LOAD-CHANGER FOR VEHICLES Technical field of the invention
This invention relates to a load-changer for vehicles comprising a rotatable cog- or tooth-wheel mounted on the edge of a load-carrier included in the vehicle and being arranged to engage a track provided with cogs or holes, said track being arranged on the under side of a load-object in question for instance a house, means being provided to dampen the tendency of the load-object to swing around the cog-wheel in connection with that the centre of gravity of the load-object passes the cog¬ wheel. Load-changers of this kind, that in practice are often used for loading houses for recreation purposes, are advantageous in so far as they do not need any space between the drivers cabin and the house or load-object loaded onto the load-carrier. In other words, they permit a maximum utilization of the load-carrying capacity of the load-carrier.
State of the art
A load-carrier of the type generally described above has previously been disclosed in the US Patent Specification 3221913. This known construction suffers however from a number of in practice most troublesome drawbacks. Thus the construction in question presupposes that the load-carrier consists of a platform body permanently mounted on the frame or chassis of the vehicle. This platform per se has a certain constructional height that intrudes on the allowable total height of the vehicle and thus reduces the maximum possible height of the load-object in question. The fixed platform body also reduces the flexibility of the vehicle in regard of the possibilities of use. Two triangular, upright, guiding plates are arranged on the platform, against each of which a roller on the load object engages for the damping of the load object when this is pulled onto the platform body. These guiding plates constitute a troublesome obstacle at the loading of at least some kinds of goods on the platform body, and if the wish
is to avoid these obstacles a lengthy work is necessary in order to demount and remove the plates. Furthermore two chains are included in the construction that are applied in the extension of two bow-shaped ramps, on one hand intruding in the payload space of the load object, and on the other hand requiring a lengthy work when being demounted from the load object.
Short description of the inventive concept
The present invention aims to remove the above- mentioned drawbacks and to create a load-changer that by simple and cheap means permits a convenient and quick change of load-objects of the most different kinds, also including platform bodies per se. These and other aims are, according to the characteristics of the invention, obtained in that said damping means includes at least one arm, swingably mounted on the load carrier, to which arm a spring or piston-cylinder mechanism is connected, that in connection with the loading of the load object on the load-carrier, keeps the arm in a position inclined upwards-forwards from the area of the cog-wheel, wherein thearm can be brought to engage a guide extending along the load object, said mechanism initially counteracting the weight of the load object since the centre of gravity of the load object has passed the cog-wheel and then allowing the arm, and thereby also the load object, to be successively swung down into a plane essentially parallel to the load-carrier.
Further elucidation of the state of the art
In the US Patent Specification 3229839 a further load-changer is disclosed that works with a cog-wheel, mounted on the backward end of a platform body and co¬ operating with an angular cog-track on the load object. However, in order to pull the load object onto the plat¬ form body, two rather complicated winches are also necessary which have .to be connected to and disconnected from the load object in connection with a loading respec¬ tively a discharging of this load object.
Short description of the attached drawings
In the drawings Fig 1 is a simplified perspective view showing parts of a vehicle equipped with the load- changer according to the invention, Fig 2 a perspective view of a likewise simplified load object intended to be pulled onto the vehicle according to Fig. 1, Figs 3 and 4 perspective views illustrating two different stages in connection with the pulling of the load object onto the vehicle, Fig. 5 an extremely enlarged perspective view illustrating details in the load-changer according to the invention, and Fig. 6 and 7 perspective views showing an alternative embodiment of the load-changer in two different functional conditions.
Detailed description of an preferred embodiment of the invention
In Fig.l 1 generally denotes a vehicle that in an conventional way includes a wheel-carried frame 2 whereof two lengthwise beams and a backward crossbeam 3 are shown in the drawing. A cross-piece 4 also extends between the lengthwise beams.
The load object according to Fig. 2, in its entirety denoted with 5, is in this case shown to consist of a frame composed by on one hand two lengthwise side beams in the form of U-profiles 6,6', and on the other hand a suitable number of crossbeams 7. It should be noted that the U-profiles 6,6' are open inwards, towards the centre of the frame. In practice this frame can form an integrated part of either a simple platform body or a house of the kind that can be used for camping or recreation purposes. The frame in question can also be a part of other optional load objects that one wishes to pull up onto the vehicle frame 2, if required. On the under side of the frame shown in Fig. 2, more specifically on the under side of the cross-pieces 7, a track 8 provided with cogs or holes is arranged, that, in the example shown, is shown to consist of a box-girder,
onto whose under side a chain has been welded, forming a rigid track extending along the entire length of the frame. At the forward end of this track two hooks 9,9' are fixedly attached for purposes that will be described i below.
Two ears 10,10' are welded onto the backward beam 3 of the vehicle frame 2 carrying a rotatable shaft 11, in the middle of which a cog-wheel 12 is arranged that in this case can be brought to rotate by means of an electric motor 13 and a gear belonging thereto, more specifically by means of a chain transmission 14. In Fig. 1 a chain 15 is shown to be arranged on the cog¬ wheel 12 that in an inactive condition can be stored in a container 16 mounted in the area below the cog-wheel 12.
On the two ears 10,10' furthermore two swingable arms 17,17* are mounted, being mutually connected by means of a cross-member 18. Between this cross-member 18 and the cross-piece 4 of the frame 2, a spring or piston- cylinder mechanism 19 extends, that at its opposite ends, in a conventional way, is hingedly attached to the cross- member 18 as well as to the cross-piece 4. A backwardly extending plate 20 is also mounted on the cross-member 18, the function of which is better shown by the description below and with reference to Fig. 5.
On an end link of the chain 15, "two pins 21,21' are mounted projecting on both sides of the end link, each being rigidly attached to an eyelet 22,22' (that in the example shown is in the form of a chain link) in order to allow the automatic coupling of the chain to the hooks 9,9'. Each such eyelet is in turn rigidly attached to a supporting plate 23,23' that in Fig.5 lies against the plate 20. Three recesses are formed in the backward end of this plate that are mutually separated by means of two fingers 24,24' being inclined upwards- backwards relative to the plate 20.
The function of the load-changer according to the invention
In Fig. 1 and 2 the load object 5 is shown separated from the vehicle 1. More specifically the load object or the frame 5 is imagined to rest on the ground or the floor behind the vehicle. In this position a spring mecha¬ nism 19 keeps the two swing arms 17,17' in a state of readiness wherein they are directed obliquely upwards- forwards from the backward end of the vehicle frame 2. When it is desired to lift the frame 5 onto the backward end of the vehicle frame 2 , the chain 15 is pulled out of the storage container 16 whereafter the coupling device, formed by the pins 21,21' and the eyelets 22,22', manu¬ ally is coupled to the hooks 9,9'. In the following stage the motor 13 is started, so that the cog-wheel is brought to rotate. This results in that the forward end of the frame 5 is lifted somewhat upwards by the chain 15 being wound up by the cog-wheel 12. Somewhat before the entire chain has been wound up, the swing arms 17,17', consis¬ ting of U-beams, will engage the U-profiles 6,6' of the frame 5 serving as guides, as shown in Fig. 3. After some further rotation of the cog-wheel 12 the hooks 9,9' will automatically be released from their engagement with the eyelets 22,22 ',which, in the position shown in Fig. 5, are stopped in their forward movement by the plate 20. In this position, the cog- or chain-track 8, that is fixedly attached to the under side of the frame 5, engages the cog-wheel 12, so that the continued pulling of the frame 5 onto the load-carrying frame 2 is taken over by this fixed and rigid chain-track. In this connection, the frame 5 is guided and held in a reliable way by the arms 17,17'. When the frame 5 has been moved so far that the centre of gravity of the frame 5 has passed the cog-wheel 12 (whose centre axis coincides with the swing centre of the arms 17,17"), the spring mechanism 19 will initially counteract theweight of the load object, and then allow the arms 17,17' to be successively swung down, and thereby also the frame 5 itself, into a plane essentially parallel to the load carrying frame 2. In other words, the spring
mechanism 19 ensures a soft and controlled down-swinging movement of the frame or load object 5; something which is especially important when the load object is very heavy (which is the case of such superstructures as houses). After the frame 5 has been fully swung down it is moved forward to its forward end position by a continued rota¬ tion of the cog-wheel 12, which co-operates with the chain-track 8 along whole length of the frame 5.
When the load object is discharged the procedure is carried out in the opposite way. By the co-operation between the cog-wheel 12 and the chain-track 8, the frame 5 is first moved backwards into a position wherein its center of gravity passes the cog-wheel 12, in which posi- tion the swing arms 17 are brought to softly swing up, from their horisontal positions into their inclined positions. In connection with the cog-wheel 12 nearing the end of the chain-track 8, the hooks 9,9' engage the eyelets 22,22' of the coupling device whilst moving the chain 15, that is in a state of readiness, so that the chain is brought into engagement with the cog-wheel 12 before the track 8 leaves the cog-wheel. By these means, the load-carrying function of the chain-track 8 is taken over by the chain 15 so that the chain carries the forward end of the frame when the cog-wheel 12 is further rotated. The movement of the chain is continued until the frame 5 again entirely rests against the ground.
Short description of an alternativeembodiment of the invention in this embodiment, the previously described chain- track 8 is replaced by a profile, in its entirety denoted with 25, that includes two sidewardly extending flanges 26,26' between which there is a web in which a number of holes 27 are recessed for engaging the cog-wheel 12'. The profile 25 includes two sections 25',25", extending angularly to each other, of which the first-mentioned is attached to the under side of the load object in question (for instance a house) whilst the other extends vertically
upwards, for instance along a front wall of the load object in question.
On both sides of the cog-wheel 12' two locking fingers 28,28' are arranged, that are sidewardly movable, from and to each other. Each of these fingers includesa sleeve 29,29' rotatably journalled on the shaft 11 and has at their opposite ends, an inwardly projecting rotatable roller 30,30'. Springs 31,31' are arranged between the sleeves 29 and the adjacent ears 10",10"' striving to move the locking fingers towards each other into the position shown in Fig. 6 and against the action of which the locking fingers in a suitable manner (not shown) are separable into the position shown in Fig. 7.
The described device functions in the following way. When the desire is to load the load-object in question, the locking fingers 28,28' are moved sidewards,aside from each other, whereupon the vehicle is backed towards the load object so that the cog-wheel 12' engages the holes 27 in the track25. Then the fingers 28,28' are released, so that the springs 31,31' bring them to move against each other, into the position shown in Fig. 6, wherein the rollers 30,30' engage behind the flanges 26,26'. In this position the locking fingers cause a locking between the vehicle and the load object so that these cannot be separated from each other. Then the motor 13' is started, so that the cog-wheel is brought to rotate; something that results in that the track section 25" will climb upwards relative to the vehicle, whilst lifting the forward end of the load object. After that the cog-wheel 12 has passed the section25", it automatically engages the horizontal under section 25 ' , meaning that the forward end of the load-carrier, which has now been lifted to the level of the backward end of the load-carrying frame 2, starts to advance inwards over the load-carrying frame. This is continued until the load object in its entirety has been advanced to its forward end position on the load carrying frame.
An obvious advantage of the embodiment according to the Figures 6-7, compared to the embodiment according to Figures 1-5, is that the vehicle can be connected to the load object without there being any need for a manual coupling to the load object. In other words, the vehicle driver can remain sitting in the cabin and there,by mecha¬ nical means,control the locking fingers 28,28' and the motor 13 ' .
Conceivable modifications of the invention
It is evident that the invention is not limited only to the embodiments described above and' shown in the drawings. Thus any kinds of cog-formed wheels respectively cog- formed or hole-provided tracks can be used if they only can engage each other in the way described. Further it is possible to use two chains or tracks respectively instead of only one as exemplified above. It is also possible to arrange for a manual rotation of the cog-wheel, although in practice a separate motor is preferred for this purpose. The described mechanism 19 can in practice either consist of a pneumatic and/or mechanical spring or consist of a double-acting hydraulic cylinder by the means of which the downswinging movement of the load object can be controlled as desired. Such a hydraulic cylinder can advantageously be utilized for tilting the frame or load object 5 when discharing the same from the vehicle frame 2 and in connection with such an embodiment the swing arms 17,17' may be much longer than shown in the drawings, e.g. about half the length of the vehicle frame.