Abstract:
An improved system for installing and removing bolts or nuts from flanged joints or the like which includes a primary wrench for engaging the head of the bolt and rotating the bolt during the high-torque phase of removal or installation; a low-torque motor engaged with the wrench for rotating the bolt during the low-torque phase of removal or installation; a source of hydraulic fluid for driving the low-torque motor during the low-torque phase, and driving the high-torque wrench during the high-torque phase; and valving means for instantly sensing the high-torque and low-torque phases, in order to drive the hydraulic wrench or the motor depending on the torque required.

Description:
This application is a continuation of U.S. Ser. No. 08/734,305, filed Oct. 21, 1996, now abandoned, which was a continuation of U.S. Ser. No. 08/600,469, filed Feb. 12, 1996, now abandoned which was a continuation of U.S. Ser. No. 08/261,430, filed Jun. 17, 1994, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field Of The Invention 
     The present invention relates to torquing systems. More particularly, the present invention relates to an improved torque wrench system which provides for the makeup and removal of threaded bolts with a single tool during both high torque and low torque phases of the makeup or removal process. 
     2. General Background 
     In the makeup or break down of large structures, such as, for example rig risers, the sections of the riser are flanged together with bolts threadedly engaged to flanges on the end of each section, and made up very tightly to complete the structure. Of course, there are numerous other types of structures which utilize this same system of makeup, utilizing very large bolts to flange together sections of the structure. 
     When this type of makeup system is utilized, there is usually required at least two tools in the makeup. First, a high speed, low torque motor or wrench is utilized to begin the threading of the bolt into the flange. However, as the bolt is tightened, it requires a very high amount of torque, in the neighborhood of 40 thousand ft. lbs. in order to complete the makeup. Therefore, a second tool, such as a hydraulic ratchet, is utilized, which imparts a very high torque to the bolt, and completes the makeup procedure. Of course, when the bolts must be removed, the high torque wrench would be utilized to commence the removal of the bolt, and then, to increase the speed of removal, a high speed low torque motor or the like would be engaged. This two step process is very time-consuming, and inefficient. However, up to now, this was the state of the art in the makeup and removal of such bolts from structures. 
     There were several patents found in the art which address the subject matter of torque applied to bolts, or the like, and these are referred to in the Prior Art statement submitted concurrently herewith. 
     SUMMARY OF THE PRESENT INVENTION: 
     The system of the present invention solves the shortcomings in the art in a simple and straightforward manner. What is provided is an improved system for installing and removing bolts from flanged joints or the like which includes a primary wrench for engaging the head of the bolt and rotating the bolt during the high-torque phase, a low-torque motor engaged with the wrench for rotating the bolt during the low-torque phase of removal or installation; a source of fluid for driving the low-torque motor during the low-torque phase, and driving the high-torque wrench during the high-torque phase; and valving means for sensing the high-torque and low-torque phases, in order to drive the hydraulic wrench or the motor depending on the torque required. 
     Therefore, it is a principal object of the present invention to provide a combination high-torque, low-torque system for installing or removing bolts or the like from structures; 
     It is a further object of the present invention to provide a system for removing bolts from flanged structures with a single combination tool which works under both low-torque or high-torque conditions, depending on the condition sensed by the system; 
     It is a further object of the present invention to provide a system for removing or installing bolts having a very low clearance and normally inaccessible to wrenches having both high speed low torque and low speed high torque capacities. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings, in which like parts are given like reference numerals, and wherein: 
     FIG. 1 illustrates a schematic of the improved system of the present invention in a resting state; 
     FIG. 2 illustrates a schematic of the improved system of the present invention in the low-torque operational phase of the system; 
     FIG. 3 illustrates a schematic of the improved system of the present invention in the high-torque operational phase of the system; 
     FIG. 4 illustrates a high-torque hydraulic wrench secured to a bolt head during use in the system of the present invention; and 
     FIG. 5 illustrates an exploded view of the hydraulic wrench adaptable to tighten or loosen bolts during operation in the system of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 through 5 illustrate the preferred embodiment of the present invention, with FIGS. 1 through 3 illustrating the system in schematic view by the numeral  10 . Before turning to the schematic views of the system, reference is made to FIG. 4 which illustrates the system engaged to a bolt head in installation or removal of the bolt. As illustrated system  10  comprises in combination a primary hydraulic wrench  12 , which is a hydraulic wrench adapted to tighten or loosen bolts or nuts in very high-torque situations (40,000 ft. lb range), and is of the type generally disclosed in U.S. Pat. No. 5,097,730, issued to Bernard et al, and incorporated herein by reference thereto. Generally, the wrench  12  would include a wrench body  14 , secured to a socket  18 , adapted thereto for engaging the head  20  of a bolt  22  threadably secured to a flange  24  as seen in FIG.  4 . For purposes of discussion, the system  10  may be adapted to the head of bolt  22 , or to a nut  22 , depending on the circumstances. Therefore, for purposes of discussion on the terms nut or bolt shall be used interchangeably, and would include any threaded member. 
     Wrench  12  would further include a hydraulic cylinder  26 , having a hydraulically driven piston  28  (See FIG.  1 ), moved inward and outward from cylinder  26 . The distal end of piston  28  includes a means for rotating a drive ratchet head  29 , engaged to the head  20  of bolt  22  to rotate the bolt  22 . The hydraulic fluid into cylinder  26  is provided through lines  30 ,  32 , which depending on the flow would impart the inward and outward movement of the piston  28  during operation. This construction is known in the art and generally disclosed in U.S. Pat. No. 5,097,730, previously referenced. 
     Turning now to the novel combination of the invention, FIG. 4 illustrates in combination with wrench  12 , a hydraulically driven motor  40 , of the type which would be a low-torque motor (500 ft. lbs. or below), which would have the ability to rotate bolts or nuts which have been loosened and must simply be rotated out of their threaded ports. As illustrated in FIG. 4, motor  40  would include an upper body  42 , having a pair of hydraulic lines  44 ,  46  thereinto for imparting rotation to a shaft (not illustrated) which would engage the upper face of the wrench drive ratchet head  29  in order to rotate the drive ratchet head  29  under low-torque, high speed conditions, in order to complete the removal of the bolt after the bolt is loosened by the high-torque wrench, or to impart initial high rotation of the bolt  22  when it is first placed into a typical threaded port. The manner in which this combination operates in order to undertake these two tasks is explained in reference to FIGS. 1 through 3. 
     Turning now to those figures, there is illustrated, in schematic form, the system in the resting state in FIG.  1 . As illustrated, motor  40  is engaged to the drive ratchet head  29  via shaft  31  (seen in FIG.  5 ), which is in turn engaged to a drive socket  33  which engages both the wrench  12  and the head  20  bolt  22  to be tightened. Motor  40  includes the pair of hydraulic lines  44 ,  46  referred to earlier, which supply the flow of hydraulic fluid into and out of motor head  42 . Further, there is illustrated hydraulic cylinder  26  of wrench  12  which likewise is supplied with hydraulic fluid from lines  32 ,  34  which feed off of lines  44 ,  46  respectively. As seen, lines  32 ,  34  feed into hydraulic cylinder chamber  26 , for imparting forward or rearward movement to piston member  28  within hydraulic cylinder  26  as required. Further, there is included a check valve  45  in line  44  which prevents fluid from flowing into port  43  in motor head  42 , but allows flow of fluid out from port  43 . Also, there is a reverse flow regulating valve  48  in line  34  which will allow fluid to flow into a first port  27  in cylinder  26  only upon reaching previously set fluid pressure. The flow line  33 , which comprises flow line  32  and flow line  34 , includes a first flow path  44  for transmitting fluid under low torque conditions from a fluid source  50  to the low torque fluid driven rotary motor  40  and from the low torque motor  40  back to the fluid source  50 . There is further included a second flow path  46  for transmitting fluid under the high torque condition from the fluid source  50  to the high torque wrench means  12  and from the high torque wrench means  12  back to the fluid source. There is also included a flow line, for transmitting fluids to and from the fluid source  50 , the flow line forming a part of both the first flow path  44  and the second flow path  46 . There is also a valve means which is defined by check valve  45  in flow line  34  as seen in FIGS. 1 and 2. 
     In FIG. 1 the hydraulic fluid from a source  50 , is flowing through line  44 , and is halted at check valve  45 , and routed into line  32  which feeds into a second port  30  in cylinder  26 , and has pushed the piston  28  within cylinder  26  rearward. In this position, neither the motor  40  or the wrench  12  is operating to rotate a bolt or nut  22 , but is in what is called the “resting state”. 
     In FIG. 2, the socket  33  has engaged a nut  22 , which needs to be tightened in the direction of arrow  52 . Hydraulic fluid is then allowed to flow through line  46 , from source  50 , in the direction of arrows  47 , under low pressure initially. The valve  48  will not allow the fluid to enter first port  27 , beneath the required minimum pressure, so the fluid flows through line  46  into motor  40 , where the fluid flow begins to rotate the shaft  31  of motor  40  at high speed, imparting high-speed rotation to bolt  22 , under very low torque. The hydraulic fluid flowing through motor  40  will flow from motor  40  through line  44 , by one-way check valve  45 , and return to fluid source  50 . This fluid flow will continue as long as the torque required is below 500 ft. lbs. of torque, and the low-torque motor  40  is able to rotate the nut or bolt  22 . 
     When the bolt has been tightened to a degree that the low-torque, high-speed motor  40  cannot rotate it, reference is made to FIG.  3 . In that figure, the motor  40  is unable to be driven further, the fluid pressure builds up in lines  46  and  34 , and valve  48  opens under the required pressure, allowing fluid into first port,  27  of cylinder  26 . Piston  28  in cylinder  26  is driven forward by the fluid pressure, and the distal end of piston  28  engages the ratchet head  29  to impart high-torque rotation to bolt head. Once the arm moves fully forward, the fluid flow is manually switched to line  44  where it engages check valve  45 , flows through line  32  into second port  30  in cylinder  26 , and moves the piston rearward, in the direction of arrow  60 . The fluid to the rear of piston  28  is forced out of first port  27 , and returns to the source  50  via line  46 . This process is repeated, until the bolt has been completely tightened to the required high torque, and then the system may then be applied to another bolt or nut  22 . 
     Should one wish to loosen the nut or bolt  22  in the process, reference is made to FIG.  5 . In that FIGURE, there is illustrated wrench  12  which would simply be inverted 180 degrees, and the hydraulic lines  44 ,  46  to the motor  20  would be switched, so that the rotation of the hydraulic motor  40  would be opposite from the original rotation format. In this format, the process as described in FIGS. 2 and 3 would be undertaken, to impart the high-torque wrench  12  to the bolt or nut head  22  in order to initially loosen it. Following the loosening of the bolt  22  to a low-torque status, the hydraulic pressure would therefore drop, the motor  20  would begin to rotate and loosen the bolt  22 , and the fluid would not enter cylinder  26 , held in check by valve  48 . 
     The following table lists the part numbers and part descriptions as used herein and in the drawings attached hereto. 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 PARTS LIST 
               
             
          
           
               
                   
                 Description 
                 Part Number 
               
               
                   
                   
               
               
                   
                 system 
                 10 
               
               
                   
                 hydraulic wrench 
                 12 
               
               
                   
                 wrench body 
                 14 
               
               
                   
                 socket 
                 18 
               
               
                   
                 head 
                 20 
               
               
                   
                 bolt 
                 22 
               
               
                   
                 flange 
                 24 
               
               
                   
                 hydraulic cylinder 
                 26 
               
               
                   
                 first port 
                 27 
               
               
                   
                 piston 
                 28 
               
               
                   
                 drive ratchet head 
                 29 
               
               
                   
                 second port 
                 30 
               
               
                   
                 shaft 
                 31 
               
               
                   
                 fluid lines 
                 32, 34 
               
               
                   
                 drive socket 
                 33 
               
               
                   
                 hydraulic motor 
                 40 
               
               
                   
                 motor head 
                 42 
               
               
                   
                 port 
                 43 
               
               
                   
                 hydraulic lines 
                 44, 46 
               
               
                   
                 check valve 
                 45 
               
               
                   
                 reverse flow 
                 48 
               
               
                   
                 regulating valve 
               
               
                   
                 fluid source 
                 50 
               
               
                   
                 arrow 
                 52 
               
               
                   
                 arrow 
                 60 
               
               
                   
                   
               
             
          
         
       
     
     Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.