# Patent

## Title
Basic unit for the erection of a sliding-door

## Abstract

The housing assembly 36, manually operable lead screw member 44 and motor-driven wheel 60 form a unitary door mover which can be removed as a unit from the door-mounted support plate 34 or mounted as a unit on that plate. When this door mover is first put on the plate 34, the rubber-tired wheel 60 may be a short distance off the floor F, as shown in phantom in FIG. 4, in which case the door mover is on the door but cannot be used to move the door. The handle 45 may be turned in a direction to lower the rubber-tired wheel 60 into frictional rolling engagement with the floor, so that when motor 65 is turned on, this wheel causes the door 10 to move in the corresponding direction. If an electrical power failure occurs or the motor drive becomes disabled for some other reason, the handle 45 may be turned to raise the rubber-tired wheel 60 off the floor so that the door section can be opened or closed by a person pushing on it.

## Background
## Claims

1. A motorized drive unit for a sliding door section comprising: housing assembly for rolling engagement with a floor adjacent the door section; wheel for imparting rotation to the wheel from the motor; selectively operable to raise or lower said housing assembly on said door section, whereby to position said wheel in or out of engagement with the floor.

2. A drive unit according to claim 1 wherein said manually operable means comprises: threadedly engaging said lead screw member; said housing assembly; respect to the door section, whereby rotation of the lead screw member in one direction raises said housing assembly on said door section and rotation of the lead screw member in the opposite direction lowers said housing assembly on said door section.

3. A drive unit according to claim 1 wherein said means for mounting said housing assembly on said door section comprises: extending substantially vertically on one side of the door section; said support plate to permit up-and-down adjustment of said housing assembly on said support plate; and said manually operable means comprises: receiving said lead screw at its lower end, said bearing means fixedly positioning said lead screw vertically with respect to said housing assembly; holding said nut stationary with respect to said rigid support plate when the lead screw is rotated.

4. A drive unit according to claim 3 wherein: piece holding said nut and means for attaching said mounting piece to said support plate.

5. A drive unit according to claim 3 wherein: which are open at the bottom for slidable insertion onto said support plate from above at said side edges of the support plate.

6. A drive unit according to claim 5 wherein: holding said nut and means for bolting said mounting piece to said support plate.

7. In a sliding door assembly for use on a building having a floor and a door opening above said floor, and means for slidably supporting a door section for horizontal movement across said door opening, the improvement which comprises: ends and a panel extending across the front of said frame; building adjacent said door opening, said wheel having a horizontal axis of rotation extending substantially perpendicular to said panel; to the wheel from the motor; door section; said housing means; respect to the door section frame whereby rotation of the lead screw member in one direction raises said housing means on said door section and rotation of the lead screw member in the opposite direction lowers said housing means on said door section.

8. A sliding door assembly according to claim 7 wherein: to said housing means comprises bearing means fixedly supported by said housing means and rotatably receiving said lead screw member at its lower end; with respect to the door section frame is a mounting piece supported from said door section frame and holding said nut member stationary.

9. A sliding door assembly according to claim 8 wherein: housing means and said door section panel; means and said door section panel.

10. A sliding door assembly according to claim 9 and further comprising: positioned between said door section panel and said housing means, said support plate having opposite vertical side edges; channels which are open at the bottom for slidable insertion onto said support plate from above at said side edges of the support plate, said guide members being slidably adjustable vertically on said support plate;