention allow this goal to be achieved and lead to a twofold advantage, firstly, the procedure and the device for applying a sealant was improved; and, secondly, a new method and a New device created for this, ura the above improvement to make it extremely effective. In the first place was a special method of ejecting oinos sealant developed with high viscosity, which led to an increase in productivity to around 300 pieces per minute,

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Second was the process of forming the opening points of the can ends with the process for Applying the sealant connected so that these operations are carried out sequentially and continuously can be. In the past, a can lid with opening points was produced by a pressing process. whereupon a sealant was applied to the openings at another location. In this case the position of the can lid must be aligned with the device for applying the Dichtunasmittsls matches. This way of working not only requires a lot of time for alignment, but also leads to inaccuracy when applying the sealant, so that the applied sealant is not in the right place sits. According to the invention, the sealant can be applied exactly at a predetermined location by dor Pressing process and the process of applying the sealant be connected without such alignment being required.

It is mainly the aim and purpose of the invention to improve the process for applying a sealant, thereby increasing productivity and making the process suitable for mass production. Furthermore, it is the aim and purpose of the invention to carry out the pressing process and the process for applying the sealant one after the other with the aid of a synchronized drive device.

The invention is explained in more detail below with reference to drawings. Show in the drawings?

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FIG. 1 shows a plan view of a conventional can lid with an opening; place η

Figure 2 shows a cross section along the line II-II in Figure 1

Figure 3 is a plan view of a partial section of the can lid

Figure 4 shows a cross section through a conventional one

Device for applying a sealant

FIG. 5 is a plan view of the conventional device shown in FIG

Figs. 6 and 7 are views showing the relationship between a sealant and a pressure stamp at a conventional one procedure

Figure δ shows a cross section through an embodiment a device according to the invention for applying the sealant

FIG. 9 is a plan view of that shown in FIG contraption

Figure Io shows an enlarged view of a detail of the device according to the invention, according to v / elcher the sealing means against the Druckstempe'l is extruded,

Figure 11 is a plan view of a stand with / working table according to the embodiment of the invention

FIG. 12 is a schematic side view of the device according to the invention

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FIG. 13 is a plan view of an upper press element

FIG. 14 is a plan view of a disk for support the can lid

FIG. 15 shows a cross section through one in FIG

shown working table representing a press (I) along the line X-X

FIG. 16 shows an enlarged illustration of an opening point of a can cover in consecutive order Pre3stüren and

FIG. 17 shows a cross section through one in FIG. 11

Apply shown / work table (V) of a sealant along the line Y-Y.

As mentioned above, the present invention achieved a two-fold improvement. The first aspect of improvement is shown below described.

A good example of an opening point of a can end is shown in ϊ; -ur 1, 2 and 3. One or two opening points 2 are provided in a can lid 1 * If the öffnuncj ^ set 2 are pressed from the outside, they can can be opened easily. The opening points have a cut one Section and are broken in this part. The dashed line b in Figure 3 represents the cut Section, while the solid line a shows the uncut part. The cut section nut be reinforced on its back by the application of a sealant 3. This state is indicated by points in Figure 3 shown. An example of a sealant is a composition of polyvinyl chloride, a plasticizer, a stabilizer and other additives. The sealing

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medium has a viscosity of about 3,000 at 40 ° C 4,000 centipoise. Since the sealant has such a high viscosity, it is not easy to apply and There are extensive difficulties in attempting to achieve uniform coating or mass production guarantee.

There are several conventional devices for applying such a sealant. One of those devices is shown in Figures 4 and 5 as a typical example.

As FIGS. 4 and 5 show, a container 6 with a sealing means 5 is set up on the floor. A can lid 1 is held in place by means of a holding device which is arranged above the container 6. A vertically displaceable piston 8 is provided in the container 6 and a pressure ram η is attached to the top of the end of the piston 8. The piston 3 moves downward during operation, so that the plunger 7 sinks into the sealing means 5 and. a suitable tightness of the sealant adheres to the surface of the punch 7. The piston 3 is then moved upwards and the pressure ram 7 is brought into contact with the rear side of the can lid 1. This leads to the sealing agent adhering to the edge of the opening points 2. During the next work cycle, the can lid 1 is released, whereupon the next can socket is fed in and the piston 3 is moved downwards to lower the pressure ram 7 into the sealing agent 5 permit. The push rod 7 rises up again after receiving a suitable tight sealant. The sealant adheres to the edge of the opening position in the same way as described above.

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len 2 on. The process described above is repeated.

Recently, there has been a need for an increase in productivity, the conventional one described above Apparatus for applying a sealant has been studied from this point of view. It turned out, that the achievable with this known device throughput is 75 pieces per minute and various difficulties occur when trying to increase productivity. The cause of the low efficiency of the conventional Device zurr. Application of the sealant can be seen on the basis of FIGS. 6 and 7. As the sealant 5, as mentioned above, has such a high viscosity, the pressure die 7 cannot easily be inserted into the Immerse the sealant when the ram is 7 in drops the container filled with sealant. As As shown in Figure 6, the sealant forms a curved surface above the edge of the pressure stem 7 and runs not over the area of the punch 7,

However, if a certain, very short period of time is allowed to elapse, the sealant will undergo Effect of gravity, so that the lower portion of the curved surface is as shown in FIG over the edge of the upper surface of the pressure star pel 7 slips over. When the ram 7 rises, a small amount of the sealant is pushed off and on the peripheral edge the surface of the plunger 7 held and then zurr. Applied to the can lid. With regard to FIG. 7, it is well known that the The amount of material spread over the surface of the

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bulging sealant greatly by changing the The level of the sealant in the container is affected. Of the The level of the sealant must now fluctuate within -0.5, for example. The amount of sealant applied is also strongly influenced by the speed of the plunger. In mass production, for example with a production of 300 pieces per minute, therefore, many difficulties arise because of the foregoing mentioned problem of the level of the sealant and because of the speed of the print stack. Furthermore it is difficult to apply the sealant uniformly in an appropriate amount.

The present invention has overcome the foregoing difficulties and has made a remarkable improvement in the Productivity achieved. While in conventional production a throughput of about 75 pieces per minute at most is achieved, the throughput was increased to about 300 pieces per minute with the aid of the invention.

According to the invention one does not push the pressure stamp into a sealing means, but moves it freely upwards in the space and below. The sealant is applied with the help of an external pressure from a narrow slot surrounding the push button extruded the surface of the plunger. The extruded sealant is picked up by the rising plunger. This thought led to the first aspect of the invention.

An embodiment of the first aspect of the invention is shown in FIGS. 3 and 9. In general two opening points are punched at the same time. However, they can sometimes also be punched individually and separately will. For the purpose of simplifying the description, the latter case is explained below. Which he-

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Coating device according to the invention has an outer finish 13 with a bottom part 9, an inner wall Io and an outer wall 11. The outer frame 13 has a chamber 12 for receiving a sealant. An inlet port 14 for the sealing means is provided in the outer wall 11. A dachshund part 15 is at the upper end of the outer frame 13 attached. A central hole 15p is in the inner wall Io of the outer frame 13 is formed. A central hole is also provided in the cover part 15. These central holes 15, and 152 have the same central axis and the same Inside diameter. A gap 16 is between the top the inner wall Io and the underside of the cover part 15 are provided in the central region of the device.

A piston 17 is moved up and down in the central holes 15 and 15 with the aid of an external force (not shown). A plunger 18 is on the top of the piston attached.

Between the circumference / and of the plunger 13 and the inner walls of the central holes 15 and 15 ₂ , a small amount of play is provided. The piston 17 has a vent opening 19 which connects the inside of the piston 17 with the outer atmosphere. A can lid 1 is arranged above the plunger 13 and is held by means of an overhead frame, not shown. The donor lids are fed one after the other and synchronously with the movement of the plunger 18. The pressure ram 18 rises to the position shown with dashed lines in order to deliver the sealing agent to the lower surface of the can lid 1. When the plunger IS begins its downward movement, the can lid 1 is moved away and a fresh one

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- Io -

Can lid fed. The plunger 18 moves down to a predetermined point and stops there for a moment to take a fresh charge of the sealant, whereupon the plunger rises again to the Dispense sealant onto the fresh can lid. The movement of the can lids is as described above Way synchronized with the supply of the sealant.

The most essential feature of the invention is the state in which the sealing means is about to be applied to the pressure stamp 18 to hike. This is shown in Figure Io. Dcis Sealing means c is extruded from a slot 16 between the cover part 15 and the top of the inner wall Io. In meanwhile, the ram 18 rises from the bottom to the top to scrape off the protruding sealant c. There If the sealant has a high viscosity, the excess sealant remains on the outside of the pusher be liable. The excess sealant is removed from the inner wall of the central hole 15 of the lid part 15; In other words, it means that the inner wall of the central hole 15 plays an essential role in removing the excess Sealant that adheres to the outside of the plunger 18 plays.

The main features of the invention are that the sealant c protrudes from the slot 16 and then the excess sealant from the pressure ram 18 with the help of the inner wall of the central hole 15, removed.

The sealant that is outside the reporting device has been heated to a suitable temperature, pressure is applied into chamber 12 through inlet port 14.

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A device, not shown, is provided to regulate the amount and the pressure of the sealing agent to be supplied, so that the state shown in Figure Io can be achieved. The vent opening 19 is provided in the piston 17 for the following reason. When the plunger rises to apply the sealant to the undersurface of the can lid and is about to leave, there is a slight negative pressure in the piston 17. This negative pressure is destroyed by blowing air through the vent 19 in the lower part of the piston 17 can flow through. In the absence of a vent, the negative pressure affects the sealant and tends to degrade the uniformity of the sealer.

The second aspect of the invention will now be described.

In general, a pressing operation is required prior to the application of a sealant in order to form the openings in a can lid. Experience shows that the efficiency of the pressing process reaches about 300 pieces or more per minute, even if the efficiency depends on the. The shape of the openings or other factors varies slightly. Since the conventional sealant application process is very poor in efficiency, it is not essential to combine the sealant application process with the pressing process in one integrated system. However, the first aspect of the invention has made it possible to reduce the efficiency of the process. ^1st Increase application of the sealant to about 300 pieces per minute. This improvement creates the prerequisite that these two operations can be connected to one another in a combined system in order to achieve maximum efficiency. In the

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The work step for pressing from work step was in the past separately for applying the sealant. It was therefore necessary to remove the can ends after the opening points were formed to a separate device for applying the sealant. «It was tedious and time consuming align the plunger and the opening point with one another. The present invention has eliminated these drawbacks and permits can ends to be mass produced with opening points under stable conditions by adding the Features of the first point of view are used. The process of pressing and the process of applying the sealant are in particular in a summarized system therefore connected with each other that the two operations with the help of a synchronizing drive system carried out one after the other.

The second aspect of the invention is explained with reference to FIGS. 11 to 17.

As can be seen from Figure 11, 8 work tables (I) to (VIII) are arranged on an annular stand 23, The Work tables are distributed over the perimeter with the same name. Of the Work table (VIII) is used for. Feeding of new can lids, the work tables (I) to (IV) are work tables for presses. The work tables (V) and (VI) are work tables for applying the sealing putty 2 Is. The 7th work table (VII) is used for removing the finished lid, FIG. 11 only shows the general arrangement of the work tables. Everyone The work table has its own structure, which is described below.

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As can be seen from Figure 12, the apparatus for pressing generally has an annular stand 23, a disk 25 for receiving the can lid and a semi-ring-shaped press element 26. The upper i'atrizonfomen are vorgesshen in semi-ring-shaped press element 26 at locations _for the associated, as Work tables in the stand 23 that are used for presses correspond, as shown in FIG. The semicircular press member 26 moves continuously up and down. A drive device for the press element is accommodated in an upper frame 27. The disk 25 for receiving the can dachshunds is, as shown in FIG. 14, rotatably mounted and intermittently rotatable about the same shaft as the stand 23. The drive device is provided in the central cavity of the stand 23.

In order to be able to describe the above combination better, FIG. 15 shows a cross section through the work table (I) along the line X-X in FIG. 11. FIG. 15 shows that the press element 26 is lowered and the can lid 1 presses, the can lid 1 is between the male mold 28 and the one in the press room 26 Katrizenfornen 27 held to the opening points to train. The following device according to the invention is used for. Raising the obaren Pressenoler.ientes 26 after End of the molding process. As can be seen from Figure 15, there is an auxiliary disk 24 in the disk supporting the can lid intended. A circular cavity or recess is provided in the can lid receiving disc 25, and the auxiliary disk 24 to receive. Screw bolts 2S are with the auxiliary disk 24 screwed. The screw bolts 29 grip

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fen through holes of the double cover 1 supporting disk 25 and are biased against these disks with the aid of a spring 3o. A hole through which the central projection of the upper press element 26 can reach is formed in the center of the auxiliary disk 24. A space 31 is provided in the lower half of the above-mentioned hole. This space 31 supports the flange portion of the can lid. When the upper press element 26 is raised in the embodiment shown in FIG. The auxiliary disk 24 forms a unitary structure with the disk 25 supporting the can lid. The can lid 1 is lifted off the lower cartridge molds 28 at the same time. When the disc 25 supporting the can lid is then rotated v. ^T ill, therefore, does not interrupt the projection of the stator 23, this rotation.

A can lid 1 to be processed is first fed to the work table (VIII) acting as a press. The can lid must be supported by the auxiliary disk 24 at the same time as the feed. This can be achieved by having a suitable upper press element is also used on the work table (VIII) acting as a press, so that the flange section of the can lid can be held in space 31. When the operation in the pressing work table (I) is finished and the upper press element has been raised, will the disc 25 supporting the can lid is then rotated by a distance corresponding to a work table. Of the Can dachshund 1 is fed to the pressing work table (II) in this way.

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The internal structure of the pressing work tables (II), (III) and (IV) is essentially the same as that of the work table (I) acting as a press, with a few minor differences in the male and female molds. The opening projections formed by these work tables acting as press are shown in FIG. The curves in FIG. 16 show the shapes of the openings which are formed by the work tables acting as presses. The curve (I ¹ ) is formed by pressing on the work table (I). The bulge Λ of this curve represents a wedge that becomes an opening point. In the curve (II ¹ ), the bead section is cut through by the pressing process on the work table (II). The curve (III ¹ ) shows an overlapping part that was created by pressing in the bead shown with a dashed line and stretched onto the work table (III) acting as a press. A recessed section is formed in part A by a pressing process on the work table (IV). The end portions are raised to reinforce the overlapping portion of the bead. This is shown by curve (IV ¹ ). The curve (V) shows that a sealant was applied to the inner surface, particularly to the overlapping area of the opening. The invention is not limited to the pressing process described above for producing the openings. The shape and size of the openings are arbitrary. In the above embodiment, the opening has a rhombic shape, for example. However, other shapes, such as a circle, an ellipse, or a combination of these shapes are also useful. The cut section or the overlap area can also be chosen arbitrarily. In order to be able to describe the application of the sealant, a cross section through the working

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table (V) for applying the sealant along the Line Y-Y shown in Figure 11. FIG. 17 shows a can lid in a floating state, the can lid is, however, in reality supported on the disk on which the can lid is supported. The work table shown in FIG for applying the sealant has the following structure.

An outer side wall 11 surrounds a chamber 12 for receiving a sealant. The outer wall 11 is provided with an inlet opening 14 for the sealant. A central hole 15 ₂ is formed in the upper part of an inner wall Io of an outer frame 13. A central hole 15 is provided in a cover part 15 of the outer frame 13. An intermediate space 16 is formed between the top of the inner wall Io of the outer frame 13 and the bottom of the cover part 15 in its Mt te.

A piston 17 can be moved up and down _{in the central holes 15 2 and 15.} The piston 17 is constantly moved up and down by a device provided at the lower end. A pressure ram 18 is attached to the upper end of the piston 17.

The piston 17 moves due to the up and down movements of a lever 2o provided at the lower end Device up and down. The Hebol 2o is with a facility for the vertical movement of the press element on the work table acting as a press. The pressing process on the work table acting as a press is therefore synchronized with the piston 17 of the work table for applying the sealant carried out. In other words, this means that at the same time as the pressing process, the

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kenden workbenches the sealant from the Γ-back stamp is applied to the can lid.

The sealant is heated to a flowable state and forced through the inlet opening 14 into the casing 12 by means of a purine or the like. The sealing means is extruded in the illustrated way from a slot IG which is formed in the upper section of the Κατ-r.er 12. The plunger 13 rises from the inside up to scrape off the protruding sealant. Since the sealant has a high viscosity, the excess sealant will adhere to the outside of the punch 18. The excess liquid is removed from the inner walls of the central hole 15 and discharged to the outside through an outlet opening specially provided for this purpose.

The process shown in Figure 17 for applying the sealant relates to one of the two openings 2, dia are shown in Figures 1 and 2. The other opening 2 can with a work table applying the sealant be coated, which is arranged next to the work table shown in Ficur 17. The process of applying of the sealant using the work table next to it is the same as in Figure 17.

The erfindungsgoiu'.ße J.usführuaqsform is based on the Figure 11 briefly summarized: A can lid with a flanged Section angry. Folding is fed to the work table (VIII) and from the auxiliary disk shown in FIG supported with the washer 25 to the <\ ufnahr: e of the can lid connected is. The disc 25 for receiving the can lid rotates intermittently. The can lids therefore move from one / work table to the next and v / ground after loading

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motion stopped for a short period of time. During the The can ends are pressed and coated with a stop. This cycle of movement and stopping is repeated. The can lid fed from the work table (VIII) is placed in the Work tables (I), (II), (III) and (IV) pressed to form the opening points. Then the process for applying the sealant to the workbench (V) or (VI) carried out while simultaneously the following Can lids are pressed. The finished can lids are withdrawn from the work table (VII).

As mentioned in the foregoing, the aim and purpose of the invention was to improve manufacturing efficiency of can lids, the opening points of which are coated with a sealant. Because of the first According to the invention, the method of applying a sealant having a high viscosity is technically improved and because of the second. Aspect of the invention is the pressing process for producing the openings in can ends carried out in a synchronizing manner before the coating process. These two aspects of the invention are not limited to the particular embodiments shown in FIGS. 11, 12, 13 and 14. It are rather changes and modifications within the framework and Spirit of invention possible.

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Claims (4)

Claims C l, j method for the production of can lids, in which opening points are pressed into a can lid and a sealant is applied to the opening points, characterized in that in a device with an annular stand, a plurality of pressing work tables, one behind the other at predetermined intervals are arranged on the stand, a disc supporting the can lids, which is movably arranged on the stand and with holes supporting the can lids, which are designed in the disc to support the can lids at the same intervals as the pressing work tables, the disc for support the can lid is movable over the stinder while the can lids are supported by the holes, the disc to support the can lid stops for a short period of time every time the can lid has reached a pressing work table, and that the can lid during the stopping a pressing operation and the like is thrown; that the disc moves further to support the can lid by a gap and the pressing process begins on the next pressing work table when the pressing process is finished and a press element has lifted; that openings are formed on the can lid as the can lid passes through a series of these press / work tables; that further / work tables for applying a sealant are provided at the same intervals as the pressing work tables in the course of the movement path of the disk for supporting the can lid; that a pressure provided in the work table for applying the sealant 509848/0459 - 2ο - Stamp this from a slot in the peripheral wall of the application Worktable scrapes off extruded sealant / when the can lid hits the top of the sealant applied work table has reached, and the sealant on the inside of the opening points of the Can lid is applied; and that in the above connected operations of pressing and applying the Sealing means the vertical movement of the pressure ram with the vertical movement of the press element on the pressing element Work table is synchronized. 2. Device for the production of can lids, there- characterized in that in an annular stand (23) with a plurality of work tables (I-VIII) arranged at predetermined intervals, one of which (VIII) is a work table to which a can lid (I) is to be fed first, and of which several Subsequent work tables pressing work tables (I-IV) and of which at least one work table following the pressing work tables (I-IV) is a work table (V> VI) to: application of a sealant and the last work table is a work table (VII) from from which the finished can lid is peeled off, a vertically movable semi-annular plate (26) is provided above the feeding work table (VIII) and the pressing work tables (I-IV); . that the semi-annular plate (26) ö with press elements (27) allows us that correspond to the underlying work tables; that one of the opening point of the can lid (1) corresponding matrices form ar. of each press Entes ENEL (27) is provided lower F.rice and Ir * atrizenforrr cooperating Patrizenfom (22) is provided in each underlying work table ₁ It of ^; da.J 509848/0 a rotatable disc 25 for supporting the can lids the annular stand (23) is arranged and the can lids supporting disc (25) is annular and has can end supporting holes in the same Spacing how the work tables are arranged; that the sealant applying work table (V, VI) the in the transport direction of the pressing work tables (I-IV), a pressure camouflage (18) and a device for extruding and supplying the sealing agent (c) to the pressure die (18); and that the device also has a device for synchronizing the vertical movement of the plunger (IS) with the vertical movement of the Press elements (26) above the pressing work tables (I-IV) and means for rotating the disc (25) supporting the can ends in the manner that the disc (25) stops when the two devices are in motion and moves when they are stationary. 3, device according to claim 2, characterized in that that an auxiliary disk (24) to support a can lid (1) used v / ird and the auxiliary disk (24) by means of a spring device (3o) nlt the disc (25) supporting the can lid is connected in such a way that the auxiliary disc (24) is in a recess fits, which is formed on the underside of the can lid supporting disc (25). 4. Apparatus according to claim 2, characterized by a device consisting of a vertically movable piston (17) 'which is placed in the / work table (V, VI) for applying the sealant is provided, a pressure stamp (IS) arranged on the top of the piston (17) and a device (16) for: Extruding a sealant onto the ram (13) j 509848/0459 so that the sealant on the inner surfaces of the opening points (2) is applied when the can lid (1), which after treatment in the pressing workbench with Opening points is provided in front of the work table Application of the sealant achieved. 50 9 848/0459 -49. Blank page