All terrain vehicle and method of operating same

• US 4,727,949 A
• Filed: 01/12/1987
• Issued: 03/01/1988
• Est. Priority Date: 03/05/1984
• Status: Expired due to Fees

• Current Assignee: Watercraft Offshore Canada Ltd.
• Original Assignee: Watercraft Offshore Canada Ltd.
• Inventors: Rea, Kenneth A., Reynolds, Alan H.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Watts, Charles R.
• Application Number:
  US07/002,571
• Time in Patent Office: 414 Days
• Field of Search: 180/8.2, 180/8.5, 180/8.7, 180/9.1, 180/9.22, 180/9.23, 180/9.32, 180/9.4, 180/9.44, 180/9.46, 180/14.1, 180/14.2, 280/492, 280/493, 280/494, 114/270
• US Class Current: 180/9.32
• CPC Class Codes: B60D 1/42 for being adjustable
• CPC Class Codes: B62D 55/0655 Articulated endless track vehicles steering specially adapted for trailers B62D13/00; articulated buses B62D47/025; tractor-trailer combinations or road trains comprising a uni-axle unit and a uni-axle trailer B62D53/02

Abstract

An all terrain vehicle has two vehicle units and an articulating link which interconnects the vehicle units in tandem. Each vehicle unit has a body and a pair of spaced crawler tracks which are powered for moving the respective vehicle unit. The articulating link has two longitudinally spaced apart pitch hinge assemblies, each of which cooperates with a respective vehicle unit to permit relative rotation therebetween about a horizontal pitch axis without interference between the vehicle units. Pitch swivelling means associated with one particular pitch hinge assembly can force relative rotation about the particular pitch axis between a particular vehicle unit and the link, so that one vehicle unit can be rotated forcibly relative to the other vehicle unit to negotiate marginal terrain. The remaining pitch hinge assembly can be either freely hinged to permit rotation about the remaining pitch axis or alternatively can have a similar pitch swivelling means. The vehicle also has a yaw hinge assembly for steering, and optionally has a roll hinge assembly to permit relative rotation about the link between the vehicle units, particularly for self-righting on hard terrain, and also for additional control and versatility. A single vehicle unit can be operable independently of the other, but performance is increased considerably by utilizing at least two vehicle units in tandem connected by the articulating link. The vehicle combination can climb up or down vertical walls of limited height from hard terrain, or can negotiate a vertical wall disposed above water a height dependent on draft of the vehicle. The vehicle combination is a self-righing from an inverted position on land or immersed in water.

Claims

1. A method of self-righting an articulated vehicle combination which is inverted and immersed in water, the vehicle combination having two vehicle units and an articulating link means which interconnects the vehicle units when aligned in tandem along a central longitudinal axis, each vehicle unit having a watertight body provided with a relatively low center of gravity when the body is in an upright position, the method being further characterized by:

(a) from an aligned inverted position in which the vehicle units are aligned with the central axis, forcibly rotating one particular vehicle unit relative to the articulating link means about a first pitch axis disposed normally to the longitudinal axis so that the vehicle bodies rotate towards each other causing lower ends of the bodies to be submerged further in the water and upper ends of the bodies to rise upwardly out of the water to attain an unstable inverted raised position,

(b) permitting the combination in the raised unstable position to fall laterally onto one of its sides, and then rotating the particular vehicle unit in an opposite direction to attain the aligned position once more in which the vehicle bodies lies on their sides in the water,

(c) yielding to a bouyancy force generated on the vehicle combination which acts through a center of bouyancy spaced from the center of gravity, which force tends to rotate the vehicle bodies to attain an upright position.

2. A method as claimed in claim 1 further characterized by:

(a) forcibly rotating the remaining vehicle unit about a respective second pitch axis which is parallel to and spaced longitudinally from the first pitch axis, the first and second pitch axes being adjacent the particular and remaining vehicle units respectively.

8. A method as claimed in claim 2, in which the vehicle combination is immersed in water, and is required to climb out of the water onto the obstacle, the method being further characterized by:

(a) providing floatation adjacent lower portions of the vehicle unit to resist submerging the rear vehicle unit as a result of rotation of the vehicle units relative to the water surface during rotation of the front vehicle unit relative to the articulating link.

9. A method as claimed in claim 8, in which the vehicle combination is immersed in water, and is required to climb out of water onto the obstacle, the method being further characterized by:

(a) powering the crawler tracks so that more power is applied to the rear tracks than the front tracks to increase propulsion available from the water.

3. A method of self-righting an articulated vehicle combination on land, in which the vehicle combination has first and second vehicle units and an articulating linek means which interconnects the vehicle units when aligned in tandem along a central longitudinal axis, the articulating link means having roll hinge assembly to provide relative rotation about the longitudinal axis between the two vehicle units, the method of self-righting being characterized by:

(a) from an algined inverted position in which the vehicle units are aligned with the central longitudinal axis, forcibly rotating the first vehicle unit relative to the second vehicle unit about a link longitudinal axis through half a revolution, so that the first vehicle unit becomes upright,

(b) rotating about a generally vertical axis the first vehicle unit relative to the articulating link means to restrict the first vehicle unit against further rotation about the longitudinal axis to ensure that the second unit will rotate in preference to the first unit,

(c) forcibly rotating the second vehicle unit relative to the first vehicle unit about the link longitudinal axis through half a revolution, so that the second vehcile unit becomes upright.

4. A method of operating an articulated vehicle combination to negotiate an obstacle having a steep wall, the method including the steps of:

(a) providing an articulated vehicle combination having front and rear vehicle units and an articulating link means which interconnects the two vehicle units, the articulating link means having two longitudinally spaced apart pitch hinge assemblies cooperating with respective vehicle units to permit relative rotation between each vehicle unit and the link means about respective front and rear generally horizontal pitch axes, each vehicle unit having a body having a pair of spaced parallel crawler tracks,

(b) powering the crawler tracks of each vehicle unit for movement in a forward direction,

(c) applying a rotating force between the articulating link means and the front vehicle unit to rotate the front vehicle upwardly about the front pitch axis relative to the articulating link means to cause a front portion of the front vehicle unit to rise,

(d) concurrently permitting the articulating link means to rotate downwardly about the rear pitch axis relative to the rear vehicle unit,

(e) engaging the obstacle with the crawler tracks of the front vehicle unit and drawing the front vehicle unit upwardly on the obstacle,

(f) concurrently permitting the articulating link means to rotate upwardly about the rear pitch axis relative to the rear vehicle unit,

(g) concurrently applying with the rear vehicle unit a generally forward force to the articulating link means which becomes a generally upward force applied to the front vehicle unit to assist in moving the front vehicle unit upwardly on the obstacle concurrently with driving force from the crawler tracks of the front vehicle unit,

so that the front vehicle unit eventually assumes a relatively stable position on the obstacle spaced above the rear vehicle unit.

5. A method as claimed in claim 4 further characterized by:

(a) providing the crawler tracks with upper and lower track runs, the lower track runs of each vehicle unit having upwardly sloping front and rear portions,

(b) when the front vehicle unit is rotated upwardly about the front pitch axis by applying the rotating force, engaging the obstacle with the front portions of the lower crawler track runs to assist in drawing the front vehicle unit upwardly.

6. A method as claimed in claim 5 further characterized by:

(a) when the front vehicle unit is rotated upwardly about the front pitch axis, engaging the ground with the rear portions of the lower crawler track runs which are powered to assist in driving the front vehicle unit forwardly to engage the obstacle.

7. A method as claimed in claim 5 further characterized by:

(a) when the front vehcile unit has attained a stable position on the obstacle, raising the front portion of the rear vehicle unit by force from the articulating link means,

(b) engaging the ground with the rear portions of the lower crawler track runs of the rear vehicle to assist in driving the vehicle combination forwardly.

10. A method of self-righting an articulated vehicle combination on land, the method being characterized by:

(a) providing an articulated vehicle combination having first and second vehicle units, and an articulating link means which interconnects the vehicle units in tandem, the articulating link means having a link longitudinal axis and two longitudinally spaced apart pitch hinge assemblies cooperating with the respective front and rear vehicle units to permit relative rotation between the vehicle units and the link means about respective front and rear generally horizontal pitch axes, the articulating link means having a roll hinge assembly and power means to apply a rotating force between the two vehicle units to cause relative rotation therebetween about the link longitudinal axis,

(b) from an aligned inverted position in which the vehicle units are aligned with the link longitudinal axis, applying force to the first vehicle unit to forcibly rotate the first vehicle unit relative to the second vehicle unit about the link longitudinal axis through a half revolution, so that the first vehicle unit becomes upright,

(c) forcibly rotating the second vehicle unit relative to the first vehicle about the link longitudinal axis through half a revolution, so that the second vehicle unit becomes upright.

11. A method as claimed in claim 10 further characterized by:

(a) prior to rotating the second vehicle unit, rotating about a vertical axis the first vehicle unit relative to the articulating link means to ensure that the second unit rotates in preference to the first unit.

12. A method as claimed in claim 10 further characterized by:

(a) prior to rotating the first vehicle unit relative to the second vehicle unit, forcibly restricting the second vehicle unit against rotation as a reaction to rotating the first vehicle unit,

(b) prior to rotating the second vehicle unit relative to the first vehicle unit, forcibly restricting the first vehicle unit against rotation as a reaction to rotating the second vehicle unit.