Abstract:
A torque sensing and control device for tools comprises: a torque sensing and transmitting adapter fabricated with rib structure and mounted on or built in a fastening tool; at least a torque sensor secured on at least a rib evenly spaced and formed on the adapter and operatively sensing a torque signal when applying a torque on a work or object when rotatably operating the fastening tool; and a digital display control module operatively receiving the torque signal, displaying a torque data and generating an audio or visual warning signal for reminding the user for stopping operation of the fastening tool, or for switching off power or air supply to the fastening tool, and or actuating a delay control to restart a next fastening operation in a pre-determined time interval.

Description:
BACKGROUND OF THE INVENTION 
   A conventional tool for fastening screws or bolts is not provided means for knowing an applying torque whether it is enough or not for tightly fastening the screws or bolts on a work piece. If the torque is not enough to fasten the screws or bolts, the work piece may be easily loosened due to vibration, thereby easily causing danger. If it is too tight, the screws or bolts may be destructed as subjected to undurable torque force (such as over the yield point thereof) to thereby damage the work piece instantly. 
   In order to sense a torque for a rotating member, U.S. Pat. No. 7,307,517 disclosed a wireless torque sensor which is located on the rotating member to generate signals indicative of a torque associated with the rotating member to sense the torque. Such a prior art comprises a torque sensing element configured upon a substrate in association with an antenna for sending and receiving wireless signals and adhered on the rotating member. However, when subjected to high-speed rotation of the rotating member, a great centrifugal force may easily release torque sensor from the rotating member, or under violent vibration especially when the bonding adhesive is aged and delaminated, thereby losing the sensing effect of the torque sensor. 
   The present inventor has found the drawbacks of the prior arts and invented the present anti-vibration torque sensing and control device for tools. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is to provide a torque sensing and control device for tools comprising: a torque sensing and transmitting adapter mounted on or built in a fastening (or torque) tool; at least a torque sensor secured on at least a rib formed on the adapter and operatively sensing a torque signal when applying a torque on a work or object when the fastening tool is rotated; and a digital display control module operatively receiving the torque signal, displaying a torque data and generating an audio or visual warning signal for reminding the user for stopping operation of the fastening tool, or for switching off power or air supply to the fastening tool, and or actuating a delay control to delay a fastening operation in a pre-determined time interval until the next fastening operation. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a first preferred embodiment of the present invention. 
       FIG. 2  is an exploded view of the present invention as shown in  FIG. 1 . 
       FIG. 3  is an expended view showing the torque sensing and transmitting adapter of the present invention. 
       FIG. 4  shows another preferred torque sensing and transmitting adapter of the present invention. 
       FIG. 5  shows a control process flow chart in accordance with the present invention. 
       FIG. 6  shows a second preferred embodiment of the present invention. 
       FIG. 7  is an exploded view showing the embodiment as shown in  FIG. 6 . 
       FIG. 8  shows a third preferred embodiment of the present invention. 
       FIG. 9  is an exploded view of the embodiment as shown in  FIG. 8 . 
       FIG. 10  shows a fourth preferred embodiment of the present invention. 
       FIG. 11  is an exploded view of the embodiment as shown in  FIG. 10 . 
   

   DETAILED DESCRIPTION 
   The present invention comprises: a torque sensing and transmitting adapter  1  mounted on or built in a fastening (or torque) tool  2 ; and a digital display control module  3 . The fastening tool  2  may be a pneumatic tool, an electric-operated tool or a hand-operated tool. The digital display control module  3  may be built in the tool  2 , or may be externally connected to the tool  2 , not limited in the present invention. The torque signal as sensed by the torque sensing and transmitting adapter  1  may be transmitted to the digital display control module  3  either by wire transmission or by wireless transmission. 
   As shown in  FIGS. 1˜5 , the present invention comprises: a torque sensing and transmitting adapter  1  secured to or mounted on a pneumatic fastening tool  2 , and a digital display control module  3 . 
   The digital display control module  3  may be connected with a pneumatic power source  31  such as a compressed air source, and also connected to the fastening or torque tool  2  by a conduit or an air hose  32  as shown in  FIG. 2 , whereby when the torque as sensed reaches a pre-determined value, the control module  3  may shut down a valve (not shown) provided on the conduit  32  to stop the air supply. 
   The torque sensing and transmitting adapter  1  includes: a metallic body  11 , a plurality of ribs  12  formed on the metallic body  11 , a plurality of cavities  13  recessed in the metallic body  11  to define each rib  12  in between two neighboring cavities  13 , at least a torque sensor  14  having a plurality of strain gauges formed on the ribs  12 , and a plurality of anti-vibration means  15  such as made of shock-absorbing elastomers inserted, plugged, filled, bonded or molded into the cavities  13  for firmly fastening, holding, bonding or molding the torque sensor  14  including the strain gauges and their relevant electronic circuit elements in the cavities  13  to prevent from separation of the torque sensor  14  from the metallic body  11  due to adhesive aging or delamination, and serious violent vibration during tool operation. 
   The materials for making the anti-vibration means  15  should be selected from that will not retard or weaken the transmission of torque signals by the torque sensors  14 . 
   A jacket member  16  may be provided for encasing the adapter  1  having the anti-vibration means  15  filled or inserted or molded in the cavities  13  ( FIG. 3 ) for protecting the adapter  1  from being broken or damaged . 
   The body  11  of the adapter  1  is formed a recessed hole  111  at the rear adapter portion for coupling a driving shaft  20  of the tool  2 , and an output shaft  112  (or a female connector) formed at the front portion of the adapter for connecting a socket  21  which is coupled to a driver bit  22  or a bolt  23  (or nut) as shown in  FIG. 2 . 
   The torque sensor  14  includes: at least one strain gauge secured on one rib  12  by adhesive or by other joining methods for sensing a torque signal corresponding to a deformation of the rib when subjected to a torque as effected by a rotating motor shaft  20  of the fastening tool  2 ; an amplifier for amplifying the torque signal as sensed by the strain gauges; a logic algorithm for logically computing a strain value of the toque signal for obtaining a corresponding torque value; an input means for inputting a relationship between the torque value and the strain value into a memory module (after assembly and upon calibration of the sensor); and a transmitter for transmitting the torque value to the digital display control module  3  by wire transmission or by wireless transmission; and wherein the memory module is provided for memorizing a relationship between the torque value and the strain value. 
   The torque sensor  14  further includes a power source supply  14   a  for powering the torque sensor  14 , including: a rechargeable battery, a replaceable battery, a utility power supply connected externally, or a power generating device built in the adapter  1 . 
   The number of the strain gauges and torque sensors of the present invention are not limited, and may be adjustably varied according to the precision requirement for measuring the torque. 
   The digital display control module  3  includes: a display for displaying a torque value as pre-set or as finally measured; a set of push buttons for pre-setting a desired torque value; a receiver for receiving an output torque signal as transmitted by the torque sensor  14  by wire transmission or by wireless transmission; and a logic control module for controlling an actuation of a power source or pneumatic (air) source, whereby upon a comparison of a torque value as transmitted and measured from the torque sensor  14  with a pre-set torque value in the digital display control module  3  until obtaining an equal torque value, the control module will produce an audio or visual warning signal to remind the user to stop a fastening operation of the fastening tool, or to shut off an air (or power) supply by switching off an air valve or a solenoid valve (by closing an air valve) to the fastening tool  2 , or to actuate/start a delay control to delay the fastening operation in a pre-determined time interval until the next fastening operation. 
   As shown in  FIG. 5 , a process flow chart is disclosed for showing the logic operation and control process flow in accordance with the present invention, in which the numerals in  FIG. 5  are explained and indicated as follows (Note: The left process steps indicate a calibration process, while the right process steps indicating the operation process): 
   A. Calibration Process ( 41 ): 
   
       
       
         
             410  . . . Starting the calibration; 
             411  . . . Driving the adapter  1  by the fastening tool  2 ; 
             412  . . . Strain produced on the strain gauge of the torque sensor; 
             413  . . . Logic operation by the logic algorithm to obtain strain value ε; 
             414  . . . Input the relationship between torque T and strain value ε; 
             415  . . . Calculating the torque T with the mathematic formula:
   T=Kε+C,   
wherein K, C is respectively a constant;
 
             416  . . . Memorizing the mathematic formula:
   T=Kε+C   
into a memory module; and
 
             417  . . . Ending the calibration.
 
B. Process Operation of the Adapter ( 42 ):
 
             420  . . . Starting the torque sensing and transmitting adapter  1 ; 
             421  . . . Actuating the adapter  1  by the fastening tool  2 ; 
             422  . . . Logic operation by the logic algorithm to obtain the strain value ε′; 
             423  . . . Finding a corresponding torque value T′ through a calibrated formula:
   T′=Kε′+C   
by using the memory module;
 
             424  . . . Displaying a torque value T′ by the control module; 
             425  . . . Comparing and determining T′=T″ by the control module; 
             426  . . . Producing warning signal, or switching off the power source, and or re-starting the power source in a pre-determined time interval; and 
             427  . . . Ending.
 
C. Input of the desired/pre-set torque value T″ ( 43 ):
 
             430  . . . Input the desired torque T″; and 
             431  . . . Control the digital display control module.
 
D. Delay Control ( 44 ):
 
         
       
     
  
   A delay control may be provided for switching off the fastening operation in a pre-set time interval when reaching the preset torque value. Afterwards, the fastening operation will be re-started, e.g., after the pre-set several seconds. 
   The present invention is superior to the prior arts with the following advantages:
     1. The strain gauges of the torque sensors  14  are firmly fastened or bonded by the anti-vibration means  15  to prevent from their releasing from the adapter  1  to increase the operation reliability and prolong the service life. This is because the strain gauge is mounted on the rib  12 , especially on a side wall of a cavity  13  contiguous to the rib  12 , and will be “integrally formed” together with the anti-vibration means  15  for resisting violent vibration.   2. The strain gauge is mounted on the rib to greatly increase its sensitivity for sensing a slight deformation when subjected to a rotational torque applying force.   3. Once the anti-vibration means or shock absorber  15  is filled, bonded or molded into the cavity  13 , the electronic elements and circuit of the torque sensor  14  will be integrally formed with the anti-vibration means or shock absorber  15  to “interlock” the sensor parts for increasing their resistance to the vibrational shock, thereby preventing damage of the present invention and preventing from any unexpected intermittent fastening operation of the tool  2 .   

   As shown in  FIGS. 6 and 7 , another preferred embodiment of the present invention discloses a torque sensing or transmitting adapter  1  which is built in the fastening tool  2 . By the way, the adapter  1  may be further protected by a shell  16   a,  which is made of materials causing no interference to the transmission of the torque signal as transmitted by the present invention. Then, the adapter  1  is connected to a pneumatic impact mechanism (or ram means)  20   a  which is further covered by a front cover  20   b.    
   As shown in  FIGS. 8 and 9 , an electric (rechargeable) fastening tool  2  is disclosed and is electrically driven by an electric power source  31  which may be a battery ( FIG. 9 ) and upon transmitting of a control signal through the wire  32  between the control module  3  and the power source  31  (or by wireless control), the fastener tool  2  may be switched on or off conveniently. Numeral  30  indicates a utility power source. 
   If the electric tool  2  is powered by an externally connected power source, a solenoid valve (not shown) may be provided in the wire  32  for switching off the external power supplied to the tool  2  by actuating such a solenoid valve. 
   In  FIGS. 10 and 11 , a hand-operated tool  2  is disclosed to be connected with the adapter  1  of the present invention, and be controlled by the control module  3 . 
   The present invention may be further modified without departing from the spirit and scope of the present invention. 
   The ribs  12  are preferably formed in the adapter  1  in an evenly-spaced arrangement for a dynamic balance during rotation of the tool shaft  20 .