GB2263423A

GB2263423A - Manufacturing welded metal fence.

Info

Publication number: GB2263423A
Application number: GB9200670A
Authority: GB
Inventors: Terence Hobdell
Original assignee: PLASGALV Ltd
Current assignee: PLASGALV Ltd
Priority date: 1992-01-14
Filing date: 1992-01-14
Publication date: 1993-07-28
Anticipated expiration: 2012-01-14
Also published as: GB2263423B; BE1003742A6; GB9200670D0

Abstract

An apparatus (1) and process for manufacturing a welded metal picket fence (2) having a number of spaced-apart pickets (3) mounted on and extending across a pair of spaced-apart support rails (4). The apparatus (1) has support beds (10) on which rails (4) and pickets (3) are mounted. A loaded bed (10) is positioned beneath a carriage (26) which traverses the bed (10) in steps. At each step, welding machines 25 on the carriage (26) are positioned at an intersection of the rails (4) and pickets (3). A ram operated picket holding arm 30 extends to engage and hold a picket (3) against the rails (4) while welding heads (35) make welds between each side of the picket (3) and the rails (4). When all the pickets (3) have been welded to the rails (4) to form the fence the bed (10) is wheeled clear of the carriage (26) and unloaded. A second bed (10) loaded with pickets (3) and rails (4) is positioned under the carriage (26), the second bed (10) having been loaded whilst the first fence was being welded. <IMAGE>

Description

"Apparatus and process for manufacturing fencing'1 This invention relates to an apparatus and process for manufacturing fencing.

According to the invention, there is provided a fence manufacturing apparatus for producing a welded metal picket fence having a number of spaced-apart pickets mounted on and extending across a number of spaced-apart support rails, the apparatus comprising a fence support bed having a number of spaced-apart rail mounts for mounting two or more rails substantially parallel on the bed, adjacent each rail mount a number of spaced-apart upright picket positioning posts to position pickets laid on the bed across the rails and engaging the posts substantially perpendicularly to the rails, an end stop for engagement by lower ends of the pickets mounted on the bed for alignment of the pickets, a welding machine mounted on a carriage which is movable across the bed for welding the pickets to the rails, positioning means to position the welding machine at each intersection of picket and rail, a picket holding arm on the carriage extendable to engage and hold a picket against the rail and its associated picket positioning posts, the welding machine having a pair of welding heads movable between a retracted stored position and an extended operative position for welding each side of the picket to the rail.

Preferably a number of welding machines are provided on the carriage for simultaneous welding of one or more pickets to each rail.

In a further embodiment, the fence support bed is mounted on a movable bed carriage for movement of the bed between a welding position under the welding machine carriage and a loading position clear of the welding machine carriage.

Preferably a pair of fence support beds are mounted side-byside on the bed carriage so that when one of the beds is in the welding position the other is in the loading position.

In another embodiment a fence unloader is provided for removing a fence from each fence support bed, comprising a pusher frame mounted under the bed and extendable through the bed to engage and raise a fence on the bed clear of the bed, a fence engagement member slidable on the frame in the raised position to move the fence over a side of the bed, a fence carrier pivotally mounted at one side of the bed and pivotable between a horizontal position extending laterally of the bed for reception of a frame from the sliding fence engagement member and an upright ground engaging position.

In another aspect the invention provides a process for manufacturing a metal picket fence using the apparatus as described above, comprising the steps: (a) preparing a number of pickets and rails, (b) mounting a number of rails spaced-apart and substantially parallel on the bed with the bed in a loading position, laying a number of pickets across the rails and substantially perpendicular to the rails against the picket positioning posts and end stop, (c) moving the bed to the welding position and moving the welding machine carriage over the bed positioning a welding machine at each intersection between at least one picket and the rails, (d) extending the picket holding arm to engage and hold the picket against the rails and picket positioning posts, (e) moving the welding heads of each welding machine to the operative position and simultaneously welding along each side of the picket where it engages the rails, (f) retracting the welding heads and picket holding arm and moving the welding machine carriage across the bed in steps to weld each picket to the rails, (g) returning the bed carriage to the loading position and unloading the fence from the bed, and (h) delivering each fence to a galvanising station for galvanising the fence.

In another embodiment, the process includes the further steps of: (a) shot blasting the galvanised fence in a controlled manner to roughen the surface of the fence, (b) delivering the fence to a spray booth and spraying a coloured polyester powder coating onto an exterior of the fence, and (c) conveying the fence to an oven and baking the fence to melt and fix the polyester coat onto the face.

The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a fence manufacturing apparatus according to the invention, Fig. 2 is a plan view of the apparatus, shown in another position, Fig. 3 is a perspective view of portion of the apparatus, Fig. 4 is a perspective view of portion of the apparatus, in use, Fig. 5 is an end view of the apparatus, Fig. 6 is a detail perspective view of portion of the apparatus, Fig. 7 is a detail side elevational view of portion of the apparatus, Fig. 8 is a detail perspective view of portion of the apparatus, shown in use, Figs. 9 and 10 are detail elevational views of portions of the apparatus, Fig. 11 is a flow chart illustrating a fence manufacturing process according to the invention, Fig. 12 is an elevational view of a fence section formed by the apparatus, Figs. 13 and 14 are sectional views of pickets forming portion of the fence section, Fig. 15 is a detail elevational view of a head portion of a picket, Fig. 16 is a side elevational view of the head portion of the picket, Fig. 17 is an elevational view of a fence section mounted on support posts, Fig. 18 is a plan view of the fence section of Fig. 15, Figs. 19 to 21 are perspective views of cleats used to mount the fence section on support posts, Fig. 22 is an exploded elevational view illustrating the mounting of a fence section on the supports by means of the cleats, Fig. 23 is a perspective view of portion of the fence and a support showing the mounting of the fence on the support, Fig. 24 is a side sectional view of the fence portion of Fig. 23, and Fig. 25 is a plan, partially sectioned view showing a corner mounting arrangement for the fence.

Referring to the drawings, and initially to Figs. 1 to 10 thereof, there is illustrated a fence manufacturing apparatus according to the invention indicated generally by the reference numeral 1. Referring briefly to Fig. 12, the apparatus 1 is for manufacturing a welded steel picket fence 2 having a number of spaced-apart pickets 3 mounted on and extending across a pair of spaced-apart support rails 4.

The apparatus 1 has a pair of fence support beds indicated generally by the reference numeral 10 mounted side-by-side on a bed carriage 11 supported on wheels 12 which engage complementary spaced-apart parallel tracks 13. Each bed 10 has an open frame construction having a number of spaced-apart channel section rail mounts 15 extending substantially parallel between opposite sides 16 of the bed 10. Adjacent each rail mount 15 and extending between the sides 16 parallel to the rail mounts 15 are channel section beams 17, each carrying a number of spaced-apart upright picket positioning posts 18 to position pickets 3 1aid on the bed 10 across rails 4 and engaging the posts 18 substantially perpendicularly to the rails 4 (see Fig. 4). An upstanding end stop 20 extends between the sides 16 at each outer free end 21 of the bed 10.

A welding machine 25 (Fig. 5) is mounted on a carriage 26 above the bed 10, the carriage 26 being movable across the bed 10 for welding pickets 3 to rails 4 mounted on the bed 10.

The welding machine 25 includes positioning means to position the welding machine 25 at each intersection of picket and rail on the bed 10. A picket holding arm 30 is mounted on the carriage 26 and is extendable by means of a ram 32 to engage and hold a picket 3 against the rail 4 and its associated picket positioning posts 18 (see Figs. 5 and 8). Two welding machines 25 are provided on the carriage 26 mounted above each rail mount 15 for simultaneous welding of the pickets 3 to the two rails 4 of the fence 2. Each welding machine 25 has a pair of spaced-apart welding heads 35, the spacing between the welding heads 35 corresponding to the width of a picket 3.

The welding heads 35 are movable between a retracted stored position, as shown in Fig. 5, and an extended operative position, as shown in Fig. 8, for forming a weld 38 between each side of a picket 3 and a rail 4. Each welding head 35 is fed with welding wire from supply reels 36 on the carriage 26. Referring now in particular to Figs. 3, 9 and 10 a fence unloader incorporated in the apparatus 1 for removing a fence 2 from each fence support bed 10 will be described. The fence unloader comprises a pusher frame 40 attached by a pivot mounting 41 to one side 16 of the bed 10. A fence engagement member 42 is slidably mounted on the frame 40. A ram 45 mounted on the carriage 11 extends upwardly to engage a free end 46 of the frame 40.The ram 45 is operable to move the frame 40 from a stored position beneath the bed 10, as shown in Fig. 9, through the bed 10 to engage and raise a fence 2 on the bed 10 clear of the bed 10. Mounted alongside the bed 10 is a fence carrier 50 pivotally mounted on an upright support post 51. The fence carrier 50 is pivotal between a horizontal position, as shown in Fig. 10, for reception of a fence 2 from the sliding fence engagement member 42, and an upright ground engaging position, as shown in Fig. 9, in which the fence 2 can be lifted clear of the fence carrier 50. A catch 52 is engageable with the fence carrier 50 to retain it in the upright position.

In use, a pair of rails 4 are mounted on the rail mounts 15.

Then a number of pickets 3 are mounted across the rails 4 and abutting associated picket positioning posts 18 and the end stop 20. The carriage 11 is then wheeled along the tracks 13 beneath the welding machine carriage 26. The carriage 26 is moved and positioned at the first intersection of a picket 3 and the rails 4. Operation of the ram 32 extends the picket holding arm 30 to engage the picket 3 holding it against the rails 4 and picket positioning posts 18, as shown in Figs. 5 and 8. Each pair of welding heads 35 extends downwardly to the operative position and welds along each side of the picket 3 to secure it to the rail 4. Upon completion of the welds the welding heads 35 and picket holding arm 30 are retracted, the carriage 26 moves to the next picket 3 and the welding process is repeated. Each picket 3 is thus welded to the rails 4 to form the fence 2.

While the welding operat#ion is being carried out another set of rails 4 and pickets 3 are mounted on the second bed 10 which is in the loading position. When a fence 2 has been completed the carriage 11 is moved along the tracks 13 to position the next set of rails 4 and pickets 3 beneath the carriage 26. While welding is being carried out the completed fence 2 can be unloaded and more rails 4 and pickets 3 mounted on the bed 10.

For unloading, and referring in particular to Figs. 9 and 10, the ram 45 is extended so the pusher frame 40 moves up through the bed 10, the fence engagement member 42 engaging an underside of the fence 2 and lifting the fence 2 clear of the bed 10. Then the fence carrier 50 is pivoted into the horizontal position. Next the fence engagement member 42 is slid along the frame 40 to extend out over a side of the bed 10 for transfer of the fence 2 onto the fence carrier 50. The fence carrier 50 can then be pivoted to the upright ground engaging position, shown in Fig. 9, and the fence 2 lifted off the fence carrier 50 with suitable lifting gear.

Completed fences 2 are delivered to a galvanising station 52 (Fig. 11) where they are galvanised. The fences 2 may be further processed to give them a coloured external polyester coating. To do this each fence 2 is mounted on a conveyor which delivers the fence 2 to a shot blasting station 53.

Shot blasting is carried out in a controlled manner to roughen the outer surface of the fence 2 without braking the galvanised coating. Then the fence 2 is conveyed to a spray booth where a coloured polyester powder coat is sprayed onto an exterior of the fence 2. Downstream of the spray booth 54, the fence 2 is delivered into an oven 55 where it is baked to melt and fix the polyester coat onto the fence 2.

Referring now to Fig. 13, a cross-sectional view of a picket 3 is shown having a generally V-shape for improved strength.

Fig. 14 shows an alternative cross-section for a picket 3.

Figs. 15 and 16 show one type of head 60 formed on pickets 3, the head 60 being cut to provide three prongs 61, each of the side prongs 61 being bent forward.

Figs. 17 and 18 show fence sections 2 in use mounted on upright ground engaging support posts 65. Each support post 65 is of I-section material. Fig. 19 shows an L-shaped cleat 66 for mounting the fence sections 2 onto the support posts 65. Each arm 67, 68 of the cleat 66 has an elongate slot 69 for through passage of a bolt to fasten the cleat 66 to the post 65 and rail 4 -of the fence section 2. Fig. 20 shows a cleat 70 similar to the cleat of Fig. 18 but used for a corner mounting of the fencing 2 shown in Fig. 25. Fig. 21 shows another similar type of cleat 72. In this case a pair of bolt holes 73 are provided in one arm 68 of the cleat 2. This enables the cleat 72 to be mounted on a support post 65 with the arm 67 in one of four positions, giving four height settings for mounting a fence 2 on the support post.

Referring to Figs. 22 to 24 the mounting of the rails 4 of the fence 2 to the support post 65 is shown, bolts 75 fastening the cleat 66 to the rail 4 and post 65. It will be noted in particular from Figs. 23 and 24 how the rail 4 nests within a channel 76 formed on each side of the post 65. This is advantageous from both a security and aesthetic point of view.

It will be appreciated that while the manufacture of a picket fence has been described the apparatus and process can also be used for gate manufacture.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.

Claims

1. A fence manufacturing apparatus for producing a welded metal picket fence having a number of spaced-apart pickets mounted on and extending across a number of spaced-apart support rails, the apparatus comprising a fence support bed having a number of spaced-apart rail mounts for mounting two or more rails substantially parallel on the bed, adjacent each rail mount a number of spaced-apart upright picket positioning posts to position pickets laid on the bed across the rails and engaging the posts substantially perpendicular to the rails, an end stop for engagement by lower ends of pickets mounted on the bed for alignment of the pickets, a welding machine mounted on a carriage which is movable across the bed for welding the pickets to the rails, a positioning means to position the welding machine at each intersection of picket and rail, a picket holding arm on the carriage extendable to engage and hold a picket against the rail and its associated picket positioning posts, the welding machine having a pair of welding heads movable between a retracted stored position and an extended operative position for welding each side of the picket to the rail.

2. Apparatus as claimed in claim 1, wherein a number of welding machines are provided on the carriage for simultaneous welding of one or more pickets to each rail.

3. Apparatus as claimed in claim 1 or claim 2, wherein the fence support bed is mounted on a movable bed carriage for movement of the bed between a welding position under the welding machine carriage and a loading position clear of the welding machine carriage.

4. Apparatus as claimed in claim 3, wherein a pair of fence support beds are mounted side-by-side on the bed carriage so that when one of the beds is in the welding position, the other is in the loading position

5. Apparatus as claimed in any of claims 1 to 4, wherein a fence unloader is provided for removing a fence from each fence support bed comprising a pusher frame mounted under the bed and extendable through the bed to engage and raise a fence on the bed clear of the bed, a fence engagement member slidable on the frame in the raised position to move the fence over a side of the bed, a fence carrier pivotally mounted at one side of the bed and pivotal between a horizontal position extending laterally of the bed for reception of a frame from the sliding fence engagement member and an upright ground engaging position.

6. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.

7. A process for manufacturing a metal picket fence using the apparatus as claimed in any of claims 1 to 6, comprising the steps: (a) preparing a number of pickets and rails, (b) mounting a number of rails spaced-apart and substantially parallel on the bed with the bed in a loading position, laying a number of pickets across the rails substantially perpendicular to the rails against the picket positioning posts and end stop, (c) moving the bed to the welding position and moving the welding machine carriage over the bed and positioning a welding machine at each intersection between at least one picket and the rails, (d) extending the picket holding arm to engage and hold the picket against the rails and picket positioning posts, (e) moving the welding heads of each welding machine to the operative position and simultaneously welding along each side of the picket where it engages the rails, (f) retracting the welding head and picket holding arm and moving the welding machine and carriage across the bed in steps to weld each picket to the rails, (g) returning the bed carriage to the loading position and unloading the fence-from the bed, and (h) delivering each fence to a galvanising station for galvanising the fence.

8. A process as claimed in claim 7, wherein the process includes the further steps of: (a) shot blasting the galvanised fence in a controlled manner to roughen the surface of the fence, (b) delivering the fence to a spray booth and spraying a coloured polyester powder coating onto an exterior of the fence, (c) conveying the fence to an oven and baking the fence to melt and fix the polyester coat onto the fence.

9. A process substantially as hereinbefore described with reference to the accompanying drawings.

10. A picket fence whenever produced by the process of any of claims 7 to 9.