Patent Application
20050002769
The present invention relates generally to a pivoting lift attached to a vehicle which includes a mounting assembly, a lift assembly, and a load holding member for raising or lowering a load into and out of a vehicle, such that the load can be fully or partially supported by each level during the loading and unloading process.
Heavy and bulky material or equipment are difficult to handle both from different heights and different locations. The material or equipment used, however, must be readily transportable from one location to another. For instance, a large equipment storage box or generator may be used at a variety of different job sites, and will typically be hauled from one site to the next by a pickup truck or van.
One problem with transporting such equipment is the loading or unloading of the equipment into and out of the vehicle. Often the material or equipment is too heavy to manually load or unload without risk of injury, or it must be broken down into smaller sections, requiring numerous trips to move it from the vehicle to a work location. Consequently additional people are required, a hoist or forklift is used, or the vehicle is equipped with a lift.
However most lifts are expensive, require a lot of time to attach to the vehicle and they are not easy to load or unload. Usually it is very difficult to secure the load while raising or lowering. Only if the vehicle is dedicated to transportation of material or equipment, can the cost of the lift be justified. Additionally lifts available presently, suspend the load at the upper level and require the operator to move the load off of a suspended load holding member, across gaps between the lift and vehicle.
It would be advantageous to have a low cost removable lift that did not sag, have gap issues when loading or unloading, and could be used for other lifting situations away from the vehicle.
The present invention relates generally to a vehicle mounted pivoting material or equipment lift that moves items from one level to another. The lift gives the user a more economical alternative, often with little or no installation costs to raise or lower material in or out of a vehicle. The pivoting or swing feature makes it easier for the user to load and unload since the load holding member can be pivoted toward, and over the other level, then lowered onto it. This provides a stable surface for loading and unloading. Other lifting solutions will sag or have uneven transitions and gaps, making it more difficult and possibly unsafe to load or unload. Additionally if one uses an item such as a forklift, pallet jack, dolly, or other device to load/unload the load holding member, the lift assembly does not have to support this additional weight, since the load holding member can be fully or partially supported by the structure of each level.
One specific application of this invention is for loading and unloading items from a vehicle such as a pickup truck, van, or trailer. To date, lifts associated with these types of vehicles require the operator to load the item onto the load holding member and then transfer the load off the suspended load holding member onto the second level. With this invention one pivots the load over the vehicle, and the operator never has to go out onto the suspended load holding member to load or unload items. Additionally, most lifts associated with vehicles require a lot of work to install. Many require modifications or welding for installation. With the depicted versions of the invention they can all be mounted either by simply securing an adapter in a hitch receiver, or with minor bolting of an adapter to the vehicle. There are many different styles of mounting adapters and load holding members, each with a specific application advantage.
The invention will hereafter be described with reference to the accompanying drawings, wherein like referenced numerals denote like elements, and;
The illustrated version of the solid load holding member unit has a tilting load holding member (35). The tilting load holding member offers the advantage of providing a smooth transition to each level, without any gaps or joints. This offers significant advantages since the vehicle angle changes with the load in it, and the ground angle in relation to the vehicle varies as well. This tilting load holding member can be created by many means. In the version depicted, a tilt arm (36) with connected tilt rollers (48), raises or lowers the front edge of the load holding member, as the cable becomes tight or slack.
Variations of the load holding member allow the user to load specific items with ease. A drum clamp (33) or hook attachment is available for 55 Gal drums, and fork attachments (34) make it easy to load pallets and larger wheeled items. Many other special load holding members can be configured to load specific items. In the case of water craft applications, special cradle forks that fit the bottom contour of the watercraft are used.
Due to the quick connection feature and variety of mounting means, the main lift assembly (59) can be easily disconnected from one mounting means and transported to another. For instance a user could disconnect the unit from their vehicle hitch receiver and roll it to another vehicle, or mounting location. It could also be transferred to a straddle base accessory (42) that allows the user to use it as a mobile lift load holding member unattached from the vehicle. {Note: A set of ground rollers (60) are attached to the rear of the elongate member assembly (3).} The lift assembly (59) is disconnected from the vehicle by creating slack in the cable when the load holding member and elongate member are fully on the ground. Then with the pivot/transit lock pin (29) removed, the pivot guide assembly (30) is pulled up and out of the mounting adapter (1, 11). The operator can rest the assembly on top of the adapter and secure it at the top of the elongate member. Some users use a bar or “C” clamp to lift the assembly up and secure it at the top of the elongate member for easy installation the next time.
The hitch adapter is mounted to the hitch receiver (61) by two bolts (12). The bolts are used instead of a hitch pin to eliminate any play that exists between the hitch adapter and the receiver. This play could cause the lift to rock or tilt, when rotating the unit with a load.
In many situations there is an advantage to have the unit travel in a position close to the vehicle, and then be able to swing out of the way to open a van door or tailgate. This can be accomplished by using a swing arm adapter (46) that allows the unit to swing out and away from the vehicle. However, when you swing the unit out, the cantilevered load on the mounting means increases, reducing the capacity the lift can support only connected to the vehicle. Thus to retain the full capacity of the lift, a drop down support foot (43) can be lowered to engage the ground to help support the load. In the version shown, the support foot (43) is raised and lowered manually and locked in place by a compression clamp (44). Means such as an acme screw or hydraulic jack could be used to raise and lower this foot, the same way as a trailer jack stand.
The swing joint (62) illustrated is also very unique that it is economical to manufacture, and that the lock pin (45) fits into a fixed gap in the pivot bar joint in three positions. The pin is captured in any of the three positions by a partial round cut in the end of the pivoting joint member (63). Thus, the pin is sandwiched between the round contour cut on the pivoting member (63) and the side of the stationary member (64). In the illustrated versions a hitch pin (13) is used to retain the joint lock pin (45).
For users that want the most lifting capacity, quickest setup without the support foot adapter, the standard offset hitch adapter (11) works with pickups with the tailgate (65) removed. (All recent models of pickup trucks tailgates are removable without tools in less than a minute.) For those users optional sliding up/down tailgate (40) kit is available. The user only has to install two channel members (41) to the sidewalls of the their truck. The channels are mounted forward, so as not to interfere with the factory tailgate (65). The light weight tailgate (40) can be easily slid into or out of the channels (41). Additionally with the factory tailgate removed, it is a lot easier to climb in and out of the vehicle to move loads further forward to a transit position.
Another key variation of this invention is a unit with a two stage elongate member assembly. This feature allows the lift to raise items above the pivot guide assembly stops (66). On this version the load holding member is connected to a second set of rollers {guide (16) and side thrust (18)} that ride on the outside flanges of the elongate member (19). The elongate member travels up and down in relation to the pivot guide assembly (30), and the load holding member (31, 33-35) travels up and down in relation to the elongate member (19). Additional pulleys (67) are mounted at the bottom and top of the elongate member assembly. Depending on where the pulleys are mounted, and how the cable is reaved, the load holding member or the elongate member can be made to raise first. Then when the first moving item hits its upward travel stop, the second item will raise. (The 2nd set of travel stops for the load holding member can either be fixed as depicted (68), or bolt on adjustable. The adjustable stops allow the user to change the upper stop position for their specific vehicle or application.) The travel sequence is created in reverse on the way down. Each variation again has a specific application advantage. On the two stage version depicted, the elongate member (23) lowers first, then the load holding member, or in this case, the forks (34).
In the vehicle application the two stage elongate member adds the ability to raise loads to a height above the bed (69) of the truck such as the sidewalls (70) of a pickup truck. Thus larger/wider items that would hit the sidewall with a single stage elongate member will now pivot clear. Then depending on how wide the item is, it can be lowered down between the sidewalls or set on top. Additionally this second stage guide assembly allows the user to load/unload an item to a third level above the truck bed height. A specific example is that a user could load or unload an item at a commercial truck dock. These docks are usually significantly higher than the height of a standard pickup or van bed.
Also on the two stage version depicted, the elongate member has a larger set of transit rollers (22) on the bottom that contact the ground before the bottom cross brace. If the ground is a hard smooth surface like asphalt or concrete the user could back the vehicle up so that the forks or load holding member would slide under a load such as a pallet or gang box. (Note: This can also be accomplished with a single stage version without the tilting feature.)
A further variation of the unit is one that is mounted to a trolley (49) that rolls back and forth in the vehicle bed. This version allows the user to load and position an item at the front of the vehicle without having to climb into the truck bed. The “U” shaped trolley (49) runs on a set of tracks (50) mounted to the bed of the vehicle. Rollers on the trolley (52) engage the track to guide the trolley in a straight direction in and out of the vehicle. There are a variety of tracks each with an advantage in specific applications. Again like the elongate member, the trolley is guided by sets of rollers to accept the different loads. Each track must take the loads of the trolley when the lift is pointed forward and backwards. The depicted version uses an inverted “V” track (50) and “V” groove wheels (52). In the specific version depicted, pins attached to the trolley “U” tips, engage lock tubes (71) attached to the track at the rear of the truck. These lock pins not only stop the trolley from running off the end of the track, but they will also take the upward loads when the unit is rotated facing out from the truck.
(Raising an item from a lower level (the ground) to a higher level (the truck bed)):
The operator raises the load holding member (31, 33-35) off the truck bed (69), by rotating the crank handle (6) in the clockwise direction.
As the winch (56) is cranked, the cable (57) is wound around the winch drum (72). In this version the cable runs from the winch drum to a pulley (67) attached to the load holding member tilt arm. The other end of the cable is attached to a pin (73) on the pivot guide assembly (30). This creates a two to one cable ratio. This is used since many standard manufactured brake winches have poor gear ratios. The 2 to one cable allows using a standard winch for this version, and does not require extreme handle force. This allows users with varied strengths to raise the load holding member even when fully loaded. As the cable becomes tight it pulls up on the load holding member tilt arm (74).
As the arm pivots, the tilt rollers (48) push against the elongate member flange (75), which pushes the bottom of the load holding member away from the elongate member. The load holding member is connected to the elongate member at two top pivot points (37) one on each side of the elongate member outer flanges. Thus as the load holding member base is pushed away from the elongate member, the load holding member pivots to a position slightly above level. At this point the tilt arm (74) will come in contact with the load holding member and rotation stops.
Now as the winch continues to pull the cable, the elongate member and attached load holding member will raise together.
The elongate member is guided up and down by several sets of rollers attached to the pivot guide assembly (30). Two sets of rollers (16) on each side of the elongate member transfer the forces created by the cantilevered load, to the pivot guide tube assembly (30). Additionally two other sets of rollers (18) transfer any side thrust loads, created by a load not centered side to side on the load holding member.
The load holding member will continue to rise until the bottom cross member (14) of the elongate member comes in contact with the elongate member travel stops (88) mounted to the pivot guide assembly (30).
When the load holding member is fully raised the bottom of the elongate member is also clear of the elongate member pivot stop pin (76) on the down travel stop (15). This pin was captured in an arc contour on the bottom cross brace of the elongate member (5). This prevents the unit from being rotated off the travel stop when the elongate member is not raised and the lock pin (29) is not inserted.
The operator now removes the pivot lock pin (29) and rotates the pivot guide assembly from facing into the vehicle, to facing out.
When the load holding member is facing directly backwards the operator inserts the lock pin (29) again. Note: On more premium versions the lock pin is retained, guided, and spring loaded. An operator only has to pull on a cable below the pivot arm to release the pin and start turning. When the unit is facing straight back the pin snaps back into a second lock pin position.
The operator replaces the pivot/transit lock pin (29) to keep the lift assembly steady and in position during lowering.
Now the load holding member is lowered by rotating the crank handle (6) in the counterclockwise direction, spooling out cable from the drum (72) and allowing the elongate member and load holding member to lower. At any time if the operator releases the crank handle, the load holding member will stay in the current position, held in place by the automatic brake mechanism of the winch (56).
When the bottom of the elongate member contacts the ground the elongate member travel will stop and the load holding member tilt arm (36) will start to rotate down. Eventually the front edge of the load holding member will contact the ground level, unless the vehicle is on extreme terrain conditions. If this were the case it would not be a safe condition to load or unload.
When the load holding member is at the lower level, the operator loads the items to be lifted onto the load holding member (31, 33-35), and secures them as required with straps or rope to the tie down loops(32).
The operator then cranks the winch handle (6) in the clockwise direction to raise the load holding member. The sequence is reverse of the lowering process, where the load holding member tilts to a position slightly above level, and then the elongate member raises up until it contacts the up stops (88).
The operator then again removes the pivot/transit lock pin (29), and rotates the load holding member facing the vehicle again.
The pivot/transit lock pin (29) is replaced, and the operator rotates the handle (6) counterclockwise to lower the load.
As the elongate member lowers, the bottom of the elongate member contacts the elongate member travel stop (15) clamped to the vehicle mounting adapter (1, 11). (Note: This travel stop is adjustable and secured to the adapter by a compression clamp (78). The adjustment allows for variations in height between the mounting point, and the truck bed. It also allows the user the ability to set the incline at which the load holding member will contact the bed.)
Again as the operator continues to crank the handle (6) the load holding member (35) tilts down until the front edge contacts the truck bed.
The operator now removes the load from the load holding member (35) and moves it to the desired position in the truck bed and secures it for transit.
If this is the last item that the operator is going to load, the pivot lock pin (29) is secured with a hitch pin or locking cap. This pivot lock pin is called the transit lock pin since it keeps the pivot guide assembly from rotating or bouncing out of the mounting adapter (11).
Thus is should be apparent that there has been provided in accordance with the present invention a material or equipment lift that fully satisfies the objective and advantages set forth above. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Variations such as changing the lifting means from a winch to something else like a hydraulic ram, rollers being replaced by slide blocks, etc. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope.
| Number | Date | Country | |
|---|---|---|---|
| 60468068 | May 2003 | US |
