PRESSURE WAVE DEVICE WITH DOUBLE VALVE DEVICE

Description

[0001] The invention relates to a device for treating the human or animal body with mechanical pressure waves which are generated by the impact of an accelerated projectile on an applicator.

[0002] Devices of this type have been known for some time and are increasingly being used. Mechanical pressure waves are used to treat patients (whether human or animal). These waves are coupled by placing an applicator on the patient's body and are generated by the collision of an accelerated projectile with the applicator. The applicator does not necessarily have to be a single piece, but can also be composed of several different parts or materials.

[0003] A proven and widely described technique for accelerating the projectile is pneumatic. This technique involves applying pneumatic overpressure to a volume on one side of the projectile as it moves along a path, e.g., in a tube.

[0004] In the prior art, a switching valve is used for this purpose. This valve is connected to a pneumatic supply, in particular a compressor with adjustable output pressure. Its pulse accelerates the projectile from an end of the travel path distal to the applicator toward the applicator. The pneumatic actuation is deactivated when the proximal end of the travel path is reached, i.e., when the projectile impacts the applicator.

[0005] In the state of the art, the return movement is carried out with the help of a counter-pressure chamber, i.e. a storage volume into which the projectile moving towards the applicator displaces the air in front of it, thus essentially inflating this storage volume.

[0006] In the previously published EP 2 181 730 B1, which was revoked in the opposition appeal proceedings due to lack of feasibility, a targeted pressure limitation in this counterpressure chamber is discussed in addition to a control of the opening time of the switching valve for acceleration, which is not further specified. This document also mentions the use of a second switching valve for returning the projectile to its distal starting position after being acted upon by the first switching valve.

[0007] US 2014 / 350438 A1 describes a ballistic pressure wave device according to the preamble of claim 1, which is designed to generate particularly intense waves for crushing body concretions. Among other things, a pneumatic solution with a second valve is proposed for projectile redirection.

[0008] US 2009 / 326425 A1 describes a ballistic pressure wave device whose pneumatic system is designed to cause at least two collisions as a result of an acceleration process of the projectile.

[0009] DE 20 2010 009 899 U1 describes an electromagnetic pressure wave device that proposes a second electromagnet to return the projectile and prevent damage to a return spring.

[0010] The object of the present invention is to provide, on this basis, a device of the type described with a pneumatic device for projectile movement which is improved with regard to the forward and backward movement of the projectile.

[0011] To achieve this object, the device according to claim 1 is proposed. Preferred embodiments are the subject of the dependent claims.

[0012] Accordingly, the device according to the invention comprises, as part of its pneumatic device, a double valve device for pressurizing the projectile in both directions, i.e., toward the applicator and vice versa, away from it in the return direction, i.e., e.g., the combination of a first and a second valve. The time phases in which the projectile is pneumatically pressurized so that it moves in the direction indicated by the first valve, e.g., the activation phase of a first valve, are referred to below as the first activation time, and conversely, a time phase of reversed activation of the projectile is referred to as the second activation time.

[0013] According to the invention, the device should be designed (in particular, a control device present therein should be designed) to end a second activation time before the projectile has been completely moved back, i.e., after only a partial return movement. Furthermore, the first activation time should also begin before the complete return and thus also after only a partial return movement, but not necessarily simultaneously with the end of the second activation time. Overall, this can and should ensure that the projectile (at least in certain control states) no longer moves back completely, but rather reverses its path after part of the path and before its end (with the stop).

[0014] According to the invention, a shortening of the movement distance to an effective length compared to the geometrically possible movement distance is achieved by an early end of the second switch-on time and an onset of the (following) first switch-on time before the distal end of the movement distance is reached.

[0015] This results in various possibilities and advantages that can be utilized depending on the application. For example, the impact velocity of the projectile on the applicator can be varied and, in particular, controlled independently of the pneumatic pressure used. The shorter the effective acceleration distance (assuming a constant accelerating pressure), the lower the impact velocity. In this respect, the invention offers a further degree of freedom.

[0016] In particular, by shortening the effective acceleration distance, particularly low impact velocities can be achieved that would not be achievable by reducing the pressure alone. Experience has shown that the pneumatic drives discussed here require a certain minimum pressure to even be able to move the projectile in a defined manner. This can, for example, be the result of static friction between the projectile and the inner surfaces of the tube section that guides it. According to the invention, the velocity can be reduced even further by shortening the distance, assuming a pressure sufficient for safe and defined projectile movement.

[0017] An additional advantage may be the ability to increase the operating frequency for a given desired impact velocity compared to the conventional approach (utilizing the entire geometrically defined travel distance). If the desired impact velocity can be achieved with a pressure lower than the available pressure, and instead of reducing this pressure (e.g., by means of a pressure reducer or by controlling the pressure source) in the manner described, the effective travel distance is shortened, the projectile requires less time for both the forward and reverse movement.

[0018] The combination of two switching valves was discussed above, which represents one possibility for a double valve device provided according to the invention. In this variant, the two valves can be controlled (preferably independently of each other) by the control device. Alternatively, a single valve can be used, referred to here as a "combination valve," which, depending on the control by the control device, has at least two switching states: a first for actuating the projectile in the direction toward the applicator and a second for actuating it in the reverse direction. While the combination valve is in the first switching state, a first valve opening time is provided, and in the second switching state, a corresponding second valve opening time.

[0019] In these two switching states, the pneumatic connection to be actuated in the other switching state is preferably ventilated by the combination valve, so that, for example, during the forward movement on the side of the projectile proximal to the applicator, approximately ambient pressure prevails and, in contrast to the conventional procedure with a counterpressure chamber, there is no dynamic pressure that increases from collision to collision.

[0020] Even when two separate valves are used, at least one of the two valves is preferably a two-way valve, which accordingly carries out ventilation unless it is switched to apply pneumatic pressure.

[0021] The possibility of controlling the projectile's impact velocity by actually using the portion of the possible travel distance was already discussed above. An additional possibility is to overlap a first activation time (responsible for pressurizing the projectile during execution) with a subsequent or preceding second activation time (responsible for pressurizing in the opposite direction) as the projectile accelerates toward the applicator. During such an overlap period, e.g., immediately before the projectile impacts the applicator, the pneumatic pressures on both sides of the projectile at least largely compensate each other, so that the projectile remains virtually force-free (apart from friction).In this way, the impact speed can be additionally influenced without changing the level of the pneumatic pressure.

[0022] For the combination valve described above, this means an additional switching state in which pressure is applied on both sides.

[0023] A combination of both options, i.e. the use of only a portion or even a variation of the portion used, of the movement distance on the one hand, and an overlap of the activation times of the two valves on the other, can certainly be useful. For example, an overlap period before the projectile hits the applicator can limit the deflection speed, whereby (compared to acceleration over the entire movement distance) the average speed still remains relatively high. If acceleration occurs initially and then no further acceleration during the overlap period, a higher speed level is reached comparatively early than with continuous acceleration up to the collision (assuming the same collision speed). For example, ifIf, on the one hand, a particularly low impact velocity is to be achieved with minimal acceleration pressure (as explained above), but without increasing the frequency (too much), an acceleration can occur, for example, in the initial phase of the forward movement during a first activation time, and then be terminated by an overlap of the two activation times. The projectile then remains (very roughly) at the achieved speed, but more time passes until the collision, in a sense due to a section of the path not used for acceleration. Thus, the overlap time offers an additional degree of freedom within the scope of the invention.

[0024] Of course, control states with various such overlap times can exist, including an overlap time of zero. Furthermore, an overlap time can also exist after the collision. If, exceptionally, the entire movement path is used, there can in principle also be an overlap time or a partial overlap time after the reversal of movement at the distal end of the movement path. In a repetitive movement, the projectile can be reflected at this end and initiate the movement in execution simply as a result of the momentum exchange.

[0025] Furthermore, at a given pneumatic pressure, excessive re-acceleration and collision of the projectile with a stop at a distal end of the travel path from the applicator can be avoided if the full travel path is (exceptionally) used in the respective control state. Furthermore, an overlap period after the collision can extend the time for the re-moval without increasing the actual travel path, if this is desired with regard to a specific combination of frequency and impact velocity (at a given pressure).

[0026] In particular, when varying an overlap time of the two switch-on times, the second switch-on time can be varied with regard to its duration and / or its start, wherein the first switch-on time can preferably remain constant.

[0027] Another possibility for other control states and in this sense the opposite of the described overlap time is a gap time between the first and the second switch-on time, or vice versa, whereby in this sense a gap time between a first and the subsequent second switch-on time is meant (and not vice versa, i.e. in the sense of the sequence of a first switch-on time following a second in the vicinity of a distal reversal point of the projectile movement).

[0028] Such a distance time leads, in a similar way to the overlap time, to a quasi force-free moment of movement of the projectile and can therefore be used in a similar way, whereby in a device there can also exist control states with an overlap time and other control states with a distance time (and possibly also those with direct contact of the first and the second switch-on time in the sense of a distance time zero).

[0029] In particular, a distance time can reduce the projectile's velocity upon impact. Furthermore, a certain deceleration can be achieved during the return movement if all or part of the distance time occurs after impact. This was already explained above in a similar way for the overlap time.

[0030] In the above explanations, it has been repeatedly emphasized that it is not necessary to change the pneumatic pressure. It is, in fact, preferable to maintain this pressure unchanged during operation and in various control states.

[0031] In the simplest case, the pneumatic device can have a connection for supply from a pneumatic line network, e.g., in a hospital, or from a compressed gas cylinder. However, a pneumatic compressor is preferred, with which the device according to the invention is location-independent and more mobile than a compressed gas cylinder. Pneumatic compressors are already known in connection with such devices. However, the invention offers the above-mentioned aspect of not necessarily having to change the supply pressure in different control states with different projectile impact velocities. In other words, the compressor can run at the same speed in such different control states.

[0032] Of course, this can simplify compressor control, especially if it always runs at the same speed when switched on. Furthermore, the compressor can be operated near or at its maximum efficiency (in terms of speed). Furthermore, it is possible to adapt noise reduction measures, such as a dampening bearing for the compressor or a sound-insulating enclosure, to the vibration behavior of the compressor at a constant speed.

[0033] A special design option of the invention lies in the ability to directly and quickly influence the impact physics between the projectile and the applicator, particularly the impact velocity, simply by changing the valve opening times or durations. Compared to changing the supply pressure, this influence is particularly rapid, so that in an iterative operating state, the impact velocity and / or the duration of the combined back-and-forth movement—in other words, a momentary frequency—can be changed from one impact process to the next. The state of the art does not allow for such rapid and free influence.

[0034] Typical impact velocities, even under less rapidly changing or unchanging conditions, are in the range between 2 m / s and 30 m / s. For impact physics, the impact impulse is particularly important, which for typical projectile masses between 1 g and 10 g can therefore range between 2 gm / s and 300 gm / s, preferably between 10 gm / s and 150 gm / s.

[0035] In a special embodiment, the device has a measuring device that can measure the passage of the projectile at a point along its travel path. This measuring device is coupled to the control device. This allows, for example, the passage of the projectile shortly before impact or virtually as it hits the applicator to be recorded, so that the activation times (particularly with regard to their start and end) can be adjusted to the time of impact.

[0036] Such detection can be achieved optically, for example, using a light barrier or the like, but preferably inductively using a measuring coil. This can detect the projectile using residual magnetism or purely inductively (by changing the stray inductance).

[0037] In the following, the invention is explained in more detail using exemplary embodiments, whereby the individual features can also be essential to the invention in other combinations within the scope of the claims.

[0038] In detail, Figure 1 shows a perspective view of a device according to the invention, with a central housing part omitted for clarity; Figure 2 shows a longitudinal section through the device from Figure 1 opposite Figure 1right-left reversed position; Figure 3 a schematic diagram of the handpiece with an associated base unit; Figure 4 a sequence of schematic time course diagrams 4a) to d) to explain the mode of operation; Figure 5 a schematic representation of a combination valve to explain an alternative embodiment to the Figures 1 and 2 .

[0039] Figure 1 shows a handpiece of a device according to the invention in perspective view with pneumatic valves pointing forward-left, namely a first valve 1 and a second valve 2. On the right you can see a pneumatic supply connection 3 and on the left two screw rings 4 and 5, each knurled on the outside for easier handling, for holding the applicator 6, which is explained in more detail below. This is in Figure 1 on the far left with its patient-facing surface just visible and otherwise in Figure 2shown. It could also be constructed in several parts.

[0040] In the middle area of ​​the device Figure 1 one can see a plurality of tubes running in the transverse direction, the middle one with the reference number 7 containing and guiding the projectile 8, which can be seen in section in Figure 2. In front of this, one can see two parallel pneumatic connecting pipes 9 and 10 between the two valves 1 and 2, wherein the pipe 9 serves to supply a pressurization to the second valve 2 and the pipe 10 conversely serves to vent this second valve 2 via an outlet provided at the first valve 1. This plurality of pipes is in this embodiment of a Figure 1 surrounded by the casing cover 11 shown by the line below the tube 10 and the two lines above the projectile guide tube 7. This casing cover 11 runs in Figure 1in the rear area and covers only a part of the circumference. It is designed at its respective axial edges, similar to a beading, by a rounded inward fold, which is easy to grip. Figure 1 indicated at the upper edge. The housing cover 11 can therefore serve as a handle during practical handling. The spacer 13 stabilizes the structure and mechanically connects the two ends of the handpiece.

[0041] A flexible compressed air supply line leading from a pneumatic compressor to the device (see 51 in Figure 3 ) is not shown here and is to be connected to the already mentioned connection 3. Analogously, an electronic control line (52 in Figure 3 ) from an external control to valves 1 and 2 is not shown, which can be designed in the same way as the compressed air supply line.

[0042] Figure 2shows a longitudinal section along an imaginary central longitudinal axis of the aforementioned cylindrical shape of the entire device, which is also a central longitudinal axis of the projectile guide tube 7. To illustrate the dimensions: The length of the projectile guide tube 7 in this embodiment is 145.5 mm and the remaining illustration in Figure 2 is to scale. In this projectile guide tube, the projectile is 8 in Figure 2shown on the right and thus in contact with the applicator 6, which is held by the described screw ring 4 and 5 in a manner known per se. The applicator 6 is elastically mounted in the axial direction by a bellows-like elastomer ring 14 and pneumatically sealed by a further elastomer ring 12. Alternatively, a device structure with regard to the applicator 6 and its holder and seal according to, for example, EP 2 529 679 (also independent of the cap shown there) or EP 2 095 843 (also independent of the ceramic material discussed there) is also possible and preferred.

[0043] Figure 2shows on the left an inner channel 21, which connects the pneumatic connection 3 to the first valve 1. The first valve 1 can therefore switch a supply pressure present at the pneumatic connection 3, depending on the control, to a radial channel 22, which opens below a damper element 23 and is thus connected to the internal volume of the projectile guide tube 7. The projectile is thus acted upon or accelerated towards the applicator 6 via this channel 22 during an initial activation time. Independently of this, the pneumatic supply pressure is passed on to the second valve 2 via the channel 24 and the tube 10.

[0044] In the second alternative switching position, the channel 22 and thus also the internal volume of the projectile guide tube 7 are divided between the distal end (in Figure 2 left) and the projectile 8 ventilated.

[0045] In the second valve 2, which is basically constructed mirror-symmetrically to the first valve 1, the pneumatic supply pressure applied via the tube 10 can alternatively be passed radially upwards via the channel 25 to a volume surrounding the projectile guide tube 7 (in Figure 2 as a slot above and below the tube 7), which leads from the connection of the channel 25 to the right, i.e. in the direction of the applicator 6, and there is connected between the applicator 6 and the proximal end of the projectile guide tube 7 to the inner volume of the projectile guide tube 7 (from the Figure 2The pneumatic supply pressure can thus be switchably applied to the internal volume of the projectile guide tube 7 between the applicator 6 and the projectile 8 via the channel 25. However, in this example, the pneumatic connection is somewhat poorer than on the opposite side of the projectile guide tube 7 due to a smaller effective opening cross-section, so that delays become noticeable sooner or more severely here at higher air flow velocities (higher frequencies, higher pressures).

[0046] Alternatively, the second valve 2 in the other switching position can block the connection of the internal volume of the tube 10 to it and ventilate the channel 25 and thus the internal volume of the projectile guide tube 7 to the right of the projectile 8, i.e. connect it to the outside atmosphere via a pneumatically highly conductive connection.

[0047] The two valves 1 and 2 can therefore apply pneumatic pressure to the projectile from both sides, independently of each other and thus simultaneously or alternately, or can ventilate the interior of the projectile guide tube 7 on both sides.

[0048] The reference number 30 in Figure 2denotes a ring-shaped permanent magnet at the distal end of the movement path of the projectile 8 (coinciding with the length of the projectile guide tube 7) relative to the applicator 6. With this magnet 30, the projectile 8, constructed of ferromagnetic material, can be easily fixed at this distal end of the movement path. By applying pressure to one side using the valve 2, the projectile can also be returned to this position and optionally also held there, particularly at the start of operation or in the case of a non-ferromagnetic projectile. In this respect, the permanent magnet 30 can optionally be omitted, especially if the reflections explained below are to be enabled at this distal end of the movement path even at low impact velocities of the projectile 8.

[0049] 31 denotes a point at which the passage of projectile 8 through the corresponding point of the travel path could be detected using a measuring coil, with this point being relatively close to applicator 6. In the simplest case, a slight residual magnetism of projectile 8 is utilized here, but one could of course also detect and evaluate the change in the inductance of coil 31 using alternating current. The collision of projectile 8 with applicator 6 can also be determined using a microphone or motion sensor in the experimental setup. Furthermore, the impact velocity of projectile 8 can be determined in the experimental setup, for example, using two light barriers positioned just in front of applicator 6.

[0050] Figure 3 shows a block diagram with the Figures 1 and 2The device shown in the top right-hand corner is designated summarily by the reference numeral 40. This device 40 is a hand-held, mobile handpiece, as is already known from relevant devices in the prior art. It is connected via two lines 51 and 52 to a base station 50, which contains a pneumatic compressor 53 and a controller 54. The compressor 53 is connected to the handset 40 via line 51, namely a pneumatic flexible hose line, and the controller 54 is connected via the electrical line 52 (optionally integrated with the line 51), via which the controller can access the two valves 1 and 2 mentioned above and supply them with power. Communication with the handpiece 40 can also take place via line 52, in particular if a controller or part of the controller is additionally provided there.

[0051] The controller 54 also controls the compressor 53 with regard to its speed and, of course, its switching on and off. Like the compressor 53, it is powered by a power supply 55. A pressure control or control valve that influences the speed can also be integrated into the compressor 53. Furthermore, the controller 54 is connected to a display 56, which can be built into the base unit 50 or implemented separately. The base unit 50 is operated via a touch-sensitive display 56 and / or via a button arrangement not shown here.

[0052] The user can thus control the function of the device 40 using such buttons and, in any case, using the display 56, with the control 54 specifying, in particular, the opening and closing times and thus also the opening durations of the two valves 1 and 2. Partial tasks of the control 54 can also be integrated into the handpiece 40, particularly with regard to the control of valves 1 and 2.

[0053] For a basic understanding of the control of the two valves, reference can be made to the older patent EP 2 213 273 B1. The embodiment therein largely corresponds to the above explanations and the Figures 1 and 2with the exception of the existence of the second valve 2 and the omission of the counterpressure chamber. Furthermore, the cited embodiment assumes a specific valve opening time of the sole valve there at a specific pressure, whereas the projectile acceleration in the present case varies due to the proportion of the first valve opening time, even outside the overlap time and thus even at a constant pressure. For the following explanations, a pressure of 4 bar can be assumed as an example.

[0054] Figure 4 shows a sequence of four individual schematic time-course diagrams (4a) to 4d), in which the solid curve represents the opening and closing process of the first valve 1, and the dashed curve represents the opening and closing process of the second valve 2. The raised part of the curve thus corresponds to the first / second switching time.

[0055] The Figures 4a) to d) show a sequence of pressurisation pulses of the two valves 1 and 2 according to the following table of values: Value table

[0056] Frequency [Hz] 35 35 35 35 Projectile speed [m / s] 4.3 5.4 7.3 10 Opening time of valve 1 [ms] 0 0 0 0 Closing time of valve 1 [ms] 9 10 11 13 Opening time of valve 2 [ms] 17 17 17 17 Closing time of valve 2 [ms] 23 23 23 23 Time of impact [ms] 21.6 21.3 21 21.1

[0057] Specifically, after each (shown) collision between the projectile 8 and the applicator 6, the projectile is accelerated in the reverse direction, both by the momentum exchange and by the pneumatic pressure during the remainder of the second activation time. However, it is not moved to the distal end of the maximum possible travel distance, but is decelerated by the pneumatic counterpressure that sets in with the subsequent first activation time (with the accelerating pressure no longer applied). As a result, the projectile ultimately reverses its direction of travel before reaching the distal end and accelerating again in the execution direction.This acceleration ends with the respective end of the first activation time, with the projectile continuing to fly approximately force-free during the subsequent separation time, colliding with applicator 6 approximately at the same time as the beginning of the following second activation time (or slightly earlier or later). Then, the same cycle follows once more.

[0058] The difference between the four individual representations is the increasing duration of the first activation times and thus the decreasing intervals to the second activation times. Consequently, the travelled section of the maximum possible movement distance decreases from Figure 4 a)to d). Since the accelerating pressure remains constant, the collision speed also increases simultaneously upon collision with applicator 6. The collision speed can be further influenced by selecting different separation times or, not shown here, overlap times.

[0059] For a typical barrel length in the range of 145.5 mm, the values ​​from the table show that at a frequency of 35 Hz, as in this example, only a portion of the barrel length can be utilized. Even if the projectile maintained a constant collision speed of 4.3 m / s during its back-and-forth motion within the barrel, it would only cover a total distance of 60 mm in half the orbital time, which is significantly less than the actual barrel length. Thus, with current technology, such high collision frequencies combined with comparatively low collision speeds are not possible.

[0060] Strictly speaking, the Figures 4a) to d) show the electrical control times of both valves 1 and 2, i.e., the output signals of control unit 54. Valves 1 and 2 are spring-loaded solenoid valves that open purely magnetically and close due to the force of the tensioned spring when the magnet is no longer acted upon. Accordingly, the movements of the valve body are slightly delayed compared to the control signals shown, by an estimated 4 ms for opening and 2 ms for closing. The delay times are therefore actually approximately 2 ms longer than shown.

[0061] With a so-called pilot valve with pneumatic support during opening, the situation would be qualitatively comparable.

[0062] Of course, in another embodiment with a "combination valve" one can create very similar conditions as in Figure 4shown in diagrams a) to d), but the overlap time would then mean a different switching state of the valve. Such a combination valve is shown in Figure 5 shown schematically. The letter K denotes the combination valve, which accordingly controls the two valves 1 and 2 from the Figures 1 and 2 Two lines V1 and V2 are shown on the right and left, of which V1 has a connection to the left side (according to Figure 2 ) of the projectile guide tube 7, e.g., via the channel section 22 (analogous to the first valve 1). Accordingly, the right line V2 means a connection to the right side of the projectile guide tube 7 (analogous to the second valve 2), e.g., via the channel section 25.

[0063] The upper line is in Figure 5with the keyword "pressure supply" and the symbol "1" (not to be confused with the reference symbol 1) for the first valve; similarly, the lower line connection is labeled with the keyword "ambient pressure" and the symbol "0" within the figure, thus indicating a ventilation opening.

[0064] In the combination valve K there is a symbolically represented slide S, which moves in the vertical direction (relative to Figure 5 ) can be moved between four different switching positions. The top one shows how the Figure 5 As shown, port V1 is pressurized and port V2 is pressurized with pneumatic supply pressure. In the third position from the top, the reverse is true, and in the currently activated second position from the top, both ports V1 and V2 are pressurized. Finally, the lowest position shows simultaneous pressurization of both ports V1 and V2.

[0065] One could therefore imagine a combination valve K constructed in this or a similar way instead of the two individual valves 1 and 2 from the exemplary embodiment in the Figures 1 and 2 present, whereby the remaining explanations and in particular the Figures 3 and 4 apply mutatis mutandis to this as well.

[0066] Because the impact speed of the projectile 8 can be controlled solely by switching the two valves 1 and 2, the pneumatic compressor 53 ( Figure 3 ) at a given fixed operating frequency, where it has maximum efficiency. Furthermore, the pneumatic compressor can be particularly effectively insulated against vibration and noise at a given operating frequency.

[0067] In principle, the control device 54 can vary the impact velocity and also the time interval between collisions between the projectile 8 and the applicator 6 from one individual event to the next. It can therefore influence the impact physics significantly faster and more variably and, in particular, is not tied to periodic events.

Claims

1. Apparatus for treatment of the human or animal body with mechanical pressure waves, the apparatus comprising: - a projectile (8) guided in the apparatus along the movement path, - an applicator (6) at one end and a stop at another end of the movement path, - pneumatic means for application of pneumatic pressure to the projectile (8) for the purpose of movement along the movement path, wherein the projectile (8) is adapted for striking onto the applicator (6) for generating the mechanical pressure waves, which pneumatic means has a double valve means (1, 2) for application of pneumatic pressure to the projectile (8) in the direction towards the applicator (6) during a first activation time and for application of pneumatic pressure to the projectile (8) in the reverse direction during a second activation time and a control means (54) for controlling the double valve means (1, 2), characterized in that the apparatus is adapted, after a partial return movement in a second activation time, to end this second activation time, to start a first activation time and, by the application of pneumatic pressure to the projectile (8) after only a part of the movement path and before the end with the stop, to reverse the movement of the projectile (8) from a return movement into a forward movement.

2. Apparatus according to claim 1, in which the double valve means (1, 2) has a first valve for application of pneumatic pressure to the projectile (8) in the direction towards the applicator (6) and a second valve for application of pneumatic pressure to the projectile (8) in the reverse direction, which valves can preferably be controlled independently of one another by the control means (54).

3. Apparatus according to claim 1, in which the double valve means (1, 2) has a "combination valve" which, depending on the control by the control means (54), assumes a first switching state for application of pneumatic pressure to the projectile (8) in the direction towards the applicator (6) or a second switching state for application of pneumatic pressure to the projectile (8) in the reverse direction, wherein in each of these switching states the pneumatic connection used in the respectively other switching state for application of pneumatic pressure to the projectile (8) is ventilated by the combination valve.

4. Apparatus according to claim 2, in which at least one of the two valves is a two-way valve which applies pneumatic pressure to a pneumatic volume between itself and the projectile (8) in a first switching position during the respective activation time for application of pneumatic pressure to the projectile (8) and which ventilates this pneumatic volume in a second switching position.

5. Apparatus according to one of the preceding claims, adapted to control an impact speed of the projectile (8) upon impact onto the applicator (6) and in the process to vary the part of the movement path covered by the projectile (8) before the rotation of the movement of the projectile (8).

6. Apparatus according to one of the preceding claims, adapted to allow the first and the second activation time to overlap in an overlap time.

7. Apparatus according to one of the preceding claims, in which the control means (54) is adapted to vary in different control states with the overlap time zero a separation time between a first and a second activation time.

8. Apparatus according to one of the preceding claims, adapted so that during the control the pneumatic supply pressure applied to the double valve means (1, 2) remains unchanged for the application of pressure.

9. Apparatus according to one of the preceding claims, wherein the pneumatic means comprises a pneumatic compressor (53), wherein the apparatus is adapted to allow the compressor in the activated state to run at different control states with different impact speeds of the projectile (8) at the same rotational frequency, preferably in principle in the activated state to run at always the same rotational frequency.

10. Apparatus according to one of the preceding claims, wherein the projectile (8) can be moved with an impact pulse of between 2 gm / s and 300 gm / s upon impact onto the applicator (6).

11. Apparatus according to one of the preceding claims, adapted to vary, in an iterative operating state with directly successive forward movements of the projectile (8) for impact onto the applicator (6) and return movements, the impact speed from one to the next such combined forward and return movement.

12. Apparatus according to one of the preceding claims, having a measuring means (31) for detecting a passage of the projectile (8) at a point of the movement path, which measuring means (31) is coupled to the control means (54).