Abstract:
A device for impacting a fastener in one embodiment includes a trigger, a trigger disabling mechanism changeable between a first condition wherein operation of the trigger is not disabled and a second condition wherein operation of the trigger is disabled, and a nose piece configured to change the trigger disabling mechanism from the second condition to the first condition, the nose piece including a first nose portion removably coupled to a second nose portion, the first nose portion and the second nose portion defining a channel therebetween through which a fastener is driven.

Description:
FIELD OF THE INVENTION  
       [0001]    This invention relates to the field of devices used to drive fasteners into work-pieces and particularly to a device for impacting fasteners into work pieces. 
       BACKGROUND  
       [0002]    Fasteners such as nails and staples are commonly used in projects ranging from crafts to building construction. While manually driving such fasteners into a work piece is effective, a user may quickly become fatigued when involved in projects requiring a large number of fasteners and/or large fasteners to be driven into a work piece. Moreover, proper driving of larger fasteners into a work piece frequently requires more than a single impact from a manual tool. 
         [0003]    In response to the shortcomings of manual driving tools, power-assisted devices for driving fasteners into work pieces have been developed. Contractors and homeowners commonly use such devices for driving fasteners ranging from brad nails used in small projects to common nails which are used in framing and other construction projects. Compressed air has been traditionally used to provide power for the power-assisted (pneumatic) devices. 
         [0004]    Various safety features have been incorporated into pneumatic and other power nailers. One such device is commonly referred to as a work contact element (WCE). A WCE is incorporated into nail gun designs to prevent unintentional firing of the nail gun. A WCE is typically a spring loaded mechanism which extends forwardly of the portion of the nail gun from which a nail is driven. In operation, the WCE is pressed against a work piece into which a nail is to be driven. As the WCE is pressed against the work piece, the WCE compresses the spring and generates an axial movement which is transmitted to a trigger assembly. The axial movement is used to reconfigure a safety device, also referred to as a trigger disabling mechanism, so as to enable initiation of a firing sequence with the trigger of the nail gun. 
         [0005]    While the use of a WCE is very effective in preventing inadvertent firing of a nail gun, the location of the WCE can be problematic. Specifically, the WCE blocks the view that an operator has of the location on the work piece into which a nail or other fastener is to be driven. For projects which require fasteners to be driven into precise locations, the visual interference caused by the WCE can result in inaccurate placement of the fastener in the work piece. 
         [0006]    What is needed is a safety system which can be used to prevent inadvertent nail gun firing while providing an operator with an unobstructed view of the location into which a fastener is to be driven. What is further needed is a system which provides easy access for clearing jams in the nail drive channel. 
       SUMMARY  
       [0007]    In accordance with one embodiment, there is provided a device for impacting a fastener which in one embodiment includes a trigger, a trigger disabling mechanism changeable between a first condition wherein operation of the trigger is not disabled and a second condition wherein operation of the trigger is disabled, and a nose piece configured to change the trigger disabling mechanism from the second condition to the first condition, the nose piece including a first nose portion removably coupled to a second nose portion, the first nose portion and the second nose portion defining a channel therebetween through which a fastener is driven. 
         [0008]    In accordance with another embodiment, a device for impacting a fastener includes a nose assembly with a base portion, a first nose section configured to be slidably positioned on the base portion, and a second nose section removably coupled to the first nose section, the first nose section and the second nose section defining a path along which a fastener is driven by the device, a trigger mechanism for initiating a firing sequence, and a trigger disabling mechanism for disabling the trigger mechanism, the trigger disabling mechanism responsive to the position of the first nose section, such that when the first nose section is in a first position the trigger disabling mechanism disables the trigger mechanism and when the first nose section is in a second position the trigger disabling mechanism does not disable the trigger mechanism. 
         [0009]    In accordance with a further embodiment, a method of impacting a fastener includes removably coupling a first nose section and a second nose section, forming an angle with an arm of a lever and the upper surface of the first nose section, moving the coupled nose sections from a first position to a second position whereat a first surface of a spreader is in contact with the arm and a second surface of the spreader is in contact with the upper surface of the first nose section, enabling operation of a trigger when the coupled nose sections are in the second position, and forcing a fastener along a channel formed by the coupled nose sections. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0010]      FIG. 1  depicts a side perspective view of a fastener impacting device in accordance with principles of the present invention; 
           [0011]      FIG. 2  depicts a top perspective view of the nose assembly of the fastener impacting device of  FIG. 1 ; 
           [0012]      FIG. 3  depicts an exploded perspective view of the nose assembly of  FIG. 2 ; 
           [0013]      FIG. 4  depicts a partial side perspective view of the nose assembly of  FIG. 2  without the base section showing the upper nose section lying on the lower nose section; 
           [0014]      FIG. 5  depicts a partial side perspective view of the nose assembly of  FIG. 2  without the base section showing the upper nose section in a locked coupled condition with the lower nose section and the spreading wedges of the lever positioned between opposing wedge walls of the lower nose section and the upper nose section; 
           [0015]      FIG. 6  depicts a side plan view of the nose assembly of  FIG. 2  as the upper nose section of the nose assembly contacts a work piece; 
           [0016]      FIG. 7  depicts a side plan view of the nose assembly of  FIG. 2  in a position whereat the angle between the upper arm of the lever and the upper surface of the upper nose section matches the angle defined by the ramps and the lower portion of the spreader such that the upper nose section and lower nose section have been received into an opening of the nose assembly spreader and the upper arm of the lever has come into contact with the ramps of the spreader as the nose assembly contacts a work piece, which causes a trigger disabling mechanism to be reconfigured; and 
           [0017]      FIG. 8  depicts a side plan view of the nose assembly of  FIG. 2  wherein the angle between the upper arm of the lever and the upper surface of the upper nose section does not match the angle defined by the ramps of the spreader and the lower portion of the spreader, thereby inhibiting movement of the upper nose section and lower nose section into an opening of the nose assembly spreader so that the trigger disabling mechanism is not reconfigured. 
       
    
    
     DESCRIPTION  
       [0018]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains. 
         [0019]      FIG. 1  depicts a fastener impacting device  100  including a housing  102  and a fastener cartridge  104 . The housing  102  defines a handle portion  106  from which a trigger  108  extends, a receptacle area  110  and a drive section  112 . The fastener cartridge  104  in this embodiment is spring biased to force fasteners, such as nails or staples, serially one after the other, into a loaded position adjacent the drive section  112 . The receptacle area  110  may be used to connect a source of compressed air or other source of power to the fastener impacting device  1   00 . 
         [0020]    Located adjacent to the drive portion  112  is a nose assembly  114 . Referring to  FIG. 2 , the nose assembly  114  includes a base  120 , a lower nose section  122  and an upper nose section  124 . The base  120  includes a bed  126  shown in  FIG. 3 . Two guide rails  128  and  130  extend along the bed  126  and through an opening  132  defined in part by a spreader  134 . The spreader  134  includes a lower portion  136  and a pair of ramps  138  which extend upwardly from the lower portion  136  and increase in height from the forward portion of the ramps  138  to the rear portion of the ramps  138 . A pair of spring wells  140  are positioned at the bottom of the bed  126  and a pair of guide channels  142  (only one is sown in  FIG. 2 ) are located adjacent to, and on the opposite sides of, the bed  126 . 
         [0021]    The lower nose section  122  includes a number of forward facing wedges  144  and a pair of wedge walls  146 . A pair of guides  148  and a bracket  150  are located at the sides of the lower nose section  122 . A spring stop  152  is located on the bottom of the lower nose section  122  which may be shaped complementary to the guide rails  128  and  130 . 
         [0022]    The upper nose section  124  includes a number of rearward facing wedges  154  and a pair of wedge walls  156 . A bracket  158  is located on the upper surface of the rearward end portion  160  of the upper nose section  124 . The forward end portion  162  defines a channel port  164 . 
         [0023]    The remaining components of the nose assembly  114  shown in  FIG. 3  are identified with reference to assembly of the nose assembly  114 . Initially, two springs  170  are positioned in the spring wells  140 . The lower nose section  122  is then placed on the bed  126  by aligning one of the guides  148  with a slot  172 . A depth control nut  174  is positioned within the bracket  150  and a guide rod  176  is inserted through a first guide bore  178 , the bracket  150 , and the depth control nut  174  and into a second guide bore  180 . At this point, the guides  148  are aligned with the guide channels  142 . 
         [0024]    The lower nose section  122  is then moved slightly rearwardly (toward the ramps  138 ) which brings the spring stop  152  into contact with the springs  170 . Additionally, one of the guides  148  moves partially into one of the guide channels  142 . Insertion of the pin  182  into the pin hole  184  prevents the lower nose section  122  from moving forwardly to a location whereat the guide  148  nearest to the pin would no longer be within the guide channel  142  and aligned with the slot  172 . With the exception of the biasing force of the springs  170 , however, the lower nose section  122  is free to move rearwardly into the opening  132 . Thus, the lower nose section  122  is slidingly maintained on the bed  126  by a guide  148  located within a guide channel  142  on one side and by the bracket  150  which is slidably constrained by the guide rod  176  on the other side. 
         [0025]    The upper nose section  124  is coupled with the lower nose section  122  by generally aligning the wedge walls  146  with the wedge walls  156 . This allows the rearward facing wedges  154  to move past the forward facing wedges  144  so that the upper nose section  124  is fully supported by the lower nose section  122  as shown in  FIG. 4 . Once the upper nose section  124  is placed upon the lower nose section  122 , the end portions of the upper nose section  124  and the lower nose section  122  located underneath the upper arm  192  define a cross section that is slightly smaller than the size of the opening  132 . 
         [0026]    The upper nose section  124  may then be moved in the direction of the arrow  200  in  FIG. 4 . This movement initiates a coupling between the rearward facing wedges  154  and the forward facing wedges  144 . Thus, the lower nose section  122  and the upper nose section  124  form a nose piece  198 . Additionally, a gap is generated between each opposing pair of the wedge walls  146  and the wedge walls  156 . Once sufficient gaps are present, the lever  188 , which is constantly biased to rotate in the clockwise direction as viewed in  FIG. 4 , rotates the spreading wedges  196  into the gaps between the wedge walls  146  and the wedge walls  156 . 
         [0027]    The bias of the lever  188  forces the wedge walls  146  and the wedge walls  156  farther apart, thereby providing additional coupling between the rearward facing wedges  154  and the forward facing wedges  144  as shown in  FIG. 5 . As shown in  FIG. 5 , the end portions  202  and  204  of the lower nose section  122  and the upper nose section  124 , respectively, define an opening, generally indicated by reference number  206 , to a channel defined by the lower nose section  122  and the upper nose section  124  which is aligned with, and opens to, the channel port  164  shown in  FIG. 2 . 
         [0028]    Operation of the fastener impacting device  100  is described with reference to  FIGS. 1 ,  3  and  5 . An operator, after providing an energy source to the fastener impacting device  100  using the receptacle area  110 , grasps the handle  106 . The operator moves the fastener impacting device  100  toward a work piece  210  shown in  FIG. 6  by moving the fastener impacting device  100  in the direction of the arrow  212 . Initial contact with the work piece  210  is made by the upper nose section  124 . Continued application of pressure forces the springs  170  against the spring stop  152  (see  FIG. 3 ) generating a bias of the lower nose section  120  in a direction toward the work piece  210 . 
         [0029]    Biasing of the lower nose section  120  forces the rearward facing wedges  154  and the forward facing wedges  144  (see  FIG. 5 ) toward a tighter coupling since the upper nose section  124  is immobilized by the work piece  210 . As the springs  170  compress, the base  120  moves toward the work piece  210 , causing relative movement between the lower nose section  122  and the bed  126 . Thus, the nose piece  198  formed by the coupled lower nose section  122  and upper nose section  124  is received more deeply into the opening  132 . 
         [0030]    Reception of the nose piece  198  into the opening  132  continues until the upper arm  192  of the lever  188  contacts the ramps  138  as shown in  FIG. 7 . Because the lever  188  is pivotably connected to the upper nose section  122  which is immobilized by the work piece  210 , continued movement of the fastener impacting device  100  forces the ramps  138  against the upper arm  192  pushing the upper arm  192  in an upward direction as viewed in  FIG. 7 . 
         [0031]    As the upper arm  192  is biased in the upward direction, upward movement of the nose piece  198  is restrained by the lower portion  136  of the spreader  134 . Accordingly, the force applied to the upper arm  192  generates a bias on the spreading wedges  196 . Thus, the constant bias of the lever  188 , in the counterclockwise direction as viewed in  FIG. 7 , is augmented by the force of the ramps  138  against the upper arm  192 . Accordingly, the coupled rearward facing wedges  154  and the forward facing wedges  144  are biased toward a locked condition as the spreading wedges  196  are pushed into the gap between the opposing wedge walls  146  and  156  (see  FIG. 5 ). 
         [0032]    When the nose piece  198  is in a locked coupled condition, the spreading wedges  196  are rotated into the gap between the opposing wedge walls  146  and  156  such that the upper arm  192  is pivoted to an angle with respect to the upper surface of the upper nose section  124  which allows the nose piece  198  to extend through the opening  132  to cause reconfiguration of a trigger disabling mechanism to a condition which allows the trigger  108  to initiate a firing sequence. 
         [0033]    The trigger disabling mechanism (not shown) may be mechanically repositioned by the nose piece  198 . Alternatively, a signal indicative of the position of one or more of the movable portions of the nose assembly  114  may be used to control reconfiguration of the trigger disabling mechanism. In a further embodiment, the trigger disabling mechanism electrically disables the trigger  108 . In any event, once the angle between the upper arm  192  and the upper surface of the upper nose section  124  is equal to the angle defined by the ramps  138  and the lower portion  136  of the spreader  134 , the nose piece  198  can be positioned with respect to the base  120  such that the trigger disabling mechanism enables initiation of a firing sequence by the trigger  108 . 
         [0034]    Once the trigger disabling mechanism no longer inhibits operation of the trigger  108 , the operator initiates a firing sequence to impact a fastener by activating the trigger  108 . In response, a fastener is driven along the channel defined by the lower nose section  122  and the upper nose section  124 . The fastener is then driven through the channel port  164  and into the work piece  210 . The depth to which the fastener is driven into the work piece  210  may be controlled by positioning of the depth control nut  174 . Subsequently, the operator moves the fastener impacting device in a direction away from the work piece  210 . This removes the compressive pressure from the springs  170  which then force the nose piece  198  along the bed  126  to an extended position whereat initiation of a firing sequence by the trigger  108  is again inhibited. 
         [0035]    The upper nose section  124  and the lower nose section  122  may not be in a locked coupled condition when the upper arm  192  contacts the ramps  138 . So long as the upper nose section  124  and the lower nose section  122  are coupled and the nose assembly  114  is not jammed, the additional force provided by the contact with the ramps  138  can force the upper nose section  124  and the lower nose section  122  into a locked coupled condition. 
         [0036]    If, however, the upper nose section  124  and the lower nose section  122  are misaligned or the nose assembly  114  is jammed, the spreading wedges  196  will not be able to force the upper nose section  124  and the lower nose section  122  into a locked coupled condition. Accordingly, the angle formed between the upper arm  192  and the upper surface of the upper nose section  124  will be less than the angle defined by the ramps  138  and the lower portion  136  of the spreader  134  as depicted in  FIG. 8 . 
         [0037]    Consequently, reception of the upper nose section  124  and the lower nose section  122  into the opening  132  is inhibited once the upper arm  192  contacts the ramps  138 . The upper nose section  124  and the lower nose section  122  are thus inhibited from being positioned so as to cause reconfiguration of the trigger disabling mechanism to a configuration which allows the trigger  108  to be used to initiate a firing sequence. 
         [0038]    The nose assembly  114  may be disassembled to clear a fastener which is stuck in the channel between the lower nose section  122  and the upper nose section  124 . Disassembly of the nose assembly  114  is accomplished by first depressing the upper arm  192  of the lever  188 . As the upper arm  192  is moved toward the upper surface of the upper nose section  124 , the spreading wedges  196  are pivoted out of the gap between the opposing wedge walls  146  and  156 . 
         [0039]    Once the spreading wedges  196  are clear of the gap between the opposing wedge walls  146  and  156 , the upper nose section  124  is forced in a direction away from the ramps  138 . As described above, movement of the lower nose section  122  in the direction away from the ramps  138  is inhibited by the pin  182 , which may be in the form of a screw or other removable component. As the lower nose section  122  contacts the pin  182 , continued movement of the upper nose section  124  causes the rearward facing wedges  154  and the forward facing wedges  146  to de-couple. The upper nose section  124  may then be lifted off of the lower nose section  122  to clear the nose assembly  114 . 
         [0040]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.