CZ306045B6 - Gardening shears with a mechanism of cutting tool rotation using stranded wire - Google Patents

Abstract

The present invention relates to hand held gardening shears with a disk-shaped cutting tool for cutting branches of fruit tree species, wherein the cutting operation is ensured by rotation of the disk-shaped cutting tool by means of a stranded wire. Rotation of the disk-shaped cutting tool (4), mounted on a driving roller and a pin (16) in the second jaw (3) of the shears, takes place during a cut, i.e. when the handles (6) and (7) of the shears are pressed through the mediation of a stranded wire (8). The stranded wire (8) is pressed through the mediation of a nosepiece (10) in a groove of the shears first jaw (1). The stranded wire (8) is routed about a driving roller (9), on which it is fixedly secured by a pressed driver (11) inserted into a cutout of the driving roller (9). Further, the stranded wire (8) is routed into a handle (6), where it is permanently held through the mediation of a spring (12), a pressed nosepiece (13), a washer (18), a holder (14) and an adjusting screw (15), in tight state. The force of the compression spring (12) can be adjusted by means of the adjusting screw (15).

Description

Garden shears with a mechanism for rotating the disc cutting knife using a cable

Field of technology

The invention relates to manual secateurs with a mechanism for rotating a disc cutting knife by means of a cable for cutting fruit tree branches.

Prior art

For cutting branches of fruit trees, lever single-blade or double-blade mechanical secateurs are commonly used, or secateurs with a gear, which ensures the increase of the pressure of the penetrating blade into the cut material. In all these secateurs systems, the blade-knife is pressed against the cut material during cutting, penetrating into the cut material and thus separating it. The required shear forces (blade pressure) are developed by a lever or other mechanical transmission. The disadvantage of this system of mechanical shears is the movement of the knife blade during cutting only perpendicular to the cut material, which thus penetrates the cut material only by pressure, which can deform and damage the cut material, which is not desirable for live fruit trees. This shortcoming is partially eliminated by curving the knife blade.

Improving the cutting process in terms of reducing the required cutting force and especially improving the cutting of live branches, ie not cutting the cut material only by knife pressure requires two movements of the knife, perpendicular and sliding or rotating, which garden shears of current manufacturers do not allow.

From the prior art, Pat. GB 596744 A, FR 2534449 A, CS 235882 B and JP 2003117265 A solve this problem of secateurs with a disc cutting knife or with a rotating cutting jaw. Here, the rotation of the disc knife is ensured by means of a toothed gear, FR 2534449 A, or by means of a pin and a link, GB 596744 A, or by means of a movable lever with a pin, CS 235882 B.

These solutions have certain shortcomings resulting from wear, strength and play in the proposed mechanisms.

According to Pat. CN 201243517 Y the movable jaw of the scissors is controlled by a cable. However, these are telescopic scissors, where the cable remotely controls only the movable fixed jaw of the scissors, not the rotation and at the same time the movement of a circular knife, as in this PV.

The essence of the invention

The essence of the invention lies in the application of the mechanism of rotation of the disc cutting knife, to manual secateurs, where the rotation of the disc knife is ensured by means of a cable, and where the disc knife replaces a fixed cutting knife.

Explanation of the drawing

The features of the invention are shown in the accompanying figures, in which Fig. 1 is a front view of the scissors and Fig. 2 is a section A-A of Fig. 1.

-1 CZ 306045 B6

Example of an embodiment of the invention

Figures 1 and 2 show an example of an embodiment of secateurs with a mechanism for rotating the disc cutting knife by means of a cable. The components of these shears, in particular the disc cutting knife 4 and the support part of the cutting mechanism of the knife 2, are made of hardenable steel and are tempered. The cable 8 with the pressed steel ends 10, 13 and the carrier 11 can be a high-strength steel cable with a diameter of 1 to 3 mm, depending on the size and purpose of the scissors. The remaining parts of the shears can be made of common structural steels, and combinations of plastic, possibly composite and steel moldings.

The first scissor jaw 1 includes a lower support part 2 of the cutting mechanism (knives) and a handle 6. The second scissor jaw 3 includes a handle 7 and a disc cutting knife 4, which is mounted via a square or polygon on the drive pulley 9 and the pin 16. The first jaw 1 of the scissors is connected to the second jaw 3 of the scissors by a pin 5.

The kinematic connection of the disc cutting knife 4 to the first scissor jaw 1 is secured by a cable 8. The cable 8 is firmly fastened in the groove of the first scissor jaw 1 by its pressed end 10, the cable 8 encircles the carrier pulley 9, to which it is firmly attached 11 inserted into the cut-out of the drive pulley 9 of the disc cutting knife 4, the other end of the cable 8 being tensioned by means of a compression spring 12, a washer 18 and a pressed end 13, which are accommodated in a holder 14 in the handle 6 of the first scissor jaw 1.

By pressing the handles 6 and 7 of the scissors, the disc cutting knife 4 with the driving pulley 9 is rotated around the pin 5, which causes the cable 8 to be tensioned, which through the carrier 11 and the driving pulley 9 rotates the disc cutting knife 4 around the pin 16 counterclockwise. of the hands, approaching the disc cutting knife 4 to the lower part of the cutting mechanism of the knife 2 and at the same time compressing the compression spring 12.

It is particularly advantageous that the compression spring 12 ensures the opening of both scissor jaws after the cut has been released after the handles 6 and 7 have been released, thus replacing the otherwise necessary spring which is placed between the scissor handles.

The compression spring 12 is accommodated in a holder 14, which is located in the handle 6 and which is tensioned with the compression spring 12 by an adjusting screw 15, which makes it possible to set the optimum force for opening the jaws of the scissors.

The disc cutting knife 4 is mounted on a square or polygon, which is a part of the drive roller 9, by means of which the disc cutting knife 4 is rotated. This solution of mounting the disc cutting knife 4 makes it possible to rotate the disc cutting knife 4 on the square or polygon of the drive roller 9 in case of its local blunting, and thus to gradually use the entire ground circumference of the disc cutting knife 4 until its further sharpening.

The drive pulley 9 is fastened to the end of the second scissor jaw 3 with the disc cutting knife 4 by means of a pin 16.

Part of the jaw 3 forms the safety cover 17 of the disc cutting knife 4 in its upper uncut part.

Claims (3)

PATENT CLAIMS Garden shears with a mechanism for rotating the disc cutting knife by means of a cable, which have one fixed jaw and the other rotating in the form of a disc cutting knife (4), characterized in that the disc cutting knife (4) is connected to the first shearing jaw (1) cable (8), where the cable (8) is fixed by its first end by means of a pressed end (10) firmly in the groove of the first jaw (1) of the scissors, the cable (8) being wrapped around the driving pulley (9), to which it is firmly attached a pressed carrier (11) inserted into the recess of the carrier pulley (9) of the disc cutting knife (4), the other end of the cable (8) being provided with a compression spring (12), a washer (18) and a pressed end (13) which are accommodated in holder (14) in the handle (6) of the first scissor jaw (1). Secateurs with a mechanism for rotating the disc cutter by means of a cable according to claim 1, characterized in that the compression spring (12) is accommodated in a holder (14) which is located in the handle (6), wherein to set the optimum opening force the handle (6) and (7), the holder (14) with the compression spring (12) is provided with an adjusting screw (15). Secateurs with a mechanism for rotating the disc cutting knife by means of a cable according to claims 1 and 2, characterized in that the disc cutting knife (4) is mounted on a square or polygon, which is part of the drive roller (9).