Sliding door operator

Claim 2

An automatic door operator used in opening and closing a door which is mounted upon a door frame for sliding movement in a vertical plane between open and closed positions in response to movement of traffic adjacent the door, said door operator comprising: a drive cylinder for mounting relative to said door frame having first and second fluid inlets; a piston slideably movable within said drive cylinder through door opening and door closing strokes between said first and second fluid inlets; a drive means for connecting said piston to a door to drive the door through the door opening and door closing strokes; a means for supplying pressurized fluid from a suitable source thereof connected to said first and second fluid inlets and operable to supply pressurized fluid to either of said first and second fluid inlets; control means interconnecting said supplying means with said first fluid inlet and connecting said second fluid inlet to exhaust continuously throughout an opening stroke and connecting said supplying means to said second fluid inlet and connecting said first fluid inlet to exhaust continuously throughout a closing stroke; said control means including means for reducing the pressure of fluid acting on said piston from a side thereof in communication with one of said fluid inlets connected for supplying pressurized fluid to said cylinder after said piston has moved part way along on a stroke; and exhaust metering means metering the exhaust flow of fluid at least as the door approaches the end of its stroke.

Claim 3

An automatic door operator as defined in claim 1 which includes separate opening cycle metering controls metering the exhaust from said second fluid inlet during an opening stroke and closing cycle metering controls metering the exhaust from said first fluid inlet during a closing stroke.

Claim 4

An automatic door operator as defined in claim 2 wherein each of said metering controls includes separate cushioning controls rendered operative to cushion a door as it approaches the end of its stroke.

Claim 5

An automatic door operator as defined in claim 3 wherein said control means includes including inlet metering means operative during at least a portion of the opening stroke to meter the fluid flow to said operator.

Claim 6

An automatic door operator used in opening and closing a door which is mounted upon a door frame for sliding movement in a vertical plane between open and closed positions in response to movement of traffic adjacent the door, said door operator comprising: a drive cylinder for mounting relative to said door frame having first and second fluid ports; a piston slideably movable within said drive cylinder through door opening and door closing strokes between said first and second fluid ports; a drive means for connecting said piston to a door to drive the door through the door opening and door closing strokes; means for supplying pressurized fluid from a suitable source thereof connected to said first fluid port and operable to supply pressurized fluid thereto; control means coupled to said supplying means connecting said source to said first fluid port and connecting said second fluid inlet to exhaust continuously throughout an opening stroke of the door; said control means including means for reducing the pressure of fluid supplied through said first port on an opening stroke after a portion of said stroke has been completed; and exhaust metering means metering the exhaust flow of fluid at least as the door approaches the end of its stroke.

Claim 7

An automatic door operator used in opening and closing a door which is mounted upon a door frame for sliding movement in a vertical plane between open and closed positions in response to movement of traffic adjacent the door, said door operator comprising: a drive cylinder for mounting relative to said door frame having first and second fluid ports; a piston slideably movable within said drive cylinder through door opening and door closing strokes between said first and second fluid ports; a drive means for connecting said piston to a door to drive the door through the door opening and door closing strokes; means for supplying pressurized fluid from a suitable source thereof connected to said first fluid port and operable to supply pressurized fluid thereto; control means coupled to said supplying means connecting said source to said first fluid port and connecting said second fluid inlet to exhaust continuously throughout an opening stroke of the door; said control means including means for reducing the pressure of fluid supplied through said first port on an opening stroke after a portion of said stroke has been completed; and exhaust metering means metering the exhaust flow of fluid at least as the door approaches the end of its stroke.

Claim 8

An automatic door operator used in opening and closing a door which is mounted upon a door frame for sliding movement in a vertical plane between open and closed positions in response to movement of traffic adjacent the door, said door operator comprising: a drive cylinder for mounting relative to said door frame having first and second fluid inlets; a piston slideably movable within said drive cylinder through door opening and door closing strokes between said first and second fluid inlets; a drive means for connecting said piston to a door movable through door opening and door closing strokes; means for supplying pressurized fluid from a suitable source thereof for moving said piston in said cylinder; first and second pneumatic switches; cam means carried on said door adapted to shift said switches in response to the position of the door relative to said frame; a directional control valve means for alternating connecting said first and second fluid inlets selectively to said means supplying pressurized fluid and to exhaust respectively; a speed control valve connected between said directional control valve and exhaust for metering the exhaust flow at different rates; a shuttle valve controlling the mode of operation of said speed control valve between said different rates; a secondary speed control valve connected between said directional control valve means and said first fluid inlet selectively metering the inlet flow from said supply means; a solenoid valve; a transfer valve connected to said solenoid valve and said means supplying pressurized fluid and further connected to said pneumatic switches; and conduit means interconnecting said pneumatic switch with said shuttle valve, and secondary speed control valve.

Claim 9

An automatic door operator used in opening and closing a door which is mounted upon a door frame for sliding movement in a vertical plane between open and closed positions in response to movement of traffic adjacent the door, said door operator comprising: a drive cylinder for mounting relative to said door frame having first and second fluid inlets; a piston slideably movable within said drive cylinder through door opening and door closing strokes between said first and second fluid inlets; a drive means for connecting said piston to a door movable through door opening and door closing strokes; means for supplying pressurized fluid from a suitable source thereof for moving said piston in said cylinder; first and second pneumatic switches; cam means carried on said door adapted to shift said switches in response to the position of the door relative to said frame; a directional control valve means for alternating connecting said first and second fluid inlets selectively to said means supplying pressurized fluid and to exhaust respectively; a speed control valve connected between said directional control valve and exhaust for metering the exhaust flow at different rates; a shuttle valve controlling the mode of operation of said speed control valve between said different rates; a secondary speed control valve connected between said directional control valve means and said first fluid inlet selectively metering the inlet flow from said supply means; a solenoid valve; a transfer valve connected to said solenoid valve and said means supplying pressurized fluid and further connected to said pneumatic switches; and conduit means interconnecting said pneumatic switch with said shuttle valve, and secondary speed control valve.

Claim 10

The automatic door operator of claim 1 wherein said pressure reducing means comprises means for reducing the pressure of fluid acting on said piston during a door opening stroke after said piston has traversed a portion of said door opening stroke in said cylinder.

Claim 11

The automatic door operator of claim 7 wherein said pressure reducing means includes a fluid valve actuated by movement of said door on an opening stroke.