EP0536233B1 - Device for driving a longitudinally reciprocating tool - Google Patents

Abstract

A device for driving a tool in axial direction in the course of a vibration-like forward and reverse movement, which operates at high efficiency with a rapidly oscillating stroke frequency and can be used as an easily handled hand-held appliance because, due to the drive, an especially advantageous ratio of the weight and volume to the power exerted at output is feasible. This drive consists of a piston (8) movable non-positively to and fro, which feeds oil to a working piston (22) and moves the latter correspondingly to and fro against the pressure of a spring (25) acting on the working piston (22) and against the external air pressure. The tool to be drive is preferably connected with the working piston (22) by means of the counterpressure spring (25). Working cylinder (20) and master cylinder (9) are connected with each other by a flexible hose (14) to prevent any weight transmission to the hand-held appliance. (FIG.

Description

The invention relates to a device for driving a tool that can be moved back and forth in the axial direction.

Such tools and drives are known, for example as pneumatic hammers, pneumatic knives and the like, which operate according to this principle. These drives make a lot of noise even when idling, even if you only want a small amount of power for the drive. In the known drives, the weight and volume of the tool in relation to the power also leaves something to be desired, and the tool therefore requires a large amount of manual effort to operate.

From FR-A 2 402 127 a telemotor system is known in which a drive unit moves a piston in a cylinder, which acts on an oil column which acts on a piston acts in a cylinder of an implement and, for example, moves the cutting edge of a hedge trimmer. The return of the master cylinder piston against the force-exerting cam disc is done by the springs acting on the piston. Since springs work too slowly, such drives can only be used for tools with a low stroke frequency. Otherwise, lifting and knocking occur between the piston and the cam disk. At a faster stroke frequency, for example greater than 12 Hz, there is also outgassing in the oil. As a result, the efficiency of the power transmission between the driving motor and the driven tool is greatly impaired. In addition, there is a risk of cavitation phenomena with such outgassing. The efficiency between the input and output of such a system is relatively poor, since the entire work done by the drive during a work cycle must be performed in the first half of the full cycle. In addition, the engine output to be delivered is not distributed linearly in this first half of the working cycle. Rather, it increases proportionally up to the end of the first half of the working cycle and then falls back to almost zero after this point has been overcome. Therefore, almost no engine power is transmitted in the second half of the full cycle.

Similar systems with the same disadvantages are shown in AU-A-490,039 and CH-A-267 482.

According to AU-A-490,039, which shows a device with the features defined in the preambles of independent claims 1 and 2, an eccentric disc acts via a ball bearing ring on a piston which actuates an oil column against the pressure of a spring in the working cylinder, or two counter-rotating drive devices are acted upon by the eccentric disc in accordance with FIG. 5 such that two oil columns on the opposite sides of the drive piston for the Tool work. Such a drive has the disadvantage that the oil column or the oil columns are briefly subjected to an undesired negative pressure with each work cycle, in particular if a rapid oscillation of the working cylinder piston is desired, so that cavitation phenomena occur. If two oil columns working in opposite directions are provided, they work because they are not completely incompressible and, moreover, due to the pressure fluctuations in the lines, cause cross-sectional changes in the lines with a time delay which is not acceptable for the generation of a fast oscillating movement, because with rapid oscillation Shocks occur in the drive and / or the aforementioned effect of the Cavitation, both of which lead to premature destruction of the system.

The object of the invention is to provide a drive with a rapidly oscillating stroke frequency and high efficiency between drive (motor) and output (tool), which is designed such that the tool is advantageous to handle as a light, small in volume, but very powerful handheld device.

This object is solved by the features of claims 1 or 2.

• a) eine hohe Antriebskraft mit hohem Wirkungsgrad zu schaffen in Form einer axial oszillierenden schnellen Hubfrequenz,
• b) die Antriebskraft auf ein Handgerät zu übertragen ohne Übertragung des Gewichtes des Antriebes auf das Handgerät,
• c) beim Abtrieb ein besonders gutes Verhältnis zwischen Gewicht und Volumen und der freizusetzenden Kraft zu schaffen,
• d) die Kraftübertragung hindernden Kavitationen (Ausgasungen aus dem Medium) weitgehendst zu vermeiden. Darüber hinaus ermöglichen die Lösungen gemäß den Ansprüchen 1 und 2 auch
• e) ein leichtes Auswechseln des Werkzeuges,
• f) ein nahezu geräuschloses Arbeiten des Antriebes und auch
• g) ein erschütterungsfreies Arbeiten. Ferner ist der Antrieb
• h) leicht zu reinigen, und er kann
• i) auch unter Wasser benutzbar sein.

Claims 1 and 2 simultaneously solve the following subtasks:

• a) to create a high driving force with high efficiency in the form of an axially oscillating fast stroke frequency,
• b) to transfer the driving force to a handheld device without transferring the weight of the drive to the handheld device,
• c) to create a particularly good ratio between weight and volume and the force to be released during downforce,
• d) avoid cavitation (outgassing from the medium) as much as possible to prevent the transmission of force. In addition, the solutions according to claims 1 and 2 also enable
• e) easy replacement of the tool,
• f) an almost silent operation of the drive and also
• g) vibration-free work. Furthermore, the drive
• h) easy to clean and it can
• i) can also be used under water.

Sub-task a) is a prerequisite for an economically and economically sensible drive that can be designed so that it works with the greatest possible efficiency.

• c) das Werkzeug auch berufsmäßig, beispielsweise als Entbeinmesser benutzen zu können, und zwar über einen längeren, ununterbrochenen Arbeitszeitraum, ohne daß der Benutzer (Metzger) durch das Gewicht oder eine schlechte Griffigkeit eines solchen Werkzeuges (Messers) ermüdet.

Sub-task b) serves to be able to drive a hand-held device in which the weight of the drive is not transferred to the hand-held device, so that the hand-held device does not become excessively heavy with the desired performance, and in connection with

• c) the tool can also be used professionally, for example as a boning knife, over a longer, uninterrupted working period, without the user (butcher) being tired by the weight or poor grip of such a tool (knife).

The drive according to the invention is supposed to have the reverse effect that the handling of the tool is made considerably easier.

The solution to sub-task d) has the effect that cavitations are to be avoided in every hydraulic transmission system and because cavitations, in particular in the drive according to the invention, would have a performance-reducing effect on the handheld device, so that these phenomena do not occur.

The solution to sub-task e) results in a quick and easy change, for example the cutting blade of a butcher knife, because such knives often have to be sharpened and the knife with the actual knife drive should not be removed from the working step during this time.

• g) bewirkt, eine Ermüdung verursachende Vibrationen, welche darüber hinaus als unangenehm empfunden werden, auf ein Mindestmaß herabzusenken.

The solution to sub-task f) is to avoid noise pollution, which is annoying to the user and in particular harmful to health, and to solve the sub-task

• g) causes vibrations causing fatigue, which are also perceived as unpleasant, to be reduced to a minimum.

The solution to sub-task h) is expedient because, for example, a knife, including the drive, must be cleaned and such cleaning is expediently carried out by immersing it in the cleaning liquid (water) during the run.

Finally, solving sub-task i) means that the tool (knife) can also be used under water can be subjected to electric shock without fear of the user.

Further features to be extracted from the subclaims show advantageous configurations for solving secondary tasks, such as being able to set the stroke frequency, the stroke height and the force even during operation of the tool (knife).

Overall, the drive is the prerequisite for creating a rapidly oscillating handheld device with high efficiency, which is of significant economic importance and which is particularly user-friendly.

If an electric motor is provided for driving the piston of the master cylinder, this advantageously acts on the at least one eccentric disk in order to set it in rotation. The eccentric disk then expediently carries the ball bearing on its circumference, the inner shell of which is connected to the eccentric disk, is advantageously shrunk onto the circumference of the disk, that is to say it rotates with the eccentric disk, and the outer shell of which is non-rotatable but can carry out a linear movement, such that the piston of the master cylinder articulated on it executes a reciprocating as well as a forced movement by the eccentric disk.
The piston of the master cylinder can also be articulated laterally with its piston rod on the eccentric disk.

The drive according to the invention has the advantage that both the force and the frequency and the stroke of the piston of the working cylinder can be easily regulated. The frequency is determined by the speed of the drive motor. The maximum stroke is predetermined by the design of the eccentric disc. Precise regulation and lowering of the stroke is possible through the measures described on the basis of the drawing. The force primarily determines the pressure of the displaced liquid. This force can be regulated by a pressure relief valve. This makes the drive extremely versatile. Details on this can be found in the subclaims and the description of exemplary embodiments.

Another advantage is that the master cylinder can not only drive the piston of a working cylinder, but can also act on a plurality of pistons, each of which drives a tool, by branching the transmission lines.

Since hydraulic drives often lose the transmission medium, hereinafter referred to simply as oil for the sake of simplicity, an automatic oil refill device with a venting device is provided between the master cylinder and the working cylinder or connected to the working cylinder itself.

The connecting hoses between master cylinder and working cylinder are useful with easily detachable plug-in couplings for the desired connection provided so that a tool without oil loss with its special drive is easily interchangeable with another.

In addition, each working piston has at least one counter-pressure spring, which counteracts the oil pressure when the piston is displaced in the master cylinder. In addition, the outside air pressure continues to act on the piston of the working cylinder and increases the effect of the counter pressure spring. The oil column is thus moved back and forth between the piston of the master cylinder and the piston of the working cylinder, without the oil ever falling below a predetermined minimum pressure during a work cycle and thereby causing cavitation phenomena. This measure makes a significant contribution to enabling a rapidly oscillating frequency of the oil column.

With adjustable oil pressure (force) and adjustable stroke height and stroke frequency, an extremely precise fine adjustment for the back and forth movement of the connected tool can also be guaranteed. The counter-pressure spring can also be used, for example, to couple the tool to the working cylinder piston, which makes it easy to replace the tool.

Fig. 1

den schematischen Aufbau der Anlage;

Fig. 2

ein geändertes Ausführungsbeispiel;

Fig. 3

einen Schnitt nach der Linie III-III der Fig. 2;

Fig. 4

ein geändertes Ausführungsbeispiel;

Fig. 5

ein geändertes Ausführungsbeispiel;

Fig. 6

ein geändertes Ausführungsbeispiel;

Fig. 7

ein geändertes Ausführungsbeispiel;

Fig. 8

ein geändertes Ausführungsbeispiel.

Exemplary embodiments of the invention are shown in the drawing, namely:

Fig. 1

the schematic structure of the system;

Fig. 2

a modified embodiment;

Fig. 3

a section along the line III-III of Fig. 2;

Fig. 4

a modified embodiment;

Fig. 5

a modified embodiment;

Fig. 6

a modified embodiment;

Fig. 7

a modified embodiment;

Fig. 8

a modified embodiment.

1, an electric motor 1 is provided which drives a shaft 2 which runs in ball bearings 3, 4. On the shaft 2 an eccentric 5 is fixed, which rotates about the drive axis A-A of the shaft. The eccentric 5 carries a ball bearing 6, the inner shell 6a of which is advantageously shrunk onto the eccentric disk 5. The balls run between the shell 6a and an outer shell 7, which is not rotatable. However, the shell 7 can be moved back and forth in the direction of the line B-B. It is articulated to a piston rod 7a. The piston rod 7a carries a piston 8 and moves it back and forth in a master cylinder 9.

In the working space 10 behind the piston 8 there is oil as the transmission medium, which is produced with the help of an automatic oil refill device 11 has been supplied to the work area 10 and automatically refills if there is an oil loss. In addition, the oil refill device 11 has a ventilation device 12 in its cover. The working space 10 also has an outlet opening 12a for the oil. When the piston 8 moves forward (to the right in FIG. 1), the oil is pressed into a hose line 14 via the outlet opening 12a. The hose line 14 is flexible, but its cross section and its longitudinal extent are almost uninfluenced. A media pre-pressure screw 40 acts on the cylinder volume to compensate for a minimal pressure loss due to expansion of the hose. The transmission medium oil is fed to a working cylinder 20 when the piston 8 moves forward. A quick coupling 15 is provided in the line 14 in order to be able to produce different connections to different work tools. The quick coupling is sensitive to pressure and prevents oil loss when changing the connection of another tool. The working cylinder 20 has a piston 22, on which the oil acts when the piston 8 advances, in such a way that the piston 22 moves in the direction of the arrow 24. If the piston 8 moves back in the master cylinder 9, that is towards the eccentric, the oil pressure in the line 14 is reduced. A negative pressure is created in the working space 23 of the cylinder 20 so that it moves back, that is to the right in FIG. 1. The tool to be moved (not shown) is fastened to the piston 22 with the aid of a spring 25. In order that the movement of the tool and thus the piston 22 takes place with the desired speed, the spring simultaneously acts as a counter-pressure spring on the working piston 22. By adjusting the pressure in The oil line 14, for example with the help of a pressure relief valve, can be an extremely precise control the power of the tool. The force of the spring is such that it does not hinder the forward movement of the piston and thus the tool, but on the other hand ensures that the piston 22 is returned sufficiently quickly.

With the help of the adjusting screw 40, the volume of the compressed oil is changed at the same time, so that a greater or lesser amount of oil is pressed into the line 14 with each forward movement of the piston 8 and stroke control is thus possible.

According to FIG. 2, the reciprocable piston 8 in FIG. 1 is replaced by a piston 41 which has an inclined surface 42. In this embodiment, the piston 41 closes the inlet opening 43 for the refill device 11, depending on the inclination of the inclined surface sooner or later. The set screw 40a is additionally connected to the piston 41 in such a way that the piston can be rotated about its axis B-B, so that the inclination of the inclined surface 42 to the oil inlet opening 43 changes. That is, when the piston is reciprocated, the inlet opening 43 is opened or closed depending on the inclination of the inclined surface. 3, the adjusting screw 40a for adjusting the inclination of the inclined surface has two cams 50, 51 which lie in corresponding recesses in the piston and which rotate the screw 40a about the axis B-B. The set screw is locked in the desired position.

6, a plurality of inlet openings 43a, 43b, 43c can be provided one behind the other, which the piston closes one after the other as it moves. This allows the Liquid displacement and thus the stroke movement of the working piston 22 can also be regulated by the adjusting screw now successively closing one or more of the inlet openings. The inclined surface of the piston need not be provided for this. In any case, one of the inlet openings provided must always be open.

4, the system is designed simultaneously for several working cylinders, for example for working cylinders 31 to 36, as shown schematically by branching the connecting lines at points 52 to 57. The mode of action is the same.

Fig. 5 shows an embodiment in which two master cylinders 9 and 65 are provided. The piston 8 of the master cylinder 9 is in turn moved back and forth by the eccentric disc 5. The piston 66 of the master cylinder 65 is driven accordingly by an eccentric disk 64. The disk 5, like the disk 64, is connected to an associated piston 8, 66. The eccentric discs 5 and 66 are arranged on the shaft 2 of the electric motor 1 offset by 180 °, so that when the piston 8 is in the right position in the cylinder, the piston 66 is in the left position of the cylinder 65, that is , Pistons 8 and 66 work in opposite directions. The piston 8 presses oil through the line 14 into the working space 23 of the cylinder 27. The piston 66 presses oil via the line 67 into the space 68 in front of the piston 22 (complementary working space). The opposing oil pressure in rooms 23 and 68 now pushes the piston 22 back and forth. The spring for returning the piston can thus be omitted.

Fig. 7 shows a modified embodiment. The master cylinders 9 and 65 of FIG. 5 are connected to two working cylinders 20 and 70 via lines 14 and 67. One line 14, 67 is assigned to one of the working cylinders 20, 70. The pistons 22, 71 of the working cylinders 20, 70 act on a plate 72 or a lever which can be moved back and forth about an axis 73 in the direction of the arrow 76. The plate 72 acts on the tool so that it executes the oscillating movement again. 5, which has the same effect that the oil supply lines on the side facing away from the tool open into the working cylinder.

8, the master cylinder 9 acts via the line 14 on the working cylinder 20 with the interposition of a pressure-sensitive changeover valve 75. A line 74 leads from the valve 75, which leads into the refill device 11. This device works as follows:
If the piston of the cylinder 9 moves to the right, it presses the oil flowing in from the refill container 11 via the line 14, the now open valve 75 into the cylinder 20 and also moves its piston to the right. If the piston in cylinder 9 moves to the left, a negative pressure is created in line 14. The valve 75 now connects the cylinder 20 to a line 74 which opens into the oil refill container 11. Since the piston of the cylinder 9 opens the opening of the oil refill container, the piston sucks oil out of the refill container 11, which flows in via line 74, from the working space of the cylinder 20. If the piston 9 moves to the right, the valve 75 switches over, so that the connection the lines 14 to the working cylinder is given again. With this design, the oil is in a cycle and not in an exclusive oscillating movement. This design has the advantage that the oil can be cooled, for example, by flowing through a cooling device.
This design is also suitable for a precise force setting for the movement of the tool if the pressure application of the valve 75 is selected or set appropriately.

The advantages of the present invention are seen in the following features:

Characterized in that the piston of the master cylinder is articulated on the cam disc 5, it is moved back and forth by the drive motor 1. He accordingly pushes the oil column in line 14 back and forth accordingly and thus presses once on the piston 22 of the working cylinder and on the other hand sucks the oil column back again and thus the piston 22. This backward movement is caused by the spring 25 acting on the piston 22 significantly supported, also by the external air pressure which acts on the piston 22.

The training according to the invention shows the further advantages:
Due to the selected drive, the weight and volume can be in an extremely favorable ratio to the transmitted force. If the weight of the working cylinder with piston is around 40 grams with a stroke length of 12 to 13 millimeters and the piston is moved at a frequency of ten Hertz, a force of 100 kilograms is generated per stroke, by driving an electric motor of 750 Watt.

As can also be seen from the numerical example above, the drive works with an extraordinarily high degree of efficiency. This is due to the fact that the power output of the drive motor is transmitted almost uniformly as both forward and backward movement to the piston of the master cylinder by the non-positive transmission of the rotary movement of the motor shaft during an entire revolution.

The drive works almost silently. The coupling of a work unit is easily possible through the quick coupling 15 in the transmission line 14. The connection is subject to virtually no wear. The coupling enables the implement to be quickly replaced with another implement.

The vibration in the oscillating implement, which is normally transmitted to the implement in conventional systems, for example in the case of a drive with compressed air, is derived here from the work unit by the oil pressure column as the drive means. As a result, the implement itself is almost vibration-free.

To these advantages also contributes that the actual drive, that is, the master cylinder unit and the working cylinder unit is not rigid, but is connected to one another by a flexible hose, so that the loads and in particular the weight of the transmitter unit are not transferred to the working unit.
Even for the highest power transmission, only small hose cross-sections are necessary for the transmission line.
In the above force weight example, only a hose with an outer diameter of five millimeters is required. Due to the low weight and the thin, flexible supply hose, excellent handling of each work unit is possible, as already mentioned above.
Since the drive unit is sealed, it can also be used with devices that run under water or at least can be cleaned with liquid.
The entire system is almost maintenance-free and has a very long life expectancy.
The system is easy to manufacture. The manufacturing costs are low, and much cheaper than a compressed air system or the like in the same performance size.

The work unit is not directly connected to electrical power, so that underwater operation is also possible.
Even with high power transmission, the working cylinder, which is directly connected to the tool, is still very small.
Another advantage is that the stroke frequency, the stroke height and the force of the tool unit can be regulated continuously and independently of one another, even during operation.
Any liquid can be used as a transfer medium for simple applications.

Reference numbers

1

Electric motor

2nd

wave

3rd

ball-bearing

4th

ball-bearing

5

Eccentric disc

6

ball-bearing

6a

inner shell

7

outer shell

7a

Piston rod

8th

piston

9

Master cylinder

10th

Working cylinder

11

Oil refill device

12th

Ventilation device

12a

Outlet opening for the oil

14

Hose line

15

Quick coupling

20th

Working cylinder

22

Piston in the working cylinder

23

working space

24th

arrow

25th

feather

26

Counter pressure spring

27

cylinder

28

Joint piece

29

Hose line

30th

Screw connection

31

Working cylinder

32

Working cylinder

33

Working cylinder

34

Working cylinder

35

Working cylinder

36

Working cylinder

40

Set screw

40a

Set screw

41

Piston of the master cylinder

42

Oblique surface (end face) of the piston 41

43

Inlet port for the transmission medium (oil)

43a

drilling

43b

drilling

43c

drilling

44

Locking screw

50

cam

51

cam

52

Branch of the oil transmission line

53

Branch of the oil transmission line

54

Branch of the oil transmission line

55

Branch of the oil transmission line

56

Branch of the oil transmission line

57

Branch of the oil transmission line

64

second eccentric disc

65

cylinder

66

piston

67

management

68

complementary work space

70

second working cylinder

71

Piston (extension)

72

Plate or lever

73

axis

74

second hose line

75

Diverter valve

76

arrow

A-A

Axis of the electric motor

B-B

Axis of the master cylinder

Claims (34)

1. Device for driving a longitudinally reciprocating tool, wherein:

   - a reciprocating piston (8, 41, 66), which displaces or draws in a fluid medium which actuates a piston (22) in a working cylinder (20, 27, 31-36), is provided in a master cylinder (9, 65),

   - an eccentric disc (5, 64) moves the piston (8, 41, 66) of the master cylinder (9, 65) forward;

   - the master cylinder (9, 65) is separated spatially from the working cylinder (20, 27, 31-36) to prevent any weight transmission;

   - the master cylinder (9, 65) and the working cylinder (20, 27, 31-36) are connected with each other by a flexible hose or pipeline (14, 29);

   - the piston (22) of the working cylinder (20, 27, 31-36) is under the influence of at least one counterpressure spring (25, 26);

   - the external air pressure contributes towards supporting the return of the working-cylinder piston (22);

   - a ball bearing (6) is provided on the external diameter of the eccentric disc (5, 64), whose internal race (6a) revolves with the eccentric disc (5, 64) and whose external race (7) is unrotatable but linearly reciprocable,
   characterized in that the external race (7) is connected flexibly with the piston (8, 41, 66) of the master cylinder (9, 65) and the piston (8, 41, 46) of the master cylinder (9, 65) reciprocates.
2. Device for driving a longitudinally reciprocating tool, wherein:

   - a reciprocating piston (8, 41, 66), which displaces or draws in a fluid medium which actuates a piston (22) in a working cylinder (20, 27, 31-36), is provided in a master cylinder (9, 65);

   - an eccentric disc (5, 64) moves the piston (8, 41, 66) of the master cylinder (9, 65) forward;

   - the master cylinder (9, 65) is separated spatially from the working cylinder (20, 27, 31-36) to prevent any weight transmission;

   - the master cylinder (9, 65) and the working cylinder (20, 27, 31-36) are connected with each other by a flexible hose or pipeline (14, 29);

   - the piston (22) of the working cylinder (20, 27, 31-36) is under the influence of at least one counterpressure spring (25, 26);

   - the external air pressure contributes towards supporting the return of the working-cylinder piston (22), characterized in that

   - the piston (22) of the master cylinder (9, 65) with its piston rod (7a) is linked laterally to the eccentric disc (5) and the piston (22) of the master cylinder (9, 65) reciprocates.
3. Device according to claim 1 or claim 2, characterized in that the tool (27) is coupled to the working-cylinder piston (22) with the aid of the counterpressure spring (26).
4. Device according to claim 1 or claim 2, characterized in that the fluid medium used executes an oscillating reciprocating movement on movement of the tool.
5. Device according to claim 1 or claim 2, characterized by the configuration as a self-contained system operating with partial vacuum and overpressure.
6. Device according to claim 1, characterized in that the external race is connected by means of a joint piece (28) with the piston rod (7a) of the piston (8) of the master cylinder (9).
7. Device according to claim 1, characterized in that the eccentric disc (5) is connected with a driving motor (electric motor (1)) whose speed is regulable.
8. Device according to claim 1 or claim 2, characterized in that a switch provided on the tool unit (20, 22, 26, 27) induces the switching on and off of the respectively selected drive (motor drive or electromagnetic drive).
9. Device according to claim 8, characterized in that the switch is connected electrically by a cable with the driving unit (1, 60).
10. Device according to claim 9, characterized in that the cable is run together with the hose (14) or pipeline.
11. Device according to claim 1 or claim 2, characterized in that a switch is provided on the tool unit for stroke frequency adjustment (motor speed change).
12. Device according to claim 11, characterized in that a dimmer is provided as the switch.
13. Device according to claim 1 or claim 2, characterized in that the device has an automatic refill device (11) for compensating a loss of fluid operating medium and for filling up the system.
14. Device according to claim 1 or claim 2, characterized in that the device has an automatic bleeding and venting unit (12) for the fluid medium.
15. Device according to claim 1 or claim 2, characterized in that the master cylinder (9) and/or the working cylinder (20) has an adjusting screw (40) penetrating the working area of the cylinder to compensate pressure losses due to the volume of the hose (29) being changed.
16. Device according to claim 1 or claim 2, characterized in that the face end of the piston (41) of the master cylinder (9), viewed in the direction of movement of the piston, is designed as an oblique face (42) and the effective inclination of the oblique face (42) of the piston (41) is adjustable round its axle and engagable by turning the piston (41).
17. Device according to claim 1 or claim 2, characterized in that the intake opening (43) of the automatic refill device (11) for the fluid medium in the master cylinder (9) is designed as a longitudinal slot or in the form of several bores (43a, 43b, 43c) in series in cylinder direction so that, depending on the position of the piston (8, 41), the latter closes one or more of these openings or the longitudinal slot earlier or later along its working path.
18. Device according to claim 17, characterized in that the intake openings (43a, 43b, 43c) in the cylinder wall of the master cylinder (9) can be shut off in succession except for at least one by means of an engagable adjusting screw.
19. Device according to claim 1 or claim 2, characterized in that the hose (14) between the master cylinder (9) and the working cylinder (20) is flexible but is almost unexpandable in the cross section and in the length.
20. Device according to claim 19, characterized in that the hose (14) is of spiral design.
21. Device according to claim 1 or claim 2, characterized in that the master cylinder (9) acts simultaneously on more than one working cylinder (31 through 36) by means of branched pressure lines (29).
22. Device according to claim 1 or claim 2, characterized in that the pressure line (14) between the master cylinder (9) and the assigned working cylinder (20) is detachable and connectable by means of an automatically closing rapid-action coupling (15).
23. Device according to claim 22, characterized in that the coupling is provided in the proximity of the working cylinder (20).
24. Device according to claim 22, characterized in that one part (29) of the hose (14) is connected with the tool unit (screwed (30)).
25. Device according to claim 1 or claim 2, characterized in that the driving motor (1) acts on more than one eccentric disc (5, 64) and each eccentric disc is assigned to a master cylinder with at least one working cylinder.
26. Device according to claim 1 or claim 2, characterized in that the master cylinder (9) is connected via a pressure-sensitive change-over valve (75) with the working piston (22) by means of a first line (14), and a second line (74) leads back from the change-over valve (75) via the oil refill device (11) to the master cylinder (9) in such a way that on the feed movement of the piston (8) of the master cylinder (9) via the line (14) the oil is pressed into the working cylinder (10) and on the reverse movement of the piston (8) of the master cylinder (9) the change-over valve (75) makes the oil flow back to the refill device (11) via the line (74) due to the pressure of the working-cylinder piston (22).
27. Device according to claim 1 or claim 2, characterized in that the piston (22) in the working cylinder (20) assigned to it is under the influence of at least one spring (25) exerting a counterpressure on the piston (22) depending on size and pressure.
28. Device according to claim 1 or claim 2, characterized in that the fluid medium used is a hydraulic oil.
29. Device according to claim 28, characterized in that the fluid medium is a food-compatible hydraulic oil if the device is used in the field of food processing.
30. Device according to claim 1 or claim 2, characterized in that the fluid medium used is a gas liquefied under pressure and corresponding temperature.
31. Device according to claim 1 or claim 2, characterized in that the unit (working cylinder (20) with hose (14)) is so impervious to the external environment that it can operate in fluids (under water).
32. Device according to claim 1 or claim 2, characterized in that an adjustable pressure relief valve, which causes the pressurized fluid medium to overflow from a predetermined pressure onwards into the reservoir of the refill system (11) for power regulation, is provided for regulation of the piston force in the system.
33. Device according to claim 1 or claim 2, characterized in that the working cylinder is mounted in or on a rubbery lining for the prevention or at least minimization of vibrations in the working device.
34. Device according to claim 1 or claim 2, characterized in that the natural resonance of the counterpressure spring (26) is tuned to the work of the working cylinder for minimization or for prevention of vibrations.

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