Palisade fencing pales

Abstract

A method and apparatus (1, Figure 1) for manufacturing palisade fencing pales 4 includes means for providing a continuous feed of individual pales 100n along a first axis and orientated to be elongate

Description

Field of the Invention The present invention relates to the manufacturer of palisade fencing pales. Background of the Invention Palisade fences typical comprise a plurality of posts secured into the ground, horizontal rails secured to the posts and vertical pales secured to the horizontal rails. Palisade fencing pales are typically formed from strip metal and may have any number of cross-sectional profiles though, most commonly V-section, D-section and W-section profiles which are achieved by cold rolling strip metal. An objection of the present invention is to provide alternative / improved methods and apparatus for manufacturing palisade fencing pales. Summary of the Present Invention In accordance with the present invention, there is provided a method of manufacturing palisade fencing pales and corresponding apparatus as claimed in the accompanying claims. More specifically, the method comprises the steps of providing raw material, along a first axis, wherein the material is folded and cut to form fence pales, the pales form a continuous feed of individual fencing pales, orientated to be elongate in the direction of the first axis; and for successive fencing pales, accelerating a pale along the first axis, halting that pale along the first axis, and moving that pale off the first axis before it is caught up by the next pale. Wherein the fence panel is moved in a direction perpendicular to the first axis via a chain conveyor. The orientation of the fencing pales may be maintained during the accelerating, halting and / or moving steps. The feed and acceleration may be provided by the same roller-pair used to remove newly formed individual fencing pales from a press used to form those individual fencing pales from strip metal. 09 01 24 Brief Description of Drawings The present invention will now be described, by way of example only, with reference to the following figures in which: Figure 1 is a schematic diagram of apparatus for manufacturing palisade fencing pales from strip metal; Figures 2 and 3 are derivatives of photos showing a sequence of roller-pairs for cold rolling the strip metal; Figure 4 is a table illustrating the stages of forming a bent-over edge (a 'Dutch bend') of the strip metal with particular roller-pairs; Figure 5 is a cross-section of the W-type palisade fencing pales formed by cold rolling with the roller pairs of figs. 2 and 3. Figure 6 is a schematic diagram illustrating the stamping / shearing of the strip metal to form the ends of the palisade fencing pales; Figures 7 and 8 are derivatives of photos showing the moveable press of fig. 1; Figure 9 is a schematic diagram illustrating the apparatus for parallel arranging of the pales of fig. 9; and Figure 10 is a schematic diagram illustrating the parallel arranging of the pales; Figures 11 and 12 are derivatives of photos showing the parallel arranging mechanism of fig. 9; and Figure 13 is a cross-section of the palisade fencing pales formed by cold rolling with the roller pairs of figs. 2 and 3. Referring to figure 1 which is a schematic diagram of the manufacture of palisade fencing pales from strip metal, a rotatably mounted coil 2 of strip metal 3 is shown as feeding the strip metal into a series of roller-pairs for cold rolling to form the desired cross-sectional profile for the fencing pales. The roller-pairs designated stage 1 (SI), stage 2 (S2) and stage 3 (S3) roller-pairs are used to form, amongst other profile features, a bent-over edge (known as 'a Dutch bend'). Figs. 2 and 3 are derivatives of photos showing roller-pairs with fig. 2 showing stage 1 roller-pairs 21, 21' which have axes parallel to the plane of the strip metal being rolled and fig. 3 showing the stage 2 roller-pair 30, 31' which have axes perpendicular to the plane of the strip metal being rolled. Fig. 4 is a table illustrating the stages of forming a bent-over edge of the strip metal with particular roller-pairs for both edge profiles which are initially substantially flat (in column 'Edge Profile IQ and also angled (in column 'Edge Profile 2'). As shown in the 'Stage 1' rows, stage 1 roller-pairs deform the edge of the metal strip so that its extremity (for both Edge Profiles 1 and 2) becomes substantially vertical. Subsequently, a stage 2 roller-pair (having axes perpendicular to the plane of the strip metal and the axes of stage 1 roller-pairs) causes the substantially vertical edge output from stage 1 roller-pairs for both Edge Profiles 1 and 2 to bend back on itself, i.e. significantly beyond 90° from the plane of the original strip metal (e.g. 160° or 170°) which is beyond the capability of stage 1 roller-pairs. Lastly, a stage 3 roller-pair (having axes parallel to the plane of the strip metal being rolled and perpendicular to the axes of the stage 2 roller-pair) compress the bent-over edge of the strip metal. Ideally, the compression is such that the thickness of the bent-over edge adjacent the extremity of the original edge of the strip metal is less than that of the new bent-over edge. Many permutations to the above stage 1, 2 and 3 arrangement are contemplated including in relation to the number of roller-pairs used in each stage. Also, stage 1, 2 and 3 roller-pairs whilst primarily responsible for the Dutch bend can also to used form features of the desired pale profile which are unrelated to the edge of the strip metal. For example, those other features shown in figure 5 which is a cross-section of the presently formed W-type palisade fencing pales illustrating Dutch bends on both edges. Referring back to figure 1, the last of the roller-pairs for cold rolling to form the desired cross-sectional profile for the fencing pales feeds the metal strip 3 into a moveable press 5 which is responsible for stamping / shearing of the strip metal to form the ends of the palisade fencing pales and certain other features. Specifically, referring to fig. 6, the press is used to cut / shear out a cut-out section 60 from the strip 3 which has a flat end 63 which is common with the bottom of one pale 4 and a pointed end 64 which is common with the pointed end of the adjacent pale 4' of the strip 3. At the same time, i.e., in a single action with the cutting / shearing out of the cut-out section 60, two holes 61, 61' are punched and indentations / embossments 65, 65 are formed. The apertures serve as means for securing the pales to corresponding fencing rails and the indentations / embossments 65, 65' adjacent the apertures 61, 61' assist in securing fasteners used with the adjacent apertures 61, 61'. The press is moveable in that is configured to both move in parallel with the continuous feed of strip metal 3 when pressing the strip metal and to move back to a previous position when not pressing the strip metal 3. This ensures optimally pressing function (e.g., clean cuts / shearing, accurate punching / pressing and the like) because relative movement between the pressing elements and the continuously fed metal strip is avoided (or at the very least minimised) whilst maintaining a continuous feed of strip metal and thus continuous output of fencing pales. As shown in fig. 7, the press is composed of 3 pressing elements 71, 71', 72 which are each supported on a common moving platform 70. Thus, the 3 pressing elements 71, 71', 72 move in unison on the common platform. Pressing elements 71, 71' punch the apertures 61, 62 and form the adjacent indentations / embossments 65, 65 in the pales. Central pressing element 72, 70' is used to cut / shear out the cut-out section 60. For the purpose of manufacturing the specific pales described, each punching element operates symultaneously. However, it is possible that only individual pressing elements and / or specific combinations of pressing elements could be operative to form various permutations of pale design. Thus, the pressing function of each element is ideally individually controlled. Also, to minimise the moving weight of the press, some or all of the pressing elements 71, 71', 72 and the underlying platform 70 could be made of Aluminium. Referring back to figure 1, a continuous feed of individual fencing pales is output from moveable press 5 along an axis and moved off-axis by apparatus 8 for parallel arranging of the pales whereafter a finishing process is applied to parallel pales. More specifically, referring to fig. 9, means 90 both provides a continuous feed of individual fencing pales along a first axis from the moveable press and orientated to be elongate in the direction of the first axis, and accelerates those the pales along that axis. For example, a roller-pair used to both receive the end of the metal strip emerging from the moveable press 5 prior to pressing and remove newly formed individual fencing pales from the moveable press 5 could also be used to accelerating the pales. Figure 10 is a schematic diagram illustrating the parallel arranging of the pales over time epochs t=0 to t=n. Specifically, successive pales (1000, 1001 ...) are accelerated along the feed axis (indicated by the arrow), halted and then moved perpendicularly, off-axis. The acceleration and halting must be done sufficiently quickly to ensure that each pale has enough time to be moved off axis before being caught up by the next pale (i.e. that following it out of the moveable press). Once perpendicularly arranged, a finishing process to create a trident shape can be applied, including applied to multiple pales at the same time (2x illustrated in fig. 10). An advantage of this arrangement is that if the finishing process takes longer than the pressing of the moveable press, arranging and processing multiple pales in parallel means that the longer finishing process can still be done without having to pause the feed of pales to avoid a backing up of pales for the finishing processing. Referring to figs. 11 and 12, means for halting successive accelerated fencing pales along the first axis includes a flexible barrier 1101 to first slow down the accelerated pales and, thereafter, an end stop and alignment means 1104 to halt the pales and guide the pales on to a chain conveyor 91. In particular, a series of rollers aligned with the first axis receives the halted pales and the rollers have an adjustable height so as to be able to lower the halted pales on to interlaced chains of the the chain conveyor 91. The chain conveyor has attached to the chains collecting members 1103 which are configured to collect and align the halted pales, thereby moving the collected pales off-axis. In the above arrangement, the orientation of the fencing pales is maintained during acceleration, halting and moving off axis. The collecting members are consistently spaced so as to uniformly distribute the collected pales on the chain conveyor. Furthermore, clamping means can be used to clamp multiple pales on the chain conveyor simultaneously in order to subject those clamped multiple pales to a simultaneous finishing activity on the chain conveyor. For example, as shown in fig. 12 and 13, the clamp comprises restraining members 1105, 1105'that have the same profile as the pales which hold the pales securely when clamp 7 is used to apply the trident shape to the pales. Other embodiments implementing the claimed invention will suggest themselves to persons skilled in the art. 09 01 24

Claims

1. A method of manufacturing palisade fencing pales comprising the steps of:providing, along a first axis, a continuous feed of individual fencing pales (lOOn), orientated to be elongate in the direction of the first axis; andfor successive fencing pales, accelerating a pale along the first axis, halting that pale along the first axis, and moving that pale off the first axis before it is caught up by the next pale;wherein the off-axis movement is achieved using a chain conveyor, configured to move the halted pale in a direction perpendicular to the first axis.

2. A method according to claim 1 wherein the orientation of the fencing pales (lOOn) is maintained during the accelerating step.

3. A method according to claim 1 or claim 2 wherein the orientation of the fencing pales (lOOn) is maintained during the halting step.

4. A method according to any preceding claim wherein the pales (lOOn) are moved off the first axis in a direction perpendicular to the first axis.

5. A method according to any preceding claim wherein the pales (lOOn) are moved off the first axis in a direction in the plane of the individual fencing pales (lOOn) or the plane of metal strip (3) as orientated during the manufacture of individual fencing pales (lOOn) from that metal strip.

6. A method according to any preceding claim wherein a feeding gap is formed between successive discrete fencing pales (lOOn) corresponds to less than 30% of the length of a fencing pale.09 01 247. A method according to claim 6 wherein the feeding gap between successive fencing pales corresponds to less than 20% of the length of a fencing pale.

8. A method according to claim 6 wherein the feeding gap between successive fencing pales (lOOn) corresponds to less than 10% of the length of a fencing pale.

9. Apparatus (1) for manufacturing palisade fencing pales comprising:means for providing a continuous feed of individual fencing pales along a first axis and orientated to be elongate in the direction of the first axis; andmeans for accelerating successive fencing pales along the first axis,means (1101, 1104) for halting successive fencing pales along the first axis, andmeans (1103) for moving successive fencing pales off the first axis before one is caught up by the next pale;wherein the means for moving (1103) comprises a chain conveyor having a plurality of commonly geared, parallel chains collectively forming the conveyor, configured to move the halted pale in a direction perpendicular to the first axis.

10. Apparatus (1) according to claim 9, wherein the means for accelerating is configured to maintain the orientation of the fencing pales during acceleration.

11. Apparatus (1) according to claim 9 or claim 10, wherein the means for halting is configured to maintain the orientation of the fencing pales during halting.

12. Apparatus (1) according to any of claims 9 to 11, wherein the means for moving is configured to maintain orientation of the fencing pales during moving off the first axis.09 01 2413. Apparatus (1) according to any of claims 9 to 12, wherein the means for moving is configured to move the fencing pales off the first axis in a direction perpendicular to the first axis.

14. Apparatus (1) according to any of claims 9 to 13, wherein the means for moving is configured to move the fencing pales off the first axis in a direction in the plane of the individual fencing pales or the plane of metal strip as orientated during the manufacture of individual fencing pales from that metal strip.

15. Apparatus (1) according to any of claims 9 to 14, wherein the means for providing comprises a roller-pair.

16. Apparatus (1) according to any of claim 15, wherein the means for providing and the means for accelerating comprises the same roller-pair, wherein that roller-pair is used to remove newly formed individual fencing pales from a press used to form those individual fencing pales from strip metal.

17. Apparatus (1) according to any of claims 9 to 16, wherein the means for halting comprises a flexible barrier for slowing down the accelerated pales.

18. Apparatus (1) according to any of claims 9 to 17, wherein the means for halting comprises alignment means for aligning halted pales prior to those halted pales being moved off axis by the moving means.

19. Apparatus (1) according to any of claims 9 to 18, wherein the means for halting comprises a series of rollers aligned with the first axis for receiving the accelerated pales.

20. Apparatus (1) according to any of claims 9 to 19, wherein the means for halting is configured to have an adjustable height so as to enable the halted pales to be lowered on to the means for moving.

21. Apparatus (1) according to claim 1 wherein the chains have attached thereto collecting members which are configured to collect and align the halted pales, thereby moving the collected pales off-axis.

22. Apparatus (1) according to claim 21 where the collecting members are consistently spaced so as to uniformly distribute the collected pales on the chain conveyor.

23. Apparatus (1) according to any of claims 9 to 22, further comprising clamping means configured to clamp multiple pales on the chain conveyor simultaneously in order to subject those clamped multiple pales to a simultaneous forming activity on the chain conveyor.

24. Apparatus (1) according to claim 23, wherein the clamp comprises restraining members that have the same profile as the pales.

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