EP2905378A1 - Tamping device - Google Patents

Abstract

In a tamper (T) of a screed (E), with a tamper strip (1) which is attached to connecting rods (2), in each of which an eccentric bushing (B) is rotatable on an eccentric portion (A) of a drive shaft (W ) is relatively rotatable and in different strokes of Tamperleiste (1) defining relative rotational positions drehkuppelbar with the eccentric portion (A), wherein between the rotational positions by reversing the direction of rotation of the drive shaft (W) is reversible, the eccentric bushing (B) in the relative rotational positions a for switching from one rotational position to another automatically or remotely releasable and / or engageable locking and / or coupling device (V) against unwanted leaving the rotational position lockable.

Description

The invention relates to a tamper device specified in the preamble of claim 1. Art.

The stroke of the Tamperleiste a tamper device in a screed must be changed, for example, depending on the installation thickness or other installation parameters. Usually, this is done so that exposed during an operation stop the eccentric drive mechanism of Tamperleiste and solved with tools clamped on the eccentric Exzenterbuchse and rotated by hand relative to the eccentric and tightened again. As a result, the sum of the effective in the stroke direction of the Tamperleiste eccentricities of the eccentric and the eccentric bush and thus the stroke changed. This procedure is cumbersome and time consuming, since in a screed usually several tamper devices are arranged, for example, in a pull-screed at least four tamper bars and eight connecting rods.

Out EP 2 325 392 a Tampervorrichtung is known in which the stroke of the tamper bar in the installation operation remotely controlled by a constant drive shaft rotational direction via a transmission mechanism which engages between the eccentric bush and the eccentric portion. This eliminates a manual adjustment of the stroke of the Tamperleiste.

In a generic tamper according to EP 2 325 391 B1 is a change in the stroke of Tamperleiste without tools possible, by a reversal of the direction of the drive shaft. Between the eccentric bushing and the eccentric portion, a driver and a curved track are provided with end stops for the driver, wherein the distance seen in the direction of rotation between the stops is greater than the circumferential extent of the driver. When reversing the direction of rotation, for example, due to the moment of inertia of the eccentric bushing and resulting from the compression effect of the tamper bar reaction forces the eccentric bushing is rotated relative to the rotating eccentric until the driver comes to rest from one end stop against the other end stop. The two end stops define different relative rotational positions between the eccentric bushing and the eccentric section, in which different strokes of the tamper strip result from the different sums of the eccentricities of the eccentric section and the eccentric bush in the stroke direction of the tamper strip, for example 4.0 mm in the one relative rotational position and 0 mm in the other relative rotational position. Even though the Tampervorrichtung is convertible without tools, it is characterized by a simple structure, compared with those in the tamper according to EP 2 325 392 A provided drive devices between the eccentric bushings and the eccentric sections. Especially in versions of such Tampervorrichtungen that work with low mass and / or friction and / or compression forces, the Umstellprinzip can not be used sufficiently reliable.

The invention has for its object to improve a tamper device of the type mentioned in that the stroke of the tamper without tools can indeed change by reversing the direction of rotation, but not changed unintentionally. It is to be increased even when reversible by reversing direction tamper devices that work with low mass and / or friction and / or compression forces, reliability.

Incidentally, the overall disclosure of the EP 2 325 391 A is hereby incorporated by reference, and becomes features not discussed in detail in the following description EP 2 325 391 A1 directed.

The stated object is achieved with the features of claim 1.

According to the invention, a changeover from a relative rotational position of the eccentric bushing on the eccentric section to another takes place by reversing the direction of rotation of the drive shaft. Further, since the eccentric bushing is locked in the respectively set relative rotational position with respect to the eccentric section via the locking device, the stroke path of the tamper strip can no longer change unintentionally even in critical operating situations, as long as no reversal of rotation is controlled. The locking action or force of the locking device is chosen so that in unfavorable operating situations acting on the eccentric bushing forces or moments can not overcome the locking device, but the locking device is released only at a desired change by reversing the direction of rotation of the drive shaft.

In an expedient embodiment, two end stops in a curved path and a driver are provided between the eccentric bushing and the eccentric portion, which are rotatable relative to each other about a center of rotation during the change, wherein the respective contact of the driver defined at the end stops two relative rotational positions of the eccentric bushing. The locking and / or coupling device locks the eccentric bush at least in these two relative rotational positions against movements due to external torques, which could cause an unwanted change in the relative rotational position. This concept offers the advantage, during operation of the tamper device in the set direction of rotation of the drive shaft and high-torque to transmit positively and thus safely, without necessarily mitzubelasten the locking and / or coupling device. However, the concept of the invention is not limited to the combination of dog, end stops and the locking and / or coupling device, but it could even be the device itself partially act as a driver / end stop. Furthermore, the inventive concept is not limited to two relative rotational positions, but it could, for example by means of the locking and / or coupling device, a larger number of relative rotational positions are selectively set by a reversal of direction of the drive shaft.

Suitably, the locking and / or coupling device is solvable or surmountable by forces generated during the conversion, resulting from the angular acceleration and / or angular velocity and / or the moment of inertia and / or a remote-controlled braking of the eccentric bushing. The release of the locking and / or coupling device can, suitably, even be done only within or outside a predetermined time window.

In a further expedient embodiment, in the changeover with the locking and / or coupling device, preferably by spring force on the eccentric bush even an additional Umstell-torque generated in the direction of the respective relative rotational position. In this case, an over-center spring mechanism can be used. For example, from the moment of inertia of the eccentric bush a changeover impulse arises, with which the eccentric bushing releases the set relative rotational position and begins to move in the direction of another rotational position, finally the additional shifting torque reliably moving the eccentric bushing into the new relative rotational position , optionally in addition to the Umstellimpuls generated by the reversal of direction. Further, the changeover torque generates the locking force respectively.

Suitably, with the locking and / or coupling device, a, preferably limited, locking force by spring force and / or by Drehreibung and / or generated magnetically and / or hydraulically and / or pneumatically. The locking force is possibly just limited so that occurring in unfavorable operating situations on the eccentric sleeve Fremdumstellmomente can not produce unwanted change in the stroke of the Tamperleiste.

In another expedient embodiment, a pivotable spring support, preferably a spring-loaded in the extension direction telescope or a bending spring is arranged, which is supported with bias in an abutment of the eccentric bushing, and in the transition from the relative rotational positions defining spring rest positions against bias up to a Dead center can be shortened and extended beyond the dead center under the bias voltage. The spring support thus generates the additional Umstell-torque after exceeding the dead center, with which the eccentric bush is reliably brought into the newly selected relative rotational position and then held in this.

Suitably, the locking and / or coupling device is designed as kraftbeaufschlagbare locking device with at least one locking element and locking recesses. The locking effect results in this example, a combination of a positive connection and a positive connection.

In another expedient embodiment, a, preferably radial, spring-loaded latching element is supported in the eccentric bushing and is located on the eccentric section, e.g. provided on the driver, the relative rotational positions correspondingly placed locking recesses for the locking element. In the achieved after a conversion relative rotational position of the eccentric bush engages the locking element in one of the locking recesses in order to reliably prevent unwanted turning back of the eccentric bushing.

In another embodiment, a first spring acting on the detent element is supported in the eccentric bushing on a centrifugal mass body which is movable radially in a fluid chamber and which is supported in the eccentric bush via a second spring, which acts counter to the first spring. Preferably, between the centrifugal mass body and a motion guide for this a fluid throttle gap is provided which attenuates a shift of the centrifugal mass body under the centrifugal force and generates a time window within and / or outside of which a changeover can only be made or made. Preferably, in this case, the latching element and the latching recesses in each case even cooperate purely positively, since the centrifugal mass body is able to completely excel the latching element from the latching recess. In this embodiment, it is conceivable to optionally assign the latching element and the latching depressions at the same time the functions of the driver and the end stops, which are thus unnecessary.

In a further expedient embodiment, a latching element is attached to a centrifugal mass body spring-loaded in the release direction of the locking and / or coupling device here to the center of rotation. The locking element engages in an eccentric section fixed Curved track, for example, driver, a, which has a Umstellabschnitt and at its two ends in end stops in approximately radial, oriented in the locking direction locking recesses for the locking element. Again, the locking element and the locking recesses may be entrusted with the function of the driver and the end stops, although a combination is also possible. In this embodiment, when the eccentric bush has reached the relative rotational position and rotates at an angular velocity that has moved the centrifugal mass body away from the center of rotation, the spring-loaded locking element enters into the engagement position into a detent recess. The changeover is initiated by the direction of rotation reversal of the drive shaft. The locking element and the locking recesses take over the functions of the driver and the end stops, which are thus unnecessary.

In an alternative embodiment, a latching element is attached to a in the locking direction of the locking and / or coupling device from the center of rotation spring-loaded centrifugal mass body. The detent element engages in an eccentric section-fixed curved path, e.g. in the driver, one which has a Umstellabschnitt and at both ends in end stops in approximately radial, in the release direction here to the center of rotation oriented locking recesses. Again, the locking element and the locking recesses take over the functions of the driver and the end stops. In this embodiment, a changeover is possible only above a limit speed of the eccentric bush, and as soon as the centrifugal mass body lifts the latching element out of the latching recess.

The reliability with respect to changes in order to change the stroke of the tamper bar is further increased in an embodiment in which on the eccentric bushing, preferably a centrifugally movable therein against spring centrifugal mass body, and the connecting rod a, preferably spring-loaded, friction element and a friction surface are provided for the friction element. With the spring load of the friction element can be a braking torque for the eccentric set. In this case, the friction surface can extend, while omitting the locking recesses defining the desired relative rotational positions, only between the two detent recesses. The cooperation between the friction element and the friction surface, the conversion is supported, for example, in embodiments of eccentric bushings with low moment of inertia or embodiments of tamper strands with low angular acceleration. The frictional torque generated by the cooperation between the friction element and the friction surface to assist the changeover acts only outside the relative rotational positions. The locking function results in the respective relative rotational position and at a corresponding angular velocity of the eccentric bush, for example correspondingly low or correspondingly high angular velocity, in which the centrifugal mass body is displaced inwardly by its spring action or outward by the centrifugal force.

In an alternative embodiment, the locking and / or coupling device is designed as a predetermined locking force generating Drehreibschlusskupplung between the eccentric bush and the eccentric portion. In this embodiment, the conventional principle of easy rotatability of the eccentric bushing on the eccentric portion is eliminated, and these two components are fixed to each other by the Drehreibschlusskupplung with predetermined locking force. The eccentric bush is connected to a brake body, preferably a brake disk. At least one relative to the eccentric bushing stationary supported friction element, preferably a brake pad or a brake caliper, cooperates with the brake body, which is remotely operable on the brake body between a release and braking positions. The locking force of the Drehreibschlusskupplung is set so high that occurring in critical operating situations moments on the eccentric bush, which want to rotate relative to the eccentric, the locking force can not overcome. By the intended braking, e.g. upon or in combination with reversing the direction of rotation of the drive shaft, the locking force of the rotational recoil clutch is overcome to change the eccentric bushing between relative rotational positions. The Drehreibschlusskupplung makes it possible to omit the driver and the end stops, but may also be useful in combination with the driver and the end stops of a curved path. The braking force may be mechanical, e.g. be generated by a Bowden cable, hydraulic, electric or pneumatic, without having to take to change the stroke tools to help.

Since the Drehreibschlusskupplung can produce a predetermined, relatively high locking force permanently, which can be overcome by a desired remote-controlled deceleration of the eccentric bushing, it is even possible to set any number of relative rotational positions and safely comply with each operation of the tamper device. It may be appropriate that over the brake body more than two different relative rotational positions of the eccentric bush are adjustable, and that from the predetermined, preferably adjustable, locking force in the Drehreibschlusskupplung in each selected relative rotational position results from the locking force resulting holding torque, the is higher than from the operation of the tamper on the eccentric bush occurring, unwanted foreign torques.

Fig. 1

eine Ansicht einer Tampervorrichtung einer Einbaubohle,

Fig. 2

einen Schnitt in der Ebene II - II in Fig. 1, in gegenüber Fig. 1 vergrößertem Maßstab,

Fig. 3

eine perspektivische Teilschnittdarstellung einer Ausführungsform einer Tampervorrichtung,

Fig. 4

eine weitere Perspektivansicht der Ausführungsform von Fig. 3,

Fig. 5

eine Radialschnittdarstellung einer weiteren Ausführungsform einer Tampervorrichtung,

Fig. 6

einen Radialschnitt einer weiteren Ausführungsform einer Tampervorrichtung,

Fig. 7

eine perspektivische Teilschnittansicht einer weiteren Ausführungsform einer Tampervorrichtung,

Fig. 8

einen Radialschnitt eines Teils einer weiteren Ausführungsform einer Tampervorrichtung, ähnlich der von Fig. 6,

Fig. 9 und 10

einen Achsschnitt und einen Radialschnitt eines Teils einer weiteren Ausführungsform einer Tampervorrichtung,

Fig. 11

eine weitere Ausführungsform einer Tampervorrichtung in schematischer Darstellung,

Fig. 12

eine weitere Ausführungsform eines Details einer Tampervorrichtung, und

Fig. 13

eine weitere Ausführungsform in einem halben Radialschnitt.

Embodiments of the subject invention will be explained with reference to the drawings. Show it:

Fig. 1

a view of a tamper device of a screed,

Fig. 2

a section in the plane II - II in Fig. 1 , in opposite Fig. 1 enlarged scale,

Fig. 3

3 is a partial perspective sectional view of an embodiment of a tamper device,

Fig. 4

another perspective view of the embodiment of Fig. 3 .

Fig. 5

a radial sectional view of another embodiment of a tamper device,

Fig. 6

a radial section of another embodiment of a tamper device,

Fig. 7

2 is a partial perspective sectional view of another embodiment of a tamper device;

Fig. 8

a radial section of a portion of another embodiment of a tamper device, similar to that of Fig. 6 .

FIGS. 9 and 10

an axial section and a radial section of part of a further embodiment of a tamper device,

Fig. 11

a further embodiment of a tamper device in a schematic representation,

Fig. 12

a further embodiment of a detail of a tamper device, and

Fig. 13

another embodiment in a half radial section.

Fig. 1 and 2 schematically show a tamper T a screed E of a paver. The tamper device T is used for precompression of paving material when installing a covering of bituminous or concrete paving material with a selectable covering thickness.

The tamper device T has at least one tamper strip 1 which acts cyclically on the paving material with essentially vertical work cycles with a selectable stroke. The respective Tamperleiste 1 is mounted on two connecting rods 2, which derive the working cycles by the rotation of a rotationally driven drive shaft W and transmitted to the Tamperleiste 1. The drive shaft W is stationarily supported on a frame 4 of the screed E in bearing blocks 3, which are fixed with mounting screws 8, and their altitude by adjusting screws 9 are adjustable to align, for example, the bottom dead center of the stroke of the tamper strip 1 with a frame 4 mounted on the bottom side screed plate 6.

The drive shaft W has in the region of the respective connecting rod 2 an eccentric portion A, on which an eccentric bushing B is arranged and rotatably mounted in the eye of the connecting rod 2. The drive shaft W is driven via a direction of rotation reversible drive motor M (hydraulic motor or electric motor) and, for example, a belt or chain drive 10. Alternatively, a drive motor M running in one direction of rotation could be provided which selectively drives the drive shaft W in one or the other direction of rotation via a reversing gear (not shown) which reverses the direction of rotation.

Fig. 2 shows by dotted lines the eccentricity of the eccentric portion A of the drive shaft W. The eccentric bushing B has a cylindrical inner bore which is disposed on the cylindrical outer periphery of the eccentric portion A, and has an eccentric cylindrical outer periphery which is rotatable in the connecting rod 2 in the eye. From the sum of the eccentricities of the eccentric portion A and the eccentric bushing B, in the direction of the stroke of the tamper strip 1, the extent of their stroke results. By changing the relative rotational position between the eccentric bushing B and the eccentric section A, the sum of the eccentricities is larger or smaller and changes accordingly the stroke of the tamper 1. A change between different relative rotational positions of the eccentric bushing B is in the tamper T by a reversal of the Drive shaft W executed without tools.

In the embodiment of the tamper device T in the 3 and 4 are between the eccentric portion A and the eccentric bushing B a driver M, here on the eccentric portion A, and a curved path 29 with two end stops 16 for the driver M is provided. The two end stops 16 are circumferentially spaced further than the circumferential extent of the carrier M and here define two different relative rotational positions between the eccentric bushing B and the eccentric portion A, between which can be changed by a reversal of the direction of rotation of the drive shaft W without tools.

In the embodiment of the 3 and 4 the eccentric bushing B is for example mounted with a plain bearing on the eccentric portion A of the drive shaft W. The connecting rod 2 is mounted on the eccentric bushing B via a bearing arrangement. The rotational resistance of the eccentric bushing B on the eccentric portion A is low, as well as the rotational resistance of the eccentric bushing B in the connecting rod 2. The eccentric bushing B, for example, as an option, an end flange 11 outside the Connecting rod 2, which engages over the eccentric portion A with a wedge 14 rotatably fixed carrier M from the outside.

In addition to the rotary coupling formed between the eccentric bushing B and the eccentric section A by the installation of the driver M on the respective end stop 16, which rotary coupling acts only in one direction of rotation, a locking and / or coupling device V is provided according to the invention, with which the eccentric bush B in each case set relative rotational position relative to the eccentric portion A is locked, against rotation opposite to the currently selected direction of rotation of the drive shaft W.

According to Fig. 4 is in the end flange 11, the teilumfängliche curved path 29 recessed, which defines the end stops 16 for the driver M. Further, in the end flange 11 a, preferably approximately radially, latching element R is fixed, which contains, for example, a spring-loaded ball 12, which is formed with a Mitnehmer M shaped detent recess 13 in each case at contact of the driver M at an end stop 16 relative rotational position of the eccentric bushing B engages relative to the eccentric portion A and generates a locking force which prevents the driver M and / or the eccentric bush B from rotating away from the set relative rotational position. The changeover range is indicated by 15.

The locking force, generated by the interaction between the latching element R and the latching recess 13 is selected so that it can be replaced by in unfavorable operating situations of the tamper device T, for. can not be overcome by the eccentric bushing B resulting Fremdverstellmomenten, but is overcome only at a reversal of the drive shaft W, for example, by the then becoming moment of inertia of the eccentric bushing B. The then occurring moment of inertia is still supported by the rotational resistance of the eccentric bushing B in the connecting rod 2 on the larger bearing diameter relative to the smaller bearing diameter of the eccentric bushing B on the eccentric A.

In the embodiment in FIG Fig. 5 another type of locking and / or coupling device V is provided for the tamper device T. Namely, the eccentric bushing B, for example, in its end flange 11, an outwardly tapering, V-shaped abutment recess 17 for a spring support 18 which is spring-biased in the extension and pivotally supported on the circumference of the eccentric portion A with a pivot piston 19. On the pivot piston 19, a latching element R-carrying pot piston 20 is telescopically displaceable, which contains a spring used with bias 21, which presses the locking element R with bias in the abutment recess 17. In this way becomes an over-center spring mechanism created, which has its dead center 22 in the middle between here two defined relative rotational positions of the eccentric bushing B.

The locking and / or coupling device V of Fig. 5 will be useful in conjunction with the basis of 3 and 4 explained driver M and the end stops 16 used to additionally lock the set relative rotational position of the eccentric bushing B.

In a conversion by reversing the direction of rotation of the drive shaft W, the moment of inertia of the eccentric bushing B, possibly with the aid of higher rotational resistance in the eye of the connecting rod 2 is used to first compress the spring support 18 until the dead center 22 is run over and the eccentric bushing B in the direction of other relative rotational position moves. The bias in the spring support 18 generates from the dead center 22 a supporting torque in the direction of arrow 23 to the new relative rotational position. This torque in the direction of the arrow 23 also generates the locking force in the respective relative rotational position.

Instead of the spring support 18 and a bending spring could be used, which acts similar to the spring support 18 between the eccentric portion A and the eccentric bushing B.

Fig. 6 illustrates a working in conjunction with centrifugal embodiment of the locking and / or coupling device V of the tamper T. This embodiment takes into account a characteristic of the tamper T, namely that the required locking force decreases in the set relative rotational position with increasing angular velocity of the eccentric bushing B. If the required locking force (sufficient to prevent an unwanted adjustment of the eccentric bushing B) is above the moment of inertia of the eccentric bushing B to be achieved, in the embodiment in FIG Fig. 6 used the opportunity to use in addition to the angular acceleration and the angular velocity in a conversion.

In Fig. 6 the locking element R is guided for cooperation with the locking recess 13 in the eccentric portion A approximately radially movable in a centrifugal mass body 25 and supported therein by a first spring 24 which acts in the direction of the center of rotation on the locking element R. The centrifugal mass body 25 is guided radially displaceably in a fluid chamber 26 (filled with a liquid or with a gas, such as air), for example, piston-shaped and enclosed by a sliding bearing 27, wherein between the outer periphery of the centrifugal mass body 25 and the sliding bearing 27 defines a fluid throttle gap X. is. The centrifugal mass body 25 is supported via a second prestressed spring 28 on a closure of the fluid chamber 26. The locking force generated by the locking and / or coupling device V. is dependent on the angular velocity of the eccentric bushing B, that it is only then reduced when the spring 28 springs in accordance with the centrifugal force due to the extension movement of the centrifugal mass body 25 accordingly. This occurs from an angular speed (a limit speed) at which the centrifugal force of the centrifugal mass body 25 plus the force of the first spring 24 is greater than the force of the second spring 28th

If the tamper device T operated below the limit speed, a locking force remains effective, which can not be overcome by the moment of inertia of the eccentric bushing B at a reversal of direction. This means that in this condition a conversion may not be possible. If, however, the tamper T operated above the limit speed, the locking force is only so low or canceled that the moment of inertia of the eccentric bushing B in a reversal of the drive shaft W is sufficient to allow the locking element R escape from the locking recess 13 and perform the changeover. In this case, even a time window can be taken into account, after which a changeover is possible. This time window is defined by the length of time the centrifugal mass body 25 has moved far enough outwards, i.e., after the tamper device T has run above the limit speed until the volume of fluid above the centrifugal mass body passes through the fluid restriction gap X, e.g. has emptied down and then only the locking force has dropped so far that the moment of inertia of the eccentric bushing overcomes the locking force when the direction of rotation is reversed. The fluid throttle gap X forces a damped displacement of the centrifugal mass body 25 and determines the extent of the time duration of the time window.

An advantage of the embodiment of Fig. 6 is that at low angular velocities a very high locking force is effective. Since the centrifugal mass body 25 is able to dig out the locking element R, the locking and / or coupling device V can not only act as a locking device (with positive and positive locking), but even a purely positive engagement situation of the locking element R is possible.

Fig. 7 and 8th show exemplary embodiments in which a centrifugal mass body 25 directly interacts with a cam track 29 'in the driver M on the eccentric section A.

The locking element R is in Fig. 7 arranged directly on the centrifugal mass body 25 and engages in the curved path 29, which is here designed with an example arcuate Umstellabschnitt and at both ends of each extending approximately radially outwardly latching recess 13, so to speak, the end stops 16 of 3 and 4 can form, and also are effective for the lock V in the reverse direction. The centrifugal mass body 25 is acted upon by a spring, not shown, to the center of rotation. A changeover is initiated by a reversal of the direction of rotation of the drive shaft W. The locking element R moves within the curved path 29 and is then introduced into a latching recess 13 when the eccentric bushing B has reached the relative rotational position and at the same time there is a corresponding angular velocity, which moves the centrifugal mass body 25 away from the center of rotation. As long as no corresponding angular velocity is reached, a conversion is not possible. The centrifugal mass body 25 is spring-loaded here in the release direction of the locking device V.

In the embodiment in FIG Fig. 8 is the curved path 29 'in the driver M on the eccentric portion A designed reversed as in Fig. 7 , The locking recesses 13 'extend inwardly approximately radially to the center of rotation. The latching element R may be fixedly mounted on the centrifugal mass body 25, which is supported by the prestressed spring 28 in the fluid chamber 26 and optionally displaceable using the fluid throttle gap in the sliding bearing 27. Here, therefore, the centrifugal mass body 25 is biased in the locking direction of the locking device V. A changeover is only possible if the eccentric bushing B runs above a predetermined limit speed at which the centrifugal mass body 25 has been displaced sufficiently far in the release direction of the locking and / or coupling device V, for example within the mentioned time window and by reversing the direction of rotation of the drive shaft W. ,

A similar embodiment as that of Fig. 8 will be in the FIGS. 9 and 10 shown. Here is a combination of the locking element R with a centrifugal mass body 25 and a friction surface 30 and a Gegenreibfläche 31, for example, on the connecting rod 2, indicated. The interaction between the friction element or the friction surface 30 and the counter friction surface 31 supports the changeover. This may be advantageous in embodiments of tamper devices T, the eccentric bushing B has a very low inertial mass (small moment of inertia in reversal of rotation of the drive shaft W), or in Tampervorrichtungssträngen that can perform only a small angular acceleration. However, the additionally generated friction torque acts only outside of the adjusted relative rotational positions of the eccentric bushing. The height of the respectively acting friction torque can, for example, by a in Fig. 9 shown tension spring 28 'can be adjusted. A lock in the respective relative rotational position is possible only at a corresponding angular velocity, depending on how the locking recesses 13 'of the cam track 29' are oriented, ie inward or outward, according to the Fig. 7 and 8th , ie a correspondingly low or a corresponding high angular velocity. The centrifugal mass body 25 is here by a not shown Applied spring, for example, in the direction of the center of rotation. The cam track 29 'is in the over the wedge 14 with the eccentric section A coupled driver M gebüdet. The locking element R is a projection on the centrifugal mass body 25, which participates in the rotational movement of the eccentric bushing B, but is radially movable therein.

In the above-described embodiments of Fig. 3 to 10 can be exposed to low frictional resistance between the eccentric bushing B and the eccentric portion A of the drive shaft W, which would favor unintentional rotational adjustments of the eccentric bushing B without influencing the locking and / or coupling device V.

In the embodiments in the FIGS. 11 and 12 the locking and / or coupling device V is formed as Drehreibschlusskupplung between the eccentric bushing B and the eccentric portion A, ie between these two components acts a high coefficient of friction, so that the rotational resistance between them is so high that critical operating situations no unwanted rotation of the eccentric bushing B relative can cause the eccentric section A. However, since the friction clutch can not be overcome by the moment of inertia of the eccentric bush when reversing the direction of rotation, is in the embodiments of the FIGS. 11 and 12 operated remotely deceleration of the eccentric bushing B, as soon as a change takes place, for example, here by a reversal of direction.

According to Fig. 11 the eccentric bushing B is fixedly connected to a brake body 32, for example a brake disk 33, to which a friction element 34, for example a brake caliper 35, is assigned. The brake caliper 35 is adjusted by a mechanism 36 and a remote control 38 between the release position shown and brake positions on the brake body 32, wherein the friction element is supported stationary at 37 relative to the eccentric bushing B, for example in the screed frame 4 of Fig. 1 and 2 ,

In the embodiment in FIG Fig. 12 is as a brake body 32, for example, a brake disc 33 fixedly connected to the eccentric bushing B, wherein the locking and / or coupling device V is designed as Reibschlusskupplung between the eccentric bushing B and the eccentric section A with correspondingly high rotational resistance. On the brake body 32 engages a friction element 34 here in the form of a brake lever 41 with a braking surface 39, which is mounted stationary at 37, for example on the screed frame 4, and is held by a tension spring 40 in a release position, not shown. On the brake lever 41, the remote control 38 engages, for example, a Bowden cable with which the braking surface 39 against the force of the spring 40 to the brake body 32 can be applied to the eccentric bush B at a conversion or to a Brake change until the high rotational resistance in the friction clutch is overcome.

Since the high rotational resistance in the Drehreibschlusskupplung between the eccentric bushing B and the eccentric portion A always sufficient to prevent unwanted adjustments of the eccentric bush, with the locking and / or coupling device V any number of relative rotational positions of the eccentric bushing B can be adjusted, or can the stroke the Tamperleiste are continuously adjusted, for example by the drive shaft W is very slowly rotated until reaching a desired relative rotational position at a reversal of direction with braked brake body 32. A reversal of the direction of rotation is not necessarily required for a changeover here. A driver M and end stops 16 or the cam track 29, 29 'may be provided, but are not mandatory.

This in Fig. 11 shown friction element 34 can be operated mechanically, hydraulically, electrically or pneumatically remotely, either on the screed or in the paver.

In the embodiment in FIG Fig. 13 is the locking and / or coupling device V between eg the end flange 11, the eccentric bushing B and the eccentric portion A of the drive shaft W designed so that the eccentric bushing B is coupled to the eccentric portion A by a braking torque then non-rotatably when the drive shaft W a predetermined Boundary speed exceeds, however, is relatively rotatable below the limit speed and reversible by a reversal of direction in another rotational position, for example due to the moment of inertia and / or rotational resistance in the connecting rod 2. In the new rotational position, the eccentric bushing B and the eccentric portion A are first coupled together again non-rotatably, as soon as the limit speed in the new direction of rotation is exceeded.

The rotatably coupled by means of the wedge 14 with the drive shaft W driver M engages the cam track 29 in the end flange 11 of the eccentric bushing B and can be intercepted at each of two of the two different rotational positions defining abutment surfaces 16. In the driver M at least one radial bolt 42 is fixed (expediently two diametrically opposed bolts 42) which passes through a plain bearing bush 27 in a radial bore 43 in the centrifugal mass body 25 and the centrifugal mass body 25 radially movable. The centrifugal mass body 25 may (indicated by dashed lines) be a nearly semicircular shell. A similar, eg mirror-image centrifugal mass body 25 may be guided diametrically opposite to the second pin 42. On each centrifugal mass body 25, a half-shell-shaped brake pad 44 may be loose or adhered, which may cooperate with an inner friction surface 32 in the end flange 11, when the centrifugal mass body 25 is displaced by centrifugal force (above the limit speed of the drive shaft W) to the outside. The thus effective braking torque couples the eccentric bushing B to the drive shaft W, so that the catch M intercepted at the end stop 16 in a direction of rotation no longer leaves this rotational position in the reverse direction of rotation. The centrifugal mass body 25 is for example acted upon by a spring 45 (tension spring) in the direction of the axis. The tension spring 45 determines, for example, the limit speed and acts, for example, between the two half-shell-shaped brake pads 44th

In all embodiments, spring forces, frictional forces, momentum forces or forces of centrifugal force, inertia or imbalance can be used to lock the eccentric bushing B in the respective relative rotational position, or forces generated by hydraulic, pneumatic or magnetic means.

Claims (15)

Tamper device (T) a screed (E), in particular a road finisher, with a tamper strip (1) which is attached to connecting rods (2), in each of which an eccentric bushing (B) is rotatable on an eccentric portion (A) of a rotationally driven Drive shaft (W) rotatable relative to the eccentric portion (A) and in different strokes of Tamperleiste (1) defining relative rotational positions drehkuppelbar with the eccentric portion (A), wherein between the rotational positions by a reversal of the drive shaft (W) can be switched without tools, characterized in that the eccentric bushing (B) in the respective rotational position can be locked against leaving the rotational position by means of a locking and / or coupling device (V) which can be released and / or engaged independently for switching from one rotational position to another automatically or remotely controlled. Tamper device according to claim 1, characterized in that between the eccentric bushing (B) and the eccentric portion (A) two end stops (16) and a driver (M) are provided, which in the change relative to each other about a center of rotation of the eccentric portion (A) rotatable are, wherein the respective system of the driver (M) at the end stops (16) defines two different relative rotational positions of the eccentric bushing (B), and that the locking and / or coupling device (V), the eccentric bushing (B) at least in these two relative Rotary positions locked. Tampervorrichtung according to claim 1, characterized in that the locking and / or coupling device (V) by forces generated during the conversion is solvable or surmountable, the angular acceleration and / or the angular velocity and / or the moment of inertia and / or braking of the Eccentric bush (B) result, preferably within a predetermined time window. Tamper device according to claim 1, characterized in that during the changeover with the locking device (V), preferably by spring force on the eccentric bushing (B) an additional Umstell-torque in direction (23) to the respective relative rotational position can be generated, preferably with an over-center -Federmechanismus. Tamper device according to claim 1, characterized in that a, preferably limited, locking force of the locking device (V) by spring force and / or by Drehreibung and / or magnetic and / or hydraulic and / or pneumatic and / or centrifugal force generated dependent. Tamper device according to claim 4, characterized in that on the eccentric portion (A) a pivotable spring support (18), preferably in the extension direction spring-biased telescope (19, 20) or a bending spring, is arranged under the bias in an abutment (17) Exzenterbuchse (B) is supported, and in the change from the relative rotational positions defining spring support positions against the bias to a dead center (22) shortened and after exceeding the dead center (22) under the bias is extended. Tamper device according to claim 1, characterized in that the locking and / or coupling device (V) as kraftbeaufschlagbare locking device with at least one of the eccentric (A) or the eccentric bushing (B) supported locking element (R) and on the eccentric bush (B) or on Eccentric portion (A) supported locking recesses (13, 13 ') is formed. Tamper device according to claim 7, characterized in that in the eccentric bushing (B) a, preferably radial, spring-loaded locking element (R) is supported and on the eccentric portion (A), preferably the driver (M), the relative rotational positions correspondingly placed locking recesses (13) are provided for the locking element (R). Tamper device according to claim 8, characterized in that a first, the latching element (R) acted upon spring (24) in the eccentric bush (B) on a radially in a fluid chamber (26) movable centrifugal mass body (25) is supported, extending over a second Spring (28, 28 ') in the eccentric bush (B) is supported, wherein, preferably, between the centrifugal mass body (25) and a movement guide (27) for the centrifugal mass body (25) in the fluid chamber (26) a fluid throttle gap (X) is provided , and wherein, preferably, the latching element (R) and the latching recesses (13, 13 ') cooperate positively. Tamper device according to claim 8, characterized in that a latching element (R) is mounted on a in the release direction of the locking and / or coupling device (V) to the center of rotation spring-loaded centrifugal mass body (25) and engages in a eccentric fixed cam track (29) having a Umstellabschnitt and at both ends in end stops (16) in approximately radial, in the locking direction oriented locking recesses (13) for the locking element (R). Tamper device according to claim 8, characterized in that a latching element (R) is mounted on a in the locking direction of the locking and / or coupling device (V) to the center of rotation spring-loaded centrifugal mass body (25) and engages in an eccentric fixed cam track (29 '), the one Adjustment section and at both Ends at end stops (16) in approximately radial, oriented to the center of rotation locking recesses (13 '). Tamper device according to at least one of the preceding claims, characterized in that on the eccentric bushing (B), preferably the spring force movable centrifugal mass body (25), and the connecting rod (2), a preferably spring-loaded friction element (30) and a friction surface (31 ) are provided for the friction element, and that the friction surface (31), with the recesses of the relative rotational positions defining locking recesses (13 ', 13) only between the two locking recesses (13, 13') extends. Tamper device according to claim 3, characterized in that the locking and / or coupling device (V) as a predetermined raised locking force between the eccentric bushing (B) and the eccentric portion (A) permanently generating Drehreibschlusskupplung is formed, and that the eccentric bush (B) with a brake body (32), preferably a brake disc (33) is connected to the at least one relative to the eccentric bushing (B) stationary supported friction element (34), preferably a brake pad (39) or a brake caliper (35) cooperates during the changeover that is remotely operable on the brake body (32) between a release and brake positions. Tamper device according to claim 13, characterized in that on the brake body (32) more than two different relative rotational positions of the eccentric bushing (B) are adjustable, and that from the predetermined, preferably adjustable, locking force in the Drehreibschlusskupplung in each relative rotational position, a holding torque for the eccentric bushing (B) results, which is higher than from the operation of the tamper device (T) on the eccentric bushing (B) occurring external torques. Tamper device according to claim 1, characterized in that the locking and / or coupling device (V) as by centrifugal force above a limit speed of the drive shaft (W) engageable engageable below the limit speed by spring force disengageable rotational position brake, and a changeover between relative rotational positions the eccentric bush (B) can be executed by reversing the rotational direction in each case below the limit rotational speed, the brake of at least one spring-loaded centrifugal mass body 25 in the carrier M, a brake pad (44) on the centrifugal mass body (25) and on the eccentric bush (B) a friction surface (32) for the brake pad (44).

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