Drainage device equipped with an attachment sleeve for construction, particularly a building roof or a terrace

A drainage device for installation on a construction slab provided with an open drainage flow pipe, the drainage device capable of limiting the flow rate of rainwater entering the drainage flow pipe, the drainage device comprising:

• a drainage head including:
• a head portion having a circumferential wall portion at its lowermost end that is sized to encircle the open end of the drainage flow pipe, the head portion defining an interior volume and having at least one orifice placing the interior volume in fluid communication with the exterior of the head portion;
• a shoulder attached to, and extending radially inwardly from the lowermost end portion of the circumferential wall portion;
• and
• a drainage pipe attached to the shoulder extending away from the head portion and having an outer diameter less than the inner diameter of the drainage flow pipe so that the drainage pipe may be received within the drainage flow pipe;
• an attachment sleeve at least partially deformable, secured to the drainage head and capable of fixedly engaging the interior wall of the drainage flow pipe such that the drainage device is securely held in place;
• a compression washer attached on the attachment sleeve;
• and
• a stressing element movable in relation to the drainage head and capable of axially moving the compression washer to cause outward radial deformation of the attachment sleeve.