Implements or apparatus for applying pushing or pulling force – Portable implements or apparatus for tensioning flexible... – Including expansible chamber fluid motor drive
Reexamination Certificate
1999-09-08
2001-10-16
Marcelo, Emmanuel M. (Department: 3653)
Implements or apparatus for applying pushing or pulling force
Portable implements or apparatus for tensioning flexible...
Including expansible chamber fluid motor drive
C254S263000, C254S030000, C298S002000, C298S005000, C294S114000, C414S451000
Reexamination Certificate
active
06302380
ABSTRACT:
BACKGROUND OF THE INVENTION
Geological grouting is a versatile construction technique used in a variety of applications. Injection casing or piping is driven into the ground. Grout is then pumped under pressure through the above-ground end of the installed casing, out the underground end, and into the surrounding soil. The grout itself can be made from many different materials proportioned in a wide range of amounts depending on the specific grouting application. Cementitious grout, for example, is a mixture of hydraulic cement and water, with or without aggregates and with or without admixtures. Hydraulic cements react with water to form a hardened paste that maintains its strength and durability in water and also maintains its properties upon drying.
Grouting applications include slabjacking, subsealing and soil grouting. In slabjacking, pressure grouting is used to raise a depressed section of pavement or other concrete element by forcing a flowable grout under it. Subsealing is where a cement-grout mixture is pumped under pressure through a packer installed in an access hole drilled in a slab to fill voids and depressions under the slab and reduce damage caused by excessive pavement deflections. For soil grouting, soil is grouted to increase its bearing capacity, reduce or halt settlement, increase shear resistance to stabilize it against lateral movement, reduce waterflow, or increase the cohesive strength of friable ground prior to excavation. Soil grouting includes permeation grouting, where a thin grout is used to permeate the soil and fill pores and voids between soil particles; deep-soil mixing, where soil and injected grout are mixed together to make a soil-cement material in place; jet grouting, where a cement-and-water grout is injected under very high pressure to form a concrete-like column; and compaction grouting, described below.
Compaction grouting is a soil stabilization process where weak or compromised sub-soils are re-compacted. This technique involves driving injection casing into the soil in five to eight foot sections until good refusal is achieved, usually when the casing reaches bedrock or bearing strata. Pressure grouting is then performed in vertical stages throughout the length of the casing hole. The vertical stages are created by extracting a section of casing a fixed length, typically one to three feet, and then pumping a quantity of stiff, sand-and-cement grout through the casings. An operator monitors an external pressure gauge and pump stroke counter at a pump head attached to the casing end. The operator also records the pressures achieved and the quantity of grout injected at each stage. A fully extracted section of casing is removed between stages, the pump head is reattached, and the extraction and grouting sequence is repeated. The stiff grout does not permeate the soil but maintains a grouted mass, three feet or more in diameter. By displacing the soil and forming a bulblike or columnlike form, the grout significantly increases the soil density at a radial distance of one to six feet or more from the soil-grout interface.
SUMMARY OF THE INVENTION
In compaction grouting applications, injection casings are essentially nailed into the ground and require great power and lift capability to extract. Thus, an effective tool and method of extracting injection casings between stages of grout pumping is required. Prior devices for pulling elongated objects from the ground typically suffer from limitations in the areas of transportability, strength, grip effectiveness, casing reusability and stability that severely hamper their overall effectiveness for compaction grouting. The portable injectioncasing extractor apparatus and method according to the present invention provides injection casing extraction capability in compaction grouting applications without these limitations.
For example, pulling devices typically suffer from a combination of insufficient lifting power and structural strength to meet the demands of many compaction grouting jobs, resulting in frequent failure and breakdowns. Further, the puller chucking mechanisms used to secure elongated objects to a lifting device frequently require multiple manual operations to engage and disengage, greatly slowing an extraction process conducted in stages. Some puller chucking mechanisms also lack gripping strength or tend to damage casing by denting, gouging or crushing the casing wall.
By contrast, the portable injection-casing extractor apparatus and method (“extraction tool”) according to the present invention has dual hydraulic cylinders for a lifting force capable of pulling sections of grout injection casing out of the ground at an operator-controlled rate. A heavy-duty base plate and chassis provide the structural strength to support operation of the dual cylinders. The cylinders are powered by a remote hydraulic power unit or “mule.” The cylinders have an attached progressive chuck mechanism that provides sure engagement of the injection casing at the beginning of a lifting stage and release at the end of a lifting stage, without manual intervention between stages or the use of complex automatic control mechanisms. The amount of force applied to casing walls by the progressive chuck is self-limiting, protecting the casings from damage. The teeth of the progressive chuck are advantageously maintained generally flush to the casing wall during gripping and extraction steps, which avoids gouging, denting and crushing movements that would also damage the casings. These features advantageously allow casings to be reused after removal by the extraction tool.
Further, pulling devices are often awkward to transport to a construction site. If wheels are provided for transportation, they are in contact with the ground at all times, creating extractor instability during operation. Further, these devices are frequently difficult to position on installed casings. Operators are often required to lift a heavy pulling device and place it over the end of an installed casing that is protruding from the ground. In addition, these devices typically require external ladders and steps for the tool operator to remove casing sections and to disassemble, reassemble and monitor the pump head and gauges located high above the tool.
The extraction tool according to the present invention is compact for limited access applications, and, being mounted on turf tires, the tool is easily moved and operated by one or two workers in typically rough terrain conditions. An integrated handle facilitates transporting and positioning of the tool and allows sufficient leverage for a single operator to move the tool between its operating position and its transport position. The tool is so well-balanced and stable that it can maintain either its operating position or its transport position without operator support. An open-face base plate and chuck design allows the tool to be rolled into position on injection casings without lifting the tool. The installed injection casings held within the open-face base plate and chuck also provide lateral support for the tool, further increasing its stability. The weight and balance of the extraction tool provide sufficient stability for adult male to safely stand on tool. Integrated steps and platforms provide operator access to locations high above the tool. These features allow an operator to disassemble casing sections, disassemble and reassemble the pumping hose connection and to monitor pressure and stroke gauges at the casing end without the need for external platforms and ladders. The turf tires are offset from the ground in the tool's operating position, also enhancing its stability.
One aspect of the present invention is an extraction tool for progressively jacking a shaft from its surrounding media. The extraction tool has a lift with a stationary end and a moveable end, a block assembly attached to the moveable end, and a plurality of opposing grips. The block assembly defines an interior space configured to accommodate the shaft. The grips can be positioned within the inter
Hernandez Luis Enrique
Pak Naepu Joseph
Ultimo, Sr. Frank D.
Marcelo Emmanuel M.
Smith Glenn R.
Ultimo Organization, Inc.
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