CUTTING DEVICE

Description

State of the art

[0001] A cutting device, in particular a garden cutting device, has already been proposed.

[0002] DE 10 2010 016 296 B4 already discloses a cutting device with two blades movable relative to one another, with two handle elements movable relative to one another, and with a drive unit that, in an operating state, is designed to assist a movement of the second blade relative to the first blade. Reference is also made to DE 42 09 530 C1. Disclosure of the invention

[0003] The invention relates to a cutting device having the features of claim 1. Advantageous further developments emerge from the dependent claims.

[0004] The cutting device is preferably designed as a pair of scissors, particularly preferably as garden shears. The two blades, which are movable relative to one another, are preferably pivotally mounted relative to one another.

[0005] In this context, a "garden cutting device" is understood to mean, in particular, a cutting device intended for use on plants. Preferably, this is understood to mean, in particular, a cutting device intended for cutting plants, hedges, bushes, branches, and / or other objects deemed appropriate by a person skilled in the art. A "cutting element" in this context is understood to mean, in particular, an element of the cutting device intended for direct contact with an object to be cut. Preferably, this is understood to mean an element intended for directly dividing an object to be cut. In principle, it is conceivable that at least one of the cutting elements is designed to be passive, such as an anvil and / or a passive cutting edge.Preferably, however, at least one cutting element has an active cutting edge, in particular a blade, which is intended for active cutting. Furthermore, in this context, a "grip element" should be understood in particular to mean an element that forms at least part of a handle. This should preferably be understood to mean an element that is at least partially gripped by an operator during operation. Preferably, both grip elements are gripped by an operator during operation, in particular with the same hand. In this context, "supporting a movement of the second cutting element relative to the first cutting element" should be understood in particular to mean that a force is generated by the drive unit, which acts at least partially in a direction parallel to the operator force.This should preferably be understood to mean that in at least one operating state, a manual force, which in particular causes a closing movement of the cutting elements relative to one another, is supported by a force additionally generated by the drive unit.

[0006] In this context, a "self-shifting clutch unit" is understood to mean, in particular, a clutch unit that is actuated independently of external, particularly electrical, switching signals, in particular a control unit. Preferably, this is understood to mean a clutch unit that is actuated independently of explicit switching signals, in particular for switching between clutch states. Preferably, this is understood to mean, in particular, a clutch unit that is actuated based on mechanical influencing factors. Particularly preferably, this is understood to mean, in particular, a clutch unit that is actuated depending on at least one parameter of a drive and / or output side. Various self-shifting clutch units that would be considered appropriate by a person skilled in the art are conceivable, such as centrifugal clutches, overrunning clutches, and / or safety clutches.The clutch unit can therefore be designed, in particular, to be speed-actuated, torque-actuated, direction-actuated, and / or force-flow-actuated. Furthermore, in this context, "decoupling the drive unit" should be understood as a decoupling of the drive unit from a closing mechanism of the cutting device.

[0007] The inventive design of the cutting device allows for advantageous decoupling of the drive unit. This enables, in particular, advantageously smooth manual operation of the cutting device. Furthermore, a clutch unit can advantageously be provided, which is advantageously actuated without electrical switching signals. This makes it possible, in particular, to dispense with a control unit for controlling the clutch unit. This preferably makes it possible to provide a particularly reliable clutch unit. In particular, a clutch unit can be provided that is designed to be actuated independently of a power supply.

[0008] It is further proposed that the at least one self-switching clutch unit is provided to decouple the drive unit in at least one operating state in order to implement fully manual operation. In this context, "fully manual operation" is to be understood in particular as an operating state in which the cutting device is operated independently of the support of the drive unit. Preferably, this is to be understood as an operating state in which the cutting device is operated exclusively by the active force of an operator. Particularly preferably, this is to be understood as an operating state in which the drive unit is decoupled and therefore cannot be used to support a movement of the second cutting element relative to the first cutting element.This allows for advantageously smooth manual operation of the cutting device. In particular, this allows the cutting device to be used advantageously even without the drive unit, for example, in the absence of a power supply and / or for light cutting work.

[0009] Furthermore, it is proposed that the at least one self-shifting clutch unit be designed as a one-way clutch. In this context, a "one-way clutch" is understood to mean, in particular, a self-shifting clutch that is directionally actuated and / or force-flow actuated. Preferably, the one-way clutch is at least directionally actuated. Preferably, the one-way clutch is designed to open and / or close depending on a direction of rotation, in particular a drive and / or output side of the clutch unit, and / or depending on a direction of a force acting on the one-way clutch. Regarding the direction of a force acting on the one-way clutch, a distinction can be made, for example, as to whether the force acts on the one-way clutch from the drive side or the output side.The overrunning clutch is preferably designed to open or close the drive unit in at least one operating state depending on a direction of rotation, in particular a drive and / or output side, and / or depending on a direction of force acting on the overrunning clutch. This makes it possible to provide, in particular, a particularly advantageous self-switching clutch unit. In particular, this makes it possible to advantageously facilitate smooth manual operation of the cutting device. This makes it possible to provide a particularly reliable clutch unit.

[0010] It is further proposed that the at least one self-shifting clutch unit has at least one clamping body. The self-shifting clutch unit preferably has several, in particular at least three, clamping bodies. The self-shifting clutch unit preferably has several clamping bodies arranged one behind the other in the circumferential direction. In this context, a "clamping body" is to be understood in particular as an element of the clutch unit which, in at least one operating state, in particular in a closed state of the clutch unit, is intended to clamp between two rotating elements of the clutch unit that are rotatably mounted relative to one another. In a clamped state, the clamping body is preferably connected to one rotating element in a form-fitting manner in the direction of rotation and to the other rotating element in a force-fitting manner, in particular by friction.This should preferably be understood to mean, in particular, an element which is provided, depending on an operating state of the coupling unit, to couple the rotating elements of the coupling unit to one another in a rotationally fixed manner or to decouple the rotating elements of the coupling unit relative to one another with regard to movement in the circumferential direction. When the coupling unit is in the closed state, the clamping bodies are preferably clamped between the rotating elements. Preferably, at least one of the rotating elements of the coupling unit has ramps by means of which a radial distance between the rotating elements varies. If the clamping bodies are moved into an area with a small radial distance, the ramp-free rotating element is rotationally driven by means of friction. If the clamping bodies are moved into an area with a large radial distance, the ramp-free rotating element is not rotationally driven because friction is not sufficient.Various clamping bodies that would appear appropriate to a person skilled in the art are conceivable; however, the clamping bodies are preferably at least partially cylindrical or at least partially spherical. This makes it possible to provide, in particular, a particularly advantageous self-engaging clutch unit. In particular, this makes it possible to provide an advantageous, particularly structurally simple, overrunning clutch. This makes it possible to provide, preferably, a particularly reliable self-engaging clutch unit.

[0011] It is further proposed that the at least one self-engaging clutch unit has at least one cage receiving the clamping body and a braking element which is provided for braking the cage in at least one operating state. The clutch unit preferably has a plurality of clamping bodies which are received in the same cage. The cage preferably receives the clamping bodies in separate receiving areas. Preferably, the braking element is provided in at least one operating state to increase the inertia of the cage. Preferably, the braking element is provided to prevent unwanted twisting of the cage. Particularly preferably, the braking element is provided to prevent twisting of the cage up to a defined force application. Preferably, the braking element is spring-mounted. In particular, the braking element is pressed against the cage with a defined force.In this context, a "cage" is understood to mean, in particular, an element of the coupling unit that is provided for positioning and / or guiding the at least one clamping body, in particular in the circumferential direction. The cage is preferably provided to space a plurality of clamping bodies apart from one another in the circumferential direction and, in particular, to distribute them evenly over a circumference. Particularly preferably, the cage is provided to guide a plurality of clamping bodies relative to one another in the circumferential direction. This makes it possible, in particular, to achieve an advantageously defined movement of the clamping bodies. In particular, with a plurality of clamping bodies, it is possible to ensure that the clamping bodies perform the same movement in the circumferential direction. Controlled clamping of the clamping bodies can preferably be enabled. Furthermore, the braking element can prevent unwanted movement of the at least one clamping body.In particular, this prevents unwanted jamming. Furthermore, it can be achieved that the clamping bodies are only rotated when a force is applied by a positive-locking rotating element of the clutch unit. In particular, the braking element can reliably open the clutch unit. Preferably, the braking element can ensure that the clamping bodies remain stationary during an opening movement of the clutch unit, thus enabling the clutch unit to open.

[0012] It is further proposed that the at least one self-engaging clutch unit comprise at least one pawl element. The pawl element is preferably designed to be actuated by one of the handle elements. Preferably, the at least one self-engaging clutch unit also comprises a ratchet wheel, into which the pawl element engages in at least one state. In this context, a "pawl element" is to be understood in particular as an element which, in at least one operating state, is intended to engage with an element mounted rotatably relative to the pawl element. The pawl element is preferably designed to prevent a direction of rotation of the element relative to the pawl element and preferably to permit an opposite direction.Particularly preferably, a pawl element should be understood as an element which, in at least one operating state, is provided to engage with a ratchet wheel and to prevent a direction of rotation of the ratchet wheel relative to the pawl element and preferably to release an opposite direction of rotation of the ratchet wheel. Preferably, the pawl element is provided, in at least one operating state, to engage with a toothing of the ratchet wheel. The ratchet wheel preferably has asymmetrical tooth flanks. In particular, one tooth flank is so steep that the pawl element clamps against the tooth flank, and one tooth flank is so flat that the pawl element can slide over it and be lifted by it. In particular, a particularly advantageous self-shifting clutch unit can be provided. In particular, an advantageous one-way clutch can be provided.Preferably, this makes it possible to provide a particularly reliable self-switching clutch unit.

[0013] It is further proposed that the cutting device have at least one cable winch that can be driven by the drive unit and at least one cable that is at least partially wound on the cable winch and that is at least partially stretched between the handle elements. The cable is preferably stretched between the ends of the handle elements facing away from the cutting elements. The cable is preferably firmly fixed to one handle element and fastened to the other handle element via the cable winch. In particular, a free length of the cable can be changed via the cable winch. The cable winch is preferably designed so that it can be driven by the drive unit via the coupling unit. The cable winch is preferably designed so that it can be separated from the drive unit via the coupling unit in at least one operating state. The cable winch particularly preferably forms an output side of the coupling unit.In this context, a "cable winch" is understood to mean, in particular, a cable drum, in particular a cylindrical cable drum, which is designed to be driven by a drive unit in at least one operating state. This allows for an advantageous force application by the drive unit. In particular, this allows for a simple construction to support a movement of the second cutting element relative to the first cutting element. An operator can thus be advantageously assisted by the drive unit during a closing movement. Furthermore, the force applied by the drive unit on the handle elements can provide an advantageously high torque. This, in turn, allows the power of the drive unit to be kept low.

[0014] It is also proposed that the at least one cable be stretched between the handle elements in a region between a gripping area of ​​the handle elements and a pivot joint, via which the handle elements are pivotable relative to one another. The cable is preferably stretched between the handle elements close to the pivot joint, in particular closer than 10 cm, preferably closer than 8 cm, and particularly preferably closer than 5 cm to the pivot joint. A "grip area" in this context is understood to mean, in particular, an area of ​​the handle elements in which the handle elements are regularly gripped by an operator. This advantageously prevents an operator from being disturbed by the cable. Furthermore, the cable can advantageously be designed to be short. This advantageously allows a cable winch to be designed to be particularly small. Furthermore, a low speed of the cable winch enables rapid closing of the cutting device.

[0015] It is further proposed that the at least one self-switching clutch unit be at least partially integrated into the at least one cable winch. Preferably, the clutch unit is at least partially encompassed by the cable winch. Preferably, the cable winch forms a functional component of the clutch unit. In this context, "the clutch unit being integrated into the cable winch" should be understood in particular to mean that the clutch unit is at least partially spatially arranged within the cable winch or is at least partially encompassed by the cable winch. Preferably, the clutch unit is functionally integrated into the cable winch. Preferably, the cable winch directly forms a rotating element, in particular an external rotating element, of the clutch unit.In this context, "at least partially encompassing" should be understood in particular to mean that the cable winch surrounds the coupling unit in at least one plane within an angular range of at least 90°, preferably at least 180°, and particularly preferably at least 360°. This advantageously minimizes the number of components. Furthermore, it allows for an advantageously compact design. In particular, intermediate shafts can be dispensed with.

[0016] It is further proposed that the cutting device has at least one spring element connected to the cable winch, which is designed in particular as a spiral spring and which is intended to tension the cable in at least one operating state. The spring element is preferably provided to ensure tension in the cable. The spring element is preferably provided to apply a force to the cable winch, in particular a force in the circumferential direction. The spring element is particularly preferably provided to act on the cable via the cable winch with a tensile force. In particular, the cable should be kept taut via the spring element. The spring element preferably has a spring force that is lower than the spring force of an opening spring.A "spring element" is understood in particular to mean a macroscopic element that has at least one extension and / or number of windings that, in a normal operating state, is elastically variable by at least 10%, in particular by at least 20%, preferably by at least 30%, and particularly advantageously by at least 50%. It is understood that in particular, a counterforce is dependent on a change in the extension and / or number of windings and is preferably proportional to the change, counteracting the change. An "extension" of an element is understood in particular to mean a maximum distance between two points of a perpendicular projection of the element onto a plane. A "macroscopic element" is understood in particular to mean an element with an extension of at least 1 mm, in particular of at least 5 mm, and preferably of at least 10 mm.The spring element ensures that the rope remains taut, especially during fully manual operation. This advantageously prevents accidental knotting of the rope. Furthermore, the rope can be wound up without the need for a motor.

[0017] It is also proposed that the at least one self-switching clutch unit be arranged in a first handle element of the handle elements, at an end facing away from the cutting elements. Preferably, the at least one self-switching clutch unit is arranged in a housing of the first handle element. This allows for an advantageously compact design. Furthermore, this allows for a particularly advantageous weight distribution. In particular, a weight of the clutch unit can be arranged directly in the area of ​​an operator's hand. This, in turn, allows for a high level of operating comfort.

[0018] It is further proposed that the cutting device have at least one gear unit arranged in a first handle element of the handle elements. The gear unit is preferably arranged in a housing of the handle element. In this context, a "gear unit" is to be understood in particular as a transmission gear unit with a transmission ratio greater than 2, preferably greater than 10, and particularly preferably greater than 50. This allows for an advantageously compact design. Furthermore, a particularly advantageous weight distribution can be achieved. In particular, the weight of the gear unit can be arranged directly in the area of ​​an operator's hand. This, in turn, makes it possible to achieve a high level of operating comfort. Furthermore, in particular, an appearance can be achieved that is at least similar to that of conventional hand-operated garden shears.

[0019] Furthermore, it is proposed that the drive unit and the gear unit be arranged spatially between the cutting elements and the at least one self-engaging clutch unit. Preferably, the cutting elements and the at least one self-engaging clutch unit are each arranged on opposite sides of an imaginary geometric cuboid that just completely encloses the drive unit and the gear unit. Preferably, the drive unit, the gear unit, and the clutch unit are arranged in the first handle element. This allows for an advantageously compact design. Furthermore, this allows for a particularly advantageous weight distribution.

[0020] It is further proposed that the at least one transmission unit has at least two gear stages, between which the at least one self-shifting clutch unit is arranged. The transmission unit preferably has two gears, in particular two planetary gears, between which the clutch unit is arranged. The clutch unit is preferably arranged between the gears of the transmission unit, viewed along a drive flow. The clutch unit is particularly preferably integrated into the transmission unit. This makes it possible, in particular, to achieve an advantageously compact design. Furthermore, this makes it advantageously possible to keep a torque acting on the at least one self-shifting clutch unit low.

[0021] It is further proposed that the cutting device has at least one force sensor which is integrated into a second handle element of the handle elements. Preferably, the cutting device has at least one control unit which is connected to the force sensor and is provided for controlling the drive unit. Preferably, the control unit is provided for controlling the drive unit depending on a signal from the force sensor. Particularly preferably, the control unit is provided to activate the drive unit when a defined measured value of the force sensor is overwritten. Preferably, the force sensor is coupled to a handle region of the second handle element. Particularly preferably, the handle region is movably mounted relative to a base body of the second handle element.The force sensor is preferably designed to detect a force acting on the second handle element, particularly relative to the first handle element. The force sensor can preferably be designed to detect both a precise force and merely an exceedance of a limit force. This advantageously allows the force exerted by an operator on the cutting device to be detected. For example, it is possible to detect how much force an operator must exert on the cutting device.

[0022] It is further proposed that the cutting device have at least one displacement sensor. The displacement sensor is preferably designed as a Hall sensor. The displacement sensor is preferably provided to detect an angular position of the handle elements relative to one another. The cutting device preferably has at least one control unit which is connected to the displacement sensor and is provided to control the drive unit. Particularly preferably, the control unit is provided to deactivate the drive unit by means of a measured value from the displacement sensor when an end position of the handle elements relative to one another is reached. This advantageously makes it possible to detect precisely one angular position of the handle elements relative to one another. In particular, this makes it possible to reliably stop the drive unit in an end position of the cutting device.

[0023] Furthermore, a method for operating a cutting device is proposed. It is proposed that, if a defined operator force is exceeded, the drive unit is connected to a closing mechanism of the cutting device. This makes it possible to provide an advantageously comfortable cutting device. Furthermore, it is particularly possible to ensure that the drive unit is only connected during heavy cutting work. This allows energy consumption to be kept low.

[0024] Furthermore, it is proposed that when the cutting device reaches an end position, the drive unit stops automatically and is briefly driven against a drive direction to open the coupling unit. A "drive direction" is understood to mean, in particular, a direction of rotation of the drive unit in which the drive unit rotates during regular operation, in particular to support a cutting movement. This advantageously enables rapid opening of the cutting device. In particular, this allows advantageously intuitive operation. It allows reliable opening of the coupling unit.

[0025] Alternatively, it is proposed that when the cutting device reaches its end position, the drive unit is automatically deactivated, and the coupling unit is automatically disengaged when the drive unit ceases to rotate. This advantageously enables rapid opening of the cutting device. In particular, this advantageously allows for intuitive operation.

[0026] The cutting device according to the invention and the method are not intended to be limited to the application and embodiment described above. In particular, the cutting device according to the invention and the method may have a number of individual elements, components, and units that differs from the number stated herein to fulfill a function described herein. drawing

[0027] Further advantages will become apparent from the following description of the drawings. The drawings illustrate four exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0028] They show: Fig. 1 shows a cutting device according to the invention with two cutting elements, two handle elements and a drive unit in a schematic partial sectional view, Fig. 2 shows the cutting device according to the invention and forces acting during operation in a schematic view, Fig. 3 shows a partial section III of the cutting device according to the invention with a clutch and a gear unit in a schematic sectional view, Fig. 4 shows the clutch unit, a cable winch and a spring element of a cutting device according to the invention in a schematic view, Fig. 5 shows the clutch unit of the cutting device in a coupled state in a schematic view, Fig. 6 shows the clutch unit of the cutting device in a disengaged state in a schematic view, Fig. 7 shows a flow chart of a method for operating the cutting device according to the invention, Fig.8 shows an alternative cutting device according to the invention with two cutting elements, two handle elements and a drive unit in a schematic partial sectional view, Fig. 9 shows a partial section of the alternative cutting device according to the invention in a schematic sectional view in section IX-IX, Fig. 10 shows a partial section of the alternative cutting device according to the invention in a schematic sectional view in section XX, Fig. 11 shows a partial section of the alternative cutting device according to the invention in a schematic sectional view in section XI-XI, Fig. 12 shows a partial section of the alternative cutting device according to the invention in a schematic sectional view in section XII-XII, Fig. 13 shows a further alternative cutting device according to the invention with two cutting elements, two handle elements and a drive unit in a schematic partial sectional view, Fig.14 shows a schematic representation of the drive unit and a gear unit of the further alternative cutting device according to the invention, Fig. 15 shows a partial section of the alternative cutting device according to the invention with a coupling unit, Fig. 16 shows a partial section XVI of the alternative cutting device according to the invention with a coupling unit, Fig. 17 shows a schematic partial sectional representation of a further alternative cutting device according to the invention with two cutting elements, two handle elements and a drive unit, and Fig. 18 shows a schematic exploded representation of the further alternative cutting device according to the invention. Description of the embodiments

[0029] Figure 1shows a cutting device 10a according to the invention. The cutting device 10a is designed as a garden cutting device. The cutting device 10a is designed as a pair of garden shears. In principle, however, another design of the cutting device 10a that would appear appropriate to a person skilled in the art would also be conceivable. The cutting device 10a has two cutting elements 12a, 14a that can be moved relative to one another. The cutting elements 12a, 14a can be pivoted relative to one another. A first cutting element 12a is designed as a passive cutting edge with a cutting edge. The second cutting element 14a is designed as an active cutting edge with a blade edge. Furthermore, the cutting device 10a has two handle elements 16a, 18a that can be moved relative to one another. The handle elements 16a, 18a can be pivoted relative to one another. The handle elements 16a, 18a are designed to be pivoted relative to one another via a pivot joint 42a.The cutting elements 12a, 14a are also designed to be pivotable relative to one another via the pivot joint 42a. The pivot joint 42a is arranged between the handle elements 16a, 18a and the cutting elements 12a, 14a. A first handle element 16a and the first cutting element 12a are firmly connected to one another and arranged on different sides of the pivot joint 42a. Furthermore, the second handle element 18a and the second cutting element 14a are firmly connected to one another and arranged on different sides of the pivot joint 42a. The handle elements 16a, 18a are intended to be grasped by an operator. The handle elements 16a, 18a are intended to be grasped by an operator with the same hand. In principle, however, it would also be conceivable for the cutting device 10a to be designed for two-handed operation. Furthermore, an opening spring 50a is arranged in the pivot joint 42a. The opening spring 50a is arranged between the handle elements 16a, 18a.The opening spring 50a is designed as a helical spring. The opening spring 50a is intended to push the handle elements 16a, 18a apart when the handle elements 16a, 18a are not under load, thereby opening the cutting device 10a.

[0030] The cutting device 10a further comprises a drive unit 20a. The drive unit 20a is configured as an electric motor. The drive unit 20a is configured as a 3.6 V electric motor. The drive unit 20a is arranged in the first handle element 16a. The drive unit 20a is arranged in a handle housing 44a of the handle element 16a. The handle housing 44a comprises two housing shells in which the drive unit 20a is firmly received.

[0031] The drive unit 20a is provided in an operating state to support a movement of the second cutting element 14a relative to the first cutting element 12a. The drive unit 20a is provided to support a closing movement of the cutting device 10a, executed via the handle elements 16a, 18a, during heavy cutting work. This can reduce the force required by an operator ( Figure 2 ).

[0032] Furthermore, the cutting device 10a has a gear unit 38a. The gear unit 38a is designed as a gear transmission. The gear unit 38a has a gear ratio of 130:1. In principle, however, another gear ratio that would appear appropriate to a person skilled in the art would also be conceivable. The gear unit 38a is arranged in the first handle element 16a. The gear unit 38a is arranged in the handle housing 44a of the handle element 16a. The gear unit 38a has several rigid axles that are fixedly arranged in the handle housing 44a. Gears are mounted on the axles of the gear unit 38a via a sliding fit. For the sake of clarity, the toothing of the individual gears is not shown. The gear unit 38a can be driven directly by the drive unit 20a. Power is transmitted from the drive unit 20a to the gear unit 38a via a pinion ( Figure 3 ).

[0033] The cutting device 10a further comprises a self-switching clutch unit 22a. The self-switching clutch unit 22a is designed as a freewheel clutch. The clutch unit 22a is arranged in the first handle element 16a. The clutch unit 22a is arranged in the handle housing 44a of the handle element 16a. Furthermore, the clutch unit 22a is arranged at an end of the first handle element 16a facing away from the cutting elements 12a, 14a. The self-switching clutch unit 22a is provided for decoupling the drive unit 20a in at least one operating state in which the drive unit 20a is deactivated. The self-switching clutch unit 22a is provided for decoupling the drive unit 20a to realize fully manual operation. The clutch unit 22a has an inner rotating element 46a and an outer rotating element 48a. Furthermore, the coupling unit 22a has several clamping bodies 24a.The clamping bodies 24a are arranged between the inner rotating element 46a and the outer rotating element 48a. The clamping bodies 24a are arranged one behind the other in the circumferential direction around the inner rotating element 46a. The clamping bodies 24a are designed as a ball. In principle, however, another design of the clamping bodies 24a that would appear sensible to a person skilled in the art would also be conceivable. The inner rotating element 46a has a plurality of ramps 49a arranged one after the other in the circumferential direction. A number of ramps 49a corresponds to a number of clamping bodies 24a. The clamping bodies 24a are movably arranged between the ramps 49a, whereby a rotation of the inner rotating element 46a causes the clamping bodies 24a to be driven. If the inner rotating element 46a is driven in the circumferential direction against a ramp incline, the clamping bodies 24a roll up the ramps 49a and are pressed against the outer rotating element 48a. The outer rotary element 48a is rotated.The coupling unit 22a is closed in this state, as shown in the . Figure 5 is shown. If, however, the outer rotary element 48a is driven, regardless of the direction of rotation, the clamping bodies 24a remain in a valley of the ramps 49a and are spaced from the outer rotary element 48a. There is no rotational drive. The coupling unit 22a is open in this state, as shown in the Figure 6is shown. The inner rotating element 46a of the clutch unit 22a is designed to be drivable by the drive unit 20a. A gear of the gear unit 38a is pressed onto the inner rotating element 46a of the clutch unit 22a. The inner rotating element 46a is driven by the drive unit 20a via the gear unit 38a. The gear unit 38a and the drive unit 20a form a drive side of the clutch unit 22a. The drive unit 20a and the gear unit 38a are spatially arranged between the cutting elements 12a, 14a and the self-engaging clutch unit 22a.

[0034] The self-engaging clutch unit 22a has a cage 26a that accommodates the clamping bodies 24a. The cage 26a accommodates the clamping bodies 24a in separate receiving areas. The cage 26a serves to position and guide the clamping bodies 24a in the circumferential direction. The cage 26a is provided to space the clamping bodies 24a apart from one another in the circumferential direction and to distribute them evenly. The cage 26a is partially annular. The cage 26a is mounted on the inner rotating element 46a of the clutch unit 22a. Furthermore, the clutch unit 22a has a braking element 28a, which is provided for braking the cage 26a. The braking element 28a is provided to increase the inertia of the cage 26a. The braking element 28a is provided to prevent unintentional twisting of the cage 26a. The braking element 28a is intended to prevent rotation of the cage 26a up to a defined force.The braking element 28a is designed as a spring element. During operation, the braking element 28a engages in recesses on an outer side of the cage 26a. For this purpose, the cage 26a has a plurality of recesses arranged successively in the circumferential direction on an outer side. The braking element 28a is fastened in the handle housing 44a of the handle element 16a and presses against the cage 26a with a defined force. The braking element 28a is fastened with its two ends in the handle housing 44a of the handle element 16a, with a free center of the braking element 28a pressing against the cage 26a (. Figure 3 , 4 ).

[0035] The cutting device 10a further comprises a cable winch 32a that can be driven by the drive unit 20a. The cable winch 32a is designed as a partially hollow-cylindrical cable drum. The cable winch 32a is arranged in the first handle element 16a. The cable winch 32a is arranged in the handle housing 44a of the handle element 16a. The cable winch 32a is arranged on a side of the coupling unit 22a facing away from the cutting elements 12a, 14a. The self-engaging coupling unit 22a is partially integrated into the cable winch 32a. The coupling unit 22a is partially encompassed by the cable winch 32a. The cable winch 32a is formed integrally with the outer rotating element 48a of the coupling unit 22a. The cable winch 32a forms the outer rotating element 48a of the coupling unit 22a. Furthermore, the cable winch 32a forms an output side of the coupling unit 22a. The cutting device 10a also has a cable 34a wound on the cable winch 32a.The cable 34a is stretched between the two handle elements 16a, 18a. The cable 34a is firmly connected to the handle element 18a at an end of the second handle element 18a facing away from the cutting elements 12a, 14a. On the first handle element 16a, the cable 34a is variably wound onto the cable winch 32a, with one end of the cable 34a also being firmly connected to the cable winch 32a. The free length of the cable 34a can be varied via the cable winch 32a (Fig. Figure 3 , 4 ).

[0036] Furthermore, the cutting device 10a has a spring element 36a connected to the cable winch 32a. The spring element 36a is designed as a spiral spring. The spring element 36a is arranged in the first handle element 16a. The spring element 36a is arranged in the handle housing 44a of the handle element 16a. The spring element 36a is arranged on a side of the cable winch 32a facing away from the cutting elements 12a, 14a. One end of the spring element 36a is fixedly connected to the handle housing 44a of the handle element 16a, and one end is fixedly connected to the cable winch 32a. The spring element 36a is provided to tension the cable 34a. The spring element 36a is provided to ensure tension in the cable 34a. For this purpose, the spring element 36a is designed to apply a circumferential force to the cable winch 32a. The spring element 36a is designed to exert a tensile force on the cable 34a via the cable winch 32a.In particular, the spring element 36a is intended to keep the cable 34a under tension. The spring element 36a has a spring force F VS that is lower than the spring force F OS of the opening spring 50a (. Figure 2 , 4 ).

[0037] The cutting device 10a further comprises a control unit 52a. The control unit 52a is arranged in the first handle element 16a. The control unit 52a is arranged in the handle housing 44a of the handle element 16a. The control unit 52a is provided for controlling the drive unit 20a. In principle, both pure control of the drive unit 20a and regulation of the drive unit 20a can be carried out. For this purpose, the control unit 52a supplies the drive unit 20a with energy. The control unit 52a is arranged between the drive unit 20a and the pivot joint 42a. The control unit 52a is connected to an energy storage unit 54a. The drive unit 20a can be supplied with energy by the control unit 52a via the energy storage unit 54a. The energy storage unit 54a has two battery cells 56a, 58a. The battery cells 56a, 58a are each made of lithium-ion cells.In principle, however, another design of the battery cells 56a, 58a that would appear sensible to a person skilled in the art would also be conceivable. The first battery cell 56a is arranged in the first handle element 16a. The first battery cell 56a is arranged in the handle housing 44a of the handle element 16a. The first battery cell 56a is arranged directly next to the control unit 52a. The second battery cell 58a is arranged in the second handle element 18a. The second battery cell 58a is arranged in a handle housing 60a of the second handle element 18a. The battery cells 56a, 58a are each connected to the control unit 52a (. Figure 1 , 2 ).

[0038] The cutting device 10a further comprises a force sensor 40a. The force sensor 40a is integrated into the second handle element 18a of the handle elements 16a, 18a. The force sensor 40a is arranged in the handle housing 60a of the second handle element 18a. Furthermore, the force sensor 40a is coupled to a handle region 62a of the second handle element 18a. The handle region 62a forms a support surface 64a on the second handle element 18a for a hand, in particular the fingers, of the operator. The handle region 62a is pivotable relative to the handle housing 60a to a limited extent about an axis 66a. The handle region 62a is supported at a free end against the handle housing 60a by means of a spring 68a. The spring 68a forms part of the force sensor 40a. When the cutting device 10a is closed, the handle area 62a is pivoted with the free end against the handle housing 60a against a spring force of the spring 68a.The force sensor 40a is arranged between the handle housing 60a and the handle region 62a. The force sensor 40a detects a force acting between the handle housing 60a and the handle region 62a. Thus, the force sensor 40a can advantageously sense a force acting on the second handle element 18a relative to the first handle element 16a. The force sensor 40a has the spring 68a and a switch 72a. The switch 72a consists of two contact elements, with a first contact element arranged at the free end of the handle region 62a and the second contact element arranged opposite the first contact element on the handle housing 60a. The switch 72a closes with its free end against the handle housing 60a when the handle region 62a approaches the handle housing 60a at a defined distance. In principle, however, it would also be conceivable for the switch 72a to be designed as a pressure switch that triggers upon contact. This would eliminate the need for a second contact element.In conjunction with a defined spring force of the spring 68a, a force can be defined at which the switch 72a of the force sensor 40a closes. This makes it possible to provide a particularly cost-effective and structurally simple force sensor 40a. In principle, an alternative design of the force sensor 40a that would appear sensible to a person skilled in the art would also be conceivable. For example, it would be conceivable for the force sensor 40a to have a piezo crystal arranged between the handle area 62a and the handle housing 60a. This would allow a currently applied force to be explicitly detected. This would allow a triggering force of the force sensor 40a to be freely defined by software (. Figure 2 ).

[0039] The force sensor 40a is connected to the control unit 52a. The control unit 52a is designed to control the drive unit 20a depending on a signal from the force sensor 40a. The control unit 52a is designed to activate the drive unit 20a when a defined measured value of the force sensor 40a is overwritten. The control unit 52a is designed to activate the drive unit 20a when the switch 72a of the force sensor 40a is closed. Furthermore, the control unit 52a is designed to stop the drive unit 20a when the switch 72a of the force sensor 40a is opened.

[0040] Furthermore, the cutting device 10a has a displacement sensor 70a. The displacement sensor 70a is designed as a Hall sensor. In principle, however, another design of the displacement sensor 70a that would appear appropriate to a person skilled in the art would also be conceivable. The displacement sensor 70a is arranged in the pivot joint 42a of the cutting device 10a. The displacement sensor 70a is intended to detect an angular position of the handle elements 16a, 18a relative to one another. For this purpose, the displacement sensor 70a has two magnets connected to the second handle element 18a, which are connected to the second handle element 18a in the pivot joint 42a. The displacement sensor 70a also has a sensor element. The sensor element is connected to the first handle element 16a in the pivot joint 42a. If the sensor element is located directly above the first magnet, the cutting device 10a is fully open. If the sensor element is located above the second magnet, the cutting device 10a is completely closed.In this position, the cutting device 10a is in an end position (. Figure 2 ).

[0041] The displacement sensor 70a is connected to the control unit 52a. The control unit 52a is designed to deactivate the drive unit 20a using a measured value from the displacement sensor 70a when the handle elements 16a, 18a reach an end position relative to one another or when the cutting device 10a is fully closed.

[0042] During operation of the cutting device 10a, a distinction can be made between a manual mode of the cutting device 10a, in which a complete cutting force F cut is applied by an operator, and an assisted mode, in which a part of the cutting force F cut is also applied by the drive unit 20a.

[0043] A method for operating the cutting device 10a is described below.

[0044] The cutting device 10a is constantly in an operating mode. In principle, however, it would also be conceivable for the cutting device 10a to have an operating switch by means of which the cutting device 10a can be activated and deactivated. Alternatively, it would also be conceivable for the cutting device 10a to be activated, for example, by a defined closing and / or opening sequence of the cutting device 10a itself. Deactivation could be conceivable, for example, on a time-dependent basis.

[0045] If an operator wishes to perform a cutting operation during operation, for example, on a branch, they must position the object to be cut between the cutting elements 12a, 14a of the cutting device 10a. The cutting elements 12a, 14a can then be closed by pressing the handle elements 16a, 18a together relative to one another, particularly as with conventional garden shears. The handle elements 16a, 18a are manually pressed together by an operator in a step 118a. Subsequently, in a further step 120a, the control unit 52a monitors a signal from the force sensor 40a. The control unit 52a monitors the force required for a cutting operation. The control unit 52a checks whether the switch 72a of the force sensor 40a is open or closed.

[0046] If the force required by an operator for the cutting process F user is less than the force defined by the force sensor 40a, which is required to close the switch 72a, the cutting device 10a is used in manual mode. If the switch 72a is open, step 120a is repeated in the following branch 122a. In manual mode, the handle elements 16a, 18a are manually pivoted against each other by an operator. In manual mode, the cable 34a is wound onto the cable winch 32a by means of the spring element 36a. Since a force acts on the coupling unit 22a from an output side, the coupling unit 22a is in an open state. The cable winch 32a can therefore be rotated without resistance from the gear unit 38a and the drive unit 20a. In this state, the rope 34a is kept under tension by the spring element 36a.If an operator reduces the force applied to the gripping elements 16a, 18a, for example, because a cutting operation has been completed, the gripping elements 16a, 18a are pushed apart by the opening spring 50a, and the cutting device 10a is opened. The cable 34a is unwound from the cable winch 32a against the spring force of the spring element 36a.

[0047] If an energy storage unit 54a of the cutting device 10a is empty, the cutting device 10a can be used in manual mode, whereby the drive unit 20a remains deactivated even if a force defined by the force sensor 40a is exceeded. The drive unit 20a is not activated, which also keeps the clutch unit 22a open.

[0048] If the force required by an operator for the cutting process F user is greater than the force defined by the force sensor 40a required to close the switch 72a, the cutting device 10a is used in an assisted mode. A change from a manual mode to an assisted mode generally occurs during a cutting process. In the manual mode, the handle elements 16a, 18a are manually pivoted against one another by an operator. If a hard object is being cut, the handle elements 16a, 18a must be pressed against one another with great force by an operator. If such a high force is applied that the switch 72a closes against a spring force F gs, this is sensed by the control unit 52a. The control unit 52a then activates the drive unit 20a.If it is determined in branch 122a that switch 72a is closed, drive unit 20a is activated via control unit 52a in a step 124a. Accordingly, drive unit 20a is connected to a closing mechanism of cutting device 10a when a defined operator force is exceeded. Drive unit 20a then drives inner rotating element 46a of coupling unit 22a via gear unit 38a. Drive unit 20a is driven in drive direction 41a. Coupling unit 22a is closed and drives cable winch 32a. Cable 34a is wound onto cable winch 32a. Grip elements 16a, 18a are now compressed or contracted by a drive force Fas in addition to an operator force Fuser. In this operating state, the drive unit 20a applies an additional force to the cutting elements 12a, 14a during a partially manual movement.The drive force Fas acts on the cable 34a via the cable winch 32a. Subsequently, in a further step 126a, a signal from the displacement sensor 70a is checked via the control unit 52a. The relative position of the handle elements 16a, 18a to one another is checked via the displacement sensor 70a. If it is determined in a branch 128a that a current position deviates from an end position, a further step 130a checks whether the switch 72a of the force sensor 40a is open or closed. If the switch 72a is closed, step 126a is repeated via a branch 132a. If the switch 72a is open, the drive unit 20a is automatically stopped in a step 134a via a branch 132a. The drive unit 20a is stopped when the switch 72a of the force sensor 40a opens.If the force sensor 40a detects that an operator's force is being reduced by opening the switch 72a, the drive unit 20a is stopped by the control unit 52a. If it is determined in a branch 128a that a current position of the cutting device 10a corresponds to an end position, the drive unit 20a is automatically stopped in step 134a. If the position sensor 70a detects that the cutting device 10a is in an end position or in a closed state, the drive unit 20a is stopped by the control unit 52a. After the drive unit 20a has been stopped, the drive unit 20a is briefly driven counter to a drive direction 41a in a further step 136a to open the coupling unit 22a. The drive unit 20a is driven by the control unit 52a only over a small angular range counter to a drive direction 41a and is then deactivated.After deactivation of the drive unit 20a, the process is started again from the beginning (. Figure 7 ).

[0049] In principle, however, it would also be conceivable for the coupling unit 22a to be automatically decoupled if the drive unit 20a ceases to rotate. In particular, it would be conceivable for the cutting device 10a, when the drive unit 20a stops rotating, to be at least partially opened by the opening spring 50a, and for the cable winch 32a to be partially rotated via the cable 34a counter to a drive direction 41a of the drive unit 20a. This would result in the outer rotating element 48a rotating toward an inner rotating element 46a of the coupling unit 22a, and the coupling unit 22a would be opened. In principle, however, another method for opening the coupling unit 22a that would appear appropriate to a person skilled in the art would also be conceivable.

[0050] In the Figures 8 to 17Three further embodiments of the invention are shown. The following descriptions and the drawings are essentially limited to the differences between the embodiments, whereby with regard to components with the same designation, in particular with regard to components with the same reference numerals, reference is also made to the drawings and / or the description of the other embodiments, in particular to the Figures 1 to 7 To distinguish the embodiments, the letter a is added to the reference numerals of the embodiment in the Figures 1 to 6 In the examples of the Figures 8 to 17 the letter a is replaced by the letters b to d.

[0051] Figure 8shows an alternative cutting device 10b according to the invention. The cutting device 10b is designed as a garden cutting device. The cutting device 10b is designed as a pair of garden shears. The cutting device 10b has two cutting elements 12b, 14b that are movable relative to one another. Furthermore, the cutting device 10b has two handle elements 16b, 18b that are movable relative to one another. The handle elements 16b, 18b are pivotable relative to one another via a pivot joint 42b. Furthermore, an opening spring 50b is arranged near the pivot joint 42b.

[0052] The cutting device 10b further comprises a drive unit 20b. The drive unit 20b is arranged in the first handle element 16b. The drive unit 20b is arranged in a handle housing 44b of the handle element 16b. The drive unit 20b is arranged at an end of the first handle element 16b facing away from the cutting elements 12b, 14b.

[0053] Furthermore, the cutting device 10b has a gear unit 38b. The gear unit 38b is arranged in the first handle element 16b. The gear unit 38b is arranged in the handle housing 44b of the handle element 16b. The gear unit 38b is arranged on a side of the drive unit 20b facing the cutting elements 12b, 14b. The gear unit 38b can be driven directly by the drive unit 20b. The gear unit 38b is driven directly by a pinion of the drive unit 20b. The gear unit 38b has two planetary gears 74b, 76b. A first planetary gear 74b directly follows the drive unit 20b. A self-shifting clutch unit 22b is arranged between the first planetary gear 74b and the second planetary gear 76b. The transmission unit 38b accordingly has at least two transmission stages, between which the self-shifting clutch unit 22b is arranged.The transmission unit 38b has four gear stages, with three gear stages being arranged upstream of the clutch unit 22b, viewed along a drive flow, and one gear stage being arranged downstream of the clutch unit 22b. The clutch unit 22b is arranged spatially and along a drive flow between the planetary gears 74b, 76b of the transmission unit 38b (. Figure 8 ).

[0054] The cutting device 10b has the self-engaging clutch unit 22b. The self-engaging clutch unit 22b is designed as a freewheel clutch. The clutch unit 22b is arranged in the first handle element 16b. The clutch unit 22b is arranged in the handle housing 44b of the handle element 16b. The clutch unit 22b has an outer rotating element 46b and an inner rotating element 48b. Furthermore, the clutch unit 22b has a plurality of clamping bodies 24b. The clamping bodies 24b are arranged between the outer rotating element 46b and the inner rotating element 48b. The clamping bodies 24b are arranged one behind the other in the circumferential direction around the inner rotating element 48b. The clamping bodies 24b are designed as cylinders. In principle, however, another design of the clamping bodies 24b that would appear appropriate to a person skilled in the art would also be conceivable. The outer rotary element 46b has on its inner side a plurality of ramps 49b arranged successively in the circumferential direction.A number of ramps 49b corresponds to a number of clamping bodies 24b. The clamping bodies 24b are movably arranged between the ramps 49b, whereby upon rotation of the outer rotary element 46b, the clamping bodies 24b are driven. If the outer rotary element 46b is driven in the circumferential direction against a ramp gradient - in the drive direction 41b - the clamping bodies 24b roll into a narrower area between the outer rotary element 46b and the inner rotary element 48b and are pressed against the inner rotary element 48b. This results in rotational drive of the inner rotary element 48b. The coupling unit 22b is closed in this state. If, on the other hand, the inner rotary element 48b is driven, regardless of the direction of rotation, the clamping bodies 24b remain in a valley of the ramps 49b and are freely arranged between the rotary elements 46b, 48b. No rotational drive occurs. The coupling unit 22b is open in this state, as shown in the . Figure 10is shown. If the outer rotating element 46b is driven counter to a drive direction 41b, the clamping bodies 24b are moved into the valley of the ramps 49b and are also freely arranged between the rotating elements 46b, 48b. The outer rotating element 46b of the clutch unit 22b is designed to be drivable by the drive unit 20b. The outer rotating element 46b of the clutch unit 22b forms a planet carrier of the first planetary gear 74b. The outer rotating element 46b is driven by the drive unit 20b via the first planetary gear 74b. The first planetary gear 74b and the drive unit 20b form a drive side of the clutch unit 22b. The inner rotating element 48b of the clutch unit 22b forms a sun gear of the second planetary gear 76b. The second planetary gear 76b forms an output side of the clutch unit 22b.

[0055] The self-shifting clutch unit 22b has a cage 26b that accommodates the clamping bodies 24b. The cage 26b is partially disc-shaped. Several axially projecting, circular-segment-shaped webs are mounted on a disc-shaped base body of the cage 26b, which extend between the clamping bodies 24b. The cage 26b is mounted on the inner rotating element 48b of the clutch unit 22b.

[0056] Furthermore, the coupling unit 22b has a braking element 28b, which is provided for braking the cage 26b. The braking element 28b is designed as a spring element. The braking element 28b is designed as a spiral spring. The braking element 28b is arranged with one end fixedly in a recess on an outer side of the cage 26b. The braking element 28b extends spirally around the cage 26b in the circumferential direction. A free end is supported on a housing 75b of the coupling unit 22b, wherein the free end is pressed against the housing 75b by means of a spring force and generates a braking effect ( Figure 12 ).

[0057] The cutting device 10b further comprises a cable winch 32b that can be driven by the drive unit 20b. The cable winch 32b is designed as a cable drum. The cable winch 32b is arranged in the first handle element 16b. The cable winch 32b is arranged in the handle housing 44b of the handle element 16b. The cable winch 32b is mounted on both sides via a ball bearing 77a, 77a' in the handle housing 44b of the handle element 16b. The cable winch 32b is arranged on a side of the second planetary gear 76b facing the cutting elements 12b, 14b. The cable winch 32b forms an output side of the clutch unit 22b, with the second planetary gear 76b effecting a transmission between the cable winch 32b and the clutch unit 22b. The second planetary gear 76b allows the torque acting on the clutch unit 22b to be kept low. The cutting device 10b also has a cable 34b wound on the cable winch 32b.The cable 34b is also mounted in a guide sleeve 78b in the first handle element 16b. The cable 34b is stretched between the two handle elements 16b, 18b. The cable 34b is firmly connected to the second handle element 18a in an area between the pivot joint 42b and an end of the second handle element 18a facing away from the cutting elements 12b, 14b. The cable 34a is variably wound on the cable winch 32a on the first handle element 16a. The cable 34b is stretched between the handle elements 16b, 18b in an area between a gripping area of ​​the handle elements 16b, 18b and the pivot joint 42b. This advantageously prevents an operator from being disturbed by the cable 34b. Figure 8 , 9 ).

[0058] Furthermore, the cutting device 10b has a spring element 36b connected to the cable winch 32b. The spring element 36b is designed as a spiral spring. The spring element 36b is arranged in the first handle element 16b. The spring element 36b is arranged in the handle housing 44b of the first handle element 16b. The spring element 36b is arranged around a planet carrier of the second planetary gear 76b. One end of the spring element 36b is fixedly connected to a housing 79b of the second planetary gear 76b, and one end is fixedly connected to the planet carrier of the second planetary gear 76b. The housing 79b of the second planetary gear 76b forms a ring gear of the planetary gear 76b. A shaft of the cable winch 32b is connected in a rotationally fixed manner to the planet carrier of the second planetary gear 76b. The spring element 36b is provided to tension the cable 34b ( Figure 9 , 11 ).

[0059] The cutting device 10b further includes a control unit 52b. The control unit 52b is connected to an energy storage unit 54b. The energy storage unit 54a includes a battery cell 56b. The battery cell 56b is located in the first handle element 16b. The battery cell 56b is located in the handle housing 44b of the handle element 16b. The battery cell 56b is located on a side of the gear unit 38b facing the second handle element 18b.

[0060] The cutting device 10a further comprises a force sensor 40b. The force sensor 40b is integrated into the second handle element 18b of the handle elements 16b, 18b. The force sensor 40b is arranged in a first lever 80b of the second handle element 18b, which is fixedly formed with the pivot joint 42b. Furthermore, the force sensor 40b is coupled to a handle region 62b of the second handle element 18b. The handle region 62b forms a support surface 64b on the second handle element 18b for a hand, in particular the fingers, of the operator. The handle region 62b is pivotable relative to the lever 80b to a limited extent about an axis 66b. The handle region 62b is supported at a free end of the lever 80b against the lever 80b by means of a spring 68b. The spring 68b forms part of the force sensor 40b. When the cutting device 10b is closed, the handle area 62b is pivoted against the lever 80b against a spring force of the spring 68b.The force sensor 40b is arranged between the lever 80b and the gripping area 62b. The force sensor 40a has the spring 68b and a switch 72b. The switch 72b has a pressure element 81b that protrudes from the lever 80b. Opposite the pressure element 81b of the switch 72b on the gripping area 62b is a pressure surface that is provided for actuating the pressure element 81b. The switch 72b closes when the pressure element 81b is pressed in a defined manner by the pressure surface. It would also be conceivable in principle for the force sensor 40b to differentiate between different degrees of pressing in the pressure element 81b in order to be able to infer the exact currently applied force. The force sensor 40b is connected to the control unit 52b.

[0061] Furthermore, the cutting device 10b has a position sensor (not shown). The position sensor is connected to the control unit 52b.

[0062] Figure 13shows a further alternative cutting device 10c according to the invention. The cutting device 10c is designed as a garden cutting device. The cutting device 10c is designed as a pair of garden shears. The cutting device 10c has two cutting elements 12c, 14c that can be moved relative to one another. Furthermore, the cutting device 10c has two handle elements 16c, 18c that can be moved relative to one another. The handle elements 16c, 18c are designed to be pivotable relative to one another via a pivot joint 42c. The cutting elements 12c, 14c are also designed to be pivotable relative to one another via the pivot joint 42c. The pivot joint 42c is arranged between the handle elements 16c, 18c and the cutting elements 12c, 14c. Furthermore, an opening spring (not visible) is arranged in the pivot joint 42c.

[0063] The second handle element 18c is formed in two parts. The second handle element 18c has a base body 100c and a gripping area 62c. The gripping area 62c forms a support surface 64c on the second handle element 18c for a hand, in particular the fingers, of the operator. The gripping area 62c can be pivoted relative to the base body 100c to a limited extent about an axis 66c. The base body 100c is fixedly connected to the second cutting element 14c. The opening spring (not visible further) engages the gripping area 62c of the second handle element 18c.

[0064] The cutting device 10c further comprises a drive unit 20c. The drive unit 20c is arranged in the first handle element 16c. The drive unit 20c is arranged in a handle housing 44c of the handle element 16c. The drive unit 20c is arranged at an end of the first handle element 16c facing away from the cutting elements 12c, 14c.

[0065] Furthermore, the cutting device 10c has a gear unit 38c. The gear unit 38c is arranged in the first handle element 16c. The gear unit 38c is arranged in the handle housing 44c of the handle element 16c. The gear unit 38c is arranged on a side of the drive unit 20c facing the cutting elements 12c, 14c. The gear unit 38c can be driven directly by a pinion 82c of the drive unit 20c. The pinion 82c of the drive unit 20c meshes with a gear 86c pressed onto a spindle 84c. The spindle 84c meshes with another gear 88c, which has a rotational axis running perpendicular to the spindle 84c. The another gear 88c meshes with a ratchet wheel 90c of a self-engaging clutch unit 22c. The ratchet wheel 90c is driven by the drive unit 20c via the gear unit 38c. The ratchet wheel 90c is arranged in the pivot joint 42c. The ratchet wheel 90c is rotatably mounted relative to the handle elements 16c, 18c ( Figure 14 ,15 ).

[0066] The cutting device 10c has the self-switching clutch unit 22c. The self-switching clutch unit 22c is designed as a freewheel clutch. The clutch unit 22c is arranged in the pivot joint 42c. The self-switching clutch unit 22c is provided for decoupling the drive unit 20c in at least one operating state in which the drive unit 20c is deactivated. The self-switching clutch unit 22c is provided for decoupling the drive unit 20c to realize completely manual operation. The self-switching clutch unit 22c has a pawl element 30c. The pawl element 30c is designed to be actuated by the second handle element 18c. The pawl element 30c has two articulated arms 92c, 94c. A first arm 92c is rotatably connected to the second handle element 18c with an end facing away from the second arm 94c.The first arm 94c is rotatably connected to the base body 100c of the second handle element 18c. The second arm 94c is spring-loaded by a spring 96c. The spring 96c presses the second arm 94c against the ratchet wheel 90c. Furthermore, the second arm 94c is connected to the handle portion 62c of the second handle element 18c via a lever element 98c. The second arm 94c of the pawl element 30c can be pulled out of engagement with the ratchet wheel 90c via the lever element 98c against the spring 96c. This occurs in particular when the handle portion 62c is only acted upon by the opening spring (not visible). This ensures that the coupling unit 22c opens even when no operator pressure is applied to the handle portion 62c. If, however, an operator exerts pressure against the grip area 62c, the second arm 94c is pressed against the ratchet wheel 90c via the spring 96c.If the ratchet wheel 90c is driven by the drive unit 20c in the drive direction 41c, the ratchet wheel 90c tilts against the pawl element 30c and exerts a torque against the base body 100c of the second handle element 18c via the pawl element 30c. A force is generated that assists in closing the cutting device 10c. The second handle element 18c can then be more easily rotated by an operator against the first handle element 16c. If, however, the cutting device 10c is closed manually, the pawl element 30c can slide over the ramps of the ratchet wheel 90c against the spring force of the spring 96c. The cutting device 10c can thus be closed without the assistance of the drive unit 20c.If the second handle element 18c is released by an operator, the pawl element 30c is pulled out of the locking wheel 90c via the lever element 98c and the cutting device 10c can open automatically by means of the opening spring (not visible). Figure 15 , 16 ).

[0067] Furthermore, the cutting device 10c has a control unit (not further visible). The cutting device 10c further has a force sensor 40c. The force sensor 40c is integrated into the second handle element 18c of the handle elements 16c, 18c. The force sensor 40c is arranged in the base body 100c of the second handle element 18c. Furthermore, the force sensor 40c is coupled to a handle region 62c of the second handle element 18c. The force sensor 40c is arranged between the base body 100c and the handle region 62c. The handle region 62c is supported at a free end of the base body 100c against the base body 100c by means of a spring. The spring forms part of the force sensor 40c. When the cutting device 10c is closed, the handle region 62c is pivoted against the base body 100c against a spring force of the spring. The force sensor 40c has the spring and a switch.The switch closes when the gripping area 62c approaches the base body 100c at a defined distance. The force sensor 40c is connected to the control unit 52c. In principle, an alternative design of the force sensor 40c that would be considered appropriate by a person skilled in the art would also be conceivable. For example, it would be conceivable for the force sensor 40c to have a piezoelectric crystal arranged between the gripping area 62c and the base body 100c (Fig. Figure 13 , 15 ).

[0068] Furthermore, the cutting device 10c has a position sensor (not shown). The position sensor is connected to the control unit 52c.

[0069] Figure 17shows a further alternative cutting device 10d according to the invention. The cutting device 10d is designed as a garden cutting device. The cutting device 10d is designed as a pair of garden shears. The cutting device 10d has two cutting elements 12d, 14d that are movable relative to one another. Furthermore, the cutting device 10d has two handle elements 16d, 18d that are movable relative to one another. The handle elements 16d, 18d are designed to be pivotable relative to one another via a pivot joint 42d. The cutting elements 12d, 14d are also designed to be pivotable relative to one another via the pivot joint 42d. The pivot joint 42d is arranged between the handle elements 16d, 18d and the cutting elements 12d, 14d. Furthermore, an opening spring (not visible) is arranged in the pivot joint 42d.

[0070] The second handle element 18d is constructed in two parts. The second handle element 18d has a handle housing 60d and a handle portion 62d. The handle portion 62d forms a support surface 64d on the second handle element 18d for a hand, in particular the fingers, of the operator. The handle portion 62d is pivotable relative to the handle housing 60d about an axis 66d. The handle portion 62d is supported at a free end against the handle housing 60d by a spring 68d.

[0071] The cutting device 10d further comprises a drive unit 20d. The drive unit 20d is arranged in the first handle element 16d. The drive unit 20d is arranged in a handle housing 44d of the handle element 16d. The drive unit 20d is arranged at an end of the first handle element 16d facing away from the cutting elements 12d, 14d.

[0072] Furthermore, the cutting device 10d has a gear unit 38d. The gear unit 38d is arranged in the first handle element 16d. The gear unit 38d is arranged in the handle housing 44d of the handle element 16d. The gear unit 38d can be driven directly by a pinion 82d of the drive unit 20d. The pinion 82d is arranged on a side of the drive unit 20d facing away from the cutting elements 12d, 14d. The pinion 82d of the drive unit 20d meshes with a gear 104d pressed onto a shaft 102d. The shaft 102d is guided past the drive unit 20d in the direction of the pivot joint 42d. The shaft 102d meshes with a further gear 106d via a toothing provided on a side facing the gear 104d. The further gear 106d is rotationally fixedly connected to a spindle 108d, which meshes with a ring gear 110d of a self-shifting clutch unit 22d (not shown).The ring gear 110d is driven by the drive unit 20d via the gear unit 38d. The ring gear 110d is arranged in the pivot joint 42d. The ring gear 110d is rotatably mounted relative to the handle elements 16d, 18d (. Figure 14 , 15 ).

[0073] The cutting device 10d has the self-switching clutch unit 22d. The self-switching clutch unit 22d is designed as a freewheel clutch. The clutch unit 22d is arranged in the pivot joint 42d. The self-switching clutch unit 22d is provided for decoupling the drive unit 20d in at least one operating state in which the drive unit 20d is deactivated. The self-switching clutch unit 22d is provided for decoupling the drive unit 20d to implement fully manual operation. The self-switching clutch unit 22d has a driving element 112d. The driving element 112d is designed to be actuated by the second handle element 18d. The driving element 112d is designed to be actuated by the grip region 62d of the second handle element 18d. A ball 114d is arranged on the driving element 112d via a spring 113d.The driving element 112d is pressed toward the ball 114d by a further spring 115d. The driving element 112d and the ball 114d are mounted tangentially in the second handle element 18d along a main extension direction 117d of the second handle element 18d. The ball 114d rests against a guide surface 116d of the handle region 62d. The guide surface 116d, viewed along the main extension direction 117d of the second handle element 18d, has various planes arranged next to one another. The guide surface 116d has two planes with different heights relative to the main extension direction 117d. Depending on the position of the handle region 62d relative to the handle housing 60d of the second handle element 18d, the guide surface 116d is displaced relative to the ball 114d. The ball 114d rests at different points on the guide surface 116d depending on the position of the handle area 62d relative to the handle housing 60d.Depending on a contact point of the ball 114d on the guide surface 116d, a tangential displacement of the driving element 112d is caused by the different planes of the guide surface 116d.

[0074] If the handle area 62d is pressed with high force against the handle housing 60d against the spring force of the spring 68d, the driving element 112d is pressed tangentially in the direction of the pivot joint 42d via the link surface 116d. The driving element 112d is pressed against an internal toothing of the ring gear 110d. The driving element 112d also has a toothing in this contact area. In this state, the clutch unit 22d is closed. When the clutch unit 22d is closed, a torque can be exerted on the driving element 112d by the drive unit 20d via the ring gear 110d. A torque is transmitted from the driving element 112d to the second handle element 18d. When the ring gear 110d is driven in the drive direction 41d, a force is generated which assists in closing the cutting device 10d. The second handle element 18d can then advantageously be easily rotated by an operator against the first handle element 16d.

[0075] If the gripping area 62d is pushed away from the gripping housing 60d by the spring 68d, the driving element 112d is tangentially spaced from the internal toothing of the ring gear 110d via the cam surface 116d and the spring 115d. In this state, the clutch unit 22d is opened. If the cutting device 10d is closed with only slight force, or if the cutting device 10d is opened, the driving element 112d is disengaged from the ring gear 110d, and the gripping elements 16d, 18d can be rotated without resistance from the gear unit 38d and the drive unit 20d. In this state, manual operation takes place.

[0076] Furthermore, the cutting device 10d has a control unit (not further visible). The cutting device 10d further has a force sensor 40d. The force sensor 40d is integrated into the second handle element 18d of the handle elements 16d, 18d. The force sensor 40d is arranged in the handle housing 60d of the second handle element 18d. Furthermore, the force sensor 40d is coupled to a handle region 62d of the second handle element 18d. The force sensor 40d is arranged between the handle housing 60d and the handle region 62d. The handle region 62d is supported at a free end of the handle housing 60d against the handle housing 60d by means of the spring 68d. The spring 68d forms part of the force sensor 40d. When the cutting device 10d is closed, the handle portion 62d is pivoted against the handle housing 60d against the spring force of the spring 68d. The force sensor 40d comprises the spring 68d and a switch 72d.The switch 72d closes when the handle area 62d approaches the handle housing 60d at a defined distance. The force sensor 40d is inserted such that the switch 72d is closed when the ball 114d reaches a second plane of the guide surface 116d, so that the clutch unit 22d is closed simultaneously. The force sensor 40d is connected to the control unit 52d.

[0077] Furthermore, the cutting device 10d has a position sensor (not shown). The position sensor is connected to the control unit 52d.

Claims

1. Cutting device, in particular a garden cutting device, with at least two cutting elements (12a, 14a; 12b, 14b; 12c, 14c; 12d, 14d) which are movable relative to one another, with two grip elements (16a, 18a; 16b, 18b; 16c, 18c; 16d, 18d) which are movable relative to one another, and with at least one drive unit (20a; 20b; 20c; 20d) which is provided, in at least one operating state, to at least assist a movement of the second cutting element (14a; 14b; 14c; 14d) relative to the first cutting element (12a; 12b; 12c; 12d), characterized by at least one self-switching coupling unit (22a; 22b; 22c; 22d) which is provided for decoupling the drive unit (20a; 20b; 20c; 20d) from a closing mechanism of the cutting device in at least one operating state in which the drive unit (20a; 20b; 20c; 20d) is deactivated.

2. Cutting device according to Claim 1, characterized in that the at least one self-switching coupling unit (22a; 22b; 22c; 22d) is provided to decouple the drive unit (20a; 20b; 20c; 20d) in at least one operating state, in order to implement a fully manual operation.

3. Cutting device according to one of the preceding claims, characterized in that the at least one self-switching coupling unit (22a; 22b; 22c; 22d) is designed as an overrun coupling.

4. Cutting device according to Claim 3, characterized in that the at least one self-switching coupling unit (22a; 22b) has at least one clamping body (24a; 24b).

5. Cutting device according to Claim 4, characterized in that the at least one self-switching coupling unit (22a; 22b; 22c; 22d) has at least one cage (26a; 26b) receiving the clamping body (24a; 24b) and a braking element (28a; 28b) which is provided for braking the cage (26a; 26b) in at least one operating state.

6. Cutting device at least according to Claim 3, characterized in that the at least one self-switching coupling unit (22c; 22d) has at least one pawl element (30c; 30d) which is configured so as to be actuatable in particular by one of the grip elements (18a; 18b; 18c; 18d).

7. Cutting device according to one of the preceding claims, characterized by at least one cable winch (32a; 32b) which can be driven by the drive unit (20a; 20b), and at least one cable (34a; 34b) which is wound at least partially on the cable winch (32a; 32b) and is at least partially tensioned between the grip elements (16a, 18a; 16b, 18b).

8. Cutting device according to Claim 7, characterized in that the at least one self-switching coupling unit (22a; 22b) is at least partially integrated into the at least one cable winch (32a; 32b).

9. Cutting device at least according to Claim 7, characterized by at least one spring element (36a; 36b) which is connected to the cable winch (32a; 32b) and is configured in particular as a helical spring and which is provided for tensioning the cable (34a; 34b) in at least one operating state.

10. Cutting device according to one of the preceding claims, <b>characterized by at least one gear unit (38a; 38b; 38c; 38d) which is arranged in a first grip element (16a; 16b; 16c; 16d) of the grip elements (16a, 18a; 16b, 18b; 16c, 18c; 16d, 18d).

11. Cutting device according to Claim 10, characterized in that the drive unit (20a) and the gear unit (38a) are arranged spatially between the cutting elements (12a, 14a) and the at least one self-switching coupling unit (22a).

12. Cutting device according to Claim 10, characterized in that the at least one gear unit (38b) has at least two gear stages, between which the at least one self-switching coupling unit (22b) is arranged.

13. Cutting device according to one of the preceding claims, characterized by at least one force sensor (40a; 40b; 40c; 40d) which is integrated in a second grip element (18a; 18b; 18c; 18d) of the grip elements (16a, 18a; 16b, 18b; 16c, 18c; 16d, 18d).

14. Method for operating a cutting device (10a; 10b; 10c; 10d) according to one of the preceding claims, characterized in that when a defined operator force is exceeded, the drive unit (20a; 20b; 20c; 20d) is connected to a closing mechanism of the cutting device (10a; 10b; 10c; 10d).

15. Method according to Claim 14, characterized in that when an end position of the cutting device (10a; 10b; 10c; 10d) is reached, the drive unit (20a; 20b; 20c; 20d) stops automatically and is briefly driven counter to a drive direction (41a; 41b; 41c; 41d) in order to open the coupling unit (22a; 22b; 22c; 22d).