Automatic sliding door closure device

An automatic sliding door closure device in combination with a sliding door, the combination comprising:

• a sliding door track within a door opening having a door frame;
• a sliding door slidably engaged with the sliding door track;
• a housing attached to an end of the sliding door;
• a pulley rotatably mounted within the housing;
• a first gear rotatably mounted within the housing having a plurality of radially spaced teeth;
• a cable having an exterior end for attachment to the door frame and an interior end connected to the first gear, the cable rotating the first gear when the sliding door is slid along the sliding door track;
• tensioning means engaged with the first gear tensioning rotation of the first gear as the sliding door is slid along the sliding door track;
• a second gear rotatably mounted within the housing having a plurality of radially spaced teeth in meshed relation with the teeth of the first gear, the second gear rotating in an opposite direction from the rotation of the first gear;
• second tensioning means engaged with the second gear tensioning rotation of the second gear as the sliding door is slid along the sliding door track;
• a connecting arm connected to the housing;
• an airtight cylinder oriented parallel with the sliding door track of the sliding door having a hollow interior cavity;
• a plunger arm connected to the connecting arm sized and shaped for movement within the hollow interior cavity of the airtight cylinder as the sliding door is slid along the sliding door track;
• a flexible member connected to the plunger arm slidably contacting walls of the hollow interior cavity of the airtight cylinder for creating an air cushion within the airtight cylinder;
• and
• an airflow control valve within a wall of the airtight cylinder for controlling intake and outlet of air into the airtight cylinder, the airflow control valve controlling closure speed of the sliding door.

An automatic sliding door closure device, the device comprising:

• a first gear including a pulley;
• a cable having a first end for attachment to a top of a horizontal door frame during use and with an opposite end of the cable directly connected to the pulley, the cable being wound with multiple turns on the pulley, the cable and the pulley being operationally oriented during operation with the cable winding and unwinding off the pulley;
• at least one tensioning means for connection to a sliding door during use, the tensioning means tensioned by the cable during use;
• the first gear engaged with the tensioning means, the tensioning means tensioning rotation of the first gear;
• and
• an air tight cylinder having an air piston, which are generally shaped and constructed to be oriented parallel with a sliding door track of a sliding door, said air piston linked to the tensioning means providing controlled release of the tension in the tensioning means controlling closure speed of a sliding door during use.

An automatic sliding door closure device, the device comprising:

• a cable having a first end attached to a door frame during use;
• at least one tensioning means connected to a sliding door during use, the tensioning means tensioned by the cable during use;
• a first gear engaged with the tensioning means, the tensioning means tensioning rotation of the first ear;
• an air piston linked to the tensioning means providing controlled release of the tension in the tensioning in the tensioning means controlling closure speed of the sliding door during use;
• the first gear has a pulley portion for keeping the cable on a front face of the first gear;
• and
• a second gear engaged with the first gear and second tensioning means tensioning rotation of the second gear.

An automatic sliding door closure device, the device comprising:

• a cable having a first end attached to a door frame during use;
• at least one tensioning means connected to a sliding door during use, the tensioning means tensioned by the cable during use;
• an air piston including a piston rod linked to the tensioning means, said piston rod causing a pushing action as the piston rod is moved into the said air piston thus providing a controlled release of the tension in the tension means to control closure speed of the sliding door using use;
• and
• a first gear engaged with the tensioning means, the tensioning means tensioning rotation of the first gear.