Patent Application
20180213857
This application relates to kneepads in general and more particularly to a kneepad including an interior cushioning having a memory such that both the exterior and interior of the kneepad provide increased comfort to the wearer.
A first type of kneepad has padding material for covering the knee and a relatively rigid exterior portion. This first type of kneepad is frequently used by those participating in physical activities including not only exercise, but also individual or team sporting events. The rigid portion is designed to protect the knee from a sudden, short duration impact.
A second type of kneepad is frequently used by those participating in outdoor or indoor labor-intensive tasks where kneeling is involved. Non-limiting examples include tasks such as gardening and floor, tile, and carpet installation. This second type of kneepad also includes padding material for covering the knee but does not require enhanced protection against sudden, short duration impact. This second type of kneepad provides protection against continuous or longer duration pressure on the knee rather than merely protection against sudden impact. Of course there are no restrictions on how either type of kneepad may be used. The present disclosure relates primarily to the second type of protective kneepad.
Kneepads that are worn for prolonged periods of time to provide protection against continuous pressure on the knee have, historically, failed to provide a desired balance of both comfort and protection. As a non-limiting example, kneepads that are worn for prolonged periods of time have provided protection but not comfort to the kneecap, or patella, and have failed to take into account that not all users have an identically configured patella and further have failed to take into account that most users tend to interchange kneepads such that a kneepad is not necessarily worn on the same knee each times the kneepads are used.
The present kneepad overcomes the shortcomings of prior kneepads by providing an improved kneepad of the type that typically provides the desired protection coupled with enhanced comfort.
The present kneepad takes into account the fact that the surfaces upon which the user is kneeling are hard but rarely flat. For example, if the user of the kneepad is engaged in installation of flooring, the wearer will frequently kneel along the edge of a piece of tile, wood or laminate or occasionally kneel on some debris. Similarly if the wearer of the kneepad is engaged in outdoor manual labor it is highly unlikely that the ground is flat, rather, there may be small pebbles, roots of plants, etc. The pressure applied against the patella by kneeling is not expected to be uniformly distributed. The wearer does not necessarily wear the same kneepad on the same knee during successive uses of the kneepad. The present kneepad accommodates the above by providing a somewhat flexible, outer shell that may include a planar surface and that assists in stabilizing the kneecap of the wearer. The present kneepad includes protuberances and recesses to assist in adapting to uneven pressure on the wearer and unevenness of the surface upon which kneeling occurs.
Furthermore, kneepads have not been accommodating to the temporary shifting of the user's weight during normal use thus increasing user discomfort. The present kneepad accommodates this situation by providing an internal memory so that when the user's weight is temporarily shifted, the kneepad is ready to adapt to the contour of the knee in different positions thus enhancing the comfort to the user.
The foregoing benefits and advantages of the improved kneepad will become more apparent upon reading the following detailed description of the invention taken in conjunction with the drawings.
In the drawings, wherein like reference numerals identify corresponding parts:
Referring now to the drawings and particularly
The shell 20 will now be described in greater detail. The shell may be formed as a nylon coating on a flexible, semi-rigid plastic material. The exterior of the shell is illustrated as including a series of protuberances and recesses or depressions therebetween. More specifically, the exterior or face 22 of the shell may include an elongated protuberance 30 extending slightly more than half the vertical length of the shell and having a width approximating one-fourth of the horizontal width of the shell. Above the protuberance 30 are a series of spaced apart generally horizontal protuberances 32. At the bottom of the protuberance 30 are a pair of generally triangular protuberances 34, 36 and on each side of the protuberance 30 is a generally triangular protuberance 38, 40. The protuberances are separated by depressions or recesses generally identified by reference numeral 42. The shell, and more specifically the combination of protuberances and depressions, provide resilience and absorb the effect of unevenness on the surface where the wearer is kneeling thus increasing the comfort for the wearer. The precise configuration of each protuberance and the resulting configuration of the depressions between protuberances may be varied. The protuberances located most remotely from the periphery 25 may define a planar surface 43 to aid in stabilizing the kneecap against movement.
The shell 20 is preferably formed of a semi-rigid plastic material and the exterior of the shell is preferably covered with nylon or other fabric.
It is also of importance to provide air pockets to allow for movement of the knee and of the interior portions of the kneepad. One technique to achieve these cushioning air pockets is not to fill all of the cavities in the interior of the shell. The unfilled cavities provide air pockets to allow for movement of the interior portions of the kneepad. Thus movement of interior portions of the kneepad is accommodated without increasing the pressure on the patella thus enhancing the comfort for the wearer.
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A method of manufacturing a kneepad will now be explained with reference to the drawings. The shell 20 may be a composite product having as a front face 22 of a rugged fabric material, preferably nylon, and an interior face 24 of a harder material which may be a flexible, semi-rigid plastic material. The flexible, semi-rigid plastic material is first formed with the desired protuberances and recesses and then the fabric may be compression molded onto the flexible, semi-rigid plastic material. The shell 20 as just described may be placed in a mold with the interior face 24 exposed. Inserts 44, 45 are placed in at least some of the recesses or cavities in the interior face 24 of the shell. A suitable insert material is a thermoplastic elastomeric gel material or soft foam or other material that will conform to the shape of the user without placing too much stress on the user. Thus, for example in the situation where the insert material is to be used in a kneepad, the material must conform to the shape of the knee without placing excessive stress on the kneecap and adjoining nerves, ligaments or other body parts.
The insert 46 is now placed on the interior of the shell. The insert is preferably formed of EVA with a series of grooves 48 and a large central recess 50 on the underside to accommodate gel 45 placed in the central cavity 30. The insert includes apertures 52 except that there are preferably no apertures in the region of the central recess.
A next step in the manufacture/assembly of the kneepad is to place a polyurethane material 54 over the EVA insert 46. This is accomplished by flowing liquid polyurethane into the EVA. The liquid polyurethane may be thought of as a foam and also known as “memory foam”. The benefit of depositing the polyurethane 54 as a liquid or foam is that the polyurethane fills the exposed grooves 48 in the EVA. The polyurethane will also flow through the apertures 52 in the EVA layer so that some polyurethane will be disposed between EVA layer and the interior 24 of the shell. However, it is important that the urethane not fill the entire space between the interior 24 of the shell and the EVA layer, rather it is important to include at least one air cavity or air pocket 62. The air cavity or air pocket provides a space into which internal portions of the kneepad may move without exerting additional pressure on the knee of the wearer.
The remaining polyurethane that does not flow into the grooves and apertures will solidify forming a layer 54 on top of the EVA layer 46.
The aforementioned steps are carried out in a mold as is conventional in the manufacture of kneepads and, therefore, further details of the mold are not described. The molding process takes approximately five minutes or less thus allowing sufficient time for the polyurethane foam to expand and solidify or cure. The rear fabric 60 may now be applied such as by stitching to the periphery 25 of the kneepad and the fastening straps 26, 28 may be stitched to the fabric sides or the edges of the front face 22 of the kneepad. The rear or back fabric layer can be made of wear-resistant material, such as a styrene butadiene rubber or other similar materials. The back fabric layer may be attached to the remaining components of the knee pad by placing the back fabric layer on top of the remaining components before the mold is closed or after the molding is complete.
It should be appreciated that various terms have been used in describing the kneepad and a method of manufacturing the kneepad. Relative terms such as but not limited to top/bottom and terms describing shapes such as but not limited to rectangle and triangle are for illustrative and descriptive purposes except where those terms appear in the claims.
The foregoing is a complete description of the preferred embodiment of the present kneepad. Various changes and modifications may be made without departing from the spirit and scope of the foregoing. The invention, therefore, should be limited only by the scope of the following claims.
