Medical knife

Patent metadata

Field	Value
Publication number	US-9808279-B2
Application number	US-201214110503-A
Country	US
Kind code	B2
Filing date	Apr 27, 2012
Priority date	Apr 28, 2011
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A medical knife includes a blade plate and a blade portion formed at the distal end of the blade plate. Cutting edges extend from the distal end to the proximal end of the blade portion. Two blade surfaces in the width direction of a back-face portion of the blade portion are formed to gradually increase a distance between opposite side and cutting edge from one of the distal end and the proximal end to the other. The two blade surfaces in the width direction of a front-face portion of the blade portion are formed such that the distance between the opposite side and the cutting edge becomes equal in a zone corresponding to a distal end of the cutting edge and a zone corresponding to a proximal end of the cutting edge, over the entire cutting edge from the distal end to the proximal end of the cutting edge.

First claim

The invention claimed is:

1. A medical knife comprising:
a handle having a grip portion and extending in one direction;
a blade plate extending from the handle in a manner intersecting the handle, the blade plate including a distal end and a proximal end; and
a blade portion formed at the distal end of the blade plate, wherein
the blade portion has a front-face portion and a back-face portion, the front-face portion being formed on an upper side in a thickness direction of the blade plate where the grip portion is arranged, the back-face portion being formed on a lower side in the thickness direction of the blade plate opposite to the grip portion,
four blade surfaces in total are formed at two sides in a width direction of the blade plate intersecting the thickness direction of the blade portion in both the front-face portion and the back-face portion of the blade portion, each side in the front-face portion having a single blade surface, each side in the back-face portion having a single blade surface, the blade surfaces being inclined from a middle portion in the width direction to opposite outer ends in the width direction in the blade plate to cooperatively decrease a thickness dimension,
an outer end at which each one of the blade surfaces of the front-face portion and the corresponding one of the blade surfaces of the back-face portion cross each other form a cutting edge extending from the distal end to the proximal end of the blade portion,
each blade surface of the front-face portion and the back-face portion is defined by the corresponding cutting edge and an opposite side formed on the front-face portion and the back-face portion,
the two blade surfaces in the width direction of the back-face portion of the blade portion are formed to gradually increase a distance between the opposite side and the cutting edge from one of the distal end and the proximal end to the other, and
the two blade surfaces in the width direction of the front-face portion of the blade portion are formed such that the distance between the opposite side and the cutting edge becomes uniform over the entire cutting edge from the distal end to the proximal end of the cutting edge,
in the front-face portion and the back-face portion of the blade portion, a boundary between the opposite blade surfaces in the width direction is formed between a point at which the cutting edges of the blade surfaces in the width direction cross each other and a peak at which the opposite sides of the blade surfaces in the width direction cross each other, a middle surface being formed between the opposite sides of the blade surfaces in the width direction,
in the blade plate, the cutting edges in the width direction of the blade portion extend from the point to an end, a maximum width-direction distance is defined between the ends of the cutting edges in the width direction,
the distance between the opposite side and the cutting edge in each blade surface in the width direction of the back-face portion of the blade portion is greater than the distance between the opposite side and the cutting edge in each blade surface in the width direction of the front-face portion of the blade portion, and
the inclination angle between each blade surface of the front-face portion of the blade portion and a plane including the cutting edge in the width direction is set to a value greater than the inclination angle between each blade surface of the back-face portion of the blade portion and said plane.

2. The medical knife according to claim 1 , wherein
the blade plate is bent toward the front-face portion of the blade portion with respect to the handle, and
a length of the blade plate from the distal end to the proximal end of the blade portion is set to a value not less than ten times and not more than fifty times the thickness of the blade plate.

3. The medical knife according to claim 1 , wherein
in the blade portion, a separation angle between the cutting edges in the width direction is set to a value not less than 60 degrees and not more than 120 degrees.

4. The medical knife according to claim 1 , wherein
the two blade surfaces in the width direction of the back-face portion of the blade portion are formed to gradually increase the distance between the opposite side and the cutting edge from the distal end to the proximal end.

5. The medical knife according to claim 1 , wherein
the two blade surfaces in the width direction of the back-face portion of the blade portion are formed to gradually increase the distance between the opposite side and the cutting edge from the proximal end to the distal end.

6. The medical knife according to claim 1 , wherein
a mark is formed on a line segment connecting the ends of the cutting edges in the width direction to each other or on a proximal or distal side with respect to the line segment, and
the distance between the mark and the point and the width-direction distance between the ends of the cutting edges in the width direction are equal to each other.

7. The medical knife according to claim 1 , wherein
the middle surface of the front-face portion of the blade portion and the middle surface of the back-face portion of the blade portion is formed parallel to each other.

8. The medical knife according to claim 1 , wherein
the blade surfaces in the width direction is shaped symmetrical with respect to a plane in the thickness direction including the boundary between the blade surfaces in the width direction.

9. The medical knife according to claim 1 , wherein
the inclination angle of each blade surface of the back-face portion of the blade portion is set to a value not more than a half of the inclination angle of each blade surface of the front-face portion of the blade portion.

Assignees

• Mori Makoto
• Amemoto Hidetoshi
• Hasebe Kazuyuki
• Kai R&D Center Co Ltd

Inventors

• Mori Makoto
• Amemoto Hidetoshi
• Hasebe Kazuyuki

Classifications

• F04C2270/0421

  Controlled or regulated · CPC title

• A61F9/0133

  Knives or scalpels specially adapted therefor · CPC title

• A61B17/3211 Primary

  Surgical scalpels, knives; Accessories therefor · CPC title