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Patent Searching and Data


Title:
RESTRICTOR PLATE
Document Type and Number:
WIPO Patent Application WO/2008/104740
Kind Code:
A1
Abstract:
A restrictor plate for use in a connection in roadside furniture, the restrictor pla comprising an aperture for receiving a connector and a slot adjacent to and connected with said aperture, the width of the slot being less than the width of said aperture.

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Inventors:
MUSTARD, Trevor, Raymond (Oakham, Rutland LE15 6HB, GB)
Application Number:
GB2008/000559
Publication Date:
September 04, 2008
Filing Date:
February 18, 2008
Export Citation:
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Assignee:
CORUS UK LIMITED (30 Millbank, London SW19 4WY, GB)
MUSTARD, Trevor, Raymond (Oakham, Rutland LE15 6HB, GB)
International Classes:
E01F15/04; F16B43/00
Foreign References:
DE202005013218U1
US4908245A
US4550933A
DE29714671U1
DE19758253A1
US6926461B1
US4126403A
Attorney, Agent or Firm:
EVANS, Claire (Fry Heath & Spence LLP, The GablesMassetts Road,Horley, Surrey RH6 7DQ, GB)
Download PDF:
Claims:

CLAIMS

1. A restrictor plate for use in a connection in roadside furniture, the restrictor plate comprising an aperture for receiving a connector and a slot adjacent to and connected with said aperture, the width of the slot being less than the width of said aperture.

2. A restrictor plate according to claim 1, the slot extending from the aperture to one edge of the restrictor plate.

3. A restrictor plate according to claim 1 or claim 2, wherein the restrictor plate comprises one or more further apertures and one or more further slots, each slot being adjacent to and connected with an aperture, the width of each slot being less than the width of the associated aperture.

4. A restrictor plate according to claim 3, wherein the apertures and slots are positioned in a row.

5. A restrictor plate according to claim 3 or claim 4, wherein the restrictor plate is such that the amount of force required to release a connector from an aperture is substantially the same for each aperture.

6. A restrictor plate according to any of claims 3 to 5, wherein the width of each of the apertures is substantially equal.

7. A restrictor plate according to any of claims 3 to 6, wherein the width of each of the slots increases on going from the slot closest to the edge of the restrictor plate to the slot furthest from the edge of the restrictor plate.

8. A restrictor plate substantially as described herein or as illustrated in the drawings.

9. A restrictor plate according to any preceding claim and a connector for use with the restrictor plate, the width of the slot being less than the width of said connector.

10. Roadside furniture comprising a connection including a slotted bracket and a restrictor plate according to any one of claims 1 to 8.

Description:

RESTRICTOR PLATE

The invention relates to a restrictor plate for use in a connection in roadside furniture. The term "roadside furniture" as used herein means items which are commonly installed besides roads such as safety barriers, signs and lamp posts.

The restrictor plate of the present invention is particularly useful in roadside furniture connections which include a slotted bracket. Such a connection is the subject of the applicant's co-pending application, UK Patent Application No. 0601599.4, and applications based on that application, which relate to a safety barrier which uses slotted brackets to connect the beam to the posts which support that beam.

Using slotted brackets to connect the posts to the beam means that the connection between the beam and posts in the event of an impact on a post is 'strong' in the lateral direction of the beam in order to support the barrier on impact, but λ weak' in the axial direction of the beam in order to reduce the severity of the impact and to prevent excessive damage to the vehicle. However, a problem with such slotted brackets is that they may not provide sufficient resistance in the axial direction of the beam for the posts on either side of the impact zone. Some axial resistance is required on either side of the impact zone in order to put the beam into tension to help contain the vehicle.

It is an object of the invention to seek to mitigate this problem.

Accordingly, the invention provides a restrictor plate for use in a connection in roadside furniture, the restrictor plate comprising an aperture for receiving a connector and a slot adjacent to and connected with said aperture, the width of the slot being less than the width of said aperture.

The invention also provides a restrictor plate according to the invention and a connector for use with the restrictor plate, the width of the slot being less than the width of said connector.

By having a slot which is narrower in width than the aperture, and, in particular, narrower than the width of the connector, the restrictor plate will allow a connector which has been placed in the aperture of the restrictor plate to disconnect from the restrictor plate, while providing resistance to such disconnection. Thus, if the restrictor plate is used in combination with a slotted bracket, it can provide some degree of axial resistance. The amount of axial resistance can be controlled by varying the width of the slot in relation to the width of the connector. Thus, the restrictor plate can be designed so that it will release a connector in the event of a direct impact on the post on which the restrictor plate is mounted, but will not release a connector in the event of an impact on either side of the post on which the restrictor plate is mounted. Thus, the restrictor plate will allow the slotted bracket to perform its function of allowing a post which has been subject to a direct impact to disconnect from the beam, thereby reducing the severity of the impact on the vehicle, but at the same time will prevent the posts on either side of that post from disconnecting from the beam, thereby putting the beam into tension, and so helping to contain the vehicle.

The slot may extend from the aperture to one edge of the restrictor plate.

The restrictor plate may comprise one or more further apertures and one or more further slots, each slot being adjacent to and connected with an aperture, the width of each slot being less than the width of the associated aperture. The apertures and slots may be positioned in a row.

Providing a plurality of apertures allows for assembly tolerances as there will be choice of apertures which can be used for the connector.

The restrictor plate may be such that the amount of force required to release a connector from an aperture is substantially the same for each aperture.

The width of each of the apertures may be substantially equal.

The width of each of the slots may increase on going from the slot closest to the edge of the restrictor plate to the slot furthest from the edge of the restrictor plate.

The invention will now be illustrated with reference to the following drawings of which:

Figure 1 shows a plan view of a restrictor plate according to the invention; and

Figure 2 shows a perspective view of the underside of a safety barrier including the restrictor plate of Figure 1.

The restrictor plate 1 shown in the drawings comprises a rectangular plate of sheet steel.

The restrictor plate 1 comprises three circular apertures 2a, 2b, 2c for receiving a connector (not shown). The three apertures 2a, 2b, 2c are positioned in a row.

The restrictor plate 1 also comprises four slots 3a, 3b, 3c, 3d, each slot being adjacent to and connected with an aperture 2a, 2b, 2c so that there is a slot 3a, 3b, 3c, 3d on either side of each aperture 2a, 2b, 2c, the slots 3a, 3b, 3c, 3d being positioned in a row in line with the row of apertures 2a, 2b, 2c. The apertures 2a, 2b, 2c and slots 3a, 3b, 3c, 3d join together to form a cut out in the restrictor plate 1 extending from one edge 4 of the restrictor plate to a point about two thirds of the way across the restrictor plate 1.

The width x of each of the apertures 2a, 2b, 2c is equal. The width y of each of the slots 3a, 3b, 3c increases on going along the row from the slot 3a closest to the edge 4 of the restrictor plate 1 to the slot 3c furthest but one from the edge 4 of the restrictor plate 1. These widths are calculated such that the amount of force required to release a connector from any one of the apertures 2a, 2b, 2c is substantially the same for each aperture. All three slots 3a, 3b, 3c are narrower than the connectors, with the result that the restrictor plate 1 has to be deformed to allow a connector to pass through the slot. In the illustrated

embodiment, the fourth slot 3d which is furthest from the edge 4 of the restrictor plate 1 is the same width as the adjacent slot, slot 3c, but it may be wider than that slot.

Figure 2 shows the restrictor plate 1 in use in a safety barrier 5. The safety barrier comprises a beam 6 mounted on a plurality of posts 7, one of which is shown in Figure 2. The beam 6 is connected to the post 7 by a slotted bracket 8. The bracket 8 consists of two separate strips 9 which are welded to the top of the post 7 on either side of a cut out 10 in the top of the post 7 such that a gap is left between the two strips 9. The gap forms a slot 11 in the bracket 8, which is in line with the axis of the beam 6. Two restrictor plates 1 are positioned beneath the slotted bracket 8 on either side of the post 7 such that the three apertures, 2a, 2b, 2c and four slots 3a, 3b, 3c, 3d in each restrictor plate 1 are aligned with the slot 11 in the bracket 8, and so that the edge 4 of each restrictor plate 1 faces the post 7. Thus, the cut out in each restrictor plate 1 is also in line with the axis of the beam 6.

In use, a connector such as a bolt (not shown) is passed through a bolt hole 12 in the beam 6, through the slot 11 in the bracket 8 and through one of the apertures 2a, 2b, 2c in the restrictor plate 1. Any one of the three apertures 2a, 2b, 2c may be used, three apertures 2a, 2b, 2c being provided merely to allow for assembly tolerances.

In the event of an impact directly on the post 7, the resistance provided by any of the slots 3a, 3b, 3c which are positioned between the connector and the edge 4 of the restrictor plate 1 will be such that the slot(s) 3a, 3b, 3c will be forced open so releasing the connector from the restrictor plate 1 and allowing the connector to slide out of the slot 11 in the bracket 8. Thus, the restrictor plate 1 will still allow the slotted bracket 8 to perform its function of reducing the severity of the impact on the vehicle.

However, in the event of an impact on one of the posts on either side of the post 7, the resistance provided by any of the slots 3a, 3b, 3c, positioned between the connector and the edge 4 of the restrictor plate 1 will be sufficient

to prevent the connector from being released from the restrictor plate 1 so preventing the connector from sliding out of the slot 11 in the bracket 8. Thus, the post 7 will not disconnect from the beam 6, with the result that the beam will be put into tension by taking load to ground via the post, and so will help to contain the vehicle.

Thus, the restrictor plate 1 provides an appropriate level of resistance along the axis of the beam both for a direct impact on any post 7 and an impact on either side of a post 7 which has undergone a direct impact.

In the above embodiment described above, the restrictor plate 1 is used as part of a connection in a safety barrier. However, it may also be used in the connections of other items of roadside furniture such as signs or lamp posts.