JPH022647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe cutter with a simple structure in which the blade is fed by a ratchet mechanism.

The present invention particularly provides a new and simple pistol-shaped pipe cutter, which allows the cutter blade to be easily fed by simply holding the handle and pulling the feed lever, which corresponds to the trigger of a pistol. It is an object of the present invention to provide a pipe cutter that is suitable for cutting pipes in narrow working spaces such as pipe burying construction sites, has a simpler structure than conventional pipe cutters, and is easier to operate and handle.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

The pipe cutter according to the present invention has a main body 1 having a handle 3, and a support arm 5 having a substantially semicircular arc shape.
are integrally formed. Holding rollers 7, 7 for stably holding the pipe P to be cut at at least three points on the outer circumference of the pipe together with a roller cutter blade 11 (described later) are rotatably supported on the support arm 5 around shafts 9, 9. . The number of holding rollers 7, 7 may be two or more. Further, the holding rollers 7, 7 are preferably rotary bodies, but may be mere immovable contacts. Furthermore, the holding rollers 7, 7 themselves are also connected to the roller cutter blade 1.
It is also possible to use a roller cutter blade similar to 1 and a three-blade type cutter. However, if the holding roller is also configured as a roller cutter blade, the roller width W in the pipe axial direction as shown in FIG. 2 cannot be obtained, and the pipe P may wobble in the axial direction. It is desirable to provide In any case, the holding rollers 7, 7, including the above-mentioned modifications, are specified as pipe holding contacts in the present invention.

A cutter blade feed shaft 13 having a roller cutter blade 11 rotatably supported at its tip is mounted in the shaft groove 2 formed in the main body 1 so as to be movable in the axial direction thereof, that is, in the radial direction of the pipe P. The feed shaft 13 has, for example, a rectangular cross section, and ratchet teeth 15 are formed on its lower surface. A ratchet pawl 23, which is rotatably supported on the feed lever 21 via a pivot pin 20, is engaged with the ratchet tooth 15. Feed lever 2
1 is rotatably supported by the main body 1 via a pivot pin 17. The pawl 23 is engaged with a pin 6 implanted in the main body 1, and the pawl 23 can make a slight see-saw movement using the pin 6 as a fulcrum in accordance with the operation of the feed lever 21. One end of a first torsion coil spring 29 provided on the main body 1 is pressed against the pawl 23, and the pawl 23 is always biased counterclockwise in FIG. The other end of the spring 29 is locked to the main body 1 or the feed lever 21. On the other hand, one end of a second torsion coil spring 31 provided on the main body 1 is locked to the feed lever 21, and the feed lever 21 is always biased counterclockwise about the pin 17. The other end of the second spring 31 is connected to the main body 1
Alternatively, it can be locked by the claw 23.

Guide walls 33 and 3 integrally formed with the main body 1
A lock pawl 35 is provided in the groove 41 formed by the lock pawl 35.
is inserted so as to be movable in the vertical direction. The locking pawl 35 is constantly pressed upwardly by a spring 39 disposed in a groove provided at its lower end, so that the locking pawl 35 is normally engaged with the ratchet teeth 15 of the feed shaft 13. The locking pawl 35 has a notched shoulder 36, and the end hook 22 of the feed lever 21 is engaged with this shoulder 36, and the hook 22 pushes down the locking pawl 35 against the spring 39 and latches the locking pawl 35. It can be unlocked from tooth 13. The guide walls 33 and 34 are the feed lever 21
is discontinuous so that the tip hook 22 can protrude into the groove 41 to engage the shoulder 36 of the lock pawl 35. Ratchet pawl 23, lock pawl 35, hook 22, first and second springs 29, 3
The first class is a recess 4 that is continuous with the shaft groove 2 of the main body 1.
By fixing the lid cover 45 (FIG. 2) to the main body 1 with screws or the like, it becomes invisible from the outside.

In the pistol-shaped pipe cutter constructed as described above, by holding the handle 3 and pulling the feed lever 21, which corresponds to the trigger of a pistol, the feed shaft 13 is intermittently advanced in the radial direction. That is, when the feed lever 21 is pulled toward the handle 3 side, the feed lever 21 rotates clockwise around the pin 17, and as a result, the support shaft 21 of the pawl 23 (therefore, the pawl 23
Since the pawl 23 moves in a clockwise arc around the pin 17, the pawl 23 advances the feed shaft 13 by one step in the pipe radial direction via the ratchet teeth 15. When the feed lever 21 is released, the spring 31 returns it to its initial position. Therefore, the feed lever 21
If you rotate the entire cutter around the pipe P while repeatedly operating the trigger, the roller cutter blade 11
It bites into the pipe P little by little and can eventually cut the pipe P. Note that the lock pawl 35 is for preventing the feed shaft 13 from moving to the left in FIG. It's getting old.

When the feed shaft 13 is returned to the initial position after the pipe P has been cut, the feed lever 21 may be rotated in a direction away from the handle 3, that is, counterclockwise. By doing this, the ratchet pawl 23 is pulled down diagonally to the left in FIG. The feed shaft 13 is pushed down by the hook 22 of the feed lever 21, so the feed shaft 13 is pushed down by the hook 22 of the feed lever 21.
3, 35, and therefore the cutter blade 1
1 can be moved back significantly by the return spring 60. Note that 14 is a knob of the feed shaft 13 that serves as a handle when moving the feed shaft 13 forward.

In the above configuration, in order to cut the pipe P, it is necessary to rotate the entire cutter at least around the circumference of the pipe P. Depending on the work site, it may not be possible to rotate the entire cutter around the pipe P once. In such a case, it is advantageous to replace all the holding rollers 7 with roller cutter blades similar to the roller cutter blades 11 as described above. That is, in that case, the pipe P
Since three different points on the outer periphery of the cutter are to be cut at the same time using three blades, it is sufficient to hold the handle 3 and move the cutter back and forth within a certain angle range while repeating the trigger operation by the feed lever 21. .
However, in the case of such a three-blade cutter, all three roller cutter blades are located in one plane that includes the cutting line of the pipe, so the pipe P is actually held in line contact by the three roller cutter blades. It's nothing more than that. Therefore, the pipe P or the cutter may wobble in the axial direction, and in such a case, guide means for holding the pipe on both sides of the cutter body are required. For example, the first
A pair of scissor-shaped guide arms 50A and 50B as shown by imaginary lines in FIG. 2 can be considered. Guide arm 50A,
50B is pivoted at a fulcrum 51 fixed to the feed shaft 13, and one end thereof is connected by a compression spring 53. A pipe P is held between the other ends of the guide arms 50A and 50B. Guide arm 50A, 50
B gradually expands as the blade of the feed shaft 13 moves forward, and gradually shifts the point of contact with the pipe P while holding the pipe P between the blades. The strength of the compression spring 53 is preferably set so that it can clamp the pipe P with a certain degree of force in its free state.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of a pipe cutter according to the present invention, FIG. 2 is a plan view of FIG. 1, and FIG.
The right side view of the figure, and FIG. 4 is the left side view of FIG. DESCRIPTION OF SYMBOLS 1...Main body, 3...Handle, 7...Holding roller, 11...
Roller cutter blade, 13... feed shaft, 15... ratchet tooth, 21... feed lever, 23... ratchet claw.

Claims (1)

[Claims] 1 A main body having a handle, a plurality of pipe holding contacts attached to the main body, and a roller cutter blade that is disposed opposite to the contacts and holds the pipe together with the contacts at at least three points on the circumference. a feed shaft with ratchet teeth that is movably mounted in the main body in the radial direction of the pipe and holds the roller cutter blade at its tip; and a feed lever that is pivotally supported on the main body and has a ratchet claw that engages with the ratchet teeth of the feed shaft. 1. A ratchet type pipe cutter, characterized in that the feed shaft can be intermittently fed in the radial direction of the pipe by holding the handle and operating the feed lever.