TECHNICAL FIELD

The present invention relates to an arrangement for lifting and lowering loads, this arrangement being referred to in the following simply as a hoist arrangement, and then particular¬ ly to a hoist arrangement which is constructed and adapted for coaction with a rear part of a vehicle, particularly a load-carrying vehicle, such as a truck, such as for coaction with the rear part of the chassis of a truck.

The invention relates more particularly to the kind of hoist arrangement that includes two mutually parallel arms whose one end-parts are rigidly connected to an arrangement of pivot shafts journalled for rotation in journal bearing means, wherein the arms can be rotated or swung reciprocat¬ ingly about said shafts by one or more first drive arrange¬ ments, wherein second end-parts carry one or more connecting means which are adapted for firm but readily released coaction with a load and/or a load-carrying container, and wherein the arms are spaced apart so as to lie on respective sides of the load or the load-carrying container concerned, which in practice means that the arms will be located on respective sides of the chassis.

The shafts about which the two arms rotate are located furthest to the rear and level with the chassis and the rear chassis frame.

Hoist arrangements of this kind are used to lift and move dumper containers, among other things

DESCRIPTION OF THE PRIOR ART

Hoist arrangements of the kind described in the introduction are known to the art in several different designs. For

CORRECTED

instance, in the case of an earlier known hoist arrangement which is constructed to tilt or tip a load-supporting platform, this arrangement being referred to as a "load rearranging or load shifting means" a platform-cassette can be moved from a rear chassis part to an underlying supportive surface and vice versa, by virtue of the front part of the platform-cassette being provided with a centrally positioned, fixed eye which coacts with a hook means fixedly mounted on the free end of a centrally positioned arm arrangement.

A lower arm of this arm arrangement is rotatably attached to the rear part of the chassis and extends towards the driver's cabin and can be rotated by a hydraulic piston-cylinder device which is mounted on the chassis adjacent the driver's cabin and extends rearwardly therefrom.

The upper free end of the arm coacts rotatably with a short manoeuvering arm ^' or link arm, whose position relative to the arm is controlled by a second piston-cylinder device.

The free end of the manoeuvering arm carries the hook means, which includes a lifting hook.

The described arm arrangement, which has a lower long arm and an upper shorter manoeuvering arm can be used to cause the lifting hook and the front part of the platform-cassette to move upwardly and rearwardly in an arcuate path with regard to said front part, so as to tip the platform-cassette around a rear axle or rear runners, and when necessary to activate further tipping movement for the purpose of removing the platform-cassette from the vehicle and placing said cassette on a supportive surface located immediately behind the vehicle.

The same hoist arrangement and the same arm arrangement can be used to lift a platform-cassette from a supportive surface immediately behind the vehicle and to move the cassette along

load-supporting rails, rollers or the like, and may also be used to position the platform-cassette in relation to the rear chassis part of the vehicle or truck.

It is also known in the case of such hoist arrangements to change the relative positions of the arm parts of the arms in the arm arrangement so as to move a platform-cassette which contains a heavy cargo or load rearwardly in a horizon¬ tal direction until the gravitational centre of the platform- cassette and the cargo is located so close to the rotational axle or runner as to enable the platform-cassette to be tipped or tilted by rotating one or both arms upwards, therewith enabling the strain on the tilting mechanism to be reduced.

This movement of the platform-cassette is achieved with the aid of a first piston-cylinder device mounted in the centre of the chassis, and a second piston-cylinder device which functions to change the angle of rotation between the two arms.

There is also known to the art a hoist arrangement which includes two parallel lifting arms of fixed lengths, wherein the arms are intended to coact with a dumper-type container, either directly or via lifting lines, and which are mounted on a horizontal axle adjacent the rear part of the chassis. The lifting arms are each arranged on a respective side of the container and are each capable of being rotated about a rotary axle common to both arms, by means of a respective individual hydraulic piston-cylinder device.

The parallel arms have a fixed length and are rotatably mounted on the rear part of the chassis and normally extend obliguely upwards and forwards.

The aforesaid two hydraulic piston-cylinder devices are mounted on the vehicle chassis adjacent the driver's cabin

and extend obliquely upwards and rearwards.

The arms are therewith able to lift and move a dumper from the platform of a load-carrying vehicle or truck to ground level immediately behind the vehicle, and vice versa, with the aid of said hydraulic piston-cylinder devices.

It is also known that a centrally positioned arm arrangement constructed to rearrange the position of platform-cassettes cannot be used to lift and move or switch dumper containers and vice versa, meaning that a vehicle equipped with one of the known hoist arrangements can only be used for one or the other of said tasks, and not both.

SUMMARY OF THE INVENTION

TECHNICAL PROBLEMS

When considering the present standpoint of techniques as described in the aforegoing, it is evident that a first hoist arrangement adapted for work with platform-cassettes cannot be used to manoeuvre and lift dumper-type containers, and that a second hoist arrangement which is adapted for work with dumper containers can only be used to lift and move platform-cassettes with great difficulty. It is evident from this that a technical problem resides in providing conditions which will enable one single hoist arrangement, a third type of hoist arrangement, to be given a construction and func¬ tional ability which will enable it to be used for handling both a platform-cassette and a dumper container when one of these is to be lifted from the load-carrying rear chassis part of the vehicle and moved to a supportive surface, or vice versa.

It will also be seen that a technical problem resides in providing a hoist arrangement which is not only successful in solving the aforesaid technical problem but which can also

be used as a tailboard hoist, particularly when the rear chassis part supports a platform-cassette or an auxiliary unit which imparts a van-like function or some similar function to the vehicle.

It will also be seen that a technical problem resides in providing a tailboard lift which is able to hoist loads to a level which is much higher than the level of the rear vehicle chassis part.

It will also be seen that a further technical problem is one of providing a novel hoist arrangement which is so construct¬ ed that one and the same load-carrying vehicle, such as a truck, equipped with such a hoist arrangement will be able to lift a platform-cassette or a dumper container from the load-carrying surface of the vehicle and move said cassette or container to a level which is much lower than a pl-ane or surface defined by the supportive outer parts of the vehicle tyres, for instance through a distance of two metres, and also to a level above the vehicle loading surface and-behind the vehicle.

It will also be seen that in the case of a hoist arrangement of the kind in question, a technical problem resides in realizing the significance of making the side-mounted arms flexurally rigid and telescopic and to pivotally mount the arms on the rearmost chassis part and therewith enable the telescopic arm sections to be given significant lengths or height differences, preferably lengths which are slightly greater than the length of a dumper container.

It will also be seen that another technical problem resides in realizing that the aforedescribed facility will require only two drive arrangements and to draw from this the conclusion that one of these drive arrangements shall consist in two hydraulic parallel-operated piston-cylinder devices which are commonly controlled and each of which is mounted

on a respective side of the vehicle chassis frame, while the other drive arrangement shall consist in two hydraulic, parallel-operated piston-cylinder devices which function to impart to the parallel arms a common rotary movement in a vertical plane about one and the same rotational axle arrangement positioned adjacent the rearmost chassis part and at the same level, or essentially the same level, as the chassis.

Another technical problem resides in the ability of providing the rear chassis part and/or the hoist arrangement with hydraulic, vertically adjustable support legs each arranged on a respective side of the vehicle chassis frame.

It will also be seen that a technical problem resides in realizing the significance of providing each of the two arms with an individual arm rotating mechanism which is activated by a piston-cylinder device and which enables its associated arm to be rotated through an angle greater than 180°, and preferably greater than 200°.

It will also be seert that in the case of a hoist arrangement which includes side-mounted telescopic arms which can be telescoped individually by a respective piston-cylinder device a technical problem resides in realizing the signifi¬ cance of utilizing a beam which extends between the free end- parts of said arms and which is provided with connecting means on the end-parts of said beam and which readily coact releasably with corresponding connecting means on the free- ends of the arms for a dumper-container function.

It will also be seen that a technical problem resides in realizing the significance of positioning a hook-like connecting means centrally on the beam, so that the hoist arrangement can be adapted to a dumper-container function with the aid of said beam.

Another technical problem is one of realizing that when the beam, which is firmly but releasably connected to the end- parts of the arms, is removed from the arms a dumper-contain¬ er can be lifted by allowing connecting means particularly configured to the free end-parts of the arms to coact with lifting cables, ropes, lines or the like, that are also att: hed to the dumper-container.

It will also be seen that a technical problem resides in realizing the significance of positioning the aforesaid two, hydraulically operated piston-cylinder devices and the telescopic arm parts coacting therewith adjacent two chassis beams which extend along respective sides of the vehicle chassis and adjacent opposing side edges intended to receive a load-bearing platform or platform-cassette, or immediately outside opposing side-edges of a dumper container.

Another technical problem is one of providing conditions with the aid of simple means which will enable the aforesaid beam to be locked firmly in a position on the chassis adjacent the driver's cabin, when the hook of the aforesaid hook arrange¬ ment is inseparably attached to a lifting eye fixedly mounted on a platform-cassette.

Another technical problem resides in providing conditions which will enable the hook to be detachably secured to the lifting eye and released therefrom solely when the platform- cassette rests on a supportive surface behind the vehicle, and which will ensure that the hook remains latched and inseparable from the lifting eye in any other position of the platform-cassette.

It will also be seen that a technical problem is one of providing simple means which will enable the extension and shortening of the telescopic arms to be controlled synchro¬ nously through the medium of hydraulic valves or couplings or like devices incorporated in the hydraulic system, or with

the aid of other means,

SOLUTION

The present invention is intended to provide a solution to one or more of the aforesaid technical problems and take as its starting point a hoist arrangement which is adapted for coaction with a rear part of a vehicle, such as a truck, and then for coaction with the rear part of the vehicle chassis. The arrangement is comprised of two mutually parallel arms which are fixedly connected at their lower end-parts to a pivot shaft arrangement mounted in journal bearings in the rearmost part of the chassis, and further includes one or more drive arrangements which function to rotate the arms reciprocatingly in a vertical plane on said shaft arrange¬ ment, and wherein the other free end-parts of the arms carry one or more connecting means adapted -for firm but readily released coaction with a load and/or a load-bearing contain¬ er, and wherein the arms are mutually separated from a chassis centre line as ¹ to be located at or adjacent to a respective side of the chassis or at or adjacent a respective side of a container' or a so-called platform-cassette.

In accordance with the invention, each arm of the aforesaid hoist arrangement is comprised of a plurality of telescopic sections which are flexurally rigid and rotationally rigid in coaction with one another; and in that the telescopic sections of each arm can be extended and retracted synchro¬ nously with the aid of a respective drive arrangement and, when required, with the aid of a control circuit.

According to proposed embodiments which lie within the scope of the inventive concept, the aforesaid drive arrangements each consist in a hydraulically operated, enclosed piston- cylinder device, one device on each side of the vehicle chassis frame.

The inventive arrangement also includes vertically adjustable support legs positioned on a respective side of the vehicle chassis frame, at the rear part thereof.

According to one embodiment of the invention, the arms, or the arm sections, can be rotated in a vertical plane via an arm rotating mechanism which coacts with one or two piston- cylinder devices for rotation of the arms through an angle greater than 180°, and preferably through an angle of about 200°.

The arrangement also includes a beam which extends between the end-parts of the two arms or arm sections and which is provided with a hook-like coupling means in the centre of the beam and with two coupling means on the ends thereof.

According to one particular embodiment of the invention, a hook-like coupling means is positioned centrally of the vehicle and the aforesaid beam is fixedly but readily releasably connected to the outer end-parts of the arms with the aid of second coupling means.

According to one embodiment of the invention, the aforesaid two hydraulically operated piston-cylinder devices are mounted adjacent, preferably on the outside of, two longitu¬ dinally extending chassis beams and adjacent mutually opposing side-edges of a load-bearing platform which serves as a container, or immediately outside mutually opposing side edges of a dumper container.

According to another embodiment, the beam is provided with means which enable the beam to be locked in a position relative to the chassis and adjacent the driver's cabin and to hold the platform-cassette firmly in its locked position.

The hook-like means is intended to coact inseparably with a lifting eye on the front end-wall of the platform-cassette

when the beam is in its locked state.

According to one embodiment, the arrangement includes hook- associated and lifting-eye associated means which will only allow the hook to coact releasably with the hook-like means or which will prevent any such coaction solely when the hook¬ like device occupies a specific position in relation to the lifting eye, this position being relevant when the platform- cassette is located immediately behind or obliquely beneath the level of the vehicle.

According to another embodiment, the arrangement includes means for enabling the telescopic arm sections of one arm to be extended or retracted synchronously with the telescopic arm sections of the other arm.

ADVANTAGES

Those advantages that are primarily afforded by an inventive hoist arrangement are found in the provision of conditions which enable a platform-cassette and a dumper-type container to be lifted and moved from a supportive surface to a vehicle load-carrying surface, or vice versa, with one and the same vehicle provided with an inventive hoist arrangement, where said surface and location of the platform-cassette or the dumper-container may be some metres beneath a plane defined by the support surfaces of the vehicle tyres.

In addition, the inventive hoist arrangement can be readily modified structurally to operate as a tailboard hoist, with the telescopic arms facing vertically upwards.

The main characteristic features of an inventive hoist arrangement are set forth in the characterizing clause of the following Claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

An inventive hoist arrangement will now be described in more detail with reference to an embodiment at present preferred and also with reference to its application on different load- carrying vehicles, and also with reference to the accompany¬ ing drawings, in which

Figure 1 is a perspective view of a truck on which a plat- form-cassette rests on the rear chassis part of the truck;

Figure 2 illustrates correspondingly a dumper-container resting on the rear chassis part of the truck;

Figure 3 is a side view of the truck shown in Figure 1;

^• Figure 4 is a perspective view of a truck and a platform- cassette and shows the cassette in three different ^' possible positions, i.e. a position in which the cassette rests on the rear chassis part of the vehicle to a position in which the cassette rests on a supportive surface directly behind the vehi¬ cle, and an intermediate cassette position;

Figure 5 is a side view of a platform-cassette which func¬ tions as a standard tiltable load-bearing plat¬ form;

Figure 6 is an end view of the Figure 5 illustration;

Figure 7 is a side view of the truck shown in Figure 1 and includes an enlarged view of the arm rotating mechanism, but with the arms omitted for the sake of clarity;

Figure 8 is a side view which illustrates the different positions of a dumper-container as the container is lifted and moved from a vehicle resting posi¬ tion to a position in which it rests on a support- ive surface oriented in a plane of the support parts or support surfaces of the vehicle tyres, and two intermediate positions;

Figure 9 is a side view which illustrates the possibility of placing a dumper-container (or a platform- cassette) on a plane which is located much lower than the aforesaid supportive surface;

Figure 10 is a perspective view of a truck equipped with a hoist arrangement, and shows a dumper-container resting on a platform-cassette;

Figure 11 is a side view of a truck which is equipped with

- a hoist arrangement adapted for a load rearrange- ment function, and which is intended to lift and move stacks of four plant-cassettes from a ground position to a position on the truck;

Figure 12 illustrates a position prior to the plant-cas- settes being transferred to the rear chassis-part of the truck;

Figure 13 is a side view which illustrates one example of road haulage to a planting site;

Figure 14 illustrates the transfer of a top plant-cassette from the truck to a "track", and also shows where an earlier load-rearrangement function is now used as a lifting function for lifting an uppermost container or plant-cassette;

Figure 15 is a side view of a truck with which the hoist arrangement is used as a tailboard hoist, with its load-receiving surface or loading surface in a position in which the load-receiving space is closed;

Figure 16 shows the tailboard hoist in a fully open position and with the load-receiving surface in a fully lowered position;

Figure 17 shows the tailboard hoist with the loading surface in a slightly raised position, and in a further raised position in broken lines;

Figure 18 is a perspective view of the rearmost part of the truck chassis and shows the pivot shaft arrange¬ ment and the link arrangement;

Figure 19 is an enlarged view of part of the equipment shown in Figure 18;

Figure 20 is a side view of the link arrangement by means of which a piston-cylinder device is able to rotate an arm through 200°, said Figure showing the link arrangement in a starting position;

Figure 21 shows the link arrangement when the arm is rotated through 45°;

Figure 22 shows the link arrangement when the arm is rotated through 180° ;

Figure 23 shows the link arrangement when the arm is rotated through 200° ;

Figure 24 is a horizontal view of the free-ends of two parallel arms with an enlargement of one end-part;

Figure 25 is a side projection of said end-part in an en¬ larged view;

Figure 26 is a horizontal view of a beam which is provided with a centrally positioned hook-shaped holder means and two end-related holder means, of which one is shown in an enlarged view;

Figure 27 is a side view which shows an initial position for separable coaction between the hook means and a lifting eye means, when a platform-cassette is placed behind the truck and rests on the support¬ ive surface;

Figure 28 illustrates inseparable coaction between the hook means and the lifting eye means when the beam is fixed to the chassis;

Figure 29 is a cross-sectional view of a telescopic arm which consists in three sections, and shows the sections fully extended, with certain parts being shown in an enlarged view;

Figure 30 is a cross-sectional view of the three arm sec- tions when fully retracted, with certain parts being shown in an enlarged view;

Figure 31 is a cross-sectional view of the telescopic arms; and

Figure 32 is an end view of a platform-cassette with the beam locked firmly to the platform-cassette and the chassis by means of the hook means.

DESCRIPTION OF EMBODIMENTS AT PRESENT PREFERRED

Figure 1 is a perspective view of a vehicle, in this case of

a truck 1, which is supported on a supportive surface or plane A by means of the vehicle wheels 2, 3, 4 and 5 and their load-absorbing surface parts 2a, 3a, 4a and 5a.

The truck 1 includes a chassis which in the illustrated case has two rear, parallel chassis beams la, lb which are constructed to take-up loads in a known manner.

The following description assumes that the chassis beams support means 7a which in turn supports a platform-cassette 6 and/or a dumper-container 7. The means 7a may have differ¬ ent forms, and may vary from support circuits to loading surfaces or rails.

The present invention refers to the use of a particular hoist arrangement 10 which is adapted for coaction with a rear part of the chassis of the vehicle 1, such•as the rearmost part la' of said chassis. (See Figure 18).

The hoist arrangement.10 includes two mutually parallel arms of which a first arm is referenced 11 in Figure 1 and a second arm is referenced 12, although this arm is hidden in Figure 1.

In the case of the Figure 1 embodiment, one end-part of respective arms 11 (12) of the complete hoist arrangement is fixedly connected to a rotatable shaft 13.

The second arm 12 is identical to the arm 11 and has one end- part 12a fixedly connected to a rotatable shaft 13', similar to the end-part of the first arm 11.

The arms 11, 12 can be rotated reciprocatingly in a vertical plane by drive arrangements 14, 14' (see Figures 18-23), and the mutually opposed other free end-parts lib, 12b carry one or more connecting means (11', 12') which are adapted for firm, but readily released coaction with a load and/or a

load-accommodating container 7.

The arms 11, 12 are spaced apart so as to lie on a respective side of the parallel chassis beams la, lb, and outwardly of said beams.

The embodiment illustrated in Figures 1 and 3 and described with reference to a platform-cassette 6 requires the cassette to rest on slide rails 7 or rear rollers positioned in the normal travel direction of the truck.

Figure 2 illustrates a truck of the type shown in Figure 1 but which is intended to carry a dump-container 7, wherein the truck has been provided to this end with a support surface 7a or with discrete support parts.

There is nothing to prevent the use of a platform-cassette 6 which is able to rest on a requisite support surface 7a and allow this support surface to carry the dumper-container 7.

The hoist arrangement 10 is identical with the hoist arrange¬ ment shown in Figure 1.

Each arm 11 and 12 is comprised of a plurality of telescopic, mutually coactable, flexurally rigid and load-absorbing sections lid, lie and llf, these sections being extended and retracted relative to one another by means of a drive arrangement (not shown in the Figure) .

Figure 3 illustrates the arm sections lid, lie and llf in an almost fully extended position.

The arms 11 and 12 are rigidly connected to one another through the medium of an axle 113, and can therewith be swung in unison on the shafts 13, 13' by means of one, or two, piston-cylinder devices 8 (8') which acts/act on a respective rotary or pivot arrangement 14, 14'.

The drive arrangement, the arrangement 8 located adjacent the arm 11, is comprised of a hydraulically operated piston- cylinder device, wherein one such device is mounted on each side of the chassis frames la, lb of the truck, so as to activate both arms 11 and 12 through the medium of the axle 113.

Figure 4 is intended to illustrate the movement pattern of the platform-cassette 6 as it is swung upwards and thereafter moved rearwards, by first retracting the arm sections lid, lie and llf into one another and, when necessary, extending the arm sections further out from one another - this latter possibility not being shown in Figure 4.

A beam 9 having a centrally positioned connecting means or coupling means 19 in the form of a hook extends between the end-parts of the two arms or arm sections.

The connecting means 19 is centrally positioned and the beam 9 can be firmly, but readily releasably joined to the end- parts lib, 12b of the arms 11, 12 through the medium of further coupling means (50, 50a) positioned for this purpose.

It will be seen from Figure 6 in particular that the two arms 11 and 12, each with their respective inbuilt hydraulically operated piston-cylinder device, are positioned adjacent to and on the outside of two longitudinally extending chassis beams la, lb and adjacent mutually opposing side-edges of a load-bearing platform or platform-cassette 6 which serves as a container, or immediately outside mutually opposing side- edges for a dumper-container 7.

Figure 7 is a side view of a truck, on which a dumper- container support surface 7a has been mounted on the truck chassis, while Figure 8 illustrates the different positions of the dumper-container 7 as it is lifted and moved from the truck 1 and placed to rest on a surface A located immediately

behind or at a distance from the truck 1, and vice versa.

The dumper-container 7 can be deposited still further behind the truck 1, by extending the telescopic arm sections of respective arms 11 and 12.

Figure 9 is intended to show that a dumper-container 7 can be deposited onto a surface B which is located far beneath the surface A, by fully extending the telescopic arm sections lid, lie and llf.

In practice, the horizontal distance between the surfaces A and B may be more than two metres, although hardly more than four metres.

Figure 10 is a perspective view of a truck 1 which carries a platform-cassette 6 and a dumper-container 7 placed on top of the cassette 6.

This Figure shows connecting means 11', 12' for connecting hoist lines 16, 16a to the outer extremities lib, 12b of the arms 11 and 12.

Figures 11 to 14 illustrate a practical application of the inventive hoist arrangement 10.

Figures 11 and 12 illustrate a truck 1 which includes a loading platform or a load-receiving surface 7a. Plant- carrying cassettes 20 four storeys high rest on a supportive surface 20' and are lifted by means of the arms 11, 12 from an underlying surface A onto the load-receiving surface 7a of the truck, with the aid of the beam 9, the hook 19 and a lifting eye 19a, this function being referred to as a load- rearranging function.

Figure 13 is intended to illustrate a road transporter which is assumed to be driven towards a planting area and shows the

truck 1 loaded with plant-cassettes 20 and towing a trailer which transports a terrain tractor (TRACK) 21. The surface 20' on which the plant-cassettes are carried is held firmly to the chassis la by virtue of the beam 9 being firmly locked to the chassis (see 9a in Figure 28).

Figure 14 shows how the uppermost plant-cassette 20a can be placed on the load-receiving surface 21a of the tractor 21 with the aid of extended arms 11 and 12 and without the aid of the beam 9 (the dumper function) .

Figures 15-17 are intended to illustrate the use of the hoist arrangement 10 as a tailgate or tailboard hoist.

In this case, the hoist arrangement includes two mutually parallel posts 30 (30a), with the upper part 30' of the post 30 being shown in coaction with the upper part lib of the arm 11.

In the Figure 15 illustration, the tailboard or load-receiv¬ ing surface 31 is positioned so as to close-off the loading area in the vehicle.

In the Figure 16 illustration, the posts 30 (30a) have been rotated by the arms 11 and 12 to a vertical position and the tailboard 31 is now able to function as a load-receiving surface. This is illustrated in Figure 17 by a person 32 standing on the horizontal tailboard 31.

It will be noted that the height to which the tailboard 31 can be lifted in this horizontal position is not restricted to the height of the chassis and that the tailboard can be raised to a much higher position, as the broken line position 31' is intended to illustrate.

The height to which the tailboard can be lifted is restricted solely by the total extended length of the telescopic

arm-sections, i.e. by the length of fully extended arms.

Figures 18 and 19 are perspective views of the rear part of the truck and the chassis beams la, lb and also show shafts 40 and 42 belonging to the linkage and pivot arrangement (13, 14; 13', 14').

Figures 20-23 illustrate different positions of the linkage arrangement 14, these positions being governed by the positions of the piston-cylinder arrangement 8.

In addition to the pivot shafts 40 and 42, the Figures also show further pivot shafts 41, 43 and 44 and the link arrange¬ ment 45 and 46.

Respective arms 11, 12 are connected to a link arrangement 14, 14' which is related to a line L which extends between said pivot shafts 40 and 42.

Rotational movement of the shafts 40 and 42 or a change in the rotation position of said shafts is immediately translat¬ ed to corresponding and commensurate pivotal movement of the arms in a vertical plane.

Between the positions shown in Figures 20 and 21, the shafts 40, 42 have turned through an angle of about 45°. In the position shown in Figure 22, the shafts 40, 42 have turned through an angle of about 180°, while in the position shown in Figure 23 said shafts 40, 42 have turned through an angle of 200°, as indicated by the line L.

As will be seen from Figure 24, the outer parts 11' and 12b of the arms 11 and 12 carry separate connecting means 50, 50a, said means being mounted on the inside of respective arms and being intended to hold a respective hoist line 16, 16a.

Also provided are other connecting means 60, 60a which are intended to coact with beam-end related connecting means 70, 70a.

Figure 25 is intended to show that a groove 80 is adapted for coaction with a screw 90.

A pin 91 (91a) is intended for insertion into a recess 60 (60a) .

Figure 27 is intended to show that the hook device 19 can be inserted to a position beneath the lifting eye 19a and then raised into coacting engagement therewith.

A part-circular camming surface 19' moves past an edge 19a'.

When the hook 19 is rotated relative to the lifting eye 19a, for instance to the position shown in Figure 28, the afore¬ said edge 19a' will lock the hook against unintentional release from the lifting eye.

The arrangement includes a reciprocatingly movable latching member 9a which when moved in a first direction functions to lock the beam 9 firmly to the chassis la.

Figure 29 is a cross-sectional view of an extended telescopic arm 11, while Figure 30 shows the arm 11 fully retracted.

The arm section lid encloses a piston unit 100 having a centrally positioned pipe 100a for supplying oil to a cylinder unit 101 included in the arm section lie, via a connection 100b.

A chain arrangement 102 having an extension illustrated in Figure 29 is adapted to move the arm sections llf and lie synchronously with movement of the piston-cylinder arrange¬ ment, such that movement of the arm sections llf and lie will

be relatively the same.

Figure 30 illustrates a retracted telescopic arm with requisite piston-cylinder arrangement, said arm being shown in cross-section with certain parts of the arm enlarged.

Figure 31 is a cross-sectional view of the arm 11 in the state shown in Figure 30.

Figure 32 illustrates the platform-cassette 6 and the lifting eye 19a, and shows the movable latching member 9a in a latching position, by virtue of pins being secured in holes.

The synchronized movement between the piston-cylinder devices coacting with respective arms 11 and 12 may also be achieved with the aid of hydraulic control valves, or with mutually coacting chains and chain wheels, in coaction with means which control displacement so that the chain wheels move synchronously with one another.

It will be understood that the invention is not restricted to the aforedescribed and illustrated exemplifying embodiment thereof and that modifications can be made within the scope of the inventive concept as defined in the following Claims.