Cutting tool with a flat force profile

Patent metadata

Field	Value
Publication number	US-10843352-B2
Application number	US-201515781356-A
Country	US
Kind code	B2
Filing date	Dec 9, 2015
Priority date	Dec 9, 2015
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

Various embodiments disclosed herein related to a hand operated cutting tool. The hand operated cutting tool may include a first cutting member; a first handle coupled to the first cutting member; a second handle having a second cutting member; and a pivot connection pivotably coupling the first handle to the second handle. The first cutting member may include a cutting device that defines a bow-shaped cutting profile, wherein the bow-shaped cutting profile facilitates an acceleration of a cut-point position defined by an interaction of the first and second cutting members as the first and second handles move from a fully open position to a fully closed position.

First claim

What is claimed is:

1. A hand operated cutting tool, comprising:
a first cutting member with a first cutting edge;
a first handle coupled to the first cutting member;
a second handle coupled to a second cutting member with a second cutting edge; and
a pivot connection pivotably coupling the first handle to the second handle;
wherein the first and second cutting edges provide a cut-point position at a location where the first and second cutting edges interact, the first cutting edge defines a first convex bow-shaped cutting profile and the second cutting edge defines a second convex bow-shaped cutting profile, such that due to the shape of the first convex bow-shaped cutting profile and the second convex bow-shaped cutting profile, a cutting edge angle between the first and second cutting edges at the cut-point position increases throughout a movement when the first and second handles move from a fully open position to a fully closed position to facilitate an acceleration of the cut-point position, and
a cut force profile of the hand operated cutting tool which is substantially linear throughout movement of the first and second handles from the fully open position to the fully closed position.

2. The hand operated cutting tool of claim 1 , wherein a substantially linear relationship exists for the cutting edge angle between the first and second cutting members at the cut-point position as a function of bulk blade opening angle as the first and second handles move from the fully open position to the fully closed position.

3. The hand operated cutting tool of claim 1 , wherein a substantially linear relationship exists for a distance between the cut-point position and the pivot connection as a function of an angle between the first and second cutting members at the cut-point position as the first and second handles move from the fully open position to the fully closed position.

4. The hand operated cutting tool of claim 1 , wherein the second convex bow-shaped cutting profile matches the first convex bow-shaped cutting profile.

5. The hand operated cutting tool of claim 1 , wherein the hand operated cutting tool includes one of a scissors and a shears.

6. The hand operated cutting tool of claim 1 , wherein movement of the first and second handles from the fully open position to the fully closed position corresponds with approximately thirty-five degrees of angular motion.

7. The hand operated cutting tool of claim 1 , wherein the second convex bow-shaped cutting profile corresponds with a different radius of curvature than the first convex bow-shaped cutting profile.

Assignees

• Fiskars Finland Oy Ab

Inventors

• Cunningham Daniel

Classifications

• B26B13/06 Primary

  characterised by the shape of the blades · CPC title

• B26B13/28

  Joints (B25B7/06 takes precedence) · CPC title