Medical edged tool

Abstract

A medical edged tool according to the present invention comprises a blade body held between a holder and a cover. The blade body has: a blade edge that extends from a cutting tip in a plan view and has a cutting edge at least in a portion thereof; a back edge that extends from the cutting tip; and a first edge part that extends in a direction at a first angle with respect to the back edge. The holder has a recess-shaped blade body holding recess part formed along the shape of the blade body. The blade body holding recess part has a configuration including, at a position where the first edge part abuts, a first inclined portion that is inclined in a direction perpendicular to the first edge part in a plan view, and at a position where the back edge abuts, a second inclined portion that is inclined in a direction perpendicular to the back edge in a plan view.

Description

Medical blades

[0001] One aspect of the present invention relates to a medical blade.

[0002] Conventionally, there have been scalpels (medical blades) that include a handle, a blade, and a slider (movable body), and the handle is held by hand, and the slider attached to the blade moves, allowing the blade to be retracted. In such scalpels, the handle and slider are assembled together, which are made of plastic. However, because the slider moves inside the handle, rattles can occur between the slider and the handle. In this case, because the blade is attached to the slider, rattles can occur in the blade relative to the handle.

[0003] In contrast, the medical blade described in Patent Document 1 is configured with a handle, a blade, and a movable body having a cover. In this configuration, the blade is attached to the handle, so even if rattle occurs between the handle and the movable body, the blade itself will not rattle.

[0004] Another medical knife is described in Patent Document 2.

[0005] JP 2017-86590 A JP 2018-143322 A

[0006] However, in the medical blade described in Patent Document 1, the blade is sandwiched between the blade overlapping portions of the plastic handle, but rattle can occur between the resin material and the blade. More specifically, the two blade overlapping portions each have a slightly inclined convex portion and a concave portion, which causes the blade to be sandwiched between the blade overlapping portions so that the rear end of the blade is slightly curved, but rattle can occur in the width direction of the blade. In particular, medical blades used for precise work require a blade that can prevent even this slight rattle.

[0007] Furthermore, among the 17 Sustainable Development Goals (SDGs) adopted at the United Nations Summit, Goal 3 is "Good Health and Well-Being," which aims to ensure healthy lives and promote well-being for all people of all ages. Under these circumstances, there is a demand for the supply of safer and easier-to-use medical equipment.

[0008] In order to solve the above problems, the present invention provides, for example, the following means.

[0009] One embodiment of the medical blade of the present invention is a medical blade in which a blade body is clamped between a holder and a cover, wherein the blade body has, in a planar view, a cutting edge extending from a cutting edge and having a cutting tip on at least a portion thereof, a back edge extending from the cutting edge, and a first edge portion extending in a direction forming a first angle with respect to the back edge, the holder has a concave blade body holding recess formed along the shape of the blade body, and the blade body holding recess has, at a position where the first edge portion abuts, a first inclined portion that is inclined in a direction perpendicular to the first edge portion in a planar view, and at a position where the back edge abuts, a second inclined portion that is inclined in a direction perpendicular to the back edge in a planar view.

[0010] According to the above-described medical blade, the blade is bent in the thickness direction by the first and second inclined portions of the blade-holding recess of the holder, while the blade is clamped between the holder and the cover. This allows for a relatively simple configuration that prevents the blade from wobbling in the longitudinal, width, and rotational directions. This allows for a medical blade that can accurately incise a targeted area. Using such a medical blade provides a safe and easy-to-use instrument, contributing to SDG Goal 3, "Ensure good health and well-being for all."

[0011] In the above medical blade, preferably, the blade body further has a second edge portion extending from the end of the spine opposite the cutting point in a direction having a second angle with respect to the spine edge in a planar view, and the first edge portion extends from the second edge portion toward the blade edge in a direction having a third angle with respect to the second edge portion in a planar view.

[0012] According to the above-mentioned medical blade, the back edge and the first edge connected to the second edge continuing from the back edge are respectively provided with a second inclined portion and a first inclined portion, so that the blade can be more stably clamped between the holder and the cover.

[0013] In the above medical blade, the third angle is preferably 90°.

[0014] In the above medical blade, preferably, the blade body has a long hole-shaped through hole extending parallel to the direction of extension of the back edge and formed in the thickness direction, the holder has a convex blade body insertion portion that is inserted into the through hole, and the through hole is formed so as to intersect a straight line connecting the center in the extension direction of the first inclined portion and the center in the extension direction of the second inclined portion in a planar view.

[0015] In the above medical blade, the straight line connecting the center of the first inclined portion in the extension direction with the center of the second inclined portion in the extension direction intersects with the through hole through which the blade insertion portion is inserted, which allows the blade to be held more stably in the holder and more effectively prevents the blade from rattling.

[0016] FIG. 1 is a perspective view of a medical blade as viewed from a first direction. FIG. 2 is a perspective view of the medical blade with the slider moved to expose the blade as viewed from the first direction. FIG. 3 is a perspective view of the medical blade with the slider removed as viewed from the first direction. FIG. 4 is a perspective view of the medical blade with the slider and cover removed as viewed from the first direction. FIG. 5 is an enlarged perspective view of the medical blade with the slider, cover, and blade removed, leaving only the holder as viewed from the first direction. FIG. 6 is an enlarged perspective view of the holder of the medical blade as viewed from a second direction. FIG. 7 is a perspective view of the medical blade as viewed from a second direction. FIG. 8 is a perspective view of the medical blade as viewed from a third direction. FIG. 9 is a perspective view of the medical blade with the slider removed as viewed from a third direction. FIG. 10 is a perspective view of the cover and blade of the medical blade as viewed from a third direction. FIG. 11 is a perspective view of the cover of the medical blade as viewed from the third direction. Fig. 12 is a side view of the medical blade. Fig. 13 is a side view of the medical blade with the slider moved to expose the blade body. Fig. 14 is a side view of the medical blade with the slider removed. Fig. 15 is an enlarged plan view of the blade body placed on the holder. Fig. 16 is a plan view of the medical blade with the slider removed. Fig. 17 is a cross-sectional view taken along line A-A in Fig. 16.

[0017] A medical blade according to one embodiment of the present invention will be described in detail with reference to the drawings. The medical blade according to the present invention is a so-called medical scalpel. The embodiment described below is merely an example of the present invention and is not intended to limit the technical scope of the present invention. In each drawing, the same components are designated by the same reference numerals, and redundant explanations will be omitted.

[0018] 1 to 5 are perspective views of the medical blade 1 as viewed from a first direction. FIG. 1 shows the blade body 4 covered by the slider 5, FIG. 2 shows the blade body exposed by moving the slider 5, FIG. 3 shows the blade body with the slider 5 removed, and FIG. 4 shows the blade body with the cover 3 removed. That is, FIG. 4 is a perspective view of the holder 2 and blade body 4 of the medical blade 1. FIG. 5 is an enlarged view of the medical blade 1 with the slider 5, cover 3, and blade body 4 removed, leaving only the holder 2. FIG. 6 is an enlarged perspective view of the holder 2 shown in FIG. 5 as viewed from a second direction different from the first direction. FIG. 7 is a perspective view of the medical blade 1 as viewed from the second direction.

[0019] Figures 8 to 11 are perspective views of the medical blade 1 as viewed from a third direction. Figure 8 shows the blade 4 covered by the slider 5, Figure 9 shows the state with the slider 5 removed, Figure 10 shows the state with the holder 2 removed, and Figure 11 shows the state with the blade 4 removed. That is, Figure 11 is a diagram showing the cover 3 of the medical blade 1. Figures 12 to 14 are side views of the medical blade 1. Figure 12 shows the state with the blade 4 covered by the slider 5, Figure 13 shows the state with the slider 5 moved to expose the blade 4, and Figure 14 shows the state with the slider 5 removed.

[0020] In this specification, the state in which the holder 2, the cover 3, the blade 4, and the slider 5 are connected may be referred to as a connected state or an assembled state.

[0021] The drawings show an X-axis, a Y-axis, and a Z-axis. The direction in which the blade body 4 extends is the X-axis direction, and the thickness direction of the medical blade 1 is the Z-axis direction, and the X-axis, Y-axis, and Z-axis are directions that intersect perpendicularly with each other.

[0022] As shown in the drawings, the medical blade 1 of this embodiment includes a holder 2, a cover 3, a blade 4, and a slider 5. The holder 2, cover 3, and slider 5 are made of resin, and the blade 4 is made of metal. In the medical blade 1, the blade 4 is sandwiched between the holder 2 and the cover 3 (see FIGS. 3, 9, 14, etc.). The slider 5 is slidably attached to the holder 2 and cover 3, which are connected together. As the slider 5 slides, the medical blade 1 changes state between a stored state (see FIG. 1) in which the slider 5 covers the blade 4 to prevent it from being exposed, and a usage state (see FIG. 2) in which the blade 4 is exposed.

[0023] 15 is an enlarged plan view of the blade body 4 placed in the holder 2. The blade body 4 is formed from a plate-shaped metal and has a cutting edge that is ground as described in detail below. The blade body 4 has a cutting edge 42 extending from a cutting point 41, a spine edge 43 extending from the cutting point 41, a second edge portion 44 extending from the spine edge 43, and a first edge portion 45 extending from the second edge portion 44 toward the cutting edge 42. In a plan view, the blade body 4 is formed with the cutting edge 42, the spine edge 43, the second edge portion 44, and the first edge portion 45 as outer edges.

[0024] The cutting edge 42 extends from the cutting point 41 and has at least a portion that is ground. The cutting edge 42 is composed of a curved cutting edge 42a, a straight cutting edge 42b, and a notch 42c. The cutting edge is formed on the entire curved cutting edge 42a and partway along the straight cutting edge 42b. The curved cutting edge 42a curves outward in a convex shape. The straight cutting edge 42b is linear, and the notch 42c is cut out so that it curves inward in a substantially arc-like shape from a straight line that is an extension of the straight cutting edge 42b. In this embodiment, as described above, the entire curved cutting edge 42a and a portion of the straight cutting edge 42b form the cutting edge, but the location where the cutting edge is formed may be changed.

[0025] The spine edge 43 extends from the cutting edge 41 and is composed of a curved spine edge 43a and a straight spine edge 43b. The curved spine edge 43a is gently curved, while the straight spine edge 43b extends linearly, so the spine edge 43 can also be said to be approximately linear. Near the center of the spine edge 43 is an inclined abutment portion 43c that abuts against the second inclined portion 25c of the holder 2 when the blade 4 is clamped between the holder 2 and the cover 3.

[0026] A second edge 44 extends from an end (corner) 43d of the spine edge 43 opposite the cutting edge 41 toward the cutting edge 42. The second edge 44 is linear. The angle θ1 formed between the linear spine edge 43b, which is the linear portion of the spine edge 43, and the second edge 44 is 120°.

[0027] A first edge 45 extends from an end (corner) 44a of the second edge 44 opposite to an end (corner) 43d where the second edge 44 connects with the spine edge 43 toward the cutting edge 41 of the cutting edge 42. The first edge 45 is linear. The angle θ2 between the second edge 44 and the first edge 45 is 90°, i.e., a right angle. The angle between the extension of the spine edge 43 and the extension of the first edge 45 is 30° (= θ1 + θ2 - 180°).

[0028] The blade body 4 has a through-hole 46 formed on the inside in a plan view, penetrating in the thickness direction. The through-hole 46 extends in an elongated hole shape parallel to the X direction, which is the direction in which the spine edge 43 extends. More specifically, the length of the through-hole 46 in the Y-axis direction, which is the width direction, changes in the order of the first width portion 46a, the second width portion 46b, and the third width portion 46c from the cutting edge 41 side. The widths are such that the first width portion 46a < the second width portion 46b < the third width portion 46c.

[0029] [Holder 2] The holder 2 is a component that is connected to the cover 3 by fitting, and when the cover 3 and the blade 4 are connected, the holder 2 clamps the blade 4 together with the cover 3. The holder 2 has a grip 21 that is held by the user. The end of the grip 21 on the opposite side of the blade 4 in the longitudinal direction has a tapered shape that narrows in the width direction toward the tip.

[0030] 4 and 5, the holder 2 has a convex blade insertion portion 22 that is inserted through the through hole 46 of the blade 4 and the through hole 31 of the cover 3 when in the coupled state (see FIG. 10). The blade insertion portion 22 is shaped to fit the through hole 46 and the through hole 31. That is, the blade insertion portion 22 has a first width portion 22a, a second width portion 22b, and a third width portion 22c that correspond to the first width portion 46a, the second width portion 46b, and the third width portion 46c of the through hole 46. The length of these widths is such that the first width portion 22a < the second width portion 22b < the third width portion 22c.

[0031] The holder 2 has recesses 22d, 22e, and 22f recessed in the width direction (Y-axis direction) at the base of the blade insertion portion 22. The recesses 22e and 22f are formed on opposite sides in the Y-axis direction. These recesses 22d, 22e, and 22f are provided at positions corresponding to the protrusions 31d, 31e, and 31f of the cover 3, and in the coupled state, the protrusions 31d, 31e, and 31f are inserted into the recesses 22d, 22e, and 22f, respectively, and the holder 2 and the cover 3 fit together.

[0032] The holder 2 has a concave blade-holding recess 25 formed to conform to the shape of the blade 4. The blade-holding recess 25 is formed in a position facing the cover 3, and is formed as a surface (a surface located on the negative Z-axis side) that is one step lower than a cover-opposing surface 26 that faces the cover 3 without the blade 4 in between. The cover-opposing surface 26 is flat along the XY plane. The holder tip 2a on the tip side (positive X-axis side) of the blade-holding recess 25 has the same shape as the cover tip 3a of the cover 3 in a plan view.

[0033] 5 and 6, the blade holding recess 25 has a first inclined portion 25a at a position where the first edge 45 of the blade 4 abuts in the coupled state. The first inclined portion 25a is inclined so as to be recessed from the edge 25b toward the inside, in other words, it is inclined in a direction perpendicular to the extension direction of the first edge 45 of the blade 4 in a plan view. As a result, in the coupled state, the first edge 45 of the blade 4 abuts against the inclined surface of the first inclined portion 25a.

[0034] 6, the blade holding recess 25 has a second inclined portion 25c at a position where the linear back edge 43b of the blade 4 abuts in the connected state. The second inclined portion 25c is inclined so as to be recessed from the edge 25d toward the inside, in other words, it is inclined in a direction perpendicular to the extension direction of the linear back edge 43b of the blade 4 in a plan view. As a result, in the connected state, a part of the linear back edge 43b of the blade 4 abuts against the inclined surface of the second inclined portion 25c.

[0035] 5, 6, and the side views of Fig. 14, the blade holding recess 25 has a third inclined portion 25e at a position continuous with the first inclined portion 25a. The third inclined portion 25e is inclined along the longitudinal direction (X-axis direction) of the holder 2. More specifically, the third inclined portion 25e is inclined toward the +Z-axis side as it approaches the -X-axis side.

[0036] 5 and 6 , the holder 2 has connecting holes 23a, 23b, 23c, and 23d. The connecting hole 23d is a rectangular through-hole extending in the longitudinal direction (X-axis direction). The connecting holes 23a, 23b, and 23c are provided at positions corresponding to the connecting protrusions 32a, 32b, and 32c of the cover 3. In the connected state, the connecting protrusions 32a, 32b, 32c, and 32d of the cover 3 are inserted into the connecting holes 23a, 23b, 23c, and 23d, and the holder 2 and the cover 3 are fitted together.

[0037] The area around the position where the connecting hole portion 23b is formed is a cover-facing inclined surface 26a that faces the inclined edge portion 35a of the cover 3, and the inclination toward the cover 3 (Z-axis + side) increases as the area approaches the edge.

[0038] The holder 2 has a through-hole 25s that is circular in plan view near the center of the third inclined portion 25e of the blade holding recess 25. In the connected state, the blade 4 is visible through the through-hole 25s. The blade 4 has a letter or symbol indicating the type of blade 4 printed on it at a position visible through the through-hole 25s.

[0039] As shown in Figures 8 and 9, the holder 2 has two finger rests 27a and 27b extending in the longitudinal direction on the surface opposite the side facing the cover 3 (the surface located on the negative side of the Z axis). Finger rests 27a and 27b are each convex and extend in the longitudinal direction, and are arranged side by side with a gap in the width direction. The holder 2 has a convex finger rest 27c extending in the longitudinal direction on the surface located on the positive side of the Y axis (see Figure 6). Finger rests 27a, 27b, and 27c have corrugated projections and depressions formed in the longitudinal direction. These projections and depressions prevent fingers placed on finger rests 27a, 27b, and 27c from slipping during use.

[0040] As shown in FIGS. 12 and 13, when viewed from the side, the finger rest 27a has notches 27d and 27e recessed toward the negative Z-axis side.

[0041] [Cover 3] The cover 3 is a member that is connected to the holder 2 by fitting, and in a connected state with the holder 2 and the blade 4, the cover 3 clamps the blade 4 together with the holder 2. The cover tip portion 3a, which is the tip side of the cover 3, has the same shape in plan view as the holder tip portion 2a, which is located on the tip side (positive side of the X axis) of the blade holding recess 25 of the holder 2 (see Figures 11, 5, 3, etc.).

[0042] 10 and 11 , the cover 3 has a through hole 31 through which the blade insertion portion 22 of the holder 2 is inserted when the cover 3 is in the connected state. This through hole 31 has an elongated shape similar to the through hole 46 of the blade body 4, and its width (length in the Y-axis direction) varies in the longitudinal direction. Specifically, the through hole 31 has a first width portion 31a, a second width portion 31b, and a third width portion 31c corresponding to the first width portion 46a, the second width portion 46b, and the third width portion 46c of the through hole 46 of the blade body 4. The relationship between these widths is such that the first width portion 31a < the second width portion 31b < the third width portion 31c. The bottom of the through hole 31 on the side facing the holder 2 is formed with protrusions 31d, 31e, and 31f that protrude in the width direction (see FIG. 11 ). These protrusions 31d, 31e, and 31f are provided at positions corresponding to the recesses 22d, 22e, and 22f of the holder 2 (see FIGS. 5 and 6), respectively.

[0043] 11 , the cover 3 has a curved blade holding recess 34 formed at a position facing the first inclined portion 25a and the third inclined portion 25e of the holder 2. The curved blade holding recess 34 is inclined along the first inclined portion 25a and the third inclined portion 25e of the opposing holder 2, and has a shape that is partially recessed relative to the flat holder opposing surface 35 that is aligned along the XY plane. The curved blade holding recess 34 has edges 34a, 34b, and 34c that are aligned with the second edge 44, the first edge 45, and the notch 42c of the blade 4.

[0044] As shown in FIGS. 10 and 11 , the cover 3 has connecting protrusions 32a, 32b, 32c, and 32d and a hole 33. The hole 33 is a rectangular through-hole extending in the longitudinal direction (X-axis direction). The connecting protrusion 32d is provided adjacent to the hole 33 and is a rectangular convex portion that extends in the longitudinal direction (X-axis direction) like the hole 33. The connecting protrusions 32a, 32b, and 32c are provided at positions corresponding to the connecting holes 23a, 23b, and 23c (see FIG. 4 ) of the holder 2. The connecting protrusion 32d is provided at a position corresponding to the connecting hole 23d of the holder 2. In the connected state, the connecting protrusions 32a, 32b, 32c, and 32d are inserted into the connecting holes 23a, 23b, 23c, and 23d of the holder 2, respectively, and the holder 2 and the cover 3 are fitted together. The tip of the connecting protrusion 32b is hook-shaped, and this hook-shaped portion engages with the connecting hole 23b of the holder 2, thereby preventing the connecting protrusion 32b from slipping out of the connecting hole 23b.

[0045] The area around the position where the connecting protrusion 32b is formed is an inclined edge 35a that faces the cover-facing inclined surface 26a of the holder 2. The inclined edge 35a is inclined along the cover-facing inclined surface 26a of the holder 2. Specifically, the inclined edge 35a is an inclined surface that faces away from the holder-facing surface 35 (towards the +Z axis side) as it approaches the edge.

[0046] 1 to 3, the cover 3 has two finger rests 37a and 37b extending in the longitudinal direction on the surface (the surface located on the +Z axis side) opposite the side facing the holder 2. Like the finger rests 27a and 27b of the holder 2, the finger rests 37a and 37b each have a convex shape extending in the longitudinal direction and are arranged side by side with a gap in the width direction. The finger rests 37a and 37b have wavy projections and recesses formed in the longitudinal direction.

[0047] As shown in FIGS. 12 and 13, when viewed from the side, the finger rest 37a has notches 37d and 37e formed in a recessed shape toward the +Z axis side.

[0048] Figure 16 is a plan view of the medical blade 1 with the slider 5 removed. Figure 17 is a cross-sectional view taken along the line A-A in Figure 16. Figure 15 shows the line A-A at the same position as that of Figure 16. The blade 4 is held between the holder 2 and the cover 3 in a state where it is curved in the thickness direction with the line B forming the line A-A as the center line of curvature.

[0049] 17, which is a cross-sectional view, and FIG. 15, which is a plan view, the first edge 45 of the blade 4 is clamped between the first inclined portion 25a of the holder 2 and the curved blade holding recess 34 of the cover 3. More specifically, the first edge 45 of the blade 4 abuts against the first inclined portion 25a of the holder 2, and is curved toward the cover 3 (the negative Z-axis side) due to stress.

[0050] 17, which is a cross-sectional view, and FIG. 15, which is a plan view, the inclined abutment portion 43c located near the center of the spine 43 of the blade body 4 is sandwiched between the second inclined portion 25c of the holder 2 and the cover tip portion 3a of the cover 3. More specifically, the inclined abutment portion 43c of the blade body 4 abuts against the second inclined portion 25c of the holder 2, and is curved toward the cover 3 side (Z-axis negative side) due to stress.

[0051] As shown in the cross-sectional view of FIG. 17 and the side view of FIG. 14, in the coupled state, the blade body 4 is clamped between the holder 2 and the cover 3 in a curved state in the thickness direction, convex toward the holder 2 (convex toward the negative Z-axis direction) along a line B connecting the central portion 25t in the extension direction of the first inclined portion 25a of the holder 2 and the central portion 25u in the extension direction of the second inclined portion 25c. In other words, the line B indicating the direction in which the blade body 4 curves in the thickness direction (the second direction) is a line connecting the central portion of the first edge portion 45 of the blade body 4 to the central portion in the extension direction of the inclined abutment portion 43c. Due to the relative positions of the first inclined portion 25a and the second inclined portion 25c, the line B forms a predetermined angle (30°) with the X-axis, which is the longitudinal direction of the medical blade 1. This line B intersects with the through-hole 46 of the blade body 4.

[0052] [Slider 5] As shown in Figures 1 and 2, the slider 5 is attached to the connected holder 2, cover 3, and blade 4, and is slidable in the longitudinal direction (X-axis direction). The slider 5 has two longitudinally extending elongated holes 51a and 51b on the surface located on the +Z-axis side as shown in Figures 1 and 2, and two longitudinally extending elongated holes 52a and 52b on the surface located on the -Z-axis side as shown in Figure 8. The finger rests 37a and 37b of the cover 3 are inserted into the elongated holes 51a and 51b, and the finger rests 27a and 27b of the holder 2 are inserted into the elongated holes 52a and 52b. As shown in Figures 1, 2, 8, and 12, the slider 5 has a side frame 53 formed between the elongated holes 51a and 52a on the surface located on the -Y-axis side. A knob 53a is formed near the longitudinal center of the side frame 53. 7, the slider 5 has a long hole 54 on the surface located on the +Y-axis side. The finger rest 27c of the holder 2 is inserted into the long hole 54.

[0053] The side frame 53 of the slider 5 has protrusions 53b and 53c that protrude outward, i.e., toward the + and - sides of the Z axis, on both sides of the width at a position close to the knob 53a on the + side of the X axis. The protrusions 53b and 53c are formed in positions facing each other. When the slider 5 is in a storage state covering the blade 4 (see Figures 12 and 1, etc.), the protrusions 53b and 53c engage with the recesses 37d and 27d, respectively. When the slider 5 is moved from the storage state to an in-use state exposing the blade 4 (see Figures 13 and 2, etc.), the protrusions 53b and 53c engage with the recesses 37e and 27e, respectively.

[0054] The slider 5 has a through hole 5a through which the blade 4 can be inserted when sliding (see FIG. 7).

[0055] [Using the Medical Blade 1] When changing the medical blade 1 from the stored state to the use state, the user pinches the knob 53a of the slider 5 with their fingers and pulls it up, while sliding the slider 5 toward the negative side of the X-axis. At this time, the convex portions 53b and 53c of the slider 5 are disengaged from the concave portions 37d and 27d, allowing the slider 5 to slide. When the slider 5 is moved toward the negative side of the X-axis, the convex portions 53b and 53c of the slider 5 engage with the concave portions 37e and 27e, preventing the slider 5 from moving further toward the negative side of the X-axis. This puts the medical blade 1 into a use state in which the blade body 4 is exposed (see FIG. 2). The movement of the slider 5 is restricted not only by the engagement between the convex portions 53b and 53c and the concave portions 37e and 27e, but also by the longitudinal edges of the finger rests 27a, 27b, 37a, and 37b abutting against the edges of the elongated holes 52a, 52b, 51a, and 51b, respectively.

[0056] When using the medical blade 1 in the usable state, for example, the user holds the finger rests 27a, 27b, 27c, 37a, and 37b with the thumb and index finger. At this time, the user holds the grip 21 with the middle finger, ring finger, and little finger to stabilize the medical blade 1 so that it does not rattle. Note that the way the medical blade 1 is held can vary depending on the user and the usage situation.

[0057] [Modifications] The medical blade 1 of the present invention is not limited to the shape described in the above embodiment, and may be partially modified from the shape of the embodiment without departing from the spirit of the invention.

[0058] The angles θ1 and θ2 of the blade body 4 may be changed arbitrarily. That is, the angle θ1 is not limited to 120°, and the angle θ2 is not limited to 90° (a right angle). In this case, the angle between the extension of the spine edge 43 and the extension of the first edge 45 is also not limited to 30°. However, in order to position the first inclined portion 25a and the second inclined portion 25c so that the blade body 4 can be stably clamped, the angle between the extension of the spine edge 43 and the extension of the first edge 45 is preferably between 10° and 80°. It is preferable to determine the angles θ1 and θ2 so that the angle between the extension of the spine edge 43 and the extension of the first edge 45 is the above angle. Note that the angles shown in the embodiment are preferable because they allow the shape of the end of the blade body 4 opposite the cutting edge 41 to be relatively compact while allowing the second direction, which is the curvature direction of the blade body 4, to be in an appropriate direction. Furthermore, even if the angle between the extension line of the spine edge 43 and the extension line of the first edge 45 is set to the above-mentioned range of 10° to 80°, the first inclined portion 25a extends in a direction different from the direction in which the second inclined surface 25c extends, and the blade body 4 can be pressed to bend in two different directions. This effectively prevents the blade body 4 from rattling.

[0059] In the blade body 4, the cutting edge 42 and the back edge 43 each have a partially curved shape, but at least one of the cutting edge 42 and the back edge 43 may be linear.

[0060] The blade body 4 may not necessarily have the second edge portion 44, and may have a first edge portion 45 connecting the spine edge 43 and the cutting edge 42. Alternatively, the blade body 4 may have an additional edge portion in addition to the first edge portion 45 and the second edge portion 44. Even in such a case, the blade body 4 can be stably clamped as long as the positional relationship between the blade body 4 and the first inclined portion 25a and the second inclined portion 25c is appropriate.

[0061] [Features of Medical Knife 1] The medical knife 1 is configured to hold the blade 4 with a holder 2 and a cover 3. The holder 2 and the cover 3 are configured to clamp the blade 4 while bending it in the thickness direction (Z-axis direction) along a curvature direction that intersects with the X-axis direction, which is the direction in which the back edge 43 of the blade 4 extends, in a plan view, and that forms a predetermined angle with respect to the X-axis direction.

[0062] With this medical blade 1, the holder 2 and cover 3 clamp the blade 4 while bending it in the thickness direction (Z-axis direction) along a curved direction at a predetermined angle, rather than parallel to the back edge 43 of the blade 4. This prevents the blade 4 from wobbling not only in the longitudinal direction of the blade 4 but also in the width direction of the blade 4. This makes it possible to provide a medical blade 1 that can accurately incise a targeted area.

[0063] Furthermore, in the medical knife 1, the blade body 4 has a through-hole 46 that is elongated and extends parallel to the X-axis direction along which the back edge 43 extends, and is formed in the thickness direction (Z-axis direction). The holder 2 has a convex blade body insertion portion 22 that is inserted into the through-hole 46. The through-hole 46 of the blade body 4 is formed so as to intersect with the second direction in which the blade body 4 curves. As a result, the curvature direction of the blade body 4 intersects with the through-hole 46 through which the blade body insertion portion 22 is inserted, and the blade body 4 can be more stably held by the holder 2 and the cover 3. This makes it possible to provide a medical knife 1 that more effectively prevents rattling of the blade body 4.

[0064] In the medical blade 1, the blade body 4 includes a cutting edge 42, a back edge 43, and a first edge portion 45 on its outer edge in a planar view. The cutting edge 42 extends from the cutting edge 41 and has at least a cutting edge. The back edge 43 extends from the cutting edge 41. The first edge portion 45 extends in a direction forming a first angle (e.g., 30°) with respect to the back edge 43. The holder 2 has a concave blade body holding recess 25 formed along the shape of the blade body 4. This blade body holding recess 25 has a first inclined portion 25a and a second inclined portion 25c. The first inclined portion 25a is inclined in a direction perpendicular to the first edge portion 45 in a planar view at a position where the first edge portion 45 abuts. The second inclined portion 25c is inclined in a direction perpendicular to the back edge 43 in a planar view at a position where the back edge 43 abuts. In this way, the medical blade 1 is configured such that the blade 4 is curved in the thickness direction by the first inclined portion 25a and the second inclined portion 25c of the blade holding recess 25, and therefore, with a relatively simple configuration, it is possible to prevent the occurrence of rattle in the longitudinal direction, width direction, and rotation direction of the blade, resulting in a medical blade that can accurately incise a targeted area.

[0065] Furthermore, in the medical knife 1, the blade body 4 has a second edge 44 that extends from an end 43d of the spine 43 opposite the cutting edge 41 in a direction that forms a second angle (e.g., 120°) with respect to the spine 43 in a plan view. The first edge 45 extends from the second edge 44 toward the cutting edge 42 in a direction that forms a third angle (e.g., 90°) with respect to the second edge 45 in a plan view. With this configuration, the spine 43 and the first edge 45 connected to the second edge 44 continuing from the spine 43 are provided with the second inclined portion 25c and the first inclined portion 25a, respectively, allowing the blade body 4 to be more stably clamped between the holder 2 and the cover 3.

[0066] In addition, in the medical knife 1, the through-hole 46 of the blade body 4 is formed so as to intersect with a straight line B that connects the center of the first inclined portion 25 a in the extension direction with the center of the second inclined portion 25 c in the extension direction in a plan view. With this type of medical knife 1, the blade body 4 can be more stably held by the holder 2 and the cover 3, and rattle of the blade body 4 can be more effectively prevented.

[0067] DESCRIPTION OF SYMBOLS 1... Medical blade, 2... Holder, 2a... Holder tip, 21... Grip portion, 22... Blade insertion portion, 22d, 22e... Recessed portion, 23a, 23b, 23c, 23d... Connecting hole portion, 25... Blade holding recessed portion, 25a... First inclined portion, 25c... Second inclined portion, 25e... Third inclined portion, 25s... Through hole, 26... Cover facing surface, 26a... Cover facing inclined surface, 27a, 27b, 27c... Finger rest portion, 3... Cover, 3a... Cover tip, 31... Through hole, 31d, 31e... Convex portion, 32a, 32b, 32c, 32d... Connecting convex portion, 33... Hole portion, 34... Curved blade holding recessed portion, 34a, 34b... Edge portion, 35... Holder facing surface, 35a...Inclined edge portion, 37a...Finger rest portion, 37d...Recessed portion, 37e...Recessed portion, 4...Blade body, 41...Cutting edge, 42...Edge, 42a...Curved edge, 42b...Straight edge, 42c...Notched portion, 43...Back edge, 43a...Curved back edge, 43b...Straight back edge, 43c...Inclined abutment portion, 44...Second edge portion, 45...First edge portion, 46...Through hole, 5...Slider, 5a...Through hole, 51a, 51b, 52a, 52b, 54...Elongated hole, 53...Side frame, 53a...Knob, 53b, 53c...Protruding portion

Claims

1. A medical blade that clamps a blade body between a holder and a cover, wherein the blade body has, in a plan view: - a cutting edge that extends from a cutting tip and has a cutting edge at least in part; - a back edge that extends from the cutting tip; - a first edge portion that extends in a direction having a first angle with respect to the back edge, and the holder has a concave blade body holding recess formed along the shape of the blade body, and the blade body holding recess has: - a first inclined portion that inclines in a direction perpendicular to the first edge portion in a plan view at a position where the first edge portion abuts; - a second inclined portion that inclines in a direction perpendicular to the back edge in a plan view at a position where the back edge abuts. Medical blade.

2. The blade body further has, in a plan view, a second edge portion that extends from an end of the back edge on the side opposite to the cutting tip in a direction having a second angle with respect to the back edge, and the first edge portion extends from the second edge portion toward the cutting edge in a direction having a third angle with respect to the second edge portion in a plan view. The medical blade according to claim 1.

3. The medical blade according to claim 2, wherein the third angle is 90°.

4. The blade body has an elongated hole shape that extends parallel to the extending direction of the back edge and has a through hole formed in the thickness direction, and the holder has a convex blade body insertion portion that is inserted into the through hole, and the through hole is formed so as to intersect a straight line connecting a central portion in the extending direction of the first inclined portion and a central portion in the extending direction of the second inclined portion in a plan view. The medical blade according to claim 1.

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