The present disclosure relates to a gripping tool.
Patent Documents 1 to 4 disclose gripping tools for holding objects to be gripped. Hair tweezers and tweezers for thorns are examples of gripping tools.
A gripping tool of Patent Document 1 includes two elastic gripping parts. One of the two gripping parts has a flat first gripping surface, and the other has a second gripping surface having a smaller area than the first gripping surface.
Patent Document 2 discloses a pair of tweezers as a gripping tool that includes first and second arms elastically connected to each other at their proximal ends. The first and second arms have first and second gripping portions, respectively, at their distal ends. The first and second arms have a convex cross-sectional shape to obtain sufficient strength. Additionally, the first arm includes first and second guide parts projecting toward the second arm, and the second arm includes first and second guide portions projecting toward the first arm. When the guide parts and the guide portions engage with one another, the gripping portions hold a gripping object in a “proper state.” The guide parts and the guide portions also serve as stoppers that come into contact with the inner surfaces of the second and first arms. The “proper state” refers to a state in which the stoppers stop the two gripping portions from separating from each other. The rigidity of each gripping portion is reinforced by a reinforcing plate. As such, the gripping portion itself does not have elasticity.
Patent Document 3 discloses a pair of tweezers as a gripping tool that includes two arm parts and a connecting portion that elastically connects the two arm parts. Each arm part has a pinching portion at its distal end. One of the two arm parts includes a reinforcing plate extending over its entire length, and the other has two gripping plates each extending over approximately a half of the entire length. When the two arm parts are pressed toward each other, the reinforcing plate is inserted between the two gripping plates, and reinforcing walls reinforce the gripping plates. This provides a sufficient rigidity even when the tweezers are made of synthetic resin.
Patent Document 4 discloses a pinching tool as a gripping tool that includes a support portion and two action portions extending from the support portion. Each action portion has a through-hole or a cutout section near its distal end.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2017-192458
Patent Document 2: Japanese Laid-Open Utility Model Publication No. 6-52806
Patent Document 3: Japanese Laid-Open Utility Model Publication No. 6-75416
Patent Document 4: Registered Utility Model No. 3178053
Referring to
As shown in
As shown in
The arms 100 and 102 are connected to the gripping portions 104 and 105, respectively. After the arms 100 and 102 are pressed in the closing directions and the distal ends of the gripping surfaces 104a and 105a come into contact with each other as shown in
As the arms 100 and 102 are further pressed in the closing directions, the fulcrum point C moves toward the proximal ends of the gripping surfaces 104a and 105a in the range in which the arms 100 and 102 can be elastically deformed. When a moment acts on the gripping portions 104 and 105 about this fulcrum point, the distal ends of the gripping surfaces 104a and 105a are separated from each other as shown in
As a result, the gripping surfaces 104a and 105a cannot hold short hairs that do not reach the proximal ends of the gripping portions 104 and 105. This is the first problem.
Furthermore, the proximal ends of the gripping portions 104 and 105 may pinch and cut long hairs extending beyond the proximal ends of the gripping portions 104 and 105 toward the connecting portion 103. This is the second problem.
Patent Document 1 does not have the first problem because the front ends of the gripping surfaces do not open when holding a gripping object. However, since the second gripping surface is smaller in area than the first gripping surface, stress is concentrated on the part in contact with the gripping object. The part of the gripping object held by the second gripping surface may break depending on its material. Patent Document 1 therefore fails to solve the second problem.
Patent Document 2 discloses, as an example that is not in a “proper state,” that the front ends of the gripping portions are not properly in contact with each other when there are clearances between the inner surfaces of the arms and the guide portions and the guide parts. Patent Document 2 presumably solves the first problem 1 because the stopper provides a “proper state.”
However, although not described in Patent Document 2, if sections of the arms between the stoppers and the gripping portions are further pressed in the closing directions, the front ends of the gripping portions may fail to be properly in contact with each other. In this case, the second problem is not solved.
Additionally, with Patent Document 2, it is difficult to set the guide portions and the guide parts to come into contact with the inner surface of the corresponding arm. For example, the thickness of the gripping object determines the distance between the gripping portions holding the gripping object. For this reason, the “proper state” is not necessarily achieved with every gripping object.
Patent Documents 3 and 4 fail to disclose specific methods for solving the first problem 1 and the second problem.
It is an objective of the present disclosure to provide a gripping tool that is capable of, when a gripping object is held between gripping portions, limiting the opening between the front ends of the gripping portions and also limiting breaking of the gripping object held between the gripping portions.
In accordance with one aspect of the present disclosure, a gripping tool includes first and second arms connected to each other at proximal ends thereof, a first gripping, a first gripping portion at a distal end of the first arm, the first gripping portion having a first gripping surface, and a second gripping portion at a distal end of the second arm, the first gripping portion having a second gripping surface. The first and second arms are configured such that the first and second gripping surfaces are in planar contact with each other when the first and second arms are pressed in closing directions toward each other. At least one of the first and second gripping portions is an elastic part extending toward the proximal end. The elastic part is configured to, when the first and second arms are further pressed in the closing directions from a state in which the first and second gripping surfaces are in planar contact with each other, be elastically deformed while maintaining the planar contact between the first gripping surface and the second gripping surface.
Referring to
As shown in
When the user presses the arms 12 and 14 toward each other, the distal ends of the arms 12 and 14 are closed. This state is referred to as a closed state. When the pressing on the arms 12 and 14 is cancelled, the distal ends of the arms 12 and 14 return to a state in which they are separated from each other. This state is referred to as an open state. As used herein, the expression that “the arms 12 and 14 are pressed” refers to a state in which the arms 12 and 14 are pressed toward each other, that is, in closing directions.
As shown in
As shown in
The first arm 12 has a first bulging portion 34 defining the groove 30. The first bulging portion 34 extends in a trapezoidal shape toward the second arm 14. The first bulging portion 34 is located between the stopper 18 and the second bulging portion 32. The stopper 18 comes into contact with the first arm 12 when the arms 12 and 14 are pressed, thereby stopping the arms 12 and 14 from further coming closer to each other. That is, the stopper 18 sets the amount of movement when the arms 12 and 14 are pressed. The thickness (the dimension in the up-down direction) of the first arm 12 may be uniform except for the first bulging portion 34.
As shown in
The second arm 14 has a first extension section, which extends between the bulging portion 32 and the stopper 18, and a second extension section, which extends between the stopper 18 and the connecting portion 16. The first and second extension sections have the same thickness.
As shown in
The elastic part 24 has a second gripping surface 22a. The second gripping surface 22a is substantially parallel to the first gripping surface 20a. The second gripping surface 22a faces the first gripping surface 20a. The second gripping surface 22a is a curved surface having the same radius of curvature as the first gripping surface 20a. Specifically, the first gripping surface 20a is a curved concave surface, and the second gripping surface 22a is a curved convex surface. The elastic part 24 is thinner than the first gripping portion 20. The gripping portion 20, which is thicker than the elastic part 24, has higher rigidity than the elastic part 24.
As shown in
When further pressed from the first closed state shown in
In the second closed state shown in
When the state transitions from the first closed state to the second closed state occur, the stopper 18 comes into contact with the inner surface of the first arm 12 thereby stopping the further movement of the arms 12 and 14. The stopper 18 is set to have a size (protruding height) corresponding to a proper moving distance of the arms 12 and 14. The stopper 18 is preferably arranged near the gripping portions 20, 22 or the elastic part 24 so that an excessive pressing force is not applied to the gripping surfaces 20a and 22a and therefore the gripping object held between the gripping surfaces 20a and 22a.
As shown in
An operation of the gripping tool 10 configured as described above is now described.
In the first closed state, the gripping surfaces 20a and 22a are in planar contact with each other. At this time, the elastic part 24 is not elastically deformed.
As shown in
A situation is now described in which the gripping tool 10 holds a gripping object (not shown) such as a hair. When a hair is held between the gripping portions 20 and 22 in the first closed state, the gripping surfaces 20a and 22a are in a state close to planar contact. The “state close to planar contact” refers to a state in which the gripping surfaces 20a and 22a are not in contact in part due to the presence of the gripping object. In this state, the gripping object receives a weak constraining force. When the arms 12 and 14 are further pressed from the first closed state, the elastic part 24 is elastically deformed. At this time, the gripping surfaces 20a and 22a still hold the gripping object in a state close to planar contact. That is, the front ends or the proximal ends of the gripping surfaces 20a and 22a do not act as a fulcrum point, which would otherwise cause a moment about the fulcrum point.
Accordingly, the gripping surfaces 20a and 22a can sandwich the gripping object with their entire extension in the front-rear direction. This limits the opening between the distal ends of the gripping portions 20 and 22. Moreover, since a load is not concentrated on any particular section of the gripping object, the gripping object held between the gripping portions is unlikely to break.
When deformed to have a greater radius of curvature, the first arm 12 may or may not slide in the direction of arrow b. The gripping surfaces 20a and 22a maintains a state close to planar contact with respect to the gripping object even when the first arm 12 slides as well as when it does not slide.
As the arms 12 and 14 are further pressed from the first closed state, the groove 30 between the stoppers 18 becomes narrower as shown in
The present embodiment has the following features.
(1) Of the arms 12 and 14, the gripping portion 22 of the arm 14 is formed by the elastic part 24 extending toward the connecting portion 16. When the arms 12 and 14 are further pressed in the closing directions from a state in which the gripping surfaces 20a and 22a are in planar contact, the elastic part 24 is elastically deformed while maintaining the planar contact between the gripping surfaces 20a and 22a.
As a result, when the gripping portions 20 and 22 hold the gripping object, the distal ends of the gripping portions 20 and 22 are unlikely to open, and the gripping object held between the gripping portions 20 and 22 does not break.
(2) The arms 12 and 14 are elastically connected by the connecting portion 16. As such, when the pressing is cancelled, the arms 12 and 14 return from the closed state to the open state.
(3) The first arm 12 is curved in an arcuate shape. When the elastic part 24 is elastically deformed, the first arm 12 slides along the second gripping surface 22a. This maintains the planar contact between the gripping surfaces 20a and 22a. That is, even if the arms 12 and 14 are elastically deformed while holding the gripping object, the gripping surfaces 20a and 22a are maintained in a state close to planar contact.
(4) The gripping portions 20 and 22 have the inclined surfaces 26 and 28, each defined by an inclined cut on the right side. As a result, it is easy to insert the gripping object between the gripping surfaces 20a and 22a from the right side of the gripping portions 20 and 22 having the inclined surfaces 26 and 28.
(5) The second arm 14 has the stopper 18. The stopper 18 limits excessive elastic deformation of the arms 12 and 14. This reduces the likelihood that an excessive pressing force is applied to the gripping object held between the gripping surfaces 20a and 22a.
(6) The gripping surfaces 20a and 22a are curved surfaces. Since the gripping surface 20a in contact with the elastic part 24 slides in a manner conforming to the elastic deformation of the elastic part 24, the planar contact between the gripping surfaces 20a and 22a is easily maintained.
(7) The gripping tool 10 can also be used for the purposes of plucking thorns or fine fish bones.
Referring to
The following description mainly focuses on the configurations of the gripping tool 10 of the second embodiment that differ from those of the first embodiment. Same reference numerals are given to the same configurations as those of the first embodiment, and the detailed descriptions thereof are omitted.
As shown in
The elastic part 25 has a first gripping surface 20a substantially parallel to the second gripping surface 22a. The first gripping surface 20a is a curved surface having the same radius of curvature as the second gripping surface 22a. Specifically, as in the first embodiment, the first gripping surface 20a is a curved concave surface, and the second gripping surface 22a is a curved convex surface. The elastic part 25 is thinner than the section of the first arm 12 excluding the bulging portion 34. The elastic part 25 has the same thickness as the elastic part 24. As such, the elastic part 25 has a higher elasticity than the other part of the first arm 12.
As shown in
When further pressed from the first closed state, the arms 12 and 14 are brought into a second closed state shown in
Although not shown, the distal ends of the arms 12 and 14 including the sections 12a and 14a of the second embodiment each have an inclined surface on the right side. That is, as in the first embodiment, one side of each arm 12, 14 is cut, resulting in a smaller width (the dimension in the right-left direction).
An operation of the second embodiment is now described.
When further pressed from the open state shown in
At this time, the L-shaped sections 12a and 14a in contact with each other receive forces acting away from each other. Although not clearly shown in
When the gripping tool 10 holds a gripping object (not shown) such as a hair, in the first closed state, the gripping surfaces 20a and 22a are in a state close to planar contact. In this state, however, the constraining force applied to the gripping object is weak. When the arms 12 and 14 are further pressed from the first closed state, the elastic parts 24 and 25 are elastically deformed. In this state, the gripping surfaces 20a and 22a still hold the gripping object in a state close to planar contact.
This allows the gripping surfaces 20a and 22a to sandwich the gripping object with their entire extension in the front-rear direction. As such, unlike conventional configurations, the distal ends of the gripping portions 20 and 22 are unlikely to open. Moreover, since a load is not concentrated on any particular section of the gripping object, the gripping object held between the gripping portions is unlikely to break.
The above-described embodiments and the following modifications can be combined as long as the combined modifications remain technically consistent with each other.
The arms 12 and 14 may be bent to form an obtuse angle between the proximal end and the distal end.
As in the conventional example shown in
The configuration of the connecting portion 16 may be modified. For example, a shaft may rotationally support the rear ends of the arms 12 and 14, and an elastic member, such as a coil spring, a leaf spring, or a torsion coil spring, may be arranged between the arms 12 and 14. In this case, a stopper for limiting the opening of the arms 12 and 14 is preferably provided to stop the arms 12 and 14 from opening more than necessary.
The arms 12 and 14 may extend linearly.
The arms 12 and 14 do not have to include inclined surfaces. Alternatively, the arms 12 and 14 may have an inclined surface (tapered surface) on each of the right and left sides, or may have an inclined surface only on the left side.
The gripping surfaces 20a and 22a may be flat.
Number | Date | Country | Kind |
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2019-131637 | Jul 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/027540 | 7/15/2020 | WO | 00 |