IE49467B1

IE49467B1 - Semi-trailer body for a bulk material transport vehicle,in particular a lorry

Info

Publication number: IE49467B1
Application number: IE220179A
Authority: IE
Original assignee: Rothalit Gmbh
Priority date: 1978-12-09
Filing date: 1979-11-16
Publication date: 1985-10-16
Also published as: DK212490A; DK212590D0; IE792201L; EP0012227A1; DK212490D0; DK212690D0; EP0012227B1; DK212690A; DK212590A; DK485779A

Abstract

1. Semitrailer body for a bulk material transport vehicle, in particular a lorry, with a self-supporting box superstructure open at the top (4, 72), the rear end wall of which is configured as a hinged tailboard (28), and with a thrust plate (26) that runs in longitudinal guides (51, 86, 91) disposed along the side walls (10, 11) of the superstructure and is impelled by means of an hydraulic multiple-cylinder piston rod installation (23, 92) which is braced to the superstructure via a horizontal coupling (22), characterized by the fact that the thrust plate (26) forms the other end wall of the box body (3), and the multiple-cylinder piston rod installation (23), located essentially outside the box superstructure, is supported by a support frame (17-21) joined to the box body (3), in which arrangement the horizontal coupling (22) is fitted to a frame cross-tie (17) which is attached to converging side-panel end plates (18, 19) of the frame.

Description

The invention relates to a semi-trailer body for vehicles which transport bulk material, in particular lorries Such vehicles are not only used on building sites and waste tips, but also are often used to transport material on public roads. In particular, they are used to transport sludge-like bulk material, for example for waste tips and washery refuse tips, and, as a result, particularly stringent regulations are laid down to ensure that the public roads are kept clean and in a safe condition. In particular, it is important that the vehicles should not damage the road structure when travelling empty. These regulations also aim at preventing the vehicles from soiling the roadway with lumps of earth which are wedged between the double tyres and are thrown onto the road surface during travel at high speed.

The invention is based on a vehicle of this kind which is already known from US-A-3,953,170. In the case of this vehicle, the box body is immovably connected to the chassis and is unloaded, via the rear pivotable flap, by the pusher blade which runs in the longitudinal guide. Such vehicles do not possess some of the drawbacks of dumping lorries, in particular rear dumping lorries, i.e. reduced stability with the loading surface tipped up, excessive noise and vibration during transport, and the dangers associated with driver errors which, for example, during transport of empty loads, can lead to the box body swinging upwards in an uncontrolled manner.

In the case of the already known vehicle, the pusher blade is arranged between the front end wall and the pivotable flap. This makes it necessary for the multiple-cylinder and piston arrangement to be accommodated partly in the area between the pusher blade and the front end wall and partly in the actual loading area. The volume of the box body occupied as a result of this cannot be used for the transport of bulk material. Since, moreover, this part of the box body lies at the front, the rear axle of the vehicle is subjected to greater loads than the rear axle of the tractive vehicle, which is located underneath the saddle and usually acts as the drive axle. In particular, such vehicles are not suitable for transporting refuse, because their loading capacity is too low compared to their body and because they possess unfavourable driving and stability characteristics.

The object of the invention is to design the already known vehicle such that Its stability can be improved and such that the multiple-cylinder and piston arrangement can be braced to the vehicle in an improved manner.

According to the invention, there is provided a semitrailer body for a vehicle, in particular a lorry, for transporting bulk material, comprising a self-supporting box body open at the top, the rear end wall of which is constructed as a pivotable flap, and a pusher blade which runs in longitudinal guides arranged along the side walls of the box body and is driven by means of a hydraulic multiple-cylinder and piston rod arrangement which is braced to the body via a horizontal joint, the pusher blade forming the other end wall of the box body, the multiple-cylinder and piston rod arrangement, which is located essentially outside the box body, being braced to a bracing frame connected to the box body and the horizontal joint being arranged on a frame crossbeam which is attached to converging side parts of the frame.

According to the invention, the intrinsic rigidity 10 of the box body is used in place of the front end wall and the space located between the driver's cabin and the front side of the box is used for the bracing frame. The latter carries away the reactive forces of the multiple-cylinder and piston arrangement via its frame crossbeam and the converging side parts and diverts them into the box body as inwardly acting forces when the bulk material is emptied. According to the invention, the centre of gravity of the loaded box body can be displaced further forwards, as a result of which the saddle and consequently the rear axle of the tractive vehicle are subjected to greater loads.

Since a relatively light constructional form is sufficient for the above-described frame structure and since the multiple-cylinder and piston arrangement is located mainly outside the box body, practically the entire volume of the box can be used for the transport of bulk material.

Moreover, the quantity and weight of the loads do not limit in any way the applicability of the invention. Therefore, semitrailers with a 50-tonne payload can be • 49467 built relatively cheaply for applications which do not involve travelling on public roads. As a result, the costs of waste removal are practically halved. It is thus also possible to replace heavy lorries and very heavy lorries which, as is known, have extremely high purchase prices.

A further advantage consists in the fact that, if necessary, despite the relatively low degree of stability of the body on waste ground, it is possible to dispense with double tyres and hence eliminate most of the road cleaning operations hitherto required.

Each guide of the pusher blade consists advantageously of a channel section with an inwardly oriented opening and a bottom adjacent the corresponding side wall of the box; in this respect, the pusher blade is preferably provided with blocks which slide in the channel sections. These blocks may be made of low-friction plastic.

It has also proved advantageous to keep the bulk material away from the channel sections. This is achieved in a simple manner by providing the upwards-facing longitudinal walls of the channel sections with guide plates which run obliquely towards the side walls and upwards.

According to an advantageous embodiment of the invention, hydraulic drive cylinders also provide the « kinetic energy for the pivotable flap and locking bolts which engage in recesses in the body and in the flap. A differential-pressure circuit controls the working cylinder in a time sequence preset for actuation of the pusher blade, flap and bolts. - 49467 However, such a hydraulic drive is not always the best solution. In fact, it can happen that the differential pressure circuit results in complete opening of the flap before the pusher blade has started the process of expelling the bulk material. In that case, the material issues unevenly. After unloading, the flap cylinder returns the flap from its open position directly to its closed position, due to the differential pressure circuit, before the pusher blade returns. This can under certain circumstances entail 48467 the danger of an accident, because workman overseeing the process of expulsion of the material and the return of the pusher blade can accidentally become caught between the flap and the pusher blade.

The invention offers the possibility of eliminating any possible disadvantage of a differential pressure circuit for the actuation of the pusher blade, flap and locking device, and in particular of providing the preconditions for improved unloading and improved safety against accidents; for this purpose, the (flap) pivot drive is provided by the drive of the pusher blade, which carries, on its inner face, cams whose front faces and upper faces form forwardly and upwardly curved support tracks, which support the pivotable flap on its inner face, and the flap locking device possesses pivoting catch hocks, hinged to the body, and each having one linkage rod leading to the front end wall of the box, which linkage rod cooperates with the pusher blade when the catch hook engages in a bolt fixed to the flap, and is prestressed 20 in the direction of release of the bolt.

This results in the advantage of having a mechanical actuation of the flap, and mechanical locking and unlocking thereof, the energies of movement to be provided to these members being applied by means of the pusher blade drive, which is constructed as a multiple telescopic cylinder, as the pusher blade advances.

However, the greater development of force by the telescopic cylinder which this requires only becomes necessary at the end of the material expulsion process, in order to raise the flap. Before then, the unlocked flap improves the process of unloading with numerous bulk materials, because it controls, through its weight, the flow of the issuing bulk material, before being lifted up by the cams of the pusher blade. The force required to lift it can readily be applied by the cylinder, which at that stage has largely been relieved of its load. Using cams, it is possible not only to control the point in time at which the flap is moved io but also the nature of its movement, so that the closing movement can be slowed down and hence be made such that when the pusher blade is advancing a certain time is required before the flap closes, which time can be utilised as a safeguard against accidents.

The linkage rods can terminate under the frame and at any given tine each be connected to a rocker arm, serving to provide the longitudinal guiding of the pusher blade, vilile at the same time arms are directed to the rocker arms.

Specifically, it is then possible to arrange 2o that the rocker arms each carry, at their free ends, one roller which rides on the underside of the corresponding arm; to do this, tension springs hinged to the body and to the linkage rods may be used to prestress the latter. In these embodiments, the pusher blade first compresses the load before the catch, hook linkage rod is actuated and the flap is unlocked. This does not matter because the bulk material in general possesses sufficient compressibility to allow a movement, of the pusher blade, of the ' 49467 order of magnitude required to actuate the rocker arm.

The actuation of the flap can also be improved in this connection, if the cams are congruently constructed and are fixed in pairs, at a lateral distance from one another, in the region of the upper edge of the pusher t blade, and if the pivot hinges of the flap are attached to the body, at a point to the rear of, and above, the plane of the flap.

Yet a further advantage can be achieved by means lo of the invention if the longitudinal guides and the members which are fixed to the pusher blade and cooperate with the guides are modified so that on actuating the pusher blade a sequence of movements with little friction is achieved; this is most simply brought about if the longi15 tudinal guides are divided into guide bars located on the upper and lower edges of the side walls, on the inside of the box, and if the pusher blade possesses, on its outside, arms which are provided with one or more fingers running along the guide bars· 2o The effect of this is in fact to provide additional orifices through which the bulk material can move out of the way. As a result of the use of guide fingers, the surfaces which cooperate with one another when the pusher blade is in motion are made smaller, so that the forces exerted on the bulk material are substantially increased and the friction-increasing effect of the bulk material which has penetrated into the guides is substantially reduced. This division of the longitudinal guides furthermore results in part of the guiding mechanism being located at the top and there serving to absorb the tilting moment of the pusher blade. Hence, when it moves back, the pusher blade can no longer tilt so easily about a horizontal axis· For various reasons, a mechanical actuation of _ the flap and of its locking device is furthermore advantageous, for which it is possible to utilise the pusher blade drive f realised by means of the multiple telescopic cylinder mentioned, as the pusher blade advances and hence 10 as the telescopic cylinder develops its greatest force. This, admittedly, presupposes that as the pusher blade moves backwards and forwards, it also cannot tilt about a vertical axis· This is achieved if the guide bars, for the corresponding arm, which are located at the lower edges cf the side walls, each possess a guide track for lateral guide fingers and support fingers.

Advantageously, the pusher blade is guided on sections which both prevent tilting of the plate about its axes and prevent clogging up with bulk material. For this purpose, it is provided, on the one hand, that the longitudinal guides located at the lower edges of the side walls are inwardly open angle sections, the inner faces of whose sidepieces form the gtri.de tracks. On the other hand, the longitudinal guides are so constructed that the upper guide bars consist of downwardly open angle sections. whose upper sidepieoe is in each case covered with a guide plate, and that the upper arms of the pusher blade are each provided with a guide finger which engages under the upper sidepiece of the angle section.

In the improved vehicle provided hy the Invention, the sliders of the upper longitudinal guides are constructed as horizontal guide fingers made from iron rod, which project, from the arms, under the horizontal sidepieces of the upper angle-piece and are located on the ends of the arms. The sliders corresponding to the lower guide angle-pieces are also made from iron rod. In each group, an iron rod which rests on the bottom sidepiece, and a further iron rod which is guided on the lateral sidepiece of the lower anglepiece is provided. Though this arm arrangement has the advantage that the pusher blade itself does not have to possess cut-outs for the sliders, there are practical difficulties· It has in fact been found that in spite of the high surface load of the sliders, resulting from their virtually linear contact with the guide angle-pieces, the pusher blade tends to tilt, and that furthermore there is premature wear of the iron rod, which further considerably increases the tendency of the pusher blade to tilt after it has been in use for a considerable time.

However, the wear of the sliders can be reduced, and the tendency of the pusher blade to tilt on its guides can be eliminated if, according to the invention, the sliders of each group are combined together, in one structural unit, in a runner which is supported on the bottom sidepiece of the angle section and is such that its lateral face exhibits slight play relative to the lateral sidepiece of the angle section, and that each of the sliders corresponding to the upper longitudinal guides is mounted as a pair with a further slider on the arms which are located partially under the longitudinal guides and parallel to these, and these sliders are in the form of rounded earns, one of the sliders of each pair being fixed to the end of the arm and the other being fixed next to the pusher blade.

The wear above all affects the lower sliders since the latter not only have to withstand the substantial weight of the pusher blade, but also the forces which are transmitted by the bulk material, inter alia via the inclined guide plate, onto the guides. The runners are 10 subjected to relatively low pressures per unit area and can be produced from tough steel which is relatively resistant to abrasion resulting from frictional stresses Since furthermore the runners tend to slide over obstacles, above all over portions of the bulk material which may rest on the guide angle-pieces, this tendency is counteracted by increasing the number of the upper sliders by providing the cams which catch the pusher blade on each side under the lower horizontal leg of the upper longitudinal guide. As a result it is possible, in spite of 2o the low pressures per unit area, to eliminate the tendency of the pusher blade to tilt, even if the runners have won to a certain degree. Nevertheless, mounting the pusher blade in the guide, which is thus of very tight construction, presents no difficulties since, with the rear flap opened or removed, the pusher blade can be introduced from the back into the trailer body, that is to say into the guide, for example by means of a fork-lift truck.

The lateral play of the runners is obtained by matching the runners to the particular trailer body because the 48467 bodies show relatively large variations in respect of their internal width. For this reason it is advantageous to connect the runners, for example by welding, to lateral brackets of the pusher blade. In general, a small amount of play, of the order of magnitude of 5 mm, suffices.

In the text which follows, the Invention is explained in more detail in relation to drawings which merely show illustrative embodiments. In these: lo Figure 1 shows a side view, omitting all details not required for an understanding of the invention, of a semi-trailer according to the invention, Figure 2 shows a plan view of the subject of Figure 1, with only the semi-trailer being depicted, Figure 3 shows a broken view of the semi-trailer body, in cross-section, Figure 4 shows a hydraulic circuit diagram, Figure 5 shows a semi-trailer according to the - invention, in side view, the tractor not being shown, Figure 6 shows-a picture, extending up to the centre line, of the flap, in the direction of the arrow A of Figure 5, Figure 7 shows a section along line III-III of Figure 5, Figure 8 shows a side view, but incomplete in the sense of omitting all details not required for an understanding of the invention, of a pusher blade with its guides, in side view, Figure 9 shows an end-on view of the subject of Figure 8, Figure 10 shows a plan view of the subject of Figure 8, partly, in cross-section along line III-III· of Figure 8, Figure 11 shows a detail of the area of Figure 9 marked X, Figure 12 shows a detail of the area of Figure 8 marked Z and Figure 13 shows a detail of the area of Figure 8 io marked Y.

On the saddle 1 of a three-axle tractor 2 rests the semi-trailer 3, having a self-supporting body 4, which at its rear end, at 5, is equipped to accommodate a double axle 6 and 7 with single tyres 8 and 9 respectively.

The body is a box body which, as shown in the plan view in Figure 2, has parallel side walls 10 and 11 and a plane floor 12 on two parallel side members 13 and 14 and several cross-members 15· Accordingly, the box forms a selfsupporting body. At its front end, the box has a 2o chassis marked 16 in its entirety. This possesses a brace 17, converging side portions 18 and 19 and parallel frame members 20 and 21 which are connected to the converging side portions 18 and 19 and to the box itself.

A multiple cylinder-piston arrangement 23 is hingedly connec25 ted to the , brace 17 via a horizontal hinge-joint 22.

The end of the piston rod 24 of the arrangement 23 is, for its part, located above a horizontal hinge-joint 25 in a pusher blade 26 which forms the front end wall of the box, whilst the rear end wall is formed by a pivotable flap 28.

This flap 28 is fixed by its upper edge to two lateral hinge-joints 29 (Figure 1) on the upper edge of the box at 30. It can be pivoted from its closed posi5 tion shown in solid lines in Figure 1, into the open position, shown in dash-dot lines, by means of a cylinderpiston arrangement 32, like the cylinder-piston arrangement 23· For this purpose, the cylinder 33 is hinged to a horizontal hinge-joint 34, whilst the piston rod is hinged lo to the flap 28 via a horizontal hinged joint 35· Furthermore, the flap can be locked by means of an additional hydraulic cylinder-piston arrangement 36. The locking cylinder 37 (Figure l) is hinged at 38 to the flap 28, whilst its piston rods 39 are hinged at 40 to a locking bolt 41, which can engage in a corresponding recess 42 of an inclined downward extension 43 of the floor.

The pusher blade 26 consists of a rectangular frame 45, consisting of hollow sections and covered on both sides with a sheet-metal panel, 46 and 47 respectively.

An upper angle section 44 serves as a damming bar, that is to say as a weir, which prevents the bulk material from flowing over the upper edge (the upper frame member of the pusher blade 26). It is connected to a further profile 45z, of triangular cross-section, which forms a damming bar which surrounds the pusher blade 26 in a frame-like manner, so that the pusher blade 26 can compress the charge of material at the end face of the blade.

As shown in Figure 3, the pusher blade 26 possesses at the bottom, on each side, a block 50 consisting of a low-friction plastic. The block slides in a longitudinal guide 51 which is formed by a channel section whose base 52 is connected to the side panel 53 of the particular side wall 10 of the body. A guide plate 56 running at 5 an angle from the upper side wall 54 of the box section 51 outwards as far as the side wall 10 serves to deflect the bulk material and is scraped clean by a correspondingly shaped plate 57 of the pusher blade 26.

The differential pressure circuit depicted in Figure 4 shows that the various cylinder-piston arrangements are controlled so that the multiple cylinder-piston arrangement 23 cannot drive the pusher blade 26 up to the closed rear flap 28. This is because when the pump 60 is switched through by means of the two-way valve 61, a low pressure first builds up in the line 63 and this pressure must, according to the illustrative embodiment shown, rise to 26 bar before the switch and safety valve arrangement 64 applies pressure to the piston ring surface of the piston-cylinder arrangement 37 and the locking bolt is withdrawn. As the pressure rises further to 60 bar, the flap is pivoted upwards by means of the circuit 65 corresponding to the piston-cylinder arrangement 32, before the control 66, allotted to the multiple cylinder-piston arrangement, can be caused to respond, as a result of the pressure rising to 100 bar, and sets the pusher blade 26 in motion.

In operation, the vehicle is loaded in the conventional manner through its upper opening 67 (Figure 1). Whilst this is taking place, the rear flap 28 is closed and · 49467 the pusher blade 26 is in the front end position shown in Figure 1· After the vehicle has been loaded, the material is transported. At the end of the transportation, the hydraulic circuit shown in Figure 4 is actuated in accordance with the differential pressures described above, so that first the locking of the rear flap 28 is released, then the flap is pivoted up from its starting position, shown in Figure 1, into the end position shown in dot-dash lines, and finally the pusher blade 26 can be lo set in motion, from left to right in the arrangement shown in Figure 1, by means of the multiple cylinder-piston arrangement 23· As the pusher blade moves, the load in the box 3 is forced out backwards over the inclined surface 41· During this process, the vehicle can be 15 static or can move forwards in order to apply a layer of greater or lesser thickness, depending on the speed of unloading and the speed of travel.

According to Figure 5» the semi-trailer 71 for bulk material transport, depicted there, has a box body 2o 72 and an unloading device 73. The box is open at the top, at 74, and can therefore be loaded by means of the usual loading equipment. The unloading device works in such a way that the box 72 does not have to be tipped if the charge is being unloaded backwards, in the direction of the end wall, constructed as a pivotable flap 75, of the box 72, which is constructed as a self-supporting body. Unloading is effected by means of the box wall located at the end opposite the flep 75, which end wall is constructed as a pusher blade and is designated 76 in its entirety.

This pusher blade is inclined so that its principal plane points upwardly forwards in the direction of travel of the vehicle, indicated by the arrow 77· On its inner face, the pusher blade carries projecting guide plates 78 and 5 79, which hold the bulk material together, so that, during unloading, the material cannot escape upwards, and therefore cannot be forced out of the box 72 through the opening 74. On the outer face 80 and in the area of each side wall, 83 and 84 respectively (Figures 6 and 7) of the box io 72, the pusher blade 76 carries arms 81 and 82 respectively At the free end of the upper arms 81, an iron rod projects, as shown in Figure 7» in the direction of the particular side wall, in this case 84, and this iron rod runs under an angle profile 86. The angle profile 86 constitutes a longitudinal guide and is covered at the top by a protective plate 87· Iron rods 88, again projecting in the direction of the particular side wall, are fixed to the lower arms 82, and these, like the iron rods 85 on the upper arms, form guide fingers and cooperate with horizontal iron rods 89 which serve as lateral guides. The longitudinal guide for the components 88 and 89 on the lower arms 82 also consists of an angle section 91, which is fixed to the lower edge 90 of the particular side wall 84.

The pusher blade Is driven by a multiple telescopic cylinder 92 which is so arranged that the piston surfaces of the telescopes are subjected to pressure when the pusher blade 76 is intended to force the load out of the box 72. The connection of the pusher blade 76 to the multiple • 494 telescopic arrangement 92 is effected, as shown at 94 in Figure 5, by means of a hinge-joint;, a corresponding hinge-joint 96 serves as an abutment and is located in a frame 97 which is attached to the pusher blade side of the box 72 and serves to absorb the forces.

A locking mechanism for the flap 75 is provided on both sides of the box body and under the truck floor 99, as well as within the box section. As may be seen from Figure 6, each side of the flap is provided with a bolt 100, which is in the form of an iron rod projecting laterally from the flap 75 and cooperating with a catch hook 101. As shown in Figure 5, this, catch hook is, for its part, hinged to the body at 103 and has two arms. The other arm 104 is hinged, at 105» to a linkage rod 106 which can be adjusted to particular lengths by means of a tumbuckle 107· The linkage rod leads to the front end of the box body, where a bracket 108 is attached, which carries a horizontal hinge-joint 109 for a rocker aim 110. The free end of the rocker arm is fitted with a roller 112 which can be actuated by the free end of the corresponding lower arm 82, so that the end, hingedly connected at 114, of the linkage rod is drawn forwards. On the other hand, the linkage rod is under stress in the opposite direction from a tension spring 115, which spring is connected to the body at 116 and to the linkage rod 106 at 117· On the inner face 120, and in the upper part, of the guide plate 79, which in side view is roughly Z-shaped to S-shaped, a cam 121, fixe.dly connected to the pusher blade, is present in the area of each side wall 83, 84 of 467 the box body. This cam has an essentially upwardsloping underside 122, which is plane until it encounters a sharper curvature 123. The sharper curvature 123 extends over the entire end face of the cam 121 and merges into the convex top face 124. The two cams 121 cooperate with the inner face 125 of the flap 75, as is shown in the right-hand part of Figure 5, which depicts, in dot-dash lines, the position of the flap during emptying.

In operation, and whilst loading the box 72, the pusher blade 76 is in the front position shown in solid' lines in Figure 5· The flap 75 is closed, as shown in solid lines in the right-hand part of Figure 5· The catch hooks 101 have engaged and hold the flap 75 in its closed position by means of the bolts 100, because the roller 112 of the tilting lever 110 rests on the underside of the arms 12. In this state, the spring 115 is tensioned. When the vehicle is laden, it can he driven, for example to a waste tip. There, the drive 92 is actuated. At this stage, the flap 75 is still closed, hut the arrangement of the rollers 112 on the front ends of the arms 82 has the effect that after a short travel of the blade 76 the roller is released and as a result the spring 115 is enabled to move the linkage rod 106 to the right of Figure 5, whilst pivoting the rocker 110. As a result, the arm 104 is pivoted anti-clockwise and the hook 101 releases the holt 100. The further movement of the pusher blade then causes the load to slide over the truck floor 99, and causes the material, issuing over an inclined guide plate 128, to raise the flap 5- Whilst the material is being forced out, the flap 5 acts as a levelling blade and causes the bulk material to flow out over the guide plate 128 in a controlled maimer.

When the pusher blade 76 has moved backwards sufficiently far, its cams 121 reach the inner face 125 of the flap 75· As a result of this, the flap 75 is forcibly raised, and the remainder of the load can be expelled completely because the flap is in the position shown in dot-dash lines in Figure 5· This completes the discharge process· To make the vehicle ready to drive off again, the pusher blade drive 92 is actuated so as to apply pressure to the ring faces of the telescopic arrangements. As a result, the pusher blade 76 moves to its frontmost position. Before this is reached, the inner, face 125 of the flap slides on the curved zones 123 and 124 of the cams 121, whereby the flap is actuated and returned in the appropriately controlled manner to its closed position. Whilst this happens, the catch hooks 101 are held in their open position by the action of the springs 115· However, when the pusher blade 76 assumes its front position, its arms 82 pivot the rockers 110 via the rollers 112 and carry the arms 104 with them via the linkage rod 106, as a result of which the hooks 101 drop into the locking position.

The cams 121 are of congruent shape and are mounted, in the region of the side edges 130, 131 of the pusher blade, laterally spaced apart, in such a way that the upper guide track 124 is approximately above the upper edge of the box opening 74- The flap 75 is connected on each . 49467 side to a hinge—joint 135 by means of a bracket 136.

The hinge—joint is also above the box opening 74, and the brackets 136 are angled upwards and forwards from the plane of the flap 75· As a result, the curved section 5 123 of the cam, in particular, can open and close the flap with an advantageous transmission ratio.

Tilting of the blade in the clockwise direction, when viewed as in Figure 5, is made impossible by the guide fingers 85 being supported under the upper, hori10 zontal sidepieces 86a of the angle sections 86; in the counterclockwise direction, on the other hand, the fingers 88 on the arms 82 prevent such tilting. Together with the fingers 88a, the fingers 88 furthermore support the blade on the horizontal sidepiece 91a of the angle section. Tilting of the blade 76 about its vertical middle axis is prevented by the fingers 89, 89a on the arms 82, because of these being supported against the vertical legs 91b of the angle sections 91· The end faces of the guide fingers 85 also contribute to this guiding action by being supported against the vertical sidepieces 86b of the upper angle sections 86.

The guide fingers 85, 88 and 88a are made from lengths of iron rod, which are each welded, by one of their end faces, to the profiles of the arms, whilst the guide fingers 89, 89a, which also consist of lengths of iron rod, are welded in position by their cylindrical faces.

Figure 9 shows, in dot-dash lines, in cross-section, the skip 141 of a lorry or lorry trailer, especially of a semi-trailer, which is not shown in detail. It possesses 48467 a floor 142, and side walls 143 and 144 vertical thereto, and is otherwise open at the top. The upper longitudinal edges are furthermore provided with reinforcing profiles in box form, and these are shown at 145 and 146. Such a skip can be filled with bulk material from above, the pusher blade being located, in its starting position, directly behind the lorry cab. The pusher blade which can be seen in particular in Figures 8 and 9 is a box-like construction consisting of hollow members 147 to 149· This construction is provided, on the side facing the bulk material, with a central plate 150, located in the plane of the pusher blade, which is followed by a lower inclined guide plate 151· At the top, the central plate 150 adjoins a plate 152, which is also inclined and has an angled terminal portion 153 which prevents the bulk material from being forced upwards out of the skip when the pusher blade travels in the discharge direction marked by the arrow a in Figure 8· The lower guide plate 151 serves on the one hand to compress the bulk material in the region of 2o the pusher blade 155 between the plates 150 and 152, and on the other hand to convert the forces generated in the bottom zone of the pusher blade into a vertical component which holds the blade - which on the side facing the bulk material is inclined upwardly backwards - in the lower guide. As may be seen in Figure 13, the guide plate 151 is extended downwards by an angle-shaped stripper plate 156, which prevents fine bulk material from being left behind.

Below the two box-shaped hollow members 148 and 149 of the pusher blade 155, and at the back of the latter, is located a guide fork, of which the two prongs 158 and 159 serve as bushes for a hinge bolt 160, to which is connected a multiple-telescoping jack 161, which is shown in dot-dash lines in Figure 8 and is supported against the stationary part of the trailer body. This cylinder 161 applies the forces which move the pusher blade in the direction of the arrow a when the bulk material is forced out, and return it to its starting position after the skip 141 lo has been emptied.

These movements of the pusher blade are effected in guides consisting of stationary and of movable components As can be seen from Figure 9, angle sections 162, 163 are fixed to the inside of the vertical walls 143 and 144 of the skip at the upper longitudinal edges, that is to say next to the reinforcing sections 145 and 146. Each of the angle sections is covered at the top with an inclined plate 164, 165, which is intended to cause bulk material to slide over these guides into the skip. Since each side of the blade is provided with identical guides, it suffices to describe only one of the guides in more detail.

The guide of the pusher blade is supplemented by angle sections 166, 167, which are located in the lower corners between the skip side walls 143» 144 and the floor 1Z>2· The movable parts are in the form of sliders.

As can be seen, in particular, in Figure 10, upper arms 169 and lower arms 170 are attached to the rear face 168 of the pusher blade 155· One of the lateral guides corresponds to each of these arms· A slider 171 and a slider 171a rests on each of the arms 169, so that an arrangement in pairs results. The slider 171a is attached to the upper face 172 of the blade, whilst the slider 171 which cooperates with it is fixed to the free end 173 of the arm 169· Each slider consists of a rounded, preferably semi-cylindrical stub, with the rounded side allotted to the upper leg 174 of the corresponding angle profile 162, 163, that is to say exhibiting, relative thereto, a play b of about 5 mm. This play applies to both sliders 171 and 171a.

On its free end, at 175, the lower arm 170 carries a skid 176, which combines in itself a lateral sliding guide and a bottom sliding guide. To it corresponds a second group of guides, which are also combined with one another in one skid I77, attached in front of the blade 155, below the inclined guide plate 151. The details may be seen from Figure 11. According to this, a comer junction-plate 180 of approximately triangular shape is located on the outer lateral member or end plate I79 of the blade 155 · The lower horizontal sidepiece of the comer plate 180 carries a bracket 181, onto which the actual runner 177 is fixed by welds 182, 183. The whole is of welded construction, that is to say the bracket 181 is also welded, at 184, and the comer plate 180 Is also welded, at 185· The runner 177 has a lateral rounded portion 186, which is the transition from the bottom face 187 of the skid to its lateral guide face 188· Between this face 188 and the lateral sidepieoe 189 of the angle plate 167, on whose bottan sidepieoe 190 the runner 177 rests, there is again an amount of play b of the order of magnitude of 5 mm.

As may be seen from comparing Figures 10 and 11, the rounded portion 186 is supplemented by a lateral rounded portion 192, and the actual lateral guide faces 188 are shorter than the size of the runner, because the latter possesses lateral recesses 193 and 194· The total effect is to provide very tight guiding of the pusher blade in the four longitudinal guides consisting of angle sections. These longitudinal guides io are open at the rear end of the skip, so that the pusher blade can be inserted from this side, with the aid of a fork-lift truck· The lateral guides are also covered over. This is done by means of stripper plates, of which one may be seen at 195 in Figure 10.

Claims

1. CLAIMS ·

1. A semi-trailer body for a vehicle, in particular a lorry, for transporting bulk material, comprising a selfsupporting box body open at the top, the rear end wall of which is constructed as a pivotable flap, and a pusher blade which runs in longitudinal guides arranged along the side walls of the box body and is driven by means of a hydraulic multiple-cylinder and piston rod arrangement which is braced to the body via a horizontal joint, the pusher blade forming the other end wall of the box body, the multiple-cylinder and piston rod arrangement, which is located essentially outside the box body, being braced to a bracing frame connected to the box body and the horizontal joint being arranged on a frame crossbeam which is attached to converging side parts of the frame.

2. A semi-trailer body according to Claim 1, in which each guide consists of a channel section, with its opening facing inwards, and with its bottom adjacent the corresponding side wall of the box body, and the pusher blade comprises blocks which slide In the channel sections.

3. A semi-trailer body according to Claim 1 or 2, in which the upward-facing longitudinal wall of each channel section possesses a guide plate which runs at an angle upwards and towards the side walls.

4. A semi-trailer body according to any one of Claims 1 to 3, in which the pivotable flap possesses a pivot drive mechanism comprising a piston-cylinder arrangement, and a mechanism for locking to the box body, which mechanism comprises a piston/cylinder arrangement, the drive of the pusher blade being connected to the piston/cylinder arrangements of the rear wall flap by means of a differential pressure circuit.

5. 5. A semi-trailer body according to any one of Claims 1 to 3, in which the flap is provided with a pivot drive mechanism and possesses a mechanism for locking to the box body and in which the drive of the pusher blade serves as the (flap) pivot drive mechanism which blade carries, on its inner 10 face, cams, whose front faces and upper faces form forwardly and upwardly curved support tracks, which support the pivotable flap on its inner face, and the flap locking mechanism possesses pivoting catch hooks, hinged to the box body, and each having one linkage rod, leading to the front end wall of 15 the box body, which linkage rod cooperates with the blade when the catch hook engages in a bolt fixed to the flap, and is prestressed in the direction of release of the bolt.

6. A semi-trailer body according to Claim 5, in which the linkage rods terminate under the frame and at any given time 20 are each connected to a rocker arm, and at the same time arms are directed to the rocker arms serving to provide the longitudinal guiding of the pusher blade.

7. A semi-trailer body according to Claim 5 or 6, in which the rocker arms each carry, at their free ends, a 25 roller which rides on the lower side of the corresponding arm.

8. A semi-trailer body according to any one of Claims 5 to 7, in which tension springs, hinged to the box body and to the linkage rods, are used to prestress the latter.

9. A semi-trailer body according to any one of Claims 5 to 8, in which the cams are congruently constructed and are fixed as a pair, at a lateral distance from one another in the region of the upper edge of the pusher blade, and the hinge joints of the flap are attached to the box body at a point to the rear of, and above, the plane of the flap.

10. A semi-trailer body according to Claim 1, in which the longitudinal guides are divided into guide bars located on the upper and lower edges of the side walls, on the inside of the box body, and the pusher blade possesses, on its outside, arms which are provided with one or more fingers running along the guide bars.

11. A semi-trailer body according to Claim 10, in which the guide bars, for the corresponding arm, which are located on the lower edges of the side walls, each possess a guide track for lateral guide fingers and support fingers.

12. A semi-trailer body according to Claim 10 or 11, in which the longitudinal guides, located on the lower edges of the side walls, are inwardly open angle sections, the inner faces of whose sidepieces form the guide tracks.

13. A semi-trailer body according to any one of Claims 10 to 12, in which the upper guide bars consist of angle sections open towards the bottom, whose upper side piece is in each case covered at any given time with a guide plate, and the upper arms of the pusher blade are each provided with a guide finger which engages under the upper side piece of the angle section.

14. A semi-trailer body according to Claim 1 or any one of Claims 10 to 13, wherein angle sections open towards the top are provided in the lower comers between the box body side walls and floor, and angle sections open towards the bottom are provided at the 5 upper longitudinal edges of the box body side walls, these angle sections acting respectively as lower and upper longitudinal guides for sliders cooperating with the sections, pairs of the sliders being associated with each of the lower longitudinal guides, one slider of each pair being attached next to an inclined guide 10 plate of the pusher blade and the other being located on an arm projecting rearwardly of the pusher blade, the pusher blade having, on each side, an upper arm with at least one slider, provided thereon, for the two upper longitudinal guides, in which the sliders of each pair are combined together, in 15. One structural unit, in a runner which is supported on the bottom side piece of the angle section and is shaped to fit in such a way that its lateral face exhibits slight playrelative to the lateral side piece of the angle section, and each of the sliders corresponding to the upper longitudinal 20 guides is mounted as one of a further pair with a further slider on the arms, which are located partially under the upper longitudinal guides and parallel to these, and these sliders are in the form of rounded arms, one of the sliders of each further pair being fixed to the end of the arm and the other being fixed next 25 to the pusher blade.

15. A semi-trailer body according to Claim 14, in which the runners attached next to the inclined guide plate are fixed to lateral brackets of the pusher blade. 48467

16. A semi-trailer body according to Claim 14 or 15, in which a degree of play which corresponds to the play of the runners is provided between the rounded cams and the upper guides. 5

17. A semi-trailer body according to Claim 1, substantially as hereinbefore described with reference to or as illustrated in Figs. 1-3 of the accompanying drawings.

18. A semi-trailer body according to Claim 1, substantially as hereinbefore described with reference to or as 10 illustrated in Figs. 5-7 of the accompanying drawings.