GB2559359B

GB2559359B - Stackable frame

Info

Publication number: GB2559359B
Application number: GB1701665.0A
Authority: GB
Inventors: Hall Martin; Neilson Ray
Original assignee: BELLE ENGINEERING SHEEN Ltd
Current assignee: BELLE ENGINEERING SHEEN Ltd
Priority date: 2017-02-01
Filing date: 2017-02-01
Publication date: 2019-07-10
Anticipated expiration: 2037-02-01
Also published as: GB201701665D0; GB2559359A

Description

STACKABLE FRAME

TECHNICAL FIELD

The present disclosure relates to a stackable frame and particularly to a frame for protecting an item of light plant equipment. Aspects of the invention relate to a frame, to an assembly comprising a frame and an item of plant equipment located within the frame, to a stack of two or more frames, and to a method of assembling a stack of frames.

BACKGROUND

Items of portable plant or construction equipment such as motors, generators, mixing devices, pumps, hydraulic power packs, poker power units and pressure washers may be prone to damage if not properly protected in use, as well as being inconvenient to store and handle. In order to provide protection against in-use damage, items of plant or construction equipment may be provided with a protective frame extending around the item. Such a frame may take the form of a cuboidal frame of tube or angle section struts to which the item of plant or construction equipment is attached. However, known protective frames are often still difficult to handle, particularly with dedicated lifting equipment. In addition, many known designs of protective frame do not allow stacking of frames. Even in cases where stacking of protective frames is possible, stacked frames are often not stable. For this reason it is common for items of plant or construction equipment to be kept in boxes when in storage, and for delivery to and from locations for use.

It is an aim of the present invention to address disadvantages associated with the prior art.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a protective frame for an item of plant equipment that is configured to be stacked together with one or more similar frames in use, wherein the frame comprises a lifting element at an inboard location with respect to the frame that provides a lifting point by which the frame may be lifted in use, and a base that defines a base aperture that is configured to receive the lifting element of a similar frame which may be positioned underneath the frame in use; wherein the lifting element comprises first and second side faces and first and second shoulders, and the base aperture comprises first and second side edges and first and second end faces; wherein the first and second side faces of the lifting element are configured to respectively engage the first and second side edges of the base aperture of a further frame which may be positioned on top of the frame in use, and the first and second shoulders of the lifting element are configured to respectively engage the first and second end faces of the base aperture of the further frame, such that cooperation between the lifting element of the frame and the base aperture of the further frame at least substantially prevents movement of the frame relative to the further frame. The item of plant equipment may be, for example, a device or machine for use in construction, manufacturing, landscaping, gardening, or domestic DIY. The item of plant equipment may be, for example, a motor, a generator, a mixing device, a pump, a hydraulic power pack, a poker power unit or a pressure washer.

The lifting element may be provided at a top face of the frame. The lifting element may be spaced apart from the side edges of the frame, and may extend at least a portion of the distance across the top face of the frame at the inboard location.

By providing the frame with a lifting element providing a lifting point by which the frame may be lifted in use, handling of the frame is facilitated. By providing the frame with a base aperture that is configured to receive a lifting element of a similar unit, the stacking of multiple frames is facilitated. By configuring the base aperture to prevent movement of the frame relative to a similar unit positioned underneath the frame in at least one direction the stability of a stack of multiple frames is improved. The base aperture may be configured to provide positive location of the frame relative to a similar unit positioned underneath the frame by engaging the lifting element of the lower unit, and may substantially prevent backwards and forwards movement of the frame in a length and/or width direction of the frame.

The frame may be at least substantially cuboidal, although other shapes are also possible, including a circular or oval cylinder or a polygonal cylinder having any appropriate number of sides. The frame may be a metal frame, for example a steel frame, although other materials are also possible. The frame may generally be formed by a plurality of strut sections. The frame may generally be formed by a first and second substantially rectangular elements defining a pair of opposing faces of the frame and a plurality of connecting elements extending between the first and second substantially rectangular elements, for example at the corners and/or bases of the substantially rectangular elements, although other constructions are also possible. The major components of the frame may be welded together, or alternatively clamped, bolted or bonded together. The frame may define an internal volume of less than 1,5m3 or less than 0.5m3.

The base aperture may be provided at an approximately central location with respect to the frame and/or at a location close to the centre of gravity of the frame or an item of plant equipment received in the frame.

The base of the frame may comprise a plate. The base aperture may be provided in the plate. Where the base of the frame comprises a plate, the base of the frame may be partially, substantially, or entirely closed. The plate may be configured to provide additional protection to an item of plant equipment located in the frame, and/or to improve stability and/or load distribution especially when the frame is placed on a soft or uneven surface. Alternatively the base aperture may be provided, for example, between a pair of adjacent struts or between a pair of adjacent plates forming part of the base of the frame.

The base aperture may have a shape that corresponds to and/or at least substantially matches the shape of at least a portion of the lifting element. (It will be appreciated that corresponding shapes are shapes that are designed to cooperate with each other, and that matching shapes are shapes that are generally the same as each other.) For example, the base aperture may have a shape that corresponds to and/or at least substantially matches the shape of an interface portion of the lifting element, the interface portion of the lifting element being a portion of the lifting element that is configured to be received within the base aperture of a similar unit which may be positioned on top of the frame in use. By arranging the base aperture to have a shape that corresponds to and/or at least substantially matches the shape of the interface portion of the lifting element it is possible to improve the engagement between the base aperture and a lifting element of a similar unit which may be positioned underneath the frame in use.

The base aperture may be configured to receive the lifting element of a similar frame which may be positioned underneath the frame in use with a small clearance, and optionally with a tight fit. For example, the base aperture may have a dimension (for example a length and/or a width) that is no more than 10mm or no more than 5mm or no more than 1 mm greater than an equivalent dimension of an interface portion of the lifting element.

The base aperture may comprise an elongate slot. The base aperture may be substantially rectangular in shape, although other shapes are also possible, including triangular, square and circular. The base aperture may comprise first and second opposing side edges and first and second opposing end faces.

The base aperture may be configured to at least substantially prevent movement of the frame in both directions along a first horizontal axis of the frame relative to a similar unit which may be positioned underneath the frame in use with the lifting element of the similar unit received in the base aperture of the frame. The first axis may be aligned with a length direction or alternatively a width direction of the frame. It will be appreciated that the first axis is horizontal when the frame is in its normal orientation for use with the base of the frame sitting on a substantially flat, level surface. In some embodiments the base aperture may be configured to prevent movement of the frame in a first direction along the first axis by engaging the lifting element of the unit underneath the frame with at least a portion of a first side edge of the base aperture, and to prevent movement of the frame in a second direction opposite to the first direction by engaging the lifting element of the unit underneath the frame with at least a portion of an opposing second side edge of the base aperture.

The base aperture may be configured to at least substantially prevent movement of the frame in both directions along a second horizontal axis of the frame perpendicular to the first axis relative to a similar unit which may be positioned underneath the frame in use with the lifting element of the similar unit received in the base aperture of the frame. In some embodiments the base aperture may be configured to prevent movement of the frame in a first direction along the second axis by engaging the lifting element of the unit underneath the frame with at least a portion of a first end face of the base aperture, and to prevent movement of the frame in a second direction along the second axis opposite to the first direction by engaging the lifting element of the unit underneath the frame with at least a portion of an opposing second end face of the base aperture.

The base aperture may include at least one projection extending into the aperture. The projection(s) may be configured to reduce the contact area between one or more edges of the aperture and a lifting element of a similar unit which may be received in the base aperture in use.

The lifting element may comprise a plate, and may generally take the form of a blade. The plate may be substantially planar, and may extend in a substantially vertical plane when the frame is in its normal orientation for use.

The lifting element may extend between opposing first and second sides of the frame. The lifting element may extend either along a length direction of the frame or along a width direction of the frame.

The lifting element may be provided at an approximately central location with respect to the frame and/or at a location close to the centre of gravity of the frame or an item of plant equipment received in the frame. The lifting element may extend at least a portion of the distance across the frame at the approximately central location. For example, the lifting element may extend across the frame between opposing first and second sides of the frame at a location approximately in the centre of the first and second sides. Alternatively the lifting element may be at another inboard location with respect to the frame, that is at another location spaced apart from the side edges of the frame, preferably in a central region of the frame. The lifting element may be arranged directly above the base aperture, which may facilitate stable stacking of a plurality of frames.

The lifting point may comprise a lifting aperture provided by the lifting element, for example a hole extending through a portion of the lifting element. The lifting aperture may be a lifting eye, and may be configured to receive a lifting hook for lifting the frame.

The frame may be provided with a locking element. The locking element may be configured to allow the frame to be releasably locked to another frame. The locking element may be selectively switchable between a first configuration for locking the frame to another frame and a second configuration for releasing the frame from the other frame.

The locking element may optionally comprise a removable element such as a locking pin that is configured to be detached from the frame. In this case the locking element may be coupled to the frame when in the first configuration and detached from the frame when in the second configuration.

The locking element may be provided on the lifting element of the frame. For example, the locking element may be received and retained in a locking element aperture provided in the lifting element of the frame, which may be separate to the lifting aperture. In this case the locking element may be configured to engage the base of a similar unit which may be positioned on top of the frame in use in order to prevent the similar unit from being lifted off the frame, thereby locking the frames together. Alternatively the locking element may be provided on the base of the frame. In this case the locking element may be configured to engage the lifting element of a similar unit which may be positioned underneath the frame in use in order to prevent the frame from being lifted off the similar unit, thereby locking the frames together.

At least a portion of the lifting element may have a shape that corresponds to and/or at least substantially matches the shape of the base aperture. For example, the lifting element may comprise an interface portion (that is a portion of the lifting element that is configured to be received within the base aperture of a similar unit which may be positioned on top of the frame in use) having a shape that corresponds to and/or at least substantially matches the shape of the base aperture as viewed from above the frame in plan view. In some embodiments the interface portion of the lifting element may be substantially planar and/or blade-like such that the interface portion has an elongate rectangular shape in plan view, although other shapes are also possible, including triangular, square and circular.

The lifting element comprises opposing first and second side faces that are configured to respectively engage first and second side edges of a base aperture of a similar unit which may be positioned on top of the frame in use. Where the lifting element is formed by a plate the first and second side faces may be opposing first and second major surfaces of the plate.

The lifting element comprises opposing first and second shoulders that are configured to respectively engage first and second end faces of a base aperture of a similar unit which may be positioned on top of the frame in use. The first and second shoulders may extend between the first and second side faces. It will be appreciated that the shoulders need not be provided at outer-most ends of the lifting element, but may instead be inboard of the outer-most ends of the lifting element. The shoulders may define an interface portion of the lifting element that is configured to be received within the base aperture of a similar unit which may be positioned on top of the frame in use.

Each of the first and second shoulders may define an engagement surface. The engagement surfaces may be substantially planar and/or extend in substantially vertical planes.

The frame may comprise only one lifting element. Alternatively the frame may be provided with two or more lifting elements, for example first and second lifting elements each extending between opposing first and second sides of the frame at locations spaced apart from each other, preferably both at inboard locations with respect to the frame. Were the frame comprises multiple lifting elements, the base may define multiple base apertures each configured to receive a respective lifting element of a similar unit which may be positioned underneath the frame in use, or alternatively a single base aperture that is configured to receive two or more lifting elements of a similar unit which may be positioned underneath the frame in use.

The frame may define a cage that is configured to receive the item of plant equipment therein such that the item of plant equipment is at least partially surrounded by the cage. In some cases the item of plant equipment may be entirely surrounded by the cage such that no part of the item of plant equipment protrudes outwardly from the cage, although in other cases one or more portions of the item of plant equipment may protrude outwardly from the cage. The lifting element preferably protrudes above a top surface of the cage.

The frame may be at least substantially open along at least one side face. The frame may optionally be at least substantially open along each side face, for example along all 4 side faces in the case of a square or rectangular shaped frame. The frame may additionally be at least substantially open along its top face.

At least one substantially open side face may be provided with a strut extending across the open side face. The strut may provide additional protection to the item of plant equipment, and may be used to display branding and/or information relating to the frame and/or an item of plant equipment housed within the frame. The strut may be at least substantially planar.

According to a further aspect of the present invention there is provided an assembly comprising a frame as described above, and an item of plant equipment located within the frame. Items of plant equipment include, for example, devices or machines for use in construction, manufacturing, landscaping, gardening and domestic DIY. The item of plant equipment may be an item of light plant equipment, and may be readily portable. The item of plant equipment may be, for example, a motor, a generator, a mixing device, a pump (such as a water pump), a hydraulic power pack, a poker power unit or a pressure washer. The item of plant equipment is preferably mounted to the frame, for example by one or more fasteners, as opposed to simply sitting within the frame.

According to a further aspect of the present invention there is provided a stack of two or more frames as described above, comprising a first frame and a second frame arranged on top of the first frame, wherein the lifting element of the first frame is received in the base aperture of the second frame in order to at least substantially prevent movement of the second frame relative to the first frame in at least one direction.

The locking element of one of the first and second frames may be engaged so as to prevent the second frame from being lifted off the first frame.

According to a further aspect of the present invention there is provided a method of assembling a stack of protective frames for items of plant equipment, the method comprising placing a second frame on top of a first frame, and further comprising receiving a lifting element of the first frame within a base aperture provided in a base of the second frame as the second frame is placed on top of the first frame. The lifting element may be provided at an inboard location with respect to the first frame, and may provide a lifting point by which the first frame may be lifted in use. The method may be performed using a pair of frames according to the first aspect of the present invention. The first and/or second frames may include any of the features described above, and the method may further include any steps associated with the normal operation of a frame as described above.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figures 1 to 6 illustrate a frame according to an embodiment of the present invention;

Figures 7 to 10 illustrate a stack of frames according to an embodiment of the present invention;

Figure 11 schematically illustrates the interaction between the frames in the stack illustrated in Figures 7 to 10;

Figure 12 schematically illustrates a slot provided in a base of a frame according to an alternative embodiment of the invention; and

Figure 13 schematically illustrates a lifting element of a frame according to an alternative embodiment of the invention.

DETAILED DESCRIPTION

Figures 1 to 6 illustrate a protective frame 1 for a portable generator 100. The frame 1 is illustrated in isolation in Figures 1 and 2, and with a generator 100 mounted therein in Figures 5 and 6. The frame 1 is stackable together with one or more further similar frames, as described in detail below.

As shown in Figures 1 and 2, the frame 1 is generally cuboidal, and has a main body formed by first and second rectangular frame elements 2, 3 of bent metal tube section. Each of the frame elements 2, 3 comprises an upper strut 2a, 3a, a lower strut 2b, 3b, and a pair of vertical struts 2c, 2d, 3c, 3d connecting the upper strut 2a, 3a to the lower strut 2b, 3b. The upper struts 2a, 3a are at the top of the frame 1 when the frame 1 is in its normal orientation for use, as illustrated in Figures 1 and 2.

The first and second frame elements 2, 3 are connected to each other by first and second connecting struts 4, 5, by a lifting element 10, and by a base plate 20. Each of the first and second connecting struts 4, 5 extends between and is welded to an upper corner of each of the first and second frame elements 2, 3 at a respective upper corner of the frame 1. The lifting element 10 extends between and is welded to the upper struts 2a, 3a of the first and second frame elements 2, 3 at an approximately central location along the upper struts 2a, 3a. The base plate 20 extends between and it welded to the lower struts 2b, 3b of the first and second frame elements 2, 3. It will be appreciated that in other embodiments the major components of the frame 1 could equally be assembled together using another technique besides welding. For example, one or more of the connecting struts 4, 5, the lifting element 10 and the base plate 20 could equally be clamped, bolted or bonded to the frame elements 2, 3.

The frame 1 comprises a base 1a at its lower edge (when the frame is in its normal orientation for use, as illustrated in Figures 1 and 2) that is formed by the lower struts 2b, 3b of the first and second frame elements 2, 3 and the base plate 20. The frame 1 further comprises a top face 1b at its upper edge that extends between the upper struts 2a, 3a of the first and second frame elements 2, 3. The frame 1 further comprises first, second, third and fourth side faces 1c, 1 d, 1e and 1f each extending between the base 1a and the top face 1b, the first and second side faces 1c, 1d being defined by the first and second frame elements 2, 3, and the third and fourth side faces 1e, 1f extending between the first and second side faces 1c, 1d. The frame 1 has a first horizontal axis X extending in a length direction of the frame 1 (parallel to the first and second side faces 1c, 1d), a second horizontal axis Y extending in a width direction of the frame 1 (perpendicular to the first and second side faces 1c, 1 d), and a vertical axis Z. It will be appreciated that the terms ‘horizontal’ and ‘vertical’ should be interpreted as when the frame is in its normal orientation for use, such as when the lower struts 2b, 3b are resting on a flat and level surface.

The first and second frame elements 2, 3, the connecting struts 4, 5 and the base plate 20 together define a protective cage within which the generator 100 is received when assembled together with the frame 1, as illustrated in Figures 5 and 6. In the present embodiment the generator 100 is received entirely within the frame 1 such that no part of the generator protrudes outwardly from the frame 1.

The side faces 1c to 1f of the frame 1 are generally open, which reduces the weight of the frame 1 and improves access to the generator 100 and allows efficient ventilation in use of the generator 100. However, the frame 1 is additionally provided with a pair of substantially planar side struts 6, 7 which extend respectively across the first and second side faces 1c, 1d of the frame 1. Each of the side struts 6, 7 extends between and is bolted to the vertical struts 2c, 2d, 3c, 3d of a respective one of the frame elements 2, 3, and provides additional protection to the generator 100 when the generator 100 is received in the frame 1 as well as providing additional structural rigidity to the frame 1. The side struts 6, 7 may additionally be used to display branding and/or information relating to the frame 1 and/or the generator 100, for example a rating plate for the generator 100.

The generator 100 is mounted to the base plate 20 by a plurality of bolts such that the generator 100 is securely retained with respect to the frame 1. Since the base plate 20 extends across a majority of the base 1a of the frame 1 leaving the base 1a of the frame 1 substantially closed, the base plate provides additional protection to the underside of the generator 100 in addition to providing a convenient attachment point via which the generator 100 can be mounted to the frame 1. The base plate 20 also provides improved stability for the frame 1, especially when the frame 1 is placed on soft ground. The base plate 20 comprises a substantially rectangular, elongate through slot 21 located approximately in the centre of the base 1a of the frame 1. The slot 21 extends in a width direction of the frame 1 (parallel to the second horizontal axis Y), and has a length of approximately 40% of the width of the frame 1. In the present embodiment the slot has a length of approximately 205mm and a width of approximately 8.4mm. The slot 21 is provided at a location directly below the lifting element 10, and has a shape that corresponds to and substantially matches the shape of an interface portion of the lifting element as viewed from above in plan view. The slot 21 may, for example, be laser cut into the base plate 20. The purpose of the slot 21 is described in detail below.

The lifting element 10 is provided at a central location with respect to the frame 1 directly above the slot 21 formed in the base plate 20, and is connected to the upper struts 2a, 3a of the first and second frame elements 2, 3 at an approximately central location along each of the upper struts 2a, 3a. The lifting element 10 takes the form of a flat plate or blade that is arranged in a vertical plane (when the frame 1 is in its normal orientation for use, as illustrated in Figures 1 and 2), and has first and second major side faces 11a, 11b that face outwardly towards the end faces 1e, 1f of the frame 1.

As illustrated in Figures 3 and 4, the lifting element 10 has a lower edge that is substantially flush with the undersides of the upper struts 2a, 3a of the first and second frame elements 2, 3. However, the lifting element 10 extends above the top surface 1b of the frame 1 as defined by the upper struts 2a, 3a to form the highest point of the frame 1. In the present embodiment, the lifting element 10 has an upper edge that generally slopes upwardly towards the centre of the frame 1, and thus has a shape somewhat like a shallow, upwardly pointing arrowhead.

At the centre of the lifting element 10 a tongue or interface portion 12 protrudes upwardly from the main body of the lifting element 10 at a location directly above the slot 21 formed in the base plate 20. The interface portion 12 is defined between a pair of shoulders 13a, 13b in the form of short, vertical walls that extend upwardly from the main body of the lifting element 10.

The interface portion 12 of the locking element 10 has a blade-like shape that corresponds to and substantially matches the shape of the slot 21 in plan-view. In the present embodiment the interface portion 12 has a width (between the side faces 11a, 11b of the lifting element 10) of 8mm, and a length (between the shoulders 13a, 13b) of 198mm. The interface portion 12 therefore has a width that is slightly smaller than the width of the slot 21 and a length that is slightly smaller than the length of the slot 21. The interface portion 12 of the lifting element 10 is configured to be received in the slot provided in the base of a similar unit which may be located on top of the frame 1 when a plurality of frames 1 are stacked together, and to cooperate with the slot of the similar unit located on top of the frame to ensure stable engagement between the frame and the unit above. Similarly, the base aperture 21 is configured to receive the interface portion of the lifting element of a similar unit which may be located underneath the frame 1 when a plurality of frames 1 are stacked together, and to cooperate with the interface portion of the lifting element of the similar unit located below the frame to ensure stable engagement between the frame and the unit below.

The interface portion 12 of the lifting element 10 includes a central through-hole that provides a lifting eye or lifting aperture 14 for the frame 1. The lifting aperture 14 provides a single central lifting eye by which the frame 1 may conveniently be lifted, for example using a lifting assembly including a hook for engaging the lifting aperture 14, thereby facilitating handling of the frame 1. The interface portion 12 also includes a further through-hole or locking element aperture 15, which is visible in Figure 3. The locking element aperture 15 receives a locking pin 16 that extends through the locking element aperture 15 and protrudes from both sides of the lifting element 10, as illustrated in Figure 4. The locking pin 16 is removable from the locking element aperture 15, and may be retained in the locking element aperture 15 by an interference fit and/or by an additional retaining device. The further through-holes provided in the lifting element 10 that are visible in Figures 3 and 4 are cosmetic and may be omitted in other embodiments.

The stacking together of a plurality of frames 1 as illustrated in Figures 1 and 2 will now be described with reference to Figures 7 and 8. The stack includes a first frame at the base of the stack and a second frame located on top of the first frame. The first frame (at the base of the stack) is designated as T, and features of the first frame are identified using the same reference numbers used in Figures 1 and 2 with the addition of a single dash ’. The second frame (located on top of the first frame) is designated as 1”, and features of the second frame are identified using the same reference numbers used in Figures 1 and 2 with the addition of a double dash ”. Figures 7 and 8 omit the generator that is housed within each frame T, 1” in order to improve clarify and provide a clear view of the interface between the frames 1, although it will be appreciated that the frames T, 1” may be stacked in the manner described below while a generator 100 is housed within each of the frames. The first and second frames T, 1” with their respective generators 100’, 100” housed therein are illustrated in Figures 9 and 10.

In an initial step a first frame 1’ with a generator housed therein (but not illustrated in Figures 7 and 8) is placed on a surface, for example on the ground in a warehouse where the frame and generator assembly is to be stored. The first frame 1’ may be manoeuvred into the desired location for example using a lifting assembly including a lifting hook that is engaged with the lifting aperture 14’ of the first frame T. The first frame 1’ is preferably left with its locking pin 16’ engaged with the locking element aperture 15’.

When it is desired to stack the second frame 1” (with its generator housed therein) on top of the first frame T, the locking pin 16’ is first removed from the locking element aperture 15’ of the first frame T. The second frame 1” may then be lifted (for example using a lifting assembly including a lifting hook that is engaged with the lifting aperture 14” of the second frame 1”) onto the top surface of the first frame T, as illustrated in Figure 7. When the second frame 1” has been lifted onto the top of the first frame T, the interface portion 12’ of the lifting element 10’ of the first frame 1’ is received within the slot 21” provided in the base plate 20” of the second frame 1”. Figure 11 schematically illustrates the interface portion 12’ of the lifting element 10’ of the first frame 1’ received in the slot 21” in the base plate 20” of the second frame 1” in plan view from above the base plate 20” of the second frame 1”. In Figure 11 the clearance between the interface portion 12’ of the lifting element 10’ of the first frame 1’ and the slot 21” in the base plate 20” of the second frame 1” has been exaggerated to improve clarity. However, in the present embodiment the clearance gap is small at 0.4mm in the width direction of the slot 21” and 7mm in the length direction of the slot 21” in order to improve engagement between the interface portion 12’ and the slot 21”.

The location of the lifting element 10’ of the first frame 1’ in the slot 21” in the base plate 20” of the second frame 1” provides positive location of the second frame 1” with respect to the first frame T, and improves the stability of the stack of frames T, 1”. In particular, the first and second side faces 11a’, 11b’ of the lifting element 10’ of the first frame 1’ are configured to engage the side edges of the slot 21” of the second frame 1” in order to resist movement of the second frame 1” relative to the first frame 1’ in either direction along the length axis X” of the second frame 1”, and the shoulders 13a’, 13b’ of the lifting element 10’ of the first frame 1’ are configured to engage the end faces of the slot 21” of the second frame 1” in order to resist movement of the second frame 1” relative to the first frame 1’ in either direction along the width axis Y” of the second frame 1”.

Once the second frame 1” has been placed on top of the first frame 1’ with the lifting element 10’ of the first frame T received in the slot 21” in the base plate 20” of the second frame 1”, the locking pin 16’ of the first frame 1’ may then be replaced in the locking element aperture 15’, as illustrated in Figure 8. Once the locking pin 16’ has been replaced in the locking element aperture 15’, the locking pin 16’ acts to prevent removal of the second frame 1” from the top of the first frame 1’ until the locking pin 16’ has been removed, thereby increasing the security of the stack of frames and preventing accidental movement of the second frame 1” with respect to the first frame T.

It will be appreciated that one or more further frames (including generators housed therein) may also be placed on top of the second frame 1” in a similar manner such that a larger stack of frames may be assembled. In this way a plurality of frame and generator assemblies may be stored together in a secure and space efficient manner.

When it is desired to remove the second frame 1” from its position on top of the first frame T, for example if the second frame 1” and the generator housed therein are to be transported to a different location for use, the locking pin 16’ of the first frame 1’ must first be removed from its engagement with the locking element aperture 15’. After the locking pin 16’ of the first frame 1’ has been removed, it is then possible to lift the second frame 1” away from the first frame Γ, for example using a lifting assembly including a lifting hook that is engaged with the lifting aperture 14” of the second frame 1”. The locking pin 16’ of the first frame T is then preferably replaced in the locking element aperture 15’ to prevent accidental misplacement of the locking pin 16’.

The frame of the present invention may be particularly advantageous when used to protect plant equipment that is to be stored centrally, for example at one or more warehouse locations, and distributed on demand, for example when the equipment is hired out for use. In general, plant equipment that is intended to be stored centrally and distributed on demand is stored and transported on pallets or in boxes. However, pallets and boxes used to carry plant equipment take up additional space, and may be lost or become damaged when the equipment is sent out for hire. However, by providing a protective frame such as the frame described above that is readily and securely stackable, it is possible to simplify the process of storing and handling the equipment housed within the frame, as well as providing protection to the equipment in use.

Many modifications may be made to the above example without departing from the scope of the present invention as defined in the accompanying claims. For example, the frame may have a different overall construction to that described above including a pair of rectangular frame elements joined by a plurality of connecting elements. In addition, frames in accordance with the present invention may equally be used to protect other types of plant equipment besides generators. For example, in other embodiments frames in accordance with the present invention may be used in combination with portable motors, mixing devices, pumps, hydraulic power packs, poker power units and pressure washers. In addition, while the slot in the above described embodiment is provided in a structural portion of the frame, in other embodiments the base aperture could instead be provided by a separate base element or stand attached to the main body of the frame. For example, a frame substantially as described above could be provided with a plastics base or stand that is attached to the lower struts 2b, 3b, wherein the base or stand is configured to sit on top of a similar unit placed underneath the frame, and defines a base aperture configured to receive the lifting element of the unit underneath when the frames are stacked together.

In addition, while the interface portion of the lifting element and the slot both have matching elongate rectangular shapes in plan view in the above-described example, other shapes are also possible for the interface portion and the aperture provided in the base. For example, Figure 12 illustrates an alternative shape that may be used for the slot 21 provided in the base plate 20 of the frame 1 described above. The alternative slot 21 illustrated in Figure 12 includes a pair of inwardly facing projections 22 on each side edge of the slot that project into the slot. The projections 22 are configured to engage the side faces 11a, 11b of the lifting element 10 of a similar frame in order to reduce the contact area between the edges of the slot 21 and the lifting element of a similar frame when received in the slot.

In other embodiments the lifting element could equally comprise a vertically-extending interface portion with a different shape to the blade-like or rectangular shape described above, for example a triangular, square or circular shape. For example, Figure 13 illustrates an alternative design of lifting element 10 including a triangular interface portion 12 that projects upwardly from a body of the lifting element 10. In this alternative example the lifting aperture 14 of the lifting element 10 (by which the frame is configured to be lifted) is provided by a separate eye 17 that is attached at the top of the interface portion 12. A frame including a lifting element 10 as illustrated in Figure 13 may additionally comprise a correspondingly shaped aperture in its base in order to cooperate with the lifting element of a similar frame placed underneath the frame in use.

Claims

1. A protective frame for an item of plant equipment that is configured to be stacked together with one or more similar frames in use, wherein the frame comprises a lifting element at an inboard location with respect to the frame that provides a lifting point by which the frame may be lifted in use, and a base that defines a base aperture that is configured to receive the lifting element of a similar frame which may be positioned underneath the frame in use; wherein the lifting element comprises first and second side faces and first and second shoulders, and the base aperture comprises first and second side edges and first and second end faces; wherein the first and second side faces of the lifting element are configured to respectively engage the first and second side edges of the base aperture of a further frame which may be positioned on top of the frame in use, and the first and second shoulders of the lifting element are configured to respectively engage the first and second end faces of the base aperture of the further frame, such that cooperation between the lifting element of the frame and the base aperture of the further frame at least substantially prevents movement of the frame relative to the further frame.

2. A frame according to claim 1, wherein the base of the frame comprises a plate, and the base aperture is provided in the plate.

3. A frame according to claim 1 or claim 2, wherein the base aperture has a shape that corresponds to and/or at least substantially matches the shape of at least a portion of the lifting element.

4. A frame according to any preceding claim, wherein the base aperture comprises an elongate slot.

5. A frame according to any preceding claim, wherein the base aperture is configured to at least substantially prevent movement of the frame in both directions along a first horizontal axis of the frame relative to the further frame when the lifting element of the further frame is received in the base aperture. d Ω

6. A frame according to claim 5, wherein the base aperture is configured to at least substantially prevent movement of the frame in both directions along a second horizontal axis of the frame perpendicular to the first axis relative to the further frame when the lifting element of the further frame is received in the base aperture.

7. A frame according to any preceding claim, wherein the lifting element comprises a plate.

8. A frame according to any preceding claim, wherein the lifting element extends between opposing first and second sides of the frame.

9. A frame according to any preceding claim, wherein the lifting element is provided at an approximately central location with respect to the frame and/or at a location close to the centre of gravity of the frame or an item of plant equipment received in the frame.

10. A frame according to any preceding claim, wherein the lifting point comprises a lifting aperture provided by the lifting element.

11. A frame according to any preceding claim, wherein the frame is provided with a locking element that is configured to allow the frame to be locked to another frame.

12. A frame according to any preceding claim, wherein at least a portion of the lifting element has a shape that corresponds to and/or at least substantially matches the shape of the base aperture.

13. A frame according to any preceding claim, wherein each of the first and second shoulders defines an engagement surface, wherein the engagement surfaces are substantially planar.

14. A frame according to any preceding claim, wherein the frame comprises only one lifting element.

15. A frame according to any preceding claim, wherein the frame is at least substantially open along at least one side face.

16. A frame according to claim 15, wherein at least one substantially open side face is provided with a strut extending across the open side face.

17. A frame according to any preceding claim, further comprising an item of plant equipment mounted within the frame.

18. A stack of two or more frames according to any preceding claim, comprising a first frame and a second frame arranged on top of the first frame, wherein the lifting element of the first frame is received in the base aperture of the second frame in order to at least substantially prevent movement of the second frame relative to the first frame in at least one direction.

19. A stack according to claim 18 when dependent on claim 11, wherein the locking element of one of the first and second frames is engaged so as to prevent the second frame from being lifted off the first frame.

20. A method of assembling a stack of protective frames for items of plant equipment, the method comprising placing a second frame according to any of claims 1 to 17 on top of a first frame according to any of claims 1 to 17, and further comprising receiving the lifting element of the first frame within the base aperture of the second frame as the second frame is placed on top of the first frame.