Abstract:
A hand grip for use on a handle of an assistive mobility device or a bicycle has a body and an integral fin. Both are designed to damp vibration and reduce the force experienced by a user&#39;s hand. This is accomplished by using different thicknesses of an elastomeric material in the structural layer of the hand grip and by designing the fin to flex. The grip is covered with a soft elastomeric outer layer that provides additional cushioning.

Description:
RELATED APPLICATIONS 
     This application claims priority to U.S. provisional patent application Ser. No. 61/548,829, filed 19 Oct. 2011, the contents of which are incorporated herein by reference. 
     FIELD 
     The present technology relates to an ergonomic hand grip that provides shock absorption and reduces fatigue. More specifically, the present technology is a hand grip of varying thickness to permit support while also absorbing shock and vibration. 
     BACKGROUND 
     Many hand held devices have hand grips that provide some shock absorption. Similarly, sporting equipment, such as golf clubs and bicycles, has grips that reduce the force of impact and damp vibration. 
     For example, US Publication No. 20110219909 discloses a handlebar with dampers underneath the hand grips. The dampers are preferably constructed of an elastomeric or rubber-type material whereas the body of the handlebar assembly is formed of a more rigid material, such as a metal, like steel or aluminum based materials, and/or carbon fiber material. It is disclosed that the dampers are formed of a more pliable and resilient material having durometer values between about A25, a durometer value comparable to a rubber band, and about A55, a durometer value comparable to a door seal. Also disclosed are supplemental or optional grip assemblies that are configured to cooperate with handlebar assembly and dampers. The core of the grip assemblies includes a window or opening that extends in a longitudinal direction along a substantial portion of core. When the core is engaged with body of handlebar assembly, the opening overlies and exposes all or a substantial portion of the hand side of the dampers underneath. This allows the vibration or oscillation damping performance of handlebar assembly to be augmented by the vibration or oscillation damping performance attributable to grip assembly. The grip has an ear that extends in a radially outward direction from core near the outboard end of the core. This is for indexing the grip with respect to the core. 
     In US Publication No. 20090072455 a damper is disclosed for various applications, including sporting equipment. The damping portion comprises a first tube, a second tube and a layer of resilient material configured so that the first tube is disposed about the second tube, and the layer of resilient material is positioned between the first and second tubes. 
     US Publication No. 20040048701 discloses a vibration absorbing grip including a grip body formed by a multi-layer material. The material preferably includes a first elastomeric layer of vibration absorbing material which is substantially free of voids therein. A second elastomeric layer which includes an aramid material therein and is disposed on the first elastomeric layer. The aramid material distributes vibration to facilitate vibration damping. A third elastomeric layer is disposed on the second elastomeric layer and is adapted to be gripped by a user. 
     U.S. Pat. No. 6,959,469 discloses a pliable handle for a hand held device. As in the previous mentioned patents, there is provided a core member and an outer sheath, with gel being disposed between the core member and the outer sheath. The pliable handle is designed to deform and conform to the shape of the user&#39;s hand. The applied force causes movement of the gel, the pliable handle having a “memory effect” that causes the handle to temporarily deform for a period of time to the deformed shape before the handle returns to its original shape. 
     Some grips are designed to provide different amounts of damping in different parts of the hand grip, by using materials of differing durometer. For example, US Publication No. 20090271951 discloses a hand grip for hand tools and the like contains a plurality of elastomeric compositions to protect the users hand during use. As proposed a plurality of gel inserts are provided with varying degrees of hardness and density to provide an improved ergonomic design while insuring the integrity of the handle. Three layers are provided with the innermost layer being the hardest with a hardness of approximately 95 on the A Durometer scale, the middle layer having an intermediate hardness of approximately 55 on the A Durometer scale and the outermost layer being the softest with a hardness of approximately of 20 on the A Durometer scale. 
     The shape of the hand grip can also play a role in decreasing fatigue. For example, US Publication No. 20050039565 discloses an ergonomic hand grip. The first component is an outward protrusion of the rear portion of the grip, that is positioned towards the portion of the palm that lies under the fourth and fifth (ring and pinkie) fingers. This disperses pressure over Guyon&#39;s Canal (Ulnar Canal). The second component is an outward protrusion of the front portion of the grip, which may be positioned under the index, middle, ring and pinkie fingers. The protrusions of the front and rear portions increase the diameter of the grip itself, and improve the leverage of the handgrip. An inward curve of the grip under the thumb area may optionally be provided. 
     US Publication No. 20090114257 discloses the use of a damping compound that is resilient and is formed in part over the handle of a walking aid. The handle is ergonomically shaped. 
     As disclosed in WO/2010/069070, an ergonomic hand grip provides an ergonomic shaped handle having elastomeric inserts of various densities (durometers) on the grip surface area that complement the hand during usage of an assistive mobility device, such as a crutch or walking stick. 
     SUMMARY 
     A simplified hand grip that is ergonomically shaped and shock absorbing is provided. The simplified design allows for ease of manufacturing by reducing both the number of steps required and the range of materials used. At the same time, the hand grip provides superior support, vibration damping and impact absorption, thereby reducing fatigue for the user. Both ulna nerve irritation and wrist compression are reduced. The hand grip comprises an optional inner core, a structural layer made of a single elastomeric material, formed into a body and a fin and an outer covering made of a single material. The structural layer is harder than the outer layer. The fin provides support to the thenar eminence during the heel strike of a user&#39;s hand, while at the same time, also cushions the heel strike by flexing in response to the pressure exerted. The fin extends laterally and longitudinally from the body at the proximal and central regions and decreases in thickness distally. A concave region between the fin tip and the body accept a user&#39;s thumb. The body has a narrow proximal region, a narrow distal region and a thicker central region. The body has a generally cylindrical central bore for locating the grip on a tube, such as a bicycle handlebar or a handle of an assistive mobility device. The body has a distal end and a proximal end. The distal end has a locking member for locking the hand grip over the tube and the proximal end is sized to accept an end cap. 
     It is preferred that the fin has a lateral offset relative to a vertical axis of the hand grip and that offset be about 15 to about 30 degrees. 
     It is advantageous for the core to have a durometer rating of at least about 85 A, the structural layer to have a durometer rating of about 30 A to about 50 A and the outer layer to have a durometer rating of about 20 A to about 35 A. 
     Cushioning by the fin is promoted by having the flexibility of the fin increase toward the fin tip. 
     It is preferred that the fin has a longitudinal depression and is integral with the body as this allows the thenar eminence to fit comfortably on the fin and the hand to rest comfortably on the grip. 
     In order to allow for adjustments to be made, the hand grip preferably has a clamp in the vicinity of the proximal end, for clamping the hand grip to the handle. 
     It is preferred, for ease of putting the grips on the handle and aligning the grips, that the core has slots and a retainer aperture in the vicinity of the proximal end. 
     In another embodiment, an assembly for use with an assistive mobility device is provided. The assembly comprises a handle and an ergonomic hand grip. The hand grip comprises a body, a fin, and a clamp. More specifically, the body comprises a proximal end, a distal end, and a core therebetween, the core defining a central bore along a longitudinal axis for accepting the handle, the core having slots and a retainer aperture in the vicinity of the proximal end. Both the body and fin comprise a structural layer of a single material of variable thickness, and an outer layer of a single material of essentially consistent thickness. The core has a durometer rating of at least about 85 A, the structural layer has a durometer rating of about 30 A to about 50 A and the outer layer has a durometer rating of about 20 A to about 35 A. The fin is shaped to flexibly support a user&#39;s thenar eminence, extends from the body laterally and longitudinally, terminates in a fin tip distally, has a lateral offset relative to a vertical axis of the hand grip of about 15 to about 30 degrees, has a lateral depression, increases in flexibility distally and is integral with the body. The clamp adjustably retains the hand grip to the handle. 
     In yet another embodiment, an ergonomic, force-absorbing hand grip for use on a bicycle handlebar is provided. The hand grip comprises:
         a body, the body comprising:   a structural layer of variable thickness; an optional core; a central bore for accepting the handlebar; an outer layer of essentially consistent thickness, the structural layer being harder than the outer layer; an inboard end; an outboard end, and a centrally located protrusion;   a fin, the fin being integral with and extending laterally from the body, terminating in a distally disposed tip, terminating in a distally disposed tip, and having a fin return defining, with the body, a concave region, and comprising: the structural layer; and the outer layer, the structural layer of variable thickness and the outer layer of essentially consistent thickness; and   a clamp, the clamp for releasably retaining the hand grip on the handlebar and for allowing for adjustment of the grip;   a clamp, the clamp for releasably retaining the hand grip on the handlebar and sized to fit over the inboard zone of the core,
 
wherein differences in thickness in the structural layer provide differences in force-absorption in the hand grip.
       

     For ease of construction, it is preferable that each of the core (if present), structural layer and the outer layer is composed of a single material. The material used for the core has a durometer rating of at least about 85 A, the material used for the structural layer has a durometer rating of about 30 A to about 50 A and the material used for the outer layer has a durometer rating of about 20 A to about 35 A. 
     It is preferable that the fin is shaped to flexibly support a user&#39;s thenar eminence and has a lateral offset relative to a vertical axis of the hand grip of about 15 to about 30 degrees. 
     To assist in locating a user&#39;s hand, the hand grip may have a flange in the vicinity of the inboard end. 
     For safety when traveling in traffic, the hand grip may have a light in the outboard end. 
     If the hand grip is to be used on a road bike, it is preferable that the body comprises an upper section and a lower section. In order to attach the upper section to the lower section, mating members may be disposed on a longitudinal margin thereof. 
     For ease of construction, it is preferable that the fin be integral with the lower section of the body. 
     For ease of assembly, it is preferred that the hand grip be provided with two clamps, the clamps being two piece clamps for fitting over the hand grip and handlebars. 
    
    
     
       FIGURES 
         FIG. 1  is a perspective view of an embodiment of the present technology, with the proximal end exploded. 
         FIG. 2  is a longitudinal section view of the embodiment of  FIG. 1 . 
         FIG. 3  is a plan view of the fin of the embodiment of  FIG. 1 . 
         FIG. 4  is a proximal end view of the fin on the body. 
         FIG. 5A  is a distal end view of the fin on the body and  FIG. 5B  is a sectional view taken along line  5 B in  FIG. 3 . 
         FIG. 6  is a perspective view of the embodiment of  FIG. 1 , mounted on a handle. 
         FIG. 7  is a perspective view of an alternative embodiment of the present technology, mounted on a bicycle handlebar, with the outboard end exploded. 
         FIG. 8  is a perspective view of an alternative embodiment of the present technology. 
         FIG. 9  is a clamshell view of an alternative embodiment of the present technology. 
     
    
    
     DETAILED DESCRIPTION 
     Definitions 
     Distal refers to away from the body in relation to a crutch or assistive mobility device. 
     Proximal refers to toward the body in relation to a crutch or assistive mobility device. 
     Outboard in the context of a bicycle refers to the direction that is toward the end of the handlebar. 
     Inboard in the context of a bicycle refers to the direction that is toward the stem of the handlebar. 
     DESCRIPTION 
     A hand grip, generally referred to as  10  is shown in  FIG. 1 . The hand grip has a body  12  and an integral fin  14 . The body has a central region  16 , a distal region  18 , a proximal region  20 , a distal end  22  and a proximal end  24 . The fin  14  extends distally from the proximal  20  and central region  16 . The central region  16  has a protuberance  26 . A split ring or C-type clamp  28  is located at the proximal end  24  and encircles the innermost layer or core  60  of the hand grip  10 . The clamp  28  has a fastener  30  that when tightened, compresses the clamp  28  and the core  60 . The fastener  30  extends through a clamp aperture  61  and a vertically disposed retainer aperture  62  to assist in aligning the hand grip  10  and clamp  28 . The distal end  22  terminates in a flange  32 . 
     As shown in  FIG. 2 , the distal and proximal regions, generally shown as  18  and  20 , are thinner in cross sectional area than is the central region, generally referred to as  16 , with a gradual increase in cross sectional area in the distal region  18  and the proximal region  20 , leading to the protuberance  26 . The cross sectional area also increases around the distal end  22  in the flange  32 . A central bore  36  extends along a longitudinal axis  38  of the hand grip  10  between a distal aperture  40  and a proximal aperture  42 . The dimensions of the body are as follows:
         the length is about 110 to about 150 mm long, preferably about 120 mm to about 140 mm, more preferably about 130 mm long;   the width is about 25 to about 35 mm wide, preferably about 30 mm wide at the narrowest point, increasing to about 35 mm to about 45 mm wide, preferably about 38 mm wide, including at the flange  32  and the protuberance  26 ; and   the diameter of the central bore  36  is about 20 to about 25 mm in diameter, preferably about 22 mm.       

     Also shown in  FIG. 2 , the innermost layer of the hand grip  10  is a hard plastic core  60 , having a durometer rating of at least about 80, preferably about 85 and more preferably about 85 to about 90 on the A durometer scale. Alternatively, the core  60  is integral with the structural layer  70  and therefore has the same durometer rating as the structural layer  70 . To be clear, either the structural layer  70  or the core  60  form the inner layer  60  and the inner layer  60  defines the central bore  36 . The central bore  36  of the core  60  is sized to fit snugly over the tube  50 . As shown in  FIG. 1 , the proximal zone  64  of the core  60  has at least one slot  66  extending into the core  60 . The slot allows the circumference of the core  60  to be reduced under the pressure of the clamp  28 , thereby retaining the hand grip  10  in place. 
     As shown in  FIG. 2 , the middle layer of the hand grip  10  is a structural layer  70 . The structural layer  70  is composed of a single elastomeric thermoplastic, such as, but not limited to Ethylene Vinyl Acetate. The material can be foam or a soft plastic polymer or alternatively, a high-density polyethylene (HDPE), such as ThermoLyn™ RCH 500. It is formed into the body  12 , the protuberance  26 , the fin  14  and the flange  32 . 
     The material used in the structural layer has a durometer rating of about 30 to about 55, preferably about 35 to about 50 and more preferably about 40 to about 45 on the A durometer scale. Rather than using a number of materials of differing durometer ratings to provide differences in the degree of support and damping, the present technology uses differences in thickness to provide differences in the degree of support and damping. This simplifies construction of the hand grip and provides superior support, vibration damping and impact absorption, thereby reducing fatigue for the user. 
     With regard to the body  12 , the middle layer  70  is about 0.5 mm to about 2 mm thick, preferably about 1 to about 1.5 mm thick on the distal  18  and proximal regions  20  of body  12 , increasing gradually to about 1 mm to about 2.5 mm, preferably about 2 mm thick at the protuberance  26 . The distal end  22  terminates in a flange  32  of about 5 mm thick. 
     With regard to the fin  14 , the middle layer  70  is about 7 mm to about 12 mm, preferably about 8 mm to about 10 mm, more preferably 9 mm thick on the proximal base  110  (see  FIG. 4 ), and is about 0 mm to about 0.5 mm preferably 0 mm thick on each of the distal base  118  and the fin tip  102  (see  FIG. 5 ). 
     An outer layer  82  covers the structural layer  70 . It is a washable material and can be provided in a number of colours. The material is preferably a single elastomeric thermoplastic, such as, but not limited to Ethylene Vinyl Acetate (EVA). The preferred EVA product is Lunalastik™, a product used in making orthotics. It has a density of approximately. 0.23 g/mm 3  and a durometer rating of about 25 on the A scale. Other durometer ratings that are acceptable are about 20 to about 35 and preferably about 22 to about 30. The outer layer  82  is a uniform thickness in the range of about 0.5 to about 2 mm, preferably about 0.5 to about 1.5 mm and most preferably about 1 mm. If additional padding is required, different thicknesses can be used rather than using materials of different durometer ratings. This simplifies construction the hand grip and provides superior support, vibration damping and impact absorption, thereby reducing fatigue for the user. 
     When used with mobility devices, the smooth outer layer  82  is preferred, while sculpting may be preferred for bicycles. This can be in the form of ridges, dimples, waffles or any other surface contour, as would be known to one skilled in the art. In this case, the outer layer  82  is made of a rubberized or rubbery layer. The durometer ratings are about 20 to about 35 and preferably about 22 to about 30 on the A durometer scale. 
     The fin  14  flexes in response to force. An average person will cause the fin to deflect between about 3 mm to about 6 mm, more specifically about 4 mm to about 5 mm, with the deflection increasing distally. This damps the impact of the hand on the hand grip  10 , whether as a result of striking a cane, crutch or walking stick on the ground, or as a result of a bicycle traveling over rough terrain. 
     Details of the fin  14  are shown in  FIGS. 3 ,  4 , and  5 . As shown in  FIG. 3 , which is a plan view, the fin, generally referred to as  14  has a ridge  100 , a tip  102 , a fin return  104 , and a concave region  106 . The dimensions are as follows:
         the ridge  100  is about 70 mm to about 90 mm long (along the longitudinal axis  38 ), preferably about 75 mm to about 85 mm, most preferably 80 mm long; about 15 mm to about 35 mm high (normal to the longitudinal axis  38 ), preferably about 20 mm to about 30 mm, most preferably 25 mm high at the lowest point, increasing in a curvilinear manner to the tip  102 ;   the tip  102  is about 35 mm to about 55 mm high (normal to the longitudinal axis  38 ), preferably about 40 mm to about 50 mm, most preferably about 45 mm high at the highest point; and   the fin return  104  defines the concave region  106  between the fin  14  and the body, generally referred to as  12 , the concave region being about 15 mm to about 25 mm, preferably 20 mm wide between the underside of the fin  14  and the body  12  and about 10 mm to about 15 mm deep (along the longitudinal axis). The thumb of the user sits in the concave region  106 . The dimensions of the fin  14  and body  12  are such that the user is able to align the first joint of their thumb with the inner margin  108  of the concave region  106  and wrap their thumb at least partially around the body  12 .       

     As shown in  FIG. 4 , which is a proximal end view, the fin, generally referred to as  14 , has a ridge  100 , a proximal base  110  and a lateral offset  112 . Notably, the fin  14  decreases in width laterally i.e. from the proximal base  110  to the ridge  100 . The dimensions are as follows:
         the ridge  100  is about 4 mm to about 6 mm, more preferably about 5 mm;   the proximal base  110  is about 7 mm to about 14 mm wide, preferably about 8 mm to about 12 mm, more preferably 10 mm wide; and   the lateral offset  112  is about 15 to about 30 degrees, more preferably about 20 to about 25 degrees and most preferably at 23 degrees from a vertical axis  114 . The offset mimics the angle at which the user&#39;s thumb naturally extends from the remainder of the user&#39;s hand.       

     As shown in  FIG. 5A , which is a distal end view, the fin  14  has a distal base  118 , a fin tip  102 , and a longitudinal depression  116  with each of the fin tip  102  and the inner margin  108  of the concave region  106  preferably lacking the structural layer  70 . As shown in  FIG. 5B , the fin  14  decreases in width from the distal base  118  to the fin return  104  and the fin tip  102 . As can be seen by comparing the dimensions of the distal base  118  and the proximal base  110 , the fin decreases in width from the proximal base  110  to the distal base  118 . The dimensions are as follows:
         the distal base  118  is about 0.5 mm to about 4 mm wide, preferably 1 mm to about 3 mm, more preferably 2 mm wide;   the fin tip  102  is about 1 mm to about 2.5 mm wide, preferably 1.5 mm to about 2 mm wide, more preferably 2 mm wide;   the fin return  104  is about 1 mm to about 2.5 mm wide, preferably 1.5 mm to about 2 mm wide, more preferably 2 mm wide; and   the longitudinal depression  116  is formed to rest the user&#39;s thenar eminence and is about 10 mm deep decreasing proximally to nothing over about 30 mm.       

       FIG. 6  shows a hand grip  10  on a tube or bar  50 . This may be, for example, but not limited to a handle or a crutch hand support. The clamp  28  holds the hand grip  10  in place on the handle  50 . The flange  32  extends radially outward in the vicinity of the distal end  22  to assist in hand placement. An end cap  54  is located in the distal aperture  40 . 
     The hand grip  10  is ergonomically designed. The heel of a user&#39;s hand rests on the fin  14 , while the thumb fits around the hand grip  10  at the distal region  18 . The protuberance  26  fits into the palm of the hand, providing cushioned support. The fourth and fifth finger close around the hand grip  10  at the proximal region  20 . As there is a gradual increase in cross sectional area in the distal  18  and proximal  20  regions, differences in hand sizes can be accommodated by shifting the hand on the hand grip  10  until a comfortable fit is found. Additionally, placement of the hand grip  10  on the tube  50  can be optimized by rotating the grip  10  and by moving it longitudinally along the tube  50 . Once the hand grip  10  placement is optimized, the clamp  28  is tightened over the hand grip  10  and tube  50 , immobilizing the hand grip  10 . 
     As shown in  FIG. 7 , when used on a bicycle handlebar  150 , the clamp  28  may be located on the inboard end, generally referred to as  122  or may be on the outboard end, generally referred to as  124 . The fin tip  102  extends towards the inboard end  122 . The core  60  has an inboard zone  164  that extends beyond the structural layer  70  and the outer layer  82  to allow for the clamp  28  to tighten around the core  60 , just as the clamp is tightened around the proximal zone  64  of the core  60  when used on the handle  50  of an assistive mobility device. The inboard zone  164  of the core  60  has at least one slot  66  extending into the core  60 . The slot allows the circumference of the core  60  to be reduced under the pressure of the clamp  28 , thereby retaining the hand grip  10  in place. The clamp  28  has a fastener  30  that when tightened, compresses the clamp  28  and the core  60 . The fastener  30  extends through a clamp aperture  61  and a vertically disposed retainer aperture  62  to assist in aligning the hand grip  10  and clamp  28 . A flange  132  is located in the vicinity of the inboard end  122 . The flange  132  extends radially outward to assist in hand placement. An end cap  54  is located in the outboard aperture  140 . The outboard end  124  may be retained with a clamp  56  and fastener  58 . As would be appreciated, there is a left and a right hand grip  10 , each being mirror images of the other. 
     As shown in  FIG. 8 , the end cap  54  can be replaced with a light  220  and power source  222 . The power source may be integral with the light, or may be separate, for example, a separate battery. A switch  224  is provided for turning the light  220  on and off. The switch can be pressure activated or motion activated. It may be separate from the light, as shown, or integral to the light. The light provides a safety feature as it shines in the direction of travel if mounted on an assistive mobility device and at right angles to the direction of travel if mounted on a bicycle, allowing motorists to see a user crossing a road in front of them. 
     In an alternate embodiment, the body  12  of the hand grip  10  is split longitudinally into two sections, a body upper section  212  and a body lower section  213 , as shown in  FIG. 9 . Each of the core  60 , structural layer  70 , and outer layer  82  are configured to allow the hand grip  10  to be fitted on the handlebars of road bikes, similarly to affixing aerobars. The core upper section  230  and the core lower section  232  have mating members  234 . The mating members are preferably releasable and are a tongue in groove type of mating members. The structural layer upper section  240  abuts the structural layer lower section  242 . Similarly, the outer layer  82 , or cover has an outer layer upper section  250  that abuts an outer layer lower section  252 . The fin  14  is preferably located on one of the sections and is not split. Two piece clamps  260  with fasteners  262  for tightening the clamps  260  fit over the inboard end  270  and the outboard end  272  of the core  60 , which extend beyond the structural layer  70  and outer layer  82 , to allow the hand grip  10  to be retained on the handlebar  50  close to the stem. As would be appreciated, there is a left and a right hand grip  10 , each being mirror images of the other. 
     The foregoing is a description of an embodiment of the present technology. As would be known to one skilled in the art, variations that do not alter the scope of the technology are contemplated. For example, the core may be formed from the structural layer, resulting in the hand grip being two layers—the structural layer and the outer layer. This would be a preferable design if injection molding is used. The split ring clamps may be replaced with two piece clamps or other clamps that function to retain the grips. The grips may be permanently affixed to the handles or bars, using for example, but not limited to, an adhesive. The slots in the core may be replaced with a series of slits or a more malleable material may be used to construct the core. The hand grip can be used on any device or apparatus where load bearing on the hands occurs, for example, but not limited to, exercise equipment, walking sticks, and walkers.