| 摘要 |
A tilt-up door for a building having a relatively wide door opening having a door frame including top and bottom horizontal members and vertical side members connected to the top and bottom horizontal members. The vertical side members can have a horizontally extending pivot shaft tube positioned between the top and bottom horizontal members, and outwardly extending cam followers adjacent to the top horizontal member. U-shaped channels can extend vertically along opposite sides of the door opening with the U-shaped channels facing each other and the door opening. The U-shaped channels can have generally horizontal track members extending from the top edge of the door opening and the horizontal tracks can have a curved cam surface. Carriages each including a horizontal pivot shaft journal can be positioned in the U-shaped channels for vertical movement in the U-shaped channels. Pivot shafts can rotatably connect a pivot shaft tube to a pivot shaft journal with the outwardly extending cam followers engaging one of the cam surfaces. An actuator can be connected to the carriages to move the carriages in the U-shaped channels. The tilt-up door is mounted for vertical movement and for tilting movement about the horizontal axis of the pivot shafts in the door opening when the actuator is operated to move the carriages vertically in the U-shaped channels and the first and second cam followers along the respective cam surfaces to tilt the door to a generally horizontal position as the door is moved vertically upward.
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