Cargo-handling Device Having A Tilt-adjusting System

Abstract

A cargo-handling device having a load-supporting bed that can be elevated from a parallel first position to a second parallel second position and then tilted by a tilt-adjusting system to a nonparallel third position to match an adjacent plane surface for loading or off-loading of cargo. The bed can be returned to the first position and restored to its parallel orientation from the nonparallel third position without further actuation of the tilt-adjusting system.

Description

BACKGROUND OF THE INVENTION

The efficient handling of a cargo by a cargo-handling device, particularly cargo that is transported by aircraft, requires cargo unitization which can be in the form of loaded pallets and containers. These pallets and containers have been maximized dimensionally to minimize the total number of shipping units that are handled. However, the increased dimensions of the shipping units reduce door opening clearances so that loading and off-loading requires an increased amount of time to accurately position the shipping unit so that neither the door frame nor the unit is damaged as the unit moves through the door opening. Therefore, a cargo-handling device must accurately position the shipping unit relative to the door opening or to the plane of an adjacent load-bearing surface where there is no door opening.

Where the adjacent load-bearing surface is the cargo compartment floor of an airplane, the cargo-handling device must also adjust to the plane surface of the floor when the floor shifts about the roll axis of the airplane during loading and off-loading of cargo.

OBJECTS OF THE INVENTION

Accordingly, it is an object of the invention to provide a new and improved cargo-handling device.

It is an object of the invention to provide a cargo-handling device having an adjustable load-supporting surface.

It is an object of the invention to provide a cargo-handling device having a tilt-adjusting system.

SUMMARY OF THE INVENTION

Briefly, in accordance with the invention, a cargo-handling device is provided having a load-supporting bed carried by a base and movable by an elevating means from a first position where the bed and base are parallel to a second position where the bed and base are parallel but spaced apart. A tilt-adjusting system selectively changes the tilt of the bed to a third, nonparallel position and automatically changes the bed to the second parallel position when the elevating means moves the bed from the third nonparallel position to the first parallel position.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which may be regarded as the invention, the organization and method of operation, together with further objects, features, and the attending advantages thereof, may best be understood when the following description is read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an elevation view of one form of cargo-handling device, wherein the invention finds particular use, in a first position.

FIG. 2 is an elevation view of the cargo-handling device of FIG. 1 in a second position.

FIG. 3 is a plan view of the tilt-adjusting system of the invention.

FIG. 4 is an elevation view of the tilt-adjusting system of FIG. 3.

FIG. 5 is an elevation view of the cargo-handling device of FIG. 1 in a third position developed by the tilt-adjusting system of FIG. 3.

FIG. 6 is a schematic view of a cargo-handling device such as the device of FIG. 1 in an operating location adjacent a vehicle having a roll characteristic.

FIG. 7 is an enlarged elevation view of the tilt-adjusting system of FIG. 3 in one operating position to adjust the tilt of the cargo-handling device of FIG. 6.

FIG. 8 is an enlarged elevation view of the tilt-adjusting system of FIG. 3 in another operating position to adjust the tilt of the cargo-handling device of FIG. 6.

FIG. 9 is an enlarged elevation view of the tilt-adjusting system of FIG. 3 as the device moves into the first position of FIG. 1.

DESCRIPTION OF THE INVENTION

Referring to FIG. 1, one form of cargo-handling device 10 is shown wherein the tilt-adjusting system 12 of the present invention can find particular use. The cargo-handling device 10 has a base 14 and a load-supporting bed 16 interconnected by an elevating means such as the crossed scissors legs 18 and 20 which are paired with similar scissors legs (not shown). The scissors legs 18 and 20 are pivotally connected at 22. A linear actuator such as a hydraulic ram 24 acts upon the crossed scissors legs 18 and 20 to lift or move the load-supporting bed 16 from the adjacent position as shown by FIG. 1 to a spaced apart second position as shown by FIG. 2. Scissors leg 18 is pivotally connected to the load-supporting bed 16 at pivot connection 26 with a suitable roller 28 at the other end adapted to roll in a complementary track on the base 14. Scissors leg 20 is pivotally connected to the base 14 at pivot connection 30 and has a cam follower roller 32 described hereinafter in greater detail.

In the adjacent or stored position as shown by FIG. 1, the load-supporting bed 16 defines a plane which is substantially parallel with a similar plane defined by base 14. Similarly, in the spaced apart or elevated position as shown by FIG. 2, the load-supporting bed 16 again defines a plane which is substantially parallel with the plane defined by the base 14.

Referring to FIGS. 3 and 4, the tilt-adjusting system 12 has a cam 36 suitably formed into a dogleg configuration such as is shown by FIG. 3 so that the cam develops a predetermined cam surface profile. The cam follower roller 32 engages the cam surface profile of cam 36 and transverses the cam as the scissors legs 18 and 20 are adjusted by the hydraulic ram 24.

The cam 36 is rotatably supported at end 40 in a suitable bearing 42. End 44 of cam 36 is connected to one end of a connecting link 46 that is connected to a stub shaft 48. Shaft 48 is rotatably positioned by similar bearings 50, preferably with the longitudinal axis of the stub shaft 48 positioned concentrically with the rotational axis of the cam 36. The rotational axis of the cam 36 extends longitudinally through a first cam portion 52 which is journaled at end 40 in the bearing 42. An actuating rod 54 connected to and extending outwardly from the stub shaft 48 is connected to a yoke 58 that extends from a suitable actuator 60 which is considered to be conventional. The link 46, stub shaft 48, and rod 54 are generally arranged to function mechanically as a bell crank arrangement 56. A second cam portion 62 of cam 36 develops the major portion of the dogleg configuration of the cam. When the cam 36 is rotated about the longitudinal cam axis by the bell crank arrangement, the second cam portion 62 generates an imaginary warped surface.

In FIG. 5, the tilt-adjusting system 12 of the cargo-handling device 10 has been rotated to adjust the tilt or pitch of the load-supporting bed 16 so that the plane defined by the bed is no longer substantially parallel with the plane defined by the base 14. The bell crank arrangement rotates the cam 36 about its longitudinal cam axis and drives the roller or cam follower 32 along the cam surface profile until a desired tilt of the load-supporting bed 16 is reached.

The cargo-handling device 10 with the tilt-adjusting system 12 of the present invention adjusts the tilt of a load-supporting bed when loading or off-loading cargo into or from an adjacent plane surface such as the cargo compartment floor of an airplane as schematically shown by FIG. 6. Airplane 70 has a longitudinally extending roll axis 72 about which the airplane may roll or shift as cargo is loaded or off-loaded.

When the airplane 70 is at rest and is either empty of or evenly loaded with cargo, the plane surface defined by the cargo compartment floor of the airplane is coextensive with the plane surface defined by the load-supporting bed; this coextensive plane is represented by line 74 in FIG. 6. When the airplane 70 rolls or shifts about the roll axis 72 in the counterclockwise direction as viewed in FIG. 6, the plane of the floor is tilted. The tilt or pitch of the load-supporting bed 16 is adjusted by the tilt-adjusting system 12 so that the plane of the bed is coextensive with the floor as represented by line 76 in FIG. 6 when the tilt-adjusting system 12 is positioned as shown by FIG. 7.

When the airplane 70 rolls or shifts about the roll axis 72 in the clockwise direction as viewed in FIG. 6, the plane of the floor and the plane of the bed are maintained coextensive as represented by line 78 when the tilt-adjusting system 12 is positioned as shown by FIG. 8.

It is desirable to be able to rapidly remove the cargo-handling device 10 from the area adjacent to a cargo carrier or storage area. The load-supporting bed 16 in the nonparallel relationship with base 14 as shown by FIG. 5 is automatically returned to the parallel collapsed or stored position as shown by FIG. 1 where the bed 16 is adjacent to the base 14 without the further adjustment of the tilt-adjusting system 12, i.e. rotation of the cam 36 by the bell crank arrangement 56. As the load-supporting bed 16 is returned by the elevating system from the third position as shown by FIG. 5 to the first position as shown by FIG. 1, the roller or cam follower 32 traverses the cam surface profile of cam 36 until the cam follower reaches the first cam portion 52 which lays coextensively along and generally concentric with the longitudinal cam axis. Since the first cam portion is substantially parallel with not only the bed 16 but also the base 14, the load-supporting bed 16 is automatically returned to its parallel relationship with the base so that the bed can be collapsed and stored with the base without adjustment of the bell crank arrangement 56 and correspondingly the cam 36.

As will be evidenced from the foregoing description, certain aspects of the invention are not limited to the particular details of construction as illustrated, and it is contemplated that other modifications and applications will occur to those skilled in the art. It is, therefore, intended that the appended claims shall cover such modifications and applications that do not depart from the true spirit and scope of the invention.

Claims

I claim:

1. A cargo-handling device comprising:

a. a base,

b. a load-supporting bed carried by said base,

c. a lift means adapted to move said bed relative to said base from a first position to a selected second position, and

d. tilt-adjusting means independent of said lift means for moving said bed from said second position to a predetermined third position so the slope of said bed relative to said base is adjusted,

e. said tilt-adjusting means further moving said bed from the slope said third position to the slope of said second position continuously as said lift means moves said bed from said third position through said second position to said first position.

2. The device of claim 1 in which said base and said bed are substantially parallel in said first position.

3. The device of claim 2 in which said base and said bed are substantially parallel in said second position and substantially nonparallel in said third position.

4. The device of claim 1 in which said bed is longitudinally extending and defines a longitudinal bed axis, and in which said lift means includes a cam follower adapted for selective engagement with said tilt-adjusting means, said tilt-adjusting means includes:

a. a rotatable cam means defining a longitudinal cam axis and having a predetermined cam surface profile comprising:

1. a first cam surface portion generally concentric with the longitudinal cam axis, and

2. a second cam surface portion generally transverse to said first cam surface portion and rotatable about the cam axis so that an imaginary warped surface is generated as said first and second cam surface portions are rotated, and

b. actuator means selectively rotating said cam means so that the cam follower engages a predetermined one of said first and second cam surface portions of said cam means and is driven to alter the tilt orientation of said bed relative to said base.

5. The device of claim 4 in which said actuator means includes:

a. link means connected to at least said second cam surface portion, and

b. support means connected to a selected one of said base and bed to rotatably position said cam means for driven rotation about the cam axis.

6. The device of claim 4 in which said cam follower means traverses at least said first and second cam surface portions as said lift means moves said bed from said third position through said second position to said first position.

7. The assembly of claim 6 in which the longitudinal cam axis of said first cam portion surface is substantially parallel with the longitudinal bed axis.

8. The assembly of claim 6 in which said lift means is a scissors linkage having at least first and second paired members pivotally and movably positioned between and in selective engagement with said base and said bed.

9. The assembly of claim 8 in which said cam follower means is connected to said scissors linkage and said tilt-adjusting means is connected to said bed.

10. In a cargo-handling device wherein a load-supporting bed connected to a base and movable relative thereto by a lift mechanism that includes a cam follower, the combination with the cam follower of a tilt-adjusting system comprising:

a. a rotatable cam means connected to a selected one of the bed and base, said cam means having a predetermined cam surface profile including:

1. a first cam surface portion positioned in a predetermined orientation relative to a selected one of the bed and base, and

2. a second cam surface portion extending in a nonparallel orientation relative to said first cam surface portion, and

b. an actuator means selectively rotating said cam means so that the cam follower engages a predetermined one of said first and second cam surface portions of said cam means and alters the orientation of the bed relative to the base.

11. The tilt-adjusting system of claim 10 in which said first cam surface portion is substantially parallel with the base.