Abstract:
The present invention relates to a hand-held working tool, such as a setting device used for driving fastening elements such as nails, bolts, pins and the like into a surface, or an at least partially percussive hand-held tool having a housing part ( 11 ) and a working mechanism such as a setting or striking mechanism arranged inside the housing of the device and having at least one sensing device ( 17 ) for sensing acceleration forces occurring during a setting or striking pulse as well as a handle. For improving this type of hand-held working tool ( 10 ) an interface ( 30 ) for data communication and data output is arranged on the hand-held working tool.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a hand-held device having a housing and a work mechanism such as a setting or striking mechanism in said housing of the device and at least one sensing device for detecting acceleration forces  a (t) occurring during a setting or striking impulse and having a handle part, wherein an interface for data communication and/or for data output arranged on the said hand-held tool. The invention also relates to an interface for utilization with a hand-held device, wherein an interface unit includes a device for data communication with the interface for data communication with said hand-held working tool. 
   There is a great variety of such working tools, for example setting tools that can be operated with solid, gaseous or liquid fuels or with air pressure or compressed air are operated. In combustion-operated setting tools, a setting piston is operated using combustion gases, by which fastening elements are then driven into a surface. Such working tools can, however, also be found in at least partially percussive hand-held tools, such as percussion drills or chiseling-devices. Further examples of such tools are power drills, hammer drills, picks, screw-driving tools, grinding devices, circular saws, chainsaws and jigsaws. 
   2. Description of the Prior Art 
   Such working tools include acceleration, impact or vibration transmitted to the operator of the device via a working mechanism configured as a setting or striking mechanism in the housing of the device and can have detrimental effects on the operator as a result of intensive usage of such hand-held tools. It is therefore reasonable to limit the exposure time of an operator to such working tools. 
   One problem lies in the determination of the acceleration values transmitted to the specific operator of a working tool. Setting tools or drills can be run on various power settings. Generally, only the parameters for the maximum vibrations that occur are stated, and it is therefore difficult for the operator to determine the exact acceleration value for a specific setting of the tool the operator is using. If the stated maximum acceleration of a working tool for the determination of the maximum working or exposure time on the working tool is used, then the tool may be used by the operator only for a short period of time. 
   Accordingly, an acceleration sensor, which acts as a switch for operating a safety switch disclosed in EP 0 345 655 for known similar type of power drill. Via this safety switch, the electric device is switched off at specific rotational acceleration values independent of the bearing. In this hand-held tool, only acceleration peaks are detected, which serve to switch off the hand-held tool in case of tool blockage. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is to provide a working tool wherein the above-mentioned drawbacks are eliminated and the operator receives information relating to acceleration or vibration strain within an accepted time interval. This is achieved by a hand-held device having a housing and a work mechanism such as a setting or striking mechanism in said housing of the device and at least one sensing device for detecting acceleration forces  a (t) occurring during a setting or striking impulse and having a handle part, wherein an interface for data communication and/or for data output arranged on the said hand-held tool. This objective is also achieved by an interface for utilization with a hand-held device, wherein an interface unit includes a device for data communication with the interface for data communication with said hand-held working tool. 
   Accordingly, it is sufficient if an interface for data communication and/or data output of a sensing device for the picking up of acceleration and/or vibration strain is arranged on the hand-held working tool. The data picked up by the sensing device relating to acceleration and/or vibration load can be displayed to the operator via the internal data output in the device, or transferred to an external device via the interface for data communication, whereby this data can be displayed to the operator. 
   Advantageously, the hand-held tool has an evaluation and storage mechanism for processing and storing the data picked up by the sensing device. This measure enables the data picked up by the sensing device to be processed and filtered in the device so that only the data that is relevant to the criteria, upon which the evaluation of the data in the evaluation and storage unit is based, are transmitted or output via the interface. Advantageously, the sensing device has an acceleration sensor arranged on a handhold of the hand-held tool. Accelerations acting on an operator can thus be picked up using the acceleration sensor. 
   The sensing device comprises a discriminating means which enables the differentiation of accelerations and impulses caused by real setting pulses and accelerations and impulses caused by other acceleration forces. The discriminator can be used as a pressure sensor for gaseous media in conjunction with the working volume. The gas compression waves caused by a setting operation in the working mechanism can be evaluated using this pressure sensor and the data acquired by the acceleration sensor and thus associated with the setting process. 
   The discriminator means could also be coupled with an electronic trigger switch to assure that the actual firing process is detected by the discriminator means. 
   It is advantageous for an external data output if the interface arranged on the hand tool is an external interface unit, which is configured as a vibration dosimeter or vibration load measuring device, which can receive the data via a device for data communication from the interface to the data communication device on the hand-held tool. This interface can also regulate the data conveyed by the sensing device via an evaluation and storage device for processing and storing. Accordingly, an evaluation of the data measured can also take place in the external interface. If the interface features a visual data reproduction unit, then the operator can read current acceleration or vibration dosis rates on the data reproduction unit, i.e. the display, on the external interface, in the shape of a watch or a small device that can be clipped to a belt. The data reproduction unit can be controlled via control units. 
   Data output can be carried out via signals, such as visual or acoustic signals. These signals can send out an alarm when a maximum permitted acceleration dosis rate or acceleration force from the interface has been determined. Such signals can be applied to the interface or the hand-held tool directly. 
   The evaluation and storage mechanism can include a microprocessor running an algorithm or a program, which conveys a physiological strain gauge out of the accelerator measurement data to an operator identified by the evaluation and storage device attached to the device or interface. In another feature it would also be advantageous when providing user-specific information to have a chip card or magnetic strip card on which user-specific identifying characteristics are stored. The data stored here could either be transmitted to the evaluation and storage mechanism of the interface or the hand-held tool via a data reading device or via the interface for data communication or the device for data communication. 
   In an advantageous embodiment, a method to trigger the microprocessor to leave the sleep-mode of the sensor mechanism and/or the microprocessor is provided. Power is saved when the sensor mechanism and/or the microprocessor are transported into a sleep-mode, which can be stopped by a trigger impulse or a trigger method. The power intake in sleep-mode can average three micro amperes in comparison to a power intake of 10 milliamperes in an active-mode. Such triggers can also be provided for with the same advantages for the electronic controls of the interface. 
   Advantageously, the sensor mechanisms and/or the evaluation and storage mechanism arranged on the hand-held tool or on the interface contain a method for real-time measurements. The measuring data can thus be attributed to real times and time periods particularly important for the calculation of acceleration force or vibration dosis rates, which have an effect on operators. 
   Preferably, the evaluation and storage mechanism is separated into various storage sectors, to which a specific operator could be assigned via user-specific identification characteristics. Thus, the same interface can be utilized by numerous operators on the same day whereby the individual storage sections act as accounts for the operators, in which acceleration forces allocated to each operator are stored. These storage sections can be provided in the evaluation and storage mechanism in the device and in the evaluation and storage mechanism in the interface. 
   Advantageously, the interface is a vibration dosimeter in the form of a vibration or acceleration force measuring device carried by the operator of the hand-held tools during the working day, which sums up all acceleration forces or acceleration forces recorded during the day and shows them to the operator. 
   The vector acceleration values  a (t), the time t and time segments T, the number of events such as the number of settings n, the number of working activities i and their duration T i  are measured by the device. From the acceleration values  a (t) frequency-adjusted oscillations or acceleration values a hv (t) can be calculated, which are used in application of the following formula for calculating the acceleration load A attained on a workday in a work period T 0 . 
           A   =                 ⁢     (       1   /     T   0       ⁢       ∑     1   =   1     n     ⁢           ⁢       a   hvi   2     ⁢     T   i           )             
wherein:
     a hvi =total value of oscillations or accelerations of the i th  operation with a working tool,   n=number of single oscillation effects such as setting operations,   T i =duration of the i th h operation (i.e. one hour working with a working tool).   
   The calculated value A from the storage and evaluation mechanism, which is allotted to a specific operator, is constantly compared with a maximal acceleration value A max . If the maximal acceleration value A max  is surpassed, the operator is notified (acoustically or visually). 
   The previously illustrated sensor mechanism and the electrical mechanisms required for the working of this device have to be supplied with power. In hand-held tools such as setting tools this can be provided by one or numerous batteries or accumulators or by at least partially hammering hand-held tool devices via a mains connection or a connection to a generator. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the invention, its operating advantages and specific objects of the invention, reference is made to the drawings wherein: 
       FIG. 1   a  shows a partially sectional view of a first embodiment of a hand-held tool in the form of a setting tool in accordance with the present invention; 
       FIG. 1   b  shows a block diagram of the hand-held tool in  FIG. 1   a;    
       FIG. 2  shows an interface in the form of a vibrational strain measuring device for use in accordance with the present invention; 
       FIG. 3  shows a block diagram of the interface in  FIG. 2 ; 
       FIG. 4  shows a block diagram of the second embodiment of a hand-held tool in accordance with the present invention; 
       FIG. 5  shows a block diagram of the second embodiment of an interface, for use in accordance with the present invention; 
       FIG. 6   a  shows a third embodiment of an interface in the form of a vibrational strain measuring device in accordance with the present invention; 
       FIG. 6   b – 6   d  shows a fourth embodiment of an interface in the form of a vibrational strain measuring device in accordance with the present invention; 
       FIG. 7   a  shows a side view of a third embodiment of a hand-held tool with an integrated vibrational strain measuring device in the form of an at least partially hammer hand tool device in accordance with the present invention; 
       FIG. 7   b  shows a block diagram of the hand-held tool in  FIG. 7   a;    
       FIG. 8  shows an interface for data evaluation using a processor in accordance with the present invention; 
       FIG. 9  shows a side view of a pressure sensor used as a discriminator in a setting tool in accordance with the present invention; and. 
       FIG. 10  schematic, a diagram in which the load values a hv (t) are plotted against time t and the number n of vibrations. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A hand-held tool, as shown in  FIG. 1   a , is represented by a setting tool. Such a hand-held tool  10  includes a working mechanism  12  such as a hammer mechanism in a housing  11  comprising a piston  15  guided in a piston guide  14  driven by an expanding agent, not shown in the drawings, when an arranged trigger switch  13  on a setting tool, especially on a handhold  16 , and if necessary further safety switches are actuated. The forward-driving piston  15  in a setting process is used to drive a fastening element in front of the piston into a surface. 
   During such a setting process the operator is exposed to acceleration a(t) or vibrations. The present setting tool houses a sensor mechanism  17 , which at least includes an acceleration sensor  18  and a discriminator  19  such as a pressure-sensitive sensor  19 . 1  connected to the hammer mechanism (see  FIG. 9 ) to record the acceleration and vibrations a(t) released in an actual setting process. Alternatively, a temperature sensor could be utilized as a discriminator. The discriminator  19  serves to differentiate impulses and accelerations caused by the actual setting process from accelerations that are caused when a hand-held tool  10  is dropped or when accelerations are created in some other manner without an actual setting process having taken place. 
   The acceleration sensor  18  and the discriminator  19  are also connected to an evaluation and storage mechanism  20  arranged in the setting tool, to which the data assimilated from the sensors  18 ,  19 ,  19 . 1  are transmitted via data lines. An interface  30  is also arranged alongside the evaluation and storage mechanism  20 , in the hand-held tool, presenting data communication with an external interface, as shown in the existing example (see  FIG. 2 ,  3 ,  5 ,  6   a  and  6   b  for comparisons). The interface  30  is equipped for data transmission with an antenna  34  or a contact socket for cable contact to the interface or with an infrared transmitter/receiver. Additionally, a visual signal  33  connected to the evaluation and storage mechanism  20  is arranged in the setting tool  10 . This signal  33  shows the operator when wear parts, such as the piston  15 , have to be replaced after a certain amount of completed settings. 
     FIG. 1   b  includes the design and function of the sensor mechanism  17  and the evaluation and storage mechanism  20 . A micro processor  21  in the evaluation and storage mechanism  20  will be aroused from its sleep-mode, previously incorporating the microprocessor  21 , by the acceleration sensor  18  via an initialization impulse  23 . A Piezo-bimorph sensor is used as the acceleration sensor  18 . A filter  29  such as an analogue/digital converter measures the first value from the acceleration sensor  18  just 100 micro seconds after “waking” and every 52 micro seconds a new value is recorded until a specific sum of 150 of measuring values have been attained. The evaluation  21 . 1  in the microprocessor  21  is carried out via an algorithm  22  simultaneously generating a software-controlled data filter  21 . 2 , which determines the data that is to stored as acceleration values belonging to an actual setting process or working process in a storing unit  25  of the evaluation and storage mechanism. A discriminator  19  such as a temperature or pressure-sensitive sensor (see  19 . 1  in  FIG. 9 ) is also provided alongside the acceleration sensor  18  on the hand-held tool. 
   If the discriminator  19  is shown as a pressure sensor (see  19 . 1  in  FIG. 9 ) then the data will be added to the filter  29 , as illustrated in  FIG. 1   b , which transforms the measuring data to digital data and feeds the data to the microprocessor  21  for further processing and evaluation. The data from the discriminator  19  recognizes actual setting processes. When the algorithm  22  or evaluation program in the microprocessor  21  recognizes a real setting, then the measuring data taken from the acceleration sensor  18  is transmitted to the storage unit  25 . Additionally, a setting was carried out in a special storage section of the storage unit  25 , and thus information on the number n ( FIG. 10 ) of completed setting processes with the setting device or hand-held tool is contained in the storage unit  25 . The evaluation and storage mechanism  20  also acts as a real-time medium  24  for conveying the absolute starting time to and the temporal period T ( FIG. 10 ) of a setting process and the acceleration values(t) in this setting process. In the storage unit  25 , appropriate times t 0 , T are attributed to the acceleration and vibration values a(t), a hv (t). 
   The evaluation and storage mechanism  20  is also designed to recognize a setting process without a discriminator  19 , i.e. when a discriminator  19  fails due to an operational disturbance. The algorithm  22  provides for the condition that the maximum of the first 15 measuring values must have a value above 20 and below half of the maximum of all measuring values, and that the maximum must occur before the 80 th  measuring value. When these conditions are met, then the process is stored as a setting. 
   The microprocessor  21  returns to the sleep-mode after a period of waiting e.g. 200 milliseconds (in order to prevent a double trigger). Additionally, the discriminator  19  can include a temperature sensor. The measuring values of the temperature sensors can also be digitally relayed to the evaluation and storage mechanism  20  and directly imported to the storage unit  25 , synchronously with the detected acceleration  a (t), a hv (t), A and time data t 0 , T (dotted line in  FIG. 1   b ). In a further feature, the storage unit  25  and the microprocessor  21  are connected to an interface  30  for data communication. The data collected are transmitted to an external interface, via this interface  30 , such as that illustrated in the  FIGS. 2 ,  3 ,  5 ,  6   a ,  6   b  and  8 , where the data is made available to an operator or service personnel. Further details can be found in the descriptions for the corresponding Figs. 
   The operator sees a visual signal  21  on the microprocessor  21 , via a signal means  33 , shown as a light-emitting diode, upon reaching a specific number of settings completed which tells him/her that certain wear parts of the hand-held working tool  10  must be replaced. The microprocessor  21  thus transmits an appropriate alarm to the signal  33  upon attaining n=30.000 setting processes in the storage unit  25 . 
   In the  FIGS. 2 and 3 , the first embodiment of a portable interface  110  is illustrated as a vibration strain measuring device similar to a watch. The interface  110  is arranged on a watch  111  for an operator to be able to wear this interface  110  on his/her wrist. The interface  110  shows a data reproduction unit  131  such as an alphanumeric display according to  FIG. 2 . The operator is shown the percentage of the attained vibration or acceleration force A on a working day via this display, 
   wherein: 
           A   =                 ⁢     (       1   /     T   0       ⁢       ∑     1   =   1     n     ⁢           ⁢       a   hvi   2     ⁢     T   i           )             
and wherein:
     a hvi =total value of oscillations or accelerations of the i th  operation with a working tool,   n=number of single oscillation effects such as, for example, setting operations,   T i =duration of the i th  operation (i.e. one hour working with a working tool).   
   The operator can control the reproduction on the display or switch between various operating modes using the controls  132 . Another feature on the interface  110  is an acoustic signal  133 . 2 , in the form of a piezo buzzer and a visual signal  133 . 1 , in the form of a light-emitting diode. An antenna  134  serves to receive and send data in communication with the interface  30  arranged on the hand-held tool via the antenna  34 . In the block diagram in  FIG. 3 , the switching of the interface is shown schematically. As illustrated, the interface shows a device for data communication  130 , which is in direct connection to the controls  132 , the signals  133 , and the data reproduction unit  131 . The device for data communication  130  can also be provided with a microprocessor and permanent storage memory such that the acceleration force or vibration strain recorded on the working tool can be temporarily stored in a change of devices by the operator n and then transmitted to a further hand-held tool at the beginning of operations with this new tool, thus providing the operator a complete overview of all vibrations or accelerations A recorded on one day. The sum of all recorded dosis rates or strains A can of course be directly viewed on the vibration strain measuring device or on the interface. If the maximum, permissible vibrational strain, A max  is reached—this is pre-set using controls  132 —then the device for data communication  130  sends an alarm to the signals  133  or  133 . 1  and  133 . 2 . The operator is thus informed visually and acoustically of having reached the maximum acceleration or vibration strain A max . 
   As illustrated in the block diagram in  FIG. 4 , a hand-held tool according to the invention, shows a sensing device with an acceleration sensor  18  and a discriminator  19 , the measuring values are fed directly into a filter  29  such as a digital/analogue converter, which transmits the data directly to an interface  30  for data communication. For the initialization of the filter  29  and the interface  30 , an initialization impulse is triggered via the acceleration sensor  18  such as an Piezo-ceramic pick-up, through which the sensing device is awakened from its sleep mode. When such a hand-held working tool, like a setting device, is put into operation, the raw and unprocessed acceleration data conveyed, which has not been evaluated in the sensing device of the hand-held working tool, is sent as an electromagnetic impulse via the interface  30  for data communication and an antenna  34 . 
   This data is picked up by an interface according to  FIG. 5 , which the operator of the hand-held tool carries. 
   As illustrated in  FIGS. 5 and 6   a , the interface  110  can be clipped onto the belt of the operator. The illustrated alternative interface  110  also shows a vibration strain measuring device, which is differentiated from the interface  110  shown in  FIGS. 5 and 6   a  by two main points. The interface  110 , as illustrated in  FIGS. 5 and 6   a , comprises an evaluation and storage unit  120  showing a storage unit  125  divided up into various storage sections  126 . n an additional feature, the evaluation and storage unit contains a microprocessor  121  for the evaluation  121 . 1  and filtering  121 . 2  of data via the program or the algorithm  122  running in the microprocessor. The data sent from the hand-held tool  10 , according to  FIG. 4 , is received via an antenna  134  on the device for data communication.  130  arranged on the interface and transmitted to the microprocessor  121 . At the beginning of a data transmission, the microprocessor  121  is first awakened from a sleep-mode via an initialization impulse  123 . This impulse  123  results from the first radio signal being sent to the device for data communication  130 . A real-time means  124 , in the form of a real-time watch, is provided to record the starting time t 0 . Via the device for data communication  130  and the attached antenna  134 , the interface  110  also comes into contact with the input  27 , which is shown as a transponder card, chip card, magnetic stripe card or key-access card. In input  27  are identification characteristics such as user-specific information stored, via which the interface  110  allots a specific operator and a specific storage section  126  of the storage unit  125  to the specific operator from the data received by a setting device. 
   This feature is preferred when the vibration strain measuring device is not on the operator, but attached to a hand-held tool using appropriate means of fixing. If the operator changes the hand-held tool during working time, then the measured acceleration values can always be allotted to the operator using the tool within the storage unit  125 . 
   The current operator of the hand-held working tool can thus always read the vibration or acceleration force recorded on this working tool on the data reproduction unit  131 . A further preferred feature is a writable memory for the input  27 , in which the daily strain attained can be stored by a specific operator. If the operator changes the working tool, then this information on acceleration or vibration strains recorded up to that moment in time can be carried over to the next working tool via the input and to the next vibration strain measuring device or interface  110 . 
   The alternative interface  110 , as illustrated in  FIG. 6   b , is also a vibration strain measuring device, yet it is distinguishable from the interface illustrated in  FIG. 5 and 6   a  in that the data assimilated from the input  27 , which is featured with a key-access card with magnetic strip ( FIG. 6   d ), is not collected via the device for data communication  130  and the antenna  134 , but via a separate means of collecting data  28  arranged in soft magnetic heads, which can read the data from the magnetic strip  27 . 1  on the means of collecting data  28  or the key-access card ( FIG. 6   c ). 
     FIGS. 7   a  and  7   b  illustrate a further embodiment of a hand-held working tool  10 . 1 , which is at least a partially striking hand-held working tool. A vibration strain measuring device is arranged directly on this hand-held tool  10 . 1 . for the exact registration of accelerations or vibrations  a (t) and the acceleration force A, to which the operator is exposed, is at least an acceleration sensor  18  arranged on a handhold  16  of the hand-held working tool. As illustrated in  FIG. 7   a , controls  32 , a data reproduction unit  31 . 1  such as an alphanumeric display and a visual and acoustic signal  33 . 1  and  33 . 2  are arranged on the hand-held tool  10 . 1 , the function of which is described in  FIGS. 1–6   a.    
   As illustrated in the block diagram of  FIG. 7   b , the alternative evaluation and storage mechanism  20  shows a storage unit  25  that contains numerous storage sections  26  in comparison to mechanism illustrated in  FIG. 1   b . Additionally, this sensing device includes an interface  110  for data output such as a data reproduction unit  31 . 1  ( FIG. 7   a ) in addition to the interface for data communication  30  with the antenna  34 . The data reproduction unit  31 . 1  and signal elements  33  respond directly to the evaluation and storage mechanism  20 . An operator, who has been identified according to a means of input  27 , such as a magnetic stripe card on the data reading device  28  of the hand-held tool  10 . 1 , can extract the conveyed acceleration force from accelerations and vibrations from the data reproduction unit  31 . 1 . Surpassing this maximum, permitted daily acceleration force will be shown by a signal  33  in the form of an acoustic or visual signal. The descriptions in  FIGS. 1   a ,  1   b  and  5  can be viewed to gain additional information concerning reference numbers not explicitly explained. 
   Measuring data from a hand-held working tool  10 ,  10 . 1  are read via the interface, as illustrated in  FIG. 8 , and then directly transmitted to the data reproduction unit  131  on the interface  110 , as well as to the port  135  connected to a computer  140  such as a PC, on which the data are evaluated using the appropriate software in view of the hand-held working tool  10 ,  10 . 1  ( FIG. 1   a  and  FIG. 7   a ) previously carried out settings n, working hours Σ|T|, acceleration values a(t), acceleration force A and wear parameter V etc. 
   It should be noted, that the interface illustrated in  FIG. 8  can include an appropriate assembly, as illustrated in  FIGS. 3  and/or  5 . Thus, the previous description refers to these Figs. 
   If the hand-held tool  10  is shown as the first embodiment in the form of a setting device, then it is advantageous to use a pressure sensor  19 . 1  as discriminator  19  (see  FIG. 9 ). This pressure sensor is arranged on a setting device such that the connection nozzle  19 . 2  protrudes into a conducting space  12 . 1  for combustion gas in the setting device. When a setting process on the setting device is triggered, then the expanding gas-or the combustion gas flow into this space  12 . 1  whereby the compression wave over the connection nozzle  19 . 2  is sensed by a pressure absorber  19 . 3  with a semi-conductor pressure sensor  19 . 4 . The pressure pick-off  19 . 3  is arranged on part of the housing  19 . 7  of the setting device cushioned from vibrations using a spring element  19 . 6  and cushion tube  19 . 5 . The pressure sensor  19 . 1  is then connected with the evaluation and storage mechanism via electrical lines  19 . 8 . 
   The connection nozzle  19 . 2  can also be connected to part of the device via a tube, in which the ignition of the propellant creates a gas compression wave (not illustrated here), instead of directly protruding into a space  12 . 1 . 
   In the diagram in  FIG. 10 , the amounts of the acceleration values  a (t) of two setting processes (n=2) are plotted as frequency-valued acceleration or oscillation values a hv (t) against the time t. At the point in time t 0  to the sensing device or the microprocessor of the hand-held working tool and/or the interface are awakened. 
   The acceleration values a hv (t) of a setting lie within a time period T.