AU2021101547A4

AU2021101547A4 - A device for cutting pipes

Info

Publication number: AU2021101547A4
Application number: AU2021101547A
Authority: AU
Inventors: Kenneth Meyers Turner; Roderick James Turner
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2021-06-03
Anticipated expiration: 2029-03-26

Abstract

The present invention relates to a pipe cutting device including an elongate rigid shaft having a first end portion for connection to a rotating drill chuck, and a second end portion having a blade attaching means for removably attaching a circular saw blade thereto; an elongate cylindrical outer sleeve having a length less than that of said shaft; a retaining ring adapted to encircle the shaft towards the first end thereof, and be secured thereto by way of a retention member, such that when the retaining ring is secured to the shaft, it prevents lateral movement of the sleeve along the longitudinal length of the shaft. 2/3 6 12 8 9 3 7 5 2 FIG3 7 12 FIG4

Description

2/3

6 12 8

9 3 7 5 2

FIG3

7

12

FIG4

A DEVICE FOR CUTTING PIPES TECHNICAL FIELD

[0001] The present invention relates generally to the cutting of plastic piping, which is commonly used in residential, commercial and industrial buildings. More particularly, more particularly the present invention relates to a rotary cutting tool for cutting the wall of a pipe from inside the pipe through an opening at one end of the pipe.

BACKGROUND

[0002] It is common practice in the building construction industry for plumbers to install large diameter pipe, such as plastic waste pipe, before finish flooring is installed. The pipe is left overlong so that it may be cut down to the necessary level of the finish floor as required after the floor has been finished. If this level is above the finish floor, the pipe may be cut simply with a hacksaw. Generally, it is necessary to cut off the end at a level below the level of the floor for proper connection of a water closet, shower pan, or bathtub. There is not enough space around the pipe at the desired level to admit a hacksaw. The pipe is often cut away with a chisel or other hand tool which is awkward, labor intensive and may leave an irregular cut end.

[0003] The problem has been recognized for some time, and there have been many attempts previously made to provide rotary cutters that attempt to solve the problem. A variety of mechanisms for controlling the depth of cut and mechanisms for controlling the path of the cutting tool have previously been developed.

[0004] However, many of the previous approaches have resulted in devices that are quite complex, and as a result can be difficult to operate, and expensive. Accordingly, the plumber is not anxious to invest in an expensive tool, and so that most plumbers still use awkward hand tools that they already have in their toolboxes for other purposes, even though they are not well suited to this application.

[0005] For example, United States patent no. 5,815,926 describes an internal pipe cutter, which includes an elongated shaft having an upper end adapted for connection to a rotational power tool and a lower end to which a rotary cutting blade may be perpendicularly attached. A set collar is slidably mounted on and adjustably positioned along the shaft. A gripping sleeve is disposed around the set collar and is slidably and rotatably mounted on the shaft whereby the gripping sleeve and the set collar are conjointly positionable along the shaft and whereby the shaft and the set collar conjointly rotate independent of the gripping sleeve. The gripping sleeve includes a guide flange at a lower end thereof wherein the guide flange abuts the open end of the pipe as the rotary cutting blade is circled within the inside of the pipe. Accordingly, the set collar is locked on the shaft such that when the guide flange abuts the open end of the pipe, the rotary cutting blade will be at a desired level.

[0006] The set collar 30 is locked on the shaft 20 such that when the guide flange 43 abuts the open end 7 of the pipe 6, the rotary cutting blade 12 will be at a desired level. When at the desired level, a set screw 32 is threadingly mounted in the set collar 30 and is used for locking the set collar 30 in a particular position along the shaft 20. This arrangement is relatively complex, and in use, the gripping sleeve is not inserted within the pipe that is to be cut.

[0007] United States patent no. 4,932,125 describes a cutting tool is designed to cut through plastic pipe from within. This operation is required when a pipe is mounted in a floor or wall and must be cut off below the level of the floor for installation of plumbing fixtures. A rotary shaft with a rotary saw blade at one end is adapted for rotating in an electric drill at a second end. The shaft is journaled in a sleeve. A locking collar is slideably mounted on the sleeve. The collar is locked on the sleeve at a particular level so that when the underside of the collar engages the cut end of the exposed pipe, the blade will cut the wall at the desired depth. The collar is kept in contact with the pipe end as the sleeve is moved in a circle against the inside of the pipe so that the inside cut will be at a uniform depth. A thumbscrew 19 threadably mounted in the collar 16 can be used to lock the collar against the sleeve at any particular level. This arrangement is relatively complex, and in use, the gripping sleeve is not inserted within the pipe that is to be cut.

[0008] United States patent publication no. 2012/0102753 describes a cutting tool principally used as an inside pipe cutter for plastic pipe which consists of a threaded round rod with the top end connected to a rotating drill and the bottom end connected to a rotating saw blade. The center portion of the rod is loosely enclosed within a sleeve which the operator holds to position the inside pipe cutter within the top of an open pipe to be cut by the rotating saw blade. The cutting tool may also be used as an outside pipe cutter.

[0009] 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 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. This arrangement is relatively complex, and requires the sleeve to be retained at both the upper and lower ends, between the two sets of threaded positioning nuts.

[0010] Therefore, it is desirable to create an alternative pipe cutting device, which overcomes, substantially ameliorates or at least provides an alternative to the previous approaches undertaken.

DISCLOSURE OF THE INVENTION

[0011] In a first aspect, the present invention relates to a pipe cutting device including: an elongate rigid shaft having a first end portion for connection to a rotating drill chuck, and a second end portion having a blade attaching means for removably attaching a circular saw blade thereto; an elongate cylindrical outer sleeve having a length less than that of said shaft; a retaining ring adapted to encircle the shaft towards the first end thereof, and be secured thereto by way of a retention member, such that when the retaining ring is secured to the shaft, it prevents lateral movement of the sleeve along the longitudinal length of the shaft; whereby, in use, an operator inserts the pipe cutting device into a pipe, and grips a portion of the outer sleeve to guide the cutting head to a desired position within the pipe, when the cutting head is located at the desired position, the operator continues to grip the portion of the outer sleeve holding the cutting head at the desired position, and activates the drill, thereby causing the shaft and the retaining ring secured thereto to rotate within the outer sleeve, which itself does not rotate, and rotating the blade in order to cut off a predetermined portion of the pipe.

[0012] Preferably, the retention member is a roll pin, and is preferably made of metal.

[0013] Preferably, the outer sleeve includes a plurality of markings regularly spaced along its longitudinal length, which when in use, provide a guide to the user of the depth within a pipe that the device has been inserted. Most preferably, the markings are at intervals of 10mm.

DESCRIPTIONOFFIGURES

[0014] Embodiments of the present invention will now be described in relation to figures, wherein:

FIG 1 is a perspective view of a prior art pipe cutting device, which is designed to be inserted internally within a plastic pipe to be cut, having a rotatable shaft adapted for engagement with a drill chuck at one end, and for engagement with a blade at the other distally located end.

FIG 2 is a perspective view of a prior art pipe cutting device in use within a pipe which is being cut.

FIG 3 is a plan view of the pipe cutting device of the present invention.

FIG 4 is an isometric view of the pipe cutting device shown in FIG 3;

FIG 5 is a bottom end view of the pipe cutting device shown in FIG3, and specifically showing the blade engagement portion.

FIG 6 is a top end view of the pipe cutting device shown in FIG 3, and specifically showing the drill chuck engagement portion and the roll pin retainer member.

DETAILED DESCRIPTIONOFPREFERRED EMBODIMENTS

[0015] The present invention will now be described with reference to the accompanying drawings. FIGS 3 and 4 show the pipe cutter 1 of the present invention, which includes a shaft 5 that has a first end 2 arranged to engage with a drill chuck (not shown), and a second end 3 distally located, which is arranged to have a circular cutting blade 4 secured thereto, which is not shown in these drawings. Whilst it is not shown in these drawings, the blade 4 is secured to the second end 3 of the shaft 5 via a securing means 9, which can be loosened and tightened using an Allen key, and a washer 10 would be positioned between the securing means 9 and the blade 4.

[0016] The shaft 5 is positioned within, and encircled by, an outer sleeve 6. A retaining ring 7 is adapted to be positioned upon the shaft 5 towards the first end 2, and retained at that position by way of a retention member in the form of a roll pin fastener 8, which is inserted through an aperture that passes through both the retaining ring and the shaft. A roll pin (also known as a spring pin or tension pin) is a type mechanical retainer/fastener that secures the position of two or more parts of a machine/device relative to each other. Roll pins have a body diameter which is larger than the hole diameter, and a chamfer on either one or both ends to facilitate starting the pin into the hole. The spring action of the pin allows it to compress as it assumes the diameter of the hole. The force exerted by the pin against the hole wall retains it in the hole, therefore a roll pin is considered a self-retaining fastener.

[0017] In this arrangement, once the roll pin 8 is inserted through the aperture of the retaining ring 7 and the shaft 5, the retaining ring is secured to the shaft. The arrangement of the retaining ring 7 and roll pin fastener 8 permits rotation of the shaft 5 within the outer sleeve 6, but prevents lateral movement of the sleeve along the longitudinal length of the shaft. Once secured to the shaft 5 by way of the roll pin 8, the retaining ring 7 rotates along with the shaft within the outer sleeve.

[0018] In order that the circular saw blade 4 can cut the pipe, the elongate cylindrical outer sleeve 6 has a length less than that of the shaft 5. The outer sleeve 6 includes markings along the longitudinal length spaced apart at regular intervals, which provide a guide to the user as to the depth of insertion of the device of the present invention into a pipe. In the embodiment shown in the drawings, these markings are lines 12 that circumferentially extend around the outer sleeve 6. It is preferred that these markings are spaced apart at intervals of 10mm, although any suitable spacing may be used.

[0019] In use, an operator inserts the pipe cutting device 1 into a pipe, and grips a portion of the outer sleeve 6 to guide the cutting head, including the circular saw blade 4 to a desired location within the pipe. When the cutting head is positioned at the desired location (which can be assisted by using the line markings 12 on the external surface of the outer sleeve 6), the operator continues to grip the portion of the outer sleeve 6, thereby holding the cutting head at the desired located, and activates the drill (not shown). When activated, the drill causes the shaft 5 to rotate within the outer sleeve 6, which itself does not rotate, and thereby rotates the blade 4 to cut off a predetermined portion of the pipe.

[0020] As discussed above, the arrangement of the retaining ring 7 secured to the shaft 5 by way of the roll pin fastener 8 permits rotation of the shaft and retaining ring within the outer sleeve 6, but prevents lateral movement of the outer sleeve 6 along the longitudinal length of the shaft. The arrangement between the outer sleeve 6 and the shaft 5, and specifically the arrangement of the retaining ring 7 being secured on the shaft 5 by way of the roll pin 8 allows for the blade 4 to rotate/spin when the drill is operated. However, because the outer sleeve 6 does not rotate, it allows for the operator to grip the sleeve 6 during cutting operation, and to steady the pipe cutting tool 1 and direct the cut to be made to the pipe.

[0021] The user/operator can grasp onto the tool using the outer sleeve 6, and if the chuck of the drill happens to come loose, the user can pull the pipe cutter 1 back up through the pipe using the hand, which is gripping the outer sleeve 6, and can then re-insert the first end 2 of the shaft back into the drill and tighten the chuck back onto the shaft. The outer sleeve 6 enables the pipe cutter 1 to be more stable because the operator can hold onto the outer sleeve during operation of the pipe cutter 1, and guide the cutting head, which includes the blade 4, for a more accurate cut, which also adds an element of safety when using the pipe cutting device 1 of the present invention.

[0022] FIG 5 shows a bottom end view of the pipe cutter device 1 of the present invention. Specifically, it shows the connection area for the blade 4, which is removably secured to the second end 3 of the shaft 5 via a securing means 9 and a large washer 10. The blade 4 preferably is simply an 'off the shelf' commercially available product, and can be selected to suit the particular requirements of the job when cutting the pipe. The blade securing means 9 incorporates an Allen key screw to allow longer life of screws - particularly when compared with Philips Head or Flat Head screw, which can be easily worn off by drivers, especially when tightening the securing means 9 in order to secure the blade 4 onto the shaft 5 of the pipe cutter 1. It is very simple to change the blade 4. Located at the second end 3 of the shaft 5, there are two flat sections for a spanner or wrench to grasp firmly, whilst inserting the Allen key into the screw on the end of the securing means 9, and then simply turning to respectively tighten or loosen the securing means to install or remove the blade 4.

[0023] FIG 6 shows a top end view of the pipe cutter device 1 of the present invention. Specifically, it shown the first end 2 of the shaft 5, which is adapted to engage with a drill chuck. This first end 2 portion of the shaft 5 is preferably shaped to better facilitate the engagement with the drill chuck.

[0024] While the invention has been described with reference to preferred embodiments above, it will be appreciated by those skilled in the art that it is not limited to those embodiments, but may be embodied in many other forms, variations and modifications other than those specifically described. The invention includes all such variation and modifications. The invention also includes all of the steps, features, components and/or devices referred to or indicated in the specification, individually or collectively and any and all combinations or any two or more of the steps or features.

[0025] In this specification, unless the context clearly indicates otherwise, the word "comprising" is not intended to have the exclusive meaning of the word such as "consisting only of", but rather has the non-exclusive meaning, in the sense of "including at least". The same applies, with corresponding grammatical changes, to other forms of the word such as "comprise", etc.

[0026] Other definitions for selected terms used herein may be found within the detailed description of the invention and apply throughout. Unless otherwise defined, all other scientific and technical terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the invention belongs.

[0027] Any promises made in the present document should be understood to relate to some embodiments of the invention, and are not intended to be promises made about the invention in all embodiments. Where there are promises that are deemed to apply to all embodiments of the invention, the applicant/patentee reserves the right to later delete them from the description and they do not rely on these promises for the acceptance or subsequent grant of a patent in any country.

Claims

CLAIMS:

1. A pipe cutting device including: an elongate rigid shaft having a first end portion for connection to a rotating drill chuck, and a second end portion having a blade attaching means for removably attaching a circular saw blade thereto; an elongate cylindrical outer sleeve having a length less than that of said shaft; a retaining ring adapted to encircle the shaft towards the first end thereof, and be secured thereto by way of a retention member, such that when the retaining ring is secured to the shaft, it prevents lateral movement of the sleeve along the longitudinal length of the shaft; whereby, in use, an operator inserts the pipe cutting device into a pipe, and grips a portion of the outer sleeve to guide the cutting head to a desired position within the pipe, when the cutting head is located at the desired position, the operator continues to grip the portion of the outer sleeve holding the cutting head at the desired position, and activates the drill, thereby causing the shaft and the retaining ring secured thereto to rotate within the outer sleeve, which itself does not rotate, and rotating the blade in order to cut off a predetermined portion of the pipe.

2. A pipe cutting device of claim 1 wherein the retention member is a roll pin.

3. A pipe cutting device of claim 2 wherein the roll pin is made of metal.

4. A pipe cutting device of claim 1 wherein the outer sleeve includes a plurality of markings regularly spaced along its longitudinal length, which when in use, provide a guide to the user of the depth within a pipe that the device has been inserted.

5. A pipe cutting device of claim 4 wherein the markings are at intervals of 10mm.