Overhead door for a container having a vertical opening such as a truck trailer

{
  "publication_number": "US3934635A",
  "country": "US",
  "kind": "A",
  "title": "Overhead door for a container having a vertical opening such as a truck trailer",
  "abstract": "An overhead door for the vertical opening of a truck trailer comprises a plurality of panels connected together by hinges, which extend the width of the panels and are confined within the panel. The panels, which are preferably formed of plastic, are counterbalanced by a spring, which is movable with the panels. The spring is wound by gears, which are connected thereto, cooperating with racks on the horizontal portions of the tracks on which the panels are movably supported. The bottom panel is locked to the trailer body by a locking mechanism, which is carried by the lowermost panel and cooperates with locking pins on the mounting angles on which the vertical portions of the tracks are supported.",
  "claims": [
    "1. A manually movable overhead door for closing an opening in a wall of a container including a plurality of panels, hinge means for connecting said panels to each other, track means supported by walls of the container on each side of the door, said panels being movably supported by said track means, said track means on each side of the door including a vertical portion, a horizontal portion, and a curved portion connecting said vertical portion and said horizontal portion to each other, each of said horizontal portions being disposed substantially inwardly in the container of the vertical portion of said track means, a carriage connected to the uppermost of said panels and movably supported only on said horizontal portions of said track means irrespective of the position of said panels, counterbalance means supported on said carriage to exert a counterbalance force to said panels in accordance with the position of said panels on said track means, and means to decrease the counterbalance force produced by said counterbalance means as said panels are raised toward the full open position of the door, said decreasing means including means supported on each side of the door and means cooperating with said supported means and acting on said counterbalance means to decrese the counterbalance force as said panels are raised toward the full open position of the door, said supported means including a rack supported on each side of the door, each of said racks terminating prior to the plane containing the door when the door is in its closed position, and said cooperating means including gear means connected to said counterbalance means and engaging the teeth of each of said racks, each of said racks being supported by said track means, each of said racks extending for only the length of said horizontal portion of said track means, said counterbalance means including a spring having one end fixed to said carriage and its other end connected to said gear means, said gear means being rotatably mounted on said carriage whereby rotation of said gear means unwinds said spring as said panels are raised toward the full open position of the door, means to lock the lower most of said panels when the door is in its closed position, said lock means including first means adjustably supported on each side of the door and second means carried by the lower most of said panels and cooperating with each of said first means, said second means of said lock means including a first pair of members movably supported by the lower most of said panels, a second pair of members connected to said first pair of members and movably supported by the lower most of said panels, means cooperating with said second pair of members to move each of said first pair of members into engagement with a corresponding one of said first means, and said cooperating means being removably supported by said lower most panel to enable said first and second pairs of members to be adjustably positioned in accordance with the width of said door.",
    "2. The door according to claim 1 including: flexible sealing means carried on the bottom of said lowermost panel to sealingly engage the floor of the container; and resilient means connecting each of said first pair of members to the corresponding one of said second pair of members to compensate for wear of said sealing means.",
    "3. A manually movable overhead door for closing an opening in a wall of a container including a plurality of panels, hinge means for connecting said panels to each other, track means supported by walls of the container of each side of the door, said panels being movably supported by said track means, said track means on each side of the door including a vertical portion, a horizontal portion, and a curved portion connecting said vertical portion and said horizontal portion to each other, each of said horizontal portions being disposed substantially inwardly in the container of the vertical portion of said track means, a carriage connected to the upper most of said panels and movably supported only on said horizontal portions of said track means irrespective of the position of said panels, counterbalance means supported on said carriage to exert a counterbalance force to said panels in accordance with the position of said panels on said track means, means to decrease the counterbalance force produced by said counterbalance means as said panels are raised toward the full open position of the door, means to lock the lower most of said panels when the door is in its closed position, said lock means including first means adjustably supported on each side of the door and second means carried by the lower most of said panels and cooperating with each of said first means, said second means of said lock means including a first pair of members movably supported by the lower most of said panels, a second pair of members connected to said first pair of members and movably supported by the lower most of said panels, means cooperating with said second pair of members to move each of said first pair of members into engagement with a corresponding one of said first means, and said cooperating means being removably supported by said lower most panels to enable said first and second pairs of members to be adjustably positioned in accordance with the width of said door.",
    "4. The door according to claim 3 including: flexible sealing means carried on the bottom of said lowermost panel to sealingly engage the floor of the container; and resilient means connecting each of said first pair of members to the corresponding one of said second pair of members to compensate for wear of said sealing means.",
    "5. A manually movable overhead door for closing an opening in a wall of a container including a plurality of panels, hinge means for connecting said panels to each other, track means supported by walls of the container on each side of the door, said panels being movably supported by said track means, said track means on each side of the door including a vertical portion, a horizontal portion, and a curved portion connecting said vertical portion and said horizontal portion to each other, each of said horizontal portions being disposed substantially inwardly in the container of the vertical portion of said track means, a carriage connected to the upper most of said panels and movably supported only on said horizontal portions of said track means irrespective of the position of said panels, counterbalance means supported on said carriage to exert a counterbalance force to said panels in accordance with the position of said panels on said track means, means to decrease the counterbalance force produced by said counterbalance means as said panels are raised toward the full open position of the door, linkage means connecting each side of said carriage to each side of the upper most of said panels to enable said panels to be disposed in a vertical position to close the opening while said carriage remains on said horizontal portions of said track means.",
    "6. The door according to claim 5 in which each of said linkage means includes: a first link having one end pivotally connected adjacent the uppermost end of said uppermost panel and its other end pivotally connected to the end of said carriage closest to said uppermost panel; a second link having one end pivotally connected to said uppermost panel adjacent its lowermost end and its other end pivotally connected to said carriage inwardly of the pivotal connection of said first link to said carriage; the pivotal connection of said second link to said carriage being above the pivotal connection of said first link to said carriage; and each of said pivotal connections of said links to said carriage remaining in the same horizontal planes irrespective of the position of said panels."
  ],
  "description_excerpt": "When a truck trailer has an overhead door to close its vertical opening, the trailer can be backed directly to a loading dock and the door lifted after the truck has been backed to the dock. When a truck trailer has swing type doors, it is necessary for the driver to stop the vehicle before the dock is reached, open each swing door and secure it to the side of the trailer, return to the vehicle, and back the trailer to the loading dock. Thus, the overhead door significantly reduces the time required to position a truck trailer at a loading dock.\n\nWhile the overhead door has the foregoing advantage over swing doors, the previously available overhead doors have had disadvantages that have reduced their use in place of swing doors notwithstanding their advantages. One disadvantage has been the heavier weight of the overhead door compared with the swing doors. This increased weight increases the cost of operation of the truck trailer.\n\nThe overhead door of the present invention satisfactorily overcomes the foregoing problem by weighing significantly less than the previously available overhead doors, which have been formed of plywood or plywood with an aluminum skin. The overhead door of the present invention is formed of panels made of a strong, hard, rigid thermoplastic which will not easily chip, peel, warp, or break. One suitable example of the material of the panel of the present invention is ABS type thermoplastic.\n\nIn the previously available overhead doors, the panels have been connected to each other by a hinge system in which the hinges are exposed.",
  "cpc": [
    "E05D 15/248",
    "E05D 13/1261",
    "E05F 15/67",
    "E05Y 2201/604",
    "E05Y 2201/708",
    "E05Y 2900/106",
    "E05Y 2900/516"
  ],
  "ipc": [
    "E05D 15/24"
  ],
  "assignees": [
    "KRS IND Inc"
  ],
  "inventors": [
    "Henry Kin"
  ],
  "filing_date": "1972-10-17",
  "publication_date": "1976-01-27",
  "grant_date": "1976-01-27",
  "priority_date": "1972-10-17",
  "application_number": "US-29833172-A",
  "family_id": "23150043",
  "cited_by_count": 39,
  "citations": [
    "US2015402A",
    "US2703236A",
    "US2978021A",
    "US3110512A",
    "US3311159A",
    "US3436862A"
  ]
}