Abstract:
A heated motorcycle handgrip is securable to a motorcycle handlebar and includes a grip housing that has a first end adapted to receive the handlebar, and a second end opposite the first end. The grip housing includes a heating element that is operable to provide a heat output, and a heater control dial is coupled to the second end of the handgrip to control the heat output of the heating element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a divisional of U.S. patent application Ser. No. 10/615,814 filed Jul. 9, 2003, which claims priority to U.S. Provisional Application No. 60/395,575, filed Jul. 12, 2002, the entire contents of which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to vehicle controls, and more particularly to heated motorcycle handgrips.  
       BACKGROUND  
       [0003]     Providing heated handlebar grips for motorcycles and similar vehicles is known. Heated grips provide additional warmth and comfort for the hands of a motorcycle operator when the heated grips are activated. Prior heated grips utilize various control devices that allow the operator to adjust the relative amount of additional heat provided by the handgrips. Generally, the control switches or dials used to adjust the heat level of the handgrips are mounted near the instrument panel of the motorcycle, or at another location remotely located from the handgrip itself. Such location of the heat adjusting controls requires the motorcycle operator to remove one of his hands from the handgrip in order to adjust the amount of heat provided by the handgrip.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention is directed to a heated motorcycle handgrip including a grip housing that has a first end adapted to receive the handlebar, and a second end opposite the first end. The grip housing includes a heating element, and a heater control dial is coupled to the second end of the handgrip to control the heat output of the heating element. In one aspect of the invention, the control dial includes a diameter that is smaller than the diameter of the grip housing. In another aspect of the invention, the control dial includes a rib to enhance engagement of the grip by the user.  
         [0005]     In another aspect of the invention, the left and right grips are connected by a wire. The wire is positioned inside the handlebars to provide protection to the wire and to provide an aesthetically pleasing appearance.  
         [0006]     Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a perspective view of a motorcycle.  
         [0008]      FIG. 2  is a rear view of the motorcycle handlebar including heated handgrips embodying the invention.  
         [0009]      FIG. 3  is an enlarged section view taken along line  3 - 3  of  FIG. 2 .  
         [0010]      FIG. 4  is sectional view taken along line  4 - 4  of  FIG. 3 .  
         [0011]      FIG. 5  is a schematic view of the electronic circuitry and control system for the heated handgrips.  
         [0012]      FIG. 6  is a perspective view of the left handgrip of  FIG. 3 . 
     
    
       [0013]     Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The use of “consisting of” and variations thereof herein is meant to encompass only the items listed thereafter. The use of letters to identify elements of a method or process is simply for identification and is not meant to indicate that the elements should be performed in a particular order.  
       DETAILED DESCRIPTION  
       [0014]      FIG. 1  illustrates a motorcycle  10  including a front wheel  14 , a rear wheel  18 , an engine  20 , and a frame  22  including a steering assembly  26  interconnecting the front and rear wheels  14 ,  18 . The steering assembly  26  is pivotable about a steering axis and includes a handlebar  30  for imparting such pivotal motion to the steering assembly  26 . The handlebar  30  includes first and second handlebar grips  34 ,  36  that are grasped by an operator for control of the motorcycle  10  during motorcycle operation.  
         [0015]     Referring now to  FIG. 2 , the first grip  34  is secured to the left-hand end portion of the handlebar  30 , and the second grip  36  is secured to the right-hand end portion of the handlebar  30 . A left control housing  40  is positioned inwardly of the first grip  34 , and a right control housing  44  is positioned inwardly of the second grip  36 . The control housings  40 ,  44  are secured to the motorcycle handlebar  30  in a known manner and also secure the grips  34 ,  36  to the handlebar  30  in a manner to be described further below. The left and right control housings  40 ,  44  include operator switches  48  that communicate with and control various devices on the motorcycle  10 , such as the ignition, the starter, the turn signals, the horn, and other devices as is well known in the art. The illustrated handlebar  30  is a generally continuous tube that is typically made of a metal such as steel. However, it should be appreciated that other types of handlebars such as two-piece handlebars (e.g. “clip-ons”) may also be used in accordance with the present invention.  
         [0016]     The handlebar grips  34 ,  36  of the present invention are heatable by resistive heating elements embedded within the grips  34 ,  36 . To accommodate such resistive heating, electrical power is provided to the grips  34 ,  36  by power wires  52  that extend from the left control housing  40  and are coupled to an auxiliary power port  56  provided on the motorcycle  10 . The auxiliary power port  56  may comprise a power supply unit that is integral with the motorcycle  10 , or may comprise additional wiring and circuitry that are coupled to the motorcycle wiring harness, and/or directly connected to the motorcycle battery. In the illustrated embodiment, the power wires  52  provide electrical power to the left grip  34 , and jumper wires  60 , which extend through the center of the handlebar  30  and are therefore hidden from view, provide electrical power to the right grip  36 . Other embodiments of the invention may route the jumper wires  60  in a different manner, such as outside of the handlebar  30 .  
         [0017]     With reference to  FIG. 3 , each grip  34 ,  36  receives an end  64  of the handlebar  30 . As is known in the art, the right grip  36  is rotatably secured to the handlebar end  64  such that the right grip  36  can act as a motorcycle throttle control. The right grip  36  includes a generally cylindrical housing  68  having an inner end  72 , an outer end  73 , and an inner diameter that is slightly larger than the outer diameter of the handlebar  30 . The inner end  72  of the housing  68  includes a circumferentially extending rib  76  that includes a radially recessed, circumferentially extending groove  82 . The groove  82  receives a throttle cable  86  that is further coupled to the motorcycle throttle body (not shown). Rotation of the right grip  36  with respect to the handlebar  30  adjusts the throttle cable  86  to open and close the motorcycle throttle and subsequently change the speed of the engine  22 . While the use of the right grip  36  as the motorcycle throttle control is well known in the art, it should be appreciated that the positions of the grips  34 ,  36  could be reversed, such that the throttle control is on the left.  
         [0018]     Surrounding the housing  68  is a generally resilient grip sleeve  90 . The sleeve  90  is preferably a resilient polymer that is injection molded around the housing  68 . Embedded within the sleeve  90  and surrounding the housing  68  is a wire heating element  94  that is coupled to the jumper wires  60  adjacent to the end  64  of the handlebar  30 . The heating element  94  is wrapped around the housing  68  from the outer end  73  to the inner end  72 , and back to the outer end  73 . Such a configuration allows for electrical coupling of the heating element  94  to the jumper wires  60  at a single end of the grip  36 . Alternative embodiments of the invention may include alternatively configured heating elements, such as planar heating elements and the like. A substantially rigid circumferential ring  98  extends around the grip sleeve  90  near the inner end  72  of the housing  68  and cooperates with the circumferential rib  76  to provide a groove  100 . The groove  100  receives a wall  102  of the control housing  44  to secure the grip  36  to the handlebar end  64 . A removable end cap  110  is coupled to the outer end  73  of the housing  68  and substantially seals the inside of the grip  36  and the handlebar end  64 .  
         [0019]     The left grip  34  includes an outer grip housing  112  and an inner grip housing  113  that cooperate to define an annular space  114  that receives the end  64  of the handlebar  30 . As such, the outer grip housing  112  surrounds the end  64  of the handlebar  30 , while the inner grip housing  113  received by the generally cylindrical chamber defined by the end  64  of the handlebar  30 . The left grip  34  is generally cylindrical and includes an inner end  115 , an outer end  116 , and defines a central axis  119 . Similar to the right grip  36 , the outer housing  112  is surrounded by a generally resilient grip sleeve  120  that is preferably molded around the outer housing  112 . A radially outwardly extending circumferential rib  124  extends around the inner end  115  of the grip  34 . The circumferential rib  124  cooperates with a substantially rigid circumferential ring  130  (similar to the ring  98 ) to provide a circumferentially extending groove  132  near the inner end  115 . The groove  132  receives a wall  134  of the left control housing  40  to secure the grip  34  to the handlebar  30 . Unlike the right grip  36 , the left grip  34  is fixed against rotation with respect to the handlebar  30 . While the rotatable connection of the right grip  36  to the handlebar  30  is generally conventional, the engagement of the groove  132  with the wall  134  of the control housing  40  in the left grip  34  eliminates the need to use adhesive to secure the grip  34  to the handlebar  30 , thereby simplifying installation and/or removal of the grip  34 .  
         [0020]     Referring also to  FIG. 4 , the outer housing  112  defines a radially outwardly facing and axially extending channel  135  that extends from the inner end  115  of the outer housing  112  toward the outer end  116 . The channel  135  receives the power wires  52 , which extend along the channel  135  and around the end  64  of the handlebar  30 . The power wires  52  further extend into the inner housing  113  where the power wires  52  are coupled to electronic control circuitry  136  that is operable to control the heating of the grips  34 ,  36 . Substantially all of the electronic control circuitry  136  is positioned inside of the inner housing  113  and is therefore also positioned inside the handlebar  30 . A wire heating element  138  is connected to the control circuitry  136  through wire  137  that extends from the inner housing  113  and around the end  64  of the handlebar  30 . In the illustrated embodiment, the heating element  138  is wrapped around the outer housing  112  from the outer end  116  to the inner end  115 , and back to the outer end  116 . Such a configuration allows for electrical coupling of the heating element  138  at a single end of the grip  34 .  
         [0021]     To assist in regulating the heating of the grips, a temperature sensor in the form of a thermistor  142  is embedded in the left grip sleeve  120 . The thermistor  142  is preferably embedded near a central portion of the left grip sleeve  120 . A thermistor could also or alternatively be embedded in the right grip sleeve  90 . The thermistor  142  communicates with the control circuitry  136  via thermistor wires  143  that extend from the inner housing  113 , around the end  64  of the handlebar  30 , and along the channel  135  to the central portion of the grip sleeve  120 .  
         [0022]     In addition to the thermistor  142 , a heater control in the form of a variable resistor  154  is coupled to the outer end  116  of the grip  34  to assist in regulating the heating of the grips  34 ,  36 . The variable resister  154  includes an extending shaft portion  158  that is rotatable with respect to the grip  34  to adjust the resistance of the variable resistor  154 . The variable resistor  154  is generally adjustable between a range of resistance values, and may also include an OFF position, wherein the resistor  154  is substantially the same as an open switch and the resistance value is substantially infinite.  
         [0023]     The shaft portion  158  is coupled to a heater control dial  162  that is positioned on the outer end  116  and is rotatable about the central axis  119 . The dial  162  is rotatable by the motorcycle operator to adjust the resistance of the variable resistor  154 , which in turn controls the heating of the grips  34 ,  36 , as will be discussed further below. By positioning the dial  162  on the outer end  116  of the grip  34 , temperature adjustments may be made without removal of the operator&#39;s hand from the grip  34 .  
         [0024]     The dial  162  has an outer diameter that is smaller than the outer diameter of the grip  34 , thus reducing the likelihood that the dial  162  will unintentionally be rotated. In addition, the dial extends a distance beyond the end of the grip  34  and includes a plurality angularly spaced-apart ribs that define graduation marks  166  (sees  FIGS. 2 and 6 ). The graduation marks  166  extend radially from a peripheral wall portion of the dial  162  and extend axially from an end wall portion of the dial  162 . The graduation marks  166  indicate a relative angular position of the dial  162  with respect to the grip sleeve  120 . The end of the dial  162  includes a concave portion  165 , and the graduation marks  166  extend into the concave portion  165  such that the operator of the motorcycle can manipulate the dial  162  by placing and rotating a finger within the concave portion  165 . The angular position of the dial  162 , as established by the operator, substantially corresponds to a desired heat level of the grips  34 ,  36 . The sizing and positioning of the dial  162 , and the provision of raised graduation marks  166 , facilitates easy operation of the dial  162  by the operator, particularly when the operator is wearing protective gloves. The assembly including the dial  162  and the variable resistor  154  can include a resilient O-ring  168  that substantially seals the inside of the grip  34  and the handlebar end  64 .  
         [0025]     When referring to the outer diameter of the dial, grip, or grip sleeve, it is intended to mean the general outer periphery of the dial, grip, or grip sleeve. For example, the outer periphery will actually be a diameter when the grip sleeve is tubular, however the outer periphery can take different shapes in the case where the grip sleeve is oblong or non-symmetrically-shaped.  
         [0026]     As mentioned above, the inner housing  113  includes control circuitry  136  that controls the operation of the heating elements  94 ,  138  based on inputs produced by the variable resistor  154  and the thermistor  142 . The control circuitry  136  is schematically shown in  FIG. 5 . The control circuit  136  includes a power supply circuit  174  and a temperature control circuit  178 . The power supply circuit  174  includes a voltage regulator  182  and associated electrical components that provide filtering functions. In one embodiment, the voltage regulator  182  is National Semiconductor&#39;s LM78L05 three terminal positive regulator, and coverts a +12 volt signal into a +5 volt signal for use by the temperature control circuit  178 .  
         [0027]     The temperature control circuit  178  includes a programmable device  186 , electrical components associated with the programmable device  186 , and a switch  198 . In one embodiment, the programmable device  186  is Microchip&#39;s PICT12C671 8-pin, 8-bit CMOS microcontroller with an A/D converter and an EEPROM data memory. The programmable device  186  receives a desired temperature input corresponding to the relative angular position of the dial  162  as established by the motorcycle operator, and an actual temperature input corresponding to the temperature sensed by the thermistor  142 . The variable resistor  154  produces the desired temperature input, and a voltage divider formed by the thermistor  142  and the electrical components associated with the programmable device  186  produces the actual temperature input.  
         [0028]     Based on the inputs, the programmable device  186  generates an output signal that controls operation of the parallel wired heating elements  94 ,  138 . When the actual temperature input is less than the desired temperature input, the output signal closes the switch  198 , thereby turning the heating elements  94 ,  138  ON. When the actual temperature is more than or equal to the desired temperature input, the output signal opens the switch  198 , thereby turning the heating elements  94 ,  138  OFF. In one embodiment, the switch  198  is International Rectifier&#39;s IRL3102 power MOSFET.  
         [0029]     The heat level of the heating elements  94 ,  138  is thus controlled in a first respect by the motorcycle operator adjusting the dial  162  to a desired angular position, thereby establishing the resistance of the variable resistor  154 . The resistance of the variable resistor  154  produces the desired temperature input that is utilized by the control circuitry  136 . In a second respect, the thermistor  142  senses the actual temperature of the grip sleeve  120  and establishes a resistance value corresponding to the sensed temperature. The resistance value of the thermistor  142  in combination with the resistance values of the electronics associated with the programmable device  186  produce the actual temperature input that is utilized by the control circuitry  136 . The control circuitry  136  regulates the flow of electrical power through the heating elements  94 ,  138  in response to the inputs. The cooperative association of the variable resistor  154  and the thermistor  142  by way of the control circuitry  136  provides substantially constant grip  34 ,  36  temperatures regardless of the ambient temperature of the surroundings.  
         [0030]     As mentioned above, the control circuitry  136  receives electrical power via the power wires  52 . The power wires  52  are coupled to a relay  200 , which in turn is coupled to the positive terminal (+) and the negative terminal (−) of a power source  202  (e.g., battery) of the motorcycle  10 . The electrical conduit that connects the relay  200  to the positive terminal (+) preferably includes an in-line fuse  204 . The relay  200  is also electrically coupled to a switch  206  (e.g., the motorcycle ignition) that signals the relay  200  to turn ON and OFF. When the relay  200  turns ON, power is transmitted via the power wires  52  to the control circuitry  136  and the heating elements  94 ,  138  are turned ON and OFF as described above. The power wires  52  are coupled to the relay  200  at positive node  208 , and ground node  210 . The nodes  208 ,  210  substantially correspond to the electrical connector that couples the power wires  52  to the auxiliary power port  56  (see  FIG. 2 ). The power wires  52  include a first power wire  52 + that transmits a +12 volt signal, and a second power wire  52 − that transmits a ground signal. When the relay  200  turns OFF, power is no longer transmitted via the power wires  52  to the control circuitry  136  and the heating elements  94 ,  138  remain OFF.  
         [0031]     As is illustrated in  FIG. 3 , the jumper wires  60  extend from the right grip  36 , through the handlebar  30 , and are coupled to the inner housing  113  at a socket connector  212 . The socket connector  212  is schematically represented in  FIG. 5  by nodes  216  and  220 . Similar to the power wires  52 , the jumper wires  60  include a first jumper wire  60 + that transmits a +12 volt signal, and a second jumper wire  60 − that transmits a ground signal.  
         [0032]     The control circuitry  136  and the other electrical components (e.g., the power relay  200 , the fuse  204 , the switch  206 , the power source  202 , the jumper wires  60 , the power supply circuit  174 , the temperature control circuit  178 , the switch  198 , the variable resistor  154 , the thermistor  142 , and the heating elements  94 ,  138 ) described above represent one embodiment of the electronic circuitry and control system for use with the grips  34 ,  36 . Other embodiments of the electronic circuitry and control system for use with the grips  34 ,  36  may be alternatively configured and/or constructed.  
         [0033]     In operation, the grips  34 ,  36  are turned ON by closing the switch  206  and/or adjusting the dial  162  such that the variable resistor  154  is in a non-OFF position. With electrical power flowing to the control circuitry  136  via the power wires  52 , the controller  186  receives and compares the resistance input values provided by the thermistor  142  and the variable resistor  154 , and adjusts the switch  198  accordingly to turn the heating elements  94 ,  138  ON and OFF as described above. As the grips  34 ,  36  reach elevated temperatures, the motorcycle operator may further adjust the grip temperature by rotating the dial  162 . Because the dial  162  is positioned on the outer end  116  of the grip  34 , the motorcycle operator can adjust the grip temperature without having to remove his/her hand from the left grip  34 .