RELATED APPLICATIONS
None
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable
REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING
Not Applicable
BACKGROUND OF THE INVENTION
A number of joint protection devices have been developed. For instance, those used for sports generally have a hard outer shell with a pad attached to the hard outer shell by a fabric sheath or covering. The device is attached to a person by elastic straps or by placing the device in a pocket of a garment. The pad is commonly made of foam, formed from a carbon polymer. A variation has been to eliminate the hard outer shell and replace it with a durable cloth cover. An elastic band is generally used to attach to the device to the user.
Workers that are required to be on their knee or elbows have adopted some of these joint protection devices with mixed results. For instance, placing hard shell knee protection devices over a workers pants is uncomfortable to walk in and the hard shell tends to rock from side to side in use. Similar problems have been found for elbow protection devices.
One solution has been to place foam pads in specially designed pockets in the knee of pants. There have been a number of problems with this design, including the foam pads have to be removed to wash the pants and the workers knees tend to roll off the edge of the foam pads. In addition, none of these solutions meet the new OHSA requirement for flame resistant or flame retardant clothing (FRC). Carbon based polymers are highly flammable.
Thus there exists a need for a joint protection device that is comfortable to wear all day and meets the flame retardant/flame resistant requirements.
BRIEF SUMMARY OF INVENTION
A joint protection device that overcomes these and other problems has a frame of an elastomeric material. The elastomeric material has a flash point above 500 degrees Celsius. A solid face is attached to the frame. The solid face has a first side and a second side and has a high gas permeability for an elastomer. A hardness adjustable structure is attached to the second side of the solid face. The hardness adjustable structure does not support microbiological growth. In one embodiment, the elastomer is a silicone rubber, which meets the FRC requirements. This also makes the device flexible so that it is more comfortable to wear.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a front view of a joint protection device in accordance with one embodiment of the invention;
FIG. 2 is a side view of a joint protection device in accordance with one embodiment of the invention;
FIG. 3 is a cross sectional view of the joint protection device of FIG. 1 in accordance with one embodiment of the invention;
FIG. 4 is an alternative embodiment of the cross sectional view of the joint protection device of FIG. 3 in accordance with one embodiment of the invention;
FIG. 5 is a front view of a joint protection device in accordance with one embodiment of the invention; and
FIG. 6 a flow chart of the steps used in creating a joint protection device in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention is directed to a joint protection device that has a frame of an elastomeric material. The elastomeric material has a flash point above 500 degrees Celsius. A solid face is attached to the frame. The solid face has a first side and a second side and has a high gas permeability for an elastomer. A hardness adjustable structure is attached to the second side of the solid face. The hardness adjustable structure does not support microbiological growth. In one embodiment, the elastomer is a silicone rubber, which meets the FRC requirements. This also makes the device flexible so that it is more comfortable to wear.
FIG. 1 is a front view of a joint protection device 10 in accordance with one embodiment of the invention. The device 10 has a frame 12. In one embodiment the frame 12 is made of an elastomeric material that has a flash point above 500 degrees Celsius. A hardness adjustable structure 14 is attached to the frame 12. The hardness adjustable structure 14 has a plurality of voids 16. In one embodiment, the plurality of voids 16 are arranged in a two dimensional hexagonal close packed structure. The voids 16 are shown in a uniform arrangement, but alternative embodiments have non-uniform patterns of voids and different sizes and shapes of voids. In one embodiment, the hardness adjustable structure is made of a material that does not support microbiological growth. The hardness of the structure 14 can be adjusted by changing the size and spacing of the voids 16. Note that the embodiment of the device 10 in FIG. 1 is for knees, however the invention is not limited to knee protection devices.
FIG. 2 is a side view of a joint protection device 10 in accordance with one embodiment of the invention. This figure shows that the device 10 is not flat but has a curved shape. The face 18 that is not against the joint is a solid face 18 in one embodiment. The advantage of a solid face 18 is that it prevents the joint from coming into contact with liquid. It also provides additional protection from small sharp points such as nail heads or staples.
FIG. 3 is a cross sectional view of the joint protection device of FIG. 1 in accordance with one embodiment of the invention. The device 10 has a frame 12. One face 18 of the device is solid. A plurality of cylindrical voids 16 are formed in the face 20 of the device 10 that is placed against the users joint. Note that the cylindrical voids 16 are not perpendicular to the face 20 or the face 18 but are sloped. In one embodiment, the slope is designed to be equal to the expected direction of travel of the joint when impacting an object. So in the case of a knee protection device the knee is likely to be traveling up so the voids 16 are sloped up from the face 20 to the face 18. This provides the maximum protection in the direction most likely to experience a large blow. The joint protection device 10 may be attached to the user by placing it in a cloth cover with elastic straps. Alternatively, it may also be attached by placing it in clothing the user wears. The invention is not limited to any particular method of attaching the protection device to the user.
In general, the joint protection device 10 is made of a single material. The preferred material is a nonorganic polymer such as silicone rubber. Most of the prior art devices are made of organic polymers. Silicone rubber offers good resistance to extreme temperatures, being able to operate normally from −55° C. to +300° C. Silicone rubber has a flash point of +750° C. At the extreme temperatures, the tensile strength, elongation, tear strength and compression set can be far superior to conventional rubbers. Organic rubber has a carbon to carbon backbone which can leave them susceptible to ozone, UV, heat and other ageing factors that silicone rubber can withstand well. This makes it one of the elastomers of choice in many extreme environments. Silicone rubber has a high gas permeability compared to organic elastomers, which allows it to breath. It is water resistant, is a good electrical insulator, and has low toxicity but does not support microbiological growth. This makes it a much better material than organic polymer foams used in most prior art joint protection pads. The silicone rubber of the present device may be solid or it may be foamed. Foaming the silicone rubber can allow for different hardness of the device. For instance, fewer bubbles will produce a harder device, while more bubbles and open cell foams will produce a lower hardness. The hardness of the device can also be adjusted by the formulation of the silicone rubber or some combination of these methods.
FIG. 4 is an alternative embodiment of the cross sectional view of the joint protection device of FIG. 3 in accordance with one embodiment of the invention. In this embodiment, the voids 16 extend all the way through. This embodiment also shows voids 16 that are perpendicular to the face 20. There are applications where a solid face 18 is not desirable. Having voids 16 all the way through the device provides additional cooling for the user and allows sweat to dissipate. Note that the thickness of the device varies along its length and may also vary along its width.
FIG. 5 is a front view of a joint protection device 30 in accordance with one embodiment of the invention. This joint protection device 30 is designed for elbow joints. The device 30 has a frame 32 and a solid face 34. The voids are channels 36 that form bumps or dimples 38. By varying the size of the dimples 38 or voids 36 the hardness of the structure is adjustable to provide the best protection and comfort for the user. For instance, a rigid shell may provide great protection from sharp impacts, but is not comfortable for the user if the joint is experiencing constant pressure. The hardness can also be varied selecting a foamed silicone. This can be used in conjunction with the changes in the pattern of voids.
FIG. 6 a flow chart of the steps used in creating a joint protection device in accordance with one embodiment of the invention. The process starts, step 100, by selecting an elastomeric material with a flash point above 500 degrees Celsius at step 102. A joint on the human body is then selected for protection at step 104. The most common joints for protections are knees, elbows, hips, and shoulders all though other joints may also be protected such as ankles, wrists, etc. A shape that covers the joint is created at step 106. The shape may be contoured to the shape of the joint. At step 108, a plurality of voids are defined to create a predefined hardness, which ends the process at step 110. In one embodiment, the process includes the step of determining a likely pressure to be experienced by the joint. For instance, if the user is carpet layer the expected pressures are mainly the weight of the user against a hard surface. However, it also includes protecting the user against carpet staples damaging the knee. As a result, the hardness needs to be high enough to prevent damage from carpet staples and nails but low enough to be comfortable for the user to be on their knees for hours. Based on this requirement the pattern of voids is changed. For instance, the voids may be small so that staples cannot penetrate the device, but there may be a large number of voids to provide a comfortable cushion. The pattern of voids may vary. For instance, the hardness may not have to be as high on the sides of the knee as opposed to the front of the knee. If the intended user is an oil worker, the most important requirement may be the need to meet the flash fire requirements. This would dictate a silicone rubber. An oil worker is more likely to have large impacts with their knees and they spend less time crawling around on their knees. As a result, a device with a higher hardness is called for and the voids are arranged to meet this requirement.
Thus there has been described a joint protection device that has a frame of an elastomeric material. The elastomeric material has a flash point above 500 degrees Celsius. A solid face is attached to the frame. The solid face has a first side and a second side and has a high gas permeability for an elastomer. A hardness adjustable structure is attached to the second side of the solid face. The hardness adjustable structure does not support microbiological growth. In one embodiment, the elastomer is a silicone rubber, which meets the FRC requirements. This also makes the device flexible so that it is more comfortable to wear.
While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alterations, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alterations, modifications, and variations in the appended claims.
Patent Application
20180140025
