Claims
- 1. In a gravity box of the type including a side wall with a side discharge opening, a vertically sliding door mounted for reciprocal movement in channel means on the side wall to open and close the discharge opening, the improvement comprising, in combination:
- a door operating mechanism for positively raising and positively lowering the sliding door, said mechanism including
- a pivot shaft with a cable spool thereon, said shaft defining a pivot axis, said shaft attached to the side wall above the maximum open travel position of the door;
- a vertically projecting door support bracket connected to the door, said bracket having an end extending vertically above the shaft pivot axis when the door is in the closed position;
- a flexible cable connected at one end to the door and having an intermediate section of the cable wrapped around and attached at an intermediate point to the spool and with the opposite end of the cable attached to the bracket end; and
- means for rotating the spool about the axis of the shaft to wind the cable in one direction and unwind the cable in the opposite direction on the spool to thereby positively raise or lower the door.
- 2. The improvement of claim 1 wherein said bracket comprises a longitudinal bracket member projecting from a top edge of the door, and including a guide on the side wall to guide the bracket member and retain the shaft and spool.
- 3. The improvement of claim 1 wherein the means for rotating the shaft comprises a manually operable wheel having a diameter greater than the cable spool to provide a mechanical advantage for turning the spool.
- 4. The improvement of claim 1 including adjustable means for connecting the cable to the spool.
- 5. The improvement of claim 1 wherein the length of the cable is adjustable.
- 6. The improvement of claim 1 wherein the bracket comprises a channel member for enclosing the cable.
Parent Case Info
This is a continuation-in-part application of prior application Ser. No. 446,461 filed Dec. 3, 1982, now abandoned.
US Referenced Citations (6)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
446461 |
Dec 1982 |
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