JP2000015517A - Pipe cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe cutter which can carry out the cutting preperation of a relatively light pipe easily. SOLUTION: To one side free end of a rotary clamp arm 37, a pipe dead weight support roller 36 in order to support the pipe to cut from the lower side is rotatably installed, and to the other side free end, a clamp roller 39, in order to clamp the pipe to cut from the upper side upper than the horizontal surface, passing through the center axis of the pipe, between a stationary support roller 4 and the roller 36, is installed rotatable, and a cutter mechanism in order to cut the piped is installed rotatable to a frame 3. And when the pipe to cut is loaded to the support roller 36 of the arm 37, the arm 37 is rotated by making the rotating center axis as the center, and the roller 36 supports the pipe together with the stationary support roller 4 from the lower side, and the clamp roller 39 clamps the pipe from the upper side between the stationary support roller 4 and the support roller 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pipe cutter, and more particularly to a pipe cutter for cutting a plastic pipe.

[0002]

2. Description of the Related Art The applicant of the present invention has filed a pipe cutter which can easily prepare for cutting a relatively heavy pipe prior to the present application (Japanese Patent Application No. 9-34111).
No. 73). This pipe cutter is rotatably attached to a pipe's own weight support roller which moves vertically downward due to the weight of the pipe itself when the pipe to be cut is placed, and a pipe's own weight support roller. A pair of first arms and, between the pair of first arms, a second arm rotatably attached to the pipe's own weight support roller so as to face the first arm. Each first arm and second
Each arm has a first clamp roller and a second clamp roller at its free ends, and a cutter mechanism including a rotary blade and a motor for rotating the rotary blade is provided on one of the first arms. Mounted freely.

In the pipe cutter having the above structure, when the pipe to be cut is placed on the pipe's own weight supporting roller, the pipe's own weight supporting roller is moved downward by the weight of the pipe. As a result, the first arm and the second arm are moved. The arms are pivoted upward about the pipe's own weight support rollers such that first and second clamp rollers respectively attached to the free ends of these arms clamp the pipe between the pipe's own weight support rollers. Thus, preparation for cutting the pipe can be easily performed. In this state,
By rotating the motor and the rotary blade rotated by the motor with respect to the first arm, the rotary blade is brought into contact with the pipe, and the peripheral wall of the pipe is cut by the rotary blade. Subsequently, the entire peripheral wall of the pipe is cut by turning the pipe by hand.

[0004]

However, since the above-mentioned pipe cutter has a structure in which a cutter mechanism, which is a considerably heavy object, is attached to the first arm, it is necessary to rotate the first arm with a relatively lightweight pipe. In such a case, there is a trouble that the operator has to rotate the first arm (and the second arm) by pushing down the pipe by hand, and the first arm In order to facilitate the rotation of the first arm, it is desired to reduce the weight of the first arm. However, when attaching a heavy cutter mechanism to the first arm to be lightweight, the rigidity of the first arm is secured. There was a problem that it was difficult to do. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the related art, and has as its object to provide a pipe cutter that can easily prepare for cutting a relatively lightweight pipe.

[0005]

In order to achieve the above object, a pipe cutter according to the present invention comprises a frame and a stationary support rotatably mounted on the frame for supporting a pipe to be cut from below. A roller, a pivot shaft attached to the frame and having an axis extending parallel to the rotation axis of the stationary support roller, and a pivot pivotally mounted on the pivot shaft and having two free ends. A clamp arm, and at one free end of the rotating clamp arm,
A pipe weight support roller for supporting the pipe to be cut from below is rotatably mounted, and the other free end of the rotating clamp arm is cut between the stationary support roller and the pipe weight support roller. A cutter mechanism for cutting the pipe, which is rotatably mounted on a frame to be clamped from above a horizontal plane passing through the center axis of the pipe and is rotatably mounted on the frame, is provided. When the pipe to be cut is placed on the pipe's own weight supporting roller of the rotating clamp arm, the rotating clamp arm rotates around the center axis of rotation, and the pipe's own weight supporting roller is together with the stationary supporting roller. The pipe is supported from below, and the clamp roller clamps the pipe between the stationary support roller and the pipe's own weight support roller from above. It is.

In the present invention, there is provided a stopper for preventing the rotation center axis of the pipe's own weight support roller from rotating away from the stationary support roller beyond a vertical plane passing through the axis of the rotation center axis. preferable. Also,
It is preferable to have a stopper for preventing the rotation center axis of the pipe's own weight support roller from rotating downward beyond a horizontal plane passing through the rotation center axis of the stationary support roller.
Furthermore, the clamp roller moves the pipe above the outer peripheral point of the pipe where a plane extending through the center axis of the pipe supported by the stationary support roller and the pipe's own weight support roller is positioned from the rotation center axis of the stationary support roller. It is preferred to clamp from

Further, the cutter mechanism includes cutter means for cutting the pipe, a prime mover for driving the cutter means, and a switch for turning on and off the prime mover. It is preferable to have a switch lock mechanism for locking in a state. Still further, there is provided a cutter mechanism urging means for urging the cutter mechanism to rotate the cutter mechanism with respect to the frame, and the cutter mechanism urging means comes into contact with a pipe to be cut by the cutter means. When the cutter mechanism is at the dead point, which is the position immediately before, the cutter mechanism is not urged in any direction.When the cutter mechanism is rotated by the user's hand from the dead point toward the pipe, the cutter mechanism is connected to the pipe. Preferably, when the cutter mechanism is rotated by a user's hand to move the cutter mechanism away from the dead point and away from the pipe, the cutter mechanism is biased away from the pipe.

It is preferable that the cutter mechanism urging means is a torsion spring having one end attached to the frame and the other end attached to the cutter mechanism.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. Referring to the drawing,
A pipe cutter according to the invention is indicated generally by the reference numeral 1. As can be clearly seen from FIG. 3, the pipe cutter 1 has a pair of spaced-apart support plates 2A and 2B, and a plurality of beams 3 connecting the support plates 2A and 2B. 2B and the beam 3 constitute a frame of the pipe cutter 1. Stationary support roller 4 for supporting a pipe to be cut from below
Extends between the support plates 2A and 2B, and the stationary support roller 4
The top of the stationary support roller 4 is
It is rotatably supported by support plates 2A and 2B in a manner protruding upward beyond A and 2B. The outer peripheral portion of the stationary support roller 4 is made of rubber to increase a frictional engagement force with a pipe to be cut.

A cutter mechanism 10 for cutting a pipe is rotatably mounted on the support plate 2A adjacent to the stationary support roller 4. This cutter mechanism 10
A rotating member 12 having a substantially semicircular cross section is rotatably attached to a projecting rod 11 projecting outward from the support plate 2A. FIG. 1 (front view)
When viewed from above, the housing 13 having an overall L-shape is fixed. The housing 13 houses a motor (not shown) inside, and the motor is connected to a switch provided on a grip portion of the housing 13, that is, a trigger 14 and a connection cord C extending outside the housing 13. I have. The connection cord C is connected to an external power supply, and the trigger 14 is an on / off switch for the motor, and is driven by the user when gripped by the user.

Above the trigger 14, a switch lock mechanism SL for locking the trigger in a switch-on state.
Is provided. The switch lock mechanism SL includes a sliding member SL1 urged downward by a spring (not shown).
Is provided. As shown in FIG. 2, the sliding member SL1 is in the switch-on state when the trigger 14 is gripped by the user, that is, when the tip of the trigger 14 passes through the sliding member SL1 and is inside the housing 13. When it is moved, it is moved downward by the force of the spring (not shown) to engage with the free tip of the trigger 14 and prevent the trigger 14 from moving outward from the housing 13. . Thereby, the switch lock mechanism S
L keeps the trigger 14 locked in the switched-on state even after the user releases the trigger 14 after the user switches on the trigger 14 once.

As can be clearly seen in FIG.
, A rotary blade support member 15 is attached via a spacer member S to a side surface opposite to the support plate 2A.
The rotary blade support member 15 is an L-shaped member having a U-shaped cross section, and includes a pair of side walls 15A and a bottom wall 15B connecting these side walls 15A. Side wall 1 of rotary blade support member 15
A rotary shaft (not shown) to which a rotary blade 16 is fixed is rotatably attached to 5A. The rotary shaft of the rotary blade 16 penetrates the spacer member S, and an output shaft of a motor of the housing 13 (not shown). ). The rotary blade 16 includes a cutting cutter 16A and a chamfer cutter 16B. A safety cover 17 having a U-shaped cross section is rotatably attached to a side wall 15A of the rotary blade support member 15. The safety cover 17 includes a pair of side walls 17A rotatably attached to the side wall 15A of the rotary blade support member 15 and a top wall 17B connecting these side walls 17A. Mounted pivot (not shown)
1 is urged by an urging means (not shown) so as to rotate counterclockwise when viewed in FIG. 1 and is brought into contact with a first stopper (not shown).

A bracket 18 having a hanging plate portion 18A is fixed to a bottom wall 15B of the rotary blade support member 15. Screw holes (not shown) in the hanging plate portion 18A
Is formed in the screw hole.
9 is screwed. One end 1 of the adjusting shaft 19
9A, a circular handle 20 is fixed to the other end 19A.
B is a stopper housing 2 fixed to the support plate 2A and containing the rotating member 12 of the cutter mechanism 10 therein.
Faces one. The stopper housing 21 includes an abutment plate 21A facing the end 19B of the adjustment shaft 19,
It has a rear wall 21B facing the flat portion F of the rotating member 12, and a side wall 21C that supports the distal end of the protruding rod 11, which is the rotation axis of the rotating member 12. When the cutter mechanism 10 is in the state before starting the pipe cutting shown in FIG. 1, that is, when the cutter mechanism 10 is at the standby position, the rear wall 21B of the stopper housing 21 is connected to the flat portion F of the rotating member 12 of the cutter mechanism 10.
To prevent the cutter mechanism 10 from rotating clockwise beyond the position shown in FIG.

On the other hand, the cutter mechanism 10 is shown in FIG.
When in a position suitable for cutting the pipe, i.e., in the operating position, the abutment plate 21A of the stopper housing 21 abuts the end 19B of the adjustment shaft 19 of the cutter mechanism 10 so that the cutter mechanism 10 This helps to prevent the anti-clockwise rotation beyond the position shown in FIG. In other words, when cutting the pipe, the cutter mechanism 1
0, in particular, depending on the diameter of the pipe to be cut or the thickness of the surrounding wall, prior to the pipe cutting operation, so that its rotary blade 16 is positioned in a position suitable for cutting the pipe.
It is necessary to adjust the distance of the end 19B of the adjustment shaft 19 of the cutter mechanism 10 to the abutment plate 21A of the stopper housing 21. This adjustment can be made by turning the circular handle 20 to change the distance of the end 19B of the adjustment shaft 19 to the abutment plate 21A. To fix the set distance, a thumbscrew 19C is screwed onto the adjustment shaft 19.

As shown in detail in FIG.
, A cutter mechanism urging means for urging the housing 13 to rotate the housing 13 with respect to the support plate 2A, that is, a torsion spring S is provided. One end S1 of the torsion spring S is a support plate 2
A is attached to the locking end of the extension member E, and the other end S
2 is attached to the housing 13. When the rotary blade 16 is at a position just before the rotary blade 16 contacts the pipe, that is, at a dead point, the torsion spring S has both ends S1,
Since S2 and the projecting rod 11 are located on the same plane, the housing 13 is not urged in any direction (see FIG. 4A), and the housing 13 is slightly counterclockwise when viewed from the dead point in FIG. When rotated by the user's hand in the direction, the housing 13 is moved in the direction indicated by the arrow in FIG.
That is, when the housing 13 is biased counterclockwise as viewed in FIG. 1, while the housing 13 is slightly clockwise rotated by the user's hand as viewed in FIG. 13 is urged in the direction indicated by the arrow in FIG. 4C, that is, clockwise when viewed in FIG.

Therefore, when the user once turns the housing 13 counterclockwise slightly beyond the dead point by hand, even if the user subsequently releases his / her hand from the housing 13, the torsion spring The housing 13 urged by S is rotated counterclockwise, and the rotary blade 16 is held at a position suitable for cutting the pipe. Each support plate 2A, 2B is also provided with a horizontally extending slot 31 on the opposite side to the stationary support roller 4 being mounted, the slot 31 having a plurality of downwardly facing receiving holes 32 at the bottom. Have. A support shaft (not shown) extends through a slot 31 in each support plate 2A, 2B, and each end of the support shaft is positioned in any of a plurality of downwardly-receiving holes 32 in each slot 31. Is done. A circular handle 3 at each end of the support shaft
A vertical support plate 33 is fixed to the support shaft between each circular handle 30 and each support plate 2A, 2B.

Each vertical support plate 33 extends upward beyond the tops of the support plates 2A, 2B, and as best seen in FIG. 3, the upper ends of these support plates 33 are connected to one another by web members 33A. Each of the vertical support plates 33 also includes, in a region above the tops of the support plates 2A and 2B, a rotation center axis, that is, a rotation center rod 34 projecting away from the support plates 2A and 2B, Stationary support roller 4 above the support shaft (not shown) and above the support shaft
At a position close to the slot 3 of each support plate 2A, 2B.
1 is provided with a stopper rod (not shown) protruding into it. A first clamp arm 35 is provided adjacent to each vertical support plate 33 on the opposite side of the support plates 2A and 2B. Each first clamp arm 35 has a circular through-hole (not shown) slightly larger than the diameter of the rotation center rod 34 of the vertical support plate 33. A central rod 34 extends therethrough. Each first clamp arm 35 also has a stationary support roller 4
, That is, a support end 35A. Between these support portions 35A, a pipe weight support roller 36 for supporting a pipe to be cut from below.
Is extended, and each end of the pipe's own weight support roller 36 is rotatably supported by each support portion 35A. The material and diameter of the pipe's own weight supporting roller 36 are the same as those of the stationary and stationary supporting roller 4.

A second clamp arm 37 is provided on the opposite side of each vertical support plate 33, adjacent to each first clamp arm 35, and these second clamp arms 37, as best seen in FIG. 38. Each second clamp arm 37 has a long base portion 3
7A and a free end, ie, a short support portion 37B, which is angled with respect to the long base portion 37A so as to extend toward the stationary support roller 4. Between these short support portions 37B, a clamp roller 39 for clamping a pipe to be cut between the stationary support roller 4 and the pipe's own weight support roller 36 from above extends.
Each end of the clamp roller 39 is rotatably supported by each short support portion 37B. The outer peripheral portion of the clamp roller 39 also increases the frictional engagement force with the pipe to be cut,
Made of rubber.

The base part 3 of each second clamp arm 37
7A are formed with guide slots 40 extending along the longitudinal direction of the base portion 37A. Each of the guide slots 40 passes through the pivot center rod 34 of the vertical support plate 33 passing through each of the first clamp arms 35. Extend. The base portion 37A of each second clamp arm 37 is also formed with a straight slot 41 extending parallel to the guide slot 40, the straight slot 41 having a plurality of circular slots 42 having a diameter larger than its width. Locking circular handle 43 for fixing the first clamp arm 35 and the second clamp arm 37 at 90 ° (relative to each other)
Are detachably attached to the first clamp arm 35. Each locking circular handle 43 has a circular handle portion 43A.
And a shaft portion (not shown) fixed to the handle portion 43A, which is larger than the width of the straight slot 41 of the second clamp arm 37 and is shaped to fit into the circular slot 42.
And a screw hole is formed in the shaft portion (not shown). An externally threaded rod (not shown) threaded into the threaded hole of the locking circular handle 43 projects from each first clamp arm 35 and extends into the straight slot 41 of the second clamp arm 37. The axis of the externally threaded rod of the first clamp arm 35 is the center axis of the circular through hole (not shown) (therefore, the center axis of the rotation center rod 34 of the vertical support plate 33 passing through the circular through hole) and the pipe's own weight supporting roller. It is positioned on the same plane as the rotation axis 36.

When changing the position of the second clamp arm 37 with respect to the first clamp arm 35, that is, according to the diameter of the pipe to be cut,
When changing the distance between the clamp arm 6 and the clamp roller 39, the shaft portion (not shown) of the locking circular handle 43 is removed from the male threaded rod of the first clamp arm 35 (by unscrewing), and the second clamp arm 37 is disengaged. Circular slot 42
And the engagement of the locking circular handle 43 with the shaft portion is released. Next, the second clamp arm 37 is moved with respect to the first clamp arm 35 so that one of the plurality of circular slots 42 of the second clamp arm 37 is moved to the first clamp arm 3.
5, the screw hole of the shaft of the locking circular handle 43 is screwed into the male threaded rod of the first clamp arm 35, and the shaft of the locking circular handle 43 is clamped to the second clamp. The arm 37 is fitted into the circular slot 42. The vertical movement of the second clamp arm 37 with respect to the first clamp arm 35
5 is prevented by the fitting of the shaft of the locking circular handle 43 locked to the circular slot 42 of the second clamp arm 37, and the first clamp arm 35 centered on the shaft of the locking circular handle 43. Pivotal movement of the second clamp arm 37 with respect to the rotation center rod 34 extending through both members of the first clamp arm 35 and the second clamp arm 37.
And the engagement of the second clamp arm 37 with the guide slot 40.

First clamp arm 35 locked to each other
The second clamp arm 37 constitutes a rotating clamp arm that rotates integrally around the rotation center rod 34. Further, when changing the distance between the stationary support roller 4 and the pipe's own weight support roller 36 and the clamp roller 39 in accordance with the diameter of the pipe to be cut, the support shaft (not shown) is held downward by holding the circular handle 30. Receiving hole 32
(The vertical support plate 33 attached to the support shaft, the first clamp arm 35 attached to the vertical support plate 33, the second clamp arm attached to the first clamp arm 35, etc.). (Lift upward) and move the support shaft relative to the stationary support roller 4 to position the support shaft in one of the plurality of downwardly-receiving holes 32.

As shown in FIG. 1, the first clamp arm 3
5 and the second clamp arm 37, that is, the state before the rotating clamp arm clamps the pipe, that is,
When in the pipe receiving position for receiving pipes, this pivoting clamp arm
Is supported by a second stopper (not shown) so as not to rotate counterclockwise around the rotation center rod 34 beyond the pipe receiving position. That is, the second stopper is always connected to the pipe's own weight support roller 3.
6 serves to prevent the rotation center axis 6 from rotating away from the stationary support roller 4 beyond a vertical plane passing through the axis of the rotation center rod 34. On the other hand, as shown in FIG. 2, when the rotary clamp arm clamps the pipe, that is, when the rotary clamp arm is in the clamp position, the rotary clamp arm is moved around the rotary center rod 34 of the vertical support plate 33 as shown in FIG. A third stopper (not shown) so as not to rotate clockwise beyond the clamp position shown in FIG.
Supported by That is, the third stopper
This serves to prevent the rotation center axis of the pipe's own weight support roller 36 from rotating downward beyond a horizontal plane passing through the rotation center axis of the stationary support roller 4.

When the rotating clamp arm is at the pipe receiving position shown in FIG. 1, the vertical support plate 33 centered on the support shaft (not shown) and the members connected thereto, as viewed in FIG. Clockwise rotation is prevented by the stopper rod (not shown) of the vertical support plate 33 abutting against the upper edge of the slot 31 of each of the support plates 2A and 2B, and the rotation clamp arm is moved to the clamp position of FIG. In some cases, the clockwise rotation of the vertical support plate 33 and the members connected thereto as viewed in FIG. 2 is prevented by the reaction of the pipe against the rollers 4, 36, 39. Next, the operation (operation) of the pipe cutter 1 of the above embodiment will be described. Rotating clamp arms 35, 3
7, and when the cutter mechanism 10 is at the pipe receiving position and the standby position shown in FIG. 1, respectively, the pipe to be cut is placed on the stationary support roller 4 and the pipe's own weight support roller 36 of the first clamp arm 35. Then, the first clamp arm 35 and the second clamp arm 37 locked to the first clamp arm 35
1 rotates clockwise around the rotation center rod 34 of the vertical support plate 33 as viewed in FIG. 1 due to the weight of the pipe. Since neither the first clamp arm 35 nor the second clamp arm 37 has a cutter mechanism, which is a considerably heavy object, even a relatively lightweight pipe can be connected to the pipe of the first clamp arm 35. The first clamp arm 35 and the second clamp arm 37, that is, the rotary clamp arm can smoothly rotate only by being placed on the weight support roller 36, and the rigidity of the rotary clamp arm can be improved. Is not reduced.

The rotation of the rotation clamp arms 35 and 37
The third stopper (not shown) stops at the clamp position shown in FIG. The rotating clamp arms 35 and 37
In the clamp position (1), the rotation center axis of the pipe's own weight support roller 36 of the first clamp arm 35 is on the same horizontal plane as the rotation center axis of the stationary support roller 4. On the other hand, the clamp roller 39 of the second clamp arm 37 extends from the rotation center axis of the stationary support roller 4 through the central axis of the pipe to be cut supported from below by the stationary support roller 4 and the pipe's own weight support roller 36. The pipe contacts the pipe above the outer peripheral point of the pipe where the plane P is located, and clamps the pipe between the stationary support roller 4 and the pipe's own weight support roller 36 from above. Next, when the trigger 14 of the cutter mechanism 10 at the standby position shown in FIG. 1 is grasped, the sliding member SL1 of the switch lock mechanism SL is urged downward by a spring (not shown), and the trigger 14 is engaged in the switch-on state. Stop. Therefore, it is not necessary for the user to hold the trigger 14 thereafter. When the trigger 14 is turned on, the motor operates and the rotary blade 1 is turned on.
6 is rotated. With the rotary blade 16 kept rotating,
The housing 13 is manually moved against the spring force of the torsion spring S.
The support plate 2 beyond the dead point of the rotary blade 16
A is rotated counterclockwise around the protruding rod 11 of A as viewed in FIG. Then, after that, even if the hand is released from the housing 13, the housing 13 is automatically rotated by the spring force of the torsion spring S to a position suitable for the rotary blade 16 to cut the pipe. That is, the end 19B of the adjustment shaft 19 is
Is rotated to a position where it abuts with the abutment plate 21A of
It will be locked at such a position. Thus, even if the user does not hold the housing 13 by hand, the rotary blade 16 is held at a position suitable for cutting the pipe.

The rotary blade 16, in particular, the cutting cutter 16A
Approximately at the same time when the outer cover contacts the outer peripheral surface of the clamped pipe, the safety cover 17 also contacts the outer peripheral surface of the pipe. When the housing 13 is further rotated in the counterclockwise direction, the safety cover 17 that is in contact with the outer peripheral surface of the pipe is kept in contact with the outer peripheral surface of the pipe and receives the urging force of the urging means (not shown). On the contrary, the housing 13 is pivoted around the pivot shaft (not shown).
Rotates clockwise with respect to. As a result, the safety cover 17 always covers the rotary blade 16 from above while the rotary blade 16 is cutting the pipe, and prevents a worker from being injured by a cut piece of the pipe. The rotary blade 16 pressed against the pipe first has its cutting cutter portion 16A partially cutting the peripheral wall of the pipe, and subsequently, the chamfering cutter portion 16B chamfers the partially cut peripheral wall of the pipe. I do.

Subsequently, the entire peripheral wall of the pipe is cut and chamfered by turning the pipe by hand. As mentioned above,
Once the trigger 14 is switched on, the rotary blade 16 continues to rotate even after the trigger 14 is released, and the housing 13 is moved once beyond the dead point position immediately before the rotary blade 16 comes into contact with the pipe. If rotated in the counterclockwise direction as viewed in FIG. 1, the rotating blade 16 is automatically biased to a position suitable for cutting the pipe even when the hand is released from the housing 13 and held there. Therefore, the user of the pipe cutter 1 can use both hands to turn the pipe, thereby improving the accuracy of pipe cutting, and eliminating work by a plurality of persons to improve work efficiency. Can be increased. Although a thrust force is applied to the pipe by the chamfering cutter section 16B, the rollers 4 for clamping the pipe,
Since the outer peripheral portions of 36 and 39 are made of rubber and a frictional engagement force exists between these rollers and the pipe, the thrust force causes the pipe to move in the axial direction with respect to the pipe cutter 1. Never.

The present invention is not limited to the above-described embodiment, but allows various modifications as described below. For example, in the above-described embodiment, the stationary support roller 4 for clamping the pipe, the pipe's own weight support roller 36, and the clamp roller 39 are provided between the support plates 2A and 2B and the support portion 3 respectively.
5A and between the support portions 37B, but without extending between them, each roller 4,
36, 39, each support plate 2A, 2B, each support part 3
5A, each one may be rotatably attached to each support portion 37B.

[0028]

As described above, the present invention can provide a pipe cutter that can easily prepare for cutting a relatively lightweight pipe.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a pipe cutter of the present invention, showing a cutter mechanism and a rotating clamp arm (a first clamp arm and a second clamp arm) at a standby position and a pipe receiving position, respectively. It is.

FIG. 2 is a front view of the pipe cutter of FIG. 1, showing the cutter mechanism in an operative position and the rotating clamp arm in a clamp position.

FIG. 3 is a side view of the pipe cutter of FIG. 1;

FIG. 4 is a schematic partial enlarged view showing a mounting state of a torsion spring from a back surface of a pipe cutter.

[Explanation of symbols]

2A, 2B / support plate 3 / beam 3 (frame) 4 stationary support roller 10 cutter mechanism 34 center pivot rod (center axis) 35 / first clamp arm 37 / second clamp arm (rotary clamp arm) 36 Pipe weight support roller 39 Clamp roller

Claims (7)

[Claims] 1. A frame, a stationary support roller rotatably mounted on the frame for supporting a pipe to be cut from below, and mounted on the frame, parallel to a rotation axis of the stationary support roller. A rotation center axis having an extending axis, a rotation clamp arm rotatably mounted on the rotation center axis and having two free ends, one free end of the rotation clamp arm; A rotatable pipe weight support roller for supporting a pipe to be cut from below is rotatably mounted on the portion, and the stationary support roller and the pipe weight support roller are provided at the other free end of the rotating clamp arm. A clamp roller for clamping the pipe to be cut from above a horizontal plane passing through the center axis of the pipe is rotatably mounted on the pipe, A rotatively mounted cutter mechanism for cutting the pipe, wherein when the pipe to be cut is placed on the pipe's own weight support roller of the rotary clamp arm, the rotary clamp arm rotates Rotating around a central axis, the pipe's own weight support roller supports the pipe together with the stationary support roller from below, and the clamp roller controls the pipe,
A pipe cutter for clamping the stationary support roller and the pipe's own weight support roller from above. 2. A stopper for preventing the rotation center axis of the pipe's own weight supporting roller from rotating away from the stationary support roller beyond a vertical plane passing through the axis of the rotation center axis. Item 4. The pipe cutter according to Item 1. 3. A stopper for preventing the rotation center axis of the pipe's own weight support roller from rotating downward beyond a horizontal plane passing through the rotation center axis of the stationary support roller. 2. The pipe cutter according to 2. 4. A pipe extending from the center axis of rotation of the stationary support roller through a central axis of a pipe supported by the stationary support roller and the pipe's own weight support roller, above an outer peripheral point of the pipe where the plane is located. The clamp roller clamps the pipe from above.
The pipe cutter according to claim 3. 5. The cutter mechanism comprises: cutter means for cutting a pipe; a prime mover for driving the cutter means; and a switch for turning on / off the prime mover. The pipe cutter according to any one of claims 1 to 4, further comprising a switch lock mechanism for locking in an ON state. 6. A cutter mechanism urging means for urging the cutter mechanism so as to rotate the cutter mechanism with respect to the frame, wherein the cutter mechanism urging means is configured to cut the cutter mechanism. When at the dead point, which is the position immediately before contact with the pipe to be made, the cutter mechanism is not urged in any direction, and the cutter mechanism is rotated by the user's hand from the dead point toward the pipe. When the cutter mechanism is turned by a user's hand so as to move away from the pipe from the dead point, the cutter mechanism is urged away from the pipe. The pipe cutter according to claim 5, wherein 7. The pipe cutter according to claim 6, wherein the cutter mechanism urging means is a torsion spring having one end attached to the frame and the other end attached to the cutter mechanism.