PRODUCING SAME"

FIELD OF THE INVENTION

[0001] The invention relates to a horizontally cored object and a method of producing same. The invention is particularly suited to producing foam that is horizontally cored in a manner that is suitable for use in a self-inflating mattress.

BACKGROUND TO THE INVENTION

[0002] The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was published, known or part of the common general knowledge in any jurisdiction as at the priority date of the application.

[0003] A self-inflating mattress typically comprises at least one piece of shaped foam between two fluid impervious layers that are joined at their perimeter to form an airtight enclosure. The shaped foam is important in that it allows the mattress to spontaneously inflate when air is introduced. However, in most (if not all) cases, the shaped foam must also act as a thermal insulator against a cold surface and/or as protection from rough surfaces.

[0004] The problem with this approach is that self-inflating mattresses are often used by persons while travelling and thus the volume and mass of the shaped foam are particularly important. One way of reducing the volume and mass of shaped foam is to core the shaped foam.

[0005] The shaped foam can be cored either vertically or horizontally. Creating vertical cores is the easiest as the shaped foam can be drilled using an arrangement similar to a drill press or cut using a fixed shape die.

[0006] While creating a vertical core in this manner may resolve the issue of volume and mass of the shaped foam, the vertical cores allows for heat to travel down from the user's body to the ground. Thus, shaped foam having vertical cores reduces the thermal insulating properties of the self-inflating mattress in which they are installed. [0007] For this reason, it is desirable to produce self-inflating mattresses having horizontal cores. Manufacturing shaped foam having horizontal holes presents problems in themselves.

[0008] Chief among these is the problem of compression deformity. To elaborate, as foam is considerably wider than it is thick, as a vertical core is drilled pressure is applied to the foam that causes compression. However, this compression is rarely uniform in relation to the horizontal drilling plane. This means that while the hole may be perfectly horizontal during the drilling process, when the foam slab decompresses following removal of the drill, the resulting core may not be straight. This impacts on the performance of the self-inflating mattress.

[0009] It is therefore an object of the present invention to provide a method of producing a horizontally cored object, such as a foam slab for a self-inflating mattress, that overcomes, or at least substantially ameliorates the aforementioned problems.

SUMMARY OF THE INVENTION

[0010] Throughout this document, unless otherwise indicated to the contrary, the terms "comprising", "consisting of", and the like, are to be construed as non-exhaustive, or in other words, as meaning "including, but not limited to".

[0011] According to a first aspect of the present invention there is a method of producing a horizontally cored object, comprising the steps of: making a horizontal slit in a first surface of the object to a first depth using cutting means;

cutting the object at the first depth using the cutting means, the cutting means following a pattern that produces a horizontal core and returns the cutting means to its original position before following the pattern; and

moving the cutting means so as to exit the object by way of the horizontal slit.

[0012] In one version of the method, the cutting means follows a pattern that produces the horizontal core by way of the substep of horizontally moving the cutting means relative to the fixed position of the object. In an alternative version, the cutting means follows a pattern that produces the horizontal core by way of the substep of horizontally moving the object relative to the fixed position of the cutting means. [0013] The method may also include the step of making at least one horizontal planar cut to the object at at least one predetermined height.

[0014] According to a second aspect of the present invention there is a horizontally cored object made according to the method of the first aspect of the present invention. Ideally, the pattern of the horizontal core in the horizontally cored object comprises a plurality of tessellating cores.

[0015] According to a third aspect of the present invention there is an air mattress incorporating a horizontally cored object according to the second aspect of the present invention.

[0016] According to a third aspect of the present invention there is an apparatus for producing a horizontally cored object, the apparatus comprising: at least one cutting station, the at least one cutting station incorporating cutting means;

at least one cutting surface,

where, the cutting means of the cutting station(s) are able to be adjustably positioned relative to the cutting surface(s) both vertically and horizontally such that the cutting means is operable to: make a horizontal slit in the upper surface of an object to a first depth; follow a pattern that produces a horizontal core and returns the cutting means to its original position before following the pattern; and

exit the object by way of the horizontal slit.

[0017] In a first configuration of the apparatus, the at least one cutting station is of fixed position and the apparatus further incorporates transportation means for horizontally moving the object relative to the fixed position of the at least one cutting station. In such a configuration, it is preferable that the transportation means comprises at least one conveyor belt.

[0018] In a second, alternative, configuration of the apparatus, the object is of fixed position and the at least one cutting station has movement means for horizontally moving each cutting station relative to the fixed position of the object. [0019] Preferably, the cutting means is one or more of the following: one or more non-heated cutting wires; one or more heated cutting wires; one or more rotating elements; one or more sawing elements. Furthermore, it is preferable that the cutting means be further operable to make at least one horizontal planar cut to the object at at least one predetermined height. This then allows the cutting means to not only make the horizontal cores, but also to finish off the object.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a first perspective view of an apparatus for horizontally coring an object in a first step of the method of producing same according to the present invention.

Figure 2 is a first perspective view of an apparatus for horizontally coring an object as shown in Figure 1 in a second step of the method of producing same according to the present invention.

Figure 3 is a first perspective view of an apparatus for horizontally coring an object as shown in Figure 1 in a third step of the method of producing same according to the present invention.

Figure 4 is a first perspective view of an apparatus for horizontally coring an object as shown in Figure 1 in a fourth step of the method of producing same according to the present invention.

Figure 5 is a first perspective view of an apparatus for horizontally coring an object as shown in Figure 1 in a fifth step of the method of producing same according to the present invention.

Figure 6 is a first perspective view of an apparatus for horizontally coring an object as shown in Figure 1 in a sixth step of the method of producing same according to the present invention.

Figure 7 is a first perspective view of an apparatus for horizontally coring an object as shown in Figure 1 in a seventh step of the method of producing same according to the present invention. Figure 8 is a first perspective view of an apparatus for horizontally coring an object as shown in Figure 1 in an eighth step of the method of producing same according to the present invention.

PREFERRED EMBODIMENTS OF THE INVENTION

[0021] Throughout this specification the term "object" is to be understood as meaning any item of manufacture regardless of shape and/or size that can be cut by way of cutting means as contemplated by this invention.

[0022] In accordance with a first embodiment of the invention there is an apparatus 10 for producing a horizontally cored object 1 .

[0023] The apparatus comprises a first cutting station 12 and a second cutting station 14. A movable path 16 extends between the first cutting station 12 and the second cutting station 14. In this embodiment, the moveable path 16 comprises a first conveyor belt 18 and a second conveyor belt 20. The first conveyor belt 18 and second conveyor belt 20 facilitate transport of objects in a forward and reverse direction as illustrated by directional arrows F and R.

[0024] The first cutting station 12 comprises four uprights 22a through 22d. Uprights 22a and 22b are placed at opposing positions relative to the first conveyor belt 18 to form a first upright pair. Uprights 22c and 22d are also placed at opposing positions relative to the first conveyor belt 18 but at a location further along the first conveyor belt 18 in direction F. Uprights 22c and 22d form a second upright pair.

[0025] Each upright 22 in its respective pair is connected to its other upright by way of a bridging strut 24. The bridging struts 24 provides additional strength to the first cutting station 12.

[0026] Each upright 22 has a transportation channel 26 provided on an internal side 28. The internal side 28 of each upright 22 is the side that faces the first conveyor belt 18.

[0027] Each transportation channel 26 is adapted to receive a retaining element (not shown) of a cutting frame 30.

[0028] In addition to the retaining elements, the cutting frame 30 comprises a pair of side structures 32 and a plurality of cutting elements 34. Each cutting element 34 extends between the side structures 32 in a direction transverse to the direction of movement of the first conveyor belt 18.

[0029] The retaining elements are located at respective ends of each side structure.

[0030] The first cutting station 12 is mechanised such that the cutting frame 30 is able to move up and down within the transportation channels 26 in the directions illustrated by directional arrows U and D. Furthermore, movement of the cutting frame 30 within the transportation channels 26 is controlled by appropriate control means 36. In this embodiment the control means 36 is a CNC-based controller.

[0031] The second cutting station 14 comprises two uprights 38a, 38b. Uprights 38a and 38b are placed at opposing positions relative to the second conveyor belt 20. The uprights 38a, 38b are connected by way of a bridging strut 40. The bridging struts 40 provides additional strength to the second cutting station 14.

[0032] Each upright 38 has a transportation channel 42 provided on an internal side 44. As with the first cutting station 12, the internal side 44 of each upright 38 is the side that faces the second conveyor belt 20.

[0033] Each transportation channel 42 is adapted to receive a cutting mount 46. A cutting element 48 extends between the cutting mounts 46. In this manner, the cutting element 48 extends between the cutting mounts 46 in a direction transverse to the direction of movement of the second conveyor belt 20.

[0034] The second cutting station 14 is also mechanised such that the cutting mounts 46 are able to move up and down within the transportation channels 26 in the directions illustrated by directional arrows U and D.

[0035] As with the cutting frame 30, movement of the cutting mounts 46 within the transportation channels 38 is controlled by the control means 32. The control means 32 also controls the operation of the first conveyor belt 18 and second conveyor belt 20.

[0036] The apparatus 10 will now be explained in the context of its intended use. In doing so, the applicant also explains the method 100 of producing a horizontally cored object 1 . [0037] The control means 32 operates to move both the cutting frame 30 and the cutting mounts 46 to their highest possible position within their respective transportation channels 26, 38 (Step 102)

[0038] A foam slab 2 is placed on the first conveyor belt 18 at a marked position prior to the first cutting station 12. Following placement of the foam slab 2, the control means 32 causes the first conveyor belt 18 to transport the foam slab 2 in direction F. This movement continues until the foam slab 2 is positioned centrally underneath the cutting frame 30. (Step 104).

[0039] The control means 32 then causes the cutting frame 30 to lower (step 106). Lowering of the cutting frame 30 in this manner eventually causes the cutting elements 34 to commence cutting of the foam slab 2. As the cutting elements in this embodiment are in the form of wires, the cut made into the foam slab 2 is in the nature of a slit at this time. This cut will be referred to hereafter as the first original cut.

[0040] Once the cutting frame 30 has been lowered to a predetermined position, cutting of the horizontal cores commences.

[0041] In this embodiment, the cutting of the first horizontal cores 50 is achieved by continuing to lower the cutting frame 30 while at the same time causing the first conveyor belt 18 to move in the direction R. This causes a 7" cut in the foam slab 2 when viewed side on as shown in Figures 3 and 4 (step 108).

[0042] Once this "/" cut has reached its desired length, the cutting frame 30 stops and remains at this lowest point. The first conveyor belt 18 is then activated to move in the direction F. This causes a further horizontal cut to be produced in the foam slab 2 (step 1 10).

[0043] To finish off this first horizontal core 50, the cutting frame 30 is raised while at the same time the first conveyor belt 18 is activated to move in the direction R. This causes a "\" cut in the foam slab 2 when viewed from the side (step 1 12). If performed correctly, when the "\" cut is completed, the cutting elements 34 of the cutting frame 30 should be in the position it was at prior to commencement of the 7" cut (i.e. At its position following completion of step 106). Thus, when the cutting frame 30 is again raised the cutting elements 34 exit through the first original cut made in the foam slab 2 (step1 14). [0044] It is to be noted here that as the cutting frame 30 exits through the first original cut there is no intention to perform any new cuts, rather simply to travel along the path of the original cut. In this manner, the slit nature of the first original cut is maintained. This in turn produces a situation where there is no perceptible break in the resulting shaped foam and thus, in practice, prevents the user's body heat from being transferred vertically when in use.

[0045] The first conveyor belt 18 is then caused to move in the direction R for an amount equal to half the distance between adjacent original cuts (step 1 16). Once this position has been reached, the cutting frame 30 is again lowered to a predetermined position prior to commencing cutting of the second horizontal core 52 (step 1 18). Note that in order to do this, this predetermined position must be higher than the apex 54 of the first horizontal core 50.

[0046] Hereafter, this cut will be referred to as the second original cut. As with the first original cut, the second original cut is in the nature of a slit.

[0047] Cutting of the second horizontal core 52 then commences in a similar manner to the cutting of the first horizontal core 50. To elaborate, the cutting frame 30 is maintained at the height of the predetermined position while the first conveyor belt 18 moves in the direction R. This continues until such time as the cutting elements 34 are in close proximity to the apex 54 of a next adjacent first horizontal core 50 (step 120). The cutting frame 30 is then lowered, while at the same time the first conveyor belt 18 is activated to move in the direction F (step 122). This continues until the cutting elements 34 are in close proximity to both the next adjacent first horizontal core 50 and the prior adjacent first horizontal core 50. This produces a "\" cut.

[0048] The cutting frame 30 is then raised, while the first conveyor belt continues to move in the direction F (step 124). This continues until the cutting frame 30 returns to the same height as the predetermined position and places the cutting elements 34 in close proximity to the apex of the prior adjacent first horizontal core 50. Hence, this action produces a "/" cut.

[0049] The cutting frame 30 again maintains the height of the predetermined position while the first conveyor belt 18 is now activated to move in direction R (step 126). This continues until such time as the cutting elements are at the point where the second original cut terminated. The cutting frame 30 is then raised so that the cutting elements exit through the second original cut (step 128).

[0050] In this manner, the first and second horizontal cores 50, 52 form a tessellating pattern of triangles in the foam slab 2.

[0051] With the first and second horizontal cores 50, 52 now having been cut into the foam slab, the first conveyor belt 18 is activated to move in direction F (step 130). This continues until such time as the foam slab 2 is transferred to the second conveyor belt 20. The second conveyor belt 18 is then activated to move in direction F until such time as the foam slab is positioned in front of the second cutting station 14 (step 132).

[0052] When so positioned, the cutting mounts 46 are lowered to a first height (step 134). This first height is representative of a position of the foam slab 2 just above the second horizontal cores 52.

[0053] The second conveyor belt 18 is then activated to move in direction F. In doing so, the cutting element 48 slices a top layer off the foam slab 2 (step 136). This also removes any burrs in the upper portions of the foam slab 2 that may have been created during the course of manufacture of the first and second horizontal cores 50, 52.

[0054] With removal of this top layer, the second conveyor belt 20 is activated to move in direction R such that the foam slab 2 is returned to its position just in front of the second cutting station 14 (step 138). Once clear of the second cutting station 14, the cutting mounts 46 are again lowered to a second height (step 140). This second height is representative of a position of the foam slab 2 just below the first horizontal cores 50.

[0055] The second conveyor belt 20 is then once again activated to move in direction F. In doing so, the cutting element 48 slices through the foam slab 2 and thereby creates a finalised foam element for a self-inflating mattress (step 142).

[0056] It should also be appreciated by the person skilled in the art that the above invention is not limited to the embodiment described. In particular, the following modifications and improvements may be made without departing from the scope of the present invention:

• [0057] The invention may be used to cut horizontal cores of any pattern or geometric shape. However, the applicant is of the opinion that the tessellated triangle pattern described in this specification is the optimal geometric shape for the horizontal cores.

• [0058] The invention has been described in the context of a cutting wire, but the invention can utilise other cutting mechanisms. For instance, cutting of the shaped foam may be achieved by heated wires, rotation or sawing. However, it is an important, but not essential, consideration of the invention that the cutting mechanism allow the production of first and second original cuts that are in the nature of a slit.

• [0059] The second cutting station 14 may incorporate more than one cutting element.

• [0060] Alternatively, the first and second cutting stations 12, 14 may be merged into a single cutting station. The single cutting station may have a single cutting element, or may incorporate more than one cutting element.

• [0061] The control means 36 may operate using a combination of Human Machine Interface and Programmable Logic Control systems. Alternatively, the control means 36 may operate using Computer Numerical Control systems.

• [0062] While the invention has been described such that the number of cutting elements in the cutting frame is equal to the number of first horizontal cores to be produced in the foam slab, the invention can be modified such that the cutting frame makes multiple cuts into the foam slab to produce the first horizontal cores and multiple cuts into the foam slab to produce the second horizontal cores.

• [0063] The cutting station may have a fixed resting position for the foam slab, with the components making up the first and/or second cutting stations 12, 14 able to move relative to the resting position to perform the cuts as described above. Similarly, the first and or second conveyor belts may be height adjustable, such that there is no need to move the cutting means.

• [0064] The first and second conveyor belts may be merged into a single movable path.

• [0065] Other transportation means may be used to convey the foam slab 2 between the first and second conveyor belts as would be readily apparent to the person skilled in the art.

• [0066] The control means may be situated near the first and/or second conveyor belts or located remotely thereto. [0067] It should be further appreciated by the person skilled in the art that the above variations and modifications, not being mutually exclusive, can be combined to form yet further embodiments that fall within the scope of the present invention.