Patent Publication Number: US-2012031938-A1

Title: Arm gripper

Description:
PRIOR RELATED APPLICATIONS 
     Not applicable. 
     FEDERALLY SPONSORED RESEARCH STATEMENT 
     Not applicable. 
     REFERENCE TO MICROFICHE APPENDIX 
     Not applicable. 
     FIELD OF THE INVENTION 
     The invention relates to arm grippers that are worn on an athlete&#39;s or worker&#39;s arm, and serve to give the arm a better grip for implements, such as a ball or tool. 
     BACKGROUND OF THE INVENTION 
     It is well known in sports and industry to add tacky polymers to apparel, such as gloves, in order to increase the users gripping power over implements such as a ball, golf club, reins, javelin, hammer, etc. Indeed, many such gloves are readily available on the market, including the Sure Grip® sports glove, the Ariat® Air Grip Gloves for equine sports, the various Maxgrip® gloves, and many industrial gloves. 
     As an alternative or in addition thereto, many companies offer tacky gripping surfaces directly on the sporting implement or tool. Thus, tennis rackets, golf clubs, bike handles, reins, hammers, screwdrivers, etc. come with a variety of tacky surfaces and surface coverings to increase the users grip on the device. 
     However, until the invention herein, no one has addressed the need for gripping power along the length of the arm, and a needs remains for grippers that provide superior grip along at least the forearm. Such need is particularly apparent in football or rugby, where the ball is often carried in the crook of the arm and can easily be dislodged, but can be used in many sport and work environments. 
     SUMMARY OF THE INVENTION 
     The invention herein generally relates to arm grippers, especially forearm grippers that increase the users grip on any sporting implement or tool. Although designed with the football player in mind, such forearm grippers clearly have utility wherever forearm grip is desired to be improved. For example, rugby players also carry the ball in the crook of the arm, and there are other less common uses, such as for pole climbing, catching animals, wrestling and the like. 
     Generally speaking the arm gripper comprises a tube that fits at least over the forearm and has a coating or partial coating of a tacky material, such as a polymer or gel or other material having a tacky surface. 
     Gels may be particular preferred because by definition a gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough, and are defined as a substantially dilute crosslinked system that exhibits no flow when in the steady-state. By weight, gels are mostly liquid, yet they behave like solids due to a three-dimensional crosslinked network within the liquid. It is the crosslinks within the fluid that give a gel its structure (hardness) and contribute to stickiness (tack). 
     Alternatively, the tube itself may be partially or completed composed of tacky polymer. The tube is preferably elastomeric to ensure a good fit over a variety of arm sizes and low cost, but a range of common sizes, such as small medium and large, may also be provided. 
     In preferred embodiments, the tube is a unitary knitted elastomeric tube, but the tube can also be made of stretch polymers, such as the neoprene used to make diving suits and the like, or stretch weaves such as stretch terry cloth. The tube can also be laminar, that is polymers can be backed with fabric or different types of fabric can be employed in layers as needed. In yet other embodiments, the tube is fitted and closes with a reversible fastener such as a zipper, Velcro, snaps or the like. 
     The tacky polymeric coating can be applied in any pattern, including stripes, dots, herringbone, checkered, solid patches, and the like. With repeating patterns, different polymers can also be applied, e.g., in different spots. In some embodiments, the coating solution can also contain one or more pigments. 
     Preferably the tacky polymer coats only the inner surface of the tube, thus allowing for minimum cost and allowing the other side of the elastomer to have its full stretch capacity. However, in other embodiments, the tube may be patterned all the way around, thus allowing the user to rotate the tube in the event that one surface becomes dirty. 
     In yet other embodiments, the knit or weave pattern of the tube itself has texture (e.g., a waffle weave, enteric, cable, or ribbed and the like), further contributing to gripping power. Alternatively, the coating pattern can be such as to add texture. For example, raised dots, stripes, herringbone, suction cups, and similar patterns can add significant texture, which in addition to the tacky polymer, will contribute to grip. In yet other embodiments, a ribbed knit is used, and only the raised ribs are coated with tacky polymer. Such a design allows complete stretch of the knit, coupled with superior tacky gripping power. 
     It is well known in the art how to make such elastomeric tubes in a cost effective manner, and materials include natural fibers such as cotton, wool, hemp, bamboo, silk, linen, cashmere, or mohair, as well as synthetic fibers such polyethylene terephthalate (Dacron®), polyester, polyamides (nylon), acrylic, olefin, and spandex. 
     The natural fibers are preferred for their absorbency. The presence of cotton and wool helps absorb perspiration. Luxury fibers such as silk, linen, cashmere, or mohair can also be blended in for softness, but add to the cost. Linen can be knitted into high stress areas, such as the elbow, for reinforcement. Linen is a relatively strong fiber and adds durability as well as absorbency and comfort. Silk is usually quite smooth and absorbent. It makes a good layer next to the skin, but is less durable. 
     Synthetic fibers, particularly nylon, are strong and make an excellent choice for adding to the natural fibers and improving wear resistance. Besides durability, synthetic fibers add shrink resistance. The tube can be 10-100% nylon or merely reinforced at the elbow with this durable fiber. 
     Acrylic fibers are long wearing and add a cushiony softness. Olefin fibers do not absorb moisture, but both olefin and acrylic have wicking ability. This means that moisture travels along the fiber away from the skin. Acrylic and olefin can be worn next to the skin, with a wool or cotton layer thereover to absorb moisture. 
     Stretch fibers, including spandex, elastic or rubber, are preferably also included in tube construction. These will help the tube stay in place, hugging the arm. Spandex is especially preferred. While elastic or rubber yarns can be used, they tend to deteriorate from body oils and do not last as long as spandex stretch yarns. Also, the elastic can bind more than spandex. 
     Therefore, the preferred tube is a cotton and/or wool fiber blended with Dacron, acrylic or olefin, and having significant spandex (5-25%, preferably 15-20%) for stretch. Microfibers (fiber with less than 1 denier per filament) are particularly preferred for their soft hand. 
     Preferably, the coating is applied directly to the tube, and cured in place by drying, heating, UV light, irradiation, or combinations thereof, as needed for the polymer used. In other embodiments, a separate piece of fabric or leather with tacky polymer can be attached to the tube by sewing; gluing or other wise bonding the sheet to the tube underneath. In yet other embodiments, the tacky coating can itself be in the form of a sheet that is attached to the tube. For example, neoprene sheets of appropriate durometer are commercially available. 
     Generally the tube need not travel beyond the elbow, but in some embodiments it may be preferred to provided a fitted tube with an elbow bend or opening at the elbow, in the style of the commonly available elbow braces, and thus the gripper can provide both elbow support as well as gripping function. In such instances, the tacky polymer can also be applied beyond the elbow and along the upper arm. 
     In preferred embodiments, the tube is further equipped with a strap and Velcro tab or other fastener at the wrist that can be used to tighten the fit at the wrist, thus preventing the tube from sliding up the arm. If desired, a second strap can be added to wrap around the arm, just above or below the elbow. In this way the tube is fully secured against rough usage, such as would be encountered in football and other contact sports. Yet another variation is to include a pair of straps that cross in the middle and attach at the other end. Further, the straps themselves can also be printed with tacky polymer. 
     The straps can be held with a releasable plastic clip such as is found on back packs. However, Velcro is preferred for its low bulk and ease of use. The Velcro hooks can attach to a loop area on the tube (or vice versa), or the Velcro strap be combined with a D ring or other metal or plastic loop in the fold back Velcro style that binds the strap to the strap via the hooks and loops. 
     The tube can be combined with additional structural features, such as straps (discussed above), fabric support bands, polymeric inserts for support, pockets for magnets, and the like, as needed to provide increased structural support to the elbow or for additional therapeutic usefulness of the device. Padding can also be added to the tube, particularly at high risk areas, such as over the elbow. 
     The polymers used to form the tacky coating must be soft polymers, and preferably also have high tensile strength, high elongation, and are abrasion resistant. Preferred polymers have a hardness of from about 10 to about 60 Shore A (as measured by ASTM D2240-05 (2010) Standard Test Method for Rubber Property—Durometer Hardness) but more preferably are about 20-50 or 30-40 Shore A. 
     Pressure sensitive adhesives (polymers) can also be used create a tacky material. Pressure sensitive adhesives are well known as described in various handbooks, and tack can be ascertained using ASTM D 3121-94, Standard Test Method for Tack of Pressure-Sensitive Adhesives by Rolling Ball wherein the distance the ball rolls is inverse to tackiness. An appropriate rolling ball tack value would be about 1-10 cm, 2-8 cm, 3-7 cm, or about 5 cm. More or less may be useful depending on conditions of use. 
     Preferably the tacky polymers also have a tensile strength of about 400 to about 1700 psi (as measured by ASTM D412-06ae2 Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension), an elongation of about 200 to 1400%, preferably 300-800% (as measured by ASTM D1456-86 (2010) Standard Test Method for Rubber Property—Elongation at Specific Stress), and a tear resistance of about 50 to about 400 PLI (as measured by ASTM D624-00 (2007) Standard Test Method for Tear Strength of Conventional Vulcanized Rubber and Thermoplastic Elastomers). 
     Thus, tacky polymers include the natural or synthetic rubbers, silicones, polyurethane, styrene/ethylene-butylene/styrene block copolymers, plasticized polyvinyl chloride elastomers, cross-linked acrylic polymers, nitrile-butadiene polymers, plasticized polyvinyl chloride elastomers, polyurethane elastomers, fluoroalkyl acrylate copolymers, and the like. 
     An oil-modified, styrene/ethylenebutylene/styrene block copolymer composition sold by the Shell® Chemical Company under the trademark Kraton® G-2706 may be preferred. The Kraton G-2706 can be dissolved by high temperature and high shear mixing in ethyl benzene or other aromatic hydrocarbon in the range of 10% to 45% solids. The tacky coating solution is then applied to the contact surface and dried, so as to form the tacky polymer coating. Other tacky polymers by Shell® can include Kraton® G-2705, Kraton® G-2706, Kraton® G-7705, and the like. 
     The Kraton® based coating solutions can be directly applied to porous leather or fabric with excellent adhesion. A separate coat of primer or other pre-treatment may be required on other materials, such as waterproofed leather or polyurethane foam coated fabrics. 
     Another preferred tacky polymer is the cross linkable acrylic polymers such as sold by Union Carbide® Co. under designation “Acrylic Emulsion #874.” The material is preferably heat cured, a temperature range of 150° F. to 350° F. being generally satisfactory. 
     Other commercially available tacky coatings include the various silicone fabric coatings available from Dow Corning®. Dow Corning® brand silicone fabric coatings are available as room temperature vulcanizing (RTV) and liquid silicone rubber (LSR) elastomers, including 3-3442 Flowable, and 3-3559 Semi-flowable, as well as the 9252 Series LSR available in various viscosities, especially the 250 viscosity product recommended for high grip gloves. The properties of the Dow silicone coatings are provided below: 
     
       
         
           
               
               
               
               
               
               
               
               
               
               
               
             
               
                   
               
               
                 Dow 
                   
                   
                   
                   
                   
                   
                   
                   
                 Tack- 
                 Skin- 
               
               
                 Corning ® 
                 Elongation 
                 Color 
                 Tensile 
                 Tear 
                 Modulus, 
                   
                   
                   
                 Free 
                 Over 
               
               
                 brand 
                 at Break, 
                 after 
                 Strength, 
                 Strength, 
                 100%, 
                 Trans- 
                 Durometer, 
                 Viscosity, 
                 Time, 
                 Time, 
               
               
                 Product 
                 percent 
                 Curing 
                 MPa 
                 kN/m 
                 MPa 
                 parency 1   
                 Shore A 
                 mPa-s 
                 minutes 
                 minutes 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 Room Temperature Vulcanizing Elastomers 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 3-3442 
                 450 
                 Clear 
                 1.3 
                 2.5 
                 0.35 
                 ** 
                 19 
                 60,000 
                 — 
                 13 
               
               
                 Flowable 
               
               
                 Textile 
               
               
                 Sealant 
               
               
                 3-3559 
                 550 
                 Crystal 
                 1.5 
                 3.0 
                 0.34 
                 *** 
                 17 
                 48,000 
                 — 
                 4 
               
               
                 Semi- 
                   
                 Clear 
                   
                   
                   
                   
                   
                 (thixo) 
               
               
                 Flowable 
               
               
                 Textile 
               
               
                 Sealant 
               
               
                 732 Multi- 
                 550 
                 Clear 
                 2.2 
                 5 
                 0.4 
                 ** 
                 25 
                 Paste 
                 20 
                 5-10 
               
               
                 Purpose 
               
               
                 Sealant 
               
               
                 734 
                 315 
                 Clear 
                 1.5 
                 3 
                 — 
                 ** 
                 27 
                 45,000 
                 13 
                 7 
               
               
                 Flowable 
               
               
                 Sealant 
               
               
                 3-7246 
                 300 
                 Clear 
                 1.7 
                 — 
                 — 
                 ** 
                 30 
                 55,000 
                 20 
                 — 
               
               
                 Textile 
               
               
                 RTV 
               
            
           
           
               
            
               
                 Liquid Silicone Rubbers 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 9252 
                 280 
                 Crystal 
                 4.3 
                 6 
                 1.0 
                 *** 
                 36 
                 25,000 
                 N/A 
                 N/A 
               
               
                 Series 
                   
                 Clear 
               
               
                 LSR/ 
               
               
                 250 
               
               
                 Viscosity 
               
               
                 9252 
                 300 
                 Crystal 
                 6.0 
                 8 
                 1.0 
                 *** 
                 40 
                 50,000 
                 N/A 
                 N/A 
               
               
                 Series 
                   
                 Clear 
               
               
                 LSR/ 
               
               
                 500 
               
               
                 Viscosity 
               
               
                 9252 
                 450 
                 Crystal 
                 7.0 
                 15 
                 1.0 
                 *** 
                 40 
                 90,000 
                 N/A 
                 N/A 
               
               
                 Series 
                   
                 Clear 
               
               
                 LSR/ 
               
               
                 900 
               
               
                 Viscosity 
               
               
                 3631 LSR 
                 800 
                 Crystal 
                 5.0 
                 16 
                 0.28 
                 *** 
                 19 
                 90,000 
                 N/A 
                 N/A 
               
               
                   
                   
                 Clear 
               
               
                   
               
               
                   1 All ratings are relative to each other. Best = ***** Worst * 
               
            
           
         
       
     
     Additional tacky polymers designed specifically for increased grip are described in U.S. Pat. No. 5,886,089, U.S. Pat. No. 5,625,900, EP2181826, US2010104762, US2010050319, WO2010022024, US2010031850 and U.S. Pat. No. 5,633,286, each incorporated herein by preference. 
     A commercially available tacky polymer is Super Grip®. This is an spray-on, air-cure, non-yellowing, tackified synthetic rubber coating that bonds to most types of fabrics to prevent slipping. The resulting coating is machine washable and stays flexible, and the product is very easy to apply. Patterns can still be achieved with spray on polymers with the use of a stencil. 
     In one embodiment, the tacky polymer coats a portion of the tube by applying the polymer in the form of a dispersion solution or emulsion. For example, natural or synthetic rubber dispersions or solutions are applied to the contact surface and then air-dried or heat-cured. Highly plasticized polyvinyl chlorides are applied in the form of a solution or of a plastisol dispersion and then air-dried or heat-fused. Liquid silicone rubbers are applied, at 100% solids, along with a vulcanizing catalyst, at room temperature. Soft, tacky, cross linkable acrylic polymer is applied as a water emulsion, dried and heat cured. Polyurethane elastomers are applied from solution or a two component 100% solids reactive mixture can be applied using a machine having a suitable metering and mixing device. The polymer can either be a coating on the surface of the treated article or it can completely or partially penetrate or impregnate the fabric of the tube. As described above, the tube itself can be partially or wholly composed of tacky polymer, provided it has sufficient durability for its intended use. Durability can also be improved with a laminar construction, e.g., a polymer can be backed with a fabric coating, or threads can be included in the polymer matrix for increased durability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1 . shows a simple embodiment of the sport gripper. 
         FIG. 2 . shows various patterns that the tacky polymer can be applied. 
         FIG. 3  shows a full arm embodiment, with an elbow cutout for and Velcro straps for fit. 
         FIG. 4  shows a closed loop variation of a Velcro strap. 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The sport gripper  10  of  FIG. 1  has a soft, tacky, elastomeric polymer material  30 , which gives tube  20  increased gripping power. It is applied to the inner area of the tube, has a soft, tacky feel, and stays soft and tacky even in extremely cold conditions. While feeling slightly tacky to the touch, the elastomer retains its integrity and does not separate and stick to other surfaces. Preferably, tacky polymer material  30  is a silicone elastomer. In this case, a pattern of polymer dots is shown. 
       FIG. 2 , shows other common patterns including stripes, herringbone, solids, checkerboards, hatches, and random. 
     Another embodiment of the sport grip  10  of the invention is shown in  FIG. 3 , comprising a tube  20  and striped tacky polymer  30  and a Velcro straps  40 . Elbow cutout  60  is also shown. 
     While a simple direct Velcro closure is shown in  FIG. 3 , and a fold back Velcro fastener plus D-ring is shown in  FIG. 4 . Generally speaking the use of the fold back design improves the Velcro&#39;s closing power, and comprises a D ring  45 , D-ring attachment  47  and Velcro strap  40 .