Patent Application
20120102753
The present invention relates to the cutting of plastic piping which is commonly used in residential, commercial and industrial construction. The inside cutting tool of the present invention is useful to precisely and smoothly cut such piping so that it can be assembled and joined together with other piping and fittings.
Plastic piping, such as PVC, ABS, and CPVC, is now generally used for piping utilities Plastic has supplanted ceramic, cast iron and other metals in general piping applications. Plastic pipe must be cut to a certain length to be removed or replaced when removing or. repairing piping installations, This has required the development of new cutting methods. Former use of hacksaws and prior art outside cutters have proved onerous and .imprecise. In many cases a regular saw would not be useful without opening up a wall, floor or ceiling behind which a broken pipe is frequently located.
It is an object of the present invention to provide an improved inside cutting tool for use as a simple and precise cutting method for plastic and composition pipe.
This and other objects and advantages of the present invention will become apparent to those skilled in the art from the following drawings and detailed description.
FIG, 2 is a top view of the inside pipe cutter of
Referring now to the above drawings by numerals of reference, there is shown in
A hollow cylindrical sleeve 8 has its inside surface 33 longitudinally and loosely enclosing the center portion 5 of the rod 2. The sleeve 8 is positioned over the central portion 5 of the rod 2 by a pair of threaded positioning nuts 13,14 at the top end of the rod 2 below the hexagonal end 21, and by the pair of threaded locking nuts 6,7 locking the circular saw blade 12. A top washer 9 is positioned on the rod 2 below the threaded positioning nut 14. A bottom washer 15 is positioned on the rod 2 above the threaded locking nut 6 in order to assure that the sleeve is loosely held longitudinally on the rod 2. Additional longitudinal spaces 16, 17, of about 1/16″, below the top washer 9 and above the bottom washer 15, respectively, are provided by the operator loosely holding the sleeve 8 longitudinally above the rod 2 while using the inside cutting tool 1.
After assembly of the above elements of the inside cutting tool 1, the operator may lubricate the center portion 5 of the rod 2, the inside of the sleeve 8, and the washers 9,15, which allows the rod 2 to freely and smoothly rotate within the sleeve 8 which is firmly held by a hand of the operator.so that saw blade 12 is steadily held within the open pipe top 31 of the pipe 30 to make a smooth and efficient cut of the pipe 30. The sleeve 8 may alternatively be made of plastic.
Another feature of the sleeve 8 is to have measurement calibrations 20 marked longitudinally on the outside sleeve surface 34. The calibrations 20 enable the operator to place the blade 12 of the inside pipe cutter 1 at a precise position below the open end 31 of the pipe 30 so that the precisely cut pipe 30 can be joined exactly with another pipe or pipe fitting,
A further feature of the inside pipe cutter 1 of the present invention 1 is to have a short metal, plastic or fiber chain 19 attached to the outside surface 34 above the top of the sleeve 8. The other end 37 of the chain 19 is attached to the outside periphery 38 of a metal loop or ring 39. The operator places his thumb or wrist within the loop 39 while he is holding the inside pipe cutter 1 with his hand to cut the pipe 30. Should the hexagonal end 21 of the inside pipe cutter 1 be inadvertently detached from the rotating drill chuck so that the inside pipe cutter 1 falls within the open pipe 30 then the operator can easily use the loop 39 and attached chain 19 as a leash to retrieve the inside pipe cutter 1 for reattachment of the hexagonal end 21 to the drill chuck and to continue cutting operation.
The inside pipe cutter 1 and the saw blade 12 may be made in different sizes to suit the sizes of the piping application.
The method of operation of the inside pipe cutter 1 of the present invention is as follows:
The present invention has been defined by the disclosure hereinabove, but it should be understood that this is by way of illustration only and that the present invention is not necessarily limited thereto. Modifications and variations will be apparent from the disclosure without departing from the present invention as those skilled in the art will readily understand. Accordingly, such modifications and variations of the disclosed present invention are considered to be within the purview and scope of the present invention and the following claims:
