Land vehicles: bodies and tops – Tops – Roll-up covers
Reexamination Certificate
1999-08-09
2001-03-13
Pape, Joseph D. (Department: 3612)
Land vehicles: bodies and tops
Tops
Roll-up covers
C296S100140
Reexamination Certificate
active
06199935
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is directed generally to flexible covers for open top load-carrying boxes on land vehicles, and more specifically to power driven apparatus for deploying and retrieving such flexible covers over the open top of the load-carrying boxes. The invention has special utility in connection with trucks and trailers used to carry loads of particulate materials such as grain, feed, coal, gravel, and the like.
A variety of apparatus for applying flexible covers is known from the prior art. For example, Michel, U.S. Pat. No. 5,002,328, discloses a motorized drive system for covering and uncovering the top of an open truck box. A lateral edge of the flexible cover is fixed to one side of the box while the other lateral edge is attached to a roll tube. A reversible rotary motor rotates the roll tube to either remove the cover from the top of the box or to deploy the cover over the box. The position of the roll tube is, in part, controlled by an extensible arm and, in part, by a cable return mechanism adapted to apply a constant tension during the winding and unwinding of the cover over the tube.
Tsukamoto, U.S. Pat. No. 4,673,208, discloses a similar power operated cover roller mechanism involving pivotally mounted levers and a special chain and sprocket arrangement to secure the cover over the truck bed. The power is supplied to the pivotally mounted levers through power cylinders
19
and
20
coupled to the pivotally mounted levers. Klassen, U.S. Pat. No. 5,328,228, discloses yet another pivotally mounted lever assembly for rolling a cover over a truck bed and cargo. The roller is moved through a series of pulleys by virtue of a motor affixed to one side of the truck body.
Odegaard, U.S. Pat. No. 4,834,445, discloses yet another cover deployment apparatus carried by an arm which is itself pivoted to another arm coupled to one side of the container body. The motor operating the roller carrying the flexible cover is disposed at the very end of the first arm and spring tension members are employed to urge the first arm toward the fully deployed position. Fredin, U.S. Pat. No. 4,225,175 discloses yet another similar arrangement for applying a flexible cover over a container using a pivoted arm moved by a power cylinder
9
.
Wilkens, U.S. Pat. No. 5,765,901, discloses a similar roll-up assembly in which a hand crank rather than a motor is employed. The hand crank is designed to be secured to the trailer on either side depending upon whether the cover is in the open or closed position. Another hand crank system is shown in Harris et al., U.S. Pat. No. 5,466,030 which exposes or covers one side of a freight container rather than an open top.
Haddad, Jr., U.S. Pat. No. 5,275,459, discloses a cover deployment mechanism for use on a trailer wherein an arm is provided on each side of the trailer, the two arms having a tie rod between them to which the flexible cover is attached. Each of the two arms include an electrically insulating spacer so that in the event of an inadvertent contact with an overhead power line, such contact should not damage any portion of the mechanism. Somewhat similar mechanisms are shown in Bailey, U.S. Pat. No. 4,893,864, and Cappello, U.S. Pat. No. 3,549,198. A double cover arrangement deployed in a similar manner is shown in Haddad, Jr., U.S. Pat. No. 5,573,295.
Despite this variety of apparatus for applying flexible covers in the prior art, a need still exists for a reliable mechanism capable of covering a load without binding using a power mechanism that can be controlled from the cab of the vehicle. It is of particular interest to have such a mechanism that can accommodate a wide variety of trucks and trailers that may have upper perimeters of varying shape and curvature.
SUMMARY OF THE INVENTION
A flexible sheet cover apparatus in accordance with the present invention is used in conjunction with a load-carrying box on a land vehicle. The box generally has a floor, a pair of parallel side walls extending upward from the floor, a front wall and a back wall also extending upward from the floor. The front and back walls are coupled to the pair of side walls to form a generally rectangular container, the container having an upper perimeter defined by a top edge of each of the walls encompassing an open top. A flexible sheet cover has a first end secured adjacent a top edge of one of the walls and a second end attached to a roller. The roller has opposite ends projecting beyond the top edges of a selected two non-contiguous walls forming the load-carrying box such as the front and back walls. A motor is coupled to the roller for rolling and unrolling the flexible sheet cover. An arm has a first end coupled to the roller and a second end including a slot. A pin is coupled to the load-carrying box and engaged in the slot to define a pivot for the arm so that the roller can remain in constant contact with the top edges of the selected two non-contiguous walls forming the load-carrying box as the flexible sheet cover is rolled on and off the open top.
The arm preferably comprises a box beam of fixed length having an outer member, an inner member confronting the load-carrying box, and side joining members joining the outer member to the inner member, the inner member including the slot engaging the pivot pin. The motor is preferably fixed to the arm between the roller and the slot. A drive unit couples the motor to the roller, the drive unit being enclosed within the box beam. The drive unit preferably comprises a first pulley coupled to the motor, a second pulley coupled to the roller. An endless band such as a belt or chain couples the first and second pulleys together for substantially coordinated movement.
In one embodiment of the present invention, a bracket is fixed to the load-carrying box to connect to the arm. The bracket includes a lateral slot receiving the pin to provide for lateral movement of the pivot point for the arm. In one embodiment of the present invention a biasing spring is included that has a first end fixed to the arm and a second end fixed to the load-carrying box. The biasing spring promotes contact between the roller and the top edges of the selected two non-contiguous walls forming the load-carrying box. In the preferred embodiment the selected two non-contiguous walls forming the load-carrying box constitute the front wall and the back wall. In that embodiment the load-carrying box can also include a plurality of bows coupling the tops of the two side walls together, the bows being generally parallel with the top edges of the front and back walls.
One feature of the present invention is a sliding pivot provided by a pin member engaged in a slot in a lower portion of the arm that provides for a continuous contact between the rolled portion of the flexible sheet cover and the top edges of the two non-contiguous walls supporting the roller as the flexible sheet cover is deployed and retrieved. This feature can be used with either a fixed position pivot pin or with a laterally movable pivot pin engaged in a lateral slot in a bracket attached to a wall of the load-carrying box.
Another feature of the present invention is a pivoted arm having a box beam construction of sufficiently large cross-section to contain a drive mechanism for transferring power to the roller connected at the upper end of the arm from a motor connected to the arm at a much lower position. The construction permits the motor to be fixed to the arm at a low center of gravity position rather than be directly coupled to the roller at the upper end of the arm. The box beam constructions also contributes to the strength of the arm to support the roller and flexible sheet cover while retaining light weight to minimize the torque requirements on the motor.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following description of preferred embodiments that references the accompanying drawings.
REFERENCES:
patent: 4834445 (1989-05-01), Odegaard
patent: 48
Waltz Kevin
Waltz Paul
Locke Reynolds LLP
Pape Joseph D.
LandOfFree
Flexible sheet cover apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Flexible sheet cover apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flexible sheet cover apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2480726