Patent ID: 8745821

Claim:
An auto-closing device for a sliding door comprising: a base having a chamber defined in the base; a track channel defined in an outer surface of the base and communicating with the chamber; and at least one guiding channel defined in the base and communicating with the chamber, and each one of the at least one guiding channel having an end provided with a positioning recess; a linear damper mounted in the chamber of the base and comprising a housing; and an expansion rod retractably mounted on the housing; a slider mounted slidably in the chamber along the track channel, extending out from the base via the track channel, connected to the expansion rod of the linear damper and comprising a holding recess for receiving a portion of said sliding door; and a positioning pin mounted on the slider, mounted slidably in the at least one guiding channel in the base and selectively engaging the positioning recess of the at least one guiding channel; a spring having an end connected with the slider; and an adjusting device connected to an end of the spring opposite to the slider and having an adjusting frame having a first end connected securely to the spring and a second end provided with a threaded hole; and an adjusting bolt mounted rotatably on the base and screwed into the threaded hole in the adjusting frame wherein the adjusting frame is hollow and has a securing hole defined in the first end of the adjusting frame and engaging an end of the spring opposite the slider.