Patent Publication Number: US-2012030918-A1

Title: Nose assembly for fastener installation tool

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Section 111(a) application relating to commonly owned, co-pending U.S. Provisional Application Ser. No. 61/300,302 entitled “SELF-CONTAINED SHIFTING INSTALLATION NOSE ASSEMBLY,” filed Feb. 1, 2010, the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to tools for installing mechanical fasteners and, more particularly, to nose assemblies of tools for installing mechanical fasteners having a lock collar. 
     BACKGROUND OF THE INVENTION 
     Certain fasteners, such as blind bolt fasteners, require the insertion of a lock collar to mechanically lock a pin and sleeve of the fastener together at the completion of a fastener installation process. Having a lock collar installed between the pin and the sleeve increases stability and durability of the joint. The lock collar typically carries the installation loads until the pin presents its locking feature to the lock collar, at which time the lock collar moves to form the lock. 
     SUMMARY OF THE INVENTION 
     In an embodiment, a nose assembly for a fastener installation tool includes a housing and a piston received within the housing. In an embodiment, the piston includes a first end and a second end opposite the first end, the second end of the piston being adapted to engage a fastener installation tool, and a collet having a fastener engagement end with a plurality of jaws. In an embodiment, the nose assembly includes a nose cap having an orifice, the nose cap being attached to the housing and engaging the first end of the piston. In an embodiment, the nose assembly includes a seating anvil positioned between the first end of the piston and the nose cap. In an embodiment, the seating anvil includes an extended front portion, the extended front portion of the seating anvil being movable between a retracted position, in which the extended front portion is retained within the nose cap, and an extended position, in which the extended front portion advances through the orifice of the nose cap. 
     In an embodiment, the nose assembly is adapted to engage a fastener having a sleeve, a pin that engages the sleeve, and a lock collar that mechanically locks the pin and the sleeve with one another. In an embodiment, the extended front portion of the seating anvil is adapted to drive the lock collar to mechanically lock the pin and the sleeve with one another when the seating anvil is in its extended position. In an embodiment, the nose assembly is preset with a shifting pressure. In an embodiment, the nose assembly senses a set position of the pin when a lock groove of the pin aligns with the lock collar. In an embodiment, the seating anvil is moved to its extended position after the shifting pressure has been reached and the pin and the sleeve have been set. In an embodiment, the nose assembly exerts no pressure on the lock collar of the fastener when the pin and the sleeve are being set. 
     In an embodiment, the nose assembly includes a hydraulic shifting mechanism. In an embodiment, the hydraulic shifting mechanism includes a sealed, self-contained hydraulic control valve. In an embodiment, the nose assembly includes a pneumatic shifting mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference is made to the following detailed description of the embodiments considered in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a side cross-sectional view of a nose assembly for a fastener installation tool in accordance with an embodiment of the present invention, the nose assembly being shown engaged with a fastener in an initial step of a fastener installation process; 
         FIG. 2  is a side cross-sectional view of the nose assembly shown in  FIG. 1 , which is shown engaged with a fastener in a subsequent step of the fastener installation process; 
         FIG. 3  is a side cross-sectional view of the nose assembly shown in  FIG. 2 , which is shown engaged with a fastener in a subsequent step of the fastener installation process; 
         FIG. 4  is a side cross-sectional view of the nose assembly shown in  FIG. 3 , which is shown engaged with a fastener in a subsequent step of the fastener installation process; 
         FIG. 5  is a side cross-sectional view of the nose assembly shown in  FIG. 4 , which is shown engaged with a fastener in a subsequent step of the fastener installation process; and 
         FIG. 6  is a side cross-sectional view of the nose assembly shown in  FIG. 5 , which is shown in a subsequent step of the fastener installation process. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Referring to  FIG. 1 , in an embodiment, a nose assembly  10  for an installation tool includes a housing  12  and a piston  14  received within the housing  12  and having a first end  16  and a second end  18  opposite the first end  16 . In an embodiment, the second end  18  of the piston is operationally attached to a fastener installation tool (not shown in the Figures). In an embodiment, the piston  14  includes a collet  15  having a fastener engagement end  17  having a plurality of jaws  20 . In an embodiment, the housing  12  includes a nose cap  22  that engages and caps the first end  16  of the piston  14 . In an embodiment, the nose cap  22  includes an external surface  24 , whose purpose shall be described hereinafter. In an embodiment, the nose assembly  10  includes a seating anvil  26  that is positioned between the nose cap  22  and the first end  16  of the piston  14 . In an embodiment, the seating anvil  26  moves within the nose cap  22  and is operationally connected to the piston  14 . In an embodiment, the seating anvil  26  has an extended front portion  28  that advances through an orifice  30  of the nose cap  22 . The purpose and function of the seating anvil  26  shall be described hereinafter. 
     Still referring to  FIG. 1 , in an embodiment, the nose assembly  10  is adapted to engage a fastener  100  having a sleeve  102 , a pin  104  and a lock collar  106 . The fastener  100  is inserted into a hole of a work piece  108 . In an embodiment, the lock collar  106  resides in a locking pocket  110  of the sleeve  102 . In an embodiment, the pin  104  includes a head portion  112  and a lock groove  114 . In an embodiment, a pull portion or pintail  116  of the pin  104 , which is inserted through the nose cap  22  and seating anvil  26  and into the housing  12  of the nose assembly  10 . In an embodiment, the jaws  20  of the collet  15  grip the pintail  116  of the pin  104 . In an embodiment, the seating anvil  26  surrounds the pintail  116  of the pin  104 . 
     Referring to  FIG. 2 , in an embodiment, the jaws  20  of the collet  15  of the nose assembly  10  continue to grip the pintail  116  of the pin  104 , and the collet  15  is pulled away from the nose cap  22  by a force generated by the tool. As a result, the collet  15  pulls the pintail  116  of the pin  104 , and the surface  24  of the nose cap  22  engages the workpiece  108 . Referring to  FIG. 3 , in an embodiment, as the pin  104  is pulled by the collet  15 , the head portion  112  of the pin  104  presses on a free wall portion  118  of the sleeve  102  extending from the work piece  108 , and deforms the free wall portion  118  to form a bulb  120 . 
     Referring to  FIG. 4 , in an embodiment, a shift pressure is reached and the pin  104  is set and the sleeve  102  is upset (i.e., deformed), the extended front portion  28  of the seating anvil  26  advances through the orifice  30  of the nose cap  22  and drives the lock collar  106  into the locking pocket  110  of the sleeve  102  and into the lock groove  114  of the pin  104 , creating a mechanical lock between the sleeve  102  and the pin  104 .  FIG. 5  shows a detailed view of this step of the installation process. Referring to  FIG. 6 , in an embodiment, after the extended front portion  28  of the seating anvil  26  drives the lock collar  106  to create a mechanical lock between the sleeve  102  and the pin  104  the fastener  100  is set, and the seating anvil  26  retracts and the extended front portion  28  retracts through the orifice  30  of the nose cap  22 . In an embodiment, the pintail  116  is broken off from the pin  104 , dropping into a catching bag (not shown in the Figures), leaving no foreign object debris. 
     As described above, the nose assembly  10  allows for the installation of the lock collar  106  after the pin  104  is set and the sleeve  102  is upset (i.e., deformed) by the pin  104 . In an embodiment, the nose assembly  10  exerts no or a minimal pressure on the lock collar  106  while the nose assembly  10  pulls the pin  104  away from the work piece  108 . In an embodiment, by separating an action of pulling the pin  104  to upset the sleeve  102  and an action of setting the lock collar  106  to mechanically lock the pin  104  and the sleeve  104  in the set fastener  100 , the nose assembly  10  provides the installation tool with a capability to sense the set position of the pin  104 . In an embodiment, the nose assembly  10  separates the action of setting the pin  104  and automatically driving the lock collar  106  by sensing either (1) when the lock groove  114  of the pin  104  aligns with the lock collar  106 , or (2) when a predetermined pulling pressure on the pin  104  is reached. In an embodiment, during the installation process, the nose assembly  10  senses when the matching locking groove  114  of the pin  104  becomes available and drives in the lock collar  106  while the pin  104  still continues to be set. In an embodiment, the nose assembly  10  allows users of the installation tool to confirm that the fastener  100  is installed correctly in a proper grip range. In an embodiment, the nose assembly  10  adapts to existing installation tools. 
     In some embodiments, the nose assembly  10  is preset to initiate the shift to seat the lock collar  106  when a preset pressure condition occurs. In an embodiment, Table 1 below provides an exemplary correspondence between fasteners having certain diameters and the preset pressures at which the embodiments of the invention switch from primarily pulling on the pin  104  to setting the lock collar  106 . 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Material &amp; Diameter 
                 Shift Load in Lbf 
               
               
                   
                   
               
             
            
               
                   
                 CRES 5 Dia 
                 1,200 to 1,500 
               
               
                   
                 CRES 6 Dia 
                 1,800 to 2,100 
               
               
                   
                 Alloy Steel 5 Dia 
                 1,400 to 1,700 
               
               
                   
                 Alloy Steel 6 Dia 
                 2,200 to 2,500 
               
               
                   
                   
               
            
           
         
       
     
     In some embodiments, the nose assembly  10  employs a hydraulic shifting mechanism. In some embodiments, the nose assembly  10  employs a factory sealed, fully self-contained, hydraulic control valve. In some embodiments, the nose assembly  10  employs a pneumatic shifting mechanism. In some embodiments, the nose assembly  10  is maintenance-free and tamper-proof and never needs adjustment in service. In some embodiments, the nose assembly  10  allows to maintain a continuous installation consistency for a prolonged use period of a tool equipped with the nose assembly  10 . In some embodiments, the factory preset condition of the nose assembly  10  requires no adjustments during operation, even if different batches of fasteners are to be installed. In some embodiments the nose assembly  10  eliminates a need for having fasteners with any additional components, such as commonly used “drive anvils/washers;” thus eliminating or minimizing the risks associated with discarded fastener components that create foreign object debris that may be retained in a production structure. 
     It will be understood that the nose assembly  10  described herein is merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the full spirit and the scope of the embodiment described herein. Accordingly, all such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.