Combination running board and sidestep having a linear drive

Abstract

Running board assembly for a motor vehicle having a passenger cab and a box. The running board assembly includes a linear actuator assembly partly disposed within a housing assembly, a running board operably coupled to the linear actuator assembly and movable relative to the housing assembly between a stowed position tucked underneath the vehicle, a cab entry position generally outwardly from the vehicle to support a user entering or exiting the passenger cab, and a box side step disposed generally outwardly from the vehicle and rearward of the cab entry position to provide a user with side access to the box, and a motor operably coupled to the linear actuator assembly for driving the linear actuator assembly in opposing first and second directions. The linear actuator assembly converts rotary input to linear motion to cause a drive arm having a linkage assembly to move the running board between the positions.

1 . A running board assembly for a motor vehicle, said running board assembly comprising:
 a housing assembly;   a linear actuator assembly partly disposed within said housing assembly;   a running board operably coupled to said linear actuator assembly and movable relative to said housing assembly between at least a stowed position and deployed position; and   a motor operably coupled to said linear actuator assembly for driving said linear actuator assembly in opposing first and second directions to move said running board horizontally between at least said stowed position and deployed position.   
     
     
         2 . The running board assembly according to  claim 1 , further comprising a drive arm operably coupled to said linear actuator assembly and fixedly secured to said running board for pivotally moving said running board between said at least stowed and deployed positions. 
     
     
         3 . The running board assembly according to  claim 2 , wherein said linear actuator assembly includes a rotatable ball screw member operably coupled to said motor, and wherein rotation of said ball screw member drives pivotal movement of said drive arm. 
     
     
         4 . The running board assembly according to  claim 3 , wherein said drive arm includes a first link pivotably connected to a second link at a joint, wherein rotation of said ball screw member drives relative movement of said first link and second link for pivotally moving said running board between said at least stowed and deployed positions. 
     
     
         5 . The running board assembly according to  claim 3 , wherein said housing assembly includes a tube portion and said ball screw member is disposed within said tube portion. 
     
     
         6 . The running board assembly according to  claim 5 , wherein said linear actuator assembly includes a worm member and self locking member operably coupled toward one end of said ball screw member and disposed within said housing assembly. 
     
     
         7 . The running board assembly according to  claim 6 , wherein said linear actuator assembly includes a ball nut operably connected to said ball screw member with internal ball return. 
     
     
         8 . The running board assembly according to  claim 7 , wherein said linear actuator assembly further comprises an actuator shaft tube operably coupled to said ball screw member, and, at a second end to a spherical bearing, said spherical bearing pivotably connected to said first link of said drive arm. 
     
     
         9 . The running board assembly according to  claim 2 , wherein said drive arm includes a stow stop engageable with said running board to stop said running board in said stowed position and an end stop engageable with said running board to stop said running board in said deployed position. 
     
     
         10 . The running board assembly according to  claim 1 , including an electronic control unit operably coupled to said motor and electronically controlling operation thereof. 
     
     
         11 . The running board assembly according to  claim 10 , wherein said electronic control unit is programmed to turn off said motor after a predetermined number of armature revolutions to stop said running board in said cab entry position. 
     
     
         12 . A running board assembly for a motor vehicle, said running board assembly comprising:
 a housing assembly with a linear actuator assembly;   a running board operably coupled to said linear actuator assembly and movable relative to said housing assembly between a plurality of positions;   a drive arm fixedly secured to said running board and operably coupled to said linear actuator assembly, said drive arm including a first stop engageable with said running board to stop said running board in one of said plurality of positions and a second stop engageable with said running board to stop said running board in another of said plurality of positions;   a motor operably coupled to said linear actuator assembly for driving said drive arm to pivotally move said running board horizontally between said a plurality of positions; and   an electronic control unit operably coupled to said motor and programmed to turn off said motor after a predetermined number of armature revolutions to stop said running board in said cab entry position.   
     
     
         13 . The running board assembly according to  claim 12 , further comprising a switch member transmitting a signal to said electronic control unit to move said running board between said a plurality of positions upon the opening and closing of a motor vehicle door. 
     
     
         14 . The running board assembly according to  claim 12 , further comprising a switch member electronically connected to said electronic control unit and providing a signal thereto for moving said running board into and out of at least one of said a plurality of positions. 
     
     
         15 . A running board assembly for a motor vehicle, said running board assembly comprising:
 a mounting bracket adapted for attachment to the motor vehicle;   a running board movable relative to said mounting bracket between a stowed position tucked underneath the motor vehicle and at least one deployed position, to provide a user with access to the motor vehicle;   a motor operably coupled to said running board for driving horizontal movement thereof;   an electronic control unit electronically connected to said motor, said electronic control unit selectively programmable to turn off said motor to stop said running board in said cab entry position; and   a housing assembly with a linear actuator assembly partly disposed therein and including a rotatable worm member and a lead worm that is self locking operably coupled to said motor, said housing assembly including a steel tube portion for receiving a rotatable ball screw member of said linear actuator assembly that is operably coupled to said worm member, said linear actuator assembly coupled to said motor for driving said linear actuator assembly in opposing first and second directions to move said running board between said stowed position and said at least one deployed position.   
     
     
         16 . The running board assembly according to  claim 15 , further comprising a switch member electronically connected to said electronic control unit and providing a signal thereto for moving said running board into and out of at least one of said positions. 
     
     
         17 . The running board assembly according to  claim 15 , further comprising a drive arm operably coupled to said linear actuator assembly and fixedly secured to said running board for pivotally moving said running board between said stowed and at least one deployed, positions. 
     
     
         18 . The running board assembly according to  claim 17 , wherein said drive arm includes a first link pivotably connected to said linear actuator and pivotably connected to a second link at a joint, said second link pivotably connected to said running board, wherein rotation of said ball screw member drives relative movement of said first link and second link for pivotally moving said running board between said stowed and at least one deployed, positions. 
     
     
         19 . The running board assembly according to  claim 18 , wherein said joint is pivotably connected to a hub structure pivotally securing said drive arm to said mounting bracket. 
     
     
         20 . The running board assembly according to  claim 17 , wherein said drive arm includes a first stop engageable with said running board to stop said running board in said stowed position and a second stop engageable with said running board to stop said running board in said deployed position.