Patent Application
20120279802
The invention relates to access or work platforms that may be removably mounted to a vehicle, to provide improved access to the engine, windows or roof of such vehicles.
The prior art includes several different tire mount platform devices. Examples include those disclosed in U.S. Pat. Nos. 2,575,503; 2,848,150; 2,851,312; 2,973,052; 4,947,961; 5,133,429; 6,044,928; and 6,550,578; the disclosures of which are incorporated by reference. Clearly, the general idea of mounting a work or access platform to a vehicle tire is known.
Problems with prior-art wheel-mounting platform devices, however, include that many offer only a single step or platform, thus limiting or restricting access (e.g., ascending to the engine compartment/hood area) and usability on different-sized vehicles. In the prior art embodiments that include more than one step, only two steps are provided and they are arranged substantially vertically. It is more difficult to climb vertically-disposed steps than steps mounted diagonally, and vertical steps offer less flexible access when loading, securing or unloading cargo from a roof of a vehicle.
Furthermore, when climbing vertically-arranged steps, one may be forced to use one hand to hold on to the vehicle if the vehicle body bulges out beyond the tire. A different step orientation may alleviate this requirement, freeing both the user's hands to carry tools, supplies, a light, beverage or the like as he mounts the steps.
Another shortcoming of prior art tire mounting steps and/or platforms is that their height is of limited adjustability. Many such platforms simply hang from the top of the tire, so it may be difficult to step onto the platform when attached to very large tires, and it may be difficult to raise or lower heavy cargo when there is a tall step.
Yet another disadvantage of prior-art tire-mount platform devices is that many attach to the top of the wheel and simply dangle clown. If the vehicle does not have the parking brake set and for automatics, the transmission placed in “park,” then the vehicle may accidentally roll. This results in the step(s) falling off the wheel, with a high chance of injury to the user.
An adjustable tire-mount access device that addresses these shortcomings may be of significant value in this field.
Embodiments of the invention provide height-adjustable tire-mount platforms that offer improved access to upper portions of vehicles, such as engine compartments, windows, roofs, roof racks, and so on. Embodiments may be particularly useful on pickup trucks, vans, SUVs and service vehicles.
An extendable tire-mount device in accordance with the present invention may include one or more of extendable legs, diagonal positioning when mounted, a flexible and adjustable mounting harness, and a tire-side face on the platform that is concave or recessed to better fit the tire. The extendable legs may be rungless, merely extending the legs of the runged section; or may provide additional rungs to facilitate climbing.
Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.”
Embodiments of the invention are generally similar to, and give the visual impression of, fixed or extendable stepladders, but all include a structure or component for securing the embodiment to a tire, so that a user can more easily access out-of-reach areas on a taller vehicle for cleaning, repair or storage manipulation.
Lower portion 200 comprises side rails 210, 215; rungs 220 and a rear brace 230. The lower ends of rails 210 and 215 may be capped by anti-scratch, anti-slip feet 212 and 217. Upper portion 240 comprises side rails (not identified), rungs (one of which is identified as 260), and a top 270. This embodiment has a single securing strap identified as 290.
Embodiments of the invention are to be placed against and secured to the tire of a vehicle, to allow the user to climb the ladder safely and reach higher points on the vehicle. For example, an embodiment may be secured to the front tire of a front-engine truck to allow a mechanic to reach the engine bay more easily, or an embodiment may be secured to the rear tire of a van to allow the user to reach storage bins or luggage placed on the top of the vehicle.
Although the profile of the scallop is difficult to describe in words, it is easy to compute using standard engineering computer-aided design (“CAD”) tools. Furthermore, since embodiments may be used with a variety of tire sizes and at differing angles of lean against the tire, the precise size and shape of the scallop (including top profile 430 and side profile 440) is not critical. An embodiment may comprise scores, protrusions, lugs or the like (indicated generally at 460) to help keep the top step from sliding from side to side against the tire.
The complex shape of the top step of an embodiment can be manufactured easily by molding it of plastic, or with somewhat greater difficulty by forming it from sheet metal or cutting it from another material. In a preferred embodiment, the top step is molded from thermoplastic resin.
The ladder structure of an embodiment may be constructed of any conventional materials, using any conventional techniques. For example, side rails of the upper and/or lower parts may be made from fiberglass channels, aluminum channels, wood or another material. Rungs and braces may be fiberglass, metal or wood. Side rails and rungs may be joined by screws, rivets, glue, welding, or other techniques. Protective feet at the bottom of side rails may be plastic, rubber, or metal. Extension-locking mechanisms may be shear pins, as discussed above, or compression/friction fittings, ratchets or other structures.
An embodiment may sized to fit a range of tires, but generally, the width of an embodiment is preferably within about ±20% of the diameter of the applicable tire, and the length such that the embodiment can be leaned against the tire at an angle from about 45° to about 80° from the horizontal. (This implies a ladder length from slightly longer than the tire diameter to almost 1.5 times the tire diameter. Of course, an extendable embodiment may be suitable for use with a wider range of tire sizes.) Narrower ladders may provide inferior access for the user, while vehicle fenders or wheel wells may interfere with wider ladders. Very short ladders are not much use, whereas overly long ladders may be inconvenient to transport, or may be more difficult to secure to the tire.
The strap or web to secure an embodiment to a tire may be made of nylon webbing, rope, chain, metal cable, elastic bands or cords, or combinations of such materials. It is preferred that the main horizontal securement strap pass around the tire above the horizontal centerline of the wheel (to avoid the axle, brake mechanisms, etc.) and below about 75% of the diameter of the tire. If the horizontal strap is too high, it may tend to slide further up to the top of the tire, thus impairing the secure attachment. However, it is appreciated that tire-tread features (e.g., side traction lugs) may help keep the strap in place. Other parts of the securing web (e.g., coronal and auxiliary positioning straps) may be placed to provide easy access to length adjusters and/or suit single or double-tire wheels. In some embodiments, the securing web may be constructed of fabric in a half-wheel-cover configuration. The lower edge of such a half wheel cover is similar in positioning and purpose to the main horizontal strap of other embodiments.
Several specific embodiments of the present invention have been described with reference to corresponding Figures. However, those of skill in the art will recognize that changes in materials and configurations may be made without departing from the general principles of the invention. Such changes and alternate implementations are understood to be captured according to the following claims.
This U.S. patent application claims the benefit of provisional application No. 61/518,229 filed 2-May-2011 and provisional application No. 61/505,275 filed 7-Jul.-2011.
| Number | Date | Country | |
|---|---|---|---|
| 61518229 | May 2011 | US | |
| 61505275 | Jul 2011 | US |
