Specifically, though not exclusively, the extractable plane is usefully applied as special equipment for commercial vehicles such as vans and the like, where it constitutes a useful loading plane, displaceable from the inside to the outside of the vehicle and vice versa.
Known extractable planes, comprising essentially a frame which is mobile in translation in two directions on a fixed frame, to which the mobile frame is slidably coupled by parallel guides, can perform the task of enabling a desired movement of goods, but usually exhibit the drawback of enabling a stable position (of the mobile loading plane with respect to the fixed part) only in some predetermined positions, in which positions a mechanical blocking, normally a friction blocking of some kind, is used to prevent relative movement of the mobile loading plane and the fixed part. When not in one of these predetermined positions, the mobile loading plane is free to slide on the fixed part.
This is the cause of numerous drawbacks which can emerge during normal use of the known-type extractable planes and means that in order to work with an acceptable degree of security the plane must be located in one of the predetermined positions, where blocking is guaranteed.
From WO 01/21040 A a pull-out shelf is known with means which allow stepless locking of the shelf in optional positions between an inner and an outer end position.
The main aim of the present invention is to realise an extractable plane which obviates the above-described drawbacks and limitations in the prior art.
An advantage of the invention is its simplicity.
A further advantage of the invention represented by the ease with which the operation can perfectly safely position the extractable loading plane in the desired position.
These aims and advantages and more besides are attained by the present invention, as it is characterised in the appended claims.
Further characteristics and advantages of the present invention will better emerge from the detailed description that follows, of a preferred but nonlimiting example of the invention, in a preferred but non-exclusive embodiment thereof, illustrated by way of example in the accompanying figures of the drawings, in which:
With reference to the figures of the drawings, they show a bottom plane of a commercial vehicle, at which an extractable plane is predisposed, which extractable plane is for moving loads from inside to outside of the vehicle, and vice versa.
The extractable plane essentially comprises a mobile frame 3 which can translate in two directions on a fixed frame 2, to which the mobile frame 3 is slidably coupled by parallel guides, from a position in which it is situated completely internally of the loading chamber of the vehicle, to a position in which it is located outside the vehicle, and vice versa.
In a first embodiment of the invention, the fixed frame 2 is characterised in that it comprises at least a longitudinal hollow seating 20, parallel to an extraction direction thereof, exhibiting a longitudinal groove 21 having a smaller width than a width of the hollow seating 20. The hollow seating 20 is of such a size as to house internally thereof, with a predetermined amount of play, a simple bar 4 which exhibits an end thereof fixed to the mobile frame 3 and bears, solidly fixed thereto, an appendage which is laterally (or radially) projecting 40, which appendage 40 is predisposed and of such a size as to exit freely from the longitudinal groove 21. The projecting appendage 40 can be arched, i.e. hook-shaped.
Special elastic means, interacting with the mobile frame 3, maintain the bar 4 rotated about an axis thereof in at least one blocking position (see figure 2), in which position the projecting appendage 40 is pressed into contact with an external surface of the fixed frame 2, close to the longitudinal groove 21 so that at least a part of the surface of the bar 4 is pressed against a part of the internal surface delimiting the hollow seating 20. Thus, due to the friction generated by the contact, an axial blocking of the bar 4 to the relative hollow seating 20 obtains, and thus of the mobile frame 3 to the fixed frame 2, which prevents movement of the one in relation to the other.
Other means, interacting between the mobile frame 3 and the bar 4, are provided for enabling a rotation of the bar 4 about an axis thereof between the blocking position and at least an unblocked position, at which the projecting appendage 40 is freely housed and slidable internally of the longitudinal groove 21.
In particular, the elastic means preferably comprise a spring 5, predisposed for interacting between the mobile frame 3 and the bar 4 in order to maintain the bar 4 rotated about an axis thereof in the blocked position in which the projecting appendage 40 is pressed in contact against the external surface of the fixed frame 2, close to the longitudinal groove in order that at least a part of the surface of the bar 4 is pressed against a part of the internal surface delimiting the hollow seating 20.
In terms of construction, the hollow seating 20, parallel to the extraction direction, and the relative longitudinal groove 21, are afforded in a length of shaped element 23 which constitutes an integral part of the fixed frame 2.
The external surface is thus simply a part of the external surface of the length of shaped element 23.
The length of shaped element 23 also affords an open longitudinal hollow seating 24, in which guide and sliding organs are coupled, by means of which the mobile frame 3 is slidably coupled to the length of shaped element 23 in the extraction direction.
In the illustrated embodiment, two of the shaped elements 23 are included in the fixed frame 2, which two shaped elements 23 are solidly constrained to one another by crossbars, and which two shaped elements 23 are symmetrically arranged with respect to a median longitudinal plane of the fixed frame 2.
Two lengths of element 33 are part of the mobile frame 3, which lengths of element 33 are identical to the lengths of element 23, are parallel to one another and are also side-by-side with and parallel to the lengths of element 23 and are thus symmetrically arranged with respect to a median longitudinal plane of the mobile frame 3.
The two lengths of element 33 are also solidly constrained to one another by at least a front crossbar 35 and by at least a back crossbar 36.
The lengths of element 23 and 33 are reciprocally side-by-side so that the respective open hollow seatings 24 and 34 are reciprocally facing in order to house the guide and sliding organs which are constituted by wheels 27 and 37.
The wheels 27 are pivoted on the lengths of element 23 and are constrained to roll in the open hollow seatings 34 of the lengths of element 33. The wheels 37 are pivoted on the lengths of element 33 and are constrained to rotate in the open hollow seatings 24 of the lengths of element 23.
The coupling of the wheels 27 and 37 in the hollow seatings 34 and 24 of the lengths of element 33 and 23 creates a reciprocal constraint of the mobile frame 3 to the fixed frame 2, by virtue of which the mobile frame 3 can move only guidedly with respect to the fixed frame 2 in a parallel direction to the lengths of element 23.
In the preferred embodiment, each of the hollow seatings 20 houses, with a predetermined amount of play, a bar 4 which exhibits an end which is axially fixed to the front crossbar 35 of the mobile frame 3 and bears, solidly constrained thereto, a projecting appendage 40.
At the ends of the bars 4, small levers 41 are constrained only axially to the crossbar 35; the small levers 41 enable a manually-commanded partial rotation of the bars 40, by an amount which is sufficient to bring them from the blocked position (in which the projecting appendage 40 is pressed in contact with the external surface close to the longitudinal groove 21 so that, by contract, at least a part of the surface of the bar 4 is pressed against a part of the internal surface delimiting the hollow seating 20), into the unblocked position (in which the single projecting appendage 40 is freely housed and slidable internally of the corresponding longitudinal groove 21).
The ergonomic arrangement of the levers 41 enables the user to manoeuvre the levers 41 using the same grip as on the crossbar 35 for displacing the mobile frame 3 with respect to the fixed frame 2.
On releasing the levers 41, the rotation induced on the bars 4 by the springs 5 immediately blocks the mobile frame 3 with respect to the fixed frame 2, in any position of extraction.
Also included, though not illustrated in the accompanying figures, is the creation of some blocking positions (for example endrun) achieved by friction connections between the projecting appendage 40 and the length of element 23. A blocking of this type is very simply achieved by including, at the desired blocking positions, incisions on the edges of the longitudinal grooves 21 in which the projecting appendages can be inserted.