EP3408055B1 - Screwdriver having a changeable direction freewheel lock - Google Patents

Description

Field of technology

The invention relates to a screwing tool with a direction-reversible freewheel locking mechanism, comprising an output member which is mounted in a bearing eye of a drive member so as to be rotatable about an axis and has a peripheral toothing and an output profile section, and locking members which are located in a pocket of the drive member and each have a locking toothing for rotationally locking engagement in the peripheral toothing.

State of the art

The US 2013/0291688 A1 describes a screwing tool of the type described above with two locking members which can optionally engage with a toothing in a peripheral toothing of an output profile section.

A similar tool is used in the EP 2 633 952 A2 and in the US 6 584 875 B1 described.

A screwing tool in the form of a ratchet wrench describes the EN 10 2014 113 758 A1 . A drive member is formed there by an elongated body which has an open-end wrench profile at one end and a ring wrench profile at the other end. The output profile (ring wrench profile) is formed by an output member which is rotatably mounted in a bearing eye and has a peripheral toothing. A locking body is provided which has two locking toothing sections which each engage in the peripheral toothing in one of the two switching positions in order to block the rotation of the output member relative to the drive member in one of the two directions of rotation. The locking body forms a first locking member, which, in a first switching position of a switching element, lies in a locking gusset, which is opposite a second locking gusset. By turning the switching element, the locking body can be moved within a pocket so that a second locking element lies in the second locking gusset. The two locking elements are connected to one another using the same material.

Summary of the invention

The invention is based on the object of further developing the direction-switchable freewheel lock in a manner that is advantageous for use.

The object is achieved by the invention described in claims 1 and 5.
The locking members are preferably not connected to one another using the same material. The locking members can preferably move against one another in a hinge-like manner. For this purpose, the hook projections are provided, which engage with one another. Each locking member has a locking toothing that runs on a circular arc line, the center of which coincides with the center of the peripheral toothing in the tooth engagement position. It is provided that in the two switching positions in which the output member can be rotated in one direction of rotation but is locked in the other direction of rotation, only one of the two switching members engages with its locking toothing in the peripheral toothing. The locking members are essentially designed to be hingedly symmetrical. Each locking member can have a switching extension, with the two switching extensions preferably protruding into the same switching recess of a switching member. A spring-loaded control flank can be arranged within the switching member. The control flank can be formed by a curved surface of a switching plunger. The switching plunger can be inserted into a hole in the switching element and acted upon by a switching spring. The switching spring can in turn be supported on a locking plunger, which interacts with a locking cam, which engages in a locking recess in each of the two switching positions. The locking cam can be connected to the locking plunger in the same material. However, the locking cam is preferably formed by a locking ball, which is acted upon by the locking plunger. The switching element can lie in a bore in the drive element so that it can rotate about an axis parallel to the axis of rotation. When the direction of the freewheel lock is changed, the switching element is rotated about its axis. It displaces the two locking elements, which are preferably coupled to one another, in an azimuthal direction in a pocket of the drive element, which forms two locking gussets opposite one another in an azimuthal direction, with each locking gusset being formed by a wall of the pocket and by a section of the peripheral toothing. The section of the wall of the pocket runs at an incline or curve relative to the peripheral toothing in such a way that an imaginary extension of the pocket wall intersects the peripheral toothing. A contact flank of the locking body rests on this wall and runs in a wedge shape to the locking teeth. In one of two switching positions, the output member can rotate freely in a freewheeling direction and is rotationally locked in a locking direction. When torque is applied to the output member in the locking direction, the locking member is pressed into the respective locking gusset by teeth of the locking teeth engaging with the peripheral teeth. The contact flank of the locking body lies on the wall of the locking gusset. When the locking bodies are moved from one switching position to the other, the ends of the switching extensions slide over the curved surface of the switching plunger. The two switching elements move in a joint-like manner towards one another, so that in an intermediate position in which the curved surface of the switching plunger engages the free ends of the switching extensions, both locking teeth of the locking body are simultaneously in mesh with the peripheral teeth. When switching, the switching plunger moves in a radial direction relative to the axis of rotation of the switching element and tensions the switching spring. In their plane of movement, which runs perpendicular to the axis of rotation, the switching elements have a substantially L-shaped contour, with one L-leg forming an arm that forms the locking teeth and the contact flank, and an arm of the other L-leg, which runs essentially transversely to this, forming the switching extension. The switching extension forms an arm with longitudinal sides pointing away from one another, which merge into one another at their ends to form a curve or a point. These end regions of the longitudinal flanks of the switching extensions are acted upon by the control flank, which is preferably formed by the desired surface of the switching plunger. In the switching positions, the locking locking element acts upon the longitudinal flank of the locking extension pointing away from the locking teeth. The non-locking locking element acts upon the longitudinal flank of the switching extension pointing towards the locking teeth. The result is that the locking teeth of the non-locking locking member are acted upon in a direction away from the peripheral teeth and the locking teeth of the locking locking member are acted upon into the peripheral teeth. When switching, the control flank essentially engages in the apex area of the two longitudinal flanks, so that in an intermediate position there is a relative rotation of the two locking members, in which both locking teeth engage the peripheral teeth simultaneously. The two locking members form an overlap area in which the interlocking hook projections are arranged. The hook projections engage with each other with such a pivoting movement play that the locking members can pivot from an operating position in which the locking teeth lie on a common circular arc line to another operating position in which the two centers of the locking teeth are spaced apart from each other. In the operating position, in which the locking teeth run on a common circular arc, the two switching extensions lie congruently on top of each other. In the other operating position, the switching extensions are offset from each other in such a way that they can be moved towards each other can be brought into alignment like a scissor joint, whereby the joint is formed by the interlocking hook projections. The switching extensions are sections of the overlapping areas.

Short description of the drawings

Fig. 1

in einer perspektivischen Darstellung ein Schraubwerkzeug in Form eines Schraubenschlüssels mit einem Maulprofil an einer Endseite und einem Ringprofil an der gegenüberliegenden Endseite;

Fig. 2

eine Draufsicht auf das Schraubwerkzeug;

Fig. 3

vergrößert den Ausschnitt III in Fig. 2 und derart aufgebrochen, dass das Freilaufgesperre sichtbar ist, wobei das Freilaufgesperre eine derartige Betriebsstellung einnimmt, dass sich ein Abtriebsglied 2 im Gegenuhrzeigersinn gegenüber einem Antriebsglied 1 drehen lässt;

Fig. 4

eine Darstellung gemäß Fig. 3, jedoch beim Umschalten eines Schaltgliedes 3 in einer Zwischenstellung;

Fig. 5

eine Darstellung gemäß Fig. 3, bei der das Freilaufgesperre ein Drehen des Abtriebsgliedes 2 gegenüber dem Antriebsglied 1 im Uhrzeigersinn ermöglicht;

Fig. 6

den Schnitt gemäß der Linie VI - VI in Fig. 4;

Fig. 7

eine erste Explosionsdarstellung der Elemente des Freilaufgesperres und

Fig. 8

eine zweite Explosionsdarstellung der Elemente des Freilaufgesperres.

The invention is explained in more detail below using exemplary embodiments. They show:

Fig.1

in a perspective view, a screwing tool in the form of a wrench with a jaw profile on one end and a ring profile on the opposite end;

Fig.2

a top view of the screwing tool;

Fig.3

enlarges section III in Fig.2 and broken open in such a way that the freewheel lock is visible, wherein the freewheel lock assumes an operating position such that an output member 2 can rotate anti-clockwise relative to a drive member 1;

Fig.4

a representation according to Fig.3 , but when switching a switching element 3 in an intermediate position;

Fig.5

a representation according to Fig.3 , in which the freewheel lock enables the output member 2 to rotate clockwise relative to the drive member 1;

Fig.6

the section according to line VI - VI in Fig.4 ;

Fig.7

a first exploded view of the elements of the freewheel lock and

Fig.8

a second exploded view of the elements of the freewheel lock.

Description of the embodiments

The screwing tool shown in the drawings has an external shape as shown in the EN 10 2014 113 758 A1 shown and described. The screwing tool has an elongated drive member 1, which has a wrench opening at one free end and a bearing eye 6 at its opposite free end. An annular output member 2 is rotatably mounted in the bearing eye 6 with an output profile, which is an internal polygon profile. The output member 2 can also have a different shape, for example form an output polygon, which then forms the output profile. The output member 2 has a peripheral toothing 5 with a large number of radially outward-pointing teeth, the straight tooth flanks of which are roof-shaped.

In a peripheral area of the bearing eye 6 there is a pocket which forms two locking gussets 17, 27 which are opposite one another in the circumferential direction. The locking gussets 17, 27 are formed by walls 18, 28 of the pocket which extend in an arc shape from a bearing bore for supporting a switching element 3 to the radially inner edge of the bearing eye 6 and whose extension intersects the circumferential toothing 9.

In the pocket 17, 27, two locking members 10, 20 formed by separate bodies are mounted, which form locking bodies that touch each other and in overlapping areas 15, 25 also lie on top of each other in some areas, but are pivotably associated with one another. The locking members 10, 20 are designed to be symmetrical to one another. They have an L-shape extending in the plane of movement, with one L-leg being formed by an arm 19, 29 and a second L-leg by a switching extension 13, 23. The two arms 19, 29 point away from one another. The switching extensions 13, 23 adjoin the respective overlapping areas 15, 25 and overlap.

The two locking members 10, 20 are coupled to one another in a joint-like manner. To this end, they each form a hook projection 32 in the overlapping area 15, 25. The two hook projections each engage in a niche. The two hook projections 32 have sufficient movement play so that the locking members 10, 20 can pivot against one another.

The switching extension 13, 23 forms a longitudinal flank pointing towards the arm 19, 29, which merges into a concavity 16, 26, which is followed by a contact flank 12, 22. The arm 19, 29 has two longitudinal flanks running essentially parallel to one another, which merge into one another at the free end 14, 24 of the switching extension 13, 23, forming a curve or a peak.

The contact flank 12, 22 merges into a locking toothing 11, 21, forming an acute angle. The locking toothing 11, 21 extends along a circular arc line, the radius of which corresponds to the radius of the circular arc line along which the peripheral toothing 5 extends. The locking toothing 11, 21 extends into the overlap area 15, 25, in which sections of the switching elements 10, 20, which also include the switching extensions 13, 23, lie one above the other in the direction of the axis a.

The switching extensions 13, 23 engage in a switching recess 30, which is a radial opening in a cavity of the switching element 3. Within the cavity of the switching element 3 there is a switching plunger 7, which has a curved surface 7' pointing radially outwards, which forms a control flank. A switching spring 8 is supported on a locking plunger 9 and acts on the switching plunger 7 in a radially outward direction. The locking plunger 9 acts on a locking ball 33, which can engage in one of two locking recesses 31 in order to prevent the switching element 3 from rotating in one of its two switching positions. The free end 14, 24 of the switching extension 13, 23 forms apex surfaces pointing away from one another, on which the switching flank 7' acts in order to exert a spring force on the locking element 10, 20.

In a first switching position, in which the locking member 10 is located in the locking gusset 17 and rests with its contact flank 12 against the wall 18 of the locking gusset 18, the locking teeth 11 of the locking member 10 engage in the peripheral teeth 5 (see Figure 3 ). If a clockwise torque is applied to the output member 2, the output member 2 cannot rotate within the bearing eye 6. The locking member 10 wedges itself in the locking gusset 17.

The control flank 7' acts on a crest flank of the free end 14 of the switching extension 13 in the direction of the locking gusset 17. The control flank 7' engages the longitudinal flank of the switching extension 13 pointing away from the locking teeth 11.

The control flank 7' engages a crest flank of the free end 24 of the switching element 20 in such a way that the locking teeth 21 of the locking element 20 do not engage with the peripheral teeth 5.

If a torque is applied to the output member 2 in an anti-clockwise direction, the locking member 10 can be displaced in the direction out of the locking groove 17, whereby the contact flank 12 slides along the wall 18 and the locking teeth 11 separate from the peripheral teeth 5, so that the output member 2 can be freely rotated relative to the drive member 1.

To switch over, the switching element 3 is rotated clockwise, whereby the free end 14, 24 of the switching extension 13, 23 of the locking element 10, 20 slides along the control flank 7'. In an intermediate position, the apex areas of the ends 14, 24 are acted upon by the control flank 7' in such a way that the locking elements 10, 20 move relative to one another in a hinge-like manner. In this intermediate position, both locking teeth 11, 21 engage in the peripheral teeth 5. The two locking elements 10, 20 pivot about their hinge connection, which in the embodiment is formed by the two interlocking hook projections 32, until the switching extensions 13, 23 come into a congruent overlapping position.

Based on this in the Figure 4 In the intermediate position shown, in which the locking teeth 11, 21 of both locking members 10, 20 are simultaneously in mesh with the peripheral teeth 5, the switching member 3 is displaced further in a clockwise direction for switching and now acts on the longitudinal flank of the arm 29 of the locking member 20 pointing away from the locking teeth 21 and the longitudinal flank of the arm 19 of the locking member 10 pointing towards the locking teeth 11. This again results in a joint-like relative displacement of the two locking members 10, 20 to one another. The locking teeth 11 of the locking member 10 emerges from the peripheral teeth 5.

In the end position, the locking member 20 is acted upon by the force of the switching spring 8 in the locking groove 27 assigned to it, so that the contact flank 22 is supported on the wall 28 of the locking groove 27 and the locking teeth 21 of the locking member 20 engages in the peripheral teeth 5. The locking teeth 11 of the locking member 10, which performs a non-locking function in this switching position, is located outside the peripheral teeth 5 (see Figure 5 ).

The two locking members 10, 20 are designed in such a way that the two locking teeth 11, 21 extend along the same circular arc when the two switching extensions 13, 23 lie overlapping one another. When the direction of rotation changes, the control flank 7' acts on the apex areas of the switching extensions 13, 23 that are not in the overlapping position in such a way that the locking members 10, 20 pivot against one another in such a way that in an intermediate position the two switching extensions 13, 23 assume an overlapping position, but when the switching member 3 pivots further they move again from the overlapping position to a non-overlapping position.

List of reference symbols

1 Drive link 27 Locking gusset 2 Output link 28 Wall 3 Switching element 29 poor 4 Output profile 30 Switch recess 5 Circumferential gearing 31 Recess 6 Bearing eye 32 Hook projection 7 Switching stamp 33 Locking ball 7' Control flank 8th Switch spring 9 Locking stamp 10 Locking link 11 Locking teeth 12 Investment flank 13 Switching extension 14 End 15 Overlap area 16 Vaulting 17 Gusset/pocket 18 Wall 19 poor 20 Locking link 21 Locking teeth 22 Investment flank 23 Switching extension 24 End 25 Overlap area 26 Vaulting

Claims (10)

1. Screwing tool with a directionally reversible freewheel gearing, having an output member (2) which is mounted rotatably about an axis (a) in a bearing lug (6) of a drive member (1) and has a circumferential toothing (5) and an output profile section (4), and two locking members (10, 20) which are inserted in a pocket (17, 27) of the drive member (1), two locking members (10, 20), each having a locking toothing (11, 21) for rotationally locking engagement in the circumferential toothing (5), which are two bodies which can be displaced relative to one another, characterized in that the two locking members (10, 20) are tied to one another in an overlap region (15, 25) by hook projections engaging in one another.
2. Screwing tool according to claim 1, characterized in that the locking members (10, 20) each have a switching extension (13, 23), the switching extensions (13, 23) projecting into the same switching recess (30) of a switching member (3).
3. Screwing tool according to claim 2, characterized in that the switching projections (13, 23) are acted upon by a spring-loaded control flank (7') in such a way that in the two switching positions, in which the rotatability of the output member (2) is locked in relation to the drive member (1) in a different direction of rotation in each case, only one of the two locking teeth (11, 21) is in engagement in the circumferential teeth (5) in each case.
4. Screwing tool according to claim 3, characterized in that the switching member (3) has a switching plunger (7) which forms the control flank (7') and is acted upon by a switching spring (8).
5. Screwing tool with a directionally reversible freewheel gearing, having an output member (2) which is rotatably mounted about an axis (a) in a bearing lug (6) of a drive member (1) and has a circumferential toothing (5) and an output profile section (4), and two locking members (11, 21) which are inserted in a pocket (17, 27) of the drive member (1), each having a locking toothing (11, 21) for rotationally locking engagement in the circumferential toothing (5), which are two bodies which can be displaced relative to one another, with a switching member (3) which can be switched between two switching positions, the rotatability of the driven member (2) relative to the drive member (1) being blocked in each of the two switching positions in a different direction of rotation and in each case only one of the two locking teeth (11, 21) being in engagement in the peripheral teeth (5), the switching member (3) having a switching plunger (7) forming a control flank (7'), which is acted upon by a switching spring (8), characterized in that the locking members (10, 20) each have a switching extension (13, 23), the overlapping switching extensions (13, 23) projecting into the same switching recess (30) of the switching member (3) and being acted upon by the control flank (7').
6. Screwing tool according to one of the preceding claims, characterized in that the locking members (10, 20) can be displaced relative to one another in a hinge-like manner, the locking toothing (11, 21) of each locking member (10, 20) having teeth which, in a tooth engagement position in the circumferential toothing (5), run on a circular arc around the axis (a).
7. Screwing tool according to one of claims 2 to 6, characterized in that both locking teeth (11, 21) are simultaneously in engagement with the circumferential teeth (5) when the switching element (3) is switched to an intermediate position.
8. Screwing tool according to one of claims 2 to 7, characterized in that the switching member (3) for switching the direction of the freewheel gearing by displacing the locking members (10, 20) in the circumferential direction about the axis (a) from the one pocket (17) into the other pocket (27) opposite thereto in the circumferential direction, in a bore of the drive member (1) enabling rotation of the switching member (3), the pockets (17, 27) each being formed by a wall (18, 28) and a section of the circumferential toothing (5).
9. Screwing tool according to one of claims 3 to 8, characterized in that the curved surface of the switching plunger (7) forming the control flank (7') engages on the end (14, 24) of the switching extension (13, 23).
10. Screwing tool according to one of claims 4 to 9, characterized in that the switching spring (8) is supported on a latching plunger (9) and has a latching element (33) which engages in a latching recess (31) in the switching position.

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