GB2328857A

GB2328857A - Footwear with a suction-release duct

Info

Publication number: GB2328857A
Application number: GB9818695A
Authority: GB
Inventors: Clifford Frank Cogger
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-08-28
Filing date: 1998-08-28
Publication date: 1999-03-10
Also published as: GB9718040D0; GB9818695D0

Abstract

An item of waterproof footwear (2, Fig. 1) comprises a duct 6 which enables a fluid, typically air, to flow beneath a foot portion of the footwear so as to release the suction formed when the footwear is raised from within a mass of viscous material, such as mud. Preferably, a lower end of the duct comprises a one-way valve 8 which is closed when the footwear enters the viscous material and is opened when the footwear is lifted therefrom. The one-way valve may be a flap valve. A method of providing an item of footwear with a suction-release duct is also described.

Description

WATERPROOF FOOTWEAR Field of the Invention This invention relates to waterproof footwear and the term "foottiear" as used herein is to be interpreted broadly as including not only such items as boots (which are items of footwear) but also such items as waders and dry suits (which include footwear).

When walking andlor working in mud, silt, slurry or similar viscous material, a person wearing waterproof footwear can find movement very difficult or even impossible because of the suction effect resulting from sealing of the material around the wearer's leg, preventing or restricting the flow of air or liquid to beneath the wearers foot when he or she attempts to raise it.

The resulting suction effect reduces mobility, causes instability and increases the effort required for movement, thereby producing fatigue. A boot may be pulled from the wearer's foot or, where this is not possible, the wearer may become trapped.

It is accordingly an object of the present invention to provide an improved form of waterproof footwear.

Summarv of the Invention According to a first aspect of the present invention there is provided an item of waterproof footwear which includes or is provided with a suction release duct to enable air or liquid to flow beneath the foot portion of said item of footwear when it is being raised within a mass of viscous material.

The suction release duct preferably has a one-way valve which is closed when the item of footwear is subject to downward pressure and is opened when the item of footwear is subject to upward pressure.

The one-way valve is preferably a simple flap valve.

According to a second aspect of the present invention there is provide a method of adapting an item of waterproof footwear, which method includes providing the item of footwear with a suction release duct to enable air or liquid to flow beneath the foot portion of said item of footwear when it is being raised within a mass of viscous material.

Brief Description of the Drawings Figure 1 shows a boot fitted with a first form of suction release duct, Figure 2 is a sectional view of a suction release duct fitted with a one-way valve, Figure 3 shows a boot fitted with a second form of suction release duct, Figure 4 shows the lower part of an item of footwear, e.g. a boot, wader or dry suit, fitted with a suction release duct opening on to the underside of the footwear, and Figure 5 shows the lower part of an item of footwear, e.g. a boot, wader or dry suit, fitted with a suction release duct opening on to the heel of the footwear.

Descrigton of the Preferred Embodiments Figure 1 of the drawings shows a suction release duct I attached to the back of a waterproof boot 2 by means of an adhesive or adhesive tape. The suction release duct 1 is formed of a flexible material and may have the configuration shown in Figure 2, i.e. a one-way valve in the form of a nonnally closed flap 3 is provided at the lower end of the duct 1. When the boot 2 is moved downwardly, the flap 3 will prevent the entry of material into the duct 1, thereby preventing it from becoming clogged. When, however, the boot 2 is moved upwardly and a suction effect is obtained beneath the boot 2, the flap 3 will open, i.e. it will be pulled open downwardly to allow air or liquid within the duct to move downwardly through the open valve. The suction action will thus be released and the restraint to upward movement of the boot 2 will be counter-acted.

As an altemative to attachment of the duct 1 to the boot 2 by means of an adhesive, the lower end of the duct 1 may be provided with a gaiter for attachment to the foot portion of the boot 2 and the upper end of the duct 1 may be provided with a clip for fitment over the upper rim of the boot 2.

Figure 3 shows an arrangement in which the suction release duct 4 is formed as an integral part of the waterproof boot 5, i.e. it is moulded into the boot 5 and the lower end of the duct 4 terminates half-way down the heel of the boot 5. The lower end portion of the duct 4 thus functions as a one-way valve preventing the entry of mud into the duct 4 during downward movement of the boot 5, but permitting opening of the lower end of the duct 4 when the boot 5 is moved upwardly.

In the arrangement shown in Figure 4, the suction release duct 6 extends through to the bottom of the heel 7 of the boot, wader or the like. A normally closed flap 8 is provided beneath the heel 7 and the arrangement is again such that, when the boot, wader or the like is moved downwardly, the flap 8 is in its closed position whereas, when the boot, wader or the -like is moved upwardly, the flap 8 will move into its open position to counter the effect of any suction beneath the heel 7.

Figure 5 shows an arrangement in which the suction release duct 9 terminates at the heel 10 of the boot, wader or the like, the heel 10 including an integral moulded extension 11 which covers the lower end of the duct 9. The extension 11 acts as a shroud to protect the lower end of the duct 9. Thus, although the duct 9 is normally closed by the extension 11 there is a gap between the lower end of the duct 9 and the adjacent surface of the extension 11 thereby allowing air or liquid to pass from the duct 9 through this gap as suction occurs beneath the boot, wader or the like, As shown in the drawings, the suction release duct may be formed as a separate element which is attached by, for example, an adhesive or by means of a gaiter, to the boot, wader or the like.

Altematively, it may be an integrally moulded part of the boot, wader or the like. Various modifications may be made to the particular arrangements shown in the drawings which are purely by way of example.

Claims

Claims:

1. An item of waterproof footwear which includes or is provided with a suction release duct to enable air or liquid to flow beneath the foot portion of said item of footwear when it is being raised within a mass of viscous material.

2. An item of footwear as claimed in Claim 1, in which the suction release duct has a one-way valve which is closed when the item of footwear is subject to downward pressure and is opened when the item of footwear is subject to upward pressure.

3. An item of footwear as claimed in Claim 2, in which the one-way valve is a flap valve.

4. A method of adapting an item of footwear, which method includes providing the item of footwear with a suction release duct to enable air or liquid to flow beneath the foot portion of said item of footwear when it is being raised within a mass of viscous material.

5. An item of footwear as claimed in any one of Claims I to 3, constructed and arranged to function substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

6. A method as claimed in Claim 4, substantially as hereinbefore described with reference to the accompanying drawings.