EP3010690B1

EP3010690B1 - Apparatus for producing an underfloor fibreboard turn element for underfloor heating

Info

Publication number: EP3010690B1
Application number: EP14814229.2A
Authority: EP
Inventors: Arne JEBSEN; Per VINGER
Original assignee: Hunton Fiber As
Current assignee: Hunton Fiber As
Priority date: 2013-06-18
Filing date: 2014-06-17
Publication date: 2018-08-01
Anticipated expiration: 2034-06-17
Also published as: DK3010690T3; EP3010690A1; PL3010690T3; NO336434B1; LT3010690T; EP3010690A4; NO20130845A1; WO2014204318A1

Description

Field of the invention.

The present invention relates to an apparatus for manufacturing of low underfloor fibreboard elements for flooring, according to the preamble of claim 1. Such an apparatus is known from DE2456054A1 .

Background.

Flooring fibreboard elements adapted for underfloor heating typically are made of a low density wood fibre material and have one or more elongated grooves, recesses or notches in at least one surface, for accomodating an elongated heating element, such as an electrical heating cable or a pipe for heated water. The low density underfloor fibreboard element to which the present invention relates provides for good thermal insulation and has good sound proofing properties. Heated floors are built by laying out a number of underfloor fibreboard elements on a floor base of a room, with an unbroken surface of the fibreboards facing the floor base, and the other surface with open grooves or notches facing the room space, and in alignement with each other such that the grooves or notches of one board element are aligned with grooves or notches of one or more adjacently located board elements. With that arrangement, a heating element, such as e.g. a cable or a pipe, can conveniently be disposed in continuity across a room embedded within typically straight grooves or notches of the adjacently located underfloor fibreboards. The depth and width of the grooves or notches in a surface of the underfloor fibreboard element are typically dimensioned to match cross dimensions of the typically standardised heating cable or pipe, and underfloor fibreboard element thickness is designed dependent of thermal insulation charateristics of the fibreboard material to limit heat loss through the part of the underfloor fibreboard that is between the bottom of groove or notch and the underlying base floor to a design value. The floor is completed by overlaying the underfloor fibreboards with a harder type of flooring material, such as e.g a hardwood floor or a combination of higher density floorboards and tiles of wood, vinyl, or ceramic material.
For practical purposes, each elongated heating element is flexible to some degree an is provided with an end-to-end length that is several times the cross dimension of the room for which it is to be used in, and the heating element is disposed in the underfloor fibreboard in a meandering pattern, i.e. it is typically routed through a number of adjacently located underfloor fibreboards in a generally straight line of elongated grooves or nothes from a first side of the room to a second side, and after making a turn of typically 180 degrees close to the wall of the second side, it is routed back to the first side of the room in a generally straight line in a neighbouring line of elongated grooves or nothes in the underfloor fibreboards. The radius of the turn is limited, typically by the bending properties of the cable or a flexible pipe employed to provide heating of the floor, or by the design of the underfloor heating that dictates the spacing between neighbouring lines of heating cable or pipe. To obtain characteristics of the part of the underfloor in which the turn is made that correspond to characteristics of parts of the underfloor where the the cable or pipe is routed in straight lines across the room in straight grooves or nothes of the fibreboards, underfloor turn elements are provided, made of same type of fibreboard are provided with correspondingly dimensioned curved grooves or notches.
A known method for mass production of underfloor fibreboard turn elements for underfloor heating involves cutting grooves or notches in a fibreboard by marking or positioning a surface of fibreboard element according to a design of a shape and position of a turn groove or notch for the fibreboard element, and moving a groove or notch cutting router tool in a pattern on the surface of the fibreboard element in accordance with the marking or positioning.

Objects of the invention.

It is an object of the invention to provide an apparatus for producing an underfloor fibreboard turn element for underfloor heating that provides safe, efficient and economical mass production of underfloor fibreboard turn elements with predictable and uniform characteristics, and avoids one or more of the drawbacks of previously known apparatuses and methods for producing an underfloor fibreboard turn element for underfloor heating.

Summary of the invention.

The present invention provides apparatus for producing an underfloor fibreboard turn element for underfloor heating, the features of which apparatus is recited in the accompanying independent patent claim 1.
Features of embodiments of the apparatus of the invention are recited in the accompanying dependent patent claims 2 - 5.

Description of drawings.

In the accompanying drawings,

Figure 1 is a first perspective view drawing of an apparatus for producing an underfloor fibreboard turn element according to the invention;
Figure 2 is a second perspective view drawing of central elements of the apparatus illustrated in figure 1;
Figure 3 is a perspective view drawing showing details of central elements of the apparatus illustrated in figures 1 and 2;
Figure 4 is a top view drawing showing further details of central elements of the apparatus illustrated in figures 1, 2, and 3;
Figures 5a and 5b are perspective view drawings showing details of cutter means comprised in the cutter device apparatus illustrated in figure 4;
Figures 6a and 6b are perspective view drawings showing details of jack type moving means for moving the cutter means in comprised in the cutter davice illustrated in figures 2, 3, and 4;
Figure 7 is a perspective view drawing showing details of a carriage comprised in the the apparatus illustrated in figure 4;
Figure 8 is a perspective view drawing showing details of a board cutter comprised in the the apparatus illustrated in figures 1, 2, 3 and 4;
Figure 9 is a top view drawing showing further details of central elements of the means assemblies with axially cutting cutter wheel as illustrated in figures 5a and 5b; and
Figure 10a a top view drawing of the axially cutting cutter wheel comprised in the assemblies illustrated in figures 5a, 5b and 9;
Figure 10b is a photographic perspective view illustration of an embodiment of a cutter wheel comprised in the cutter wheel assemblies illustrated in figures 5a, 5b, and 9;
Figure 11 is a photographic perspective view illustration of an embodiment of a radially cutting cutter wheel comprised in the a board cutter illustrated in figure 8; and
Figures 12A and 12B are top wiev drawings of examples of a partly processed fibreboard turn element and a fully processed fibreboard turn element, respectively.

Deatailed description and embodiments.

In the following, the apparatus of the invention and method of operation will be described by way of examplary embodiments and with reference to the accompanying drawings.
Figure 1 illustrates an embodiment of the apparatus 1 of the invention with only some protective covers 211b in place and some walls 211a of the centrally located cutter device 200 removed to allow observation of parts of its interior, and shows the following apparatus elements: first reservoir 100a for fibreboards 2a to be processed in the apparatus 1, a cutter device 200 comprising a main frame 210 supporting a cutter means with a plurality of rotatable cutter wheels having respective pluralities of cutting tools on their circumferences for cutting in a common plane, a first lifter 310 and a fibreboard feeding device 300 for feeding the fibreboard from the reservoir to the cutter device, a transporting device 400 with a second lifter 410 for transporting the processed fibreboard from the cutter cevice 200 to a storage device 100b for storage of fibreboards 2b that have been processed in the cutter device 200. This embodiment also includes a pallet transporting device 500, disposed under the cutter device 200, for transporting an empty pallet from the first resevoir to the second reservoir, or vice versa.
Figure 2 illustrates in further detail parts of the first transporting device 300, the second transporting device 400, and the cutter device 200, of the embodiment which has been generally illustrated in figure 1, with protective covers 211b on the sides removed and walls 211a in place. The first transporting device 300, located to the left of the cutter device 200 in this embodiment, is arranged to feed one piece of fibreboard at a time from the first reservoir and onto the surface plane the plane base 250 of the cutter device 200 that is visible in figure 2. Not shown in figure 2 is a positioning device for positioning and securing the fibreboard on the plane base 250, which has been removed for illustration purposes in figure 2 to show the plane base 250. The exemplary cutter means 220a of the illustrated embodiment includes four rotatable cutter wheels 223a carried by an elongated cutter frame. The cutter frame is supported by jacks 240 acting as moving means for moving the cutter means in a direction towards the plane base 250, and for moving the cutter means away from the plane base 250 and back into the interior of the cutter device 200. By this arrangement, the cutters of the cutter wheels are moveable to pass through opening 251 in the plane base 250, which opening 251 advantageously is race track shaped in the embodiment illustrated in figure 2, and past the surface plane of the plane base 250, to allow them to reach a surface of a fibreboard that is resting onto the surface plane of the plane base 250 and to cut circular grooves or notches in the surface of the fibreboard. Additionally, a board cutter 270 is advantageously arranged at an end of the cutter device facing the second transporting device, or optionally integrated with the second transporting device, for splitting the fibreboard 2b that has been processed in the cutter device 200, preferably along a straight line that intersects the centers of circular grooves or notches that the cutter wheels have cut in the processed fibreboard.
With reference to the partial cut-away perspective view illustration of figure 3, further details of the cutter device 200 are explained in the following. Two service panels 211b are shown in figure 3, only as representative examples of a number of removable service panels, which are considered secondary elements with regard to the main purpose of the apparatus of the invention, and which for service purposes could be removed for gaining access to the interior of the cutter device 200. Similarly, cover panels 211a are also as representative examples of secondary elements with regard to the main purpose of the apparatus of the invention. The cutter device 200 advantageously further comprises one or more further cutter means 220b, including three or other number of rotatable cutter wheels 223b, with same or different geometry or cutters as those of other cutter wheels, carried by respective an elongated cutter means frame 221b, which is movable into an operational position in the area of the opening 251 in the plane base 250. To move one cutter means 220a away from the operational postion and into an idle position, and to move another cutter means 220b from an idle position and into the operational position, so as to switch from one cutter meanns 220a to another cutter means 220b, the cutter device 200 advantageously comprises a cutter means carriage 230 in its interior, arranged to move on rails attached to the main frame 210 or to some other supporting arrangement inside the cutter device 200. The carriage 230 also serves to position the cutter means 220a, 200b for engagement with a set of jacks 240. The jacks 240 serve as the moving means for moving the one of the cutter means 220a, 220b that is located in the operational position, towards and away from the plane base 250. In the illustration of figure 3, the positioning device 260 for positioning and securing the fibreboard on the plane base 250, is shown in its proper position, thereby mostly obscuring the view of the plane base 250. The complex structure elements of the the positioning device 260 shown in figure 3 is represented mostly by a number of pneumatic actuators that are used to control the position of the fibreboard and to secure it on the plane base 250 when the cutting operation is carried out by the cutting means 220a, 200b.
With reference to the partial cut-away plan view illustration of figure 4, further details of the cutter device 200 are explained in the following. In the illustration of figure 4, top cover panels 211a and the positioning device 260 shown in figure 3 have been removed, to show more details of the further cutter means 220b, the plane base 250, the arrangement of the cutter means carriage 230, and the board cutter 270. Both cutter means 220a and 220b are provided with jack adapters 222, for each receiving and engaging with a part of a respective one of the jacks 240 for controlled movement, in a substantially axial direction of the cutter wheels, of cutter means 220a, 220b when located in the operational position. The elongated cutter frame 221a, 221b have openings 232 matching a set of locators 229 of the carriage to allow accurately positioning of the cutter means 220a, 220b in accordance with the position of the carriage 230. The carriage 230 runs on rails 261, and a drive arrangement 262 driven by a motor 263, advantageously embodied by a chain and gear arrangement, is located within the cutter device 200 to move the carriage between different positions on the rails 261, and hence also to move the cutter means 220a, 220b between idle and operational positions. For moving the cutter means 220a, 220b between idle and operational positions, the jacks holding the cutter means 220a in the operational position are lowered to place the cutter means 220a onto the locators and to be supported by the carriage, and further to disengage from the jack adapters of the cutter means 220a, leaving the cutter means 220a free to be moved by the carriage away from the operational position.
With reference to figures 5a and 5b, details of the cutter means 220a, 220b are explained in the following. The cutter means comprises a cutter wheel drive 226, typically priovided by one or more electric motors, coupled to the cutter wheels 223a, 223b for driving the cutters wheels to rotate about respective cutter wheel axes. The illustated embodiment of figure 5a comprises four cutter wheels 223a, each connected by a respective hub 224 to a drive shaft of a respective drive motor 226, allowing four turn notches or grooves to be cut in a fibreboard in a single operation. This arrangement allows for controlling the drive of each of the cutter wheels individually. The assemblies of cutter wheels and drives are attached to the cutter means frame 221a in positions that correspond to positions of the fibreboard at which the turn notches or grooves are to be cut. In the illustration of figures 5a and 5b is also indicated the plurality cutting inserts 225 that are located at raised parts at the circumference of each the cutter wheels, which cutting inserts 225 have cutting edges oriented in correspondence with the axis of roration of the respective cutter wheel. A baffle 227 is arrange around each cutter wheel 223a, 223b to catch chips and dust that is produced during the cutting operation, which baffle 227 extends into a duct portion 228 for connection to vacuum arrangement that enables transportation of chips and dust away from the area in which the respective cutter wheel is operating. To ensure efficient funtioning of the baffle also when the cutter wheels are being moved towards and away from a fibreboard during cutting of notches or grooves, an edge portion of the baffle which would face or touch the fibreboard includes a lip made from a higly resilient material, such as e.g. a rubber material. Similar to what has been explained for and illustrated in figure 5a, does figure 5b illustrate another cutter means embodiment 221b which comprises three cutter wheels 223b having a larger diameter than the cutter wheels 223a of the cutter means embodiment 223a, by which three turn notches or grooves of larger turn radius can be cut in a fibreboard in a single operation.
With reference to figures 6a and 6b, details of a jack type embodiment of the moving means 240 for moving the cutter means 220a, 220b towards and away from the fibreboard to be cut are explained in the following. Generally the jack type moving means 240 comprises a frame 241, a rotatable screw shaft 224, a plunger 245 with threads that are in engagement of a threaded portion of the screw shaft 224, and a drive motor 242 with a gear or chain transmission 243 for coupling the drive motor to the screw shaft 224. By operating the drive motor to drive the screw shaft into rotation about its shaft axis in different directions of rotation relative to the plunger, the plunger will move in accordingly along the shaft axis. A tapered head section 246 of the plunger is shaped according to a matching interior shape of a jack adapter 222 provided on respective ones of the cutter frames 221a, 221b, for providing accurate positioning of the cutter means with respect to the moving means, hence also with respect to the fibreboard to be processed into a turn element with a plurality of turn notches or grooves for floor heating loops.
With reference to figure 7, details of the carriage 230 for exchanging of the cutter means 220a, 220b cut are explained in the following. The carriage comprises a carriage frame with a plurality of wheels 231 an locating posts 232. The wheels are preferably adapted with cuiding rims for guided movement of the carriage along rails 261. Since the rails 261 are not part of the carriage, the broken lines in figure 7 are merely to indicate the typical location of the rails 261 relative to the wheels 231. The locating posts 232 are each preferably formed with an end tip of a pointed or cylindrcal shape that is matched to be received in corresponding holes or indentations 229 provided in the cutter means 220a, 220b.
With reference to figure 8, details of the board cutter 270 for cutting straight notches or grooves or splitting the fibreboard after processing in the cutter device 200 are explained in the following. The board cutter 270 comprises a frame 271, a rotatable cutter shaft 274, one or more radially cutting cutter wheels 272a, 272b and a circular saw blade 273 attached to the rotatable cutter shaft 274, and a drive motor 275 with a gear, belt or chain transmission 276 for coupling an output of the drive motor 275 to the rotatable cutter shaft 274. The radially cutting cutter wheels 272a, 272b and a circular saw blade 273 are arranged to protrud thorough slots in a surface of the frame which is arrangable in the same plane as the plane of the plane base 250 of the cutter device, and their protrusions are adjusted in hight relative to the plane in consideration of the thickness of the fibreboard, such that when it is passed by the board cutter, only the saw blabe will cut throuh the fibreboard to split the fibreboard, while the radially cutting cutter wheels 272a, 272b cut notches or grooves that extend only partly into the fibreboard.
In an alternative embodiment of the apparatus of the invention, the board cutter 270 for cutting straight notches or grooves or splitting the fibreboard could be located so as to split the board and cut the straight or linear grooves or notches in the fibreboard before the board reaches the position on the plane base for the cutting of the circular grooves or notches. As an example of such location, the the board cutter 270 could be integrated with the feeding device or arranged between the arranged between the cutter device and the feeding device, for splitting the processed fibreboard (2b) along a straight line that could be drawn through, and therby comprise, the centers of circular grooves or notches cut by the cutter wheeels.
With reference to figure 9, details common to the cutter wheels 223a, 223b and structure of the surrounding baffle 227 and duct 228 are explained in the following. The exemplary cutter wheel illustrated in figure 9 carries a total of 10 cutting inserts 225 that are located at raised parts at the circumference of each the cutter wheels, and has a total of six relative ly large circular ventilation openings that each have a diameter that is about 25% of the overall diameter of the cutter wheel, throug which openings some parts of a few concentric circular features of the bottom of the baffle 227 are visible. The cutter wheel is swon attached by way of the hub 224 to a shaft of a motor. The cutting inserts 225 have cutting edges oriented in correspondence with the axis of roration of the respective cutter wheel, by which the cutting edges are facing upwards and out of the paper plane of figure 9. The openings in the cutter wheel are vent openings provided to allow for air to flow through the wheel for cooling of the cutting inserts and for facilitating transportation of chips and dust to the duct portion 228, and to reduce the mass of the cutter wheel in order to facilitate efficient control of the speed of rotation of the cutter wheel. The baffle 227 for reducing emission of noise and for catching chips and dust that is produced during the cutting operation, is generally of a circular shape that is larger in diameter than the outer diameter of the cutter wheel. In the view of figure 9, the ring shaped feature of circular rim with a small notch or gap at the lower part of the drawing is representing the lip of a resilient and flexible material, which by making contact with the first surface of the fibre board during the cutting operation will efficiently seal off the interior of the 227 baffle to avoid noise and chips and dust from escaping to the surroundings. The small notch or gap in the lip that is shown in at the lower part of the drawing allows for air to be sucked into the interior of the baffle to replace air being sucked out through the duct portion 228 by a vacuum arrangement that provides the transportation of chips and dust away from the area of the cutter wheel, thereby eliminating bulid-up of a vacuum in the interior of the baffle. For the purpose allowing air to be sucked into the interior of the baffle, the notch or gap in the lip may be replaced or supplemented by another suitable opening, preferably an opening in a wall part of the baffle that is located away from duct portion 228, and also such that a flow of air from the opening to the the duct portion 228 wil flow through openings in the cutter wheel.
With reference to figures 10a and 10b, further details of features that are common to and that are different between the cutter wheels 223a, 223b are explained in the following. The exemplary cutter wheel illustrated in figure 10a corresponds to the larger cutter wheel 223a which has also been shown in the illustration of figure 9, whereas the exemplary cutter wheel illustrated in figure 10b corresponds to the larger cutter wheel 223b which has also been shown in other of the accompanying figures. Accordingly, the number of cutting inserts 225 could differ depending on the size of the cutter wheel, which for the illustrated embodiments are 10 cutting inserts for the larger cutter wheel and 8 cutting inserts for the smaller cutting wheel. For both cutter wheels shown in figures 10a and 10b, they are shown detached from the shaft of the motor 226 and, therefore, without the hub 224. Six smaller circular features surrounding the central opening of the cutter wheels represent openings or holes for bolting the cutter wheels to the hub 224, which hub is advantageously the same for attaching any applicable size of cutter wheel to a shaft of any motor 226. Accordingly, the distance from the outer circumference of hub to the outer circumference of the cutter wheel will differ depending on the diameter of the cutter wheel, and hence also the space available for making vent openings in the wheel for allowing air to flow through the wheel. That difference is also illustrated by the difference in the number and dimensions of openings in the cutter wheels illustrated, where the larger cutter wheel of figure 10a has six relative large openings, and the smaller cutter wheel of figure 10b has eight smaller openings. The location of the cutting blades or cutting inserts 225 on axially raised rim portions of the cutter wheel at the cirumference of the cutter wheel is clearly illustrated in the perspective view photo illustration of figure 10b of the smaller cutter wheel with eight cutting blades or cutting inserts 225. Advantageously, the cutting blades or cutting inserts 225 are in a radially staggered arrangement to provide an effective cutting width that define the width of grooves or notches that are cut in the fibreboard, and the cutter inserts may be forvided with a plurality of cutting edges that allow cutting in a raidal direction in addition to the cutting in the axial direction. Advantageously, the cutter wheels 223a, 223b are fitted with additional cutting blades or cutting inserts 225-1 attached to a side of one or more of the raised portions of the cutter wheel to provide clean and efficient cutting of sides of the turn notches or grooves in the fibreboard turn element. In the illustration of figure 10b, every second one of the raised portions carries an additional cutting insert 225-1 on a side facing radially outwards relative to centre of the cutter wheel.
It has been found that using the axially cutting cutter wheels disclosed herein in the apparatus of the invention for cutting circularly shaped notches in a fibreboard turn element for underfloor heating and operating the cutter wheels at a certain rotational speed depending on the dimensions of the cuttcr wheel, the production can proceed to process a large number of fibreboards substantially uninterrupted for very long periods of time, and in particular that the tendency for the shavings or the cuttings to catch fire during the cutting operation, or the tendency for the binder free or almost binder free fibreboard element itself to catch fire during the cutting operation, is substantially eliminated. More particularly, by testing different combinations of axially cutting cutter wheel diameters and speeds of rotation, it has been found that when operating the apparatus with the larger axially cutting cutter wheels 223b having an outer diameter OD of 322 mm and an inner ID diameter of 278mm, see also figure 9, implying that the set of axially cutting blades or cutting inserts have an effective cutting width of 22 mm, to rotate at 900 rpm (revolutions per minute), the resulting grooves or notches of a width of about 22 mm are cut repeatedly with excellent quality and the fibre board does not fray, and there is substantially no tendency for the cuttings, shavings or fibreboard to catch fire. With the aforementioned diameter and speed of rotatation of the larger axially cutting cutter wheels, the axially cutting cutter blades or or cutting inserts that are attached at the rim of the larger axially cutting cutter wheels operates at an average cutting speed relative to the fibreboard of about 850 m/s (meters per second). As for the smaller axially cutting cutter wheels 223a having having an outer diameter OD of 219 mm and an inner diameter ID of 181mm, see also figure 9, implying that the axially cutter blades or cutting inserts have a width of 19 mm, when operated to rotate at 1200 rpm (revolutions per minute), the grooves or notches are cut repeatedly with excellent quality and the fibre board does not fray, and there is substantially no tendency for the cuttings, shavings or fibreboard to catch fire. With the aforementioned diameter and speed of rotatationof the smaller axially cutting cutter wheels, the axially cutting cutters that are attached at the rim of the larger axially cutting cutter wheels operates at an average cutting speed relative to the fibreboard of about 755 m/s (meters per second). Although exact values for speed of rotation and cutter wheel dimensions are given for the axially cutting cutter wheel examples above, experiments have shown that the apparatus of the invention could be operated with slightly higher or lower speed of rotation of the axially cutting cutter wheels, and still obtain the advantageous result of a minimal risk of the cuttings, shiavings or fibreboard cathing fire during the operation of cutting the circular grooves or slots in the fibreboard.
With reference to figure 11, further details of features the radially cutting cutter wheels 272a, 272b are explained in the following. The radially cutting cutter wheels 272a, 272b are generally disc shaped cutter wheels with first and a second axially oriented disc sides, a radially oriented circiumference side, and on the radially oriented circiumference side a plurality of cutting inserts 278 with respective cutting edges oriented to cut in a radial direction of the wheel. The exemplary radially cutting cutter wheel illustrated in figure 11 carries six raidally oriented cutting inserts 278 on its outer circumference. Advantageously, the cutter wheels 272a, 272b are fitted with additional axially cutting cutting inserts 278-1 and 278-2 attached at a circumference edge of respective ones of first and a second axially oriented disc sides. The examplary radially cutting cutter wheel illustrated in figure 11 carries three axially cutting cutting inserts 278-1 attached at a circumference edge of the first axially oriented disc side, and three axially cutting cutting 278-2 attached at a circumference edge of the second axially oriented disc side. The advantageous findings disclosed in the previous paragraph above, that using the axially cutting cutter wheels disclosed herein in the apparatus of the invention and operating them at a certain speed, or closed to a particular speed of rotation, provides excellent cutting results and the fibre board does not fray, and there is substantially no tendency for the cuttings, shavings or fibreboard to catch fire, are found to be applicable also to the radially cutting cutter wheels 272a, 272b for cutting straight or linearly shaped notches in a fibreboard turn element for underfloor heating. More particularly, by testing different combinations of radially cutting cutter wheel diameters and speeds of rotation, it has been found that when operating the apparatus with the radially cutting cutter wheels 272a, 272b having an outer diameter of 200 mm, to rotate at 2300 rpm (revolutions per minute), and moving at the same time the fibreboard past the radially cutting cutter wheel at a speed of 7 m/s (meters per second), the straight grooves or notches are cut repeatedly with excellent quality and the fibre board does not fray, and there is substantially no tendency for the cuttings, shavings or fibreboard to catch fire. With the aforementioned diameter and speed of rotatation of the radially cutting cutter wheels, and also the speed of moving the fibreboard past the cutter wheell during the cutting of the straight grroves or notches, the radially cutting cutter blades or or cutting inserts that are attached at the rim of the radially cutting cutter wheels operate at an average cutting speed relative to the fibreboard of about 1452 m/s (meters per second). Although exact values for speed of rotation and cutter wheel dimensions are given for the radially cutting cutter wheel example above, the apparatus of the invention could be operated with slightly higher or lower speed of rotation of the axially cutting cutter wheels, and still obtain the advantageous result of a minimal risk of the cuttings, shavings or fibreboard catching fire during the operation of cutting the straight or linear grooves or slots in the fibreboard.
Reference is now made to the top view drawing of figure 12A, illustrating the processed side of an example of a partly processed fibre board turn element made from a 1800 mm long, 600 mm wide, and 36 mm thick fibreboard element. The partly processed fibre board has been processed in the apparatus of the invention in a first step, when posistioned on the plane base 250 with the side to be processed facing the set of cutter wheels, in which the axially cutting cutter wheels have made a plurality of circular notches or grooves 11 in the side to be processed. For this particular example, the apparatus of the invention was configured with the three larger radially cutting cutter wheels 223b in the operating position, and were operated to cut three circular grooves or notches 11 of an aveerage diameter of 300 mm and a center spacing of about 600 mm into the side to be processed of the fibre board, resulting in the pattern of three grooves or notches shown in figure 12A. The cutting inserts 225 have for this example an effective cutting width of 22 mm and were of a generally rectangular shape, and operated to cut three 22 mm wide grooves or notches with straight sides and bottoms to a depth of about 23 mm into the plate of 36 mm thickness, thereby keeping about 13 mm of fibreboard material at the bottom of the grooves or notches.
Reference is now made to the top view drawing of figure 12B, illustrating the processed side of an example of a fully processed fibreboard that provide the underfloor fibreboard turn elements 10, obtained by processing the board illustrated in figure 12A in the apparatus of the invention in a second step in which the partly processed fibreboard has been conveyed past and processed by the board cutter 270 as disclosed above in connection with figure 11, in which second step the radially cutting cutters of the board cutter 270 have made a plurality of straight or linear grooves or notches 13, in this particular example two straight or linear grooves or notches 13, into the surface to be processed. The processed board has also bee cut or split by the saw of the board cutter 270, into two 300 mm wide halves, thereby providing the underfloor fibreboard turn elements 10 having semicircular grooves or notches 12, which underfloor fibreboard turn elements 10 are ready for use for assembling an underfloor for underfloor heating.

Claims

Apparatus (1) for producing an underfloor fibreboard turn element (10) for underfloor heating having a plurality of turn notches or grooves for floor heating loops, the apparatus comprising
- a first reservoir (100a) for fibreboards to be processed (2a) in the apparatus (1),

- a cutter device (200) comprising a main frame (210) supporting a cutter means (221) including an elongated cutter frame (221) holding a plurality of rotatable axially cutting cutter wheels (223) with axes of rotation oriented in parallel, each of said cutter wheels having a plurality cutters (225) arranged on a circumference thereof with first cutting edges oriented axially away from the wheel and so as to cut in a common plane oriented perpendicular to said axes of rotation, a plane base (250) for supporting and positioning a fibreboard with a first surface thereof in a surface plane being in parallel with the common plane of the cutters and having an opening (251) for the cutter wheels, and a drive means (226) for rotating the cutter wheels, and the cutter device (200) further comprising a moving means (240) for moving the cutter means in a direction towards and away from the plane base for the cutters of the cutter wheels to pass through the opening in the plane base and past the surface plane,

- a feeding device (300) for feeding the fibreboard from the reservoir to the plane base of the cutter device, characterised in that it comprises:
- a positioning device (260) for positioning and securing the fibreboard on the plane base in a predetermined position with the first surface against the plane base and such that the cutter wheels on passing through the opening cut respective circular grooves or notches in predetermined parts of the first surface of the fibreboard,

- a storage device (100b) for storage of fibreboards processed (2b) in the cutter device, and

- a transporting device (400) for transporting the processed fibreboard from the plane base to the storage device.
The apparatus of claim 1, further comprising
a board cutter (270), integrated with the transporting device or arranged between the arranged between the cutter device and the transporting device, for splitting the processed fibreboard (2b) along a straight line comprising the centers of circular grooves or notches cut by the cutter wheeels.
The apparatus of claim 1, further comprising
a board cutter (270), integrated with the feeding device or arranged between the arranged between the cutter device and the feeding device, for splitting the processed fibreboard (2b) along a straight line comprising the centers of circular grooves or notches cut by the cutter wheeels.
The apparatus of claim 2 or 3, wherein
the board cutter (270) comprises a circular saw blade fixedly attached to a rotatable shaft for splitting the processed fibreboard.
The apparatus of claim 4, wherein first and a second circular and radially cutting cutter tools are fixedly attached to the rotatable shaft on respective, opposite sides of the saw blade, and spaced for cutting respective straight grooves or notches in the processed fibreboard (2b) in areas of the first surface located to respective sides of the circular grooves or notches cut by the cutter wheeels.
The apparatus of claim of any one of the previous claims, wherein the apparatus is configured to operate the axially cutting cutting wheels for thereon attached cutting blades or cutting inserts to cut the grooves or notches in the fibreboard element with a cutting speed in a range from about 750 m/s to about 850 m/s.