JP7383296B2 - Cutter - Google Patents

Description

The present invention relates to a single-edged cutter, and particularly to a single-edged pipe cutter for cutting resin pipes.

As pipe cutters for cutting resin pipes, those described in Patent Documents 1 to 3 are known.

The pipe cutters described in these documents are similar to single-edged scissors that have a moving blade and no static blade. An example of a conventional single-edged pipe cutter is shown in FIGS. 6 to 8.

The pipe cutter 1A shown in FIG. 6 has a moving blade 2 having a ratchet gear 3 and a first handle 4 having a receiving portion 6 connected by a pivot 7, and further includes a second handle 5 that is paired with the first handle 4. is connected to the first handle 4 by a pivot 8.

The receiving part 6 is a member that replaces the stationary blade of scissors, and has a slit (not shown) into which a moving blade enters in the center of the concavely curved pipe support surface.

Further, a second handle 5 is connected to the moving blade 2 via a link mechanism 9 in which two links 9a and 9b are connected by a hinge pin 9c, and the second handle 5 is further engaged with the teeth 3a of the ratchet gear 3. A ratchet pawl 10 that rotates the ratchet gear 3 and a stopper pawl 11 that prevents the ratchet gear 3 from rotating back are provided.

The ratchet pawl 10 and the stopper pawl 11 are urged by a spring 12 and a spring 13 in the direction of meshing with the teeth 3a of the ratchet gear 3, respectively.

The ratchet gear 3, which is integrated with the moving blade 2, has an outer peripheral surface on an arc centered on the pivot 7, and teeth 3a are arranged on the outer peripheral surface. Further, a portion of the ratchet gear 3 has an inner circumferential surface, and a stopper 15 is provided on the inner circumferential surface to be received by a stopper pin 14 fixed to the receiving portion 6.

Furthermore, the link 9a of the link mechanism 9 is connected to the second handle 5 using a hinge pin 17, and the link 9b is connected to the movable blade 2 using a hinge pin 18.

In the pipe cutter 1A configured in this way, when the second handle 5 is opened, the moving blade 2 is pulled through the link mechanism 9, and as shown in FIG. 7, the moving blade 2 rotates around the pivot 7. and open it to the specified position.

In this state, the pipe to be cut is set in the receiving part 6. The receiving portion 6 has a concavely curved pipe support surface 6a, into which the resin pipe 30 to be cut is inserted.

Thereafter, the second handle 5 is operated, and when the second handle 5 is closed, the ratchet pawl 10 engages with the teeth 3a of the ratchet gear, pushing the ratchet gear 3 to rotate. Due to this rotation, the movable blade 2 cuts into the resin pipe 30 as shown in FIG.

At this time, the stopper pawl 11 is pushed by the rotating ratchet gear 3 and escapes to a position where it is released from engagement with the teeth 3a.

The cutting of the movable blade 2 by the operation of the second handle 5 is such that when the second handle 5 is opened again, the locking position of the ratchet pawl 10 relative to the teeth 3a of the ratchet gear 3 shifts by about one to two teeth, and then When the second handle 5 is closed, the ratchet gear 3 is pushed by the amount of deviation and rotates.

As a result, the movable blade 2 gradually cuts into the resin pipe 30 by operating the second handle 5, and the resin pipe 30 can be cut in the state shown in FIG. 8.

Utility Model Publication No. 53-105090 Publication No. 54-83683 Publication No. 58-117263

In this type of pipe cutter, the cutting operation progresses while the cross section formed by cutting the resin pipe 30 comes into contact with the blade surface of the moving blade 2, which creates sliding resistance and requires extra force for the cutting operation. It happens.
Further, since an unnecessary load is applied to the cross section of the resin pipe 30, there is a problem that it may break or crack in an unintended direction.
Such a problem occurs not only when the object to be cut is a pipe, but also with single-edged cutters in general.

Therefore, the problem to be solved by the present invention is to reduce the sliding resistance caused by the contact of the cross section of the object to be cut with the blade surface of a single-edged cutter, reduce the force required for cutting work, and to This is to prevent cracks from occurring.

In order to solve the above problems, the single-edged cutter according to the invention has a first handle having a receiving part for the object to be cut, a movable blade pivoted to the first handle, and a movable blade that opens and closes. The movable blade is fully opened by operating the second handle in a direction away from the first handle, and the second handle is moved closer to the first handle. The cutter is a single-edged cutter that closes the movable blade by operating the moving blade in a direction, and uses the closed movable blade to cut the object to be cut supported by the receiving part, and the blade surface of the movable blade has a surface of the object to be cut. The structure is such that a through hole or a recess is provided on the trajectory of the cross section to avoid contact with the cross section.

In the single-edged cutter according to the invention, a link mechanism that connects the second handle to the moving blade, a ratchet gear formed integrally with the moving blade, a ratchet pawl that meshes with teeth of the ratchet gear, and the A stopper pawl is provided for preventing return rotation of the ratchet gear, and the moving blade and the first handle, and the first handle and the second handle are each pivotally connected at different locations, and the ratchet pawl and The stopper claw is provided on the second handle, and when the second handle opens for the first time, the ratchet gear is pulled via the link mechanism to fully open the closed movable blade. By the closing operation of the second handle, the ratchet pawl that is engaged with the teeth of the ratchet gear rotates the ratchet gear, and the movable blade moves in the closing direction, and by repeating the opening and closing operation of the second handle, the ratchet pawl is engaged with the teeth of the ratchet gear. The locking position of the ratchet pawl with respect to the teeth of is gradually shifted, and the amount of cutting of the movable blade into the object to be cut supported by the receiving portion increases, so that the object to be cut is cut. is preferable.

Further, although the object to be cut by the single-edged cutter according to the invention is not particularly limited, it is preferable that the pipe cutter is configured to be a resin pipe, and the receiving portion is an arc-shaped recessed receiving portion.

As described above, the cutter according to the invention has a configuration in which a through hole or a recess is provided on the trajectory of the blade surface of the moving blade along which the cross section of the object to be cut passes in order to avoid contact with the cross section. The sliding resistance between the movable blade and the already cut part of the object to be cut is reduced, making it possible to reduce the force required for the cutting operation.
Furthermore, since the load applied to the cross section of the object to be cut is reduced, it is possible to prevent the object from breaking or cracking in an unintended direction.

A side view of the pipe cutter of the embodiment in a state where the moving blade is fully opened. A vertical cross-sectional view of the pipe cutter according to the embodiment, with the movable blade placed in a half-open state. A vertical cross-sectional view of the pipe cutter according to the embodiment, with the movable blade in a fully closed state. (a) is a side view of the movable blade, (b) is a sectional view indicated by the arrow in (a), and (c) is a sectional view indicated by the arrow in (a) in another example. Side view of another example of moving blade Side view of a conventional pipe cutter with the moving blade fully open Side view of a conventional pipe cutter with the moving blade half open It is a sectional view of a side view of a conventional pipe cutter in a state where the movable blade is fully closed.

Embodiments of the present invention will be described below with reference to the drawings.
The pipe cutter 1 shown in FIGS. 1 to 3 is used to cut resin pipes, and is particularly suitable for cutting large diameter resin pipes 30.

The pipe cutter 1 includes a moving blade 2 having a ratchet gear 3, a first handle 4 having a receiving portion 6, a second handle 5 paired with the first handle 4, and the second handle 5. A link mechanism 9 that connects the movable blade 2 to the moving blade 2, a ratchet pawl 10 that meshes with the teeth 3a of the ratchet gear 3, and a stopper pawl 11 that prevents the ratchet gear 3 from rotating back.

The movable blade 2 is a blade made of carbon tool steel or the like, and when it becomes damaged and difficult to cut, it is replaced with a resharpened one or a new one. The ratchet gear 3 is a gear that is integrated with the moving blade 2. The ratchet gear 3 is a fan-shaped gear that rotates about the pivot 7 as a fulcrum.

The ratchet gear 3 has an outer peripheral surface on an arc centered on the pivot 7, and teeth 3a are arranged on the outer peripheral surface.

As shown, the ratchet pawl 10 and the stopper pawl 11 are urged by a spring 12 and a spring 13 in the direction of meshing with the teeth 3a of the ratchet gear 3, respectively. Furthermore, the movable blade 2 is pivotally coupled to the first handle 4 using a pivot 7, and the second handle 5 is pivotally coupled to the first handle 4 using a pivot 8.

Further, the ratchet pawl 10 is rotatably attached to the second handle 5 using a pivot 8, and the stopper pawl 11 is rotatably attached to the second handle 5 using a hinge pin 16 that connects the first and second handles.

The link mechanism 9 has two links 9a and 9b connected by a hinge pin 9c.The link 9a is connected to the second handle 5 using a hinge pin 16, and the link 9b is connected to the moving blade 2 using a hinge pin 18. are connected.

A hook-type opening stopper 19 for holding the first and second handles 4 and 5 in the closed position is provided at the rear end of the first handle 4. Although the opening stopper 19 is constructed of a hook type in the figure, it may be constructed of a chain or the like.

As shown in FIGS. 4A and 4B, the movable blade 2 of the pipe cutter 1 is provided with an oblong through hole 2b that penetrates between the left and right blade surfaces 2a.
The through hole 2b is located on the trajectory through which the cross section of the pipe 30 passes, and contact between the cross section and the blade surface 2a is avoided or suppressed.
Therefore, the occurrence of sliding resistance caused by the already cut part (cross section) of the pipe 30 rubbing against the blade surface 2a of the moving blade 2 is suppressed, the force required for cutting work is reduced, and the unnecessary load on the pipe is suppressed. This prevents cracks and cracks from occurring.
Note that the shape of the through hole 2b is not limited as long as at least a portion thereof is located on the trajectory through which the cross section of the pipe 30 passes, and may be, for example, a pair of left and right semicircles as shown in FIG.
In addition, instead of the through hole 2b, as shown in FIG. 4(c), contact between the cross section of the pipe 30 of the left and right blade surfaces 2a is avoided or suppressed on the trajectory along which the cross section of the pipe 30 passes. Such a recess 2c may be provided.
Here, if the size, formation position, shape, etc. of the through holes 2b and the recesses 2c are adjusted so that the contact area with the pipe 30 is 50% or less compared to the case where these do not exist, good contact can be achieved. It can exert an avoidance or suppression effect.

A film such as electroless nickel plating containing fluororesin (Ni--B plating) can be further formed on the blade surface 2a of the moving blade.
By forming the film in this way, the sliding resistance when cutting the pipe is further reduced. Even if it is a composite pipe, it becomes possible to cut it well without crushing or damaging the heat insulating layer 33.

The configuration of the pipe cutter 1 according to the embodiment is as described above, and the method of using the same will be explained next.
First, the first opening operation of the second handle 5 causes the ratchet gear 3 to be pulled and rotated via the link mechanism 9, and the movable blade 2, which had been closed, is fully opened at once.

Next, as the second handle 5 closes, the ratchet pawl 10 engaged with the teeth 3a of the ratchet gear 3 pushes the ratchet gear 3 to rotate. As the movable blade 2 rotates, the moving blade 2 moves in the closing direction and cuts into the pipe 30 supported by the circularly recessed receiving part 6.
The cross section of the pipe 30 is located on the blade surface 2a of the movable blade 2, but since the through hole 2b is present here, the contact area between the cross section and the blade surface 2a is reduced.

Thereafter, the second handle 5 is opened and closed continuously, and as the opening and closing operations are repeated, the locking position of the ratchet pawl 10 relative to the teeth 3a of the ratchet gear 3 gradually shifts.

Through this operation, the amount of cutting of the movable blade 2 into the pipe 30 supported by the receiving part 6 increases little by little, and finally the cutting edge enters the slit provided in the pipe support surface 6a of the receiving part 6, and the pipe 30 is completely cut. It will be cut off.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, and is intended to include all modifications and variations within the meaning and scope equivalent to the claims.

In the embodiment, a pipe cutter that uses a ratchet gear, a link mechanism, a ratchet pawl, etc. is shown as a pipe cutter suitable for cutting large diameter resin pipes, but these are omitted and the pipe cutter is suitable for cutting small diameter resin pipes. Preferably, the movable blade 2 is integrally provided with the second handle 5, and the movable blade 2 is connected to the first handle 4 by a pivot 7, so that the second handle 5 can input input using only the leverage. It is good also as a structure which amplifies and operates the moving blade 2.

Further, in the embodiment, the object to be cut is the resin pipe 30, but the object to be cut is not limited to this. Depending on the shape of the object to be cut, the shape of the receiving portion 6, etc. can be changed as appropriate.

1 Pipe cutter 1A of the embodiment Conventional pipe cutter 2 Moving blade 2a Blade surface 2b Through hole 2c Recessed portion 3 Ratchet gear 3a Teeth 4 First handle 5 Second handle 6 Receiving portion 6a Pipe support surface 7 Pivot 8 Pivot 9 Link Mechanism 9a Link 9b Link 9c Hinge pin 10 Ratchet pawl 11 Stopper pawl 12 Spring 13 Spring 14 Stopper pin 15 Stopper 16 Hinge pin 17 Hinge pin 18 Hinge pin 19 Opening stopper 30 Resin pipe 31 Inner pipe 32 Outer pipe 33 Heat insulation layer

Claims (3)

a first handle (4) having an arcuate recessed receiving portion (6) for receiving a resin pipe (30) to be cut;
a moving blade (2) pivotally coupled to the first handle (4);
A second handle (5) for opening and closing the movable blade (2) is provided,
fully opening the movable blade (2) by operating the second handle (5) in a direction away from the first handle (4);
further, operating the second handle (5) in a direction approaching the first handle (4) to close the movable blade (2);
A single-edged pipe cutter that cuts the resin pipe (30) supported by the receiving part (6) with its closing movable blade (2),
The blade surface (2a) of the movable blade (2) is on a trajectory through which the cross section of the resin pipe (30) passes, and overlaps with the receiving portion (6) when the movable blade (2) is fully closed. A pipe cutter that is provided with an oblong circular through hole (2b) or recess (2c) only at a position to avoid contact with the cross section. a link mechanism (9) that connects the second handle (5) to the moving blade (2);
a ratchet gear (3) integrally formed with the moving blade (2);
a ratchet pawl (10) that meshes with the teeth (3a) of the ratchet gear (3);
comprising a stopper pawl (11) for preventing return rotation of the ratchet gear (3);
The moving blade (2) and the first handle (4) and the first handle (4) and the second handle (5) are each pivot-coupled at different locations,
The ratchet pawl (10) and the stopper pawl (11) are provided on the second handle (5),
The first opening operation of the second handle (5) pulls the ratchet gear (3) via the link mechanism (9) and fully opens the movable blade (2), which had been closed.
Due to the closing operation of the second handle (5), the ratchet pawl (10) that is engaged with the teeth (3a) of the ratchet gear (3) rotates the ratchet gear (3) and rotates the movable blade (2). moves in the closing direction,
By repeating the opening and closing operations of the second handle (5), the locking position of the ratchet pawl (10) with respect to the teeth (3a) of the ratchet gear (3) gradually shifts and is supported by the receiving portion (6). The pipe cutter according to claim 1, wherein the resin pipe (30) is cut by increasing the cutting amount of the movable blade (2) into the resin pipe (30) . The pipe cutter according to claim 1 or 2, wherein the blade surface (2a) of the moving blade (2) is coated with a film made of electroless nickel plating containing fluororesin.

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