CN1040407C - Improved processing method and equipment for corrugated board - Google Patents

Abstract

The present invention relates to an improved method and apparatus for corrugating paperboard wherein two pieces of corrugated material are joined at the ends of their corrugations. End gears (16a, 16b, 15a, 15b) are arranged at least at the ends of corrugating rolls (4, 6) connected end to end. End gears may or may not be adjacent and may be provided at both ends of the corrugation roll to facilitate end-to-end connection.

Description

Improved processing method and equipment for corrugated board

The present invention relates to an improved method and apparatus for forming a paperboard structure in which two pieces of corrugated material are joined at their corrugated groove ends. The above construction is disclosed in Australian Patent No. 567833, which is hereby incorporated by reference.

Australian Patent No. 609089 (11926/88) also discloses an apparatus for forming such corrugated paperboard. In addition, there are variations of the basic apparatus, such as the recently disclosed four-roll apparatus in Australian Patent No. 615,053, in which one of the corrugating rollers is used as a carrier roller to transfer the joined material Parts to the liner connection area, while in US Patent No. 4,935,082 a toothed belt is used instead of the carrying roller. The invention described and defined here is equally applicable to the variants of the basic apparatus described above in which the bellows ends must be connected.

One of the major difficulties in producing a paperboard structure in which two pieces of corrugated material are adequately joined at their corrugation groove ends is precisely aligning the top ends of the grooves of the pieces of corrugated material along the full width of the pieces of corrugated material. This problem arises from misalignment caused by pressure along the entire length of the bellows between the ends.

The present invention is based on the discovery that the problem of maintaining corrugation roll flute ends aligned results from the general lack of rigidity of the overall board making equipment. The lack of rigidity is considered to be mainly due to the lack of rigidity of its support frame and corrugating rolls and roll shafts during operation. Thus the corrugation rolls and frame movement results in misalignment of the corrugation groove ends of the rolls.

The prior art approach to the problem of aligning intermeshing corrugation rolls differs from the above described approach of maintaining alignment of the corrugation rolls in groove end contact. The problem of aligning intermeshing corrugation rolls to adjust the inter-trough spacing is discussed in US Patent No. 4,196,046, which represents the aforementioned prior art. This patent shows the use of a pair of intermeshing helical gears with an axial adjuster connectable to one of the teeth to adjust the spacing between intermeshing corrugation roll grooves. Due to the ability to adjust the spacing of the meshing rollers, mechanical wear and cardboard breakage due to increased spacing can be reduced.

It is an object of the present invention to improve upon and overcome some of the problems of the apparatus disclosed in AU609089 and previously discussed AU615,053 and US4,935,082 of similar construction to provide improved corrugated fiberboard Processing methods and equipment. Therefore, the product quality and production efficiency of the cardboard are improved.

The invention provides an improved construction of the basic device and the above-mentioned device as a modification thereof.

Accordingly, the present invention provides an improved converting apparatus capable of forming a corrugated board having two fluted corrugated sheets interconnected at the flute ends, comprising at least two pairs of synchronized corrugating rolls so that the two fluted corrugated sheets can be orientated The grooved end is accurately connected with the grooved end, wherein, there are end gears matched with the corrugation rollers, which are arranged to align the grooved ends of each roller, so that the grooved corrugated plates are connected end to end accurately.

In particular, the corrugating rollers are provided with end gears for assisting in the docking of flute end to flute end and moving the corrugated pieces of material together for the end-to-end connection described above.

Preferably, a set of end gears are mounted on respective ends of said corrugating rolls.

The provision of cooperating end gears helps to maintain equal surface speeds at the connected flute ends, thus allowing precise alignment of the corrugating rolls relative to each other. In this way, alignment of the corresponding corrugated sheet flute ends is achieved, which is critical to obtain consistently enhanced board properties and minimize the weight of the material piece and liner. Australian Patent No. 567,833 describes the advantages of providing a paperboard structure of this type.

End gears are preferably, but not necessarily, mounted at the respective ends of each pair of central corrugating rolls and comprise a full face gear and a split face gear for gap adjustment.

Clearly, the prior art devices do not discuss or even address the use of end gears in connection with joining pieces of corrugated material together at their grooved ends where they should be aligned and joined. The prior art deals only with the actual corrugated product production process and engaging corrugating rolls.

The end gears are preferably contiguous end gears and are preferably mounted a short distance from the grooved surface of each corrugation roll to help reduce roll twist. The use of adjacent end gears ensures that conventional vacuum corrugation rolls with standard sized journals can be used and the torsional deflection that typically occurs is minimized. By installing adjacent end gears at both ends of the corrugation roller, the overall rigidity of the equipment is further enhanced, and the torsion of the roller shaft can be minimized.

The end gears may also be non-adjacent end gears. Or can be installed outside the vacuum collector, or outside the equipment rack. Non-contiguous gears can be used when the corrugation roll has a large journal and thus has the ability to resist the strong torsional stress caused by the point-to-point pressure generated during the connection of the corrugation groove groove end to groove end.

End gears are best ground precisely for precise meshing.

The end gears can be spur gears or helical gears.

Gears can be split. If there are gears at each end then they are best spliced at each end. The split gears can then mesh with gears with larger face widths on other corrugation rolls. This arrangement helps eliminate backlash and transmits at least 50% of the applied torque, thereby further preventing twisting of the corrugation roll and roll shaft.

When a helical gear is used as an adjacent end gear and the helical gear is axially adjusted, a spacer is required between the corrugation roller and the end face of the helical gear.

If helical gears are mounted on both ends of the roller, the helix on each gear can be reversed to ensure that the thrust forces cancel each other out. If the helical gear is mounted at only one end, additional thrust bearing capacity is required to resist the axial thrust generated by the helical gear and to prevent twisting of the corrugating roll and roll shaft resulting from end-to-end alignment.

The present invention also provides an improved process for forming a corrugated laminate having two fluted corrugated sheets interconnected at the ends of the corrugations, wherein the two fluted corrugated sheets are aligned by synchronously moving corrugating rollers to reach the corrugation grooves end to end of the corrugation groove, and the corrugation roller also has a mating end gear.

A preferred embodiment of the present invention is described below with reference to the accompanying drawings.

Figure 1 shows a schematic diagram of an assembly of the type disclosed in Australian Patent No. 609089.

Figure 2 is a cross-sectional view of a corrugation roll adjacent to an end gear.

Figure 1 illustrates an assembly of the type disclosed in Australian Patent No. 609089. The pieces of corrugated material 1 and 2 are held on roll stands (not shown) and are conveyed, typically through a preheater (not shown), to pairs of corrugating rolls 3 and 4 and 5 and 6 ( Labels 3 and 5). The material parts 1 and 2 are corrugated and adhesive is applied to at least one surface of the material part 1 or 2 by means of a bonding station 7 . As the pieces of corrugated material 1 and 2 are brought together by rollers 4 and 6, they are joined together end-to-end groove-to-groove. The two joined pieces of corrugated material are fed onto carrier rolls 12 and after being glued at the groove ends, are transported to the bonding area. The liner 9 and the end of the corrugated groove are brought into contact and heated by a heater 11 at the bonding area. Carrier rolls 12 then convey the composite liner and material piece to an area where the product is loaded onto an inclined conveyor 14 for delivery to the corrugating machine cranes.

Depending on the modification of the basic equipment, it can be seen that the carrying roller 12 can be replaced by a toothed belt.

Figure 2 illustrates an embodiment of the invention wherein the end gears 15A and 15B, 16A and 16B are mounted on corrugating rollers 4 and 6 of the assembly which align and connect pieces of corrugated material on a groove-to-groove-end basis. This embodiment illustrates the use of split spur gears 15A, 15B, 16A, 16B adjacent corrugating rolls 4 and 6 . It should be pointed out that in order to maximize the rigidity of the equipment and minimize the torsion of the aligned corrugation rolls, end gears must be installed at the end of each aligned corrugation roll. The end gears 15A, 15B, 16A and 16B are housed in the space between the vacuum collector 17 and the corrugating rollers 6 and 4 in this example. It should be noted that if the corrugated rollers are not allowed to wear repeatedly, space for relative axial movement between the four corrugated rollers may be allowed. Vacuum collector 17 and its passage to corrugation rolls 4 and 6 may pass through end gears 15A, 15B, 16A and 16B to communicate with corrugation rolls 6 and 4 . The vacuum collector 17 is spring loaded by spring means 19 to ensure a firm and resilient contact connection between the end gears ( 15A, 15B, 16A and 16B) and the vacuum collector 17 .

The end gear does not always have to be adjacent to the corrugation roll, depending on the diameter of the corrugation roll with the larger diameter shaft. In larger diameter rolls, large diameter rolls are used when greater groove height and smaller groove spacing are required. In this case, the end gears do not have to be adjacent to the corrugation rollers, and can even be mounted outside the main casing. In addition, since the larger rolls are available, it is possible to separate the end gears from the corrugation rolls when a different kind of finger is used instead of vacuum to hold and carry the cardboard on the corrugation rolls.

In order to produce a particular corrugation flute, as disclosed in Australian Patent No. 567833, the diameter of the corrugation rolls and shafts should be limited so as to form the desired flute spacing and depth. In these instances, it is necessary to abut the end gears in order to achieve maximum rigidity of the device.

Furthermore, extending the surface width of the split spur gear 16A helps to eliminate backlash and ensure the transmission of acting torque. In general, the face width of the end gear is governed by the required braking torque, which is usually at least 3 times the resulting driving torque. End gears 16A and 16B are driven by cooperation with end gears 15A and 15B, and in turn drive roller 12 via a ring gear connected to carrier roller 12 . Likewise, if a toothed belt is used, the end gears also drive the belt.

The end gears 15A, 15B and 16A, 16B may be mounted on the rotational shafts of the corrugating rollers 4 and 6 by any locking means, such as multi-stage locking bushes 21 . The only time a locking mechanism is required is when the gears are held precisely in place, transmitting high circular forces without circular motion.

Set screws 20 are used to fix the split gears 15A and 15B to each other and can be used for mutual adjustment between the gears to reduce backlash. Likewise, set screw 20 can also be used to split gears 16A and 16B. Depending on the proximity to the corrugating rollers, the end gears 15A, 15B, 16A and 16B may have a shroud (not shown) to cover the cardboard being processed and prevent the board from becoming entangled in the rotating end gears.

It should be noted that while end gears must be used at least in corrugation rolls which are directly involved in corrugation groove end-to-groove end-to-end processing, end gears can also be used in other rolls such as load rolls, toothed belts and other mechanisms.

The frame 18 may also be reinforced or modified to increase the rigidity of the frame and thereby achieve greater rigidity of the equipment.

The above-mentioned improvements to existing equipment help to produce better cardboard products and increase the efficiency of cardboard production, resulting in reduced mechanical wear and raw material usage.

Claims (8)

1. An improved processing apparatus capable of forming a corrugated board having two fluted corrugated sheets interconnected at the flute ends, comprising at least two pairs of synchronized corrugating rolls so that the two fluted corrugated sheets can be oriented into fluted ends and Accurate groove end connection, characterized in that there are end teeth cooperating with the corrugation rollers, which are arranged to align the groove ends of each roller, so that the grooved corrugated boards are accurately connected end to end. 2. The apparatus of claim 1 wherein the surface speeds of the groove ends of each pair of corrugating rollers are equal. 3. The apparatus of claim 1, wherein a set of end gears are provided at respective ends of the corrugating rolls. 4. The apparatus of claim 1, wherein the end gear is an adjoining end gear. 5. The apparatus of claim 1, wherein the end gears are spur gears or split gears. 6. The apparatus of claim 1 wherein at least one end gear is split. 7. Apparatus as claimed in claim 6 wherein the split end gear cooperates with a gear having a wider surface to help eliminate backlash. 8. An improved process for forming a corrugated board having two fluted corrugated sheets interconnected at the flute ends, wherein the two fluted corrugated sheets are aligned by synchronously moving corrugating rollers to achieve flute end to corrugation The connection of the groove end is characterized in that the corrugated roller also has a matching end gear.

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