GB2606690A - Gantry - Google Patents

Abstract

A gantry 1 has a pair of supports 2 for supporting a beam 5. Each support 2 has a support frame 3 and a beam support, such as a cradle 4, which is mounted on the support frame 3 so as to be turnable, possibly using elongate slots (22 fig.6). The beam support or frame may have one of tubular members 9, 10, where the radially inner member 10 may turn, the members forming a central mast 6. The support frame may have side arms 8 being pivotally connected to the beam support and may be height adjustable. The support frame may also have a base, 7, a ground engaging stabiliser (28 fig.7) and wheels (30 fig.9) which may be configurable for ground engagement or not. A pair of bags with wheels may be provided to transport a dismantled gantry; each support weighing less than 80Kg.

Description

Gantry This invention relates to a gantry.

It is known to provide gantries which are mobile between different sites, and which may be dismantled so as to be portable. A known portable gantry has a pair of so-called A-frame supports each mounted on ground engaging wheels and each having a cradle for supporting a load bearing beam extending between the supports. The supports each have a base mounted on the wheels and the bases are positioned spaced apart and parallel to each other, which aligns the seats of the cradles for receiving the beam. The beam can be used to support a trolley movable along the beam to carry a load horizontally from one part of the site to another. The bases need to be long enough to provide stability to the gantry, but this can mean that in some restricted environments it can be very difficult to position the gantry as desired to move the load to a desired location.

The invention provides a gantry comprising a pair of portable supports for supporting a beam spanning between the supports for carrying a load, each support comprising a support frame and a beam support, wherein the beam support is mounted on the support frame so as to be turnable relative thereto.

By each beam support being mounted on its support frame so as to be turnable relative thereto, each support frame can be adjusted to different positions relative to the longitudinal direction of the beam.

This assists with positioning the support frames in a confined space while permitting the beam to adopt a desired orientation for load carrying and for depositing the load at a desired target location. For example, when working in an office building environment, it is sometimes desirable to position the beam close to a wall, such as when using the gantry to install duct work of an air-conditioning system. With known gantries the length of the bases of the supports can mean that it is not possible to get the beam sufficiently close to a wall. By being able to turn the support frames relative to the longitudinal direction of the beam, the beam can be positioned relatively close to the wall.

If it is desired to move the gantry with the beam in place, the support frames can be turned relative to the longitudinal direction of the beam to assist such movement. For example, this may make the gantry easier to manoeuvre through a doorway.

The gantry may be used with a variety of beams, of different cross-sections and with different lengths. In use, the support frames belonging to the respective supports are positionable relative to each other by being located on the ground at a spacing. The spacing is variable to suit the required span of the beam. Thus, the support frames are not connected to each other, but are freely movable relative to each other to a desired spacing The beam support may be mounted on the support frame so that relative vertical movement of the beam support and the support frame is restricted while allowing relative turning. Thus the beam support and the support frame may be reliably assembled together.

In an embodiment, one of the beam support and the support frame comprises a tubular member and the other comprises a radially inner member, wherein the tubular member and the radially inner member extend vertically, and wherein the radially inner member is turnably received in the tubular member.

The radially inner member is located radially inwardly of the tubular member, and can be turned relative to the tubular member in which it is received.

The radially inner member may have a circular cross-section. It may be solid across its cross-section or it may be a second tubular member.

The support frame may comprise one or more openings through which a shaft extends horizontally, the beam support may comprise one or more openings through which the shaft extends horizontally, and the one or more openings of at least one of the support frame and the beam support may be a pair of horizontally extending elongate slots.

The beam support and the support frame may be relatively turnable by relative rotation of the tubular member and the radially inner member, with the shaft allowing such relative rotation whilst restricting relative vertical movement between the beam support and the support frame. Thus a secure turnable connection can be provided.

The elongate slots may be positioned opposite each other. The shaft can extend horizontally from one side of the beam support and the support frame to the other side thereof, through the opposite elongate slots.

The one or more openings of the other of the beam support and the support frame may be a second pair of horizontally extending slots. Alternatively, the or each opening is circular in vertical cross-section. In the embodiment in which the radially inner member is a second tubular member, the one or more openings may 3 -be a pair of openings positioned opposite each other. Each of the pair of opposite openings may be circular in vertical cross-section.

The shaft may belong to a bolt or pin.

Each support frame may comprise a central mast on which the respective beam support is mounted and relative to which the beam support is turnable.

Loads from the beam can be carried directly from the beam support to the central mast, whilst the mast provides a convenient member on which the beam support may turn. The beam support may have a downwardly facing bearing surface which engages an upwardly facing bearing surface of the central mast. The mast may comprise a tube, in which case a top of the tube may provide the upwardly facing bearing surface. The beam support may have a plate which provides the downwardly facing bearing surface. Thus the plate of the beam support may rest on the top of the tube while being able to transmit downward load from the beam support to the tube.

Each beam support may comprise a vertically extending tubular member mounted on the respective support frame and turnable relative thereto. In embodiments in which the beam support has a plate, the tubular member may extend downwardly from the plate. In embodiments having a central mast which comprises a tube, the tubular member of the beam support may nest with the tube of the mast. The tube of the mast may fit inside the tubular member of the beam support.

The beam support may be fixable in position on its respective support frame once it has been turned into a desired position. As discussed above, a horizontally extending shaft may be provided. The shaft may belong to a threaded bolt, and a nut placed on the bolt may be used to fix the beam support in position on the support frame once turned into the desired position.

Each support frame may comprise a pair of side arms. These can provide stability.

The side arms may be arranged in an upside down "V" and may be pivotably mounted at the apex of the upside down "V".

The side arms may be connected to the beam support. With such an arrangement, the stability of the support provided by the side arms for the beam support is good, compared to a situation in which the side arms are attached lower down, for example to the central mast of the support frame.

The side arms may be pivotably connected to the beam support. 4 -

The side arms may be pivotably mounted to be pivotable in a vertical plane.

In the embodiments having a horizontally extending shaft, the shaft may form a connection between the side members, the tubular member and the radially inner member. The shaft may extend through the horizontally elongate slots and the one or more openings.

Each support frame may comprise a base extending between the side arms. In use, the base engages the ground and can spread loading over its length. In embodiments having a central mast, this may transmit load to the centre of the base, which may then spread the load. In this specification ground means any surface on which the gantry rests, which may for example be a floor in a building or an outside surface.

Each support frame may comprise a ground engaging stabiliser extending from the base. This will be useful to provide stability when the beam support and the support frame are relatively turned, for example to a configuration in which a general plane of the support frame is not perpendicular to a longitudinal direction in which the beam support is to support the beam, because the extent of the base out of the vertical plane of the beam centre line may be reduced.

The stabiliser may be movably mounted to the base so as to be adjustable relative thereto. This can improve stability by adjusting the stabiliser to spread the load as desired and as permitted by the local site.

The stabiliser may be slidably mounted to the base, for example being received slidably in a tube of the base.

Each support frame may be provided with a plurality of wheels for engaging the ground. These may be used to assist easy manoeuvring of the gantry without dismantling it, and may be useful when turning the support frame relative to the beam support, for example when moving the gantry through a doorway.

In normal use, when the gantry is to be used to provide support for the beam carrying a load, the wheels will be removed from ground engagement. This allows the load to be carried to the ground by the base of each support frame, thereby spreading the load and avoiding concentrated loading at the wheels. The base may then be ground engaging along its length.

In an embodiment, each wheel belongs to a wheel unit for mounting the wheel in a first configuration for ground engagement, and the wheel unit can adopt a second configuration in which the wheel is not for ground engagement. This second configuration may involve removal of the wheel unit and setting it aside, or

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in the second configuration the wheel unit may be stowed in a stowed position on the gantry, for example on a respective base on which the wheel unit is mounted in the first configuration.

In the first configuration the wheel unit may be connected to the support frame by a pin arranged horizontally and extending through apertures in the wheel unit and the support frame. The pin can be withdrawn from the apertures to allow the wheel unit to adopt the second configuration.

In the embodiment in which the wheel unit in the second configuration is stowed in a stowed position, the pin may also be used to retain the wheel unit in the stowed position. Thus a single pin may advantageously be used to connect the wheel unit to the support frame in both configurations of the wheel unit. The apertures in the wheel unit and the support may also be used to receive the pin when it retains the wheel unit in the stowed position. This can assist in providing an arrangement with a minimum of parts.

Each support frame is height adjustable. This allows the beam support to be supported at a desired height. In embodiments having a central mast, this may be length adjustable, for example by being telescopic. In embodiments having side arms, these may be length adjustable, for example by being telescopic.

The gantry may be capable of being dismantled. This can enable easy transport of the gantry to a site where it is to be erected.

The gantry may further comprise a pair of bags, and wherein each support can be dismantled so that when dismantled the support fits into a respective bag of the pair thereof.

The bags can provide convenient storage for the supports.

Each support may be portable in its bag.

Each bag may be provided with external wheels.

The external wheels may assist portability, for example by allowing the bag to be manoeuvrable by one person. The external wheels may be provided at one end of the bag. A handle may be provided at the other end of the bag. The handle may be held and the bag moved along on its external wheels.

Each bag containing a respective support may have a mass of 80 kg or less. Each bag may have a mass of 70 kg or less, for example 60 -70 kg.

The beam supports may each have an upwardly facing surface for engagement by a beam which is to be supported. The upwardly facing surfaces may be at a height off the ground on which the gantry stands of 3 m or less. In 6 -embodiments in which the support frames are height adjustable, they may be adjustable such that the maximum height of their upwardly facing surfaces off the ground is 3 m.

The beam support may comprise a cradle. This may receive the beam thereon, for example cradled in a cradle cavity.

Certain preferred embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a schematic end view of a gantry; Figure 2 is a schematic side view of the gantry; Figure 3 is a schematic plan view of a cradle of the gantry; Figure 4 is a schematic end view of the cradle; Figure 5 is a schematic side view of the cradle; Figure 6 is a perspective view of a top part of the gantry including a modified cradle.

Figure 7 is a schematic plan view of a pair of bases of the gantry; Figure 8 is a schematic plan view of the bases in a turned configuration; and Figure 9 is a schematic cross-sectional view of a part of one of the bases where a wheel is mounted.

Referring to Figures 1 and 2, a gantry 1 comprises a pair of portable supports 2 for supporting a beam 5 spanning between the supports 2 and for carrying a load, each support 2 comprising a support frame 3 and a beam support in the form of a beam supporting cradle 4 mounted on the support frame 3, wherein each cradle 4 is turnably mounted on its respective support frame 3. Each support frame 3 further comprises a central mast 6 and a base 7 from the centre of which the central mast extends upwardly to the cradle 4. Each support frame 3 also comprises a pair of side arms 8 arranged in an upside down "V" pivotably mounted at their upper ends at the apex of the upside down "V" to the central mast 6, and pivotably mounted at their lower ends to the opposite ends of the base 7.

The central mast 6 and the side arms 8 are telescopic. The central mast has an outer tube 9 secured centrally of the base 7 and extending vertically upwardly, and an inner tube 10 concentrically located in the outer tube 9 and extending vertically upwardly from the outer tube 9 to an upper portion of the central mast 6. Each side arm 8 has an outer tube 11 extending upwardly in inclined manner from an end of the base 7, and an inner tube 12 concentrically located in 7 -the outer tube 11 and extending upwardly in inclined manner from the outer tube 11 to the upper portion of the central mast 6.

Each support frame 3 is height adjustable, so that the height at which the cradle 4 is supported may be adjusted. In this embodiment, height adjustment is possible because of the telescopic configuration of the central mast 6 and the side arms 8. The outer tube 9 and the inner tube 10 of the central mast each includes pairs of horizontally aligned apertures (not shown) at vertical spacings. A pair of apertures in the outer tube 9 may be aligned with a pair of apertures in the inner tube 10 when the central mast 6 has a desired height, and then a bolt (not shown) may be passed through the aligned apertures to connect the outer and inner tubes.

The bolt will be load-bearing, because it serves to carry load from the cradle 4 to the central mast 6.

The outer tube 11 and the inner tube 12 of each side arm 8 each includes pairs of horizontally aligned apertures (not shown) at spacings along the length of the respective tube. A pair of apertures in the outer tube 11 may be aligned with a pair of apertures in the inner tube 12 when the central mast 6 is adjusted to a desired height, and then a bolt (not shown) may be passed through the aligned apertures to connect the outer and inner tubes.

Figures 3-6 show further details of the cradle 4 (modified in Figure 6), and Figure 6 shows further details also of the top of the support frames 3.

The cradle 4 shown in Figures 3-5 comprises a main plate 13 and a pair of horizontally spaced upstanding side walls 14, creating a cradle cavity 15 in which the beam 5 may be cradled and supported. In the modification shown in Figure 6, the cavity 15 is created by a "U" shaped saddle 16 which is supported on the main plate 13, the saddle 16 having upstanding side walls 14a which are taller than those of the cradle 4 shown in Figures 3-5.

The main plate 13 of the cradle 4 is formed with two pairs of vertical apertures 17, with each aperture being located near the corners of the main plate. A clamping member 18, shown only in Figures 4 and 6, having a pair of vertical apertures 19 is securable to the main plate 13 by a pair of bolts 20 each of which extends through an aperture 17 of the main plate 13 and an aperture 19 of the clamping member 18. One or two clamping members 18 may be used.

In use, a beam 5 is supported in the cradle cavity 15 and is clamped between the main plate 13 and the clamping member(s) 18. The cradle cavity 15 8 -and the clamping arrangement allow for different heights of beam. In this embodiment, the beam is an "I" beam, as seen in Figure 1.

As seen in Figures 4-6, the cradle 4 has a tubular member 20 extending downwardly from the main plate 13, forming a cradle mounting portion for mounting the cradle on the support frame 3. The top part of the central mast 6, which in this embodiment belongs to the central mast inner tube 10, is received concentrically in the tubular member 20 and forms a mounting portion of the support frame 3. The inner tube 10 has at its upper end an upwardly facing annular surface which is engaged by a lower surface of the main plate 13 (this engagement is not shown).

Load from the beam 5 is transmitted to the cradle 4, and from there to the top part of the central mast by virtue of the lower surface of the main plate 13 engaging the upwardly facing annular surface of the inner tube 10.

The tubular member 20 of the cradle 4 comprises a pair of horizontally extending elongate slots 21 arranged opposite to each other. The inner tube 10 of the central mast 6 comprises a pair of horizontally extending openings 22. A shaft of a bolt 23 extends through the slots 21 and the openings 22 to form a connection between the central mast 6 and the cradle 4. Because the openings 22 are elongate, the cradle 4 supported on the inner tube 10 of the central mast 6 can be turned relative to the inner tube 10 with the bolt 23 in place but in a loose condition.

Thus the mounting portion of the cradle 4 is turnably mounted on the mounting portion of the support frame 3. When a desired turned position is reached, a nut 24 on the bolt may be tightened. This connection restricts relative vertical movement of the cradle 4 and the central mast 6 of the support frame 3 whilst allowing relative turning.

In this embodiment, the elongate slots are provided in the tubular member of the cradle 4. In an alternative embodiment, elongate slots may be provided in the inner tube 10 of the central mast 6, and openings which are not elongate may be provided in the tubular member 20. In another embodiment, elongate slots may be provided in both the tubular member 20 and the inner tube 10.

In this embodiment, the central mast 6 comprises an inner tube 10, but in an alternative embodiment the central mast 6 may comprise a solid member, for example of circular cross-section. This solid member may be received concentrically in the tubular member 20 and may be formed with an opening in the form of a bore across the solid member, which may have a cylindrical shape for receiving the bolt 23, or may have an hour glass shape in horizontal section to 9 -provide circumferentially elongate slots at the radially outer surface of the solid member for receiving the bolt 23.

It is not necessary for the bolt 23 to transmit load from the cradle 4 to the central mast 6. As discussed above, the load may be transmitted from the main plate 13 to the upwardly facing annular surface of the inner tube 10 (or in the case of the central mast comprising a solid member, from the main plate 13 to an upwardly facing surface of the central mast), so that the bolt 23 may serve to hold the relative turned position of the cradle and the central mast and to restrict relative vertical movement of these components, but is not subject to high shear loads.

As seen in Figure 6, each side arm inner tube 12 of the support frame 3 is formed with a pair of horizontally extending apertures arranged opposite to each other. The bolt 23 extends also through these pairs of apertures. Thus a connection is formed between the side arms 8 and the central mast 6, as well as between the side arms 8 and the cradle 4. The side arms are pivotably connected to the central mast and the cradle by the bolt 23. This pivotal connection allows the inclination of each side arm 8 to alter as the height of the central mast 6 is adjusted. Figures 7 and 8 show the bases 7 of the support frames 3. Each base 7 comprises a pair of elongate ground engaging members 25 which extend horizontally and spaced apart from each other. A central cross piece 26 is provided to support the central mast 6 and is securely mounted to bridge between the ground engaging members at a location longitudinally centrally thereof. Load is carried from the central mast 6 to the central cross piece 26 and from there may be spread to both ground engaging members 25.

At each longitudinal end of the ground engaging members 25 an end cross piece 27 is provided. The end cross piece 27 is a square tube (see Figure 9). In each end cross piece 27 a ground engaging stabiliser 28 is slidably received. Figure 7 shows the bases 7 of the two support frames 3 of the gantry 1 arranged parallel to each other. A line L between the centres of the two bases lies in a vertical plane in which the central longitudinal axis of the beam supported by the gantry also lies. As shown in Figure 7, line L and the beam 5 extend perpendicularly to the bases 7. This is similar to the situation in known gantries. Figure 8 shows a configuration in which the bases 7, and the support frames 3 to which they belong, have been rotated through 60° from the position shown in Figure 7. Therefore, instead of being at an angle of 900 to the line L which lies in the same plane as the beam 5, they are at an angle of 30° to the line L. The effect -10 -of this is that the ends of the bases 7, where the end cross pieces 27 are provided, are nearer to the line L. Therefore, for example, when it is desired to locate the beam 5 nearer to a wall, the relative rotation of the support frames 3 and the cradles 4 (which each support frame supports) allows the line L and the beam 5 which lies in the same vertical plane as this line L to come closer to the wall.

In order to assist stability of the gantry 1 when the support frames 3 are turned relative to the cradles 4, the ground engaging stabilisers 28 which extend from the ends of each base 7 are provided. The stabilisers 28 are movably mounted in the end cross pieces 27 so that they may be repositioned as appropriate to avoid being obstructed where they engage the ground. In the view shown in Figure 8, the stabilisers 28 have not been repositioned, but they are capable of being repositioned.

Figure 9 shows a removable wheel unit 29 having a wheel 30. Each support frame 3 has a wheel unit 29 removably mounted at each longitudinal end. The wheel unit 29 has a pair of spaced plates 31 which support the wheel 30 for rotation. The plates 31 depend downwardly from an upwardly facing cup 32 which has a base plate 33 and a cup tube 34. The cup tube 34 is concentrically received in a base tube 35 secured between the ground engaging members 25 of the base 7. The base tube 35 is provided with a radially outwardly and circumferentially extending flange 39.

The cup tube 34 is formed with a pair of horizontally aligned apertures 36. The base tube 35 is formed with a pair of horizontally aligned apertures 37. A pin 38 extends through the apertures 36 and 37 to connect the cup tube 34 of the wheel unit 29 to the base tube 35 of the base 7.

Vertically downward load is transmitted from the base 7 via the flange 39 of the base tube 35 to the base plate 33 of the wheel unit. The pin 38 serves to connect the wheel unit 29 and the base 7 but is not subjected to shear loading as a result of vertically downward load on the support frame 3 to which the base 7 belongs.

The pin 38 is tied to the support frame 3 by a tie 40. It is removable from the apertures to allow the wheel unit 29 to be removed from the base. The wheel unit may be turned upside down and the unit inserted downwardly into the base tube 35, and the pin may then be reinserted to retain the wheel unit 29 in a stowed position in which it does not engage the ground.

In an alternative embodiment, the wheel may be removable from ground engagement by pivoting to a stowed position.

The gantry 1 may be provided with a wheel unit 29 at the longitudinal ends of each base 7, so having four wheel units altogether. VVhen it is desired to move the gantry from one place to another without disassembling it, the wheel units may be put in their position of use below the ground engaging members 25. The support frames 3 may be swivelled relative to the beam 5, for example moving from the condition shown in Figure 7 to that shown in Figure 8 without the stabilisers 28 being present, so allowing the gantry to be manoeuvred through a narrow space such as a doorway. When it is desired to use the gantry to support a load carried by the beam 5, the wheel units 29 are removed from their ground engagement so that load may be transmitted from the ground engaging members 25 directly to the ground, in a spread out manner. The wheel units 29 are preferably pinned into their stowed positions by their pins 38.

Figure 9 also shows a plate 41 projecting upwardly from the ground engaging member 25. This plate 41 is provided with a pivotal mounting 42 to which one of the side arms 8 may be pivotally mounted. This allows the side arm to pivot on the base 7 when the height of the support frame 3 is adjusted.

Claims (20)

1. -12 -Claims 1. A gantry comprising a pair of supports for supporting a beam spanning between the supports for carrying a load, each support comprising a support frame and a beam support, wherein the beam support is mounted on the support frame so as to be turnable relative thereto.
2. 2. A gantry as in claim 1, wherein the beam support is mounted on the support frame so that relative vertical movement of the beam support and the support frame is restricted while allowing relative turning.
3. 3. A gantry as claimed in claim 1 or 2, wherein one of the beam support and the support frame of each support comprises a tubular member and the other comprises a radially inner member, wherein the tubular member and the radially inner member extend vertically, and wherein the radially inner member is turnably received in the tubular member.
4. 4. A gantry as in claim 3, wherein the radially inner member is a second tubular member. 20
5. 5. A gantry as claimed in claim 3 or 4, wherein the support frame comprises one or more openings through which a shaft extends horizontally, wherein the beam support comprises one or more openings through which the shaft extends horizontally, and wherein the one or more openings of at least one of the support frame and the beam support is a pair of horizontally extending elongate slots.
6. 6. A gantry as claimed in any preceding claim, wherein each support frame comprises a central mast on which the respective beam support is mounted and relative to which the beam support is turnable.
7. 7. A gantry as claimed in any preceding claim, wherein each support frame comprises a pair of side arms.
8. 8. A gantry as it claimed in claim 7, wherein the side arms are arranged in an upside down "V" and are pivotably mounted at the apex of the upside down "V".-13 -
9. 9. A gantry as claimed in claim 7 or 8, wherein the side arms are connected to the beam support.
10. 10. A gantry as claimed in claim 9, wherein the side arms are pivotably connected to the beam support.
11. 11. A gantry as claimed in any of claims 7 to 10, wherein each support frame comprises a base extending between the side arms.
12. 12. A gantry as claimed in claim 11, wherein the support frame comprises a ground engaging stabiliser extending from the base.
13. 13. A gantry as claimed in claim 12, wherein the stabiliser is movably mounted to the base so as to be adjustable relative thereto.
14. 14. A gantry as claimed in any preceding claim, wherein each support frame is provided with a plurality of wheels for engaging the ground.
15. 15. A gantry as claimed in claim 14, wherein each wheel belongs to a wheel unit for mounting the wheel in a first configuration for ground engagement, and wherein the wheel unit can adopt a second configuration in which the wheel is not for ground engagement.
16. 16. A gantry as claimed in claim 15, wherein in the first configuration the wheel unit is connected to the support frame by a pin arranged horizontally and extending through apertures in the wheel unit and the support frame, and wherein the pin can be withdrawn from the apertures to allow the wheel unit to adopt the second configuration.
17. 17. A gantry as claimed in any preceding claim, wherein each support frame isheight adjustable.
18. 18. A gantry as claimed in any preceding claim, further comprising a pair of bags, and wherein each support can be dismantled so that when dismantled the support fits into a respective bag of the pair thereof.-14 -
19. 19. A gantry as claimed in claim 19, wherein each bag is provided with external wheels.
20. 20. A gantry as claimed in claim 18 or 19, wherein each bag containing a respective support has a mass of 80 kg or less.