MEAT TRIMMER, CLUTCH ASSEMBLY FOR IT AND USE THE SAME

Description

[0001] The invention relates to a coupling arrangement on a hand tool rotatably driven by a drive train with a flexible drive shaft, comprising a one-hand safety shut-off according to the preamble of claim 1. The invention further relates to the use of a coupling arrangement according to the invention in a meat trimmer as a hand tool. The invention also relates to a meat trimmer comprising a coupling arrangement according to the invention.

[0002] DE 20 2010 005 399 U1 discloses a coupling arrangement on a hand tool, in particular a meat trimmer, which is rotatably driven by a drive train with a flexible drive shaft and features a one-hand safety shut-off. A coupling with a control pin and a coupling stud is provided between the output end of the drive train and a gear for driving the hand tool. Applying an operating lever causes the control pin to be axially displaced into a coupling position, in which the drive train and the gear for driving the hand tool are coupled via the coupling. Releasing the operating lever causes the control pin to be axially displaced backward, thus decoupling the drive train and the gear. In this way, an emergency or safety shut-off to prevent accidents is implemented via the operating lever.The drive train remains in a constant position regardless of whether the operating lever is actuated. Despite a locking mechanism on the operating lever, it is possible for the hand tool to be started unintentionally by accidentally engaging the lever, for example, if the hand tool is dropped on the ground.

[0003] DE 20 2023 100 684 U1 discloses a generic coupling arrangement on a hand tool rotatably driven by a drive train with a flexible drive shaft, featuring a one-hand safety shut-off, in particular a meat trimmer with an operating lever for moving the drive train into a coupling position in which a positive connection is established between a gear driving the hand tool during operation and the drive train, or for disengaging the drive train and the gear. The hand tool can be started or stopped via the operating lever. However, it is also possible that the hand tool could be started by unintentionally engaging the operating lever.

[0004] The object of the present invention is therefore to provide a coupling arrangement on a rotary-driven hand tool, in particular a meat trimmer, which enables safe, one-handed operation for starting and stopping the hand tool. Furthermore, this object is achieved by a use or a meat trimmer according to the invention.

[0005] To solve the problem, the invention, in conjunction with the preamble of claim 1, is characterized in that, to drive the hand tool, the operating lever and additionally a locking element provided on the handle must be actuated, wherein by actuating the operating lever the output end of the drive train is directly moved axially towards the front end into a coupling position in which a positive locking connection is established between the gear and the output end of the drive train, and wherein by actuating the locking element a blocking position is released in which the locking element blocks an axial advance of the drive train into the coupling position and thus the actuation of the operating lever.

[0006] The particular advantage of the invention is that a reliable one-hand safety operating shutdown for a hand tool can be specified, which enables a safety shutdown or emergency shutdown of the hand tool as well as a removal or separation of the hand tool from the drive train with the flexible drive shaft via the safety element and the operating lever as actuating elements.

[0007] In the locked position, the locking element prevents axial movement of the drive train into the clutch position via the operating lever. This eliminates the possibility of unintentional activation of the hand tool by engaging the operating lever due to an accident or an operator's clumsy movement.

[0008] To operate or drive the hand tool, both the operating lever and the locking element must be actuated. Actuating the locking element moves it from the locked position to a release position, in which it is disengaged from the drive train, thus allowing the output end of the drive train to be axially advanced into the coupling position. The operating lever cannot be operated without actuating the locking element.

[0009] According to the invention, the drive train has a driver that projects radially in relation to the flexible drive shaft, and a locking lever is articulated to the handle as a locking element, the locking lever being arranged axially in front of the driver of the drive train so that axial movement of the drive train into the clutch position is blocked. The locking lever is preferably held in the locked position as the rest position by a lever spring.

[0010] According to a further development of the invention, a clutch spring is provided in the housing recess, axially positioned between the gear and the output end of the drive train. This spring presses the output end of the drive train axially towards the rear end of the housing recess into a disengaged rest position, in which the positive connection between the drive train and the gear is released. Advantageously, the clutch spring thus forms a return element for the operating lever, since releasing the operating lever causes the clutch spring to push the drive train back into the disengaged position, thereby moving the operating lever, which is engaged with the drive train, accordingly. In the event of unintentional release of the operating lever or dropping of the hand tool in the event of an accident, an automatic emergency or safety shutdown occurs.

[0011] According to a further development of the invention, the operating lever is held on the handle via an adjustable guide so as to be radially displaceable with respect to the housing recess of the handle housing, such that the operating lever engages the drive train. In a locking position, the guide axially secures against displacement of the output end of the drive train to the rear end of the housing recess beyond the disengagement position, and in an exposure position, the guide exposes the driver so that the drive train can be removed from the housing recess beyond the insertion opening.

[0012] The guide for the operating lever thus provides a locking mechanism for the drive train in the locked position. Furthermore, the guide allows for the drive train to be released or completely removed from the handle, or inserted into the handle, with a simple movement when the guide is in its exposed position.

[0013] According to a further development of the invention, the guide for the operating lever has a guide spring which holds the guide in the locking position as the rest position.

[0014] In this way, it is ensured during normal use of the hand tool that the drive train is held securely on the handle and can only be removed by the operator by applying a hand force to the operating lever that counteracts the guide spring.

[0015] According to a further development of the invention, the guide for the operating lever has at least one elongated hole, wherein a pivot joint for the operating lever, preferably formed by a pivot pin or a pivot screw, passes through the elongated hole. Advantageously, an adjustment path for the guide of the operating lever is defined along a longitudinal extension of the elongated hole. The elongated hole thus provides a stop element for the uncovered and locked positions of the guide.

[0016] Preferably, a guide spring is arranged in each of the at least one elongated hole of the guide.

[0017] According to a further development of the invention, the positive locking connection between the gear and the output end of the drive train in the coupling position is formed by a coupling sleeve with a sleeve ring and with at least two and preferably three cylindrical pins arranged radially around the sleeve ring in the same distribution on the one hand, and a coupling pin engaging positively in the coupling sleeve with a number of radially around the sleeve and axially oriented longitudinal recesses corresponding to the cylindrical pins of the coupling sleeve on the other hand.

[0018] The coupling sleeve and the coupling pin thus provide a rotary coupling for the coupling arrangement according to the invention.

[0019] Advantageously, the cylindrical pins and the longitudinal recesses are shaped to correspond to each other in such a way that the rotary coupling is self-locking. For this purpose, it is advantageous if the longitudinal recesses of the coupling pin have a greater radial width than the cylindrical pins and if a minimal residual web remains between each longitudinal recess. The residual webs preferably have a thickness that is less than or equal to the diameter of the cylindrical pins. Furthermore, the residual webs preferably have a chamfer or radius towards an end face of the coupling pin that faces the coupling sleeve. It is also advantageous if the longitudinal recesses have a chamfer or radius at least at their radial edges. The cylindrical pins are preferably dimensioned in cross-section such that they project radially inwards towards the sleeve ring in certain sections.The self-alignment mechanism of the rotary coupling achieved in this way works as follows: When engaging or attaching the coupling sleeve to the coupling pin, if the remaining webs meet the cylindrical pins, the remaining webs are automatically deflected from the round cross-section of the cylindrical pins in such a way that the cylindrical pins are received in the longitudinal recesses.

[0020] According to a further development of the invention, the coupling pin is provided by the gear and the coupling sleeve by the drive train.

[0021] Preferably, the coupling sleeve is designed as a fitting and is mounted onto an output-side end of the flexible drive shaft by means of an annular cylindrical shaft axially opposite the sleeve ring. The annular cylindrical shape of the shaft means that the coupling sleeve has a bore at the level of the shaft, through which it can be mounted onto the flexible drive shaft. Advantageously, this design allows the part of the drive train that engages with the gear and is therefore subject to increased wear to be a replaceable wear part.

[0022] According to a further development of the invention, a ring-shaped stop element is held on the handle housing and surrounds the handle at a radial distance, which defines a stop for the locking lever in the blocking position or for the operating lever in a pivoted position corresponding to the disengagement position of the drive train.

[0023] The stop element is preferably designed in a split-ring shape, so that the circumference of the stop element can be adjusted, for example by means of a screw or the like that can be inserted into an annular gap of the stop element. This also simplifies assembly.

[0024] The hand tool is in particular a meat trimmer with a circular blade which is rotatably mounted in a blade guide held on the head and which can be driven by the gear via a blade tooth ring engaging with the gear.

[0025] To solve the problem, the invention has the features of claim 12. Accordingly, the coupling arrangement according to the invention is used in a meat trimmer as a hand tool.

[0026] To solve this problem, the invention has the features of claim 13. Accordingly, a meat trimmer according to the invention comprises a coupling arrangement according to the invention and a circular blade which is rotatably mounted in a blade guide held on the head of the coupling arrangement and which can be driven by the gear via a blade tooth ring engaging in the gear of the coupling arrangement.

[0027] Further advantages, features, and details of the invention can be found in the dependent claims and the following description. Features mentioned therein can be essential to the invention, either individually or in any combination. Features and details of the coupling arrangement described according to the invention naturally also apply in connection with the meat trimmer according to the invention and its use, and vice versa. Thus, the disclosure relating to the individual aspects of the invention can always be referred to reciprocally. The drawings serve only as examples to clarify the invention and are not limiting in nature. They show: Fig. 1 a perspective rear view of a meat trimmer with a coupling arrangement according to the invention and with an inserted drive train in a disengaged position, wherein a locking lever of the coupling arrangement according to the invention is held in a blocking position, Fig. 2 a perspective close-up view of the meat trimmer according to Fig. 1 From the front, Fig. 3 shows a close-up view of the meat trimmer. Fig. 1 from the side, Fig. 4 a close-up view of the meat trimmer after Fig. 1 In the side section, Fig. 5 shows a simplified side section view of the meat trimmer according to Fig. 1 with the inserted drive train in the disengaged position, Fig. 6, detail W from Fig. 5 , Fig. 7 a close-up view of the meat trimmer according to Fig. 1 in the lateral full section, with opposite Fig. 1 the safety lever is moved into a release position, Fig. 8 a simplified side sectional view of the meat trimmer according to Fig. 7 with the inserted drive train in the disengaged position, Fig. 9, detail X from Fig. 8 , Fig. 10 a close-up view of the meat trimmer according to Fig. 1 in the lateral full section, with opposite Fig. 7 an operating lever of the coupling arrangement according to the invention is moved into a pivoting position, Fig. 11 a simplified side sectional view of the meat trimmer according to Fig. 10 with the inserted drive train in a coupling position, Fig. 12, detail Y from Fig. 11 , Fig. 13 a perspective rear view of the meat trimmer according to Fig. 1 with a guide for the coupling arrangement according to the invention in an exposed position, Fig. 14 a detailed view of the meat trimmer according to Fig. 13 In the side section, Fig. 15 shows a simplified side section view of the meat trimmer according to Fig. 13 with the introduced drive train in an uncoupled, intermediate position, Fig. 16, detail Z from Fig. 15 , Fig. 17 a close-up view of a handle of the meat trimmer according to Fig. 1 insertable part of the drive train in full section and Fig. 18 a gear and a coupling sleeve of the meat trimmer according to Fig. 1 in an exploded view.

[0028] A preferred embodiment of a meat trimmer 1 with a coupling arrangement according to the invention is described in the Fig. 1 bis 18 specified.

[0029] The meat trimmer 1 comprises a circular blade 41, rotatably driven about a rotational axis R, as a hand tool. This blade can be coupled to a drive train 10 with a flexible drive shaft 11 by means of the coupling arrangement according to the invention. The circular blade 41 is rotatably mounted in an annular blade guide 42, which is held to a head piece 2 of the coupling arrangement by means of two connecting screws 40.1, 40.2. The circular blade 41 has an annular cutting edge 33 on a first blade end face and an annularly rotating blade tooth ring 34 on an opposite second blade end face. The circular blade 41 can be driven by means of a gear 6 mounted in the head piece 2 of the coupling arrangement. For this purpose, the gear 6 has a tooth ring 46 which engages with the blade tooth ring 34 of the circular blade 41 during operation of the meat trimmer 1.

[0030] As a further component of the coupling arrangement according to the invention, a rod-shaped, longitudinally extended handle 3 is connected to the head piece 2 at a front end. The handle 3 has a substantially cylindrical handle housing 4 with a substantially cylindrical housing recess 5 enclosed by the handle housing 4, which extends continuously from the front end to an opposite rear end of the handle 3, so that an insertion opening 44 is formed at the rear end of the handle 3, through which the drive train 10 with the flexible drive shaft 11 can be inserted into or removed from the housing recess 5.The handle housing 4 is enclosed on the outside towards the head piece 2 with spacer rings and in particular with a plastic handle 39, which provides a secure grip for the operator of the meat trimmer 1 and prevents slipping along the handle 3, thus ensuring improved operating safety.

[0031] The coupling arrangement further provides a locking lever 7 as a locking element and an operating lever 8 in the area of ​​the rear end of the handle 3, each of which is pivotably hinged to the handle housing 4 of the handle 3.

[0032] The operating lever 8 is designed to directly displace the drive train 10, which is inserted into the housing recess 5 to drive the circular blade 41, axially along a drive axis A, about which the section of the drive train 10 received in the housing recess 5 rotates during operation, such that an output end of the drive train 10 can be moved into a coupling position towards the front end of the handle 3. In the coupling position, a positive connection is established between the drive train 10 and the gear 6. Likewise, by means of a counter-rotating pivoting movement of the operating lever 8, the drive train 10 can be moved towards the rear end of the handle 3, so that the coupling position and the positive connection between the output end of the drive train 10 and the gear 6 are released in a disengagement position, i.e., the drive train 10 and the gear 6 are disengaged from each other.

[0033] The coupling arrangement further includes a coupling spring 9, which acts as a force-acting element and return element. It is located in the housing recess 5 in the area of ​​the front end of the handle 3, between the gear 6 and the output end of the drive train 10. The coupling spring 9 remains in the housing recess 5 of the handle 3 when the drive train 10 is removed. The coupling spring 9 is designed as a coil spring, allowing a coupling pin 13 of the gear 6 and the output end of the drive train 10 to project partially into the coupling spring 9. The coupling spring 9 is intended to hold the drive train 10, inserted into the housing recess 5, in the disengaged position as its rest position. Therefore, an operator must apply hand force via the operating lever 8 to press the drive train 10 against the coupling spring 9 into the engaged position.

[0034] The safety lever 7 is an essential component of the one-hand safety shut-off specified by the coupling arrangement. The safety lever 7 is located on the side axially opposite the operating lever 8 with respect to the handle 3 and the drive axis A, and serves to prevent unintentional operation of the circular blade 41 or unintentional engagement of the drive train 10 with the gear 6. Therefore, to operate the meat trimmer 1 or to drive the circular blade 41, the safety lever 7 must be actuated and moved into a pivoted position relative to the handle 3 in order to allow the drive train 10 to engage with the gear 6 via the operating lever 8.

[0035] A split-ring shaped stop element 20 is held on the handle housing 4 of the handle 3 by a retaining screw 32, which serves as a stop for the operating lever 8 in the swivel position.

[0036] In the coupling arrangement according to the invention, this is achieved structurally by the drive train 10 having a driver 14 that projects radially with respect to the drive axis A or flexible drive shaft 11. The locking lever 7 is held in a rest position, pivoted outwards relative to the handle 3, by a lever spring 21 and, in the locking position, is arranged axially with respect to the drive axis A in front of the driver 14 of the drive train 10, which is inserted into the housing recess 5 of the handle 3. Advancement of the drive train 10 into the coupling position is therefore blocked as long as the locking lever 7 is in the locking position. The operating lever 8 cannot be actuated when the locking lever 7 is in the locking position.This increases operational safety, as unintentional activation of the hand tool by engaging the operating lever due to an accident or an awkward movement by the operator is prevented.

[0037] Furthermore, the safety lever 7 and the operating lever 8 are arranged and dimensioned on the handle 3 in such a way that the operator can simultaneously grip both levers 7 and 8 with one hand, thus enabling one-handed operation. This provides the operator with a comfortable and, in particular, safe means of operating and starting (starting) or stopping (stopping) the meat trimmer 1.

[0038] The coupling arrangement further includes a guide 15 for the operating lever 8, by which the drive train 10 can be optionally secured against unintentional detachment from the handle 3 or exposed for complete removal or detachment from the handle 3.

[0039] The guide 15 has a U-shaped or fork-shaped bracket 48, held on the handle 3, with two radially outwardly projecting legs of equal length, each containing an elongated hole 16.1, 16.2. The operating lever 8 has two retaining arms 38.1, 38.2, each with an opening and arranged at the level of the elongated holes 16.1, 16.2. A pivot screw 17, axially secured by a pivot nut 18, passes through the openings and the elongated holes 16.1, 16.2. In this way, a pivot joint is formed for the operating lever 8.

[0040] Furthermore, the guide 15 has a guide spring 19 held in the elongated holes 16.1, 16.2, which serves as a return element and holds the guide 15 in a locking position as its rest position. In the locking position of the guide 15, the operating lever 8 is positioned axially in sections with respect to the drive axis A behind the driver 14 of the drive train 10 via two locking lugs 36.1, 36.2, whereby the guide 15 secures the drive train 10 against axial displacement towards the rear end of the housing recess 5 of the handle 3. The pivot screw 17 is thereby engaged with an upper end of the elongated holes 16.1, 16.2 via the guide spring 19.

[0041] The Fig. 1 bis 6 Figure 1 shows the meat trimmer 1 with levers 7 and 8 in their rest position and unactuated state, respectively. The locking lever 7 is held in the locked position, pivoted away from the handle 3, by the lever spring 21, which is a torsion spring. The operating lever 8 is held in the pivoted position, pivoted away from the handle 3.

[0042] The swivel position forms a rest or starting position for the operating lever 8, provided the drive train 10 is inserted into the housing recess 5 of the handle 3 up to the disengagement position. In this case, the clutch spring 9 acts as a return element for the operating lever 8. The guide 15 for the operating lever 8 is held in the locking position, in which the driver 14 of the drive train 10 is axially secured by the locking lugs 36.1, 36.2 of the operating lever 8. The drive train 10 and the gear 6 are thus decoupled from each other or disengaged. Drive of the circular blade 41 is therefore not possible.

[0043] The Fig. 7 bis 9 The illustrations show various views of the meat trimmer 1, in which the locking lever 7 is moved from the pivoted locking position to the release position, pivoted relative to the handle 3. In the release position, the locking lever 7 is pivoted against a restoring force applied by the lever spring 21 and is oriented essentially parallel to the rod-shaped handle 3. A locking cam 37 of the locking lever 7 is pivoted out such that axial insertion of the driver 14 towards the front end of the handle 3 is permitted. Actuation of the operating lever 8 is thus possible in this release position of the locking lever 7, allowing the drive train 10 to be moved from the disengaged position to the engaged position.

[0044] The Fig. 10 bis 12 Figure 1 shows the meat trimmer 1 with the locking lever 7 in the pivoted release position and with the operating lever 8 moved from the pivoted position to the pivoted position. This pivoting movement, or actuation of the operating lever 8, axially advances the driver 14 of the drive train 10 towards the front end of the handle 3 until the output end of the drive train 10 is engaged. In the engagement position, the output end of the drive train 10 engages with the gear 6, creating a positive connection. The operating lever 8 has locking lugs 36.1 and 36.2 that engage with the driver 14 for this purpose. The positive connection between the gear 6 and the drive train 10 allows the circular blade 41 to be driven rotaryally by the drive train 10.The drive train 10 is coupled via a drive end (not shown) opposite the output end to a drive motor or the like, which provides the required drive energy. The clutch spring 9 is tensioned.

[0045] The Fig. 13 bis 16 The figures show the meat trimmer 1 with the guide 15 for the operating lever 8 in an exposed position. The operating lever 8 has been pulled downwards by the operator against the restoring forces of the guide springs 19, relative to the plane of the drawing, by applying an actuating force. The locking lugs 36.1, 36.2 are now in a position radially outside the driver 14 of the drive train 10, relative to the drive axis A. The pivot screw 17 is engaged at the lower end of the elongated holes 16.1, 16.2. The elongated holes 16.1, 16.2 define an adjustment path for the guide 15. In the exposed position of the guide 15, the driver 14, and thus the entire drive train 10, can be completely removed from the housing recess 5 of the handle 3 towards the rear end. The locking lever 7 is in the pivoted release position.

[0046] The Fig. 17 The figure shows, section by section, the drive train 10 with the subsection that can be inserted into the housing recess 5 of the handle 3. The flexible drive shaft 11 is largely encased by a flexible corrugated hose 26, with the drive shaft 11 being exposed or not encased by the corrugated hose 26 in the area of ​​the output end. A coupling sleeve 12 is fitted onto the end of the flexible drive shaft 11 in the area of ​​an annular cylindrical shaft 25. The shaft 25 of the coupling sleeve 12 is rotatably mounted via a flanged bushing 27. The flanged bushing 27, in turn, is inserted into an output-side end face of a crimped hose sleeve 43. The crimp is indicated by reference numeral 31.

[0047] The hose sleeve 43 forms a second, wear-preventing sheath for the part of the drive train 10 that can be inserted into the housing recess 5 of the handle 3. At an end section opposite the drive axis A of the flanged bushing 27, the annular driver 14 is pushed onto the hose sleeve 43 and axially secured by retaining rings 29.1, 29.2.

[0048] To facilitate the sliding of the retaining rings 29.1, 29.2 onto the hose sleeve 43, the latter has an end chamfer.

[0049] A support sleeve 30 is attached to the flanged bushing 27. This support sleeve is fitted onto the output end of the flexible drive shaft 11 and radially surrounds the shaft 25 of the coupling sleeve 12. A sealing ring 28 or O-ring is arranged between the shaft 25 and the support sleeve 30, which serves to axially secure the flexible drive shaft 11.

[0050] The coupling sleeve 12 has an axially exposed sleeve head 51, which projects radially from the shaft 25 of the coupling sleeve 12 with a right-angled shoulder. Axially, the sleeve head 51 of the coupling sleeve 12 rests against the flanged bushing 27. In the head region, the coupling sleeve 12 has an annular sleeve ring 23 into which three radially evenly spaced cylindrical pins 22 are pressed. The sleeve ring 23 and the cylindrical pins 22 radially enclose a coupling opening 49 of the coupling sleeve 12, which is open at its end face. The coupling opening 49 is formed by a continuous stepped bore, which has a first bore diameter at the level of the sleeve ring 23 that is adapted to the coupling pin 13 of the gear 6, and a second bore diameter at the level of the shaft 25 that is adapted to a shaft diameter of the flexible drive shaft 11.Therefore, the stepped bore makes it possible to place the shaft 25 onto the flexible drive shaft 11.

[0051] The Fig. 18Figure 1 shows an isometric exploded view of the gear 6 and the coupling sleeve 12. The coupling sleeve 12 and the gear 6 form a self-locking rotary coupling which, in the engaged position of the drive train 10, can transmit a drive torque from the drive train 10 to the gear 6. For this purpose, the gear 6 has, at one end of the coupling pin 13 provided by the gear 6 opposite the toothed ring 46, a number of longitudinal recesses 24 corresponding to the number of dowel pins 22 of the coupling sleeve 12. The longitudinal recesses 24 are arranged radially evenly, analogous to the dowel pins 22. In the engaged position of the drive train 10, the longitudinal recesses 24 are in contact with the dowel pins 22 of the coupling sleeve 12. The dowel pins 22 project radially from the sleeve ring 23 of the coupling sleeve 12.

[0052] The self-locking mechanism of the coupling provided by the gear 6 and the coupling sleeve 12 is achieved by chamfering or radiusing the longitudinal recesses 24 at their edges, i.e., in the region of their radial edges and in the region of the edge facing the gear ring 46. Furthermore, the longitudinal recesses 24 of the gear 6 each have a radially larger section or a greater radial width than the cylindrical pins 22 of the coupling sleeve 12. A narrow residual web 50 remains between each of the longitudinal recesses 24, which is deflected from the round cross-section of the cylindrical pins 22 when the coupling sleeve is inserted. The thickness of this residual web 50 corresponds essentially to the diameter of the cylindrical pins 22.

[0053] The coupling arrangement according to the invention is of course not limited to its preferred use in a meat trimmer 1 and can be used in various hand tools, in particular those driven rotaryally by means of a drive train 10 with a flexible drive shaft 11. For example, in a circular saw, an angle grinder, a rotary sander, a high-speed multi-tool, a dental drill, or the like.

[0054] Furthermore, according to an alternative embodiment of the clutch arrangement according to the invention, a differently designed return element for the drive train 10 or for the operating lever 8 is provided instead of the clutch spring 9. For example, the return element can be designed as a spring arranged between the operating lever 8 and the handle housing 4, which holds the operating lever 8 in the pivoted position as its rest position, whereby the drive train 10 is, as before, forcibly moved along with the pivoting movement of the operating lever 8 and is brought into the disengaged position.

[0055] Identical components and component functions are identified by the same reference numerals.

Claims

1. A coupling arrangement for a one-hand safety operation shut-down on a hand tool rotationally drivable by a drive train (10) with a flexible drive shaft (11), the coupling arrangement - comprising a rod-shaped handle (3) with a tubular handle housing (4) and with a cylindrical housing recess (5) enclosed by the handle housing (4) in any case on the encasing-side and an insertion opening (44) at a rear end of the handle housing (4), wherein the drive train (10) can be pushed with an output end into the housing recess (5) via the insertion opening (44), - comprising a head piece (2) which is detachably connected to the handle (3) at a front end thereof, - comprising a gearwheel (6) received in the head piece (2) for driving the hand tool, - further comprising an operating lever (8) articulated to the handle housing (4), - comprising a return element for the drive train (10) and / or operating lever (8), wherein, for driving the hand tool, the operating lever (8) is to be actuated, wherein, by actuation of the operating lever (8), the output end of the drive train (10) is directly displaced axially toward the front end into a coupling position, in which a form-fitting connection is established between the gearwheel (6) and the output end of the drive train (10), characterized in that, by actuation of a safety element additionally provided on the handle (3), a blocking state is resolved, in which the safety element blocks an axial advancement of the drive train (10) into the coupling position and thus the actuation of the operating lever (8), wherein the drive train (10) has a driver (14) protruding radially with respect to the flexible drive shaft (11), and in that further a safety lever (7) is articulated to the handle (3) as a safety element, wherein the safety lever (7), in the blocking state, is arranged axially in front of the driver (14) of the drive train (10) with respect to the housing recess (5), so that an axial advancement of the drive train (10) into the coupling position is blocked.

2. The coupling arrangement according to claim 1, characterized in that a coupling spring (9) received axially between the gearwheel (6) and the output end of the drive train (10) is provided as a return element in the housing recess (5), said coupling spring pressing the output end of the drive train (10) in the housing recess (5) axially toward the rear end into a rearward decoupling position as a rest position, in which the form-fitting connection between the drive train (10) and the gearwheel (6) is resolved.

3. The coupling arrangement according to claim 1 or 2, characterized in that the operating lever (8) is held on the handle (3) to be radially displaceable with respect to the housing recess (5) of the handle housing (4) via a shiftable guide (15) in such a way that the operating lever (8) axially secures the driver (14) of the drive train (10) - in a locking state of the guide (15) against a displacement of the output end of the drive train (10) toward the rear end of the housing recess (5) beyond the decoupling position and - in an exposing state of the guide (15) exposes the driver (14), so that the drive train (10) is removable from the housing recess (5) beyond the insertion opening (44).

4. The coupling arrangement according to claim 3, characterized in that the guide (15) for the operating lever (8) has a guide spring (19) which holds the guide (15) in the locking state as a rest state.

5. The coupling arrangement according to any of claims 1 to 4, characterized in that the guide (15) for the operating lever (8) has at least one elongated hole (16.1, 16.2), a pivot joint for the operating lever (8) that is preferably formed by a joint bolt and / or a joint screw (17) being passed through the elongated hole (16.1, 16.2).

6. The coupling arrangement according to claim 5, characterized in that the guide spring (19) is arranged in the at least one elongated hole (16.1, 16.2) of the guide (15).

7. The coupling arrangement according to any of claims 1 to 6, characterized in that the form-fitting connection between the gearwheel (6) and the output end of the drive train (10) in the coupling position is formed by - a coupling sleeve (12) with a sleeve ring (23) and with at least two and preferably three cylindrical pins (22) arranged in the sleeve ring (23) in a radially circumferential, uniformly distributed manner, on the one hand, and - a coupling journal (13) engaging in the coupling sleeve (12) in a form-fitting manner with a number of radially circumferential, uniformly distributed and axially oriented longitudinal recesses (24) which corresponds to the cylindrical pins (22) of the coupling sleeve (12), on the other hand.

8. The coupling arrangement according to claim 7, characterized in that the coupling journal (13) is provided by the gearwheel (6) and the coupling sleeve (12) is provided by the drive train (10).

9. The coupling arrangement according to claim 8, characterized in that the coupling sleeve (12) is designed as an attachment piece and is put on to an output-side end of the flexible drive shaft (11) with a ring-cylindrical shank (25) which lies axially opposite the sleeve ring (23).

10. The coupling arrangement according to any of claims 1 to 9, characterized in that a ring-shaped stop element (20) circumferentially disposed around the handle (3) with a radial spacing is held on the handle housing (4), which stop element defines a stop for the safety lever (7) in the blocking state and / or for the operating lever (8) in the pivot-out state which corresponds to the decoupling position of the drive train (10).

11. The coupling arrangement according to any of claims 1 to 10, characterized in that the hand tool is a meat trimmer (1) having a circular knife (41) which is rotatably mounted in a knife guide (42) held on the head piece (2) and which can be driven by the gearwheel (6) via a knife-toothed ring (34) engaging in the gearwheel (6).

12. A use of a coupling arrangement according to any of claims 1 to 11 in a meat trimmer (1) having a circular knife (41) as a hand tool.

13. A meat trimmer (1) comprising a coupling arrangement according to any of claims 1 to 11 and comprising a circular knife (41) which is rotatably mounted in a knife guide (42) held on the head piece (2) of the coupling arrangement and which can be driven by the gearwheel (6) via a knife-toothed ring (34) engaging in the gearwheel (6) of the coupling arrangement.