Hydraulic and earth engineering – Earth treatment or control – Rock or earth bolt or anchor
Reexamination Certificate
1999-10-15
2001-10-16
Will, Thomas B. (Department: 3673)
Hydraulic and earth engineering
Earth treatment or control
Rock or earth bolt or anchor
C405S259600, C405S288000, C211S070000
Reexamination Certificate
active
06302623
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to roof bolting and drilling apparatus.
The roof bolting process involves at least seven different steps. A drill steel is loaded into a rotational drive or drilling unit, a rock surface is drilled, and the drill steel is removed from the rotational drive or drilling unit. Next, a chemical anchor is loaded into the bored hole, a roof bolt is loaded into the rotational drive or drilling unit, and the roof bolt is rotated so as to mix and thus set the chemical anchor. After the chemical anchor has been secured, a nut is tightened on the roof bolt.
U.S. Pat. Nos. 3,756,669 and 4,076,337 disclose roof bolting apparatus and devices for holding roof bolts or drill steel.
SUMMARY OF THE INVENTION
U.S. Pat. application Ser. No. 09/141,736, now U.S. Pat. No. 6,185,675 which is assigned to the assignee hereof, discloses a roof bolting apparatus including a top plate mounted on top of a timber jack. The top plate provides a U-shaped bight including a mechanical centralizer. The centralizer locates a rod or drill steel along the rotational axis of the rotational drive or drilling unit. The centralizer includes opposed yoke members or jaws which move together to surround the rod or drill steel and hold the rod relatively close to the rotational axis of the rotational drive unit. The jaws are moved toward and away from each other by respective hydraulic assemblies. Each hydraulic assembly includes a cylinder mounted on the top plate, and a piston rod having an outer end on which the associated jaw is mounted.
The present invention is an improvement of the centralizer disclosed in U.S. Ser. No. 09/141,736, now U.S. Pat. No. 6,135,674. The invention provides an integrated drill steel guide/hydraulic actuator which occupies minimal space. Two opposed, noncircular jaws move within slots in the top plate or head plate. A hydraulic actuator is integrated into each jaw, providing linear motion for extension and retraction. Placing the actuator inside the jaw provides spatial efficiency. All porting to provide hydraulic fluid to the actuators is bored internally within the head plate and the actuator rods. Lubrication is provided to the jaw running surfaces via leakage from the actuator when the jaw is retracted. This small leakage effectively lubricates and flushes the jaw running surfaces.
More particularly, the invention provides a roof bolting apparatus comprising a frame, a rotary drive mounted on the frame for rotating a workpiece rod used in a mining operation, a timber jack rod supported by the frame, the timber jack rod having an upper end and having therein a hydraulic passage, a top plate mounted on the timberjack rod for movement therewith, the top plate having therein a hydraulic circuit communicating with the hydraulic passage in the timber jack rod, and first and second hydraulic cylinders movably mounted on the top plate, the cylinders communicating with the hydraulic circuit in the top plate, and each cylinder having an end defining a jaw, such that hydraulic fluid flow into the cylinders causes the ends of the cylinders to move toward each other, thereby causing the jaws to move together for holding the workpiece rod therebetween.
The invention also provides a roof bolting apparatus comprising a frame having a lower end, a rotary drive mounted on the frame adjacent the lower end thereof for rotating a workpiece rod used in a mining operation, a timber jack rod supported by the frame for translational and longitudinal movement relative to the frame, the timber jack rod having an upper end and having therein a hydraulic passage with inlet and outlet ends, a top plate mounted on the upper end of the timber jack rod for movement therewith, the top plate having therein a hydraulic circuit communicating with the outlet end of the hydraulic passage in the timber jack rod, first and second opposing pistons fixed to the top plate by first and second piston rods, respectively, and first and second movable cylinders slidably mounted on the first and second pistons, respectively, such that each cylinder is divided by the associated piston into inner and outer chambers communicating with the hydraulic circuit in the top plate, each cylinder having an inner end through which the associated piston rod extends, and each cylinder having an outer end defining a jaw, such that hydraulic fluid flow into the outer chambers of the cylinders causes the outer ends of the cylinders to move toward each other, thereby causing the jaws to move together for holding the workpiece rod therebetween.
The invention also provides a roof bolting apparatus comprising a frame having upper and lower ends, a rotary drive mounted on the frame adjacent the lower end thereof for rotating a workpiece rod used in a mining operation, first and second timber jack rods supported by the frame for translational and longitudinal movement relative to the frame, each timber jack rod extending from the upper end of the frame, having an upper end and having therein a hydraulic passage with inlet and outlet ends, a top plate mounted on the upper end of the timber jack rod for movement therewith, the top plate having therein a hydraulic circuit communicating with the outlet ends of the hydraulic passages in the timber jack rods, and the top plate having therein first and second guide recesses, the guide recesses having respective inner walls, first and second opposing pistons fixed to the top plate by first and second piston rods, respectively, first and second cylinders housed in the first and second guide recesses, respectively, for linear movement relative to the top plate, the guide recesses and the cylinders having complementary non-circular shapes so as to prevent rotation of the cylinders relative to the top plate, the first and second cylinders being slidably mounted on the first and second pistons, respectively, such that each cylinder is divided by the associated piston into inner and outer chambers communicating with the hydraulic circuit in the top plate, each piston rod having therein hydraulic passages communicating between the hydraulic circuit and the chambers of the associated cylinder, each cylinder having an inner end through which the associated piston rod extends, and each cylinder having an outer end defining a jaw, such that hydraulic fluid flow into the outer chambers of the cylinders causes the outer ends of the cylinders to move toward each other, thereby causing the jaws to move together for holding the workpiece rod therebetween, and lubrication between the inner walls and the cylinders being provided by controlled leakage of hydraulic fluid from the cylinders.
A principal feature of the invention is the provision of an extremely compact centralizer that has a minimum number of components.
Another principal feature of the invention is a significant reduction of maintenance. The centralizer of the invention has very low wear rates.
Another principal feature of the invention is the provision of a centralizer with excellent drill steel centricity.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings.
REFERENCES:
patent: 3756669 (1973-09-01), Bucelluni
patent: 4076337 (1978-02-01), Childress
patent: 4215953 (1980-08-01), Perraud
patent: 4226559 (1980-10-01), Prebensen
patent: 4398850 (1983-08-01), Talvensaari
patent: 4420277 (1983-12-01), Hibbard et al.
patent: 4832536 (1989-05-01), Spross et al.
patent: 5114279 (1992-05-01), Bjerngren et al.
patent: 5165825 (1992-11-01), Wallin
patent: 5556235 (1996-09-01), Morrison et al.
patent: 5597367 (1997-01-01), Trzmiel et al.
patent: 6135674 (2000-10-01), Neilson
Joy MM Delaware Inc.
Pechhold Alexandra K.
Price David R.
Will Thomas B.
LandOfFree
Roof bolting apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Roof bolting apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Roof bolting apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2574385