Patent Publication Number: US-8978521-B2

Title: Torque adapter with ratchet reverse feature

Description:
RESEARCH OR DEVELOPMENT 
     This invention was made with government support under Contract No. F33657-99-D-2051 awarded by the United States Air Force. The Government has certain rights in this invention. 
    
    
     BACKGROUND OF THE INVENTION 
     This application relates to a work tool for transmitting torque, wherein a drive ratchet is provided with a direction-reversing feature. 
     Various types of tool are known for transmitting torque between an input and an output. One known type of tool is utilized to assemble tie rods in gas turbine engines. The tool has an input which receives a drive wrench, and receives rotation centered along a first axis. By turning this tool, a linkage is driven through an angular range, such that rotation is transmitted axially to an underside of the tool, and then back through a ratchet output. The specifications for assembling tie rods require that there be serially tightening and loosening of nuts and/or bolts. 
     Ratchets are provided with a direction-reversing button that can be actuated to reverse the direction that the nut will be driven as the ratchet turns. However, in some work applications, the button is not easily accessible, and an assembly person must repeatedly remove the tool, actuate the button, and then re-install the tool. 
     SUMMARY OF THE INVENTION 
     In a featured embodiment, a torque transmittal tool has an input socket to receive a drive input from a drive tool. The input socket causes a first link to rotate through a range of rotation upon rotation of the input socket. The first link is fixed to rotate with an extension link, which is fixed to rotate with an output link. The output link includes an output ratchet for transmitting rotation, and has a torque reversal button that may be actuated to change a direction of rotation of the output ratchet. An actuator for the output link has an unactuated position where a contact surface is spaced away from the torque reversal button, and an actuated position at which the contact surface actuates the torque reversal button. 
     In another embodiment according to the previous embodiment, the actuator is a fork having arms extending along a side of the output link. The output link is biased outwardly relative to the fork. The fork is moveable relative to the output link such that one of the arms is the contact surface for actuating the torque reversal button. 
     In another embodiment according to any of the previous embodiments, a guide on at least one side of the output link is guided in a slot on at least one of the arms in the fork. 
     In another embodiment according to any of the previous embodiments, there are guides on both of two sides of the output link, and received in a slot in each of the arms. 
     In another embodiment according to any of the previous embodiments, a spring biases the output link outwardly of the fork. 
     In another embodiment according to any of the previous embodiments, the spring biases a pin which is in contact with the output link. 
     In another embodiment according to any of the previous embodiments, the fork has an extending portion extending away from the arms in a direction away from the output socket such that the extending portion is easily accessible during a work application. 
     In another embodiment according to any of the previous embodiments, a spring biases the output link to the unactuated position. 
     In another embodiment according to any of the previous embodiments, the spring biases a pin which is in contact with the output link. 
     In another embodiment according to any of the previous embodiments, the actuator has an extending portion extending away from the arms in a direction away from the output socket such that the extending portion is easily accessible during a work application. 
     In another featured embodiment, a method of assembling includes the steps of rotating an input socket with a drive tool, and the input socket causing a first link to rotate through a range of rotation. The first link is fixed to rotate with an extension, which is fixed to rotate with an output link. The output link rotates an output ratchet on a member to be tightened or loosened. The output ratchet has a torque reversal button that may be actuated to change the direction of rotation of the output ratchet. An actuator is moved for the output link from an unactuated position where a contact surface is spaced away from the torque reversal button, to an actuated position at which the contact surface actuates the torque reversal button. 
     In another embodiment according to the previous embodiment, the actuator is a fork having arms extending along a side of the output link, with the output link biased outwardly relative to the fork. The fork is moveable relative to the output link such that one of the arms is the contact surface for actuating the torque reversal button. 
     In another embodiment according to any of the previous embodiments, a guide on at least one side of the output link is guided in a slot on at least one of the arms in the fork. 
     In another embodiment according to any of the previous embodiments, there are guides on both of two sides of the output link, and received in a slot in each of the arms. 
     In another embodiment according to any of the previous embodiments, a spring biases the output link outwardly of the fork. 
     In another embodiment according to any of the previous embodiments, the spring biases a pin which is in contact with the output link. 
     In another embodiment according to any of the previous embodiments, the fork has an extending portion extending away from the arms in a direction away from the output socket such that the extending portion is easily accessible during a work application. 
     In another embodiment according to any of the previous embodiments, a spring biases the output link to the unactuated position. 
     In another embodiment according to any of the previous embodiments, the spring biases a pin that is in contact with the output link. 
     In another embodiment according to any of the previous embodiments, the actuator has an extending portion extending away from the arms in a direction away from the output socket such that the extending portion is easily accessible during a work application. 
     These and other features may be best understood from the following drawings and specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a torque transmitting tool. 
         FIG. 2  shows a work application for the  FIG. 1  tool. 
         FIG. 3A  shows an output end of the tool. 
         FIG. 3B  shows another view of the output end. 
         FIG. 3C  shows an actuated position of the output end. 
     
    
    
     DETAILED DESCRIPTION 
     A tool  20  is illustrated in  FIG. 1  having a drive input socket  22  with a square  24  to receive a drive input. A socket drive  25  operates as known to receive rotation from input  22  and cause a first link  26  to rotate through an angular range. Link  26  is connected to an extension link  28 , which is in turn fixed to an output link  30 . Link  30  drives an output ratchet  32  which may be received on a bolt or nut to be tightened or loosened. 
     A fork  33  includes side arms  34  with slots  36  receiving guide members  38  from the output link  30 . The fork is an actuator as will be disclosed. A pin  40  biases the output link  30  to the position illustrated in  FIG. 1 . 
     A button  140  operates as known to allow the reversal of direction of the output ratchet  32  when rotation is received from the linkage  26 / 28 / 30 . That is, when the first link  26  rotates extension link  28  to rotate output link  32  in one direction, the output ratchet  32  can be driven to rotate in either direction. A connection  141  causes this reversal whenever button  140  is actuated. Connection  141  may be as known. 
     As shown in  FIG. 2 , the extension link  28  allows input from a tool  42  to cause socket  25  to rotate linkage  26 / 28 / 30  through an angular range (see angle A in  FIG. 3A ). 
     By doing this, the input at  22  translates to a colinear output at output ratchet  32 , on a bolt  44 . The purpose of the three-bar linkage provided by links  26 / 28 / 30  is to move beyond a portion  46  of the work piece that is being assembled. In the illustrated embodiment, this may all be part of a gas turbine engine. 
     The specifications for assembling the work piece  46  require repeated tightening and then loosening of associated bolts ( 44 ) or nuts. It would be most efficient if an assembler could simply actuate the reversal through the direction-reversing button  140 . However, it is not accessible due to the remainder of the work piece  46 . 
     Thus, in the prior art, an assembler has been required to repeatedly remove the tool, actuate the button, and then reassemble the tool. The use of the fork  33  in combination with the link  30  overcomes this limitation in the prior art. 
     As shown in  FIG. 3A , a spring  41  biases pin  40  and output link  30  outwardly of a channel  200  in fork  33 . The output link  30  is shown mounted on one of several heads of bolts  44  that are to be tightened and then loosened. The torque reversal button  140  is shown to be outward and beyond the end of the arms  34 . However, button  140  would not be accessible to an assembler. 
     As shown in  FIG. 3B , guides  38  are received in slots  36 , such that the output link  30  can move under the bias of spring  41  and pin  40 . 
     As shown in  FIG. 3C , the fork  33  has now been forced against the spring force  41  such that the arms  34  now move towards the button  140  and one contacts the direction-reversing button  140 . A contact surface  139  actually contacts the button  140 . With this contact, the direction that the ratchet  32  will turn has been changed. The assembler need not disassemble the tool, but merely apply a force F, such as at the extending end portion end  39  of the fork  33 . Portion  39  is easily accessible during assembly. 
     In the non-actuated position shown in  FIG. 3B , the fork  33 , which is an actuator, has contact surface  139  spaced from button  140 . Contact surface  139  is in contact with the button  140  in the actuated position of  FIG. 3C . 
     Once the button  140  has been actuated, the force F can be released, the spring  41  and pin  40  will bias the arms  34  back away from the button  140 , and back to the FIG.  3 A/ 3 B position, and assembly can continue, with the ratchet  32  now turning the bolt head  44  in the opposed direction. 
     With the disclosed invention, the complexity of the assembly process is greatly reduced, as is the time required. 
     Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.