DE112011103080T5 - Device for cutting and chamfering a plastic pipe - Google Patents

Abstract

What is provided is a pipe cutting device, and in particular a device for cutting a water or drainage pipe and chamfering the ends thereof. The apparatus includes two lower back-up rolls and two upper back-up rolls for further rotatably supporting the pipe and two guide wheels disposed between the two lower rolls. Further, the apparatus includes a tool for cutting and chamfering the tube.

Description

Field of the invention

The present invention relates to a pipe cutting device, and more particularly to an apparatus for cutting, for example, a water or drainage pipe and chamfering the ends thereof.

Background of the invention

Typically, water or drainage pipes are made of a polymeric material, e.g. As polyvinyl chloride (PVC), wherein one end of the tube is a nut end which forms a receptacle, and the other end of the tube is a butt end with a chamfered or beveled circumference. The tubes are typically made in standard diameters and lengths, and several of the tubes may require trimming on site to provide tubes of the required length.

Usually, a rubber seal is used to seal the joint where two pipes are connected. The seal is received in an annular recess formed at the nut end of one of the tubes. The butt end of the other tube engages the radially inner surface of the seal to form the seal. The butt end of a standard length pipe typically includes a chamfer or bevel so that the gasket will not be rolled or damaged out of the recess when the butt end is inserted during the installation process. If the pipe has to be cut to length at the job site, typically the original beveled or bevelled butt end is cut off and a new butt end is formed. Workers often try on the job site to bevel the edge of the tail end of such cut-to-length pipes to avoid damage to the seal. However, the use of hand tools for cutting or grinding often results in an irregular beveled edge.

After the piping system has been installed, government requirements often require that the system be pressurized and meet specific pressure drop parameters. If the system fails the pressure test, the leaks that caused this failure must be found and corrected. Often the source of such leaks is a damaged or displaced gasket at the juncture of two pipes. The cost of finding and repairing such leaks can be very significant. Accordingly, a reduction in the frequency of such leaks is highly desirable.

Cutting devices according to the prior art are in the U.S. Patent Nos. 5,027,681 ; 6,938,313 ; and 4,412,401 described. However, these devices are not suitable for accurately cutting and chamfering plastic pipes.

The object of the present invention is to provide a new portable device, which is particularly intended for cutting and chamfering of pipes, especially plastic pipes, by means of which device the problems described above are avoided and the device is easy to use while the Cutting or chamfering takes place quickly and accurately.

This object is achieved by means of the device according to the invention mainly characterized in that the elements for rotating and holding the tube from the upper support rolls are formed together with pivotable and supporting guide wheels, in combination with a movable cutting tool comprising the tube both cuts and ants.

In this way, a reliable and inexpensive hand-operated device for cutting and chamfering a pipe, in particular a plastic pipe, created.

Summary of the invention

The present invention provides a pipe cutting device which securely holds a pipe for safe and controlled machining of the pipe and which can be used to clean and accurately cut and chamfer pipes, particularly PVC pipes. However, the device can also be used for cutting and chamfering copper, steel or stainless steel pipes and other plastic pipes.

The invention in one form thereof comprises a device for cutting and chamfering a pipe, such as a plastic pipe. The apparatus includes a lower frame having two lower back-up rollers for rotatably supporting the pipe when laid thereon. Also provided is an upper frame having two upper support rollers to further rotatably support the tube when placed on the lower support rollers and lower the upper support rollers on the tube. The upper frame is part of a clamping assembly for clamping the tube in a secured position between the supporting lower and upper rollers. To rotate the tube, means are provided for rotating one or more of the upper or lower rollers.

Important for the device according to the present invention is at least one guide wheel, which is arranged, for example, either between the two upper rolls or the lower rolls, preferably between the two lower rolls. The guide wheel is forced resiliently and rotatably to the surface of the pipe when the pipe is placed between the upper and lower backup rolls. The wheel is pivotable to guide the tube longitudinally back and forth between the upper and lower support rollers. The present inventor has surprisingly found that such a guide wheel is required not only for guiding the tube between the upper and lower rollers in its longitudinal direction, but also for rotating the tube in a fixed position with respect to the cutting tool used in the present invention.

In contrast to prior art devices, the device according to the present invention uses a cutting tool having a cutting edge and a separate bevel cutting edge. When the cutting tool, and particularly its bevel blade, is pressed against the surface of the tube, it exerts a force on the tube which would move it backwards unless the above-mentioned guide wheel were resiliently urged and forced to the surface of the tube ,

Therefore, the present invention utilizes the combined action of the forces exerted by the upper and lower rolls in conjunction with the guide wheel to counteract the forces exerted by the cutting tool. To fully control these forces, the guide wheel may be pivoted (twisted) with respect to the surface of the pipe to compensate for the variable force exerted by the cutting tool as it is pressed against the surface of the pipe during the cutting and chamfering operation.

In other words, the guide wheel can be pivoted so that the rotation axis of the guide wheel is not parallel (oblique) with respect to the rotation axes of the guide rollers or the pipe. Therefore, the guide wheel can be moved between a first position, in which the axis of rotation of the guide wheel is parallel to the axes of rotation of the support rollers, and a second position, in which the axis of rotation of the guide wheel is not parallel to the axes of rotation of the support rollers.

In particular, when plastic pipes are cut and chamfered, the force applied to the upper back-up roll causes some ovality of the pipe, so that the pipe moves in its longitudinal direction without using the guide wheel. To control this movement and to stop the movement in the correct position, the guide wheel is used because an inclination of the axis of rotation of the guide wheel, which is in contact with the tube, exerts an additional force in the longitudinal direction on the tube. Therefore, any longitudinal movement of the tube can be accelerated, retarded or even stopped by suitable pivoting of the guide wheel.

In a preferred embodiment, the device comprises two guide wheels which are resiliently urged and forced to the surface of the tube. It may be an advantage if both guide wheels have identical axes of rotation.

In one embodiment of the present invention, the apparatus includes a tensioning assembly for clamping the pipe in a secured position between the lower and upper backup rolls. The chuck assembly includes a lever arm pivotally mounted to a frame. A tension member is disposed on the lever arm and pivotal movement of the lever arm moves the tension member between a clamping position in which the tension member locks the tube between the lower and upper rollers and a disengaged position wherein the tension member is spaced from the frame by the frame allowing the pipe to be inserted and removed. A biasing member having a first end fixed relative to the frame and a second end operatively coupled to the lever arm biases the tension member toward the tube when the tension member is positioned near the clamping position and biases the tension member away from the clamping member Pipe before, when the clamping element is positioned near the released position.

An advantage of the present invention is that, by securely clamping the tube, it can reduce inaccuracy in cutting and chamfering the tube caused by warping of the tube or by sliding a wet tube. Features of the present invention which enable secure clamping of the tube individually and in combination facilitate the use of the lower frame with two lower support rollers for rotatably supporting the plastic pipe when laid on it; the upper frame having two upper backup rolls for further rotatably supporting the plastic pipe when laid on the lower backup rolls and the upper backup rolls lowered onto the pipe; and two guide wheels which are disposed between the two lower rollers and resiliently and rotatably urged to the surface of the plastic pipe when the pipe is placed between the upper and lower support rollers, wherein the wheels are rotatable to longitudinally back and forth between the pipe to guide the upper and lower support rollers.

• • Vorsehen eines unteren Rahmens mit zwei unteren Stützwalzen zum drehbaren Stützen des Kunststoffrohrs, wenn es darauf gelegt ist;
• • Vorsehen eines oberen Rahmens mit mindestens einer oberen Stützwalze, um das Kunststoffrohr weiter drehbar zu stützen, wenn es auf die unteren Stützwalzen gelegt ist und die obere Stützwalze auf das Rohr gesenkt ist;
• • Vorsehen von Mitteln zum Drehen einer oder mehrerer der oberen oder unteren Walzen, um das Rohr zu drehen;
• • Vorsehen mindestens eines Führungsrads, das drehbar zur Oberfläche des Kunststoffrohrs gedrängt wird, wenn das Rohr zwischen die oberen und unteren Stützwalzen gelegt ist, wobei das Rad schwenkbar ist, um das Rohr längs vor und zurück zwischen den oberen und unteren Stützwalzen zu führen; und
• • Vorsehen eines verschiebbaren Schneidwerkzeugs mit einer Schneide und einer getrennten Fasenschneide; wobei
• • das Rohr so zwischen den oberen und unteren Walzen eingespannt ist, dass es einen elliptischen Querschnitt erhält;
• • das Schneidwerkzeug gegen die Oberfläche des sich drehenden Rohrs gedrückt wird, während die Führungsräder so geschwenkt sind, dass die durch das Schneidwerkzeug ausgeübte Kraft kompensiert wird, wodurch das Rohr während des Schneidens und Anfasens in derselben Stellung gehalten wird.

In another aspect of the present invention, there is provided a method of cutting and chamfering a plastic tube, the method comprising the steps of:

• Providing a lower frame with two lower back-up rollers for rotatably supporting the plastic pipe when placed thereon;
• Providing an upper frame with at least one upper back-up roll for further rotatably supporting the plastic pipe when laid on the lower back-up rolls and the upper back-up roll is lowered onto the pipe;
• Providing means for rotating one or more of the upper or lower rollers to rotate the tube;
• Providing at least one guide wheel which is rotatably urged to the surface of the plastic pipe when the pipe is placed between the upper and lower support rollers, the wheel being pivotable to guide the pipe longitudinally back and forth between the upper and lower support rollers; and
• • providing a slidable cutting tool with a cutting edge and a separate bevel cutting edge; in which
• • the pipe is clamped between the upper and lower rolls to give it an elliptical cross-section;
• The cutting tool is pressed against the surface of the rotating tube while the guide wheels are pivoted so as to compensate for the force exerted by the cutting tool, thereby maintaining the tube in the same position during cutting and chamfering.

Short description of the drawing

1 is an overall view of the device for cutting and chamfering a plastic pipe according to the present invention.

2 is a side view of the device.

3 is an overall view of the device, wherein the tube to be cut and to be probed tube is inserted.

Detailed description of the invention

General views of a pipe cutting device ( 1 ) according to the present invention are in the 1 and 3 shown while 2 a side view of the device is.

In a preferred, in the 1 - 3 In the embodiment shown, the device ( 1 ) a lower frame ( 10 ) with two lower support rollers ( 2 ) for rotatably supporting the pipe ( 6 ), when placed on it, together with an upper frame ( 9 ) with upper support rollers ( 3 ) for further rotatable support of the tube ( 6 ), when it is inserted (see 3 ). The upper frame ( 9 ) is part of a clamping assembly ( 10 ) for clamping the tube ( 6 ) in a secured position between the supporting lower ( 2 ) and upper ( 3 ) Rolls. To the pipe ( 6 ), means are provided for rotating one or more of the upper or lower rollers (not shown).

Two guide wheels ( 4 ) are between the two lower rollers ( 2 ) arranged. The guide wheels ( 4 ) are resilient and rotatable to the surface of the tube ( 6 ) forced / pushed when the pipe ( 6 ) between the upper ( 3 ) and lower ( 2 ) Backup rolls is placed. The wheels ( 4 ) are pivotable around the pipe ( 6 ) along back and forth between the lower ( 2 ) and upper ( 3 ) To guide back-up rolls.

In the 1 and 3 are two upper rollers ( 3 ) for directly supporting the pipe ( 6 ) and are in a framework ( 9 ), which via a lever arm ( 10 ) can be raised or lowered. Two lower rollers ( 2 ) are also provided to provide a lower support of the tube ( 6 ). The device ( 1 ) contains at least one driven roller while the others are non-driven rollers or idlers. Guide wheels ( 4 ) are also provided to ensure that the pipe ( 6 ) is held in the same position during the cutting and chamfering process. The guide wheels ( 4 ) as well as the upper ( 3 ) and the lower ( 2 ) Rollers couple directly to the pipe ( 6 ) and support it. The upper rollers ( 3 ) are over a frame ( 9 ) on a lever arm ( 10 ), where they form a pipe clamping element together with the lever arm. The lever arm ( 10 ) is pivotable on the frame ( 9 ) and moves the upper rollers ( 3 ) into and out of coupling with a pipe ( 6 ). 3 shows the upper rollers ( 3 ) in a clamping position, wherein the rollers with the tube ( 6 ) are mounted on the lower rollers ( 2 ) rest.

The device has a cutting tool ( 5 ) which is slidable and has a cutting edge and a separate chamfer cutting edge. In a preferred embodiment, the device has at least two cutting edges which can optionally be used, depending on the material of the tube. For example, the device may include a turret ring with at least two positions that allows the use of the different cutting edges. The cutting tool may be located between the two upper backup rolls.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5027681 [0005]
• US 6938313 [0005]
• US 4412401 [0005]

Claims (10)

Contraption ( 1 ) for cutting and chamfering a pipe ( 6 ), comprising: a lower frame ( 10 ) with two lower support rollers ( 2 ) for rotatably supporting the plastic pipe ( 6 ), if it is laid on it; An upper frame ( 9 ) with at least one upper support roller ( 3 ) to the plastic pipe ( 6 ) to further rotatably support, when it on the lower support rollers ( 2 ) and the upper support roller ( 3 ) is lowered onto the pipe; • means for rotating one or more of the upper ( 3 ) or lower ( 2 ) Rollers to the plastic tube ( 6 ) to turn; • a guide wheel ( 4 ) rotatable to the surface of the plastic tube ( 6 ) is urged when the pipe ( 6 ) between the upper ( 3 ) and lower ( 2 ) Is placed, whereby the wheel ( 4 ) is pivotable to the pipe ( 6 ) along back and forth between the lower ( 2 ) and upper ( 3 ) To guide back-up rolls; and a sliding cutting tool ( 5 ) with a cutting edge and a separate bevel cutting edge. Apparatus according to claim 1, comprising two guide wheels, preferably arranged on holding elements between the two lower support rollers. Device according to claim 1 or 2, wherein the upper frame comprises two upper support rollers ( 3 ). Contraption ( 1 ) according to any one of claims 1-3, wherein the means for rotating one or more of the upper or lower rollers is an electric motor comprising one of the support rollers ( 2 . 3 ) either directly or via a transmission means, such as a belt. Contraption ( 1 ) according to claim 3 or 4, wherein the holding elements are forks. Contraption ( 1 ) according to any one of claims 1 to 5, wherein the guide wheels ( 4 ) with a stem ( 7 ) are pivotally connected to the holding elements. Apparatus according to claim 5 or 6, comprising a friction element in contact with the holding elements or the stem ( 7 ), wherein the friction element is arranged to allow a manual movement of the stem and prevent movement in a situation in which no force on the stem ( 7 ) is exercised. Contraption ( 1 ) according to any one of claims 1 to 7, wherein the cutting tool ( 5 ) by means of a stem ( 8th ) is displaceable. Contraption ( 1 ) according to any one of claims 1 to 8, wherein the separate bevel cutting edge of the cutting tool ( 5 ) at an angle of less than 90 degrees and more than 0 degrees to the direction of rotational movement of the tube and is substantially in such a plane through the axis of rotation that with the bevel cutting bevels on the cut edge of the tube ( 6 ) can be generated. Method for cutting and chamfering a pipe ( 6 ), the method comprising the following steps: providing a lower frame ( 10 ) with two lower support rollers ( 2 ) for rotatably supporting the plastic pipe ( 6 ), if it is laid on it; • providing an upper frame ( 9 ) with at least one upper support roller ( 3 ) to the plastic pipe ( 6 ) to further rotatably support, when it on the lower support rollers ( 2 ) and the upper support roller ( 3 ) is lowered onto the pipe; Providing means for rotating one or more of the upper or lower rolls around the plastic pipe ( 6 ) to turn; Providing at least one guide wheel ( 4 ) on holding elements between the two lower rollers ( 2 ) and rotatable to the surface of the plastic tube ( 6 ) is pushed when the tube between the upper ( 3 ) and lower ( 2 ) Is placed, whereby the wheel ( 4 ) is pivotable to the pipe ( 6 ) along back and forth between the lower ( 2 ) and upper ( 3 ) To guide back-up rolls; and • providing a slidable cutting tool ( 5 ) with a cutting edge and a separate bevel cutting edge; where the pipe ( 6 ) between the upper ( 3 ) and lower ( 2 ) Rollers is clamped so that it receives an elliptical cross-section; • the cutting tool ( 5 ) against the surface of the rotating tube ( 6 ) while the guide wheel ( 4 ) is pivoted so that by the cutting tool ( 5 ) force is compensated, whereby the pipe ( 6 ) is kept in the same position during cutting and chamfering.

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