Stair system for vehicle

1. A stair system for providing access to a cargo platform of a commercial vehicle, the stair system movable between a deployed configuration and a stowed configuration, the stair system comprising:

at least one mounting bracket configured to be attached to the cargo platform of the vehicle;

a stair assembly pivotally attached to the at least one mounting bracket at a first pivot location, the stair assembly comprising a first support frame comprising a pair of opposing frame rails and a plurality of step platforms secured to the frame rails of the first support frame, wherein at least one frame rail comprises a side plate comprising an elongated slot extending along a length of the side plate; and

a handle assembly pivotally attached to the at least one mounting bracket at a second pivot location and pivotally and slidably attached to the side plate of the at least one frame rail of the stair assembly, the handle assembly comprising at least one hand rail having a lower end and an upper end, and at least one second support frame connected to the at least one hand rail; and

at least one pin coupling the at least one second support frame to the at least one frame rail of the stair assembly, the at least one pin at least partially disposed in the elongated slot of the side plate of the at least one frame rail;

wherein, when stair system moves between the stowed configuration and the deployed configuration, the stair assembly and the handle assembly move concurrently;

wherein, when in the stowed configuration, the stair system is configured to be positioned beneath the cargo platform and to extend generally parallel to the cargo platform; and

wherein, when in the deployed configuration, the stair system is configured to extend outwardly and downwardly from a side of the cargo platform, and the upper end of the at least one hand rail is configured to extend over an upper side of the cargo platform.

2. The stair system of claim 1 , wherein, when the stair system is in the deployed configuration, an uppermost step platform of the plurality of step platforms of the stair assembly is configured to be located vertically lower than an upper side of the cargo platform.

3. The stair system of claim 1 , wherein, when the stair system moves between the stowed configuration and the deployed configuration, the pin is operable to travel along the elongated slot of the side plate of the at least one frame rail and both the stair assembly and the handle assembly are operable to rotate about the pin.

4. The stair system of claim 3 , further comprising a motor assembly operable to drive the stair system between the stowed configuration and the deployed configuration under power, the motor assembly comprising a motor, a motor shaft, a gear drive and an output shaft;

wherein the motor shaft is coupled to a drive gear of the gear drive and the output shaft is coupled to a driven gear of the gear drive; and

wherein the output shaft is rotatably supported by the at least one mounting bracket at the second pivot location; and

wherein the output shaft is connected to the at least one frame rail.

5. The stair system of claim 4 , further comprising at least one sensor configured to detect an obstacle to movement of the stair system between the stowed configuration and the deployed configuration.

6. The stair system of claim 5 , further comprising a controller in communication with the motor and the at least one sensor; and

wherein the controller interrupts operation of the motor assembly in response to the at least one sensor detecting the obstacle to movement of the stair system between the stowed configuration and the deployed configuration.

7. The stair system of claim 6 , further comprising a notification system in communication with the controller and configured to generate at least one of a visual indicator and an audible indicator in response to the at least one sensor detecting the obstacle to movement of the stair system between the stowed configuration and the deployed configuration.

8. A commercial vehicle comprising the stair system of claim 7 , wherein the at least one mounting bracket of the stair system is attached to at least one of an underside of the cargo platform of the vehicle or a side rail of the cargo platform of the vehicle.

9. The stair system of claim 1 , further comprising a motor assembly operable to drive the stair system between the stowed configuration and the deployed configuration under power, the motor assembly comprising a motor, a motor shaft, a gear drive and an output shaft;

wherein the motor shaft is coupled to a drive gear of the gear drive and the output shaft is coupled to a driven gear of the gear drive; and

wherein the output shaft is rotatably supported by the at least one mounting bracket at the second pivot location; and

wherein the output shaft is connected to the at least one frame rail.

10. A commercial vehicle comprising the stair system of claim 9 , wherein the at least one mounting bracket of the stair system is attached to an underside of the cargo platform of the vehicle.

11. A commercial vehicle comprising the stair system of claim 9 , wherein the at least one mounting bracket of the stair system is attached to side rail of the cargo platform of the vehicle.

12. A stair system attached to a vehicle cargo platform and movable between a deployed configuration providing access to a storage area of the cargo platform and a road-ready stowed configuration, the stair system comprising:

a mounting bracket attached to the cargo platform;

a stair assembly pivotally attached to the mounting bracket at a first pivot axis, the stair assembly comprising a first support frame comprising a first frame rail and a second frame rail, a plurality of step platforms secured between the first frame rail and the second frame rail, a first side plate attached to first frame rail and comprising a first elongated slot extending along a first length of the first side plate;

a handle assembly pivotally attached to the mounting bracket at a second pivot axis and pivotally and slidably attached to the first side plate of the first frame rail, the handle assembly comprising a first hand rail having a first lower end and a first upper end and a first handle support frame connected to the first hand rail;

a first fastener coupling the first handle support frame to the first side plate, the first fastener at least partially disposed in the first elongated slot of the first side plate;

wherein, when the stair system moves between the stowed configuration and the deployed configuration, the first fastener is operable to travel along the first elongated slot of the first side plate of the first frame rail, and both the stair assembly and the handle assembly are operable to rotate about the first fastener;

wherein, in the deployed configuration, the stair system extends outwardly and downwardly from the cargo platform, and the first upper end of the first hand rail extends over an upper side of the cargo platform; and

wherein, in the stowed configuration, the stair system does not occupy the cargo storage area and remains attached to the cargo platform.

13. The stair system of claim 12 , wherein the stair assembly further comprises a second side plate attached to the second frame rail and comprising a second elongated slot extending along a second length of the second side plate; and

the handle assembly further comprises a second hand rail having a second lower end and a second upper end and a second handle support frame connected to the second hand rail;

the stair system further comprising a second fastener coupling the second handle support frame to the second side plate, the second fastener at least partially disposed in the second elongated slot of the second side plate;

wherein, when the stair system moves between the stowed configuration and the deployed configuration, the second fastener is operable to travel along the second elongated slot of the second side plate of the second frame rail;

wherein, in the deployed configuration, the second upper end of the second hand rail each extends over an upper side of the cargo platform; and

wherein, in the stowed configuration, the stair system is positioned beneath the cargo platform and extends generally parallel to an underside of the cargo platform.

14. The stair system of claim 13 , further comprising a motor assembly operable to drive the stair system between the stowed configuration and the deployed configuration under power, the motor assembly comprising a motor, a motor shaft, a gear drive and an output shaft;

wherein the motor shaft is coupled to a drive gear of the gear drive and the output shaft is coupled to a driven gear of the gear drive; and

wherein the output shaft is rotatably supported by the mounting bracket at the second pivot axis; and

wherein the output shaft is connected to the first frame rail and the second frame rail.

15. The stair system of claim 14 , further comprising at least one sensor configured to detect an obstacle to movement of the stair system between the stowed configuration and the deployed configuration.

16. The stair system of claim 15 , further comprising a controller in communication with the motor and the at least one sensor; and

wherein the controller interrupts operation of the motor assembly in response to the at least one sensor detecting the obstacle to movement of the stair system between the stowed configuration and the deployed configuration.

17. The stair system of claim 16 , further comprising a notification system in communication with the controller and configured to generate at least one of a visual indicator and an audible indicator in response to the at least one sensor detecting the obstacle to movement of the stair system between the stowed configuration and the deployed configuration.

18. A commercial vehicle comprising:

a passenger cab;

a cargo platform located rear of the passenger cab comprising an upper side, an underside, a side rail and a cargo storage area;

a stair system attached to the cargo platform and movable between a deployed configuration and a stowed configuration, the stair system comprising:

a pair of mounting brackets attached to one of the underside of the cargo platform and the side rail the cargo platform;

a stair assembly pivotally attached to the mounting brackets at a first pivot axis, the stair assembly comprising a first support frame comprising a first frame rail and a second frame rail, a plurality of step platforms secured between the first frame rail and the second frame rail, a first side plate attached to first frame rail and comprising a first elongated slot extending along a first length of the first side plate and a second side plate attached to the second frame rail and comprising a second elongated slot extending along a second length of the second side plate; and

a handle assembly pivotally attached to the mounting brackets at a second pivot axis and pivotally and slidably attached to the first and second side plates of the first and second frame rails of the stair assembly, the handle assembly comprising a first hand rail having a first lower end and a first upper end and a first handle support frame connected to the first hand rail and a second hand rail having a second lower end and a second upper end and a second handle support frame connected to the second hand rail;

a first fastener coupling the first handle support frame to the first side plate, the first fastener at least partially disposed in the first elongated slot of the first side plate;

a second fastener coupling the second handle support frame to the second side plate, the second fastener at least partially disposed in the second elongated slot of the second side plate;

wherein, when the stair system moves between the stowed configuration and the deployed configuration, the first fastener is operable to travel along the first elongated slot of the first side plate of the first frame rail, the second fastener is operable to travel along the second elongated slot of the second side plate of the second frame rail, and both the stair assembly and the handle assembly are operable to rotate about the first fastener and the second fastener;

wherein, in the deployed configuration, the stair system extends outwardly and downwardly from the side rail of the cargo platform, and the first upper end of the first hand rail and the second upper end of the second hand rail each extend over the upper side of the cargo platform; and

wherein, in the stowed configuration, the stair system does not occupy the cargo storage area and remains attached to the cargo platform.

19. The commercial vehicle of claim 18 , wherein, in the deployed configuration, an uppermost step platform of the plurality of step platforms of the stair assembly is located vertically lower than the upper side of the cargo platform; and

wherein, in the stowed configuration, the stair system is positioned beneath the cargo platform and extends generally parallel to the underside of the cargo platform.