Patent Description:
The present invention finds application within the sector of the construction and maintenance of tyre test tracks.

It is well known that, due to operational wear, such tracks must be periodically maintained, and often resurfaced.

However, following a resurfacing process, the roughness characteristics of the surface are evidently altered, often to the point that these are no longer such as to guarantee compliance with the regulations for the sector, and at the same time, no longer such as to ensure an adequate level of adherence.

In fact, it is known, that tests performed on tyres must be carried out under standardized conditions with respect to many parameters, including the coefficients of adhesion and surface roughness. This is in order to render all of the tests performed comparable and similar therebetween, even if performed at different times and/or in different places.

The problem of maintaining test tracks in such a way that they are constantly compliant with the regulations is therefore strong felt.

At present, one solution that has been adopted to alleviate the problem in relation to the periodic resurfacing of tracks, is to use a trolley, pulled by a vehicle (for example. a tractor), and equipped with a plurality of locked tyres, i.e., not free to rotate around the axis thereof.

The sliding of these tyres upon the road surface, typically asphalted, leads to wear, and the rubber that detaches therefrom adheres to the road surface thereby improving the characteristics thereof in terms of grip and roughness, thus preserving a condition of compliance with the test regulations for longer.

Such a system has the obvious drawback however that the tyres, in the area of contact with the asphalt, undergo severe wear, until reaching the point wherein a flat-spot is formed on the tread.

The trolley is therefore equipped with a mechanism that makes it possible for the tyres to be rotated at such an angle that a new portion of tread faces the asphalted surface. Such a rotation operation must however be performed manually, wheel by wheel. This involves a series of manual processes that slow down the surface maintenance operation and therefore the productivity and efficiency of the treatment process. In particular, in order to be able to adjust the position of the wheels every time, it is necessary to:.

These operations are then repeated for each tyre or tyre carrier axle of the trolley.

<CIT> discloses a wheeled towable structure comprising the features of the preamble of independent claim <NUM>.

The purpose of the present invention is, therefore, to solve those problems left unresolved by the prior art, by providing a towable structure as defined in claim <NUM>. Further characteristics of the present invention are defined in the corresponding dependent claims.

In particular, one object of the present invention is to speed up those operations necessary for the rotation and locking of the tyres so as to render the entire treatment process more continuous, faster, and therefore more efficient.

Other clear advantages over the prior art, together with the characteristics and usages of the present invention, will become clear from the following detailed description of the preferred embodiments thereof, given purely by way of a non-limiting example.

Reference will be made to the drawings in the attached figures, wherein:.

The present invention will be described below with reference to the above figures. Referring first to <FIG> and <FIG>, a possible embodiment of a towable wheeled structure <NUM>, according to the present invention, comprises a frame <NUM> on which a plurality of groups of wheels <NUM> are mounted.

In the following part of the present description, and for all of the embodiments described, the same numerical references will be attributed to the parts of each group of wheels.

Each group <NUM>, in turn, comprises one or more rubber wheels <NUM>, equipped with tyres, and mounted so at to rotate at a respective wheel axis A.

Preferably, each group of wheels <NUM> comprises two coaxial, paired rubber wheels <NUM>. Furthermore, the towable structure <NUM> comprises means <NUM>, <NUM>', <NUM>, <NUM>', <NUM> for locking the rotation of the wheels <NUM> of each group of wheels <NUM> at a plurality of predetermined angular locking positions.

The structure provides means for actuating the means for locking the rotation of the rubber wheels <NUM>, configured in such a way as to allow the wheels <NUM> of each group to rotate from one locking position to another, during the operation of said towable structure.

The following <FIG> and <FIG> refer to a second possible embodiment of the present invention, according to which a towable structure <NUM> further comprises a pair of maneuvering wheels <NUM>, connected to the frame <NUM> by means of an articulated mechanism <NUM> which, when operated, allows for the positioning of the maneuvering wheels <NUM> in at least two positions.

The two positions are respectively illustrated in the following <FIG> and <FIG>.

In a first treatment position (<FIG>) the maneuvering wheels <NUM> are raised from the ground, and the rubber wheels <NUM> are therefore in contact with the ground.

In a second maneuvering position (<FIG>), the maneuvering wheels are in contact with the ground, whilst the rubber wheels <NUM> are raised from the ground. The maneuvering wheels <NUM> are mounted idling upon the respective axes thereof. In this second maneuvering position, therefore, the structure <NUM> can be more easily towed and maneuvered upon the maneuvering wheels <NUM>, without the rubber wheels <NUM>, which are usually locked in rotation, offering resistance to towing.

According to both embodiments described up to now, the structure <NUM>, <NUM> can advantageously comprise - as shown in <FIG> - a plurality of hydraulic jacks <NUM> for lifting the structure itself, so that the rubber wheels <NUM> are detached from the ground. This is particularly useful and advantageous, for example, in order to be able to easily replace the tyres of the rubber wheels <NUM>, and/or in order to perform other maintenance operations upon the structure and/or upon the group of wheels <NUM>.

In each of the possible embodiments, the number and arrangement of the group of wheels <NUM> can be chosen on the basis of the sizing of the structure and on the basis of the treatment coverage to be obtained.

For example, in the embodiments described, the groups of wheels <NUM> are arranged upon six axes A, parallel to each other and orthogonal to a towing direction T of the structure <NUM>, <NUM>.

According to a preferred embodiment, the group of wheels <NUM> are distributed on each of said six parallel axles A, such that the footprint of the rubber wheels <NUM> of groups on different axes partially overlaps to fully cover the overall gauge S of the towable structure <NUM>, <NUM>. The term overall gauge S refers to the distance S between the outer faces of the two outermost rubber wheels <NUM>, along a direction orthogonal to the towing direction T. This arrangement is exemplified in <FIG> and <FIG>.

According to a possible embodiment, eight groups of wheels <NUM> are envisaged, arranged staggered as described above, thus making it possible to cover an overall gauge of about <NUM> meters.

The following <FIG> and <FIG> show a group of wheels <NUM>, respectively in perspective and exploded view.

According to a preferred embodiment of the present invention, the rubber wheels <NUM> of each group of wheels <NUM> are rotationally integral therebetween, mounted on the common wheel axis A.

The group of wheels <NUM> is mounted on a small frame <NUM> that is rendered integral to the frame <NUM> of the towable structure <NUM>, <NUM>.

The means for locking the rotation of the wheels <NUM> comprise a pair of flanges <NUM>, <NUM>', coaxially therebetween, and mounted in such a way as to rotate integrally around a flange axis F.

The flanges <NUM>, <NUM>' are equipped with a plurality of slots that are denoted respectively by the numbers <NUM> and <NUM>' in the figures.

Furthermore, the locking means also comprise a pair of pins <NUM>, <NUM>', integral with the frame <NUM>, and adapted to interfere, when operated, each with the slots <NUM>, <NUM>' of one of the flanges <NUM>, <NUM>'.

Furthermore, the locking means comprise a transmission system <NUM>, for example a crown and chain mechanism, that connects the flange axis F to the wheel axis A, thereby rendering them integral in rotation.

The mechanism for locking the rotation of the wheels <NUM>, the operation thereof will be described in greater detail below, has the already anticipated function of making it possible to lock the rotation of the wheels <NUM> of each group of wheels <NUM> at a plurality of predetermined angular locking positions.

Advantageously, the locking means can be operated in such a way as to allow for the rotation of the wheels <NUM> of each group from one locking position to another, during the operation of said towable structure, without interrupting the road surface treatment operations.

The following <FIG> and <FIG> show a tyre of the group of wheels <NUM>, whereupon, purely by way of example and for the sole purposes of this description, indications are given in relation to possible sectors of a tyre and corresponding to as many predetermined positions. In the example, there are twelve positions, numbered from '<NUM>' to '<NUM>', each therefore corresponding to twelve angular sectors <NUM>, each of <NUM>°.

As illustrated in the subsequent <FIG>, the slots <NUM>, <NUM>' are made at the peripheral circumference of each flange <NUM>, <NUM>', equally distributed along such a circumference.

Preferably, the slots <NUM>, <NUM>' all have the same length P along the circumference.

Furthermore, the flanges <NUM>, <NUM>' of the same pair of flanges of the same group of wheels <NUM> are mounted out of phase with respect to one another such that the beginning of each slot <NUM> on a first flange <NUM> corresponds to the end of a slot <NUM>' on a second flange <NUM>'. In this way each point of correspondence between the slots <NUM>, <NUM>' defines a corresponding predetermined position. According to the example described above, <FIG> show the two flanges <NUM>, <NUM>', each thereof envisages six only (respectively indicated by <NUM> and <NUM>') equally angularly spaced therebetween by <NUM>°.

The two flanges <NUM>, <NUM>' are mounted out of phase as shown in the figure, in such a way that the points of correspondence of the respective slots determine the twelve predetermined positions (again numbered from' <NUM> 'to' <NUM> ') corresponding to the twelve tyres sectors.

<FIG> shows the two flanges <NUM>, <NUM>' superimposed, in partial transparency, in order to clearly show the points of correspondence of the slots <NUM>, <NUM>' and therefore the twelve predetermined positions.

The rotational blocking, as already clarified, occurs by means of two pins <NUM>, <NUM>' which, when actuated, interfere respectively with one of the slots <NUM>, <NUM>' of the flanges <NUM>, <NUM>', thereby causing it to be blocked in rotation. The actuation of the pins is preferably performed by the actuation means which comprise a hydraulic actuation mechanism for the pins. Here it can be assumed that the hydraulic actuation component of the pins is within the reach of a person skilled in the art who will be able to choose the correct hydraulic actuators and size the circuit appropriately, without having to provide the details thereof herein. The hydraulic force for supplying these components can, for example, be taken from a tractor that pulls the structure, by means of a power take-off shaft thereof.

In order to illustrate in more detail what has just been described, the following <FIG> shows some components in partial transparency.

The following figures from 14A to 14C illustrate the passage from one predetermined position to another predetermined position.

The two pins <NUM>, <NUM>' operate alternately. <FIG> shows the pin <NUM>' which interferes, considering the direction of rotation R of the parts indicated in the figure, with one end of a slot <NUM>' of the flange <NUM>'. This interference evidently blocks the flange <NUM>' in rotation. Insofar as the flange <NUM>' is integral in rotation with the wheels <NUM>, the wheels <NUM> are also blocked due to such interference at the predetermined position corresponding to the sector <NUM> denoted by '<NUM>' on the tyre.

During this step, the pin <NUM> is not operational and does not perform any function and therefore can - as in the figure - be retracted without interfering with the corresponding slot <NUM> of the flange <NUM>.

The following <FIG> shows a transition step, between one position and another.

During this step, the two pins <NUM> and <NUM>' reverse the function and position thereof. The pin <NUM>' retracts and relinquishes the interference and locking function, whilst the pin <NUM> extends and interferes with the slot <NUM> of the flange <NUM>.

In this position, obviously, the flanges <NUM>, <NUM>', and therefore the wheels <NUM>, can rotate according to the direction of rotation R indicated in the figure.

Claim 1:
Wheeled towable structure (<NUM>, <NUM>), comprising:
• a frame (<NUM>) on which a plurality of groups of wheels assemblies (<NUM>) are mounted, each group (<NUM>) comprising one or more rubber wheels (<NUM>), equipped with tyres and mounted so as to rotate at a respective wheel axis (A);
• means (<NUM>, <NUM>', <NUM>, <NUM>', <NUM>) for locking the rotation of the wheels of each group of wheels (<NUM>) in predetermined locking positions;
• means for actuating said means (<NUM>, <NUM>', <NUM>, <NUM>', <NUM>) for locking the rotation of the rubber wheels (<NUM>), configured to move the wheels of each group (<NUM>) from a locking position to another during the movement of said towable structure (<NUM>, <NUM>),
characterized in that said means (<NUM>, <NUM>', <NUM>, <NUM>', <NUM>) for locking the rotation comprises a pair of flanges (<NUM>, <NUM>') coaxially mounted so as to rotate integrally around a flange axis (F) and respectively equipped with a plurality of slots (<NUM>, <NUM>'), and a pair of pins (<NUM>, <NUM>') integral with a frame (<NUM>) of said group of wheels (<NUM>) and adapted to interfere, when operated, each with the slots (<NUM>, <NUM>') of one of said flanges (<NUM>, <NUM>'), said means (<NUM>, <NUM>', <NUM>, <NUM>', <NUM>) further comprising a transmission system (<NUM>) which connects said flange axis (F) to said wheel axis (A).