Patent Description:
In particular, the invention relates to a system for the movement of a balustrade of an ice rink, preferably a hockey rink, between two possible configurations.

The invention is also related to a method for the movement of at least one partition, in particular of a partition of a balustrade of an ice rink.

The International Ice Hockey Federation currently establishes that ice hockey rinks must extend for a length of <NUM> metres and a width varying between <NUM> metres (primarily used in North America) and <NUM> metres (primarily used in Europe and in the rest of the world).

Usually, the training buildings comprise hockey rinks of both measurements to allow players to train both according to the North American game style, and according to the European style.

Rarely, in fact, the perimeter balustrade delimiting the playing field is repositioned to vary the dimensions of the hockey rink because it would require performing maintenance on the entire surface of ice for each repositioning. In fact, performing this procedure envisages constraining the components of the balustrade directly on the surface of ice, inevitably forming ruts or dams that must be covered over and smoothed following a repositioning.

Alternatively, as shown in the patent document <CIT>, an ice hockey rink can be constituted by a plurality of modules arranged consecutively to each other by an operator, who also has the task of laying a covering sheet containing a quantity of water to be frozen so as to form the surface of the hockey rink.

Similarly to the previous one, this procedure requires a considerable amount of time for the preparation of the playing field, and consequently, also high costs for its formation and maintenance.

Another known prior art is disclosed in document <CIT>.

In this context, the technical task underpinning the present invention is to provide a system for the movement of at least one partition that obviates the drawbacks of the prior art mentioned above.

An object of the present invention is to provide a system for the movement of at least one partition, in particular the partition of a balustrade of an ice rink, through which it is possible to carry out the displacement of at least one partition in a simple and fast manner and which does not require periodic maintenance operations following each displacement.

In particular, an object of the present invention is to provide a system for the movement of at least one partition through which the dimensions of an ice rink can be reduced in the shortest possible time and with the minimum effort in order to further improve the quality of the players' trainings in the various conditions (i.e. in the various configurations of the rink).

Another object of the present invention is to provide a method for the movement of at least one partition of a balustrade of an ice rink, in particular a hockey rink.

The stated technical task and specified objects are substantially achieved by a system and a method for the movement of at least one partition, which comprise the technical features disclosed in the independent claim. The dependent claims correspond to further advantageous aspects of the invention.

It should be highlighted that this summary introduces, in simplified form, a selection of concepts which will be further elaborated in the detailed description given below.

The invention is related to a system for the movement of at least one partition, in particular a partition of a balustrade of an ice rink. The system comprises at least one partition that extends vertically upwards from a support surface between a lower portion thereof and an upper portion thereof. In addition, the system comprises at least one movement member associated with the partition and configured to move the latter between a first operating position and a second operating position along a movement direction substantially parallel to the support surface. In particular, the movement member comprises a first fixed portion with respect to the support surface and a second movable portion, approaching or moving away, with respect to the first fixed portion. The second movable portion is connected to the partition at least in a movement condition of the movement member, wherein the second movable portion moves away from or approaches the first fixed portion, so as to move the partition on the support surface between the first operating position and the second operating position.

The system also comprises a control unit of the movement member operatively connected to the latter to move the second movable portion in an automated manner.

A balustrade for an ice rink, in particular a hockey rink, comprises a plurality of systems for the movement of at least one partition described previously. In particular, the partitions are mutually connected consecutively and are arranged at the perimeter to delimit the playing field, preferably having a shape of a quadrilateral. The movement members are arranged outside the playing field and each of them is associated with at least one partition. In fact, the latter are configured to move the partitions along the movement direction between the respective first operating position and the respective second operating position so as to modify the surface extension of the playing field, respectively, between a maximum configuration, wherein said partitions in the first operating position define a widened perimeter, and a minimum configuration, wherein the partitions in the second operating position define a restricted perimeter compared to the widened perimeter.

A method for the movement of at least one partition, in particular the partition of a balustrade of an ice rink, from a first operating position thereof to a second operating position thereof, comprising the steps of:.

Further characteristics and advantages of the present invention will become clearer from the indicative, and therefore non-limiting, description of a preferred but not exclusive embodiment of a system for the movement of at least one partition, as illustrated in the appended drawings, in which:.

With reference to the drawings, they serve solely to illustrate embodiments of the invention with the aim of better clarifying, in combination with the description, the inventive principles at the basis of the invention.

The present invention is addressed to a system for the movement of at least one partition, in particular a partition of a balustrade of an ice rink. With reference to the figures, the system for the movement of at least one partition has been generically indicated by the number <NUM>, while a balustrade has been generically indicated by the number <NUM>.

The other numerical references refer to technical features of the invention which, barring indications otherwise or evident structural incompatibilities, the person skilled in the art will know how to apply to all the variant embodiments described.

Any modifications or variants which, in the light of the description, are evident to the person skilled in the art, must be considered to fall within the scope of protection established by the present invention, according to considerations of technical equivalence.

<FIG> shows a system <NUM> for the movement of at least one partition <NUM>, in particular the partition <NUM> of a balustrade <NUM> of an ice rink.

The system <NUM> comprises at least one partition <NUM> that extends vertically upwards from a support surface S, between a lower portion <NUM> thereof and an upper portion <NUM> thereof.

The system <NUM> further comprises at least one movement member <NUM> associated with the partition <NUM> and configured to move the latter between a first operating position and a second operating position along a movement direction M substantially parallel to the support surface S. In particular, the movement member <NUM> comprises a first fixed portion <NUM> with respect to the support surface S and a second movable portion <NUM>, approaching or moving away, with respect to the first fixed portion <NUM>. In addition, the second movable portion is connected to the partition <NUM> at least in a movement condition of the movement member <NUM>, so as to move the partition <NUM> on the support surface S between the first operating position and the second operating position.

Preferably, the support surface S comprises a sheet of ice of predefined thickness, below which devices are placed that are provided for cooling and maintaining the freezing temperature of the sheet of ice. According to one aspect of the invention, the support surface S defines an ice rink, such as for example a hockey rink. Even more preferably, therefore, the first and the second operating positions of the partition <NUM> are located above the support surface S. The movement member <NUM> is instead arranged outside the support surface S, at an adjacent treadable surface C which extends in a coplanar manner as an extension of the support surface S.

Finally, the system <NUM> comprises a control unit <NUM> of the movement member <NUM> operatively connected to the latter to move the second movable portion <NUM> in an automated manner. In other words, the control unit <NUM> is configured to manage the movement of the second movable portion <NUM> with respect to the first fixed portion <NUM>, and therefore the movement of the partition <NUM> between the first and the second operating positions.

According to one aspect of the invention illustrated in <FIG> and in <FIG>, the system <NUM> comprises connection members interposed between the partition <NUM> and the second movable portion <NUM> of the movement member <NUM>. Preferably, the connection elements comprise a hook <NUM> arranged at the second movable portion <NUM> and a pin <NUM> arranged at the lower portion <NUM> of the partition <NUM>. In particular, the hook <NUM> and the pin <NUM> form a shape coupling to define the connection between the movement member <NUM> and the partition <NUM> during the movement of the latter between the first and the second operating positions.

According to one aspect of the invention, the movement member <NUM> can be configured between a retracted condition (<FIG>) and an extended condition (<FIG>). In the retracted condition the second movable portion <NUM> is arranged at a closer distance with respect to the first fixed portion <NUM>, while in the extended condition the second movable portion <NUM> is arranged farther away from the first fixed portion <NUM> with respect to the retracted condition.

The movement of the second movable portion <NUM> from the retracted position to the extended position determines the movement of the partition <NUM> from the first operating position towards the second operating position, as a result of the connection of the latter with the second movable portion <NUM>. Alternatively, as will be explained in greater detail below, when the partition <NUM> is in the second operating position or in an intermediate position between the first and the second operating positions, the movement from the retracted condition to the extended condition of the second movable portion <NUM> is performed to again connect the same second movable portion <NUM> with the partition <NUM> so as to move the latter either to the second operating position or to the first operating position as a function of the starting position.

According to another aspect of the invention, the movement member <NUM> in the retracted condition can be configured between an operating retracted position (<FIG>) and a resting retracted position (<FIG>). In the operating retracted condition the movement member <NUM> is arranged above the extension of the support surface S (i.e. the treadable surface C) so that the second movable portion <NUM> faces the lower portion <NUM> of the partition <NUM> to be connected thereto. Instead in the resting retracted condition, the movement member <NUM> is arranged in a housing <NUM> afforded below the extension of the support surface S (i.e. the treadable surface C).

In other words, the movement member <NUM> can advantageously be positioned in the housing <NUM> when its use is not necessary, i.e. when the partition <NUM> must not be moved. Even more advantageously, the housing <NUM> is afforded below the treadable surface C to avoid being a hindrance to an operator passing in the vicinity of the partition <NUM>.

According to a preferred aspect of the invention illustrated in the figures from <NUM> to <NUM>, the system <NUM> comprises a box-shaped body <NUM> which is shaped so as to contain the movement member <NUM> at least in the resting retracted condition.

Preferably, as can be seen in <FIG>, <FIG>, the box-shaped body <NUM> is inserted into the housing <NUM> afforded below the treadable surface C at the movement member <NUM>. In this way, when the movement member <NUM> is in the resting retracted condition inside the box-shaped body <NUM>, the latter can be advantageously closed with a cover to define a treadable surface C for an operator which continues outside the support surface S of the playing field.

Preferably, the movement member <NUM> is simply arranged inside the box-shaped body <NUM> to be moved manually from the resting retracted position to the operating retracted position, and vice versa, as long as the inside of the box-shaped body <NUM> is accessible to an operator. In other words, the movement member <NUM>, as better visible in <FIG>, can be constrained by an operator to a transverse bracket present inside the box-shaped body <NUM> so as to be provided in the operating retracted position. Alternatively, the movement member <NUM> is connected to the internal walls of the box-shaped body <NUM> by means of the hinges arranged on a side of the box-shaped body <NUM> itself. Advantageously, the hinges allow the movement of the movement member <NUM> between the resting retracted condition and the operating retracted condition in manual or automatic mode.

According to a further aspect of the invention, the movement member <NUM> in the extended condition can be configured between an intermediate extended condition and a final extended condition. In the intermediate extended condition, the second movable portion <NUM> is farther away from the first fixed portion <NUM> such that the partition <NUM> is in an intermediate position between the first operating position and the second operating position. Instead in the final extended condition, the second movable portion <NUM> has the maximum possible distance from the first fixed portion <NUM> and, at the same time, the partition <NUM> is in the second operating position.

According to one aspect of the invention, when the movement member <NUM> abuts in the final extended condition, the partition <NUM> is located in an intermediate position between the first and the second operating positions. The system <NUM> thus comprises an extension rod <NUM> that can be installed between the second movable portion <NUM> and the partition <NUM> for moving the latter in the second operating position. As explained in greater detail below, the interposition of the extension rod <NUM> takes place with the partition <NUM> arranged in the intermediate position and the movement member <NUM> in the operating retracted condition.

Preferably, the extension rod <NUM> and the second operating portion <NUM> are two elements which have the same shape and are thus interchangeable.

According to one aspect of the invention shown in the accompanying figures, the first fixed portion <NUM> comprises a cylinder <NUM> and the second movable portion <NUM> comprises a piston <NUM> slidably inserted along the cylinder <NUM>. In detail, the cylinder <NUM> extends between a first end <NUM> thereof and a second end <NUM> thereof along a direction transversal to the partition <NUM>. The piston <NUM> is instead projecting with respect to the cylinder <NUM> at least when the movement member <NUM> is in the extended condition. When the movement member is located in the retracted condition, the piston <NUM> is inserted totally or nearly totally (for example, excluding the end which can be connected with the partition <NUM> to which the hook <NUM> can be connected) inside the cylinder <NUM>. Instead in the extended condition, the piston <NUM> is further extracted from the cylinder <NUM> with respect to the retracted condition such that it can be connected to the partition <NUM>.

Preferably, the piston <NUM> used is of the double-effect type such that it can slide in both directions of the movement direction M.

According to another aspect of the invention, the cylinder <NUM> and the piston <NUM> substantially have the same longitudinal extension.

Preferably, the longitudinal extension of the piston <NUM> is approximately equal to half the distance between the first and the second operating positions of the partition <NUM>.

Even more preferably, the movement member <NUM> comprises a cylinder <NUM> and two pistons <NUM>, of which one is the extension rod <NUM> and is installed in order to move the partition <NUM> from the intermediate position to the second operating position, or vice versa.

According to a further aspect of the invention, the box-shaped body <NUM> has a longitudinal extension at least equal to that of the cylinder <NUM> and, in addition, the cylinder <NUM> is inserted in the box-shaped body <NUM> and constrained by means of one or more hinges which allow extraction. Alternatively, according to an aspect not shown, the first fixed portion <NUM> comprises a pinion and the second movable portion <NUM> comprises a rack slidably movable with respect to the pinion. In detail, the rack extends along a direction transversal to the partition <NUM> between a first end thereof and a second end thereof that can be connected to the partition <NUM>. According to one aspect of the invention, the system <NUM> comprises at least one motor associated with the movement member <NUM> and configured to move the second movable portion <NUM> closer or farther away with respect to the first fixed portion <NUM>. Preferably, the motor is of the hydraulic or pneumatic or electric type.

Advantageously, the control unit <NUM> is connected to the motor (or motors if more than one is present) to actuate the movement member <NUM> in a controlled and automated manner.

Even more advantageously, through the motor(s) present, the control unit <NUM> is configured to start the movement of all the movement members <NUM> (in the case where there is more than one) connected to the respective partitions <NUM>.

According to one aspect of the invention illustrated in <FIG>, the partition <NUM> comprises a sliding rail <NUM> arranged below the lower portion <NUM> and interposed with the support surface S to make the same partition <NUM> slide along the movement direction M.

Preferably, the sliding rail <NUM> comprises a plate made of polymeric or plastic material and such as to allow the reduction of the friction with the support surface S and thus facilitate the sliding of the partition <NUM> between the first and the second operating positions.

According to a further aspect of the invention, the movement device <NUM> is also configured to lift the partition <NUM> during the movement between the first and the second operating positions.

An alternative embodiment (not shown) envisages providing a crane or a hoist, or a system of pulleys so as to lift the partition <NUM> even only a few centimetres, so as to move it between the first and the second operating positions without causing direct contact with the support surface S. In other words, according to the present embodiment, the movement member <NUM> is configured to raise the partition <NUM> according to a substantially vertical direction so as to lift it in relation to the support surface S and to then move it along the movement direction M (substantially horizontal) towards the first, the second or an intermediate operating position, before lowering it again in contact with the support surface substantially along the aforementioned vertical direction.

The crane, the hoist or the system of pulleys comprises a constrained portion in an integral position with respect to the support surface S and a connection portion able to join or grasp the partition <NUM> to move it. Advantageously, the constrained portion of the crane, the hoist or the system of pulleys is firmly connected to a surface external to the support surface S, or to a vertical wall or to the ceiling of a possible structure in which the system <NUM> is provided.

<FIG> and <FIG> illustrate a balustrade <NUM> for an ice rink, in particular a hockey rink, which comprises a plurality of systems <NUM> described previously. In particular, the partitions <NUM> are mutually connected consecutively and arranged at the perimeter to delimit the playing field. Preferably the partitions <NUM> are arranged in such a way as to define a perimeter substantially having the shape of a quadrilateral. For a hockey rink, in fact, the shape to be obtained is that of a rectangle with rounded corners.

Outside the ice rink, and therefore outside the perimeter defined by the partitions <NUM> that delimits the support surface S, the treadable surface C is defined on which a plurality of movement members <NUM> is arranged, each of which is associated with at least one partition <NUM>. The movement members <NUM> are configured to move the partitions <NUM> along the movement direction M between the respective first operating position and the respective second operating position so as to modify the surface extension of the playing field, respectively, between a maximum configuration (<FIG>) and a minimum configuration (<FIG>).

In the maximum configuration, the playing field has a maximum surface extension (in the case of a hockey rink, for example, the allowed maximum according to the regulations and used mainly in Europe) and consequently the partitions <NUM> are arranged in the first operating position to define a widened perimeter. In the case of a hockey rink, the playing field has a first width L1 represented by the two short sides of the perimeter.

Instead in the minimum configuration, the playing field has a minimum surface extension (in the case of a hockey rink, for example, the allowed minimum according to the regulations, used mainly in North America) and consequently the partitions <NUM> are arranged in the second operating position to define a more restricted perimeter with respect to the widened perimeter of the maximum configuration. In the case of a hockey rink, the playing field has a second width L2, less than L1, still represented by the two short sides of the perimeter.

According to one aspect of the invention, the balustrade <NUM> comprises at least one pair of removable partitions <NUM> arranged on two opposite sides of the perimeter of the playing field. In particular, each removable partition <NUM> is arranged on the two sides of the perimeter that can be shortened to modify the surface extension of the playing field from the maximum configuration to the minimum configuration.

Preferably, the removable partitions <NUM> are arranged opposite to each other with respect to a longitudinal or transverse plane that crosses the playing field.

Even more preferably, in the case of a hockey rink for example, the removable partitions <NUM> are arranged on the sides of the perimeter that define the width of the playing field and, therefore, are opposite to each other with respect to a plane perpendicular to the length of the playing field.

The removable partitions <NUM>, therefore, virtually divide the perimeter of the balustrade <NUM> into two disjointed half-perimeters. In other words, a virtual straight line drawn to join the opposite removable partitions <NUM> affects the perimeter by dividing it into two opposite parts.

According to one aspect of the invention, the movement direction M is parallel to the two sides of the perimeter on which the pair of removable partitions <NUM> is arranged and, consequently, is perpendicular to the other sides of the perimeter.

Thus, as better explained below, the movement members <NUM> are configured to move the two half-perimeters mutually closer to or farther away from each other along the movement direction M.

In particular, they move closer if the removable partitions <NUM> have been removed and the playing field must be restricted in the minimal configuration, while they move father away to insert the removable partitions <NUM> so as to expand the size of the surface of the playing field in the maximum configuration.

According to one aspect of the invention illustrated in <FIG> and in <FIG>, sixteen movement members <NUM> are arranged around the balustrade <NUM>, divided equally between the two half-perimeters.

A respective movement segment <NUM> is arranged for each curved portion of the balustrade <NUM>, while there are six remaining movement segments <NUM> for the comprised rectilinear segments substantially defining the length of the playing field, each of which is associated with a respective partition <NUM>. Advantageously, the control unit <NUM> is configured to simultaneously activate each movement member <NUM> so as to simultaneously move each partition <NUM> defining a half-perimeter.

In this way, therefore, the half-perimeters are moved mutually.

According to one aspect of the invention, a first portion of the plurality of partitions <NUM> has a transverse planar extension, while a second portion of the plurality of partitions <NUM> has a transverse curved extension. Advantageously, the planar partitions <NUM> are mutually interchangeable and define the straight segments of the perimeter, while the curved partitions <NUM> are mutually interchangeable and define the curved segments of the same perimeter.

Preferably, the removable partitions <NUM> are planar partitions <NUM>.

With regard to an operating example of the system <NUM> for the movement of at least one partition <NUM>, shown in <FIG>, it derives directly from what is described above and which is referred to below.

To move a partition <NUM> from a first operating position thereof to a second operating position thereof, it is necessary to provide the partition <NUM> on the support surface S and at least one movement member <NUM> on the treadable surface C such as to constrain the first fixed portion <NUM> and connect the second movable portion <NUM> to at least the partition <NUM>.

The control unit <NUM> is then configured to move farther away, by means of a possible motor, the second movable portion <NUM> from the first fixed portion <NUM> along the movement direction M. Consequently, the partition <NUM> connected to the movement member <NUM> is made to translate from the first operating position to the second operating position.

According to one aspect of the invention, the same movement member <NUM> must be previously extracted from the housing <NUM> and/or from the box-shaped body <NUM> if it is arranged in its interior in the resting retracted condition. In this way, the movement member <NUM> is provided above the treadable surface C such that the second movable portion <NUM> is connected to the partition <NUM> to be moved.

In the case wherein the movement of the second movable portion <NUM> between the retracted condition and the final extended condition does not allow the movement of the partition <NUM> in the second operating position, it is envisaged that the second movable portion <NUM> is disconnected from the partition <NUM> such that the movement member <NUM> is returned to the operating retracted condition. Hereinafter, an extension rod <NUM> is interposed and connected between the second movable portion <NUM> and the partition <NUM>. A subsequent further configuration of the movement member <NUM> in the final extended condition involves the movement of the extension rod <NUM> along the movement direction M and therefore of the partition <NUM> from the intermediate position to the second operating position.

The provision of a plurality of partitions <NUM> mutually connected perimetrally to form a balustrade <NUM> and to delimit a playing field determines that the plurality of movement members <NUM> are positioned outside the playing field, at the treadable surface C. In particular, the movement members <NUM> are equally distributed along the perimeter of the playing field, having a substantially rectangular shape with rounded corners.

Preferably, there are two pairs of removable partitions <NUM> along the two shorter sides of the perimeter. In other words, for each short side (which also determines the width of the playing field) two removable partitions <NUM> are preferably present, each having a width of two metres.

In addition, the removable partitions <NUM> divide the perimeter into two disjointed half-perimeters, each comprising two curved segments and a straight section which defines the length of the playing field (i.e. corresponding to a long side of the perimeter).

As a result of the removal of the two pairs of removable partitions <NUM>, the two half-perimeters of the balustrade <NUM> are spaced apart by a distance of about four metres.

According to one aspect of the invention, eight movement members <NUM> are uniformly arranged along each half perimeter to move it entirely along the movement direction M for a distance of two metres so as to move it closer to the opposite half-perimeter and reduce the extension of the playing field from the maximum configuration to the minimum configuration.

Each movement member <NUM> is installed in a housing <NUM> afforded at the level of the treadable surface C, preferably in a box-shaped body <NUM> arranged inside the housing <NUM>.

In order to move the two disjointed parts of the balustrade <NUM>, therefore, the cover of each box-shaped body <NUM> must be opened and the respective movement member <NUM> must be moved from the resting retracted condition to the operating retracted condition, in which it faces a respective partition <NUM> above the treadable surface C such that the second movable portion <NUM> is connected to the same partition <NUM>.

In addition, each movement member <NUM> is connected to the control unit <NUM> which manages the movement of each partition <NUM> of the balustrade <NUM> in an automated and preferably simultaneous manner.

Preferably, therefore, the balustrade <NUM> is fixed in position with horizontal uprights <NUM> to prevent an undesired movement. The uprights <NUM> are arranged parallel to the support surface S and the treadable surface C and, moreover, are constrained to the latter in addition to the partitions <NUM> to define a rigid and robust connection.

Once the extension of the playing field is reduced from the maximum configuration to the minimum one and the uprights <NUM> are provided to lock the partitions <NUM>, part of the ice support surface S extends beyond the balustrade <NUM>. To allow the safe passage of operators and to avoid the possibility of damaging the sheet of ice, the movement members <NUM> are arranged in the resting retracted condition and a treadable panelling is provided above the uprights <NUM> that avoids contact with the icy surface.

Advantageously, therefore, the present invention avoids ruining the sheet of ice of the playing field, for example with holes or the creation of grooves, to lock a partition <NUM> or the balustrade <NUM> in position.

In addition, the provision of a rail between each partition <NUM> and the support surface S guarantees a low-friction sliding that does not ruin the same support surface S.

Claim 1:
A balustrade (<NUM>) for an ice rink, in particular a hockey rink, comprising:
- a plurality of systems for the movement of at least one partition (<NUM>) extending vertically upwards from a support surface (S) between a lower portion (<NUM>) thereof and an upper portion (<NUM>), wherein a plurality of partitions (<NUM>) are mutually connected consecutively and arranged around the perimeter to delimit the playing field, preferably in the form of a quadrilateral, each system comprising:
- at least one movement member (<NUM>) associated with a respective partition (<NUM>) and configured for moving it at least along a movement direction (M) substantially parallel to the support surface (S) between a first operating position and a second operating position; said movement member (<NUM>) comprising a first fixed portion (<NUM>) with respect to said support surface (S) and a second movable portion (<NUM>), approaching or moving away, with respect to said first fixed portion (<NUM>) and connected to said partition (<NUM>) at least in a movement condition of said movement member (<NUM>) in order to move the partition (<NUM>) on the support surface (S) between the first operating position and the second operating position at least along said movement direction (M);
- a control unit (<NUM>) of the movement member (<NUM>) operatively connected to the latter to move said second movable portion (<NUM>) in an automated manner;
wherein said balustrade (<NUM>) comprises a plurality of movement members (<NUM>) arranged outside the playing field and each movement member (<NUM>) is associated with at least one partition (<NUM>); said plurality of movement members (<NUM>) being configured for moving said partitions (<NUM>) along said movement direction (M) between the respective first operating position and the respective second operating position to modify the surface extension of the playing field respectively between a maximum configuration, wherein said partitions (<NUM>) in the first operating position define a widened perimeter, and a minimal configuration, wherein said partitions (<NUM>) in the second operating position define a restricted perimeter with respect to the widened perimeter.