Abstract:
The present invention generally relates to control mechanisms and more specifically to a control mechanism which is adaptable to a steering wheel of a vehicle. Most control mechanisms of auto-piloting systems which must be installed on existing vehicles usually require more specific parts and more expensive installations. The control mechanism according to embodiments of the present invention includes components readily installable into the cabin of an existing vehicle and involves elements sandwiching the steering wheel of the vehicle which are operatively mounted to a motoring assembly actuatable by the user of the vehicle.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Application No. 60/660,997, filed Mar. 14, 2005, which is hereby incorporated by reference. 

   FIELD OF THE INVENTION 
   The present invention generally relates to control mechanisms. More specifically, the present invention is concerned with a control mechanism for a steering wheel of a vehicle. 
   BACKGROUND OF THE INVENTION 
   The constant need to increase productivity and to design reliable tools to accomplish various productive activities has led to a plurality of developments in many fields of technology. 
   In agriculture, many types of tools and working vehicles are available to accomplish the various tasks at hand. The number of tasks and the size of fields and lands which needs to be taken care often necessitate very efficient machineries and tools, especially when the laws of market and productivities are involved. 
   These past years, many agricultural operations have been automated to achieve more precision and to optimize time, money and product resources. As an example, auto-piloting systems have already been introduced for agricultural vehicles. 
   Most of these auto-piloting systems necessitate an electro-hydraulic control box mounted on the steering servo-direction of the vehicle. Even though this solution proves to be robust and reliable since the user stays in control on board of the vehicle when the system is operating, such auto-piloting systems often requires specific parts for specific vehicles and a more expensive installation involving hydraulics. Further, the installation of such systems on existing vehicle may annul the warranty of other parts of vehicles which were not initially designed to interface with the components of the control mechanisms. 
   OBJECTS OF THE INVENTION 
   An object of the present invention is therefore to provide a steering wheel control mechanism which is easily fabricated and installed on new and existing vehicles. 
   A further object of the present invention is to provide a steering wheel control mechanism which allows the user of a vehicle to operate and disable the steering mechanism upon request. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the appended drawings: 
       FIG. 1  is a perspective view of a steering control mechanism according to an embodiment of the present invention; 
       FIG. 2  is a top plan view of the steering control mechanism of  FIG. 1 ; 
       FIG. 3  is a bottom plan view of the steering control mechanism of  FIG. 1 ; 
       FIG. 4  is a side elevation view of the steering control mechanism of  FIG. 1 ; 
       FIG. 5  is a partially exploded perspective view showing a steering assembly of the steering control mechanism of  FIG. 1 ; 
       FIG. 6  is a perspective view showing a mounting structure of the steering control mechanism of  FIG. 1 ; 
       FIG. 7  is a perspective view showing a motoring assembly of the steering control mechanism of  FIG. 1 ; 
       FIG. 8  is a perspective view of a steering control mechanism according to a second embodiment of the present invention; 
       FIG. 9  is a side elevation view of the steering control mechanism of in  FIG. 8 ; and 
       FIG. 10  is a side elevation view showing a steering assembly of the control mechanism of  FIG. 8 . 
       FIG. 11  is a block diagram of a controller in communication with a global positioning satellite (GPS) system. 
       FIG. 12  is a block diagram of a controller in communication with a remote control device, such as a joystick. 
   

   DETAILED DESCRIPTION 
   The present invention relates to an auto-piloting system with a control mechanism for a steering wheel of a vehicle. 
   The auto-piloting system generally includes a controller (not shown) linked to a GPS (not shown) for controlling a steering wheel control mechanism  40 , as illustrated in  FIGS. 1 to 4 . The control mechanism  40  includes a steering assembly  42 , a mounting structure  44 , a motoring assembly  46 , a guiding structure  48 , and an actuating assembly  50 . 
   The control mechanism  40  is mountable to the steering wheel  52  of a vehicle and generally extends in the vicinity of the steering wheel  52 , integrated or not to the frame of the steering wheel or to the vehicle. 
   Turning now to  FIG. 5 , the steering assembly  42  includes a top element  54  and a bottom element in the form of a ring gear  56  which altogether sandwich the steering wheel  52  in a clamping assembly using a plurality of fasteners  57  inserted in corresponding openings  59  in the top and bottom elements  54 ,  56 . 
   The top element  54  is a ring shaped or plated structure which may be provided with a cover (not shown) for mounting a control element or for esthetic reasons, as will be further explained hereinbelow. 
   The ring gear  56  includes a structural body  60  with a peripheral geared surface  62  extending away from the bottom portion  52   a  of the steering wheel  52 . The body  60  is so configured and sized as to be installed around the bottom portion  52   a  and/or in contact with arms  52   b ,  52   c ,  52   d  extending from the bottom portion  52   a  of the steering wheel  52 . The geared surface  62  is so configured and sized as to cooperate with the motoring assembly  46 , as will be further explained hereinbelow. Optionally, the ring gear  56  is made in two parts that are fixedly mountable to one another for facilitating the installation of the ring gear  56  around the bottom portion  52   b  of the steering wheel  52  of an existing vehicle without requiring the removal of the steering wheel from the vehicle. 
   The mounting structure  44  is shown in more details in  FIGS. 4 and 6 . The mounting structure  44  includes a top mounting surface  44   a , a bottom mounting surface  44   b , an actuating selector structure  64 , a slot  66 , a pivotal connector  67  and a T-slot  68 . 
   As illustrated in  FIG. 4 , the mounting structure  44  is securely mounted to the vehicle  69  via supporting brackets  45   a ,  45   b ,  45   c , such that the steering wheel  52  is able to be turned upon operation of the control mechanism  40 . The supporting brackets  45   a ,  45   b ,  45   c  further helps to provide pivotal and translational adjustability via slots  45   d ,  45   e  and pins  45   f ,  45   g  to allow the installation of the control mechanism  40  on various types of vehicle  69  and steering wheel  52 . 
   As illustrated in  FIG. 6 , the top mounting surface  44   a  of the mounting structure  44  faces the steering wheel  52  and generally provides a rigid area for mounting the guiding structures  48  and for mounting and operating the motoring assembly  46  and the actuating assembly  50 . 
   The actuating selector structure  64  includes three recesses  64   a ,  64   b ,  64   c  corresponding to selectable engaged and disengaged positions of the actuating assembly  50  for operating the control mechanism  40  between an engaged configuration and a disengaged configuration. The recesses  64   a ,  64   b ,  64   c  are selectable via the slot  66  and the pivotal connection  67  arrangement linking the mounting structure  44  with the actuating assembly  50 , as will be further explained hereinbelow. In the illustrative embodiment, recess  64   b  corresponds to the engaged position and recesses  64   a ,  64   c  both correspond to the disengaged position. 
   The T-slot  68  extends on the mounting structure  44  such as to provide a locking capacity for stopping the operation of the control mechanism  40  by involving the actuating assembly  50  in the disengaged position and the motoring assembly  46 , as will be further explained hereinbelow. 
   The motoring assembly  46 , illustrated in more details in  FIG. 7 , includes a supporting structure  70 , an electric motor  72 , a worm gear  74 , a driving assembly  76 , a lock structure  78  and switches  79   a ,  79   b ,  79   c  ( FIG. 3 ). 
   The supporting structure  70  includes an attachment portion  70   a  so configured and sized as to be mounted to the mounting structure  44  and a holding portion  70   b  for supporting the electric motor  72  and for positioning the worm gear  74  in a meshing cooperation with the ring gear  56  ( FIG. 5 ). In the illustrative embodiment, the attachment portion  70   a  is slidably mountable within the T-slot  68  ( FIG. 6 ). 
   The electric motor  72  is in communication with the controller, such as for example via a cable (not shown), such that a signal generated by the auto-piloting system and processed by the controller is capable of imparting a specified operating condition to the worm gear  74  via the electric motor  72 , as will be further explained hereinbelow. 
   The worm gear  74  is so configured and sized as to mesh with the ring gear  56 . Further, the worm gear  74  is rotatably mounted to the holding portion  70   b  via a shaft  74   a  that is operatively linked to the electric motor via the driving assembly  76 . In the illustrative embodiment, the driving assembly  76  includes a belt  76   a  operatively connected to pulleys  76   b ,  76   c  that are respectively mounted to the electric motor  72  and to the shaft  74   a.    
   The lock structure  78  is mounted to and extends from the attachment portion  70  toward the actuating assembly  50  and includes a slider aperture  78   a  in the vicinity of the actuating assembly  50  for stopping or disengaging the operation of the control mechanism  40 , as will be further explained hereinbelow. 
   The switches  79   a ,  79   b ,  79   c , illustrated as limit-switches in  FIG. 3 , are generally mounted on the bottom surface  44   b  of the mounting structure  44  and positioned in such a way as to cooperate by direct contact or by signal with the actuating assembly  50  for switching the electrical power from the controller to the electric motor  72  between an “on” and “off” mode, and for recognizing the positions and the transitions between the positions of the actuating assembly  50 , as will be further explained hereinbelow. 
   Turning back to  FIG. 6 , there is furthermore illustrated two guiding structures  48 , each including a housing  80  and three roller guides  82 . The housing  80  includes a recessed passage  80   a  for supporting the guides  82  and allow passage of the ring gear  56  therethrough. The housing  80  is fixedly mounted and oriented with respect to the mounting structure  42  ( FIG. 5 ) such that geared surface  62  ( FIG. 5 ) of the ring gear  56  ( FIG. 5 ) is received with a clearance within the passage  80   a  and such that the guides  82  support the body  60  ( FIG. 5 ) of the ring gear  56  ( FIG. 5 ). 
   In the illustrative embodiment, the guides  82  have a generally v-shaped configuration which cooperates with edges (not shown) of the body  60  ( FIG. 5 ), thereby maximizing the relative alignment between the steering assembly  42  and the motoring assembly  46 . Alternatively, the guides  82  could be directly mounted to the mounting structure  42 . 
   Finally, the actuating assembly  50  illustrated in  FIG. 6  includes a handle portion  86 , a joint assembly  88 , a link  90 , a spring member  91 , pins  92   a ,  92   b  and a cam  94  ( FIG. 3 ). The handle portion  86  extends from the control mechanism  40  such as to be readily gripped by a user of the vehicle, generally in the vicinity of the steering wheel  52 . 
   As introduced hereinabove, the handle portion  86  is selectively positionable with respect to the notches  64   a ,  64   b ,  64   c , for actuating the control mechanism  40  from an engaged configuration to a disengaged configuration. In the illustrative embodiment, the handle portion  86  includes a roller  86   a  for facilitating the passage of the handle portion  86  in between the various recesses  64   a ,  64   b ,  64   c.    
   The joint assembly  88  is fixedly mounted on one side to the handle portion  86 . The joint assembly  88  is so pivotally mounted to the link  90  as to pivot about an axis defined by a pin  93 , in order to allow the disengagement of the handle portion  86  from the various recesses  64   a ,  64   b ,  64   c  without having to bend the link  90  in the process. 
   The link  90  generally ensures the movable connection between the actuating assembly  50  and the mounting assembly  44  via the pin  92   a  engaged in the pivotal connection  67  and the pin  92   b  engaged in the arcuate slot  66 . 
   The spring member  91  is generally mounted to the joint assembly  88  and extends toward the link  90  such as to exert an adjustable tensioning force opposing to the relative pivotal movement between the joint assembly and the link  90  about pin  93 . When the tensioning force is brought to a minimal level, a movement of the steering wheel  52  is generally enough to disengage the steering mechanism  40 , as will be further explained hereinbelow. 
   As better seen in  FIG. 3 , the pin  92   a  is mounted to the link  90  and terminates with the cam  94 , which includes contactors in the form of projections  94   a ,  94   b ,  94   c . The cam  94  is generally positioned and oriented with respect to the switches  79   a ,  79   b ,  79   c  such that contactor  94   b  is in contact with the switch  79   b  (the “on” mode) when the actuating assembly  50  is engaged with recess  64   b  (the engaged position), and such that the contactor  94   a ,  94   c  is in contact with the switches  79   a  or  79   c  (the “off” mode) when the actuating assembly  50  is engaged with recess  64   a  or  64   c  (the disengaged position). The various positions of the cam  94  are recognized by the switches  79   a ,  79   b ,  79   c  which may therefore respond with a corresponding signal to the controller (not shown) for controlling the electrical power to the motoring assembly  46 . Optionally, the electrical power may be put back into the “on” mode as soon as the contactors  94   a ,  94   c  depart from the switch  79   a  or  79   c , and may be put back into the “off” mode as soon as the actuating assembly  50  departs from the switch  79   b  for helping the user of the control mechanism  40  to engage or disengage the worm gear  74  with the ring gear  56 . 
   This arrangement provides for the passage of the control mechanism  40  from its engaged configuration to its disengaged configuration, as will be further explained hereinbelow. Generally stated, the pivoting motion of the link  90  around the pin  92   a  by the user is transformed into a lateral linear movement of the motoring assembly  46  by the contact of the pin  92   b  and the slider aperture  78   a  while the lock structure  78  is engaged in the T-slot  68 . 
   The operation of the control mechanism  40  described herein will be explained when integrated to a vehicle provided with an auto-piloting system including an external controller in signal communication with a GPS system (such as controller  1100  in communication with GPS system  1110  (see  FIG. 11 )). First, the GPS system acquires a position of the vehicle. The external controller receives the information regarding the position of the vehicle and is able to read, receive, stock, compare or calculate various controllable parameters, such as for example, instant vehicle position, speed, and acceleration. 
   For instance, the controller may be provided with a reference path corresponding to the path the vehicle has to follow for a specific vehicular application. The reference path is compared to the position received from the GPS and the controller decides what level of curvature and speed has to be applied to the steering wheel  52  via the control mechanism  40  for achieving an effective and appropriate piloting of the vehicle. 
   The controller then establishes that the vehicle has to go in a first direction at a first speed for tending toward the reference path. A command containing that information is translated into a corresponding signal regarding the direction of rotation and the speed at which the electric motor  72  must go for a specific period of time to meet the requirements of the command of the controller. 
   When the control mechanism  40  is in its engaged configuration, corresponding to the handle portion  86  being in its engaged position and corresponding to the connector  94   b  of the cam  94  being in contact with the switch  79   b , the electric power is put in the “on” mode such that the electric motor  72  is activated. 
   At that time, the electric motor  72  is able to operate the worm gear  74  according to the command from the controller, at the specific speed and rotation direction and for the specific period of time. The worm gear  74  in a meshing cooperation with the geared surface  62  of the ring gear  56  carries the steering assembly  42  such that the steering wheel  52  of the vehicle is moved according to the command of the controller (not shown). It should be pointed out here that the supporting brackets  45   a ,  45   b ,  45   c  will prevent the motoring assembly  46  from rotating upon operation of the steering assembly  42 . 
   The user of the vehicle may further need to stop the command or remove the auto-piloting system, by operating the actuating assembly  50 . First the user moves the handle portion  86  from the engaged position in the recess  64   b  to the disengaged position in either one of the recesses  64   a ,  64   c.    
   In doing so, the disengaged configuration of the control mechanism  40  is initiated, corresponding to either one of the connectors  94   a ,  94   c  of the cam  94  being in contact with its corresponding switch  79   a ,  79   c , such that the electric power is put in the “off” mode and inactivates the electric motor  72 . Further to this, when the handle portion  86  is put in its disengaged position, the pin  92   b  travels within the slot  66  such as to carry the link  90  about the pivotal connection  67  and such as to abut with the lock structure  78  within the slider aperture  78   a.    
   The lock structure  78  and the motoring assembly  46  are therefore free to travel linearly within the T-slot  68  of the mounting structure  44  such as to either force or oppose to the meshing between the worm gear  74  and the ring gear  56 . This external force has a tendency “unmesh” the cooperation between the motoring assembly  46  and the steering assembly  42 , concluding thereby the switch from the engaged configuration to the disengaged configuration of the control mechanism  40 . 
   When the control mechanism  40  is in its disengaged configuration, the steering wheel  52  may be manually operated by the user of the vehicle. 
   For re-activating the control mechanism  40  from its disengaged configuration to its engaged configuration, the user moves the handle portion  86  from its disengaged position in either recesses  64   a  or  64   c  toward its engaged position in the recess  64   b . At that time, the connectors  94   a ,  94   c  are no longer in contact with respective switches  74   a ,  74   c , which may trigger a signal to the controller (not shown) regarding the re-activation of the electric motor  72  for re-operating the worm gear  74  in order to facilitate the meshing of the worm gear  74  with the ring gear  56 . 
   In doing so, the pin  92   b  is carried within the slot  66  such as to pivot the link  90  about the pivotal connection  67 . The pin  92   b  further abuts with the lock structure  78  within the slider aperture  78   a , in such a way as to force the motoring assembly  46  to travel within the T-slot  68  of the mounting structure  44 . At that time the meshing cooperation between the worm gear  74  and the ring gear  56  is re-established and the contact between the connector  94   b  of the cam  94  with the switch  79   b  may be made to allow for the electric power to be put back to the “on” mode and re-activate the electric motor  72  and the control mechanism  40  thereby. 
   As stated hereinabove, an alternative way of disabling the control mechanism  40 , requires that the user directly steer the steering wheel  52  in one direction, such that the tensioning force in the spring member  91  is overcome by the transmission of the force deployed by the user via the steering wheel  52 , the ring gear  56  and the worm gear  74  such that the attachment portion  70   a  of the motoring assembly  56  starts sliding in the T-slot  68 . The lateral linear movement of the motoring assembly  46  may then activate the pivoting motion of the link  90  around the pin  92   a  via the contact between the pin  92   b  and the slider aperture  78   a  if the force deployed by the user is enough to overcome the tensioning force in the spring member  91 . In the latter case, the roller  86   a  may then leave its encapsulation in the recess  64   b  by the pivotal movement of the joint assembly  88  about the pin  93  such that the actuating assembly  50  may be forced out its engaged position. 
   A person skilled in the art will easily understand that the control mechanism  40  described herein may be used with a plurality of different controlling systems. For example, the GPS signal to the controller may be replaced by a signal provided by a user looking at a camera positioned on the vehicle or by a user positioned at a distance from the vehicle. The user is provided with a commanding means, such as for example a joystick  1200 , or an outside steering wheel in signal communication with the controller  1210  via emitted signals received by the controller  1210  (see  FIG. 12 ). 
   A steering mechanism  140  according to a second embodiment of the invention is illustrated in  FIGS. 8 to 10 . For concision purposes, only the differences between the steering mechanism  140  and the steering mechanism  40  illustrated in  FIGS. 1 to 7  will be described hereinbelow. 
   In this illustrative embodiment, the steering mechanism  140  includes a steering assembly  142 , a mounting structure  144 , a motoring assembly  146 , a cable  147  forming a closed loop, and an actuating assembly  150 . 
   The steering assembly  142 , as illustrated in more details in  FIG. 10 , includes a top element  154  and a bottom assembly  156  sandwiching the steering wheel  152 . The bottom assembly  156  is generally made of two stacked pulleys  156   a ,  156   b  including grooves  157  which are so configured and sized as to cooperate with the cable  147 . 
   The mounting structure  144  is supporting the motoring assembly  146  and is positioned, as shown in the illustrative embodiment of  FIG. 8 , on the floor of a cabin of a vehicle. The motoring assembly  146  includes an electric motor  146   a  driving a pulley  146   b . The pulley  146   b  cooperates with the pulleys  156   a ,  156   b  via the cable  147  for steering the wheel  152  of the vehicle when the actuating mechanism  150  is in its engaged position. 
   The cable  147  includes an external guide envelope  147   a , an internal cable member  147   b  longitudinally sliding within the external guide envelope  147   a , and an internal tensioning member (not shown). The internal member  147   b  is configured and sized as to matingly cooperate with the grooves  157  of the pulleys  156   a ,  156   b  and as to be driven by the pulley  146   b  of the motoring assembly  146 . The external guide envelope  147   a  allows alignment of the cable member  147   b  with grooves  157 . 
   The actuating mechanism  150  includes a switch control board  150   a  generally mounted on the top element  154  and in communication with an electric clutch (not shown). 
   In operation, the control mechanism  140  allows to steer the wheel of a vehicle when the internal tensioning member (not shown) of the cable  147  is tensioned, corresponding to the electric clutch (not shown) being engaged with the pulley  146   b.    
   At that time, the internal cable member  147   b  is matingly engaged with the pulleys  156   a ,  156   b ,  146   b  such that upon operation of the electric motor  146 , the rotation of pulley  146   b  provides a corresponding rotation of the steering wheel  152  through the fixed (under tension) connection between the internal cable member  147   b  and the grooves  157  of the pulleys  156   a ,  156   b.    
   When the switch control board  150   a  of the actuating mechanism  150  is put in its “off” mode, corresponding to a signal disengaging the electric clutch (not shown) from the pulley  146   b , the tension provided to the internal tensioning member (not shown) of the cable  147  is not enough for driving the steering wheel  152 . 
   At that time, the fixed (under tension) connection between the internal member  147   b  and the grooves  157  of the pulleys  156   a ,  156   b  is set loose, such that the steering wheel  152  and the steering assembly  142  are allowed to move with respect to the cable  147 . 
   Alternatively, the electric clutch (not shown) may be replaced by a tensioner in contact with the internal tensioning member (not shown) of the cable  147  for providing the tension level to the internal tensioning member when the switch control board  150   a  is in the “on” mode. 
   Although the present invention has been described hereinabove by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims.