Fastener tool

Abstract

A tool including a fastener rotating output member and mechanism for indicating if a fastener rotated by said output member has been tightened to a prescribed torque and/or for providing an indication of the length of time for which the fastener was tightened.

What is claimed and desired to be secured by Letters Patent is: 
     
       1. A tool for tightening fasteners comprising: an output member adapted to have a fastener engaging member attached thereto; a motor; means drive-connecting said motor to said output member; means for supplying operating energy to the motor; torque responsive means operable as the fastener being tightened reaches a selected torque to concomitantly produce a signal to indicate that the fastener has been tightened to the selected torque and to interrupt the flow of operating energy to the motor; and means activatable by the signal generated by the signal generating means to provide on or in the proximity of the fastener which has been tightened a visual indication of the reaching of the selected torque by the fastener. 
     
     
       2. A tool for tightening fasteners comprising: a housing; a fastener rotating output member rotatably supported from said housing; means in said housing for rotating said output member; and torque responsive means in said housing which is operable when the fastener being tightened has reached a selected torque to produce an electrical signal to indicate that the fastener was tightened to the selected torque, said signal generating means comprising a switch and means for actuating said switch when said selected torque is reached and the means for actuating said switch comprising an actuator movable toward and away from said switch, means biasing said actuator away from said switch, passages through which an operating fluid can flow to said actuator to move it toward said switch against the force exerted by said biasing means and thereby actuate said switch, and means for so controlling the flow of fluid through said passages to said switch actuator that the actuator is displaced to actuate the switch when said selected torque is reached. 
     
     
       3. A tool for tightening fasteners comprising: a fastener rotating output member; means for rotating said output member; and means operable when the fastener being tightened has reached a selected torque to produce one signal to indicate that the fastener has been tightened to the selected torque and a second signal indicative of the length of time for which the output member was rotated, said second signal thereby providing a differentiation between properly and improperly tightened fasteners. 
     
     
       4. A tool for tightening fasteners comprising: a fastener rotating output member; means for rotating said output member; torque responsive means operable when the fastener being tightened has reached a selected torque to terminate the rotation of the output member and prevent further tightening of the fastener; and means operable to produce a signal indicative of the length of time for which the output member was rotated, said signal thereby providing a differentiation between properly and improperly tightened fasteners. 
     
     
       5. The tool of claim 4, wherein the signal producing means further includes means for producing a second signal when said fastener reaches the selected torque which will provide an indication that the fastener has been tightened to the selected torque. 
     
     
       6. The tool of claim 4, wherein the means for rotating the fastener includes a motor which is energizable to rotate the output member and de-energizable to stop the rotation of said member and wherein said signal generating means comprises a timer means; means for actuating said timer means concurrently with the energization of said motor; and means for terminating the timing action of said timer means concurrently with the deenergization of said motor. 
     
     
       7. The tool of claim 6, wherein said timer means is electrically operated; wherein said tool further comprises circuit means for connecting said timer means across an electrical power source; wherein the means for actuating said timer means comprises a first switch and means for so actuating said first switch as to complete the continuity of said circuit means when said motor is energized; and wherein the means for terminating the timing action of the timer means comprises a second switch and means for so actuating said switch when said selected torque is reached as to interrupt the continuity of said circuit means. 
     
     
       8. The tool of claim 7, wherein said first and second switches are magnetically actuatable; wherein said signal generating means further comprises first and second magnetic switch actuators mounted in said tool for movement toward and away from said first and second switches, respectively, means biasing said actuators away from said switches, and passages through which an operating fluid can flow to said actuators to move them toward said switches against the forces exerted by said biasing means and thereby actuate said switches; and means for so controlling the flow of fluid through said passages to said switch actuators that the first actuator is displaced to actuate the first switch when the motor is energized and the second actuator is displaced to actuate the second switch when the motor is deenergized. 
     
     
       9. The tool of claim 8, wherein said motor is a pneumatic motor and wherein the means for controlling the flow of operating fluid comprises a first valve which is manually actuatable to allow operating fluid to flow to and energize said motor and to flow to and displace said first switch actuator in the switch actuating direction and a second valve automatically operable when the selected torque is reached to terminate the flow of operating fluid to and de-energize said motor and to so effect the flow of fluid to said second actuator as to displace said second actuator in the switch actuating direction. 
     
     
       10. The tool of claim 9, together with means including said first valve which is manually actuatable following the actuation of at least one of said switches to so alter the flow of fluid to the actuator associated with each actuated switch as to permit the associated biasing means to displace the actuator away from and effect the deactuation of the switch. 
     
     
       11. The tool of claim 10, together with means for resetting said second valve. 
     
     
       12. The tool of claim 11, together with means from which it can be ascertained if said second switch means has been actuated prior to the actuation of the resetting means, whereby said signal generating means further provides a signal indicating whether the fastener was tightened to the selected torque. 
     
     
       13. A tool for tightening fasteners comprising: a housing, a fastener rotating output member rotatably supported from said housing; a pneumatic motor in said housing; means drive-connecting said motor to said output member; means for supplying operating fluid to said motor; means for generating a signal; and means for both shutting off the supply of fluid to the motor and actuating the signal generating means when a fastener being tightened has been tightened to a selected torque, said signal generating means comprising means providing a path through which the operating fluid can flow to generate a pneumatic signal and a fluid actuatable valve means movable between first and second positions in which it respectively interrupts and permits the flow of fluid through said path. 
     
     
       14. The tool of claim 13, together with means providing a flow passage through which operating fluid can flow to said motor and to said fluid actuatable valve and means providing a valve seat in said passage and wherein the means for actuating the signal generating means comprises a valve member disposed in said passage and movable toward and away from said valve seat to control the flow of operating fluid through said passage; a valve stem means supporting said valve member in said passage; an actuator; means biasing said actuator to a position in which said actuator so engages said valve stem means as to hold the valve member away from the valve seat; and means operable as the fastener is tightened to the selected torque to move said actuator out of engagement with said valve stem means and thereby free said valve member for movement toward said seat. 
     
     
       15. The power-operated tool of claim 14, together with a wall means surrounding said valve member and cooperating with said member to restrict the flow of operating fluid through said passage, whereby there is a pressure drop across said valve member which generates a force for moving the valve member toward the valve seat in the absence of a restraint on the valve member. 
     
     
       16. The tool of claim 13, wherein said operating fluid supply means comprises a first valve which is manually displaceable to an open position to allow operating fluid to flow into the interior of the tool housing; and wherein the means for actuating the signal generating means and shutting off the flow of operating fluid to the motor comprises a second, normally open valve movable to a closed position when said selected torque is reached, said tool further including means through which said fluid can so flow as to maintain said fluid actuatable valve means in said first position when said first and second valves are open and as to displace said valve means to said second position when the selected torque is reached. 
     
     
       17. The tool of claim 16, together with means operable following the displacement of said fluid actuatable valve means to said second position and the subsequent closing of the first valve to return said fluid actuatable valve means to its first position and said second valve to its open position. 
     
     
       18. A tool for tightening fasteners comprising: a housing; a fastener rotating output member rotatably supported from said housing; a pneumatic motor in said housing; means drive-connecting said motor to said output member which comprises means operable beginning with the exertion of a rotation resisting force by the fastener being tightened to brake and thereby reduce the speed and absorb the kinetic energy of the rotating drive component(s) of the tool and thereby keep said energy from being applied to and overtightening the fastener engaged by the output member; means for supplying operating fluid to said motor; means for generating a signal, and means for both shutting off the supply of air to the motor and actuating the signal generating means when a fastener being tightened has been tightened to a selected torque. 
     
     
       19. A tool for tightening fasteners comprising: a housing, a fastener rotating output member rotatably supported from said housing; a pneumatic motor in said housing; means drive-connecting said motor to said output member; means for supplying operating fluid to said motor; means for generating a signal; and means for both shutting off the supply of air to the motor and actuating the signal generating means when a fastener being tightened has reached a selected torque, said signal generating means comprising flow means through which the operating fluid can flow to generate a pneumatic signal, a fluid actuatable valve means movable between a first position in which said valve means permits flow of the pneumatic fluid to said motor and inhibits the flow of said fluid to said flow means and a second position in which said valve means terminates the flow of the pneumatic fluid to the motor and removes the inhibition on the flow of the fluid through the flow means, and means for effecting the movement of the valve means from the first to the second of the positions thereof when said selected torque is reached. 
     
     
       20. The tool of claim 19, together with selectively operable means which, when operated, will result in the interruption of the flow of pneumatic fluid through said flow means. 
     
     
       21. A tool for tightening fasteners comprising: a housing; a fastener rotating output means rotatably supported from said housing; a pneumatically activatable marking means for providing on or in the proximity of the fastener being tightened a visual indication of the reaching of a selected torque by the fastener, said marking means being housed at least in part in said rotatably supported output means; a pneumatic motor in said housing; means drive-connecting said motor to said output means; means for supplying operating fluid to said motor, flow means through which operating fluid can flow to activate said marking means; valve means operable when actuated to both shut off the supply of operating fluid to the motor and effect a flow of fluid through said flow means; and means for automatically actuating said valve means when the fastener being tightened has reached the selected torque. 
     
     
       22. A tool of claim 21, wherein said marking means comprises a member which, when displaced, will result in the producing of said visual signal, means including a slidably mounted piston for displacing said member, and means providing fluid communication between said flow means and said piston so that said operating fluid will operate upon said piston and cause the piston to displace said member and activate said marking means. .Iadd. 
     
     
       23.  A tool for tightening fasteners comprising: a fastener rotating output member; means for rotating said output member; means operable to terminate the rotation of the output member when a fastener being tightened has been tightened to a selected torque; and means operable concomitantly with the rotation of the output member for measuring the length of time for which said member is rotated in tightening the fastener to the selected torque and for thereby providing a signal indicative of whether the output member has been rotated for a length of time which will result in the fastener being properly tightened to make a satisfactory joint. .Iaddend. .Iadd.24. A tool for tightening fasteners comprising: a fastener rotating output member; means for rotating said output member; means operable to terminate the rotation of the output member when a fastener being tightened has been tightened to a selected torque; and means which is operable when the fastener has been tightened to said torque for providing an indication of whether the output member has been rotated for a length of time which will result in the fastener being properly tightened to make a satisfactory joint. .Iaddend. .Iadd.25. The tool of claim 24 wherein said signal generating means includes a timing circuit means for generating an output signal which will have a selected minimum voltage if the fastener is tightened for the length of time necessary to insure proper tightening. .Iaddend. .Iadd.26. The tool of claim 25 together with a first switch means operable from one to the other of two states concomitantly with the initiation of a fastener tightening operation to initiate the timing sequence of the timing circuit means and a second switch means operable from one of the other of two states concomitantly with the tightening of the fastener to a selected torque to terminate the timing sequence of the timing circuit means. .Iaddend. .Iadd.27. The tool of claim 25 wherein the timing circuit means includes a series connected resistor and capacitor and a switch operable from one to the other of two states to connect said capacitor to a source of electrical energy concurrently with the initiation of a fastener tightening operation. .Iaddend.