GROOVE CUTTING METHOD AND APPARATUS The present invention relates, in general, to a method and apparatus for the formation of an elongate construction or building member, especially a member having a slot extending along each longitudinal side thereof and having a lateral groove extending or depending from the or each said slot (hereinafter also referred to as a key-hole type slot and groove). More particularly, but not* exclusively, the invention relates to a method and apparatus for the formation (manufacture) of an elongate member of the type required to make up or create a structure, such as for example a fence, of the type described in Australian Patent Application No. 48609/90. For ease of explanation, throughout the ensuing description reference will be made to an especially preferred embodiment of the present invention, intended for the creation or formation of a plurality of elongate members, constructed of timber or the like material, intended for usage in the "building up" of a retaining wall for a garden bed, flower bed, lawn or the like, or perhaps a mowing strip. It should be realised, however, that the invention is not to be considered to be restricted only to any such preferred usage, and that the product of the invention lends itself to usage in a variety of other contexts. By way of example only it should be understood that elongate members constructed utilising the method and apparatus of the present invention could be employed in the manufacture or creation of culverts or gutters, pathways, fences (curved or otherwise), planter troughs, planter tubs, compost bins, fish ponds, sand pits, water tanks and even free-standing screens of the type employed in office environments and the like. In other words products created utilising the method and apparatus of the present invention cam be employed in any context wherein it is desired to join adjacent pieces of timbers.

In accordance with the known art there currently exist a number of different types of so-called garden edging, intended to retain earth or the like within a pre-determined area whilst at the same time to function as a lawn or mowing strip, as a purely or primarily decorative edging, or perhaps as formwork for concrete, bitumen or the like surfacing material. The edging used in accordance with the known art suffers, however, in terms of both lack of real flexibility of use and, perhaps equally as importantly at least from a marketing point of view, lack of aesthetic appeal. The arrangement described and defined

in the present applicant's Australian Patent Application No.4860990 represents a significant and extremely practical advance over the previously known ar

It must be realised, however, that known manufacturing techniques did not lend themselves to manufacture, on any practical and economic scale, of the plurality of substantially elongate members needed to create a wall structure or barrier in accordance with the aforementioned

Australian Patent Application No. 48609/90. The present invention addresses that problem and provides a method and apparatus for large-scale production of such elongate members. In accordance with one aspect of the present invention their is provided a method for the formation of an elongate construction or building member, said method including: forming at least one longitudinal slot in a strip of timber or the like material of indeterminate length; and forming at least one groove extending from the or each said slot and substantially laterally of said slot, wherein the or each said groove is formed in a progressive manner.

In accordance with a further aspect of the present invention there is provided a method for cutting at least one groove or the like in an elongate member having at least one slot or the like formed therein and extending substantially longitudinally thereof, said groove or the like extending from said slot or the like and substantially thereof, wherein said elongate, slotted member is moved progressively relative to a cutting means adapted to form, and progressively enlarge the or each said groove.

In accordance with a further aspect of the present invention there is provided an apparatus for the formation of at least one groove or the like in an elongate member having at least one slot or the like formed th erein and extending substantially longitudinally thereof, the or each said groove(s) extending from said slot and substantially laterally thereof, said apparatus including a cutting means including a plurality of cutting members, arranged on a common axis, consecutive ones of said cutting members exhibiting a progressively enlarged effective working or cutting profile, the arrangement being such that movement of said elongate member relative to said cutting means causes progressive formation and enlargement of said at least one groove in a series of consecutive cutting operations.

In order that the invention may be more clearly understood and put into practical effect there shall now be described in detail preferred

embodiments of an apparatus and associated method in accordance with the invention. The ensuing description is given by way of non-limitative example only and is with reference to the accompanying drawings, wherein:

Fig. 1 is a top plan view of an apparatus in accordance with the invention, intended to form lateral grooves in an elongate member of timber or the like material having longitudinal slots formed therein in any known manner;

Fig. 2 is a view taken along the line 2-2 of Fig. 1; Fig. 3 is a sectional view of a first embodiment of a cutting means in accordance with the invention, illustrating the arrangement which allows for an ever-increasing profile of cut to be achieved, thereby to form the groove;

Figs. 4 is a view taken along the line 4-4 of Fig. 1, showing one stage in the progressive cutting of a groove in an elongate member;

Fig. 5 is a sectional view of a partially-cut elongate member in accordance with the invention; and

Fig. 6 is a view of a completed elongate member in accordance with the invention, having slots and grooves formed therein and at both sides thereof.

With reference firstly to Figs. 5 and 6, there is shown therein an elongate element 1 of the type employed to form a retaining wall structure of the general type referred to in Australian Patent Application No. 48609/90. The element 1 includes two opposed longitudinally-extending slots 2 each having a groove 3 depending substantially normally therefrom and extending therealong, said slots 2 and associated grooves 3 being adapted to receive and retain a substantially complementary-shaped connecting means (not shown) allowing for interconnection of or with adjacent similarly configured elongate members 1 whereby to create or build up a retaining wall structure. In the arrangement as illustrated the elongate member 1 is substantially hexagonal in shape, but it should be realised that the actual shape thereof does not constitute part of the invention. Indeed the overall shape of the member 1, in terms of _. length, breadth and thickness, can readily be varied or adapted to suit differing use requirements. It should also be realised that, whilst in accord with an especially preferred embodiment of the invention slots 2 and grooves 3 are first formed in a strip of timber of indeterminate length, with the thus formed strip then being cut to size and shaped as required, an alternative procedure could

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- 4 - equally well be followed, wherein an elongate strip of timber is first cut to size as required for use, and then slots 2 formed therein, with grooves 3 then being cut in the slots 2. In the second-mentioned embodiment means will be provided to store the pre-cut, pre-slotted, cut to size strips of timber for subsequent delivery to an apparatus for forming grooves 3 therein. Such storage means could take the form of a hopper or the like receptacle or reservoir (not showri)'which is adapted to feed individual cut, sized strips for the formation of slots 2 and grooves 3 therein, in a manor to be described thereinafter in more detail. In one preferred embodiment of the present invention the method involves the cutting of a substantially elongate strip of timber or the like material of indeterminate length, having longitudinal slots 2 formed therein in any known manner, into a plurality of individual elongate members 1 of any given length and any desired shape. More especially members 1, of a length of approximately six inches, and of the substantially hexagonal shape illustrated in Fig. 6, may be formed. Alternatively, means may be provided for guiding an elongate strip of shaped timber or the like, h ving slots 2 already formed therein, through a work station whereby to allow for formation of the grooves 3 therein. With the preferred embodiments of the applicant's apparatus, as illustrated, the cutting teeth are so shaped and sited as to cut the grooves 3 to an ever-increasing depth as the elongate member or strip 1 is passed through the cutting station 12, in a manner to be described hereinafter in more detail.

The present applicant's arrangement employs a conveyor assembly, generally designated 21, for feeding elongate members 1 of a pre- ordained length, or alternatively a strip of indeterminate length, through the cutting station 12 to a collecting means (not shown), at which point the completed elongate members 1 can be stored or packed in any known manner, or alternatively the continuous strip can then be packed, or first cut to size and then stored or packed. The conveyor assembly 21 will be made up of pressure rolls or rollers, chains with associated lugs, gate means, pulleys, etc., in accordance with known techniques.

In an especially preferred embodiment (not shown) the conveyor assembly 21 will include at least one substantially continuous chain having at least one lug or protrusion thereon. In use the lug or protrusion will come into contact with a trailing end or edge of an elongate member and thereby serve

to push such member through the overall work station 12, whereby to have the grooves 3 and/or slots 2 formed therein. To ensure correct positioning of the elongate members for the cutting operation(s) the present applicant's apparatus also includes a plurality of pressure rollers disposed on predetermined distance above the chain - upon which the members 1 are to be disposed - whereby to preclude unwanted vertical movement or lifting off thereof. It should be understood, however, that any known form of conveyor assembly can be employed and that the actual conveyor assembly or means for movement of said elongate members or strip does not constitute part of the invention. Within the cutting station 12 and along each side thereof there are disposed opposed blade members 30, of any suitable material (preferably metallic), each having cutting means, generally designated 31, disposed therealong and depending downwardly therefrom. By virtue of the fact that the cutting teeth 31 are downwardly dependent from the blade members 30, then any timber shavings cut from the elongate member 1 will drop away, under the influence of gravity, thereby in effect minimising the possibility of fouling of subsequent teeth. Such an arrangement effectively removes the need for the use of complicated, and expensive, extraction systems. In the embodiments shown in the drawings the cutting means 31 include a plurality of cutting teeth 31 all sited on a common axis and adapted, in use, to be disposed within the relevant slot 2 of an elongate member 1 whereby to allow for ultimate formation of the groove 3 therein, in a substantially progressive manner. The teeth 31 and associated blade members 30 preferably are fixed in place relative to the conveyor belt or the like means and the elongate members or elongate strip 1 are, or is, in effect "dragged" thereacross. Each blade 30 is mounted, in any known manner, as for example by means of bolts 32, in a block 33. As shown, for example, in Fig. 4, the blocks 33 serve to provide a limit stop for lateral movement of the member 1 within the work station, thereby restraining the member against unwanted lateral movement and ensuring correct siting of the groove 3 relative to the slot 2.

With the present applicant's arrangement the cutting profile of successive cutting teeth 31 within the cutting station 12 is varied from entry to exit thereof, whereby to allow for progressive cutting out of the grooves 3. In other words, the cutting station 12 includes a plurality of teeth 31, each of a different (slightly) cutting profile when viewed in cross-section, the arrangement

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- 6 - being such that successive teeth 31 are responsible for the progressive cutting of a small amount of material, giving rise to a progressive enlarging of the cut whereby to ultimately create the desired groove 3.

The end result of the use of the method and apparatus in accordance with the present invention is an elongate member 1 of the type shown, for example, in Hg. 6. A plurality of such members 1 can thereafter be packed in any suitable manner, in conjunction with a plurality of interconnecting means of the type generally referred to in the aforementioned Australian Patent Application No. 48609/90, whereby to allow the user to create a retaining wall, barrier or the like to suit his purposes.

The apparatus in accordance with the present invention can be such as to form the slots 2 and grooves 3 either sequentially (in consecutive actions) or simultaneously. In one embodiment a motor driven saw blade of any known type can first be employed to cut opposed lateral slots along each side of elongate members 1 of any given length, with the thus slotted members

1 then being passed through the afore-described cutting station 12 for the formation of grooves 3 therein.

In an alternative arrangement, an elongate piece of timber of indeterminate length may first have longitudinal slots formed therein in any known manner, then be passed through a work station of the aforementioned type to have the grooves 3 cut therein, and thereafter cut in any known manner into smaller pieces of any desired length dimension and/or shape.

In the especially preferred embodiment illustrated the arrangement is such that the cutting teeth 32 are stationary, with the elongate members 1 being moved therealong whereby to form the groove 3. It should be understood, however, that in a further embodiment of the invention the elongate members 1 could be held stationary and the cutting teeth 32 moved relative thereto in any suitable and known manna:.

The method and apparatus in accordance with the present invention make it possible, in an extremely practical and cost effective manner, to produce on a large scale shaped timber or the like material members having key-hole type slots and grooves on opposed sides thereof. The method and apparatus in accordance with the invention lend themselves to high speed operation and production, this in marked contrast to known woodworking techniques. In that regard it must be realised that conventional woodworking

techniques could not be readily employed for purposes of the cutting, in strips of timber or the like material, of grooves and slots of the relative sizes envisaged by the present applicant's method and apparatus.

In yet a further alternative, an elongate strip of timber or the like material can have merely one longitudinal slot therein, with the groove extending laterally, and substantially normally, form each side of said slot.

In dosi g, it should be understood that the aforegoing description refers merely to preferred embodiments of a method and apparatus in accordance with the invention and that variations and modifications will be possible thereto without departing from the spirit and scope of the invention.

It should also be realised that the actual shape of the grooves and slots formed using the method and apparatus is not of the essence of the invention. Indeed, by appropriately altering the shape (profile) of the cutting teeth a groove of any particular shape or configuration can be formed. Furthermore the slots in the elongate members may be found in any known manner, be it on a separate machine spatially removed from the groove-cutting work station in accordance with the present applicant's arrangement, or at a preliminary work station making up part of the applicant's apparatus. The actual means for forming the slots do not constitute an essential feature or part of the invention.