The invention relates to pipe cutting and chamfering tools.
Waste pipes for example the well known brown pipes made of plastics material are conventionally first severed in two portions using a hand saw and then once the respective ends of the portions are exposed, they are sequentially chamfered. The usual method employed is a hand file although automatic chamfering tools exist which are placed on an individual pipe portion end and then rotated until a chamfer is achieved around the circumference of the pipe on a single end portion.
Chamfering tools require the pipes to be accessed in their longitudinal direction. Thus, chamfering in confined spaces, for example when fitting a junction to a buried pipe, would normally require dismantling and/or displacement of the buried pipe, which are both difficult and time wasting.
One of the problems the invention addresses is how to cut and chamfer pipes even when these are difficult to access. Another object of the invention is to reduce the number of actions required to cut and chamfer a pipe.
The following prior art documents are acknowledged: DE 2305633; U.S. Pat. No. 6,129,488; and U.S. 4,084,463. DE 2305633 fails to show a tool which would be portable since it is destined to be mounted on a workbench. It also requires the insertion of the pipe through the open ends of a ring. The prior art tool would therefore not be suitable for operation in spaces which would be difficult to access or off-site.
In a first broad independent aspect, the invention provides a pipe cutting and chamfering tool comprising one or more cutting portions for severing the pipe into two portions; one or more chamfering portions for chamfering the edges of said pipe portions; wherein the cutting and chamfering portions is or are configured to be driven; characterised in that said tool incorporates a jaw for securing the tool onto a pipe from its side and for guiding the relative displacement of said pipe and said cutting and chamfering portions.
In a subsidiary aspect, the pipe is displaced by the operator whilst the cutting and chamfering portions remain in their position. Alternatively, the cutting and chamfering portions are displaced whilst the pipe is held in its position.
In a subsidiary aspect, said means for securing the tool onto a pipe incorporates a jaw. This is particularly advantageous because it allows the tool to be fitted onto a pipe from its side. It also improves the security of attachment of the tool to the pipe.
In a further subsidiary aspect, said jaw incorporates a number of rollers which engage the pipe when said jaw is secured onto said pipe and which act as said guiding means. This configuration is particularly advantageous because it allows the operation to be carried out with greater accuracy than would otherwise be achieved.
In a second broad independent aspect, the invention provides a pipe cutting and chamfering tool which is shaped and configured to be held and carried by hand comprising one or more cutting portions for severing the pipe into two portions; one or more chamfering portions for chamfering the edges of said pipe portions; wherein the cutting and chamfering portions is or are configured to be driven; and the tool incorporates a handle for carrying the tool whilst using the tool.
This configuration is particularly advantageous because it allows pipes to be cut and chamfered in one operation and outside of a workshop or without requiring a work bench. It also allows cutting and chamfering to take place in confined spaces without requiring dismantling or any displacement of the soil pipe. It also minimises the time required for installing a waste pipe system. In addition, it allows the chamfering to be carried out with greater accuracy than any manual system.
In a subsidiary aspect, the tool comprises a clamp for securing the tool onto the pipe and one or more cutting and chamfering portions is or are driven to displace about the circumference of the pipe. This configuration allows the cutting and chamfering operations to be of greater accuracy than would otherwise be the case.
In a further subsidiary aspect, the tool comprises a clamp for securing the tool onto the pipe which incorporates a guide for locating the one or more cutting and chamfering portion relative to the pipe as it is or they are manually displaced about the circumference of the pipe whilst being driven for cutting and chamfering. This configuration is particularly advantageous because it allows the operation to be partly manually operated whilst preserving the velocity of the cutting and chamfering operations.
In a further subsidiary aspect, one or more cutting portions is or are integrally formed with one or more chamfering portions. This configuration is particularly advantageous because it allows the blades to cut the pipe and to chamfer the pipe by using a shaving operation. It also may allow the blades to be replaceable blades.
In a further subsidiary aspect, the cutting and chamfering portions are incorporated into one or more drive trains which is or are driven about the circumference of said pipe. This allows advantageous accuracy to be achieved as well as flexibility to fit around the circumference of the pipe.
In a further subsidiary aspect, the drive train is circular and incorporates a releasable closure means which when opened allows the tool to be removed from the pipe and when closed allows the drive train to rotate about the circumference of the pipe. This allows the tool be fitted onto the pipe from a lateral direction which is particularly advantageous when the pipe is located in a confined space.
In a further subsidiary aspect, the drive train is a chain, which incorporates the cutting and chamfering portions. This allows the drive train to be particularly flexible in order to open and close from a lateral direction onto the pipe.
In a further subsidiary aspect, the tool further comprises a mechanism for automatically switching the displacement of one or more of the cutting and chamfering portions from clockwise to anticlockwise. This configuration is particularly advantageous because it allows a reduced number of cutting and chamfering portions and reduces the amount of displacement required for each individual cutting and chamfering portion.
In a further subsidiary aspect, the tool further comprises a spigot protruding from the tool for engagement with a rotary power tool. This configuration allows the tool to be driven by a rotary power tool without necessarily incorporating the power driving components within the tool.
In a further subsidiary aspect, the one or more cutting and chamfering portions interacts or interact with one or more springs, which, in use, urges or urge the portions towards the pipe. This allows the system to accommodate variations in the diameter of a given soil pipe whilst still maintaining the necessary accuracy for the cutting and chamfering operations.
In a third broad independent aspect, the invention provides a jaw for use with a pipe cutting and chamfering tool according to the first aspect, incorporating means for receiving and securing a power tool; wherein said jaw is sized and shaped to be secured about a pipe.
In a subsidiary aspect, said jaw incorporates a number of rollers which engage the pipe when said jaw is secured onto said pipe and which act as said guiding means.
The chain 4 incorporates a break 7, which allows the jaw to be opened and closed. The chain may incorporate a releasable attachment means such as a latch between the portions on either side of break 7. It is also envisaged that no releasable attachment means between the end portions of the chain may be required. In an embodiment where the chain rotates for example by only a fifth of the circumference in an anticlockwise direction and then back to its starting position in a clockwise direction no releasable attachment means need to be used. Jaw half 2 and jaw half 3 incorporate a hinge 8 and a break 9. On either side of the break 9 there may be releasable attachment means such as a tongue and groove arrangement between the halves to ensure that the jaw remains sufficiently locked during the cutting and chamfering operations.
Chain 4 may incorporate as shown in exploded view 10 a number of wagons, 11 and 12 which are joined together to form a train by a number of linkage members such as members 13 and 14. Wagons 15 and 16 may be driven through appropriately sized apertures in the linkage members and wagons.
Each individual wagon incorporates two cutting edges 17 and 18, which extend in the direction of the circumference. In addition, there is provided on at least one side a chamfering cutting edge 19, which is angled in a range from 5 to 45 degrees dependent upon the chamfering angle required. The chamfering angle is preferred to be 30 degrees from the longitudinal direction of a pipe when fitted inside the jaw. Wagon 11 would incorporate a chamfering edge such as edge 19 in the opposite direction. The wagons may also incorporate both chamfering edges in a first type of wagon and both cutting edges in a second type of wagon. The number of wagons may be varied. In an embodiment where the train is rotated by only a quarter of the circumference a single group of cutting and chamfering wagons may be provided to cover a quarter of the circumference of a pipe. Similarly, only three groups of cutting and chamfering portions may be disposed to cover a third each of an inner circumference of the jaw. In such arrangement, it is particularly advantageous to set the clockwise and anticlockwise rotation to a third of the circumference. It is also envisaged that only one group is provided and then rotated around the entire circumference to realise the cutting and chamfering operation.
Cutting head 28 may be replaced by cutting head 33 with a sharp and smooth edge 34.
Chamfering head 30 may be replaced by chamfering head 35 with two sloping edges 36 and 37 which are separated by a projection 38 in order to precisely locate the chamfering head between the severed edges of a pipe. Ring 22 may be biased towards the inside of the jaw and sized and shaped so that when placed about a pipe the cutting and chamfering heads tightly engage the circumference of the pipe.
Cutting and chamfering head 48 is releasable from the housing 45. The cutting and chamfering head incorporates a number of radial cutting lines 53, which slope away from a centre cutting point 54.
The interlocking semi circular members 55 and 60 combine to form an annular pipe cutting and chamfering tool about a pipe. The retraction and extraction of semi circular member 55 is show by arrow 57.
The pipe cutting and chamfering tool member 56 incorporates a pawl 60. The pipe cutting and chamfering tool member 55 is inserted into member 56. The rack of teeth 58 are passed over the pawl 60, which forms an overall ratchet means that locks member 55 to 56 indicated by arrow 57.
Housing 87 is secured to half 84 and incorporates at its proximal extremity an opening 94 for receiving the head of a rotary power tool. The housing 87 may take the form of a split housing allowing the housing to be clamped to the head of the rotary tool. Any appropriate clamping means may be employed to secure the rotary power tool to the housing. The invention also envisages that the jaw 82 may be an integral part of a rotary power tool.
The jaw of the preceding figures may be formed in a plurality of sizes or may be extendable to and from a plurality of sizes such as in particular: 82 mm, 110 mm, and 160 mm.
This application is a national stage entry of PCT/GB2008/001010 filed Mar. 19, 2008, under the International Convention.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB08/01010 | 3/19/2008 | WO | 00 | 9/17/2010 |