SCREWDRIVER TOOL WITH GEAR RATIO

Description

field of technology

[0001] The invention relates to a screwing tool with a transmission gear arranged in a handle for multiplying an angle of rotation transmitted from the handle to a blade protruding from the handle or to a chuck for receiving a blade, and with a locking means. State of the art

[0002] A screwing tool of this type is already known from DE 35 00 127. The screwing tool described therein has a handle consisting of two sections. A planetary gear is located in one section facing a blade, which can transmit a rotational movement of the handle to a rotational movement of the blade, increasing the speed. Furthermore, a locking mechanism is located within the handle, which can be used to switch between left and right rotation.

[0003] A similar screwing tool is known from WO 2011 / 0996541 A1. The handle has two handle parts that can be rotated relative to each other.

[0004] CN 108789255 A describes a gear for speed increase that can be arranged in a screwdriver handle.

[0005] A similar gear mechanism is described in WO 2004 / 014609 A2. DE 23 07 186 A1 describes a screwdriver with a blade permanently attached to the handle.

[0006] From WO 2016 / 028727 A1, a reversible planetary gear for a screwing tool is already known, in which the gear can be locked with a blocking pin. Summary of the invention

[0007] The invention is based on the object of further developing the screwing tool mentioned at the beginning in a manner that is advantageous in use.

[0008] The problem is solved by the invention specified in the claims.

[0009] A blocking member can be moved from a release position, in which the transmission gear is active, to a blocking position, in which the transmission gear is no longer active. In the release position, a rotational angle applied to the handle is transmitted by the transmission gear to the blade or chuck for receiving the blade, increasing the rotational angle. In the blocking position, the blade or chuck is rotationally fixed to the handle. The screwing tool according to the invention can have two handle sections, which can be rotated relative to one another in the release position of the blocking member and which are kinematically rigidly connected to one another in the blocking position of the blocking member. In particular, it is provided that the blocking member is axially displaceable relative to a direction of extension of the handle or the blade. The two handle sections can be formed as one or more parts.They can, in particular, consist of several parts plugged together. For example, it is provided, in particular, that the first handle section consists of two axially interconnected parts. The blocking member can be displaceably assigned to the handle section facing away from the blade and can be arranged, in particular, in the region of the front end of the handle, wherein the front end of the handle body forming the second handle section has a front opening there, into which a push button is arranged, in particular inserted, with which the blocking member can be displaced. In a preferred embodiment, the push button is displaceable against the elastic restoring force of a push button spring.The push button is preferably designed as a momentary-action button which, after each actuation, returns from an initial position, which is accompanied by an elastic deformation of the push button spring, to its initial position, in which position it lies flush with the particularly curved end face of the handle section. Each actuation of the push button leads to a displacement of the blocking member, with a first actuation moving the blocking member from the release position to the blocking position, where it is then held by means of a holding means, as described below. A second actuation of the push button leads to a release of the holding means and to a return displacement of the blocking member from the blocking position to the release position. For this purpose, the blocking member is loaded with a blocking member spring, which loads the blocking member from the blocking position towards the release position.In a preferred embodiment, the reduction gear is designed as a planetary gear. The reduction gear preferably has two gear levels. In a first gear level, there is a first gear, in particular a sun gear, with a large-diameter toothing. This large-diameter gear meshes with small-diameter toothings of second gears, in particular planet gears. The small-diameter toothings of the second gears are rotationally fixedly connected to large-diameter toothings of the second gears, which lie in a second level in which a third gear, which is in particular a second, small-diameter sun gear, is arranged. The large-diameter gear is rotationally fixedly connected to the handle section facing away from the blade.For this purpose, the large-diameter first gear can have a coupling section, which is particularly designed as a polygon and which engages in a form-fitting cavity of the first handle section, such that the coupling section is connected in a rotationally fixed manner to the first handle section. The third gear, in particular the small-diameter sun gear, is rotationally fixedly connected to the blade, a chuck, or a drive extension that can transmit torque to the blade. The third gear, in particular the small-diameter sun gear, can be connected to a drive axle, which in turn is connected to a chuck. It is provided in particular that the second gears are planetary gears and that a web carrying the second gears is rotationally fixedly connected to the second handle section, which is rotatable relative to the first handle section in the release position of the blocking member.If the second handle section closest to the blade is held by a user's hand, for example the left hand, the second gears, in particular the planetary gears, assume a fixed gear position. A rotary motion transmitted from the second handle section via the large-diameter gear, in particular the sun gear, to the second gears, in particular the planetary gears is transmitted, for example, with a factor of 1:4 to the third gear, in particular the small sun gear, which is connected to the chuck or the blade, so that when the handle is rotated, an angle of rotation increased by a factor of 4 is transmitted to the blade or the chuck. In the release position, the handle section farther from the blade can be turned both anti-clockwise and clockwise by the user's other hand, in particular the right hand. The blade then rotates at an increased speed in the same direction of rotation.The screwdriver designed in this way is particularly suitable for quickly tightening screws with metric threads. Such screws are used in electrical installation technology, so that in a preferred embodiment, the screwing tool is a VDE screwing tool in which the chuck and the handle sections are made of an electrically insulating material, in particular plastic. The blade inserted into the chuck has a steel core surrounded by an electrically insulating sheath, from which only the working tip of the screwing tool protrudes. The gears of the transmission gear can be made of plastic or metal. At least when the gears are made of metal, they can be encapsulated by the handle in an electrically insulating manner.To meet VDE requirements, it is generally sufficient for the blade to be completely coated in plastic and for the chuck to be designed so that only such plastic-coated blades can be used. The two handle sections can then also be made of other materials.

[0010] In a further development of the invention, it is provided that the preferably axially displaceable blocking member is assigned to the first handle section. The blocking member can have a toothing that has at least one tooth or at least one tooth gap. The toothing can be a broad- or end-face toothing or also a circumferential toothing. In the blocking position, this toothing engages with a counter-toothing that has at least one tooth gap or at least one tooth. The counter-toothing is preferably assigned in a rotationally fixed manner to the second handle section and / or in a rotationally fixed manner to the web of the planetary gear. In particular, it is provided that the planet gears extend between an annular body forming the counter-toothing and the web, wherein the axes of the planet gears engage in bearing openings in the annular body and the web. The web can be formed by a plate that carries several planet gears.The plate can be connected to an extension of the second handle section by means of pins. The pins can be molded onto the plate from the same material. However, they can also be formed by the axes of the planetary gears. The extension engages in a cavity in the first handle section and is rotatably mounted therein. The end of the extension can have hooks that hook into the first handle section. Starting from a blocking element in a release position, the push button displaces the blocking element into a blocking position upon initial actuation. In this blocking position, the blocking element is held by the switching element. The switching element is held in the displaced position by means of holding means. This is preferably achieved by holding projections on the switching element, which engage under holding shoulders, for example on a link piece, which is inserted into the front opening of the first handle section and which also holds the push button.The link piece can have guide grooves that guide the guide ribs of the switching element. The ends of the guide ribs facing the push button form retaining projections. With sufficient axial displacement of the switching element, the ribs emerge from the guide grooves. Since the push button transmits a torque to the switching element when it is actuated, the switching element can rotate through an angle at which the retaining projections engage under retaining shoulders of the link piece. Upon a second actuation, the push button again applies torque to the switching element, causing the switching element to rotate further until it reaches a rotational position in which the ribs are again aligned with the guide grooves, thus moving the switching element back to its original position. At the same time, the blocking element moves out of the blocking position, with the teeth of the blocking element disengaging from the mating teeth.To apply the torque, the mutually facing end faces of the push button and switching element form helically toothed sections. Short description of the drawings

[0011] An embodiment of the invention is explained below with reference to the accompanying drawings. They show: Fig. 1a view of an embodiment of the invention, Fig. 2the section along the line II - II in Figure 1 , Fig. 3 the section along the line III - III in Figure 2 , Fig. 4 in the section plane according to Figure 2 broken-open handle, in which a toothing 15 of a blocking member 5 is not in an engagement position with a counter toothing 16 of a ring body 17, Fig. 5 a second perspective broken-open view, in which the toothing 15 is in a tooth engagement position with the counter toothing 16, Fig. 6 a first exploded view of the essential gear elements, Fig. 7 enlarged section VII in Figure 6, Fig. 8a second perspective view, Fig. 9enlarges section IX in Figure 8 . Description of the embodiments

[0012] The screwing tool described in the exemplary embodiments has a handle 1 consisting of a first handle section 6 and a second handle section 7. The first handle section 6 consists of two handle section components 6', 6", which are connected to one another to form a parting line 41. The parting line 41 extends in the area of ​​the handle section 6 with the largest diameter and surrounds a cavity.

[0013] The first handle section 6 forms a rounded end face with a front opening 34 into which a guide piece 28 is inserted. Located in the guide piece 28 is a pressure piece 8 that is axially displaceable relative to an axis A, from which spring arms extend, which have hooks 31 at the end that engage behind the steps 32 of the guide piece 28.

[0014] A push-button spring 22 is supported on a base 33 of the link piece 28, which acts as a compression spring and urges the push-button 8 in the axial direction away from the link piece 28. Pins 39 can protrude from the underside of the link piece 28 opposite the base 33, with which the link piece 28 is non-rotatably fastened to the first handle section 6.

[0015] The underside of the push button 8 bears a switching toothing 29 that forms inclined flanks. This switching toothing 29 interacts with a counter-switching toothing 30 of a switching element 23. The switching element 23 is a substantially cylindrical body that is guided in a bottom opening of the gate piece 28. Ribs 24' protrude from a cylindrical wall of the switching element 23 in a uniformly distributed circumferential manner, forming inclined retaining projections 24.

[0016] At an angle offset to the guide grooves 27 in the base 33 there are retaining shoulders 25 which interact with the retaining projections 24.

[0017] The functionality of this push button arrangement is as follows: Starting from an operating position in which the counter-switching toothing 30 rests against the switching toothing 29, the switching element 23 can be displaced through the opening in the base 33 by a linear displacement of the push button 8, whereby the ribs 24' are guided in the guide grooves 27. The inclined flanks of the switching toothing 29 and the counter-switching toothing 30 are angularly offset from one another in such a way that a torque is exerted on the switching element 23, which causes the switching element 23 to rotate when the ribs 24' leave the guide grooves 27. As soon as the ribs 24' have left the guide grooves 27, the switching element 23 rotates relative to the link piece 28 and the push button 8, so that the angular offset of the switching toothing 29 to the counter-switching toothing 30 is canceled out.After an axial retraction of the push button 8, the retaining projections 24 engage under the retaining shoulders 25, so that the switching element 23 is locked in a retracted position after the initial actuation. Since the retaining projections 24 and the retaining shoulders 25 are inclined, the switching element 23 rotates slightly further during the retraction.

[0018] If the push button 8 is released, it moves in the axial direction back to the starting position due to the force of the relaxing push button spring 22, whereby the switching teeth 29 move away from the counter-switching teeth 30.

[0019] Upon a second actuation, the inclined flanks of the switching teeth 29 engage with the inclined flanks of the counter-switching teeth 30 in such a way that a torque is again exerted in the same direction on the switching element 23. Here, too, the switching teeth 29 and the counter-switching teeth 30 are angularly offset from one another. This means that the switching element 23, after a slight axial displacement, can rotate further into a position in which the ribs 24' are aligned with the guide grooves 27, so that the switching element 23 can return to its original position.

[0020] Along with the displacement of the switching element 23, a blocking element 5, which is also arranged in the end face opening 34, is displaced in the direction of the axis A. The blocking element 5 is assigned to the first handle section 6 in a rotationally fixed manner and has a broad side toothing 15 consisting of several teeth. A blocking element spring 26 is provided which urges the blocking element 5 in the direction of the switching element 23, so that the blocking element spring 26 can apply the necessary force to bring the switching element from a displaced position back into the starting position in the manner described above.

[0021] Within the first handle section 6 is a transmission gear 2, which in the exemplary embodiment is a planetary gear. A web 14 and an annular body 17 form a cage that supports the axes 40 of several planetary gears, three in the exemplary embodiment. Teeth protrude from the annular body 17 in the direction of the blocking member 5, forming a mating toothing 16. The toothing 15 can be brought into meshing engagement with the mating toothing 16. The annular body 17, which is otherwise rotatable relative to the first handle section 6, is then locked to the first handle section 6.

[0022] The planetary gear 2 has a large-diameter sun gear 9, which is non-rotatably connected to the first handle section via a polygonal section forming a coupling section 20. For this purpose, the coupling section 20 is inserted into a contoured cavity 21 of the first handle section. The blocking element spring 26 can be supported on an end face of the coupling section 20.

[0023] The planetary gears 11 have small-diameter gears 12 that mesh with the large-diameter sun gear 9. The small-diameter gears 12 are rotationally fixedly connected to large-diameter gears 13, which in turn mesh with a second, small-diameter sun gear 10. The large-diameter sun gear 9 forms a drive gear, which, via the planetary gears 11, has a transmission ratio of 4:1 with the output gear formed by the small-diameter sun gear.

[0024] The second handle section 7, which is rotatably associated with the first handle section, has an extension 19 that projects into a cavity in the first handle section. The extension 19 can only extend into the handle section 6" arranged between a handle section region 6' and the second handle section 7. It is secured there by means of hooks 35, axially fixed but rotatable. The extension 19 is connected in a rotationally fixed manner to the cage supporting the planetary gears 11. In particular, it is connected in a rotationally fixed manner to the web 14 formed by a plate. For this purpose, pins 18 engage in front-end openings of the extension 19. Instead of the pin 18, extensions of the axes 40 can also engage in the openings.

[0025] Within the extension 19 is a chuck 4, which is also secured within the second handle section 7 via locking means. A blade 3 can be inserted into the chuck 4. An output shaft 36, which is rotationally fixedly connected to the small-diameter sun rim 10 or forms the small-diameter sun gear, forms a torque transmission section 37, which is inserted into a torque transmission opening of the chuck 4 and can thus transmit rotation to the chuck 4. A round section 38 of the output shaft 36 passes through the coupling section 20 or the large-diameter sun gear 9, so that the large-diameter sun gear 9 can rotate freely relative to the output shaft 36. The output shaft 36 also supports the blocking member spring 26 and passes through a central opening of the blocking member 5 and projects into a central opening of the switching element 23.An axial displacement of the chuck 4 and the associated output shaft 36 is not provided.

[0026] The screwdriving tool functions as follows: In the release position, in which the toothing 15 of the blocking member 5 does not engage the counter-toothing 16, an angular velocity increased by a factor of 4 can be transmitted from the handle to the blade 3 in both directions of rotation by turning the first handle section 6 and holding the second handle section 7. Since the steel core of the blade, except for the working tip, is completely encased in an electrically insulating material, and the chuck and handle sections are made of an electrically insulating material, the screwdriving tool can be used on live parts. In the release position of the blocking member, the screwdriving tool assumes a fast screwing position in which screws can be screwed into a thread at high speed.By moving the blocking member 5 from the release position to the blocking position, in which the toothing 15 engages the counter-toothing 16, the screwdriving tool reaches a power screwing position. Switching between the quick-screwing position and the power screwing position is achieved by pressing the push button 8 once. In the power screwing position, the planetary gear arrangement, i.e. the annular body 17 or the web 14, is indirectly connected in a rotationally fixed manner to the first handle section 6. This means that the second handle section 7 is also connected in a rotationally fixed manner to the first handle section 6. In the blocking position, the screwdriving tool can be operated like a conventional screwdriver. The torque can be transmitted to the blade 3 via both the first handle section 6 and the second handle section 7.

[0027] The invention defined in each claim may additionally comprise one or more of the features indicated in the above description, in particular by reference numerals and / or in the list of reference numerals.

Claims

1. A screwdriver tool with a transmission gearing (2), which is arranged in a handle (1) and serves for multiplying a rotation angle transmitted from the handle (1) to a blade (3) protruding from the handle (1) or to a chuck (4) for receiving a blade (3), - with an axis (A) extending in the extending direction of the handle (1) or the blade (3) - with a pushbutton (8) - wherein the pushbutton (8) can be displaced from a first starting position in the direction of the axis (A) against a first restoring force of a pushbutton spring (22) and returns to the first starting position after each actuation, which is accompanied by an elastic deformation of the pushbutton spring (22), - with a blocking element (5), which can be moved from a release position into a blocking position in the direction of the axis (A) against a second restoring force of a blocking element spring (26), - wherein the blade (3) or the chuck (4) is secured to the handle (1) in a rotationally fixed manner in the blocking position, - wherein in the release position the rotation angle is transmitted in such a way that the rotation angle is increased, - wherein the pushbutton (8) displaces the blocking element (5) into its blocking position upon a first actuation, - wherein holding means (24, 25) are provided and hold the blocking element (5) in the blocking position, - wherein a second actuation of the pushbutton (8) leads to a release of the holding means (24, 25) and to a return displacement of the blocking element (5) from the blocking position into the release position effected by the second restoring force.

2. The screwdriver tool according to claim 1, characterized by a transmission gearing (2) that comprises first and second toothed wheels and is arranged in the handle (1), wherein the blocking element (5), which is assigned to the first handle section (6) in a rotationally fixed manner, has a toothing (15) that comprises at least one tooth or tooth space and in the blocking position engages with a mating toothing (16), which comprises at least one tooth space or tooth and is assigned to a second handle section (7) that is rotatable relative to the first handle section (6) or to a web (14) of the transmission gearing (2) in a rotationally fixed manner, whereby a ring body (17), which forms the mating toothing (16), supports the axes of the second toothed wheels, particularly the planetary wheels (11).

3. A screwdriver tool with a transmission gearing (2), which comprises first and second toothed wheels, is arranged in a handle (1) and serves for multiplying a rotation angle transmitted from the handle (1) to a blade (3) protruding from the handle (1) or to a chuck (4) for receiving a blade (3), and with a blocking element (5), which can be moved from a release position into a blocking position and in the blocking position secures the blade (3) or the chuck (4) to the handle (1) in a rotationally fixed manner, wherein the blocking element (5), which is assigned to the first handle section (6) in a rotationally fixed manner, has a toothing (15) that comprises at least one tooth or tooth space and in the blocking position engages with a mating toothing (16), which comprises at least one tooth space or tooth and is assigned to a second handle section (7) that is rotatable relative to the first handle section (6) or to a web (14) of the transmission gearing (2) in a rotationally fixed manner, and wherein a ring body (17), which forms the mating toothing (16), supports the axles of the second toothed wheels, particularly the planetary wheels (11), characterized in that the blocking element (5) can be displaced into the blocking position by means of a pushbutton (8), which is arranged in a face side opening (34) of the first handle section (6), against the restoring force of a blocking element spring (26) that acts upon the blocking element (5) in the direction of its release position.

4. The screwdriver tool according to one of the proceding claims, characterized in that the reduction gearing is an epicyclic gearing (2).

5. The screwdriver tool according to claim 4, characterized in that a large-diameter first toothed wheel, particularly a sun wheel (9), is connected to a first handle section (6) in a rotationally fixed manner.

6. The screwdriver tool according to claim 4 or 5, characterized in that a small-diameter third toothed wheel or sun wheel (10) is connected to the blade (3) in a rotationally fixed manner.

7. The screwdriver tool according to one of the claims 4, 5 or 6,characterized in that one or more second toothed wheels or planetary wheels (11) have a small-diameter toothing (12), which meshes with the first toothed wheel or a large sun wheel (9), and a large-diameter toothing (13), which meshes with the third toothed wheel or small sun wheel (10).

8. The screwdriver tool according to claim 2 to 7, characterized in that a web (14), which carries the axles (40) of the second toothed wheels or the planetary wheels (11), is connected in a rotationally fixed manner to a second handle section (7) that is rotatable relative to the first handle section (6).

9. The screwdriver tool according to one of the proceding claims, characterized in that the blade (3) or the chuck (4) rotates upon a counterclockwise rotation and upon a clockwise rotation of the handle section (6), during which the second handle section (7) is held firmly, in the same rotating direction with at least double, three-times or at least four-times the rotational speed of the first handle section (6).

10. The screwdriver tool according to one of the claims 2 to 9, characterized in that the second handle section (7) supports the chuck receiving the blade (3), wherein said chuck and particularly also the two handle sections (6, 7) consist of an electrically insulating material.

11. The screwdriver tool according to one of the claims 4 to 10, characterized in that a web (14), which is formed by a plate and carries multiple planetary wheels (11), is connected to an extension (19) of the second handle section (7), which protrudes into a cavity of the first handle section (6), by means of pins (18).

12. The screwdriver tool according to one of the claims 5 to 11, characterized in that a coupling section (20), which is connected to the large-diameter sun wheel (9) in a rotationally fixed manner and / or realized polygonally, engages into a fittingly shaped cavity (21) of the first handle section (6).

13. The screwdriver tool according to any one of claims 3 to 12, characterized in that the pushbutton (8), which can be displaced against a restoring force of a pushbutton spring (22), displaces upon a first actuation the blocking element (5) into its blocking position with a switching element (23) that can be axially displaced from a second starting position, wherein holding means (24, 25) are provided and hold the switching element (23) in the position, in which it is displaced from the second starting position, while holding the blocking element (5) in the blocking position.

14. The screwdriver tool according to any one of claims 1 to 13, characterized in that the holding means (24, 25) are released from their holding position by means of a second actuation of the pushbutton (8), so that a blocking element spring (26), which displaces the blocking element (5) back into the release position, displaces the switching element (23) back into the starting position.

15. The screwdriver tool according to one of the proceding claims, characterized in that a switch toothing (29) of the pushbutton (8) has oblique flanks, which interact with flanks or oblique flanks of a mating switch toothing of the switching element (23) in order to exert a torque upon the switching element (23) during the axial displacement of the switching element (23) between the starting position and the displaced position, wherein the switching element (23) has ribs (24') that are guided in a guide groove (27) and form holding projections (24), which engage underneath holding shoulders (25) in an end phase of the displacement of the switching element (23) after a rotation of the switching element (23), and wherein the switch toothing (29) exerts upon a second actuation of the pushbutton (8) a torque upon the switching element (23) due to the oblique flank contact with the mating switch toothing (30) such that the switching element is after an axial displacement additionally rotated in such a way that the ribs (24') enter the guide grooves (27).