Patent Publication Number: US-2016243711-A1

Title: Hand tool for processing goods

Description:
The invention relates to a hand tool for processing, particularly cutting goods under the application of ultrasonic energy. 
     In numerous industrial applications, particularly in the food industry, products need to be provided in predetermined dimensions. Often, food products, such as bread, meat, sausages or cheese are cut in slices and are packed. For this purpose, cutting tools are used, with which the processed good is cut under the application of ultrasonic energy. Such a device is disclosed in [1], EP2551077A1. This device comprises holding devices and guiding devices, with which the cutting tools are held and guided, in order to process the goods. 
     [2], EP0543628A1, discloses a method for cutting food products under the application of ultrasonic energy. Thereby, ultrasonic signals in the frequency range between 10 kHz and 60 kHz and with amplitudes in the range between 20 μm and 200 μm are applied to a blade. 
     Often goods are processed manually. E.g., for examining the product quality cuts are made through a processed good. However, also in shops, e.g. in a bakery or at a meat market, goods, such as bread, meat or cheese, needs to be cut manually, often fine and precise, which is not possible with conventional knives, even when the processed goods are mechanically fixed. 
     Furthermore, in industrial processes and in the hotel and restaurant industry it is often required, to add an atomised powder to a processed good, which often is not reached as desired, wherefore the added powder is normally distributed by stirring. 
     [3], U.S. Pat. No. 5,695,510, discloses a surgical knife, to which ultrasonic energy is applied. However, knives of this kind cannot be used for the above described purposes. 
     [4], U.S. Pat. No. 6,785,970B1, discloses a knife that is oscillated by means of a motor, which however requires space and energy. Furthermore, with the mechanically oscillating knife a desired cutting quality cannot be reached. 
     The present invention is therefore based on the object of providing an improved hand tool, with which goods can advantageously manually be processed, particularly be cut or atomised, under the application of ultrasonic energy. 
     The hand tool shall have a compact structure and shall easily be manageable. In spite of this requirement, the hand tool shall allow precisely processing relatively large goods, particularly bread, meat, cheese and vegetables without effort and with little force. 
     The hand tool shall operate efficiently so that it can operate with an external or a local power supply unit and that it exhibits also in autonomous operation relatively little weight. 
     The ultrasonic energy shall be transferable practically without losses to a sonotrode. Furthermore, sufficient ultrasonic energy shall be available whenever required so that mechanically firm goods can be processed as well. Further, the hand tool shall be built with a stable structure so that mechanically firm goods can be processed over a longer period of time without the occurrence of wear. 
     These objects are reached with a hand tool that comprises the features defined in claim  1 . Preferred embodiments of the invention are defined in further claims. 
     The hand tool comprises a tool part that is held in a preferably hollow cylindrical housing body of a housing part and that comprises an ultrasonic transducer with at least one piezo element, which serves for delivering ultrasonic energy to a blade that is connected to the tool part. 
     According to the invention a plurality of piezo elements are provided, which are separated from one another by contact elements and which comprise each a transfer opening, which is traversed by a transducer rod that is connected, directly or indirectly, to a coupling rod that is connected in one piece to the blade and that a pressing element is provided that is connected to the transducer rod and that presses the piezo elements against a locating surface of an element which is connected, directly or indirectly, to the coupling rod and which mechanically couples the piezo elements with the coupling rod. 
     In preferred embodiments the transducer rod
     a) is a part of the coupling rod and is therefore connected in one piece with the coupling rod; or   b) is held at the front side by a press fitting or a threaded connection in an opening provided in the coupling rod; or   c) is held at the front side by a press fitting or a threaded connection in a first cylinder opening of a connecting cylinder that is connected to the coupling rod.   

     The connecting cylinder, if provided,
     a) is part of the coupling rod and therefore connected to the coupling rod in one piece; or   b) comprises at the front side a second cylinder opening, in which a bolt that is provided on the coupling rod is held by a press fitting or a threaded connection; or   c) comprises at the front side a massive or hollow cylindrical cylinder bolt, which is held within the opening of the coupling rod by a press fitting or a threaded connection; or   d) comprises at the front side a second cylinder opening, in which a first bolt member of a connecting bolt is held by a press fitting or a threaded connection and that in the rod opening of the connecting cylinder a second bolt member of the connecting bolt is held by a press fitting or a threaded connection.   

     In preferred embodiments the coupling rod and the transducer rod or the coupling rod and the connecting cylinder are welded together, so that practically a unitary connection between the transducer rod and the coupling rod and possibly connecting pieces provided in therebetween, such as the connecting cylinder and the connecting bolt, results. 
     In preferred embodiments the transducer rod is coaxially aligned with a proximal portion of the coupling rod, so that the section of the tool part that is provided with the ultrasonic transducer can be arranged with little space requirement in a cylindrical housing body, which can be used as handle. 
     With all variations of the connection of the transducer rod to the coupling rod, a compact setup of the cutting tool is achieved. The transducer rod and the coupling rod preferably form a unitary metal body so that loss free coupling and an even more compact setup can be reached. 
     Due to the advantageous design of the tool part the ultrasonic transducer can be equipped with larger and more powerful piezo elements, preferably hollow cylindrical or annular plates and still comprise compact dimensions. The annular piezo-disks can have an outer diameter, which is a multiple of the inner diameter or of the diameter of the transducer rod, respectively, so that ultrasound waves can be transferred with high energy to the coupling rod and to the sonotrode. 
     In a preferred embodiment, four to ten annular piezo disks, which are separated from one another by contact elements, are held in series. The contact elements, preferably brass plates, cover the piezo elements preferably completely and comprise connecting contacts. 
     The piezo elements and the contact elements, which are seated on the transducer rod and which are preferably separated from the transducer rod by an insulation tube, are pressed by the pressing element against a locating surface, which is provided at the end of the connecting cylinder or of the coupling rod which is facing the ultrasonic transducer. The locating surface is preferably a annular ring area, which is congruent to the front surface of the neighbouring piezo elements. Hence, mechanical ultrasonic energy supplied by the piezo elements is transferred from the front side via the locating surface to the connecting cylinder or directly to the coupling rod and via the backside across the pressing element and the transducer rod to the connecting cylinder or directly to the coupling rod. Ultrasonic energy is therefore fed along to different paths into the coupling rod. 
     The transducer rod preferably comprises an external thread that holds the pressing element, which comprises an internal thread. By turning the pressing element the transducer block held between the pressing element and the locating surface can be pressed together. 
     The coupling rod exhibits a circular, triangular, square or polygonal cross-section that is preferably adapted to the range of the applied operating frequencies. 
     In preferred embodiments, temperature sensors are provided that are held in openings provided in the coupling rod, in the connecting bolt, and/or in the transducer rod. The connecting lines of the installed sensors are preferably arranged in a cable channel, which coaxially traverses the transducer rod. By means of the temperature sensors the temperatures of the coupling rod and of the transducer rod can be measured. Depending on the measured temperatures the ultrasonic generator can advantageously be controlled, in order to reduce or stop application of ultrasonic energy to the tool part during unfavourable operating conditions. This allows recognising unfavourable operating behaviour and avoiding damage on the tool part. Preferably an additional piezo element is provided, which senses oscillations on the transducer rod, on the connecting cylinder or on the coupling rod. Analysing the amplitudes of the oscillations in the given frequency ranges allows selecting optimal operating frequencies and avoiding operating frequencies, for which a sub-optimal energy transfer to the sonotrode or to the processed goods occurs. 
     The advantageous structure of the tool part therefore allows simple assembly of the tool part and simple integration into the housing part. 
     For this purpose, the transducer rod or the connecting cylinder or the coupling rod is preferably provided with or connected to an outer flange, which is held by an inner flange that extends into the cross-section of the hollow cylindrical housing body. 
     Furthermore, the housing body preferably comprises an internal thread, which holds a threaded element, such as a crown nut, that is provided with an external thread and that can press the outer flange provided at the tool part against the inner flange provided at the housing part. The threaded element is inserted into the hollow cylindrical housing body and is turned in the internal thread until the outer flange and the inner flange abut with a desired pressure. In preferred embodiments, an elastic element is provided between the inner flange and the outer flange, which acoustically decouples the tool part and the housing part from one another. 
     The inner flange is preferably provided at the front side of the housing body. Hence, the tool part is held at the front side of the housing body, wherefore at the backside, inside the housing part, ample space is available in which further device parts can be arranged. E.g., an ultrasonic generator can be arranged that is supplied with a supply voltage and that can deliver electrical ultrasound signals in the frequency range from 25 kHz up to 50 kHz. Preferably a controllable ultrasonic generator is provided that can selectively deliver the desired frequencies. Alternatively, electrical ultrasound signals can also be supplied via a connecting cable. In addition, a power supply unit, e.g. a battery or an accumulator, can be provided inside the housing body, which supply the electrical energy required for the hand tool. The supply voltage, e.g. DC-voltage, can be delivered via a connecting cable. 
     Inside the housing body preferably a printed circuit board with electrical and electronic modules is arranged, with which the hand tool can be controlled. The electrical modules of the ultrasonic generator can also advantageously be arranged on the printed circuit board. 
     Preferably a flexible printed circuit board is provided that surrounds the transducer block or the connecting cylinder at least partially. In this manner, the printed circuit board scarcely requires space and can advantageously be coupled, in preferred embodiments, with metallic elements of the tool part. Preferably an insulated metal substrate IMS is used as flexible printed circuit board, with which heat loss of the electrical and electronic modules is led away and preferably forwarded to a metal body, e.g. to the connecting cylinder. 
     For controlling the hand tool, preferably a control ring is provided, which surrounds the housing body and is rotatably held therefrom. By turning the control ring, which preferably comprises magnetic elements, electrical switching elements can be actuated, in order to select a desired mode of operation of the hand tool. 
     Inside the housing body preferably a cooling coil is arranged, through which a cooling agent can flow. For cooling purposes, the cooling coil can advantageously be connected to the metal substrate of the printed circuit board. 
     The coupling rod and the blade are adapted to the requirements of the user. The coupling rod extends preferably along a curve and stands with an end piece preferably perpendicularly on the back of the blade, whereby optimal coupling of ultrasonic energy results. 
     As required, the blade is aligned with the cutting edge forwards, to the side or backwards. Hence, the hand tool can be adapted to any working process. If required, it can be arranged that the sonotrode, i.e. the blade, can be exchanged. 
    
    
     
       Below the invention is described with reference to drawings. Thereby show: 
         FIG. 1  an inventive hand tool  10  in a preferred embodiment, which comprises a housing part  2 , in which a tool part  1  is held that comprises a coupling rod  12  that is connected on the front side to a blade  11 ; 
         FIG. 2 a    the hand tool  10  of  FIG. 1  in an explosion view with the housing part  2  cut along cutting line S-S of  FIG. 3 a   , an ultrasonic transducer  15  with a transducer rod  151  that is connectable via a connecting cylinder  14  and a connecting bolt  13  to the proximal first rod member  121  of the coupling rod  12  and that is coaxially aligned thereto; 
         FIG. 2 b    the ultrasonic transducer  15  of  FIG. 2 a    in an explosion view with the transducer rod  151 , an insulation tube  153 , annular piezo elements  154 , annular contact plates  155  and a pressing element  152 ; 
         FIG. 3 a    a side view of the hand tool  10  of  FIG. 1 ; 
         FIG. 3 b    a sectional view with a cut through the hand tool  10  along cutting line S-S shown in  FIG. 3   a;    
         FIG. 4  a part of the hand tool  10  of  FIG. 3 a    with a sectional view with a first cut along the cutting line S-S through the connecting cylinder  14  and the housing body  21  and with a second cut perpendicular thereto through a crown nut  22 , with which the connecting cylinder  14  is pressed against an inner flange  214  provided at the front side of the housing body  21 ; 
         FIG. 5 a    a sectional view with a cut along cutting line S-S of  FIG. 3 a    through the ultrasonic transducer  15  and the transducer rod  151  as well as the connecting cylinder  14  and the connecting bolt  13  that connects the connecting cylinder  14  to the first rod member  121  of the coupling rod  12 ; 
         FIG. 5 b    the connecting cylinder  14 , the connecting bolt  13  and the first rod member  121  of the coupling rod  12  of the sectional view of  FIG. 5 a   , which are released from one another; 
         FIG. 6 a    the hand tool  10  of  FIG. 3 a    in a further preferred embodiment with a cut along cutting line S-S; 
         FIG. 6 b    the connecting cylinder  14  and the first rod member  121  of the coupling rod  12  of sectional view of  FIG. 6 a    released from one another; 
         FIG. 7 a    a preferably designed connecting cylinder  14  and a coupling rod  12  matching thereto released from one another; 
         FIG. 7 b    in sectional view the connecting cylinder  14  and the coupling rod  12  of  FIG. 7 a    connected thereto; 
         FIG. 8  the coupling rod  12  in a preferred embodiment, with a first rod member  121  forming the connecting cylinder  14  and with a second rod member  122  holding a blade  11  that is aligned in a plane perpendicular to the first rod member  121 ; 
         FIG. 9  the coupling rod  12  in a preferred embodiment with a first rod member  121  forming the transducer rod  151  and with a second rod member  122  holding a blade  11  that is aligned in a plane parallel to the first rod member  121 , which exhibits a circular cross section; 
         FIG. 10 a    a coupling rod  12  with a triangular cross section; 
         FIG. 10 b    a coupling rod  12  with a square cross section; and 
         FIG. 10 c    a coupling rod  12  with an octagonal cross section. 
         FIG. 1  shows an inventive hand tool  10  in a preferred embodiment. The hand tool  10  comprises a tool part  1  that is held within a housing part  2 , which comprises a hollow cylindrical housing body  21 . 
     
    
    
     In a detailed view  FIG. 1  shows that a connecting cylinder  14  is extending out of the housing body  21  and is connected to a first rod member  121  of a coupling rod  12 , whose second rod member  122  stands perpendicularly on the back  112  of a blade  11 . The blade  11  exhibits the form of a segment of a circle and comprises a cutting edge  111  that is extending along a circular line. The blade  11  can also have a different design and can form for example a part of a polygon. 
     The housing body  21  is equipped at the front side with a control ring  24  that can conveniently be turned for changing the mode of operation of the hand tool  10 . E.g., an ultrasonic generator provided inside the housing part  2  can be switched on. E.g., suitable values for the frequency and/or the amplitude of the ultrasound signals or pre-programmed operation modes can be selected that have been evaluated for processing the goods. On the backside the housing body  21  closed by a terminating element  23 . In this embodiment, the hand tool  10  is equipped with a connecting cable  7 , via which a supply voltage or ultrasound signals are supplied to the hand tool  10 . The terminating element  23  is preferably equipped with a connector, which is connectable to a cable  7 , via which a supply voltage and/or data are transferable. E.g., with the supply voltage an accumulator can be charged. However, with the transferred data the hand tool can also be programmed in order to be adapted to a specific purpose of use. E.g., frequencies or frequency intervals are selected, which are suitable for processing specific goods. 
     The hand tool  10  has a compact structure and comprises, in spite of the relatively large tool part  1 , a relatively small housing part  2  that can conveniently be held with one hand. Under the application of ultrasonic energy, the blade  11  allows easily and precisely cutting goods or finely atomising powdery goods that have been put onto the blade  11 . 
       FIG. 2 a    shows the hand tool  10  of  FIG. 1  in explosion view. The housing part  2  with the housing body  21 , the annular control member  24  and the terminating member  23  are cut along the longitudinal axis. The tool part  1  comprises an ultrasonic transducer  15 , which is shown in  FIG. 2 a    as a unit and in  FIG. 2 b    in explosion view. 
     The ultrasonic transducer  15  comprises six hollow cylindrical or annular piezo elements  154 , which are separated from one another by five annular contact elements or contact plates  155 . The piezo elements  154  exhibit a disk-shape and are provided with a transfer opening  1541 . E.g., piezo elements  154  with a thickness in the range of 2 mm-8 mm are provided. The contact elements  155  are for example brass plates having a thickness in the range from 1/10 mm-½ mm and comprise also a transfer opening  1551 . Furthermore, the contact elements  155  are provided with connecting contacts. The transfer openings  1541 ,  1551  are traversed by a transducer rod  151  and an insulation tube  153 , which insulates the piezo elements  154  and the contact elements  155  against the metal transducer rod  151 . 
     The transducer rod  151  comprises an opening  1511  at the front side and an external thread, on which a pressing element  152  is seated that is used for pressing the piezo elements  154  and the contact elements  155  against one another. In an opening  1511  provided at the front side of the transducer rod  151  a temperature sensor  42  is inserted, with which the temperature of the ultrasonic transducer  15  can be measured. 
       FIG. 2 a    shows further that the transducer rod  151  can be fixed by a press fitting or a threaded connection in a first cylinder opening  141  that is provided at the end piece of a connecting cylinder  14 , which is facing the ultrasonic transducer  15 , as shown in detail in  FIG. 4 . At this end piece of the connecting cylinder  14  a locating surface A is provided, which has approximately the same cross section as the piezo element  154  adjacent thereto. With the pressing element  152  the transducer block  158  that comprises the piezo elements  154  and the contact elements  155  lying in between can therefore be pressed against the locating surface A, in order to reach optimum coupling. Thereby, the transducer block  158  and the connecting cylinder  14 , which are connected in a force locking manner and form locking manner, form a unit, via which the ultrasound waves are transferred optimally to the blade  11 . 
     At the end piece, which is facing blade  11 , the connecting cylinder  14  comprises a second cylinder opening  142 , in which a second bolt member  132  of a connecting bolt  13  can be fixed by a press fitting or a threaded connection. In addition, the connecting bolt  13  comprises a first bolt member  131 , which can be fixed by a press fitting or a threaded connection in a rod opening  1210  of the first rod member  121  of the coupling rod  12 . The second rod member  122  of the coupling rod  12  extends along a curve perpendicular to the back  112  of the blade  11  and is connected with it in one piece, preferably by welding. 
     It can be seen that the elements of the transmission chain for the ultrasound signals are firmly connected with one another and with the compact structure of the tool part  1  a low loss transmission of the ultrasound signals to the blade can be reached. In preferred embodiments described below this transmission chain is further simplified and shortened, so that an even more compact structure of the tool part and a practically optimal transmission of the ultrasound signals can be reached. 
     The connecting cylinder  14  shown in  FIG. 2 a    comprises an outer flange  144 , which serves for mounting the tool part  1  within the housing body  21  that comprises an inner flange  214  at the front side. The housing body  21  further comprises an internal thread  210 , into which a threaded element with an external thread  221 , namely the shown crown nut  22  can be turned. With the crown nut  22  the outer flange  144  of the connecting cylinder  14  can be pressed against the inner flange  214  of the housing body  21 , in order to fix the tool part  1  within the housing part  2 . Between the inner flange  214  and the outer flange  144  preferably an elastic element is provided, which mechanically holds the two connected elements securely, but inhibits the transmission of ultrasonic energy. 
       FIG. 2 a    further shows a flexible printed circuit board  3  with electrical elements  31 ,  32 , e.g. multi-coloured light emitting diodes that indicate the mode of operation of the hand tool  10 . Hence, the control ring  24  can be turned until the light emitting diodes  31 ,  32  indicate that the desired mode of operation has been reached. The flexible printed circuit board  3 , preferably a bendable insulated metal substrate IMS, is equipped with electrical and electronic modules, which preferably allow controlling and monitoring operation of the hand tool  10 . Further, modules of the ultrasonic generator  30  can be arranged on the printed circuit board  3 . 
       FIG. 2 b    shows that the ultrasonic generator  30  is connected via generator lines  150  to the connecting contacts of the contact elements  155 , so that an alternating voltage in the ultrasound region can be applied to the installed piezo elements  154 , which are deformed accordingly. 
     The ultrasonic generator  30  is connected to a power supply unit  300 , which may be present in form of an accumulator or batteries, is also installed in the hand tool  10 . Alternatively, a supply voltage can be supplied via connecting line  7 , as shown in  FIG. 1 . 
     The ultrasonic generator  30  is also connected to a control unit  350 , with which the ultrasonic generator  30  is controllable preferably such that ultrasound signals with a desired operating frequency and amplitude are delivered. Further, intervals can be programmed, with which the operating frequency is changed or alternated. As mentioned, the control unit  350  can be arranged on the flexible printed circuit board  3 . 
     The flexible printed circuit board  3  is preferably bent cylindrically with a radius that is slightly smaller than the inner radius of the hollow cylindrical housing body  21 . In this manner, a relatively large printed circuit board can be integrated with little space requirement inside the housing body  21 . 
       FIG. 3 a    shows a side view of the hand tool  10  of  FIG. 1  as well as a cutting line S-S. 
       FIG. 3 b    shows a sectional view with a cut through the hand tool  10  along the cutting line S-S shown in  FIG. 3 a   . The elements of the tool part  1  and of the housing part  2  as well as the elements of the flexible printed circuit board  3 , on which optionally the control unit  350  and the ultrasonic generator  30  are provided, have been described. Further shown are five generator lines  150  that are connected to the contact elements  155 , two measurement lines  410  and  420  that lead to the first and to the second temperature sensor  41 ,  42 , as well as further electrical lines  310 . All lines  150 ,  310 ,  410  and  420 , which are schematically shown, can lead to the control unit  350  and/or to the ultrasonic generator  30 , which can be arranged on the flexible printed circuit board  3  or externally to the hand tool  10 . Switches can further be provided with which the lines  150 ,  310 ,  410  and  420  can be interrupted or closed. 
       FIG. 3 b    further shows a cooling coil  5  through which a cooling agent can flow in order to transfer heat from the interior of the housing body  21  to the outside. In preferred embodiments the cooling coil  5  surrounds the ultrasonic transducer  15 , so that its temperature is regulated to an ideal value and heat losses can be led away. 
       FIG. 4  shows a part of the hand tool  10  of  FIG. 3 a    with a first cut along cutting line S-S through the connecting cylinder  14  and the housing body  21  and a second cut perpendicular thereto through the crown nut  22 , with which the connecting cylinder  14  is pressed against the inner flange  214  provided at the front side of the housing body  21 . The close coupling of the ultrasonic transducer  15 , which by means of the pressing element  152 , e.g. a pressing nut having an internal thread, is pressed against the connecting cylinder  14 , is well visible. 
       FIG. 5 a    shows a sectional view with a cut along cutting line S-S of  FIG. 3 a    through the ultrasonic transducer  15  and the transducer rod  151  as well as through the connecting cylinder  14  and the connecting bolt  13 , which connects the connecting cylinder  14  with the first rod member  121  of the coupling rod  12 . 
       FIG. 5 b    shows in the sectional view of  FIG. 5 a    the connecting cylinder  14 , the connecting bolt  13  and the first rod member  121  of the coupling rod  12  that are released from one another. 
       FIG. 6 a    shows the hand tool  10  of  FIG. 3 a    in a further preferred embodiment with a cut along cutting line S-S. In this embodiment the connecting bolt  13  shown in  FIG. 4  is not used. Instead at the first rod member  121  of the coupling rod  12  a rod bolt  1211  is provided, which is inserted into a front sided cylinder opening  142  of the connecting cylinder  14 . The rod bolt  1211  is preferably connected to the connecting cylinder  14  by a press fitting and/or a threaded connection and/or a welded connection. The detailed view of  FIG. 6 a    shows the front side of the connecting cylinder  14  having a welded seam  6  which connects the connecting cylinder  14  to the first rod member  121  of the coupling rod  12 . By avoiding the connecting bolt  13  the transmission chain is reduced, wherefore a closer coupling of the ultrasonic transducer  15  to the sonotrode, i.e. the blade  11  results. 
     This example shows the alignment of the blade  11  in the kind of a kebab-knife with backward oriented cutting edge  111 . The example shows that the inventive hand tool  10  allows advantageously executing any possible cutting movement by suitably aligning the blade  11 . 
       FIG. 6 b    shows in the sectional view of  FIG. 6 a    the connecting cylinder  14  and the first rod member  121  of the coupling rod  12  separated from one another. 
       FIG. 7 a    shows a preferred design of the connecting cylinder  14  and a coupling rod  12  matching thereto that are separated from one another. The connecting cylinder  14  comprises a hollow cylindrical connecting bolt  143 , which can be inserted into a rod opening  1210  provided in the first rod member  121  of the coupling rod  12 . This embodiment has the advantage that measurement lines can be guided up to the coupling rod  12  in order to contact e.g. a temperature sensor  41  or an ultrasound sensor or a piezo element that is installed in the rod opening  1210 . Also in this embodiment, a close coupling of the ultrasonic transducer  15  to the blade  11  is present. 
       FIG. 7 b    shows in sectional view the coupling rod  12  of  FIG. 7 a    that is connected to the connecting cylinder  14 . 
       FIG. 8  shows a sectional view of a preferred embodiment of the coupling rod  12 , whose first rod member  121  forms the connecting cylinder  14  and whose second rod member  122  holds a blade  11 , which is aligned in a plane perpendicular to the first rod member  121 . Hence, the first rod member  121  is designed at its end as connecting cylinder  14 . Hence, the transducer rod  151  shown in  FIGS. 2 a , 2 b    and  4  can be connected directly to the coupling rod  12 . Thereby, the transducer block  158  is pressed directly against the locating surface A provided at the first rod member  121 , so that nearly optimal coupling results. 
       FIG. 9  shows a further preferred embodiment of the coupling rod  12 , whose first rod member  121  forms the transducer rod  151  and whose second rod member  122  holds a blade  11 , which is aligned in a plane parallel to the first rod member  121 , which has a circular cross section. The first rod member  121  of the coupling rod  12  forms at its end also the transducer rod  151  that preferably comprises the same dimensions as the transducer rod  151  of  FIG. 2 a   . Hence, in this embodiment of the invention the transducer block  158  with the piezo elements  154  is directly coupled to the coupling rod  12 , wherefore a direct coupling without transmission losses is reached. Preferably, the cross section the piezo elements  154  and the cross section of the locating surface A provided at the coupling rod  12  are adapted to one another. 
       FIGS. 9, 10   a ,  10   b  and  10   c  show that the coupling rod  12  can comprise cross sections which are adapted to the operating frequencies and to the application. 
       FIG. 9  shows a coupling rod  12  with a circular cross section.  FIG. 10 a    shows a coupling rod  12  with a triangular cross section.  FIG. 10 b    shows a coupling rod  12  with a square cross section.  FIG. 10 c    shows a coupling rod  12  with an octagonal cross section. 
     REFERENCE LIST 
     
         
           1  tool part 
           10  tool 
           11  blade 
           111  cutting edge 
           112  back of the blade 
           12  coupling rod 
           121  first rod member 
           1210  rod opening 
           1211  rod bolt 
           122  second rod member 
           13  connecting bolt 
           131  first bolt member 
           132  second bolt member 
           14  connecting cylinder 
           141  first cylinder opening 
           142  second cylinder opening 
           143  cylinder bolt 
           144  outer flange 
           15  ultrasonic transducer 
           150  generator lines 
           151  transducer rod 
           1511  receiving bore 
           152  pressing element 
           153  insulation tube 
           154  piezo elements 
           1541  transfer opening in the piezo element 
           155  contact element 
           1551  transfer opening in the contact elements 
           158  transducer block 
           2  housing part 
           21  housing body 
           210  internal thread 
           214  inner flange 
           22  threaded element, crown nut 
           221  external thread 
           23  terminating element 
           24  control ring 
           3  flexible printed circuit board 
           30  ultrasonic generator 
           300  power supply unit 
           31 ,  32  electrical elements 
           310  electrical lines 
           350  control unit 
           41  first temperature sensor 
           410  first sensor line 
           42  second temperature sensor 
           420  second sensor line 
           5  cooling coil 
           6  welded seam 
           7  connecting cable