EP3894134B1 - Torque wrench which can be used as a ratchet - Google Patents

Description

field of technology

The invention relates to a screwing tool with a torque output body that defines an axis and is mounted in a housing, with a torque transmission section that has a large number of indentations, with a torque transmission body that is prestressed by a force from an energy store and engages in at least one of the indentations for the torque-transmitting coupling of the torque transmission section to the housing, which torque-transmitting coupling is canceled when the torque-transmitting body leaves the recess in an edge-controlled manner when a limit torque is exceeded against the force of the force accumulator that can be set by an adjusting device.

State of the art

A screwing tool of the type described above is known from DE 20 2018 003 607 U1 . The screwing tool described there has a housing with a head and a drive arm projecting from the head. In the head there is a torque output body with a square section onto which a socket or another screw output tool can be attached. The torque output body has external teeth with gaps between teeth. A torque transmission body engages in one of the gaps and is acted upon by a tappet, which in turn is acted upon by a compression spring. The preload of the compression spring can be adjusted. The set preload of the compression spring defines a limit torque, which is transmitted from the housing to the torque output body. If the torque exceeds the limit torque, the torque transmission body emerges from the depression. This takes place in a ramp-controlled manner. The blocking element can then den the recess overrun the limiting tooth. The drive arm, which protrudes radially from an axis of rotation from the head, can thus be pivoted freely, so to speak, without the torque output body also rotating. Only limited torques can thus be transmitted to a screw connection with the screwing tool.

The DE 10 2008 055 581 A1 describes a torque wrench with a head in which a freewheel gear is arranged. The head sits in a forked end of a two-part arm. A first part of the arm, which includes the fork, is pivotally attached to the second part of the arm, which includes a handle. If a limit torque is exceeded, the two arm parts can pivot slightly against each other, which is accompanied by a clicking noise that indicates that a limit torque has been reached.

The DE 10 2012 103 782 A1 describes a ratchet wrench in which a torque output body is arranged in a head, from which a drive arm protrudes, which body is connected to the head via an overrunning ratchet. In the freewheel locking mechanism there is a movable polygonal section that can optionally protrude from one of the broad sides of the torque output body, so that a screw connection can be turned both clockwise and counterclockwise with the screwing tool.

Screwing tools of the type described above are also disclosed in CN201020685 , DE 10 2017107 784 A1 , US 3,707,893A and the US 7,458,297 B1 showing the preamble of claim 1.

Summary of the Invention

The invention is based on the object of further developing the screwing tool in a way that is advantageous in terms of use. The object is achieved by the invention specified in the claims.

A screwing tool designed according to the invention is characterized first and foremost by the fact that a switching element is provided. The switching element can be shifted from a release position to a blocking position. In the release position, the torque-transmitting body can, as previously described, leave the depression when a limit torque is reached. However, this is not possible in the blocking position. In the release position, the tool has the function of a torque wrench. In the blocking position, the tool has the function of a conventional screwing tool, with which torques that are above the limit torque can also be transmitted. In particular, it is provided that the screwing tool has a freewheel gear between the torque transmission section and the torque transmission body, so that the screwing tool can be used as a ratchet wrench in the blocked position, as is shown in FIG DE 10 2012 103 782 A1 is described. In a further development of the invention or the prior art or the invention, a freewheel gear is provided in the torque transmission path between the torque output body and the torque transmission section. As a result of this configuration, the torque wrench can also be used in tight spaces, since pivoting back and forth, for example, of a grip arm arranged on a head, is sufficient to gradually transfer a rotational movement to a screw connection. In the final phase of tightening a screw connection, the torque transmitted from the screwing tool to the screw connection increases until a limit torque is reached. The torque transmission body then slips out of the depression in the torque transmission section, so that the screw connection can only be screwed with an adjustable limit torque.

In a preferred variant of the invention, a switching element is provided which is designed as a sleeve part. The sleeve part is opposite Housing movable. In particular, it can be displaced relative to the housing. The switching element can interact with at least one blocking element. However, the switching element preferably interacts with a plurality of blocking elements. The blocking element can be a ball. The housing can have a window in which the blocking element is arranged. The housing and in particular an arm of the housing preferably has a tube in which the at least one window is arranged. If several blocking elements are provided, the housing has several windows. A plunger can be arranged inside the housing. The ram is in the power transmission path between the torque transmission body, which can be a ball, and the energy accumulator, which can be a compression spring. The plunger can have one or more blocking recesses. The blocking recesses are arranged in such a way that they are spatially associated with a window of the housing when the torque-transmitting body is located in one of the plurality of depressions. By moving the switching element and in particular by moving the switching element relative to the housing, the switching element can be shifted back and forth between a release position and a blocking position. In the release position, the blocking element can emerge from the blocking recess in order to enter, for example, an escape space of the switching element. In this position, the plunger can move relative to the housing. In particular, it can move linearly in the tube. In the blocking position, the blocking element is prevented from emerging from the blocking recess, for example in that an opening in the window pointing in the outer direction of the housing is closed by an abutment flank of the switching element. In the blocking position, the blocking element cannot leave the blocking recess. If a torque is applied to the housing, this torque is transmitted to the torque transmission section with the torque transmission body, which engages in a form-fitting manner in a recess in the torque transmission section. Designed as a circular cylinder Torque transmission body is in a recess whose bottom is adapted to the outline contour of the torque transmission body. The bottom of the depression extends in particular along an inner cylindrical surface. In a cross-sectional plane, the base between the two tips of the teeth delimiting the recess runs on a circular arc line, the arc angle being less than 90°. The sections of the bottom wall of the depression adjacent to the teeth thus form inclined flanks in order to apply force to the torque transmission body when a torque is applied. In the blocking position, these forces are dissipated via the blocking elements into the housing, ie in particular the pipe. The torque transmission section is connected to the torque output body via the one-way gear, so that the torque is transmitted to the torque output body. The latter can have an output pin on which a nut or the like can be placed in order to transmit the torque to a screw head or a nut. In the blocking position, the plunger cannot move relative to the housing. The depression has inclined flanks or rounded flanks that convert the torque into a force that pushes the torque-transmitting body out of the depression. The force acts on the plunger, which is acted upon by the spring of the energy store. If the switching element is in the release position, the plunger can be displaced with the technical success described above, that when an adjustable limit force is exceeded, the torque transmission body slips out of the depression and, for example, overruns a tooth limiting the depression in order to enter a further depression. In the blocking position, displacement of the tappet is not possible, so that the torque transmission body is permanently held in a form-fitting manner in the recess. The torque transmission section preferably has a gear-like shape with teeth distributed uniformly in the circumferential direction, between which the indentations are located. The torque transmission section rotatably mounted in a head of the housing, which is preferably located radially outside of the torque output body can thus rotate by any angular degrees within its bearing opening in the head when the torque applied to it exceeds the limit torque. The torque output body can have an output pin, which is adjustable relative to the axis of rotation in the axial direction, as can be seen from FIG DE 10 2012 103 782 A1 is known. The content of this document is included in its entirety in the disclosure content of this application. The output pin has a polygonal section on both sides, which can optionally protrude from one of the two broad sides of the head pointing away from one another, so that the screwing tool can be screwed in both a clockwise and counter-clockwise direction. In a development of the invention, it is provided that the tappet has two, three or four or more blocking recesses arranged on a peripheral surface. The blocking recesses are spatially assigned to a window in which a blocking element lies. The blocking recesses or the windows can be arranged in a uniform circumferential distribution around an axis of extension of the drive arm. At the end of the drive arm there can be an adjustment device which can be used as a handle or is adjacent to a handle and can be used to adjust the force of the energy store and thus the limit torque by turning the handle. A locking element can be provided with which the rotation of the adjustment device can be blocked. The drive arm preferably protrudes in the radial direction relative to an axis of rotation of the screw. The teeth of the torque transmission section preferably protrude radially outwards, so that they form external teeth. The torque transmission body lying in the tooth gap is preferably shifted out of the depression in the radial direction. The plunger is also displaced in the radial direction in relation to the direction of screwing rotation in order to compress the prestressed spring arranged in a cavity in the drive arm. The drive arm is therefore preferably designed as a tube. On this tube, the switching element can be linear be slidably arranged, preferably with the switching element being arranged immediately adjacent to the head.

Brief description of the drawings

Fig. 1

eine perspektivische Darstellung eines Schraubwerkzeuges;

Fig. 2

eine Draufsicht auf das Schraubwerkzeug;

Fig. 3

die Ansicht in Richtung des Pfeiles III in Figur 2;

Fig. 4

den Schnitt gemäß der Linie IV - IV in Figur 3;

Fig. 5

den Schnitt gemäß der Linie V - V in Figur 3;

Fig. 6

den Schnitt gemäß der Linie VI - VI in Figur 3;

Fig. 7

den Schnitt gemäß der Linie VII - VII in Figur 3;

Fig. 8

eine Darstellung gemäß Figur 4, wobei jedoch ein Drehmomentübertragungskörper 7 aus einer Vertiefung 6 herausgetreten ist und einen Zahn 15 überläuft;

Fig. 9

eine Darstellung gemäß Figur 5, jedoch in einer Betriebsstellung gemäß Figur 8;

Fig. 10

eine Darstellung gemäß Figur 4, jedoch mit von einer Freigabestellung in eine Blockierstellung verschobenem Umschaltglied 12;

Fig. 11

eine Darstellung gemäß Figur 5, jedoch in der in Figur 10 dargestellten Betriebsstellung;

Fig. 12

einen Schnitt gemäß der Linie XII - XII in Figur 2 und

Fig. 13

eine Explosionsdarstellung.

An embodiment of the invention is explained below with reference to the accompanying drawings. Show it:

1

a perspective view of a screwing tool;

2

a plan view of the screwing tool;

3

the view in the direction of arrow III in figure 2 ;

4

the cut according to the line IV - IV in figure 3 ;

figure 5

the cut according to the line V - V in figure 3 ;

6

the cut according to the line VI - VI in figure 3 ;

7

the cut according to the line VII - VII in figure 3 ;

8

a representation according to figure 4 , However, a torque transmission body 7 has emerged from a recess 6 and overruns a tooth 15;

9

a representation according to figure 5 , but in an operating position according to figure 8 ;

10

a representation according to figure 4 , but with shifted from a release position to a blocking position switching element 12;

11

a representation according to figure 5 , but in the in figure 10 illustrated operating position;

12

a cut according to the line XII - XII in figure 2 and

13

an exploded view.

Description of the embodiments

The screwing tool shown in the figures has a housing 1 which has a head 2 at a first end. The head 2 has a cavity in which a rotatable body is seated. The rotatable body is in several parts. It has a torque output body 4 with a polygonal cavity in which an output pin 22 is inserted, which can be displaced in relation to the axis of rotation A of the torque output body 4 in order to protrude with a polygonal section either on one or the other broad side of the head.

The torque output body 4 is a in the figure 7 recognizable freewheel gear coupled to a torque transmission section 5. For this purpose, the torque transmission section 5 has a cavity in which the torque output body 4 is inserted. The torque output body 4 has external teeth, in which a locking body 17 lying in a bearing recess 18 of the torque transmission section 5 can engage. The blocking body 17 is acted upon by a spring into a blocking position, so that when the torque transmission section 5 rotates clockwise the torque output body 4 is entrained in rotation. If, on the other hand, the torque transmission section 5 is rotated counterclockwise, the counter teeth of the blocking body 17 can emerge from the outer teeth of the torque output body 4 so that the torque transmission section 5 can rotate freely relative to the torque output body 4 . With regard to the design of the freewheel gear is on the DE 10 2016 101 400 A1 and to the one mentioned therein DE 10 2014 113 758 A1 referred. The disclosure content of these documents is included in the disclosure content of this application.

Like the figures 4 , 8 or 10 As can be seen, the torque transmission section 5 has teeth 15 which point radially outwards in relation to the direction of screwing rotation and are arranged in a uniform circumferential distribution around the center. The wall of the depression 6 is formed by a curve. The rounding corresponds to a rounding of a torque transmission body 7 formed by a cylinder, which can engage in one of the depressions 6 .

The torque transmission body 7 is acted upon by a tappet 8 which extends in a cavity of a drive arm 3 which protrudes in the radial direction from the head 2 in relation to the direction of screwing rotation. The plunger 8 is acted upon by a compression spring 19 which forms an energy accumulator and which is prestressed. By means of an adjustment device 20, which is assigned to a handle 24 arranged at the free end of the drive arm 3, the prestressing of the compression spring 19 can be adjusted. By turning the adjusting device 20 , a clamping element 27 coupled via a thread to a tube 23 formed by the arm 3 is shifted axially with respect to the tube 23 . A display 25 observable through a window 21 is provided is, on which the currently set torque is displayed. The clamping element 27 acts against a pressure piece 26 which acts on the spring 19 which is supported on the plunger 8 with its other end.

The ram 8 has a total of four blocking recesses 10 arranged in a uniform circumferential distribution on its jacket wall (see Fig figure 6 ), in each of which a blocking element 9 rests in the form of a sphere. Relative to an axis of extension of the drive arm 3, each of the four blocking elements 9 can move in a radial direction within a window 11 of the tubular drive arm 3 in order to emerge from the blocking recess 10 in a release position of a switching element 12. For this purpose, the switching element 12 and in particular its inner wall has an escape space 13.

The switching element 12 is designed as a sleeve-like slide and is located on the outside of the drive arm 3, in the immediate vicinity of the head 2. By shifting the switching element 12 in an axial direction relative to the axis of extension of the drive arm 3, the switching element 12 can be moved from a release position to a blocking position to be brought. In the release position in the Figures 4 to 9 is shown, the blocking elements 9 can emerge from the blocking recesses 10 in the radial direction, so that the plunger 8 can move within the drive arm 3 . On the tube 23, which is firmly connected to the head 2, sits a casing 28 which is flush with the handle 24 is connected. On its side pointing towards the head 2 , this casing has a step which forms an end stop for the switching element 12 . In the release position, in which the torque wrench tool can be used, the switching element 22 rests against the casing 28 . The outer surface of the switching element 12 merges flush with the outer surface of the casing 28, which is attached to the tube 23 by means of grub screws 29.

In the in the Figures 10 and 11 illustrated blocking position of the switching member 12 is outside the window 11, an abutment edge 14 which is formed by the inner wall of the switching member 12. The blocking elements 9 , which lie in the blocking recess 10 , are supported on this abutment flank 14 , so that they cannot emerge from the blocking recess 10 and thus prevent the plunger 8 from being able to move axially in relation to the direction in which the drive arm 3 extends. The inner radius of the abutment flank 14 running on an inner cylindrical surface is only slightly larger than the outer radius of the tube 23 having the windows 11. In the blocking position, the switching element 12 is at a distance from the casing 28.

The functioning of the screwing tool is as follows:

Because of the above-described one-way gear between the torque output body 4 and the torque transmission portion 5, an output pin 22 can be rotated in a constant rotary motion by swinging the drive arm 3 back and forth about the screw axis. The direction of rotation of the screwing tool can be reversed by moving the output pin 22 in an axial direction in relation to the screwing direction.

Is the switch 12 in the Figures 4 to 9 shown release position, in which the plunger 8 can move relative to the drive arm 3, a limited torque can be transmitted to a screw connection with the screwing tool. If the torque is below one by means of the setting device 20 adjustable limit torque, so remains during the screwing of the torque transmission body 7 in one of the several recesses 6, as the Figures 4 and 5 show. A torque is transmitted from the housing 1 to the torque transmission section 5 via the torque transmission body 7 . The trough that forms the depression 6 forms an inclined flank that converts the torque into a radial force that acts against the prestressing force of the spring 19 . The consequence of this is that the torque transmission body 7 and with it the plunger 8 are displaced in the radially outward direction with respect to the screw axis of rotation, which is accompanied by an increase in the spring tension. When the ram 8 is displaced in the direction of the pressure piece 26, a pin of the pressure piece 26 moves in a cavity of the ram 8. The compression spring 19 extends around the pin or the jacket of the cavity Well 6 out how it dies Figures 8 and 9 show. The torque transmission body 7 runs over a tooth 15 of the external toothing of the transmission section 5 and can dip into the adjacent depression 6 . In this case, the torque transmission section 5 is not also displaced by the pivoting movement of the drive arm 3 . If the drive arm 3 pivots further about the screwing axis, the adjoining teeth 15 are also overrun, so that no higher torque than the limit torque is transmitted to the torque output body 4 .

If the switching element 12 in the Figures 10 and 11 Blocking position shown shifted, so the blocking elements 9 can not come out of their associated blocking recesses 10 because they are bound by the abutment flank 14 positively in the blocking recesses 10. In this operating position, the torque transmission body 7 cannot leave the depression 6 assigned to it, even if a limit torque is exceeded, so that in the blocking position of the switching element 12 Torques can also be transmitted that are greater than the limit torque and the screwing tool can be used as a "normal" ratchet/ratchet. The forces transmitted from the torque transmission body 7 to the ram 8 are transmitted to the walls of the window 11 of the tube 23 via the blocking elements 9 designed as a ball. Since the pipe 23 is firmly connected to the head 2, the forces are diverted back into the head 2.

The above statements serve to explain the inventions covered by the application as a whole, which also independently develop the state of the art at least through the following combinations of features, whereby two, several or all of these combinations of features can also be combined, namely:

A screwing tool which is characterized in that a freewheel gear 16 , 17 , 18 is provided in the torque transmission path between the torque and torque output body 4 and the torque transmission section 5 .

A screwing tool which is characterized by a switchover member 12 which can be displaced from a release position into a blocking position, which in the release position allows the torque transmission body 7 to leave the recess but blocks it in the blocking position.

A screwing tool which is characterized in that the switching element 12 is a sleeve part which is guided in a displaceable manner on the housing 1 and which interacts with at least one blocking element 9 which is movably mounted in particular in a window 11 of the housing 1 and which, in particular in the blocking position, moves into a blocking recess 10 of a ram 8 is tied up, which is arranged in the force transmission path between the torque transmission body 7 and the force accumulator 19 .

A screwing tool which is characterized in that the ram 8 has two, three, four or more blocking recesses 18 arranged on a peripheral surface, each for the entry of an associated blocking element 9 .

A screwing tool which is characterized in that the switching element 12 forms an escape space 13 for the blocking element 9 in the release position with a first section of its inner wall and an abutment flank 14 for the blocking element 9 in the blocking position with a second section of its inner wall.

A screwing tool which is characterized in that the torque output body 4 is arranged in a head 2 formed by the housing 1, with a drive arm 3 protruding from the head 2, in which a spring forming the energy accumulator 19 is arranged, which with the interposition of the plunger 8 the torque transmission body 7 acts.

A screwing tool, which is characterized in that the indentations 6 are formed by tooth gaps arranged between teeth 15 .

A screwing tool, which is characterized in that the switching member 12 is linearly displaceable with respect to the extension direction of the drive arm 3 between the blocking position and the release position.

A screwing tool, which is characterized in that the recess 6 is a trough, the wall of which extends along the axis A in cross section of a circular arc, the radius of which corresponds in particular to the radius of the torque transmission body 7 designed as a cylinder, the arc length being less than a quarter of a circle, the sections of the wall of the recess 6 adjoining the teeth forming inclined flanks, for steering the torque transmission body 7 out of the recess 6 .

List of References

1 Housing 25 Advertisement 2 Head 26 Pressure piece 3 drive arm 27 clamping element 4 torque output body 28 sheathing 5 torque transmission section 29 grub screw 6 deepening 7 torque transfer body 8th pestle A axis 9 blocking element 10 blocking recess 11 Window 12 switching element 13 escape room 14 abutment flank 15 Tooth 16 gearing 17 locking body 18 bearing recess 19 spring/ force accumulator 20 adjustment device 21 Window 22 output trunnion 23 Pipe 24 Handle

Claims (12)

1. A screw driving tool comprising a torque output element (4) which defines an axis (A) and is mounted in a housing (1), a torque transmission section (5) with a plurality of depressions (6), a torque transmission element (7), which is pretensioned by a force of a force accumulator (19) and engages in at least one of the depressions (6), for coupling the torque transmission section (5) to the housing (1) so as to transmit a torque, said torque-transmitting coupling being released when the torque transmission element (7) leaves the depression in an edge-controlled manner against the force of the force accumulator (19), which can be adjusted by an adjustment device (20), when a torque limit is exceeded, characterised by a switchover element (12), which can be moved from a release position into a blocking position, which in the release position permits the torque transmission element (7) to leave the depression, but in the blocking position blocks it.
2. The screw driving tool according to claim 1, characterised in that a freewheel gear (16, 17, 18) is provided in the torque transmission path between torque output element (4) and the torque transmission section (5).
3. The screw driving tool according to any one of the preceding claims, characterised in that the switchover element (12) is a sleeve part guided displaceably on the housing (1) and cooperates with at least one blocking element (9).
4. The screw driving tool according to claim 3, characterised in that the blocking element (9) is mounted movably in a window (11) of the housing (1).
5. The screw driving tool according to claim 4, characterised in that the blocking element (9) is captured in the blocking position in a blocking recess (10) of a ram (8), which is arranged in the force transmission path between the torque transmission element (7) and the force accumulator (19).
6. The screw driving tool according to claim 5, characterised in that the ram (8) comprises two, three, four or more blocking recesses (18) arranged on a peripheral area in each case for the entry of an assigned blocking element (9).
7. The screw driving tool according to any one of claims 3 to 6, characterised in that the switchover element (12) forms with a first section of its inner wall a bypass space (13) for the blocking element (9) in the release position and forms with a second section of its inner wall an abutment edge (14) for the blocking element (9) in the blocking position.
8. The screw driving tool according to any one of the preceding claims, characterised in that the torque output element (4) is arranged in a head (2) formed by the housing (1), wherein a drive arm (3) projects from the head (2), in which a spring forming the force accumulator (19) is arranged, which with the interposition of the ram (8) acts on torque transmission element (7).
9. The screw driving tool according to any one of the preceding claims, characterised in that the depressions (6) are formed by tooth gaps arranged between teeth (15).
10. The screw driving tool according to any one of claims 1 to 9, characterised in that the switchover element (12) is linearly displaceable relative to the direction of extension of the drive arm (3) between the blocking position and the release position.
11. The screw driving tool according to any one of the preceding claims, characterised in that the depression (6) is a trough, the wall of which extends in cross-section to axis (A) along a circular arc line.
12. The screw driving tool according to claim 11, characterised in that the radius of the trough corresponds to the radius of the torque transmission element (7) constituted as a cylinder, wherein the arc length is smaller than a quarter circle, wherein the sections of the wall of the depression (6) adjacent to the teeth form inclined edges, so as to guide the torque transmission element (7) out of the depression (6).

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