GB2599643A

GB2599643A - Rolling goal frame

Info

Publication number: GB2599643A
Application number: GB2015662.6A
Authority: GB
Inventors: Butler Christopher
Original assignee: Harrod UK Ltd
Current assignee: Harrod UK Ltd
Priority date: 2020-10-02
Filing date: 2020-10-02
Publication date: 2022-04-13
Anticipated expiration: 2040-10-02
Also published as: GB202015662D0; GB2599643B

Abstract

A goal frame (1, fig 1) has a plurality of rolling support assemblies 10 which include a ground engaging rolling body 11 which is spherical and able to rotate omnidirectionally. Each rolling support assembly further includes a bearing assembly (20, fig 4) and a retaining structure 30 where the bearing assembly has at least one upper rolling body (21, fig 10) which is rotatably with the ground engaging rolling body. The upper rolling body may be spherical and rotatable omnidirectionally. The bearing assembly may contain a housing (22, fig 8) which partially encloses the upper rolling body where the housing includes a wiper (24, fig 10).

Description

Rolling goal frame This invention relates to portable goal frames that are mounted on wheels or casters so that the goal frame can more easily be moved around on the pitch between games.

Wheeled goal frames are used for example in football (which is to say, soccer or association football) on both natural and artificial pitches. For better manoeuvrability it is known to mount the wheels on trailing axles to form casters, for example, as taught by W02020128536 Al and GB2576113 A. However, if too much force is applied to a caster that happens to be misaligned with the direction in which the goal frame begins to move, then the wheel may gouge the turf or twist or ruck an artificial pitch covering.

It is a general object of the present invention to provide a more convenient arrangement for moving a football goal frame.

Accordingly, the invention provides a goal frame as defined in the claims.

The goal frame includes a plurality of rolling support assemblies for moving the goal frame over a ground surface. Each rolling support assembly including a ground engaging rolling body, wherein in an active state of the goal frame, the mass of the goal frame is supported on the ground engaging rolling body, and the ground engaging rolling body rests on the ground surface and is rollable over the ground surface.

The ground engaging rolling body is spherical, and each rolling support assembly further includes a bearing assembly, and a retaining structure.

The bearing assembly includes at least one upper rolling body, which is rotatable in rolling contact with the ground engaging rolling body to transfer the mass of the goal frame to the ground engaging rolling body.

The retaining structure is arranged to retain the ground engaging rolling body in a use position beneath the upper rolling body, while the ground engaging rolling body is rotatable omnidirectionally in use.

Further features and advantages will be evident from the following illustrative embodiment which will now be described, purely by way of example and without limitation to the scope of the claims, and with reference to the accompanying drawings, in which: Fig. 1 shows a football goal frame with four rolling support assemblies; Fig. 2 is an end view of the goal frame; Fig. 3 shows one of the rolling support assemblies; Figs. 4 and 5 show the rolling support assembly with the housing removed, respectively in the rest state (Fig. 4) and the active state (Fig. 5); Fig. 6 is an enlarged view of the pivoting linkage forming part of the load transfer mechanism of the rolling support assembly; Figs. 7,8 and 9 show the ground engaging rolling body and retaining structure of the rolling support assembly; Fig. 10 is a section taken in a vertical plane at X -X of Fig. 9; Fig. 11 is a schematic drawing illustrating the translational displacement of the ground engaging rolling body between the retaining rollers; and Fig. 12 shows an adaptation of the linear bearings of the retaining structure.

Reference numerals appearing in more than one of the figures indicate the same or corresponding features in each of them.

Referring to Figs. 1 and 2, the goal frame 1 may be for example a football goal frame, and may have dimensions as defined in the regulations of the International Football Association Board or the relevant national Football Association. The goal frame may include a horizontal crossbar 2 supported between a pair of vertical posts 3. The vertical posts may extend from the forward ends of a pair of parallel, horizontal bottom bars 4 which are joined by a horizontal rear bar 5 extending in parallel with the crossbar 2 to support a lower edge of the net (not shown). A diagonal braces may be arranged between each vertical post 3 and the adjacent bottom bar 4. A pair of net support posts 6 may extend upwardly from the corners where the bottom bars 4 join the rear bars.

Each bar of the goal frame 1 may have a channel 7, best seen in Fig. 3, for use in fixing the net to the frame as known in the art.

The goal frame includes a plurality of rolling support assemblies 10 for moving the goal frame over the generally horizontal ground surface G, which may be a natural or artificial turf. For example, as illustrated, there may be four rolling support assemblies 10, two of which support each respective bottom bar 4.

Referring to Figs. 4 and 5, each rolling support assembly 10 includes a spherical, ground engaging rolling body 11, hereafter referred to as the ground ball 11. In an active state of the goal frame, as shown in Fig. 5, the mass of the goal frame 1 is supported on the ground ball, and the ground ball 11 rests on the ground surface G and is rollable over the ground surface G. The ground ball 11 can rotate omnidirectionally about its centre, so that the goal frame can be pushed in any direction without reorienting the ground ball. The ground ball 11 may have a diameter D of at least 150mm, for example, about 200mm or more.

Each rolling support assembly 10 also includes a bearing assembly 20, and a retaining structure 30.

The bearing assembly 20 includes at least one upper rolling body 21, which is rotatable in rolling contact with the ground ball 11 to transfer the mass of the goal frame to the ground ball. The retaining structure 30 is arranged to retain the ground ball 11 in a use position beneath the upper rolling body 21.

It is possible for the upper rolling body 21 to be a wheel or roller rotating on an axle, perhaps in the manner of a caster, as taught by GB2493370 (A) to Omnicaster Ltd of Stroud, GB. Preferably however, as illustrated, the upper rolling body 21 is spherical and is rotatable omnidirectionally about its centre in use. This ensures that the upper rolling body 21 cannot become oriented in a direction that could resist momentarily the rotation of the ground ball in the direction of movement of the goal frame, and so potentially cause the ground ball to gouge the pitch surface as the goal frame begins to move. It will be appreciated of course that since the spherical curvature of the ground ball is always presented to the direction of motion, any potential damage from a stuck ground ball will be relatively less severe than in the case of a conventional caster with a ground-engaging wheel rotating on an axle, where the flat side of the wheel or its frame could be forced into the pitch if it happens to be pointing in the wrong direction.

The bearing assembly 20 may include a bearing housing 22, with the upper rolling body 21 being partially enclosed in the bearing housing 22 as best seen in Fig. 10. The bearing housing may enclose a plurality of ball bearings 23, and optionally also an internal guide (not shown) as known in the art, around which the ball bearings can circulate. The ball bearings 23 (or other conventional bearing arrangement) transfer the mass of the goal frame between the bearing housing 22 and the spherical upper rolling body 21, which may be a steel ball, so that the upper rolling body 21 can rotate omnidirectionally about its centre relative to the bearing housing.

The bearing housing 22 may include a wiper 24, with an edge 24' of the wiper being arranged in sliding contact with the upper rolling body 21 to exclude dirt from the bearing housing 22.

The upper rolling body 21 may be a ball with a relatively large diameter, for example, 20mm or 25mm or more. By enclosing the upper rolling body in a bearing housing, preferably with a wiper, the assembly of internal ball bearings 23 or other load transfer arrangement is protected against dirt picked up by the ground ball 11, which tends to detach at the point of contact between the ground ball 11 and the upper rolling body 21. Thus, the mechanism can operate reliably in muddy conditions.

Referring to Figs. 7 -10, the retaining structure 30 may include an annular frame 31 and a plurality of struts 32 which connect the bearing assembly 20 to the annular frame 31. The struts 32 may be fixed to the bearing housing 22, and are spaced apart around the annular frame 31 to define a cage enclosing an upper portion of the ground ball 11.

The retaining structure 30 may include a plurality of rollers 34, which are spaced apart around the ground ball 11. As shown, there may be for example, three rollers 34 equally spaced around the ground ball 11, although more could be provided if desired.

Each roller 34 is rotatable in rolling contact with the ground ball 11 to transfer forces acting in parallel with the ground surface G between the retaining structure 30 and the ground ball 11. In this way, the rollers 34 bear against the ground ball 11 to move the ground ball 11 with the goal frame 1 over the ground surface.

As shown, each roller may be arranged to rotate in use about a fixed axis 35 which is arranged in parallel with the ground surface G. Conveniently, each axis 35 may be defined by an axle mounted on a respective one of the struts 32, which may be pressed or cast to define two spaced, opposed flanges through which the axle fixing can pass, as shown.

The rollers 34 may be spaced apart from the ground ball 11 to accommodate a translation displacement of the ground ball 11, in parallel with the ground surface G and relative to the retaining structure 30, in the active state.

This displacement allows the ground ball 11 to remain spaced from the roller or rollers in front of the ground ball 11. At the same time, it enables the ground ball 11 to remain in rolling contact with the roller or rollers 34 that are positioned behind the ground ball 11 in the direction of travel, to the extent that their axial alignment relative to the direction of travel allows them to rotate with the ground ball. At the same time, it enables the ground ball to slide past the rollers that are not positioned exactly behind it in the direction of travel, and to the extent that their axial alignment renders them unable to rotate with the ground ball. This minimises friction when the rollers are mounted on fixed axles in a relatively simple arrangement.

If desired, a different rotary or fixed pad bearing arrangement could be used as lateral bearings instead of the rollers 34.

Each rolling support assembly 10 may include a plurality of upper rolling bodies 21 which are arranged in an array in rolling contact with the upwardly facing surface of the ground ball 11. Alternatively, as illustrated, each rolling support assembly 10 may include only one upper rolling body 21, which is aligned with the ground ball 11 on a generally vertical axis Xv, perpendicular to the ground surface G, when the ground ball 11 is equidistant from each of the rollers 34.

In this case, in order to maintain the proper load transfer relationship, the retaining structure 30 may be configured to constrain the translation displacement of the ground ball 11 to a maximum distance d from any contact position of the ground engaging rolling body with any respective one of the rollers 34, wherein (d 0.05 D). For example, the maximum distance d may be not more than 0.02D or 0.01D. It will be understood that when the ground ball 11 is located vertically centrally below the upper rolling body 21 on a horizontal ground surface and equidistant from the rollers 34, it can move a maximum distance of 0.5d before contacting any one of the rollers 34.

Fig. 11 illustrates this relationship schematically for an arrangement of four or more, diametrically opposed rollers 34', similar to the three rollers 34 of the illustrated embodiment. The ground ball 11 is shown in contact with the left-hand roller 34', so that its maximum horizontal displacement d is approximately equal to the width of the gap between the surface of the ground ball 11 and the opposite roller 34'. The diameter D of the ground ball 11 is much larger than the maximum displacement distance d, so that the contact point between the ground ball 11 and the single upper rolling body 21 remains close to the vertical central axis of the ground ball 11, ensuring that the mass of the goal frame imposes only a small side loading on the rollers 34'.

The ground ball 11 may be solid or hollow and may be made from metal or plastics or any other suitable material. It may include a hollow or solid, spherical core 12 enclosed in a moulded spherical shell 13. The shell may be made from plastics material, while the core could be, for example, a hollow metal sphere or a solid foamed plastics sphere.

Alternatively, the ground ball 11 may be a hollow plastics rotomoulding or a solid plastics reaction injection moulding.

By moulding a spherical plastics shell 13 over a more rigid, solid or hollow core 12, e.g. a metal core, the ground ball 11 may benefit from a degree of resilience in the plastics shell, which improves its rolling behaviour over a variety of hard and soft ground surfaces, while maintaining its overall shape so that it does not jam in the retaining structure 30.

Fig 10 illustrates how a wiper 14, not shown in the other figures, may be included in each rolling support assembly, either alternatively or additionally to wiper 24. The wiper 14 could be a ring or sheet of plastics or rubber or other flexible or resilient material. An edge 14' of the wiper is arranged in sliding contact with the ground ball 11 to remove dirt from the ground ball as it rotates.

A full size football goal frame is large and heavy, and so it is desirable to lower the goal frame 1 so that its bottom bars 4, 5 rest directly on the ground surface G when it is not being moved. This helps to stabilise the goal frame 1 in use, and to prevent the ground balls 11 from gradually becoming embedded in a soft pitch surface.

Referring again to Figs. 4 and 5, this can be achieved by arranging each rolling support assembly 10 to include a load transfer mechanism 40, which is operable in use to transfer a mass of the goal frame 1 selectively to and from the ground ball 11 so as to define the active state (Fig. 5) and a rest state (Fig. 4) of the goal frame 1. In the rest state, the mass of the goal frame 1 is not supported on the ground ball 11, so that the ground ball 11 is relieved of the load. For example, the bottom bars 4 and 5 could be arranged to rest directly on the ground surface G in the rest state, as shown in Fig. 2. The load transfer mechanism may define the active state and the rest state by raising and lowering the bearing assembly 20 relative to the bars and posts 2, 3, 4, 5 of the goal frame 1 (which is to say, lowering and raising the bars and posts relative to the bearing assembly 20).

It will be understood of course that the mass of the goal frame supported by each ground ball 11 will be a part of its total mass, which may be entirely supported on the ground balls 11 in the active state. For example, where four ground balls 11 are provided, each ground ball may support on average 25% of the total mass of the goal frame 1.

Each rolling support assembly 10 may include a support structure SO, wherein the bearing assembly 20 is mounted on the retaining structure 30, and the retaining structure 30 is mounted on the support structure 50 and movable in use relative to the support structure SO between the active state and the rest state, as shown in Figs. 4 and 5.

As illustrated, the retaining structure 30 may be slidably mounted within the support structure 50 and movable, in use, in translation relative to the support structure SO and in a direction perpendicular to the ground surface G, between the active state and the rest state.

In such arrangements, the support structure SO may include a pair of annular frames 51 connected together in spaced relation by a plurality of rods 52, the rods 52 extending in use perpendicular to the ground surface G. The retaining structure 30 may include linear bearings 36 (which is to say, bearings that can move in translation) which are slidably mounted on the rods 52. The annular frame 31 of the retaining structure 30 may be captive on the rods 52 and movable in translation between the annular frames 51 of the support structure, in which case the linear bearings 36 may be fixed to the annular frame 31, as shown. The annular frames 51, 31, 51 may be stacked in coaxial relation.

Fig. 12 shows an adaptation in which each linear bearing 36 is replaced by a linear bearing assembly 36', comprising an inner linear bearing 60 in the form of a sleeve which can slide along the rod 52, and which can also rotate through a limited angular displacement, relative to the axis of the rod 52, within an outer bearing shell 61. This partially decouples the inner linear bearing 60 from forces acting in rotation on the annular frame 31 which might otherwise cause the linear bearings to jam on the rods 52. The outer bearing shell 61 may be a plastics moulding so that the bearing assembly 36' may be clipped into a hole in the frame 31, as known in the art.

As illustrated, the support structure 50 may connect together two collinear bars 4', 4" forming part of one bottom bar 4 of the goal frame, wherein the bars 4', 4" extend in use in parallel with the ground surface G to rest on the ground surface in the rest state.

Together, the annular frames 51 and rods 52 of the support structure maintain the bars 4', 4" in rigid relation. This can be accomplished as shown by fixing two connectors 53 to the annular frames 51 so that the connectors 53 extend in opposite directions in collinear relation along an axis Xh that intersects a central vertical axis Xv (which is to say, a central axis that lies perpendicular to the ground surface G) of the support structure 50. The connectors 53 are received fittingly inside the bars 4', 4" which are fixed, e.g. screwed or clamped to the connectors 53. The fixings may be recessed into the channels 7 of the bars as shown in Fig. 3.

As best seen in Fig. 3, the support structure SO may include a housing 54, 55, which may include a lower housing 54, which may be a rigid, metal or plastics structure, and an upper housing 55, which may be a rounded or domed structure and may be blow moulded, or padded, or made from or coated with an elastomer, e.g. rubber or silicone. The retaining structure 30 may be configured to retract the ground ball 11 into the housing 54, 55 in the rest state, as shown in Figs. 1, 2 and 3, e.g. by lowering the housing over the ground ball, and optionally also raising the ground ball off the ground into the housing.

In order to retain the ground ball 11 in the event that it passes over a hollow in the ground, the annular frame 31 may include retaining tabs 33 which extend radially inwardly below the equator of the ground ball 11. The tabs 33 are spaced apart from the ground ball 11 while it rests on the ground, but extend radially inwardly to a position radially inward of the projected circumference of the ground ball 11, so that they retain the ground ball 11 when it is unloaded or retracted into the housing.

As best seen in Figs. 3, 4 and 5, the load transfer mechanism 40 may include a handle 41, which may be arranged to fold down over the housing 54, 55. The load transfer mechanism 40 may operable to move the retaining structure 30, relative to the support structure 50, from the rest state to the active state by raising the handle 41 away from the ground surface G, and to move the retaining structure 30, relative to the support structure 50, from the active state to the rest state by lowering the handle 41 towards the ground surface G. In this way, the force applied to the handle 41 assists the Ii-movement of the bars of the goal frame 1 in the required direction as the mechanism operates.

As best seen in Fig. 6, the load transfer mechanism 40 may include a pivoting linkage 42 which is configured to pass through an intermediate position between the rest state (Fig. 4) and the active state (Fig. 5, Fig. 6). The linkage 42 raises the goal frame 1 away from the ground surface Gas it moves from each of the rest state and the active state towards the intermediate position. In this way, the mechanism 40 is made bistable so that it is retained in each of the rest state and the active state by the mass of the goal frame 1, which must be raised to change the state of the mechanism 40 by moving the linkage 42 through the intermediate or over-centre position. In the illustrated example, the linkage 42 includes an upper bar 43 and a lower bar 44 connected at a pivot 45 which is movable in either direction through the over-centre position defined by a collinear position of the bars 43, 44.

In summary, a goal frame 1 is supported via upper rolling bodies 21 on spherical ground balls 11 which can rotate omnidirectionally to move the goal frame over the pitch. Each ground ball 11 is retained beneath the upper rolling body 21 by a retaining structure 30, which may include horizontal rollers 34. A load transfer mechanism 40 may be operable to transfer the load of the goal frame selectively to and from the ground ball 11.

In alternative embodiments, the goal frame could include one or more, additional rolling support assemblies, for example, at the bottom bars 4 or the rear bar 5, to reduce the load on each ground ball. Alternatively, the goal frame could include only two or three rolling support assemblies, optionally in combination with conventional rollers or wheels.

In alternative embodiments, the load transfer mechanism could include a different, geared or hydraulic actuator assembly, e.g. a screwjack or a lever providing additional mechanical advantage.

In alternative embodiments, the bearing assembly 20 and retaining structure 30 could be fixed relative to the bars of the goal frame 1, without any load transfer mechanism, so that the goal frame is permanently supported on the ground balls 11.

The bars of the goal frame could be configured other than as shown, either for football or for another sport.

Many further adaptations are possible within the scope of the claims.

In the claims, reference numerals and characters are provided in parentheses, purely for ease of reference, and should not be construed as limiting features.

Claims

CLAIMS1. A goal frame (1) including a plurality of rolling support assemblies (10) for moving the goal frame over a ground surface (G); each rolling support assembly (10) including a ground engaging rolling body (11), wherein in an active state of the goal frame, the mass of the goal frame (1) is supported on the ground engaging rolling body (11), and the ground engaging rolling body rests on the ground surface and is rollable over the ground surface; wherein the ground engaging rolling body (11) is spherical, and each rolling support assembly (10) further includes: a bearing assembly (20), and a retaining structure (30); the bearing assembly (20) including at least one upper rolling body (21); the at least one upper rolling body (21) being rotatable in rolling contact with the ground engaging rolling body (11) to transfer the mass of the goal frame to the ground engaging rolling body (11); the retaining structure (30) being arranged to retain the ground engaging rolling body (11) in a use position beneath the upper rolling body (21); the ground engaging rolling body (11) being rotatable omnidirectionally in use.
2. A goal frame according to claim 1, wherein the upper rolling body (21) is spherical and is rotatable omnidirectionally in use.
3. A goal frame according to claim 2, wherein the bearing assembly (20) includes a bearing housing (22), the upper rolling body (21) being partially enclosed in the bearing housing (22); and the bearing housing (22) includes a wiper (24), an edge (24') of the wiper being arranged in sliding contact with the upper rolling body (21) to exclude dirt from the bearing housing (22).
4. A goal frame according to any preceding claim, wherein each rolling support assembly (10) includes a ground engaging rolling body wiper (14), an edge (14') of the ground engaging rolling body wiper being arranged in sliding contact with the ground engaging rolling body (11) to remove dirt from the ground engaging rolling body (11).
5. A goal frame according to any preceding claim, wherein the retaining structure (30) includes an annular frame (31) and a plurality of struts (32) connecting the bearing assembly (20) to the frame (31), the struts (32) being spaced apart around the annular frame (31) to define a cage enclosing an upper portion of the ground engaging rolling body (11).
6. A goal frame according to any preceding claim, wherein the retaining structure (30) includes a plurality of rollers (34) spaced apart around the ground engaging rolling body (11), each roller (34) being rotatable in rolling contact with the ground engaging rolling body (11) to transfer forces acting in parallel with the ground surface (G) between the retaining structure (30) and the ground engaging rolling body (11); wherein each roller (34) is arranged to rotate in use about a fixed axis (35) parallel with the ground surface (G), and the rollers (34) are spaced apart from the ground engaging rolling body (11) to accommodate a translation displacement of the ground engaging rolling body (11), in parallel with the ground surface (G) and relative to the retaining structure (30), in the active state.
7. A goal frame according to claim 6, wherein each rolling support assembly (10) includes only one said upper rolling body (21), and the ground engaging rolling body (11) has a diameter D, and the retaining structure (30) is configured to constrain the translation displacement to a maximum distance d from any contact position of the ground engaging rolling body (11) with any respective one of the rollers (34); wherein d 0.05 D.
8. A goal frame according to any preceding claim, wherein the ground engaging rolling body (11) has a diameter D of at least 150mm.
9. A goal frame according to any preceding claim, wherein the ground engaging rolling body (11) includes a spherical core (12) enclosed in a moulded spherical shell (13).
10. A goal frame according to any preceding claim, wherein each rolling support assembly (10) includes a load transfer mechanism (40); the load transfer mechanism (40) being operable in use to transfer a mass of the goal frame (1) selectively to and from the ground engaging rolling body (11) so as to define the active state and a rest state of the goal frame; wherein in the rest state, the mass of the goal frame (1) is not supported on the ground engaging rolling body (11).
11. A goal frame according to claim 10, wherein each rolling support assembly (10) includes a support structure (50), and the bearing assembly (20) is mounted on the retaining structure (30), and the retaining structure (30) is mounted on the support structure (SO) and movable in use relative to the support structure (50) between the active state and the rest state.
12. A goal frame according to claim 11, wherein the retaining structure (30) is slidably mounted within the support structure (50) and movable, in use, in translation relative to the support structure (50) and in a direction perpendicular to the ground surface (G), between the active state and the rest state.
13. A goal frame according to claim 12, wherein the support structure (50) includes a pair of annular frames (51) connected together in spaced relation by a plurality of rods (52), the rods (52) extending in use perpendicular to the ground surface (G), the retaining structure (30) including linear bearings (36) slidably mounted on the rods (52).
14. A goal frame according to claim 13, wherein the retaining structure (30) includes a third annular frame (31) and a plurality of struts (32) connecting the bearing assembly (20) to the third annular frame (31), the struts (32) being spaced apart around the third annular frame (31) to define a cage enclosing an upper portion of the ground engaging rolling body (11); the third annular frame (31) being captive on the rods (52) and movable in translation between the annular frames (51) of the support structure (SO).
15. A goal frame according to any of claims 12 -14, wherein the support structure (50) includes a housing (54, 55), and the retaining structure (30) is configured to retract the ground engaging rolling body (11) into the housing (54, 55) in the rest state.
16. A goal frame according to any of claims 12 -15, wherein the load transfer mechanism (40) includes a handle (41), and is operable, in use: to move the retaining structure (30), relative to the support structure (SO), from the rest state to the active state by raising the handle (41) away from the ground surface (G), and to move the retaining structure (30), relative to the support structure (50), from the active state to the rest state by lowering the handle (41) towards the ground surface (G).
17. A goal frame according to claim 16, wherein the load transfer mechanism (40) includes a pivoting linkage (42), the linkage (42) being configured to pass through an intermediate position between the rest state and the active state, and to raise the goal frame (1), in use, away from the ground surface (6), when moving from each of the rest state and the active state towards the intermediate position.
18. A goal frame according to any of claims 11 -17, wherein the support structure (50) connects together two collinear bars (4', 4") of the goal frame (1), the bars (4', 4") extending in use in parallel with the ground surface (G) to rest on the ground surface (G) in the rest state.