Plastic Pipe Drilling Casing Shoe Threading Joint
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Solution Overview
Problem
Current methods for plastic pipe drilling are inefficient due to the need for a steel pipe in the initial phase and difficulties in coupling plastic pipes with readymade threadings, leading to high manufacturing costs and potential damage to drilling equipment.
Innovation Solution
A method and apparatus that allows for a reliable mechanical joint between a casing shoe and a plastic pipe by threading the casing shoe onto the pipe during installation, eliminating the need for preworked threadings and reducing the length of the coupling stem, thereby avoiding material differences and thermal expansion issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a steel pipe is used in the initial phase of drilling, then the structural strength and reliability are improved, but the weight and manufacturing cost increase
Solution Approach 1:
The patent changes the material parameter from steel to plastic (polyethylene) for the casing pipe, while maintaining structural integrity through proper pipe wall thickness design and coupling mechanisms. This parameter change reduces weight and cost while eliminating the need for initial steel pipe use
Solution Approach 2:
The patent employs disposable or replaceable plastic coupling elements that can be easily installed and removed. These couplings are designed to be sufficient for the drilling operation duration, eliminating the need for permanent steel pipe installations in the initial phase
2Ease of operation
If plastic pipes with preworked threadings are used for coupling, then the ease of installation is improved, but the reliability of the joint deteriorates due to threading differences between steel and plastic
Solution Approach 1:
The patent introduces a steel coupling element as an intermediary between the plastic pipe sections. This steel coupling acts as a mediator that accepts threading from plastic pipes without the threading problems that occur when steel pipes are directly threaded, thereby maintaining both ease of installation and joint reliability
Solution Approach 2:
The patent segments the coupling system into separate functional components: plastic pipe sections for the drilling function and steel coupling elements for the mechanical connection function. This segmentation allows each component to be optimized for its specific purpose without the compromises required in integrated designs
3Ease of manufacture
If readymade threaded plastic pipes are coupled with steel casing shoes, then the ease of manufacture is improved, but harmful factors increase due to metal fragments entering the soil
Solution Approach 1:
The patent uses disposable plastic pipe sections that are installed for the duration of the drilling operation and then removed. Since these plastic sections are temporary and non-metallic, they eliminate the problem of metal fragments contaminating the soil while maintaining manufacturing simplicity
4Reliability
If a long coupling stem with elasticity means is used to join plastic pipes, then the reliability of the joint is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the elastic damping function from the coupling stem itself and places it in separate damping elements (such as rubber rings or springs) that are positioned within the coupling mechanism. This extraction simplifies the overall coupling structure while maintaining the necessary reliability and shock absorption
Data Source
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AI summary
The invention relates to a method and apparatus for plastic pipe drilling, which apparatus has a drilling device (1 ) that consists of a casing part manufactured from a plastic based material and a drilling unit (3) that exists inside the casing part, which drilling unit (3) includes first drilling means for drilling a center hole and second drilling means (5) for reaming the center hole for the casing part (2). The drilling means (4, 5) are coupled mutually in power transmitting manner during drilling and they are removable from each other or arranged to be contractible radially, in order to enable removal of the drilling means from a drilled hole. A casing shoe (8) is being mounted at an end of the casing part (2) for pulling of the casing part (2) into the hole to be drilled by the drilling unit (3). The casing shoe (8) is provided with working means (X), whereby the casing shoe (8) is being mounted at the end of the casing part (2) by cutting threads in the casing part (2), in order to achieve a joint (Y) between the casing and the casing shoe (2, 8) that transmits pulling in a longitudinal direction of the drilling unit (3).