Torque control apparatus

Abstract

A torque-applying apparatus having one or more torque motors each arranged for forcibly threading a first threaded member into tightened association with a corresponding second threaded member. A control is provided for controlling the operation of each torque motor to firstly seat the first threaded member relative to the second threaded member by a rapid threading operation at a low torque. When the seated condition of all of the threaded members is sensed, the control automatically operates each torque motor to slowly apply gradually increasing higher torque to provide a preselected maximum-torque, tightened condition of the threaded members.

We claim: 
     
       1. In a torque-applying apparatus having torque means for forcibly threading a first threaded member into tightened association with a second threaded member, control means for controlling the operation of said torque means comprising: seating means for causing said torque means to develop a force in threading the first member into a seated association with said second threaded member;   means for sensing the amount of torque applied between said threaded members; and   setting means responsive to said sensing means for causing said torque means to develop a gradually increasing higher .[.force.]. .Iadd.torque .Iaddend.for applying a preselected maximum torque between said seated threaded members to provide a preselected tightened condition of said threaded members.   
     
     
       2. The torque-applying control apparatus of claim 1 wherein said means for causing said torque means to develop a higher .[.force.]. .Iadd.torque .Iaddend.includes means for slowly increasing the applied torque whereby the applied torque may be accurately limited to said preselected maximum torque when sensed by said sensing means. 
     
     
       3. The torque-applying control apparatus of claim 1 wherein said torque means comprises fluid pressure means and said means for causing said torque means to develop a higher .[.force.]. .Iadd.torque .Iaddend.includes restrictor means for slowly increasing the applied torque whereby the applied torque may be accurately limited to said preselected maximum torque when sensed by said sensing means. 
     
     
       4. The torque-applying control apparatus of claim 1 wherein said seating means comprises means for causing said first member to be threaded at high speed at low torque and said setting means comprises means for causing said torque .[.force.]. to be slowly increased to said preselected maximum. 
     
     
       5. The torque-applying control apparatus of claim 1 further including means for discontinuing application of torque between said threaded members substantially immediately upon reaching said maximum torque. 
     
     
       6. The torque-applying control apparatus of claim 1 further including means for indicating the amount of torque applied between said threaded members. 
     
     
       7. The torque-applying control apparatus of claim 1 wherein said torque means comprises rotary pneumatic motor means. 
     
     
       8. The torque-applying control apparatus of claim 1 wherein said torque means comprises rotary pneumatic motor means for rotating said first threaded members and said sensing means comprises a torquemeter interconnected between said motor means and said second threaded member. 
     
     
       9. The torque-applying control apparatus of claim 1 including indicating means for providing a signal whenever the torque applied between the threaded members is less than a preselected low torque. 
     
     
       10. The torque-applying control apparatus of claim 1 including indicating means for providing a signal whenever the torque applied between the threaded member is greater than a preselected high torque. 
     
     
       11. The torque-applying control apparatus of claim 1 including indicating means for providing a signal whenever the torque applied between the threaded members reaches the preselected maximum torque. 
     
     
       12. In a torque-applying apparatus having torque means for forcibly threading a first threaded member into tightened association with a second threaded member, control means for controlling the operation of said torque means comprising: means for sensing the amount of torque applied between said threaded members;   setting means responsive to said sensing means for causing said torque means to develop a gradually increasing .[.force.]. .Iadd.torque .Iaddend.for applying a preselected maximum torque between said seated threaded members to provide a preselected tightened condition of said threaded members; and   means for causing said torque means to apply a pulse of high torque momentarily between said threaded members at the initiation of application of the low seating torque therebetween by said seating means to positively initiate the threading operation.   
     
     
       13. The torque-applying control apparatus of claim 12 wherein said pulse applying means comprises means for utilizing energy stored in the torque means at the conclusion of a prior torque-applying threading operation. 
     
     
       14. The torque-applying control apparatus of claim 12 wherein said pulse applying means comprises means for momentarily operating said setting means for developing said high torque. 
     
     
       15. The torque-applying control apparatus of claim 12 wherein said torque means comprises means operated by fluid pressure and said pulse applying means comprises means for momentarily applying high fluid pressure to said torque means. 
     
     
       16. In a torque-applying apparatus having torque means for forcibly threading a plurality of first threaded members into tightened association with a corresponding plurality of second threaded members, control means for controlling the operation of said torque means comprising: seating means for causing said torque means to develop a .[.force.]. .Iadd.torque .Iaddend.in threading the first members into seated association with said second members;   means for sensing the amount of torque applied between said threaded members;   setting means responsive to said .[.sening.]. .Iadd.sensing .Iaddend.means for causing said torque means to develop a gradually increasing higher .[.force.]. .Iadd.torque .Iaddend.for applying a preselected maximum torque between said seated threaded members to provide a preselected tightened condition of each of said threaded members; and   means for preventing operation of said setting means until each of said first threaded members is in seated association with its associated second threaded member.   
     
     
       17. The torque-applying control apparatus of claim 16 wherein said torque means comprises means operated by fluid pressure and means for applying substantially the same pressure to torque each pair of associated first and second threaded members. 
     
     
       18. The torque-applying control apparatus of claim 16 werein said torque means comprises means operated by fluid pressure and said .[.seating.]. .Iadd.setting .Iaddend.means includes a flow restrictor .[.in the fluid pressure means.]. for controlling the buildup of torque .[.pressure.]. applied between said threaded members. 
     
     
       19. The torque-applying control apparatus of claim 16 wherein said torque means comprises a plurality of fluid operated means and .Iadd.said apparatus includes .Iaddend.a plurality of pressurized-fluid supply controls associated one each with said fluid operated means. 
     
     
       20. The torque-applying control apparatus of claim 19 wherein a common fluid pressure source is provided with each of said supply controls being connected thereto. 
     
     
       21. The torque-applying control apparatus of claim 19 wherein each of said supply controls includes adjustable means for slowly increasing .Iadd.the fluid pressure provided to the fluid operated means for correspondingly gradually increasing .Iaddend.the applied torque. 
     
     
       22. In an apparatus for applying torque to a first threaded member to sequentially firstly seat and then set said member relative to a second threaded member with a preselected maximum torque, a fluid operated torque motor means, means for sensing torque applied between said first and second members, means for causing torque to be delivered from said torque motor means to seat said first member relative to said second member by a relatively low torque, high speed threading of the first member to the seated condition, second means responsive to the sensing means sensing the seated condition for causing the torque delivered from said torque motor means to slowly increase to set said seated threaded member, and means responsive to the sensing of the preselected maximum torque by said sensing means to terminate torque delivery from the torque motor means with the first member set accurately at said preselected torque. 
     
     
       23. The torque applying apparatus of claim 22 wherein said first means comprises solenoid operated apparatus associated with said torque motor means for causing the torque delivery therefrom to be said low torque delivery. 
     
     
       24. The torque applying apparatus of claim 22 wherein said second means comprises solenoid operated apparatus associated with said torque motor means for causing the torque delivery therefrom to be said slowly increasing torque delivery. 
     
     
       25. In an apparatus for applying torque to a first threaded member to sequentially firstly seat and then set said member relative to a second threaded member with a preselected maximum torque, torque means, means for causing said torque means to thread the first member to a seated condition on the second member, sensing means sensing said seated condition, and mechanism associated with said torque means for causing said torque means to provide a low kinetic energy gradually increased torque delivery between said first and second members to tighten said seated members to a preselected-torque seated condition, and means for terminating the torque delivery substantially immediately upon reaching said seated condition. 
     
     
       26. Torque applying apparatus of claim 25 wherein said mechanism includes electrically actuated control means and said sensing means provides an electrical signal suitable to actuate said mechanism control means. .Iadd. 27. The torque-applying control apparatus of Claim 1 wherein said torque means includes a torque motor and said setting means includes means for slowly building up the input to the torque motor to provide the gradually increasing torque between said seated threaded members. .Iaddend..Iadd. 28. The torque-applying control apparatus of Claim 12 wherein said torque means includes a torque motor and said setting means includes means for slowly building up the input to the torque motor to provide the gradually increasing torque between said seated threaded members. .Iaddend..Iadd. 29. The torque-applying control apparatus of Claim 16 wherein said torque means includes a torque motor and said setting means includes means for slowly building up the input to the torque motor to provide the gradually increasing torque between said seated threaded members. .Iaddend..Iadd. 30. The torque-applying control apparatus of Claim 25 wherein said torque means includes a torque motor and said setting means includes means for slowly building up the input to the torque motor to provide the gradually increasing torque between said seated threaded members. .Iaddend.