AU2011200865A1

AU2011200865A1 - Metatarsal guards for footwear

Info

Publication number: AU2011200865A1
Application number: AU2011200865A
Authority: AU
Inventors: Georg Johann Hannweg
Original assignee: SHEZI IND HOLDINGS Pty Ltd T A NEPTUN BOOT
Current assignee: SHEZI INDUSTRIAL HOLDINGS Pty Ltd T/A NEPTUN BOOT
Priority date: 2003-11-21
Filing date: 2011-02-28
Publication date: 2011-04-14
Anticipated expiration: 2024-11-16
Also published as: AU2011200865B2; AU2004231162A1; ZA200309331B

Description

AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention title: METATARSAL GUARDS FOR FOOTWEAR The following statement is a full description of this invention, including the best method of performing it known to us: duwm A0116759764v1 120137844 METATARSAL GUARDS FOR FOOTWEAR This is a divisional application divided out of Application No. 2004231162, the entire contents of which are incorporated by reference. 5 FIELD OF THE INVENTION This invention relates to metatarsal guards for footwear and in particular gumboots. BACKGROUND OF THE INVENTION 10 Any discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these mattes formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the 15 priority date of each claim of this application. Legislation has placed the onus on management in industry to ensure the safety of workers and protect them from injury. Protective footwear is well-known and traditionally involved the inclusion of steel toe caps, mainly in lace-up shoes and boots. However it became apparent 20 that the metatarsal zone of the foot also required protection and accordingly attempts were made to provide guards which are capable of being fitted to lace-up boots, usually being secured by means of the laces. These guards are however of no use for gumboots. Several strap-on metatarsal guards have been developed for gumboots, but 25 these have a number of disadvantages. Not the least of these is durability in that leg straps do not last and under-foot straps are easily severed. In addition stones and the like easily become trapped between the guard and the gumboot leading to discomfort. The development of modern polymeric materials enables manufacturers to 30 move away from metal guards and instead use hardened polymeric materials, for example polycarbonate. These still need to bend however and one of the major difficulties facing manufacturers is the trade-off between strength and flexibility. Even with the inherent flexibility of such materials, bonding a rigid guard to a gumboot remains an extremely difficult task and even when achieved, they are 35 susceptible to being dislodged or trapping stones beneath them. duwm A0116759764v1 120137844 One method of increasing flexibility without loss of strength is by the use of softer polyvinylchloride moulded into a web pattern which is designed to permit flexibility as well as absorb shock. Unfortunately, much of the flexibility is lost once such guards are bonded onto a gumboot. 5 The flexibility of these webs is improved if the external covering layer is removed, but this leaves the web open for dirt and stones to clog the web. Similarly, an armadillo type overlapping arrangement works well but allows entrapment of stones. 10 SUMMARY OF THE INVENTION According to a first aspect of the invention, there is provided a metatarsal guard for a gumboot comprising a moulded polymeric material and includes one or more impact absorption zones, the zones being compressible at least transversely relative to the longitudinal axis of the gumboot. 15 In the preferred form of the invention, a plurality of impact absorption zones are provided, the zones being spaced apart and separated by zones of diminished impact absorption to permit flexion of the guard during walking. The zones of diminished impact absorption may be dimensioned to prevent reduction in protection offered by the guard such that during flexion, the zones of impact 20 absorption abut or are at least aligned in close proximity. Also in the preferred form of the invention, the guard comprises a generally arcuate structure both longitudinally and transversely, dimensioned to extend from a point midway up the shin portion of a gumboot to a point at or near the point at which a reinforced toe cap of the gumboot ends, and which spans the 25 convex metatarsal and instep portions of the gumboot. The guard comprises a moulded, resiliently deformable polymeric material, preferably polyvinylchloride and includes a series of recesses and raised zones when viewed from the underside thereof, the recesses including one or more formations for absorbing impact. These formations may comprise integral ridges 30 which are preferably zigzag transversely across the width of the recesses. Other formations may also be effective, but the zigzag formations have been found to permit flexibility without loss of protection. The raised zones comprise the zones of diminished impact absorption and when viewed from the upper side of the guard, comprise channels separating the 35 impact absorption zones which appear in this view, as ridges. duwm A0116759764v1 120137844 The series of zones is bordered by a bonding zone which forms the zone of attachment during manufacture of the gumboot. The guard is bonded directly to the gumboot using a heat setting adhesive to render it integral with the gumboot and incapable of removal. 5 In the one form of the invention, the absorption zones comprise a plurality of complementally shaped formations arranged in predetermined, spaced apart locations permitting compression of the zones. In one form of the invention, the complementally shaped formations may comprise spaced apart rows of zigzag fins. Also in the preferred form, the guard comprises a bonding zone, one or 10 more impact absorption zones and an integral cover element. The bonding zone preferably comprises a peripheral strip bordering the absorption zone. The cover element may comprise a layer of polyvinylchloride over the absorption zones, the layer including one or more ridges and/or grooves which 15 alternately provide reinforcing and flexibility. In the one form of the invention, the guard is dimensioned such that a single absorption zone extends from at or near the point at which a reinforced toe cap of the gumboot ends, to a point midway up the shin portion of the gumboot. Typically, a generally triangular shape with rounded apices is preferred. 20 According to a second aspect of the invention, a gumboot includes a metatarsal guard either bonded thereto or integrally formed therewith, the guard including one or more impact absorption zones, the zones being compressible at least transversely relative to the longitudinal axis of the gumboot. In an alternate form, several discrete, spaced apart absorption zones are 25 provided, the generally triangular shape being defined by the bonding zone. The grooves or spaces between the absorption zones permit retention of flexibility during walking or other bending of the gumboot. EMBODIMENT OF THE INVENTION 30 Embodiments of the invention are described below with reference to the accompanying drawings and photographs in which: Figure I is a side view of a gumboot with a cross-section of the guard according to the invention; Figure 2 is a boot of the guard of Figure 1; 35 Figure 3 is a photograph of the guard and boot of Figure 2; duwm A0116759764v1 120137844 Figure 4 is a side view of a gumboot with a X-section of an alternative form of the guard; Figure 5 is a similar view of gumboot with a further alternative guard; Figure 6 is a photo of the guard and boot of Figure 5; 5 and Figure 7 is a bottom view of the guard of Figure 5. In Figure I, a gumboot 10 includes an integral metatarsal guard 12 of moulded polyvinylchloride bonded thereto. The guard in this preferred form of the invention comprises a series of 10 alternating zones of impact absorption 14 and diminished impact absorption 16 which take the form of ridges and channels respectively when viewed from above. The impact absorption zones are recessed on the underside 18 thereof and include transverse zigzag ridges 20 spanning the width of the recesses. The height of the absorption zone (or the depth of the recess) permits compression of the 15 zone to disperse the force of any impact, while the zigzag ridges 20 are, like the entire guard, inherently compressible to further absorb and disperse the force of impact, thereby offering a two-step impact absorption action. The inherent elasticity of the guard also further assists in deflecting glancing impacts thereon. The ridges preferably have defined walls 22 and edges 24 as opposed to 20 being arcuate to increase rigidity. The channels 16 are designed to dimensioned to permit flexion of the gumboot during walking, without reducing protection. This arrangement permits a degree of comfort and wearability not possible with rigid metatarsal guards which are not formed integrally with the gumboot. 25 In Figure 4, a gumboot 10 includes a metatarsal guard 12 of moulded polyvinylchloride bonded thereto. The guard comprises a bonding zone 26 in the form of a peripheral strip of PVC bordering a series of four internal impact absorption zones 28. A cover clement 30 (also integrally moulded PVC) prevents the ingress of dirt and 30 particulates into the absorption zones. In Figures 5 and 6, the guard includes a single absorption zone 32 comprising a series of complementally shaped, spaced apart, zig zagging fins 34 (Figure 7) which can be compressed together to retain flexibility during bending of the guard. 35 This arrangement is more clearly illustrated in Figure 7. duwm A0116759764v1 120137844 Reinforcing ridges 36 are provided for increased strength. The word 'comprising' and forms of the word 'comprising' as used in this description and in the claims does not limit the invention claimed to exclude any variants or additions. duwm AO116759764v1 120137844

Claims

1. A metatarsal guard for a gumboot comprising a moulded polymeric material and includes one or more impact absorption zones, the zones being compressible at least transversely relative to the longitudinal axis of the 5 gumboot.

2. A metatarsal guard according to claim 1, wherein a plurality of impact absorption zones are provided, the zones being spaced apart and separated by zones of diminished impact absorption to permit flexion of the guard during walking. 10

3. A metatarsal guard according to claim 2, wherein the zones of diminished impact absorption are dimensioned to prevent reduction in protection offered by the guard such that during flexion, the zones of impact absorption abut or are at least aligned in close proximity.

4. A metatarsal guard according to any one of the above claims which 15 comprises a generally arcuate structure both longitudinally and transversely, dimensioned to extend from a point midway up the shin portion of a gumboot to a point at or near the point at which a reinforced toe cap of the gumboot ends, and which spans the convex metatarsal and instep portions of the gumboot. 20

5. A metatarsal guard according to any one of the above claims which comprises a moulded, resiliently deformable polymeric material, and includes a series of recesses and raised zones when viewed from the underside thereof, the recesses including one or more formations for absorbing impact. 25

6. A metatarsal guard according to claim 5, wherein the polymeric material comprises polyvinylchloride.

7. A metatarsal guard according to claim 5, wherein the formations comprise integral ridges which zigzag transversely across the width of the recesses.

8. A metatarsal guard according to any one of claim 5 in which the series of 30 zones is bordered by a bonding zone which forms the zone of attachment during manufacture of the gumboot, the guard being bonded directly to the gumboot using a heat setting adhesive to render it integral with the gumboot.

9. A metatarsal guard according to any one of the preceding claims, wherein 35 the absorption zones comprise a plurality of complementally shaped duwm A0116759764v1 120137844 formations arranged in predetermined, spaced apart locations permitting compression of the zones.

10. A metatarsal guard according to claim 9, wherein the complementally shaped formations may comprise spaced apart rows of zigzag fins. 5

11. A metatarsal guard according to claim 9, in which it comprises a bonding zone, one or more impact absorption zones and an integral cover element.

12. A metatarsal guard according to claim 11, wherein the bonding zone comprises a peripheral strip bordering the absorption zone.

13. A metatarsal guard according to claim 9, wherein the cover element 10 comprises a layer of polyvinylchloride over the absorption zones, the layer including one or more ridges and/or grooves which alternately provide reinforcing and flexibility.

14. A metatarsal guard according to claim 9, wherein the guard is dimensioned such that a single absorption zone extends from at or near the point at 15 which a reinforced toe cap of the gumboot ends, to a point midway up the shin portion of the gumboot, the guard being of generally triangular shape with the apices of the triangle being rounded.

15. A gumboot including a metatarsal guard according to any of the above claims, wherein the guard is bonded to the gumboot. 20

16. A gumboot including a metatarsal guard according to any of the above claims, wherein the guard is integrally formed with the gumboot.

17. A guard substantially as described with reference to the accompanying drawings.

18. A gumboot substantially as described with reference to the accompanying 25 drawings. duwm A0116759764v1 120137844