[0001] 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.
[0002] 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.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] In the drawings, wherein like reference numerals identify corresponding parts:
FIG. 1 is a perspective illustration of a kneepad;
FIG. 2 is an illustration of a kneepad as viewed from the bottom;
FIG. 3 is an illustration of the interior of a kneepad shell;
FIG. 4 is a side view one of the steps in the manufacture/assembly of a kneepad illustrating
the position of an insert in the shell;
FIG. 5 is a front view of the insert of FIG. 4;
FIG. 6 is a diagrammatic illustration of another step in the manufacturing/assembly
of a kneepad including the placement of a memory material relative to the insert;
FIG. 7 is a cross-sectional view of the assembled kneepad; and
FIG. 8 is another cross-sectional view of the assembled kneepad.
[0010] Referring now to the drawings and particularly FIG. 1 and FIG. 2, a kneepad 10 is
generally illustrated as including a top 12, a bottom 14, left side 16 and right side
18. The kneepad includes a shell 20 having an outer surface or face 22 and an inner
surface 24. The shell extends from the top to the bottom of the kneepad and from the
left side to the right side of the kneepad. The kneepad has a periphery 25 and includes
a pair of straps 26, 28, each extending from one side of the kneepad to the opposite
side of the kneepad, in a direction opposite the outer surface of the shell and the
straps terminate in fastening material such as hook and loop fasteners. In use, the
straps encircle behind the knee of the wearer to secure the kneepad to the wearer
and are typically made of flexible material for comfort. A single strap rather than
two straps may be used. Alternatively, one or more straps with buckles may be used.
All the foregoing, except for the specific configuration of the interior and exterior
of the shell 20 as will be described below, is conventional.
[0011] 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.
[0012] 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.
[0013] FIG 3. illustrates the interior of the shell 20. The protuberances described previously
appear as a series of recesses or depressions or cavities when viewed from the interior
of the shell such as cavities corresponding to the protuberances 30, 38 and 40. To
enhance the comfort on the wearer, one or more inserts 44, 45, formed of a soft, flexible
material such as a gel or rubber is placed in one or more of the cavities. The inserts
provided within cavities tend to grip and cushion the knee thus more evenly absorbing
the weight on the patella such that the kneepad adds comfort as the wearer remains
in a kneeling position for an extended period of time as well as when the wearer moves
laterally, stands up and then kneels again, etc. Another benefit of multiple inserts
is that the kneepads are interchangeable while still providing additional comfort.
[0014] 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.
[0015] Referring next to FIG. 4 and FIG. 5, the kneepad 20 includes a flexible insert 46
generally coextensive with the overall dimensions of the interior 24 of the shell.
The insert 46 is preferably formed of "EVA" (ethylene-vinyl acetate) configured with
a series of horizontal and vertical grooves 48 to provide greater flexibility and
greater comfort to the wearer. In addition, insert 46 includes a series of apertures
52 extending through the insert.
[0016] Referring next to FIG. 6, the kneepad includes a layer of polyurethane 54 over the
insert 46. Finally, the kneepad includes a fabric layer 60 (FIG. 7) that is primarily
for cosmetic purposes in that it conceals the interior components of the kneepad,
however, the fabric layer also functions as a wear layer to minimize abrasion between
the wearer and the interior components of the kneepad.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
1. A kneepad comprising:
a shell including opposed front and rear faces,
a first resilient layer generally adjacent the rear face;
a second resilient layer generally adjacent the first resilient layer; the second
resilient layer having a rest position;
at least one air cavity between the shell and the first resilient layer to accommodate
movement of the second resilient layer; and
the second resilient layer formed of a material having a memory such that the second
resilient layer moves from the rest position in response to compressive forces applied
by the user of the kneepad and returns to the rest position when the aforementioned
compressive forces change.
2. The kneepad of claim 1, wherein the front face of the shell includes at least one
protuberance for distribution of compressive forces.
3. The kneepad of claim 1 or claim 2, further including at least one cushioning gel positioned
in a cavity in the rear face of the shell.
4. The kneepad of any preceding claim, further including at least one cushioning gel
positioned in a cavity in said first resilient layer.
5. The kneepad of any preceding claim wherein the first resilient layer comprises polyurethane.
6. The kneepad of any preceding claim further including at least one gel cushioning material.