Abstract:
A fastener actuation system for driving fasteners into a work surface separated a significant distance from a user, the system comprising a fastener actuation tool coupled to a pole assembly, the assembly including a lockout mechanism disposed within the tool. The tool may have a firing pin assembly configured such that depression of the barrel assembly against the work surface loads a firing pin into a ready-to-fire position. In addition, the tool may have a trigger sleeve slidable within the tool housing and having a ramp surface such that forward motion of the trigger sleeve may cause a trigger sear to move along the ramp surface until a point where the sear disengages and the firing pin fires. The lockout mechanism may include a ball and a receptacle, where the receptacle receives the ball if the tool is in an acceptable orientation and does not receive the ball otherwise.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is directed to a lockout mechanism for a fastener driving tool used to install fasteners in a substrate, for example in an overhead application. 
         [0003]    2. Description of the Related Art 
         [0004]    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. 
         [0005]    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. 
         [0006]    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. 
         [0007]    One solution to this problem is described in U.S. Pat. No. 7,896,210, titled “Fastener Actuation System,” and which was invented by two of the inventors named here. The &#39;210 patent describes a system including a tool and a pole assembly couplable to the tool. The pole assembly includes a lockout mechanism that prevents the tool from firing when the tool is oriented generally below a horizontal level. While this lockout mechanism is successful at preventing unintended firing of the tool, it adds additional weight to the pole assembly. In addition, the tool still may be subject to misfiring if the pole assembly is not attached. 
         [0008]    What is needed is a fastener actuation system that overcomes the drawbacks described above. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    In one embodiment, a fastener actuation system may include: a fastener actuation tool coupled to a pole assembly, the tool comprising: a housing having a barrel assembly slidable therein, the barrel assembly having a muzzle end and a breech end, a piston slidable within the barrel assembly, a breech block coupled to the housing, a firing pin assembly slidable within the breech block, a trigger sleeve, and a lockout mechanism proximate a rearward end of the tool. The system also may include a pole assembly comprising: a pole extending substantially along a length of the pole assembly, an internal rod within, and slidable with respect to, the pole, and a sleeve external to the pole and coupled to the internal rod. The lockout mechanism may include a receptacle and a ball, where the lockout mechanism operatively engages the internal rod and trigger sleeve when the ball is disposed within the receptacle and does not operatively engage the trigger sleeve when the ball is not disposed within the receptacle. When the ball is not disposed within the receptacle, a gap between the trigger sleeve and a bottom of the receptacle may be about ⅜″. 
         [0010]    The lockout mechanism may include a shaft generally aligned with the internal rod and a spring disposed around the shaft. The trigger sleeve may include a protrusion extending rearwardly that may be generally aligned with the internal rod. In addition, the housing may include a cavity having an internal wall, the trigger sleeve may include a protrusion extending rearwardly, and the ball may have a diameter, where the protrusion is spaced a radial distance from the internal wall at least a distance as large as the diameter. Moreover, a forward end of the lockout mechanism, which may taper inwardly, may be spaced a distance from the internal wall smaller than the diameter. 
         [0011]    In another embodiment, a fastener actuation tool may include: a housing, a barrel assembly at least partially contained within, and slidable with respect to, the housing, a piston within, 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, and slidable with respect to, the breech block, a trigger sleeve slidable with respect to the housing and the firing pin assembly, and a lockout mechanism disposed rearward of the trigger sleeve, the lockout mechanism including a ball and a receptacle, the ball disposed within the receptacle when the tool is in an acceptable firing position. The lockout mechanism also may include a shaft extending rearward from the receptacle. The barrel assembly further may include a cocking rod, wherein depressing the barrel assembly causes the cocking rod to contact the firing pin assembly and move the firing pin assembly into a ready-to-fire position. 
         [0012]    The housing may include a cavity having a tapered rear end. Similarly, the receiver may include a flange having a tapered underside, and the rear end and the underside may taper at substantially the same rate. In addition, the trigger sleeve may include a rearward facing protrusion, which the receptacle may be configured to receive. There also may be a gap between the protrusion and a bottom of the receptacle when the lockout mechanism is disposed in a forwardmost position and the ball is not disposed within the receptacle. The housing may include an internal wall forming a generally cylindrical cavity, and the trigger sleeve may include a protrusion generally coaxial with the cavity, where a distance between the internal wall and the protrusion is at least as large as a diameter of the ball. 
         [0013]    In still another embodiment, a fastener actuation tool may include: a housing having an internal wall forming a cavity having at least a first section and a second section, a barrel assembly at least partially extending forward of the housing&#39;s front end, a triggering mechanism slidable within the first section of the cavity, the second section of the cavity including an open rearward end and connection means configured to connect the tool to a pole assembly, and a lockout mechanism partially disposed in the cavity&#39;s first section and partially disposed in the cavity&#39;s second section, where the lockout mechanism may include a spring configured to bias the mechanism to a rearward resting position. There may be a flange between the first and second sections of the cavity and a retainer extending outward from the shaft of the lockout mechanism, and the spring may be disposed between the flange and the retainer. 
         [0014]    The lockout mechanism may include a ball, a receptacle, and a flange surrounding an open end of the receptacle. The ball may be configured to be received by the receptacle when the tool is oriented with the barrel assembly pointed upwards and to be disposed within the cavity, outside the receptacle, when the tool is oriented with the barrel assembly pointed horizontally. At angles in between, the tool may be designed, e.g., with a certain flange angle or receptacle depth, to locate the ball within or outside the receptacle. Preferably the receptacle depth may be at least about ½ 0  the ball diameter. In addition, the first section of the cavity may include a generally cylindrical portion, and the flange may be spaced radially from the generally cylindrical portion a distance less than the diameter of the ball. 
         [0015]    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 
         [0016]      FIG. 1  is a sectional view of an exemplary tool in an initial or final position. 
           [0017]      FIG. 2  is a sectional view of the tool of  FIG. 1  in a ready-to-fire position. 
           [0018]      FIG. 3  is a sectional view of the tool of  FIG. 1  just prior to being fired. 
           [0019]      FIG. 4  is a sectional view of the tool of  FIG. 1  in an orientation with firing inhibited by a lockout mechanism. 
           [0020]      FIG. 5  is a detail view of the lockout mechanism shown in  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Details of one embodiment of a tool  12  with which lockout mechanism  100  may be used may be described in U.S. Pat. No. 7,896,210, column  3 , line  26 —column  5 , line  39  of which are incorporated herein by reference. 
         [0022]    As seen in  FIG. 1 , tool  12  may include lockout mechanism  100  proximate a rear portion  21  of housing  20 . Housing  20  may include a generally cylindrical cavity  19  through which trigger sleeve  60  translates in order to load and fire tool  12 . At its rear end, cavity  19  may taper extending rearward. Preferably, tapering is generally constant along its length and about a circumference so as to form a generally frustoconical wall  24 . 
         [0023]    Wall  24  may be formed as an internal wall as part of housing  20 . Alternatively, coupler  72  may couple to housing, e.g., via threaded engagement at rear  21  of housing. Coupler  72  may be open at at least one end, and wall  24  may be formed within coupler  72 , inward from the open end. 
         [0024]    Coupler  72  may include one or more openings  73  about its perimeter, and housing  20  similarly may include one or more openings  71  about its perimeter. As coupler  72  is rotated about housing  20 , opening  73  may align with opening  71 , and fastener  75  may be inserted and/or threaded through both to prevent reverse rotation of coupler  72 . 
         [0025]    Tool  12 , e.g., at coupler  72  may include connection means  77  to releasably couple tool  12  to pole assembly  14 , e.g., with coupler  74 . As seen in  FIG. 1 , connection means  77  may include mating threading between tool  12  and pole assembly  14 . Connection means also may include a friction or interference fit, a tab/slot or spring loaded button/hole-type arrangement, or any other type of connection that allows for firm, yet releasable engagement. Connection means  77  also may include a washer, o-ring, or similar gasket  79  between couplers  72 ,  74 . Gasket  79  may assist in keeping pole assembly  14  firmly coupled to tool  12 , preventing loosening of pole assembly  14 , and/or preventing debris from entering into tool. 
         [0026]    Pole assembly  14  may include a pole  78  extending substantially the length of pole assembly  14  to a handle. 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. 
         [0027]    Second coupler  74  may extend a predetermined distance inside pole  78 , for example, via a threaded or 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   a.  Like fasteners  75 , fasteners  75   a  also may prevent reverse rotation of pole  78  relative to second coupler  74 . 
         [0028]    Pole assembly additionally includes an internal rod  82  within pole  78 , which may extend substantially along the length of pole  78 . Internal rod  82  may be coupled to cap  84 , preferably proximate one end of rod  82 . 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 . 
         [0029]    Cap  84  may be coupled in various ways to internal rod, such as by press fitting cap  84  over internal rod  82 . Alternatively, connector such as pin  86  may pass through cap  84  and internal rod  82 , as well as sleeve  88 . Pole  78  may have one or more slots 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, 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 . 
         [0030]    Turning to the detail view of  FIG. 5 , tool system  10  may include lockout mechanism  100 , which may be disposed within tool  12 . Lockout mechanism  100  may include a shaft  102  extending rearward from tool  12  through opening  116  in coupler  72  of tool  12  and opening  118  in coupler  74  of pole assembly  14 . Openings  116  and  118  may be substantially similarly sized and may be slightly larger than a diameter of shaft  102 . Second coupler additionally may include a flange  120  at opening  118 , such that inner bore of second coupler  74  may expand past flange  120 . 
         [0031]    Alternatively, second coupler  74  may not have separate flange  120 . Instead, opening  118  of second coupler may be larger than opening  116  of first coupler  72 , such that flange may be created by abutment of first coupler  72  with second coupler  74 . 
         [0032]    Shaft  102  may include a connector  114 , which also may be considered abutment means, between lockout mechanism  100  and internal rod  82 . Connector  114  may be a collar configured to fit around shaft  102  and to increase radial extent of shaft  102 . Alternatively, shaft  102  may have a threaded end, and connector  114  may comprise a nut configured to thread onto shaft, e.g., a locking nut that may resist unthreading. 
         [0033]    Lockout mechanism  100  may include spring  110 , which preferably is a compression spring. Spring  110  may surround shaft  102  and may be disposed between flange  120  and connector  114 . As such, spring  110  may serve one or more purposes, e.g., biasing lockout mechanism  100  to an initial, pre-firing position and inhibiting misfiring by biasing lockout mechanism  100  away from trigger sleeve. 
         [0034]    At an opposite end of shaft  102  from connector  114 , lockout mechanism  100  may include a receptacle or receiver  104  for receiving one or more balls  112 . Receiver  104  may include a cradle or well  106  configured to receive ball  112  when tool is oriented in an acceptable configuration, e.g., upward or generally above a horizontal. Well  106  may have a depth smaller than a diameter of ball  112 , such that ball  112  may roll out of well more easily as tool  12  is lowered from an upright configuration. The deeper well  106  is, the longer ball  112  may be retained within well  106 , permitting firing of tool  12 . Conversely, a shallower well  106  may allow ball  112  to be roll out more easily. Well  106  may have a depth between about 10% and about 90% of the radius of ball  112 , preferably between about 25% and about 75% of the radius, and in one embodiment, about 50% of the radius. 
         [0035]    Lockout mechanism  100  also may include tapered flange  108  surrounding open end of well  106 . In one embodiment, flange  108  may taper downwards from an outer edge to open end of well  106  between about 5 degrees and about 30 degrees, preferably about 15 degrees. In addition, flange may extend radially outward a sufficient distance to prevent ball  112  from falling behind flange, i.e., to prevent flange  108  from being between trigger sleeve  60  and ball  112 . 
         [0036]    At the same time, flange  108  may not extend outward so far as to contact walls of housing cavity  19 . As seen in  FIG. 5 , flange  108  may be about ½ the width of cavity diameter, ball  112  may have a diameter about ⅓ a width of cavity diameter, and protrusion  68  also may have a diameter of about ⅓ a width of cavity diameter. As such, when not in well  106 , ball  112  may move freely around protrusion  68  without becoming jammed or wedged between cavity and protrusion. Additionally, lockout mechanism  100  and trigger sleeve  60  may be sized and spaced so that ball  112  may fit between lockout mechanism  100  and trigger sleeve  60  and not cause trigger sleeve  60  to be advanced when ball  112  is not disposed within receiver  104 . For example, rear end of trigger sleeve  60  proximate protrusion  68  may be spaced a distance at least as large as diameter of ball  112  from a forward end of lockout mechanism  100 . 
         [0037]    Similarly, well  106  may partially receive protrusion  68  extending rearward from trigger sleeve  60  when tool is oriented in an unacceptable configuration, e.g., generally at or below a horizontal. In this configuration, ball  112  may not be disposed within well  106 . Additionally, lockout mechanism  100  may be configured such that, when ball  112  is not disposed in well  106 , a lockout gap LG may remain between trigger sleeve  60  and rod  82 , even when rod  82  is translated to a fully forward position. By preventing contact between protrusion  68  of trigger sleeve  60  and rod  82 , trigger sleeve  60  is prevented from sliding forward and releasing firing pin, which would lead to firing of tool. Gap may be between about 1/16″ and about 1″, preferably between about ¼″ and about ½″, and in one embodiment, about ⅜″. 
         [0038]    In addition to tip of protrusion  68  being spaced apart from a bottom of well  106 , protrusion  68  may have a tapered end, e.g., forming a frustoconical portion, so that sides of protrusion  68  also are spaced from sides of well  106 . Spacing may be large enough to prevent inadvertent contact between protrusion  68  and lockout mechanism  100  while being small enough to prevent ball  112  from passing through the gap and into well  106 . This sidewall spacing gap may be generally equal to lockout gap LG proximate the bottom of protrusion  68 . 
         [0039]      FIGS. 1-4  illustrate how tool system  10  with lockout mechanism  100  may be used. As seen in  FIG. 1 , prior to being depressed against a substrate, barrel assembly  30  of tool  12  may extend outward from tool housing  20 . Firing pin assembly  40  may be disposed in a forward position, with spring  46  in a relatively uncompressed, starting position. In addition, with respect to pole assembly  14 , sleeve  88  coupled to rod  82  both may be in a rearward position. As such, there may be a gap between rod  82  and lockout mechanism  100 . Additionally or alternatively, gap between well  106  of lockout mechanism  100  and protrusion  68  of trigger sleeve  60  may be larger than diameter of ball  112 . Even if ball  112  is disposed within well  106 , this spacing may allow for ball  112  to become unseated from well  106  to roll to an area not aligned with protrusion  68 . Conversely, if tool system  10  is in an acceptable firing position, ball  112  may roll to a position generally within well  106  and generally aligned with protrusion  68 , although a gap still may exist between ball  112  and protrusion. 
         [0040]    Turning now to  FIG. 2 , as barrel assembly  30  is pressed against substrate, cocking rod  38  may move rearward until operatively engaging firing pin assembly  40 , thereby driving firing pin assembly  40  rearward and compressing spring  46  and loading firing pin assembly  40  into a ready-to-fire position. In  FIG. 2 , ball  112  is shown within receiver  104 , although firing pin assembly  40  similarly may be loaded into ready-to-fire position even if ball is outside of receiver, as seen in  FIG. 4 . 
         [0041]    Turning further to  FIG. 3 , with firing pin assembly  40  in ready-to-fire position and ball  112  with receiver  104  of lockout mechanism, to actuate tool system  10 , sleeve  88  may be moved upwards toward tool  12 . By virtue of operative coupling, rod  82  of pole assembly  14  similarly may be moved towards tool. End of rod  82  may contact lockout mechanism  100 , e.g., via shaft  102  and/or nut  114 . As rod  82  continues to be moved forward, lockout mechanism  100  and ball  112  also move forward, bridging gap between ball  112  and trigger sleeve  60  and then causing trigger sleeve  60  to be moved forward, compressing spring  58 . Eventually, trigger sleeve  60  reaches a firing position, whereby tension on firing pin spring  46  is released, releasing firing pin assembly  40  toward a load, detonating the load. Detonation may drive piston  36  forward, driving fastener out of muzzle end  32  and into work surface. 
         [0042]    Actuating lockout mechanism  100  forward also may cause spring  110  to compress against nut  114 . 
         [0043]    After firing, the user may release the sleeve  88  or relieve forces caused by actuation of sleeve  88 . For example, one or both of springs  58  and  110  may extend back to their initial positions, biasing trigger sleeve  60  and lockout mechanism  100 , respectively, to rearward configurations, at which point tool system  10  may be readied for reloading and/or refiring. 
         [0044]    Turning to  FIG. 4 , if tool system  10  is disposed at an unacceptable angle, e.g., horizontally, and pressed against a work surface, firing pin assembly  40  may be compressed into a ready-to-fire position. In this configuration, however, ball  112  may roll into a portion of housing cavity  19  not aligned with lockout mechanism  100  and/or trigger sleeve protrusion  68 . Thus, if the user actuates sleeve  88  and/or rod  84  fully forward, lockout mechanism  100  may move forward and spring  110  may compress, but gap LG may not be bridged. Thus, trigger sleeve  60  may be prevented from moving forward, preventing firing pin assembly  40  from being released and tool  12  from firing. 
         [0045]    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.