Abstract: A lift-assisted manhole cover assembly with a flush surface and external pivot shaft. The cover includes a mounting tab that extends beyond the general periphery of the cover. The mounting tab may be connected to a shaft that is threadedly engaged with the frame. A spring may be mounted between the frame and the mounting tab, for example, in a sleeve, to provide a mechanical assist in lifting the cover. The sleeve may be disposed outside the manhole opening where it does not block access to the manhole opening.

Abstract: A cast hatch having a frame, a hinged cover and a lift assist mechanism. The lift assist mechanism includes a torsion spring with threaded ends. A slide block is threadedly mounted to one threaded end to provide an interface between the spring and the cover. A pressure block is threadedly mounted to the other end to provide an interface between the spring and the frame or support structure. In one embodiment, the lift assist includes two torsion springs. In this embodiment, the two torsion springs may be mounted to a single slide block at one end and mounted to separate pressure blocks at the other end. The pressure blocks may be generally rectangular and include an eccentrically disposed through bore to be fitted over a threaded end of the spring.