WO1992013736A1

WO1992013736A1 - Freight loading device

Info

Publication number: WO1992013736A1
Application number: PCT/US1991/000898
Authority: WO
Inventors: Glenn G. Dunbar; Robert E. Tyner
Original assignee: Dunbar Glenn G; Tyner Robert E
Priority date: 1991-02-08
Filing date: 1991-02-08
Publication date: 1992-08-20

Abstract

Apparatus for use on a highway truck (21) for loading and unloading freight; including a carriage (10) that moves longitudinally inside truck (21) on rails attached to the inside walls (56) of truck (21) the carriage (10) including carriage framework (11), boom frame (12) mounted at the center (16) of carriage framework (11) and capable of rotating approximately 360 degrees, a boom (13) extending horizontally outward from boom frame (12), and a cable hoist mounted on boom (13) to move freight into and out of truck (21).

Description

FREIGHT LOADING DEVICE

TECHNICAL FIELD

This invention relates to a device for attachment to a covered highway truck to provide the capability of moving freight onto and off the truck by one person.

BACKGROUND ART

Highway trucks have been used for hauling freight from place to place for as long as highway trucks have been in ex¬ istence. Generally, if the freight carried in the truck is large enough or heavy enough, it has been necessary to in¬ clude a helper in addition to the driver in order to handle the freight. Because human labor is expensive there have been inventions in the prior art to facilitate movement of the freight by one person.Elevator tail gates have provided some assistance where the freight could be moved on a dolly or by a hand truck to the tail gate, which is then lowered to the ground and moved away from the tail gate. If the freight was too heavy, it might have to be shipped on a flat bed open truck with a built-in hoist on the truck or a separate hoist on the ground available to load and unload the freight. Nothing has been available until recently to handle large or heavy loads in a covered bed truck.

There have recently been made available covered trucks with movable overhead cranes built into the truck. Generally, these trucks have employed rails inside the truck upon which a movable crane structure rolls lengthwise of the truck, and a cable hoist pulley mounted on a trolley moves laterally on the crane structure. In some instances the rails are made to be rearwardly extendable beyond the tail gate, if any, in order to allow the hoist to lower the freight from the truck bed di¬ rectly to the ground level, This extendable feature has been accomplished by either making the rails telescopically exten- dable or by putting the extension rails on a swinging gate stru ture. These crane components have usually been powered by hydra lic motor means, which inherently are messy and require frequen maintenance. None of these prior art devices has the capability of reaching into corners of the truck or close to its walls to handle the freight because the hoist cannot be positioned close to these structures when the hoist is on a laterally movable trolley. Accordingly, there has been a need for improved inter¬ nal truck cranes that are small, easy to operate, and capable of moving freight from any location in the truck to outside the truck at ground level.

It is an object of this invention to provide an improved freight loading device built into a covered truck which carries the freight. It is another object of the invention to provide a freight loading device with a rotatable boom system on which is a hoist that can reach substantially any location inside the truck. It is still another object of this invention to provide a freight loading device which is compact, light in weight, and powered by an electric system. Still other objects will become apparent from the more detailed description which follows.

BRIEF SUMMARY OF THE CLAIMED INVENTION

This invention relates to a freight loading and unloading device for a covered highway truck. The invention is character¬ ized by a horizontally travelling crane carriage 10 movably mounted on a pair of horizontal rails 14 positioned along the longitudinal inside walls 56 of a covered highway truck 21,and a first driving means to cause the carriage 10 to move longi¬ tudinally along those rails 14. Mounted on carriage framework 11 is a horizontally rotatable boom frame 12 and a second driving means for rotating the boom frame 12 through substan¬ tially 360 degrees in either direction with respect to carriage framework 11. A boom 13 is affixed to boom frame 12 and extends radially outwardly to a distal end 34 on which is mounted a pulley 18 and associated hoisting equipment to raise and lower freight between the truck bed and the ground, and a third dri¬ ving means to operate the hoist.

In specific embodiments of this invention the carriage framework 11 slides on rails 14 with pads 15 of a low frictio material between framework 11 and rails 14 to facilitate the movement; while boom frame 12 is mounted on wheels 38 which roll around track 17 attached to carriage framework 11; and boom 13 employs a chain cable hoist. Another preferred embodi¬ ment includes a system of sprockets and chains to move the carriage 10 along rails 14 with roller chains 33 attached to rails 14 engaged with sprockets 32 attached to carriage frame¬ work 11 and driven by electric motor 29.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organi¬ zation and method of operation, together with further objects and advantages thereof may best be understood by reference to the following description taken in conjunction with the accom¬ panying drawings in which:

FIG. 1 is a schematic perspective view of a truck employin the device of this invention;

FIG. 2 is a top plan view of the device of this invention;

FIG. 3 is a cross sectional view of the device taken at 3-3 of FIG. 2:

FIG. 4 is a side elevational view of the device of.this in vention; and

FIG. 5 is a cross sectional view taken at 5-5 of FIG. 2.

DETAILED DESCRIPTION AND BEST MODE OF EMBODIMENT

The principal features of this invention are best under¬ stood with reference to the attached drawings. The device of this invention is a carriage 10 which rests on, and moves lon¬ gitudinally of truck21 along, a pair of rails 14 mounted on the inside walls 56 of truck 21 near its roof. The carriage 10 move preferably by sliding along rails 14 as a sled without wheels, and employing pads of low friction material 15 between carriage framework 11 and rails 14, although it is entirely operable for the movement of carriage 10 to be facilitated by wheels rolling on rails 14. Generally, carriage framework 11 is a rectangular structure of beams welded, bolted, or riveted together to pro¬ duce a rigid structure. In the geometrical center 16 of carri¬ age framework 11 is a circular track 17 which supports boom frame 12, preferably mounted on a plurality of wheels 38 in a circular arrangement to permit boom frame 12 to rotate through approximately 360 degrees. Instead of having wheels 38 boom frame 12 may be made to slide on suitable skids , perhaps with the assistance of pads of low friction material, such as des¬ cribed above with respect to carriage framework 11 sliding on rails 14.Boom frame 12 supports boom 13 which extends radially outward from center 16 to the maximum length permitted by the internal dimensions of truck 21. Generally, this means thatboom 13 from its distal end 34 to center 16 is one-half of the width of the interior of truck 21. At distal end 34 of boom 13 is a pulley or sheave 18 over which cable 19 is threaded from winch means 59 on boom frame 12 to a hook at the free end of cable 19 for attachment to a package of freight 20 (see FIG. 1). Cable 19 may be a wire rope or the like, but preferably is a chain with pulley 18 designed to engage such a chain. Boom 13 is shown as a fixed length boom, but it may be telescopically ex¬ tendable.

In FIGS. 1-3 the structure of carriage framework 11 and boom frame is shown in detail. Carriage framework 11 is a rec¬ tangular structure of a plurality of lateral beams 23 and a plurality of longitudinal beams 24 symmetrical about its geo¬ metrical center 16. A substantially square central space 26 is enclosed by two each of beams 23 and 24, and circular track 17 is welded therein tangential to those beams 23 and 24, rein- forced by a plurality of connectors 25. Hanging downwardly from and supported on circular track 17 is boom frame 12 having a plurality of wheels 38, with metal or rubber treads, which roll on track 17. Boom frame 12 is also a rectangular structure to which is attached boom 13 extending outwardly from one side of boom frame 12. Motor 27 on boom frame 12 drives a friction wheel 35, made of polyurethane or other high friction material, which bears against the bottom of circular track 17, and thereby cau¬ ses boom frame 12 to rotate in either direction.

Motor 28 is mounted on boom frame 12 to drive the hoist which is described in more detail below. Motor 29 is mounted on carriage framework 11 and drives sprocket 32 which engages rol¬ ler chain 33, which is affixed at each of its ends to rail 14. Sprockets 31 are idler sprockets providing tautness to chain 33. Driven sprocket 32 is mounted on shaft 36 which is common to twin driven sprocket 32' mounted on the opposite side of car¬ riage framework 11 and engaging twin roller chain 33' affixed to twin rail 14*. There also are idler sprockets 31' to cooper¬ ate with twin driven sprocket 32' for the same purpose of taut¬ ness as mentioned above. The purpose of this identical arrange¬ ment of sprockets and chains on both sides of carriage frame¬ work 11 is to prevent any tendency for carriage 10 to become cocked and out of perfect alignment on rails 14, which might occur if the driving forces were applied only to one side of carriage 10. There also is the possibility that chains 33 and 33' may stretch after use and thereby allow some cocking of carriage 10 to occur. To cope with this possibility there are provided a plurality of spaced guides 60 along outside beams 24 (FIG. 3), each having an arm 61 attached to beam 24 to which is attached a pad 62 of low friction material which will bear against the inside edge of rail 14 or rail 14', if carriage 10 should become slightly cocked, and thereby main¬ tain the desired alignment.

All three motors 27, 28, and 29 are reversible and are con¬ nected to a remote control box (not shown) capable of being held in the hands of the operator standing outside of truck 21. Motors 27, 28, and 29 are preferably electric, but may be of any nonelectric type, e.g. hydraulic, and be entirely suitable for use in this invention.

In FIGS. 2-5 boom 13 and boom frame 12 are shown in some detail. Boom frame 12 is a rectangular structure of two or more lateral beams 39 and two or more longitudinal beams 40 welded or bolted together to form a rigid structure with boom 13 extending outwardly from one of lateral beams 39. Boom 13 is shown to be fixed in length, but may be telescopically extend¬ able, if desired. The basic length of boom 13 is about one- half of the width of truck 21 interior measured from center 16 to distal end 34. Boom 13 ,therefore, may be rotated 360 degrees without touching walls 56. If boom 13 is telescopically extend¬ able, its extended length may be any chosen amount within the limits of material strengths, although it is preferred for the extended length to be not more than about \ times the unexten- ded length. At the distal end 34 of boom 13 there is a pulley or sheave 18 over which is threaded cable 19, which preferably is a link chain with winch drum 59 and pulley 18 specially desig¬ ned to clamp around each link as it passes. Winch drum 59 may wind up chain cable 19 in overlapping layers of cable 19, or, alternatively, it may release the chain cable 19 as it is wound up and drop it into a collection box 63, which is preferred. At center 16 there is mounted a wheel or pulley 48 onto which is wound electric cables 45 and 55 connecting motors 27 and 28 to a source of electric power, shown here as a bank of electric batteries 41which may be, for example, 12- or 24- volt wet cell or gel batteries. Since boom frame 12 and motor 28 ro¬ tate through 360 degrees, cable 55 must be controlled so as not to become entangled with nearby components. Similarly, motor 27 rotates with boom frame 12 and its electric cable 45 must be controlled so as not to become entangled.Cables 45 and 55 are wound around wheel pulley 48 which is fixed at center 16 but is free to rotate horizontally around center 16. From wheel pulley 48 cables 45 and 55 pass around wheel pulley 49 and then are stretched across to beam 24 where they are clamped by fixture 53 while allowing the cables to continue on to a suitable elec¬ tric control panel which, in turn, is connected to the bank of batteries 41. Space 57 is shown here in carriage framework 11 to house such an electric control panel. Wheel pulley 49 is mounted rotatably on swinging arm 50 which pivots about pin 51 and is biased by spring 52 in a direction away from wheel pul¬ ley 48 so as to maintain cables 45 and 55 reasonably taut. As may be seen this arrangement prevents any slack in cables 45 and 55 as boom frame 12 rotates in either direction. With this system arm 50 will swing from about position 54 to position 54' as boom frame rotates through 360 degrees.

Because of the difficulties of handling cables 45 and 55 when boom frame rotates, it is preferred to limit the rotation to not more than 360 degrees. This is accomplished by limit switch means 43 which may be one or two switches, as desired. Switch means 43 is designed to shut off the power to motor 27 when switch 43 is activated. This forces the operator to re¬ verse the direction of the motor to rotate boom frame 12 to the resired position. Any suitable switch may be used. The one shown here has a wand 44 depending downwardly from the switch body which is attached to crane framework 11. Wand 44 will con¬ tact boom 13 and turn off motor 27 when boom frame 12 is rota¬ ted about 180 degrees from the position shown in FIG. 2. Other systems or arrangements may be employed to accomplish this pur¬ pose, using equipment well known in the prior art.

Near switch 43 on FIGS. 4 and 5 is a vertically adjustable roller 46 mounted on crane framework 11 and positioned to roll on the underneath surface of rail 14 or 14'. This provides a counterbalancing force to prevent carriage 10 from tipping to¬ ward the freight being hoisted by boom 13. Adjustable support 47 may be raised or lowered to bring roller 46 as close to rail 14 or 14' as desired. Carriage 10 is intended to be movable to the rear to its maximum extent when the rear panel of truck 21 is in a plane which includes center 16. This means that about one-half of the length of carriage framework 11 will extend to the rear of the rear ends of rails 14 and 14! In such a position the need for rollers 46 is obvious. Of course, if the truck owner so desires, rails 14 and 14' may be extended beyond the rear panel of truck 21 in order to gain a longer reach for the hoist.

While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scoυe of the invention.

Claims

1. A device mounted inside a highway truck for loading and unloading freight therefrom which is characterized by a pair of horizontal rails attached to the inside walls of a highway truck and a carriage mounted on said rails and movable thereon lengthwise of said truck; said carriage including a crane frame¬ work having a circular horizontal track member rigidly affixed thereto at the geometric center thereof, a boom frame rotatable on said track member to rotate said boom frame through about 360 degrees horizontally, and a boom mounted on said boom frame and extending radially outward to a distal end for a distance from said center to said distal end of about one-half the later¬ al width of the interior of said truck, said boom having a hoist with a cable and pulley means to lift freight, and motor means for moving said carriage along said rails, to rotate said boom frame, and to operate said hoist to lift and lower said freight.

2. The device of Claim 1 wherein said motor means includes an electric motor and a bank of batteries as a power source for said battery.

3. The device of Claim 1 wherein said carriage is slidable on said rails and there is included between said rails and said carriage a material having low friction properties.

4. The device of Claim 1 wherein said hoist includes a pul¬ ley mounted on said boom at its distal end, a cable engaging said pulley and having a hook for attachment to freight at its free end and a winch means for winding up said cable and down.

5. The device of Claim 1 wherein said motor means includes a first motor mounted on said crane framework and driving a sprocket engaged with a roller chain affixed at each of its ends to the same one of said rails.

6. The device of Claim 5 which includes a pair of twin sprockets rotatable on a common shaft and a pair of twin rol¬ ler chains identically positioned and fixed to said two rails, respectively, and engaging said sprockets, respectively.

7. The device of Claim 1 wherein said boom frame includes a plurality of wheels engageable with said track member by rolling thereon.

8. A travelling crane device to be mounted on the inside of a covered highway truck for moving freight on the truck and unloading freight therefrom; the device being characterized by a pair of rails mounted, respectively, on the two longitudinal inside walls of the truck near its roof; a crane carriage lon¬ gitudinally slidable on said rails, said carriage including a rigid crane supporting framework, a horizontally rotatable boom frame, and a boom hoist mounted on said boom frame; said crane framework being a rigid rectangular structure having a circu¬ lar horizontal track positioned at the geometrical center of said crane framework; said boom frame being a rigid rectangu¬ lar structure attached to which is a plurality of wheels ar¬ ranged in a circular disposition and adapted to roll on said track, and a boom extending outwardly from said boom frame to a distal end located a distance from said geometrical center of about one-half of the inside width of said truck; said boom having a pulley at said distal end, a cable running over said pulley from a hook means at the free end thereof to a windup drum means at the other end thereof; a first electric motor mounted on said crane framework to drive said carriage along said rails, a second electric motor mounted on said boom frame to drive said boom frame rotatably around said track, and a third electric motor mounted on said boom to rotate said wind- UΌ drum.

9. the crane device of Claim 8 which is additionally char¬ acterized by having an electric cable conducting power to each of said second and third motors electric motors from a station¬ ary electric battery power source affixed to said crane frame¬ work, said cables being wound on a cable storage wheel means which rotates to wind up and to unwind said cables as needed to accomodate the rotation of said boom frame.

10. The crane device of Claim 8 wherein said crane carriage is moved along said rails by the action of a sprocket driven by said first electric motor and engaging a length of roller chain attached at both of its ends to the same one of said rails.