GB2133114A

GB2133114A - Actuating means for vibrator phase adjustment for reversing

Info

Publication number: GB2133114A
Application number: GB08333859A
Authority: GB
Inventors: Wilhelm Latt
Original assignee: Weber Maschinentechnik GmbH
Current assignee: Weber Maschinentechnik GmbH
Priority date: 1982-12-29
Filing date: 1983-12-20
Publication date: 1984-07-18
Also published as: FR2538925B1; GB8333859D0; DE3248474C2; FR2538925A1; DE3248474A1; GB2133114B

Abstract

An actuating means for changing the phase relation between eccentric weights of vibrators, more especially earth compactors running forwardly and rearwardly at will, has a transmitter (Fig. 4) which can be reversed by means of an actuating lever and also a receiver (Fig. 6) which is arranged on the vibrator, which transmitter and receiver are connected to one another by means of a flexible operating cable system. The actuating means has an operating lever (not shown) secured on a shaft 12 having an eccentric pin 19 associated with an adjustable latching means 20- 23 guiding the operating lever into respectively one of its end positions. The receiver comprises a swivellable pivot pin 30, which is provided with a pivoted lever 29 and engages with eccentrically arranged setting members 35 in form-locking manner in a setting bush 37 connected to the control dog of the vibrator, moving the operating lever from one end position to the other causes a change in phase relation between the eccentric weights and hence a reversal of direction of movement of the compactor. <IMAGE>

Description

SPECIFICATION Actuating means for the clutch of reversible vibrators The invention relates to an actuating means for the clutch of reversible vibrators, more especially earth compactors running forwardly and rearwardly at will, and having a transmitter which can be adjusted by means of an actuating lever and also a receiver which is arranged on the vibrator and which is connected to the transmitter through a flexible operating cable system, the cable of the said operating system being connected to the second lever arm of the actuating or operating lever, which is of a two-arm construction and is mounted in a housing.Such transmitters and receivers connected by a flexible operating cable system are always used, not only with earth compactors, when operations, because of easy access, are to be initiated at a location which is different from that at which they are actually being conducted, and flexible operating cable systems allow a relatively unhampered positioning of the transmitter with respect to the receiver which has caused the re-positioning.

Such servicing elements such as transmitters and receivers are already manufactured in a wide range of different constructions. More especially at the transmitter end, various different latching means, switching gears and the like are known, which do not however conform to the requirements existing in connection with soil compactors, such as a robust construction, a certain servo effect with the change-over, a rapid movement from one adjustable end position into the opposite and likewise adjustable end position, and also the further condition that parts which become worn are able when necessary to be quickly replaced. For example, for stopping purposes, rocker arms are suggested, which impede a rapid and positive reversal.This means that, at the time of reversal, the coupling part of the control dog already meets an abutment surface of the abutment elements before the switching or coupling movement is completed, so that the forces which occur in such cases are to be absorbed by relatively small surface regions and the excessive surface pressures which thereby occur cause the danger of increased wear or even of actual damage. Moreover, latching means provided at both ends shorten the switching or change-over speed which normally can be achieved.Cables of the operating cable system which are wrapped around cable pulleys of the operating lever complicate the possibly necessary replacement, and toothed segments meshing in racks have a deleterious effect on the rapidity of the control operation, since they complicate the structure of the transmitter and in addition have the disadvantage that there is a danger of penetration of dirt. Moreover, the known receivers do not conform to the special requirements which occur in this case.

Accordingly, the invention seeks to develop transmitters and receivers which are coupled by an operating cable system and in which the said system is operative on a second lever arm of the actuating lever that, with a simple construction and substantial exclusion of the danger of dirt penetration, both rapid, spontaneous changeovers between two easily adjustable end positions can be carried out and also set control positions are reliably locked and, in the event of disruption, the operating cable system can be easily replaced, with readjustment of the arrangement, even by unskilled persons.

In accordance with the invention there is provided a transmitter, the operating lever of which has associated therewith an adjustable latching or locking means guiding the operating lever into respectively one of its end positions and the receiver comprises a swivellable pivot pin which is connected fast in rotation with a pivoted lever provided for acting on the cable of the operating cable system, which pin engages with eccentrically arranged setting members in formlocking manner in a setting bush connected to the control dog of the vibrator.With such an arrangement, for carrying into effect a fast and defined control movement, only the actuating lever has to be swung beyond its middle position: the latching mechanism then assists the further control or switching movement until the defined, adjustable end stop is reached, and in such manner also reliably protects the operating lever against unwanted adjustments. As regards the practical construction, it has proved desirable to connect the operating lever to a stepping wheel, which comprises an axially parallel, eccentrically held bolt or pin, against which is biased a radially extending latching pin. The latching means can be developed in a particularly sensitive manner by that end of the latching pin which is facing the eccentrically held bolt or pin being conically pointed.The same effect can also be produced, with reduced surface pressure and a lesser degree of wear, if that end of the latching pin which is facing the eccentrically held bolt or pin is made roof-shaped and the latching pin is so secured against turning movements by locking elements that the edge formed on its free end is axially parallel with the eccentrically held pin. The security against rotational movement is in this case able to be already achieved by, for example, a square section of the latching pin and of its guideway. A simple, compact structure is obtained if the latching pin, on its side remote from the point or edge, comprises a recess or cavity accommodating the essential length of the compression spring by which it is biased.For forming the adjustable stop, the housing of the transmitter preferably comprises two grub screws which can be adjusted and secured in position, the free ends of said screws engaging in the pivotal travel of the pin and limiting the pivotal range thereof. The fixing is able in this case to be effected by locking nuts or locking screws positioned thereover; a particularly simple construction is provided by a coarse-thread form of the threaded bores receiving the screws. A stable construction which can be subjected to high stress is produced when the stepping wheel comprises two axially spaced segments or flanges, which support the bolt at both ends. A particularly sensitive and easy-running latch mechanism is produced if the bolt is mounted so as to be rotatable.The latching mechanism is preferably enclosed by a housing, which has a bore through which extends a shaft journal for receiving the operating lever; the journal being mounted in the said bore. In this arrangement, housings closed on all sides can be used, with which a second shaft journal can be mounted inside the second housing shell. However, it is also possible in certain cases to dispense with the rear wall of the housing and the second shaft journal and to screw the housing in a flat position on to a wall, plate or the like which receives it and thus also forms a rear closure means.

As regards the receiver, it has proved desirable to arrange its setting bush coaxially in front of the control dog which is to be operated and to connect it to the latter so as to be immovable axially. The setting bush is advantageously arranged to be fast in rotation and axially displaceable in the housing of the receiver and to be rotatabiy connected to the free end of the control dog. For initiating the control processes, the pivot pin may comprise an eccentrically arranged driver pin, which engages in a groove or a transverse slot of the setting bush; it is also possible to permit the pivot pin to comprise a toothed segment, which meshes in a rack of the setting bush or a toothing concentrically enclosing the wall thereof.The mounting of the setting bush can be effected on both sides by members engaging in tapped collars or, if the setting bush if formed as a hollow cylinder provided at one end with the base, the bearings are able to engage around the two surfaces of the base. An adequate lubrication of the receiver is assured if this latter is enclosed by a housing which is flanged or screwed on to the housing of the controllable vibrator 1 and in which the pivot pin is mounted, and by the outwardly closed or sealed housing being open towards the vibrator. The assembly of the components of the transmitter and also of the receiver is facilitated if the housings comprise openings for introducing the components, which openings can be tightly sealed by covers.An infiltration of dirt into the operating cable system is avoided by the latter being equipped at both ends with sealing elements which seal off the core or cable thereof with respect to its casing, which sealing elements can be formed as sleeves, O-rings, rubber lips'or the like.

The features of the invention are explained in detail by reference to the following description of constructional examples and by reference to the drawings in which such examples are illustrated.

In the drawings: Figure 1 is a diagrammatic view of the vibrator with the essential parts of the reversing means, the vibrator being shown without its housing; Figure 2 is a side view of a transmitter; Figure 3 is a section on the line Ill-Ill through the transmitter of Figure 2; Figure 4 is a section parallel to the plane of the drawing and through the transmitter of Figure 2; Figure 5 is a side view of a receiver arranged on a vibrator housing; Figure 6 is a section parallel to the plane of the drawing and through the receiver of Figure 5; Figure 7 is a section on the line VIl-VIl through the transmitter of Figure 6; Figure 8 is a modified receiver which is flanged on to the housing of a vibrator; and Figure 9 is a section through the receiver of Figure 8 and shown parallel to the plane of the drawing of Figure 8.

Represented in Figure 1 are the essential parts of a reversible vibrator 1, without the housing enclosing the said parts and the bearings thereof.

Arranged on the shafts 2 and 3 are the eccentric weight 4 and also the adjusting eccentric weight 6. The shafts 2 and 3, of which one is driven, are interconnected by means of gear wheels, one of which is connected to the shaft 2 and the other, equipped with stop segments 5, is mounted on the shaft 3. The visible journal of the shaft 3 is formed with a bore, in which is displaceably arranged a control bolt 7, the free end of which carries a control key or dog 8, which is guided through a slot to a position before the end faces of the stop elements 5, which are arranged offset axially from one another.

For the operation of the vibrator 1, one of its shafts 2 or 3 is driven and the other is also driven through the gear wheels and the support of the control element bearing with its end face on the control dog 8 guided in the slot of the shaft 3. If now the control dog 7 revolving with the shaft 3 is shifted axially in one of the two directions of the double arrow 9, then it is moved away from the end face of the stop segment against which it has until now been bearing and is brought into the effective range of the other of the stop segments, so that with continued operation, the shaft 3 with the adjusting eccentric weight 6 is turned relatively to the gear wheels until the control dog 8 is positioned before the end face of the second stop segment and now, after one revolution of the shaft 3 with the adjusting eccentric weight 6 relatively in the shaft 2 with the eccentric weight 4, these are once again driven through the control dog and the second stop segment. This relative rotation gives the required phase displacement between the two eccentric weights and consequently influences the total vibration or oscillation caused by the vibrator 1.

It is the purpose of the invention to enable the displacements of the shift dog being rotated with the shaft 3 corresponding to the double arrow 9 and causing the reversal or change-over of the vibrator 1 to be carried out from any easily accessible position of an earth compactor.

Arranged at such an easily accessible position on the said compactor is the housing 10 of a transmitter 11, in the manner as represented in the side view in Figure 2 and in two sections in Figures 3 and 4. As shown in Figure 3, the housing 10 is not closed on its rear side: The closure is obtained at the time of assembly on a mounting surface and by this latter. A shaft journal of a stepping wheel 12 extends through a bore which is formed on the front side of the housing, the said journal receiving in a transverse bore the actuating lever 1 3 which is secured in position by a transverse pin.The said actuating lever 13 is constructed as a two-armed lever, of which the second flattened lever arm is embraced by a yoke 14 of an actuating cable 15, the casing 1 6 of which is guided through a hole in an angle plate 1 7 and is bolted to the latter. The angle plate can, for example, also be replaced by a plate of the earth compactor or the like. Any penetration of dirt into the actuating cable is prevented by a sleeve 1 8 of an accordion-like construction, which is connected at one end to the fork head and at the other end to the casing of the actuating cable, and which is made of preferably grease-resistant rubber or a synthetic plastics material.The connection of the fork head to the actuating lever 1 3 is provided by a bolt, which is preferably so constructed as a spring bolt that it is provided with a lateral tongue, of which the ends are resiliently bent over, so that, when the bolt is pushed on, the spring embraces the fork head from the side and secures the bolt.

The stepping wheel 12 has two flanges, and a bolt or pin 19 is mounted in an axially parallel bore. Extending from the side into the housing are two threaded holes, each containing grub screws 20, which in each case are directed on to the bolt or pin 1 9 in one of its end positions as shown in broken lines in Figure 4. Provided underneath the stepping wheel 12 is a recess or opening in the housing, in which is displaceably held a latching pin 21, one end of which is pointed in roof-like manner, while the other end thereof has a cavity, into which is fitted a compression spring 22, which is supported against the cover 23 which is held in position against the housing by means of screws.

Normally, this transmitter is disposed in one of its two end positions, which can be adjusted by the grub screws 20. If the actuating lever 13 is then moved into the opposite position, then the rotatable bolt or pin 1 9 is guided to be against one of the two inclined cover surfaces of the latching pin 21, tensioning this latter against the force of the compression spring 22, until the upper edge of the latching pin 21 is reached, in the position of the bolt or pin 1 9 which is shown in Figure 4.As shown in the actuating lever 1 3 and, with it, the stepping wheel 12 and the bolt or pin 1 9 are further rotated, the said pin 1 9 slides or rolls down on the further sloping top surface of the latching pin 21, and this pin, because of its biassing, applies further pressure to the pin 1 9 and, as a result, forces both the stepping wheel 12 and the actuating lever 1 3 automatically into their other end position. It is possible for these end positions to be easily and finely adjusted by the grub screws 20; with suitable fitting or adjustment, the result which is obtained is that these grub screws are relatively difficult to adjust and consequently, after each adjustment has been made, are automatically secured in position.It has been proved desirable for the transmitter to be filled to some extent with a grease which is not too stiff, in order to produce the necessary constant lubrication. The housing substantially closes off the internal space, so that there is no danger of any lubricant escaping or of any dirt penetrating. If necessary, the housing may additionally be sealed off relatively to the shaft journal of the stepping wheel, in the manner as shown in connection with the receivers.

The actuating or operating cable 15, which is shown broken away in Figure 2, leads to a receiver 25 such as shown in Figures 5 to 7, which is screwed on for producing simple connections directly by way of the control dog 7 to the housing 24 of the vibrator. An angle member 26 having a threaded connection with the cover 32 of the housing 33 of the receiver 25 determines that end of the operating cable 1 5 on the receiver side by screwing on the casing. The fork head 28 on the receiver side is fitted on to a pivot lever 29, which is screwed tight in rotation on to a pivot pin 30 which, sealed off by means of a packing 31, is mounted for swivelling movement in the housing 33 of the receiver and is held by means of the cover 32.As shown by the sections which are represented in Figures 6 and 7, a portion of the lower region of the pivot pin 30 is removed and a driver pin 35 is fitted into the body of the pivot pin.

The said driver pin 35 fits into a groove 36 in a setting bush 37, which is rotatable between axial bearing discs or washers 38 which are fitted on to a reduced shoulder of the control dog 7 or has a threaded connection with this latter. As a consequence, the setting bush 37 is rotatable, but is mounted on the shoulder of the control dog 7 so as to be incapable of movement in the axial direction. On the other side, the said bush 37 has a recess, into which is fitted a spring 39, which is capable of displacement in a groove in the housing 33.

If now the cable of the operating cable system 1 5 is shifted from the transmitter by adjustment of the actuating lever 13, the said cable also turns the pivot lever 29 as weli as the pivot pin 30 accommodating this latter. The driver pin of this latter is in this case also rocked and carries with it the setting bush 37, in its turn also moves the control dog 7 on which it is mounted.

Other constructional forms are also possible in principle. For example, the setting bush 37 could be screwed fast on to the shoulder of the control dog 7; however, it has been shown that, in this case, the driver pin 35 and the groove 36 are subjected to a heavier degree of wear than that which occurs with the constructional form as shown.

With the constructional form of the receiver 25 as illustrated, it is proved to be advantageous for this to be flanged on to the housing 24 of the vibrator 1, so that a satisfactory well-defined fixing and reliable position thereof are guaranteed. In this connection, it is also proved to be advantageous for the bearing of the shaft 3 of the vibrator not to be sealed: this is achieved by the housing 33 of the receiver 25 which is flanged thereon, which in its turn is sealed off in the bearing regions of the pivot pin 30 by a packing 31. In this way, the lubricant or oil bath of the vibrator 1 is also able to penetrate into the receiver housing and as a consequence provides for a constant and reliable lubrication of both the pivotable and displaceable parts and the axial bearing washers 38.

Another constructional form of the receiver is illustrated in the elevational view of Figure 8 and in an axial sectional view, parallel to the plane of the drawing, as represented in Figure 9. In this case also, the housing 41 is flanged on to the housing 24 of the vibrator 1, and the fork head 28 of the operating cable 1 5 is engaged with a pivotal lever, which may be made in one piece with the pivot pin 42, but preferably has a screw-threaded connection with this latter. The operating cable 1 5 is sealed off by a sleeve 27, which is connected at one end to the casing of the operating cable and at its other end to the fork head 28, so that the continuous lubrication of the operating cable and the protection against soiling are guaranteed.An adjustment of the actuating lever 1 3 of the transmitter 11 as shown in Figures 1 to 4 causes a swivelling of the pivoted lever in the direction of the double arrow 51.

As shown by the section in Figure 9, the pivot pin 42 is provided with a toothed rim or, since only a part thereof is required, with a toothed segment 43, which meshes with a rack 45 which is milled into a setting bush 44. The setting bush is formed as a displaceable, cylindrical hollow member which is formed with a base 46 being mounted on a shoulder of the control bolt or pin 7: Since the latter is already mounted in the shaft 3 and also the setting bush 4 is displaceable linearly and is secured by a spring 49 against rotation in the housing 41 , the diameter of the bore arranged in the base of the setting bush 44 can be kept relatively large, so that it embraces the shoulder of the setting bush with a correspondingly large clearance.The surfaces of the base are embraced on both sides by axial bearing washers 47 and 48, of which the washer 48 is fitted on to the shoulder and the washer 47 is tightened by means of a screw against the end face of the shoulder. If now the actuating lever of the transmitter is shifted from one extreme position into the other, then the pivoted lever travels through the path of the double arrow 51, the toothed segment 43 meshing in the rack 45 displaces the setting bush 44 in its guideway formed in the housing and its base, through the axial bearing washers 47 and 48, formed as thrust bearings, carries with it the control dog 7, so that it executes its displacement travel 50. Modified forms can also be used in this connection: for example, instead of a rack 45 which is milled lateraily in the setting bush 44, the entire setting bush could be surrounded by a concentric, milled toothing.However, this would probably impair the guiding of the setting bush in the housing, and preferably also the toothed segment 43 would have to be provided with a curved toothing of the type used with worm gears, and in this case the assembly could not be carried out in such a simple manner as that which has been proposed in connection with parts of the transmitter and the receiver: these parts, for example, latch pins 21 and compression springs 22 of the transmitter 11 and the pivot pins 30 and 42 of the receiver can be inserted axially at the time of assembly and can be closed off by plates 23 or covers 32 which are screwed on above them.

For simplifying what has been shown in the drawings, these have in each case been so drawn that the actuating lever 13 and respectively the pivoted lever 29 and setting bushes 37 and 44 are disposed in their middle position, and correspondingly this also applies as regards the control bolts 7. From this middle position, as soon as this is only slightly exceeded, the actuating lever 13 and, with it, through the operating cable mechanism 15, the setting bushes, pivoted levers and control dogs, are brought by the latching means into their extreme position, so that the control stroke 9 or 50 is carried out and the pivoted levers and setting bushes swing in the direction of the double arrows 40 or 51 into their end positions.

The actuating means as illustrated present a number of advantages: The adjustments can be carried out quickly and reliably in amounts which can be easily adjusted, so that, as soon as the control dog 8 of Figure 1 is brought out of the path of one of the stop segments 5, it is brought fully into the path of the other stop segment, before this latter comes into contact, so that excessive surface pressures caused by an only partial covering are safely avoided. Provision is made for the fact that the actuating lever 13, shifted only slightly beyond its middle position, springs automatically into the end position and is safely and positively arrested in such position. In this way, it is made impossible for the control dog 7 to be moved to intermediate positions and held in such positions.The adjustment, already in the transmitter, is proved to be advantageous, since after carrying out an adjusting operation, the restoring force caused by the latching means is absorbed solely in the transmitter itself by the adjusting elements and the actuating cable system, the connection between pivot pin and setting bush and also the connection between setting bush and control dog remain without these constantly loading forces, so that a small degree of wear and long operating times are produced.

The adjustment or setting of the two end positions, to be already carried out in the transmitter, is to be effected easily and quickly, even by inexperienced persons, and also the operating cable system is relatively easy to connect, so that it can be easily replaced if necessary and the adjustment mechanism, which in any case is substantially only provided for the balancing of tolerances of the actuating cable systems, is capable of being quickly readjusted.

This is assisted by the fact that the fork heads of the actuating cable are connected to the operating lever or pivoted lever by means of spring bolts, which only have to be pushed into the connecting position and are safely held in position by the action of their own spring clips. In the event of a necessary replacement, it is consequently only necessary for the actuating cable itself to be released at the transmitter and receiver ends and then reconnected and to carry out the adjustment or setting; any action or dismantling, either at the transmitter or the receiver, is unnecessary. The replacement is further simplified by the fact that standard or conventional actuating cable systems for transmitting tensile or compressive forces are used, so that the supply and stocking of spare parts is simplified. The transmitting and receiving mechanisms are easily and compactly made and have a long effective life, so that no particular attention has to be paid to them at the time of construction. They are proved to be simple, robust and inexpensive, and also the maintenance is considerably simplified by the fact that they are completely safe against the penetration of dirt and the transmitter and also the actuating cable system are provided with a permanent lubrication which is independent of temperature and which for years does not require any checking or refilling, while the transmitter is also reliably and copiously lubricated automatically by the oil bath in the vibrator.

Claims

1. Actuating means for the clutch or reversible vibrators, more especially earth compactors running forwardly and rearwardly at will, and having a transmitter which can be reversed by means of an actuating lever and also a receiver which is arranged on the vibrator and which is connected to the transmitter through a flexible operating cable system, the cable of the said operating system being connected to the second lever arm of the actuating or operating lever which is of a two-arm construction and is mounted in a housing, wherein the operating lever of the transmitter has associated therewith an adjustable latching or locking means guiding the operating lever into respectively one of its end positions and the receiver comprises a swivellable pivot pin which is connected fast in rotation with a pivoted lever provided for acting on the cable of the operating cable, which pin engages with eccentrically arranged setting members in formlocking manner in a setting bush connected to a control dog of the vibrator.

2. Actuating means according to claim 1, wherein the operating lever is connected to a stepping wheel which comprises an axially parallel, eccentrically held bolt or pin, and wherein a radially extending latching pin is biased towards the eccentrically held pin.

3. Actuating means according to claim 2, wherein that end of the latching pin which faces the eccentrically held bolt or pin is conically pointed.

4. Actuating means according to claim 2, wherein that end of the latching pin which is facing the eccentrically held bolt or pin is made roof-shaped and the latching pin is so secured against turning movements by locking elements and the edge formed on its free end is axially parallel with the eccentrically held bolt or pin.

5. Actuating means according to any one of claims 2 to 4, wherein the latching pin, on its end remote from the point or edge, comprises a recess or cavity accommodating the essential length of a compression spring by which it is biased.

6. Actuating means according to any one of claims 2 to 5, wherein the housing of the transmitter comprises two grub screws which can be adjusted and secured in position, the free ends of the said screws intervening into the pivotal travel of the eccentrically held bolt or pin and limiting the pivotal range thereof.

7. Actuating means according to any one of claims 2 to 6, wherein that stepping wheel comprises two segments or flanges provided in axially spaced relation, the said segments or flanges supporting the eccentrically held bolt or pin at both ends.

8. Actuating means according to claim 7, wherein the eccentrically held pin is rotatably mounted in the segments or flanges.

9. Actuating means according to any one of claims 2 to 8, comprising a housing which encloses the locking or latching mechanism and which comprises at least one bore, through which extends a shaft journal of the stepping wheel for accommodating the operating lever, the said journal being mounted in the said bore.

1 0. Actuating means according to any one of claims 1 to 9, wherein the setting bush of the receiver is arranged coaxially before that control dog of the vibrator which is to be actuated and is immovably connected to the latter in the axial direction.

11. Actuating means according to ant one of claims 1 to 10, wherein the setting bush arranged so as to be fast in rotation with and axially displaceably in the housing of the receiver is connected by thrust bearings to the free end of the control dog.

12. Actuating means according to any one of claims 1 to 11, wherein that pivot pin comprises an eccentrically arranged driver pin, which engages in a groove or a transverse slot of the setting bush.

13. Actuating means according to any one of claims 1 to 11, wherein the pivot pin comprises a toothed segment, which meshes with a rack of the setting bush or a toothing concentrically enclosing the wall thereof.

14. Actuating means according to any one of claims 1 to 13, wherein the setting bush is mounted on both sides by members which engage in collars which are provided.

15. Actuating means according to any one of claims 1 to 13, wherein the setting bush is formed as a hollow cylinder provided with a base at one end and the bearings embrace the two surfaces of the base.

16. Actuating means according to any one of claims 1 to 15, wherein the receiver is enclosed by a housing which is flanged on to the housing of the controllable vibrator and the pivot pin is mounted in sealed manner, and wherein the housing, closed or sealed off outwardly by a packing, is open with respect to the housing of the vibrator.

17. Actuating means according to any one of claims 1 to 16, wherein the housings for the vibrator and receiver comprises openings for the introduction of components, which openings can be tightly closed by covers.

18. Actuating means according to any one of claims 1 to 17, wherein the operating cable system is provided at both ends with sealing elements which seal off the core or cable thereof with respect to its casing.

1 9. Actuating means for the clutch of reversible vibrators substantially as shown in Figures 1 to 7, or Figures 1 to 4, 8 and 9 of the accompanying drawings and described herein with reference thereto.

20. A reversible vibrator having clutch actuating means according to any one of the preceding claims.