CA2125268A1 - Sports footwear - Google Patents

Abstract

ABSTRACT
SPORTS FOOTWEAR

Improved sports footwear comprising an insert positioned at least in the heel region, the insert comprising an elastically deformable cellular structure arranged within an elastically deformable air-impermeable casing provided with inner projections on opposing faces, the casing being pneumatically connected to controllable means, rigid with the footwear, for varying the air pressure within the casing so as to modify the elastic characteristics of the insert, each projection on one face being connected to a projection on the other face.

Description

~` 2~25268 SPORIS EOOL`WEAR

This invention relates to improved footwear for athletes, of the type containing an insert at least in the heel region, the inselt comprising an airtight flexible plastics casing enclosing a series of intercolmected elastically defolmable bodies.
I-t is well known that athletics footwear must provide a stahle support region which at the SalDe time is comIortable i-or the foot cnrld herlce for the athlete's bo(ly, ~YhiCIl is su~3jrcted to the mos1:
various types of stress. I`o solv-- the problem o~ ~omfor~: wi-th stable support, uhile also achieving a certain counter-thrust eifrect, ie cl ~)c).r1:i~1 recovery Or tlle thrust as the footwe,lr separates from the ground plus absorption of the impact against tl~e ~round, solutions of the type described in the precedi.llg paragraph have been ~roposed.
The known-art inserts positioned in the footwear heeJ. act primarily as a complex sprina, so that ~Ifter the impact of the footwear against the ground and the sinlultaneous damping eftect, there is partial restitution of the energy absorbed by the i.nsert .
oll ilnpact. Altl~ough the knowrl irlsert;s oIfer coln~ort:, stabilitv and a-.le(~lte rlami)irlg and energy recovery through a certaill rarlge of loadi.n~ arld impact velocit~, tlle~ c;lrl prove part:ially unsatisIflctory outside these rarlaes ~or e~ample, ~ootwe~lr provided with the insert ill questioll c"n sdtisly the requiremerlts of slow movemerlt but not of fast movemerlt, whereas clrl irlsert.
~signed for f;lst movenlent lould l~rove (oo rigid ror sl.ow movemerlt. In aitdi-tion to this, for e~ l foot~ear size tlle weight ~ .:~
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-` 2125268 of the wearer can vary within extremely wide limits, so that the same insert can prove either excessively rigid or excessively yielding.
The mairl object of the present invention is therefore to improve footwear provided with an insert of the type comprising an airtight casing of flexible material enclosing a plurality of interconnected elastic bodies, such that its rigidity can be matched both to the weight of the user and to the pace of nlovemerlt at any given time.
A further object of the present invention is to provide footwear with an airtigllt insert of reduced weight.
A further object of the present invention is to provide footwear with several inserts positioned in regions of the footwear which are convenient for comfort and stability.
The aforesaid objects are attained according to the invention by providing the footwear with a pumping means pneumatically connected to the insert contained in the footwear heel region to increase the rigidity of the insert, and with bleed means, also pneumatically connected to the insert, to decrease this rigidity.
The invention will be more apparent from the detailed description of a preferred embodiment thereof given hereinafter by way of non-limiting example with reference to the accompanying drawing, in which:
Eigure 1 is a side view of the improved footwear according to the invention;
Figure 2 is an exploded perspective view of the insert;
Figure 2A is a perspective view of the sole;

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2~2~268 ~igure 3 is a partial section on the line A-~ of Figure 2A with the cover for the pump ~nd bleed valve omitted;

Figure 4 shows to a different scale the sectional view of ~igure 3~ canpleted with the partial sectional view taken a:long line K~ of fig. 2 and comprising the cover;

Figure 5 is a schematic view of the pneumatic circuit of the footwear.
In the figures the reference numeral 1 indicates o~erall the sports footwear, which comprises a vamp 2 and a sole 3. The sole can also consist of one or more layers o~ plastic materials, which can be different.
In the sole in a position corresponding with the user's heel there is provided a compartment containing an insert 4 formed from an elastically deformable cellular structure 5 of thermoplastics material enclosed in an airtight casing 6 of relatiYely thin flexible plastics material such as polyurethane or the like.
Specifically, although non-limitatively, the cellular structure 5 defines a plurality of hexagonal cells 5A, some of which can be closed but only at one end, such as the cell 5Al. The cellular structure is prepared by moulding any elastic synthetic material and is free within the casing 6, ie not connected thereto. The casing 6 is formed from two parts 6A and 6B welded together, and prepared for example by vacuum-forming. The part 6A has a tray configuration with a perimetral flange 7 and an appendix 8 on one side, this appendix being centrally of semicircular shape (8A), and with two flat lateral flanges 8B. The tray part 6A also comprises an ordered series of substantially frusto-conical hollow . ~
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~ 212~268 projections 9 which extend within the interior of the casing obtained. The part 6B also comprises an appendix 10, which is substantially flat and is arranged to coincide with the appendix 8, and a series of frusto-conical hollow projections arranged to coincide with the projections 9 when the two parts 6A and 6B are joined together by welding along the superposed regions coinciding with the flanges 7 and 8B and with the inner ends 12 (see Figure 4). ;~

~efore fixing the parts 6A, 6~ of the casing 6 together, the light elastic r,el lular structure 5 is placed on one of these parts so that each of the hollow projections 9, 11 is located within a cell 5A (but obviously not within a cell 5Al, at which the parts 6A, 6B
are without projections 9, 11).
The other part of the casing 6 is then placed thereon and the parts joined together by welding along the said superposed regions to enclose the cellular structure 5 but without it being connected to the casing.
The height of the cellular structure 5 is substantially equal to the inner distance between the opposing walls 13, 14 of the casing ;
6, but such that all the internal regions of the casing are connected together pneumatically. By the joining together of the appendices 8 and 10 a duct or tube Z is formed communicating with the interior of the casing.
A cavity 15 and a channel 16 are provided in the sole 3. The cavity is pro~ided in the heel and contains the insert 4 of corresponding shape, whereas the tube Z is positioned in the channel 16, which directs it to an outer lateral appendix 114 on , .

" '., 212~268 the sole, where it terminates in an aperture in which it is fixed by a tubular appendix 115 of a plastics block 116 welded to the l outside of the appendix 114 and comprising a chamber 17 in which I
the valving member 18 of a bleed valve 19 is slidingly mounted.
The valving member 18 is of frusto-conical shape and is mounted at the end of a stem 20 of smaller cross-section. The stem passes slackl~ through a hole 21 and has a head 23. A compression spring 22 positioned between the block 16 and head 23 prevents the chamber 17 and hence the interior of the insert 4 being conrlected to atmosphere, ~hereas if the head 23 is pressed to hence withdraw the valving member 18 from the hole 21, the interior of the insert becomes connected to atmosphere via the space between the stem 20 and the hole 21 whicb guides it. -The block 116 comprises a hollow lateral appendix 24 in which there is inserted a unidirectional valve 25 of elastic material comprising a seal flange 26, a tubular part 27 and two flat lips 28 which diverge to allow air to pass in the direction of the arrow R when pressure is applied to a bellows 29 of elastic material which by means of a lateral hollow appendix 30 is sealedly connected to the appendix 24. For this purpose the appendix 30 comprises an inner flange 31 wh;ch seats in a corresponding annular groove in the appendix 24 of the block 16. -The bellows has a flat wall 29A by which it is fixed (welded) to the outer lateral appendix 114 of the sole.
The bellows 29 comprises a second tubular appendix 35, opposite the preceding, in which there is mounted an intake valve 26 comprising a tubular member 37 with a groove 3~ into which an ~. ~- ~
; :~ ' -`-` 2125268 inner flange of the appendix 35 elastically~clamps. The tubular member 37 comprises a narrow passage 39 which can be intercepted by a plastics disc 40 which moves between this passage and a series of radially arranged spaced-apart teeth 41 which prevent the disc 40 from falling.
As shown in Figure 4, a flexible cover 45 of elastomer material provided with a peripheral flange 46 is welded to the appendix 114 o~ the sole to cover and protect both the bellows pump 29 and the bleed valve 19. A hole 50 is provided iD this cover for the necessary air movements.

As Figure 4 represents a section on the lirle A-A of Figure2A
(completed by a section taken along line K-~ of fig. 2) the rcfe~ence numerals 55 indicate sections through walls common to two ~djacent cells 5A, these walls lying in the sectional plane. ln Figure 2 these walls are indicated by the same reference numerals 55.
,1, When the person wearing the footwear wishes to stiffen the insert 4, he presses repeatedly on the bellows 29. During this pressing, the air contained in the bellows is transferred into the insert 4, so stiffening it, via the delivery valve 25 (the intake valve 36 obviously being closed). Wnlerl the user releases the bellows this returns to its initial position by virtue of its elasticity, to draw air into its interior via the intake valve 36 (the delivery valve remaining closed). On achieving the required rigidity the user ceases the pumping action. If he wishes to reduce the rigidity the user discharges pressure ~rom the insert by pressing the head 23 of the bleed valve 19, to cormect the insert 4 to I ~1 atmosphere. I

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As can be seen from Figure 2A, the footwear can also comprise a second insert 200 formed as the insert 4 and positioned in a seat 201 provided in the front part of the sole 3.
A tube 202 similar to the tube Z pneumatically connects the insert 200 to the tube Z, allowing the rigidity of this second insert to : :
also be simultaneously modified. This is achieved in the following manner~
a) the part 14 and the corresponding part of the insert 200 are constructed in a single piece together with the appendix 10, which joins them together and comprises a lateral branch for connection to the block 116;
b) the part 13 and the corresponding part of the insert 200 are constructed in a single piece together with the appendix 8, which joins them together and comprises a lateral branch to be superposed on that of point a), to form together therewith the pneucatic connection to the block 116.

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Claims (12)

1. Improved sports footwear comprising at least one insert positioned at least in the heel region, said insert comprising an air-impermeable casing of flexible material and containing elastically deformable means, characterised in that means are connected to said casing for varying the air pressure within said casing, so as to modify the elastic characteristics of the insert.

2. Sports footwear as claimed in claim 1, characterised in that said means for varying the air pressure within the insert comprise pumping means associated with intake and delivery valve means for increasing said pressure, and bleed means for decreasing said pressure.

3. Sports footwear as claimed in claim 2, characterised in that the pumping means and the bleed means are both positioned on the outside of the footwear and are rigid therewith.

4. Sports footwear as claimed in claim 3, characterised in that the pumping means and the bleed means are contained within an elastically deformable cover rigid with the footwear.

5. Sports footwear as claimed in claim 2, characterised in that the pumping means comprise a bellows having two openings, one containing an intake valve and the other containing a delivery valve.

6. Sports footwear as claimed in claim 5, characterised in that the delivery valve is a lip-type valve and is positioned within a block to which the bellows is connected, this block also containing the bleed means downstream of said delivery valve.

7. Sports footwear as claimed in claim 6, characterised in that the bleed means comprise a pusher-type valve.

8. Sports footwear as claimed in claim 1, characterised in that the elastically deformable means are represented by a cellular structure, preferably of honeycomb type.

9. Sports footwear as claimed in claim 8, characterised in that the air-impermeable casing of flexible material is formed from at least two parts each comprising an integral appendix which when joined together form a tube for air passage from and to the insert.

10. Sports footwear as claimed in claim 9, characterised in that said two parts comprise, in coinciding positions, hollow projections which are directed towards the interior of the casing and are connected together at their inner ends.

11. Sports footwear as claimed in claim 10, characterised in that at least one pair of joined-together hollow projections is arranged within a cell of the cellular structure.

12. Sports footwear as claimed in claim 8, characterised in that the cellular structure is enclosed within, but not connected to, the air-impermeable casing.