Cutting tool

Provided is a cutting tool with which an operator can cut a to-be-cut material by grasping a second handle while setting a first handle stably, and in which the first handle can be changed from a stably-set mode to a grippable mode as with the second handle. The cutting tool has a sidewardly-protruding extension component disposed at the base end of the first handle, which is installed so that, with respect to a handle main body of the first handle, it can be freely changed between a transverse position substantially aligned with the axial direction of the pivotal shaft and a longitudinal position aligned with the lengthwise direction of the handle main body, and, a position holding mechanism is disposed between the extension component and the handle main body, for holding the extension component in each position.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2014-018594, filed Feb. 3, 2014. The content of this application is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a cutting tool designed to cut a material to be cut by opening and closing a pair of cutting blade bodies through opening-closing operation of a first handle and a second handle.

BACKGROUND ART

There is a cutting tool for cutting a material to be cut such as a wire, a cable, a bar, a tubing, and so forth, which comprises a pair of cutting blade bodies, and a first handle and a second handle coupled to the cutting blade bodies. This cutting tool is designed to cut a to-be-cut material by opening and closing the paired cutting blade bodies through opening-closing operation of the first and second handles.

In a cutting tool of such a conventional type, the front end side of the first handle is annexed with a circular plate or is securely fitted with a rolling preventive plate, and, with this construction, an operator is able to cut a to-be-cut material with greater force by following a step of setting the first handle stably by pushing down the circular plate or rolling preventive plate with his/her foot, and a step of carrying out opening-closing operation of the first handle by grasping the second handle with his/her hands while keeping his/her weight thereon (refer to Patent literatures 1 and 2, for example).

PRIOR ART REFERENCE

Patent Literature

Patent literature 1: Japanese Utility Model Registration No. 3109603

Patent literature 2: Japanese Examined Utility Model Publication JP-Y2 7-42574 (1995)

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In the conventional construction, however, since the circular plate or rolling preventive plate is unretractably attached to the front end side of the first handle, in a case where an operator cuts a to-be-cut material by grasping the first and second handles with his/her hands, the circular plate or rolling preventive plate constitutes an obstruction to cutting operation, and consequently the to-be-cut material cannot be cut with ease, thus causing inconvenience.

The present invention has been devised in view of the problems as mentioned supra, and accordingly its object is to provide a cutting tool with which an operator is able to cut a material to be cut by grasping a second handle while setting a first handle stably, and in which the first handle can be changed from a stably-set mode to a grippable mode as with the second handle.

Means for Solving the Problem

The following is specific problem-solving means pursuant to the present invention.

According to technical means of the present invention for solving the technical problems, there is provided a cutting tool comprising: a first handle5and a second handle6coupled to each other via a pivotal shaft17; cutting blade bodies3and4coupled to front end sides of, respectively, the first and second handles5and6; a sidewardly-protruding extension component29disposed at a base end side of the first handle5, which is installed so that, with respect to a handle main body11of the first handle5, it can be freely changed in position between a transverse position X which is substantially aligned with an axial direction of the pivotal shaft17and a longitudinal position Y which is aligned with a lengthwise direction of the handle main body; and a position holding mechanism45disposed between the extension component29and the handle main body11, for holding the extension component29in each of the positions X and Y.

Moreover, in another aspect of the technical means of the present invention, the first handle5is constructed by coupling the extension component29to the base end of the handle main body11, and, the extension component29serves as a handle grip when it is in the longitudinal position Y.

Moreover, in another aspect of the technical means of the present invention, the extension component29comprises: a component coupling member33coupled, via a pivot31, to a main body coupling member30disposed at the base end of the handle main body11; and a cylindrical member34fitted externally to the component coupling member33, which passes over the pivot31into engagement with the main body coupling member30so as to assume the longitudinal position Y.

The extension component29is allowed to rotate about the pivot31upon disengagement of the cylindrical member34from the main body coupling member30, and is restrained against rotation about the pivot31upon abutting of the front end of the cylindrical member34on the main body coupling member30in the transverse position X.

Moreover, in another aspect of the technical means of the present invention, the position holding mechanism45comprises: longitudinally positioning means47for restraining the cylindrical member34against movement relative to the main body coupling member30when the extension component29is in the longitudinal position Y; transversely positioning means48for restraining the cylindrical member34against movement relative to the component coupling member33when the extension component29is in the transverse position X; and release means49disposed in the extension component29, for releasing restraint imposed by the longitudinally positioning means47and the transversely positioning means48.

Moreover, instill another aspect of the technical means of the present invention, the cylindrical member34of the extension component29is formed with an engagement hole43. The longitudinally positioning means47has a positioning pin51which protrudes from the interior of the main body coupling member30so as to be engaged in the engagement hole43, and the transversely positioning means48has a positioning pin55which protrudes from the interior of the component coupling member33so as to be engaged in the engagement hole43, and also, the release means49has a push pin59situated inside the engagement hole43, which acts to push each of the positioning pins51and55out of the engagement hole43when pressed.

Moreover, in still another aspect of the technical means of the present invention, the position holding mechanism45has guide means63for causing the cylindrical member34to move circumferentially relative to the main body coupling member30in the longitudinal position Y and whereafter permitting its axial movement, and also causing the cylindrical member34to move circumferentially relative to the component coupling member33in the transverse position X and whereafter permitting its axial movement.

Moreover, in yet another aspect of the technical means of the present invention, the guide means63comprises: a locking projection65formed in the cylindrical member34; a first circumferential groove67and a second circumferential groove68for retaining the locking projection65formed in the main body coupling member30and the component coupling member33, respectively; a first linear groove69for guiding the locking projection65in axial movement from the first circumferential groove67to the end face of the main body coupling member30; and a second linear groove70which is positioned so as to become an extension of the first linear groove69in the longitudinal position Y, for guiding the locking projection65in axial movement from the end face of the component coupling member33to a position beyond the second circumferential groove68.

Advantageous Effects of the Invention

According to the present invention, the sidewardly-protruding extension component is attached to the base end side of the first handle so as to be freely changed in position between the transverse position which is substantially aligned with the axial direction of the pivotal shaft and the longitudinal position which is aligned with the lengthwise direction of the handle main body relative to the handle main body of the first handle, and, the position holding mechanism for holding the extension component in each of the positions is disposed between the extension component and the handle main body. Accordingly, the extension component of the first handle can be readily held in the longitudinal position aligned with the lengthwise direction of the handle main body without fail, and an operator is thus able to cut a material to be cut easily by grasping the first and second handles. Furthermore, the extension component can also be readily held in the transverse position which is substantially aligned with the axial direction of the pivotal shaft without fail, and the first handle can be set stably by utilizing the extension component, wherefore an operator is able to grasp only the second handle with his/her hands while pushing down the first handle placed in a stable condition by his/her foot, and consequently a to-be-cut material can be cut smoothly with greater force.

MODES FOR CARRYING OUT THE INVENTION

FIGS. 1 to 8show the first embodiment of the present invention. InFIGS. 1 and 2, a cutting tool1comprises: a pair of cutting blade bodies3and4having formed at their front ends cutting blades3aand4a, respectively; and a first handle5and a second handle6coupled to the cutting blade bodies3and4, respectively. The paired cutting blade bodies3and4are each held so as to be sandwiched between a pair of coupling plates8arranged in a thickness direction, and are openably and closably supported by a pair of support shafts9and10, respectively, disposed so as to pass through the coupling plates8.

The first handle5and the second handle6comprise a handle main body11and a handle main body12, respectively, made of a tubular material in cylindrical form. Mounting members13and14are fixedly attached to the front ends of, respectively, the handle main bodies11and12, and, both of the mounting members13and14are rotatably coupled to a pivotal shaft17. Moreover, the paired handle main bodies11and12are rotatably coupled, via the mounting members13and14, respectively, to their respective cutting blade bodies3and4by coupling shafts19and20, respectively.

Thus, the cutting tool is designed to cut a material to be cut by opening and closing the paired cutting blade bodies3and4about the support shafts9and10, respectively, through opening-closing operation of the first handle5and the second handle6about the pivotal shaft17. The axis of the pivotal shaft17is perpendicular to a direction in which the cutting blade bodies3and4, and the first and second handles5and6are rotationally moved (rotation surface).

The second handle6has, at its base end side, a handle grip22extending along the direction of the length of the handle main body. The handle grip22is constructed by fitting and fixing a synthetic resin-made cover member24externally to a cylindrical portion23which is an extension of the handle main body12.

InFIGS. 1 to 8, the first handle5has an extension component29formed at its base end side so as to extend sideward. The extension component29comprises: a component coupling member33coupled, via a pivot31, to a main body coupling member30disposed at the base end of the handle main body11; and a cylindrical member34fitted externally to the component coupling member33, which passes over the pivot31into engagement with the main body coupling member30so as to assume an extended position, or equivalently longitudinal position. A synthetic resin-made cover member35is fixedly fitted to the cylindrical member34exteriorly thereof.

The main body coupling member30has its front half part fixedly fitted to the base end of the handle main body11of the first handle5interiorly thereof, and has its rear half part extended rearward. An engagement recess26is formed in the front half part of the main body coupling member30, and, the base portion of the handle main body11is formed with an inwardly-extending engagement projection27corresponding to the engagement recess26. Upon engagement of the engagement projection27in the engagement recess26, the main body coupling member30is inhibited from detachment from the handle main body.

The front part of the component coupling member33is bendably coupled to the rear half part of the main body coupling member30via the pivot31. The pivot31is substantially perpendicular to the pivotal shaft17, so that the component coupling member33is free to rotate in a direction perpendicular to a cutting direction in which cutting is effected by the cutting blade body3,4.

The main body coupling member30and the component coupling member33are each shaped like a round bar. A coupling projection37in the form of a half-round bar is formed at a component coupling member33—side end (rear half part) of the main body coupling member30, and a coupling projection38in the form of a half-round bar is formed at a main body coupling member30—side end of the component coupling member33. The coupling projection37and the coupling projection38are arranged with their flat surfaces opposed to each other, and a junction between the opposed surfaces is parallel to the axis of the main body coupling member30, but is displaced from the axis in a radial direction.

The pivot31is constructed of a bolt, and, the coupling projections37and38disposed in overlapping relation to each other are rotatably coupled to each other by the pivot31. Upon the component coupling member33being brought into an extended state relative to the main body coupling member30, the coupling projections37and38are combined into a single round bar form.

The coupling projection38of the component coupling member33is made short to such an extent as to be spaced away from a step end face30aof the main body coupling member30under a condition where the component coupling member33is in an extended state relative to the main body coupling member30, and, the component coupling member33is made free to bend about the pivot31in a direction indicated by an arrow a, as well as in a reverse direction indicated by an arrow b, relative to the main body coupling member30.

Thus, the first handle5is formed by coupling the extension component29to the base end of the handle main body11. The extension component29is freely changed in position between a transverse position X which is substantially aligned with the direction of the axis of the pivotal shaft17and a longitudinal position Y which is aligned with the direction of the length of the handle main body, and, the extension component29serves as a handle grip when it is in the longitudinal position Y.

Moreover, as indicated by a solid line inFIG. 1(b), the extension component29is designed to assume both of a transverse position X to which it is moved by being bent in the arrow a direction relative to the handle main body11and another transverse position X to which it is moved by being bent in the arrow b direction relative to the handle main body11.

The cylindrical member34, which is made of a tubular material, is slidably (movably) fitted, while being retained, to the component coupling member33exteriorly thereof, and is also slidably (movably) fitted to the main body coupling member30exteriorly thereof in a manner permitting free detachment.

That part of a handle main body11—side end of the cylindrical member34which lies outside of the cover member35is formed with an engagement hole43drilled all the way through from the inner side to the outer side of the cylindrical member34in the radial direction.

In a region between the extension component29and the handle main body11, a position holding mechanism45is disposed to change the position of the extension component29from the transverse position X to the longitudinal position Y and vice versa, as well as to hold the extension component29in a changed position.

The position holding mechanism45, which is formed so as to span the main body coupling member30, the component coupling member33, and the cylindrical member34, is designed to operate in a manner such that, when the component coupling member33is bent at substantially a right angle with respect to the main body coupling member30, the cylindrical member34is moved toward the main body coupling member30relative to the component coupling member33so as to abut on the projecting end (coupling projection37) of the main body coupling member30, thereby locating and holding the extension component29in the transverse position X in a state of being bent at substantially a right angle with respect to the handle main body11, and that, when the component coupling member33is brought into an extended state relative to the main body coupling member30, the cylindrical member34is externally fitted in straddling relation to the main body coupling member30and the component coupling member33, thereby locating and holding the extension component29in the longitudinal position Y.

The extension component29is allowed to rotate about the pivot31upon disengagement of the cylindrical member34from the main body coupling member30, and is restrained against rotation about the pivot31upon abutting of the front end of the cylindrical member34on the main body coupling member30in the transverse position X.

The position holding mechanism45comprises: longitudinally positioning means47for restraining the cylindrical member34against movement relative to the main body coupling member30when the extension component29is in the longitudinal position Y; transversely positioning means48for restraining the cylindrical member34against movement relative to the component coupling member33when the extension component29is in the transverse position X; release means49disposed in the extension component29, for releasing restraint imposed by the longitudinally positioning means47and the transversely positioning means48; and guide means63for causing the cylindrical member34to move circumferentially relative to the main body coupling member30in the longitudinal position Y and whereafter permitting its axial movement, and also causing the cylindrical member34to move circumferentially relative to the component coupling member33in the transverse position X and whereafter permitting its axial movement.

The longitudinally positioning means47comprises a positioning pin51which extends from the interior of the main body coupling member30so as to be engaged in the engagement hole43of the cylindrical member34. The positioning pin51is housed, while being retained, for free radially-outward advancing/retracting movement in a main body holding hole52formed radially in the main body coupling member30, and is urged radially outwardly by a coil spring (urging member)53. In this structure, upon the extension component29being located in the longitudinal position Y, the positioning pin51is disengageably engaged in the engagement hole43so as to restrain the cylindrical member34against circumferential movement relative to the main body coupling member30and axial movement, thereby holding (locking) the extension component29in the longitudinal position Y.

The transversely positioning means48comprises a positioning pin55which extends from the interior of the component coupling member33so as to be engaged in the engagement hole43. The positioning pin55is housed, while being retained, for free radially-outward advancing/retracting movement in a component holding hole56formed radially in the component coupling member33, and is urged radially outwardly by a coil spring (urging member)57. In this structure, upon the extension component29being located in the transverse position X, the positioning pin55is disengageably engaged in the engagement hole43so as to restrain the cylindrical member34against circumferential movement relative to the component coupling member33and axial movement, thereby holding (locking) the extension component29in the transverse position X.

The release means49comprises: a support plate61attached to the cylindrical member34; and a push pin59situated inside the engagement hole43while being supported by the support plate61, which acts to push each of the positioning pins51and55out of the engagement hole43when pressed. As shown inFIG. 8, the push pin59comprises a head portion59aand a pin shaft portion59b, and is retained for free radial movement in the engagement hole43, with the head portion59aextended so as to lie outside of the cylindrical member34.

Thus, the push pin59can be operated by pressing the head portion59afrom the outside of the extension component29, and, by this push-pin59pressing operation, the positioning pin51or the positioning pin55engaged in the engagement hole43is pushed out of it, thereby achieving disengagement.

The support plate61, which is constructed of a spring plate, is fixedly held between the cover member35and the cylindrical member34so as to protrude outward in a direction toward the handle main body11, and has its protruding end bent so as to rise radially outwardly in a floating state from the cylindrical member34, and, a head portion59a—side part of the pin shaft portion59bof the push pin59is inserted, while being retained, in that protruding end part. In this way, the support plate61supports the push pin59so as to prevent it from accidentally coming off from the engagement hole43.

The guide means63comprises, as shown inFIGS. 3 to 8, a locking projection65formed in the cylindrical member34so as to project radially inwardly; a first circumferential groove67formed on the outer peripheral surface of the main body coupling member30; a first linear groove69formed so as to extend axially from the first circumferential groove67to the end face of the main body coupling member30; a second circumferential groove68formed on the outer peripheral surface of the component coupling member33; and a second linear groove70formed so as to extend axially from the end face of the component coupling member33to a position beyond the second circumferential groove68. The first circumferential groove67and the second circumferential groove68lock the locking projection65for free circumferential movement; the first linear groove69guides the locking projection65in axial movement; the second linear groove70assumes a position communicating with the first linear groove69in the longitudinal position Y, for guiding the locking projection65in axial movement from the end face of the component coupling member33to a position beyond the second circumferential groove68.

At a time when the component coupling member33is brought into an extended state relative to the main body coupling member30, by moving the cylindrical member34toward the main body coupling member30so as to be externally fitted in straddling relation to the main body coupling member30and the component coupling member33, the locking projection65is moved from the second linear groove70into engagement in the first linear groove69, and, by moving the cylindrical member34further toward the main body coupling member30until it abuts on the base end of the handle main body11, the locking projection65is moved to an intersection point of the first linear groove69and the first circumferential groove67. By moving the cylindrical member34in the circumferential direction (a direction c as shown inFIG. 8) from the intersection point, the locking projection65is disengaged from the first linear groove69and is whereafter engaged in the first circumferential groove67.

By the circumferential movement of the cylindrical member34and the consequent engagement of the locking projection65with the back of the first circumferential groove67, the positioning pin51is engaged in the engagement hole43, thereby inhibiting the cylindrical member34from further circumferential movement. In this state, the extension component29is locked in the longitudinal position Y by the longitudinally positioning means47.

Moreover, by moving the cylindrical member34in the opposite direction to the main body coupling member30so as to move the locking projection65from the first linear groove69into engagement in the second linear groove70, the cylindrical member34is brought into a state where it is externally fitted to the component coupling member33alone, thereby allowing the component coupling member33to rotate about the pivot31relative to the main body coupling member30.

With the component coupling member33bent at substantially a right angle, the cylindrical member34is moved toward the main body coupling member30so as to abut thereon relative to the component coupling member33, whereupon the locking projection65is moved to a point of intersection with the second circumferential groove68in an intermediate part of the second linear groove70. By moving the component coupling member33in the circumferential direction (the direction c shown inFIG. 8) from the intersection point, the locking projection65is disengaged from the second linear groove70and is whereafter engaged in the second circumferential groove68.

By the circumferential movement of the cylindrical member34and the consequent engagement of the locking projection65with the back of the second circumferential groove68, the positioning pin51is engaged in the engagement hole43, thereby inhibiting the cylindrical member34from further circumferential movement. In this state, the extension component29is locked in the transverse position X by the transversely positioning means48.

The following is a description about how to use the cutting tool1.

When the extension component29of the first handle5is locked in the longitudinal position Y as shown inFIG. 3, as shown inFIG. 8, the locking projection65is engaged with the back of the first circumferential groove67, and the positioning pin51is engaged in the engagement hole43.

Under this condition, in order to lock the extension component29in the transverse position X, firstly, the push pin59is pressed to push the positioning pin51into the main body coupling member30from the engagement hole43against an urging force exerted by the coil spring53. Then, by moving the cylindrical member34circumferentially in a direction indicated by an arrow c, the locking projection65is disengaged from the first circumferential groove67and is whereafter engaged in the first linear groove69, thereby permitting free axial movement of the cylindrical member34relative to the main body coupling member30and the component coupling member33.

Next, the cylindrical member34is moved toward the base end of the component coupling member33(in a direction indicated by an arrow e) so as to be detached from the projecting end of the main body coupling member30as indicated by a chain double-dashed line inFIG. 4. At this time, the locking projection65is disengaged from the first linear groove69, is engaged in the second linear groove70, and is eventually moved to the rear end of the second linear groove70. After that, the component coupling member33(extension component29) is rotated about the pivot31in the arrow a direction relative to the main body coupling member30, thereby bending the extension component29at a right angle with respect to the handle main body11.

Then, the cylindrical member34is, after being moved toward the main body coupling member30(in a direction indicated by an arrow f) relative to the component coupling member33so as to abut on the projecting end of the main body coupling member30, moved circumferentially in a direction indicated by an arrow d relative to the component coupling member33, thereby causing the locking projection65to find its way into the second circumferential groove68from the intermediate part of the second linear groove70, and then engage with the back of the second linear groove70. Moreover, the positioning pin55is engaged in the engagement hole43, whereupon the extension component29is locked in the transverse position X.

In order to change the position of the extension component29of the first handle5locked in the transverse position X as shown inFIG. 5to the longitudinal position Y, firstly, the push pin59is pressed to move the cylindrical member34circumferentially in the arrow c direction as shown inFIG. 8, so that the positioning pin55is disengaged from the engagement hole43, and the locking projection65is disengaged from the second circumferential groove68and is whereafter engaged in the second linear groove70. Then, the cylindrical member34is moved away from the coupling projection37until the locking projection65engages with the back of the second linear groove70.

Next, after rotationally moving the component coupling member33about the pivot31in the arrow b direction to locate the extension component29in the longitudinal position, as shown inFIG. 4, the cylindrical member34is moved toward the main body coupling member30(in the arrow f direction) so as to abut on the handle main body11. After that, the cylindrical member34is moved circumferentially in the arrow d direction, whereupon the locking projection65is engaged with the back of the first circumferential groove67, and also the positioning pin55is engaged in the engagement hole43, thereby locking the extension component29in the longitudinal position Y.

That is, a change in position of the extension component29necessitates a push-pin59pressing step, circumferential movement, axial movement, rotation, axial movement, and circumferential movement in the order presented, and, the axial movement cannot be achieved without effecting the circumferential movement, and also the rotation cannot be achieved without effecting the axial movement. Inconsequence, three-step operation is required. This makes it possible to prevent an accidental change in position, as well as to lock the extension component29in each of the positions without fail.

Thus, in a case where a material to be cut is hard or thick, by locking the extension component29of the first handle5in the transverse position X relative to the handle main body11, the first handle5can be set stably by utilizing the extension component29, wherefore an operator is able to cut the to-be-cut material with ease simply by grasping only the second handle6with his/her hands while pushing down the first handle5placed in a stable condition by his/her foot.

On the other hand, in a case where a material to be cut is soft or slim, by locking the extension component29of the first handle5in the longitudinal position Y relative to the handle main body11, the first handle can be changed from a stably-set mode to a grippable mode as with the second handle, wherefore an operator is able to cut the to-be-cut material quickly with ease simply by grasping the first handle5and the second handle6with his/her hands.

InFIG. 9, there is shown the second embodiment in which the front end of the half-round bar-shaped coupling projection38of the component coupling member33abuts on the step end face30aof the main body coupling member30, and, one of the corners of the front end is radiused to form an arcuate chamfer72, the center of curvature of which is coincident with the pivot31.

Accordingly, the component coupling member33is allowed to rotate about the pivot31only in the arrow a direction for a change in position from the extended state relative to the main body coupling member30, and is not allowed to rotate in a reverse direction.

In the guide means63, the main body coupling member30is formed with the first linear groove69, and the component coupling member33is formed with the second linear groove70, but no circumferential groove is formed therein. The locking projection65formed in the cylindrical member34is allowed to move only axially and linearly within the first linear groove69and the second linear groove70. Upon engagement of the locking projection65with the back of the first linear groove69, the longitudinally positioning means47is actuated to locate the extension component29in the longitudinal position Y, and, when the locking projection65is engaged with the back of the second linear groove70, the extension component29is allowed to rotate freely, and also, when the locking projection65lies in an intermediate part of the second linear groove70, the cylindrical member34abuts on the coupling projection37, and the transversely positioning means48is actuated to locate the extension component29in the transverse position X.

In the cutting tool1implemented as the second embodiment, the position of the extension component29can be changed by release operation of the release means49and linear movement of the extension component29; that is, a construction based on two-step operation is adopted.

It should be noted that the present invention is not limited to the embodiments as described hereinabove. For example, the handle main body11may be formed with a rearwardly-extending hole and a sidewardly-extending hole for insertion of the component coupling member33, and, in this case, the extension component29is detachably secured to the handle main body11so as to be freely changed in position between the transverse position X which is substantially aligned with the axial direction of the pivotal shaft17and the longitudinal position Y which is aligned with the lengthwise direction of the handle main body by the attachment to and detachment from the handle main body11.

Moreover, the position holding mechanism45for holding the extension component29in each of the transverse position X and the longitudinal position Y is not limited to the structure suggested in the afore stated embodiment, but may be implemented via another means, for example, a fastening component such as a bolt or nut, a detachable engagement structure, or otherwise.

EXPLANATION OF REFERENCE SYMBOLS