I· Cross Reference to Related Application:

This application claims priority to U.S. provisional application, Serial No, 61 /674,498, filed July 23, 2012, the contents of which are hereby incorporated by reference.

II- Fie!d of the Invention:

This invention relates generally to roof racks for work vehicles and more particularly to a clamping apparatus for releasably securing a workman's ladder to the roof rack structure.

111. Discussion of the Prior Art:

In published PCT Application WO 2009/126286 there is provided a detailed description of a vehicle roof rack used for transporting loads on the vehicle roof. The contents of that published application are hereby incorporated by reference and form part of the present application's disclosure.

That application describes an extremely strong, yet lightweight and easy to assemble, roof rack for motor vehicles and is realized using extruded aluminum tubing to create side members and crossbars for joining the side members to one another across the width dimension of a vehicle's roof. Each side member comprises a pair of elongated rails that are clamped together by a series of clamps that cooperate with attachment spines integrally formed with the rails. Attachment flanges forming a part of the extrusion on one rail on each side member facilitates the attachment of the crossbar members thereto. In this way, no welding is required in fabricating and assembling the roof rack structure.

A roof rack of the type described can be used to transport ladders of various types, e.g. step ladders and extension ladders, and so-called buogee cords or ropes may used to secure a ladder to the roof rack structure. The present invention comprises an attachment for a roof rack like that described in the aforereferenced PCT application that can be used to facilitate placement of a ladder onto the vehicle roof rack and to rapidly secure the ladder in place without the need to apply bungee cords or ropes to accomplish this end.

In a co-pending patent application serial no, 12/71 ,573, filed March 8, 2010 (published application US 2011/0214944 Al), there is described an earlier invention of applicant namely, a ladder rack for work vehicles that comprises a pair of side rails held in parallel, spaced relating by a pair of crossbars. Extending between the crossbars is at least one hook bar on which is fixedly attached a ladder clamping arm, A latch mechanism is affixed to a rearmost crossbar for re!easably securing ladders on the rack. It comprises a crank on a rotatable shaft held by brackets affixed to the rear crossbar for rotation about an axis parallel to the crossbars, A rear ladder clamping arm is affixed to the rotatable shaft and aligned wi h the front clamping arm affixed to the hook bar. The front and rear hooks are adapted to engage spaced ladder mngs of a ladder being carried on the vehicle roof rack. The present Invention is deemed to be an improvement over the invention described and claimed in the above-referenced pending U.S. published application.

SUMMARY OF THE INVENTION

The present invention comprises a clamping arrangement having a pair of longitudinally spaced clamping arms designed to engage a pair of spaced-apart ladder steps or rungs of a ladder placed horizontally on the crossbar members of the roof rack. The clamping arms are linked to one another by a longitudinally extending rod that is jo maled for rotation in rod supports that clamp to spaced-apart ones of the roof rack's crossbar members. The rod has a crank arm affixed at a rear end thereof to facilitate manual rotation of the rod.

Also clamped to spaced-apart crossbar members of the roof rack and extending parallel to said crossbar members are roiatably mounted actuator rods on which the clamping arms are attached. The rods to which the clamping arms are affixed also support a pair of rollers. Extending between the clamping arms and the longitudinally extending rod is a two-piece articulated linkage.

When the longitudinally extending rod is manually rotated, the actuating rods thai extend parallel to the crossbar members and transverse to the longitudinally extending rod are made to rotate so as to simultaneously spin the front and rear ladder clamping arms 90 ^e from a lowered position, generally parallel to the vehicle's roof, to a raised position generally perpendicular thereto. When in the raised position, the front and rear ladder clamping arms are adapted to engage spaced apart ones of ladder steps or rungs, preventing movement of the ladder relative to the roof rack during sudden starts and stops of the vehicle on which the roof rack is mounted. When the ladder clamping arms are fully raised, the two-piece articulated links employed form a rigid brace preventing bending of the ladder clamping amis as a result of inertia! forces acting on the clamped ladder.

The rollers mounted on the parallel extending actuator rods are positioned such that when the ladder clamping arms are in their lowered position, the rollers project upward above the level of the crossbar members, thereby providing rolling support for the parallel side rails of a ladder as a ladder is being either loaded onto or removed from the roof rack. When the ladder clamping arms are in their raised, ladder clamping position, the rollers are retracted such that the ladder rests upon the stationary crossbars of the roof rack.

DESCRIPTION OF THE DRAWINGS

The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the

!?.f accompanying drawings in which like numerals in the several views refer to

corresponding parts.

Figure 1 is a perspective view of a roof rack incorporating the ladder clamping apparatus of the present invention with the clamping arms fiilly erect;

Figure 2 is a view like Figure I with the clamping arms only slightly retracted;

Figure 3 is a view like Figure 2 with the clamping arms further retracted;

Figure 4 is a view like Figure 3 with the clamping arms fully retracted;

Figure 5 is a partial rear view with the actuation crank in a position causing the clamping amis to be fully extended;

Figure 6 is a partial rear view like Figure 5 with the actuating crank rotated slightly clockwise; Figure 7 is a view like Figure 6 with the actuating crank rotated further clockwise;

Figure 8 is a view like Figure 7 with the actuating crank rotated fully clockwise such that the clamping arms are fully lowered;

Figure 9 is an enlarged partial perspective view from the rear showing the clamping arm in its fully erect position;

Figure 10 is a view like Figure 9 but with the damping arm on its way down to a fully retracted position; and

Figure S ! is a view like Figure 10, but with the clamping arm fully retracted, DESCRIPTION OF THE PREFERRED EMBODIMENT

This description of the preferred embodiments is intended lo be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as "lower", "upper", "horizontal", "vertical", "above", "below", "up", "down", "top" and "bottom" as well as derivatives thereof (e.g., "horizontally", "downwardly",

"upwardly", etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as "connected", "connecting", "attached", "attaching", "join" and "joining" are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece, unless expressively described otherwise.

A vehicle roof rack on which the present invention finds use is illustrated in Figure S of the drawings and in Figure 1 of the published PCT application that is incorporated by reference herein. It includes right and left side rail assemblies 10, 1 1 heid in parallel, spaced apart relation by a plurality of transversely extending crossbar members 13, 15, 17, 19, 21. The crossbar members clamp to the extrusions comprising the left and right side rails in the manner described in the PCT application mentioned.

In Implementing the novel ladder clamping apparatus of the present invention. a journal bracket 14 incorporating a nylon sleeve bearing 16 is clamped to the frontmost crossbar member 13 arid joumaied for rotation therein is a longitudinally extending rigid rod 18 that extends parallel to the left and right side rail assemblies 10, 1 1. The opposite end of the rod ! 8 is joumaied in a bracket 20 (Figure 5) that clamps to the rearmost crossbar member 21 , Similar brackets may be provided on one or more of the crossbar members ! 5, 17, 1 intermediate the front and rear ones to provide additional support for the rod 18·

With continued reference to Figure I, a further, transversely extending actuator rod 22 is joumaied for rotation by brackets 24 that clamp onto a crossbar member 35. Affixed to rod 22 is a front ladder clamping arm 26. The manner in which the front ladder clamping arm 26 is affixed to the rod 22 will be more fully explained with the aid of Figure 9 showing an enlarged, substantially identical assembly connected to the crossbar member 19,

Extending between the ladder clamping arm 26 and the longitudinal rod 18 is an articulated linkage indicated generally by numeral 28. It comprises a pair of links 30, 32 having a ball-joint coupling the two links together at 34. A ball joint also joins link 32 to the ladder clamping arm 26 in a manner to be explained more fully below. Link 30 Is rigidly affixed to a clamp 35 fastened on the elongated longitudinally extending rod 18.

Referring now to Figure 9, a substantially identical arrangement that is used to clamp the front clamping arm 26 to the longitudinally extending rod 18 is seen as being secured to the crossbar member 1 which is inwardly adjacent to the rearmost crossbar member 21. Again, a pair of spaced-apart brackets 24' clamp So clamping ridges on the undersurface of the crossbar member 1 and a transversely extending rod 22' is joumaied for rotation in the brackets 24'. A clamp 23 is fitted about the rod 22' to tightly engage same and affixed to the clamp 23 is a slotted plate 25 to which the clamping arm 26' is affixed by bolts 29 (Fig. 6) passing through the slot 27 of the plate 25. In this way, the ladder clamping arm 26' is height adjustable over a limited range.

Referring momentarily again to Figure 3, it is to be noted that a pair of rollers 38, 40 is mounted on the front transverse actuator rod 22 in an actuator offset relation so as to rotate about a separate axis offset from that of the front transverse actuator rod 22. Figure 9 shows a similar pair of rollers 38', 40' for the rear transverse actuator rod 22',

A crank 42 is affixed to the rear end of the longitudinally extending rod 18,

By pushing on the crank, the rod 18 is made to rotate in its journal brackets 14, 14', and in doing so, rotation is imparted through the articulated linkages 28, 28' to the actuator rods 22, 22'. As a result, the pair of ladder clamping arms 26, 26' is made to move between a generally horizontal position at a level be!ow that of the crossbar members and a generally vertical position as in Figures I , 5 and 9. When the ladder clamping arms are in their vertical position, the links 30, 32 and 30', 32' become rectilinear with respect to one another and act as a stiffening brace between the arms 26, 26' and the rod 18 to prevent deflection of the ladder clamping arms due to inertia forces acting on a ladder as it is being transported.

Referring once more to Figure 1 , operatively coupled to the crank handle 42 used to rotate the rod 18 is an "over-center" mechanism that positively places the ladder clamping arms in their full extended and fully retracted positions. Specifically, the clamp device 44 that joins the crank 42 to the end of the longitudinally extending rod 18 includes a clevis 46 in which a pin 48 is pivotal ly joined. Surrounding the pin 48 is a compression spring 50 that acts against a stop member 52, that is clamped to crossbar member 21 at 54 and where the pin 48 extends through an aperture (not shown) formed through the stop member 32. The end of the spring 50 abuts solid material of the stop member 52 surrounding the aperture so that only an end portion of the pin 48 passes through the aperture. The pin serves to keep the spring from bending as it is compressed. When the crank 42 is turned in a clockwise direction as shown in Figures 5-8, past center to lower the ladder clamping arms 26, 26' to their horizontal disposition, the spring force urges the crank handle 42 further in the clockwise direction to a positive stop position where the ladder clamping amis are fully retracted. Likewise, when the crank handle 42 is now rotated back

counterclockwise past a center position, the spring 50 and pin 48 assume an angle urging the crank in the counterclockwise direction to a positive stop position where the ladder clamping arms are fully erect.

When the arms 26, 26' are lowered to the horizontal disposition, the rollers 38, 40 and 38', 40' are at an elevation above the level of the crossbar members and the 5 lateral spacing between the rollers 3§, 40 and between 38 40' are such that they will align with the rails of extension or step ladders, allowing a person to easily advance a ladder onto the roof rack due to the reduced friction afforded by the rollers. Then, when the operating crank is turned to raise the ladder clamping arms to engage a spaced pair of ladder rungs and thereby capture the ladder, the rollers will drop down

10 below the level of the crossbar members such that the ladder that has been loaded to rest upon the crossbar members rather than on the rollers.

Referring to Figures 8 and 9, when the crank arm 42 is rotated counterclockwise from the position shown in Figure 8 to that shown in Figure 9, an aperture 43 in the crank ami 42 becomes aligned with the aperture 53 in the stop

I S member 52 allowing the hasp of a padlock to be inserted through the aligned

apertures, thereby locking the ladder clamping arms 26, 26' in their elevated disposition and preventing unauthorized removal of any ladder engaged by the clamping arms.

This invention has been described herein in considerable detail in order to 0 comply with the patent statutes and to provide those skilled In the art with the

information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and trial various modifications, both as to the equipment and operating procedures, can be 3 accomplished without departing from the scope of the invention itsel

What is claimed is: