Not applicable
This invention relates generally to the design and construction of vehicle ladder racks, and more particularly, to an improved ladder rack that facilitates the loading and unloading of ladders on and from the roofs of commercial vans and other types of work vehicles while standing at the rear of the vehicle.
For the past twenty years or more, I have worked as a designer of ladder rack systems and have been awarded the below-listed U.S. patents on various improvements I have made to the above field:
U.S. Pat. Nos. 5,297,912; 6,092,972; 6,099,231; 6,427,889; 6,764,268; 6,971,563; 8,511,525; 8,857,689; 8,991,889, 9,415,726; 9,481,313; 9,481,314; and 9,506,292.
For the most part, the ladder racks involved in these patents, as well as others in the prior art, have utilized a lever to simultaneously rotate front and rear 4-bar linkages to transfer ladders from a position atop a work vehicle to a location along the side of the vehicle where a worker can readily grasp the ladder and carry it to the work site. I have now invented a ladder rack that operates on an altogether different principle.
Instead of relying on a rotational force on a crank or lever to transfer a ladder load from atop a roof of a vehicle to a position along the vehicle's side, my new ladder rack of the present invention provides a slide arrangement that allows the worker to either manually or automatically move the ladder load horizontally along the vehicle's roof for a predetermined distance and then have it shift to a somewhat vertical disposition at a location where the ladders and the slide mechanism will not come into contact with the vehicle's body. When in the vertical position, ladders can readily be removed by a person standing on the ground at the rear of the vehicle.
Likewise, ladders can be easily reloaded onto the slide mechanism and then manually or automatically lifted and transferred back to the vehicle's roof.
The present invention comprises a stationary bed member adapted to be firmly affixed to a vehicle's roof.
The bed member comprises a pair of rectilinear rails which preferably are elongated tubes of rectangular cross-section that are held in parallel, spaced-apart relation by at least one transversely extending cross-member. Affixed to each of the rails and extending from the rails front ends approximately halfway along the length dimension thereof are a pair of elongate guide members in which rollers affixed to a load support member are constrained such that the load support member can only move along the rails horizontally in translation without rotation for a predetermined distance determined by the length dimension of the guide members.
Affixed to the under surface of the stationary bed proximate its rear end are first and second bracket pairs between which a control arm and a support arm are pivotally connected. At the free end of the control arm is a cam follower roller and, as the load support member moves to a point where the guide rollers leave the guide sleeves, the cam follower roller enters a cam track on a first cam member affixed to the stationary bed. With rearward movement of the load support member, the cam follower roller elevates and thereby lifts the control arm to a point where a second cam member actuates a spring-loaded, cam-actuated locking pin that acts to latch the control arm to a latch bracket affixed to the underside of the load support member. Once so latched, the control arm causes the load support member to pivot about the support arm with continued movement of the slide member causing it to ultimately tilt to a somewhat vertical disposition and clearing the body of the vehicle on which the present invention is mounted. When in the tilted position, ladders or other load items affixed to the load support member are easily reached by a worker standing on the ground at the rear of the vehicle.
To return the load support member to its horizontal disposition on the roof of the vehicle, the worker merely lifts the lower end of the load support member until it is generally horizontal and with a slight forward pushing force, a point is reached where the second cam causes the spring-loaded latch that couples the control arm to the load support member to be released and the rollers on the load support member to again enter the horizontal roller guides on the stationary bed.
The present invention also shows a motor drive mechanism attachable to the ladder rack assembly for providing a linear drive to the load support member for providing automatic operation of the ladder rack.
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 accompanying drawings in which like numerals in the several views refer to corresponding parts:
This description of the preferred embodiments is intended to 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”, “forward”, “rearward”, 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.
Referring first to
Extending approximately halfway along the length of the side rails 14 and 16 from a front end 24 of the stationary bed 12 are metal guides 26 and 28 of a generally C-shaped cross-sectional contour. The rear ends of the metal guides are identified by numerals 29.
Positioned atop the stationary bed assembly 12 is a load support member indicated generally by numeral 30. It comprises a pair of identical aluminum extrusions 30A and 30B held together by screw clamps as at 32 (see
Also seen in
With reference to
As best seen in
Also affixed to the bottom of the load support member 30 by means of clamping bolts disposed in a longitudinally extending groove 62 formed in the extrusions 30A and 30 B are latch plates 64 (
Cam follow rollers journaled on the latch plates are identified by numeral 70. As the load support member 30 is moved to the right in the direction of the arrow 68, a cam follower roller 70 affixed to the latch plate 64 will enter the arcuate groove as seen in the cam member 42. As it traverses the curved cam track surface, as shown in
As illustrated in
With reference to
As the load support member 30 rotates clockwise when viewed in
In
Affixed to the underside of the load support member 30 at regularly-spaced intervals corresponding to the pin spacings on the chain are inverted U-shaped brackets, as at 96, 98, 100 in
Without limitation, the motor 80 may be a one-half HP DC motor that can be powered by the battery of the vehicle on which the ladder rack of the present invention is mounted. A one-half HP motor will deliver about 250 inches-pounds of torque which is more than sufficient to drive the load support member through its path of travel in both directions when carrying a ladder load. The worm drive may turn the drive sprocket 86 at about 30 RPM such that the drive system can move the load support member from its fully stowed position atop the vehicle to its full tilted position behind the vehicle in approximately 30 seconds.
A pin 102 is made to extend from the sides of links. In a working prototype of the present invention, the pins 102 are placed through links on the chain at a 12.5 inch spacing and which thereby encompasses about 10 links. The brackets 96, 98, 100 are appropriately spaced so that they will be engaged by the laterally extending pins as the chain and the load support member move with respect to one another.
This invention has been described herein in considerable detail in order to 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 embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.
This application is a non-provisional application of Application No. 62/470,477, filed Mar. 13, 2017, and claims priority from that application which is also deemed incorporated by reference in its entirety in this application.
Number | Name | Date | Kind |
---|---|---|---|
1260560 | Longenecker | Mar 1918 | A |
3193124 | Essling | Jul 1965 | A |
3471045 | Panciocco | Oct 1969 | A |
3768673 | Nydam | Oct 1973 | A |
3843001 | Willis | Oct 1974 | A |
4348054 | Shonkwiler | Sep 1982 | A |
5423650 | Zerbst et al. | Jun 1995 | A |
5454684 | Berens | Oct 1995 | A |
7137479 | Ziaylek | Nov 2006 | B2 |
7513730 | Goyanko | Apr 2009 | B2 |
8215893 | Simpson | Jul 2012 | B2 |
9526932 | Ziaylek | Dec 2016 | B1 |
20060076189 | Ziaylek et al. | Apr 2006 | A1 |
20070240936 | Brookshire, Jr. et al. | Oct 2007 | A1 |
20110038698 | Li | Feb 2011 | A1 |
20120263561 | Li | Oct 2012 | A1 |
20150125245 | Gallagher | May 2015 | A1 |
Number | Date | Country |
---|---|---|
1086857 | Mar 2001 | EP |
1535801 | Jun 2005 | EP |
1818218 | Aug 2007 | EP |
Number | Date | Country | |
---|---|---|---|
20180257578 A1 | Sep 2018 | US |
Number | Date | Country | |
---|---|---|---|
62470477 | Mar 2017 | US |