RU2813072C2 - Universal scissors (variants) - Google Patents

Abstract

FIELD: hand-held cutting tools.

SUBSTANCE: group of inventions relates to a finger-grip design for cutting tools such as universal scissors. The utility scissors include the first arm, the second arm, and the first finger grip. The second lever is pivotally connected to the first lever on the rod. Each lever is rotatable from an open position to a closed position. Each lever has a blade. The blades in the closed position form a longitudinal axis. The first finger grip is formed on the first lever. The second finger grip is formed on the second lever. The first finger grip includes a flat inner surface adapted to receive the thenar of the user's thumb. The second finger grip defines the second inner surface adapted to receive at least one finger of a user such that the combined pressure of the thenar on the flat inner surface and at least one finger on the second inner surface moves the first lever and the second lever into a closed position. The flat inner surface extends generally parallel and offset relative to the longitudinal axis when the first lever is in the closed position. In the second variant, the utility scissors comprise the above-mentioned first lever, second lever and first finger grip. The first finger grip further includes a lower part. A flat inner surface is formed from the lower portion, and the flat inner surface and the second inner surface formed by the second finger grip are generally parallel to each other when the first arm and the second arm are in the closed position.

EFFECT: group of inventions is characterized in that the configuration of the first grip provides an even distribution of force across the thenar or elevation of the thumb and thenar muscles, while the absence of curvature and protrusions on the surface eliminates the concentration of force on the thenar muscles, preventing potentially significant pain for the user.

20 cl, 11 dwg

Description

CROSS REFERENCE(S) TO RELATED APPLICATION(S)

This application is a divisional application and claims benefit from the filing date of U.S. Patent Application No. 17/184,935, filed February 25, 2021, entitled "FINGER GRIP FOR SHEARS", the contents of which are incorporated herein by reference in their entirety pursuant to paragraph 120 of title 35 United States Code of Laws.

PREREQUISITES FOR CREATION OF THE INVENTION

1. Field of technology

The present invention relates generally to hand-held cutting tools and, more particularly, to a finger-grip design for cutting tools such as utility scissors, tin snips and household scissors.

2. Description of the prior art

A variety of hand tools, such as household shears, utility shears, and tin snips, have been offered over the years in a variety of configurations to facilitate cutting a variety of materials, from light or soft materials to heavy materials such as sheet metal. Although the goal of most of these cutting tools was to be designed to allow the tools to be used comfortably, most designs often result in stress, strain, and fatigue on the user.

Although it is generally known that the strength of all fingers of a hand is more or less the same or equal, gripping or squeezing the handles of household scissors, utility scissors, or tin snips usually involves the action of one finger, the thumb, on one upper finger grip, while the remaining the four fingers act on the other or opposing finger grip to counteract the force applied by the thumb. Therefore, the thumb must exert a disproportionate force from one finger to counteract the combined opposing forces exerted by the remaining four fingers. This results in increased stress on the thumb flexor muscles. As a result, this results in user fatigue, especially when using for a long time and when cutting heavier materials such as cardboard, sheet metal, etc.

US Pat. No. 454,735 to Heinisch discloses utility scissors that include a wide outwardly and rearwardly extending saddle or support that extends beyond the palm of the hand and on which part of the hand rests when the utility scissors are used. From the saddle or support extends an extension upon which the thumb and eminence of the thumb rest, the whole palm of the hand being used to support the weight of the body when using utility scissors. However, an extended saddle or support still requires the thumb to apply force during cutting. Also, the shape of the extension and the seat or support is convex, forming one or more protruding portions that potentially apply one or more pressure points, resulting in excess pressure points and, with prolonged use, pain and fatigue for the user. A similar design is disclosed in related US Pat. No. 760, 204.

U.S. Pat. No. 968,219 to Wheeler discloses multi-purpose scissors designed for use over longer periods of time and to reduce user fatigue. Utility scissors contain an oblique thumb loop lying in a plane at an angle of 45° relative to the plane of the thumb shackle so that when the thumb is inserted into the loop flush with the wrist and after it passes through the shackle, the tang is pressed against the tang by displacing the thumb shackle. The force applied when using a thumb bow is applied almost transversely to the thumb and over the second knuckle of the thumb. Although the orientation of the thumb shackle makes the shackle more ergonomic, the force applied to counteract or resist the force of the remaining four fingers is still provided primarily by the thumb.

US Pat. No. 4,635,363 to Chapin discloses a hand-held cutting tool that includes a ring having a central axis A offset from a central plane or axis B by an angle of less than 45°. Like the previous utility scissors, while being more ergonomic than other designs, they also involve the thumb being flexed to resist the force applied by the other fingers.

Published US patent application 2011/0131813, Lin, discloses a gripper design for a pair of household scissors. The thumb receiving upper grip portion is configured to support the base portion of the thumb and is configured to receive the thumb at an oblique angle relative to the blades as in previous designs. The design is mainly intended to provide improved stability during opening or closing of household scissors by preventing unwanted deflection of the two blades of household scissors and keeping the two blades as vertical as possible during the cutting process, effectively improving cutting quality and safety.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a cutting tool, such as household scissors, tin snips or utility snips, that overcomes the inherent disadvantages of most existing cutting tools.

Another object of the present invention is to provide a cutting tool that is easy and convenient to use.

It is yet another object of the present invention to provide a cutting tool for increasing the lever force for using the tool and, at the same time, facilitating ease of use and improving user comfort.

Another object of the present invention is to provide a cutting tool that allows a user to cut thicker or harder materials with less stress on the hand, and especially the thumb.

It is a further object of the present invention to provide a cutting tool of the present type which is easy to use.

It is yet another further object of the present invention to provide a cutting tool, as mentioned above, that can be used for longer periods of time and with less user fatigue.

It is yet another further object of the present invention to provide a cutting tool that is ergonomically designed to be not only comfortable to use, but also to improve cutting accuracy and control.

To achieve the foregoing objects, as well as others that will become apparent later herein, a grip structure for a pair of household scissors or utility scissors in accordance with the present invention comprises two arms pivotally connected at a pivot point and forming substantially parallel blades at their distal ends. the indicated levers. The blades define a median cutting plane and are rotatably movable about said pivot point between open and closed positions within said cutting plane and, in the closed position, form a line or longitudinal axis with said pivot point. Each arm is formed at a proximal end relative to said finger grip pivot point, wherein the first finger grip is a large or upper finger grip formed above said line or axis, and a lower portion thereof is formed with a substantially flat inner surface proximally located and extending into a longitudinal direction generally parallel to said line or axis in said closed position of said blades, and located in a transverse plane that is substantially perpendicular to said cutting plane.

The upper finger grip is sized and configured to allow substantially complete insertion of the metacarpal bone of the thumb on the right lateral side through said upper finger grip to accommodate the eminence of the thumb, allowing the thumb to be moved to a position on the left lateral side in an orientation that is substantially parallel to said cutting plane, and positioning the thenar of the hand against said generally flat inner surface of said first finger grip, while positioning at least the outer right lateral portions of said loop against or in contact with the palm of the hand behind the thenar crease of the hand and in the area at least one of the palmar folds of the hand. The second finger grip, the lower finger grip, is located below the first finger grip, has a second inner surface and is configured and sized to be grasped by at least some of the other four fingers of the hand. Thus, the first finger grip allows the thenar and palm of the hand to resist the force applied by the fingers acting on said second finger grip, and the force applied to the thenar is uniformly applied to the thenar muscles and transferred to the surface of the palm of the hand to allow the cutting direction to be determined by the larger finger, applying a minimal bending or gripping force as opposed to the force applied by the other fingers on said second finger grip, thereby eliminating or minimizing stress or fatigue of the thumb flexor muscles.

BRIEF DESCRIPTION OF GRAPHIC MATERIALS

The above and other aspects, features and advantages of the present invention will become more apparent from the following description when read in conjunction with the accompanying drawings, in which:

Figure 1 is a left perspective view of a household scissors or utility scissors in accordance with the present invention, shown in a fully closed state;

FIG. 2 is a left side view of the household scissors or utility scissors shown in FIG. 1, showing in dotted outline the positions of the fingers during normal use;

fig. 3 is similar to FIG. 2 when household scissors or utility scissors are in a partially open state;

Figure 4 is a top view of the household scissors or utility scissors shown in Figures 1-3;

FIG. 5 is a bottom view of the household scissors or utility scissors shown in FIG. 1-A, showing in dotted outline the position of the hand during the initial insertion of the thumb and before gripping the handles;

FIG. 6 is an enlarged fragmented right side view to show details of the upper finger gripper configuration; FIG.

FIG. 7 is a cross-sectional view of the upper finger grip shown in FIG. 6 taken along line 7-7;

Fig. 8 is a bottom view of the household scissors or utility scissors shown in the previous figures, which is separated to illustrate the lower configuration of the upper finger grip and the nature of its location relative to the thenar and palm surfaces of the hand;

Fig. 9 is similar to Fig. 2 and shows another embodiment of the universal scissors, in which both finger grips are offset at an angle from the axis to position both grips above the axis;

Fig. 10 is similar to Figs. 2 and 9 and shows another embodiment of the universal scissors, in which both finger grips are linearly offset from the axis to position both grips above the axis; And

FIG. 11 is a cross-sectional view of the finger grips shown in FIG. 2 taken along line 11-11.

DETAILED DESCRIPTION

Further specifically referring to the figures, in each of which the same or similar parts are designated by the same reference numerals, and referring first to FIG. 1, household scissors, utility scissors, tin snips or other similar cutting tools are generally designated by the numeral 10. All such cutting tools will be collectively referred to herein as “utility shears.”

The utility shears 10 comprise two arms 12, 14 connected to each other on a rod 16 forming a pivot point. The arms form substantially parallel blades 12a, 14a. The blades 12, 14 define a median cutting plane CP and are rotatably movable about the shaft 16 between open and closed positions within the cutting plane. In the closed position, the blades 12, 14 form a line or longitudinal axis A with the rod 16.

Each arm is formed at a proximal end relative to the finger rod 16. The first finger grip 12b is a large or upper finger grip formed above the line or axis A. The first or upper finger grip is formed above the line or axis A and has a lower portion 12c formed with a substantially flat inner surface 12d proximally extending along a longitudinal direction which is generally parallel to the line or axis A when the blades are closed.

The first or upper finger grip 12b is sized and configured to allow substantially complete insertion of the metacarpal bone of the thumb on the right lateral side through the upper finger grip 12b to accommodate the thumb eminence or thenar eminence ("TE"), as best illustrated in FIG. .5 and 8, on the right lateral side through the finger grip 12b and to accommodate the eminence of the thumb to allow the thumb to be moved to a position on the left lateral side in an orientation that is substantially parallel to the cutting plane CP and position the thenar TE of the hand against the a generally flat inner surface 12d of the upper finger grip 12b, with at least the outer right side portion 12e of the finger grip resting on or in contact with the palm P of the hand, as best illustrated in FIG. 8, behind the thenar fold TC of the hand and in areas of at least one of the palmar folds PC1 and PC2 of the hand.

The second or lower finger grip 14b, in the embodiment shown in FIGS. 1-8, is located below the line or axis A, has a second inner surface 14d and is configured and sized to be grasped by the other four fingers or at least some of the other four fingers of the hand, as shown in Figs. 2 and 3. However, the positions of the finger grips relative to axis A are not decisive and can be offset from the axis at an angle or linearly. See, for example, Fig. 9, in which both finger grips are offset from the axis at an angle to position both finger grips above the axis, and Fig. 10, in which both finger grips are linearly offset from the axis to, by analogy, position both finger grips above the axis. Offsets may also position the finger grips under the axis and may result from offsets opposite those shown in FIGS. 9 and 10, and may also include combinations of linear and angular offsets.

The flat inner surface 12d is formed from the bottom 12c of the first finger grip 12b, wherein the flat inner surface 12d and the second inner surface 14d formed by the second finger grip 14b are generally parallel to each other when the first and second arms 12, 14 are in the closed position .

The first or upper finger grip 12b is configured as an annular loop, preferably formed with a recessed curved surface 12f at the leading or distal end, which is continuous with the flat inner surface 12d, on the left side, to accommodate the thenar membrane or skin membrane between the thumb and index finger when the thumb is substantially aligned with the blade 12a, 14a.

According to Fig. 4, the upper finger grip 12b forms a central axis A', which is deflected or offset at an angle from the cutting plane CP or axis A at an angle , which is in the range of 50°-60°.

Preferably angle equal to approximately 55°.

The inner surface 12d is substantially flat, as shown in FIG. 11, to distribute force evenly across the thenar or eminence of the thumb and thenar muscles. The lack of significant curvature or protrusion on this 12d surface eliminates the concentration of force on the thenar muscles, preventing potentially significant pain for the user. Also, for ergonomics and comfort of use of the tool, the flat surface 12d may be slightly inclined upward from the right side towards the left side to conform to the shape of the hand when gripping the upper finger grip 12b. The inclination of the flat surface is best illustrated in FIG. 11, where the surface is shown inclined downward from left to right relative to the plane NP, substantially perpendicular to the cutting plane CP. The inclination angle γ is in the range of 10°-20° and preferably in the range of 15°-17°.

In preparation for use of the utility scissors of FIG. 5, the thumb is fully inserted into the upper finger grip 12b so that the thenar TE rests on the substantially flat surface 12d and the thumb can be moved to the position shown in FIG. 8, where the thumb essentially aligned with blades 12a, 14a. After the fingers are flexed into the grasping position, the right outer side or edge of 12e rests on the palm surface PS behind the thenar crease TC and comes into contact with the palm creases PC1 and/or PC2. What is important is that the thumb, once placed in the position shown in FIG. 3, primarily stabilizes and directs the cutting while eliminating or substantially reducing the bending forces exerted by the thumb to counteract or resist the compressive force of the other four fingers, which act on the lower finger grip 14b, the force being absorbed or counteracted by the palm of the hand. In this way, the thenar muscles do not have to flex during use of the utility scissors, but can remain essentially motionless, greatly reducing strain and pressure on the thumb. The design is not only ergonomic, but also makes the utility scissors more comfortable and easier to use while eliminating fatigue, especially during prolonged use or when cutting heavier materials.

Although the utility scissors 10 shown in FIGS. 1-8 show utility scissors in which the upper jaw 12b is generally located above the axis A and the lower jaw 14b is located below the axis, the present invention can be used with utility scissors, household scissors, or metal with a different configuration. Thus, according to FIGS. 9 and 10, other conventional configurations of utility shears are illustrated, in which both the upper and lower jaws are located above the axis A. In all cases, the above-mentioned configuration for the upper jaw 12b is essentially the same.

The foregoing is considered only as an illustration of the principles of the present invention. Moreover, since numerous modifications and variations will be apparent to those skilled in the art, it is not desirable to limit the invention to the precise construction and operating principle shown and described, and accordingly, all suitable modifications and equivalents thereof that may be made are within the scope of the present invention. .

Claims (31)

1. Universal scissors containing: a first lever and a second lever pivotally connected to the first lever on the shaft, each lever being rotatable from an open position to a closed position, each lever forming a blade, the blades in the closed position forming a longitudinal axis; And a first finger grip formed on the first arm and a second finger grip formed on the second arm, wherein the first finger grip includes a flat inner surface adapted to receive the thenar of the user's thumb, and the second finger grip defines a second inner surface adapted to receive at least one finger of the user such that the combined pressure of the thenar on the flat inner surface and at least one finger on the second inner surface moves the first lever and the second lever to a closed position; wherein the flat inner surface extends generally parallel and offset relative to the longitudinal axis when the first lever is in the closed position. 2. The utility scissors of claim 1, wherein the first finger grip defines a first opening adapted to allow the thumb to pass through the first opening such that the thenar surface of the thumb is positioned on a flat inner surface during use. 3. Universal scissors according to claim 2, characterized in that the first hole is formed by a ring loop of the first finger grip and the flat inner surface forms part of the ring loop. 4. The universal scissors according to claim 3, characterized in that the first finger grip further comprises an outer right side portion that is adapted to rest against the palm of the user's hand, behind the thenar crease of the hand in the direction of the crease of the palm of the hand. 5. The universal scissors according to claim 2, characterized in that the first finger grip further includes a lower part, wherein a flat inner surface is formed from the lower part, and the flat inner surface and the second inner surface formed by the second finger grip are generally parallel to each other. when the first lever and the second lever are in the closed position. 6. The utility scissors of claim 3, wherein the first finger grip has a recessed curved surface adapted to accommodate the webbing of the hand between the thumb and index finger during use of the utility scissors. 7. Universal scissors according to claim 2, characterized in that the closed position of the first lever and the second lever is formed by the stop of the first finger grip in the second finger grip. 8. Universal scissors according to claim 2, characterized in that the first hole allows the metacarpal bone of the thumb to be inserted through it. 9. The utility scissors of claim 2, wherein the second finger grip defines a second opening adapted to allow at least one finger to pass through the second opening and be positioned on the second inner surface during use of the utility scissors. 10. Universal scissors according to claim 9, characterized in that the second inner surface is formed as part of a second annular loop. 11. Universal scissors according to claim 1, characterized in that the first finger grip defines a central axis that runs along a direction at an angle in the range from 50° to 60° relative to the cutting plane of the blades. 12. The utility scissors of claim 2, wherein the first finger grip further comprises a flat bottom surface and the flat inner surface of the first finger grip is inclined at an angle relative to the flat bottom surface. 13. Universal scissors according to claim 12, characterized in that the angle of inclination is 10°-20°. 14. Universal scissors according to claim 13, characterized in that the angle of inclination is 15°-17°. 15. Universal scissors containing: a first lever and a second lever pivotally connected to the first lever on the shaft, each lever being rotatable from an open position to a closed position, each lever forming a blade, the blades in the closed position forming a longitudinal axis; a first finger grip formed on the first arm and a second finger grip formed on the second arm, wherein the first finger grip includes a flat inner surface adapted to receive the thenar of the user's thumb, and the second finger grip defines a second inner surface adapted to receive at least one finger of the user such that the combined pressure of the thenar on the flat inner surface and at least one finger on the second inner surface moves the first lever and the second lever to a closed position; wherein the flat inner surface is generally parallel and offset relative to the longitudinal axis when the first lever is in the closed position; And wherein the first finger grip further includes a lower portion, wherein a flat inner surface is formed from the lower portion, and the flat inner surface and a second inner surface formed by the second finger grip are generally parallel to each other when the first lever and the second lever are in a closed position . 16. The utility scissors of claim 15, wherein the first finger grip defines a first opening adapted to allow the thumb to pass through the first opening such that the thenar surface of the thumb is located on a flat inner surface during use; And the second finger grip defines a second opening adapted to allow at least one finger to pass through the second opening and be positioned on the second inner surface during use of the utility scissors. 17. Universal scissors according to claim 16, characterized in that the first hole is formed by a ring loop of the first finger grip and a flat inner surface is formed on the ring loop; the first finger grip further includes an outer right side portion that is adapted to rest against the palm of the user's hand, behind the thenar crease of the hand in the direction of the palm crease of the hand; the first finger grip further includes a bottom portion, wherein a flat inner surface is formed from the bottom portion, and a flat inner surface formed by the second finger grip and the second inner surface are generally parallel to each other when the first lever and the second lever are moved to a closed position; And the first finger grip has a recessed curved surface adapted to accommodate the webbing of the hand between the thumb and index finger during use of the utility scissors. 18. The utility scissors of claim 17, wherein the second finger grip defines a second opening adapted to allow at least one finger to pass through the second opening and be positioned on the second internal surface during use of the utility scissors, and the second internal surface is formed as part of a second ring loop. 19. Universal scissors according to claim 17, characterized in that the first finger grip defines a central axis that runs along a direction at an angle in the range from 50° to 60° relative to the cutting plane of the blades. 20. The utility scissors of claim 17, wherein the first finger grip further comprises a flat bottom surface and the flat inner surface of the first finger grip is inclined at an angle relative to the flat bottom surface.

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