Mechatronic torque wrench with click mechanism adjustment device

Abstract

Mechatronic torque wrench comprising an elongated body having a handle (11) at one end, a tubular arm (12) at the opposite end and, in a substantially intermediate position, a block (13) inside which there are electronic control circuits and an electronic processing unit. At the free end of said arm (13), there is a tool head (14) provided with a seat (15) in which a plurality of inserts (16) are alternatively engageable, to engage the wrench with a corresponding type and / or size of mechanical part or element on which the wrench itself is intended to act. In said arm (13), there are sensor means for detecting the tightening conditions, such as for example sensors of the torque exerted on the mechanical part, and also a sensor for detecting the tightening angle. The wrench comprises a torque detection mechanism for torque wrenches called "click", which is triggered when the desired torque value is reached during a joint tightening operation. The wrench also comprises an adjustment device (5) of such click mechanism.

Description

[0001] Mechatronic torque wrench with click mechanism adjustment device

[0002] The present invention relates to a torque wrench of the so-called mechatronic type.

[0003] Such type of wrench is a tightening tool that comprises a mechanical part and an electronic part. The mechanical part is represented by the click mechanism, which ensures that the desired tightening is achieved through a "click signal”.

[0004] In particular, such mechanical torque detection mechanism provides the operator with the operation sensation of an applied force that is suddenly reduced when the tightening torque reaches a set / desired torque value. The electronic part monitors the tightening torque and / or angle and allows to display such data. In this way, once the tightening is completed with the activation of the "click", which can be performed without needing to look at the display with data, the operator can now check the correct tightening from the displayed data. Furthermore, the data detected by the electronic part can be transmitted to an external electronic unit.

[0005] An example of such type of wrench is provided in patent EP3774184, which describes a wrench comprising a mechanism having a spring and releasable engagement means which disengage from a first position to a second disengaged position. Typically, the engagement mechanism disengages a cam element from a cam surface when the torsion of the arm accommodating the cam corresponds to (or exceeds) the tightening torque to be exerted. The preset torque value is caused by an adjustment device that preloads the spring so as to cause such disengagement when the tightening torque value is reached.

[0006] One of the most important features for such types of wrenches, and in particular for such adjustment device, is that the preload of the spring is precisely ensured and kept over time. The repeatability performance of the wrench is indeed influenced by the reliability of such adjustment device.

[0007] The present invention proposes a solution to the above-mentioned problems by making a mechatronic torque wrench with click mechanism adjustment device, which ensures that the above- mentioned click mechanism is activated upon reaching the desired tightening, continuously over time, and not influenced by the number of tightening performed and by external factors.

[0008] One aspect of the present invention relates to a torque wrench of the so-called mechatronic type having the features of claim 1.

[0009] Further objects and advantages of the present invention will become apparent from the following description and the attached drawings, provided solely by way of exemplary and non-limiting example, in which:

[0010] Figure 1 is a perspective view of a torque wrench according to the present invention;

[0011] Figure 2 is a longitudinal sectional view of the wrench of Figure 1 highlighting the click mechanism in the resting or clickwaiting position according to the present invention;

[0012] Figure 3 is a longitudinal sectional view of the wrench of Figure 1 highlighting the click mechanism in the clicked position according to the present invention;

[0013] Figure 4 is a front view example of the wrench of Figure 1 ;

[0014] Figure 5 is a view along section A-A of Figure 4 of the wrench according to the present invention;

[0015] Figure 6a is a perspective view of a torque wrench with the click mechanism exploded of a first embodiment of the present invention;

[0016] Figure 6b is a perspective view of a torque wrench with the click mechanism exploded of a second embodiment of the present invention;

[0017] Figure 7 illustrates a perspective view of the first centering pin according to the present invention;

[0018] Figure 8 illustrates an enlarged portion of the fork according to the present invention;

[0019] Figures 9a and 9b illustrate a perspective view of the click mechanism adjustment device, respectively assembled and exploded, according to the present invention;

[0020] Figure 10a shows a longitudinal section of the wrench of Figure 1 highlighting the click mechanism adjustment device in the unlocked position;

[0021] Figure 10b illustrates a longitudinal section of the wrench of Figure 1 highlighting the click mechanism adjustment device in the locked position.

[0022] The mechatronic torque wrench according to the present invention comprises an elongated body (with respect to the X axis in the figures) having a handle 11 at one end, a tubular arm 12 at the opposite end and, in a substantially intermediate position, a block 13 inside which there are electronic control circuits and an electronic processing unit.

[0023] Advantageously, the arm has a tubular shape, but appears as a flattened tube having a height (along the Y axis in the figures) greater than the width (Z axis in the figures).

[0024] On such block, control buttons, electrical connection ports (for example, USB, Ethernet, etc.), possibly a display screen, display devices (for example, LEDs) can be provided, indicating the operating status of the wrench, the tightening progression, error notifications, battery charge status, etc. . .

[0025] Through such ports or through a wireless connection, the wrench can be connected to external processing units. A wired connection can also be provided for supplying external power.

[0026] At the free end of said arm 12, there is a tool head 14 provided with a seat 15 in which a plurality of inserts 16 are alternatively engageable. For example, each insert will be adapted to engage the wrench with a corresponding type and / or size of mechanical part or element (screw, nut, etc.) on which the tool is intended to act.

[0027] Although, for simplicity, the inserts shown are all of similar size, elongated inserts or inserts with specially shaped arms can also be provided, as known in the field.

[0028] The wrench comprises sensor means (for example, made with strain gauges arranged in the arm) for detecting the tightening conditions, such as for example sensors of the torque exerted on the mechanical part, and also a sensor (for example, a gyroscopic sensor) for detecting the tightening angle.

[0029] The mechatronic wrench comprises therein a torque detection mechanism for torque wrenches called "click", which is triggered when the desired torque value is reached during the joint tightening operation. The click results in a “free” rotation for a predetermined angle of the wrench, during which no torque is exerted on the joint. Such click allows the operator to understand that tightening has been completed. The electronic part of the wrench (sensors and the electronic board of the wrench) confirms that such tightening has been completed by the above-mentioned signalling modes (LED, display, buzzer, etc...).

[0030] Such click mechanism comprises a fork 21, associated with the tool head 14, housed inside the tubular arm. In the illustrated embodiment, such fork is made as a single body with the tool head. Furthermore, such fork, near one of its ends, is hinged through a first transverse pin 22 to the arm itself, so that it can rotate during tightening due to the force of the tool head on the joint around such pin, inside the arm, limited by the lateral size of the arm itself.

[0031] At its opposite end, such fork 21 is hinged to a central joint of a lever 24, through a second transverse pin 23.

[0032] One end of such lever is hinged, through a third pin 25, to a longitudinally sliding support 26 in the body of the wrench. Such sliding support 26 is in turn constrained to a spring 27 inserted into the handle of the wrench and fixed therein.

[0033] The spring is inserted preloaded into the handle by means of an adjustment device 5 of the spring load, which is also located in the handle and reacts against the spring.

[0034] The mechanism operates as follows: the spring 27, preloaded to a predefined value by the adjustment device 5, pushes the sliding support 26, which keeps the lever in the resting position (as shown in Figure 2). During tightening, the fork 21 is subjected to torsional stress and consequent rotation around the first pin 22. Such rotation causes the lever 24 to rotate around the second pin 23, which occurs only when the force exceeds the counterforce of the preloaded spring, moving such sliding support 26. When such force exceeds such set contrasting value, which corresponds to the desired tightening torque value, the lever rotates, releasing the fork rotation until the front end 241 of the lever itself strikes the internal surface of the tubular arm (as illustrated in Figure 3).

[0035] Such rotation of the fork 21 causes the sensation of clicking of the mechanism, and informs the operator that tightening is completed, because the desired tightening torque value has been reached.

[0036] As previously mentioned, the repeatability of the click mechanism is reliable to the extent that its movements are precise and balanced, particularly with respect to the longitudinal axis of the wrench.

[0037] According to a feature of the present invention, in order to achieve such balance, the mechanism comprises a first centering pin 3 placed transversely inside the tubular arm and housed inside the fork 21. The pin is kept in position by two holes made in the tube, which ensures high positional accuracy for the pin.

[0038] Such pin comprises a cylindrical portion 31 that ensures that the lever remains centered, and preferably also a conical portion 32, which serves as a contact point with lever 24, ensuring a centered starting position also for the lever itself.

[0039] The coupling between the centering pin and the fork 21 allows relative movement between the fork and the pin only along the axis of the pin, for example, as illustrated in Figure 5, it allows the fork to slide upward and downward but not to move rightward and leftward, thereby always keeping a centered position.

[0040] Moreover, the conical portion 32, when present, causes a unique resting or starting position for the fork. This ensures the same (stable) starting point, which improves the repeatability of the click. For such wrench models having an arm of reduced size (for example, 25 Nm wrenches compared to longer 85 Nm wrenches), where the fork is also reduced in size, a support dowel 33 for the fork, separate from the centering pin 3 and placed near the pin itself, has been inserted.

[0041] Furthermore, in order to ensure the linearity of movement of the spring and the sliding support 26, the mechanism of the invention comprises a first centering element 34 of the spring 27, placed between the sliding support and the spring itself, and a second centering element 35 placed between the spring and the adjustment device 5. Such centering elements 34 and 35 keep the spring aligned (X axis) with all the other elements of the click mechanism, thereby contributing to ensure the repeatability of the click mechanism.

[0042] The click mechanism of the present invention causes the click and the resulting impact of the lever against the tube. The click feeling is obtained from the impact of the front end 241 of the lever itself on the internal surface of the tubular arm, in a position near the handle of the wrench and far from where the torque sensor is located, thus avoiding interference with the torque reading. Typically, the torque sensor is located near the tool head, or in an intermediate position of the arm.

[0043] According to a further aspect of the present invention, the click mechanism adjustment device 5 comprises an adjustment screw 51, which pushes the rear end of such spring, having an external thread 52 which matches a corresponding thread obtained in the internal tube 111 of the handle 11. When rotated, such screw can slide inside the handle and therefore compress or release the spring 27. The rotation of such screw is induced by an adjustment insert 53 having a circular head 54 and an elongated shaped body 55 (for example, hexagonal), suitable for engaging in an equally shaped hole 56 obtained in the body of the adjustment screw 51.

[0044] Such adjustment insert can slide longitudinally inside the handle, and its head comprises a shape (for example, toothed or striped) such that it can be inserted or removed from an annular adjustment cup 57 having an opening 571 with a similar shape, located at the end of the handle and integral with it. When the head of the insert is inserted into the cup, it cannot rotate and thus keeps the adjustment device in a locked position. When the head of the insert is pushed towards the inside of the handle and removed from the cup, it can rotate, properly positioning the adjustment screw and adjusting the compression of the spring 27.

[0045] Advantageously, between the adjustment screw and the end of the spring, there is a suitable bearing 58 which allows the rotation of the screw itself, for example, it can be kept in position by a locking nut 59.

[0046] Advantageously, between the adjustment screw 51 and the head of the adjustment insert 53, there is a compression spring 60, for example combined with a cover 61, fitted onto the elongated body 55. The cover 61 is preferably screwed to the cup 57, trapping the spring 60 on the elongated body 55. Such compression spring 60 forces the head 54 of the insert to lock into the cup, thereby preventing the rotation of the insert in normal condition. When you want to adjust the compression of the spring 27, it is necessary to push the insert from the bottom of the handle towards the inside, overcoming the contrasting force of the compression spring 60, to make it slide towards the inside of the handle, allowing it to rotate.

[0047] In order to facilitate both the rotation and the pushing of the insert 53, it is provided at the centre of the circular head with a shaped seat 531, suitable for inserting a tool (for example, a key wrench) into it, with which it can both be pushed inward and rotated in a clockwise or anticlockwise direction.

Claims

CLAIMS1. Mechatronic torque wrench comprising:• an elongated body having a handle (11) at one end and a tubular arm (12) at the opposite end and in a substantially intermediate position, a block (13) inside which there are electronic control circuits and an electronic processing unit,• at the free end of said arm (1 ), a tool head (14) provided with a seat (15) in which a plurality of inserts (16) can be alternatively inserted to engage the wrench with a corresponding type and / or size of mechanical part or element on which the wrench itself is intended to act,• in said arm (12) sensor means for detecting the tightening conditions, such as for example sensors of the torque exerted on the mechanical part,• a torque detection mechanism for torque wrenches called “click”, which is triggered when the desired torque value is reached during a joint tightening operation,• the click of such click mechanism being prevented by the compression of a spring (27) inserted in the handle (11) of the wrench and occurs when the force exerted during tightening exceeds the counterforce of such spring, characterized in that such wrench comprises an adjustment device (5) of such click mechanism which acts on such spring and which comprises• an adjustment screw (51) which pushes the rear end of such spring, having an external thread (52) which matches acorresponding thread obtained in the internal tube (111) of the handle (11), such screw when rotated can slide inside the handle and therefore compress or release the spring (27),• the rotation of such screw being induced by an adjustment insert (53) having a circular head (54) and an elongated shaped body (55) suitable for engaging in an equally shaped hole (56) obtained in the body of the adjustment screw (51),• such adjustment insert slides longitudinally in the handle and its head comprises a shape such that it can be inserted or removed from an annular adjustment cup (57) having an opening (571) with a similar shape, located at the end of the handle and integral with it,• when the head of the insert is inserted into the cup it cannot rotate and therefore keeps the adjustment device in a locked position and when the head of the insert is pushed towards the inside of the handle and is removed from the cup it can rotate by appropriately positioning the adjustment screw and adjusting the compression of the spring (27).

2. Wrench according to claim 1, wherein the shaped elongated body (55) of the adjustment insert and the shaped hole (56) of the adjustment screw are hexagonal in shape.

3. Wrench according to claim 1, wherein between the adjustment screw and the end of the spring there is a suitable bearing (58) which allows the rotation of the screw itself.

4. Wrench according to claim 1, wherein between the adjustment screw (51) and the head of the adjustment insert (53)there is a compression spring (60) fitted onto the elongated body (55), such compression spring forcing the head (54) of the insert to lock into the cup, preventing the rotation of the insert itself in normal conditions.

5. Wrench according to claim 4, wherein the compression spring (60) is combined with a cover (61) screwed onto the cup (57) which traps the spring itself (60) on the elongated body (55).

6. Wrench according to claim 4, wherein when you want to adjust the compression of the spring (27) it is necessary to push the insert from the bottom of the handle inwards until it overcomes the contrasting force of such compression spring (60), to make it slide towards the inside of the handle, allowing it to rotate.

7. Wrench according to claim 6, wherein the insert (53) is provided on the centre of the circular head with a shaped seat (531) suitable for inserting a tool into it with which it can both be pushed inward and rotated in a clockwise and anticlockwise direction.

8. Wrench according to claim 1, wherein the shape of the head of the adjustment insert and the shape of the cup opening is a toothing or striped.

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