Patent Publication Number: US-2003228819-A1

Title: Material adapted to dissipate and reduce vibrations and method of making same

Description:
CROSS REFERENCE TO RELATED APPLICATION  
     [0001] This application is a continuation in part of and claims priority from the following U.S. patent applications: U.S. patent application Ser. No. 10/173,063, filed Jun. 17, 2002, entitled “Material Adapted to Dissipate and Reduce Vibrations and Method of Making Same” which is hereby incorporated by reference herein as if fully set forth in its entirety; U.S. patent application Ser. No. 10/165,748, entitled “Multi-Layer Material Adapted to Dissipate and Reduce Vibrations,” filed on Jun. 7, 2002, which is hereby incorporated by reference herein as if fully set forth in its entirety; and U.S. Patent Application entitled “Material Adapted to Dissipate and Reduce Vibrations and Method of Making Same,” filed on Jan. 17, 2003, invented by Robert A. Vito et al., serial number not yet known, which is hereby incorporated by reference herein as if fully set forth in its entirety.  
    
    
     
       BACKGROUND  
       [0002] The present invention is directed to a material adapted to reduce vibration and, more specifically, to a method of making a material adapted to dissipate and evenly distribute vibrations acting on the material.  
       [0003] Handles of sporting equipment, bicycles, hand tools, etc. are often made of wood, metal or polymer that transmit vibrations that can make the items uncomfortable for prolonged gripping. Sporting equipment, such as bats, balls, shoe insoles and sidewalls, also transmit vibrations during the impact that commonly occurs during athletic contests. These vibrations can be problematic in that they can potentially distract the player&#39;s attention, adversely effect performance, and/or injure a portion of a player&#39;s body.  
       [0004] Rigid polymer materials are typically used to provide grips for tools and sports equipment. The use of rigid polymers allows users to maintain control of the equipment but is not very effective at reducing vibrations. While it is known that softer materials provide better vibration regulation characteristics, such materials do not have the necessary rigidity for incorporation into sporting equipment, hand tools, shoes or the like. This lack of rigidity allows unintended movement of the equipment encased by the soft material relative to a user&#39;s hand or body.  
       [0005] Prolonged or repetitive contact with excessive vibrations can injure a person. The desire to avoid such injury can result in reduced athletic performance and decreased efficiency when working with tools.  
       [0006] Clearly what is needed is a method of making a material adapted to regulate vibration that provides the necessary rigidity for effective vibration distribution and for a user to maintain the necessary control of the implement; and that can dampen and reduce vibrational energy.  
       SUMMARY  
       [0007] One embodiment of the present invention is directed to a material adapted to regulate vibration by distributing and partially dissipating vibration exerted thereon. The material includes a first elastomer layer. A support structure is penetrated by and embedded on and/or within the elastomer layer. The support structure is semi-rigid and supports the elastomer layer. The support structure has a first plurality of particles therein.  
       [0008] In another aspect, the present invention is directed to a material adapted to regulate vibration by distributing and partially dissipating vibration exerted thereon. The material includes a first elastomer layer. A support structure is formed by a second elastomer layer. The support structure is located and configured to support the first elastomer layer.  
       [0009] In another aspect, the present invention is directed to a material adapted to regulate vibration by distributing and partially dissipating vibration exerted thereon. The material includes a first elastomer layer. A support structure is located and configured to support the elastomer layer. The support structure has a first plurality of gel particles therein.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010] The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It is understood, however, that the invention is not limited to the precise arrangements and instrumentality shown. In the drawings:  
     [0011]FIG. 1 is a cross-sectional view of a preferred embodiment of the material of the present invention illustrating a single layer vibration dissipating material with a support structure embedded therein, the material extends along a longitudinal portion of an implement and covers a proximal end thereof;  
     [0012]FIG. 2 is a cross-sectional view of the material of FIG. 1 separate from any implement, padding, equipment or the like;  
     [0013]FIG. 2A is a cross-sectional view of a second preferred embodiment of the material of the present invention with the support structure embedded thereon and the vibration dissipating material penetrating the support structure;  
     [0014]FIG. 2B is cross-sectional view of a third preferred embodiment of the material of the present invention with the support structure embedded within the vibration dissipating material and the vibration dissipating material penetrating the support structure, the support structure is positioned off center within the vibration dissipating material;  
     [0015]FIG. 3 is a cross-sectional view of a first preferred embodiment of the support structure as taken along the lines  3 - 3  of FIG. 2, the support structure is formed of polymer and/or elastomer and/or fibers, either of which may contain fibers, passageways extend through the support structure allowing the vibration dissipating material to penetrate the support structure;  
     [0016]FIG. 4 is cross-sectional view of a second preferred embodiment of the support structure as viewed in a manner similar to that of FIG. 3 illustrating a support structure formed by woven fibers, passageways through the woven fibers allow the support structure to be penetrated by the vibration dissipating material;  
     [0017]FIG. 5 is cross-sectional view of a third preferred support structure as viewed in a manner similar to that of FIG. 3; the support structure is formed by pluralities of fibers and particles; passageways past the fibers allow the vibration dissipating material to preferably penetrate the support structure;  
     [0018]FIG. 6 is a side elevational view of the support structure of FIG. 3;  
     [0019]FIG. 7 is perspective view of the material of FIG. 1 configured to form a grip for a bat; and  
     [0020]FIG. 8 is perspective view of the material of FIG. 1 configured to form a grip for a racquet.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0021] Certain terminology is used in the following description for convenience only and is not limiting. The words “right,” “left,” “top,” and “bottom” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the material and designated parts thereof. The term “implement,” as used in the specification and in the claims, means “any one of a baseball bat, racquet, hockey stick, softball bat, sporting equipment, firearm, or the like.” The term “particles,” as used in the claims and in the corresponding portions of the specification, means “small bits or pieces of mass each defining a volume but generally being of insufficient, length to interweave together.” Additionally, the words “a” and “one” are defined as including one or more of the referenced item unless specifically stated otherwise. The above terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.  
     [0022] Referring to FIGS.  1 - 8 , wherein like numerals indicate like elements throughout, there are shown preferred embodiments of a material, generally designated  10 , that is adapted to regulate vibration. Briefly stated, the material  10  preferably includes a vibration dissipating material  12  (preferably an elastomer layer). The vibration dissipating material  12  penetrates a support structure  17  to embed the support structure  17  thereon (as shown in FIG. 2A) and/or therein (as shown in FIG. 2B). The support structure  17  is preferably semi-rigid (but can be rigid without departing from the scope of the present invention) and supports the vibration dissipating material  12 . The support structure can be formed by a second elastomer layer of same or differing rigidity.  
     [0023] The material  10  of the present invention was the result of extensive research and was throughly tested by Villanova University&#39;s Department of Mechanical Engineering by a professor having a Ph.D. in vibratory physics. Testing of the material  10  determined that the material  10  can reduce the magnitude of sensible vibration by eighty (80%) percent. The material  10  has verified, superior vibration dissipation properties due to the embedded support structure  17  that is located on and/or in the elastomer  12 . In addition to evenly distributing vibration, the support structure  17  contributes to the absorption of vibration and supports the vibration dissipating material  12  to prevent the layer of vibration dissipating material  12  from twisting or otherwise becoming unsuitable for use as a grip or padding.  
     [0024] While it is preferred that the vibration dissipating material layer  12  be formed by elastomer, those of ordinary skill in the art will appreciate from this disclosure that the vibration dissipating material  12  can be formed by any suitable polymer without departing from the scope of the present invention. For clarity only, the vibration dissipating material  12  will be often described herein as being an elastomer without any mention of the material possibly being a polymer. However, it should understood that even when the layer  12  is only described as being an elastomer, that the present invention also includes the material  12  being a any suitable polymer.  
     [0025] The material  10  of the present invention can be incorporated into athletic gear, grips for sports equipment, grips for tools, and protective athletic gear. More specifically, the material  10  can be used: to form grips for a tennis racquet, hockey sticks, golf clubs, baseball bats or the like; to form protective athletic gear for mitts, headbands, mouth guards, face protection devices, helmets, gloves, pads, exercise pads, elevator pads, padding that is stood on, padding that is wrapped around objects to protect people from injury when colliding with such objects, hip pads, shoulder pads, chest protectors, or the like; to form seats or handle bar covers for bicycles, motorcycles, or the like; to form boots for skiing, roller blading or the like; to form footwear, such as shoe soles and inserts; to form grips for firearms, hand guns, rifles, shotguns, or the like; and to form grips for tools such as hammers, drills, circular saws, chisels or the like.  
     [0026] The elastomer layer  12  acts as a shock absorber by converting mechanical vibrational energy into heat energy. The embedded support structure  17  redirects vibrational energy and provides increased stiffness to the material  10  to facilitate a user&#39;s ability to control an implement  20  encased, or partially encased, by the material  10 . The elastomer layer  12 ,  12 A, or  12 B may include a plurality of fibers  14  (further described below) or a plurality of particles  15  (further described below). The incorporation of the support structure  17  on and/or within the material  10  allows the material  10  to be formed by a single elastomer layer without the material  10  being unsuitable for at least some of the above-mentioned uses. The support structure  17  may also include a plurality of fibers  14  or a plurality of particles  15 . However, those of ordinary skill in the art will appreciate from this disclosure that additional layers of material can be added to any of the embodiments of the present invention disclosed below without departing from the scope of the invention.  
     [0027] In the situation where the support structure  17  is formed by a second elastomer layer, the two elastomer layers can be secured together via an adhesive layer, discreet adhesive locations, or using any other suitable method to secure the layers together. Regardless of the material used to form the support structure  17 , the support structure is preferably located and configured to support the first elastomer layer (see FIGS.  1 - 2 B).  
     [0028] It is preferred that the material  10  have a single contiguous elastomer body  12 . Referring to FIG. 1, the support structure has first and second major surfaces  23 , 25 . In one embodiment, the elastomer  12  extends through the support structure  17  so that the portion of the elastomer  12 A contacting the first major support structure surface  23  (i.e., the top of the support structure  17 ) and the portion of the elastomer  12 B contacting the second major support structure surface  25  (i.e., the bottom of the support structure) form the single contiguous elastomer body  12 . Elastomer material provides vibration damping by dissipating vibrational energy. Suitable elastomer materials include, but are not limited, urethane rubbers, silicone rubbers, nitrile rubbers, butyl rubbers, acrylic rubbers, natural rubbers, styrene-butadiene rubbers, and the like. In general, any suitable elastomer or polymer material can be used to form the vibration dissipating layer  12 .  
     [0029] The softness of elastomer materials can be quantified using Shore A durometer ratings. Generally speaking, the lower the durometer rating, the softer the material and the more effective a material layer is at absorbing and dissipating vibration because less force is channeled through the material. When a soft material is squeezed, an individual&#39;s fingers are imbedded in the material which increases the surface area of contact between the user&#39;s hand and creates irregularities in the outer material surface to allow a user to firmly grasp any implement  20  covered, or partially covered, by the material. However, the softer the material, the less control a user has when manipulating an implement  20  covered by the material. If the elastomer layer is too soft (i.e., if the elastomer layer has too low of a Shore A Durometer rating), then the implement  20  may rotate unintentionally relative to a user&#39;s hand or foot. The material  10  of the present invention is preferably designed a Shore A durometer rating that provides an optimum balance between allowing a user to precisely manipulate and control the implement  20  and effectively damping vibration during use of the implement  20  depending on the activity engaged in.  
     [0030] It is preferable, but not necessary, that the elastomer used with the material  10  have a Shore A durometer of between approximately ten (10) and approximately eighty (80). It is more preferred that the elastomer  12  have a Shore A durometer of between approximately fifteen (15) and approximately forty-five (45).  
     [0031] The elastomer  12  is preferably used to absorb vibrational energy and to convert vibrational energy into heat energy. The elastomer  12  also provides a compliant and comfortable grip for a user to grasp (or provides a surface for a portion of a user&#39;s body, such as the under sole of a user&#39;s foot when the material  10  is formed as a shoe insert).  
     [0032] In one embodiment, the material  10  preferably has a Shore A durometer of approximately fifteen (15). In another embodiment, the material  10  preferably has a Shore A Shore Durometer of approximately forty two (42). In yet another embodiment, the material  10  preferably has a Shore A Durometer of approximately thirty-two (32). Of course, those of ordinary skill in the art will appreciate that the Shore A Durometer of the material  10  can varied without departing from the scope of the present invention.  
     [0033] Referring to FIGS.  3 - 5 , the support structure  17  can include any one (or combination of) of a polymer, an elastomer, particles, a plurality of fibers, a plurality of woven fibers, a cloth, and a plurality of cloth layers. If the support structure  17  and the layer  12  are both polymers or both elastomers, then they can be the same or different from each other without departing from the scope of the present invention. If vibration dissipating material is  12  if formed of the same material as the support structure  17 , then the support structure  17  can be made more rigid than the main layer  12  by embedding fibers  14  therein. It is preferable that the support structure  17  is generally more rigid than the vibration dissipating material  12 .  
     [0034] Referring specifically to FIG. 3, the support structure  17  may be formed of an elastomer that may but does not necessarily, also have fibers  14  embedded therein (examplary woven fibers are shown throughout portions of FIG. 3). Referring to FIG.  4 , the support structure  17  may be formed by a plurality of woven fibers  18 . Referring to FIG. 5, the support structure  17  may be formed by a plurality of fibers  14 . Regardless of the material forming the support structure  17 , it is preferable that passageways  19  extend into the support structure  17  to allow the elastomer  12  to penetrate and embed the support structure  17 . The term “embed,” as used in the claim and in the corresponding portions of the specification, means “contact sufficiently to secure thereon and/or therein.” Accordingly, the support structure  17  shown in FIG. 2 A is embedded by the elastomer  12  even though the elastomer  12  does not fully enclose the support structure  17 . Additionally, as shown in FIG. 2 B, the support structure  17  can be located at any level or height within the elastomer  12  without departing from the scope of the present invention. While the passageways  19  are shown as extending completely through the support structure  17 , the invention includes passageways  19  that extend partially through the support structure  17 .  
     [0035] Referring again to FIG. 2A, in one embodiment, it is preferred that the support structure  17  be embedded on the elastomer  12 , with the elastomer penetrating the support structure  17 . The support structure  17  being generally along a major material surface  38  (i.e., the support structure  17  is generally along the top of the material).  
     [0036] The fibers  14  are preferably, but not necessarily, formed of aramid fibers. However, the fibers can be formed from any one or combination of the following: bamboo, glass, metal, elastomer, polymer, ceramics, corn husks, and/or any other renewable resource. By using fibers from renewable resources, production costs can be reduced and the environmental friendliness of the present invention can be increased. Referring to FIG. 4, the fibers  14  can be woven to form a cloth  16  that is disposed on and/or within the elastomer  12 . Multiple cloth layers  16  can be epoxied or otherwise secured together and incorporated into the support structure  17 . The cloth layer  16  can be formed of woven aramid fibers or other types of fiber. The aramid fibers  14  block and redirect vibrational energy that passes through the elastomer  12  to facilitate the dissipation of vibrations. The aramid fibers  18  redirect vibrational energy along the length of the fibers  18 . Thus, when the plurality of aramid fibers  18  are woven to form the cloth  16 , vibrational energy emanating from the implement  20  that is not absorbed or dissipated by the elastomer layer  12  is redistributed evenly along the material  10  by the cloth  16  and preferably also further dissipated by the cloth  16 .  
     [0037] It is preferable that the aramid fibers  18  are formed of a suitable polyamide fiber of high tensile strength with a high resistence to elongation. However, those of ordinary skill in the art will appreciate from this disclosure that any aramid fiber suitable to channel vibration can be used to form the support structure  17  without departing from scope of the present invention. Additionally, those of ordinary skill in the art will appreciate from this disclosure that loose aramid fibers or chopped aramid fibers can be used to form the support structure  17  without departing from the scope of the present invention. The aramid fibers may also be formed of fiberglass or the like.  
     [0038] When the aramid fibers  18  are woven to form the cloth  16 , it is preferable that the cloth  16  include at least some floating aramid fibers  18 . That is, it is preferable that at least some of the plurality of aramid fibers  18  are able to move relative to the remaining aramid fibers  18  of the cloth  16 . This movement of some of the aramid fibers  18  relative to the remaining fibers of the cloth converts vibrational energy to heat energy.  
     [0039] Particles  15  can be located in either an elastomer layer  12 ,  12 A, and/or  12 B and/or in the support structure  15 . The particles  15  increase the vibration absorption of the material of the present invention. The particles  15  can be formed of pieces of glass, polymer, elastomer, chopped aramid, ceramic, chopped fibers, sand, gel, foam, metal, mineral, glass beads, or the like. Gel particles  15  provide excellent vibration dampening due their low durometer rating. One exemplary gel that is suitable for use the present invention is silicone gel. However, any suitable gel can be used without departing from the present invention.  
     [0040] The material  10  may be configured and adapted to form an insert for shoe. When the material  10  is configured to form a shoe insert, the material  10  is preferably adapted to extend along an inner surface of the shoe from a location proximate to a heel of the shoe to the toe of the shoe. In addition to forming a shoe insert, the material  10  can be located along the sides and top of the shoe to protect the wearer&#39;s foot from lateral and vertical impacts.  
     [0041] The material  10  may be configured and adapted to form a grip  22  for an implement such as a bat, having a handle  24  and a proximal end  26  (i.e., the end near to where the bat is normally gripped). The material  10  is preferably adapted to enclose a portion of the handle  24  and to enclose the proximal end  26  of the bat or implement  20 . As best shown in FIGS. 7 and 8, it is preferable that the grip  22  be formed as a single body that completely encloses the proximal end of the implement  20 . The material  10  may be also be configured and adapted to form a grip  22  for a tennis racket or similar implement  20  having a handle  24  and a proximal end  26 .  
     [0042] While the grip  22  will be described below in connection with a baseball or softball bat, those of ordinary skill in the art will appreciate that the grip  22  can be used with any of the equipment, tools, or devices mentioned above without departing from the scope of the present invention.  
     [0043] When the grip  22  is used with a baseball or softball bat, the grip  22  preferably covers approximately seventeen (17) inches of the handle of the bat as well as covers the knob (i.e., the proximal end  26  of the implement  20 ) of the bat. The configuration of the grip  22  to extend over a significant portion of the bat length contributes to increased vibrational damping. It is preferred, but not necessary, that the grip  22  be formed as a single, contiguous, one-piece member.  
     [0044] Referring to FIG. 1, the baseball bat (or implement  20 ) has a handle  24  including a handle body  28  having a longitudinal portion  30  and a proximal end  26 . The material  10  preferably encases at least some of the longitudinal portion  30  and the proximal end  26  of the handle  24 . The grip material  10  can incorporate any of the above-described support structures  17 . The aramid fiber layer  14  is preferably formed of woven aramid fibers  18 .  
     [0045] As best shown in FIGS. 7 and 8, the preferred grip  22  is adapted for use with an implement  20  having a handle and a proximal handle end. The grip  22  includes a tubular shell  32  having a distal open end  34  adapted to surround a portion of the handle and a closed proximal end  36  adapted to enclose the proximal end of the handle. It is preferable not necessary, that the material completely enclose the proximal end  26  of the handle. The tubular shell  32  is preferably formed of the material  10  which dissipates vibration.  
     [0046] Multiple methods can be used to produce the composite or multi-layer material  10  of the present invention. Briefly speaking, one method is to extrude the material  10  by pulling a support structure  17  from a supply roll while placing the elastomer layer on both sides of the support structure  17 . It is preferred, but not necessary, that the particles  15  in either of the support structure  17  or the elastomer layer are already located in their respective material on the appropriate supply roll. A second method of producing the material  10  of the present invention is to weave a fiber onto the implement  20  and then to mold the elastomer  12  thereover. Alternatively, a support structure can be pressure fit to an elastomer to form the material  10 . Those of ordinary skill in the art will appreciate from this disclosure that any other known manufacturing methods can be used to form the material  10  without departing from the scope of the present invention. Any of the below described methods can be used to form a material  10  or grip  22  having any of the above specified Shore A Durometers and incorporating any of the above-described support structures  17 .  
     [0047] More specifically, one preferred method of making the material  10  includes: providing an uncured elastomer  12 . A cloth layer is positioned on and/or within the uncured elastomer  12 . The cloth layer is formed by a plurality of woven aramid fibers  14 . The uncured elastomer  12  penetrates the cloth layer  16  to embed to the cloth  16 . The uncured elastomer  12  is at least partially cured to form the material  10 . The cloth layer  16  supports the cured elastomer  12  and facilitates the distribution and dissipation of vibration by the material  10 .  
     [0048] It is preferable that the elastomer  12  is cured so that some of the plurality of aramid fibers in the cloth layer  16  are able to move relative to the remaining plurality of aramid fibers  18 . It is also preferable that the material  10  be configured to form a grip for a bat and/or racquet having a handle  24  and the proximal end  26 . The grip  22  preferably encloses at least a portion of the handle  24  and the proximal end  26 .  
     [0049] Another aspect of the present invention is directed to a method of making a grip  22  for an implement  20  having a handle  24  and a proximal end  26 . The grip  22  is formed by a single layer material  10  adapted to regulate vibration. The method includes providing an uncured elastomer. A plurality of fibers  14  are positioned on and/or within the uncured elastomer  12 . The uncured elastomer  12  is at least partially cured to form the single layer material embedding the plurality of fibers. The single layer material  10  has first and second major material surfaces. The single layer material  10  is positioned over at least a portion of the handle  24  and over the proximal end  26  of the handle  24 . The first major material surface contacts the implement  20  and second major material surface of the single layer material  10  forms a surface for a user to grasp. This method can be used to form a grip  22  having any of the Shore A Durometers described above and can use any of the support structure  17  also described above.  
     [0050] In another aspect, the present invention is directed to a method of making a material  10  adapted to regulate vibration. The method includes providing a cloth  16  formed by a plurality of woven aramid fibers  14 . The cloth has first and second major surfaces. A first elastomer layer  12 A is placed on the first major surface of the cloth. A second elastomer layer  12 B is placed on the second major surface  25  of the cloth  16 . The first and second elastomer layers  12 A,  12 B penetrate the cloth  16  to form a single layer elastomer  12  having an embedded cloth  16  for support thereof.  
     [0051] In another aspect, the present invention is directed to a method of forming a material  10  including providing a cloth layer  16 . Positioning an elastomer  12  substantially over the cloth layer  16 . Applying pressure to the cloth layer  16  and the elastomer  12  to embed the cloth layer  16  on and/or in the elastomer  12  to form the material  10 . When using this sort of pressure fit technique, those ordinary skill in the art will appreciate from this disclosure that the cloth layer  16  and the elastomer  12  can be placed in a mold prior to applying pressure without departing from the scope of the present invention.  
     [0052] The covering of the proximal end of an implement  20  by the grip  22  results in reduced vibration transmission and in improved counter balancing of the distal end of the implement  20  by moving the center of mass of the implement  20  closer to the hand of a user (i.e., closer to the proximal end  26 ). This facilitates the swinging of the implement  20  and can improve sports performance while reducing the fatigue associated with repetitive motion.  
     [0053] It is recognized by those skilled in the art, that changes may be made to the above-described embodiments of the invention without departing from the broad inventive concept thereof. For example, the material  10  may include additional layers (e.g., two or more additional layers) without departing from the scope of the present invention. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover all modifications which are within the spirit and scope of the invention as defined by the appended claims and/or shown in the attached drawings.