JP2019025588A - Pipe wrench - Google Patents

Abstract

To provide a pipe wrench which does not damage a pipe surface when fastening.SOLUTION: In a pipe wrench, a stem of a first pipe gripping component 1 having a gripping part 1a whose inner face has a semicircular shape is rotatably supported on a tip of a rod-like handle lever 3, and a stem of a second pipe gripping component 2 having a gripping part 2a whose inner face has a semicircular shape is rotatably supported on a tip of the first pipe gripping component. Further, a tip of the second pipe gripping component is provided with an engaging piece 2b which comes into contact with a pressing part 3a at the tip of the handle lever 3, and the pipe wrench grips a pipe between the gripping part 1a of the first pipe gripping component and the gripping part 2a of the second pipe gripping component in a state that the pressing part 3a and the engaging piece 2b are engaged with each other. Inner diameters of the first pipe gripping component and the second pipe gripping component are so formed as to be smaller than a pipe outer diameter.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pipe wrench that does not damage the pipe surface during tightening and loosening.

  Conventionally, a pipe wrench has been widely used for tightening and loosening pipes. As this pipe wrench, as shown in Patent Document 1, a pipe wrench is generally held by holding a pipe between a tooth placement and a tooth arranged to face the tooth placement.

  However, in the case of the wrench, there is a problem that when the pipe is sandwiched, the tooth implant and the tooth bite into the surface of the pipe and damage the pipe. In recent years, there are many cases where a water supply pipe having a beautiful appearance with a plating process or a coating process is used on the surface, and the demand for preventing the pipe from being damaged is increasing.

  Therefore, as a pipe wrench that can be tightened and loosened without damaging the pipe, as shown in Patent Literature 2, a belt is attached to the inner surface of the pipe clamping member and the pipe is clamped and held by this belt. A tightening wrench has been proposed. However, in this case, there is a play until the belt firmly grasps the pipe, and the lever (handle) needs to be largely rotated until the tightening torque is generated. However, there is a problem that it needs to be frequently replaced because it wears out in a short period of time.

  Also, as shown in Patent Document 3, the pipe is gripped between the first pipe gripping member whose inner surface is semicircular and the second pipe gripping member whose inner surface is semicircular, so that it is tightened and loosened without being damaged. Pipe wrench has also been proposed. However, in this pipe wrench, the inner diameter of the pipe gripping member and the outer diameter of the pipe are the same. Therefore, either or both of the pipe gripping member and the pipe are not deformed and the two may not be in close contact with each other, and there is a problem that the force for gripping the pipe is small and slipping easily. Therefore, when the handle lever is rotated counterclockwise, the pipe wrench is unintentionally detached from the pipe, which makes it difficult to perform the work.

JP-A-8-19966 Japanese Utility Model Publication No. 50-136896 Japanese Utility Model Publication No. 57-34366

  The present invention solves the above-mentioned conventional problems, eliminates damage to the pipe, and has a small range of lever rotation during pipe tightening and loosening work, and works in a small work space. It aims at providing the pipe wrench which can perform.

  In the pipe wrench of the present invention made to solve the above-mentioned problems, the base portion of the first pipe gripping member having the grip portion having a semicircular inner surface is pivotally supported by the tip end portion of the rod-shaped handle lever. In addition, a base portion of a second pipe gripping member having a grip portion having a semicircular inner surface is pivotally supported at the tip end portion of the first pipe gripping member, and the tip end portion of the second pipe gripping member is also supported. Is provided with a locking piece that comes into contact with the pressing portion at the tip of the handle lever, and the gripping portion of the first pipe gripping member and the second pipe gripping state with the pressing portion and the locking piece engaged. A pipe wrench configured to grip a pipe between gripping portions of members, wherein an inner diameter of the gripping portions of the first pipe gripping member and the second pipe gripping member is formed smaller than an outer diameter of the pipe. And claim this The invention according to.

  According to a preferred embodiment, it is preferable that the inner diameter of the pipe gripping portion is 0.5 to 5% smaller than the outer diameter of the pipe, and this is the invention according to claim 2.

  According to another preferred embodiment, a compression coil spring for preventing the second pipe gripping member from rotating in the opening direction by its own weight is provided at a pivotal support portion of the first pipe gripping member and the second pipe gripping member. Is preferable, and this is the invention according to claim 3.

  According to another preferred embodiment, the locking piece is preferably formed with an arcuate recess that receives the pressing portion of the handle lever, and this is the invention according to claim 5.

  In the first aspect of the present invention, the inner diameters of the grip portions of the first pipe gripping member and the second pipe gripping member are formed smaller than the outer diameter of the pipe, and the first pipe gripping member and the second pipe gripping member are closed. The pipe gripping member and / or the pipe are slightly deformed by the pressing force so that they are brought into close contact with each other so that the pipe is gripped, so that the entire outer periphery of the pipe and the entire inner surface of the gripping portion of the pipe gripping member It will be firmly grasped in surface contact. As a result, the pipe outer peripheral surface can be reliably grasped and rotated, and the pipe surface can be prevented from being damaged.

  In the invention according to claim 2, since the inner diameter of the grip part is 0.5 to 5% smaller than the pipe outer diameter, either the pipe gripping member or the pipe, or both are slightly deformed, The outer periphery of the pipe and the entire inner surface of the gripping part are in close contact with each other, and the tightening operation can be reliably performed with sufficient frictional force.

  In the invention according to claim 3, a compression coil spring for preventing the second pipe gripping member from rotating in the opening direction by its own weight is mounted on the pivotal support portion of the first pipe gripping member and the second pipe gripping member. Therefore, when the second pipe gripping member does not open freely due to its own weight and the pipe wrench is idled with respect to the pipe and the pipe wrench is moved to a position where it can be easily operated, the handle lever and the second pipe Even if the gripping member 2 is separated, it can be prevented from coming off the careless pipe, and excellent handling properties can be exhibited.

  In the invention according to claim 4, since the locking piece is formed with an arcuate recess for receiving the pressing portion of the handle lever, the pressing force is always applied when the handle lever is operated in the pressing direction. Since a predetermined pressing force is applied to the center of the shaft, a tightening operation can be reliably performed. Further, since the contact area is large, wear of the handle lever and the pressing portion can be reduced.

It is a front view which shows embodiment of this invention. It is a top view of FIG. It is a front view which shows a 1st pipe holding member. FIG. 4 is a bottom view of FIG. 3. It is a front view which shows a 2nd pipe grip member. FIG. 6 is a bottom view of FIG. 5. It is sectional drawing which shows the recessed part of a locking piece. It is sectional drawing which shows the state before grasping a pipe with the pipe wrench of this invention. It is sectional drawing which shows the state which grasped the pipe with the pipe wrench of this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view showing a pipe wrench of the present invention, and FIG. 2 is a plan view thereof.
In FIG. 1, reference numeral 1 denotes a first pipe gripping member having a semicircular gripping portion 1a, and 2 denotes a second pipe gripping member having a semicircular gripping portion 2a. The pipe 20 (see FIG. 8) is gripped by the entire inner peripheral surface by the grip portion 1a and the grip portion 2a of the second pipe grip member 2.

  The base of the first pipe gripping member 1 is pivotally supported by a pin 4a at the tip of a round bar-like handle lever 3, while the tip of the first pipe gripping member 1 on the other end side. The base of the second pipe gripping member 2 is pivotally supported by the part by a pin 4b. Further, a locking piece 2b that comes into contact with the pressing portion 3a at the distal end of the handle lever 3 is provided at the distal end portion of the second pipe gripping member 2, and the pressing portion 3a is moved down by the pressing operation of the handle lever 3. The locking piece 2b is pushed up so that the pipe 20 is firmly gripped between the grip portion 1a of the first pipe gripping member 1 and the grip portion 2a of the second pipe gripping member 2.

FIG. 3 shows a front view of the first pipe gripping member 1, and FIG. 4 shows a bottom view thereof. A grip portion 1 a having an inner surface semicircular is formed at the front portion of the first pipe gripping member 1. The base is bifurcated so as to straddle the handle lever 3, a hole for inserting the pin 4a is formed, and the tip is also bifurcated so as to be connected to the second pipe gripping member 2. A hole for inserting the pin 4b is formed.
5 shows a front view of the second pipe gripping member 2, and FIG. 6 shows a bottom view thereof. In the second pipe gripping member 2, a hole for inserting the pin 4b is formed in the base portion, and a gripping portion 2a having a semicircular inner surface is formed in the middle. In addition, a locking piece 2b that comes into contact with the pressing portion 3a at the tip of the handle lever 3 is provided at the tip.

The pipe wrench of the present invention has a structure in which the inner diameters of the grip portions 1 a and 2 a of the first pipe gripping member 1 and the second pipe gripping member 2 are slightly smaller than the outer diameter of the pipe 20.
As a result of research conducted by the present inventor, when the gripping portions 1a and 2a have the same inner diameter as the outer diameter of the pipe 20, the pipe wrench is idled because a sufficient pressing force does not act on the pipe when gripping. I understood. Therefore, when the gripping portions 1a and 2a are formed to have an inner diameter slightly smaller than the outer diameter of the pipe 20, when the pipe gripping member is operated in the closing direction, the gripping portions 1a and 2a of the pipe gripping member are connected to the pipe. It has been found that any of 20 is slightly deformed, or both the grip portions 1a, 2a and the pipe 20 are slightly deformed, and the grip portion and the pipe are brought into close contact by the reaction force. Moreover, since the pipe gripping members 1a, 2a and the pipe 20 are in surface contact, it has been found that the pipe surface can be prevented from being damaged. In this way, it was confirmed that a sufficient frictional force was generated between the pipe gripping members 1a, 2a and the pipe 20 and the pipe wrench could reliably rotate the pipe.
Further, although the tightening operation is performed by the handle lever 3, there is an advantage that the work space can be reduced because of the slight rotation.

As a result of collecting and analyzing a lot of data on the ratio of slightly reducing the inner diameters of the gripping portions 1a and 2a, the inner diameter of the gripping portion should be 0.5 to 5% smaller than the outer diameter of the pipe. Was found to be preferred.
If it is less than 0.5%, the gripping portions 1a, 2a may be idle due to insufficient frictional force. If it is more than 5%, the gripping portions 1a, 2a bite into the pipe depending on the material and hardness of the gripping portions 1a, 2a. If the outer surface of the pipe is damaged, or if the pipe wrench is idled with respect to the pipe and the pipe wrench is moved to a position where it can be easily operated, the pipe and the pipe wrench may not be separated from each other. Let it be 0.5-5% smaller than the diameter.
Further, since the end portions of the grip portions 1a and 2a are formed in an arc shape, it is more preferable that they do not bite into the pipe and damage the outer surface of the pipe.

In addition, as shown in FIG. 2, the pivot of the first pipe gripping member 1 and the second pipe gripping member 2 is for preventing the second pipe gripping member from rotating in the opening direction by its own weight. A compression coil spring 5 is attached.
As a result, a force that suppresses the second pipe gripping member 2 from rotating with respect to the first pipe gripping member 1 due to the derivation of the elastic force in the axial direction of the pin 4b is applied. Prevents from drooping in the direction of natural opening due to its own weight.
As a result, since the second pipe gripping member 2 does not hang down, the handle lever 3 and the second pipe gripping member 2 are separated when the pipe wrench is idled relative to the pipe and the pipe wrench is moved to a position where it can be easily operated. However, it is possible to prevent inadvertent disconnection from the pipe.

As shown in FIG. 7, an arcuate recess 6 that receives the pressing portion 3 a of the handle lever 3 can be formed in the locking piece 2 b of the second pipe gripping member 2.
Accordingly, when the round bar-like handle lever 3 is operated in the pressing direction, the pressing force always acts toward the center of the concave portion 6 to provide a stable pressing force, and therefore it is preferable that the tightening operation can be performed reliably. Moreover, since the contact area is large, wear of the handle lever 3 and the pressing portion 3a can be reduced.

Next, the usage method of the pipe wrench comprised as mentioned above is demonstrated.
FIG. 8 is a cross-sectional view showing a state before the pipe is gripped by the pipe wrench of the present invention. The handle lever 3 is rotated counterclockwise about the pin 4a, and the second pipe gripping member 2 is rotated clockwise about the pin 4b, so that the tip of the second pipe gripping member 2 and the handle are rotated. A gap is formed between the tip portions of the lever 3 so that the pipe 20 can be introduced between the grip portions 1a and 2a.
At this time, a compression coil spring 5 for preventing the second pipe gripping member 2 from rotating in the opening direction due to its own weight is attached to the pivotal support portion of the first pipe gripping member 1 and the second pipe gripping member 2. Therefore, the second pipe gripping member 2 is prevented from sagging in the direction of natural opening due to its own weight. Accordingly, when the pipe wrench is idled relative to the pipe and the pipe wrench is moved to a position where it can be easily operated, it is possible to prevent the handle lever 3 and the second pipe gripping member 2 from being inadvertently detached from the pipe even if they are separated. .

After the pipe 20 is mounted, as shown in FIG. 9, the second pipe gripping member 2 is rotated counterclockwise about the pin 4b, and the pipe 20 is sandwiched between the gripping portions 1a and 2a. Next, after the pressing portion 3a at the tip of the handle lever 3 is engaged with the engaging piece 2b at the tip of the second pipe gripping member 2, the handle lever 3 is slightly rotated clockwise to 20 is fixed between the gripping portion 1a of the first pipe gripping member 1 and the gripping portion 2a of the second pipe gripping member 2.
Since the inner diameters of the grip portions 1a and 2a are smaller than the outer diameter of the pipe 20, any one of the pipe gripping members 1 and 2 and the pipe 20 is caused by the pressing force generated by the rotation of the handle lever 3. Alternatively, both of them are slightly deformed so that they are brought into close contact with each other and the pipe is gripped. As a result, since the entire outer periphery of the pipe 20 is firmly held in surface contact with the entire inner surfaces of the gripping portions 1a and 2a of the pipe gripping member, the pipe outer peripheral surface is securely gripped and rotated. Can do. Moreover, since the fixing is performed by the frictional force of the surface contact, the teeth do not bite as in the conventional case, so that the pipe surface can be prevented from being damaged.

  Thereafter, when removing the pipe wrench from the pipe 20, after the handle lever 3 is released, the engagement between the pressing portion 3a and the locking piece 2b is released, and the second pipe gripping member 2 is rotated clockwise. The tip can be opened and removed from the pipe 20 easily.

DESCRIPTION OF SYMBOLS 1 1st pipe grip member 1a Grasp part 2 2nd pipe grip member 2a Grasp part 2b Locking piece 3 Handle lever 3a Press part 4a Pin 4b Pin 5 Compression coil spring 6 Recessed part 20 Pipe

Claims (4)

The base portion of the first pipe gripping member having a semicircular gripping portion on the inner surface is pivotally supported by the tip end portion of the rod-like handle lever, and the inner surface is semicircular at the tip end portion of the first pipe gripping member. A base portion of a second pipe gripping member having a gripping portion is pivotally supported, and a locking piece abutting against a pressing portion at a tip of the handle lever is supported at a tip portion of the second pipe gripping member. A pipe wrench configured to grip the pipe between the gripping portion of the first pipe gripping member and the gripping portion of the second pipe gripping member in a state where the pressing portion and the locking piece are engaged with each other. There,
A pipe wrench characterized in that the inner diameters of the grip portions of the first pipe gripping member and the second pipe gripping member are smaller than the outer diameter of the pipe.   The pipe wrench according to claim 1, wherein an inner diameter of the grip portion is 0.5 to 5% smaller than a pipe outer diameter.   A compression coil spring for preventing the second pipe gripping member from rotating in the opening direction due to its own weight is attached to the pivotal support portion of the first pipe gripping member and the second pipe gripping member. Pipe wrench as described in   The pipe wrench according to any one of claims 1 to 3, wherein the locking piece is formed with an arcuate recess that receives the pressing portion of the handle lever.

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