The invention relates to a pulse tool, in particular a pulse nutsetter, with at least one pneumatic drive unit, which has a drive rotor and a pulse unit driven by said drive unit, wherein the drive unit, for the interruption of the air feed on receiving a cut-off pulse, is assigned a delay-dependent inertial cut-off device.
A pulse tool of this nature is known from practice and is used, for example, for screwed joints. With a screwed joint of this nature it has been found to be advantageous if the screwed joint is tightened to a defined tightening torque. A corresponding cut-off pulse, produced by the pulse unit, is assigned to the tightening torque. With the application of this cut-off pulse the inertial cut-off device acquires a corresponding delay and causes an interruption of the air feed to the pneumatic drive unit, so that the drive unit ceases to drive the pulse unit and accordingly no further pulses are produced.
The object of the invention is to improve a pulse tool of this nature such that it has or facilitates a compact design, low weight and simultaneously a fast cut-off by the inertial cut-off device.
This object is solved by the features of Patent claim 1.
According to the invention the inertial cut-off device has at least one cut-off piston for changing the air feed between the open and closed positions and which can be moved relative to the drive rotor and an, in particular annular, inertial body which can turn with the drive rotor. The cut-off piston can be simply moved from the open into the closed position, wherein in the closed position the air feed to the drive unit is completely or at least for the largest part interrupted. The inertial body is also appropriately rotated by the drive rotor. Once a pulse is set, further rotation of the inertial body optionally occurs relative to the drive body due to the corresponding inertia of the inertial body.
The inertial body has an inner contour through which at least one drive body, essentially radially adjustable relative to the drive rotor, can be deflected. The deflection of the drive body occurs accordingly on acquiring the cut-off pulse and the further rotation of the inertial body relative to the drive body. The said drive body is movably linked to a release device, provided for the cut-off piston and which can be moved between a release and a retaining position. Depending on the radial adjustment of the drive body, the release device is appropriately arranged in the region between the release and retaining positions. In the release position, release of the cut-off piston occurs so that it can be moved from its open to the closed position.
According to the invention only a few parts are required for the inertial cut-off device, which are preferably of low mass and only travel slight distances in order in particular to facilitate an appropriate adjustment of the cut-off piston into its closed position. A simple arrangement of the cut-off piston relative to the drive unit can be provided when the cut-off piston is movably mounted on an essentially cylindrical rotor extension of the drive rotor opposite the pulse unit. In this way the corresponding adjustment of the cut-off piston occurs between the closed and open positions directly along the rotor extension.
The tool can be designed more compact if the inertial body extends around the rotor extension and in particular is mounted for rotation on its free end.
An inertial body, which is simple to manufacture and which also takes up relatively little space, is an inertial body with essentially a circular external circumference and a polygonal internal circumference with corresponding inner contour. Due to the polygonal internal circumference or the internal contour a deflection of the drive body occurs with relative movement between the rotor extension and the inertial body.
The internal contour or internal circumference can be formed differently. Preferably an essentially triangular and in particular equilateral internal circumference can be considered. In order to be able to move the drive body well guided along the appropriate sides of the triangle up to the corresponding apices of the triangle, the appropriate sides of the triangle can have a convex curvature.
In order to be able to reliably arrange the drive body in the sides of the triangle during the common rotation of the inertial body and the rotor extension, the corresponding apices of the triangle can have convex inner sides. In this case this convex curvature can correspond to the curvature of the drive body.
In order to be able to load the appropriate bearing body better and more uniformly by the drive bodies, a drive body can be assigned to each apex of the triangle. In this way three drive bodies of spherical shape are on acquiring the cut-off pulse appropriately moved in the direction of the bearing body and adjust it for the release of the cut-off piston.
Generally, an appropriate pulse tool can be moved in both directions of rotation both for fastening and also for releasing a screwed joint. In order to dispense with an automatic cut-off by the inertial cut-off device when releasing the screwed joint, the polygonal internal circumference can be asymmetrical relative to the axis of rotation defined by the rotor extension. Drive balls are preferably used as drive bodies, because they do not require any specific assignment to the corresponding apices of the triangle.
In order to ensure in a simple manner that the inertial body rotates with the rotor extension when it rotates, it can have a carrier device for the drive bodies for their deflection radially outwards. That is, with the rotation of the rotor extension the drive bodies move into the apices of the triangle due to the carrier device and in this way carry the inertial body with them so that the inertial body rotates appropriate to the rotor extension or to the rotor of the drive unit.
A simple implementation of a carrier device of this nature can be conceived that has at least radial openings and a bearing body arranged in a longitudinal hole of the radial extension. The drive bodies are mounted radially adjustably in the radial openings and are prevented from falling into the corresponding longitudinal hole of the rotor extension by the bearing body.
In order to obtain good contact between the bearing body and the drive body the bearing body can be formed spherically or conically at least in the direction of the drive body.
It can be considered particularly preferable if the bearing body is part of the release device and is mounted adjustably in the longitudinal direction of the longitudinal hole. That is, that with radial adjustment of the drive bodies inwards on acquiring the cut-off pulse, the drive bodies press on the bearing body to adjust it in the longitudinal direction of the longitudinal hole, and so it facilitates as part of the release device adjustment of the cut-off piston from its open into its closed position. In order in this connection to press the bearing body in a simple manner against the drive bodies in particular before acquiring the cut-off pulse, pressure can be applied to the bearing body in the direction of the drive body.
There is also the possibility that pressure is applied to the cut-off piston in the direction of the closed position in particular by means of a piston compression spring. In this way there is the advantage that on the release of the cut-off piston it is pressed directly into the closed position by its piston compression spring, and in particular no carriage of the cut-off piston by for example the bearing body or other parts of the release device needs to take place.
In order to keep the cut-off piston securely in its open position before its release, the rotor extension can have at least one elongated hole on the circumference in which in each case a locking body is movably mounted, with which the cut-off piston is in contact from one end and a retaining sleeve of the release device, movably mounted in the longitudinal hole, is in contact from the other end. This retaining sleeve can be moved in the longitudinal direction of the longitudinal hole by moving the bearing body, wherein the locking body can move along the elongated hole and accordingly the cut-off piston moves from the open into the closed position.
In order to securely retain the cut-off piston in particular in the open position by the locking body, the cut-off piston can have an accommodating groove for the locking body in its inner side.
The seating of the retaining sleeve on the locking body can for example take place such that the locking body is in contact with a free end of the retaining sleeve. If the retaining sleeve is then moved in the longitudinal direction of the longitudinal hole, the locking body follows the free end along the elongated hole and correspondingly the cut-off piston with its accommodating groove for the locking body, so that it can be moved accordingly for the movement of the retaining sleeve from its open to its closed position.
In order to load the retaining sleeve in a simple manner opposing a corresponding adjustment by the bearing body, pressure can be applied to the retaining sleeve within the longitudinal hole in the direction of the locking body, in particular by a compression spring.
In order to prevent the locking body in a simple manner from falling into the longitudinal hole of the rotor extension, a cut-off sleeve can be arranged within the retaining sleeve and can be in contact with the bearing body with one contacting end. The cut-off sleeve and the retaining sleeve are joined for movement so that with an adjustment of the cut-off sleeve by the bearing body adjustment of the retaining sleeve occurs simultaneously. The application of pressure to the retaining sleeve can simultaneously be used for the application of pressure to the cut-off sleeve correspondingly in the direction of the bearing body.
In particular, in this connection the locking body can be in contact with an outer side of the retaining sleeve, by means of which the locking body is prevented from falling into the longitudinal hole.
Furthermore, it can be considered favourable if a threaded stud is arranged within the cut-off sleeve, the first end of which facing the drive unit has pressure applied to it in the direction of the bearing body.
With a threaded stud of this nature the cut-off pulse in particular can be adjusted in that for example the threaded stud is adjustable in the longitudinal hole for the variation of the pressure applied to it.
An advantageous embodiment can be conceived in that the threaded stud is directly screwed to the cut-off sleeve for the adjustment relative to it. In this case the cut-off sleeve is in contact with the bearing body, as described above, and through the connection to the threaded stud and the possibility of the variation of the pressure applied to it, a variation of the pressure applied to the bearing body by the cut-off sleeve arises correspondingly.
A simple possibility of applying pressure to the threaded stud can be seen when a corresponding stud compression spring with an optional collar stud is arranged between it and the first end of the threaded stud. The stud compression spring can for example be arranged between a closed end of the longitudinal hole of the rotor or of the rotor extension and the threaded stud or the collar stud.
In order to keep the cut-off piston in its open position in the idle state, a spring constant of the compression spring can be greater than a spring constant of the piston compression spring. In this way no release of the cut-off piston occurs due to the release device without the inertial cut-off device.
In order to facilitate adequate sealing of the air feed in the direction of the drive unit, the cut-off piston can have a closing flange protruding radially outwards. In the closed position it then contacts the appropriate air channels or similar features within the pulse tool to seal them.
With the previously described construction, in particular of the inertial cut-off device, it has also been found to be advantageous if the inertial body is mounted floating. This means that essentially the inertial body during its rotation is supported and also driven by drive bodies pressed radially outwards by the set force of the stud compression spring on the bearing body and rotated by the carrier device together with the rotor extension.
Further bearings for the inertial body are not necessary.
In this connection it can also be advantageous if optionally the drive bodies are secured at the side in the longitudinal direction by limit stops such as for example snap rings or similar components.
In order to facilitate easy adjustment of the threaded stud and thus easy adjustment of the cut-off pulse without having to remove a large number of parts of the pulse tool, the bearing body can have an essentially central longitudinal opening which is aligned to an insertion recess in the threaded stud. Then rotation of the threaded stud can take place through this longitudinal opening via the insertion recess and thus adjustment in the longitudinal direction can occur, by means of which the application of pressure by the stud compression spring can be varied.
In order also in this connection not have to remove any part of the housing of the pulse tool, the housing of the pulse tool can have an insertion opening for an adjustment tool, which can be inserted through it and then through the longitudinal opening of the bearing body into the insertion recess for rotating the threaded stud.
The appropriate insertion opening of the housing must generally be able to be closed, so that within the housing the appropriate air feed can occur with adequate pressure. A simple method of closing the insertion opening can be conceived when it has on its inner side a sealing seat for the sealing contact of in particular a spherical closing body. This closing body can be for example a rubber ball. The closing body is removed from its sealing seat by the appropriate adjusting tool and then the adjusting tool is inserted through into the insertion recesses in the housing. After adjustment of the threaded stud and removal of the adjusting tool, the closing body is again automatically pressed into sealing contact with its sealing seat during the establishment of the air pressure within the housing.
To prevent an automatic rotation of the threaded stud relative to the cut-off sleeve a frictionally engaged element in the form of, for example, a spring, an elastomer pin or similar component can be arranged between them. Furthermore, the cut-off sleeve can be secured against rotation via a spherical locking body relative to the rotor extension to take up the reaction on rotating the threaded stud.
In the following, an advantageous embodiment of the invention is explained in more detail based on figures enclosed in the drawing.
The following are shown:
In FIG. 2—refer also to FIG. 4—a longitudinal section in particular through the drive unit 2 and an assigned delay-dependent inertial cut-off device 5 are shown.
The drive unit 2 comprises at least one drive rotor 3, which can be rotated by corresponding air pressure within a motor cylinder 55. Air pressure is made available via an air feed 6, wherein with actuation of the corresponding release button on the handle, refer also to
The rotor 3 is connected at its end facing the pulse unit 4 to a rotor extension 52 of the impact mechanism so that in this way the pulse unit 4 is driven by the drive unit 2.
The corresponding drive rotor 3 has opposite the pulse unit 4 a cylindrical rotor extension 14. This and also in part the drive rotor 3 have centrally a longitudinal hole 24 in the longitudinal direction 25. Both the drive rotor 3 and also the rotor extension 14 are mounted for rotation relative to the motor cylinder 55 or the housing 45 of the pulse tool 1 via appropriate pivot bearings.
Within the longitudinal hole 24 some elements of the inertial cut-off device 5 are arranged. A stud compression spring 39 is used to apply pressure to a collar stud (
The threaded stud 36 is arranged in a cut-off sleeve 34 and can be adjusted relative to it, wherein generally a thread is formed between the two components. To secure a certain relative rotary position between the threaded stud 36 and the cut-off sleeve 34, a frictionally engaged element 50 in the form of an elastomer pin, a spring or similar component is provided. To secure the cut-off sleeve against rotation also at least one locking body 60 according to
The cut-off sleeve 34 contacts the bearing body 23 with its free contacting end 35, wherein a corresponding contact between the threaded stud 36 and the bearing body 23 is only present when the threaded stud 36 is appropriately screwed out of the cut-off sleeve 34, wherein the axial end positions of the threaded stud 36 are limited by locking rings 58, 59 according to
Thus, contact between the contacting end 35 of the cut-off sleeve 34 and the bearing body 23 occurs exclusively.
The cut-off sleeve 34 is at least partially inserted into a retaining sleeve 29, which similarly extends in the longitudinal direction 25 and within the longitudinal hole 24. The retaining sleeve 29 is in contact with its free end 32 with at least one locking body 28 in a spherical shape. At its other end pressure is applied to it by a compression spring 33 in the direction of the bearing body 23. This compression spring 33 is supported within the longitudinal hole 24 by a step and is supported approx. at the height of the collar stud 40.
In the region of the spherical locking body 28 the rotor extension 14 has at least one elongated hole 27, along which the locking body 28 can be moved depending on the displacement of the retaining sleeve 29 in the direction of the collar stud 40. Simultaneously, the locking body 28 contacts an outer side of the cut-off sleeve 34, so that the locking body 28 is prevented from falling into the longitudinal hole 24.
In the region of the locking body 28 or elongated hole 27 a cut-off piston 8 is arranged, which is mounted for movement outside on the rotor extension 14 in the longitudinal direction 25. This cut-off piston 8 has approx. centrally a closing flange 41 which protrudes radially outwards and which on moving the cut-off piston 8 in the direction of the drive unit 2 contacts an air distribution plate 56 for interrupting the air feed to the drive unit 2. On its inner side 30 the cut-off piston 8 has an accommodating groove 31 in which the locking body 28 is partially accommodated opposite the cut-off sleeve 34.
Outside on the cut-off piston 8 a piston compression spring 26 is arranged for applying a pressure to the cut-off piston 8 in the direction of the drive unit 2. This has a spring constant which is lower than the corresponding spring constant of the compression spring 33.
The bearing body 23 is pretensioned appropriately for the pressure application through in particular the contacting end 35 of the cut-off sleeve 34 and its connection to the threaded stud 36 as well as the pressure applied to it by the stud compression spring 39 in the direction of the bearing body 49. Its spherical or conical outer side is contacted by one, two, three or more spherical drive bodies 11. In addition these are supported by the outer surfaces of the bearing body 23 in radial openings 22 of the rotor extension 14.
Through the bearing body 23 and the radial opening 22 a carrier device 21 for these drive bodies 11 is formed so that the drive bodies 11 are carried along with rotation of the drive rotor 3 and according to the rotor extension 14. These protrude at least partially out of the radial openings 22 and contact an internal contour 10 or an internal circumference 17 of an inertial body 9 of the inertial cut-off device 5. In the illustrated embodiment three drive bodies 11 are used, refer also to
One end of the rotor extension 14 is closed off by a closing plate 57, which has a central opening.
In
In particular it can be seen from
In
If the transfer of the cut-off pulse occurs, which corresponds to an appropriate final torque for tightening a screwed joint, further rotation of the inertial body 9 takes place relative to the rotor extension 14. This further rotation leads to a movement of the drive bodies 11 radially inwards in the direction of the axis of rotation 20. This occurs through the corresponding internal contour 10 of the inertial body 9. In doing this, the drive bodies 11 press on the spherical or conical surface of the bearing body 23. This is moved by applying pressure in
With the adjustment of the retaining sleeve 29 against the pressure applied by the compression spring 33, an adjustment of the locking body 28 in the elongated hole 27 can also be made. Corresponding to this adjustment, a displacement of the cut-off piston 8 occurs due to the pressure applied by the piston compression spring 26. With adequate adjustment of the cut-off piston 8, at least a reduction of the air feed occurs until optionally the corresponding closing flange 21 contacts the air distribution plate 56. In
In this so-called closed position of the cut-off piston 8 no rotation of the drive unit 2 occurs and thus also no rotation of the pulse unit 4. As long as the release button in the handle, refer to
A corresponding return of the cut-off sleeve 34 and of the bearing body 23, by means of which the drive bodies 11 are correspondingly moved into the apices of the triangle 19, refer to
With regard to the cut-off piston 8 it should be noted that in the open position 7 as in
Number | Date | Country | Kind |
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06023568.6 | Nov 2006 | EP | regional |