Patent Description:
In this discussion, particular reference will be made to a bicycle saddle; however, the principles of the present invention may be applied in the same manner to saddles intended for a different use.

As it is known, bicycle saddles essentially comprise a frame, a shell, a padding and an outer coating.

The frame, whose functions are to allow the saddle to be connected to the saddle post and to act as a mechanical support for the shell, is normally made of metal or composite material. The shell, made of hard and rigid plastic material, is the element which gives rigidity to the saddle, acting as a support surface for the padding.

The padding, commonly made of polyurethane foam, is comprised between the shell and the outer coating.

As it is known, the method of making a saddle of this type comprises a first step in which a coating material is prepared inside a mould, which comprises a countershape surface with respect to the support surface of the saddle.

Once the coating material is positioned, it must be placed in contact with the countershape surface of the mould, in a manner as adherent as possible, so that it reproduces, in a precise manner, the surface of the mould itself. In this regard, the use of means adapted to create a vacuum (with a certain residual pressure) between the surface of the mould and the coating material is known, so that the latter adheres to the surface of the mould.

On the second half of the mould, which reproduces in negative the lower surface of the shell, a shell is positioned, so that the inner side thereof, which in use will face the padding, is visible.

Subsequently, a foamed material in liquid form, for example polyurethane, is poured onto the first half of the mould, and therefore onto the inner side of the coating material.

The mould is then closed, and the polyurethane is allowed to cure. In this case, the polyurethane foam acts as a padding and at the same time as a binder between the shell and the coating material.

The time required for curing the polyurethane foam is about six minutes. Once the curing is obtained, the mould may be opened and the saddle may be extracted from the mould itself.

At this point, operations, usually manual, may be necessary to trim the excess edges of the coating material.

Alternatively, it is possible to make the foam padding separately, with a method similar to the previous one, and then fix the various components together using specific adhesives or glues.

The background art, although widely appreciated, is not free from drawbacks both from the point of view of the production thereof and from the point of view of the comfort for the user.

The method of the background art requires very long cycle times, at least of about six minutes, the time necessary for the polyurethane foam to cure. To this cycle time, the times required to restore the equipment for the production of the next saddle must also be added.

Furthermore, this method involves multiple interventions of the operator since most of the steps are managed and carried out by specialized operators.

Furthermore, the use of glues or adhesives to fix the various components to one another creates a disadvantage in terms of environmental impact, both for the use of these substances themselves, and for the possible recyclability of the various materials with which the saddle is made.

From the point of view of the comfort of the saddle, there is an intrinsic inability of polyurethane to respond to tangential stresses since the reaction thereof to an applied stress is a simple compression. Therefore, it is not particularly adapted to accompany in an integral manner the translation of the pelvis/ischial bones of the user during use.

<CIT> and <CIT> disclose a method of making a saddle comprising a shell and a padding by arranging a shell in thermoplastic polymer inside a mould for injection moulding, comprising a die and a punch; said shell comprising a support surface, which in use faces said padding, and a support surface; said support surface being coupled to an inner wall of said punch or said die, said support surface forming a wall of the moulding cavity; closing the mould; making a padding by injection moulding a thermoplastic polymer over said shell, between said support surface and said mould.

Therefore, the need is felt to solve the drawbacks and limitations mentioned above with reference to the background art.

Therefore, the need is felt to make available a method of making a saddle which allows for very short cycle times, compared to the methods of the background art.

Furthermore, the need is felt for a method of making a saddle which is subject to limited manual operations by operators.

Furthermore, the need is felt for a method which does not involve the use of glues and adhesives, and which may therefore be an eco-sustainable method, using completely recyclable materials.

In addition, the need is felt for a saddle which is more comfortable than current saddles made with polyurethane foam.

In particular, a saddle which is more effective in accompanying in an integral manner the translation of the pelvis/ischial bones of the user during use.

Such requirements are, at least partially, met by a method of making a saddle according to claim <NUM>, and by a related saddle in accordance with claim <NUM>.

Further features and advantages of the present invention will become more comprehensible from the following description of preferred embodiments thereof given by way of non-limiting examples, in which:.

Elements or parts in common to the embodiments described will be indicated hereafter using the same reference numerals.

The method of making a saddle <NUM> comprising a shell <NUM> and a padding <NUM> according to the present invention comprises the steps as defined in appended claim <NUM>.

The polymer used in step (c) may be a thermoplastic elastomer TPE.

According to a possible embodiment, the thermoplastic polymer used for the padding may be an SBS rubber (styrene-butadiene-styrene rubber).

According to a possible alternative embodiment, the thermoplastic material used for the padding may be the one marketed under the name PEBAX®.

According to a first embodiment of the present invention, the padding has a uniform hardness. For example, the padding <NUM> may have a hardness between <NUM> and <NUM> shore A.

Therefore, in other words, the padding <NUM> may be made with a single thermoplastic polymer, as shown in the example of <FIG>.

According to a possible embodiment, the padding <NUM> may comprise an outer coating <NUM> having a hardness between <NUM> and <NUM> shore A, and an inner core <NUM> with a hardness lower with respect to the coating <NUM>.

Advantageously, the inner core <NUM> may have a hardness between <NUM> and <NUM> shore A. Preferably, the inner core <NUM> may have a hardness around <NUM> shore A.

According to the invention, the padding <NUM> is made by co-injection moulding:.

In other words, the padding <NUM> may be made with a coating <NUM> and an inner core <NUM> with a lower hardness.

The thermoplastic polymer with which the outermost layer of the padding is made, which in both cases corresponds to a material with a hardness between <NUM> and <NUM> shore A, allows the direct fixing of the padding material, by means of a chemical bond, to the shell <NUM>.

In the case in which an inner core <NUM>, with a reduced hardness, and in particular lower than <NUM> shore A, is provided, the coating <NUM> allows to effectively fix the polymer, with which the inner core <NUM> is formed, to the shell <NUM>. In other words, the thermoplastic polymer with greater hardness allows the fixing to the shell <NUM>, but also to the inner core <NUM>, which it is therefore possible to exploit for the mechanical properties thereof.

Furthermore, the coating <NUM> made with a thermoplastic polymer, in particular SBS rubber having a hardness between <NUM> and <NUM> shore A, allows to obtain:.

According to a possible embodiment of the present invention, the shell <NUM> is made of thermoplastic material with a high elastic modulus and a high hardness.

The shell <NUM> may be made of thermoplastic material, for example, of copolymer polypropylene.

The copolymer propylene used may possibly be of the loaded type. In particular, the copolymer polypropylene may be loaded with loads of a type per se known, such as fibreglass, carbon, and/or talc, etc..

Advantageously, the shell may be made of copolymer polypropylene loaded with a percentage of fibreglass between <NUM>% and <NUM>%, preferably around <NUM>%.

In this case, the elastic modulus of a copolymer polypropylene loaded with a percentage of fibreglass of about <NUM>% may have an elasticity modulus higher than <NUM>.

This solution of a copolymer polypropylene loaded with a percentage of fibreglass of about <NUM>%, allows to achieve an optimal fixing of the thermoplastic elastomer with which the padding is made, especially in the case of SBS material.

<FIG> shows a step of making the shell <NUM>. According to a possible embodiment, the shell <NUM> may be made by injection moulding in a mould <NUM> comprising the punch <NUM> and a second die <NUM>.

As it may be seen in the Figures, the punch <NUM> may be made with inserts <NUM>, <NUM>, <NUM> so as to create particular undercuts and allow the extraction of the shell from the mould. Such type of equipment is per se known to those skilled in the art and therefore it will not be further explored.

In the same manner, the ducts for feeding the polymer into the mould cavity are not shown, since they are elements per se known to those skilled in the art as well.

Once the shell <NUM> is made, the mould is opened and the second die <NUM> is replaced with the matrix <NUM> to injection mould the padding <NUM>. This mode is shown, for example, in <FIG>, in which it may be noticed that the punch <NUM> is the same, while the shape of the die <NUM>, which has now a countershape with respect to the padding <NUM>, has changed.

In <FIG>, on the other hand, an alternative embodiment is shown, in which the shell <NUM>, once made, is removed from the mould <NUM> and is positioned in a second punch <NUM>, next prepared with a second die <NUM>.

In this case, the shell <NUM> is therefore made by injection moulding inside a dedicated mould and is subsequently placed inside the mould comprising the die <NUM> adapted to make the padding <NUM>.

From the point of view of the manufactured saddle, the two methods are substantially equivalent. From a production point of view, the second method allows to divide the moulding times on two machines, with the possibility of further reducing the production times, and of creating a certain quantity of frame-shell subsets stock which may then be over moulded in another machine.

According to a possible embodiment, the shell <NUM> may be made by injection moulding, over moulding a frame <NUM>.

<FIG> shows a possible embodiment of a frame <NUM>. In particular, the frame <NUM> may comprise two bars <NUM>, <NUM>, which may be made of metal, thermoplastic material, and/or composite material.

Advantageously, said bars may be made of C40.

As it may be seen in <FIG>, the bars <NUM>, <NUM> may comprise tapered ends, arranged with radial projections adapted to allow a better adhesion to the thermoplastic material of the shell.

The advantages which may be achieved with a method of making a saddle and the related saddle according to the present invention are therefore evident.

First of all, the method, and therefore the materials used, allow to improve the performance of the product, especially in terms of comfort.

Furthermore, they allow to increase the eco-sustainability and the recycling of the materials used.

The operations required to the operators during the manufacturing of the saddle significantly decrease.

In addition, production costs significantly decrease since cycle times significantly decrease.

In this regard, the time required for the moulding cycle of a saddle <NUM>, according to the method of the present invention, is a very short time, of the order of one minute. Therefore, the cycle time is significantly lower than the cycle time of about six minutes required in the case of polyurethane padding.

Furthermore, a method of making a saddle and a related saddle have been made available, which allow to obtain a saddle more comfortable with respect to current saddles made with polyurethane foam. In particular, a saddle adapted to accompany, in an integral manner, the translation of the pelvis/ischial bones of the user during use.

Claim 1:
Method of making a saddle (<NUM>) comprising a shell (<NUM>) and a padding (<NUM>) comprising the steps of:
(a) arranging a shell (<NUM>) in thermoplastic polymer inside a mould (<NUM>) for injection moulding, comprising a die (<NUM>) and a punch (<NUM>, <NUM>); said shell (<NUM>) comprising a support surface (<NUM>), which in use faces said padding (<NUM>), and a supporting surface (<NUM>); said supporting surface (<NUM>) being coupled to an inner wall of said punch (<NUM>, <NUM>) or said die (<NUM>), said support surface (<NUM>) forming a wall of the moulding cavity;
(b) closing the mould (<NUM>);
(c) making a padding (<NUM>) by injection moulding a thermoplastic polymer over said shell (<NUM>), between said support surface (<NUM>) and said mould (<NUM>);
characterized in that
said padding (<NUM>) is made by co-injection moulding of a coating (<NUM>) which forms an outer coating of said padding (<NUM>) and which forms the contact with the surface of said shell (<NUM>); and an inner core (<NUM>) of reduced hardness.