Patent Application
20080247855
1. Field of the Invention
The present invention relates to removable carrier and lift that can be secured to a vehicle. More particularly, the present invention relates to a cart or other article that can be easily secured to and removed from a vehicle through vertical adjustment of the article relative to the vehicle using a lift.
2. Description of Related Prior Art
There are a number of devices currently available for securing and removing articles to a vehicle during transport. However, current devices typically accommodate bikes, skis, surfboards, and other lighter objects and are not sufficiently designed to easily secure larger articles. Larger items, such as heavy duty carts, can present greater problems during transport because of their increased load, difficulty in securing it to a vehicle, and maintaining the safety of other vehicles during transport of the article. Because there is so much weight, the cantilever load capabilities should be sufficiently distributed to allow for greater strength and greater stability of the article during transport.
Therefore, it is desirable to provide a novel attachment mechanism for a hitch-mounted carrier that can sufficiently sustain a larger article during vehicular transport, as well as vertically lift the article.
Accordingly, it is an object of the present invention to provide a vehicle mounted carrier comprising: a lift secured to a vehicle; a base removably secured to the lift; and one or more hooks coupled to the base for removably securing an article adapted to receive the one or more hooks. It is a further object of the present invention to provide: hooks removable from the base; locking members on the hooks comprising pivoting latches with apertures that align with apertures on at least one of the one or more hooks wherein the apertures are adapted for receiving and removing a locking pin; at least one of said one or more hooks at one or more locations on said base; a housing engaging a vehicle mount comprising: a top and a bottom, and a lead screw rotatably mounted to the housing, a drive means mounted to the housing and operatively engaging the lead screw, a removable and vertically adjustable base with a sleeve nut operatively engaging the lead screw, and the base having one or more hooks for removably securing to an article adapted to receive the hooks; one or more vertical rails generally parallel to a lead screw and operatively engaging a base; a drive means comprising an electric motor for engaging a lead screw and that operatively engages the electrical system of an automobile; a drive means comprising a hand crank actuated by a handle operatively engaging a lead screw; a removable housing cover having one or more channels for allowing vertical movement of said base; at least one of one or more hooks on a base comprises a locking member for preventing the removal of an article from the hooks.
A complete understanding of this invention can be gained through reference to the drawings in conjunction with a thorough review of the disclosure herein.
In general, the present invention is a vehicle mounted device that can bear substantially large article loads through a novel hook support. For example,
During transport, carrier attachments to vehicles endure significant stress because of the constant movement transferred from the vehicle to a carrier and its attached article. This is especially true for larger loads that extend away from the vehicle resulting in greater bending moment and shear force than common vehicle-mounted article carriers. Consequently, the carrier must be able to withstand substantial stress created by horizontal forces (varied by acceleration and deceleration) and vertical forces (created by acceleration and deceleration over varied terrain) that are compounded by the article load. Therefore, a preferred embodiment for sustaining this load is accomplished by a hook or claw assembly whereby the load is distributed to the apparatus through hooks secured to a base.
In a preferred embodiment shown in
In an exemplary embodiment shown in the exploded view of
In an optimal configuration, hooks 3 are used to align with receiving bars 4 or other attachments on a cart or article with a corresponding shape acceptable for fitting onto hooks 3. As such, hooks 3 can be lowered to an optimal clearance level below receiving bars 4 and then lifted through vertical movement of the lift 1 to a desired position relative to the ground.
In tests, tolerance thresholds for the lift 1 incorporating a small electric motor exceeded 350 lbs of load bearing capacity. Preferably, materials used for the lift 1 are comprised of aluminum or titanium, either machined or cast, because of their strength and lightweight character, but other suitable materials include other metals or even reinforced composite plastics depending on the loads to be transported.
Base 7 is used to support hooks 3 and slidably engage a lead screw 10 (
In an exemplary embodiment hooks 3 or other attachments are secured directly to base 7 either as a unitary machined or molded hook element(s) or, can attach to base 7 through one or more hook supports 8 that are removably secured to the base 7 so that hooks 3 and supports 8 can be realigned on base. In this exemplary embodiment, different attachment types can be normal or locking screws to prevent unwanted removal of hooks.
Hooks are secured to an article utilizing specially adapted receiving bars 4. In a preferred embodiment an article can be configured with one or more elongated bars welded or, removably secured to the article through known fastening mechanisms. (E.g., bolts, pins)
To lift an article off the ground, vertical movement is achieved through the use of a lead screw 10 that is generally vertically relative to the lift 1. As the screw 10 is turned, the torque from turning is converted to thrust of threaded sleeve 11 such that it moves linearly along lead screw 10. It is preferred that a Precision lead screw is used. It has been found that a minimum ½ inch diameter screw be used for per 350 lbs of load. Therefore, lead screw 10 could be smaller if lead screw 10 is supported differently. Lead screw 10 should be of sufficient diameter and thread pitch in reference to the load size to be lifted to prevent back slippage when an article is raised and lowered. Likewise, an annular threaded sleeve 11 should be at least an inch in height or greater and with sufficient thread pitch to prevent back slippage on the screw 10. Pitch, material, and lubrication should be chosen to minimize the likelihood of slippage. Additionally, motor size and pitch are complementary when factored into load bearing capacity of the lift 1.
The primary concern in any lead screw system is the amount of load to be moved. The load to be moved is determinative of the proper type and size of screw to be selected. Because the type of loads referred to in this application are being moved vertically, the nut load, or the load being forced on the threaded sleeve 11 should be equal to the weight to be moved plus the friction load. Therefore, the screw 10 and sleeve 11 will need to increase proportionately with the load.
A preferred embodiment for creating vertical lift is through an electric motor that engages gears for turning lead screw 10. Electric motor 12 may be mounted on carrier and controlled by any number of control devices commonly found in the art. Further, the power source for driving the motor can be either a portable power source such as a battery or through leads and other control units engaging a vehicle electrical source. Alternatively a manual crank or ratchet may be used in lieu of a motor as discussed herein. A preferred crank and screw combination provides for a 5/16 hex that can be turned with a wrench, socket device, or built-in handle.
In a preferred embodiment, electric motors such as those found in electric drills which generate a quarter horsepower will lift 350 lbs at 0.6 inches a second. More powerful motors or ones with variable speeds may also be used to engage a lead screw 10 to effectuate faster lifting.
In an exemplary embodiment for rotating lead screw 10, a motor is mounted to engage a gear combination where lead screw 10 is axially mounted through one of the gears and the motor axle is mounted to another gear that engages the lead screw gear. (Not shown) Vertical movement is controlled by the transfer of motor force through the rotation of the gears to lead screw 10. Speed, power, and direction can vary depending on the type of motor used in addition to the size of the threading on the lead screw 10.
To provide additional support and stabilize an article during transport, rails 13 and rail guides 14 secured to base 7 are disposed on a lift 1. Here, two parallel rails 13 are disposed vertically and generally parallel on either side of lead screw 10 and base 7. Base 7 engages rails 13 through rail guides 14 that extend from base 7 or base attachments 26 and fit over rails 13. Various embodiments exist for slides including bearing slides, track rollers, slidable material, or lubricated material engaging rail slides allowing for easier vertical movement. In a preferred embodiment, heavy duty bearing slides 14 form a straddle rail arrangement that in addition to creating a vertical guide to prevent wobbling of an article, also offsets the cantilever load created by an article or cart.
Alternatively, and in another exemplary embodiment, a hand crank (not shown) can replace a motor as a motive force for turning the gears or lead screw 10 directly. A crank may be threadably attached to threading 15 on the end of a lead screw 10 thereby allowing a person to rotate lead screw 10 in either direction to create lift of base 7. This embodiment is oftentimes preferred so as to eliminate the need for added electrical connections where power may not always be available.
Those skilled in the art will readily appreciate that alternate lifting forces, such as hydraulic and pneumatic motors, are also available and could be adapted for use on carrier.
For safety reasons, it is preferred that a removable cover 27 with channel apertures 17 be adapted to fit over lift 1 allowing for unimpeded and unhampered vertical movement of base 7 and hooks 3.
In another preferred attachment embodiment shown in
Alternatively, and because a pivoting frame assembly could be the cause of some wobbling, a frame 18 could be welded or otherwise permanently affixed to a hitch mount 21 and a support arm 19 could similarly be welded to the hitch mount 21 and frame 18.
Although several embodiments have been described, the same should not be construed as limited thereby to specific features mentioned herein, but include various other equivalent features and should only be limited in accordance with the claims appended hereto. It is understood that any suitable changes or substitutions may be made without departing from the spirit and scope of the invention.
