Abstract:
An improved knee pad for industrial applications that require kneeling, which has an outer shell, an inner cushion pad within the shell, a laminated fabric pad against the inner cushion pad and extending beyond the ends of the shell, the fabric pad being adapted for contacting a wearer; and straps for conforming the knee pad to the shape of the wearer&#39;s knee. A method for making the knee pad is also disclosed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. patent application Ser. No. 29/126,080, filed Jul. 7, 2000, and U.S. patent application Ser. No. 29/126,081, filed Jul. 7, 2000. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to knee pads for protecting the patella of a human being and to manufacturing methods for such knee pads. 
     1. Background of the Invention 
     Industrial kneepads are used in a variety of occupations that require occasional to continuous kneeling. Typical users of kneepads include baggage handlers, carpenters, roofers, tile installers, and carpet layers. Any person who is required to kneel for an extended period of time runs the risk of injuring his or her kneecap (patella). Some of the common knee injuries (Patellar Subluxation, Knee Contusion, and Bursitis, Chrondromalacia Patella Syndrome) are caused by weight, pressure, and twisting at the knee. 
     Kneepads are designed to reduce the chance of injury and to provide comfort to the user while kneeling. Typical kneepads are big and awkward and have a tendency to migrate down the legs. The most common kneepads are made of a closed cell foam that is cut into shape and placed in a cloth pouch that is attached to a plastic knee cup. Kneepads are usually fastened with elastic or webbing straps. Kneepads provide padding to the knee while the plastic kneecap provides swivel and sliding action, taking friction off the patella. 
     2 . Description of the Prior Art 
     Knee pads are known in the prior art, which consists basically of familiar and obvious structural configurations despite a large number of knee pad designs which have been developed to meet various objectives or requirements. 
     SUMMARY OF THE INVENTION 
     The present invention is a low-profile, shock absorbent knee pad which offers the patella protection from pressure, weight, and abrasion when kneeling for extended periods. 
     The invention utilizes two different ploymeric materials to form a knee pad structure. The first material is a pliable yet durable material which form the outer knee shell of the knee pad. The knee shell provides the basic structure of the device. A second, softer material is injected into a recess in the knee shell as an insert. The second, softer material provides a cushioning surface into which the user&#39;s knee can sink when in use. No blown foam is used in the invented knee pad. 
     The preferred material for the knee insert is a thermoplastic elastomer (TPE), and most preferably Santopreneg which is especially formulated to be used in combination with polyamide or polyurethane for applications where hard/soft combinations are required. The preferred material for the knee shell is a Ethylene Vinyl Acetate (EVA), especially formulated for molding flexible articles. 
     The knee cup and insert are injection molded in a one step process. These materials and processes permit the design of an extraordinarily flexible and thin knee pad. 
     OBJECTS OF THE INVENTION 
     The principal object of the present invention is to provide an improved knee pad for use by wearers who are required by their duties to kneel frequently. 
     A further object of this invention is to provide a method of manufacturing an improved knee pad. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects will become more readily apparent by referring to the following detailed description and the appended drawings in which: 
     FIG. 1 is a perspective view of a knee cup portion of the invented knee pad. 
     FIG. 2 is a top view of the knee cup of FIG.  1 . 
     FIG. 3 is a front view of the knee cup. 
     FIG. 4 is a left side view of the knee cup. 
     FIG. 5 is a rear view of the knee cup portion showing section  7 — 7 . 
     FIG. 6 is right side view of the knee cup. 
     FIG. 7 is a cross-section view of the knee cup taken along line  7 — 7  of FIG.  5 . 
     FIG. 8 is a bottom view of the knee cup. 
     FIG. 9 is a perspective view of the assembled knee pad in place on a bent knee. 
     FIG. 10 is a top view of the assembled knee pad. 
     FIG. 11 is a front view of the assembled knee pad. 
     FIG. 12 is a right side view of the assembled knee pad of FIG.  11 . 
     FIG. 13 is a rear view of the invented knee pad, i.e., from the knee side. 
     FIG. 14 is a left side view of the assembled knee pad. 
     FIG. 15 is a bottom view of the assembled knee pad. 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, and particularly to FIG. 1, a perspective view of a knee cup portion  10  of the invented knee pad, the outer shell  12  of which is visible in this view. One of the achievements of this invention is a slim profile of the knee cup. The slim profile enables the wearer to walk upright in comfort as well as perform kneeling tasks. The outer shell  12  is achieved by molding a polymer, for example, polyurethane with a pliable surface giving a rubber-like feel. The knee pad shell  12  may be polished in a number of ways depending upon application. For instance, the shell may be produced with a highly polished mold to allow the knee pad to slide, or the shell may be produced with an unpolished mold, which causes the finished shell to have a non-skid surface. 
     FIGS. 3 and 5 show a front plan view of the knee cup  10 . The lower portion of the cup contains two fastening points  16  where straps  20  (FIG.  9 ), that surround the upper leg and hold the knee in place, are joined. The pliable material permits the shell  12  to conform to the shape of the wearer&#39;s knee, insuring no gaps. The knee pad is fabricated in two steps. The knee cup  10 , illustrated in FIGS. 1 to  8  is fabricated in a single molding process. A soft cushioning polymer, preferably a thermoplastic elastomer (TPE) such as Santoprene® , or alternatively a urethane based compound or other compound having similar physical properties to Santoprene® is injection molded in a single step that forms the insert  14  shaped to fit the patella and the harder TPE, urethane, polyurethane, polypropylene, nylon, or the like, forming the outer shell  12 . The dampening insert material  14 , may alternatively be pour molded or lay-in laminated to the outer shell  12 . 
     The durometer of the Santoprene® is adjusted to provide a soft pad  14  that the wearer&#39;s knee can deform in such manner that the device is substantially fitted to the individual wearer&#39;s patella for comfort and performance under impact. The formed knee cup  10  is joined to the rest of the device by sewing along an indentation  22  along the periphery of the knee cup  10  on the side opposite the insert  14 . FIG. 7 is a cross-section view of FIG.  5 . The knee cup  10  is shown to be comprised of a polyurethane outer shell  12  and a Santoprenes insert  14 . After molding both the outer shell  12  and the insert  14  are pliable. FIGS. 2 and 8 show the concave shape of the cup  10  which is thin compared to existing knee pads. Ethylene Vinyl Acetate is injection molded on both sides to yield a finished appearance. 
     FIGS. 12 and 14 show a cushioning base  29  for placement between the knee cup  10  and wearer and extending outwardly from the knee cup  10 . Although not to be so limited, the cushioning base  29  is formed of a pad  31 , an inner material  24 , and an outer material  30 . The cushioning base  29  is affixed to the knee cup  10 . The pad  31  is preferably an EVA or urethane foam to provide suitable cushioning and comfort. Alternatively, the pad  31  can be constructed of a specialty open or closed neoprene rubber blends. The outer material  30  preferably laminated to the pad  31  and made of nylon Nylon Cordura, a tough, durable thick canvas like cloth that is stain proof, and holds moisture. Similar high strength materials having properties similar to Cordura may be used in the alternative. The inner material  24  is preferably laminated to the pad  31  for placement against the wearer. Preferably the inner material  24  is flannel: chosen for the softness of flannel which may come in direct contact with the wearer&#39;s skin. As illustrated in FIGS. 9 and 11, the outer material  30  is provided with attachment points  26  for sewing a second strap  28  which fits above the wearer&#39;s knee. 
     As illustrated in FIG. 9, a series of grooves  33  are compression formed in the pad  31  between the knee cup  10  and the second strap  28  to form a hinge which allows the knee to easily flex so that the cushioning base  29  flexes in concert with normal knee movement. 
     Referring now to FIG. 1, the outer shell  12  of knee cup  10 , is shown, The outer shell  12  of knee cup  10  has a substantially circular upper portion with a lower portion extending downward therefrom. The lower portion of the outer shell  12  has two extending members which extend opposite of one another, each extending member having a hole therein such that the extending member may be used as a fastening point  16 . Referring to FIG. 3, the outer shell  12  defines an indentation  22  along its entire periphery, such indentation being of a depth of approximately one fourth to one half of the thickness of the outer shell  12 , with a width approximating its depth. Referring to FIGS. 4 and 6, the extensions which form fastening points  16  are preferably slightly angled backwards. 
     Referring now to FIGS. 5 and 7, the rear side of outer shell  12  defines rear indentation  32 . Rear indentation  32  has a depth equal to one quarter to three quarters the thickness of outer shell  12 . Rear indentation  32  has an upper portion which is substantially circular and resides within the substantially circular upper portion of the outer shell  12 . The lower portion of rear indentation  32  is an elongate section extending downwards from the rounded upper indentation  32  and is defined by and within the lower section of the rear surface of outer shell  12 . Further referring to FIGS. 5 and 7, the inner cushion pad  14 , also referred to as the insert  14 , is of the same general shape as the rear indentation  32  formed within the rear surface of outer shell  12 , and insert  14  substantially fills the rear indentation  32  such that the rear surface of outer shell  12  is even with the rearward facing surface of insert  14 . 
     Referring now to FIGS. 9-15, the cushioning pad  29  is fixedly attached to the knee cup  10  by sewing the cushioning pad  29  to the knee cup  10  along indentation  22  of the knee cup  10 . As shown in FIG. 11, the cushioning pad  29  has an upper portion  41  having attachment points  26 , a middle portion  42  providing for the hinged movement of the upper portion from the lower portion, and a lower portion  43 . The outer surface of the lower portion  43  of the cushioning pad  29  outer fabric pad  30  is sewn directly to the knee cup  10  about indentation  22 . As shown in FIG. 1l, the cushioning pad  29  is continuous and covers the rear side of the knee cup  10 . Prior to connection to a human leg, the strap  20  is connected from one fastening point  16  to the opposing fastening point  16 , and the second strap  28  is connected from one attachment point  26  to the opposing attachment point  26 . 
     SUMMARY OF THE ACHIEVEMENT OF THE OBJECTS OF THE INVENTION 
     From the foregoing, it is readily apparent that I have invented an improved knee pad for use by wearers who are required by their duties to frequently kneel, and a method of manufacturing such improved knee pad. 
     It is to be understood that the foregoing description and specific embodiments are merely illustrative of the best mode of the invention and the principles thereof, and that various modifications and additions may be made to the apparatus by those skilled in the art, without departing from the spirit and scope of this invention, which is therefore understood to be limited only by the scope of the appended claims.