EP2756924B1 - Adjustment of a torque wrench - Google Patents

Description

The present invention relates to a torque wrench according to the features in the preamble of claim 1. A torque wrench having these features is disclosed in, for example, US Patent No. 5,383,247 DE 20 2011 050887 U1 disclosed. Torque wrenches are used to tighten screw connections with a predetermined torque. Here there are screw, for example, wheel nuts of a motor vehicle or even long screws for coupling a cylinder head on an internal combustion engine, which must be tightened with a predetermined torque, on the one hand at a low tightening torque, an independent release and the other at too high tightening torque to avoid damage to the screw or adjacent components.

Typically, a torque wrench has a handle at a free end to be operated by an applying fitter, and at the opposite end thereof a ratchet head that quickly modifies a torque wrench for a particular bolted connection by inserting sockets or nuts.

It is therefore necessary for a torque wrench to apply a high-precision tightening torque to a screw connection. Furthermore, however, a torque tool should have an adjustable firing torque to be accessible to a wide range of applications. For this purpose, torque wrenches usually have a trigger mechanism, consisting of a prestressable spring and a triggering lever, wherein the biasing force of the spring is adjustable by a rotation of the handle on the shaft of a torque wrench. If the torque wrench is then used for tightening a screw connection and the screw connection reaches the set triggering torque, then the lever strikes against an inside of the housing and gives a haptic and / or acoustic feedback to the user using the triggering torque.

For the production of torque wrenches, however, it is first necessary that the individual parts of the torque wrench be made separately from each other and then assembled. The so completed torque wrench first requires a pre-setting and then a fine adjustment of the adjustable torque, so that in later use operation a user fitter by turning the handle when setting a triggering torque, which is displayed for example on the handle with a scale, can make sure that the set torque corresponds to the desired triggering torque value.

This is for example in the EP 1 825 959 B1 an adjustment shown, in which first the spring of the release mechanism is brought into conformity with a respective corresponding release torque by Vorjustage and then a spindle drive is firmly coupled to the handle, so that by later twisting the handle itself respectively the spring of the release mechanism is biased according to the desired release torque.

Object of the present invention is therefore, starting from the prior art, to simplify the Feinjustierungsmöglichkeit a torque wrench and to produce such a torque wrench cheaper.

The aforementioned object is achieved by a torque wrench with the features in claim 1.

Advantageous embodiments of the present invention are the subject of the dependent claims.

The torque wrench according to the invention for tightening or loosening a screw connection has a shank and a handle disposed at one end of the shank, wherein on the opposite end of the handle a receptacle for a positive screw connection can be coupled, which in particular a ratchet head with square for receiving a Socket can be. In the shaft by a relative rotation of the handle relative to the shaft biased by a spring triggering mechanism is arranged, with which a release torque is adjustable, wherein the trigger mechanism has a spindle which is positively coupled to the handle and the trigger mechanism is pre-adjustable. According to the invention the torque wrench is characterized in that an adjusting ring is provided at a free end of the handle and the adjusting ring is coupled to the spindle via a positive engagement, wherein for performing the adjustment of the adjusting ring in the axial direction on the spindle is displaceable, so that the handle is no longer in rotationally fixed engagement with the spindle, wherein by turning the adjusting ring, the spindle is movable.

In the context of the invention, the adjustment process thus means a first pre-adjustment or readjustment in the production of the torque wrench as well as a readjustment already taking place during the use of the torque wrench. Thus, an adjustment process is to be understood as meaning that the triggering mechanism is finely adjusted in such a way that a respective relative rotation of the Handle made setting a release torque also corresponds to the torque applied to the screw.

For this purpose, it is necessary in the context of the invention for adjusting the release torque by relative rotation of the handle relative to the shaft that the handle itself is positively coupled to the spindle drive such that rotation of the handle causes an axial movement of the spindle relative to the shaft. To make the adjustment now, however, this positive connection between the spindle and the handle must be solved. For this purpose, the present invention provides two different ways to make a positive connection between the handle and spindle, and thus also for releasing the positive connection between the handle and spindle before.

On the one hand, it is possible that the positive connection between the handle and spindle is caused by a direct and thus direct interlocking of the handle and spindle. Optionally, it is then possible that the adjusting ring is also positively interlocked with the spindle and / or with the handle. To carry out this variant, it is therefore necessary that the interlocking toothing between the handle and spindle is released, which according to the invention by an axial displacement of the handle relative to the spindle, so that the toothing between the handle and spindle is no longer in positive engagement. The handle is thus freely rotatable without causing a rotational movement of the spindle drive. Here, the present invention now provides that the adjusting ring is still positively engaged with the spindle and the desired torque is adjusted by turning the adjusting ring and concomitant rotation of the spindle. If the desired torque of the pre-adjustment is set, the handle is aligned with the existing on the torque wrench display and brought by axial displacement in positive engagement with the teeth. By example, a lock nut, which is arranged at the end of the spindle, now accidental or unwanted axial movement of the handle relative to the spindle is avoided.

Alternatively, it is possible in the context of the invention that the handle is always relatively rotatable relative to the spindle. A non-rotatable connection between Handle and spindle are produced indirectly via the adjusting ring. Thus, the adjusting ring is positively and rotationally coupled to the spindle and in turn has a toothing possibility, which is positively engageable with the handle. Now, if the positive connection between the handle and adjusting ring, for example, by axial displacement of the adjusting, solved, it is possible by rotating the adjusting ring to move the spindle while adjusting the desired release torque in the context of pre-adjustment. The handle is then freely rotatable and can be turned to the desired value of the scale. Then is brought by axial displacement of the adjusting ring relative to the spindle of the adjusting ring in positive engagement with the handle, whereby the handle is then in turn indirectly rotationally coupled to the spindle. After carrying out the axial displacement movement, it is then possible again to secure against unintentional or unintentional displacement of the adjusting ring together with the handle by means of a lock nut or lock nut at the end of the spindle.

The present invention is further characterized in that the handle is coupled via a positive connection with the spindle, wherein the handle in particular a Innenmehrfachkantverbindung, preferably a hexagon socket, and the Innenmehrfachkantverbindung form-fitting in a corresponding Außenmehrfachkantverbindung, more preferably an external hex, the spindle engages or receives this. This makes it possible within the scope of the invention to produce a positive, torsion-proof connection between the spindle and the handle, which in a handle made of plastic and a spindle made of metallic material, even with multi-year intensive use of the torque wrench, a twist-proof coupling of the spindle and handle ensures. As a result, the manufacturing cost of the torque tool can be significantly reduced, with no additional components in the form of splints or the like for producing the twist-proof coupling of the handle and spindle are necessary. Rather, it is possible to couple the handle and the spindle by simple, interlocking nesting together. The spindle is preferably formed in one piece and of uniform material. For this purpose, preferably in the context of the invention for performing the pre-adjustment of the handle in the axial direction relative to the spindle is moved, so that no positive engagement between the spindle and handle is more present. Preferably, the handle is coupled by a lock nut at the end of the spindle. To perform the pre-adjustment, the lock nut is then not listed on the spindle or released from the spindle and then the handle at least so far moved back in the axial direction that the positive engagement between the Mehrfachkantverbindung of the spindle and handle no longer exists. The handle can thus be rotated relative to the spindle. Consequently, a rotation of the handle does not cause any movement of the spindle. The spindle can then be pre-adjusted independently of the handle and thereby performs a tensioning or relaxing movement of the spring. For this purpose, a torque value is set, which is then adjusted by turning the handle also on the display of the handle and by further axial displacement of the handle relative to the spindle such that the handle and spindle come into positive engagement, so determined that now a pre-adjustment or Fine adjustment has taken place. This may be an initial setting in the production of the torque wrench itself or else a readjustment after intensive use or in maintenance intervals of the torque wrench. Preferably, the pre-adjustment is carried out in the context of the invention on the Justierring, wherein in the Vorjustierungsposition the Justierring with the spindle is in positive engagement.

The adjusting ring is therefore preferably coupled positively and non-rotatably with the spindle. In axial displacement of the handle and the adjusting ring is axially displaced, wherein the invention provides that the adjusting ring is then still in positive engagement with the spindle when the handle is no longer in positive engagement with the spindle. A rotation of the adjusting ring then leads to a process of the spindle and thus to a clamping movement of the spring, wherein this is done independently of the handle. For this purpose, the spindle has an external toothing in particular in the region of the adjusting ring and the adjusting ring itself has a corresponding internal toothing, wherein the adjusting ring and the spindle are axially displaceable, but nevertheless non-rotatable in the Are engaged. In particular, the teeth are an external hexagon and a corresponding hexagon socket. The positive engagement of the Justierrings in the normal position of use and the optional positive coupling of Justierring and handle in the context of the invention again has the advantage that in the normal use position resulting from the rotation of the handle force to drive and process the spindle for a over the positive engagement between the handle and spindle, on the other hand, but also on the positive engagement between the adjusting ring and spindle is transferred from the hand of the applying mechanic to the spindle. Thus, it is possible to produce both the handle and the adjusting ring of a plastic material without fatigue of the material is recorded here even after years and intensive use of the adjustment.

Thus, the spindle is movable relative to the shaft, a spindle nut is provided in the shaft end, which is fixedly and positively coupled to the shaft end. A rotation of the spindle in the spindle nut thus leads to a relative movement of the spindle relative to the shaft in the axial direction, wherein in the shaft itself, in turn, a spring is provided which is stretched or relaxed due to the movement of the spindle.

So that further a positive coupling between the adjusting ring and the handle is made possible, the adjusting ring preferably has tooth-like extensions oriented in the axial direction, which can be brought into corresponding recesses of the handle for engagement. In the normal use position, therefore, if the handle and / or the adjusting ring are not in the position for pre-adjustment, thus adjusting ring and handle are in positive engagement. If now the handle, but also the adjusting ring brought into the Vorjustierposition, and the positive connection between the handle and adjusting ring is released. This allows in particular the independent adjustment of the position of the spindle and the position of the handle with corresponding display of the set torque.

Further particularly preferably, the adjusting ring in the invention at its free end at least one recess, wherein in the recess a rotating about the longitudinal axis of the spindle adjusting tool can be coupled. in this connection In particular, it is a mechanical adjustment tool, so that in an at least partially automated production of the torque wrench, the adjustment tool can be coupled to the alignment ring and a process in the axial direction of the spindle is performed by rotation.

If then a pre-adjustment has been carried out, it is further provided in the invention that the adjusting ring and / or the handle are pushed in the axial direction to the shaft and coupled by a lock nut on the spindle. Furthermore, a closure cap is then particularly preferably incorporated into the adjusting ring itself, which on the one hand prevents the ingress of dirt. Furthermore, it is possible to make a readjustment by removing the cap relative to the adjusting ring and loosening the lock nut.

In the context of the invention, the adjusting ring itself is thus accessible from the outside. It is not necessary to disassemble the torque wrenches largely or completely to make an adjustment in the context of the invention, which is particularly advantageous in a Nachjustiervorgang. The adjusting ring itself is furthermore particularly preferably designed such that it can be reached by hand and can also be adjusted by manual intervention. Thus, inevitably no special adjustment tool or a motor drive an adjustment tool is necessary to make in particular a readjustment of the torque wrench. Particularly preferably, the adjusting ring therefore at its free end on a grip option, for example, according to the principle of a wing nut. Optionally additionally or alternatively, the adjusting ring further has such a receptacle for an adjusting tool, in particular a motor-driven adjusting tool, so that the torque wrench over this at least partially mechanized or can be automatically adjusted.

Further preferably, a suspension loop is integrally formed on the handle and / or the adjusting ring and uniform material, with which it is possible to hang the torque wrench on a tool wall or the like when not in use. Due to the solid, positive connection of both handle as well as adjusting ring with the shaft and thus the torque wrench, the entire torque wrench can be hung when not in use.

Furthermore, it is possible within the scope of the invention to guide through the suspension loop a wrist strap or safety line, so that here, for example, a fall protection is given, so that the user fitter who accidentally slip the torque wrench from his hand, prevents this on the Floor hits. In addition, in an industrial manufacturing of the torque wrench may be hung, for example, on a wire rope with return spring, so that it is easily accessible to a user fitter and in turn can be easily moved out of the field.

Figur 1

einen erfindungsgemäßen Drehmomentschlüssel in einer teilweisen Draufsicht,

Figur 2a und b

den Drehmomentschlüssel in einer Längsschnittansicht in Gebrauchsposition und in Vorjustierposition und

Figur 3a und b

den Griff mit Justierring und Spindel in Explosivdarstellung.

Further advantages, features, characteristics and aspects of the present invention are the subject of the following description. Preferred embodiments are shown in the schematic figures. These are for easy understanding of the invention. Show it:

FIG. 1

a torque wrench according to the invention in a partial plan view,

FIGS. 2a and b

the torque wrench in a longitudinal sectional view in the use position and in Vorjustierposition and

FIG. 3a and b

the handle with adjusting ring and spindle in explosive representation.

In the figures, the same reference numerals are used for the same or similar components, even if a repeated description is omitted for reasons of simplicity.

FIG. 1 shows a torque wrench 1 according to the invention in a plan view. Shown are a shaft 2 and arranged at the end of the shaft 2 handle 3. The handle 3 is rotatable about the central longitudinal axis 4 of the shaft 2 and is thereby moved in the axial direction A. In this case, a release mechanism, not shown, is biased within the shaft 2 such that a desired release torque is adjustable. The respective torque value can be read on a display 5. So now a pre-adjustment or fine adjustment of the set Torque can be performed, according to the invention at the handle end 6 an adjusting ring 7 is arranged.

The functioning is in FIGS. 2a and b , which each have a longitudinal sectional view along the central longitudinal axis 4 of the torque wrench 1 of FIG. 1 shows. Regarding FIG. 2a First, a use position is shown. The handle 3 itself is arranged relatively rotatable about the central longitudinal axis 4 of the shaft 2. So that no unwanted adjustment is carried out according to the desired set release torque, a latching mechanism 8 is provided, by means of which the handle 3 and the shaft 2 are positively fixed to one another. However, now that initially by the rotation of the handle 3 relative to the shaft 2, an adjusting movement is caused, a spindle nut 10 is fixed in position on the shaft end 9 in the shaft 2. This is illustrated by two cylindrical pins or grub screws 11.

Within the spindle nut 10 itself, a spindle 12, which is displaceable in the axial direction A by rotational movement, is mounted. The spindle 12 itself is positively and rotatably coupled to the handle 3 via a spindle 12 provided on the outer hexagon 13 and a corresponding hexagon socket 14 in the handle 3 with each other. For this positive and rotationally fixed coupling between the hexagon socket 13 and hexagon socket 14 is held, a lock nut 16 is provided at the spindle end 15, which prevents axial displacement of the handle 3 relative to the spindle 12.

In an alternative embodiment, there is no direct rotationally fixed coupling between the spindle 12 and the handle 3 via the external hexagon 13. The external hexagon 13 is hereby alternatively designed to be axially displaceable on the spindle 12 as a nut. It is thus possible, an indirect coupling between the handle 3 and spindle 12 via the adjusting ring 7, in particular on the in FIGS. 3a and 3b shown teeth 20 and recesses 21 to produce. It is thus set the distance in the axial direction A by turning the hexagon socket 13 as a nut relative to the spindle 12 and then the spindle 12 is indirectly rotatably coupled via the adjusting ring 7 with the handle 3.

Now, if the handle 3 is rotated about the central longitudinal axis 4 of the shaft 2, the spindle 12 undergoes a rotational movement, on the other hand, the spindle 12 is moved in the axial direction A. A spindle head 17 then biases a spring, not shown, and sets a desired release torque over it.

To make a pre-adjustment or fine adjustment, it is provided in the invention that the positive coupling between the handle 3 and spindle 12 is detachable, the spindle 12 is pre-adjustable or finely adjusted and then the coupling between the handle 3 and spindle 12 again fixed is.

The pre-adjustment process is in FIG. 2b shown. Here, the lock nut 16 is released and the handle 3 in the axial direction A on the spindle 12 on the image plane relative pushed to the right. The external hex 13 is therefore no longer in positive engagement with the hexagon socket 14. The handle 3 is thus freely rotatable in this position in this position relative to the shaft 2, without causing a rotational movement or movement of the spindle 12.

However, now that access to the spindle 12, in particular a rotational movement of the spindle 12, is feasible, the adjusting ring 7 is positively coupled with an internal toothing 18 and against rotation to an external toothing 19. By a rotational movement of the adjusting ring 7, it is thus possible to cause a rotational movement of the spindle 12, regardless of the handle position. A possible positive engagement between adjusting ring 7 and handle 3 is negligible at this point. If, however, a positive interlocking of adjusting ring 7 and handle 3 be provided here, it would still be possible, the adjusting ring 7, in FIG. 2b not shown in detail, in the axial direction A slightly further based on the image plane to the right, so that the positive connection between adjusting ring 7 and handle 3 is released, however, still the internal teeth 18 of the Justierrings 7 with the external teeth 19 of the spindle 12 in positive and is non-rotatable engagement.

When this setting of the release torque is made, the handle 3 is moved to the desired position of the in FIG. 1 rotated display 5 so that the torque value displayed on the display 5 with the set triggering torque the trigger mechanism not shown matches. Then adjusting ring 7 and handle 3 in the axial direction A, based on the image plane to the left, moved and connected by means of the lock nut 16 fixed to the spindle 12.

FIG. 3a and b show this structure again in a perspective exploded view. Shown are the loosened from the spindle end 15 lock nut 16 and each pulled apart in the axial direction A components. Good to see the internal teeth 18 of the adjusting ring 7, which is axially movable in the assembled state with the external teeth 19 of the spindle 12 can be brought into positive engagement. Also clearly visible is the internal double hexagon 14 of the handle 3, which can be brought into engagement with the external hexagon 13 of the spindle 12 in the normal position. Also shown are teeth 20 on the adjusting ring 7, which protrude with respect to this in the axial direction A, wherein the teeth 20 in recesses 21 of the handle 3 are positively engageable for engagement, so that a further positive connection between the adjusting ring 7 and handle 3 is made in the normal position.

Furthermore, in FIG. 3b illustrated that a recess 22 is provided, wherein in the recess 22 in the axial direction A an adjusting tool can be inserted and by performing a rotational movement of the adjusting ring 7 is rotatable. Furthermore, in FIG. 3a and b clearly recognizable that the adjusting ring 7 is not fixed to a mere ring shape, but is also designed as at least partially cylindrical body which can be inserted into a hollow handle end 6. The adjusting ring 7 further has an open surface with internal teeth 24 at its end, in which a cap, not shown, can be inserted.

Further shown in FIG FIG. 1 and 2a a hanging loop 23 on the adjusting ring 7, which is material-uniform and integrally connected thereto to hang the torque wrench 1 when not in use at this. The handle 3 and / or the adjusting ring 7 are preferably made of a plastic material.

Reference numerals:

1 -

torque wrench

2 -

shaft

3

Handle

4 -

Center longitudinal axis to 2

5 -

display

6 -

handle end

7 -

Adjusting ring

8th -

latching mechanism

9 -

shank end

10 -

spindle nut

11 -

Grub screw / cylindrical pin

12-

spindle

13 -

Mother or stroke

14-

Inside double hexagon

15

spindle end

16-

locknut

17-

spindle head

18 -

Internal toothing to 7

19 -

External toothing to 12

20 -

Teeth to 7

21 -

Deepening to 3

22 -

Deepening to 7

23 -

hanging loop

24 -

Internal toothing in the adjusting ring

A -

axially

Claims (12)

1. Torque wrench for tightening or loosening a screw connection, having a shaft (2) and a handle (3) disposed on one end of the shaft (2), wherein on the end of the shaft (2) opposite to the handle (3) can be coupled a receptacle for a form-fitting screw connection, in particular a ratchet with square-end, wherein in the shaft (2) a release mechanism is disposed, which can be pretensioned via a spring by relative turning of the handle (3) relatively to the shaft (2), with which a release torque can be set, wherein the release mechanism has a spindle (12), wherein the release mechanism can be adjusted, and wherein an adjusting ring (7) is provided on a free end of the handle (3) and the adjusting ring (7) is coupled with the spindle (12) via a form-fitting engagement, characterised in that the spindle (12) is coupled in a form-fitting manner with the handle (3), wherein for carrying out the adjustment the adjusting ring (7) can be slid in axial direction (A) on the spindle (12) such that the handle (3) is no longer in torsion-proof engagement with the spindle (12), and by means of turning the adjusting ring (7) the spindle (12) can be moved.
2. Torque wrench according to claim 1, characterised in that the handle (3) is coupled via a form-fitting connection with the spindle (12), in particular the handle (3) has a polygonal socket connection, preferably a hexagonal socket (14), wherein the polygonal socket connection engages form-fittingly in an external polygonal connection of the spindle (12) corresponding thereto, especially preferably an external hexagon (13).
3. Torque wrench according to the preceding claim, characterised in that for carrying out the adjustment, the handle (3) can be slid in axial direction (A) with respect to the spindle (12) such that a form-fitting engagement is no longer present between spindle (12) and handle (3).
4. Torque wrench according to any of the preceding claims, characterised in that the spindle (12) in the region of the adjusting ring (7) is coupled in torsion-proof manner in a form-fitting manner therewith, wherein the form-fitting connection is present when the adjusting ring (7) is slid axially with respect to the spindle (12).
5. Torque wrench according to any of the preceding claims, characterised in that the spindle (12) has an outer toothing (19) and the adjusting ring (7) an inner toothing (18) corresponding thereto, wherein adjusting ring (7) and spindle (12) are axially slidable and are in this regard in torsion-proof engagement.
6. Torque wrench according to any of the preceding claims, characterised in that the adjusting ring (7) can be coupled in a form-fitting manner with the handle (3).
7. Torque wrench according to any of the preceding claims, characterised in that on the shaft end (9) of the shaft (2) a spindle nut (10) is securely coupled with the shaft (2).
8. Torque wrench according to any of the preceding claims, characterised in that the adjusting ring (7) has tooth-like appendages (20) oriented in axial direction (A), which can be brought into engagement with corresponding recesses (21) of the handle (3).
9. Torque wrench according to any of the preceding claims, characterised in that the adjusting ring (7) has on its free end at least one recess (22), wherein an adjusting tool rotating about the longitudinal axis of the spindle (12), in particular a mechanical adjusting tool, can be coupled into the recess (22).
10. Torque wrench according to any of the preceding claims, characterised in that the adjusting ring (7) is held by a locknut (16) in axial direction (A) with the spindle (12) and/or that a closure cap can be integrated into the free end of the adjusting ring (7).
11. Torque wrench according to any of the preceding claims, characterised in that on the adjusting ring (7) is provided a suspension eye (23).
12. Torque wrench according to any of the preceding claims, characterised in that the handle (3) and/or the adjusting ring (7) are formed from plastic and that the release mechanism and/or the shaft (2) are formed from a metallic material.

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