Open-close work implement

1. An open-close work implement wherein a first half member and a second half member are intersected and pivotally fitted together, the distal ends being provided with an open-close working part for holding or cutting an object, and the proximal ends being provided with an open-close operation part for opening and closing the open-close working part; said open-close work implement characterized in being configured so that when closing force is applied to the open-close operation part to close the open-close working part and hold or cut the object, the open-close operation part flexes inward as the closing force applied to the open-close operation part is increased while the object is being held; the application of increasing closing force to the open-close operation part is perceived by feeling through a hand gripping the open-close operation part or a hand or fingertips pressing the open-close operation part, or by observing the amount of flexure; flexible moving parts of the open-close operation part are provided with a contact part which draws near a receiving part due to the inward flexure of the open-close operation part and contacts the receiving part when the closing force reaches a predetermined value, and when the closing force is further increased while the receiving part and the contact part are in a state of contact, the portion proximal from the contact part further flexes or moves inward but the increased closing force is not transmitted to the open-close working part, and the holding force holding the object or the cutting force cutting the object does not increase beyond the holding force or cutting force corresponding to the closing force that was being applied to the open-close operation part at the time the receiving part and the contact part came in contact.

2. An open-close work implement wherein a first half member and a second half member constituting a pair are bonded, intersected, and pivotally fitted together at a midway point, the distal ends of the opposing first half member and second half member forming an open-close working part constituting a holding part or cutting part, and the proximal ends of the opposing first half member and second half member forming an open-close operation part for holding or cutting an object when the open-close working part of the distal ends is closed by closing force applied to press the proximal ends towards each other in an inward closing direction; said open-close work implement configured so that when further closing force is applied to the open-close operation part while the object is being held between the distal end of the first half member and the distal end of the second half member constituting the open-close working part, at least the proximal end of the first half member or the proximal end of the second half member flexes inward according to the increase in closing force; said open-close work implement also configured so that a contact part which is moved by the flexure and a receiving part contacted by the contact part are provided facing each other to the open-close operation part, the contact part is flexibly moved toward the receiving part by increasing the closing force, the contact part contacts the receiving part when the closing force reaches a predetermined value, and when the closing force applied to the open-close operation part continues to be increased further, the portion proximal from the contact part further flexes or moves inward according to the increase in closing force but the increased closing force is not transmitted to the open-close working part, and the holding force holding the object or the cutting force cutting the object does not increase beyond the peak value holding force or cutting force corresponding to the closing force that was being applied to the open-close operation part at the time the receiving part and the contact part came in contact.

3. The open-close work implement according to claim 1 , characterized in being configured so that the open-close working part is composed of the distal end of the first half member and the distal end of the second half member for holding or cutting the object by performing a closing action in which the open-close operation part, which comprises the proximal end of the first half member and the proximal end of the second half member disposed facing each other, is gripped by a hand or held by fingertips and a gap is narrowed by application of the inward-pressing closing force, and when further closing force is applied to the open-close operation part either while the object is being held between the distal end of the first half member and the distal end of the second half member of the open-close working part, or while the object is being held while being cut, at least the first half member or the second half member of the open-close operation part flexes inward; said open-close work implement also configured so that the contact part is provided to one flexible moving part of the first half member or the second half member of the open-close operation part, the receiving part is provided to the other opposing flexible moving part, the contact part and the receiving part do not come in contact until the open-close working part closes and the object is held, and the flexible moving parts are flexibly deformed by further increasing the closing force holding the object, thereby causing the contact part to draw near and contact the receiving part; wherein the contact part is provided toward the proximal end from a pivotally fitting part where the first half member and the second half member are intersected and pivotally fitted together, and toward the distal end from a pressure point where the closing force is applied when the open-close operation part is gripped or held by fingertips.

4. The open-close work implement according to claim 2 , characterized in being configured so that the open-close working part is composed of the distal end of the first half member and the distal end of the second half member for holding or cutting the object by performing a closing action in which the open-close operation part, which comprises the proximal end of the first half member and the proximal end of the second half member disposed facing each other, is gripped by a hand or held by fingertips and a gap is narrowed by application of the inward-pressing closing force, and when further closing force is applied to the open-close operation part either while the object is being held between the distal end of the first half member and the distal end of the second half member of the open-close working part, or while the object is being held while being cut, at least the first half member or the second half member of the open-close operation part flexes inward; wherein the contact part is provided to one flexible moving part of the first half member or the second half member of the open-close operation part, the receiving part is provided to the other opposing flexible moving part, the contact part and the receiving part do not come in contact until the open-close working part closes and the object is held, and the flexible moving parts are flexibly deformed by further increasing the closing force holding the object, thereby causing the contact part to draw near and contact the receiving part; and the contact part is provided toward the proximal end from a pivotally fitting part where the first half member and the second half member are intersected and pivotally fitted together, and toward the distal end from a pressure point where the closing force is applied when the open-close operation part is gripped or held by fingertips.

5. The open-close work implement according to any of claims 1 through 4 , characterized in that the portion distal from the pivotally fitting part of the first half member and the second half member constitutes the open-close working part, the proximal portion constitutes the open-close operation part, the contact part is provided near the pivotally fitting part in a state of protruding inward to either the proximal end of the first half member or the proximal end of the second half member which constitute a gripping part or fingertip-holding part of the open-close operation part, and the receiving part which comes in contact with the contact part is provided to the other proximal end.

6. The open-close work implement according to any of claims 2 through 4 , characterized in being configured so that closing force applied to the open-close operation part is transmitted to the open-close working part, holding force of the open-close working part for holding the object generated according to the closing force increases according to the increase in the closing force applied to the open-close operation part until the flexible moving parts of the open-close operation part flex and the contact part provided to one flexible moving part draws near and contacts the receiving part, and when the closing force applied to the open-close operation part is further increased beyond the point in time when the contact part and the receiving part come in contact, the holding force does not increase according to the increase in closing force applied to the open-close operation part, but the holding force decreases after reaching a peak value corresponding to a predetermined value of the closing force at the time of contact between the contact part and the receiving part.

7. The open-close work implement according to claim 5 , characterized in being configured so that closing force applied to the open-close operation part is transmitted to the open-close working part, holding force of the open-close working part for holding the object generated according to the closing force increases according to the increase in the closing force applied to the open-close operation part until the flexible moving parts of the open-close operation part flex and the contact part provided to one flexible moving part draws near and contacts the receiving part, and when the closing force applied to the open-close operation part is further increased beyond the point in time when the contact part and the receiving part come in contact, the holding force does not increase according to the increase in closing force applied to the open-close operation part, but the holding force decreases after reaching a peak value corresponding to a predetermined value of the closing force at the time of contact between the contact part and the receiving part.