Telescopic ramp

This application claims the benefit of 60/133,409, filed May 10, 1999.

This invention relates to ramps for loading and unloading trucks, trailers and vans, specifically to those ramps that pivot and telescope.

Over the years many systems have been developed in an effort to efficiently load items on and unload them off the cargo beds of trucks, trailers and vans. There have been various types of mechanical lifts, ramps, loading docks and other devices.

Trucks with ramps that tilt and telescope to the ground have been the most successful in fulfilling this job, however, most of these are attached directly to the vehicle's frame rather than on a cargo bed. U.S. Pat. 3,550,801 to Larson (1970) discloses a design that connects the ramp components to the framework of a truck that has no stationary cargo bed. U.S. Pat. 3,768,673 to Nydam et al (1973) discloses a system of limited capability. It is not powered in either its telescopic or pivoting functions. Their system shows the tailgate hinged in a downward position which is not possible with current tailgate design since the bumper would be in the way. U.S. Pat. No. 5,603,600 to Egan et al (1997) has elevated his system so that it will reside above a closed tailgate. Since the pivoting is not controlled while loading or unloading their system must be limited to light loads an operator can handle while at the same time working the winch.

Several of the many objects and advantages of the present invention are:

(1) to provide a ramp which will reside on the cargo bed of a truck, trailer or van rather than being attached to the vehicle's frame and without major alterations to the cargo bed;

(2) to provide a ramp which will be primarily self contained and can be marketed as an easy to install package;

(3) to provide a ramp which will have most of its components installed within and above the cargo bed rather than under it;

(4) to provide a ramp which will have a minimum height so as to not consume a large volume of the cargo compartment;

(5) to provide a ramp which will have a gradual incline when pivoted down and extended to the ground;

(6) to provide a ramp for a pickup truck which will allow for a modified tailgate to be located in its normal location while allowing for the ramp to reside and telescope underneath;

(7) to provide a ramp for vehicles having wheel wells that allow for the main longitudinal structural members to reside between the wheel wells;

(8) to provide a ramp for a pickup truck which will allow for the main longitudinal structural members to reside between the wheel wells, but for the portion aft of the wheel wells to extend to almost the width of the tailgate, and aft of the tailgate to extend to any desired width;

(9) to provide a ramp which will allow for its top surface to be a combination of conventional conveyor devices and stationary deck materials;

(10) to provide a ramp which may have a powered pulling system for loading as well as a powered pushing system for unloading.

Further objects and advantages are to provide a ramp system that will allow an operator to still use those areas of the cargo bed not occupied by the ramp, and since the cargo bed is still intact small items that may fall from a retracted ramp will fall on the cargo bed rather than onto the ground. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.

In the drawings, closely related figures have the same number but different alphabetic suffixes.

FIGS. 1 thru 3 show in plan view components of a ramp mounted in the cargo compartment of a vehicle having wheel wells that protrude through and above it's cargo bed.

FIG. 4 shows an isometric exploded view of the components of the previous Figs.

FIGS. 5 thru 7 show in elevation views the ramps of the previous Figs but with the vehicles nearside sidewall removed.

FIGS. 8 thru 11 show in plan view various embodiments of the ramp's deck.

FIGS. 12 and 13 show in isometric view devices useful for loading and unloading a ramp.

FIGS. 14 thru 17 show in plan and sectional views details of a pulling device incorporating a rod less cylinder.

FIGS. 18 thru 25 shows in plan and elevation views modifications required for using a vehicle's original tailgate with a ramp.

In accordance with the present invention the ramp comprises a pivoting, telescopic system which mounts on the top surface of the cargo bed of trucks, trailers and vans.

A typical embodiment 10 of the ramp of the present invention is illustrated in FIGS. 1 thru 3 showing a ramp mounted on the top of the cargo bed 12 of a vehicle having wheel wells 18 that protrude through its cargo bed and that has two sidewalls 16 and a forward wall 17 . In FIG. 1 the base assembly 20 consist of a forward base 21 that is attached to the cargo bed with fasteners 24 , and a rear base 22 attached to the rear of the cargo bed 14 with fasteners 25 . Mounting bracket 26 receives clevis 48 (FIG. 4) and bracket 28 receives hinge bracket 43 .

In FIG. 2 a pivoting frame assembly represented by 40 consist of longitudinal rails 41 that are separated by and connected to transverse members 42 . The assembly is pivotally attached to rear base 22 with brackets 43 and 28 . Notches 44 provide an access for track bearings 68 (FIG. 4) to enter rails 41 . Bearings 49 are mounted in rails 41 , with part of their outer surface disposed above rails 41 so that they may receive rails 61 (FIG. 3) that travel on them. 46 represent a system to raise the forward end of the frame. It could comprise hydraulic or pneumatic cylinders or linear actuators. 47 represents the point where the system pivotally attaches to the rails. 50 represents a device to pull a telescopic frame 60 (FIG. 3) longitudinally back and forth on frame 40 .

In FIG. 3 a telescopic frame assembly represented by 60 consist of longitudinal rails 61 that are separated by and connected to transverse members 62 and 63 . A notch 64 allows rails 61 to travel forward without contacting raising system 46 . Holes 65 are provided for attaching deck materials. Chain 70 is connected to each end of frame 60 and underneath members 62 . The chain is engaged with pulling device 50 providing a method for moving the telescopic frame back and forth. Other methods such as hydraulic or pneumatic cylinders or linear actuators would work as well.

FIG. 4 shows additional details of the parts of the previous Figs. Holes 29 represent the pivoting axis where brackets 28 and 43 connect. 67 represents the rigid connection of longitudinal rails 61 with transverse members 62 . Slots 45 are cut in each of the 41 rails allowing for the axles of track bearings 68 to travel. Rod devises 48 connect lifting system 46 with brackets 26 . Holes 66 are provided for receiving the axles of cylindrical conveyor rollers. Brackets 69 on each end of the telescopic frame provide a connection for each end of roller chain 70 .

FIG. 5 shows the ramp in it's retracted condition with the vehicle's nearside sidewall removed. Base 21 is located dose to the forward end of the cargo bed.

FIG. 6 shows the ramp in it's extended and pivoted down position. It can be seen that the underside of member 63 is tapered so that the top surface of the deck is close to the ground. Wheel well 18 can be seen in the background.

FIG. 7 shows base 21 A located close to the wheel well 18 and pivoting bracket 47 A positioned above it. This location would be desirable if more uncluttered space forward is required.

FIGS. 8 thru 13 show different deck embodiments. FIG. 8 shows the vehicle's wheel wells with the ramp between them. 80 represents the area aft of the wheel wells wider than that between the wheel wells and forward of them. 81 represents a stationary planked deck. It could be of wood, plastic, metal or some type of flexible material.

FIG. 9 shows an embodiment comprising cylindrical conveyor rollers 82 as the top surface of the ramp. FIG. 10 shows a combination of rollers 83 and stationary deck materials 84 .

FIG. 11 shows a central support member 90 that supports rollers 85 on each side and contains a pulling system 92 for loading and unloading items from the ramp. FIG. 12 shows a similar ramp but with the deck planks oriented in a transverse position.

FIG. 13 shows a ramp with widened aft end 80 A. Winch 110 is shown with protective housing 111 mounted on the forward end of the ramp.

FIGS. 14 thru 17 show a pulling system contained within the structure of the telescopic frame. Structural member 90 is slotted on its top surface providing a track for hub 92 to travel. Structural member 91 provides a container for a rod less cylinder 93 to reside. Member 91 A may be used to keep the frame symmetrical but is not needed for the pulling system, however, it could be used to contain a system to move the telescopic frame relative to the pivoting frame replacing system 50 and 70 . Member 90 may be fabricated on its sides to receive rollers 85 . Sheaves 94 change the direction of the rod less cylinder's cable 95 allowing it to travel to and connect to hub 92 . FIG. 15 shows the other end of the system and rod less cylinder 93 A. FIG. 16 shows cable 95 being connected to hub 92 at 96 .

FIG. 17 shows the incline of cable 95 from the rod less cylinder 93 to the hub 92 . This provides for a less eccentric connection of the cable to the hub.

FIGS. 18 thru 25 show two methods for modifying the tailgates of pickup trucks having ramps. One method hinges the tailgate from the telescopic frame. Original tailgate 120 is modified by removing its lower section 121 and inserting hinge rod 123 vertically in one side of the new tailgate 122 . A socket 123 A is fabricated in the telescopic frame for rotationally receiving hinge rod 123 . Locking rod 126 , topped by knob 124 , is slidably inserted in the other side of the new tailgate. A socket 125 A is fabricated in the telescopic frame for receiving locking rod 125 . The opened tailgate 122 A can be lifted out of its socket if desired.

The other method hinges the tailgate from the sidewall of the vehicle. Original tailgate 130 is modified by removing its lower section 131 and 131 A if desired and inserting hinge rod 133 vertically in one side of the new tailgate 132 . Hinge brackets 134 are attached to the sidewall 16 of the vehicle for receiving hinge rod 133 . Locking rod 136 , topped by knob 135 , is slidably inserted in the other side of the new tailgate A socket 136 A is fabricated in the other sidewall for receiving locking rod 136 . 132 A shows the modified tailgate in an opened position.

Accordingly, the reader will see that the ramp of this invention can be efficiently used on a vehicle that has a flat cargo bed. That it is not necessary to locate and connect the lifting machinery to the vehicles main structural frame, rather just mount the entire system on the cargo bed. Four bolts through the deck are all that is needed for securing it. By locating the track rollers of the telescopic frame so that they travel inside the pivoting frame, rather than on top of it, the overall height of the system is reduced to a minimum. Furthermore, the ramp has the additional advantages in that,

on vehicles having tailgates or rear doors it provides for a method for modifying the gates and doors so that the ramp can reside and operate under them;

on vehicles having wheel wells the ramp can reside and operate mesial the wheel wells and also allowing for the area aft of the wheel wells to be greater in width;

it allows for the ramp to be manufactured and marketed as a self contained package;

it incorporates the use of rectangular structural tubing in the design of the pivoting frame rails providing a track for the telescopic frame track rollers to travel in;

it provides for the top surface of the ramp to be a combination rolling and stationary devices and materials;

it provides for a compact pulling system which is located within the pivoting frame for loading and unloading cargo on and from the vehicle.

Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, the lifting cylinders on the pivoting frame could be replaced by a single cylinder; the two base members could be joined by longitudinal members; tailgates could be hinged to raise vertically, etc.

Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.