Plastic forceps

Abstract

The present invention provides resin forceps that can suppress bending deformation of the arm portion of the resin forceps, while maintaining operability and external design that are not significantly different from conventional resin forceps. [Solution] A resin forceps 1 is provided, in which a first gripping part 10 and a second gripping part 20 are connected so as to be able to swing around a pivot, and the base-side first arm 14 and base-side second arm 24 of the forceps 1 are provided with ribs 71, 72, 73, and 74 that protrude from the surface 61 or back surface 62 or outer surface 63 or inner surface 64 and extend in the longitudinal direction. The ribs include straight ribs and curved ribs that extend continuously from the straight ribs.

Description

Technical Field

[0001] The present invention relates to forceps used in the medical field, and more particularly to forceps made only of a resin material. In particular, it is a resin forceps suitable for forceps having a relatively long arm portion (handle portion), such as resin forceps for grasping a cotton ball for disinfection. The present invention also relates to a resin forceps suitable as disposable forceps.

Background Art

[0002] Conventionally, various types of forceps for medical use have been known according to purposes such as hemostasis, disinfection, and collection of biological tissues. Such forceps made of metal such as iron or stainless steel are widely used. Resin forceps, which are superior in terms of being light, easy to operate, excellent in transportability, and disposable when used in disaster areas, etc., have also come to be widely used. For example, as a disposable type of resin cotton ball forceps, plastic cotton ball forceps manufactured by Basto Spiega are generally used as general resin cotton ball forceps. This cotton ball forceps generally has a relatively long arm portion, and the cross-sectional shape of the arm portion is substantially rectangular.

[0003] Since such resin forceps have lower strength than metal ones, it is common to manufacture them using a resin material to which reinforcing fibers such as glass fibers are added in order to suppress bending and deformation during use. In addition to the general resin forceps in which the cross-sectional shape of the arm portion is substantially rectangular as described above, resin forceps with new ideas in the shape of the arm portion and the like have been proposed as patent applications.

[0004] For example, Patent Document 1 discloses forceps made of a resin material to which glass fibers are added and provided with a device for preventing twisting. The forceps described in this Patent Document 1 improve the strength by providing a plurality of sliding contact portions for preventing twisting during use and forming the outer surface of the arm in a wave shape.

[0005] On the other hand, there is a resin forceps described in Patent Document 2 that does not use resin materials with added glass fibers. In the forceps described in Patent Document 2, the arm portion is made to bend easily, so that a pressing force due to elastic deformation is actively applied to the gripping portion. Furthermore, there is a resin forceps described in Patent Document 3 that does not use resin materials with added glass fibers. The forceps described in Patent Document 3 are described as having a pentagonal to octagonal polygonal cross-section for the arm portion in order to suppress bending and deformation during use. While the cross-sectional shape of the arm portion of commonly used resin forceps is generally rectangular (rectangular with rounded corners), the resin forceps described in Patent Document 3 have succeeded in significantly improving the strength of the arm portion by devising the cross-sectional shape. And because the strength of the arm portion has been significantly improved, the resin forceps described in Patent Document 3 also have the advantage of not requiring the addition of fillers such as glass fibers for reinforcement. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2010-200838 [Patent Document 2] Japanese Patent Publication No. 2006-230767 [Patent Document 3] Japanese Patent Publication No. 2020-151046 [Overview of the project] [Problems that the invention aims to solve]

[0007] In recent years, with the growing social awareness of environmental protection, the selection of resin materials that do not contain glass fibers, etc., for such resin forceps has been welcomed. Resin materials containing glass fibers, etc., have the disadvantage of being difficult to handle in terms of disposal and recycling. Against the backdrop of the fact that the waste disposal of such resin materials containing reinforcing fibers is becoming a social problem, there is a growing social need for medical devices that are intended to be discarded, such as resin forceps, to be made of materials that are easier to handle in terms of disposal and recycling. However, unlike metal forceps, resin forceps inherently have low strength and are prone to bending. Therefore, simply replacing the material with resin that does not contain glass fibers, etc., will not result in sufficient strength, and the tendency to bend during use will become significant, making them unsuitable for practical use.

[0008] Furthermore, while the resin forceps described in Patent Document 1 incorporates features such as multiple sliding contact points to prevent twisting of the arm portion, the arm portion has a simple flat plate structure in the thickness direction, making it prone to bending in the thickness direction. In other words, although twisting can be suppressed at the sliding contact points, there is still room for improvement in suppressing the bending of the entire arm portion in the thickness direction. On the other hand, the resin forceps described in Patent Document 2 are designed with the premise that the arm portion will bend easily, and therefore have the advantage of being made of resin that does not contain glass fibers, etc. However, the fact that the arm portion is easily bendable means that the feel of operating the forceps will be different from that of conventional forceps, and there is another inconvenient aspect in that medical professionals must accept the discomfort that arises from this change in feel. In other words, because forceps are a means of applying manipulative force directly to the affected area of ​​the patient, medical professionals may be cautious about changing tools, and in particular, they are often cautious about adopting new tools that have a different feel from the tools they are accustomed to.

[0009] In this respect, the resin forceps described in Patent Document 3 have succeeded in improving the strength of the arm portion, so even if the material is replaced with a resin that does not contain glass fibers, there is no problem in terms of the strength in the bending direction of the arm portion, and it is functionally superior. However, for medical professionals who are accustomed to conventional resin forceps, the significantly different appearance may feel unnatural and they may not like to use it. Because medical settings require urgent attention, changes in the appearance of tools that have been familiar for a long time may be undesirable, and people may be cautious about changing tools. Therefore, designing tools with consideration for the psychological aspect of the user, such as ensuring that the appearance is the same as the tools they have been familiar with, is an important perspective that cannot be overlooked when developing medical devices. It can be said that the resin forceps described in Patent Documents 1 and 2 also potentially have the same problem.

[0010] The present invention was made to solve the above problems, and aims to provide a resin forceps that can suppress bending deformation in the longitudinal direction (thickness direction) of the arm portion even when manufactured with a resin that does not contain glass fibers, and is designed so that the operability and appearance are not significantly different from conventional resin forceps (resin forceps with a roughly rectangular cross-sectional shape of the arm portion). [Means for solving the problem]

[0011] The resin forceps according to the present invention are A resin forceps (1) having a first gripping part (10) and a second gripping part (20) connected so as to be able to swing around a pivot, The first gripping component (10) comprises a first gripping portion (12), a base-side first arm (14), a tip-side first arm (15), a first rotating portion (16), and a first gripping portion (17). The second gripping component (20) comprises a second gripping portion (22), a base-side second arm (24), a tip-side second arm (25), a second rotating portion (26), and a second gripping portion (27). The first grip portion (12) and the second grip portion (22) each have an annular portion into which the operator inserts their fingers. The base-side first arm (14) and the base-side second arm (24) each have a front surface (61) and a back surface (62) that are substantially orthogonal to the pivot direction, and an outer surface (63) and an inner surface (64) that are substantially parallel to the pivot direction. The base-side first arm (14) and the base-side second arm (24) each Protruding from the aforementioned surface (61) or back surface (62) have ribs (71, 72, 73, 74) extending in the longitudinal direction. This is the basic structure. Furthermore, The rib (71) provided on the outside of the surface (61) comprises a straight rib (71a) and a grip-side curved rib (71b), the grip-side curved rib (71b) extending from the straight rib (71a) toward the first grip portion (12) and having a curved shape that extends tangent to the annular curve of the annular portion of the first grip portion (12). exist. or The rib (73) provided on the outside of the back surface (62) comprises a straight rib (73a) and a grip-side curved rib (73b), the grip-side curved rib (73b) extending from the straight rib (73a) toward the second grip portion (22) and having a curved shape that extends so as to be tangent to the annular curve of the annular portion of the second grip portion (22). exist. Alternatively, a first ratchet portion (19) is integrally provided between the first grip portion (12) and the base-side first arm (14), and the rib (72) provided on the outside of the surface (61) comprises a straight rib (72a) and a ratchet portion outer edge rib (72d), and the ratchet portion side curved rib (72b) extends from the straight rib (72a) toward the ratchet portion (19) and has a curved shape that smoothly connects in the direction of extension of the ratchet portion (19). exist.

[0012] Also, in the resin pliers according to the present invention, The rotating part side connecting rib (72c) extends from the straight rib (72a) toward the rotating part (16), and as it approaches the rotating part (16), it gradually curves inward, extending to smoothly connect to the annular shape of the rotating part (16) from a tangential direction. Also, in the resin pliers according to the present invention, The ribs (71, 72, 73, 74) are provided in pairs on the edges of the surface (61) or the back surface (62). Also, in the resin pliers according to the present invention, The thickness (t) of the ribs (71, 72, 73, 74) provided on the surface (61) or back surface (62) of the base-side first arm (14) is 2% or more and 10% or less of the thickness (H) of the base portion of the base-side first arm (14). Also, in the resin pliers according to the present invention, The thickness (t) of the ribs (71, 72, 73, 74) provided on the surface (61) or back surface (62) of the base-side first arm (14) is 2% or more and 10% or less of the thickness (H) of the base portion of the base-side first arm (14).

[0013] And the resin pliers according to the present invention A resin forceps (1) having a first gripping part (10) and a second gripping part (20) connected so as to be able to swing around a pivot, The first gripping component (10) comprises a first gripping portion (12), a base-side first arm (14), a tip-side first arm (15), a first rotating portion (16), and a first gripping portion (17). The second gripping component (20) comprises a second gripping portion (22), a base-side second arm (24), a tip-side second arm (25), a second rotating portion (26), and a second gripping portion (27). The base-side first arm (14) and the base-side second arm (24) each have a surface (61) and a back surface (62) that are substantially perpendicular to the pivot axis, and an outer surface (63) and an inner surface (64) that are substantially parallel to the pivot axis. A pair of outer surface ribs (171, 173) are provided on the front and back edges of the outer surface (63) of the base side first arm (14) or base side second arm (24), and a pair of inner surface ribs (172, 174) are provided on the front and back edges of the inner surface (64), The thickness (t) of the outer surface ribs (171, 173) and inner surface ribs (172, 174) is 2% to 10% of the width (L) of the base portion of the base side first arm (14).

Advantages of the Invention

[0014] According to the present invention, it is possible to enjoy the effect of improving the strength and rigidity of the arm portion of the resin pliers. And the improvement in strength is achieved with an appearance that does not significantly differ from that of conventional general resin pliers (resin pliers with a substantially rectangular cross-sectional shape of the arm portion), so it is also possible to enjoy the effect that medical personnel can start using it without feeling uncomfortable. Furthermore, the improved strength significantly increases the possibility of achieving the required quality and strength even when manufacturing with resin that does not contain reinforcing materials such as glass fibers. This offers advantages in terms of disposal and recycling when reinforcing materials such as glass fibers are not used, as well as the ability to suppress wear on manufacturing molds. [Brief explanation of the drawing]

[0015] [Figure 1] This is an overall view of the resin forceps 1 in an embodiment of the present invention. [Figure 2] This is a view of the first gripping component 10 of the resin forceps 1 in an embodiment of the present invention, as seen from the surface side. [Figure 3] This is a view of the second gripping component 20 of the resin forceps 1 in an embodiment of the present invention, as seen from the back side. [Figure 4] This is a view of the first gripping component 10 of the resin forceps 1 in an embodiment of the present invention, as seen from the inner side. [Figure 5] This is a cross-sectional view of the base arms 14 and 24 along the BB line in Figure 3. [Figure 6] This figure shows a cross-section of a conventional resin forceps at the same position as in Figure 5. [Figure 7] This is a cross-sectional view of the second grip portion 22 along the CC line in Figure 3, according to an embodiment of the present invention. [Figure 8] This is a cross-sectional view of the base arms 14 and 24 at the same position as in Figure 3 of the resin forceps 1 in another embodiment of the present invention. [Figure 9] This is a characteristic diagram showing the relationship between test force (bending force applied to the test specimen) and displacement (bending displacement of the test specimen) in a three-point bending test according to an embodiment of the present invention. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following, the same reference numerals will be used for similar elements in all drawings, and redundant explanations will be omitted. In addition, in the descriptions within the text, reference numerals previously mentioned will be used as necessary.

[0017] Figure 1 is an overall view of the resin forceps 1 in an embodiment of the present invention. As shown in Figure 1, the resin forceps 1 is constructed by connecting the first gripping part 10 and the second gripping part 20 with a pivot pin 52 so that they can swing around a pivot.

[0018] The first gripping component 10 has a first grip portion 12 at one end, which has an annular portion into which the operator inserts their fingers. A base-side first arm 14 is provided that extends continuously from the first grip portion 12 toward the other end. A first pivot portion 16 is integrally provided at the end of the base-side first arm 14, and further beyond that, a tip-side first arm 15 is integrally provided, and further beyond that, a first gripping portion 17 is integrally provided. A first ratchet portion 19 is integrally provided between the first grip portion 12 and the base-side first arm 14.

[0019] Similar to the first gripping part 10, the second gripping part 20 has a second grip portion 22 at one end, which has an annular portion into which the operator inserts their fingers. A base-side second arm 24 is provided that extends continuously from the second grip portion 22 toward the other end. A second pivot portion 26 is integrally provided at the end of the base-side second arm 24, and further beyond that, a tip-side second arm 25 is integrally provided, and further beyond that, a second gripping portion 27 is integrally provided. A second ratchet portion 29 is integrally provided between the second grip portion 22 and the base-side second arm 24.

[0020] Figure 2 shows the first gripping component 10 viewed from the front side. Figure 3 shows the second gripping component 20 viewed from the back side. For the sake of clarity, the above-mentioned front and back surfaces are defined as follows: When the first gripping part 10 and the second gripping part 20 are assembled in a rotatable state as shown in Figure 1, the surface on which the first rotating part 16 of the first gripping part 10 and the second rotating part 26 of the second gripping part 20 come into contact is defined as the back surface, and the opposite surface is defined as the front surface. In other words, in the state shown in Figure 1, the front surface of the first gripping part 10 and the back surface of the second gripping part 20 are visible. Furthermore, for the convenience of explaining the details of the base-side first arm 14 and the base-side second arm 24, the terms "outside" and "inside" are defined as follows: When the first gripping component 10 and the second gripping component 20 are assembled in a rotatable state as shown in Figure 1, the direction in which the forceps 1 closes is defined as the inside, and the direction in which the forceps 1 opens is defined as the outside. In other words, in the state shown in Figure 1, the inner surface of the base-side first arm 14 and the inner surface 64 of the base-side second arm 24 face each other, and the side opposite to the inner surface 64 is the outer surface 63.

[0021] In this embodiment, the first gripping component 10 and the second gripping component 20 have exactly the same shape when viewed as individual components. Therefore, in the description of individual components in this specification, only one of the first gripping component 10 or the second gripping component 20 may be described, and the description of the other may be omitted. In this case, it should be understood that the other component also has the same structure as the first gripping component 10 or the second gripping component 20. While making the first gripping part 10 and the second gripping part 20 the same shape is extremely important in terms of improving the productivity of the parts, the scope of the present invention is not necessarily limited to parts that have the same shape.

[0022] Figure 4 shows the first gripping component 10 of the resin forceps 1 in an embodiment of the present invention, viewed from the inner side. The second gripping component 20, viewed from the inner side, is the same as in Figure 4. The detailed structure of forceps 1 will be described with reference to Figures 1 to 4. The first grip portion 12, located at one end of the first gripping component 10, is an annular portion with a roughly oval-shaped grip hole 54 into which the operator can insert their fingers. As can be seen in Figure 4, the thickness of the resin of the first grip portion 12 is smaller than that of other parts, and the overall weight has been reduced as much as possible while maintaining the minimum necessary strength, making it easy to operate.

[0023] A base-side first arm 14 is integrally provided from the first grip portion 12 toward the other end. The base-side first arm 14 has a surface 61 and a back surface 62 that are substantially perpendicular to the direction in which the pivot axis for the opening and closing rotation operation of the forceps 1 extends, and an outer surface 63 and an inner surface 64 that are substantially parallel to the axis direction. Note that the substantially perpendicular surface 61 does not mean that it is geometrically perfectly perpendicular, but rather indicates the approximate direction in which the surface extends, and the surface is not limited to a perfect plane. Similarly, the substantially parallel outer surface 63 does not mean that it is geometrically perfectly parallel, but indicates the approximate direction in which the surface extends, and the surface is not limited to a perfect plane. The base-side first arm 14 has an external shape that is substantially rectangular, enclosed by the four surfaces: surface 61, back surface 62, outer surface 63, and inner surface 64. More specifically, the surface 61 and back surface 62 have a complex structure with ribs 71, 72, 73, and 74 provided to improve strength, but this will be explained in detail later.

[0024] A first pivot portion 16, formed in a substantially disc shape, is integrally provided at the end of the base-side first arm 14. A pivot hole 51 is provided in the first pivot portion 16. The first pivot portion 16 of the first gripping component 10 overlaps with the second pivot portion 26 of the second gripping component 20 in surface contact with its back surface, and the two components are connected so as to be able to swing freely by inserting and fixing a pivot pin 52 so as to pass through the pivot holes 51 provided in each of the two components. The pivot pin 52 may be a pivot pin fixed by a known resin rivet type, or it may be a combination of multiple parts to form a single pivot, as described in Japanese Patent Publication No. 2021-065515, an earlier patent application of the applicant of this application. Alternatively, unlike this embodiment, the first pivot portion 16 may not have a pivot hole 51, and the pivot pin 52 may be integrally provided protruding from it and inserted into the pivot hole 51 of the second pivot portion 26.

[0025] A first arm 15 is integrally attached to the tip of the first rotating part 16, and a first gripping part 17 is integrally attached to the tip of the first arm 15. As shown in Figure 4, the first gripping part 17 has a rounded tip and a teardrop-shaped annular form with the central part hollowed out as a gripping hole 56. One side of the first gripping part 17 is the first gripping surface 18. The first gripping surface 18 is the surface that comes into contact with the object to be gripped, such as gauze, and it is preferable that the surface has fine irregularities to facilitate gripping. The tip-side first arm 15, like the base-side first arm 14, has a surface 61 and a back surface 62 that are substantially perpendicular to the pivot axis direction, and an outer surface 63 and an inner surface 64 that are substantially parallel to the pivot axis direction. Similarly, the tip-side second arm 25, like the base-side second arm 24, has a surface 61 and a back surface 62 that are substantially perpendicular to the pivot axis direction, and an outer surface 63 and an inner surface 64 that are substantially parallel to the pivot axis direction.

[0026] Furthermore, a first ratchet section 19 is integrally provided between the first grip section 12 and the base-side first arm 14. The first ratchet section 19 extends further inward from the inner surface of the base-side first arm 14. The first ratchet section 19 has ratchet teeth on its back side, which engage with the second ratchet section 29 of the second gripping component 20, allowing the gripping of the object to be held to be maintained by the ratchet mechanism. Stoppers 58 are provided near the bases of the first ratchet section 19 and the second ratchet section 29 to prevent deformation or damage due to excessive operation.

[0027] Next, we will describe the ribs 71, 72, 73, and 74, which are one of the features of the embodiment of the present invention. A longer overall length of the forceps 1 is sometimes preferred because it allows for a greater distance between the patient's affected area and the forceps user. In such cases, the base-side first arm 14 (base-side second arm 24) may be designed to be considerably longer. Furthermore, it is preferable that the tip-side first arm 15 (tip-side second arm 25) be designed to be longer, as a ratio of the length of the base-side first arm 14 (base-side second arm 24) to the length of the tip-side first arm 15 (tip-side second arm 25) makes it easier to grasp the object due to the lever principle. For these reasons, the base-side first arm 14 (base-side second arm 24) is generally long, and this is the part of the resin material that is most susceptible to deformation during use. To suppress such deformation, in embodiments of the present invention, ribs 71, 72, 73, and 74 are provided that protrude from the surface 61 of the base-side first arm 14 (base-side second arm 24) and extend in the longitudinal direction of the base-side first arm 14 (base-side second arm 24).

[0028] In the embodiment of the present invention, the ribs 71, 72, 73, and 74 are provided on the surface 61 and back surface 62 of the base-side first arm 14 and the base-side second arm 24. Figure 5 is a cross-sectional view of the base-side second arm 24 along line BB in Figure 3. Since the base-side first arm 14 has the same cross-section, Figure 5 shows both part numbers 14 and 24 simultaneously. As shown in Figure 5, the cross-section of the base-side first arm 14 (base-side second arm 24) has a roughly rectangular basic shape enclosed by the lines of the cross-sections of the four surfaces: surface 61, back surface 62, outer surface 63, and inner surface 64. The ribs 71, 72, 73, and 74 are arranged to protrude from this roughly rectangular basic shape. To make it easier to understand the features of the ribs 71, 72, 73, and 74 in the embodiment of the present invention, a comparative diagram is shown in Figure 6. Figure 6 shows a cross-section at the same position as in Figure 5 of a conventional resin forceps without ribs. The embodiment of the present invention is one in which the cross-sectional shape of Figure 6 is viewed as a roughly rectangular basic shape, and the ribs 71, 72, 73, and 74 are arranged to protrude from it. In the explanation of Figures 5 and 6, the cross-sectional shape is described as a roughly rectangular basic shape. More precisely, of the surface 61, back surface 62, outer surface 63, and inner surface 64, the surface 61 and back surface 62 are planes formed by the straight lines of the cross-section shown in Figure 5, while the outer surface 63 and inner surface 64 are curved surfaces formed by the curved lines of the cross-section shown in Figure 5. Furthermore, it is preferable that the four corners are chamfered, which is a common technique in mechanical design. The surface 61 and back surface 62 may also be curved surfaces, and the outer surface 63 and inner surface 64 may be flat surfaces. As is clear from Figures 2 and 3, these ribs 71, 72, 73, and 74 extend along the entire longitudinal direction of the base-side first arm 14 (base-side second arm 24). Therefore, the cross-section at any point along the longitudinal direction of the base-side first arm 14 (base-side second arm 24) has a shape with similar characteristics to that shown in Figure 5.

[0029] In the resin forceps 1 of the embodiment of the present invention, pairs of ribs 71, 72, 73, and 74 are provided on both the inner and outer edges of the front surface 61 and back surface 62. Providing all four ribs 71, 72, 73, and 74 in this manner is preferable to achieve further strength improvement, but it is also acceptable to provide only one pair on one side of the front surface 61 or back surface 62. Alternatively, if the strength quality requirements of the resin forceps 1 required by the user are not stringent, at least one, two, or three of the four ribs 71, 72, 73, and 74 described above may be arbitrarily selected and provided. Alternatively, the ribs may be provided on the outer surface 63 and inner surface 64 of the arms 14 and 24.

[0030] In the embodiments of the present invention, the ribs 71, 72, 73, and 74 have a thickness t and a width w, as shown in Figure 5. The thickness t of rib 71 is smaller than the thickness H of the base-side first arm 14, and the width w of rib 71 is smaller than the width L of the base of the base-side first arm 14. If the thickness t and width w are too small, it will be insufficient in terms of performance in terms of improving strength, which is undesirable. Conversely, if they are too large, the appearance will stand out as being different from conventional, familiar resin forceps, which is also undesirable, so it is preferable to keep them within an appropriate range. Specifically, in a cross-section at an arbitrary position near the middle of the longitudinal direction of the base-side first arm 14 (base-side second arm 24) as shown in Figure 5, it is preferable that the thickness t of the rib is in the range of 2% to 10% of the height H in the front-back direction of the base-side first arm 14 (base-side second arm 24). To ensure that the appearance does not differ significantly from conventional forceps without ribs, it is preferable to use a value lower than 2% to 10%. However, if appearance is not a concern, a value exceeding 10% is acceptable, and a thickness of approximately 20% is also acceptable. Furthermore, in the cross-section shown in Figure 5, it is preferable that the width (length in the inward and outward direction) w of the rib is in the range of 10% to 40% of the width (length in the inward and outward direction) L of the base-side first arm 14 (base-side second arm 24).

[0031] The thickness t of the rib described above is defined as the height from the reference line s1 (s2) to the highest point of the rib protruding in the front or back direction, with the straight lines formed by the front surface 61 and the back surface 62 in the cross-sectional view being reference line s1 and reference line s2, respectively. The height H described above is defined as the distance from reference line s1 to reference line s2. If the front surface 61 and the back surface 62 are curved surfaces rather than flat surfaces, the horizontal lines passing through the point where the curved surface intersects with the outline of the rib (the intersection indicated by arrow P in Figure 5) are considered as reference lines s1 and s2, and the values ​​measured in the same manner as above are used to define the thickness t of the rib. Furthermore, the width w of the rib described above is defined as the width in the inward-outward direction from the position located at the outermost edge of the outer surface 63 or inner surface 64 in the cross-sectional view to the point P where the rib intersects the surface 61 and the back surface 62. The width L of the base side first arm 14 (base side second arm 24) is defined as the distance between the outermost edge of the outer surface 63 and the innermost edge of the inner surface 64.

[0032] To illustrate with a specific numerical example, if the total length of the resin forceps 1 from the grip portion 12 to the grasping portion 17 is 180 mm, then the height H in the front-to-back direction of the base-side first arm 14 (base-side second arm 24) is 5 mm, the thickness t of the rib is 0.2 mm, the length L in the inward-to-outward direction is 6 mm, and the width w is 2 mm. The thickness t of the rib may be uniformly the same along the direction in which the rib extends, or it may vary along the direction in which the rib extends. For example, the thickness t may change periodically along the direction in which the rib extends. More specifically, the thickness t may be changed periodically along the direction in which the rib extends, like a sine wave, to create a roughly wave-like uneven surface.

[0033] Furthermore, some of the ribs 71, 72, 73, and 74 in the embodiments of the present invention are not only ribs that extend linearly in the longitudinal direction, but also ribs that are curved, and other types of ribs are combined to form these ribs.

[0034] First, as shown in Figures 2 and 4, the rib 72 (referred to as the inner surface rib 72) provided on the inside of the surface 61 is a rib that combines a straight rib 72a, a curved rib 72b on the ratchet side, a connecting rib 72c on the rotating side, and a ratchet outer edge rib 72d. The curved rib 72b on the ratchet side extends from the straight rib 72a toward the ratchet 19 and has a curved shape that is curved at approximately 90 degrees so as to smoothly connect in the direction in which the ratchet 19 extends. Furthermore, another ratchet outer edge rib 72d extends from the ratchet outer edge rib 72d. The ratchet outer edge rib 72d extends so as to border the outer circumference of the ratchet 19 and further extends so as to be tangent to the annular curve of the annular portion of the grip 12. On the other hand, the connecting rib 72c on the opposite side of the rotating part extends from the straight rib 72a toward the rotating part 16, gradually curving inward as it approaches the rotating part 16, and extending to smoothly connect to the annular shape of the rotating part 16 from a tangential direction. As shown in Figure 4, the thickness t of the linear rib 72a and the ratchet outer edge rib 72d is uniformly approximately the same as they extend. On the other hand, the thickness t of the rotating part side connecting rib 72c gradually increases as it approaches the rotating part 16, and the overall shape is sloped upward toward the rotating part 16. In this way, by providing the ratchet-side curved rib 72b and the rotating-side connecting rib 72c on both sides of the straight rib 72a, a wider portion of the resin forceps 1 is reinforced, making the base-side first arm 14 (base-side second arm 24) and the vicinity of both ends of it, which are most prone to bending during use, less likely to bend. Furthermore, it is preferable for the straight rib 72a, the curved rib 72b on the ratchet side, the connecting rib 72c on the rotating side, and the outer edge rib 72d of the ratchet side to be continuous without breaks in order to improve strength. However, due to manufacturing mold design considerations or design considerations, there may be breaks in the ribs where they are not continuous, as long as they do not significantly reduce the strength.

[0035] Furthermore, the rib 71 provided on the outside of the surface 61 (referred to as the outer surface rib 71) is a rib that combines a straight rib 71a, a grip-side curved rib 71b, and a rotating-side connecting rib 71c. The grip-side curved rib 71b extends from the straight rib 71a toward the grip portion 12 and has a curved shape that extends so as to be tangent to the annular curve of the annular portion of the grip portion 12. The rotating-side connecting rib 71c extends from the straight rib 71a toward the rotating portion 16 and becomes wider as it approaches the annular shape of the rotating portion 16, and is configured to connect to the wider arc portion of the annulus of the rotating portion 16. The thickness t of the straight rib 71a and the grip-side curved rib 71b is uniformly the same value. The rotating part side connecting rib 71c, like the rotating part side connecting rib 72c described earlier (see Figure 4), has a thickness t that increases as it approaches the rotating part 16, and as a whole, it has a shape that gradually slopes upward towards the rotating part 16. In this way, by providing the gripping-side curved rib 71b and the rotating-side connecting rib 71c on both sides of the straight rib 71a, a wider portion of the resin forceps 1 is reinforced, making the base-side first arm 14 (base-side second arm 24) and the vicinity of both ends of it, which are most prone to bending during use, less likely to bend. Furthermore, it is preferable for the straight rib 71a, the curved rib 71b on the grip side, and the connecting rib 71c on the rotating side to be continuous without any breaks in order to improve strength. However, due to manufacturing mold design considerations or design considerations, there may be breaks in the ribs where they are not continuous, as long as they do not significantly reduce the strength.

[0036] Furthermore, the rib 73 provided on the outside of the back surface 62 (referred to as the back surface outer rib 73) is a rib that combines a straight rib 73a and a grip-side curved rib 73b. The grip-side curved rib 73b extends from the straight rib 73a toward the grip portion 22 and has a curved shape that extends so as to be tangent to the annular curve of the annular portion of the grip portion 22. Furthermore, the ribs 74 (referred to as the inner ribs 74) provided on the inside of the back surface 62 are composed solely of straight ribs 74a. In this way, by providing not only the surface surface 61 of the base arm but also the back surface 62 of the base arm with an outer rib 73 on the back surface and an inner rib 74 on the back surface, the arm portion of the resin forceps 1 is further reinforced, making the base first arm 14 (base second arm 24) and the vicinity of both ends of the base arm, which are most prone to bending during use, less likely to bend. Ideally, both the outer rib 73 on the back surface and the inner rib 74 on the back surface should be continuous without breaks to improve strength. However, due to manufacturing mold design considerations or other design considerations, it is acceptable to have breaks in the rib within a length range that does not significantly reduce strength.

[0037] Figure 7 is a cross-sectional view of the second grip portion 22 along the CC line in Figure 3. Since the first grip portion 12 has the same cross-section, Figure 7 shows both numbering 12 and numbering 22 simultaneously. As shown in Figure 5, the cross-section of the annular portion of the first grip portion 12 (second grip portion 22) is approximately square with rounded corners, and the ribs 74a and 72d are positioned to protrude from this approximately square shape.

[0038] (Another embodiment) Figure 8 illustrates another embodiment of the present invention. This Figure 8 shows a cross-section at the same position as in Figure 5 described earlier, in another embodiment. In this other embodiment, a pair of outer surface ribs 171 and 173 are provided on the front and back edges of the outer surface 63 of the base-side first arm 14 (base-side second arm 24), and a pair of outer surface ribs 172 and 174 are provided on the front and back edges of the inner surface 64. Except for the change in the position of the ribs, it is the same as the embodiment described earlier. The thickness t of the rib is smaller than the width L of the base of the base-side first arm 14, and the width w of the rib is smaller than the thickness H of the base-side first arm 14. Preferably, the thickness t of the rib is 2% to 10% of the width L of the base of the base-side first arm 14, and the width w of the rib is 10% to 40% of the thickness H of the base-side first arm 14. In this other embodiment, as in the embodiments described above, it is preferable that the ribs include straight ribs and curved ribs that extend continuously from the straight ribs toward the gripping portion or the rotating portion. This alternative embodiment is effective in improving the strength of the forceps 1 in the opening and closing operation direction. In this alternative embodiment, it is preferable to provide all four ribs 171, 172, 173, and 174 to achieve further strength improvement, but only one pair may be provided on one side of the outer surface 63 or the inner surface 64. Alternatively, at least one, two, or three of the four ribs 171, 172, 173, and 174 described above may be arbitrarily selected and provided.

[0039] Furthermore, in yet another embodiment, some of the ribs 71, 72, 73, 74 on the surface 61 and back surface 62 described in Figure 5 may be combined with some of the ribs 171, 172, 173, 174 on the outer surface 63 and inner surface 64 described in Figure 8, or all eight ribs may be provided.

[0040] Furthermore, in yet another embodiment, the ribs 71, 72, 73, and 74 on the surface 61 and back surface 62 described in Figure 5, and the four ribs 171, 172, 173, and 174 on the outer surface 63 and inner surface 64 described in Figure 8 may be provided on the first arm 15 and second arm 25 at the tip of the forceps 1. Depending on the type of forceps 1, the length of the first arm 15 (second arm 25) at the tip may be longer than the length of the first arm 14 (second arm 24) at the base, in which case it is preferable to provide the ribs on the first arm 15 (second arm 25) at the tip. If it is desired to further improve the overall strength of the forceps 1, ribs can be placed on all arms of the first arm 14 (second arm 24) at the base and the first arm 15 (second arm 25) at the tip.

[0041] In the embodiment of the present invention, the first gripping part 10 and the second gripping part 20 of the resin forceps 1 are each integrally formed by resin injection molding. As the resin material, known resins such as polycarbonate resin, polyamide resin, polypropylene resin, ABS resin, polyethylene terephthalate resin, and polyethylene resin may be used. As described above, the first gripping part 10 and the second gripping part 20 in the embodiment of the present invention are provided with ribs 71, 72, 73, and 74 to increase their strength and rigidity, so it is not necessary to use reinforcing materials such as glass fibers, which were essential in conventional resin forceps 1. In this case, advantages such as easier handling in terms of disposal and recycling of the resin forceps 1 and reduced mold wear during manufacturing can be enjoyed. However, the present invention does not exclude the use of reinforcing materials such as glass fibers, and if further strength improvement is desired, a resin containing reinforcing materials such as glass fibers to improve strength may be used. Furthermore, while it is preferable to manufacture the pivot pin 52 from the same material as the first gripping part 10 and the second gripping part 20, it may be manufactured from a different material, especially if it is desired to further improve the function of the pivot. [Examples]

[0042] Examples of resin forceps 1 (resin forceps 1 without reinforcing materials such as glass fibers) in embodiments of the present invention, and comparative examples will be described below. (Examples) The forceps 1 having the structure described in Figures 1 to 5 and Figure 7 was manufactured by integral injection molding using polycarbonate resin without the use of reinforcing materials such as glass fibers. In other words, in this embodiment, ribs 71, 72, 73, and 74 are provided at the positions shown in Figures 1 to 5 and Figure 7. The total length of the forceps 1 (length from the tip of the grip portion 12 to the tip of the gripping portion 17) is 180 mm. As shown in Figure 5, the height H in the front-to-back direction of the base-side first arm 14 (base-side second arm 24) is 5 mm, the thickness t of the rib is 0.2 mm, the length L in the inward-to-outward direction is 6 mm, and the width w is 2 mm. (Comparative Example 1) A forceps having the same shape as the embodiment, except for the absence of ribs 71, 72, 73, and 74, was manufactured by integral injection molding using polycarbonate resin with reinforcing materials such as glass fibers. (Comparative Example 2) A forceps with the same shape as the example, except for the absence of ribs, was manufactured by integral injection molding using polycarbonate resin without the use of reinforcing materials such as glass fibers.

[0043] • Test Verification 1 (3-point bending test) The strength characteristics of the example, comparative example 1, and comparative example 2 were measured by a three-point bending test based on JIS K 7171 "Plastics - Method for determining bending properties". This test method is a three-point bending test in which force is applied to the center of a beam (girder) with both ends freely supported. The testing machine used was a plastic strength testing machine (model AG-50KNX, manufactured by Shimadzu Corporation) owned by the Toyama Prefectural Industrial Technology Research and Development Center. As the test specimen, the first arm 14 (second arm 24 on the base side) of the forceps was cut out to a length of 55 mm (cross section is approximately rectangular, 7.0 mm × 4.55 mm) and used. The distance between the support bases of the testing machine that support the left and right ends of the test specimen (distance between support points) was 40 mm, and the three-point bending test was performed by pressing the indenter of the test specimen at the midpoint. The test speed (relative movement speed between the support base and the indenter) was 2 mm / min, and the test was performed at one test speed. This test yielded a characteristic curve showing the relationship between the test force (bending force applied to the test specimen) and the displacement (bending displacement of the test specimen). Figure 9 shows the characteristic curves of the test results for the example (refer to the characteristic curves shown. Note that the straight lines shown in Figure 9 are auxiliary lines for evaluating the properties in the elastic deformation region). Although only the characteristic curve of the example is shown in Figure 9, in this test, the example, comparative example 1, and comparative example 2 all showed similar behavior of the change curve as in Figure 9. That is, from the start of applying the test force, the characteristic curve was almost linear and elastically deformable in the initial stages of the test, then it drew a plastically deformable characteristic curve beyond the elastic limit, reaching the maximum point (the point indicating the maximum value of the test force), and then drew a characteristic curve of the yield state. The values ​​of the test force and displacement at that maximum point (the point indicating the maximum value of the test force) are shown in Table 1 below. Note that the results in Table 1 are the average values ​​of three tests for the example, comparative example 1, and comparative example 2.

[0044] [Table 1]

[0045] The test results shown in Table 1 show that when Comparative Example 1, which uses a resin containing glass fibers, is changed to a resin without glass fibers as in Comparative Example 2, the strength (test force at the maximum point) decreases significantly. On the other hand, in the example with ribs, it can be seen that even when using a resin without glass fibers, strength (test force at the maximum point) comparable to that of Comparative Example 1, which uses a resin containing glass fibers, can be obtained. Furthermore, the displacement values ​​at the maximum point indicate that by providing ribs as in the example, the forceps are less prone to deflection than Comparative Example 2, and that the rigidity is significantly enhanced. It should be noted that this enhancement of rigidity should be evaluated not only for the test specimen but also as the overall rigidity of the forceps 1, as a difference in displacement when the same load is applied. This is considered appropriate for evaluating the user's perception, and will be compared and verified using the following separate test verification 2.

[0046] • Test Verification 2 (Test of Flexural Stiffness) The following tests were conducted to evaluate the overall rigidity of forceps 1. The first gripping part 10 of the forceps 1 was used as a test specimen. The first gripping portion 12 of the first gripping part 10 was fixed to a support base and fixed horizontally in a cantilevered position. A 300g weight was suspended from the first gripping portion 17 side, and the displacement of the tip of the first gripping portion 17 was measured. The measurement results are shown in Table 2.

[0047] [Table 2]

[0048] The test results shown in Table 2 confirm that by providing ribs as in the example, strength and rigidity comparable to Comparative Example 1, which uses glass fiber reinforced resin, can be obtained. While Comparative Example 2, which does not have ribs, bends significantly, it was confirmed that the rigidity of the forceps 1 as a whole is greatly enhanced by providing ribs as in the example. In particular, it is thought that the extension of not only the straight ribs 71a, 72a, and 73a, but also the curved ribs 71b, 71c, 72b, 72c, and 73b further enhances the rigidity not only of the base arm 14 but also of the connection between the gripping part 17 and the rotating part 16, which greatly influenced these test results.

[0049] It should be noted that the present invention is not limited to the embodiments disclosed above, and it is also possible to appropriately utilize, use as a substitute for, or add to technologies that are substantially the same as or have similar effects as those described in the embodiments of the present invention, as recognized by those skilled in the art. For example, in the drawings illustrating embodiments of the present invention, the gripping portions 17 and 27 are described as having a shape suitable for cotton ball forceps, but the shape and function of the gripping portions 17 and 27 should be appropriately modified according to the intended use of various forceps. Also, in the drawings illustrating embodiments of the present invention, the base arms 14 and 24 are depicted as being longer than the tip arms 15 and 25, but the lengths of these arms should also be appropriately modified according to the intended use of various forceps. [Explanation of Symbols]

[0050] 1 forceps 10 1st grip part 12. First grip section 14. Base-side first arm 15 First arm at the tip 16. First Movement 17. First Grabbing Section 18. First gripping surface 19. First ratchet section 20 Second gripping part 22. Second grip section 24 Base-side second arm 25. Second arm at the tip 26. Second Movement 27. Second Grabbing Section 28. Second gripping surface 29. Second ratchet section 51 Axle holes 52 Axle Pins 54. Hole in the grip section 56. Gripping hole 58 Stopper 61 Base side arm surface 62 Base side arm back 63 Outer surface of the base arm 64 Inner side of base arm 71 Surface outer ribs 71a Straight rib 71b Curved rib on the grip side 71c Rotating part side connecting rib 72 Ribs on the inner surface 72a Straight Rib 72b Ratchet side curved rib 72c Rotating part side connecting rib 72d Ratchet part outer edge rib 73. Outer ribs on the reverse side 73a Straight Rib 73b Curved rib on the grip side 74 Inner ribs on the reverse side 74a Straight ribs 171,173 Outer surface ribs 172,174 Inner surface ribs

Claims

1. A resin forceps (1) having a first gripping part (10) and a second gripping part (20) connected so that they can swing around a pivot, The first gripping component (10) comprises a first gripping portion (12), a base-side first arm (14), a tip-side first arm (15), a first rotating portion (16), and a first gripping portion (17). The second gripping component (20) comprises a second gripping portion (22), a base-side second arm (24), a tip-side second arm (25), a second rotating portion (26), and a second gripping portion (27). The first grip portion (12) and the second grip portion (22) each have an annular portion into which the operator inserts their fingers. The base-side first arm (14) and the base-side second arm (24) each have a surface (61) and a back surface (62) that are substantially perpendicular to the pivot axis, and an outer surface (63) and an inner surface (64) that are substantially parallel to the pivot axis. The base-side first arm (14) and the base-side second arm (24) each have ribs (71, 72, 73, 74) that protrude from the surface (61) and extend in the longitudinal direction. A resin forceps characterized in that the rib (71) provided on the outside of the surface (61) comprises a straight rib (71a) and a grip-side curved rib (71b), the grip-side curved rib (71b) extends from the straight rib (71a) toward the first grip portion (12) and has a curved shape that extends so as to be tangent to the annular curve of the annular portion of the first grip portion (12).

2. A resin forceps (1) having a first gripping part (10) and a second gripping part (20) connected so that they can swing around a pivot, The first gripping component (10) comprises a first gripping portion (12), a base-side first arm (14), a tip-side first arm (15), a first rotating portion (16), and a first gripping portion (17). The second gripping component (20) comprises a second gripping portion (22), a base-side second arm (24), a tip-side second arm (25), a second rotating portion (26), and a second gripping portion (27). The first grip portion (12) and the second grip portion (22) each have an annular portion into which the operator inserts their fingers. The base-side first arm (14) and the base-side second arm (24) each have a surface (61) and a back surface (62) that are substantially perpendicular to the pivot axis, and an outer surface (63) and an inner surface (64) that are substantially parallel to the pivot axis. The base-side first arm (14) and the base-side second arm (24) each have ribs (71, 72, 73, 74) that protrude from the back surface (62) and extend in the longitudinal direction. A resin forceps characterized in that the rib (73) provided on the outside of the back surface (62) comprises a straight rib (73a) and a grip-side curved rib (73b), the grip-side curved rib (73b) extends from the straight rib (73a) toward the second grip portion (22) and has a curved shape that extends so as to be tangent to the annular curve of the annular portion of the second grip portion (22).

3. A resin forceps (1) having a first gripping part (10) and a second gripping part (20) connected so that they can swing around a pivot, The first gripping component (10) comprises a first gripping portion (12), a base-side first arm (14), a tip-side first arm (15), a first rotating portion (16), and a first gripping portion (17). The second gripping component (20) comprises a second gripping portion (22), a base-side second arm (24), a tip-side second arm (25), a second rotating portion (26), and a second gripping portion (27). The first grip portion (12) and the second grip portion (22) have annular portions into which the operator inserts their fingers, and a first ratchet portion (19) is integrally provided between the first grip portion (12) and the base-side first arm (14). The base-side first arm (14) and the base-side second arm (24) each have a surface (61) and a back surface (62) that are substantially perpendicular to the pivot axis, and an outer surface (63) and an inner surface (64) that are substantially parallel to the pivot axis. The base-side first arm (14) and the base-side second arm (24) each have ribs (71, 72, 73, 74) that protrude from the surface (61) and extend in the longitudinal direction. A resin forceps characterized in that the rib (72) provided on the inside of the surface (61) comprises a straight rib (72a) and a ratchet outer edge rib (72d), and the curved rib (72b) on the ratchet side extends from the straight rib (72a) toward the ratchet (19) and has a curved shape that smoothly connects in the direction in which the ratchet (19) extends.

4. In the resin forceps according to claim 3, A resin forceps characterized in that the rotating part side connecting rib (72c) extends from the straight rib (72a) toward the rotating part (16), and as it approaches the rotating part (16), it gradually curves inward, extending to smoothly connect to the annular shape of the rotating part (16) from a tangential direction.

5. A resin forceps according to any one of claims 1 to 3, A resin forceps characterized in that the ribs (71, 72, 73, 74) are provided in pairs on the edges of the surface (61) or the back surface (62).

6. A resin forceps according to any one of claims 1 to 3, A resin forceps characterized in that the thickness (t) of the ribs (71, 72, 73, 74) provided on the surface (61) or back surface (62) of the base-side first arm (14) is 2% or more and 10% or less of the thickness (H) of the base part of the base-side first arm (14).

7. A resin forceps according to any one of claims 1 to 3, A resin forceps characterized in that the width (w) of the ribs (71, 72, 73, 74) provided on the surface (61) or back surface (62) of the base-side first arm (14) is 10% or more and 40% or less of the width (L) of the base-side first arm (14).

8. A resin forceps (1) having a first gripping part (10) and a second gripping part (20) connected so that they can swing around a pivot, The first gripping component (10) comprises a first gripping portion (12), a base-side first arm (14), a tip-side first arm (15), a first rotating portion (16), and a first gripping portion (17). The second gripping component (20) comprises a second gripping portion (22), a base-side second arm (24), a tip-side second arm (25), a second rotating portion (26), and a second gripping portion (27). The base-side first arm (14) and the base-side second arm (24) each have a surface (61) and a back surface (62) that are substantially perpendicular to the pivot axis, and an outer surface (63) and an inner surface (64) that are substantially parallel to the pivot axis. A pair of outer surface ribs (171, 173) are provided on the front and back edges of the outer surface (63) of the base side first arm (14) or base side second arm (24), and a pair of inner surface ribs (172, 174) are provided on the front and back edges of the inner surface (64), A resin forceps characterized in that the thickness (t) of the outer surface ribs (171, 173) and inner surface ribs (172, 174) is 2% or more and 10% or less of the width (L) of the base portion of the base side first arm (14).

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