Patent Publication Number: US-11661147-B2

Title: Actuated scratchers for a tracked vehicle

Description:
This application is a continuation of U.S. application Ser. No. 16/720,373, filed Dec. 19, 2019, which is a continuation of U.S. application Ser. No. 15/811,945, filed Nov. 14, 2017, now U.S. Pat. No. 10,549,817, issued on Feb. 4, 2020, which claims benefit of U.S. Provisional Application No. 62/421,577, filed on Nov. 14, 2016 and which application is incorporated herein by reference. A claim of priority is made. 
    
    
     BACKGROUND 
     During operation, components of a snowmobile, such as the track and slide rails, may be cooled and lubricated by sprays of loose snow that are generated during the normal operation of the snowmobile on loose snow. Additionally, devices have been developed to scratch a surface of the ice or snow to generate a spray of ice or snow when a snowmobile operates in order to provide a desired cooling and lubrication. These devices are known by many different names such as snow tillers, spray generating devices, ice or snow scratchers, and snow lubrication devices. 
     SUMMARY 
     Embodiments relate to a snowmobile comprising a main frame and a tunnel coupled to the main frame, and a skid frame assembly coupled to the tunnel. The skid frame assembly includes a rear suspension, at least one skid rail coupled to the rear suspension, and at least one actuator having a scratcher coupled thereto. The actuator has a deployed configuration and an undeployed configuration. 
     Embodiments also relate to a method for automatically deploying scratchers coupled to a snowmobile, the method comprising the steps of providing an engine. providing at least one scratcher. providing a temperature sensor, determining, with the temperature sensor, the temperature of the engine, and deploying the at least one scratcher when the temperature of the engine is greater than or equal to a predetermined threshold. 
     Embodiments relate to a method for automatically deploying at least one scratcher coupled to a snowmobile, the method comprising the steps of providing an engine having a cooling system. providing at least one scratcher, providing a temperature sensor, determining, with the temperature sensor, the temperature of the coolant within the coolant system, and deploying the at least one scratcher when the temperature of the coolant is greater than or equal to a predetermined threshold. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in difference views. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG.  1    shows a projection view of an embodiment of a snowmobile. 
         FIG.  2    shows a side view of an embodiment of a snowmobile. 
         FIG.  3    shows a projection view of an embodiment of a snowmobile. 
         FIG.  4    shows a projection view of an embodiment of a snowmobile. 
         FIG.  5    shows a projection view of an embodiment of a portion of a snowmobile. 
         FIG.  6    shows a projection view of the portion of the snowmobile of  FIG.  5   . 
         FIGS.  7 ,  9 , and  10    show side views of an embodiment of a scratcher assembly. 
         FIG.  8    shows a front view of the scratcher assembly of  FIG.  7   . 
         FIG.  11    shows an example of a logic flow chart. 
         FIG.  12    shows an embodiment of a selector switch. 
         FIG.  13    shows another example of a logic flow chart. 
         FIG.  14    shows an embodiment of a selector switch. 
         FIGS.  15  and  16    show examples of logic flow charts. 
         FIG.  17    shows an example of an electrical circuit. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIG.  1   , a tracked vehicle  1 , such as a snowmobile, comprises a frame  12  ( FIG.  3   ), one or more skis  14  attached to the frame via a front suspension  16 , a track  18 , at least one seat  20 , handlebars  22 , an engine compartment  23  ( FIG.  3   ), and an engine  24  ( FIG.  3   ). Additionally, in at least some embodiments, the seat  20  is a straddle seat. The tracked vehicle also includes, in at least some embodiments, a skid frame assembly  26  comprising a rear suspension  28  ( FIG.  2   ). In some embodiments, the rear suspension  28  is coupled to the frame  12  of the tracked vehicle, for example, via a tunnel  30 . 
     As shown in  FIGS.  2 - 5   , in at least some embodiments, the skid frame assembly  26  includes one or more skid rails  27 . As shown in  FIG.  3   , the skid rail(s)  27  include a wear strip  6  adjacent to a lower surface of the skid rail(s)  27 . In at least some examples, the one or more skid rails  27  are formed from an aluminum material, however, a polymeric material, or any other suitable material, can be employed. Combinations of materials, alloys, metals, plastics, etc., can also be used. In some examples, the skid frame assembly  26 , or at least a portion thereof, is formed from a hollow member which can be located along a longitudinal centerline of the tracked vehicle  1 , for example as shown in U.S. Pat. No. 9,321,509, the contents of which are herein incorporated by reference in their entirety. Further, in some embodiments, the skid frame assembly  26 , or at least a portion thereof, includes multiple hollow members which can be laterally offset from one another and which generally extend in the longitudinal direction of the tracked vehicle  1 . 
     With further regard to  FIGS.  3  and  4   , in some embodiments, the tracked vehicle  1  has one or more scratchers  32 . The scratchers  32  can be deployed to throw snow and/or ice into the skid frame assembly  26  to provide lubrication for the track  18  and skid frame assembly  26  and, further, to cool the engine  24 , for example via a heat exchanger  52 , which can be located beneath a portion of the tunnel  30  or as a portion of the tunnel  30 . In at least some embodiments, the heat exchanger  52  includes coolant passages (not shown) through which coolant flows to cool the engine  24 . In some embodiments, the one or more scratchers  32  are formed from a spring-steel material, though other materials can also be used. In some embodiments, the scratchers  32  are deployed in order to prevent overheating of the engine, as discussed in greater detail below. 
     With regard to  FIG.  5   , in at least some embodiments, the one or more scratchers  32  are coupled to an actuator  34 . The actuator  34 , in turn, is mounted to the skid frame assembly  26 , or other suitable portion of the tracked vehicle  1 , for example via a fastener such as a bolt, rivet, strap, etc. In at least some embodiments the actuator(s)  34  is controlled electromechanically, however the actuator can be purely mechanical (e.g., cable actuated), or it can be hydraulic, pneumatic, or any suitable combination. As will be appreciated, other actuation modes can also be employed. In some embodiments, the actuator(s)  34  comprises a rotary actuator; in some embodiments, a linear actuator is employed; some embodiments utilize a direct current motor, such as a stepper-motor; some embodiments employ a solenoid. Again, other modes can also be utilized. 
     Further, the one or more actuators  34  can mounted in any suitable location. Where the one or more actuators  34  are mounted to one or more of the skid rails  27 , they can be mounted thereto in any suitable location, for example, ahead of a shock attachment location, behind a shock attachment location, etc. As will be appreciated, other locations may also be suitable. 
     Referring to  FIG.  6   , in some embodiments, the skid frame assembly  26  includes a plurality of scratcher assemblies  54 . In at least some embodiments, the skid frame assembly  26  includes two scratcher assemblies  54 , each scratcher assembly including an actuator  34  and a at least one scratcher  32 . In some embodiments, a scratcher assembly  54  is coupled to an outer side of the skid rail  27 , as shown in  FIG.  6   , for example. 
     As shown in  FIGS.  9  and  10   , the actuator  34  has a first configuration  36  and a second configuration  38 . In the first configuration  36  the scratcher(s)  32  is retracted; in the second configuration  38  the scratcher is deployed. Upon deployment, at least a portion of the scratcher(s)  32  contacts the ground. In at least some embodiments, the scratcher(s)  32  make contact with snow or ice covering the ground. In some embodiments, the scratcher(s)  32  includes one or more bent portions  40  and one or more straight portions  42 . 
     Referring to  FIG.  7   , arrow  56  illustrates rotation of the scratcher  32  about pivot axis  58  ( FIG.  8   ), in order to deploy or retract the scratcher  32 . In  FIGS.  7  and  8   , a rotary-style actuator is illustrated, however, any suitable of actuator can be employed. 
     Referring to  FIG.  11   , an embodiment of a flow chart  50  for deploying or retracting the one or more actuators  34  is shown. In some embodiments, the tracked vehicle  1  includes a selector switch  44  ( FIG.  1   ), which can be located on the handlebars  22 , or any other suitable location (e.g., electronic display with touch-pad, body panel, etc.). The selector switch  44  can have one or more selectable configurations. As illustrated in  FIG.  12   , the selector switch  44  can be manually operable by the rider to select between the deploy configuration  60  and retract configuration  62 . In some embodiments, the selector switch  44  is 2-position toggle switch, however a rotary, momentary, or any other suitable switch can be utilized. 
     Returning to  FIG.  11   , in some embodiments, the tracked vehicle  1  includes logic for retracting or deploying the one or more scratchers  32  via the one or more actuators  34 . In some embodiments, for example, the logic will not deploy the scratchers  32  if the tracked vehicle  1  is in reverse. As will be appreciated, operating the tracked vehicle  1  in reverse with the scratchers  32  deployed could cause damage to the scratchers  32 . The logic can be implemented via an ECU (engine control unit), analog circuit, dedicated processor, or in any other suitable way. 
     With regard to  FIG.  14   , in some embodiments, the selector switch  44  is a 3-position switch. In some embodiments, the selector switch  44  is a rotary switch, for example as shown in  FIG.  14   . By way of example, and as shown in  FIG.  14   , the selector switch includes a retract configuration  62  (illustrated via “R” in  FIG.  14   ), deploy configuration  60  (illustrated via “D”), and an auto configuration  64  (illustrated via “A”). The selector switch  44  shown in  FIG.  14    can be rotated to any of the three configurations—R, D, A, respectively. 
     Referring to  FIG.  13   , an example of control logic governing the operation of the switch of  FIG.  14    is illustrated. When placed in the retract configuration, corresponding to reference numeral  62  in  FIG.  14   , the actuator  34  will retract the scratcher  32  (or maintain the scratcher(s)  32  in a retracted configuration if the scratcher is already arranged in the retracted configuration). When placed in the deploy configuration, corresponding to reference numeral  60  in  FIG.  14   , the actuator  34  will deploy the scratcher  32  if the control logic determines that the vehicle is not placed in reverse. Finally, where the switch  44  is placed in the auto configuration, corresponding to reference numeral  64  in  FIG.  14   , the actuator  34  will retract and deploy the scratcher  32  automatically. In some embodiments, the actuator  34  will deploy (maintain deployment) the scratcher  32  when two conditions are satisfied: (1) the tracked vehicle  1  is not in reverse and (2) the temperature sensor determines that the temperature has reached a predetermined threshold value. When the temperature falls below the threshold value, the scratcher(s)  32  are automatically retracted (maintained in a retracted configuration). Further, when the tracked vehicle  1  is placed in reverse the scratcher(s)  32  are automatically retracted. In some embodiments, the temperature sensor samples the coolant temperature of the coolant flowing through the engine  24 . In some embodiments, the temperature sensor measures the temperature of the engine  24  directly, for example cylinder head temperature. In some embodiments, the temperature sensor measures the ambient air temperate in the engine compartment  23 . 
     Turning to  FIG.  15   , in some embodiments, the tracked vehicle  1  doesn&#39;t have a selector switch  44  and, instead, the actuator(s)  34  automatically deploy the scratcher(s)  32  when: (1) the tracked vehicle  1  is not in reverse and (2) the temperature sensor determines that the temperature has reached a predetermined threshold value. In some embodiments, however, the selector  44  can simply be an ON/OFF switch. In an “OFF” configuration, the actuator(s)  34  do not deploy the scratcher(s)  32 . In the “ON” configuration, however, the actuator(s) deploy the scratcher(s)  32  when: (1) the tracked vehicle  1  is not in reverse and (2) the temperature sensor determines that the temperature has reached a predetermined threshold value. When the temperature falls below the threshold value, the scratcher(s)  32  are automatically retracted. Further, when the tracked vehicle  1  is placed in reverse the scratcher(s)  32  are automatically retracted. 
     With regard to  FIG.  16   , an embodiment of control logic is shown. In this instance, the actuator(s)  34  will retract (or maintain in a retracted configuration) when the temperature is below a predetermined threshold. Further, the actuator(s)  34  will retract (or maintain in a retracted configuration) when the tracked vehicle  1  is placed in reverse. 
     In some embodiments, the scratcher(s)  32  will remain in first configuration  36  regardless of sensor measurements (e.g., temperature sensor measurement), vehicle speed, forward/reverse configuration, or any other suitable inputs which might otherwise activate the actuator(s)  34 . In some embodiments, the actuator(s)  34  will retract or deploy in response to the tracked vehicle  1  traveling at a predetermined speed. For example, the actuator(s)  34  can retract the scratcher(s)  32  above a threshold speed. 
     In some embodiments, the temperature sensor will continuously evaluate the temperature of the engine or engine&#39;s cooling system, or other desired condition designed to activate the actuator(s)  34 . In some embodiments, an ECU (electronic control unit)  46  automatically controls the actuator(s)  34 . 
     With further regard to  FIG.  17   , an example of an electrical circuit  45  is shown. In some embodiments, the ECU will take inputs from the temperature sensor  4  and a reverse input switch  49 . When the ECU determines that the temperature exceeds a predetermined threshold temperature, the ECU will send a “command down” signal to the actuator  34  to deploy the scratcher(s)  32 , unless the reverse input switch  49  indicates that the tracked vehicle  1  is in reverse. Further, when the ECU determines that the temperature drops below a predetermined threshold temperature, the ECU will send a “command up” signal to the actuator  34  to retract the scratcher(s)  32 . It will be appreciated that, in some embodiments, the ECU will monitor the configuration of the actuator  34  (deployed or retracted) and no signal will be sent to the actuator  34  unless desired. For example, if the scratcher(s)  32  are retracted and the temperature sensor  4  determines that the engine temperature has exceeded the predetermine threshold temperature, the ECU will not send a “command down” signal to deploy the scratcher(s)  32  if the tracked vehicle  1  is in reverse. 
     In some embodiments, the ECU will monitor the configuration of the actuator(s) on a period basis, for example once every 500 milliseconds, or other appropriate time interval. 
     In some embodiments, the predetermined temperature threshold to deploy the scratcher(s)  32  is different than the predetermined temperature to retract the scratcher(s). For example, in some embodiments, the predetermined threshold to retract the scratcher(s) is less than the predetermined temperature used to deploy the scratcher(s)  32 . In some embodiments, this is desirable to reduce the likelihood that the scratcher(s)  32  will be repeatedly deployed and retracted. Additionally, in some embodiments, when the measured temperature decreases by a predetermined amount, the scratcher(s)  32  will retract into first configuration  36 . Further still, the ECU, via temperature sensor  4 , can determine the rate of change in temperature. In this way, the ECU can send signals to deploy or retract the scratcher(s)  32 , at least in part, based on a control system having greater inputs. For example, the ECU can rely on a PI, PD, or PID (proportional-integral-derivative) algorithm or controller. 
     While the above detailed description has shown, described, and pointed out novel features of a tracked vehicle as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made by those skilled in the art without departing from the spirit and scope of the disclosure. The application is, therefore, intended to cover any variations, uses, or adaptations of using these general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.