| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve the efficiency of digging work toward on an underground buried main pipe by using a spiral auger hardly causing a drop in earth and sand when the auger is pulled up. <P>SOLUTION: A gate valve is fitted to the vicinity of the front end of an auger emperor in such a way that a free end of the valve is allowed to swing freely on one end of the valve pivoted on a rotating shaft attached to the vicinity of the undersurface of one auger fin to close or open a space formed as an earth and sand passage between the one auger fin and a lower auger fin. As a result, the free end of the gate valve drops by its own eight to close the earth and sand passage between the upper and lower auger fins when the auger is pulled up. This prevents dug up earth and sand from dropping, so that all of dug up earth and sand can be discharged efficiently onto the ground. The auger constructed in the above manner eliminates inflow of earth and sand to an underground buried main pipe and jamming of the main pipe, remarkably reduces land subsidence movements, makes unnecessary the use of a vacuum vehicle on execution of digging/earth removal work, simplifies work while substantially reducing costs, and maintains a fine natural environment. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
