Patent Application
20050098590
This invention relates generally to a fluid-filled bladder, and, in particular, to a fluid-filled bladder for use with a strap to carry a load.
Bags are often provided with one or more straps to assist individuals carrying the bag. For example, backpacks typically have a pair of shoulder straps to allow an individual to carry the backpack. Golf bags are typically provided with one, and sometimes two, straps that allow the bag to be carried over the shoulder or shoulders of an individual. Messenger bags, such as those used by bicycle messengers, are typically provided with a single strap, with the strap strung around the neck of the user and resting on their shoulder. Backpacks, golf bags, and other bags, when fully loaded, can be quite heavy. Consequently, providing comfortable straps is considered highly desirable. Such straps typically consist of a length of webbing that connects at either end to the bag, and include padding along a central section of the strap. The padding may consist of a soft fiber, or may include an air-filled bladder.
U.S. Pat. No. 6,223,959 discloses a strap that is connected at either end to a bag. A central portion of the strap includes an air pocket formed of a plurality of non-communicating air chambers. Since the chambers do not communicate with one another, there can be no compensation for different weights and pressure points throughout the air pocket. Such a strap is limited in the amount of pressure distribution it can achieve, and is not able to conform about the surface of the user's shoulder, which may lead to fatigue and discomfort for the wearer.
It is an object of the present invention to provide a fluid-filled bladder for use with a strap to carry a load that reduces or wholly overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain preferred embodiments.
In accordance with a first aspect, a bladder for use with a strap to carry a load includes a first longitudinal chamber, a second longitudinal chamber spaced apart from and substantially parallel to the first longitudinal chamber, and a plurality of transverse chambers. Each transverse chamber is connected at a first end thereof to the first longitudinal chamber and at a second end thereof to the second longitudinal chamber, is in fluid communication with the first and second longitudinal chambers, and has a longitudinal axis extending substantially parallel to the longitudinal axis of the other transverse chambers.
In accordance with another aspect, a strap for a device carrying a load includes a pad having a central aperture formed therein and a fluid-filled bladder positioned within the central aperture and secured to the pad. A length of webbing is slidably connected to first and second ends of the pad.
In accordance with a further aspect, bag carrying device includes a bag and a length of webbing connected at opposed ends thereof to the bag. A pad has a central aperture formed therein, and the length of webbing is slidably secured to first and second ends of the pad. A fluid-filled bladder is positioned within the central aperture and secured to the pad. The bladder includes a first longitudinal chamber, a second longitudinal chamber spaced apart from and substantially parallel to the first longitudinal chamber, and a plurality of transverse chambers. Each transverse chamber is connected at a first end thereof to the first longitudinal chamber and at a second end thereof to the second longitudinal chamber, is in fluid communication with the first and second longitudinal chambers, and has a longitudinal axis extending substantially parallel to the longitudinal axis of the other transverse chambers. A flange portion surrounds the first and second longitudinal chambers and is secured to the pad. Each of a plurality of elongate transverse apertures is disposed between adjacent transverse chambers, has a longitudinal axis extending substantially parallel to a longitudinal axis of each of the other transverse apertures, and is positioned at an angle with respect to a longitudinal axis of the bladder.
In accordance with yet another aspect, a bladder for use with a strap to carry a load includes a serpentine chamber formed of plurality of longitudinal chambers and a plurality of transverse chambers. Each transverse chamber is connected at ends thereof to, and is in fluid communication with, corresponding longitudinal chambers. A flange portion surrounds the serpentine chamber. An elongate first flange aperture is formed in the flange portion proximate an endmost transverse chamber. An elongate second flange aperture is formed in the flange proximate an opposed endmost transverse chamber and has a longitudinal axis extending substantially parallel to a longitudinal axis of the first flange aperture. A longitudinal axis of each of the first and second flange apertures is disposed at an angle with respect to a longitudinal axis of the bladder. Each of a plurality of elongate transverse apertures is disposed between adjacent transverse chambers and has a longitudinal axis extending substantially parallel to a longitudinal axis of each of the other transverse apertures. The longitudinal axis of each transverse aperture is disposed at an angle with respect to a longitudinal axis of the bladder.
In accordance with yet a further aspect, a bladder for use with a strap to carry a load includes at least one longitudinal chamber and a plurality of transverse chambers. Each transverse chamber is connected at a first end thereof to at least one longitudinal chamber, is in fluid communication with the at least one longitudinal chamber and each other transverse chamber, and has a longitudinal axis extending substantially parallel to the longitudinal axis of the other transverse chambers.
Substantial advantage is achieved by providing a fluid-filled bladder for use with a bag-carrying strap. In particular, the fluid-filled bladder can provide superior cushioning, excellent pressure distribution, and improved ergonomic fit. Consequently, a user can carry heavy loads with less fatigue and discomfort, allowing a bag to be more easily carried by individuals.
These and additional features and advantages of the invention disclosed here will be further understood from the following detailed disclosure of certain preferred embodiments.
FIGS. 10A-B are front and rear elevation views, respectively, of a shoulder strap assembly incorporating the fluid-filled bladder of the present invention shown securing a backpack to a user's shoulders.
The figures referred to above are not drawn necessarily to scale and should be understood to present a representation of the invention, illustrative of the principles involved. Some features of the fluid-filled bladder for use with a strap depicted in the drawings have been enlarged or distorted relative to others to facilitate explanation and understanding. The same reference numbers are used in the drawings for similar or identical components and features shown in various alternative embodiments. Fluid-filled bladders for use with a strap as disclosed herein, would have configurations and components determined, in part, by the intended application and environment in which they are used.
The present invention may be embodied in various forms. A preferred embodiment of a bladder 8 for use with a strap for a bag is shown in
Bladder 8 may be formed of a polymer material, such as a thermoplastic elastomer, that is substantially impermeable to fluid. More specifically, the material forming bladder 8 may be, for example, a film formed of alternating layers of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer, as disclosed in U.S. Pat. Nos. 5,713,141 and 5,952,065 to Mitchell et al, each of which is incorporated herein by reference. A variation upon this material includes a center layer formed of ethylene-vinyl alcohol copolymer; two layers adjacent to the center layer that are formed of thermoplastic polyurethane; and outer layers formed of a regrind material of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer. Another suitable material is a flexible microlayer membrane that includes alternating layers of a gas barrier material and an elastomeric material, as disclosed in U.S. Pat. Nos. 6,082,025 and 6,127,026 to Bonk et al., each of which are also incorporated herein by reference. Other suitable thermoplastic elastomer materials or films include polyurethane, polyester, polyester polyurethane, polyether polyurethane, such as cast or extruded ester-based polyurethane film. Additional suitable materials are disclosed in U.S. Pat. Nos. 4,183,156 and 4,219,945 to Rudy. Among the numerous thermoplastic urethanes that are suitable for forming bladder 8 are urethanes such as Pellethane, a product of the Dow Chemical Company; Elastollan, a product of the BASF Corporation; and Estane, a product of the B.F. Goodrich Company, all of which are either ester or ether based. Still other thermoplastic urethanes based on polyesters, polyethers, polycaprolactone, and polycarbonate macrogels may be employed. Nitrogen blocking barrier materials may also be utilized. Further suitable materials include thermoplastic films containing a crystalline material, as disclosed in U.S. Pat. Nos. 4,936,029 and 5,042,176 to Rudy, hereby incorporated by reference, and polyurethane including a polyester polyol, as disclosed in U.S. Pat. Nos. 6,013,340; 6,203,868; 6,321,465; and 6,391,405 to Bonk et al., each of which are also incorporated herein by reference.
The fluid contained by bladder 8 may vary to include any of the disclosed fluids in U.S. Pat. No. 4,340,626 to Rudy, such as hexafluoroethane and sulfur hexafluoride, for example. In addition, bladder 8 may include nitrogen gas or air at a desired pressure level. In some applications, the pressure of the gas contained by bladder 8 may be at ambient pressure. In addition, a pump system may be employed that permits the individual to selectively pressurize bladder 8 to a desired pressure.
Chamber 12 is formed of a first longitudinal chamber 16, and a second longitudinal chamber 18, which is spaced apart from and extends substantially parallel to first longitudinal chamber 16. A plurality of transverse chambers 20 extends between first and second longitudinal chambers 16, 18. A first end 22 of each transverse chamber 20 is connected to and in fluid communication with first longitudinal chamber 16. Correspondingly, a second end 24 of each transverse chamber 20 is connected to and in fluid communication with second longitudinal chamber 18. Thus, chamber 12 is a contiguous chamber formed of longitudinal chambers 16, 18 and the plurality of transverse chambers 20, all in fluid communication with one another.
A longitudinal axis C of each transverse chamber 20 is substantially parallel to the longitudinal axis C of each of the other transverse chambers 20. In a preferred embodiment, each longitudinal axis C is disposed at an angle β with respect to a longitudinal axis L of bladder 8. In a preferred embodiment, angle β may be between approximately 1° and approximately 89°, more preferably between approximately 35° and approximately 60°, and most preferably approximately 50°.
An elongate transverse aperture 26 is disposed between each adjacent pair of transverse chambers 20. A longitudinal axis A of each elongate transverse aperture 26 is substantially parallel to the longitudinal axis A of each of the other elongate transverse apertures 26. In a preferred embodiment, each longitudinal axis A is disposed at an angle a with respect to longitudinal axis L of bladder 8. In a preferred embodiment, angle α may be between approximately 1° and approximately 89°, more preferably between approximately 35° and approximately 60°, and most preferably approximately 50°.
Elongate first and second flange apertures 28, 30 are positioned in opposite ends of flange 14, each located proximate an endmost transverse chamber 20. First and second apertures 28, 30 each have a longitudinal axis B that is substantially parallel to the longitudinal axis B of the other aperture. In a preferred embodiment, each longitudinal axis B is disposed at an angle Δ with respect to longitudinal axis L of bladder 8. In a preferred embodiment, angle Δ may be between approximately 1° and approximately 89°, more preferably between approximately 35° and approximately 60°, and most preferably approximately 50°.
As seen in
In the embodiment illustrated in
By positioning bladder 8 with its chamber 12 within a central portion of strap assembly 32, a user is provided with a substantial cushion to help support the load carried in bag 42.
In the embodiment illustrated in
The illustrated embodiment shows eight transverse apertures 26, however, it is to be appreciated that the number of apertures in bladder 8 may vary, and may be greater or less than the eight illustrated here. The number of apertures may vary based on the size of bladder 8, the desired size of transverse apertures 26 and the size of webbing 40.
In a preferred use, strap assembly 32 is positioned on a user's shoulders such that chamber 12 is in contact with the user's shoulder. That is, webbing 40 is positioned above chamber 12 with respect to the user's shoulder. Thus, in the embodiment illustrated in
In a preferred embodiment, webbing 40 is formed of nylon, however, it is to be appreciated that many materials will be suitable for webbing 40 including natural and synthetic materials.
In another preferred embodiment, as illustrated in
In another preferred embodiment, as illustrated in
Elongate first and second flange straps 54, 56 are positioned in opposite ends of flange 14, each located proximate an endmost transverse chamber 20. A longitudinal axis F of each of first and second flange straps 54, 56 are substantially parallel to the longitudinal axis F of the other strap. In a preferred embodiment, each longitudinal axis F is disposed at an angle θ with respect to longitudinal axis L of bladder 8. In a preferred embodiment, angle θ may be between approximately 1° and approximately 89°, more preferably between approximately 35° and approximately 60°, and most preferably approximately 50°.
In this embodiment, webbing 40 extends along second side 48 of pad 36, passing under at least some of transverse straps 52 and flange straps 54, 56. In a preferred embodiment, webbing 40 passes under each transverse strap 52 and both flange straps 54, 56. Transverse straps 52 and flange straps 54, 56 work with webbing 40 to safely secure bladder 8 and pad 36 to webbing 40, while at the same time providing the flexibility to move pad 36, as well as bladder 8, along webbing 40 to a desired location. In the embodiment shown in
Regardless of how webbing 40 is secured to bladder 8, i.e., whether webbing 40 is woven through transverse apertures 26 in chamber 12, or through transverse straps 52, by positioning bladder 8 between webbing 40 and the user's shoulder, webbing 40 can act as a compression strap, as seen in
In certain preferred embodiments, as seen in
Another preferred embodiment of a bladder 60 is shown in
A plurality of transverse apertures 72 are formed in bladder 60. Each aperture 72 is positioned between adjacent transverse chambers 66. A longitudinal axis T of each aperture 72 is substantially parallel to the longitudinal axis T of the other apertures 72. In a preferred embodiment, each longitudinal axis T is disposed at an angle π with respect to longitudinal axis V of bladder 60. In a preferred embodiment, angle π may be between approximately 1° and approximately 89°, more preferably between approximately 35° and approximately 60°, and most preferably approximately 50°.
As noted above, longitudinal axis A of each transverse aperture 26 is disposed at angle a with respect to longitudinal axis L of bladder 8; longitudinal axis B of first and second apertures 28, 30 is disposed at an angle Δ with respect to longitudinal axis L of bladder 8; longitudinal axis S of each transverse strap 52 is disposed at angle φ with respect to longitudinal axis L of bladder 8; longitudinal axis F of each of flange straps 54, 56 is disposed at angle 0 with respect to longitudinal axis L of bladder 8, and longitudinal axis T of each of aperture 72 is disposed at angle π with respect to longitudinal axis V of bladder 60. Angling transverse apertures 26, first and second apertures 28, 30, transverse straps 52, flange straps 54, 56, and apertures 72 provides a desired twist or curve in strap assembly 32 when webbing 40 is woven therethrough.
The resultant twist or curve of a strap assembly is illustrated in FIGS. 10A-B, where two strap assemblies 32A and 32B are shown securing a backpack 74 to the back of a person 76. Each strap assembly is a mirror image of the other, with the outer side of strap assemblies 32A 32B, that is, the sides of the straps not in contact with the wearer, being visible in this drawing. By angling the apertures or straps of the bladders as seen here, that is, downwardly from the inner side of a strap toward the outer side, the strap assembly is twisted appropriately to wrap around the user's shoulders. Strap assemblies 32A and 32B are especially suitable for use on a backpack, since the natural twist or curve of the strap assemblies provide an excellent ergonomic fit about the shoulders of a wearer. As seen here, a suitable strap assembly 32A for the user's right shoulder is provided, while a corresponding suitable strap assembly 32B is provided for the user's left shoulder.
It is to be appreciated that bladders in accordance with the present invention can take on many shapes. A number of examples of additional preferred embodiments are schematically illustrated in
Another preferred embodiment is shown in
Another preferred embodiment is shown in
A first end 148 of a third transverse chamber 150 is connected to and in fluid communication with second longitudinal chamber 132. A first end 152 of a fourth transverse chamber 154 is connected to and in fluid communication with second transverse chamber 132. A first end 156 of a fifth transverse chamber 158 is connected to and in fluid communication with third longitudinal chamber 134. A second end 160 of fourth transverse chamber 154 is connected to and in fluid communication with a second end 162 of fifth transverse chamber 158. This embodiment has a substantially serpentine shape, with the addition of one transverse chamber (transverse chamber 150) that is not part of the serpentine shape.
Another preferred embodiment is shown in
A longitudinal axis N of each transverse chamber is substantially parallel to the longitudinal axis N of the other transverse chambers. In a preferred embodiment, each longitudinal axis N is disposed at an angle R with respect to longitudinal axis L of bladder 128. In a preferred embodiment, angle R may be between approximately 1° and approximately 89°, more preferably between approximately 35° and approximately 60°, and most preferably approximately 50°.
In light of the foregoing disclosure of the invention and description of the preferred embodiments, those skilled in this area of technology will readily understand that various modifications and adaptations can be made without departing from the scope and spirit of the invention. All such modifications and adaptations are intended to be covered by the following claims.
