AU655402B2 - A tube and fitting scaffolding system - Google Patents

Description

A TUBE AND FITTING SCAFFOLDING SYSTEM

FIELD OF THE INVENTION

The present invention relates to a scaffolding system and relates particularly to an improved scaffolding member that facilitates more efficient erection of scaffolding structures. The invention also relates to a method and apparatus for converting conventional scaffolding tubes to be compatible with the scaffolding system of the present invention.

DISCUSSION OF PRIOR ART The present invention was developed out of concepts disclosed in Australian Patent No. 569301 in the name of Tu-Fit (Pty) Ltd. Australian Patent No. 569301 is for an anchoring device, or multi-connector, for holding up to four horizontal tubular scaffolding members to a vertical member. Figure 1 is a fragmentary section of the connector joined to a horizontal. A bolt 36 provided on the connector can be received in a terminal hole 48 provided in the horizontal scaffolding member, to lock the horizontal member to the vertical. The multi- connector has a sill 29 having a bore 30 provided with a seating formation 32 in the form of a countersunk recess, for receiving a lug 34 of the bolt 36. The undersurface of the sill 29 has an angularly profiled surface 38 which biases the axis of the bolt 26 in the direction of the line A-B, when the nut of the bolt 36 is fastened to contact the surface 38. The multi-connector also has a bore 40 for receiving a screw or a pin for locating the connector on a vertical or horizonal scaffolding member.

Some of the vertical or horizontal scaffolding members disclosed in Australian Patent No. 569301 have a plurality of holes 44 formed in a straight line on the tube and spaced apart at about 250mm. The holes 44 are provided to enable the connector to be located on the tube using a screw or pin received through the bore 40 in the connector and in one of the holes 44. The present invention is based on the discovery that if the holes 44 are provided at predetermined spaced apart distances along the length of the tube and that in addition the first hole is drilled at a predefined distance from one end of the tube, the holes 44 not only allow a connector to be located on the tube, but also provide an accurate measure of the length of the tube and enable precise positioning of coupling elements along the length of the tube relative to the position of the holes. In prior art tube and fitting scaffolding structures it is necessary to employ a tape measure and spirit level during erection of the scaffolding, to ensure that the tubular scaffolding members are aligned and connected accurately in the horizontal and vertical directions. A tape measure is employed to locate and position couplers on both vertical and horizontal assembly, whereas a spirit level is employed to ensure the members are oriented accurately in the vertical and horizontal directions. This greatly slows down the procedure for erecting the scaffolding.

Furthermore, the current practice with tube and fitting scaffolding is to adopt a strictly methodical erection sequence, using many tubes solely as erection aids, i.e. as temporary retention bracing with no structural function, while the horizontal and vertical members are aligned. There is also a tendency to accumulate random lengths of tubing, which tends to be loss generators in the sense that they increase either the cost of supply or the cost of using the tubing.

SUMMARY OF THE INVENTION

The present invention was developed with a view to providing an improved scaffolding system and scaffolding members that facilitate more efficient assembly of a scaffolding structure.

According to one aspect of the present invention there is provided an elongate scaffolding member having a plurality of indelible markings at predetermined spaced apart distances along a longitudinal surface of the member, a first of said markings nearest one end of the member being located a pre¬ defined distance from said one end whereby, in use, said markings provide an accurate measure of the length of the member and enable precise positioning of coupling elements and fittings along the length of the member.

According to another aspect of the present invention there is provided a scaffolding system comprising a plurality of elongate scaffolding members, each member having a plurality of indelible markings at predetermined spaced apart distances along a longitudinal surface of the member, a first of said markings nearest one end of the member being located a predefined distance from said one end, said predetermined distances and predefined distance being constant from member to member in the system whereby, in use, said markings provide an accurate measure of the length of the members and enable precise positioning of coupling elements and fittings along the length of the members.

Preferably the markings are spaced apart at equal predetermined distances to one another and are aligned in the longitudinal direction of the member. Preferably the markings nearest the respective ends of the member are located the same predefined distance from the respective ends of the member.

Preferably the members are further provided with an indication adjacent each end, said indications being provided to indicate to a user that a member has been cut to a standard length compatible with said scaffolding system.

Preferably said indications are provided in the form of apertures, said apertures being adapted to receive a latching element therein whereby, in use, terminal coupling elements can be locked more securely to the members. Preferably, the members are hollow tubes and said markings are in the form of small holes or dimples in the wall of the tube.

According to a further aspect of the present invention there is provided an end connector for connecting two of the above scaffolding members end to end, the connector comprising: first and second end portions adapted to engage with the ends of two scaffolding members to be joined,- and, a central spacer portion adapted to maintain the ends of the two scaffolding members spaced apart at a distance selected to enable the spacing of said indelible markings on the scaffolding members across the end to end connection to be maintained at -said predetermined distance.

Preferably said end connector is a spigot-type end connector and said end portions are adapted to be received in the ends of the scaffolding members.

Preferably said central spacer portion maintains the ends of the two scaffolding members spaced apart at a selected distance equal to the outer diameter of the scaffolding members.

In the preferred embodiment the spigot-type end connector is provided with first and second latch protrusions on the first and second end portions respectively, adapted to be received in terminal holes provided in the ends of the scaffolding members.

According to a still further aspect of the present invention there is provided a method of converting a conventional scaffolding tube, of the kind employed in tube and fitting scaffolding, to be compatible with the scaffolding system of the present invention, the method comprising the steps of: placing a first indelible marking on the tube a predefined distance from one end of the tube using a marking means; moving the tube or the marking means relative to the other a first predetermined distance in a longitudinal direction of the tube; placing a further indelible marking on the tube said first predetermined distance from the first indelible marking; and, repeating sequentially said steps of moving the tube or the marking means and placing a further indelible marking for the entire length of the tube.

Preferably said steps of placing an indelible marking on the tube involve providing an indentation in the form of a dimple in the outer surface of the tube. Advantageously a second indentation in the form of a dimple is simultaneously provided in the outer surface of the tube in a diametrically opposite location.

Preferably said step of moving the tube or the marking means comprises moving the tube relative to a stationary marking means in the form of a press. Advantageously said press is provided with a marking tool which enables the placing of two dimples spaced apart a second predetermined distance and aligned in the longitudinal direction of the member, wherein said first predetermined distance is equal to twice said second predetermined distance.

According to yet another aspect of the invention there is provided an apparatus for converting a conventional tube, of the kind employed in tube and fitting scaffolding, to be compatible with the scaffolding system of the present invention, the apparatus comprising: marking means for placing indelible markings in or on a surface of the tube; and, transport means for moving the tube or the marking means relative to the other in a longitudinal direction of the tube whereby, in use, said transport means and said marking means can be operated sequentially commencing with the placing of a first indelible marking a predefined distance from one end of the tube and thereafter at predetermined spaced apart distances along a longitudinal surface of the tube.

In a preferred embodiment said transport means comprises first and second carriages for moving the tube relative to the marking means, ^'said first carriage feeding the tube through said marking means until the tube engages with the second carriage whereupon the second carriage draws the tube through the marking means for the remainder of its length.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the nature of the scaffolding system and improved scaffolding member according to the invention can be more clearly ascertained, preferred embodiments will now be described, by way of example only, with reference to the accompanying drawings in which:

Fig. 1 is a fragmentary section of the connector disclosed in Australian Patent No. 569,301;

Fig. 2 illustrates a preferred embodiment of a scaffolding member;

Fig. 3 illustrates two applications of the scaffolding members using a conventional coupler;

Fig. 4 illustrates two types of connection between the scaffolding members;

Fig. 5 illustrates a transom end connection to the scaffolding members; Fig. 6 (a) , (b) and (c) illustrate the connection of a guard rail to the scaffolding members;

Fig. 7 shows a tarpaulin which may be connected to a scaffolding frame of the scaffolding system.

Fig. 8 is a perspective view of an apparatus for automatically converting standard lengths of tubing to form scaffolding members according to the invention;

Fig. 9 illustrates one of the carriages employed in the apparatus of Fig. 8; and Fig. 10 illustrates a tube in a start position in the apparatus of Fig. 8.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 2 illustrates a preferred embodiment of the scaffolding member according to the invention in the form of a hollow tube 10, having a plurality of indelible markings 12 at predetermined spaced apart distances along the longitudinal surface of the tube. In this embodiment, the indelible markings are spaced apart at equal distances of 250mm to one another, and are aligned in the longitudinal direction of the tube 10. The indelible markings 12 are indentations in the form of small keyholes or dimples drilled into the wall of the tube along two diametrically opposed lines extending in the longitudinal direction of the tube. In this manner, the position of the markings can be ascertained when viewing the tube from almost any angle.

A first pair of said indelible markings 12 nearest one end 14 of the member are located a predefined distance from the end 14, in this embodiment a distance of 101mm. The predefined distance of the first dimples 12 from the end 14 of the scaffolding member has been carefully selected so that when the end 14 of the member is joined to the end of another member in a scaffolding structure, the spacing of the dimples 12 remains constant from one member to an adjacent aligned scaffolding member.

Also shown in broken outline in Fig. 2 is a spigot-type end connector 16. The end connector 16 comprises two halves held together by a bolt 18 received through a central spacer portion 20 of the end connector. The central spacer portion 20 of the spigot connector is of increased diameter relative to the two end portions 22 which are received in the ends 14 of two scaffolding members 10. When the two ends 22 of the spigot connector are received in the ends of two scaffolding members 10, and the bolt 18 is turned to expand the two halves of the spigot connector, a wedging action is created by the connector within the ends of the tubes 10 to connect them end to end. The spacer portion 20 of the spigot connector expands to approximately the outer diameter of the tubes, and separates the two ends 14 of the tubes at a spaced apart distance, in this embodiment selected to be 48mm. The selected distance of 48mm was selected to be compatible with the outer diameter dimension of the tubular scaffolding member 10, which is also equal to 48mm.

The reason for locating the first of the dimples 12 nearest the end 14 of the member a predefined distance of 101mm will become evident with reference to Fig. 2. In Fig. 2 it can be seen that when two of the tubular members 10 are joined end to end with the spigot connector 16, the dimples 12 nearest the ends 14 of the respective members 10 will be spaced apart across the end to end connection by the same predetermined distance between the other markings on the tubes, namely 250mm (101 + 48 + 101 = 250mm) .

A further feature of the spigot connector 15 is the provision of two latch protrusions 24 on one half of the end portions 22, the latch protrusions 24 being sized and shaped to fit in the terminal holes 48 provided on the members 10. As the two halves of the spigot type end connector 16 expand through the action of bolt 18, the latch protrusions 24 are received in the terminal holes 48 of the scaffolding members to prevent the two members from coming apart.

The end connector of the present invention may also be provided in the form of a sleeve-type end connector, in which the central spacer portion and latch protrusions are provided internally of the sleeve. Other types of end connector can also be employed to embody the novel features of the invention.

A significant advantage of the present invention is that the scaffolding members 10 can be formed from conventional tubing which is accurately cut to length with indelible markings provided in the longitudinal direction of the tubing. The scaffolding members can therefore be used in conjunction with all conventional couplers and fittings, as well as with several new types of couplers and fittings which utilise unique locking or locating features, such as the spigot-type end connector described above.

Figure 3 illustrates the use of the scaffolding members 10 with a conventional coupler 50 for connecting scaffolding members in a mutually perpendicular configuration. The function of the coupler 50 is unhindered by the presence of the dimples 12 and terminal hole 48 in the scaffolding members 10. However, the presence of the dimples 12 facilitates accurate positioning of the members 10 in the coupler 50 as they provide reference points in relation to which various edges and parts of the coupler can be precisely aligned. For example, a bolt provided in the coupler 50 has been aligned with a dimple 12 on the vertical member 10 to precisely position the other member 10 in the horizontal position. Couplers provided on the other ends (not shown) of the horizontal member 10 can be located in relation to the corresponding dimples 12 provided on the vertical scaffolding members at those ends to ensure that the horizontal scaffolding member is oriented perfectly horizonal. In a similar fashion, the horizontal member 10 in Fig. 3 has been positioned relative to the coupler 50 by aligning a dimple 12 with the right edge of the gate on the coupler 50. To avoid fixing errors, the edge chosen should remain consistent on the same member 10. When different makes of coupler are employed then the bolt (centre) of the coupler should be aligned with the dimple.

Obviously alignment of diagonal members is also greatly simplified with the scaffolding system of the invention, although this is not illustrated in the drawings. Clearly, it is unnecessary to align connecting members directly with the dimples 12, as a tape measure or rule can still be used to measure the precise connecting point of one member along another member by using the dimples 12 as reference points. By counting the number of dimples 12 from one end of the member 10, the location of any particular dimple can be easily calculated by multiplying the number of dimples by 250mm. If the desired position of a cross member 10 is not a multiple of 250mm, then the precise position between dimples 12 can be determined using a rule or tape measure of no more than 250mm in length, with reference to the nearest dimple 12.

Figure 4 illustrates the use of the scaffolding members 10 with a multi-connector 56 of the kind described in Australian Patent No. 569,301 referred to above, and a spigot- type end connector 16 described above. In Fig. 4, the manner of connecting two horizontal members 10 to a vertical scaffolding member, with the ends 14 of the horizontal tubular members butted up against diametrically opposed sides of the vertical tube using the multi-connector 56, is clearly illustrated. In Fig. 4, it can be seen that not only is the spacing between dimples 12 maintained in the vertical direction across the end to end connection at spigot 16, but also the spacing between dimples 12 in the horizontal direction across the connection between the horizontal members at the multi- connector 56 is also maintained. This is possible, because the outside diameter of the tubular members 10 (48mm) makes up the remainder of the 250mm spacing between markings when added to the predefined spacing between the dimples 12 nearest the facing ends 14 of the horizontal members. In Fig. 4 the position of the multi-connector 56 has been located with reference to the dimples 12 on the vertical member 10.

Figure 5 illustrates the inter-connection of scaffolding members 10 using a spigot connector 16 to connect the vertical members and a transom end coupler 58 for connecting a horizontal tubular member used as a transom for supporting scaffolding boards 60. The transom end coupler 58 is a standard coupler which has been modified by the provision of a protruding portion 62 received in the end 14 of the transom member 10 and held therein by a bolt passing through the terminal holes 48 in the member 10 and a corresponding bore through the protruding portions 62 of the transom end coupler 58. In the arrangement of Fig. 5, the position of the transom end coupler 58 has been located by aligning the lower edge of the coupler with one of the dimples 12 on the vertical scaffolding member 10.

Figures 6 (a) , (b) and (c) illustrate a further application of the scaffolding members 10 using flip couplers 64 of the kind illustrated in Fig. 6 (a) . Once again, the dimples 12 on the members 10 facilitate easy and accurate positioning of the flip couplers to achieve a precise horizontal orientation for a guard rail 66 of the type illustrated in Figs. 6 (b) . The flip couplers 64 when used in connection with the scaffolding members 10, also have numerous other applications,, including the fastening of a tarpaulin or other panel similar to that illustrated in Fig. 7. The tarpaulin 68 illustrated in Fig. 7 is provided with holes along its respective edges for receiving the flip fastener of the flip couplers 64 therein, to enable the tarpaulin to be stretched between horizontal and vertical scaffolding members.

From the above description of a preferred embodiment of the scaffolding member and spigot-type end connector, it will be apparent that the scaffolding system of the present invention retains all the flexibility of conventional scaffolding members with the added value provided by the indelible markings 12, enabling precise and accurate positioning of connecting scaffolding members, couplers and fittings. Furthermore, the preferred embodiment of the scaffolding members 10 provides lower handling and maintenance costs, compared with known modular and frame scaffolding systems, as only one type of stock needs to be used for all the scaffolding members. This is standard 48mm (actually 48.4mm) diameter scaffold tube cut accurately, in increments of 250mm, to popular lengths. Typical stock sizes are 6000, 4500, 4000, 3000, 2500, 2000, 1750 and 1500mm. The actual length of the standard sizes of the tubular members is 48mm (tube diameter) shorter than the actual stated length, ie. 2000mm (stated length) = 1952mm (actual length) .

Standard length scaffolding members are provided with suitably sized holes at each end, (terminal holes) to facilitate attachment of various terminal couplers and fittings, and indelible markings or dimples are formed at 250mm centres along the whole length of the tube preferably on two diametrically opposed sides of the tube. A further function of the terminal holes in the scaffolding system of the present invention is that they serve to indicate to the user which lengths of tubing are cut to standard lengths compatible with the system. Not infrequently a length of tubing is cut to a non-standard length to suit a particular structure, and in the act of cutting the terminal hole would be removed. Obviously, this function of indicating a standard length can be provided by any form of indication adjacent the ends of the member such as, for example, a small cut-out portion at each end. The beauty of the terminal holes is that they perform a dual function.

Clearly, although the indelible markings 12 of the preferred embodiment are in the form of small indentations, keyholes or dimples, the markings may be formed in any appropriate manner, for example, by providing circumferential grooves at the predetermined spaced apart distances along the longitudinal surface of the tube. However, small keyholes or dimples aligned in the longitudinal direction of the members are the preferred form as these facilitate rotational or radial location as well as height or length location. A further advantage of the present invention is that existing conventional tube can easily be converted to be compatible with the scaffolding system of the invention at reasonably low cost.

An apparatus and method for converting conventional tubing, of the kind employed in tube and fitting scaffolding, to be compatible with the scaffolding system of the invention will now be described in detail with reference to Figures 8 to 10. The apparatus comprises marking means in the form of a power press 70 for marking the tube with indelible markings in the form of dimples, and an elaborate transport system for automatically feeding tubes 71 through the press 70. The transport system comprises parallel rails 72 upon which two transport carriages 74 and 76 are located. The first carriage 74 is arranged to push a tube 71 a predetermined distance through the press 70 and the second carriage 76 is arranged to pull the tube through the press the remaining distance, as will be described in greater detail below.

The power press 70 employed in this embodiment of the invention is a "John Heine 203" hydraulic power press, adapted to be pneumatically operated by a pneumatic cylinder 78. The power press 70 is provided with a marking tool 80 adapted to place two pairs of indentations in the form of dimples in the surface of the tube 71. In a single stroke of the press 70 four dimples are made, a first pair placed in diametrically opposed locations in the outer surface of the tube 71 and a second pair spaced 250mm from the first pair and also placed in diametrically opposed locations in the outer surface of the tube, but aligned with the respective dimples of the first pair in the longitudinal direction of the tube.

The function of carriage 74 is to position the tube 71 correctly, pierce two terminal holes 48 in one end of the tube, eject the slugs from piercing and advance the tube into the power press 70 for the first two pair of indentations. Carriage 74 then correctly positions the tube 71 for the second carriage 76 to engage. As can be seen most clearly in Fig. 9 carriage 74 comprises a chassis 82 arranged for rolling movement on rails 72. A frame 84 mounted on the chassis 82 houses a lever system comprising a pivotable lever 86 having a vertically oriented hydraulic cylinder 88 operatively connected at one end thereof, and a first hole punch 90 operatively connected at the other end thereof. A second hole punch 92 is provided vertically aligned with the first hole punch 90 and operatively connected to another lever (not visible) similar to lever 86 and operatively connected to the opposite end of hydraulic cylinder 88. When cylinder 88 operates lever 86 pivots about the pivot point 94 and causes vertical movement of hole punch 90. An equal and opposite movement of hole punch 92 is also produced.

A mandrel 96 is fixedly mounted on frame 84 and is adapted to receive the end of tube 71 thereon. Mandrel 96 is hollow and is provided with diametrically opposed apertures aligned in the vertical direction with the hole punches 90 and 92. Hence mandrel 96 performs the dual function of locating the tube on the carriage 74 and acting as a die for the hole punches 90 and 92. Hole punches 90 and 92 are designed to produce the terminal holes 48 in the end of tube 71.

Movement of the first carriage 74 is effected by two pneumatic cylinders 98 and 100 linked end to end. Cylinder 98 is connected to the chassis 82 of carriage 74 and cylinder 100 is anchored at its opposite end to a mounting block 102 on one of the rails 72. The maximum distance that carriage 74 can travel is determined by the combined strokes of cylinders 98 and 100. The position of the mounting block 102 is selected based on the standard lengths of the tubes employed in the scaffolding system. The position of the mounting block 102 must be changed when a different size tube is to be converted. Tubes up to 6 metres long can be processed with this apparatus, by positioning the mounting block 102 at the far end, (to the right in Fig. 8) , of the rails 72. Pneumatically operated tube supports 104 can be raised to support long tubes at selected points between the carriages 74 and 76 and the press 70.

Carriage 74 is also provided with a tube support 106 mounted on the front of chassis 82 to guide the tube 71 onto the mandrel 96. A first guide rail 108 is fixedly mounted to the chassis 82 of carriage 74 with a support bracket 109 and together with a second guide rail 110, which extends from one end of a chain conveyer 112 to a position adjacent the mouth of the power press 70, acts to guide a tube 71 from the chain conveyer 112 into the start position to commence the operating cycle of the apparatus. A tube stop 114 is provided ad acent the mouth of the power press 70 and is adapted to open and close by means of pneumatic cylinder 116. In its closed position the tube 71 abuts hard up against the stop 114 and is prevented from entering the mouth of the press.

The function of the chain feed conveyor 112 is to position the tube 71 ready for loading onto the first carriage 74. Tubes are hand loaded onto a primary input hopper (not shown) which loads tube one at a time when needed onto the chain feed conveyor 112. As the primary input hopper is of conventional design the technical description will commence with a tube in position on the chain conveyor 112.

The second-' carriage 76 is of similar design to the first carriage 74 and the same parts will not be described again. One difference is that carriage 76 is provided with a guide rail 120 which slopes downwardly to guide a tube away from the carriage 76, when it is ejected from the apparatus by pneumatically operated kickers (not shown) . A second difference is the manner in which carriage 76 is moved along rails 72. Carriage 76 is linked to a third carriage 122 by a pneumatic cylinder 124 that has a stroke of 500mm. The rails 72 on this side of the press are provided with a plurality of index plates 126 spaced apart 500mm, which enable the tube 71 to be indexed through the press 70 at intervals of 500mm at a time. The second and third carriages 76 and 122 are both provided with indexing systems. Carriage 76 has a carriage lock operated by a pneumatic cylinder 128 which engages when operated with an index plate 126 to lock carriage 76 in position on rails 72. The third carriage 122 is provided with an indexing lever mechanism operated by pneumatic cylinder 130. Indexing levers 132 provided on both sides of carriage 122 are adapted to engage index plates 126 and lock carriage 122 in position when cylinder 130 is operated. When the full length of tube 71 has been indexed through the press 70, and the tube has been ejected from carriage 76, the two carriages 76 and 122 are returned to the start position by means of chains 134 attached to carriage 76, running on pulleys and operated by an electrical brake and clutch motor 136.

With the exception of motor 136 and press 70 operation of all moving parts in the complete apparatus is by hydraulic and pneumatic cylinders, and even press 70 is activated by pneumatic cylinder 78. The operating sequence is electrically sensed and controlled by a programmable logic controller (P.L.C.) (not shown). A suitable configuration for the P.L.C. could be readily designed by a person skilled in the electronics arts, based on an understanding of the required operating sequence as will be described in detail below. Accordingly, details of the P.L.C. have not been included here.

The following is the sequence and method of operation of the above apparatus for converting a conventional scaffolding tube to be compatible with the scaffolding system of the present invention. Upon arrival at the chain conveyor 112 the tube 71 is sensed by a limit switch which in turn sends a signal to the P.L.C. which instructs a motor (not shown) to advance the chain conveyor (with the tube) to a designated stop position adjacent the guide rails 108 and 110. Upon arrival at this position the tube 71 is again sensed and a signal sent to the P.L.C. which also senses when the first carriage 74 is clear and in a position to receive the tube. When these conditions have been met the P.L.C. instructs the chain conveyor 112 to eject the tube onto the guide rails 108, 110 leading to carriage 74. This is accomplished by the use of a mechanical kicker (not shown) operated by a pneumatic cylinder. When the chain conveyor 112 is empty a signal is sent to the P.L.C. which will then load the chain conveyor with the next tube and the chain feed cycle will begin again.

Upon ejection from the chain conveyor 112 the tube rolls down the two guide rails 108, 110 until the tube 71 comes to a rest position adjacent the mouth of the power press 70. At this time the P.L.C. instructs cylinder 116 to advance tube stop 114 to its closed position so that the tube 71 abutts against the stop 114 and is prevented from entering the mouth of the press. Simultaneously, tube support 104 (and adjacent supports depending on the length of the tube) may be in the raised position. Tube support 104 and tube support 106 on the carriage 74 arrest the tube in the correct position to proceed with the operating cycle.

When the tube 71 is sensed by the P.L.C. to be in the correct position pneumatic cylinder 100 advances carriage 74 on rails 72 towards the press 70, forcing the tube 71 hard against the stop 114 and loading the tube onto the mandrel 96 on carriage 74. When the tube is sensed to be hard up against the stop 114 and fully loaded onto the mandrel 96 hydraulic power is applied to hydraulic cylinder 88 which operates the lever system causing the hole punches 90 and 92 to punch two terminal holes in this end of the tube 71. At this stage the punches 90 and 92 remain in the advanced position. At this point in time pneumatic power is released on the cylinder 100 allowing cylinder 116 to withdraw the tube stop 114. When these operations are sensed to be completed a small pneumatic cylinder (not shown) is operated to eject the slugs from the hollow mandrel 96 into the tube 71. Cylinder 100 is fully operated advancing the tube 71 into the mouth of the power press 70 beneath marking tool 80. Upon sensing the operation of cylinder 100 the P.L.C. instructs the operation of the power press 70 for one stroke only by use of pneumatic cylinder 78. Upon sensing the completion of this operation the P.L.C. then instructs pneumatic cylinder 98 to fully operate advancing the tube 71 a further 500mm through the power press 70 and loading the tube onto the mandrel of the second carriage 76. At this point the hole punches 90 and 92 in carriage 74 are withdrawn by operating hydraulic cylinder 88. When these operations are sensed to be completed the power press 70 is again operated for one stroke only and pneumatic cylinders 98 and 100 are fully retracted returning the first carriage 74 to its start position. The tube 71 is now controlled by carriage 76.

The function of the second carriage 76 is to act as a slave to the third carriage 122, thereby feeding the tube 71 through the power press at indexed intervals while at the same time punching the second pair of terminal holes in the other end of the tube 71.

Prior to the first carriage 74 being returned to its start position, hydraulic cylinder 88 on the second carriage 76 is powered, and in a similar manner to the first carriage 74 two terminal holes are punched in the end of the tube 71. Once again the hole punches are not withdrawn at this stage. The slugs within the mandrel of the second carriage 76 are ejected in a similar manner to that in carriage 74.

The second carriage 76 is locked in position (at the start point closest to the press 70 common to all lenghths of tube) by the carriage lock powered by the cylinder 128 which engages with the index plates 126 provided on the rails 72 on this side of the press 70. After the operation of the press for one stroke only as described above, cylinder 128 is withdrawn disengaging the carriage lock. At this point in time, and after confirmation, the P.L.C. powers pneumatic cylinder 124 which connects the second and third carriages 76 and 122 respectively and has a stroke of 500mm, drawing the second carriage 76 500mm closer to the third carriage 122 and away from the power press 70. On completion of the stroke and after confirmation the P.L.C. operates carriage lock cylinder 128 causing the carriage 76 to lock onto the second index plate 126.

Two opeations now occur simultaneously. The power press 70 is again operated via instructions from the P.L.C. for one stroke only, and cylinder 130 is powered to operate the lever system on carriage 122 so that the indexing lock levers 132 on carriage 122 are disenaged. After sensing correct operation, the P.L.C. powers cylinder 124 to extend, moving the third carriage 122 500mm away from the second carriage 76. At completion and after confirmation of this stroke cylinder 130 is again powered by the P.L.C. to cause the indexing lock lever 132 of carriage 122 to lock in the index plates 126 on the carriage rails 72.

The above sequence of operations for carriages 76 and 122 are repeated until the tube 71 is clear of the press 70 which is electronically sensed by the P.L.C. During these operations, the tube supports 104 rise and fall as required to support the tube 71. When the tube 71 is sensed to be clear of the power press 70 and all actiity has ceased, hydraulic cylinder 88 on carriage 76 is activated to withdraw the hole punches from the terminal holes in the end of the tube 71. A lever system (not shown) is then activated to eject the tube from the mandrel on carriage 76, and kickers (not shown) kick the tube 71 clear of the carriage into a waiting hopper.

After the P.L.C. has confirmed the carriage to be clear, carriages 76 and 122 are returned to the start position by means of chains 134 and motor 136. Upon return, the operating cycle is ready .to recommence. It will be apparent to those skilled in the scaffolding manufacturing and construction industries that various modifications and variations may be made to the described scaffolding system, other than those already described, without departing from the essential inventive concepts. For example, in the preferred form of the invention the scaffolding members are hollow tubular members, however elongate members of other than circular cross-section, and\or which are not hollow, can also be employed.

All such variations and modifications are to be considered within the scope of the invention, the nature of which is to be determined from the forgoing description and the appended claims.

Claims (24)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. An elongate scaffolding member having a plurality of indelible markings at predetermined spaced apart distances along a longitudinal surface of the member, a first of said markings nearest one end of the member being located a pre¬ defined distance from said one end whereby, in use, said markings provide an accurate measure of the length of the member and enable precise positioning of coupling elements and fittings along the length of the member.

2. A scaffolding member as claimed in claim 1, wherein the markings are spaced apart at equal predetermined distances to one another.

3. A scaffolding member as claimed in claim 2, wherein the markings nearest the respective ends of the member are located the same said predefined distance from the respective ends of the member.

4. A scaffolding member as claimed in claim 3, wherein the member is a hollow tube and said markings are in the form of small holes or dimples in the wall of the tube.

5. A scaffolding member as claimed in claim 4, wherein the small holes or dimples are aligned in the longitudinal direction of the member along two lines extending on diametrically opposed sides of the member.

6. A scaffolding system comprising a plurality of elongate scaffolding members, each member having a plurality of indelible markings at predetermined spaced apart distances along a longitudinal surface of the member, a first of said markings nearest one end of the member being located a predefined distance from said one end, said predetermined distances and predefined distance being constant from member to member in the system whereby, in use, said markings provide an accurate measure of the length of the members and enable precise positioning of coupling elements and fittings along the length of the members.

7. A scaffolding system as claimed in claim 6, wherein said members are hollow tubes and said markings are in the form of small holes or dimples in the wall of the tube, said small holes or dimples being spaced apart at equal predetermined distances to one another and aligned in the longitudinal direction of the members with the markings nearest the respective ends of each member located the same said predefined distance from the respective ends of each member.

8. A scaffolding system as claimed in claim 7, wherein the members are further provided with an indication adjacent each end, said indications being provided to indicate to a user that a member has been cut to a standard length compatible with said scaffolding system.

9. A scaffolding system as claimed in claim 8, wherein said indications are provided in the form of apertures, said apertures being adapted to receive a latching element therein whereby, in use, terminal coupling elements can be locked more securely to the members.

10. A scaffolding system as claimed in claim 7, wherein said predefined distance from the respective ends of each member is equal to half of said predetermined distance between the small holes or dimples less half of the outer diameter of said hollow tubes used as said scaffolding members.

11. An end connector for connecting two of the scaffolding members defined in claim 1 end to end, the connector comprising: first and second end portions adapted to engage with the ends of two scaffolding members to be joined; and, a central spacer portion adapted to maintain the ends of the two scaffolding members spaced apart at a distance selected to enable the spacing of said indelible markings on the scaffolding members across the end to end connection to be maintained at said predetermined distance.

12. An end connector as claimed in claim 11, wherein said end connector is a spigot-type end connector and said end portions are adapted to be received in the ends of the scaffolding members.

13. An end connector as claimed in claim 12, wherein said central spacer portion maintains the ends of the two scaffolding members spaced apart at a selected distance equal to the outer diameter of the scaffolding members.

14. An end connector as claimed in claim 13, wherein the spigot-type end connector is provided with first and second latch protrusions on the first and second end portions respectively, adapted to be received in terminal holes provided in the ends of the scaffolding members.

15. A method of converting a conventional scaffolding tube, of the kind employed in tube and fitting scaffolding, to be compatible with the scaffolding system of the present invention, the method comprising the steps of: placing a first indelible marking on the tube a predefined distance from one end of the tube using a marking means; moving the tube or the marking means relative to the other a first predetermined distance in a longitudinal direction of the tube; placing a further indelible marking on the tube said first predetermined distance from the first indelible marking; and, repeating sequentially said steps of moving the tube or the marking means and placing a further indelible marking for the entire length of the tube.

16. A method as claimed in claim 15, wherein said steps of ' placing an indelible marking on the tube involve providing an indentation in the form of a dimple in the outer surface of the tube.

17. A method as claimed in claim 16, wherein said steps of placing an indelible marking on the tube further comprise placing a second indentation in the form of a dimple in the outer surface of the tube in a diametrically opposite location to the first indentation.

18. A method as claimed in claim 15 further comprising the steps of cutting the tube to a standard length; and, placing terminal holes- adjacent the respective ends of the tube in order to indicate the converted tube is of standard length.

19. An apparatus for converting a conventional tube, of the kind employed in tube and fitting scaffolding, to be compatible with the scaffolding system of the present invention, the apparatus comprising: marking means for placing indelible markings in or on a surface of the tube; and, transport means for moving the tube or the marking means relative to the other in a longitudinal direction of the tube whereby, in use, said transport means and said marking means can be operated sequentially commencing with the placing of a first indelible marking a predefined distance from one end of the tube and thereafter at predetermined spaced apart distances along a longitudinal surface of the tube.

20. An apparatus as claimed in claim 19, wherein said transport means comprises first and second carriages for moving the tube relative to the marking means, said first carriage feeding the tube through said marking means until the tube engages with the second carriage whereupon the second carriage drawings the tube through the marking means for the remainder of its length.

21. An apparatus as claimed in claim 20, wherein said marking ' means comprises a power press provided with a marking tool which enables the placement of two indelible markings in the form of dimples spaced apart a second predetermined distance and aligned in the longitudinal direction, with a single stroke of the press.

22. An apparatus as claimed in claim 21, wherein said transport means further comprises a pair of parallel carriage rails upon which said first and second carriages are mounted for rolling movement, and wherein said rails are provided with a plurality of index plates spaced apart at indexed intervals along the length of the rails.

23. An apparatus as claimed in claim 22, wherein said transport means further comprises a third carriage mechanically linked with said second carriage for indexing said second carriage as it carries the tube through the press, at said indexed intervals along the rails.

24. An apparatus as claimed in claim 19, further comprising programmable logic control means operatively connected to said marking means and said transport means for controlling the operating sequence of the latter.