초록 ▼

A plug for sealing a sewer or drain conduit and for simultaneously filling the conduit so that the drainage system may be inspected for leaks. A tubular bulb made of an elastomeric material has fluid under pressure supplied to its internal cavity from one end. The bulb expands laterally of its longi

A plug for sealing a sewer or drain conduit and for simultaneously filling the conduit so that the drainage system may be inspected for leaks. A tubular bulb made of an elastomeric material has fluid under pressure supplied to its internal cavity from one end. The bulb expands laterally of its longitudinal axis to thereby seal the conduit in which it is located. Thereafter, a spill over valve coupled to the other end of the bulb releases fluid from the bulb while maintaining the expanded size of the bulb and the sealing engagement between the bulb and the conduit. The bulb may have an external waffle surface to enhance sealing and reduce the likelihood of bulb rupture from sharp pipe edges. The spill over valve includes external channels through which fluid may pass upon sufficient expansion of the overlying bulb. Embodiments are disclosed which include a second bulb for sealing a branch conduit. One of the dual bulb embodiments has a control valve for selectively permitting both bulbs to be simultaneously inflated, both bulbs to be simultaneously deflated, and the second bulb to be deflated independent and prior to the deflation of the first bulb.

대표청구항 ▼

A plug for a drainage conduit, comprising: a tubular bulb made of an elastomeric material and expansible laterally of its longitudinal axis by a predetermined amount of fluid pressure supplied to its internal cavity to thereby seal the conduit when located internally thereof; means for supplying flu

A plug for a drainage conduit, comprising: a tubular bulb made of an elastomeric material and expansible laterally of its longitudinal axis by a predetermined amount of fluid pressure supplied to its internal cavity to thereby seal the conduit when located internally thereof; means for supplying fluid under pressure to the internal cavity of the bulb through a first end of the bulb; and spill over valve means coupled to a second end of the bulb for releasing fluid from the bulb after the bulb has expanded to seal the conduit while maintaining the expanded size of the bulb and the sealing engagement between the bulb and the conduit, including a cylindrical member about which the second end of the bulb lies in contracted engagement, at least one external channel formed in the cylindrical member so that one end of the channel is connected with the internal cavity of the bulb when the bulb is expanded to seal the conduit and a support member positioned within the channel for preventing the bulb from deflecting into the channel.