GB2550886A

GB2550886A - Pipe chamfer tool

Info

Publication number: GB2550886A
Application number: GB1609362.7A
Authority: GB
Inventors: William Preston Roger
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-06-09
Filing date: 2016-05-26
Publication date: 2017-12-06
Also published as: GB201510063D0; GB201609362D0

Abstract

A chamfer tool for chamfering the bluff ends of polymer pipes comprises a spigot 1 affixed to a shaft 2 with a rubber seal 3 on the spigot. In use, the spigot and rubber seal are inserted into the bluff end of a pipe it is intended to chamfer and the rubber seal is expanded by urging a locking nut 7 against a spring 6 that in turn pushes against a hub 4. The locking nut 7 is locked into position and the hub 4 freely rotates about the shaft 2. Blades 5 are disposed in an end wall in a conformal cylindrical void provided in the hub 4. The blades 5 bear down upon the end of an inserted pipe that it is intended to chamfer as the hub 4 is rotated. Chamfering is terminated by the end of the chamfered pipe coming into contact with the end wall. The tool can then be removed by releasing the locking nut 7.

Description

Pipe chamfer tool Field of the invention

The present invention relates to tools for use in cutting and preparing pipes in the construction industry. More particularly, the present invention relates to the cutting and preparation of plastic pipes. Most particularly the present invention relates to a chamfering tool for use in preparing the cut end of pipe. A chamfer is an angling applied to the end of a pipe to remove the bluff end resulting from moulding or cutting thereby facilitating the interaction of the chamfered end with other pipes, mouldings and fittings.

This invention relates to an apparatus operable to put a preferably 30 degree chamfer on the end of a plastic pipe. It is to be understood that the invention can accommodate angles of chamfer other than 30°.

The description hereafter relates to plastic pipes of 90 mm (9.0 cm) diameter. It is to be understood that the present invention, by modification to its size, can be made to accommodate use on pipes of less than 90 mm (9.0 cm) diameter and greater than 90 mm (9.0 cm) diameter.

The prior art.

As stated above, putting a chamfer on the end of a plastic pipe enables connection of the pipe into fittings.

In the past, and to the present day, the cutting and chamfering of pipe ends has required two or more persons to cooperate with one another to enable the cutting and chamfering to be achieved. It is one object of the present invention to enable a single person to achieve the same results as previously achieved by two or more persons.

It is present practice that, on a construction site, an individual person, laying a pipe, uses a hand held file to put a chamfer on the end of a plastic pipe. It generally takes a pipe layer between 6 and 8 minutes to complete formation of a chamfer. The present invention seeks to reduce the time that an individual operator requires to create a chamfer with the chamfer tool it will take to less than 2 minutes to complete the same task.

United States Patent application US2015048558 (A1) discloses a method for chamfering the end of a pipe made from thermoplastic material, comprising the following steps: localised and circumferential heating of an axial portion of the pipe at a predetermined temperature; and plastic deformation of the heated axial portion of the pipe using a tool for forming a chamfer on the axial portion of the pipe. The present invention seeks to avoid any heating of the end of the pipe thereby reducing the size, weight and complexity of the tool and speeding its operation

United States patents application US4586408 (A) discloses a tool for chamfering the ends of plastic pipe of various diameters comprising a main body having various concentric circular grooves of different diameters which are shaped and sized to receive the square-cut ends of standard size plastic pipe. Each circular groove has an associated cutting blade mounted transversely with respect to the circumference of the pipe in a recess on the outer surface of the main body and positioned so that as the tool is rotated about the square-cut end of a pipe inserted in its correspondingly-sized groove, a chamfer is cut on the outer circular edge of the pipe. During the chamfering process, cuttings cannot enter the pipe because the open end of the pipe is covered by the tool and cuttings leave the tool through the recess. Cutting automatically ceases when the pipe end becomes seated in the groove. The present invention seeks to provide improvement there are over by avoiding need for seating of a pipe end. In groove thereby improving speed of use, by allowing automatic axial centring of the tool about a pipe end, and by allowing greater simplicity, weight and portability of the chamfering apparatus.

United kingdom published patented application GB2453791 (A) discloses a tool for chamfering plastic soil pipes and comprises a main body section provided with an abrasive area mounted on a tapered surface of the main body . The outer diameter of the tapered surface is greater than that of the pipe to be chamfered, thereby allowing for variation in pipe diameter. The abrasive is carbide grit which has been brazed onto the tapered surface which is steel. The abrasive occupies 20-50 % of the tapered surface. The tool can be fitted to a drive mechanism by means of a thread or a taper. The present invention seeks to provide improvement there over by avoiding use of abrasives. This prevents dust falling into the pipe and during the chamfering process. The present invention also better guarantees centring of the pipe and within the tool thereby avoiding variability of the chamfering angle.

Brief description of the invention.

The present invention consists in a pipe chamfering tool for chamfering the end of a pipe, the tool comprising: a cylindrical shaft with an expandable end of fixed thereto; a hub, axially slidable on the shaft and rotatable about the shaft; a spring, bearing against the hub and bearing against a locking nut on the shaft; the hub comprising one or more blades positioned to engage the end of the end of a pipe that it is desired to chamfer; where, in use to chamfer a pipe: the locking nut is released on the shaft to lower the pressure on the spring: the expandable end is inserted into the cut end of a pipe that it is desired to chamfer; the locking nut is urged along the shaft against the spring for the spring to urge the expandable end to increase in diameter to grip and hold the inside of a pipe that it is desired to chamfer while the spring also urges the one or more blades against the end of the pipe that it is desired to chamfer; the locking nut is locked against moment on the shaft and the hub is rotated around the shaft for the one or more blades to chamfer the end of the pipe that it is desired to chamfer to a preset desired chamfering angle; and when chamfering is finished, the locking nut being longitudinally released on the shaft to reduce pressure on the spring thereby allowing the expandable end to reduce in diameter for the removal of the shaft.

The invention further provides that the expandable end comprises a spigot and an elastomeric seal centrally attached thereon, the elastomeric seal increasing in diameter when the hub is urged there against.

The invention further provides that the elastomeric seal can be a rubber seal.

The invention further provides that the shaft can comprise a screw thread, the locking nut can engage the screw thread to define its position on the shaft; and the hub can comprise a bush operable to support the hub and to allow the hub to rotate about the shaft without engaging the screw thread.

The invention further provides that the locking nut can comprises clip means operable when activated to allow the locking nut to be slidable on the shaft and when deactivated to lock the locking nut in its position on the shaft; and wherein the hub comprises a bush operable to support the hub and to allow the hub to rotate about the shaft.

The invention also provides that the hub can comprise a cylindrical void for accepting insertion of the bluff end of a pipe it is intended to chamfer, that the cylindrical void can comprise comprise cylindrical walls and an end wall, and that the blades can be disposed at the end wall proximate to the cylindrical walls. I

The invention further provides that the one or more blades are four blades a angularly disposed about the hub, each blade being affixed within a blade mounting aperture to engage the end of the pipe it is desired to chamfer.

The invention further provides that each blade can comprise a cutting portion, protruding through the respective blade mounting aperture to engage the with and cut the end of the pipe that it is desired to chamfer, and a mounting portion supporting the cutting portion and attachable in association with the mounting aperture.

The invention further provides that the angle of the one or more blades is selectable to accommodate selectable chamfering angles.

Brief description of the drawings.

The invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 shows the assembled chamfer tool ready for use.

Figures2A to 2D show the blade assembly for cutting a chamfered edge, the blade assembly being viewed from different angles

Figure 3 shows an oblique view of the hub assembly.

Figure 4 shows a plan view of the hub assembly.

Figure 5 shows a side view of the hub assembly, partly disassembled, from a first direction.

And

Figure 6 shows a side view of the hub assembly, partly disassembled, from a second direction, diametrically opposite from the view of figure 5.

Detailed description.

The invention is now described, by way of an exemplary implementation.

Attention .is first drawn to Figure 1,

Figure 1 shows a spigot 1. The spigot 1 fits directly and concentrically on a distal end of a threaded shaft 2. A rubber seal 3 on the spigot 1 can be urged into the bluff end of a pipe that it is intended to chamber (not here shown) to slideably fit there within. The seal 3 elastically expands within the pipe it is intended to chamfer to hold a hub 4, squarely upon the end of the plastic pipe it is intended to chamfer.

The spigot 1 and the rubber seal 3 form and expandable end to the tool designed to fix the tool within the end of a pipe it is intended to chamfer. Those skilled in the art will be aware of many variations to create a selectably expandable and contractable tool and for attaching the tool and within a pipe it is intended to chamfer, without deviating from the invention as claimed. Those skilled in the art will also be aware that whereas a rubber seal is described here above, any elastomeric device can be so employed without deviating from the claimed invention.

Expansion of the seal 3 is controlled by a spring 6 and a locking nut 7. The locking nut 7 is provided with extensions 7 A for manual engagement when turning. The locking nut 7 is moved clockwise to advance upon the spring 6 on the thread of the shaft 2, and anti clockwise to slacken the pressure on the spring 6. The locking nut 7 Is pressed on by the spring 6. The spring 6 in turn bears upon the hub that in turn bears upon the rubber seal 3. In this way, by manually turning the locking nut 7, the rubber seal 3 can be expanded firmly to grip the spigot 1 or released to contract to allow the moment of the spigot within the end of the pipe that it is desired to chamfer a pipe or to remove the spigot 1 from a pipe that has been chamfered.

An alternative arrangement has the locking nut 7 is provided as a spring clutch device and the shaft 2 is smooth and not having a screw thread. When the spring clutch on the locking nut 7 is depressed the locking nut 7 is released to slide on the shaft 2 for the operator to compress the spring 6. When the spring is sufficiently compressed, the spring clutch on the locking nut 7 is released to lock the locking nut 7 in the position it currently occupies on the shaft 2. Removal of the tool after chamfering is achieved by depressing the locking nut’s 7 spring clutch and slightly the locking nut 7 thanked down on the shaft 2 away from the rubber seal.

The hub 4, as shown in figure 1 and more clearly shown in figure 3, is in the form of a closed end cylindrical shell where an inside portion having cylindrical walls 10 is insertable over the bluff end of the pipe it is intended to chamfer. Also shown in figure 3 and later described, is an end wall 11 through which the blades 5 protrude approximately to the cylindrical wall 10 to chamfer the outer surface of a pipe it is intended to chamfer and to halt further chamfering of that pipe by the chamfered tip of the chamfered pipe abutting the end wall 11 when chamfering is complete.

The hub 4 can be moved to rotate 360 degrees on the shaft 2. by means of a handle 9. The hub 4 rotates about the shaft 2 on a bush 8. The bush is preferably bronze for low friction and durability. Those skilled in the art, however, will be aware of other materials that can be used for fabrication of the bush 9 with out departing from the invention as claimed. As the secured hub 4 rotates against the end of the pipe it is intended to chamfer, cutting blades 5, set at the preset chamfering angle, progressively cut into the previously bluff end of the pipe that it is intended to chamfer to leave a chamfered end of that pipe.

The blades 5 are preferably four in number and equiangularly disposed (as shown in figure 1,3 and 4) about the end of the pipe it is intended to chamfer. Those skilled in the art will be aware that the number blades 5 can be more than four in number or fewer than four in number within the operation of the invention. The individual blades 5 are preferably carbide blades. Those skilled in the art will be aware that other materials may also be used for fabrication of the blades 5 without departing from the invention as claimed . In figure 1 the carbine blades 5, also shown in detail in figure 2, are housed on the inside of the hub 4, putting a 30 degree chamfer on the end of the plastic pipe.

Attention is next drawn to figure 2A to 2D showing the blade 5 from various angles. Figure 2A is a view looking down on the blade 5 from a first direction, figured 2B is a view showing the blade 5 of figure 2A from the opposite direction, figure 2C is a side view of the blade 5, and figure 2D is an oblique view of the blade 5.

The blade 5, being one of the one or more blades disposed around the edge of the hub 4 as described above, comprises a cutting portion 5A operable, in use, to engage the bluff edge of a pipe that it is intended to chamfer. The blade 5 also comprises a mounting portion 5B to support the cutting portion 58 in the hub 4, the mounting portion 5B comprising a mounting void 5C. The mounting void 5C is a circular aperture through which a screw, rivet or other protrusion can be inserted to secure the blade 5 in its respective one or more locations in the hub 4.

Attention is next drawn to figure 3 showing an oblique view of an assembled hub 4 disengaged from other equipment with the exception of 4 blades 5, and to figure 4 showing a plan view of the assembled hub 4 viewed from the opposite face from that visible in figure 3.

The hub 4 comprises blade 5 mounting apertures 4B through which the blades 5 are individually mounted, figure 3 showing a screw mount on a first face of the hub 4 with protruding cutting portions 5A and the remainder of each mounting portion 5B being visible in figure 4. The hub comprises a central aperture 4A in which is to be found the bush 8 for sliding on the shaft 2.

Finally, attention is drawn to figures 5 and 6 showing respectively the view from a first direction of a side view of the hub 4 and a view from a second diameter clay opposite direction from the view of figure 5. A handle mounting screw thread 4C allows for the mounting of the handle 9 otherwise shown in figure 1.

The hub, as shown in figure 3, provides a cylindrical void having a cylindrical wall 10 into which a pipe that it is intended to chamfer is inserted and an end wall 11 that a chamfered pipe engages when chamfering is finished.

In use, as the spigot is inserted into the inside of the end of the pipe that is desired to chamfer, the end of the pipe is inserted into the cylindrical walls for the tip of the pipe to engage the blades 5. As the rubber seal expands to position and hold the tool within the end of the pipe it is intended to chamfer, the spring 6 urges the hub 4 towards the end of the inserted pipe it is intended to chamfer. At this point, the tip of the inserted pipe it is intended to chamfer engages the blades 5. As the hub 4 is then rotated the spring 6 urges the blades 5 against the tip of the pipe it is intended to chamfer, until the tip of the chamfered pipe is stopped by the end wall 11. Chamfering is at this point complete, and reduction of the length of the pipe it is intended to chamfer by the blades 5 is avoided. The chamfered pipe is then released from the tool.

Those skilled in the art will be aware of different implementations that are possible without departing from the invention as claimed. The invention is further explained, in greater detail, by the following claims, in which:

Claims

1. A pipe chamfering tool for chamfering the end of a pipe, the tool comprising: a cylindrical shaft with an expandable end of fixed thereto; a hub, axially slidable on the shaft and rotatable about the shaft; a spring, bearing against the hub and bearing against a locking nut on the shaft; the hub comprising one or more blades positioned to engage the end of the end of a pipe that it is desired to chamfer; where, in use to chamfer a pipe: the locking nut is released on the shaft to lower the pressure on the spring: the expandable end is inserted into the cut end of a pipe that it is desired to chamfer; the locking nut is urged along the shaft against the spring for the spring to urge the expandable end to increase in diameter to grip and hold the inside of a pipe that it is desired to chamfer while the spring also urges the one or more blades against the end of the pipe that it is desired to chamfer; the locking nut is locked against moment on the shaft and the hub is rotated unwound the shaft for the one or more blades to chamfer the end of the pipe that it is desired to chamfer to a preset desired chamfering angle; and when chamfering is finished, the locking nut being longitudinally released on the shaft to reduce pressure on the spring thereby allowing the expandable end to reduce in diameter for the removal of the shaft.

2. The tool, according to claim 1, where in the expandable end comprises a spigot and an elastomeric seal centrally attached thereon, the elastomeric seal increasing in diameter when the hub is urged there against.

3. The tool according to claim 2 wherein the elastomeric seal is a rubber seal.

4. The tool according to any of claims 1 to 3 where in the shaft comprises a screw thread, the locking nut engages the screw thread to define its position on the shaft; and the hub comprises a bush operable to support the hub and to allow the hub to rotate about the shaft without engaging the screw thread.

5. The tool according to any of claims 1 to 3 wherein the shaft disposed; wherein the locking nut comprises clip means operable when activated to allow the locking nut to slidable the shaft and when deactivated to lock the locking nut in its position on the shaft; and wherein the hub comprises a Bush operable to support the hub and to allow the hub to rotate about the shaft.

6. The tool according to any of the preceding claims where the hub comprises a cylindrical void for accepting insertion of the bluff end of a pipe it is intended to chamfer, the cylindrical void comprising cylindrical walls and an end wall, the blades being disposed at the end wall proximate to the cylindrical walls.

7. The tool according to any of the preceding claims where in the one or more blades are four blades a eqiangularly disposed about the hub, each blade being affixed within a blade mounting aperture to engage the end of the pipe it is desired to chamfer.

8. The tool according to claim 7 where in each blade comprises a cutting portion, protruding through the respective blade mounting aperture to engage the with and cut the end of the pipe that it is desired to chamfer, and a mounting portion supporting the cutting portion and attachable in association with the mounting aperture.

9. The tool according to any of the preceding claims wherein in the angle of the one or more blades is selectable to accommodate selectable chamfering angles.

10. The tool substantially as described with reference to the appended drawings.