Rotary grooving tool

Abstract

A grooving device 1 is configured to roll grooves 994 into a pipe 99. The grooving device 1 comprises a fixture 50 and a grooving tool 10. In its fixing position, the fixture 50 engages with the inner wall 996 of the pipe 99 such that the central axis X1 of the grooving device 1 and the central axis X99 of the pipe 99 are coaxial, thereby fixing the grooving device 1 to the pipe end 990. The grooving tool 10 is rotatable around the central axis X1. The grooving tool 10 comprises a hydraulic piston 12 and at least one wheel holder 110. The hydraulic piston 12 is displaceable along the central axis X1 and is configured to displace the wheel holder 110 radially with respect to the central axis X1 between a resting position 1102 and a grooving position 1104. The wheel holder 110 comprises a grooving wheel 111.

Description

Technical Field

[0001] The present invention relates to a tool for grooving pipes. More specifically, the present invention relates to a grooving apparatus configured to roll an outer circumferential groove on an end of a pipe. The grooving apparatus defines a central axis. The grooving apparatus comprises a fixing member and a grooving tool. The fixing member is configurable between a release position and a fixing position. In the fixing position, the fixing member is configured to engage with an inner wall of the pipe such that the central axis of the grooving apparatus is coaxial with the central axis of the pipe, and fixes the grooving apparatus to the end of the pipe. The grooving tool is rotatable about the central axis.

Background Art

[0002] It is known for axially joining pipes to form a watertight joint that a groove is formed at each end of the pipes, and the pipes are connected by a metal joint that meshes with the grooves. A gasket is usually arranged between the pipes and the joint.

[0003] The groove is completed by rotating the pipe in the grooving tool or rotating the tool around the pipe, wherein one or more rollers apply a radial force to the outside of the pipe. The rollers impart radial deformation to the pipe, whereby the groove is formed on the peripheral edge of the pipe, and the corresponding inner portion receives the protrusion.

[0004] British Patent No. 2014072 discloses a stationary rotary cutting grooving tool comprising a pair of rollers rotatable about substantially parallel axes, one of the rollers is a driven motor and the other is freely rotatable. The driven roller is arranged inside the pipe, while the freely rotatable roller is arranged outside. During the grooving process, the pipe rotates around the driven roller, and the freely rotatable roller applies a deforming force to the outside of the tube.

[0005] Japanese Patent Laid-Open No. 2000-210723 discloses a grooving tool comprising a plurality of rollers that apply a radial force to a pipe. This tool does not have an inner support.

[0006] European Patent No. 1275447 discloses a portable rotary cutting groover in which the grooving operation is performed manually by rotating a crank. In one embodiment, the pipe is a rigidly supported pipe, so the portable rotary cutting groover rotates around the pipe. In an alternative embodiment, the portable rotary cutting groover is rigidly fixed, and the pipe to be grooved rotates relative to the pipe during the grooving operation.

[0007] International Publication No. 03 / 089159 discloses a circumferential rotary cutting groover for pipes. The circumferential rotary cutting groover is mounted on a table and includes adjustment means for positioning the circumferential rotary cutting groover on a pipe. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] British Patent No. 2014072 [Patent Document 2] Japanese Patent Publication No. 2000-210723 [Patent Document 3] European Patent No. 1275447 [Patent Document 4] International Publication No. 03 / 089159

[0009] Prior art driven rotary cutting and grooving tools have several drawbacks. Stationary tools require the pipe to be brought to the tool. This is time-consuming and often causes problems when working on construction sites where long pipes must be brought through door openings and from one floor to another. The rotation of the pipe is also a disadvantage. Rotating pipes require special supports that must be fixed against twisting if the pipe's central axis does not coincide with its axis of rotation.

[0010] The disadvantages of portable rotary cutting groovers are that they are heavy for prolonged use, and the crank's center does not coincide with the center of the pipe, meaning the crank rotates in a spiral motion. These groovers also require the pipe to be tightly clamped, for example, using a vise. [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] The present invention aims to eliminate or mitigate at least one of the drawbacks of the prior art, or to provide at least a useful alternative to the prior art. [Means for solving the problem]

[0012] This objective is achieved by the features specified in the following description and subsequent claims.

[0013] The present invention is defined by the independent claims of the patent. The dependent claims define advantageous embodiments of the present invention.

[0014] A first aspect of the present invention relates, more specifically, to a grooving device configured to roll an outer circumferential groove on the end of a pipe. The grooving device forms a central axis. The grooving device comprises a fixture and a grooving tool. The fixture can be configured between a release position and a fixing position. In the fixing position, the fixture is configured to engage with the inner wall of the pipe such that the central axis and the central axis of the pipe are coaxial, thereby fixing the grooving device to the end of the pipe. The grooving tool is rotatable about the central axis, - The grooving tool comprises a hydraulic piston and at least one wheel holder, - The hydraulic piston is displaceable in the direction along the central axis, - The hydraulic piston is configured to displace the wheel holder radially with respect to its central axis between the resting position and the grooved position. - The wheel holder is equipped with a grooved wheel.

[0015] The hydraulic piston may be displaceable parallel to its central axis.

[0016] The pipe may be a metal sprinkler pipe. The grooving depth may be set by the stroke length of the hydraulic piston. The pipe wall thickness is typically 3-5 mm. The advantage of a rotating grooving tool relative to the housing and pipe is that both the device and the pipe are stationary, i.e., not rotating. Because the pipe is not rotating, there is no risk of twisting, and grooving can be performed on curved pipes. This makes the device more versatile than stationary grooving tools, improving the health and safety of the operator.

[0017] The grooving device is handheld and does not need to be fixed in a static installation. Therefore, it is advantageous for the grooving device to have small external dimensions. The fact that the hydraulic piston is displaceable along the central axis allows for a piston region that does not substantially increase the external dimensions of the grooving device. Thus, a hydraulic piston that is displaceable along the central axis can be compact and have small external dimensions. A larger piston region of the hydraulic piston produces several other effects, which are described below. The hydraulic piston can be located within a cylinder bore. The cylinder bore may need to be filled with hydraulic fluid to displace the hydraulic piston. Compared to a smaller piston region, a larger piston region requires more hydraulic fluid to displace the hydraulic piston over a given distance. A larger volume of hydraulic fluid allows the fluid flow rate to be kept larger for a given displacement velocity, making it easier to displace the piston at an equal and constant speed. Thus, the wheel holder can be displaced at a controlled speed. Another effect is that the hydraulic pressure required to produce a given piston force is reduced in a larger piston region compared to a smaller piston region. This reduces wear on the hydraulic pump that supplies the working fluid and reduces distortion of internal components, such as the cylinder bore.

[0018] The wheel holder may be equipped with a grooving wheel. The grooving wheel may have ridges, with each side of the ridge having a smaller diameter. The effect of the smaller diameter on each side of the ridge is that the grooving depth can be set and limited by the smaller diameter that engages with the outer wall of the pipe. The grooving depth can be set by a combination of the stroke length of the hydraulic piston and the smaller diameter on each side of the ridge.

[0019] A larger diameter grooving wheel allows for the rolling of circumferential grooves on the pipe end with less force compared to a smaller diameter grooving wheel. This is known to those skilled in the art. A larger piston area of ​​a hydraulic piston displaceable along the central axis allows for a larger grooving wheel within the wheel holder without increasing the external dimensions of the grooving device. The grooving device may comprise a single hydraulic piston displaceable parallel to the central axis or multiple hydraulic pistons displaceable along or parallel to the central axis.

[0020] The hydraulic piston may be biased toward its starting position. The biasing means may be a single spring or multiple springs. A larger piston area allows for the use of a larger spring compared to what would be possible with a smaller piston area. A larger, and therefore stronger, spring allows the hydraulic piston to return to its starting position more quickly compared to a weaker, smaller spring. Thus, the grooving device is more efficient to use because the grooving wheel returns to its starting position simultaneously, thereby freeing the pipe from the grooving device.

[0021] The hydraulic piston is configured to displace the wheel holder radially relative to the central axis between a rest position and a grooving position. In the rest position, the hydraulic piston may be in a starting position, and the grooving wheel may be positioned at a distance from the pipe, that is, in a form where there is a gap between the grooving wheel and the pipe. The wheel holder may be provided with a protrusion, and the hydraulic piston may be provided with a recess. The protrusion may be placed in the recess, and may be formed in such a manner that radial displacement of the wheel holder is generated by axial displacement of the hydraulic piston. The protrusion and the recess may form an angle with the central axis, such that the wheel holder is displaced radially when the hydraulic piston is displaced parallel to the central axis. It is obvious to a person skilled in the art that multiple alternative embodiments can be configured to radially displace the wheel holder when the hydraulic piston is moved along or parallel to the central axis. One example may be such that the hydraulic piston is provided with a protrusion and the wheel holder is provided with a recess.

[0022] In the grooving position, the hydraulic piston is displaced such that the grooving wheel is adjacent to the pipe and starts to form a groove in the pipe. The grooving position may be a dynamic position where the wheel holder is displaced as the groove becomes deeper.

[0023] In a preferred embodiment, the grooving tool may be provided with at least three wheel holders. Two grooving wheels can push the pipe out from the center when the pipe is not precisely aligned with the central axis of the pipe. The advantage of having three or more grooving wheels is that three or more grooving wheels are self-centering. Accordingly, the wheel holders can be displaced at a uniform speed such that radial forces are retained within the pipe and not absorbed by the fixture.

[0024] The grooving tool may include a base element, and the wheel holder may be connected to the base element and be radially displaceable. The base element may have a slot in which a projection of the wheel holder can be radially displaced internally. The base element can receive rotational force and thus transmit this rotational force to the wheel holder attached to the base element. The hydraulic piston may be displaceable along or parallel to the central axis relative to the base element. Thus, the base element can be used to limit the stroke length of the hydraulic piston. The base element may also be used as an opposing component to bias the hydraulic piston in a way that returns it to its starting position. The effect of the above technical features relating to the base element may be that, due to the compact design, the number of parts that rotate relative to each other is reduced.

[0025] The base element may also be used to guide the working fluid from the hydraulic pump to the cylinder bore.

[0026] The grooving device may be configured to receive rotational force from a drive shaft. The drive shaft may be offset from the central axis. The grooving device may be configured to receive working fluid from a pressure line. Because the drive shaft is offset, the center of the device does not include a rotating member, which can reduce the complexity of the fixtures. Using working fluid from a pressure line reduces distortion, allowing the operator to displace the hydraulic piston.

[0027] A drive shaft offset from the central axis can transmit rotational force to the grooving device. The grooving tool may include an internal spur gear section. The base element may be firmly connected to the internal spur gear section for rotation. Thus, the drive shaft can rotate the grooving tool with less complexity of fixtures compared to a drive shaft coaxial with the central axis.

[0028] The fixture may be constructed by displacing a shaft parallel to the central axis. This makes it possible to use fixtures similar to those known in the art. By displacing the shaft, the fixture can be operated at a location remote from where the grooving tool can rotate.

[0029] The rotational force and the flow of the working fluid may be supplied by a battery-powered power unit. The grooving device and power unit may be handheld. The grooving device and power unit can be handheld because it allows for a more compact design. The advantage of a handheld grooving device is that it can be more easily positioned to properly align with the pipe, especially when the pipe is long. Being handheld also allows the user to move freely between locations where the grooving device is needed. By using battery power to supply power to the grooving device, the user can move freely between locations without needing a power source in different locations.

[0030] The grooving tool may include a visual indicator that shows the position of the hydraulic piston within the cylinder bore, thereby indicating the groove depth or when the groove is complete.

[0031] Hydraulic pumps and drive mechanisms that may be connectable to a power unit are also described. The hydraulic pump and drive mechanism may comprise a hydraulic pump, a fluid container, and a pressure line. The hydraulic pump may be connected to the fluid container and the pressure line. The hydraulic pump and drive mechanism may comprise a rotatable input shaft that is connectable to a power unit and configured to rotate the hydraulic pump. The hydraulic pump and drive mechanism may comprise a drive shaft configured to be rotated by the input shaft. The drive shaft may be offset from the input shaft.

[0032] The aforementioned hydraulic pump and drive mechanism may be a first embodiment of the hydraulic pump and drive mechanism. The hydraulic pump and drive mechanism can be mounted on the device. The device may have various specifications that need to be considered. In some devices, the power unit may need to be adapted to the device. In other devices, the power unit may need to be angled so that the length of the hydraulic pump and drive mechanism assembled with the power unit is shorter.

[0033] In a second embodiment of the hydraulic pump and drive mechanism, the position of the input shaft relative to the drive shaft may not be so important. The hydraulic pump and drive mechanism can be driven by a power unit, and the hydraulic pump and drive mechanism may comprise a hydraulic pump, a fluid container, and a pressure pipeline, and the hydraulic pump can be connected to the fluid container and the pressure pipeline. - The rotatable input shaft may be connectable to the power unit. - The input shaft may be configured to rotate the hydraulic pump. - The input shaft may be configured to rotate the drive shaft. - The hydraulic pump and drive mechanism may have a mounting portion at the distal end opposite the input shaft, the mounting portion may form a central axis, and may include a drive shaft and a pressure pipeline, and the drive transmission system may be offset from the central axis.

[0034] In the second embodiment, the input shaft may be offset from the drive shaft.

[0035] The following description is equally applicable to the first and second embodiments of the hydraulic pump and drive mechanism.

[0036] The hydraulic pump and drive mechanism may be part of a handheld device. A rotatable input shaft may be connected to a power unit so that the power unit needs to be disassembled from the hydraulic pump and drive mechanism. The rotatable input shaft may be connected to the power unit by a quick-release connector so that the power unit can be used with other tools when the hydraulic pump and drive mechanism are not in use. The power unit may be battery-powered. The power unit may be a handheld drill known in the art. The effect of this is that the hydraulic pump and drive mechanism can be configured between multiple devices and can be easily transported and used by the user.

[0037] Hydraulic pumps and drive mechanisms may be used in a variety of devices that utilize the flow of hydraulic fluid and rotational force. These diverse devices may have a variety of operating parameters. The operating parameters of the drive shaft may be the rotational speed and / or torque of the drive shaft. The operating parameters of the hydraulic pump may be the fluid flow rate and / or hydraulic pressure, depending on the specifications of the hydraulic pump. Therefore, the hydraulic pump and drive mechanism may need to be configured such that a single input shaft can accommodate both the operating parameters of the drive shaft and the hydraulic pump. Various embodiments may be required depending on the operating parameters. Several embodiments are described below.

[0038] One embodiment is one in which the input shaft can be connected to a through shaft, or is a through shaft within a hydraulic pump. The through shaft may be firmly connected to a spur gear section for rotation, and rotates the spur gear section that is firmly connected to the drive shaft for rotation. The spur gear section may be used to match the rotational speed and torque of the drive shaft so that the hydraulic pump can rotate at a first rotational speed and a first torque, and the drive shaft can rotate at a second rotational speed and a second torque.

[0039] The drive shaft may be parallel to the input shaft. This allows for the use of spur gears to match the rotational speed and torque between the input shaft and the drive shaft, even though the drive shaft is offset from the input shaft. In some cases, the spur gears do not match the rotational speed and torque, but rather simply offset the drive shaft from the input shaft. Spur gears can be used to transmit rotational force from the input shaft to multiple drive shafts. The hydraulic pump and drive mechanism may have two drive shafts, also known as a dual drive system. The advantage of a dual drive system is that the force can be distributed to the two drive shafts by related gears.

[0040] The hydraulic pump may be configured such that the drive shaft rotates via a rotationally rigid coupling between the hydraulic pump and the drive shaft. The effect of this is that the drive shaft can rotate at the same rotational speed as the hydraulic pump in this embodiment. The hydraulic pump and drive mechanism may include a reduction gear and an intermediate shaft. The input shaft may include a first spur gear that rotates a second spur gear. The second spur gear may be rotationally rigidly coupled to the intermediate shaft. The first and second spur gears can reduce the rotational speed of the intermediate shaft compared to the input shaft. The intermediate shaft may be rotationally rigidly coupled to the hydraulic pump, causing the hydraulic pump to rotate. The effect of this is that the hydraulic pump may rotate at a lower speed than the input shaft. The term "rotationally rigidly coupled" in this specification refers to two parts that may be detachable at some point, e.g., a screw-fastened coupling or a pin-fastened coupling, or two parts that may be permanently coupled, e.g., by welding, or one part may be machined as part of the other. The intermediate shaft may be, for example, a shaft machined as part of a second spur gear section or a hydraulic pump.

[0041] In an alternative embodiment, the hydraulic pump may be an external gear pump, which is known in the art. The intermediate shaft may be rotationally fixed between the first pump gear and the reduction gear in the external gear pump, and the drive shaft may be rotationally fixed to the second pump gear in the external gear pump. The effect of this is that the external gear pump can be used to offset the drive shaft from the input shaft without using a special spur gear section or having an unnecessarily large spur gear section. Thus, the three-dimensional arrangement between the input shaft and the drive shaft allows the hydraulic pump and drive mechanism to be compact, lighter, and easier to handle.

[0042] The hydraulic pump and drive mechanism may include two external gear pumps. The effects of having two external gear pumps are that the fluid discharge rate may be doubled, redundancy in the hydraulic system may be increased, or two separate hydraulic circuits may be formed. The two external gear pumps can each be connected to one drive shaft so that two drive shafts may be present in the drive mechanism. The two external gear pumps can be configured in parallel or in series. The effect of a parallel configuration may be that the flow rate of the hydraulic fluid is increased compared to a single external gear pump. The effect of a series configuration may be that the hydraulic pressure is increased compared to a single external gear pump.

[0043] The hydraulic pump and drive mechanism may be equipped with a lever. The lever may be configurable between an active position and a passive position. The lever can be used to enhance safety when using the hydraulic pump and drive mechanism. This can be done by activating or deactivating parts of the hydraulic pump and drive mechanism and / or parts of a device connected to the lever. The connected device is a device connected to the hydraulic pump and drive mechanism. In the passive position, the pressure line can be connected to a fluid container, and in the active position, the pressure line can be disconnected from the fluid container. The effect of this is that the hydraulic pump is unavailable in the passive position to create hydraulic pressure when the working fluid is introduced into the fluid container. In the active position, the hydraulic pump can create a flow of working fluid and hydraulic pressure in the pressure line. The lever may be configured to displace a shaft in a direction parallel to the drive shaft between a first position and a second position. A lever in the passive position configures the shaft to the first position. A lever in the active position configures the shaft to the second position. The shaft can form a shaft axis. The shaft axis may be coaxial with the central axis of the mounting part. The drive shaft may be offset from the shaft. The shaft can be connected to a connected device. The shaft in the second position can activate the function of the connected device. The shaft in the first position can deactivate the function of the connected device.

[0044] The lever may be a handle that can be rotated around a pivot point, a sliding switch, or a push-button.

[0045] The hydraulic pump and drive mechanism may be small and handheld. This may suggest that the hydraulic pump and drive mechanism can be oriented in all possible directions. Therefore, it is beneficial to seal the fluid container from the surrounding environment to prevent fluid from dripping through ventilation holes. When the fluid is transferred from the hydraulic pump into the connected device, the volume of the fluid in the fluid container may change. This needs to be compensated so that the hydraulic pump can operate according to its specifications. The fluid container can be connected to a volume compensation device. Fluid containers and volume compensation devices can exist in many embodiments and will be described in more detail later.

[0046] A pressure line can be connected to at least one of a safety valve and / or a flow regulator. The pressure line may also be part of a hydraulic circuit. A hydraulic pump can bring a flow of working fluid into the pressure line so that hydraulic pressure can be generated. The effect of connecting a safety valve to the pressure line is that it ensures the hydraulic pressure does not exceed a predetermined pressure. This is a safety feature. The effect of connecting a pressure line to a flow regulator is that the flow rate of working fluid from the hydraulic pump can be set to a predetermined flow velocity. This improves the operation of the connected equipment.

[0047] The hydraulic pump and drive mechanism can be configured to be connected to a rotatable device. The hydraulic pump can be connected to the rotatable device via one or more hydraulic lines. The shaft can be connected to the rotatable device. The drive shaft can be connected to the rotatable device and transmit rotational force to the rotatable device. The rotatable device may be a grooving device.

[0048] A robust fluid container for the working fluid is also described, and the robust fluid container comprises a robust housing and a discharge port. - A robust fluid container can be sealed against the surrounding environment. - A rigid fluid vessel may be equipped with an inflatable device, and the inflatable device may be installed within a rigid housing. - Inflatable devices can communicate with the surrounding environment through through-holes in their rigid housings.

[0049] The through-hole may be a hole that penetrates a wall forming a rigid enclosure.

[0050] The fluid may be oil used in hydraulic instruments.

[0051] The advantage of a rigid fluid container being sealed from the surrounding environment is that it can be positioned in any orientation without leakage from ventilation holes. This is particularly beneficial when the rigid fluid container is connected to or part of a handheld device. Inflatable devices can inflate or deflate depending on whether fluid is being drawn from or replenished into the rigid fluid container. Thus, inflatable devices provide volume compensation.

[0052] Inflatable devices expand or contract when a fluid is drawn from or returned to a rigid fluid container. To expand an inflatable device, air from the surrounding environment is drawn into the device. To contract an inflatable device, air is exhausted from the device into the space around the rigid fluid container. Expansion and contraction occur due to the pressure difference created by the fluid being drawn from or returned to the rigid housing. The effect of using air from the surrounding environment to expand or contract an inflatable device is that it reduces complexity by eliminating the need for an inflatable device to be inflated to a predetermined pressure.

[0053] Air drawn into the inflatable device from the surrounding environment may be contaminated, causing debris to accumulate inside the device over time. Through-holes can be installed in the outer cover. The effect of this is that a barrier may exist between the inflatable device and the debris in the surrounding air. The outer cover may be a filter or a mesh. The outer cover may be part of the device.

[0054] Inflatable devices may include flexible material. Inflatable devices may be bags or balloons. Inflatable devices may be equipped with metal bellows.

[0055] When a rigid fluid container is used in a handheld device, it is beneficial to have a rigid fluid container that is as compact as possible in dimensions. The inflatable device may have a longitudinal axis. The longitudinal axis may extend from a through hole to the distal end opposite the inflatable device. The inflatable device can be expanded along the longitudinal axis. The longitudinal axis may be parallel to the shaft. The shaft can be configured to expand from inside the rigid fluid container to a device outside the rigid fluid container. The shaft can extend through the rigid fluid container.

[0056] The rigid fluid container may be part of the hydraulic pump and drive mechanism.

[0057] In a second aspect, the present invention relates more particularly to a grooving system configured to roll an outer circumferential groove on a pipe end, - The grooving system comprises a grooving device according to a first aspect of the present invention, - The grooving system comprises a hydraulic pump and drive mechanism, a fluid container, and a fixing device. - The hydraulic pump and drive mechanism are connected to a power unit and configured to receive rotational force from the power unit via an input shaft. - The hydraulic pump and drive mechanism are configured to produce an output, which includes the flow of working fluid and rotational force, and the output is transmitted to the grooving device. - The fixture forms the central axis of the fixture, which is coaxial with the central axis of the grooving tool. - The fastener is configured to engage with the inner wall of the pipe and secure the pipe end to the grooving device.

[0058] The hydraulic pump and drive mechanism may be connected to the grooving device so that the drive shaft and hydraulic circuit can transmit force to the grooving tool in the grooving device. Fixing devices may be configured within the hydraulic pump and drive mechanism via levers.

[0059] The hydraulic pump and drive mechanism may be equipped with means for increasing torque and decreasing the rotational speed from the power unit to the grooving tool. The effect of this is that the rotational speed (revolutions per minute - rpm) and torque from the power unit can be adjusted to provide precise rpm and torque for the grooving tool. The rotational speed of a power unit, such as a handheld drill connected to the device, is typically 600-700 rpm. The rotational speed of the grooving tool is typically 60 rpm. Therefore, the hydraulic pump and drive mechanism can be configured to reduce the rpm by approximately 85-90%. Gear ratio adjustment can be performed by gears. Gear ratio adjustment can be performed by belts or chains. Gear ratio adjustment can be performed in one or more steps.

[0060] The hydraulic pump and drive mechanism may have at least one drive shaft positioned offset from the central axis of the grooving tool. The effect of this is that the fixture may be less complex because the drive shaft is offset from the central axis of the fixture. The hydraulic pump and drive mechanism may have two drive shafts offset from the central axis of the fixture. This is referred to as a dual drive system. The advantage of a dual drive system is that the force can be distributed to the two drive shafts by associated gears.

[0061] The drive shaft may be connected at a first end to a set of gears configured to transmit force from the input drive shaft to a drive shaft offset from the central axis of the grooving tool. The drive shaft may be connected at a second end to an internal spur gear by internal teeth. The effect of the internal teeth is that the drive shaft can be positioned closer to the central axis of the grooving tool compared to embodiments in which the ring gear has external teeth. This results in a more compact grooving system.

[0062] The hydraulic pump and drive mechanism may include a set of gears configured to transmit force from the input shaft to one or more drive shafts offset from the central axis of the grooving tool.

[0063] The fixture may comprise a plurality of segmented sections that are radially displaceable by an eccentric coupling connected to a shaft. The shaft may be displaceable along the central axis of the fixture. The fixture may comprise a plurality of segmented sections connected to several corresponding conical sections connected to the shaft. As the shaft is displaced along the central axis of the fixture, the conical sections guide the segmented sections radially, outward, or inward. In one preferred embodiment, the fixture may comprise three or more segmented sections, so that the three or more segmented sections move toward the center of the pipe.

[0064] The eccentric coupling may be operated by a lever. The lever may be accessible from the outside. The effect of this is that the lever allows for a greater torque to displace the eccentric coupling compared to, for example, a small screw or button. To achieve the same torque with a screw, the screw must have the same radius as the length of the lever. The lever also provides very good visibility of the position of the eccentric coupling. If the axial displacement of the eccentric coupling is equal to a 180-degree rotation of the shaft acting for the eccentric coupling, the position of the lever clearly indicates the position of the eccentric coupling, thereby allowing the user to confirm the arrangement of the fixed part.

[0065] The grooving system may further include a lever locking mechanism to prevent the fixing part from unintentionally disengaging from the inner wall of the pipe.

[0066] The grooving system may be configured to be handheld. Handheld, as used herein, means that the grooving system and / or power unit are designed to be held in one hand. The grooving system may have a net weight of approximately 3 to 10 kg.

[0067] The power unit may be an eccentric motor. The power unit may be a handheld drill, possibly a standardized drill. The advantage of being handheld is that the grooving system can be moved to the pipe and the grooving work can be performed on a fixed pipe. The space required for grooving is equal to the dimensions of the grooving system. The invention described herein provides a much more flexible and efficient grooving operation compared to prior art stationary and manual grooving tools.

[0068] The method for creating grooves in pipes is also described, and this method is, - A step of providing a grooving system according to a second aspect of the present invention, - The step of setting the lever to a passive position, - The step of installing the device at the end of the pipe, - The steps include setting the lever to the active position so that the fastener secures the grooving device to the end of the pipe, - While the hydraulic piston is moving the wheel holder from the resting position to the grooved position, the power unit is activated to rotate the wheel holder around the end of the pipe. - The step of continuing to rotate the wheel holder at the end of the pipe to complete the groove. Includes.

[0069] A fastener that engages with the inner wall of the pipe end and secures the pipe end to the device is also described, and the fastener is, - A shaft forming a longitudinal axis coaxial with the central axis of the device, which is axially displaceable along the axis in the direction of D1 and the opposite direction of D2, - Each of the segmented parts is radially displaceable between a release position and a fixed position, and each segmented part has a wedge-shaped inner surface and an outward-facing retaining surface, - A conical portion having a tapered wedge surface that contacts a wedge-shaped inner surface, and which is engaged with the shaft, - A release spring element that biases the segmented portion axially to the release position, It may be equipped with, When the cone portion is displaced axially in the direction D1 relative to the segmented portion, the segmented portion can be displaced radially outward toward the inner wall. When the cone portion is displaced axially in the direction D2 relative to the segmented portion, the segmented portion can be displaced radially inward toward the central axis. The conical portion may have a hole in the center of the cone, and the conical portion may be slidably engaged with the shaft in the hole in the center of the cone, and the fastener may have a stationary spring element, which can contact the cone and bias the cone axially in the direction D1.

[0070] The end of the pipe may form the central axis of the pipe. The device may form the central axis of the device. The fastener can be configured to fix the end of the pipe to the device such that the central axis of the fastener can be coaxial with the central axis of the pipe and the central axis of the device.

[0071] When the shaft is displaced in the direction of D1, the segment engages with the inner wall of the pipe, and the fastener is in the active / fixed position. When the shaft is displaced in the direction of D2, the segment disengages from the inner wall of the pipe, and the fastener is in the passive / released position.

[0072] The fastener may be configured to radially displace the segmented portion outward between a release position and a fixed position. The segmented portion may be made of a rigid material. The segmented portion may be made of a gripping surface configured to grip the inner wall of the pipe. The gripping surface may include a grooved surface, a toothed surface, or a serrated surface. A radial force can be used to radially displace the segmented portion and engage with the inner wall so that the pipe end is fixed to the device. When the segmented portion is radially displaced from the release position to the fixed position, the radial displacement may create a gap between the segmented portions. If the radial force is large compared to the thickness of the pipe, the pipe may be deformed and form a non-circular shape. For example, a fastener with two segmented portions may form an elliptical pipe, i.e., a pipe with two protrusions, and a fastener with three segmented portions may form a pipe with three protrusions, and so on.

[0073] By using a conical section to displace the segmented section radially, the conical section can take advantage of the mechanical benefits associated with the wedge section. This reduces the axial force required to securely fasten the end of the pipe to the device.

[0074] The gripping surface of the segmented portion may be part of a perfect circle in the fixed position, and the fixed position positions the segmented portion to engage with the inner wall of the pipe by forming a virtual circular circumference. The virtual circumference of the segmented portion may be similar to or substantially similar to the inner circumference of the pipe wall. The effect of the segmented portion forming a virtual circular circumference is that deformation of the pipe is minimized when the fastener engages with the inner wall of the pipe. This is important when the fastener fixes the end of the pipe while cutting or forming the outer circumference of the pipe near the end of the pipe. In the release position, the segmented portion may be positioned to form a virtual circumference when released, and this virtual circumference when released may form a non-uniform circumference. The non-uniform circumference can be formed by ridges near the center on the outer surface of each segmented portion. Each ridge may have a valley on its respective side. When the segmented portion is in the release position, a larger gap may be formed between the inner wall of the pipe and the valley. As the gap becomes larger, the pipe can swing and detach from the segmented section by the valley-shaped section, making it easier to disengage the segmented section from the inner wall of the pipe compared to the case of a circular section.

[0075] The lever may be configured to displace the shaft. The lever can have a passive position and an active position, and the lever can be locked in the active position by a lever locking mechanism. Locking the lever in the active position ensures that the lever remains securely in that position. This can be important, for example, to prevent the fixing mechanism from accidentally releasing the pipe when a groove is formed on the outer circumference of the pipe. The shaft in the fixed position can be configured to allow the device to operate. The shaft in the fixed position can, for example, connect the hydraulic pump and the device in a hydraulic pipeline. In the released position, the hydraulic pipeline between the hydraulic pump and the device can be disconnected. This increases safety because the device cannot be operated before the shaft is in the active position and the pipe is fixed to the device.

[0076] The shaft may have a conical shoulder, and the stationary spring element can bias the conical portion so that it can contact the conical shoulder when the conical portion is in the released position.

[0077] The fastener may include a first spring housing fastened to the shaft, and the release spring element can be biased between the segmented portion and the first spring housing.

[0078] The segmented section can be biased toward the released position by a release spring element. The effect of this is that, since the retraction force originates from the release spring element, the segmented section can be retracted with minimal effort by the user. The interface between the segmented section and adjacent parts can be made less complex because the release spring element can position the segmented section in a fixed position along its central axis. The release spring element may be a coil spring.

[0079] In large-scale pipe production, the diameter of the inner wall of the pipe may vary. In one embodiment, where a lever is configured to displace the conical and subsequently segmented sections to a fixed position, the variation in the inner wall diameter may prevent the lever from reaching the lever locking section. The locking section may comprise a first spring housing fastened to a shaft, and the locking spring element can bias the conical and first spring housing. The locking spring element can bias the conical section so that the segmented section is biased toward the fixed position. The effect of this is that the conical section is given axial flexibility, and consequently the segmented section has some radial flexibility at the fixed position. This flexibility allows the inner wall diameter to change when the lever is locked in the active position. The locking spring element may be a single disc spring or a plurality of stacked disc springs.

[0080] The outer surface of the segmented section may have a recess for receiving. The recess can be positioned to align with, for example, a grooving device configured to form a groove around the circumference of a pipe. A ridge may be formed on the inside of the pipe when the grooving wheel is pressed against the outer surface of the pipe to form a groove. The recess makes it possible to form a groove without deforming the segmented section or increasing the force required to create the groove.

[0081] The device may be a grooving device. The device may also be other devices that require fasteners for engaging with the inner wall of the pipe.

[0082] The following describes an example of a preferred embodiment shown in the attached drawings. [Brief explanation of the drawing]

[0083] [Figure 1] This is a perspective view of a grooving device attached to a handheld drill. [Figure 2] This is a perspective view from the right side inside the grooving device. [Figure 3] This is an axial cross-sectional view along AA of the grooving device. [Figure 4] This is an axial cross-sectional view of the grooving device along the ball bearing (BB). [Figure 5] This is an axial cross-sectional view of the grooving device along the CC line. [Figure 6] This is a cross-sectional view along the drive unit (DD) of the grooving device. [Figure 7a] This is a detailed diagram of the wheel holder, base plate, and ring-shaped hydraulic piston. [Figure 7b] This is a detailed diagram of the wheel holder, base plate, and ring-shaped hydraulic piston. [Figure 7c] This is a detailed diagram of the wheel holder, base plate, and ring-shaped hydraulic piston. [Figure 8] This is an axial cross-sectional view along the EE of the grooving device. [Figure 9a] These are cross-sectional views at different scales along the FF and GG sections of the grooving device. [Figure 9b] These are cross-sectional views at different scales along the FF and GG sections of the grooving device. [Figure 10] These are exploded views of the shaft and fasteners at different scales. [Figure 11] These are axial cross-sectional views of the shaft and fixture at different scales. [Figure 12] This is a cross-sectional view along the HH of the fastener. [Figure 13] This is a detailed enlarged view of the fixing device when the conical part slides along the shaft. [Modes for carrying out the invention]

[0084] Focusing on the present invention, it should be made clear that seals, screws, bolts, nuts, bearings, and bushings may not be referenced. It should also be made clear that all rotating parts may be supported radially and / or axially by one or more bearings. A bearing, as used herein, is any element designed to reduce friction with a rotatable part.

[0085] Figure 1 shows a grooving device 1 connected to a power unit 9 via a coupling 480. The power unit 9 is shown as a handheld drill 90. The coupling 480 is formed to fit a standard handheld drill 90. The central axis of the grooving device 1 is indicated by reference numeral X1. The illustrated grooving device 1 and handheld drill 90 can be operated with one hand or both hands. The illustrated grooving device 1 comprises a grooving tool 10, a hydraulic pump and drive mechanism 20, and a fixture 50. The hydraulic pump housing 60 comprises a first housing portion 601 and a second housing portion 602. The lever 550 is located outside the housing 40. The lever 550 is in a passive position 5502. By rotating the lever 550 180 degrees, the lever 550 can be locked into an active position 5504 (best seen in Figure 2) by a lever locking portion 560.

[0086] Refer to Figures 2-4. The input shaft 200 is positioned to connect to the handheld drill 90. The input shaft 200 is connected to the first spur gear 201 of a double spur gear section 21. The double spur gear section 21 comprises two second spur gears 202, each of which engages with the first spur gear 201. Each second spur gear 202 is rotationally fastened to its respective intermediate shaft 202a. In the illustrated embodiment, the second spur gears 202 are reduction gears because they have more teeth than the first spur gear 201. A third spur gear 203 is rotationally fastened to the intermediate shaft 202a. The third spur gear 203 engages with a fourth spur gear 204. The fourth spur gear 204 is rotationally fastened to the first end 208 of the drive shaft 207. The drive shaft 207 is offset from the central axis X1 of the grooving device. The fifth spur gear 205 is rotationally fastened to the second end 209 of the drive shaft 207. The fifth spur gear 205 engages with the inner teeth of the inner spur gear section 206. The inner spur gear section 206 is rotationally fastened to the base element 120. In the illustrated embodiment, the input shaft 200 is coaxial with the central axis X1 of the grooving device, but this is not necessary for the grooving device 1 to function.

[0087] The hydraulic pump and drive mechanism 20 are shown as a dual drive system, meaning that torque is transmitted from the handheld drill 90 to the grooving tool 10 by two drive shafts 207. An alternative embodiment (not shown) may have a single drive shaft 207 or more than two drive shafts 207.

[0088] In the active position 5504, the lever 550 is locked by the lever locking portion 560. The lever 550 is connected to the eccentric coupling 552.

[0089] Figure 3 shows that the lever 550 is in a passive position 5502, opposite to the active position 5504 (as seen in Figure 2). By rotating the lever 550, the shaft 520 is displaceable along the central axis X1 of the grooving device between a first position 5202 (as seen in Figure 3) and a second position 5204 (as seen in Figure 8). The lever 550 and the shaft 520 are connected by an eccentric coupling 552. When the lever 550 is rotated to the passive position 5502, the eccentric coupling 552 displaces the shaft 520 in a second direction D2 to the first position 5202. Here, the lever 550 is in the passive position 5502 and the shaft 520 is in the first position 5202. When the lever 550 is reversed, that is, rotated to the active position 5504, the eccentric coupling 552 displaces the shaft 520 in the first direction D1 to the second position 5204. Then the lever 550 is in the active position 5504 and the shaft 520 is in the second position 5204.

[0090] Refer to Figures 2, 3 and 8-13. The fastener 50 is positioned to engage the pipe end 990 of the pipe 99 with the grooving device 1. The central axis of the pipe 99 is identified by the reference numeral X99. The illustrated fastener 50 comprises three segmented portions 510 positioned to engage radially with the inner wall 996 of the pipe 99.

[0091] The fastener 50 and shaft 520 are best shown in Figures 10 and 11. The shaft 520 has a joint 5200 at one end and a fixing portion 5209 at the opposite end. From the joint 5200 toward the fixing portion 5209, the shaft 520 has a coupling head 5201, a hydraulic section 521, a conical section 523, a spring section 525, and a threaded section 527.

[0092] The diameter of the conical compartment 523 is smaller than the diameter of the hydraulic compartment 521. A conical shoulder 522 is formed between the hydraulic compartment 521 and the conical compartment 523. The conical compartment 523 may have a non-circular shape, such as a polygonal geometry, or it may have a keyway. The conical compartment 523 may have a key or a ridge. In Figures 10 and 12, the conical compartment 523 is depicted as a polygonal geometry, i.e., a hexagonal geometry.

[0093] The diameter of the spring section 525 is smaller than the diameter of the conical section 523. The spring shoulder 524 is formed between the conical section 523 and the spring section 525.

[0094] The screw section 527 may have the same diameter as the spring section 525, or it may have a smaller diameter than the spring section 525.

[0095] The coupling head 5201 has a through hole 5203 that is adapted to receive the eccentric coupling 552 as described above.

[0096] The pipe-stopping disc 530 has a central part 531 with a central through-hole 532. A segmented surface 533 surrounds the central part 531. An edge flange 534 surrounds the segmented surface 533. The central part 531 is stepped relative to the segmented surface 533, forming a conical recess 535. The central through-hole 532 has a diameter large enough to allow the shaft 520 to pass through. The segmented surface 533 is closer to the threaded section 527 than to the central part 531.

[0097] The conical portion 512 has a conical central hole 5123 that matches the geometry of the conical section 523. The conical portion 512 is slidably engaged with the shaft 520. The conical portion 512 has tapered wedge-shaped faces 5121 on its outer side. Three wedge-shaped faces 5121 are depicted in Figures 10 and 12. The wedge-shaped faces 5121 taper toward the joint 5200. The conical portion 512 has its smallest diameter toward the pipe-stopping disc 530, and the smallest diameter of the conical portion 512 fits into the center 531, as seen in Figures 4, 8, and 13. Each wedge-shaped face 5121 is provided with a guide portion 5122 that projects outward in the longitudinal direction. The guide portion 5122 is shown as a T-shaped guide portion 5124, as depicted in Figures 10 and 12. The longitudinal length of the conical portion 512 corresponds to the length of the conical section 523.

[0098] Each wedge-shaped surface 5121 and its corresponding guide portions 5122, 5124 engage with the segmented portion 510. Each segmented portion 510 is a sector formed by an arc-shaped outer surface 511 and a wedge-shaped inner surface 517. The arc-shaped outer surface 511 includes a receiving recess 515 and a gripping surface 516. The gripping surface 516 is shown as a rough gripping surface 516 for good gripping. The gripping surface 516 has a larger diameter than the receiving recess 515, and the outer surface 511 is stepped. The wedge-shaped inner surface 517 tapers toward the screw section 527. The wedge-shaped inner surface 517 includes a slit 5172 that engages with a guide portion 5122 projecting outward in the longitudinal direction. The slit 5172 may be a T-shaped slit 5174 (see Figure 12) that engages with a T-shaped guide portion 5124. As the segmented portion 510 moves relative to the conical portion 512 along its longitudinal direction, the segmented portion 510 moves radially.

[0099] A second spring housing 518 surrounds the shaft 520. This second spring housing 518 is provided with an inwardly projecting edge 5181 that forms the housing central hole 5183. As seen in Figure 11, the edge 5181 abuts against the segmented end face 5109 of the segmented portion 510. As seen in Figures 3, 11 and 13, the housing central hole 5183 has a diameter that allows the conical end face 5129 to pass into the second spring housing 518.

[0100] The stationary spring element 514 surrounds the spring compartment 525. In the illustrated embodiment, the stationary spring element 514 is a plurality of disc springs installed coaxially with the shaft 520. The release spring element 513 surrounds the spring compartment 525 outside the stationary spring element 514.

[0101] The threaded first spring housing 519 houses the stationary spring element 514, the release spring element 513, and the second spring housing 518, as best seen in Figures 11 and 13. The first spring housing 519 is fastened to the shaft 520 in the threaded section 527. A retaining nut 5190 secures the first spring housing 519 to the shaft 520.

[0102] The stationary spring element 514 is biased between the inner surface 5191 of the first spring housing 519 and the spring shoulder 524 and / or the conical end face 5129 (see Figures 11 and 13). The stationary spring element 514 is in contact with the conical end face 5129. The release spring element 513 is biased between the inner surface 5191 of the first spring housing 519 and the edge 5181. When the lever 550 is in the passive position 5502 and the shaft 520 is in the first position 5202, the conical portion 512 is in contact with the conical shoulder 522. The spring shoulder 524 is coplanar with the conical end face 5129. Therefore, the stationary spring element 514 is in contact with both the spring shoulder 524 and the conical end face 5129, as seen in Figures 3 and 11. The pipe-retaining disc 530 is fastened to the piston housing 13, and the edge flange 534 is retained in the corresponding step of the piston housing 13, as seen in Figures 3 and 4. The pipe-retaining disc 530 is stationary relative to the piston housing 13, and the shaft 520 is axially movable within the piston housing 13. When the shaft 520 is in the first position 5202, each segment 510 abuts against the segment surface 533 at the segment end face 5109 and the segment sliding end face 5108 opposite to it. The release spring element 513 acts on the pipe-retaining disc 530 at one end via the segment 510 and edge 5181, and on the first spring housing 519 at the opposite end. Thus, the release spring element 513 creates an axial force in a second direction D2, moving the shaft 520 in the direction of D2. As a result, the segmented portion 510 moves inward toward the central axis X1, as can be seen in Figures 3 and 11.

[0103] The pipe 99 is pushed into the inlet 130 within the piston housing 13 until it contacts the pipe retaining disc 530.

[0104] As the shaft 520 is displaced to a second position 5204 in a first direction D1 (as shown in Figure 8), the stationary spring element 514 biases the conical portion 512 against the conical shoulder 522 so that the conical portion 512 follows the movement of the shaft 520. As shown in Figure 8, the segmented portion 510 is pressed radially outward as the wedge-shaped inner surface 517 slides toward the tapered wedge-shaped surface 5121 until the gripping surface 516 contacts the inner wall 996 of the pipe 99.

[0105] The distance that the shaft 520 displaces between the first position 5202 and the second position 5204 is fixed. The radial displacement of the segmented portion 510 is also fixed unless the conical portion 512 slides along the shaft 520. The conical portion 512 and the segmented portion 510 are sized to fit with a known pipe 99 having a known inner diameter. If the inner diameter is not uniform, or if the wall thickness of the pipe 99 is larger than expected and the inner diameter is smaller than expected, the segmented portion 510 will contact the inner wall 996 before the lever 550 reaches the lever locking portion 560 if the conical portion 512 is fixed to the shaft 520. However, according to this disclosure, if the inner diameter is not uniform, or if the wall thickness of the pipe 99 is larger than expected, the conical portion 512 slides along the conical section 523. In this case, the conical portion 512 does not contact the conical shoulder portion 522, and the conical end face 5129 is no longer coplanar with the spring shoulder portion 524. The stationary spring element 514 contacts the conical end face 5129 and biases the conical portion 512 toward the coupling head 5201, as can be seen in Figure 13. As a result, even if the inner diameter is smaller than expected and the lever 550 reaches the lever locking portion 560, the segmented portion 510 is still pressed outward toward the inner wall 996 with a force sufficient to keep the pipe 99 immobile.

[0106] The segmented portion 510 is held in place by the lever locking portion 560 fixing the lever 550 to the active position 5504.

[0107] When the shaft 520 is displaced in the second direction D2 to the first position 5202 (as shown in Figure 3), the segmented portion 510 is supported by a release spring element 513 that biases it radially inward toward the first direction D1 and thus toward the central axis X1 of the grooving device as the cone portion 512 is moved in the second direction D2, and the segmented portion 510 is pulled radially inward. As shown in Figure 3, the fixture 50 is not engaged with the inner wall 996 of the pipe 99 when the shaft 520 is in the first position 5202.

[0108] In a plane perpendicular to the central axis X1, the coupling head 5201 has a non-circular shape. In Figure 9a, the coupling head 5201 is shown as an elliptical circumference. The coupling head 5201 is located within a complementaryly shaped cavity 41 within the housing 40. The coupling head 5201 is axially displaceable within the cavity 41, as seen in Figures 4 and 8. The coupling head 5201 and shaft 520 cannot rotate around the central axis X1, as shown in Figure 9a.

[0109] The shaft 520 has three functions. The shaft 520 acts as the actuating part for the fixture 50. The shaft 520 transmits torque from the pipe 99 to the housing 40, thereby preventing the pipe 99 from rotating during grooving. The shaft 520 acts as a sliding valve within the hydraulic system 6, as described below.

[0110] Refer to Figures 3 and 8 here. The receiving recess 515 is positioned to align with the grooving wheel 111. The grooving wheel 111 is described in more detail with reference to Figure 4. When the grooving wheel 111 is pressed against the outer surface of the pipe 99 to form a groove 994, a ridge 995 is formed on the inside of the pipe 99.

[0111] Refer to Figures 3 and 4 here. The hydraulic pump and drive mechanism 20 comprises a hydraulic system 6. The hydraulic system 6 comprises a volume-compensated fluid container 630. The volume-compensated fluid container 630 comprises a rigid housing 6302. The rigid housing 6302 comprises a housing 40, a flange portion 19, and a hydraulic pump housing 60. The volume-compensated fluid container 630 is sealed to the environment 6305 surrounding the grooving device 1. The rigid housing 6302 comprises a through hole 6303. An inflatable / deflatable device 6301 is connected to the through hole 6303 so as to be installed inside the rigid housing 6302 and to be fluidly connected to the environment 6305. In the illustrated embodiment, the inflatable / deflatable device 6301 is a flexible bag. The through hole 6303 is located adjacent to the internal components of the grooving tool 10. The tank pipeline 6306 connects the volume-compensated fluid container 630 to the hydraulic pump housing 60. The tank pipeline 6306 is the outlet from the volume-compensated fluid container 630 in which the working fluid 69 is stored.

[0112] As shown in Figures 4 and 6, a first gear pump 61 and a second gear pump 62 are installed in a hydraulic pump housing 60. The first gear pump 61 comprises one third spur gear 203 and one fourth spur gear 204. In the first gear pump 61, the third spur gear 203 functions as the first pump gear, and the fourth spur gear 204 functions as the second pump gear. The second gear pump 62 comprises one third spur gear 203 and one fourth spur gear 204. In the second gear pump 62, the third spur gear 203 functions as the first pump gear, and the fourth spur gear 204 functions as the second pump gear. The first gear pump 61 and the second gear pump 62 are connected in parallel. One side of the first gear pump 61 and one side of the second gear pump 62 are connected to a tank pipeline 6306. The opposite sides of the first gear pump 61 and the opposite sides of the second gear pump 62 are connected to a pressure line 632, allowing the flow and pressure of the working fluid to be supplied into the pressure line 632. The pressure line 632 is connected to a flow regulator 639 and a pressure relief valve 68 (as shown in Figure 9b). The pressure relief valve 68 is fluidly connected to a volume-compensated fluid container 630. The flow regulator 639 may be adjustable, thereby allowing adjustment of the displacement speed of the wheel holder 110. If the displacement speed is too fast, friction increases as the grooving wheel 111 rotates as desired. If the displacement speed is too slow, the material does not move as desired during the grooving operation, resulting in the failure to form the ridges 995.

[0113] The pressure pipeline 632 is routed to connect the first gear pump 61 and the second gear pump 62 to the first hydraulic swivel joint 640 (best seen in Figure 4). The shaft 520 includes a shaft return pipeline 6308 and a shaft pressure pipeline 6322. The shaft return pipeline 6308 is in fluid communication with the volume-compensated fluid vessel 630 via a return pipeline 64 connected to the volume-compensated fluid vessel 630. The shaft return pipeline 6308 is connectable to the first hydraulic swivel joint 640 and the second hydraulic swivel joint 650. The shaft pressure pipeline 6322 is connectable to the first hydraulic swivel joint 640 and the second hydraulic swivel joint 650. In this specification, a hydraulic conduit being connected to a hydraulic swivel fitting means that the working fluid is able to flow from the hydraulic conduit and through the hydraulic swivel fitting. A hydraulic conduit being disconnected from a hydraulic swivel fitting means that the working fluid is not able to flow from the hydraulic conduit and through the hydraulic swivel fitting.

[0114] The first hydraulic swivel joint 640 is configured such that the shaft 520 can rotate around the central axis X1 of the device and be displaced along it. The second hydraulic swivel joint 650 is configured such that the shaft 520 can rotate around the central axis X1 of the device and be displaced along it on the inner surface 6502 of the second hydraulic swivel joint 650. The second hydraulic swivel joint 650 is configured such that the base element 120 can rotate around the outer surface 6504 of the second hydraulic swivel joint 650 around the central axis X1 of the device.

[0115] When shaft 520 is in the first position 5202, the first hydraulic swivel joint 640 connects the pressure line 632 to the shaft return line 6308. The second hydraulic swivel joint 650 connects the shaft return line 6308 to the grooved tool hydraulic line 634. The grooved tool hydraulic line 634 is routed to connect the piston chamber 14, in which a ring-shaped hydraulic piston 12 is installed, to the second hydraulic swivel joint 650. When shaft 520 is in the first position 5202, the shaft pressure line 6322 is disconnected from the first hydraulic swivel joint 640 and the second hydraulic swivel joint 650. Thus, shaft 520 in the first position 5202 connects the first gear pump 61, the second gear pump 62, and the piston chamber 14 to the volume-compensated fluid container 630 via the return line 64.

[0116] When shaft 520 is in the second position 5204, the first hydraulic swivel joint 640 connects the pressure line 632 to the shaft pressure line 6322, and the second hydraulic swivel joint 650 connects the shaft pressure line 6322 to the grooved tool hydraulic line 634. The shaft return line 6308 is disconnected from the first hydraulic swivel joint 640 and the second hydraulic swivel joint 650. Thus, in the second position 5204, the shaft return line 6308 is connected only to the volume-compensated fluid container 630. As a result, shaft 520 in the second position 5204 connects the first gear pump 61 and the second gear pump 62 to the piston chamber 14.

[0117] Refer to Figures 2 and 4. The grooving tool 10 is configured to rotate relative to the housing 40 and around the central axis X1 of the device. As previously described, the internal spur gear section 206 is firmly fastened to the base element 120 for rotation, and thus the drive shaft 207 and the fifth spur gear 205 are configured to rotate the grooving tool 10 around the central axis X1 of the device. Refer to Figures 4, 7a and 8. The grooving tool 10 comprises a plurality of wheel holders 110. Each wheel holder 110 comprises a grooving wheel 111 on a wheel spindle 113. In the illustrated embodiment, there are shown to be three wheel holders 110. The grooving wheel 111 has a smaller diameter 1112 on each side of the ridge 112, and is configured to restrict the inward radial movement of the grooving wheel 111 when it forms a groove 994 in the pipe 99 during the grooving operation (as seen in Figure 8). An additional benefit of the smaller diameter 1112 is that it prevents the pipe end 990 extending from the groove 994 from lifting or bending radially during the grooving process.

[0118] Each wheel holder 110 is connected to a base element 120 and is radially displaceable between a resting position 1102 (as seen in Figures 3 and 4) and a grooving position 1104 (as seen in Figure 8). The resting position 1102 is readily identified by a hydraulic piston 12 biased toward a starting position 141 within a piston chamber 14. By displacing the hydraulic piston 12 from the starting position 141 to an intermediate position 145 within the piston chamber 14, the wheel holder 110 is displaced to the grooving position 1104. See Figures 5 and 7a-b. The wheel holder 110 includes two projections 1106 made to engage with corresponding slots 1202 within the base element 120. The corresponding slots 1202 are shown as dashed lines in Figure 7b. The corresponding slots 1202 can also be seen in Figure 5. The projections 1106 and the corresponding slots 1202 are radially aligned toward the central axis X1 of the grooving device.

[0119] The wheel holder 110 is connected to the hydraulic piston 12. The wheel holder 110 is displaced radially when the hydraulic piston 12 is displaced axially. In the illustrated embodiment, the wheel holder 110 has four projections 114, with two projections 114 on each side of the wheel holder 110 (see Figures 2 and 7a). The projections 114 are configured to engage with corresponding recesses 121 of the hydraulic piston 12. The recesses 121 make an angle with the central axis X1 of the apparatus (as best seen in Figures 3 and 7c). Thus, the projection 1106, the corresponding slot 1202, the projections 114 and the recesses 121 are arranged such that when the hydraulic piston 12 is displaced in a first direction D1, the wheel holder 110 is displaced radially toward the central axis X1 of the apparatus. The radial displacement depends on the angle between the projections 114 and the recesses 121 and the central axis X1 of the apparatus. As a non-limiting example, a 10 mm displacement of the hydraulic piston 12 in a first direction D1 corresponds to a 2.5 mm radial displacement of the wheel holder 110. The hydraulic piston 12 is displaceable in the first direction D1 by filling the piston chamber 14 with working fluid 69. The hydraulic piston 12 is biased in a second direction D2 by a plurality of springs 16 (as best seen in Figure 5). In the illustrated embodiment, the springs 16 are shown as coil springs.

[0120] Figures 9a and 9b show the first plug 638 for filling the volume-compensated fluid container 630 with the working fluid 69.

[0121] The hydraulic system 6 may be filled with working fluid 69. The filling process is as follows: - Remove the first plug 638. - Fill the volume-compensated fluid container 630 with the working fluid 69 until the volume-compensated fluid container 630 is full, and - Insert the first plug 638 to seal the volume-compensated fluid container 630 against the environment 6305 surrounding the grooving device 1. This includes the following step.

[0122] The power unit 9, such as the handheld drill 90, is connected to the grooving device 1 by a joint 480, as shown in Figure 1. The grooving device 1 is connected to the pipe end 990 of the pipe 99. The pipe 99 is locked to the grooving device 1 by moving the lever 550 from a passive position 5502 to an active position 5504. The lever 550 is fixed by a lever locking part 560, as shown in Figure 2. As a result, the fixing device 50 fixes the pipe 99 as described above.

[0123] The handheld drill 90 rotates the grooving tool 10 by operating a hydraulic pump and drive mechanism 20. The first gear pump 61 and the second gear pump 62 are operated in parallel to increase the hydraulic pressure to a hydraulic pressure that may be, for example, 10 bar. The pressure relief valve 68 may be set to, for example, 10 bar. The hydraulic pressure is transmitted to the piston chamber 14 and acts on the hydraulic piston 12. The hydraulic pressure is transmitted to the pressure line 632, the first hydraulic swivel joint 640, the shaft pressure line 6322, the second hydraulic swivel joint 650 and the grooving tool hydraulic line 634, and is also 10 bar. The flow regulator 639 and several springs 16 cause the hydraulic piston 12 to be slowly displaced within the piston chamber 14 along and parallel to the central axis X1 of the grooving device. As a result, the wheel holder 110 is slowly displaced radially inward, and the grooving wheel 111 slowly creates a groove 994 on the outer surface of the pipe 99 as it rotates around the pipe 99. The inflatable / deflatable device 6301 inflates with air from the environment 6305 surrounding the grooving device 1 as the working fluid 69 is moved from the volume-compensated fluid container 630 to the piston chamber 14. The inflatable / deflatable device 6301 inflates to the same volume used to displace the hydraulic piston 12.

[0124] The handheld drill 90 can be stopped before the piston stroke is complete and / or when a smaller radius 1112 contacts the pipe 99, i.e., when the groove 994 is completed. When the lever 550 is displaced to the passive position 5502 (as seen in Figures 1, 3 and 5), the working fluid 69 in the piston chamber 14 is directed to the volume-compensating fluid container 630, and the spring 16 returns the hydraulic piston 12 to the starting position 141. This returns the wheel holder 110 and the grooving wheel 111 to the resting position 1102. As the working fluid 69 returns from the piston chamber 14 to the volume-compensating fluid container 630, the inflatable / deflatable device 6301 deflates to the state it was in before displacing the hydraulic piston 12.

[0125] The smaller diameter 1112 of the grooving wheel 111 ensures that the pipe end 991 is kept straight during the grooving process and that the groove 994 is made to a predetermined depth. The predetermined depth is determined by the difference between the radius of the smaller diameter 1112 and the radius of the ridge 112.

[0126] The fourth spur gear 204 of the first gear pump 61 rotates the connected drive shaft 207. The drive shaft 207 rotates the fifth spur gear 205, which in turn rotates the inner spur gear section 206. The fourth spur gear 204 of the second gear pump 62 is similarly connected to the inner spur gear section 206. The base element 120 is fixed to the inner spur gear section 206 as shown in Figure 2. Thus, when the lever 550 is in the active position 5504 and the power unit 9 is operated, this operates the hydraulic pump and drive mechanism 20. As a result, the grooving wheel 111 is slowly and radially displaced inward into the pipe 99, and at the same time the grooving wheel 111 rolls around the entire circumference of the pipe 99.

[0127] It should be noted that the embodiments described above are illustrative rather than limiting, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, no reference numerals enclosed in parentheses shall be construed as limiting the claims. The use of the verb “comprise” and its conjugations shall not preclude the existence of elements or steps other than those described in the claims. The article “a” or “an” preceding an element shall not preclude the existence of multiple such elements.

[0128] The mere fact that certain means are described in mutually different dependent claims does not indicate that this combination of means cannot be used advantageously.

Claims

1. A grooving device (1) is configured to roll a groove (994) on a pipe end (990), wherein the grooving device (1) forms a central axis (X1), and comprises a fixing device (50) and a grooving tool (10), wherein the fixing device (50) can be configured between an open position and a fixed position, and in the fixed position, the fixing device (50) is configured to engage with the inner wall (996) of the pipe (99) such that the central axis (X1) and the central axis (X99) of the pipe (99) are coaxial, thereby fixing the grooving device (1) to the pipe end (990), and the grooving tool (10) is rotatable around the central axis (X1), - The grooving tool (10) comprises a hydraulic piston (12) and at least one wheel holder (110), - The hydraulic piston (12) is displaceable in a direction along the central axis (X1), - The hydraulic piston (12) is configured to displace the wheel holder (110) radially with respect to the central axis (X1) between the resting position (1102) and the grooved position (1104), - The wheel holder (110) includes a grooved wheel (111). A grooving device (1) characterized by the following:

2. A grooving device (1) according to claim 1, wherein the grooving device (1) comprises at least three of the wheel holders (110).

3. A grooving device (1) according to claim 1 or 2, wherein the grooving tool (10) comprises a base element (120), and the wheel holder (110) is connected to the base element (120) and is radially displaceable.

4. A grooving device (1) according to any one of claims 1 to 3, wherein the grooving device (1) is configured to receive rotational force from a drive shaft (207), and the drive shaft (207) is offset from the central axis (X1).

5. A grooving device (1) according to any one of claims 1 to 4, wherein the grooving device (1) is configured to receive a working fluid (69) from a pressure pipeline (632).

6. A grooving device (1) according to claim 4, wherein the grooving tool (10) comprises an internal spur gear portion (206).

7. A grooving device (1) according to any one of claims 1 to 6, wherein the hydraulic piston (12) is biased toward a starting position (141).

8. A grooving device (1) according to any one of claims 1 to 7, wherein the fixing device (50) can be configured by displacing the shaft (520) parallel to the central axis (X1).

9. A grooving device (1) according to any one of claims 1 to 8, characterized in that the rotational force and the flow of the working fluid are supplied by a battery-powered power unit.

10. A grooving system configured to roll grooves (994) on the end of a pipe (990), - The grooving system comprises a grooving device (1) according to any one of claims 1 to 9, - The grooving system comprises a hydraulic pump and drive mechanism (20), a volume-compensated fluid container (630), and a fixing device (50). - The hydraulic pump and drive mechanism (20) are connected to a power unit (9) and are configured to receive rotational force from the power unit (9) via an input shaft (200). - The hydraulic pump and drive mechanism (20) are configured to produce an output, the output including the flow of working fluid and rotational force, and the output is transmitted to the grooving device (1). - The fixing device (50) forms the central axis of the fixing device (50) which is coaxial with the central axis (X1) of the grooving tool (10). - The fixing device (50) is configured to engage with the inner wall (996) of the pipe (99) and to fix the pipe end (990) to the grooving device (1). A grooving system characterized by the following features.

11. A grooving system according to claim 10, characterized in that the grooving system is configured to be handheld.

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