GB2438612A

GB2438612A - Restraint for a vehicle at a loading bay

Info

Publication number: GB2438612A
Application number: GB0610943A
Authority: GB
Inventors: Nicholas Cowen
Original assignee: Castell Safety International Ltd
Current assignee: Castell Safety International Ltd
Priority date: 2006-06-02
Filing date: 2006-06-02
Publication date: 2007-12-05
Also published as: GB0610943D0

Abstract

The apparatus restrains a vehicle at a loading bay during loading/unloading. A tensioning device, such as a ratchet buckle 1, applies tension to a tension element, such as a strap or a chain, when the tensioning device and the tensioning element are connected between an anchorage on the vehicle and an anchorage at the loading bay. A detecting device (13, 14) detects that the tension exceeds a given threshold. Preferably the apparatus includes a locking device for locking the tensioning device so as to prevent release of the tension by the tensioning device, the locking device being operable only when the detecting device has detected that the tension exceeds the threshold.

Description

1 2438612

VEHICLE RESTRAINT

This invention relates to apparatus for preventing a vehicle from being driven away from a loading bay during loading/unloading.

The problem of preventing inadvertent driving away from a loading bay has been dealt with in our previous UK patent applications GB 2 402 452 A, GB 2 412 645 A, and GB 0508899.2, the contents of which are incorporation herein by reference.

It is known to use a tension element such as a chain or strap to secure a vehicle against a loading dock in icy and snowy conditions, to prevent the vehicle from slipping away during loading/unloading.

The present invention provides apparatus for restraining a vehicle at a loading bay during loading/unloading, comprising tensioning means for applying tension to a tension element when the tensioning means and the tensioning element are connected between an anchorage on the vehicle and an anchorage at the loading bay, and detecting means for detecting that the tension exceeds a given threshold.

The threshold can be chosen to be sufficiently high as to ensure that there is virtually no risk of the vehicle moving away from the loading bay (or being driven away) during loading/unloading.

The apparatus preferably includes locking means for locking the tensioning means so as to prevent release of the tension by the tensioning means, the locking means being operable only when the detecting means has detected that the tension exceeds the threshold. Thus inadvertent release during loading/unloading can be prevented.

The apparatus preferable also includes enabling/disabling means for enabling/disabling use of the loading bay to loadlunload the vehicle, the enabling/disabling means being operable to enable use of the loading bay only when the tensioning means is locked by the locking means; the enabling/disabling means preventing unlocking of the tensioning means by the locking means until the loading bay has been disabled. Thus deliberate release of tension during loading/unloading can be prevented.

The invention will be described further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a part-sectional side view of an apparatus in accordance with the invention; Figure 2 is a part-sectional plan view of the apparatus; Figure 3 is a part-sectional end view of the apparatus; Figure 4 is a side view of the apparatus in use; and Figure 5 is a plan view of the apparatus in use.

In the embodiment shown in the drawings, the apparatus comprises a tensioning device 1 which, by way of example, is in the form of a ratchet buckle which applies tension to a webbing strap 2 provided with a hook 3 for connection to an anchorage (not shown) on a vehicle. The apparatus has a hook 7 for connection to an anchorage 8 at a loading bay. The ratchet buckle 1 has a handle 4 which, by way of a ratchet, turns a spindle 6 having a slot (not shown) through which the strap 2 can be threaded. The handle 4 is swung back and forth until the strap 2 is properly tensioned. To release the tension, a pawl retaining the ratchet is released. The ratchet buckle 1 and strap 2 cooperate in the manner of a well-known ratchet tie-down available from many manufacturers and need not be described in detail here. The example illustrated is available from GT Factors Ltd. under the designation WH 75100.

The apparatus also comprises a housing 9, which is fixed to the tensioning device 1 by bolts 11, and a disc 12, which is coaxially fixed to the spindle 6. In the housing 9 a compression spring 13 is located between a wall of the housing and a plunger cam 14 fixed to a shank of the hook 7. The spring 13 is compressed as the tension applied to the strap 2 by the tensioning device 1 increases.

A bracket 16 on the housing 9 carries a lock mechanism 17 on the side of the disc 12 remote from the housing. A key 18 is trapped by the lock mechanism 17 until it is turned to cause a locking bolt 19 (Fig. 2) through one of a plurality of openings 21 in the disc 12 and into the housing 9. When the key 18 is released it can be used to enable use of the loading bay for loading/unloading, for example by unlocking a loading bay door, enabling a dock leveller (loading platform), unlocking a chain barrier, or any other means as described in GB 2 402 452 A, GB 2 412 645 A, or GB 0508899.2. These disclosures also explain how the key 18 remains trapped while use of the loading bay remains enabled.

The lock mechanism 17 is prevented from causing the bolt 19 to project into the housing 9 until a sufficient tension is built up in the strap 2 by the tensioning device 1.

In the housing 9 a rotary cam 22 with an operating knob 23 is urged by a torsion spring 24 into a blocking position (as shown in the drawings) in which the cam 22 blocks entry of the bolt 19 into the housing 9. The cam 22 is held in the position by a latch constituted by a lever 26 which is mounted on a pivot 27 in the housing 9 and which is urged by a compression spring 28 so that its free end 26a engages in a recess in the periphery of the cam 22.

As the tension applied by the tensioning device 1 increases, the plunger cam 14 acts on the lever 26 and causes it to unlatch the rotary cam 22 when the tension exceeds a given threshold. The rotary cam 22 can then be turned by means of the knob 23 until an aperture 29 (Fig. 1) in the cam 22 is in register with the bolt 19 of the lock mechanism 17, whereupon the key 18 can be turned to cause the bolt 19 to pass through one of the opening 21 in the disc 12 and into the aperture 29, thereby releasing the key 18 from the lock mechanism 17 and locking the rotary cam 22 in this unblocking position. It will be noted that the bolt 19 now prevents rotation of the disc 12 and hence prevents rotation of the spindle 6. It will also be noted that the rotatability of the cam 22 gives an indication to the user that the threshold tension has been exceeded.

To release the tensioning device 1 the key 18 (necessary to enable use of the loading bay) must first be used to disable the loading bay, then returned to the lock mechanism 17 and used to withdraw the bolt 19, whereupon the key 18 again becomes trapped.

As soon as tension in the strap 2 falls below the given threshold, the latching lever 26 will bear against the rotary cam 22 under the action of the compression spring 28 and, when the cam 22 is released by withdrawing the bolt 19, the cam 22 will spring back to its blocking position under the action of the torsion spring 24 and become latched again by the free end 26a of the lever 26.

It will be appreciated that the key 18 serves as a means for communication between the vehicle restraint apparatus and the loading bay such that use of the loading bay cannot be enabled until the apparatus has been locked in the vehicle restraining condition and, conversely, the apparatus cannot be unlocked until the loading bay has been disabled.

In an alternative embodiment, communication could be by transmission of signals between a transmitter/receiver on the apparatus and a transmitter/receiver at the loading bay. Transmission may be cable transmission or wireless transmission. A similar system (applied to a coupling arrangement) is described in GB 2 412 645 A, to which the reader is referred.

Various other modifications may be made within the scope of the invention. For example, the ratchet buckle may be replaced by any other tensioning device which is suitable for applying sufficient tension to a tension element such as a strap or chain to restrain a heavy goods vehicle and which is lockable in the tension-applying condition.

The mechanical arrangement described above for detecting the tension applied and for locking the tensioning device could be replaced by an electromechanical arrangement for detecting the tension, automatically locking the tensioning device when the tension exceeds a threshold, and emitting a signal which can be communicated to a loading bay enabling/disabling device. The apparatus could be provided with an indicator, such as a light or a buzzer, for indicating to the user that the tension applied by the tensioning device exceeds the required threshold.

Claims

CLAIMS: 1. Apparatus for restraining a vehicle at a loading bay during

loading/unloading, comprising: tensioning means for applying tension to a tension element when the tensioning means and the tensioning element are connected between an anchorage on the vehicle and an anchorage at the loading bay; and detecting means for detecting that the tension exceeds a given threshold.

2. Apparatus as claimed in claim 1, further comprising locking means for locking the tensioning means so as to prevent release of the tension by the tensioning means, the locking means being operable only when the detecting means has detected that the tension exceeds the threshold.

3. Apparatus as claimed in claim 2, in which the locking means comprises a bolt.

4. Apparatus as claimed in claim 3, in which the locking means further comprises a member having an aperture to receive the bolt, the member being movable to an active position, in which the aperture can receive the bolt, only when the detecting means has detected that the tension exceeds the threshold.

5. Apparatus as claimed in any of claims 2 to 4, further comprising: enabling/disabling means for enabling/disabling use of the loading bay to load/unload the vehicle, the enabling/disabling means being operable to enable use of the loading bay only when the tensioning means is locked by the locking means; the enabling/disabling means preventing unlocking of the tensioning means by the locking means until the loading bay has been disabled.

6. Apparatus as claimed in claim 5, in which the enabling/disabling means comprises a key which is trapped by the locking means until the locking means is operated to lock the tensioning means.

7. Apparatus as claimed in claim 5, in which the enabling/disabling device comprises a transmitter/receiver for communicating with a transmitter/receiver at the loading bay.

8. Apparatus as claimed in any preceding claim, further comprising indicating means for indicating that the detecting means has detected that the tension exceeds the threshold.

9. Apparatus as claimed in any preceding claim, in which the detecting means comprises a spring, preferably a compression spring.

10. Apparatus as claimed in any preceding claim, in which the tensioning means comprises a ratchet mechanism.

11. Apparatus as claimed in claim 10, in which the ratchet mechanism is in the form of a ratchet buckle for tensioning a tension element in the form of a strap.

12. Apparatus for preventing a vehicle from being driven away from a loading bay, substantially as described with reference to, and as shown in, the accompanying drawings.