Rubber footwear with neoprene layer
A waterproof footwear includes a neoprene sock having a floor region and a side wall extending upward therefrom terminating in an upper edge. An outer rubber layer is bonded to and covers the entire outer surface of the neoprene sock side wall. A rubber floor portion covers the floor region of the neoprene sock and an outsole is attached to the rubber layer.
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 The present invention relates generally to the field of footwear and more particularly to a waterproof rubber footwear. Waterproof footwear such as boots are used in outdoor recreational activities as well as in a number of industrial and professional uses. Specifically waterproof boots are used in hunting and fishing to ensure that the sportsman feet remain dry during the recreational activity. Additionally, waterproof boots are used in the animal husbandry and farming environments as well as by firefighters.
 One type of waterproof boot includes an outer rubber waterproof layer. The use of rubber as the waterproof material provides a number of functional benefits. One such benefit is that rubber of sufficient thickness is strong and resilient, resistant to punctures, durable, and in the area of outdoor recreational sports is scent proof. However, rubber boots are typically inflexible, heavy, and do not fully fit the foot and/or leg of the user very well.
 There have been a number of attempts to provide a waterproof boot to minimize the negative aspects of rubber. One such attempt has been made by the Muck Boot Company which has replaced the outer rubber material with a neoprene material covered with an outer layer of fabric. While the neoprene covered fabric provides a waterproof boot, the neoprene is not as durable or puncture proof as rubber. Additionally, the nylon coated neoprene absorbs and gives off scent which is undesirable for the outdoor sportsman.
 Another attempt to use a neoprene inner sock is disclosed in U.S. Pat. No. 5,937,543 entitled “Footwear having a Variable Sized Interior” by the U.S. Navy. The '543 patent discloses a neoprene inner sock that is smaller than and partially attached to the outer rubber covering so that users with different feet size may be able to use the same boot. However, U.S. Pat. No. 6,427,362 entitled “Boot with Strapping to Restrain Movement of Foot” assigned to Norcross Safety Products, L.L.C., argues that the boot disclosed in the '543 patent “cannot be easily manufactured with a predominantly rubber upper and with a predominantly rubber sole, by conventional vulcanizing methods, as closed cell neoprene foam takes a set and loses its elasticity when vulcanized” [See Col. 1 lines 35-46].
 Accordingly, it would be desirable to provide a rubber boot that is durable, puncture resistant, light weight, flexible, and scent proof, and fits and conforms to the foot in a comfortable way. It would further be desirable to combine the thermal protection of neoprene with the waterproof layer of rubber in order to provide thermal protection that still allows the boot to be lightweight and flexible.SUMMARY OF THE INVENTION
 One feature of the invention is to provide a waterproof boot that is lightweight and flexible. Another feature of the invention is to provide a lightweight waterproof boot with thermal protection. A further feature of the invention is to provide a rubber coated waterproof boot having a neoprene layer that is scent proof.
 In one embodiment, a shoe includes a neoprene sock having a floor region and a side wall extending upward therefrom terminating in an upper edge. An outer rubber layer is bonded to and covers the entire outer surface of the neoprene sock side wall. A rubber floor portion covers the floor region of the neoprene sock and an outsole is attached to the rubber layer.
 In another embodiment a waterproof boot includes an upper including an outer layer of rubber and an inner layer of neoprene. The rubber covered neoprene extends to a top edge of the upper. A floor includes a neoprene portion attached to the neoprene layer of the upper, and a rubber portion bonded to the neoprene portion and the rubber layer of the upper. An outsole is attached to the upper forming a waterproof barrier.
 In still another embodiment, a method for manufacturing a waterproof shoe includes first forming a sock from a neoprene material having an inner surface and an outer surface; a floor region configured to contact the bottom portion of a user's foot, and an upper region extending from the floor region and terminating at an upper edge. The neoprene sock is then placed over a last such that the outer surface is exposed. A rubber layer of material is placed over the entire upper region of the outer surface of the neoprene sock. The rubber covered neoprene sock is then vulcanized.
 In yet another embodiment, a footwear includes an upper including a neoprene layer having an inner surface, an outer surface, a lower edge, and an upper edge. An outer rubber layer is bonded to and covering substantially the entire outer surface of the neoprene layer. An outsole is attached to the outer rubber layer. The outer rubber layer may also be bonded to and completely cover the entire outer surface of the neoprene layer.
 In a further embodiment, a waterproof footwear includes an upper including an outer layer of rubber and an inner layer of neoprene. The rubber covered neoprene extends to a top edge of the upper. A floor includes a neoprene portion attached to the neoprene layer of the upper. A rubber portion is bonded to the neoprene portion and the rubber layer of the upper. A rubber outsole is attached to the upper forming a waterproof barrier.
 In still another embodiment a method for making footwear includes covering an upper region of a last with a layer of neoprene having an outer surface. The layer of neoprene is then substantially covered with a layer of rubber. The rubber layer and neoprene layer is then vulcanized.BRIEF DESCRIPTION OF THE DRAWINGS
 FIG. 1 is a cross sectional view of one embodiment of the waterproof footwear.
 FIG. 2 is a metal last used in the manufacture of the waterproof footwear boot.
 FIG. 3 is a sock sewn out of neoprene material.
 FIG. 4 is a neoprene sock stretched over the last of FIG. 2.
 FIG. 5 is a schematic of the rubber sheets with cement applied thereto.
 FIG. 6 is a the rubber sheets adhesively attached to the neoprene sock.
 FIG. 7 is the outsole to be adhered directly to the rubber covered neoprene.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 Referring to FIG. 1, a boot 10 includes an upper 12, an outsole 14, a midsole 16, and an insole 18. Upper 12 includes an outer rubber layer 20 extending around an inner neoprene sock 22 having an outer neoprene layer 24 and a inner fleece layer 26. The inner layer 26 could be other materials known in the art including but not limited to THINSULATE, cotton, nylon, cotton, canvas, mesh or wool. The term fleece is used herein to represent any of these materials. The neoprene layer 24 extends to a top edge 28 of the upper 12.
 Neoprene sock 22 is formed from at least two pieces of neoprene material. One piece of neoprene material defines a floor region 30 upon which a users foot rests and a second upper region 32 surrounding the sides and top of a user's foot including the ankle and calf region. The floor region 30 of the neoprene layer may be connected to the upper region 32 of neoprene by a threaded stitch 34.
 The neoprene sock 22 forms the foundation upon which the entire boot 10 is constructed. Referring to FIGS. 2-7, the neoprene sock 22 is placed upon a metal last 36 that defines the interior region of boot 10. The neoprene sock 22 is stretched over the metal last 36 with the fleece layer 26 adjacent last 36 and with the neoprene layer 24 of sock 22 facing outward. A plurality of individual rubber sheets or pieces 38 are cut to cover the exposed layer of neoprene. A bonding cement is applied to one or both of the rubber sheets and neoprene sock in order to temporarily secure the rubber pieces 38 to neoprene layer 26. The rubber sheets 38 cover both upper portion 32 of the neoprene sock 22 as well as the floor portion 30 of neoprene sock 22. In this manner rubber sheets 38 completely cover the neoprene sock 22.
 In the next step of the operation, a sole 40 including a rubber outsole 14 and a midsole 16 is adhesively applied directly to the rubber sheet 38 covering the floor portion 30 of neoprene sock 22. The sole 40 further includes an upwardly extending portion 42 that covers a lower edge 44 of the rubber layer 20 material. Finally the entire assembly is placed into an autoclave and subject to heat and pressure to vulcanize the rubber sheets 38 such that the rubber material bonds directly to the neoprene layer 24 and to outsole 40.
 In another embodiment an insole 18 is located between the floor portion 30 of neoprene sock 22 and rubber material 38 that covers the floor portion 30. Insole 18 is adhesively attached to the floor portion 30 to provide a smooth planar surface upon which the rubber material portion 38 is applied to the rubber material 38 forming the upper. Insole 18 may be formed from one or more pieces of material as is commonly known in the art. The sole 40 is then applied as discussed above prior to being vulcanized.
 In another embodiment, midsole 16 is formed of an EVA (ethyl vinyl acetate) material providing a lighter weight material than a rubber midsole. Sole 40 with an EVA midsole may be attached to the rubber upper prior to or after vulcanization. However, midsole 16 may also be formed from other materials such as polyurethane, rubber, phylon or other materials known in the art.
 The neoprene layer 24 and outer rubber sheets 38 once vulcanized provide a flexible composite which is less rigid than previously rubber boots since the neoprene material provides and allows for the outer rubber sheets 38 to retain a certain degree of resiliency. The rubber material 38 is bonded directly to the neoprene material 22 around the entire region upon which the rubber is in contact with the outer surface of a neoprene layer. As illustrated in FIG. 1 the rubber layer 20 encompasses the entire outer periphery of the neoprene sock 22 covering the bottom of floor portion 30 of a neoprene sock 22 to the top 28 edge of the upper 12 of boot 10.
 In an alternative embodiment, the outer rubber material forms an outer bond upon which an insole 18 is sandwiched between the floor portion 30 and the lower rubber material 38. However, the entire region from the heel and toe upward to the top edge 28 of boot 10 the rubber is attached to the neoprene liner or sock 22 prior to vulcanization. This continuous bonding allows for the rubber and neoprene material to provide a flexible and resilient feel for the user while also allowing for a durable puncture proof outer surface and further retaining the scent proof characteristic that is desirable for this product.
 In one preferred embodiment, the rubber layer 20 covering the neoprene layer 24 is about 0.030 inches. The neoprene sock 22 itself is 4.5 millimeters thick with the neoprene layer 24 being about 3 millimeters thick and the fleece layer 26 on the inside surface of the neoprene being 1.5 millimeters. Accordingly, the total thickness of the outer rubber layer 20, neoprene layer 24 and fleece 26 layer is approximately 0.250 inches. Of course the layers may be of other thickness as well.
 In a preferred embodiment, the neoprene layer 24 is a closed cell foam rubber which may be SBR or CR type. However, other types of neoprene may also be used and still fall within the scope of the invention. It should also be noted that the thickness of the neoprene layer 24 may be less than or greater than 0.030 inches. The rubber boot 10 as disclosed in the embodiment shown in FIG. 2 includes a midsole 16 formed of a EVA material that is substantially lighter than a similar rubber boot that does not use a neoprene layer and having a midsole formed of rubber. In fact, this type of boot disclosed is 30% lighter than similar boots with an all rubber sole and a separate THINSULATE layer that is currently used in the prior art.
 This resulting construction includes both a reduction in weight by the utilization of neoprene and by changing the way the outsole is attached to provide for a midsole made of EVA material. Additionally, there is an improved fit to the user because a neoprene rubber combination stretches and forms to a users foot. The boot may be smaller in size and volume for a particular user since it will be more snug to the foot and its greater resiliency allows for a more comfortable wear and a smaller size. The increased resiliency of the rubber coated neoprene allows a user to roll over the shaft area 46 of upper 12. Additionally, the resilient nature of the rubber coated neoprene allows the shaft area 46 to be repeatedly rolled or folded over without out the danger of cracking or failure of the rubber layer.
 The sloppy fit or loose fit that has been accompanied with large rubber boots is thereby eliminated. The large fit was required due to the inflexibility and hardness of the outer rubber material which results when the outer rubber material is bonded to the standard nylon material as used in the art. Since neoprene material provides insulative properties, the amount of fleece that would otherwise be required in the boot is reduced thereby adding to the reduction both in bulk and weight of the overall product. As illustrated in FIG. 1, the neoprene layer 24 extends from the top edge 28 of upper 12 through the vamp area 48 around the toe region across the floor of the boot, and around the heel and ankle region of the boot. In one embodiment, the neoprene layer is secured to a rubber layer completely around the entire outer periphery of the neoprene layer. In an alternative embodiment, the outer rubber layer is bonded to the neoprene layer 24 in all regions except where an insole 18 is placed between the floor portion 30 and the rubber floor covering 50. In both of these embodiments, a complete waterproof rubber layer is formed about the neoprene sock 22 independent of the sole 40. Of course it is contemplated that the rubber floor portion 50 may be omitted if desired. However, any leaking that may occur between the sole 40 and upper 12 may result in water seeping into the inner area of the boot through stitches 34, or any other seam that may be created to attach the neoprene floor portion 30 with the upper portion of the neoprene sock 22.
 In one embodiment, the upper edge of the neoprene layer in the upper of the footwear is at least 4 inches from the bottom of the sole. In another embodiment, the upper edge of the neoprene layer is at least six inches from the bottom of the sole. In certain applications such as boots, the upper edge of the neoprene layer may be at least 18 inches from the bottom of the sole. Additionally, in footwear used as hip or chest waders, the upper edge of the neoprene layer may be up to 60 inches or higher from the bottom of the sole. The neoprene material placed on the last in the method of manufacture may include a floor portion or only an upper portion. It may also be possible to construct the neoprene material while on the last, however in a preferred embodiment the neoprene material is formed into a sock having at least an upper tube portion and in another embodiment the sock includes a floor portion. In one embodiment, the upper edge of the neoprene material extends to the upper edge of the footwear and is completely covered with the outer rubber layer. In another embodiment, the upper edge of the neoprene material may be lower than the upper-edge of the outer rubber material. It is also possible that a flexible rubber section such as a folded pleat be built into a portion of the footwear proximate the upper edge of the footwear and extending only a portion of the upper periphery of the footwear. Similarly, an expansion portion maybe located proximate the upper edge of the footwear and include a piece of material that is flexible to allow for easier expansion and stretching than the neoprene and rubber bonded layers. The flexible region may include a section of rubber 60 that is not bonded to an inner layer of neoprene.
 It will be understood that the above description is exemplary embodiments and that the invention is not limited to the specific embodiments described. Various substitutions, modifications, changes, and omissions may be made in the arrangement of the elements without departing from the scope of the invention as expressed in the appended claims.
1. A footwear comprising:
- an upper including a neoprene layer having an inner surface, an outer surface, a lower edge, and an upper edge;
- an outer rubber layer bonded to and covering substantially the entire outer surface of the neoprene layer; and
- an outsole attached to the outer rubber layer.
2. The footwear of claim 1, further including a neoprene floor portion including a neoprene portion attached to the neoprene layer.
3. The footwear of claim 1, further including a rubber floor portion covering the neoprene floor portion and bonded to the outer rubber layer.
4. The footwear of claim 1, wherein the outer rubber layer includes an upper edge coterminous with the upper edge of the neoprene sock.
5. The footwear of claim 1, further including a layer of material attached to the inner surface of the neoprene layer.
6. The footwear of claim 1, wherein the rubber floor portion is bonded directly to the neoprene floor portion.
7. The footwear of claim 6, further including a midsole formed from ethyl vinyl acetate.
8. The footwear of claim 6, further including an insole located between the neoprene floor portion and the rubber floor portion.
9. The footwear of claim 5, wherein the neoprene floor region is stitched to the inner layer of neoprene.
10. The footwear of claim 1, wherein the outer rubber layer does not hold a human scent.
11. A waterproof footwear comprising:
- an upper including an outer layer of rubber and an inner layer of neoprene, the rubber covered neoprene extending to a top edge of the upper;
- a floor including a neoprene portion attached to the neoprene layer of the upper, and a rubber portion bonded to the neoprene portion and the rubber layer of the upper;
- a rubber outsole being attached to the upper forming a waterproof barrier.
12. The waterproof footwear of claim 11, including a layer of material secured to the neoprene layer distal the rubber layer.
13. The waterproof footwear of claim 12, wherein the layer of material is fleece.
14. The waterproof footwear of claim 13, including a midsole located between the outsole and floor and being formed of ethyl vinyl acetate.
15. The waterproof footwear of claim 14, further including an insole located between the floor portion and the midsole.
16. A method of manufacturing a waterproof footwear comprising:
- covering an upper region of a last with a layer of neoprene having an outer surface;
- covering substantially all of the layer of neoprene with a layer of rubber; and
- vulcanizing the rubber layer and neoprene layer.
17. The method of claim 16, further including covering a bottom portion of the last with a layer of neoprene defining a floor region.
18. The method of claim 17, further including adhering a rubber layer of material to the neoprene floor region.
19. The method of claim 17, including forming the neoprene sock by stitching a floor portion to at least one other neoprene piece of material.
20. The method of claim 18, further including securing a rubber outsole to the rubber covered neoprene layer.
21. The method of claim 20, further including securing a midsole formed from ethyl vinyl acetate to the outsole.
22. The method of claim 18, further including placing an insole between the floor portion of the neoprene material and floor portion and the rubber layer prior to the vulcanizing step.
23. The method of claim 22, further including attaching a material to the inner surface of the neoprene layer.
24. The method of claim 23, wherein the material is fleece.
25. The method of claim 16, wherein the layer of neoprene is completely covered by the layer of rubber.
International Classification: A43B001/12;