APPLYING A COATING TO ONE FACE OF A SELECTED FIRST SUB-GROUP OF PARALLEL STRIPS

TECHNICAL FIELD

The present invention relates to a method of applying a coating to one face of a selected first sub-group of parallel strips, the selected first sub-group of parallel strips comprising at least two parallel strips and being selected from a plurality of parallel strips advanced in a side by side relationship from a first support member to a second support member, at least two strips of said plurality of parallel strips not belonging to said selected first sub-group of parallel strips forming a second sub-group of parallel strips. It also applies to a selective strip coating apparatus for applying a coating to one face of a selected first sub-group of parallel strips, the selected first sub-group of parallel strips comprising at least two parallel strips and being selected from a plurality of parallel strips advanced in a side by side relationship from a first support member to a second support member, at least two strips of said plurality of parallel strips not belonging to said selected first sub-group of parallel strips forming a second sub-group of parallel strips.

Further, it also relates to a rod manufacturing apparatus, which comprises the selective strip coating apparatus.

BACKGROUND ART

In furniture manufacturing, for example, low weight elements are widely used. Such elements usually consist of a hollow body having two parallel large sheets spaced apart by a lightweight filling material. One suitable lightweight filling material is formed by strips of a wooden material, preferably a material selected among High Density

Fiberboard (HDF) and Medium Density Fiberboard (MDF). The strips extend width- wise between the two sheets of the hollow body and the edges of the strips are glued to the two sheets. To give the low weight elements sufficient stability, the lightweight filling material includes wooden rods attached by gluing to the side edges of the two sheets to interconnect the two sheets to each other. Such low weight elements can be used as building elements, door panels, and a large amount of furniture elements. Consequently, a plurality of manufacturing methods for such low weight elements have been presented. A method of continuous manufacture of a composite hollow board material comprising a first surface and a second surface, and between the first and second surfaces a plurality of distance members is disclosed in US 8,999,094 (Pettersson et al.). The method comprises providing material for the first surface from a first reel via a first guide roller towards an output lane; providing material for the second surface from a second reel via a second guide roller towards the output lane; and providing material for the distance members from a third reel towards the output lane such that the distance members comprises strips arranged, at any cross section perpendicular to the first and second surfaces and the direction of the output lane, perpendicular to the first and second surfaces and continuous along the output lane. The providing of material for the distance members comprises guiding at least some of the strips in a meandering pattern, and applying an adhesive to contact the strips on opposite edges thereof such that adhesion to the material of the first and second surfaces is enabled. The first and second guide rollers press the material of the first and second surfaces to the opposite edges of the strips, respectively, such that the material of the first and second surfaces are adhered to the strips. A machine for continuous manufacture of the composite hollow board material, and a computer program for controlling a machine for continuous manufacture of the composite hollow board material are also disclosed.

In the '094 document it is also disclosed that a plurality of strips may be joined by adhesive to form a lath or rod to be used as a distance member in the composite hollow board material. The part for preparing the lath or rod can include a cutting mechanism for cutting a sheet material into a plurality of strips. The preparation part comprises a guide mechanism for assembling the strips to run in parallel towards the output lane. An adhesive application mechanism applies adhesive such that the parallel strips can be adhered to each other. The preparation part also comprises a press mechanism such that the sandwiched parallel strips, after application of the adhesive, are pressed together and thus adhered to each other such that the lath or rod is achieved.

From FR2077902 and US 5141582 there are known two different methods presenting a general kind of prior art related to forming a single piece of a panel assembly of desired curvature by means of gluing and pressing. SUMMARY OF THE INVENTION

The object of the present invention is to provide cost efficient and flexible joining of strips to form distance elements of different dimensions, such as rods or laths to be used in low weight building elements for furniture.

In the method according to the invention, this object is achieved in that the method comprises:

- advancing a selected first sub-group of parallel strips along a first path between the first and second support members, said first path extending from a first point, being located adjacent to the first support member and at a first distance from a

longitudinal axis of the first support member, to a second point, being located adjacent to the second support member;

- simultaneously therewith advancing a second sub-group of parallel strips along a second path between the first and second support members, said second path extending from a third point, being located adjacent to the first support member and at a second distance from said longitudinal axis of the first support member, said second distance being shorter than said first distance, to a fourth point adjacent to the second support member; and

- applying the coating by means of a coating device being in coating contact with the selected first sub-group of parallel strips passing the first support member at the first distance to coat one side of the strips of the selected first sub-group of parallel strips, while the strips of the second sub-group of parallel strips simultaneously passing the first support member at the second distance being out of reach of the coating device and remaining uncoated.

Hereby, only the strips that are desired to coat may be coated on one side only, and a basis for providing a cost efficient and flexible joining of strips is provided.

Preferably, the method further comprises arranging the plurality of parallel strips in a pattern of strip-groups, where each strip-group contains at least one, and more preferably at least two, neighboring strip(s) from the selected first sub-group of parallel strips to be coated and at least one strip from the second sub-group of parallel strips to remain uncoated. Thereby, only one side of the strips, which are to be piled on one another to form a sandwiched cluster in the shape of a rod or lath, has to be coated, with the exception of the "last" strip that is uncoated in each cluster.

Alternatively or additionally the method further comprises: - providing said first support member in the form of a support bar having a plurality of ridge surfaces located at the first distance from the longitudinal axis of the first support member and a plurality of grooves arranged between the ridge surfaces and located at the second distance from the longitudinal axis of the first support member;

- forwarding each one of the strips of the selected first sub-group of parallel strips on a respective one of the ridge surfaces to be in contact with the coating device to coat a face of the strips of the first sub-group of parallel strips; and

- forwarding each one of the strips of the second sub-group of parallel strips in one of the grooves to remain out of reach of the coating device.

By using a support bar having a plurality of ridge surfaces and a plurality of grooves between the ridge surfaces, a cost efficient and flexible gluing together of strips to form distance elements of different dimensions can be achieved.

To glue the strips together to form the desired cluster, the coating that is applied to the selected first sub-group of parallel strips suitably is an adhesive type of coating.

Suitably the strips are made from a wooden material, preferably a material selected among High Density Fiberboard (HDF) and Medium Density Fiberboard (MDF). Such fiberboard is eco-friendly and may be used also for the other distance elements and the covering sheets of the low weight building element, which contributes to the cost efficiency of the method of the present invention. Preferably, the plurality of parallel strips are, downstream of the first support member, arranged in clusters, each such cluster comprising at least two, more preferably at least three, strips, the strips of each such cluster being pressed together to form a rod having a sandwiched structure. Thereby, it is easy to modify the method to cost efficiently produce rods or laths of different dimensions.

Preferably, each cluster comprises at least one, more preferably two to twenty, and most preferably two to eight, strip(s) of the selected first sub-group of parallel strips and exactly one strip of the second sub-group of parallel strips. An advantage of this embodiment is that a lath or rod can be manufactured with good mechanical properties and with a low consumption of adhesive. In the selective strip coating apparatus stated in the second paragraph above, the object of the invention is achieved in that the selective strip coating apparatus comprises: - a support bar forming the first support member and having a longitudinal axis and a plurality of ridge surfaces located at a first distance from the axis of the support bar and adapted for carrying strips of the selected first sub-group of parallel strips, and a plurality of grooves arranged adjacent the ridge surfaces and located at a second distance from the axis of the support bar, said second distance being shorter than said first distance and adapted for housing strips of the second sub-group of parallel strips; and

- a coating device positioned to be in operative contact with the strips of the selected first sub-group of strips carried by the respective ridge surfaces of the support bar, while the strips of the second sub-group of strips will be carried in the grooves and out of reach of the coating device and remain uncoated. Hereby, only the strips that are desired to coat are coated, and a basis for a providing a cost efficient and flexible joining of strips is provided.

Suitably, the support bar has the form of a support roll. Preferably, the support roll is a rotary support roll adapted to rotate around its central axis as the first sub-group of strips are carried by the respective ridge surfaces, and the ridge surfaces and the grooves extend circumferentially around the rotary support roll. The substitution of a rotary support roll for the support bar makes the apparatus less sensitive to functional trouble.

To make the strips adhere reliably to one another when piled to form a sandwiched cluster, the coating device suitably is an adhesive coating device.

The grooves in the support bar suitably are arranged in such a way that the ridge surfaces between two adjacent grooves will receive a plurality of the strips of the selected first sub-group of parallel strips to be coated.

The grooves and the ridge surfaces are preferably arranged in such a way that they form a pattern of strip-groups, where each strip-group will receive at least one strip of the first sub-group to be coated and at least one strip of the second sub-group that is to remain uncoated. Thereby, only one side of the strips, which are to be piled on one another to form a sandwiched cluster in the shape of a rod or lath, has to be coated, with the exception of the "last" strip of each cluster.

Then, each strip-group is suitably adapted to receive from two to twenty, more preferably two to eight, strips of the first sub-group to be coated and at least one, and more preferably exactly one, strip of the second sub-group that is to remain uncoated. Clusters of three to twenty-one, more preferably three to nine, strips include most of the desired rod widths. A cluster of more than twenty-one, or nine, strips would consume a relatively high amount of coating, such as an adhesive, to adhere the strips to each other, which would make the solution less environmentally friendly.

Suitably, the apparatus is provided with at least two separate support bars, each of said at least two separate support bars having its own unique arrangement of ridge surfaces and grooves, the apparatus having a selection arrangement for bringing one of said at least two separate support bars at a time into position for functioning as the first support member. Thereby, the apparatus can be adjusted, in an efficient manner, from producing rods having one combination of width and height of the rods to produce rods having another combination of width and height of the rods. To make the change easily and quickly, the selection arrangement preferably comprises a rotary magazine holding a plurality of parallel support bars, the magazine being a rotary device having a central axis of rotation parallel to central axes of the individual support bars, wherein each support bar has a unique arrangement of ridge surfaces and grooves.

In a most preferred embodiment, the magazine resembles a revolver magazine and holds at least three parallel and rotary support rolls, each of which has a unique arrangement of ridge surfaces and grooves. In the rod manufacturing apparatus stated in the third paragraph above and comprising the selective strip coating apparatus, the object of the invention is achieved in that the rod manufacturing apparatus further comprises a rod pressing arrangement located downstream of the selective strip coating apparatus and adapted for pressing clusters of strips together to form sandwiched rod structures. By pressing the clusters of strips together to form sandwiched rod structures the joining of the strips is finished and a cost efficient and flexible joining of strips is provided. A further basis for the cost efficient and flexible joining of strips is provided if the rod manufacturing apparatus further comprises a strip cutting device that is located upstream of the support bar and is adapted for cutting the plurality of parallel strips from a web-shaped board material.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be described in more detail with reference to preferred embodiments and the appended drawings. Fig. 1 is a schematic side view, partly in section, of a selective strip coating apparatus according to a preferred embodiment of the present invention and comprising a rotary magazine including three parallel support bars for supporting the strips.

Fig. 2 is a schematic side view, partly in section, of the selective strip coating

apparatus of Fig. 1 including a more detailed coater and also showing that the strips after coating are twisted a quarter of a turn.

Fig. 3 is an enlarged portion of Fig. 1 and shows cross-sectional view of a strip

supporting bar of Fig. 1 in the shape of a rotary roll having circumferential ridges and grooves.

Fig. 4 is an isometric view of the rotary magazine including three rotary support rolls having circumferential ridges and grooves and a drive for rotation. Fig. 5 is an isometric view of part of a drive end of the rotary magazine while the ridges of one roll lift some of the strips up to contact with a coating roll and other strips remain in the grooves out of contact with the coating roll.

Fig. 6 is an isometric view of the selective strip coating apparatus of Fig. 2.

Fig. 7 is an isometric view from another direction of the selective strip coating

apparatus of Fig. 2, and

Fig 8 is an isometric view showing the selective strip coating apparatus of Fig. 7 supplemented with a pressing arrangement for pressing clusters of strips together to form sandwiched rod structures. MODE(S) FOR CARRYING OUT THE INVENTION

Fig. 1 shows schematically a selective strip coating apparatus according to a preferred embodiment of the present invention and comprising a first support member 20 and a second support member 31 located downstream of the first support member 20. Further, the strip coating apparatus includes a coater 4 for applying a coating to one face of a selected first sub-group 100 of parallel strips 10 when the selected sub group is supported by the first support member 20. The selected first sub-group 100 comprises at least two parallel strips 10 and is selected from a plurality of parallel strips 10, 11 advanced in a side by side relationship from the first support member 20 to the second support member 31. At least two strips 11 of said plurality of parallel strips 10, 11 not belonging to said selected first sub-group 100 of parallel strips 10 forming a second sub-group 110 of parallel strips 11. To apply a coating to the parallel strips 10 of the selected first sub-group 100, they are advanced along a first path between the first 20 and second 31 support members. The first path extends from a first point 200, being located adjacent to the first support member 20 and at a first distance R (shown in Fig. 3) from a longitudinal axis LA of the first support member 20, to a second point 310, being located adjacent to the second support member 31. Simultaneously therewith the second sub-group 110 of parallel strips 11 is advanced along a second path between the first 20 and second 31 support members. The second path extends from a third point 201, that is located adjacent to the first support member 20 and at a second distance r (shown in Fig. 3) from said longitudinal axis LA of the first support member 20, said second distance r being shorter than said first distance R, to a fourth point 311 adjacent to the second support member 31. The fourth point 311 is located slightly upstream of the second point 310, but from a practical technical perspective the second and fourth points 310, 311 could more or less coincide. The coating is applied by means of a coating device 4, which in Fig. 1 is represented by a coating roll 40 included in the coating device 4. The coating device 4 is in coating contact with the selected first sub-group 100 of parallel strips 10 passing the first support member 20 at the first distance R to coat one side of the strips 10 of the selected first sub-group 100 of parallel strips 10, 11, while the strips 11 of the second sub-group 110 of parallel strips that simultaneously pass the first support member 20 at the second distance r are out of reach of the coating device 4 and remain uncoated. In the embodiment shown in Fig. 1, an additional support member 30 for the strips 10, 11 is provided upstream of the first support member 31. The additional support member 30 forms part of a strip cutting device 32 which additionally comprises first and second cutting arrangements 33, 34 that use the support member 30 as an anvil and cuts the strips 10, 11 from a material web WB, for example a web of High Density Fiberboard (FIDF) or Medium Density Fiberboard (MDF). The horizontal positions of the first and second cutting arrangements 33, 34 could be adjusted to obtain different widths of the strips 10, 11 formed by the cutting. The width of the strips 10, 11 as formed in the strip cutting device 32 will correspond to the height of the rods or laths formed downstream of the second support member 31, as described in more detail hereinafter.

All three support members, 30, 20, and 31 may be support bars, but preferably they are rotary rolls, and more preferred powered rotary rolls that assist in pulling/forwarding some strips 10, 11. As will be described hereinafter, the first support member 20 could be varied, and there may be, e.g., two alternative rolls 21, 22, and in this connection it may be beneficial to use a combined motor and transmission for all rolls 20, 21, 22, to have them jointly driven, which eliminates any need of start-up time and simplifies the design. The strips 10, 11 run under tension from support member 30 to support member 20 and further to support member 31. At support member 20, the group 100 of strips 10 to be coated is lifted a distance of R - r above the level of group 110 of strips 11 that are not to be coated.

Suitably, the first support member 20 is provided in the form of a support bar having a longitudinal axis LA and a plurality of ridge surfaces 203 located at the first distance R from the longitudinal axis LA of the first support member 20 and a plurality of grooves 204 arranged between the ridge surfaces 203 and located at the second distance r from the longitudinal axis LA of the first support member 20, as is best shown in Fig. 3. Further, each one of the strips 10 of the selected first sub-group 100 of parallel strips is forwarded on a respective one of the ridge surfaces 203 to be in contact with the coating device 4 to coat a face of the strips 10 of the first sub-group 100 of parallel strips, and each one of the strips 11 of the second sub-group 110 of parallel strips is forwarded in one of the grooves 204 to remain out of reach of the coating device 4. By using a support bar 20 having a plurality of ridge surfaces 203 and a plurality of grooves 204 between the ridge surfaces, a cost efficient and flexible gluing together of strips 10, 11 to form distance elements of different dimensions can be achieved. As is best shown in Fig. 5, the plurality of parallel strips 10. 11 preferably is arranged in a pattern of strip-groups 120, where each strip-group 120 contains at least one, and preferably at least two neighboring strips 10 from the selected first sub-group 100 of parallel strips to be coated and at least one strip 11 from the second sub-group 110 of parallel strips to remain uncoated. Thereby, only one side of the strips 10 which are to be piled on one another to form sandwiched clusters 121 and 12 Γ (Figs. 6 and 7) in the shape of rods or laths, has to be coated, with the exception of the "last" strip 11 that is uncoated in each cluster 121 and 12 . As best seen in Figs 6 and 7 and especially the enlarged end view in Fig. 7, between groups of clusters 121, 12 forming laths or rods, there may be positioned a plurality of single strips 11 (unglued), which will serve as spacers/reinforcements in the low weight building element (e.g. a side wall of a book case or a table top) being produced. Hence, these single strips 11 are not to be included in a lath/rod. These single-strips 11 pass the coating device 4 unglued. Thereby it is possible to have all the strips 10 of the laths or rods 121, 121 ' and also all uncoated strips 11, both those strips 11 forming parts of a lath/rod, and those strips 11 intended to be single spacers/reinforcements, in the right order from the start of the process, all the way from the cutting of strips 10, 11 from the web material WB at the strip cutting device 32 to the fixing of all parts of the low weight building element, downstream of the second support member 31. Hence, in a preferred process not only the last strip in a lath/rod passes unglued, but also single-strips pass unglued, to avoid difficult sorting exercises, which otherwise may be needed.

Thus, downstream of the first support member 20, the plurality of parallel strips 10, 11 is arranged in clusters 121 and 12Γ, where each such cluster 121 and 12Γ comprises at least two strips 10, 11. The strips of each such cluster 121, 12 are being pressed together (see figure 8) by means of a rod pressing arrangement 6 to form respective rods, each such rod having a sandwiched structure comprising strips 10 and 11.

To achieve a reliable bonding of the layers in the sandwiched cluster 121 to each other, the coating that is applied to the selected first sub-group 100 of parallel strips 10 by means of the coating device 4 preferably is an adhesive type of coating.

The strips 10, 11 suitably are made from a wooden material, preferably a material selected among High Density Fiberboard (HDF) and Medium Density Fiberboard (MDF) and may be of a thickness of about 1 to 5 mm, more often about 2 to 3 mm, and cut, by means of the strip cutting device 32, to a constant width in the range of about 7- 30 mm, preferably about 10-25 mm. As described above, the apparatus for applying a coating to one face of a selected first sub-group 100 of parallel strips 10 comprises a support bar forming the first support member 20. The support bar 20 has a longitudinal axis LA and a plurality of ridge surfaces 203 located at a first distance R (shown in Fig. 3) from the axis of the support bar 20 and adapted for carrying strips 10 of the selected first sub-group 100 of parallel strips, and a plurality of grooves 204 arranged adjacent the ridge surfaces 203 and located at a second distance r (shown in Fig. 3) from the axis of the support bar 20. The second distance r is shorter than the first distance R and adapted for housing strips of the second sub-group 110 of parallel strips 11. Further, the apparatus comprises a coating device 4 positioned to be in operative contact with the strips 10 of the selected first sub-group 100 of strips carried by the respective ridge surfaces 203 of the support bar 20, while the strips 11 of the second sub-group 110 of strips will be carried in the grooves 204 and out of reach of the coating device 4 and remain uncoated.

As is best shown in Fig. 5, the support bar suitably has the form of a support roll 20, and the support roll preferably is a rotary support roll 20 adapted to rotate around its central axis LA, see Fig. 3, as the strips 10 of the first sub-group 100 are carried by the respective ridge surfaces 203. The ridge surfaces 203 and the grooves 204 extend circumferentially around the rotary support roll 20, as best illustrated in Fig. 5.

Preferably, the rotary support roll 20 comprises a tubular shaft base 23' and a plurality of flange-like rings or discs 205 of outer radius R that are mounted on the shaft base 23' and have peripheral surfaces forming said ridge surfaces 203. If the discs 205 are axially fixed on the shaft base 23', the bottom the grooves 204 may be formed by the peripheral surface of the shaft base 23', if desired, but preferably a plurality of flange-like rings or discs 206 of outer radius r are mounted on the shaft base 23' and have peripheral surfaces forming the bottom surfaces of the grooves 204. The flange-like rings or discs 205 and 206 are pressed axially against one another by means of screws (not shown) at least one end of the shaft base 23 ' .

The coating device 4 preferably is an adhesive coating device having a reservoir 41 as shown in Figs. 2 and 6-8 for the adhesive, and the reservoir 41 has a bottom slot, in which a rotary coating roll 40 is mounted for transferring the adhesive from the reservoir 41 to the strips 10. The rotary coating roll 40 has a comparatively small diameter and may suitably have various structures on its peripheral surface. The roll 40 forms a bottom of the adhesive coating device 4, and a first doctor (not shown) makes sure that the downwards facing surface of the roll 40 carries an adhesive layer of desired thickness. Where the roll 40 touches the strips 10, the adhesive is being transferred to the strips 10. Adhesive remaining on the roll 40 is returned to the reservoir 41 past a second doctor (not shown), which may be set with a different gap toward the roll 40 than the first doctor, to supply a desired amount of adhesive as is known per se. Also the rotational speed of the roll 40 may be adjusted to increase or reduce the amount of adhesive, and more or less deep structural patterns in the peripheral surface of the roll 40 may be used to supply the desired amount of adhesive. This method of applying the adhesive is very well suited for this application, where strips 11 not to be coated are located at different locations along the roll 40.

The grooves 204 in the support bar or roll 20 suitably are arranged in such a way that the ridge surfaces 203 between two adjacent grooves 204 will receive at least one, and preferably two to twenty, more preferably two to eight, of the strips 10 of the selected first sub-group 100 of parallel strips to be coated. Further, as is best shown in Figs. 4-6, the grooves 204 and the ridge surfaces 203 are preferably arranged in such a way that they form a pattern of strip receiving ring or disc groups 207 corresponding to the strip- groups 120, where each strip receiving ring or disc group 207 will receive at least one strip 10 of the first sub-group 100 to be coated and at least one strip 11 of the second sub-group 110 that is to remain uncoated. Thereby, only one side of the strip(s) 10, which are to be piled on one another to form a sandwiched cluster 121 (Fig. 7) in the shape of a rod or lath, has to be coated, with the exception of the "last" strip 11 of each cluster 121. As shown in Figs. 2, and 6-8, after leaving the second support member 31, the strips 10 and 11 are rotated a quarter of a turn around their longitudinal axis, so that their width direction is changed from horizontal to vertical. Thus the coated side of each strip 10 in the strip group 120 now faces the uncoated side of an adjacent strip 10, with the exception that the coated side of the last strip 10 faces the uncoated strip 11.

Equipment for rotating the strips a quarter of a full turn are previously known and constitute no part of the present specification. Each strip receiving ring or disc group 207 is suitably adapted to receive at least one, more preferably from two to twenty, even more preferably two to eight, strips 10 of the first sub-group 100 to be coated and at least one, more preferably exactly one, strip 11 of the second sub-group 110 that is to remain uncoated. Clusters 121 of three to twenty- one, more preferably three to nine, strips include most of the desired rod widths.

Suitably, the apparatus is provided with at least two separate support bars or rolls 20, 21, 22 each of said at least two separate support bars or rolls 20, 21, 22 having its own unique arrangement of ridge surfaces 203 and grooves 204, and the apparatus has a selection arrangement 2, as illustrated in Fig. 4, for bringing one of said at least two separate support bars or rolls 20, 21, 22 at a time into position for functioning as the first support member 20. Thereby, the apparatus can, as an example, be changed from producing a first type of rods or laths having one combination of width and height, e.g. using the roll 20 to form first type of rods being formed from eight strips 10, 11, each having a strip thickness of 2 mm and a strip width of 12 mm, the rod formed thereby having a rod width of 8 x 2 mm =16 mm and a rod height of 12 mm to produce a second type of rods of another combination of width and height, e.g. using the roll 21 to form second type of rods being formed from 5 strips 10, 11, each having a strip thickness of 2.5 mm and a strip width of 15 mm, the rod formed thereby having a rod width of 5 x 2.5 mm =12.5 mm and a rod height of 15 mm.

To make the change easily and quickly, the selection arrangement preferably comprises a rotary magazine 2 holding a plurality of parallel support bars or rolls 20, 21, 22, the magazine 2 being a rotary device having a central axis RCA of rotation parallel to central axes of the individual support bars or rolls, and each support bar or roll 20, 21, 22 suitably has a unique arrangement of ridge surfaces 203 and grooves 204. In a most preferred embodiment shown in the drawings, the magazine 2 resembles a revolver "magazine" (i.e. a handgun revolving cylinder containing multiple chambers for rounds) and holds at least three parallel and rotary support rolls 20, 21, 22 each of which has a unique arrangement of ridge surfaces 203 and grooves 204.

As is best shown in Fig. 4, the magazine 2 has a central tubular shaft 23 and at a driven end of the shaft 23 a flange arrangement including two spaced apart large flanges 230, 231 for supporting one end of each of the support rolls 20, 21, 22 and at the other end of the shaft 23 a smaller flange 235 having an adjustable lug 232 for each one of the opposite ends of the three support rolls 20, 21, 22. A drive 26 is provided for rotating the magazine 2. The drive 26 includes a motor 260 driving a transmission 261 connected to the central tubular shaft 23 for rotating it. The transmission 261 may be a planetary gearing to give a desired reduction of the speed of the motor 260. Similarly, a drive 25 is provided for rotating the support rolls 20, 21, 22. The drive 25 includes a motor 250 driving a transmission 251 connected to all of the three support rolls 20, 21, 22 for rotating them. The transmission 251 includes a common central ring gear mounted in bearings on the central tubular shaft 23, a gear that is carried by an output shaft of the motor 250, the proximate end of each one of the support rolls 20, 21, 22 includes a gear, and toothed belts transmits the rotation of the gear on the motor 250 to the common central ring gear and from there to the gears of the support rolls 20, 21, 22. The two ends of the central tubular shaft 23 is mounted in bearings carried by a stand 27, and the belts and gears of transmission 251 are located between the stand 27 and the outer flange 230.

The selective strip coating apparatus preferably is included in a rod manufacturing apparatus in that a rod pressing arrangement 5 is located downstream of the selective strip coating apparatus and adapted for pressing said clusters 121 of strips 10, 11 together to form sandwiched rod structures. By pressing the clusters 121 of strips 10, 11 together to form sandwiched rod structures, the joining of the strips 10, 11 is finished and a cost efficient and flexible joining of strips is provided.

A further basis for the cost efficient and flexible joining of strips 10, 11 is provided if the rod manufacturing apparatus further comprises the strip cutting device 32 that is located upstream of the selective strip coating apparatus and adapted for cutting the plurality of parallel strips 10, 11 from the web-shaped board material WB. Equipment for such cutting is previously known and requires no detailed description in the present specification. INDUSTRIAL APPLICABILITY

The present invention is applicable for producing distance elements of different dimensions, such as rods or laths to be used in low weight building elements for furniture.