[0001] This invention relates to a ladder clamp for a vehicle roof rack or the like. Background to the Invention

[0002] While many different devices have been proposed at different times to deal with the problem of attaching a ladder temporarily to a vehicle roof rack or roof bars to permit the ladder to be transported, the device typically used consists of a hooked bar having a screw-thread on the main shaft of the hook, a cross-bar passing over the shaft, and a locking clamp engaged on the thread to bear against the cross-bar. In use, the hook is passed between the sides of the ladder on the roof bars and is hooked under a bar. The cross-bar is positioned across the sides of the ladder, and the locking clamp is manually rotated to clamp the cross-bar in position, and so secure the ladder. Since the hook passes between the rungs of the ladder, it prevents forward or rearward movement of the ladder when the vehicle moves, in the event of the clamping action being insufficient.

[0003] The hooked bar type of clamp is relatively simple in construction and use, but is difficult to manipulate single-handed, for example when used on taller vehicles, requiring the user to hold on to the vehicle with one hand while removing or fitting the clamp.

Summary of the Invention

[0004] According to the invention, there is provided a ladder clamp for a vehicle roof rack or the like, comprising a cross-member engageable on the two side rails of a ladder, and an elongate member carrying a hook at one end thereof, the elongate member being connected at the other end thereof to, and depending from, a lever mounted at the centre of the cross-member, whereby when the cross-member is located on the side rails of a ladder positioned on a vehicle roof rack and the hook is engaged with the roof rack the lever is oper- able to move the elongate member upwardly to bring the hook into clamping engagement with the roof rack, characterised in that the position of the hook relative to the lever is adjustable when not in clamping engagement with the roof rack to accommodate different distances between the clamp and the roof rack.

[0005] In one embodiment, the lever is movable between a first position, wherein the hook is at a first distance from the cross-member, and a second position, wherein the hook is at a smaller distance from the cross-member than said first distance, such that moving the lever to the second position tensions the elongate member to clamp the ladder between the cross-member and the roof rack. The lever is preferably configured such that, in the second position, it is in an over-centre position.

[0006] The elongate member may be a thin flexible member, the lever arrangement being configured as an over-centre buckle, whereby the length of the elongate member may be readily changed to accommodate different ladders, or multiple ladders stacked one upon another. For example, the thin flexi- ble member may be textile webbing, which may incorporate metal wire to render the webbing more resistant to cutting, whether accidental or deliberate in the course of theft.

[0007] The lever is preferably provided with latching means to hold it in place when in the second position. [0008] In an alternative embodiment, the elongate member is a toothed rod and the lever controls a ratchet drive engaging the teeth in the rod. A friction drive may be used instead of the ratchet drive.

[0009] The cross-member preferably comprises a flat plate at each end thereof engageable on the side rails of the ladder and serving to resist rotation of the cross-member when the elongate member is tensioned, and also permitting different ladder widths to be accommodated. Pegs or bolts may extend downwardly from the plates at the outermost edges thereof to ensure that the cross-member cannot slide off the ladder sideways.

[0010] A lock may be provided to prevent unauthorised removal of the lad- der, and in one embodiment the cross-member carries a separate security chain, wire or the like, to be secured around the ladder and the roof rack. This may incorporate a padlock, for example.

[0011] It will be appreciated that reference herein to roof rack includes roof bars. Brief Description of the Drawings

[0012] In the drawings, which illustrate exemplary embodiments of the invention:

[0013] Figure 1 is a perspective partial view of a ladder mounted on a vehicle roof rack, and held in place by a ladder clamp in accordance with one em- bodiment of the invention; and

[0014] Figure 2 is a similar view showing an alternative embodiment of the invention.

Detailed Description of the Illustrated Embodiment

[0015] Referring to Figure 1 , the vehicle roof rack is represented by a simple circular cross-section bar 1 supported by uprights 2 (one only shown) held by mountings on the vehicle (not shown). It will be appreciated that roof racks or bars may take a wide range of different forms. The ladder 3, of which only a short length is shown, rests across a spaced pair of the bars 1 , in conventional manner. The clamp of the invention comprises a cross-bar 4, conveniently of box section metal, for example galvanised steel or aluminium, to the underside of each end of which is secured a respective flat metal plate 5 which serves to resist rotation of the cross-bar 4 in use, and which extends the contact area with the side rails of the ladder 3. The underside of the plates 5 may be provided with a layer of rubber or the like to increase grip and minimise the risk of dam- age to the ladder. Each plate 5 has a pair of bolts or pegs 6 extending downwardly therefrom, adjacent to the outer edge thereof, to help locate the clamp on the ladder and prevent it sliding off the ladder laterally.

[0016] At the centre of the cross-bar 4 is mounted an over-centre webbing buckle 7, through which is threaded a length of webbing 8 carrying at the free end thereof a hook 9. The over-centre buckle 7 includes a lever 10 which ro- - A -

tates around a pivot 11 in such a manner that lifting the lever lowers the hook 9, while lowering the lever pulls the hook upwardly into engagement with the roof bar 1 , tensioning the webbing 8, and thereby clamping the ladder on to the roof bar by pulling the cross-bar 4 and plates 5 firmly on to the side rails of the lad- der. The lever 10 is provided with a sliding latch 12 which engages in slots in the sides of the buckle as the lever is pushed into its fully lowered position, holding it firmly in place.

[0017] To remove the ladder 3 from the roof bars 1 , the latch 12 is disengaged from the slots to permit the lever to be lifted, releasing the hook from the bar 1. This permits the clamp to be lifted off the ladder, freeing the ladder to be removed from the roof bars 1 for use. Since the lifting and lowering of the lever 10 can be achieved quickly single-handed, the fitting and removal of the clamp is a very much quicker and easier operation than with conventional ladder clamps. [0018] The threading of the webbing 8 through the buckle 7 enables the position of the hook 9 below the cross-bar 4 to be adjusted to accommodate different types of ladder having different widths of side rail, or multiple-stage ladders where the stages are stacked on upon another, for example. It will be convenient to adjust the position of the hook with the lever raised, so that the hook rests lightly against the underside of the roof bar 1 , so that lowering and latching the lever introduces the right degree of tension in the webbing to clamp the ladder firmly in place.

[0019] Referring now to Figure 2, in which corresponding components have the same reference numerals and are not described again in detail, the webbing buckle arrangement is replaced by an elongate bar 20 having a hook 21 formed in the lower end thereof. The bar 20 is formed with downwardly directed teeth 22 on one side thereof, and is mounted in a support 23, which is in turn mounted on the cross-bar 4. The support 23 consists of a pair of carrier plates 24, the nearer of which is shown as transparent in Figure 2 for the sake of clar- ity, supporting a lever 25, pivotally mounted between the plates 24, and guides (not shown) for the bar 20. The lever 25 carries on one side thereof a pivoted pawl 26 which can engage the teeth 22 so that cranking of the lever up and down causes the hook to be drawn into firm engagement with the roof bar 1. A lockable release mechanism (not shown) can be operated to disengage the pawl, permitting the bar 20 to be pulled downwardly to release the ladder, and to permit initial adjustment of the position of the hook to accommodate different sizes of ladder or roof rack, or perhaps multiple ladders stacked one upon another.

[0020] It will be understood that, in the embodiment described with reference to Figure 2, the teeth and pawl ratchet mechanism could be replaced with a simple friction drive arrangement using a wedging action, for example as used in simple sealant guns used with sealant or adhesives dispensing tubes, where an angled sprung plate through which the bar passes releases the bar for movement in one direction, but grips it to prevent movement in the return direction. [0021] Typically, a pair of the clamps in accordance with the invention will be used to secure a ladder, one for each roof bar, or engaging different cross- members of a more structured roof rack.