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(11) | EP 0 945 081 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Improvement in a method of and an apparatus for taking footprints and manufacturing the positive pattern thereof by a pneumatic system without using disposable material |
| (57) A method of taking negative footprints (1) and manufacturing positive moulds (2)
suitable for forming custom-made arch supports and/or anatomic insoles, characterized
in that in order to avoid the employment of disposable materials it provides for two
bags (5) that are exactly identical to each other, i.e. one for taking footprints
(RI) and one for manufacturing positive moulds (FP), and sealing means 7 to be put
between the two bags (RI, FP) for obtaining positive footprint (2) after having taken
negative footprint (1), said bags (5) being able to be used over and over again both
for taking negative footprints (1) and moulding positive moulds (2), thus reducing
the production costs. |
[0001] The present invention relates to orthopaedics and more particularly to an improved method of manufacturing custom-made arch supports and anatomic insoles.
[0002] The known methods of manufacturing arch supports provide for taking the footprint by plastic pastes (plasticine), foams and/or plaster casts. The positive form, on which the arch support will be moulded, is made in such cases by casting plaster or rigid polyurethane foams into the negative footprints. One problem of the known art is given by that such methods necessarily make use of disposable materials which increase the cost. Furthermore, a long processing time is requested in order for the plaster or the plastic material to be allowed to set completely as well as the moulds and the moulding tools stained with plaster to be cleaned. There is known a method filed by the same Applicant which consists of taking the footprint and manufacturing the positive moulds which are suitable for moulding custom-made arch supports without using disposable materials. Such a method has the drawback of necessarily using different devices for the several manufacturing steps. Particularly, aids are needed for taking negative footprints as well as moulders of positive moulds which can be used several times but are different from one another as specifically directed to the function that they perform.
Moreover such aids for taking negative footprints and said moulders of positive moulds are complicated both in their construction and mode of use.
A first object of the invention is therefore to overcome all of the problems of the known art by providing a method of taking a negative footprint and manufacturing positive moulds by which custom-made arch supports can be moulded in a particularly easy fashion.
A second object of the invention is to provide means that puts the above method in practice and are of simple construction and easy usability.
A third object of the invention is to provide means for putting in practice the above method which can be used both for taking negative footprints and manufacturing positive moulds.
[0003] A better understanding of the invention will ensue from the following description which illustrates only by way of example a preferred not limiting embodiment with reference to the accompanying drawings. In the drawings:
Figure 1 shows how the footprint is taken;
Figure 2 is a cross-section view of the bag which can be used as means for taking footprints or moulding positive moulds;
Figure 3 is an exploded view showing the arrangement of the several parts for moulding the positive mould;
Figure 4 is a side elevation view of means for moulding the positive mould; and
Figure 5 shows the corresponding surfaces of the negative footprint and the positive mould.
[0004] According to the invention the method to be described provides two means 5, one for taking negative footprint 1 of the patient and one for manufacturing positive mould 2 on which the moulding of the custom-made arch supports has to be made, and sealing means 7 to be put temporarily between the first two means for obtaining positive footprint 2 after having taken negative footprint 1.
A first peculiar characteristic of said means 5 is that they are exactly the same even if they can be used from time to time for taking negative footprints 1 and moulding positive moulds 2, which reduces advantageously the production costs.
A second peculiar characteristic of the invention is that each means 5 has a very simple construction. In fact such means consists essentially of a sealed bag, preferably of latex or other material, which can be easily deformed and that contains granular material 6 such as sand and is capable of taking the patient's footprint. Such a bag 5 is closed by a gas sealing tap 4 which is can be connected to a vacuum pump.
In case of a deformable bag 5 which is used as a means for taking footprints RI, the shape that it takes because of the weight borne by the patient's foot which has been put thereon is kept and made stable and sturdy enough by the fact that tap 4 communicating with the inside of the bag is connected to a vacuum pump which sucks in all of the air from the inside of bag 5. In such a way, granular material 6 inside bag 5 is compacted and keeps the same shape that it had previously taken.
Once negative footprint 1 of the foot is "frozen", deformed bag 5 is placed on a working table and a second bag 5 is placed thereon with the interposition of sealing member 7.
Upper bag 5 is capable of being deformed so as to develop positive mould 2 corresponding to negative footprint 1 in lower bag 5. To this end, said sealing member 7 consists essentially of a ring of a very soft elastic material which is capable of fitting in and sealing tightly the contour of both overlapped bags 5. Such a sealing function is very important in order to allow all of the air between the two overlapped bags 5 to be sucked in, thus causing the upper bag to become deformed and to take on a "positive" shape 2 corresponding to negative footprint 1 of lower bag 5. To this end, sealing ring 7 is provided with an intake pipe connected to a quick-coupling connector 4B outside the ring and provided with an open end 9 projecting inside the ring.
In other words, after the two bags 5 which are respectively used as a means for moulding positive moulds FP and a means for taking negative footprints RI have been overlapped so that the contours of the lower surface of the upper bag and those of the upper surface of the lower bag are put in contact with sealing ring 7, the air between the two bags is sucked in through quick-coupling connector 4B connected to pipe 9 communicating with the inside of sealing ring 7 and negative footprint 1, so that the lower surface of upper bag FP is deformed and takes the same shape as negative footprint 1 of lower bag FI.
Preferably a weight 3 is placed on the two overlapped bags 5 in order to improve the sealing and then the shaping of positive mould 2. To this end it is recommended that such a weight 3 has a flat lower face so that upper bag 5 used as moulder of positive moulds FP has no depressions or protrusions which could hinder the manufacturing of the arch supports that follows.
In the preferred embodiment herein described, a thin elastic membrane 8, preferably of cloth or thin net, is provided inside sealing ring 7 so as to prevent any undesired adhesion between negative footprint 1 and positive mould 2.
It is self-evident from the foregoing that said sealing ring 7 should have such a size as to surround negative footprint 1 and to leave a free side edge so as to make negative footprint 1 perfectly corresponding to positive mould 2.
[0005] The method herein described includes essentially the following steps:
1 - taking the patient's footprint under load by one of the bags 5 used as means for taking footprints RI (Fig. 1);
2 - matching the contours of the footprint which has been taken with the patient's foot;
3 - fixing negative footprint 1 by sucking the air from the inside of bag 5 of footprint taking means RI through tap 4 (Fig. 2);
4 - superimposing a second bag 5 used as a moulder of positive moulds FP onto negative footprint 1 of footprint taking means FI with the interposition of a sealing ring means 7;
5 - adapting by a suitable manipulation the lower surface of deformable bag 5 used as a moulder of positive moulds FP in such a way that its lower surface fits tightly the contour of the underlying negative footprint of footprint taking means RI (Fig. 3);
6 - sucking in air from the inside of sealing means 7 and negative footprint 1 by a quick-coupling connector 4B of the sealing means so that the lower surface of the moulder of positive moulds FP matches with the upper surface of footprint taking means RI filling negative footprint 1 so as to form a positive mould 2 of the patient's foot;
7 - sucking in air from the inside of bag 5 of the moulder of positive moulds FP through a tap 4 so as to fix positive footprint 2;
8 - removing weight 3 and positioning positive footprint 2 in a suitable thermoforming machine TF of the known type (not shown) and manufacturing the arch supports according to known methods.
[0006] Once the custom-made arch support or anatomic insole is manufactured, air is allowed inside bags 5 again so that they can recover their original form and be ready for a new utilization.
It is evident from the description of the steps of the above method that the latter implies advantageously a reduction of the processing time as well as a cleanliness of the working steps.
1 - taking the patient's footprint under load by one of the bags (5) used as means for taking footprints (RI);
2 - matching the contours of the taken footprint with the patient's foot;
3 - fixing negative footprint (1) by sucking the air from the inside of bag (5) of footprint taking means (RI) through tap (4);
4 - superimposing a second bag (5) used as a moulder of positive moulds (FP) onto the negative footprint formed in footprint taking means (FI) with the interposition of a sealing ring means (7);
5 - adapting by a suitable manipulation deformable bag (5) used as a moulder of positive moulds (FP) in such a way that its lower surface fits tightly the contour of the underlying negative footprint formed in footprint taking means (RI);
6 - sucking in air from the inside of sealing means (7) and negative footprint (1) by a quick-coupling connector (4B) of sealing means (7) so that the lower surface of the moulder of positive moulds (FP) matches with the upper surface of footprint taking means (RI) filling negative footprint (1) so as to form positive mould (2) of the patient's foot;
7 - sucking in air from the inside of bag (5) of the moulder of positive moulds (FP) through a tap (4) so as to fix positive footprint (2);
8 - removing weight (3) and positioning positive footprint (2) in a suitable thermoforming machine TF and manufacturing the arch supports according to known methods.