Trailer having actuatable tail ramp

• US 6,394,734 B1
• Filed: 02/10/2000
• Issued: 05/28/2002
• Est. Priority Date: 02/10/2000
• Status: Expired due to Term

• Current Assignee: Landoll Corporation
• Original Assignee: Landoll Corporation
• Inventors: Landoll, Donald R., Wassenberg, Loren F.
• Primary Examiner(s): Werner, Frank E.
• Application Number:
  US09/502,192
• Time in Patent Office: 838 Days
• Field of Search: 414/537,538,482,483,484,485,474,475,480,476,477 14/71.1,71.3,71.7 280/149.2,656 254/5 R,5 B,3 R,5 C,2 R 293/118
• US Class Current: 414/480
• CPC Class Codes: B60P 1/433 the loading floor or a part thereof being movable to form the ramp
• CPC Class Codes: B60P 3/062 Especially adapted for carrying tracked vehicles, e.g. public works machinery, battle tanks, snowmobiles

Abstract

The trailer has a deck assembly that includes a level main deck portion and a tail hinged to the main deck for vertical swinging movement between a level transport position, a downwardly and rearwardly inclined ground-loading position, and an upwardly and rearwardly inclined dock-loading position. Raising and lowering of the tail between such positions is carried out by fore-and-aft movement of the shiftable undercarriage of the trailer, such undercarriage being located under the tail and generally behind the hinge when the trailer is in its roading position with the tail in its transport position. When the undercarriage is shifted forwardly beyond a lost motion segment of travel, the tail is allowed to progressively descend by gravity to its ground-loading position. Returning the undercarriage to its roading position beneath the tail causes the tail to be raised back to its transport position. If the tail is to be raised to dock height, the undercarriage is pulled forwardly until the forward termination of its lost motion segment of travel is reached, whereupon an air bag is actuated to elevate a lifting strut member into an enabled position in contacting engagement with the underside of the tail. Thereafter, rearward movement of the undercarriage causes the lifting strut member to push the tail upwardly to the dock-loading height and to hold the tail at such position. To lower the tail back to its transport height, the undercarriage is shifted forwardly and the air bag is deflated, lowering the strut member back to its disabled position and allowing the tail to become once again fully supported by the undercarriage. When the undercarriage is thereafter returned to its rearmost roading position, the trailer is ready for travel. Only one hydraulic cylinder is required for carrying out the tail actuation, together with an air bag actuator when raising of the tail to dock height.

Claims

1. A tail trailer comprising:

a deck assembly including a main deck and a tail,

said tail being hingedly connected to said main deck for vertical movement between a level transport position, an upwardly inclined dock-loading position, and a downwardly inclined ground-loading position;

a wheeled undercarriage,

said main deck and said tail being mounted on said undercarriage for support thereby,

said undercarriage being shiftable relative to the main deck and the tail along a fore-and-aft path of travel toward and away from a rearwardly disposed roading position in which the undercarriage supports the main deck and the tail in the level transport position;

power apparatus operably coupled between said main deck and said undercarriage for effecting said shifting thereof; and

mechanism operable to cause the undercarriage to raise and lower the tail between said transport position and a selected one of the dock-loading and ground-loading positions as the undercarriage is shifted along said path of travel,

said path of travel of the undercarriage including a lost-motion segment forwardly adjacent said roading position within which the undercarriage continues to support both the main deck and the tail and the mechanism is inoperative to raise or lower the tail between the transport and ground-loading positions,

said path of travel ofthe undercarriage further including a tail-operating segment forwardly of the lost-motion segment within which the undercarriage lowers the tail to the ground-loading position as the undercarriage shifts forwardly out from under the tail and raises the tail back up to the level transport position as the undercarriage shifts rearwardly back under the tail,

said mechanism including a member on said undercarriage and a selectively operable actuator for selectively placing the member in either enabled or disabled positions,

said member being disposed when in said enabled position to operably engage and raise the tail from its transport position toward its dock-loading position as the undercarriage is shifted rearwardly within the lost-motion segment of its path of travel and to then lower the tail back down to its transport position as the undercarriage is shifted forwardly within the lost-motion segment of its path of travel,

said member being disposed when in said disabled position to remain operably disengaged from the tail throughout the path of travel of the undercarriage.

2. A tail trailer as claimed in claim 1,

said actuator being pneumatically powered.

3. A tail trailer as claimed in claim 1,

said member comprising a strut pivotally secured to the undercarriage and swingable by said actuator to said enabled position,

said strut being swingable beyond said enabled position by the tail as the strut pushes the tail toward the dock-loading position in response to rearward shifting of the undercarriage.

4. A tail trailer as claimed in claim 3,

said strut being disposed to gravitationally rest on the actuator in the disabled and enabled positions and to be lifted off the actuator by the tail as the strut pushes the tail toward the dock-loading position.

5. A tail trailer as claimed in claim 4,

said actuator comprising an air-bag.

6. A tail trailer as claimed in claim 3,

said tail having a pocket disposed for receiving and retaining an upper end of the strut against rearward movement relative to the tail when the strut is in its enabled position.

7. A tail trailer as claimed in claim 1,

said mechanism including a recess on the tail and a supporting follower on the undercarriage,

said recess having a sloping entry so disposed relative to the follower that the follower progressively enters the recess as the undercarriage is shifted forwardly within its tail-operating segment of travel and allows the tail to swing down by gravity toward the ground-loading position from the transport position.

8. A tail trailer as claimed in claim 7,

said recess and said follower being spaced from one another in a fore-and-aft direction to such an extent when the undercarriage is in said roading position as to provide said lost-motion segment of travel of the undercarriage relative to the deck assembly during which the follower is out of said recess and the tail is not raised or lowered between the transport and ground-loading positions.

9. A tail trailer as claimed in claim 1;

and

a bumper assembly projecting rearwardly from the undercarriage in underlying relationship to said tail,

said bumper assembly including a bumper pivotally secured to the undercarriage for vertical swinging movement toward and away from a normal raised position,

said bumper assembly further including a spring yieldably biasing the bumper toward said raised position,

said bumper being disposed to be engaged and forced downwardly out of said raised position by the tail against the action of said spring when the tail is lowered to said ground-loading position.

10. In a tail trailer, the improvement comprising:

a deck assembly including a main deck and a tail,

said tail being hingedly connected to said main deck for vertical movement between a level transport position and a downwardly inclined ground-loading position;

a wheeled undercarriage,

said main deck and said tail being mounted on said undercarriage for support thereby,

said undercarriage being shiftable relative to the main deck and the tail along a fore-and-aft path of travel toward and away from a rearwardly disposed roading position in which the undercarriage supports the main deck and the tail in the level transport position;

power apparatus operably coupled between said main deck and said undercarriage for effecting said shifting thereof;

mechanism operable to cause the undercarriage to raise and lower the tail between said transport and ground-loading positions as the undercarriage is shifted along said path of travel; and

a bumper assembly projecting rearwardly from the undercarriage in underlying relationship to said tail,

said bumper assembly including a bumper pivotally secured to the undercarriage for vertical swinging movement toward and away from a normal raised position,

said bumper assembly further including a spring yieldably biasing the bumper toward said raised position,

said bumper being disposed to be engaged and forced downwardly out of said raised position by the tail against the action of said spring when the tail is lowered to said ground-loading position.

11. In a tail trailer as claimed in claim 10,

said mechanism including a recess on the tail and a supporting follower on the undercarriage,

said recess having a sloping entry so disposed relative to the follower that the follower progressively enters the recess as the undercarriage is shifted forwardly and allows the tail to swing down by gravity toward the ground-loading position from the transport position.