US3718221A

US3718221A - Load transfer mechanism

Info

Publication number: US3718221A
Application number: US00187362A
Authority: US
Inventors: P Visser
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1971-10-07
Filing date: 1971-10-07
Publication date: 1973-02-27
Anticipated expiration: 1990-02-27
Also published as: JPS559398B2; IT944404B; CA945501A; DE2164915A1; JPS4844950A

Abstract

A transfer mechanism for transferring a load from one side of the mechanism to the other. A pair of main linear actuators is located at each end of the mechanism. The lower ends of the main actuators at each end are pivotally connected adjacent opposite sides of the mechanism. The upper ends of the main actuators are pivotally connected to an intermediate location on a transverse elongated boom arm which is located at each end. There is also a pair of auxiliary actuators at each end of the mechanism. These actuators likewise each have their lower ends pivotally connected adjacent the sides of the mechanism while the upper ends are connected to one end of each of the boom arms respectively.

Description

United States Patent [1 1 Visser 51 Feb. 27, 1973 [54] LOAD TRANSFER MECHANISM [75] Inventor: Peter J. Visser, Niles, Mich. I

Company,

[73] Assignee: Clark Equipment Buchanan, Mich.

[22] Filed: Oct. 7, 1971 [21] Appl. No.: 187,362

[52] US. Cl ..2l4/77 R, 212/8 R, 214/130 R [51] Int. Cl. ..B60p1/48 [58] Field of Search ..2l4/77 R, 78, 80, 130 R, 1 BD, 214/1 BV; 212/8 R, 8 A, 8 B, 35

[5 6] References Cited UNITED STATES PATENTS 3,174,630 3/1965 Tantlinger et al ..2i4/77 R 3,515,295 6/1970 Klaus ..214/77 R Primary Examiner-Robert J. Spar Attorney-Kenneth C. Witt et al.

[57] ABSTRACT A transfer mechanism for transferring a load from one side of the mechanism to the other. A pair of main linear actuators is located at each end of the mechanism. The lower ends of the main actuators at each end are pivotally connected adjacent opposite sides of the mechanism. The upper ends of the main actuators are pivotally connected to an intermediate location on a transverse elongated boom arm which is located at each end. There is also a pair of auxiliary actuators at each end of the mechanism. These actuators likewise each have their lower ends pivotally connected adjacent the sides of the mechanism while the upper ends are connected to one end of each of the boom arms respectively.

10 Claims, 6 Drawing Figures PATENTEB FEBZ T1973 SHEET 10F 3 INVENTOR PETER J. VISSER ATTORNEY PATENTEDFEBZHQB SHEET 2 0F 3 INVENTOR PETER J. VI SSER ATTORNEY PAIENTEUFEBZYISB 3 718,221

SHEET 3 OF 3 FIG. 6

o BGQ a E U 1 INVENTOR PETER J. VISSER fiW/ZZ 6. zf/da ATTORNEY LOAD TRANSFER MECHANISM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to load transfer mechanisms that are especially useful for loading and unloading railroad cars, and particularly for loading and unloading trailers, semi-trailers and containers onto and off of railroad cars. However, the invention is also adaptable for handling other types of loads onto and off of railroad cars and in addition, it is adaptable for the transferring of loads where there is no railroad car involved.

2. Description of the Prior Art The prior art discussed hereinafter is limited to load transfer mechanisms for use with railroad cars, although it will be appreciated that there are many other load transfer mechanisms.

In the handling of large loads, in transferring them onto or off of a railroad car, and particularly in loading and unloading trailers, semi-trailers and large freight containers from railroad cars, various mechanisms and vehicles have been employed. In the handling of such loads, it is known to employ a very large gantry vehicle which straddles the railroad car, picks up the load and moves it between the railroad car and the ground beside the railroad car, or vice versa.

Fork trucks also are used in the loading and unloading of trailers, semi-trailers and containers onto and off of railroad cars, in some cases by inserting the fork mechanism beneath the load to be handled, and in other cases by utilizing a lifting frame at the top to engage the load to enable the fork truck to handle it.

Both the gantry vehicles and the fork trucks require considerable space at the side or sides of the railroad car in order to accomplish the loading or unloading, and such load handling machines are expensive.

Another known arrangement for loading and unloading semi-trailers onto and off of railroad =cars is socalled circus loading in which a tractor pulls a semitrailer lengthwise along a row of railroad cars which have suitable bridging structures between them. With this type of loading or unloading it is necessary to load or unload in sequence. That is, the first semi-trailer loaded must likewise be the first one unloaded and others must follow in sequence. However, this type of loading does not require any space beside the railroad car.

All of the foregoing are in use and all of them are suitable for the handling of a considerable volume of trailers and semi-trailers or containers.

In many circumstances it is desirable to have a load transfer mechanism which can selectively load or unload a railroad car from the side in a minimum of space. There is a need too, for a mechanism of such character which is not as expensive as the higher volume machines previously discussed. .In many circumstances it is acceptable to handle the loads more slowly if it can be done selectively and with a lower cost machine.

SUMMARY OF THE INVENTION In carrying out this invention in one preferred mode, the load transfer mechanism is mounted on a semitrailer so that it may be readily transported from one location to another. Installed on the semi-trailer which forms a base for the transfer mechanism are two pairs of vertically disposed linear actuators connected adjacent each end of the base. The actuators of each pair are pivotally connected at their lower ends adjacent opposite sides of the base. Two elongated boom arms are connected to the upper ends of the actuators at the opposite ends of the mechanism respectively. The main actuators at the respective ends of the mechanism are pivotally connected at an intermediate location on their respective boom arms, while the auxiliary actuators at each end have their upper ends pivotally connected near one end of the respective boom arm. A load engaging mechanism is connected between the other ends of the boom arms.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows a schematic end elevation of the load transfer mechanism ready for operation;

FIG. 2 shows a schematic side elevation of the same mechanism;

FIG. 3 shows an end elevational view of the mechanism in a load handling position;

FIG. 4 shows an end elevational view of the mechanism in another position during the load handling operation;

FIG. 5 is a diagrammatic view illustrating the operation of the mechanism; and

FIG. 6 is a schematic end elevation of the mechanism in position to handle a different load, that is, a container instead of a semi-trailer.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, the basic parts of the load transfermechanism are shown schematically. In FIG. 1 and the other figures, the base of the transfer mechanism is shown as a semi-trailer indicated by the numeral 10 which can be readily moved from one location to another by coupling a suitable tractor to the king pin indicated at 12 (in FIG. 2), but it will be appreciated that the present load transfer mechanism can be mounted on a stationary base if desired and the vehicles to be loaded and unloaded brought to the loader instead of vice versa.

The semi-trailer illustrated has a suitable intermediate structural portion indicated at 14, wheels 16 at the rear and landing gear 18 at the front to support the front end of the semi-trailer after the tractor vehicle which moved it is detached. The semi-trailer illustrated also has a goose neck portion 20 upon which is mounted in the enclosure 22 an engine which provides the power to operate the various actuators to be described. It will be appreciated also from the subsequent description that the portion of the semi-trailer which supports the load transfer mechanism is generally rectangular in configuration, that is, that the various actuators are connected adjacent the four corners in a rectangular arrangement.

Referring to FIG. 1, the

numerals

24 and 26 indicate respectively a pair of extensible and retractible linear actuators which are hereinafter referred to as the main actuators.

Actuators

24 and 26 are pivoted on the base 10 at their lower ends about

axes

25 and 27 as indicated. Actually, both

actuators

24 and 26 comprise two actuators in the embodiment described and illustrated herein and this may be seen by reference to FIG. 2 in which the two actuators which comprise main actuator 24 are indicated by the

numerals

24a and 24b, while the two actuators which comprise main actuator 26 are indicated at 26a and 26b. Moreover, it will be observed that the arrangement just described is duplicated at the opposite end of the base 10. The fact that each of the

main actuators

24 and 26 comprises two actuators is important in respect of one feature of the present invention and this is described subsequently, but initially, in order to convey a general understanding of the structure of the invention, the

main actuators

24 and 26 will be referred to as if they are each single instead of double.

Still referring to FIG. 1, there is also a pair of auxiliary actuators indicated respectively by the

numerals

28 and 30. The lower end of actuator 28 is pivoted about the same axis as main actuator 24 in the embodiment of the invention illustrated, while the lower end of actuator 30 is pivoted about the same axis as main actuator 26. The auxiliary actuators are duplicated at the opposite end of the base in the form of the load transfer mechanism illustrated, as may be seen in FIG. 2.

While the main and auxiliary actuators are illustrated herein as piston and cylinder type expansible chamber devices, it will be appreciated that the invention is not limited to such devices, and if desired the linear actuators may be of other types such as mechanically operated screw spindles, for example.

The upper ends of the

main actuators

24 and 26 at both ends of the load transfer mechanism are pivotally connected at intermediate location 29 to a transverse boom arm 32. The upper ends of the

auxiliary actuators

28 and 30 are pivotally connected about a common axis at 34 adjacent one end of the boom arm, and this applies at both ends of the mechanism. The other ends of the boom arms in the embodiment shown support between them a lifting device 43, pivotable about a pivot axis 35. Such lifting device comprises a longitudinal member 36 (See FIG. 2) which supports depending lift arms 38 which are provided at the lower ends with suitable lift shoes 40 for engagement beneath a load in order to lift and transfer it. It will be appreciated that the arms 38 may be moved inwardly and outwardly to adjust to the load, and also that they may be moved longitudinally on the main longitudinal member 36 in order likewise to adjust to the length of the load.

FIG. 3 of the drawing shows a view in which the load transfer mechanism of the present invention has begun the transfer of a highway semi-trailer between a railroad car 46 on one side of the load transfer mechanism and the ground on the other. It will be observed that outriggers 42 are provided on both sides of the portable load transfer mechanism in order to stabilize it during the handling of a heavy load from one side to the other.

In order to get the mechanism into the position of FIG. 3, the lift arms 38 are pivoted to a horizontal position, if they are not already in such a position from a previous operation, and the main and auxiliary actuators are extended sufficiently to locate the lifting frame 43 over the highway semi-trailer indicated at 44 which has been carried piggy back on the railroad car 46. Then the lift arms 38 are pivoted downwardly to a depending position after which they are adjusted longitudinally if necessary. The load arms are then moved toward each other to position the load shoes 40 beneath the body of the semi-trailer in order to lift it.

Then the

auxiliary actuators

30 and 28 are contracted thereby lowering the left ends of boom arms 32, one at each end of the mechanism and raising the right ends of such boom arms and raising the semi-trailer 44 off of the railroad car.

FIG. 4 shows the position of the semi-trailer after it has been transferred by the mechanism of this invention to the ground on the other side of the load transfer mechanism. After this position has been reached, the load arms 38 are disengaged from the semi-trailer and the load transfer mechanism made ready for another operation.

FIG. 5 shows diagrammatically the transfer operation just described with circled numerals to indicate seven locations of the various pivot points at different positions during the transfer operation. Referring first to the solid lines, the main and auxiliary actuators and the boom arm 32 are shown and the positions of the pivot points 34, 29 and 35 are indicated. In such solid line position, the circled numeral 1 is also indicated for each of these pivot points. This is the position of the actuators and the boom arm when the mechanism is in engagement with the trailer and ready to begin the transfer operation. 1

In order to lift the semi-trailer off the railroad car, the

auxiliary actuators

30 and 28 are contracted, moving pivot point 34 from its No. 1 position to its No. 2 position, downwardly and to the right, about the arc indicated. At the same time, pivot point 35 also moves from its No. 1 to its No. 2 position, upwardly and to the left, about the arc shown. As indicated, pivot point 29 does not move during the shift from position No. l to position No. 2. The No. 2 position corresponds to the position illustrated in FIG. 3 of the drawing.

To continue the transfer of the semi-trailer to the ground on the other side of the transfer mechanism the various actuators may be operated in a manner to cause the pivot points to follow the dashed lines indicated in FIG. 5 with the circled numerals 3 indicating the positions of the three pivot points at the No. 3 position (boom arm 32 is also indicated for this position), and similarly for positions No. 4, 5, 6 and 7. Position 7 corresponds to the condition illustrated in FIG. 4 of the drawing.

During such transfer operation the

auxiliary actuators

28 and 30 are in tension, and main actuators are forcibly extended and it is the forces applied by means of the

main actuators

24 and 26 which produce the operation illustrated until the boom arms go over center. Thereafter the main actuators are retracted. During the operation described, it will be appreciated that the actuators at both ends of the transfer mechanism operate together.

It will be understood, of course, that loading of the semi-trailer onto the railroad car is accomplished by the reverse of the operation just described.

While it is desirable that the triangles formed by the

main actuators

24 and 26 and the

auxiliary actuators

28 and 30 have a common base 45 as illustrated in FIG. 5, it is not essential in accordance with the broader aspects of the present invention.

FIG. 6 shows another manner in which the invention can be used. FIG. 6 is similar to FIG. 3 except that the load handling device in this figure, instead of having depending arms, has depending cables 39 which are connected to the bottom of a container 47 which is stacked on top of another container 48, and the load transfer mechanism is ready to lift the upper container 47 from the top of container 48 and deposit container 47 on the ground on the other side of the transfer mechanism in the same manner as previously described for semi- ;trailer 44.

Referring to FIG. 2 of the drawing, it will be observed that the boom arms 32 are shown as box type structures, that is, they are hollow, and the auxiliary actuators 28 and are pivoted internally between the sides of such structure.

The

main actuators

24a, 24b, 26a, and 26b, however, are pivoted on a common shaft 29a (see the left side of FIG. 2) which extends on both sides of the box structure. This arrangement of having two

actuators

24a and 24b separated longitudinally and two

actuators

26a and 26b separated longitudinally provides for resisting forces acting on the load transfer mechanism longitudinally of the base and, of course, this applies at both ends of the mechanism.

Moreover, because of the feature just described, in a situation in which it is desired to handle a much shorter load as compared to the very long load which is illustrated, it is possible to utilize only half of the actuators and one boom arm, instead of two sets of actuators and two boom arms plus the intervening structure 43 as described and illustrated herein.

While I have described and illustrated herein a preferred embodiment of my invention, it will be appreciated that modifications may be made by those skilled in the art. Therefore, it should be understood that I intend to cover by the following claims all such modifications which fall within the true spirit and scope of my invention.

1 claim:

1. A load transfer mechanism mounted on a rectangular base and comprising two pairs of vertically disposed linear actuators connected adjacent each end of the base, one actuator of each said pair pivotally connected at its lower end adjacent one side of the base and the other actuator of each said pair pivotally connected at its lower end adjacent the other side of the base, two elongated boom arms connected to the upper ends of the said actuators at opposite ends of the base respectively, the upper ends of one pair of actuators at each end of the base pivotally connected to the respective boom arm adjacent one end thereof and the upper ends of the other pair of actuators at each end pivotally connected to the respective boom arm at a location intermediate the ends thereof.

2. A load transfer mechanism as specified in claim 1 in which a load engaging device is connected between the other ends of the two said boom arms.

3. A load transfer mechanism as specified in claim 1 in which the base is portable.

4. A load handling device as specified in claim 3 in which the portable base carries an engine for providing power for the operation of the said actuators.

5. A load transfer mechanism as specified in claim 3 in which the base is equipped with outriggers.

6. A load transfer mechanism as specified in claim 1 which includes two additional pairs of actuators located respectively at opposite ends of the base, the

said additional pairs of actuators bein connected said other respectively about the same pivot axes as t e pair of actuators.

7. A load transfer mechanism as specified in claim 6 in which a shaft projects on each side of the said boom arm at the said intermediate location, the upper ends of the said other pair of actuators at each end being pivoted on said shaft on one side of the boom arm and the upper ends of the said additional pair of actuators at each end being pivoted on the shaft on the other side of the boom arm.

8. A load transfer mechanism comprising a pair of vertically disposed main linear actuators, a boom arm, the said main linear actuators being pivotally connected to the said boom arm intermediate the ends thereof, the lower ends of the said actuators being pivotally connected at the bottom in spaced relation to form a triangle with a fixed base and sides of variable angles and lengths, a pair of vertically disposed auxiliary linear actuators pivotally connected to the said boom arm adjacent one end thereof, the lower ends of the said auxiliary actuators being pivotally connected adjacent the lower pivotal connections of the main actuators to likewise form a triangle with a fixed base and sides of variable length and angles.

9. A load transfer mechanism as specified in claim 8 in which the said main linear actuators are pivotally connected to the said boom arm about a common axis and the said auxiliary actuators are likewise pivoted to the boom arm about another common axis.

10. A load mechanism as specified in claim 8 in which the boom arm has a shaft projecting out each side coinciding with the upper pivot axis of the said main actuators, the said main actuators being pivoted on the shaft on one side of the boom arm, and a second pair of main actuators, the same as the first pair, being pivotally connected to the shaft on the other side of the boom arm, the lower ends of the said second pair of main actuators being pivoted about the same axes as the said first pair of main actuators.

t 1! k i

Claims

6. A load transfer mechanism as specified in claim 1 which includes two additional pairs of actuators located respectively at opposite ends of the base, the said additional pairs of actuators being connected respectively about the same pivot axes as the said other pair of actuators.