Handle having airtightness function used for casing of negative pressure type dust collector

A handle of a casing of a negative pressure type dust collector, one side of the dust collector being provided with a door, the handle being disposed on the door, the handle comprising:

• two pivot seats, fixed to an outer side of the door and vertically aligned with each other, the pivot seats each including a first pivot member and a second pivot member, two ends of the first pivot member being fixed to the door, a middle of a top surface of the first pivot member being formed with a recess, two ends of the second pivot member being fixed to the two ends of the first pivot member, a middle of the second pivot member being formed with a groove, the groove being sleeved on the first pivot member;
• a rotating shaft, pivotally disposed between the recess and the groove of the two pivot seats, an outer peripheral wall of the rotating shaft being provided with two positioning rings corresponding to the pivot seats, the positioning rings abutting against the two pivot seats respectively, two ends of the rotating shaft being provided with eccentric blocks respectively, each of the eccentric blocks having an extension portion extending along a tangent line thereof, an inner side of the extension portion being formed with a first contact surface, a middle portion of the rotating shaft being provided with an operating lever;
• two engaging blocks, fixed on the casing and vertically aligned with each other and located close to an outer periphery of the door, a top surface of each of the engaging blocks being provided with a hook, an inner side wall of the hook having a second contact surface, an inner side of the hook being formed with a pivot space, a bottom of each of the eccentric blocks being provided with a fixing seat for the engaging blocks to be fixed on the casing.