EP0377222B1 - Extension ladder device on a mobile platform - Google Patents

Abstract

The device comprises two opposite longitudinal guides (20) fixed under the longitudinal members (21) of the chassis (2) of a lorry, behind the rear axle of the latter; a carriage (1) which moves along the abovementioned guides (20); a platform (3) mounted such that it rotates on the carriage about a vertical axis; an upper base (4) articulated onto the platform in such a way that it can oscillate in a vertical plane; and a ladder body (5) having telescopic elements (51), which is supported in a mobile manner on the said oscillating base (4). The carriage (1) is capable of assuming a first position in which the upper platform (3) is situated behind the loading platform (22) of the lorry, and a second position in which the said carriage is located within the plan profile of the abovementioned platform. <IMAGE>

Description

The subject of the present invention is a ladder device, in fact in the form of a ladder with telescopic elements, with which is associated a plate capable of moving along it, said device being suitable for being mounted retractable on a transport vehicle such as a truck.

In the field of transport in general and, more specifically, in that of transporting furniture during relocations, there is the problem of reaching the premises where the goods are to be deposited as quickly and as easily as possible. the furniture or from which it must be taken.

One evokes here for example the apartments of the floors of a building possibly without an elevator or a goods lift, or even small constructions with very close separations or other obstacles still. For moving furniture or the like towards or from such premises, devices have long been known comprising a kind of telescopic ladder with which is associated a plate capable of moving along said ladder in order to support the load to be moved.

According to a first known solution, such a device is supported by two opposite vertical plan frames which are located along the sides of a truck and which are articulated thereto along a horizontal axis oriented transversely rearward, so that the ladder is capable of being placed in a position of use in which it is located at the rear of the truck while resting on the ground, and a rest position in which this ladder is located above the truck, to a substantially horizontal orientation.

This solution turned out to be particularly bad. It should first be noted that such a device involves the use of an appropriate transport vehicle on which said device remains permanently, thereby rendering said vehicle unusable for other purposes. Furthermore, the transport unit requires personnel assigned to guide it. Thirdly, this same machine is not suitable for loading and transport operations which must be carried out very quickly. It will also be observed that the costs of acquisition and maintenance of such a transport unit is in practice prohibitive for small or medium-sized companies.

According to another known solution, the telescopic ladder is mounted on a chassis fitted with wheels in order to constitute a real trailer proper intended to be pulled by the truck for the transport of furniture. Compared to the above solution, this second solution has the advantage that the trailer (or trolley) can be detached from the truck when its use is not necessary, but the fact remains that such a carried ladder still carries a remarkably cost high which makes it unsuitable (or inaccessible) for a large number of small or medium-sized enterprises.

In addition, the traction of such a carried ladder implies, on the part of the driver of the tractor transport unit, the possession of a specific driving license which is not required for standard type trucks.

It will also be noted that the pulling of such a carriage presents problems during distant transport, especially in cities or along winding roads such as mountain roads.

The main object of the present invention is to provide a scale device capable of remedying the above-mentioned drawbacks by offering a simple, rational, reliable structural solution, of reduced weight and relatively low cost price.

The telescopic ladder device with movable platform according to the invention is defined in claim 1.

According to the invention, the structural solution suitable for achieving the above-mentioned aim comprises two opposite longitudinal guides which are intended to be fixed under the longitudinal members of the chassis of a truck, behind the rear axle of the latter, a carriage which is movable along these guides, a platform which is rotatably mounted on the carriage along a vertical axis, an upper base which is articulated to this platform so as to oscillate in a vertical plane a ladder body with telescopic elements which is movable on said base, the carriage being able to assign a first position in which the platform upper is located behind the loading platform of the truck, and a second position in which this carriage is included in the plan profile of the platform, while in the retracted position with the base lowered, the ladder is capable of assign a first position in which it projects overhang at the rear of the base and a second position in which it projects overhang forwards beyond this base, and is housed below the truck bed with its own leg folded back against the cab.

The carriage is preferably formed by two planar frames, telescopically movable one inside the other, the outer frame being engaged in the longitudinal guides while the inner frame is provided with rear two stabilizing feet to adjustable spacing and positioning.

Furthermore, according to an advantageous embodiment of the carriage, the latter is detachably associated with the longitudinal guides, the external frame being provided towards the front with at least one central stabilizing foot.

In addition, for the angular displacements of the platform, one can provide a pivot device interposed between the carriage and said platform, while the base is articulated on the latter along a transverse axis being connected to the latter by a control member, such as for example a hydraulic cylinder.

According to yet another remarkable characteristic of the invention, between the sides of the oscillating base and the outermost element of the body of the ladder are provided combined sliding guide means which, when the frame is in the lowered position and that the body of the ladder is aligned with the longitudinal axis of the loading platform of the truck, the aforementioned body is capable of being engaged below this platform, above the rear axle and the side members of the frame.

The characteristics and the structural advantages of the invention will appear in the precise description which follows and which is given with reference to the appended drawings which illustrate, by way of example, a preferred embodiment.

Fig. 1 is a perspective view from the rear showing the object of the invention associated with a truck, in the transport position, said figure comprising cutouts to better highlight elements which would otherwise be hidden.

Fig. 2 is an overall view similar to the previous one, in which the object of the invention is shown still associated with the truck, but in the extraction position, while being ready for use.

Fig. 3 is a perspective view of the object of the invention, assumed to be detached from the truck and with the ladder in the raised position, but not deployed.

Fig. 4 is a section on a larger scale along the plane IV-IV of FIG. 2, the carriage being shown in the retracted position.

Fig. 5 is a section on an even larger scale, along the plane V-V of FIG. 4.

Above all, it will be specified that in the following pages, in the absence of a specific indication to the contrary, the terms "longitudinal" or "longitudinally" and "transverse" or "transversely" will designate orientations and / or positions which are refer to the respectively longitudinal and transverse directions of a means of transport such as a truck, a van or the like.

In fig. 1, it can be seen that the object of the invention comprises, from bottom to top, a carriage 1 which is detachably associated with the rear end of the chassis 2 of a means of transport, a platform 3 which is rotatably mounted on this carriage 1 along a vertical axis, a base 4 capable of oscillating vertically while being articulated to the platform 3 along a horizontal transverse axis (as will be better understood below), and a telescopic ladder 5 along which is intended to move a plate (not shown).

As illustrated (see also fig. 2), the carriage 1 has a telescopic structure constituted by two plane frames respectively referenced 10 and 11.

The first frame 10 comprises two tubular beams which are slidably engaged in corresponding longitudinal guides 20 of C section and which are fixed under the rear ends of the beams 21 of the chassis 2, that is to say behind the rear axle from the truck. references 22 and 23 designate the platform, respectively the cab, of this truck.

In the same way, the longitudinal members of the second frame 11 are slidably engaged in the longitudinal members of the first frame 10, the front end of which is provided with projections which cooperate with corresponding limiting stops provided at the rear of the guides 20.

These limiting stops can for example be in the form of lateral locking and unlocking keys, or any other equivalent system.

In any event, according to the invention, it is provided that these stops can be deactivated in order to allow the carriage 1 to be released from the guides 20 in the manner illustrated in FIG. 3.

This arrangement is particularly advantageous when it is desired that the truck can be used without the ladder 5, or when the operational area is not accessible by the truck, for example in the case of interior courtyards or gardens.

In accordance with what has been described above, the release or engagement of the carriage 1 is operated manually, but there may be provided control means.

For example, a small hydraulic cylinder may be used, or else a drum fitted with a crank and mounted idly on the guides 20, said drum ensuring the winding of a cable whose ends are fixed to the opposite ends of the frame 10.

Once the carriage 1 has been extracted and released as shown in fig. 2, its stability is ensured by two wheels 12 which are mounted idly on two oscillating feet 13 with adjustable spacing. We can see in fig. 1 and 3 that these feet 13 have a square configuration and comprise horizontal arms which are engaged in sliding and rotation in the rear cross member of the frame 11, which is constituted by a tubular element.

Of course, means are provided to allow the blocking of the feet 13, either in the rest position or in the position of use, for example by using locks; these means have not been shown because they are obvious to any technician.

It will also be noted that the vertical arms of the feet 13 can be associated with means allowing the orientation of the wheels 12 to be adjusted, these means being able to take the form of a screw and nut mechanism.

Furthermore, the front crossmember of the frame 10 is rotatably mounted with respect to said frame and is provided with a foot 130 fitted with a terminal wheel 120. In this case also, means are provided for blocking or unblocking the foot. 130, for example a lock or key, and possibly means for adjusting the orientation of the wheel 120, such as a screw and nut mechanism. The advantages of this third wheel 120 are clearly shown in FIG. 3. It goes without saying that two wheels 120 can be provided.

Between the platform 3 and the frame 10 is provided a pivot device which is illustrated in detail in FIG. 4 and 5 and which is arranged in the rear zone of the frame 10 (see fig. 4).

In the example shown, this pivot device comprises an outer hollow body 14 with a vertical axis (see FIG. 5) which is fixed to the frame 10 of the carriage 1, an inner hollow body 15 with a cylindrical profile which is mounted for rotation, at reduced clearance, in said body 14, an outer limiting ring 16 which is associated with the lower end of the inner body 15, a sleeve 17 which is engaged and fixed on the upper end of said body 15, as well as a ring- retaining support 18 which is interposed between the body 14 and the sleeve 17, the latter being fixed to the platform 3. In the example shown, this ring 18 is made of Teflon, but it is easily understood that it is possible to make it with a bronze piece or in the form of an anti-friction pad.

It will be observed that the pivot device may be different from that shown, for example being of the type in which a circumferential series of balls is interposed between the fixed and mobile elements.

Means have also been provided for ensuring the reciprocal angular locking of the frame 10 and the platform 3. These means have not been shown because they can be easily imagined by any technician; they can for example be constituted by two superimposed circular crowns, arranged horizontally and fixed one to the frame 10, the other to the platform 3. To these crowns is associated a locking key, said crowns being pierced for this purpose a circumferential series of perforations suitable for receiving the aforementioned key.

It will also be observed that in the illustrated case, the rotation of the platform 3 is ensured manually, but it is easily understood that one can have recourse to another system. One can for example provide a rack associated with an endless screw and mounted on the frame 10, said rack meshing with the teeth of a crown provided coaxially with the pivot device by being associated with the rotating element thereof.

With particular reference to Figs. 2 and 4, it can be seen that from the front ends of the side members of the platform 3 rise corresponding ears 30 which are connected upwards by a cylindrical bar 31 (see fig. 5), the latter supporting in rotation a sleeve 32. The latter is provided in its center with two parallel levers 33 oriented obliquely and fixed downwards to a small plane frame 34, inclined and oriented longitudinally. We will also see in fig. 4 that this small frame 34 is provided at the rear with a sleeve 35 and is equipped at the front with a socket 36 internally threaded. This sleeve 35 is mounted idly on a rear cylindrical cross member 40 which joins the side members of the base 4, while the bush 36 is included between the two aforementioned levers 33 while being articulated to these along a transverse axis.

In addition, behind the ears 30, the platform 3 comprises a cross member 37 under which is mounted for rotation along a transverse axis a cage referenced 38. In the latter is engaged in rotation, while by being immobilized axially, a threaded shaft 39 the opposite end of which is introduced into the socket 36 indicated above. Under these conditions, the base 4 and the scale 5 are liable to oscillate in a vertical plane, as clearly illustrated in FIG. 3. It goes without saying that the shaft 39 extends outside of the cage 38 to constitute an external end fitting suitable for cooperating with an actuating crank (not shown); for the angular displacement of the base 4 may be provided means different from those which have been described, for example a hydraulic cylinder, in particular with manual control.

Returning to figs. 1 to 3, it will be observed that the side members of the base 4 are fixed upwards two supports 41 which are constituted by L-shaped profiles whose dihedrons face each other.

On the vertical wings of these supports 41 are fixed longitudinal sliding pads 42, made for example of Teflon or other suitable material; one of these pads is particularly visible in fig. 5.

On the pads 42 are slidably engaged two guides 50 of C section which are fixed on the lateral faces of the external elements 51 of the scale 5. More precisely, these guides 50 are provided along the rear longitudinal edges of the external elements 51 , that is to say on the part of the scale 5 which is opposite to that along which move the loads or goods to be raised or lowered. The structure is easily understood. We will confine ourselves to noting that these guides 50 could be fixed to the supports 41, while the pads 42 would then be integral with the external elements 51 of the scale 5. Furthermore, instead of pads 42, rollers can be used crazy or to pads.

As illustrated, the ladder 5 is constituted by a series of planar frames (five in number in the case considered), each of these being formed by two parallel elements 51 of C section, open one in direction of the other and whose lower wings (considered in fig. 1) are connected by a series of crosspieces 52. In order not to overload the figs. 2 and 3, only one of these crosspieces 52 has been shown; the transverse configuration of the elements 51 is clearly shown in FIG. 5.

By way of practical example, it may be indicated that the elements 51 have a length of approximately four meters, while the spacing of the crosspieces 52 is of the order of 0.5 meters.

Furthermore, the flat frames which make up the scale 5 are mutually engaged inside each other (see fig. 1, 2, 3 and 5), and are made of a particularly resistant material while being relatively light ( such as for example an aluminum alloy or the like); they are connected to each other by a length of cable suitable for deploying and folding the assembly.

This cable length has not been shown, being well known to technicians in the field considered.

It will be observed that on the lower cross member, designated under the reference 520 in FIG. 1 and 2, of scale 5, is mounted an actuation device capable of controlling the lengthening and shortening of said scale, as well as the outward and return movement of a plate intended for elevation or lowering of loads or goods along this scale. This plate and its actuating device have not been shown because they can be of any known type, in particular of those used in the devices mentioned in the preamble.

It will only be noted that the actuating device comprises an electric or hydraulic motor, provided with two opposite power take-offs with which are associated corresponding members, the implementation of which can be selected according to whether the scale 5 or the plate must be controlled. . This plate is intended to be associated (using conventional rollers for movement and guidance) with the front wings of the elements 51 of the scale 5.

Finally, it will be observed that when the supports 41 are lowered, they are in a position which is practically identical to that occupied by the upper faces of the side members 21, so that the ladder 5 can be engaged under the platform 22 of the truck, above the rear axle thereof, with its foot turned against the cabin 23. This position is well illustrated in FIG. 1 where the carriage 1 is located behind the rear axle, below the side members 21, thus being understood in the plan profile of the above-mentioned plate 22.

Obviously, means have been provided for securing the ladder 5 in the engaged (or transport) position indicated above, these means being able to be constituted by two lateral latches; the movement of the ladder along the supports 41 can be ensured manually or in any other way. One can for example provide a drum (with its operating crank) which is rotatably mounted on a support 41 and on which a cable is wound, the ends of which are fixed to the opposite ends of the outer frame of the ladder 5. As regards concerning this, it suffices to indicate that between the supports 41 and the external frame of the ladder 5 are disposed reciprocal locking means, capable of supporting the ladder in the position of use (see fig. 3 ), which means have not been shown because they can be easily imagined by any technician, for example by using transverse latches.

Claims (8)

1. Telescoping ladder device with moving platform, especially for conveyance means such as lorries, characterised by comprising in combination:

- two opposed longitudinal guides (20) designed to be set beneath the longitudinal rails (21) of a lorry frame (2), behind the rear axle thereof and inside the plane profile of the loading platform (22);

- a carriage (1) which is able to move longitudinally along the two longitudinal guides (20) and is adapted to assume a first position in which it lies to the rear of the loading platform (22), and a second position in which it is fully accommodated beneath the latter;

- an upper platform (3) which is mounted so as to rotate on the aforesaid carriage (1) about a vertical axis;

- an upper baseplate (4) which is hinged on the platform ( 3 ) about a transversely orientated horizontal shaft (31) enabling it to swing in a vertical plane;

- and a ladder body (5) with telescoping elements (51) which moves longitudinally along the swinging baseplate (4) and which is able, when it is in the retracted position and the baseplate has been lowered, to occupy a first position in which it overhangs to the rear past said baseplate, and a second position in which it overhangs to the front past the baseplate, being located above the lorry's rear axle, with its own support folded down against the lorry cab (23).

2. Device according to claim 1, characterised in that the longitudinal guides (20) have facing open C-shaped sections, while the carriage is formed by two plane supporting members (10-11) engaging telescopically inside one another, said outer member (10) slidingly engaging in the guides (20) while the rear crosspiece of said inner member (11) is provided with two lateral stabilising feet (13) which are adapted to pivot and the spacing and positioning of which are adjustable.

3. Device according to claim 2, characterised in that the carriage (1) can be run out from the longitudinal guides (20), while the front crosspiece of the outer frame (10) is provided with at least one adjustable pivoting central stabilising foot (130).

4. Device according to any of the preceding claims, characterised in that between the longitudinal guides (20) and the carriage (1) are provided means for controlling the displacement of said carriage (1) with respective said guides (20), which means may be constituted by a hydraulic jack.

5. Device according to any of the preceding claims, characterised in that the turning platform (3) is formed by a plane construction rotatably mounted with respect to the outer supporting member (10) of the carriage (1) by means of a pivot device (14-18), the latter being associated with means for controlling the rotation of said platform and for ensuring that it locks angularly in the desired orientation, which means may be constituted by a transverse rack meshing with teeth arranged concentric to the rotating element of the aforesaid pivot device (14-18).

6. Device according to claim 5, characterised in that the swinging baseplate (4) is a plane construction which at one of its ends is hinged on the platform (3) about a transverse shaft (31) opposingly situated with respect to the pivot device (14-18), and that hinged on said transverse shaft (31) is a longitudinal lever (34) in the form of a plane supporting member whose opposite ends straddle said shaft (21) and are respectively joined to the other end of the swinging baseplate (4) and to control means such as a screw and nut device (39-36).

7. Device according to claim 6, characterised in that upwardly associated with the longitudinal members of the swinging baseplate (4) are two longitudinal supports (41) of right-angled section, the lower sides of said supports, which are orientated with their dihedral angles face to face, being adapted to come level with the upper surface of the longitudinal rails (21) of the frame (2) when the baseplate (4) is lowered, and being provided on their upper sides with retaining and sliding blocks (42) designed to cooperate with C-section guides (50) set on the sides of the outer element (51) of the ladder body (5).

8. Device according to claim 7, characterised in that between the swinging baseplate (4) and the ladder body (5) are provided means for controlling the displacement of said body (5) with respect to the baseplate (4), more particularly a drum equipped with a crank handle and rotatably mounted on said baseplate, a cable being wound around said drum and the cable ends being located at the opposing ends of the outer element (51) of the ladder body (5).

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