Patent Publication Number: US-7896210-B2

Title: Fastener actuation system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to a fastener actuation or driving system, or the components thereof, for installing fasteners in a substrate, for example in an overhead application. 
     2. Description of the Related Art 
     A variety of different fastening driving tools exist for driving fasteners into numerous substrates, including tools used to install fasteners in situations where a significant separation between the user and the muzzle of the tool exists such as when a user wants to drive a fastener into a ceiling substrate. In these situations, fasteners may be loaded individually into the muzzle end of the tool while charges to drive the fasteners may be fed into the tool at a position behind a piston. Combustion of a charge causes the piston to be driven forward, thereby driving the fastener forward and into the substrate. 
     Due to the separation that may exist between the user and the muzzle of the tool, several tools employ an apparatus for extending the user&#39;s reach and for firing the tool. Oftentimes, tools with these extensions are fired by compressing the tool against the substrate or work surface and then providing a secondary compressive force to the entire apparatus to cause the tool to fire. 
     One drawback of tools operating in this fashion is the possibility of inadvertent actuation or misfiring. Applying too much pressure initially may cause the tool to actuate prematurely, which may cause the fastener to be driven in an undesired location or orientation. Alternatively, this pressure may cause the firing sequence to occur out of order, for example, causing the firing pin to release without sufficient force to combust a cartridge, resulting in a misfire of the tool. 
     What is needed is a fastener actuation system that overcomes the drawbacks described above. 
     BRIEF SUMMARY OF THE INVENTION 
     In one embodiment, a fastener actuation system may comprise a fastener actuation tool coupled to a pole assembly. The tool may include a housing having a barrel assembly slidable therein, the barrel assembly having a rod extending generally rearward from a breech end. The tool may also include a piston slidable within the barrel assembly, a breech block coupled to the housing, a firing pin assembly slidable within the breech block, a firing pin sear coupled to the firing pin assembly, a trigger sleeve slidable with respect to the housing and firing pin assembly. In addition, the trigger sleeve may be coupled to a limiter and an advance pin, and may have a rod contacting portion at a rear end. Moreover, the tool may have an advance lever adapted to be engaged by the advance pin and a finger for advancing a load-carrying strip. 
     The pole assembly may comprise a pole extending substantially along a length of the pole assembly, a handle coupled to the pole, an internal rod within the pole and slidable with respect to the pole and a sleeve external to the pole and coupled to the internal rod. The pole assembly further may include a lockout mechanism proximate a forward end of the pole assembly, the mechanism comprising a coupler and a reinforcing sleeve at an end of the assembly; and the lockout mechanism further may comprise a channel extending inward from a rear end of the reinforcing sleeve, the channel having an outer wall that tapers inward proximate a forward end of the channel, and at least one ball movable within the channel. The sleeve may have a thickness and the at least one ball may have a diameter, such that a rear end of the channel may have a width greater than the combination of the thickness and the diameter, and further wherein the forward end of said channel may have a width less than the combination of the thickness and the diameter. 
     In another embodiment, a fastener actuation tool comprising: a housing; a barrel assembly at least partially contained within the housing and slidable with respect to the housing, a piston within the barrel assembly and slidable with respect to the barrel assembly and the housing; a breech block generally fixed with respect to the housing; a firing pin assembly at least partially contained within the breech block and slidable with respect to the breech block, the firing pin assembly comprising a firing pin tip, a spring, a rebounder and a firing pin sear. The firing pin sear may be slidable along a channel in the breech block, and a trigger sleeve may be slidable with respect to the housing and firing pin assembly. 
     The trigger sleeve may have a tapered forward surface for contacting and releasing the firing pin sear. In addition, the firing pin tip may be biased to a generally forward starting position by a compression spring, and the trigger sleeve may be biased to a generally rearward starting position by a second compression spring. 
     Depressing the barrel assembly against a work surface may load the firing pin assembly into a ready-to-fire position. In addition, sliding the trigger sleeve toward the barrel assembly may release the firing pin sear, accelerating the firing pin assembly toward a load in the breech block and detonating the load upon impact, driving the piston forward, thereby driving the fastener into the work surface. 
     An advance lever may be coupled to the housing, biased to a rest position using a torsion spring. The advance lever may also have a surface for interfacing with an advance pin coupled to the trigger sleeve, wherein forward movement of the trigger sleeve depresses an advance lever, and rearward movement of the trigger sleeve may raise the finger, thereby advancing an unused cartridge into the breech block. 
     In yet another embodiment, a fastener actuation pole assembly may comprise a pole having a tool end and a handle end, the pole extending substantially a length of the pole assembly and coupled to a handle at the handle end. The pole assembly may further include a coupler at a tool end of the pole for engaging a tool, the coupler extending a predetermined length within the pole, an internal rod within the pole and slidable with respect to the pole; and a sleeve around at least a portion of the pole, the sleeve coupled to, and slidable with, the internal rod. In addition, the pole assembly may include a reinforcing sleeve coupled to and disposed around said pole at said tool end. Moreover, the pole assembly may include a cap at a handle end of the internal rod and a slot in the pole proximate the handle end of the pole, wherein the cap may couple to the internal rod and the coupler may connect the cap to the sleeve, the coupler passing through the slot. 
     These and other features and advantages are evident from the following description of the present invention, with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a sectional view of an exemplary tool in an initial or final position. 
         FIG. 2  is a sectional view of the tool of  FIG. 1  in a ready-to-fire position. 
         FIG. 3  is a sectional view of the tool of  FIG. 1  just prior to being fired. 
         FIG. 4  is a sectional view of the tool of  FIG. 1  in a downward orientation with firing inhibited by a lockout mechanism. 
         FIG. 5  is a perspective view of a firing pin sear. 
         FIG. 6  is a perspective view of a trigger sleeve assembly. 
         FIG. 7  is a perspective view of a portion of the underside of the tool of  FIGS. 1-4 . 
         FIG. 8  is a sectional view of an exemplary tool system in a pre-firing position. 
         FIG. 9  is a sectional view of the tool system of  FIG. 7  just prior to being fired. 
         FIG. 10  is a section view of the tool of  FIGS. 1-3 , rotated 90 degrees from the view of  FIGS. 1-3 , showing the cocking rod contacting the firing pin sear to load the firing pin assembly. 
         FIG. 11  is a section view of the tool of  FIGS. 1-3 , rotated 90 degrees from the view of  FIGS. 1-3 , showing the trigger sleeve releasing the firing pin sear to fire the firing pin assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 8-9 , a novel fastener driving or actuation system  10  is shown. System  10  may comprise a tool  12  operatively coupled to a pole assembly  14  having a lockout mechanism  92 , with components of each portion described in detail below. In particular, the tool  12  may have a trigger sleeve  60  having a frustoconical forward end  62 , the trigger sleeve  60  slidable within a housing  20  such that a forward movement of the trigger sleeve  60  by a predetermined distance releases a spring-loaded firing pin sear  54 , thereby releasing the firing pin assembly  40  towards a load  17  for actuation of the tool. In addition, tool  12  may include an advance pin  29  for operatively engaging a ramp surface  23  of an advance lever  22  to automatically load the next load  17 . Moreover, pole assembly  14  may be coupled to tool  12 , e.g., releasably coupled, and may include an internal rod  82  coupled to an outer sleeve  88  for actuation of the system  10 . Actuation may result from internal rod  82  bearing against and driving forward a rod-contacting portion  70  of sleeve  60 , although actuation only may occur when system  10  is not pointed below a horizontal and therefore inhibited due to the action of lockout mechanism  92 . 
     As can be seen in  FIGS. 1-4 , tool  12  may comprise a housing  20  surrounding a barrel assembly  30 . Barrel assembly  30  may have a muzzle end  32  protruding forward from housing  20  and a breech end  34  spaced rearward from muzzle end  32  and contained within housing  20 . Barrel assembly  30  may also comprise a piston  36  disposed between muzzle end  32  and breech end  34  and slidable within barrel assembly  30 . 
     In addition, barrel assembly  30  may comprise a cocking rod  38  extending generally rearward from breech end  34 . Cocking rod  38  may be generally cylindrical, and may have a length between about 1 inch and about 3 inches, preferably between about 1½ inches and about 2½ inches, still more preferably between about 1¾ inches and about 2¾ inches. Cocking rod  38  may also be offset from a centerline of barrel assembly  30 . In this way, cartridge or load  17  may be generally aligned with centerline so that combustive and/or explosive forces acting on piston  36  cause piston  36  to be driven axially along length of barrel assembly  30 . 
     Tool  12  also may comprise breech block  42  having a forward end. Breech block  42  may have a plurality of openings forming a channel generally perpendicular to a length of breech block  42  for receiving unused cartridges  17  and evacuating spent cartridges  17 . As seen in  FIG. 1 , channel in breech block  42  may be generally aligned with grip  16 , which is useful when unused cartridges  17  are stored within and fed through grip  16 . Forward end of breech block  42  may be shaped similarly to breech end  34  of barrel assembly  30  so that barrel assembly  30  may substantially interface with breech block  42  when muzzle end  32  of tool  12  is depressed against work surface  2 . Rearward end of breech block  42  may interface with spring plug  56 , for example via an interference fit or through threaded engagement with spring plug  56 . 
     Staying with  FIGS. 1-4 , tool  12  may have firing pin assembly  40  proximate rearward end of breech block  42 , slidable with respect to breech block  42 . Firing pin assembly  40  may include firing pin tip  44 , compression spring  46 , rebounder  48  and rebound washer  50 , and rebound washer  50  may be disposed around rebounder  48 . Firing pin assembly  40  may slide within breech block  42 , but movement may be limited in both sliding directions. Rearward movement may be constrained by compression of spring  46  between spring plug  56  and rebounder  48  or rebound washer  50 . Similarly, breech block  42  may have one or more bosses  52  circumferentially disposed within breech block  42 . Forward movement of firing pin assembly  40  may then be limited by contact between rebound washer  50  and bosses  52 . 
     Firing pin assembly  40  may further comprise a firing pin sear  54 . Sear  54  may be disposed generally perpendicular to length of housing  20 , but sear  54  may have other orientations. As can be seen in  FIG. 10 , sear  54  may be biased to an initial state protruding from firing pin assembly  40  through use of spring  55 . Rearward motion of cocking rod  38  may depress firing pin sear  54 , compressing spring  55 , and holding sear  54  within firing pin assembly  40  in order to load firing pin assembly  40 . 
     Turning to  FIG. 5 , sear  54  may comprise a series of generally cylindrical portions  51 ,  53 ,  55 ,  57  having varying diameters and may further include radii of curvature or chamfers between varied diameter portions  51 ,  53 ,  55 ,  57 . Portion  51  may have a diameter between about 1 mm and about 6 mm, preferably between about 3 mm and about 5 mm, still more preferably about 3.5 mm, and a length of between about 2 mm and about 8 mm, preferably between about 4 mm and about 7 mm, and in one embodiment about 6.35 mm. Portion  53  may have a diameter between about 1.5 mm and about 6.5 mm, preferably between about 3.5 mm and about 5.5 mm, still more preferably about 4 mm. Portion  55  may have a diameter between about 5 mm and about 10 mm, preferably between about 6 mm and about 8 mm, still more preferably between about 7 mm and about 8 mm, and in one embodiment about 7.5 mm, and a length between about 1 mm and about 4 mm, preferably between about 2 mm and about 3 mm, and in one embodiment, about 2.4 mm. Portion  57  have a diameter between about 3 mm and about 8 mm, preferably between about 4 mm and about 6 mm, and in one embodiment, about 5⅓ mm, and a length between about 2 mm and about 6 mm, preferably between about 3.5 mm and about 5 mm, and in one embodiment, about 4⅓ mm. Overall, sear  54  may have a length between about 10 mm and about 20 mm, preferably between about 13 mm and about 17 mm, and in one embodiment, about 15¾ mm. 
     Housing  20  further may hold a trigger sleeve  60  slidable within housing  20  between a first and a second position. Tool  12  may comprise a second compression spring  58  between spring plug  56  and rearward end  64  of trigger sleeve  60  so as to bias sleeve  60  to a rest position. As seen in  FIG. 6 , trigger sleeve  60  may be a hollow generally cylindrical body having an open forward end  62  and a closed rearward end  64 . Forward end  62  may have a tapered wall so as to form a frustoconical forward surface  63 , narrowing in a direction into trigger sleeve  60  and away from muzzle end  32  of tool  12 . Outer portion of forward end  62  may have a diameter sized slightly smaller than inner diameter of housing  20  so as to allow trigger sleeve  60  to move freely within housing  20 . Inner portion of forward end  62  may have a diameter sized slightly larger than rear portion of breech block  42  so as to allow trigger sleeve  60  to also slide freely between housing  20  and breech block  42 . In addition, forward end  62  may have a radial notch or channel  65  from the outer portion to the inner portion, extending substantially the length of tapered portion  63 . Channel  65  may provide clearance for cocking rod  38  to pass through as cocking rod  38  moves rearward to load firing pin assembly and/or as trigger sleeve  60  moves forward to fire tool  12 . 
     Staying with  FIG. 6 , trigger sleeve  60  may have a limiter  66  such as a pin or bolt coupled to sleeve  60 . Limiter  66  may extend outward from trigger sleeve  60  and at least partially through housing  20 . As such, limiter  66  may move along a slot within housing  20 , establishing a maximum forward position for trigger sleeve  60 . 
     Rearward end  64  of trigger sleeve  60  may be a generally solid cylindrical body with a smaller generally cylindrical portion extending rearward to form protrusion  68 . Protrusion  68  may be sized to be slightly smaller than an opening in the rear end of tool  12 , the opening forming a coupler  72 . 
     Trigger sleeve  60  may have a second opening for holding advance pin  29 . Second opening may be generally diametrically opposed from limiter  66 , and advance pin  29  may extend through a channel or other opening in housing  20  toward advance lever  22 . 
     Turning to  FIG. 7 , and as also seen in  FIGS. 1-4 , advance pin  29  may move along ramp surface  23  of advance lever  22  to cam lever between several positions during operation. Advance lever  22  may be coupled to housing at one end, preferably a rearward end. Mandrel  26  and torsion spring  28  may be spaced between arms of advance lever  22 , with torsion spring  28  biasing advance lever  22  to an initial position. In addition, advance lever  22  may have advance lever finger  24  at a forward end. Finger  24  may extend to a forward end of lever  22  into grip  16  for advancing cartridges or loads  17  after tool is fired. 
     Coupler  72  may interface with a second coupler  74 , the second coupler disposed on pole assembly  14 . Turning to  FIGS. 8-9 , coupler  72  may threadingly engage second coupler  74 , but other forms of connection are possible, including, e.g., an interference fit. 
     Staying with  FIGS. 8-9 , pole assembly  14  may include a pole  78  extending substantially the length of pole assembly  14  to a handle  90 . Pole assembly  14  may come in various lengths, e.g., about 3 ft., about 6 ft. or about 8 ft. lengths, so that tool system  10  may be adaptable to a variety of uses. In addition, pole assembly  14  may include one or more extenders for coupling to a forward end of pole assembly  14  in order to further lengthen pole assembly  14 . Moreover, pole  78  may have an outer diameter of between about ½ inch and about 2 inches, preferably between about ¾ inch and about 1½ inches, still more preferably about 1 inch. Pole  78  may also have an inner diameter of between about ¼ inch and about 1½ inches, preferably between about ½ inch and about 1 inch, still more preferably about ¾ inches. 
     Second coupler  74  may extend a predetermined distance inside pole  78 , for example, via an interference fit, which may serve to reinforce pole  78 . Second coupler  74  may extend between about 1 inch and about 6 inches into pole  78 , preferably between about 1 inch and about 4 inches. In one embodiment, second coupler  74  may also fit over the end of pole  78  and extend a second predetermined distance along outside of pole  78 . Alternatively, or in addition, assembly  14  may also include a reinforcing sleeve  76  proximate second coupler  74  and extending around an outer surface of pole  78 . Reinforcing sleeve may be coupled to pole  78  and/or to second coupler  74 , for example, through the use of one or more fasteners  75 . 
     Still staying with  FIGS. 8-9 , pole assembly additionally includes an internal rod  82  within pole  78  and extending substantially along the length of pole  78 . Internal rod  82  may be coupled to cap  84 , preferably proximate handle  90 . As with pole  78 , internal rod  82  may come in various lengths, each of which is preferably shorter than its corresponding pole  78  length. For example, a 3 foot pole  78  may have an internal rod  82  about 31 inches long, a 6 foot pole  78  may have an internal rod  82  about 67 inches long, and an 8 foot pole  78  may have an internal rod  82  about 91 inches long. Internal rod  82  may also be sized smaller than inner diameter of pole  78 . Preferably, internal rod  82  may have a diameter about half that of inner diameter of pole  78 . 
     Cap  84  may be coupled in various ways to internal rod, such as by press fitting cap  84  over internal rod  82 . As shown in  FIGS. 8-9 , pin  86  may pass through cap  84  and internal rod  82 , as well as sleeve  88 . Pole  78  may have one or more slots  80  along which pin may travel, so as to allow sleeve  88  to move along a length of pole  78 , thereby actuating tool system  10 . Slots  80  may have a length between about ½ inch and about 6 inches, preferably between about ½ inch and about 2 inches, still more preferably between about ½ inch and about 1 inch, and in one embodiment, about ¾ inch. In addition, as seen in  FIGS. 8-9 , sleeve  88  may extend substantially along the length of pole  78  in order to provide a user with a variety of hand placement options. Sleeve  88  may be between about 10% and about 85% a length of pole  78 , preferably between about 40% and about 85%, still more preferably between about 65% and about 85%. However, sleeve  88  may also be relatively short, for example between about 4 inches and about 6 inches, which may provide adequate surface area for a user&#39;s hand while requiring less material to make sleeve  88 . In this case, sleeve  88  may be coupled to a secondary sleeve proximate second coupler  74  with second sleeve providing lockout functionality, as described below. 
     Returning to  FIGS. 1-4  and  8 - 9 , prior to compression against work surface  2 , tool system  10  may initially be in a configuration such as the one shown in  FIGS. 1  and/or  7 . In this configuration, barrel assembly  30  extends forward from housing  20 , firing pin assembly  40  is in a forward position—but not its most forward position, which occurs during firing—sear  54  is not engaged and trigger sleeve  60  is biased to its rearward position. In addition, advance pin  29  protruding from trigger sleeve  60  may rest against a rearward portion of ramp surface  23  on advance lever  22 , with torsion spring  28  biasing advance lever  22  to this rest position. 
     As seen in  FIG. 2 , upon depressing muzzle end  32  against a work surface  2 , barrel assembly  30 , including cocking rod  38 , slides into housing  20 . Cocking rod  38  may slide rearward through an opening in breech block  42 , engaging firing pin assembly  40 , biasing firing pin assembly  40  to a rearward position and engaging firing pin sear  54 . 
     Turning again to  FIG. 3  and  FIG. 9 , when a user wishes to trigger tool system  10 , the user slides sleeve  88  along pole  78 , which moves internal rod  82  to a forward position. Rod  82  interfaces with rod contacting portion  70  of trigger sleeve  60 , moving trigger sleeve  60  to a forward position. As trigger sleeve  60  moves forward, a portion of firing pin sear  54  may travel along tapered forward end  62  of trigger sleeve  60 , which may cause sear  54  to cam towards a release point. When the release point is reached, sear  54  may release, causing spring  58  to extend, propelling firing pin assembly  40  forward into load  17 , detonating load  17 . Detonation may drive piston  36  forward, driving fastener  4  out of muzzle end  32  and into work surface  2 . In addition, forward motion of trigger sleeve  60  may cause advance pin  29  to translate along ramp surface  23 , camming advance lever  22  with advance lever finger  24  downward into grip where lever finger  24  may engage a portion of strip holding cartridges  17 . 
     After tool system  10  has been actuated, a user may release sleeve  88 , translating internal rod  82  to its rearward position. With force applied by internal rod  82  removed, spring  58  may extend to bias trigger sleeve  60  to its rearward, rest position. As trigger sleeve  60  moves, advance pin  29  coupled to trigger sleeve  60  may also slide rearward along ramp surface  23 . Motion along ramp surface  23  may cam advance lever  22  and finger  24  toward a rest position, and camming of finger  24  may advance strip holding cartridges  17 , loading a new cartridge  17  into breech block  42 . This advancement mechanism may eliminate the need for a user to perform a separate action to advance cartridges  17 , for example through use of a manual advance. 
     Returning to  FIGS. 1-4 , tool system  10  also may include a lockout mechanism  92  to prevent misfires, e.g., when tool is angled below a horizontal level. Lockout mechanism  92  may comprise an annular channel  98  within a rear end  108  of sleeve  76 . Channel  98  may have an inner wall  100 , which may be coincident with an outer wall of pole  78 . In addition, channel  98  may have an outer wall  102 , which may be coincident with an inner wall of sleeve  76 . Outer wall  102  may taper inward frustoconically toward a forward end  106  of channel  98 . Outer wall  110  of sleeve  76  also may taper inwards in a direction from rear end toward forward end, and in the embodiment of  FIGS. 1-4 , taper of outer wall  110  of sleeve  76  may be substantially similar to taper of outer wall  102  of channel  98 . Internal taper  104  may be between about 5 degrees and about 20 degrees with respect to an axial centerline of pole assembly  14 , preferably between about 10 degrees and about 20 degrees, and in one embodiment, about 14 degrees. 
     Lockout mechanism  92  may include one or more balls  112  for movement within channel  98 . In addition, lockout mechanism  92  may include a seal  96  or other stop to retain balls  112  within channel  98 . As seen in  FIG. 1 , seal  96  may comprise an O-ring seated within a groove  94  on the outer surface of sleeve  88 . Although one ball  112  is shown in the figures, a plurality of balls may be used, e.g., about 3 balls, which may provide redundancy to the system  10 . 
       FIGS. 1-3  show tool system  10  in a non-locked out position. This position may be anywhere from upright, i.e., directly opposite the force of gravity, to about 90 degrees, i.e., about horizontal or perpendicular to the force of gravity. In this position, sleeve  88  may be able to move laterally from a start position to a firing position where forward end  89  of sleeve  88  is proximate forward end  106  of channel  98 . In addition, while sleeve  88  is actuated forward, ball  112  may roll between outer surface of sleeve  88  and outer wall  102  of channel  98 . Internal taper  104  of channel  98  may be such that ball is biased toward rear  108  of channel  98 , which is wider than forward end  106 , such that there is sufficient room between pole  78  and outer wall  102  for both sleeve  88  and ball  112 . When in a generally vertical position, system  10  may bias ball  112  so that ball  112  rests against seal  96 , leaving clearance above sleeve  88  for full motion of sleeve  88  to a firing position proximate forward end  106  of channel  98 . When system  10  is angled between a horizontal and a vertical position, ball  112  may slide along internal taper  104 , down and away from forward end  106 , leaving clearance for sleeve  88  to attain a firing position. 
     Turning to  FIG. 4 , tool system  10  is shown in a, locked-out position that occurs when system  10  is oriented in any angle greater than horizontal, i.e., perpendicular to the force of gravity. In this position, internal taper  104  may bias ball  112  toward forward end  106  of channel  98 . Forward end  106  of channel  98  may have a width between outer surface of pole  76  and forward end of taper  104  that is less than the combined width of the forward end of sleeve  88  and of ball  112 . As such, in a locked-out position, because ball  112  is biased toward forward end  106  of channel  98 , lockout mechanism  92  prevents accidental firing of tool system  10  because ball  112  prevents forward end of sleeve  88  from reaching a firing position proximate forward end  106  of channel  98 . Because sleeve  88  cannot extend forward fully, internal rod  82  cannot either, which means that forward end  62  of trigger sleeve  60  does not slide far enough to release firing pin sear  54 , so firing pin  40  is not released. 
     While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific exemplary embodiments and methods herein. The invention should therefore not be limited by the above described embodiments and methods, but by all embodiments and methods within the scope and spirit of the invention as claimed.