WO2004067421A1

WO2004067421A1 - An apparatus for driving one or more processing stations, and a chain for use in the apparatus

Info

Publication number: WO2004067421A1
Application number: PCT/SE2004/000035
Authority: WO
Inventors: Markus PALMNÄS; Lars-Ebbe Persson
Original assignee: Tetra Laval Holdings & Finance S.A.
Priority date: 2003-01-29
Filing date: 2004-01-15
Publication date: 2004-08-12
Also published as: CN100548837C; MA27714A1; SE0300208D0; CO5580813A2; ZA200505136B; PL377429A1; CN1745025A; EG23646A; SE0300208L; PL206991B1; SE525670C2

Abstract

The present invention relates to an apparatus for driving one or more processing stations, comprising an endless path (1) which includes a plurality of links (1b) of a first predetermined length (B) and at least one pinion (2) which is disposed to engage with said links (1b) and drive said endless path (1), the path (1) being disposed to support said one or more processing stations at a number of predetermined positions along the extent of the path (1), characterised in that each section of the path (1) extending between said positions, comprises at least one link (1a) of a second length (A) deviating from the first length (B). The present inThe present invention relates to an apparatus for driving one or more processing stations, comprising an endless path (1) which includes a plurality of links (1b) of a first predetermined length (B) and at least one pinion (2) which is disposed to engage with said links (1b) and drive said endless path (1), the path (1) being disposed to support said one or more processing stations at a number of predetermined positions along the extent of the path (1), characterised in that each section of the path (1) extending between said positions, comprises at least one link (1a) of a second length (A) deviating from the first length (B). The present invention further relates to a chain of the above mentioned type.

Description

An apparatus for driving one or more processing stations, and a chain for use in the apparatus

TECHNICAL FIELD The present invention relates to an apparatus for driving one or more processing stations, comprising an endless path which includes a plurality of links of a first predetermined length and at least one pinion which is disposed to engage with said links and drive said endless path, the path being disposed to support said one or more processing stations at a number of predetermined points along the extent of the path.

The present invention further relates to a chain consisting of a plurality of links of a first predetermined length which are disposed to be joined together so that they form an endless path.

BACKGROUND ART

USPS 2,741,079 discloses a packaging machine system for continuous forming of a tube from a planar web and continuous filling of the finished tube portion and subsequent transverse sealing of the tube for the formation of tetrahedral packages. The sealing is realised with a number of sealing jaws which are disposed, from opposing sides, to clamp together and fuse together plastic layers included in the packaging material. By alternatingly disposing the transverse seals in two directions at right angles to one another, the tetrahedral configuration will be achieved. Each jaw is supported by two parallel, oval endless parts in the form of two chains. Along its oval extent, each chain pair supports a number of sealing jaws which are intended sequentially to engage with and seal the tube against an opposing jaw which is supported by an opposing chain pair. In a construction of this type there are thus eight chains which are disposed in pairs on four sides of the tube. USPS 2,738,631 discloses such a construction which has moreover been provided with roller beds for realising a cam mechanism for guiding the movement of the sealing jaws against the tube on the sealing occasions.

In order to be able to satisfy different customer- and consumer needs it is necessary to be able to make packages of different sizes. In order to be able to vary the distance along the longitudinal direction of the tube between the seals, it is necessary to vary the distance between the sealing jaws along the oval section of the path. This, for example, may be put into effect by varying the number of links between the sealing jaws. However, this entails that it is only possible to vary the size of the packages in steps which correspond to the length of one link. In order further to increase the number of options, it is also possible to switch between different standard dimensions for the chains. However, the problem remains that it is the dimensions of the chain which define the options and not, as would be desirable, that it is possible without limitation to exactly select the packaging size which is desired.

WO00/64751 discloses a more recent variation with belt- or chain-driven sealing jaws. With the belt driving feature, it would in principle be possible to move the sealing jaws freely so that they can form packages of any optional size. The introduction of belts instead of chains however introduces a number of new difficulties as regards positioning and driving. Belts which are not provided with any form of cogs or teeth slip to a greater or lesser extent at the pinion, which implies that positioning must be guided and monitored with some form of sensor. In order to avoid this necessity, use is made of belts which are provided with toothing, but then the problem structure will be the same as in chain operation. The toothing has a certain pitch (the distance between the teeth) which corresponds to the link length in a chain, and the distance between the sealing jaws may thus only be changed in steps which correspond to the pitch between the teeth.

SUMMARY OF THE INVENTION The present inventions thus has for its object to realise a solution which obviates or at least reduces the above-outlined problems.

One particular object of the present invention is to realise a principle for attaining driving possibilities which in principle increase the possibility of constructing driving features which do not suffer from the above outlined limitations as regards stepwise options of distance and which nevertheless constitutes a simple and dependable solution. This object has been attained according to the present invention by means of an apparatus of the type disclosed by way of introduction which has been given the characterising features that each section of the path extending between the above mentioned points consists of at least one link of a second length deviating from the first length.

By introducing, in this manner, a unique link of a length which deviates from the length of the remaining links, it is possible to realise a drive means in which it is possible steplessly to define different distances between the processing stations which, in a packing and filling machine, for example consist of sealing jaws. This entails thus that it is possible to design the machine to produce packages of optional length without being obliged to take into consideration the standard dimensions for the links of the chains. By selecting a suitable length of the above mentioned specific links, it is possible steplessly to vary the distance between the processing stations. When a different packaging length is to be produced, the chain and pinion are changed so that a different distance between the sealing jaws will be obtained. By such means, it is possible to employ the same standard dimensions, with the result that, for example, the fixing points for the sealing jaws to the chain may be of standard design regardless of what distance between the jaws is desired. Further, any possible chain tensioners or other components which cooperate with the chain may be the same regardless of what dimensions are desired.

Hence, the design and construction according to the present invention have offered a solution by means of which it is possible to a major extent to employ standard components and only use one special link in each one of the chain sections between the different processing stations. With the present invention, it has become possible to steplessly vary the distance between the jaws, i.e. the length of the package, in relation to how rapidly they pass in connection with advancement and sealing of the tube. As was mentioned above, this has previously only been possible in steps corresponding to the lengths of the links. Preferred embodiments of the present invention are apparent from the appended subclaims. According to one preferred embodiment, the above mentioned one or more processing stations are disposed to be secured to each respective link at one or a number of predetermined positions along the longitudinal direction of the path. As was mentioned above, this entails that it is possible to employ a limited number of standardised anchorage constructions and nevertheless, by employing the special link according to the present invention, achieve stepless options as regards the distance between the processing stations.

Preferably, the apparatus comprises at least two processing stations.

Constructions featuring five to ten processing stations on each drive means are not uncommon. The exact number of processing stations, such as for example seating jaws in a packing and filling machine, depends upon the selected application of the invention.

Advantageously, the endless path is led over at least two wheels or sliding sections in order to define said endless path. This is a simple manner of realising the desired endless configuration of the path or the chain.

Preferably, the above mentioned wheel or sliding sections comprise said pinion. By employing a pinion which deflects the chain in order to define the endless configuration, a large contact or surrounding angle will be obtained for the chain around the pinion, with the result that it is possible in a reliable manner to transfer the requisite power from the pinion to the chain.

According to one preferred embodiment, the above mentioned pinion consists of toothed sections which are disposed to engage with each respective link. By employing such a construction with teeth which engage in recesses in each respective link, it is possible to transfer forces in a controlled manner and an accurate positioning of the position of the chain along its longitudinal direction will be obtained in relation to the pinion, which in turn entails that it is possible to define and regulate the position of the processing stations in a simple manner.

According to one preferred embodiment, said toothed sections are disposed at predetermined mutual spaced apart relationship which, along the mean contact circumference of the pinion, corresponds to said first predetermined length of the links, and that at least one of said distances corresponds to the length of said at least one link of a second length. By employing specially adapted pinions which engage with the links in this manner, a favourable power transmission will be obtained as well as positioning regardless of what type of link abuts against the pinion.

According to one preferred embodiment, the pinion comprises a number of toothed sections which, in number and mutual spacing, correspond to whole number multiples of the number of links of each section of the path between said one or more processing stations. For example, the pinion may be designed so that it comprises two times the requisite number of teeth with a first distance between them between two opposing positions with teeth with a second distance between them. This variation is shown in Fig. 2. Naturally, this number of multiples may also be three or more.

According to one preferred embodiment, the pinion comprises a number of toothed sections which, in number and mutual spacing, correspond to a whole number multiple of the number of links between each section of the path between said one or more processing stations divided by the number of links of said second length which each section displays. In this variation, each section of the chain includes more than one link of a deviating length. By uniform placing of these deviating links, it is possible to obtain whole number multiples divided by the number of deviating links per chain section. This further increases the freedom to design the drive means in an optional manner. The above outlined objects have also been attained by means of a chain of the type described by way of introduction which has been given the characterising feature that the chain further includes at least one link of a second length.

As was mentioned above, it is possible by such means to introduce a unique link of a length which deviates from the length of the remaining links so as to realise a chain for a drive means where it is possible to steplessly define different distances between the processing stations which, in a packing and filling machine, for example consist of sealing jaws. It is thus possible to design the machine so as to produce packages of optional length without needing to take into consideration the standard dimensions for the links of the chains. By selecting a suitable length of said special links, it is possible to steplessly vary the distance between the processing stations. When another package length is to be produced, the chain and pinion are changed so that another distance will be obtained between the sealing jaws. By such means, it is possible to employ the same standard dimensions, entailing that, for example, the anchorages for the sealing jaws to the chain may be of standard design regardless of what distance between the jaws is desired. Further, any possible chain tensioners or other components which cooperate with the chain can be the same regardless of what distance is desired.

Thus, the design and construction according to the present invention have offered a solution by means of which it is possible to a major extent to employ standard components and only use one special link in each one of the chain sections between the different processing stations. Preferred embodiments of the present invention are further apparent from the appended subclaims.

According to one preferred embodiment, the chain is disposed to support at uniform spacing from another, at least two processing stations, each section of the chain which is disposed to extend between two processing stations comprising at least one link of said second length. As a result of the possibility of disposing several processing stations on the chain and designing the chain with a unique link in each interjacent chain section, it is possible to employ the chain for a packing or filling machine or the like where, in a rapid but nevertheless simple and robust manner, it is possible to achieve a large number of processing operations per unit of time, without to this end needing to place less demand on the stepless option.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will now be described in greater detail hereinbelow, with reference to the accompanying schematic Drawings which, for purposes of exemplification, show presently preferred embodiments of the present invention according to both of its aspects. In the accompanying Drawings:

Fig. 1 shows how an endless path is led between two wheels and supports a number of seating jaws; and

Fig. 2 is a side elevation of a pinion and a part of a chain which is led about and driven by the pinion. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As is apparent from Fig. 1, the drive means consists of a chain 1, a pinion 2 and some other form of guide in the form of an additional gear rim 3 or some form of sliding surface (not shown). The chain supports a number of sealing jaws 4a-e which are disposed to clamp together a packaging tube (not shown) for the formation of packages. In Fig. 1, two jaw systems are shown of which only the right-hand is provided with reference numerals. The left-hand jaw system is a mirror reflection of the right-hand system about the contact line between sealing jaw 4a and the associated jaw belonging to the left-hand jaw system. In order to obtain the correct parallel alignment of the sealing jaws, each jaw system is usually provided with at least two chains which run parallel in an endless path. Of these two chains, only the forward chain in the plane of the paper is shown and, parallel with the plane of the drawing paper, the rear chain is offset inwards into the paper so that the axle centre for the pinion 2 and the gear rim 3 are the same also for the rear chain.

In order to produce tetrahedral packages, the jaw systems illustrated in Fig. 1 are supplemented with an additional two jaw systems which are turned through 90° in relation to the illustrated jaw systems. The jaws in these systems follow their chains and are placed on them so that they enter into engagement with the tube between each respective engagement of the illustrated jaw system.

The described drive means and the chain 1 may be employed in a large number of different practical applications. One application is, for example, a filling machine of the type which is disclosed in USPS 2,741,079 and USPS 2,738,631. Since the present invention for example does not relate to the manner in which the tube is formed or the manner in which the seal is realised, this will not be described in greater detail in the present specification. For a more detailed description of how such filling machines function, reference is made to the above mentioned patent specifications. The characterising features which are essential for an understanding of the present invention and how it may be employed in optional practical applications has been described in detail in the present specification.

Fig. 2 shows the lower pinion 2 and a part of the chain 1 in detail. As is apparent from Fig. 2, the chain comprised a plurality of links lb which have a first length B, in the manner of a conventional chain. Moreover, the chain 1 comprises, between each sealing jaw 4a-e, a special link la which has a second length A which deviates from the length B of the other links. Fig. 2 shows the positions in principle of two sealing jaws 4d-e. The two seating jaws 4d-e are secured to the chain 1 at the same position in relation to the special link la. As was mentioned above, this construction makes it possible to employ standard components to a very large extent at the same time as it is possible to steplessly select the height of the package.

The pinion 2 may be in principle any conventional gear wheel whatever whose diameter and toothing have been adapted to the total length of each repetition of the chain section between the sealing jaws. Fig. 2 shows a pinion 2 which is designed with teeth which are adapted to engage with the links lb of a standard length B and two special recesses which are adapted to receive the links la of the deviating length A. Fig. 2 shows a wheel with teeth 2b which engage with every other standard link lb, but the pinion 2 may naturally also be designed so as to engage with every link, i.e. with twice as many teeth.

The mean contact circumference has been defined so as to clarify that the distance between the flanks of the teeth is of interest in a diameter which lies slightly outside that diameter where the teeth have their bottom. In the normal case, this mean contact circumference lies approximately along the line of symmetry of the chain, but for asymmetric chains and other flank profiles of the teeth of the pinion, this position may vary somewhat.

The illustrated pinion comprises only teeth intended to engage with every other link, but naturally it is also possible to employ standard designs with toothing adapted to engage with each link of the chain. In addition, the extended section of the pinion is also shown, adapted to receive the link of deviating length without any tooth. If the deviating link is shorter than the other links, it may be difficult to design a sufficiently strong tooth, but if the deviating link is longer than the other links, it is a matter of free option to design the pinion with an extended tooth or not.

The exact form of the cross section and flank profile of the teeth depend upon what type of standard chain it is elected to employ and is not critical to realisation of the present invention. It will be readily perceived that a number of modifications of the embodiments of the present invention described herein are possible without departing from the scope of the invention as this is defined in the appended Claims.

For example, it is conceivable in certain cases that each section of the chain extending between two processing stations may include two or more links of a length which deviates from that of the remaining links in the chain. By such means, it is possible to accommodate larger length adjustments in those cases where the length of the links occasions excessively large steps in order for it, for example, purely geometrically or in terms of power transmission, to be suitable to accommodate the entire adjustment by means of a single link in each chain section. In this design, it is possible, if the special links are uniformly placed, to design the pinion as whole number multiples divided by the number of special links in each part between the sealing jaws.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for driving one or more processing stations, comprising an endless path (1) which encompasses a plurality of links (lb) of a first predetermined length (B), and at least one pinion (2) which is disposed to engage with said links (lb) and drive said endless path (1), the path (1) being disposed to support said one or more processing stations at a number of predetermined positions along the extent of the path (1), characterised in that each section of the path (1) extending between said positions includes at least one link (la) of a second length (A) deviating from the first length (B).

2. The apparatus as claimed in Claim 1, wherein said one or more processing stations (4a-e) are disposed to be secured to each respective link (lb) at one or a number of predetermined positions along the longitudinal direction of the path (1).

3. The apparatus as claimed in Claim 1 or 2, comprising at least two processing stations.

4. The apparatus as claimed in any of the preceding Claims, wherein the endless path (1) is led over at least two wheels (2, 3) or sliding sections so as to define said endless path (1).

5. The apparatus as claimed in Claim 4, wherein said wheels or sliding sections comprise said pinion (2).

6. The apparatus as claimed in any of the preceding Claims, wherein said pinion (2) includes toothed sections (2b) which are disposed to engage with each respective link (lb).

7. The apparatus as claimed in Claim 6, wherein said toothed sections (2b) are disposed at predetermined mutual spaced apart relationship which, along the mean contact circumference (C) of the pinion (2) corresponds to a multiple of said first predetermined length (B) of the links (lb), and at least one of said distances corresponds to the length (A) of said at least one link (la) of a second length (A).

8. The apparatus as claimed in Claim 7, wherein said pinion (2) comprises a number of toothed sections (2b) which, in number and mutual spacing, correspond to a whole number multiple of the number of links (lb, la) of each section of the path (1) extending between said one or more processing stations.

9. The apparatus as claimed in Claim 8, wherein the pinion (2) includes a number of toothed sections (2b) which, in number and mutual spacing, correspond to a whole number multiple of the number of links (lb, la) of each section of the path (1) extending between said one or more processing stations, divided by the number of links (la) of said second length (A) which each section displays.

10. A chain comprising a plurality of links (lb) of a first predetermined length (B) which are disposed to be joined together so that they form an endless path (1), characterised in that the chain (1) further includes at least one link (la) of a second length (A).

11. The chain as claimed in Claim 10, which is disposed to support, at uniform spacing from one another, at least two processing stations, each section of the chain which is disposed to extend between two processing stations including at least one link (la) of said second length (A).