GB2419293A

GB2419293A - Apparatus for limiting the flight of a ball

Info

Publication number: GB2419293A
Application number: GB0422793A
Authority: GB
Inventors: John Loveday
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-10-15
Filing date: 2004-10-15
Publication date: 2006-04-26
Also published as: GB0422793D0

Abstract

The invention relates to the design of a cage or "net" in which a player stands when playing or practicing a cricket or other ball game. Existing designs, particularly for large cages, suffer from the problem that they do not allow the cage to be easily moved. The problem is solved by providing a wheeled cage with a facility 5 at one end for engaging with a trolley 6. The trolley has large wheels and is designed to provide a lever action allowing that end of the cage to be lifted. A large proportion of the weight of the cage is thus carried by the relatively large wheels of the trolley. By pulling the trolley, even a large cage can be made to glide relatively effortlessly over the surface on which it rests.

Description

1 2419293

APPARATUS FOR LIMITING THE FLIGHT OF A BALL

This invention relates to apparatus for limiting the flight of a ball when playing or practicing a game such as cricket or baseball. It is conventional when practicing such games to use an enclosure commonly referred to as a "net" or "cage" to restrict flight of the ball after being pitched at, and possibly hit by, a batsman.

These net or cage structures work best if they are relatively long compared with their width, having one closed end, where the batsman stands, and an opposite open end through which the ball is bowled or pitched; but long structures are difficult to move and mobility is often essential so that the cage can be stored, for example at a side of a playing field, when not in use.

Patent specification CA2332225 describes a relatively long cage formed from a series of hoops from which a net is suspended. However, though this is movable, it relies on guy ropes for support. The need to install these during erection and to remove them after use would make the structure impracticable for use in many circumstance. Another structure employing guy ropes for support is described in patent specification GB 190604611.

Patent specifications US5370385 and US5577721 describe batting cages which have small castor wheels allowing them to be conveniently moved. However these proposals are for very small cages or screens and even these may be difficult to move over soft ground because the small wheels would be liable to sink into the ground. Providing larger wheels to prevent this problem is not a realistic option because of the cost and because the cage or screen needs to extend very close to the ground to prevent escape of the ball.

This invention arose when considering the problem of constructing a cage which is relatively large yet can easily be moved.

In its broadest aspect, the invention provides apparatus for limiting the flight of a ball when playing a game comprising a wheeled enclosure and characterized by a wheeled lifting mechanism designed to engage and lift one end of the enclosure thereby allowing the latter to be pulled across the ground.

The open end of the enclosure is preferably constructed so that there is no lateral frame member at ground level which would cause an obstruction when the cage is in use. To give stability to this structure, when it is being moved, the lifting mechanism is preferably designed so that it spans across the bottom of the open end of the enclosure. A suitable arrangement employs a linking bar which extends across the front opening and is adapted to attach to structural members at each side. Suitable brackets, catches or other means may be provided at opposite sides of the opening to engage respective ends of this bar.

These brackets or the equivalent are preferably connected to the frame by releasable connectors (eg clamps or bolts) so that they can be retrofitted to existing cages of traditional design.

To provide increased manoeuvrability, the wheel or wheels of the lifting mechanism are preferably designed to swivel. A preferred arrangement has two wheels, to give stability, and these wheels are mounted on a supporting structure that pivots relative to the linking bar previously referred to. The wheels of the lifting mechanism are preferably of larger diameter than at least some wheels of the enclosure so as to allow the former to accept weight previously applied to the latter without sinking into a soft ground surface.

The lifting effect can be achieved in many different possible ways including any conventional screw-threaded or hydraulic jacking mechanisms. However, a preferred technique is to use a levering effect. This can be achieved using a relatively long handle to provide a first lever arm (between the free end of the handle and the wheel axis) and a second, relatively short lever "arm" between the aforementioned axis and the points of engagement with the enclosure.

It would be possible to apply the aforementioned principles to structures other than cages. For example it could be used to facilitate movement of other equipment on sports grounds such as cricket screens and waterproof ground- covers. It could also be used in relation to field shelters and other specialist buildings which are required to be moveable. Thus, according to a second aspect of the invention there is provided a temporary structure adapted to be moved over the ground and having relatively small wheels liable to sink into the ground characterized by a lifting mechanism having at least one wheel, larger in diameter than the aforementioned wheels, the lifting mechanism being designed to engage and lift one end of the structure thereby reducing the weight applied to the relatively small wheels, allowing the latter to be pulled across the ground.

One embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Fig I is a perspective view illustrating a cricket cage and separate lifting mechanism constructed in accordance with the invention; and Fig 2 is a perspective view showing the lifting mechanism in more detail and in its lowered position, ready for engagement with brackets on front uprights of the cage, parts of this mechanism being shown broken away.

Referring first to Fig 1, the illustrated cricket cage is 10 metres long and 3.5 metros wide. It has a frame 1, made from tubular steel, carrying a net 2 to form an elongated structure closed at one end and open at the other. There are no cross-bars along the bottom of the cage, except at the closed end. This is necessary to avoid obstruction when in use. The absence of bottom structural supports does not lead to instability when the cage is being moved, because of the use of a linking bar to be described later.

The rear, closed, end of the cage carries two relatively large wheels 3 mounted for rotation about a fixed axis spaced above the bottom of the cage so that the latter is supported very close to the ground to prevent escape of a cricket ball.

Castor wheels 4 support the weight of the cage along its length and allow the cage to be turned.

An open end of the cage rests against the ground, as shown at the front in Fig 1, when in use.

Front uprights la of the frame I have brackets 5 attached releasably to them and provide a releasable pivot connection with a lifting mechanism in the form of a trolley 6 which will now be described with reference to Fig 2.

The trolley 6 comprises a frame 7 which carries relatively large wheels 8 provided with rubber tyres allowing them to roll easily over a soft ground surface. The wheels rotate independently about an axis X which is fixed relative to the frame 7. A handle 9 and a pivot pin 10 are attached to the frame 7.

A linking bar 11 (shown broken away in Fig 2 for ease of illustration) has a bush 12 welded to it. This bush receives the pivot pin 10, allowing the bar I I to rotate relative to the frame about the axis Z. The bar can be removed from the pin for ease of storage when not in use.

The bar I I has lateral extensions 13 at its ends, extending in the direction of the plane of the frame 7 and parallel to the axis of the pin l O. These extensions 13 carry trunnions 14 extending in the direction of axis Y. parallel to axis X. To move the cage, the trolley 6 is offered to the open end of the cage in its lowered position, as shown in Fig 2, with the trunnions 14 directly below recesses formed by the brackets 4. The handle 9 is then turned in the direction of the arrow so that the frame 7 and the bar I I carried by it rotate about axis X. This brings the trunnions 14 into engagement with the brackets 4. Further rotational movement of the handle applies a powerful lifting force to the front of the cage by virtue of the mechanical advantage defined by the ratio of the length dl of the handle 9 relative to the distance d2 between the two axes X and Y. During the lifting action the trunnions rotate in the brackets 5 about axis Y; and the frame 7 rotates on wheel bearings about axis X. When the front of the cage has been lifted, much of the weight is removed from the castor wheels 4, allowing the whole assembly to be pulled across a grassy surface using the handle 9. Turning movements are simple because the frame 7 and wheels 8 can rotate about the Z axis, allowing sideways movement of the front of the cage. The castor wheels 4 also turn to accommodate this sideways movement.

It is pointed out that the illustrated embodiment of the invention is just one example of many different variations which are possible within the scope of the accompanying claims. For example, brackets of equivalent effect to those shown at 5 could be designed to clamp onto the uprights la so they can easily be attached as a retro-fit. Another possibility, eliminating the need for the brackets 5, would be to include a quickrelease clamping mechanism as a swivel attachment at each end of the bar 11. The bar could also be designed to be adjusted in length so as to fit any design of cage. However, a prototype design built following the principles of the illustrated system has proved that the invention will allow a single person to move a very large cage easily across even a soft grassy surface.

Claims

1. Apparatus for limiting the flight of a ball when playing a game comprising a wheeled enclosure and characterized by a wheeled lifting mechanism designed to engage and lift one end of the enclosure thereby allowing the latter to be pulled across the ground.

2. Apparatus according to Claim I characterized in that the lifting mechanism has at least one wheel that is larger in diameter than wheels ofthe enclosure.

3. Apparatus according to Claim 2 characterized in that the design of the enclosure and the lining mechanism is such that, lifting of the enclosure, under the action of the lifting mechanism reduces the weight applied to wheels ofthe enclosure.

4. Apparatus according to any preceding Claim in which the enclosure has an opening at one end and characterized by means for linking the lifting mechanism to the enclosure at opposite sides of the opemng.

5. Apparatus according to any preceding Claim characterized in that the rifling mechanism is detachable from the enclosure.

6. Apparatus according to Claim 5 when dependent on Claim 4 characterized in that the means for linking is a bar designed to extend across the opening and in that means is included for providing engagement between the bar and the enclosure at opposite sides of the opening to allow lifting.

7. Apparatus according to any preceding claim characterized in that a wheel of the lifting mechanism is adapted to swivel relative to the enclosure.

8. Apparatus according to any preceding claim characterized in that the lifting mechanism defines a lever device pivoted on the axis of its wheel and providing a mechanical advantage whereby hand pressure at one end of the lever device is operable to provide a lifting effect on the 1 5 enclosure.

9. A lifting mechanism for use as part of apparatus constructed according to claim 8, characterized in that the lifting mechanism comprises a trolley which is separate from the enclosure; abutments designed to be attached to opposite sides of the enclosure; a handle forming one arm of the lever mechanism; and a connecting link designed to apply lifting force from the second lever arm onto the abutments to lift the enclosure.

10. A temporary structure adapted to be moved over the ground and having relatively small wheels liable to sink into the ground characterized by a lifting mechanism having at least one wheel, larger in diameter than the aforementioned wheels, the lifting mechanism being designed to engage and lift one end of the structure thereby reducing the weight applied to the relatively small wheels, allowing the latter to be pulled across the ground.