Patent Publication Number: US-2020290190-A1

Title: Gas spring fastener driver

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of co-pending U.S. patent application Ser. No. 15/807,724 filed on Nov. 9, 2017, which claims priority to U.S. Provisional Patent Application No. 62/419,719 filed on Nov. 9, 2016, the entire contents of both of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to power tools, and more particularly to gas spring fastener drivers. 
     BACKGROUND OF THE INVENTION 
     There are various fastener drivers used to drive fasteners (e.g., nails, tacks, staples, etc.) into a workpiece known in the art. These fastener drivers operate utilizing various means (e.g., compressed air generated by an air compressor, electrical energy, flywheel mechanisms) known in the art, but often these designs are met with power, size, and cost constraints. 
     SUMMARY OF THE INVENTION 
     The present invention provides, in one aspect, a fastener driver including a cylinder, a piston positioned and moveable within the cylinder, a driver blade attached to the piston and movable with the piston, a front nosepiece at least partially defining a fastener driving track through which fasteners are driven by the driver blade, a rear nosepiece at least partially defining the fastener driving track, and a magazine attached to the rear nosepiece and operable to supply the fasteners to the fastener driving track through the rear nosepiece. The rear nosepiece and the magazine are removably coupled to the front nosepiece as a unit. 
     The present invention provides, in another aspect, a method of operating a fastener driver. The method includes initiating a fastener driving operation by moving a driver blade, with a gas spring mechanism, from a retracted position toward a driven position, stopping the driver blade at an intermediate position between the retracted position and the driven position in response to a fastener jammed in a fastener driving track defined between a front nosepiece and a rear nosepiece of the fastener driver, detaching a battery from the fastener driver, and removing the magazine and the rear nosepiece as a unit from the front nosepiece, after the battery has been removed. 
     The present invention provides, in yet another aspect, a fastener driver including a housing, a cylinder, a piston positioned and moveable within the cylinder, a driver blade attached to the piston and movable with the piston between a first position and a second position, a gas spring mechanism onboard the housing for driving the driver blade from the first position toward the second position, a motor for returning the piston from the second position toward the first position, thereby compressing gas in the gas spring mechanism, a battery removably coupled to the housing for supplying power to the motor, a front nosepiece at least partially defining a fastener driving track through which fasteners are driven by the driver blade, an electrical switch coupled to the front nosepiece, a rear nosepiece at least partially defining the fastener driving track, and a magazine attached to the rear nosepiece and operable to supply the fasteners to the fastener driving track through the rear nosepiece. The rear nosepiece and the magazine are removably coupled to the front nosepiece as a unit, and the electrical switch is operable to detect when the rear nosepiece is removed from the front nosepiece. 
     Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of a gas spring fastener driver in accordance with an embodiment of the invention. 
         FIG. 2  is a cross sectional view of the gas spring fastener driver along line  2 - 2  of  FIG. 1 . 
         FIG. 3  is an enlarged perspective view of a portion of the gas spring fastener driver of  FIG. 1 , illustrating a magazine in an engaged position with a nosepiece of the fastener driver. 
         FIG. 4  is a side view of the portion of the gas spring fastener driver of  FIG. 3 , illustrating the magazine in a disengaged position from the nosepiece of the fastener driver. 
         FIG. 5  is a bottom view of the gas spring fastener driver of  FIG. 1 , illustrating the magazine in the engaged position. 
         FIG. 6  is a bottom view of the gas spring fastener driver of  FIG. 1 , illustrating the magazine in the disengaged position with a blocking member abutting a battery of the fastener driver. 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     DETAILED DESCRIPTION 
     With reference to  FIGS. 1 and 2 , a gas spring fastener driver  10  for driving fasteners  12  (e.g., nails, tacks, staples, etc.) into a workpiece is shown. The fastener driver  10  includes a housing  14 , a nosepiece  16  extending from the main housing  14 , and a magazine  18  for sequentially feeding fasteners  12  (e.g., collated fasteners) into the nosepiece  16  prior to each fastener-driving operation. Although the magazine  18  of the illustrated embodiment is composed of a magnesium material, in other embodiments, the magazine  18  can alternatively be composed of a different metal or metal allow, or other suitable materials. 
     As shown in  FIG. 2 , the fastener driver  10  also includes a drive blade  20  and an onboard gas spring mechanism  24  for driving the drive blade  20  coinciding with ejection of a fastener  12  from the nosepiece  16 . Accordingly, the fastener driver  10  does not require an external source of air pressure for driving the drive blade  20 . Rather, the gas spring mechanism  24  includes a storage chamber  28  of pressurized gas in fluid communication with a cylinder  32 . The cylinder  32  and a moveable piston  36  are positioned within the storage chamber  28 . 
     With reference to  FIG. 2 , the cylinder  32  and the drive blade  20  define a driving axis  44 , and during a driving cycle the drive blade  20  and the piston  36  are moveable along the driving axis  44  between a ready position (i.e., top dead center; see  FIG. 2 ) and a driven position (i.e., bottom dead center). In the driven position, the piston  36  is abutted by a bumper  46  to stop further movement of the piston  36 . The fastener driver  10  further includes a lifting assembly  48 , which is powered by a motor  52 , and which is operable to move the drive blade  20  from the driven position to the ready position. The drive blade  20  is biased to the driven position by compressed gas in the storage chamber  28 . With reference to  FIG. 1 , the fastener driver  10  further includes a handle  56  that is grasped by an operator for maneuvering the fastener driver  10 . The handle  56  and the motor  52  are both oriented substantially perpendicular to the driving axis  44 . Also, the fastener driver  10  includes a battery  60  that is removably coupled to the handle  56  along a battery insertion/removal axis  62  that is also perpendicular to the driving axis  44 . The battery  60  is electrically connectable to the motor  52  for supplying electrical power to the motor  52  to drive the lifting assembly  48 . 
     In operation, the lifting assembly  48  ( FIG. 2 ) raises the piston  36  and the drive blade  20  from the driven position and toward the ready position by energizing the motor  52 . As the piston  36  and the drive blade  20  are moved to the ready position, the gas above the piston  36  and the gas within the storage chamber  28  is compressed. Once in the ready position, the piston  36  and the drive blade  20  are held in position until released by user activation of a trigger (not shown). When released, the compressed gas above the piston  36  and within the storage chamber  28  drives the piston  36  and the drive blade  20  to the driven position, thereby driving a fastener into a workpiece. The illustrated fastener driver  10  therefore operates on a gas spring principle utilizing the lifting assembly  48  and the piston  36  to further compress the gas within the cylinder  32  and the storage chamber  28 . Further detail regarding the structure and operation of the fastener driver  10  is provided below. 
     With reference to  FIGS. 3 and 4 , the nosepiece  16  further includes a front nosepiece  64 , a rear nosepiece  68 , and an over-center spring latch  72  (i.e., a quick-release latch) operable to secure the rear nosepiece  68  to the front nosepiece  64 . Because the magazine  18  is attached or otherwise unitized with the rear nosepiece  68 , attaching the rear nosepiece  68  to the front nosepiece  64  also attaches the magazine  18  to the front nosepiece  64 . Also, when the front and rear nosepieces  64 ,  68  are interconnected, a fastener driving track or channel  76  is formed therebetween ( FIG. 3 ). The fastener driving track  76  is coaxial with the driving axis  44  and is in communication with the magazine  18  in order to sequentially receive the fasteners  12  from the magazine  18  for consecutive fastener driving operations. As illustrated in  FIG. 3 , the rear nosepiece  68  includes a first pair of projections  80  and a second pair of hooks or projections  84 , both of which extend away from the rear nosepiece  68  toward the front nosepiece  64 , positioned on opposite sides of the fastener driving track  76 . The first pair of projections  80  extend into corresponding slots  88  defined in the front nosepiece  64 . Within at least one of the slots  88  is positioned an electrical switch  92  (e.g., a microswitch,  FIG. 4 ) that is operable to detect when the projections  80  are received within the respective slots  88 . Accordingly, the electrical switch  92  is operable to detect when the rear nosepiece  68  is removed from the front nosepiece  64 , and when the rear nosepiece  68  is connected with the front nosepiece  64 . In other embodiments, each of the slots  88  may contain a switch  92  to detect when the rear nosepiece  68  is connected to and removed from the front nosepiece  64 . 
     With reference to  FIG. 3 , the spring latch  72  includes a lever  96  pivotably coupled to the front nosepiece  64  and a spring member  100 , including spaced pins  103 , that is pivotably coupled to the lever  96  in an over-center-type configuration. In turn, the spring member  100  is engageable (via pins  103 ) with the second pair of projections  84 , which are configured as hooks, that extend through respective apertures  102  in the front nosepiece  64 . When the lever  96  is pivoted to an over-center position (shown in  FIG. 3 ), the spring member  100  exerts a clamping force against the projections  84 , preventing them from being removed from the apertures  102 . Accordingly, the rear nosepiece  68  and the magazine  18  are retained to the front nosepiece  64  in an engaged position, as shown in  FIG. 3 . And, when the lever  96  is pivoted downward from the frame of reference of  FIG. 3 , the spring member  100  releases the clamping force on the projections  84 , permitting the spring member  100  to be pivoted away from the front nosepiece  64 , and permitting the rear nosepiece  68  (with the attached magazine  18 ) to be moved in a rearward direction (i.e., toward a disengaged position shown in  FIG. 4 ). 
     With reference to  FIGS. 4-6 , the rear nosepiece  68  and magazine  18  move along a first (i.e., rearward) direction  104  when moving toward the disengaged position and along a second (i.e., forward) direction  108  when moving toward the engaged position. The magazine  18  includes a blocking member  112  laterally protruding from a side thereof closest to the housing  14  and battery  60 . The blocking member  112  is located between the driving axis  44 , which is coaxial with the drive blade  20 , and the battery  60  ( FIG. 1 ). As shown in  FIGS. 5 and 6 , the blocking member  112  protrudes from the magazine  18  by a sufficient amount to overlap a portion of the battery  60 . As such, the blocking member  112  acts as a safety mechanism because an operator is required to remove the battery  60  (thereby disconnecting any power to the motor  52 ) prior to removing the magazine  18  for clearing a jammed fastener  12  from the nosepiece  16 . By removing the battery  60 , any inadvertent fastening operations are avoided. When the battery  60  remains attached to the handle  56 , the blocking member  112  interferes with a shoulder  116  ( FIG. 6 ) of the battery  60  if removal of the magazine  18  from the nosepiece  16  is attempted prior to removing the battery  60 . In the engaged position of the rear nosepiece  68  and magazine  18 , a gap  120  exists between the shoulder  116  of the battery  60  and the blocking member  112  ( FIG. 5 ). After releasing the latch  72 , the rear nosepiece  68  and magazine  18  may be moved in direction  104  until the blocking member  112  abuts the shoulder  116 , thereby limiting any further movement of the magazine  18  in direction  104  so long as the battery  60  remains attached to the housing  14 . At this point, the gap  120  now exists between the front nosepiece  64  and the rear nosepiece  68 . However, at this time, the projections  84  remain within the apertures  102  ( FIG. 4 ), preventing the magazine  18  from being removed as long as the battery  60  remains attached to the housing  14 . 
     Occasionally, a misfire or incomplete fastening operation, resulting in a jam, occurs during operation of the fastener driver  10 . That is, the fastener  12  failed to completely eject from the nosepiece  16  into the workpiece. Subsequently, the drive blade  20  is inhibited from moving through its full stroke length due to the fastener  12  blocking the fastener driving track  76 . To prevent the operator from attempting to clear the jammed fastener  12  while power is still supplied to the fastener driver  10  by the connected battery  60 , removal of the rear nosepiece  68  and the magazine  18  to access the fastener driving track  76  (to clear the jam) first requires removal of the battery  60 . After the battery  60  is removed, a fastener driving operation cannot be inadvertently initiated, and the rear nosepiece  68  and magazine  18  can be fully disengaged from the front nosepiece  64  to access the fastener driving track  76  to clear the jam. 
     Also, due to the presence of the electrical switch  92  in the slot  88  of the front nosepiece  64 , the fastener driver  10  will remain deactivated, despite reattachment of the battery  60 , until the rear nosepiece  68  and magazine  18  are reattached to the front nosepiece  64 . Upon reattachment of the rear nosepiece  68  and magazine  18 , the projection  80  contacts and closes the switch  92  (if it is normally open), thereby returning the fastener driver  10  to an active or operational state in which a fastener firing operation may be initiated. 
     Various features of the invention are set forth in the following claims.