Patent Publication Number: US-9415494-B2

Title: Fastening tool assembly

Description:
TECHNICAL FIELD 
     Various embodiments relate to fastening tool assemblies. 
     BACKGROUND 
     Various fastening tool assemblies require a large input force to load a spring, which consequently drives a fastener from the tool assembly. 
     SUMMARY 
     According to at least one embodiment, a fastening tool assembly is provided with a housing having a contact surface to contact a workpiece. A fastener outlet is provided along the contact surface to dispense fasteners therethrough. A magazine is mounted in the housing to store fasteners and to convey the fasteners to the fastener outlet. A knife is mounted in the housing for translation relative to the outlet for a latched position and a release position to drive a fastener from the magazine through the outlet during translation to the release position. A biasing member is mounted in the housing and is operably connected to the knife to bias the knife to the release position. A handle is mounted to the housing to translate relative to the housing. The handle is operably connected to the knife and the biasing member to load the biasing member and release the knife and the biasing member, thereby permitting the biasing member to return the knife to the release position to consequently drive a fastener through the outlet. 
     According to at least another embodiment, a fastening tool assembly is provided with a housing having a contact surface to contact a workpiece. A fastener outlet is provided along the contact surface to dispense fasteners therethrough. A magazine is mounted in the housing to store fasteners and to convey the fasteners to the fastener outlet. A knife is mounted in the housing for translation relative to the outlet for a latched position and a release position to drive a fastener from the magazine through the outlet during translation to the release position. A biasing member is mounted in the housing and operably connected to the knife to bias the knife to the release position. A handle is mounted to the housing to move relative to the housing. The handle is operably connected to the knife and the biasing member to load the biasing member and release the knife and the biasing member, thereby permitting the biasing member to return the knife to the release position to consequently drive a fastener through the outlet. A pair of inwardly converging ramp surfaces is formed upon the handle facing the housing. A pair of wedges engages the ramp surfaces and cooperates with the biasing member to converge as the handle is translated toward the housing. A third wedge engages the pair of wedges and the biasing member to translate toward the housing thereby loading the biasing member as the pair of wedges converge. 
     According to at least another embodiment, a fastening tool assembly is provided with a housing having a contact surface to contact a workpiece. A fastener outlet is provided along the contact surface to dispense fasteners therethrough. A magazine is mounted in the housing to store fasteners and to convey the fasteners to the fastener outlet. A knife is mounted in the housing for translation relative to the outlet for a latched position and a release position to drive a fastener from the magazine through the outlet during translation to the release position. The knife includes an aperture formed therethrough. A first biasing member is mounted in the housing and is operably connected to the knife to bias the knife to the release position. A handle is mounted to the housing to move relative to the housing. The handle is operably connected to the knife and the first biasing member to load the first biasing member and release the knife and the first biasing member, thereby permitting the first biasing member to return the knife to the release position to consequently drive a fastener through the outlet. A second biasing member biases the knife to a raised position. A latch member is pivotally connected to the housing with a catch extending into the knife aperture to retain the knife in the raised position. A cam portion is provided on the latch member spaced apart from the catch. A slider is mounted for translation in the housing in engagement with the latch member cam portion. The slider has an aperture formed therethrough. The slider cooperates with the handle so that depression of the handle translates the slider until the slider aperture aligns with the latch member cam portion whereby the latch member pivots as the cam portion extends into the slider aperture thereby releasing the catch from the knife thereby releasing the knife. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of a fastening tool assembly according to an embodiment; 
         FIG. 2  is another front perspective view of the fastening tool assembly of  FIG. 1 ; 
         FIG. 3  is a section view of the fastening tool assembly of  FIG. 1  illustrated in an unloaded position; 
         FIG. 4  is another section view of the fastening tool assembly of  FIG. 1  illustrated in a loaded position; 
         FIG. 5  is an enlarged perspective view of a release mechanism of the fastening tool assembly of  FIG. 1 , illustrated in a latched position; 
         FIG. 6  is another enlarged perspective view of the release mechanism of  FIG. 5 , illustrated in a release position; 
         FIG. 7  is another section view of the fastening tool assembly of  FIG. 1  illustrated in a release position; 
         FIG. 8  is a rear perspective view of the fastening tool assembly of  FIG. 1 ; 
         FIG. 9  is another front perspective view of the fastening tool assembly of  FIG. 1 , illustrated with a magazine in an extended position; 
         FIG. 10  is a side elevation view of a fastening tool assembly according to another embodiment; 
         FIG. 11  is a side elevation view of a fastening tool assembly according to yet another embodiment; 
         FIG. 12  is a side elevation view of a fastening tool assembly according to another embodiment; 
         FIG. 13  is a side elevation view of a fastening tool assembly according to yet another embodiment; 
         FIG. 14  is a front elevation view of the fastening tool assembly of  FIG. 13 ; 
         FIG. 15  is a front elevation view of a fastening tool assembly according to another embodiment; 
         FIG. 16  is a partially exploded perspective view of the fastening tool assembly of  FIG. 15 ; 
         FIG. 17  is schematic view of a fastening tool assembly according to yet another embodiment, illustrated in an unloaded position; and 
         FIG. 18  is another schematic view of the fastening tool assembly of  FIG. 17 , illustrated in a loaded position. 
     
    
    
     DETAILED DESCRIPTION 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
     Prior art manual fastening tool assemblies utilize a pivoting handle, with levers to gain mechanical advantage for loading a spring and driving a fastener into a workpiece. Such tool assemblies are often designed for the greatest output required of that tool, such as a large gauge fastener and a hard workpiece. A range of pivoting of the handle is limited by hand grip sizes, thereby limiting a mechanical advantage of the tool. Pivoting handle fastening tool assemblies may be difficult for all people to operate, and may lead to fatigue after repeat usage. 
     Referring to  FIGS. 1 and 2 , a fastening tool assembly  20 , such a staple gun, is illustrated according to an embodiment. The fastening tool assembly  20  includes a base housing  22  with a contact surface  24 , which may be flat as depicted, for contacting a workpiece. A fastener outlet  26  ( FIG. 3 ) is provided in the housing  22  to dispense fasteners individually from the housing  22 . A handle  28  is mounted to the housing  22  to translate relative to the housing  22  to dispense fasteners from the outlet  26 . Without a pivoting handle, a range of translation of the handle  28  is not limited by hand size; and therefore, the range can be designed for reduced input force upon the handle  28 . The fastening tool assembly  20  only requires a pressing motion perpendicular to the workpiece wherein a user&#39;s body weight can be effectively utilized to help actuate the handle  28  toward the workpiece. 
     The tool assembly  20  includes a magazine assembly  30  to store fasteners and to convey the fasteners to the fastener outlet  26 . A knife  32  is mounted in the housing  22  for translation relative to the outlet for a latched position ( FIGS. 2-5 ) and a release position ( FIGS. 6 and 7 ). Translation to the release position drives a fastener from the magazine assembly  30  through the outlet  26 . 
     With continued reference to  FIGS. 2-4 , a load spring  34  is mounted in the housing  22 . The load spring  34  is a leaf spring and engages a fulcrum  36  at one end in the housing  22 . Of course, any type of biasing member is contemplated. The load spring  34  has a free end  38  that extends into an aperture  40  in the knife  32  for driving the knife  32 . Loading of the load spring  34  biases the knife  32  to the release position. 
     The handle  28  includes a carriage  42  with a pair of slots  44  that receive bosses  46  of the housing  22 . The carriage  42  translates relative to the housing  22  due to the engagement of the slots  44  and the bosses  46 . The handle  28  also includes a shroud  48  mounted to the carriage  42  and extending partially over the housing  22 . A pair of inwardly converging ramp surfaces  50 ,  52  is formed upon the carriage  42 , facing the housing  22 . A pair of wedges  54 ,  56  having corresponding inclined surfaces  58 ,  60  that engage the ramp surfaces  50 ,  52 . The pair of wedges  54 ,  56  each also has another inclined surface  62 ,  64  facing the load spring  34 . A third wedge  66  is provided with a pair of inclined surfaces  68 ,  70  in engagement with the inboard facing inclined surfaces  62 ,  64  of the pair of wedges  54 ,  56 . The third wedge  66  includes a central fulcrum  72  that engages the load spring  34 . 
     The tool assembly  20  includes a release mechanism  74  that retains the knife  32  in the latched position depicted in  FIGS. 3-6 . As the handle  28  is translated toward the housing  22 , the pair of wedges  54 ,  56  converges as depicted in  FIG. 4 . As the pair of wedges  54 ,  56  converges, the third wedge  66  is translated toward the magazine assembly  30 , thereby deforming and loading the load spring  34 . 
     The release mechanism  74  includes a latch member  76  pivotally connected to the housing  22 . A catch  78  extends from the latch member  76  into an aperture  80  in the knife  32  to retain the knife  32  in the latched position. A cam portion  82  of the latch member  76  engages a slider  84 , which prevents rotation of the latch member  76  in the latched position. The slider is mounted for translation in the housing  22 , and includes an aperture  86  aligned to receive the cam portion  82  of the latch member  76 . 
     In the intermediate depressed position of the handle  28  in  FIG. 4 , the carriage  42  engages the slider  84 . Further depression of the handle  28  translates the slider  84  as illustrated in  FIGS. 6 and 7 , thereby aligning the slider aperture  86  with the cam portion  82 . The latch member  76  thereby rotates the cam portion  82  into the slider aperture  86 , which withdraws the catch  78  from the knife aperture  80 , and releases the knife  32 . Release of the knife  32  releases the stored load on the load spring  34  causing the load spring  34  to drive the knife  32  into an end fastener on the magazine, thereby shearing the end fastener from a sequential fastener if applicable, and driving the fastener out of the outlet  26  and into the workpiece. At an end of a range of travel of the leaf spring  34 , the leaf spring  34  impacts a damping pad  88  in the housing  22 . 
     A return spring  90  is provided in the housing  22  in engagement with the load spring  34 . The return spring  90  is compressed by the firing of the load spring  34 ; and then expands to return the load spring  34  to a raised position ( FIGS. 2-4 ), thereby also raising the knife  32 , and the third wedge  66 . As the third wedge  66  is raised, the pair of wedges  54 ,  56  diverges and raises the handle  28 . As the knife  32  is raised, the load spring  34  raises the slider  84  thereby pivoting the cam portion  82  of the latch member  76  out of the aperture  86  for pivoting the catch  78  into the knife aperture  80 . Likewise, the slider  84  prevents the latch member  76  from releasing the knife  32 . 
       FIGS. 7-9  depict that the magazine assembly  30  includes a magazine  92  that is mounted for translation in the housing  22  for extension ( FIG. 9 ) from the housing  22  adjacent the fastener outlet  26  to receive fasteners. Another latch member  94  may be pivotally mounted in the housing  22  in engagement with the magazine  92  to retain the magazine  92  within the housing  22 . A button  96  may be mounted on the housing  22  spaced apart from the outlet  26  so that manual depression of the button  96  pivots the latch member  94  out of engagement from the magazine  92  to extend the magazine  92 . 
       FIG. 10  illustrates a fastening tool assembly  98  according to another embodiment with a housing  100  and a handle  102 . Translation of the handle  102  towards the housing  100  causes a ramp surface  104  to engage and load a torsion spring  106  that drives a knife  108  upon release. 
       FIG. 11  depicts another fastening tool assembly  110  with another configuration of a housing  112  and a handle  114 , which may employ mechanisms according to any of the other embodiments. 
       FIG. 12  includes another fastening tool assembly  116  with a housing  118  and a handle  120 . A trigger  122  may be provided for actuating a release mechanism once the handle  120  is depressed. 
       FIGS. 13 and 14  illustrate a fastening tool assembly  124  with a housing  126  and a dual handle  128  for receiving additional input force from the user. The fastening tool assembly  124  may employ mechanisms according to the teachings of other embodiments. 
       FIGS. 15 and 16  illustrate another fastening tool assembly  130  with a housing  132  and a dual handle  134 . A contact surface  136  is smaller than prior embodiments for use in applications where a flat reaction surface on the workpiece is not typical. The tool assembly  130  may include a cover  138  for receipt of a fastener cartridge  140 . The tool assembly  130  may also utilize the teachings of other embodiments for the driving the fastener. 
       FIGS. 17 and 18  depict a fastening tool assembly  142  with a housing  144  and a handle  146 . The handle  146  includes a ramp surface  148  in contact with a follower  150  on a lever  152  for loading a load spring and releasing a knife. 
     While various embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.