Mining or in situ disintegration of hard material – Hard material disintegrating machines – With mine roof-supporting means
Reexamination Certificate
1999-05-20
2001-03-27
Bagnell, David (Department: 3673)
Mining or in situ disintegration of hard material
Hard material disintegrating machines
With mine roof-supporting means
C299S059000, C299S061000, C405S141000, C405S142000, C405S288000
Reexamination Certificate
active
06206478
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tunnel excavator for tunneling into the ground, such as in coal mines.
2. Description of the Related Art
Tunnel excavators used in excavating ground such as in coal mines include those comprising a forward body which is provided with a cutter for excavating the ground and rear body connected to the forward body by a propulsion jack. Such tunnel excavators bore into the ground as they move like inchworms, expanding and contracting the propulsion jack while a rear gripper established on the rear body and front gripper established on the forward body alternately push against and are separated from the tunnel.
Specifically, the propulsion jack is extended with the front gripper separated from the tunnel while the rear gripper is pressed against the tunnel and the front body moves forward relative to the rear body. Next, once the propulsion jack has extended by the prescribed stroke length, the propulsion jack is contracted with the rear gripper separated from the tunnel while the front gripper is pressed against the tunnel and the rear body is drawn forward to the forward body.
With this tunnel excavator, the propulsion reaction force of the propulsion jack is borne by the tunnel through the front gripper or rear gripper. In areas having faults, therefore, the propulsion reaction force is not attained from the grippers because the ground is broken up and it becomes impossible to tunnel forward. In areas where the ground is not strong, tunneling becomes impossible because the tunnel (walls) is destroyed by the pressure of the grippers. Backwards movement of the excavator is also difficult.
On the other hand, there are tunnel excavators which move forwards on crawlers instead of using grippers. This type of tunnel excavator is often difficult to operate because lateral sliding or the like occurs in areas where the coefficient of friction of the tunnel floor in contact with the crawlers is different on each side of the crawlers. Such tunnel excavators do not have a bearing frame to support the earth (i.e., roof and ribs of the tunnel). In the event of a fall, the various instruments constituting the excavator are damaged.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a tunnel excavator which can tunnel without being influenced by the state of the ground or earth (floor, ribs and roof of the tunnel).
Another object of the present invention is to provide a tunnel excavator which can easily move backwards regardless of the conditions of the ground or earth.
Still another object of the present invention is to provide a tunnel excavator which can prevent lateral slippage regardless of the conditions of the ground or earth.
Yet another object of the present invention is to provide a tunnel excavator which can protect instruments associated there-with from falling earth.
According to one aspect of the present invention, there is provided a tunnel excavator including bearing frames which are movable in a radial direction (or radiantly) to contact the inner surface of an excavation (tunnel). The excavator further includes crawlers to provide forwards and backwards propulsion. The crawlers are installed on a cutter supporting body which is originally provided for a cutter for excavating earth. With this tunnel excavator, forwards movement is carried out by the crawlers propelling the cutter supporting body with the bearing frames in contact with the inner surface of the excavation. Since the cutter supporting body is guided within the excavation by the bearing frames as it moves forward, forwards movement without lateral sliding can thereby be achieved. Backwards movement can be easily achieved by moving the bearing frames in a radially inward direction so as to separate from the inner surface of the excavation and moving the crawlers in reverse. Tunneling can be carried out regardless of the state of the earth because forward movement uses crawlers instead of stretching grippers against the tunnel as before. Furthermore, the instruments within the excavator can be protected from falling earth because the earth are supported by placing the bearing frames in contact with the inner surface of the excavation.
In sum, the present invention enables tunneling without being influenced by conditions of the earth, easy backward movements of the excavation machine, prevention of lateral sliding of the excavation machine, and protection of equipments in the excavation machine.
An anchor body, which is provided with separate crawlers, may be disposed behind the cutter supporting body, and the anchor body and cutter supporting body may be connected by means of a propulsion jack. When the crawlers of the cutter supporting body do not provide sufficient propulsion, greater propulsion can be attained by extending the propulsion jack with the anchor body as an element for receiving the reaction force.
Grippers, to press against or separate from the excavation, may be established on the anchor body, so as to fix or release the anchor body with respect to the excavation. If that is the case, the propulsion of the propulsion jack can be increased because the anchor body can be fixed in the excavation by the grippers.
A sub-cutter, which moves upwards and downwards within a prescribed range, may also be installed on the cutter supporting body so as to vary the height of the traveling surface of the crawlers. If that is the case, the angle at which the excavator tunnels can be directed upwards and downwards upon changing the height of the traveling surface of the crawlers by moving the sub-cutter upwards or downwards.
A plurality of propulsion jacks may be disposed in a horizontal direction at prescribed intervals. If that is the case, the extension forces and strokes of these propulsion jacks may be adjusted to change the excavation direction of the excavator to the right or left.
REFERENCES:
patent: 2862700 (1958-12-01), Gonski
patent: 4953914 (1990-09-01), LeBegue
patent: 5192116 (1993-03-01), Turner et al.
patent: 5234257 (1993-08-01), Sugden et al.
Ishino Tomofumi
Miki Takanobu
Uehara Toshiaki
Bagnell David
Ishikawajima-Harima Heavy Industries Co. Ltd.
McCormick Paulding & Huber LLP
Singh Sunil
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