A PRESSING TOOL

Field of the Invention

This invention lies in the field of producing units used in the construction of communication masts, i.e. masts or towers that are used to carry communication equipment for telephony, radar, radio and other signalling, transmission, navigation and detection means. Such masts can be used for other purposes such as lighting and illumination masts, navigation lights, power and telephony lines.

Background to the Invention

Masts are required in large numbers for mobile phone systems to relay long wave radio signals on line-of-sight, each mast establishing an area or cell and hence the name also used "cell phones". The economy of masts used in such applications in particular is especially important, although an economical mast is valuable for any application. Considerations of economic importance are the total quantity of structural steel that is usually used in the mast and the "footprint", i.e. the ground area of the foundation, that is occupied by the mast and equipment associated with the mast. In certain areas land area is at a severe cost premium, so that if the footprint can be reduced significant cost saving can be realised.

These considerations have led to the design of three-legged masts which reduce structural steel used and the footprint of the mast. This design was significantly improved by forming the structural steel angle section beams used for the tower legs from the standard 90° angle to a 60° angle at positions where bracing members are connected.

This benefit is only realised by surmounting the difficulty of forming angle section beams to the desired angle of about 60° and the present invention seeks to address this challenge.

In the specification that follows, the term "angle section beam" is to be interpreted as meaning a beam having a generally L-shaped cross section wherein the two legs of the beam can be of equal or unequal length.

Summary of the Invention

According to the invention, there is provided a pressing tool for forming at least a portion of an angle section beam, the tool including:-

- a male member presenting a first tool surface for in use receiving at least a portion of the angle section beam thereon, said first tool surface having two inclined surfaces defining an angle of less than ninety degrees between them; and

- a female member presenting a second tool surface complementary in shape to the first tool surface for in use engaging the angle section beam located on the male member; wherein the male and female members are composed of modular units so as to permit their length, and thereby the portion of the angle section beam to be formed, to be varied.

The angle defined between the two inclined surfaces of the first tool surface may be pre-selected and is typically about sixty degrees. Accordingly, a portion of an angle section beam formed using the pressing tool will have a reduced angle of about sixty degrees between its two legs as opposed to the standard angle of ninety degrees.

The modular units of the male member may be in the form of generally triangular blocks, wherein two sides of the triangle define the first tool surface. Each male modular unit may have a pre-selected thickness.

The male member may further include a knife edge extending longitudinally along an apex of the male member on which knife edge an apex region of the angle section beam is received in use. The term "knife edge" is not to be interpreted as presenting a sharp edge but a rounded edge forming a complementary fit with an internal apex region of the angle section beam.

The knife edge may be in the form of a longitudinal bar attachable to the male member along its apex. The bar may be provided in modular units having a predetermined length to accommodate various numbers of male and female modular units and thereby lengths of male and female members.

The modular units of the female member may define two inclined surfaces complementary to the inclined surfaces of the male member. Again, each female modular unit may have a pre-selected thickness.

The male and female members may accommodate angle section beams of varying leg lengths and even beams having legs of unequal lengths as long as the legs do not extend past the first and second tool surfaces.

Flanges may extend laterally from either side of base regions of the male and female modular units.

The male and female members may be located on first and second base plates respectively, which base plates may in use be fitted to a conventional metal press.

The first and second base plates may include first and second channels for receiving base regions of the male and female modular units respectively therein.

When a selected number of male and female modular units have been placed in the first and second channels (depending on the length of angle section beam to be formed), first and second brackets may be located over the flanges extending from either side of the base regions of the modular units and attached to the first and second base plates by suitable attachment means such as, for example, bolts.

The brackets may be provided as modular units of a pre-selected width to accommodate various numbers of male and female modular units and thereby lengths of male and female members.

The male and female modular units may be provided with threaded apertures arranged to be in register when the units are received by the first and second channels respectively. Threaded rods may be passed through the apertures and secured to the units by means of nuts and washers.

The male and female modular units are therefore secured to the first and second base plates respectively by the brackets and in addition, the male modular units are connected by a rod and the female modular units are connected by at least one rod.

The pressing tool may provide for transition zones between a portion of the angle section beam which has been formed (i.e. where the angle between the legs of the beam has been reduced) and regions located on either side of the formed portion where the angle between the two legs of the angle section beam is about ninety degrees.

First and second support members having inclined surfaces defining between them an angle of about ninety degrees are located in a spaced apart relationship to free ends of the male member. First and second transition zones are thereby defined between the free ends of the male member and the first and second support members, which also constrain the angle section beam with its two legs maintained at about ninety degrees to each other during forming.

Additional support for the angle section beam during forming may be provided by first and second stabilisers located in a spaced apart relationship to the first and second support members and remote the male member. An upper region of the first and second stabilisers may be conical in shape so as to easily be located in the internal apex of the angle section beam.

A spacing device for adjusting the distance between a free end region of the angel section beam and the male member may further be provided. The spacing device may include a slotted arm extending from the first base plate. A stopper member may extend substantially perpendicularly from the slot in

which a base portion of the stopper member may be slideably receivable, thereby permitting the stopper member to be displaced along the length of the arm.

In use, the desired distance between the free end region of the angle section beam and the male member is adjustable by displacing the stopper member accordingly and then resting the free end region of the angle section beam against the stopper member.

Detailed Description of the Invention

The invention will now be described by way of the following non-limiting example with reference to the accompanying drawings.

In the drawings:-

Figure 1 is a three-dimensional view of the pressing tool;

Figure 2 is a three-dimensional view of the male member of the tool of Figure 1;

Figure 3 is a three-dimensional view of the female member of the tool of Figure 1; and

Figure 4 is an exploded view of the male member of the tool of Figure 1 ; and

Figure 5 is an exploded view of the female member of the tool of Figure 1.

In the drawings, reference numeral 10 generally indicates an embodiment of a pressing tool in accordance with the present invention.

A pressing tool 10 for forming at least a portion of an angle section beam (not shown) includes a male member 12 presenting a first tool surface 14 for in use receiving at least a portion of the angle section beam thereon.

The first tool surface 14 has two inclined surfaces 16.1 and 16.2 defining an angle α of less than ninety degrees between them.

The tool 10 further includes a female member 18 presenting a second tool surface 20 complementary in shape to the first tool surface 14 for in use engaging the angle section beam located on the male member 12.

The male and female members 12 and 18 are composed of modular units 22 and 24 respectively so as to permit their length, and thereby the portion of the angle section beam to be formed, to be varied.

The angle α defined between the two inclined surfaces 16.1 and 16.2 is typically about sixty degrees. Accordingly, a portion of an angle section beam formed using the pressing tool 10 will have a reduced angle of about sixty degrees between its two legs as opposed to the standard angle of ninety degrees.

The modular units 22 of the male member 12 are in the form of generally triangular blocks as can clearly be seen in Figures 1 and 2, wherein two sides of the triangle define the first tool surface 14. Each male modular unit 22 has a pre-selected thickness. Alternatively, the units 22 can be provided in a selection of thicknesses.

The male member 12 furthers include a knife edge 26 extending longitudinally along an apex 28 of the male member 12 on which knife edge 26 an apex region of the angle section beam is received in use. The term "knife edge" is not to be interpreted as presenting a sharp edge but a rounded edge forming a complementary fit with an internal apex region of the angle section beam.

In the embodiment shown, the knife edge 26 is in the form of a longitudinal bar 30 attachable to the male member 12 along its apex 28. The bar 30 is also provided in modular units having a predetermined length to accommodate various numbers of male and female modular units 22 and 24 and thereby lengths of male and female members 12 and 18.

The modular units 24 of the female member 18 define two inclined surfaces 32.1 and 32.2 complementary to the inclined surfaces 16.1 and 16.2 of the male member 12. Each female modular unit 24 has a pre-selected thickness or can be provided in a range of thicknesses.

The male and female members 12 and 18 are able to accommodate angle section beams of varying leg lengths and even beams having legs of unequal lengths as long as the legs do not extend past the first and second tool surfaces 14 and 20. The distance 34 is accordingly selected to accommodate the largest angle section beam to be formed using the tool 10.

Flanges 36 extend laterally from either side of base regions 38 of the male and female modular units 22 and 24.

The male and female members 12 and 18 are located on first and second base plates 40 and 42 respectively, which base plates 40, 42 are in use fitted to a conventional metal press, typically a hydraulic press.

The first and second base plates 40 and 42 include first and second channels 44 and 46 for receiving base regions 38 of the male and female modular units 22 and 24 respectively, therein.

When a selected number of male and female modular units 22 and 24 have been placed in the first and second channels 44 and 46 (depending on the length "I" of angle section beam to be formed), first and second brackets 48 and 50 are located over the flanges 36 and are attached to the first and second base plates 40 and 42 by suitable attachment means such as, for example, bolts 52.

The brackets 48 and 50 are also provided as modular units of a pre-selected width to accommodate various numbers of male and female modular units 22 and 24 and thereby lengths of male and female members 12 and 18.

The male and female modular units 22 and 24 are provided with threaded apertures 54 arranged to be in register when the units 22, 24 are received by the first and second channels 44 and 46 respectively. Threaded rods 56 are passed through the apertures 54 and secured to the units 22, 24 by means of a nut-and-washer arrangement 58.

The male and female modular units 22 and 24 are therefore secured to the first and second base plates 40 and 42 respectively by the brackets 48, 50 and in addition, the male modular units 22 are connected by a rod 56 and the female modular units 24 are connected by two rods 56.

The pressing tool 10 provides for transition zones 60 between a portion of the angle section beam which has been formed (i.e. where the angle between the legs of the beam has been reduced) and regions located on either side of the formed portion where the angle between the two legs of the angle section beam is about ninety degrees.

First and second support members 62 and 64 having inclined surfaces 66 defining between them an angle of about ninety degrees are located in a spaced apart relationship to free ends of the male member 12. First and second transition zones 60.1 and 60.2 are thereby defined between the free ends and of the male member 12 and the first and second support members 62 and 64, which also constrain the angle section beam with its two legs maintained at about ninety degrees to each other during forming.

Additional support for the angle section beam during forming is provided by first and second stabilisers 70 and 72 located in a spaced apart relationship to the first and second support members and remote the male member 12. An upper region of the first and second stabilisers 70 and 72 is conical in shape as can be seen in Figure 1 so as to easily be located in the internal apex of the angle section beam.

The rod 56 passing through the male modular units 22 also extend through the first and second support members 62 and 64 as well as into the first and second stabilisers 70 and 72.

A spacing device 74 for adjusting the distance "d" between a free end region of the angel section beam and the male member 12 is provided. The spacing device includes a slotted arm 76 extending from the first base plate 40. A stopper member 78 extends substantially perpendicularly from the slot 80 in which a base portion of the stopper member 78 is slideably receivable, thereby permitting the stopper member 78 to be displaced along the length of the slot 80 and thereby the arm 76.

In use, the desired distance between the free end region of the angle section beam and the male member 12 is adjustable by displacing the stopper member 78 accordingly and then resting the free end region of the angle section beam against the stopper member 78.

If it is desired for an entire angle section beam to be formed by the pressing tool 10 such a beam can of course be formed in increments, the length of which is determined by the maximum length of the male and female members 12 and 18.

An advantage of the pressing tool of the present invention is that the length of angle section beam to be formed as well as the length of the transition zones and the distance between a free end of the angle section beam and the portion to be formed is readily adjustable without requiring great skill on the part of the person doing the adjusting. The tool can be used in a conventional press and presents a mechanically simple and cost-effective device for the forming of angle section beams.

It is to be appreciated, that the invention is not limited to any particular embodiment or configuration as hereinbefore generally described or illustrated.