CH718604A2 - Electric hand pruner. - Google Patents

Abstract

The invention relates to a portable electric shears comprising: an actuator, a transmission connecting the actuator to a movable blade (4), so as to allow movement of the movable blade (4) with respect to a counter-blade, the movable blade (4), the counter-blade, the said counter-blade comprising a support surface (25) arranged to come into contact with an object (300) and to cooperate with the movable blade (4) so that the said object (300) is cut during use of the electric portable pruning shears, said electric portable pruning shears being arranged to comprise a safety system for a user of said electric portable pruning shears, said safety system requiring that at least the movable blade (4) be made at least partly in electrically conductive material, characterized in that at least a portion of a surface of the counter-blade is made of electrically insulating material. Thanks to this portion of the counter-blade made of electrically insulating material, if a body made of conductive material comes into contact with this portion, it does not trigger the safety system of the electric portable secateurs.

Description

Technical area

The present invention relates to a portable pruner, in particular a portable pruner arranged to include a security system requiring that at least the movable blade is made at least in part of an electrically conductive material.

State of the art

[0002] A portable electric pruner is electrically powered, as a general rule by an independent power source. During its use, it is carried by a hand of the user, which also makes it possible to control it, for example using a trigger.

[0003] The power source of an electric portable pruning shear can be, for example, a battery or else a battery pack. In this case, the source is generally a separate part of the power shears. In particular, the user can carry the electric portable pruning shears with one hand and simultaneously carry on him, for example using a backpack, a harness or a belt, the power source. In another case, the power source of such a portable pruner is in the portable power tool.

[0004] A portable electric pruner comprises an actuator for transmitting a force to an external object on which it acts, in order to cut it.

[0005] A portable pruner comprises a counter-blade and a movable blade. A transmission connects the actuator to the movable blade, so as to allow movement of the movable blade relative to the counter-blade. The movable blade enables an object such as a branch to be cut, and the counter-blade acts as a support member, since it supports the branch while it is being cut. The counter-blade is not in itself dangerous for the user, because it is not sharp.

[0006] These portable electric secateurs have become more and more efficient and manage to generate a force of several kilo-Newtons. However, this efficiency has significantly increased the number of occupational accidents caused by such shears. The need for security with respect to the movement of the moving blade of these tools has therefore increased rapidly.

[0007] Various security systems in the state of the art attempt to meet this need. In particular, several security systems in the state of the art require that at least the movable blade be made at least in part of an electrically conductive material: in fact, when a hand (or a limb, or in general a portion of the body) of the user touches this movable blade, and in particular its portion made of electrically conductive material, these systems are arranged to modify the speed of the actuator, for example in order to reduce it or cancel it, and possibly trigger an alarm (audible and/or visual). In most cases, an electrical circuit closes via the hand (or in general the body) of the user when he touches this moving blade, and in particular its portion made of electrically conductive material: this closing is detected in different ways, for example via a measurement of an impedance.

[0008] A non-limiting example of such a security system is for example described in the document FR3074403. In this case, the safety system comprises a reference terminal, intended to be electrically coupled to the electric portable pruner and a contact terminal, intended to be electrically coupled to the body of a user, as well as a means of measuring a signal relating to the impedance between these terminals, so as to detect contact between the user's body and the portable electric shears. To operate, this system provides that the movable blade is made of an electrically conductive material.

[0009] Another non-limiting example of such a security system is for example described in the document WO2013136311, which also provides for the movable blade to be made of an electrically conductive material. In this case, the safety system comprises an electrically conductive element located on the handle of the electric portable pruner, so as to be in contact with the hand which holds the electric portable pruner and a circuit line which connects the movable blade to this electrically conductive element. Electric power generation means and voltage or current detection means are arranged on this circuit line. Regulation means are provided to intervene on the excitation circuit, in reaction to a detection by the detection means, when a predetermined threshold value is exceeded, to impose the stopping of the movement of the moving blade. This threshold value is a value corresponding to a value detected when the movable blade accidentally comes into contact with the hand of the user who is not holding the tool. In this case, the safety system also comprises footwear means capable of being worn by the user to ensure electrical conductivity between at least one of the user's feet and the ground.

Another non-limiting example of such a security system is for example described in the document FR3066357. In this solution the movable blade and the counter-blade are made of an electrically conductive material. The safety system comprises a first signal cable connected to an electronic control unit and to the blades, and a second signal cable connected to the electronic control unit and a handle made of an electrically conductive material, which is in contact with the skin of a user while using the power shears. The electronic control unit is configured to stop the operation of the actuator in the event of detection of a current flow between the blades and the handle, transmitted through the body of the user who comes into contact with one of the blades with his free hand.

[0011] However, if during a cut the user who is handling one of these known electric secateurs touches an electrically conductive element with the cutting head, for example a trellising wire, he involuntarily triggers the safety system, even if this contact is not dangerous for him: this causes the electric shears to stop working.

[0012] If this situation often occurs during cutting work, it unfortunately happens that users, disturbed by these unexpected or false stops, deactivate the operation of the security system, thus putting themselves in danger.

Brief summary of the invention

[0013] An object of the present invention is to provide a portable electric pruner free from the limitations of known portable pruning shears.

Another object of the present invention is to provide a portable electric pruning shear which reduces or even cancels false triggering of its security system.

[0015] Another object of the present invention is to provide a portable electric pruner which guarantees even more the safety of the user compared to known solutions.

According to the invention, these objects are achieved in particular by means of the portable electric pruner according to claim 1.

The portable electric pruner according to the invention comprises: an actuator, a transmission connecting the actuator to a movable blade, so as to allow movement of the movable blade relative to a counter-blade, the moving blade, the counter-blade, this counter-blade comprising a support surface arranged to come into contact with an object and to cooperate with the movable blade so that this object is cut during use of the shears.

The portable pruning shears according to the invention is arranged to include a safety system for the user of this portable pruning shears, this safety system requiring that at least the movable blade be made at least in part of an electrically conductive material.

According to the invention, at least a portion of a surface of the blade against is made of electrically insulating material.

[0020] Thanks to this portion of the counter-blade made of electrically insulating material, if a body made of conductive material comes into contact with this portion, it does not trigger the safety system of the portable pruning shears. Indeed, the conductive material does not allow a charge passage necessary for this triggering.

In a preferred embodiment, this surface of the blade against electrically insulating material is a surface opposite the support surface. This embodiment is advantageous when the electric portable pruner is used to cut an object, for example a branch, linked to an electrically conductive element, for example a trellising metal wire, by inserting the counter-blade between the object and the wire . In the absence of this insulating material, the metal trellising wire would have triggered the security system, without there being any real danger for the user. Thanks to the presence of the electrical insulating material on at least a portion of the surface opposite the support surface, this triggering does not take place: the user can thus continue his work, without deactivating the safety system and not being in danger.

In one embodiment, this surface of the counter-blade made of electrically insulating material is a side surface of the counter-blade. This surface is substantially perpendicular to the support surface and/or to the surface opposite the support surface.

In one embodiment, this surface of the counter-blade made of electrically insulating material is (at least) a chamfer of the counter-blade.

[0024] In one embodiment, the chamfer is adjacent to the surface of the counter-blade opposite the support surface.

[0025] In one embodiment, the entire counter-blade is made of electrically insulating material.

[0026] In one embodiment, at least a portion of the support surface is made of an electrically conductive material. This embodiment is advantageous when an electrically conductive element, for example a trellising metal wire, is located between the movable blade and the counter-blade, often without the user realizing it: in this case, since 'at least a portion of the support surface is made of electrically conductive material, the safety system is triggered, not to guarantee the safety of the user, who is not endangered, but to avoid cutting such electrically conductive element. This prevents unintentional damage to the domain infrastructure.

[0027] In one embodiment, at least part of the counter-blade and/or of the blade is reflective and/or has a fluorescent color. This makes the cutting head more visible to the user when he handles the electric portable shears and therefore increases his safety.

In one embodiment, the portion of the surface of the counter-blade made of electrically insulating material is made of at least one of the following electrically insulating materials: ceramic, polymer, fabric, enamel, varnish, lacquer, stone, glass .

In one embodiment, the portion of the surface of the counter-blade comprises a coating of electrically insulating material produced by PVD (Physical Vapor Deposition) and/or by CVD (Chemical Vapor Deposition).

Brief description of figures

[0030] Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: FIG. 1 illustrates an example of a system comprising an embodiment of the portable electric tool according to the invention . FIG. 2 illustrates a first side view of an embodiment of a cutting head of the portable electric tool according to the invention, in the closed position. Figure 3 illustrates a first side view of the cutting head of Figure 2, in the open position. Figure 4 illustrates a second side view of the cutting head of Figure 2, in the open position. FIG. 5 illustrates a perspective view of one embodiment of the cutting head of the power tool according to the invention in the open position, with an object inside the cutting head and an electrically conductive element at the below the counter blade. Figure 6 illustrates a perspective view of the cutting head of Figure 5, with both an object and an electrically conductive element inside the cutting head. FIG. 7 illustrates a first perspective view of an embodiment of the counter-blade of the portable electric tool according to the invention. Figure 8 shows a second perspective view of the counter blade of Figure 7. Figure 9 shows a third perspective view of the counter blade of Figure 7.

Example(s) of embodiment(s) of the invention

[0031] Figure 1 illustrates an example of a system comprising an embodiment of the portable electric pruner 10 according to the invention. This tool is arranged to be carried by a user, for example by a member of the user such as a hand. In a variant, this same hand makes it possible to control the tool 10 via a control device, for example a trigger 3. In this case, the portable electric pruner 10 comprises a body 5, a movable blade 4 and a counter-blade 2.

[0032] The movable blade 4 makes it possible to cut an object and comes into direct contact with this object. It is mobile during the cutting of the object and actuated by an actuator (not shown) of the portable electric shears 10, for example and in a non-limiting way an electric motor.

Against the blade 2 supports the object during its cut and it is not movable relative to the body 5 of the portable electric shears 10 during the cutting of the object. The counter-blade 2 is not actuated by the actuator of the portable electric shears 10. Its presence is necessary to make the cut. The counter-blade 2, and in particular its support surface, also comes into direct contact with this object during the cut.

In the example of Figure 1, the electric portable pruner 10 is connected by a connection element 6, a cable in the example of Figure 1, to a control box 130 of the electric portable pruner 10, placed in a support means 100 carried by the user, in the example a backpack. This control box 130 is connected via connection element 7 to one or more batteries 140 in the same support means 100, and via connection element 8 to a remote box 160, which may include a display 161, and which is generally placed on a belt 170 worn by the user. In the example shown, belt 200 is part of backpack 100.

The example of Figure 1 should not be considered limiting and other variants can be imagined, for example the replacement of at least one of the wired connection elements 6 to 8 by a wireless connection element or “wireless”, the integration of the control box 130 and/or the battery(ies) 140 into the body 5 of the tool, and/or the absence of a remote box 160, etc.

The portable pruner 10 also comprises a transmission (not shown) connecting the actuator (not shown) of the portable pruner 10 to the movable blade 4, so as to allow movement of the movable blade 4 relative to the counter- blade 2.

[0037] Non-limiting examples of transmission include a ball screw/nut system, in which the screw moves with a translational movement and the nut rotates with a rotational movement and/or in which the screw which moves with a rotational movement and the nut moves with a translational movement, connecting rods, cams, etc.

According to the invention, the portable electric pruner 10 is arranged to include a safety system (not shown) for this portable electric pruner 10, this safety system requiring that at least the movable blade 4 be made at least partly in electrically conductive material.

[0039] Indeed, when a hand (or a limb or in general a portion of the body) of the user touches this movable blade 4, and in particular its portion made of electrically conductive material, the security system is arranged to modify the speed of the actuator, for example reduce it, reverse it or cancel it, perform a reopening movement, and possibly trigger an alarm (audible and/or visual). In most cases, an electrical circuit closes via the hand (or in general the body) of the user when he touches this movable blade 4, and in particular its portion made of electrically conductive material: this closing is detected in different ways by a detection unit and this detection makes it possible to reduce, reverse or cancel the speed of the actuator, thus avoiding serious accidents to the user.

[0040] Figure 2 illustrates a first side view of an embodiment of a cutting head 1 of the power tool according to the invention, in the closed position. Figure 3 illustrates a first side view of the cutting head 1 of Figure 2, in the open position. Figure 4 illustrates a second side view of the cutting head 1 of Figure 2, in the open position. Figures 2 to 4 illustrate a non-limiting embodiment of the invention.

As seen in Figures 2 to 4, the movable blade 4 and the counter-blade 2 are superposed one on the other and connected by connection means, in the example a bolt 90 which cooperates with a sleeve (not shown), and a toothed nut 92. The toothed nut 92 can cooperate with a toothed sector 94, visible in Figure 1, in a known manner. These connection means are at least partly received by through-holes of the movable blade 4 and of the counter-blade 2, which are aligned when the two blades are superimposed. The movable blade 4 is arranged to pivot with respect to the counter-blade 2 around the axis of rotation 9, which passes through these connection means.

[0042] The movable blade 4 comprises a cutting portion 40 and an actuating portion 42, the two portions extending from the connection means 90, 92 and forming an angle between them, of approximately 90° in the example illustrated in figures 2 to 4.

In the example of Figures 2 to 4, the actuating portion 42 of the movable blade 4 comprises a connection means with the transmission of the electric portable pruner 10, a hole 44 in the example shown. The transmission, via this means, pushes the actuating portion 42, thus causing the rotation of the movable blade 4 around the axis of rotation 9. During this rotation, the cutting part 40 can move away from the counter -blade 2 (FIGS. 3 and 4), thus allowing the user to insert an object to be cut into the space which is created between the cutting part 40 and the counter-blade 2, and then can approach against the blade 2 (FIG. 2), thus producing the cut of the object. The cutting part 40 of the movable blade 4 indeed comprises a sharpened edge 46, which allows this cut.

The cutting part 40 of the movable blade of Figures 2 to 4 has a beak shape, slightly curved. However, other forms can be envisaged. The free end of the cutting part 40 in the plane of a lateral surface of the movable blade 4 has a greater width compared to the width of the cutting part in correspondence of the connection means 90, 92. words, the cutting part 40 has a section in the plane of a side surface of the movable blade 4 that is substantially triangular.

Although in the examples of Figures 2 to 4 the movable blade is not flat, in other examples (not shown) it can be flat.

The movable blade 4 is made at least in part, and often completely, in an electrically conductive material, for example and without limitation steel or hardened steel.

The counter-blade 2 comprises a support portion 20 and a fixing portion 22, the two portions extending from the connection means and forming an angle between them, greater than 90° in the example illustrated on Figures 2 to 4. The support portion 20 makes it possible to support an object to be cut during the cut and comes at least partly in direct contact with this object. The support portion 20 comprises a support surface 25, visible for example in Figures 5 and 6, which supports the object to be cut (reference 300 in Figures 5 and 6) during the cut and comes at least partly in contact directly with this object 300. This support surface 25 is substantially perpendicular to the side surfaces of the counter-blade (a side surface 26 is for example visible in FIGS. 5 and 6).

The fixing portion 22 makes it possible to fix the counter-blade 2 to the body 5 of the portable electric shears 10, in order to make the body 5 integral with the counter-blade 2.

In the example of Figures 2 to 4, the fixing portion 22 of the counter-blade 2 comprises means for fixing the counter-blade 2 with the body 5 of the electric portable secateurs 10, two holes 24 in the example shown. The fixing portion 22 may comprise a terminal (not shown) which belongs to the safety system of the electric portable pruner 10.

The support part 20 of the blade against Figures 2 to 4 has a hook shape, slightly curved. However, other forms can be envisaged. The free end of the support part 20 in the plane of a side surface of the counter-blade 2 has a greater width compared to the width of the support part in correspondence of the connection means 90, 92. in other words, the support part 20 has a section in the plane of a side surface of the counter-blade 2 that is substantially triangular.

Although in the examples of Figures 2 to 4 against the blade 2 is not flat, in other examples it can be flat.

According to the invention, at least a portion of a surface of the blade against 2 is made of electrically insulating material. In one embodiment, this portion is made of at least one of the following electrical insulating materials: ceramic, polymer, fabric, enamel, varnish, lacquer, stone, glass. In another embodiment, this portion comprises a coating of electrically insulating material produced by PVD and/or by CVD. The remaining portion of the counter-blade is generally made of an electrically conductive material, in particular the same as that used for the movable blade 4.

In a preferred embodiment, this surface of the counter-blade 2 made of electrically insulating material is a surface 28 opposite the support surface 25. At least a portion of the support surface 25 is substantially parallel to at least a portion of surface 28 opposite support surface 25.

This embodiment is advantageous when the portable electric pruner 10 is used to cut an object 300, for example a branch, linked to an electrically conductive element (for example wire) 400, for example a metal trellising wire, by inserting the counter-blade 2 between the object 300 and the wire 400, as illustrated in FIG. 5. This trellising wire is generally connected via (metal) trellising stakes to the ground. In the absence of this insulating material, the metal trellising wire 400 would have triggered the security system, without there being any real danger for the user. Thanks to the presence of the electrical insulating material on at least a portion of the surface 28 opposite the support surface 25, this triggering does not take place: the user can thus continue his work, without having to manually deactivate the security system. and not being in danger.

In one embodiment, at least a portion of the support surface 25 is made of electrically conductive material. This embodiment is advantageous when an electrically conductive (wired) element 400, for example a trellising metal wire, is located between the movable blade 4 and the counter-blade 2, often without the user realizing it. , as illustrated in Figure 6. In the example of Figure 6, the user only thinks of entering the object 300 to be cut, and he does not realize that below this object 300 there is a trellis wire 400 in contact with the support surface 25. In this case, since at least a portion of the support surface 25 is made of electrically conductive material, the security system is triggered, not to guarantee the safety of the user, which is not endangered, but to avoid cutting such an electrically conductive element 400.

In one embodiment, this surface of the counter-blade 2 made of electrically insulating material is a side surface (references 26 and/or 27, in FIGS. 5 to 9) of the counter-blade 2. This surface is substantially perpendicular to support surface 25 and/or surface 28 opposite support surface 25.

In one embodiment, at least part of the blade against 2 and / or the blade 4 is reflective and / or has a fluorescent color. This makes it possible to make the cutting head 1 more visible to the user when he manipulates the portable electric shears 10 and therefore to increase its safety.

[0058] Figures 7 to 9 illustrate perspective views of an embodiment of the counter blade 2. In this embodiment, it is possible to see the through hole 29 of the counter blade, which allows its connection to the movable blade 4 via the connection means 90, 92.

In this embodiment, the side surface 27 intended to come into contact with the movable blade 4 during its movement is not flat, but comprises a wiper sap (or wiper blade or "sap groove") 21, which makes it possible to reduce the friction surface between the blade and the counter-blade without the risk of the blades sticking, for example when cutting plants in sap. It saves time and makes pruning easier by removing dirt and sap after each cutting motion. The wiper 21 is the part of the counter-blade 2 which rubs against the movable blade 4 during its movement. It is adjacent to another surface 23 (less thick), which does not come into contact with the movable blade 4 during its movement.

[0060] In one embodiment, this surface of the counter-blade 2 made of electrically insulating material is (at least) a chamfer of the counter-blade 2. In this context, the term "chamfer" indicates a surface obtained by eliminating the edge of a blade. It is a bevel, which can be rounded, and whose function is to avoid sharp edges.

In one embodiment, the chamfer made of electrically insulating material is at least one chamfer adjacent to the surface 28 of the counter-blade 2 opposite to the support surface 25 (reference 200 in FIG. 7 and/or reference 220 in Figure 8).

In one embodiment, the bevel of electrically insulating material is that between the wiper sap 21 and its adjacent surface 23 (reference 210 in Figure 7).

In one embodiment, the chamfer(s) adjacent to the support surface 25 are made of an electrically conductive material (reference 230 in FIG. 9).

In a variant, the counter-blade 2 of the electric portable pruning shears 10 is manufactured with the following manufacturing method: provide a counter-blade 2 made of electrically conductive material, coat counter-blade 2 with electrically insulating material, remove this coating in certain areas or surfaces of the anvil 2.

[0065] This coating can be made by soaking the counter blade 2, for example by suspending it via its connection hole 29 with the movable blade 4. The coating of electrically insulating material can be made by PVD (Physical Vapor Deposition) and/or by CVD (Chemical Vapor Deposition).

In a variant, the counter-blade 2 of the electric portable pruning shears 10 is manufactured with the following manufacturing method: provide a counter-blade 2 made of electrically conductive material, coating a portion of a surface of the counter-blade 2 with electrically insulating material, for example via a varnishing step.

[0067] In both variants, the thickness of these coatings as a general rule has no limits, because the counter-blade 2 is an "inactive" zone of the portable electric shears 10. However, in order to reduce its size, it should not be too large; nor should it be too thin, due to frictional wear. In a variant, this thickness is less than or equal to 1 millimeter.

In another variant, the counter-blade 2 of the portable electric pruner 10 is manufactured with the following manufacturing method: provide a first portion of the counter-blade 2 in electrically conductive material, provide a second portion 2 of the counter-blade made of electrically insulating material, assemble the two portions.

Reference numbers used in the figures

[0069] 1 Cutting head 2 Counter-blade 3 Trigger 4 Movable blade 5 Body of the user 6 Connection element 7 Connection element 8 Connection element 9 Pivot axis 20 Support portion of the counter-blade 2 21 Wiper 22 Counter-blade fixing portion 2 23 Surface adjacent to sap-wiper 21 24 Connection hole with body 5 25 Counter-blade support surface 2 26 Counter-blade lateral surface 2 27 Lateral surface of the counter blade 2 28 Surface opposite to the support surface 25 29 Through hole of the counter blade 2 40 Cutting portion of the movable blade 4 42 Actuating portion of the movable blade 4 44 Connection hole with the transmission 46 Sharpened edge of the moving blade 4 90 Bolt 92 Toothed nut 94 Toothed sector 100 Support means (backpack) 130 Control box 140 Battery(ies) 160 Remote box 161 Display 170 Belt 200 Chamfer 210 Chamfer 220 Chamfer 230 Chamfer 300 Object to be cut 400 Element (for example wireframe) cond electric drive

Claims (10)

1. Portable electric pruner (10) comprising: – an actuator, – a transmission connecting the actuator to a movable blade (4), so as to allow movement of the movable blade (4) relative to a counter-blade (2), – the moving blade (4), – the counter-blade (2), said counter-blade (2) comprising a support surface (25) arranged to come into contact with an object (300) and to cooperate with the movable blade (4) so that said object (300) is cut during use the electric portable pruner (10), said electric portable pruning shears (10) being arranged to include a safety system for a user of said electric portable pruning shears (10), said safety system requiring that at least the movable blade (4) be made at least partly of electrically conductive material, characterized in that at least a portion of a surface of the counter-blade (2) is made of electrically insulating material. 2. Power pruner (10) according to claim 1, said counter-blade surface being a surface (28) opposite said support surface (25). 3. Portable electric shears (10) according to one of claims 1 or 2, said surface of the counter-blade (2) being a side surface (26, 27) of the counter-blade (2). 4. Portable electric shears (10) according to one of claims 1 to 3, said surface of the blade against being a chamfer (200, 210, 220). 5. Power shears (10) according to claim 4, said chamfer (200, 220) being adjacent to a surface (28) of the counter-blade opposite to said support surface (25). 6. Portable electric shears (10) according to one of claims 1 to 5, at least a portion of the support surface (25) being made of electrically conductive material. 7. Portable electric shears (10) according to one of claims 1 to 6, at least a portion of the blade against (2) being reflective and / or having a fluorescent color. 8. Portable electric shears (10) according to one of claims 1 to 7, at least a portion of the movable blade (4) being reflective and / or having a fluorescent color. 9. Portable electric shears (10) according to one of claims 1 to 8, said portion of said surface of the counter-blade (2) being made of at least one of the following electrical insulating materials: ceramic, polymer, fabric, enamel, varnish, lacquer, stone, glass. 10. Portable electric shears (10) according to one of claims 1 to 9, said portion of said surface of the counter-blade (2) comprising a coating of electrically insulating material produced by PVD and/or by CVD.