Cutting tools

Abstract

A cutting tool includes: a first blade having a cutting edge; a second blade having a cutting edge, and the second blade is pivotally connected to the first blade at a first pivot point. A first handle is pivotally connected to the first blade at a second pivot point, a second handle is pivotally connected to the second blade at a third pivot point, the first handle is pivotally connected to the second handle at an adjustable fourth pivot point, and the cutting tool further includes a switching device, the switching device includes a switching member, and the switching member allows a user to change the position of the fourth pivot point from a proximal pivot point to a distal pivot point.

Description

Technical Field

[0001] This invention relates to cutting tools, and more precisely to cutting tools having an adjustable pivot point. Background Technology

[0002] Typically, cutting tools such as hedge trimmers have two handles with blades arranged as axial extensions of the handles. The combination of these handles and blades is pivotally connected at only one pivot point, which is usually located on the blade and near the point where the blade is attached to the handle.

[0003] The cutting force that can be applied to a branch is directly proportional to the force used to orient the handles toward each other. This is based on a typical lever structure, where the cutting force can be increased by extending the length of the handles.

[0004] It is known that when cutting thicker branches, a longer lever, or handle, generates greater cutting force for easier cutting. Conversely, a shorter lever produces a faster cutting speed, which is more advantageous for cutting thinner branches. Some cutting tools utilize gears to achieve better speed by increasing or decreasing rotational speed. However, in solutions where the user can choose between two or more advantages, the cutting motion is not symmetrical, which affects the targeting of the correct branch to be cut.

[0005] The challenge is how to switch between greater cutting force and greater speed while maintaining symmetrical handle movement. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned defects and provide a new type of cutting tool.

[0007] The cutting tool is based on the concept of having three pivot points and a fourth, changeable pivot point.

[0008] One advantage derived from this invention is the ability to change the length of the lever. The user can switch the fourth pivot point further away from the handle for greater cutting force when cutting thicker branches, and closer to the handle for faster cutting of thinner branches. Attached Figure Description

[0009] In the following description, the invention will be illustrated in more detail by way of preferred embodiments with reference to the accompanying drawings, in which:

[0010] Figure 1 A cutting tool in a closed position according to an embodiment is shown;

[0011] Figure 2 It shows no switching device Figure 1 Cutting tools;

[0012] Figure 3 The image shows the open position when the proximal pivot point is selected. Figure 1 Cutting tools;

[0013] Figure 4 This shows the open position when the distal pivot point is selected. Figure 1 Cutting tools;

[0014] Figure 5 A perspective cross-sectional view of the switching device according to an embodiment is shown;

[0015] Figure 6 A perspective view of a switching device according to another embodiment is shown;

[0016] Figure 7 It shows Figure 6 A three-dimensional cross-sectional view of the switching device;

[0017] Figure 8 A perspective view of a switching device according to yet another embodiment is shown;

[0018] Figure 9 It shows Figure 8 A three-dimensional cross-sectional view of the switching device. Detailed Implementation

[0019] This invention relates to cutting tools, particularly hedge trimmers. Figure 1 A cutting tool in a fully closed position according to an embodiment is shown. The cutting tool includes a first blade 5 with a cutting edge and a second blade 6 with a cutting edge. The second blade 6 is pivotally connected to the first blade 5 at a first pivot point 7. The cutting tool also includes a first handle 1 and a second handle 2, which are elongated and may include gripping portions 3 and 4, made, for example, of a moldable material, arranged near one end of the handles 1 and 2 for better gripping. The first handle 1 is pivotally connected to the first blade 5 at a second pivot point 8, while the second handle 2 is pivotally connected to the second blade 6 at a third pivot point 9. The second pivot point 8 and the third pivot point 9 are located at the ends of the handles 1 and 2 closer to the blades 5 and 6 and opposite to the gripping portions 3 and 4.

[0020] The additional second pivot point 8 and third pivot point 9 provide more leverage and thus make cutting easier by increasing the cutting force of the blades 5 and 6 when they approach their closed position, without requiring additional force from the user. When the handles 1 and 2 are moved toward each other, the second pivot point 8 and third pivot point 9 move away from each other, which brings the first blade 5 and the second blade 6 closer together.

[0021] The first blade 5 and the second blade 6 are configured such that, below the first pivot point 7, the first blade 5 and the second blade 6 include portions 5a and 6a that are curved outward with respect to the axis of symmetry of the cutting tool, wherein portions 5a and 6a form a bend or acute angle relative to the blades 5 and 6. Therefore, the blades 5 and 6 are not straight below the first pivot point 7 as they would be in conventional scissors or hedge trimmers.

[0022] The first blade 5 and the second handle 1 can be substantially symmetrical to the second blade 6 and the second handle 2, and the distance between the first pivot point 7 and the second pivot point 8 and the distance between the first pivot point 7 and the third pivot point 9 can be the same. However, in some embodiments, this symmetry or similarity is not required, and small deviations are allowed.

[0023] Blades 5 and 6 can be identical and made of suitable steel. For example, the first pivot point 7, the second pivot point 8, and the third pivot point 9 can be achieved by means of short shafts, pins, or rivets, or nuts and bolts, made of metal. If metal nuts and bolts are used, it is preferable that the holes are the same size, rather than one hole being smaller than the other.

[0024] The cutting tool also includes a switching device 10 that connects a first handle 1 and a second handle 2 together. The switching device 10 is preferably located between handles 1 and 2 and at the same ends of handles 1 and 2 as the second pivot point 8 and the third pivot point 9, which are located at the outer edges of handles 1 and 2. The switching device 10 can be arranged at a suitable and equidistant distance from the second pivot point 8 and the third pivot point 9 by molding handles 1 and 2 such that protrusions 1a and 2a projecting laterally from handles 1 and 2 are provided between handles 1 and 2.

[0025] The first handle 1 is pivotally connected to the second handle 2 at an adjustable fourth pivot point 11, wherein the fourth pivot point 11 is switchable between a proximal pivot point 11a and a distal pivot point 11b.

[0026] The switching device 10 includes a switching element 12 that allows the user to change the adjustable fourth pivot point 11 from a proximal pivot point 11a to a distal pivot point 11b, and also allows the user to change the adjustable fourth pivot point 11 from a distal pivot point 11b to a proximal pivot point 11a. The term "proximal pivot point" herein refers to the pivot point of the switching device located closer to the user or gripping portions 3, 4, while the term "distal pivot point" herein refers to the pivot point of the switching device located closer to the blades 5, 6.

[0027] The distance between the second pivot point 8 and the adjustable fourth pivot point 11, and the distance between the third pivot point 9 and the adjustable fourth pivot point 11, can also be the same. The cutting tool, when in its fully closed position, can be substantially symmetrical with respect to its longitudinal axis, wherein the axis of symmetry of the cutting tool passes through the first pivot point 7 and the fourth pivot point 11. Specifically, when the cutting tool is in its fully closed position, the proximal pivot point 11a, the distal pivot point 11b, and the first pivot point 1 can be located on the axis of symmetry. However, in some embodiments, the adjustable fourth pivot point 11 can be offset from the axis of symmetry.

[0028] The fourth pivot point forms a quadrilateral. When the proximal pivot point 11a of the adjustable fourth pivot point 11 is engaged and activated, the resulting quadrilateral is larger than the quadrilateral formed with the distal pivot point 11b. When the handles 1 and 2 are rotated away from each other around the adjustable fourth pivot point 11, the second pivot point 8 and the third pivot point 9 move closer to each other, while the first pivot point 7 and the adjustable fourth pivot point 11 move away from each other, thereby separating the blades 5 and 6 from the closed position to the open position.

[0029] Handles 1 and 2 may also include a vibration absorber 13, which further protrudes laterally from handles 1 and 2 and is disposed between handles 1 and 2. The vibration absorbers 13 are arranged to contact and abut against each other when the cutting tool is in the fully closed position. The vibration absorbers 13 may be positioned near protrusions 1a and 2a, wherein the switching device 10 is disposed between the first pivot point 7 and the vibration absorber 13. The vibration absorbers 13 may be made of rubber and are arranged to reduce the impact on the user's joints by absorbing excess force when the cutting tool moves from the open position to the fully closed position.

[0030] Figure 2 The example shown is without the switching device 10. Figure 1 Cutting tools. Figure 2 Very similar to combination Figure 1The cutting tool described does not include the switching device 10. The protrusions 1a and 2a projecting laterally from the handles 1 and 2 may have enlarged ends further protruding from the protrusions 1a and 2a, which may include a first hole 21 and a second hole 22. The enlarged ends may be elliptical, such as... Figure 2 As shown, or alternatively, the enlarged end may be round, rectangular, or any other suitable shape. In some embodiments, the end is not enlarged, but rather reduced or equal to the size of the protrusions 1a, 2a.

[0031] In this embodiment, the first hole 21 and the second hole 22 are arranged as circular holes, wherein when the cutting tool is in the fully closed position, the first holes 21 of both protrusions 1a and 2a are arranged to be completely aligned with each other, and the second holes 22 of both protrusions 1a and 2a are arranged to be completely aligned with each other.

[0032] Figure 3 This shows the fully open position when the proximal pivot point 11a is engaged. Figure 1 Cutting tools. Figure 4 This shows the fully open position when the distal pivot point 11b is engaged. Figure 1 The cutting tool. When the proximal pivot point 11a is selected and activated, the lever distance is shorter compared to the lever distance of the distal pivot point 11b. This allows for an increase in the cutting speed of the blade. On the other hand, when the distal pivot point 11b is selected and activated, the lever distance is longer compared to the lever distance of the distal pivot point 11a. This allows for an increase in the cutting force of the blade through a longer lever, and allows the handles 1 and 2 to open wider, thereby allowing the blades 5 and 6 to open wider to accommodate thicker or denser branches.

[0033] Figure 5 A perspective cross-sectional view of a switching device 10 according to an embodiment is shown. In this embodiment, the switching device 10 may include a receiving portion 14. The receiving portion 14 herein may refer to any type of receiving portion or cover for supporting and protecting the switching member 12 or for facilitating attachment of the switching device 10 to a cutting tool. However, in some embodiments, the receiving portion 14 may not be necessary.

[0034] As shown in the accompanying drawings, a first protrusion 1a protrudes from a first handle 1, and a second protrusion 2a protrudes from a second handle 2. The protrusions 1a and 2a can be of any shape, but are designed to protrude laterally from handles 1 and 2 and are positioned between handles 1 and 2, such that the protrusions 1a and 2a are arranged to connect to each other via an adjustable fourth pivot point 11. The protrusions 1a and 2a may have at least one flat surface, wherein the protrusions 1a and 2a are slidable relative to each other. Each of the first protrusion 1a and the second protrusion 2a may include a first hole 21 and a second hole 22, wherein the first hole 21 and the second hole 22 of each protrusion 1a and 2a are aligned when the cutting tool is in the fully closed position. The adjustable fourth pivot point 11 is configured such that when the proximal pivot point 11a is engaged, the adjustable fourth pivot point 11 is located at the first hole 21, and when the distal pivot point 11b is engaged, the adjustable fourth pivot point 11 is located at the second hole 22.

[0035] Figure 5 A perspective cross-sectional view of a switching device according to an embodiment is shown. The switching element 12 may be a rocker-arm type switching element, which includes a first portion 12a and a second portion 12b. When the first portion 12a is raised, the second portion 12b is lowered, and when the second portion 12b is lowered, the first portion 12a is raised. The first portion 12a may be connected to a first pin 15, and the second portion 12b may be connected to a second pin 16. The pins 15 and 16 may be identical and designed in a cylindrical shape. However, in some embodiments, the shape of the pins may vary; for example, the pins may have different diameters.

[0036] The first portion 12a or the second portion 12b can be fixedly connected to the nearest end of the corresponding first pin 15 or second pin 16. The first pin 15 can be arranged such that, when the first portion 12a of the rocker switch is activated or pressed, the first pin 15 passes through a first hole 21 at the proximal pivot point 11a of both the first protrusion 1a and the second protrusion 2a. The second pin 16 can be arranged such that, when the second portion 12b of the rocker switch is activated or pressed, the second pin 16 passes through a second hole 22 at the distal pivot point 11b of both the first protrusion 1a and the second protrusion 2a.

[0037] When the first part 12a is activated or pressed, the second pin 16 can be arranged to rise together with the second part 12b, such that the second pin 16 passes through only one of the second holes 22 of the protrusions 1a and 2a, or does not pass through either of the second holes 22 of the protrusions 1a and 2a. This allows the handles 1 and 2 to rotate about the proximal pivot point 11a. Accordingly, when the second part 12b is activated or pressed, the first pin 15 is arranged to rise together with the second part 12a, such that the first pin 15 passes through only one of the first holes of the protrusions 1a and 1b, or does not pass through either of the first holes of the protrusions 1a and 1b, thereby allowing the handles 1 and 2 to rotate about the distal pivot point 11b. The fourth pivot point 11 can be switchable only when the cutting tool is in the fully closed position, wherein the first hole 21 and the second hole 22 are aligned.

[0038] Alternatively, the switch 12 can be any switch suitable for changing between at least two positions, such as a slider switch, button switch, rotary switch, or toggle switch, and Figures 6 to 9 Some of these switching elements are also shown. The basic principle that enables the fourth pivot point 11 to be changed between the proximal pivot point 11a and the distal pivot point 11b remains the same, that is, allowing the position of the fourth pivot point 11 to be changed by activating different positions of the switching element 12.

[0039] The receiving portion 14 can be arranged to at least partially surround the first protrusion 1a and the second protrusion 2b at the locations of the first hole 21 and the second hole 22. The receiving portion 14 can have a bottom wall 19 parallel to the protrusions 1a and 2a and including two holes aligned and corresponding to the positions of the first hole 21 and the second hole 22 of the protrusions 1a and 2a when the cutting tool is in the fully closed position, through which pins 15 and 16 can pass. The receiving portion 14 can be secured to the second protrusion 2a, for example, by an opening 20 and a bracket-like edge 23 fastened only to the second protrusion 2a, the opening 20 allowing the first protrusion 1a to slide relative to the receiving portion 14 and the second protrusion 2a when the cutting tool moves from the closed position to the open position or from the open position to the closed position.

[0040] The receiving portion 14 may further include an intermediate wall 17 disposed between and parallel to the switching member and the protrusions 21, 22. The intermediate wall 17 provides better support for the switching device 10 and guides the pins 15, 16 to their designated holes 21, 22. The intermediate wall 17 may include two holes aligned and corresponding to the first hole 21 and the second hole 22 of the protrusions 1a, 2a when the cutting tool is in the fully closed position. A neck 18 may surround the holes of the intermediate wall 17 to increase support. A bracket-like edge 23 may be attached to the intermediate wall 17.

[0041] The switching element 12 can be arranged to change its position relative to the receiving portion 14 via a structural feature, such as a shaft 24 connected to the receiving portion 14, wherein the shaft 24 is located at the junction between the first portion 12a and the second portion 12b of the switching element 12. Alternatively, the structural feature can be, for example, a rocker plate or a threaded element.

[0042] The switching device 10 may also include a spring 25. The spring 25 may be connected to a first portion 12a or a second portion 12b of the switching member 12, such that the spring 25 is arranged to hold the first portion 12a or the second portion 12b in a predetermined position, for example, holding the first portion 12a or the second portion 12b in a pressed position or a raised position. To change the position of the switching member 12, the user must press against the spring force. The spring force also prevents the switching member 12 from changing position between the proximal pivot point 11a and the distal pivot point 11b without overcoming the spring force.

[0043] like Figure 5 As shown, one end of the rocker switch may include a shoulder 26, and the spring 25 may be a spring plate that abuts against the shoulder 26 of the rocker switch. The shoulder 26 also prevents the rocker switch from rising above a predetermined position. However, other springs may also be implemented, such as torsion springs, coil springs, or clock springs.

[0044] Figure 6 A perspective view of a switching device according to another embodiment is shown, while Figure 7 A cross-sectional view of the switching device is shown. Figure 7 The implementation method is very similar to combining Figure 5 The described implementation method. Therefore, the main focus is on pointing out the differences. Figure 7 The implementation method will be described.

[0045] Figures 6 to 7The switching element 12 is shown as a two-button switching element, comprising a first portion 12a and a second portion 12b. For example, the first portion 12a and the second portion 12b can be connected to each other via a rocker arm, lever, slider, or crank solution. When the first portion 12a is pushed down, the second portion 12b rises, and when the second portion 12b is pushed down, the first portion 12a rises. Pins 15 and 16 can be directly connected to the inner surfaces of the first portion 12a and the second portion 12b.

[0046] Figure 8 A perspective view of a switching device according to yet another embodiment is shown, while Figure 9 A cross-sectional view of the switching device is shown. Figure 9 The implementation method is very similar to combining Figure 5 The described implementation method. Therefore, the main focus is on pointing out the differences. Figure 9 The implementation method will be described.

[0047] Figures 8 to 9 The switching element 12 is shown as a rotary switching element, which has a knob 12c that is rotatable about a shaft 27. The shaft 27 may be parallel to pins 15 and 16 in the longitudinal direction. The rotary switching element may include a grooved threaded portion on the inner surface of the switching element 12, which is slidably connected to the upper portions of pins 15 and 16. Holes 21 and 22 of the first protrusion 1a are arranged to hold pins 15 and 16 in the holes 21 and 22 of the first protrusion 1a. By rotating the knob 12c in one direction, the grooved threaded portion is arranged to raise the first pin 15 from the first hole 21 of the protrusion 1a toward the knob 12c and simultaneously lower the second pin 16 into the second hole 22 of the protrusion 1a. By rotating knob 12c in the opposite direction or further rotating it in the first direction after reaching the threshold, the grooved threaded portion is arranged to lower the first pin 15 into the first hole 21 and raise the second pin 16 toward knob 12c. Pins 15 and 16 may include necks 15a and 16a, and the grooved threaded portion having curved edges 28 is arranged to retain pins 15 and 16 through necks 15a and 16a.

[0048] Cutting tools such as hedge trimmers are designed to have a blade plane and a handle plane, the blade plane being defined by the cutting motion of blades 5 and 6, and the handle plane being defined by the opening / closing motion of handles 1 and 2. These planes are typically not parallel, but slightly angled, and for better ergonomics, they usually intersect at the points where blades 5 and 6 attach to handles 1 and 2.

[0049] This invention provides a symmetrical trajectory for the user's arm during the cutting motion. This is unattainable with geared cutting tools because gear mechanisms have at least two gear sections, one of which provides a pivot point for a first handle, while an adjacent gear provides a pivot point for a second handle. This results in one handle having a larger rotation angle compared to the other, thus causing asymmetrical handle movement. Asymmetrical handle movement tends to apply pressure to the hand in different ways and leads to faster fatigue.

[0050] With the gearless cutting tool according to the invention, the rotation angles of the first handle 1 and the second handle 2 remain the same, thereby providing the user with symmetrical movement. This symmetry facilitates aligning the cut to the desired position and is more ergonomic for the user.

[0051] The purpose of this invention is to provide an ergonomic cutting tool that has symmetrical movement from an open position to a fully closed position, and that can change the fourth pivot point 11 to obtain a longer lever when cutting thicker branches and a shorter lever when a higher cutting speed is required.

[0052] It is understood that the above description and accompanying drawings are for illustrative purposes only. It will be apparent to those skilled in the art that variations and modifications can be made to the invention without departing from its scope.

Claims

1. A cutting tool, the cutting tool comprising: A first blade, the first blade having a cutting edge. A second blade, having a cutting edge, is pivotally connected to the first blade at a first pivot point. A first handle, pivotally connected to the first blade at a second pivot point, the first handle including a first protrusion. A second handle, pivotally connected to the second blade at a third pivot point, includes a second protrusion, and each of the first and second protrusions includes a first hole and a second hole. The first handle is pivotally connected to the second handle at an adjustable fourth pivot point, and The cutting tool also includes a switching device, which includes a switching element that allows the user to change the position of the fourth pivot point from a proximal pivot point to a distal pivot point. The switching component includes a first part and a second part, wherein the first part of the switching component is connected to a first pin, and the second part of the switching component is connected to a second pin. The first pin is arranged to pass through two first holes at the proximal pivot point when the first portion of the switching element is activated, and the second pin is arranged to pass through two second holes at the distal pivot point when the second portion of the switching element is activated.

2. The cutting tool according to claim 1, wherein, When the cutting tool is in the fully closed position, the first pivot point, the distal pivot point, and the proximal pivot point are aligned on the same axis of symmetry.

3. The cutting tool according to claim 1, wherein, The first blade and the first handle are substantially symmetrical with respect to the second blade and the second handle, and The distance between the first pivot point and the second pivot point is the same as the distance between the first pivot point and the third pivot point.

4. The cutting tool according to claim 1, wherein, The distance between the second pivot point and the fourth pivot point is the same as the distance between the third pivot point and the fourth pivot point.

5. The cutting tool according to claim 1, wherein, The protrusion has at least one flat surface, wherein the protrusion is capable of sliding relative to each other.

6. The cutting tool according to claim 5, wherein, When the cutting tool is in the fully closed position, the first hole and the second hole of each protrusion are aligned.

7. The cutting tool according to claim 5, wherein, The switching device includes a receiving portion arranged to at least partially surround the first protrusion and the second protrusion at the locations of the first hole and the second hole.

8. The cutting tool according to claim 7, wherein, The receiving portion includes an intermediate wall parallel to the protrusion.

9. The cutting tool according to claim 7, wherein, The receiving portion includes a bottom wall parallel to the protrusion.

10. The cutting tool according to claim 1, wherein, The switching device includes a spring.

11. The cutting tool according to claim 1, wherein, The first handle includes a vibration absorber that abuts against a corresponding vibration absorber of the second handle when the cutting tool is in the fully closed position.

12. The cutting tool according to claim 1, wherein, The cutting tool is gearless.

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