Abstract:
Tool-free adjustment members in a fastener driving tool. The fastener driving tool can be used to seal closed containers such as, for example, corrugated fiberboard cartons, by applying staples to the folded flaps or other closure parts to secure them in place. The tool-free adjustment members provide customizable drive settings for a variety of different sized staples and different workpiece conditions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority from U.S. Provisional Patent Application No. 61/665,744, filed on Jun. 28, 2012, the content of which is incorporated by reference in its entirety. 
     
    
     FIELD 
       [0002]    This invention relates to fastener driving tools and more particularly to fastener driving tools including clinching mechanisms. 
       BACKGROUND 
       [0003]    Power operated fastener driving tools are traditionally used in industrial applications where compressed air provides a convenient power source. Because of the nature of the compressed air power source and the expense involved in heavy duty industrial fastener driving tools, such tools are generally not suitable for use in fastening jobs where maneuvering is required, space is limited, or compressed air is not available. Manually operated fastener driving tools are also used in industrial applications. However, in many of the jobs where manually operated fastener driving tools are used, considerable operator fatigue may be involved because a manual fastener driving tool requires a large user actuation force. 
       SUMMARY 
       [0004]    A carton closing tool of the embodiments herein includes adjustment members that adjust the tool to accommodate various staple sizes and tool drive characteristics without requiring the use of hand tools. The present invention incorporates these tool free adjustment members in a stapling tool for blind fastening of cardboard, typically packing boxes. Tools of this type contain a set of two movable anvils as part of a mechanism, such that when a staple is driven, the anvils penetrate the cardboard workpiece to clinch the staple legs and are subsequently automatically retracted. 
         [0005]    Packaging tools commonly include different adjustment devices that can affect at least one of the following: the staple leg length accepted by the tool, the tightness of the clinch, and the depth of drive. Most existing adjustment members require hand tools to actuate the adjustment members. In the embodiments described herein, the same adjustments can be made with the novel adjustment members of the present invention that do not require hand tools for adjustment. 
         [0006]    According to an aspect of the invention, there is provided fastener driving tool, comprising: a housing; a drive track within the housing; a magazine connected to the housing and configured to hold a supply of fasteners and to provide a leading fastener to the drive track; a driver configured to move downward in the drive track and drive the leading fastener into a workpiece during a drive stroke, and upward in the drive track during a return stroke; a mount connected to the driver; a clinching assembly operatively connected to the housing and to the mount, the clinching assembly being configured to engage the leading fastener during the drive stroke and move into a clinching position at the end of the drive stroke to clinch the fastener to the workpiece; and an adjuster configured to adjust the clinching assembly to accommodate fasteners having different lengths. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures. In the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0008]      FIG. 1  illustrates an exemplary fastener driving tool constructed in accordance with the teachings of the present disclosure; 
           [0009]      FIG. 2  illustrates a cross-sectional view of the fastener driving tool of the embodiment of  FIG. 1 ; 
           [0010]      FIG. 3  illustrates the fastener closing mechanism of the embodiment of  FIG. 1  in the open position; 
           [0011]      FIG. 4  illustrates the fastener closing mechanism of the embodiment of  FIG. 1  at the beginning of actuation; 
           [0012]      FIG. 5  illustrates the fastener closing mechanism of the embodiment of  FIG. 1  in the closed position; 
           [0013]      FIG. 6  illustrates a cross-sectional view of the clinching mechanism in the upstroke position; 
           [0014]      FIG. 7  illustrates a cross-sectional view of the clinching mechanism in the downstroke position; 
           [0015]      FIG. 8  illustrates a front view of the driving and clinching mechanisms with the leg length adjustment for a first leg setting; 
           [0016]      FIG. 9  illustrates a front view of the driving and clinching mechanisms with the leg length adjustment for a second leg setting; 
           [0017]      FIG. 10  illustrates a front view of the leg length adjustment cam lobes for a first leg setting; 
           [0018]      FIG. 11  illustrates a front view of the leg length adjustment cam lobes for a second leg setting; 
           [0019]      FIG. 12  illustrates a front view of the driving and clinching mechanisms with the clinch adjustment knob in a first setting; 
           [0020]      FIG. 13  illustrates a front view of the driving and clinching mechanisms with the clinch adjustment knob in a second setting; 
           [0021]      FIG. 14  illustrates a cross-sectional view of the driving and clinching mechanisms with the clinching mechanism with the clinch adjustment knob in a first setting; 
           [0022]      FIG. 15  illustrates a cross-sectional view of the driving and clinching mechanisms with the clinching mechanism with the clinch adjustment knob in a second setting ; 
           [0023]      FIG. 16  illustrates a rear cross-sectional view of the tool in a first depth of drive adjustment position; and 
           [0024]      FIG. 17  illustrates a rear cross-sectional view of the tool in a second depth of drive adjustment position, 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings, 
         [0026]      FIG. 1  illustrates an embodiment of the fastener driving or carton closing tool. Attaching to the tool body  2  is a removable magazine  10  which stores the fasteners, such as staples, prior to driving, and a tool base  3  that contacts the workpiece surface during use. 
         [0027]    As shown in  FIGS. 1 and 2 , the tool includes a variable clinch adjustment thumbwheel  5  that controls the downstroke position of the clincher arms in the clinching assembly of the tool. The variable clinch adjustment thumbwheel  5  has a gripping surface with grooves that allow the user to securely grasp the thumbwheel. By turning the thumbwheel, in a first direction or a second direction, the tool increases or decreases the space between the clinching arms in the downstroke, and thereby increases or decreases the tightness of the formed staple legs. 
         [0028]    Another adjustment member is a positionable leg length adjustment dial  7 . The dial  7  is rotatable and changes the pivot axis of the clincher arms of the clincher assembly between a first setting for a staple having a first length to a second setting for a staple having a second length without the use of hand tools. 
         [0029]    A further adjustment member is a depth of drive dial  9 . The depth of drive dial rotates between a range of positions to change how deep the staple can be fired to penetrate the workpiece. 
         [0030]      FIG. 2  shows a cross-sectional view of the tool illustrating the crank arm  34  and the motor  26  that provides power to the tool for driving the staple. Power from the motor is transferred through a gear reduction mechanism  28  to a crank arm  34  and connecting rod  36 . The connecting rod  36  is linked to a driver mounting block  22 , on which is mounted the driver blade  23  and a clincher linkage  42  of a clinching assembly  40 . 
         [0031]      FIGS. 3 ,  4 , and  5  show the driving assembly and fastener closing mechanism in the form of a clinching assembly that drives and clinches, respectively, the staple into the workpiece.  FIG. 3  shows the driving assembly in the upstroke position where the clinching assembly is in the open position.  FIG. 4  show the progression of the driving and clinching assemblies and how they move toward the downward stroke.  FIG. 5  illustrates the driving assembly in the downward stroke wherein the clinching assembly is positioned to be closed around a staple. 
         [0032]    The crank arm  34  rotates using power provided by the motor  26  to the gear reduction mechanism  28 . Rotation of the crank arm  34  pulls and pushes a connecting rod  36  around an upper pivot pin  37 , which translates the circular motion of the connecting rod into the linear reciprocating motion of a driver mounting block  22 , which may be referred to as a mount. The driver mounting block  22  is linked to the driver blade  23 , which pushes the staple into the workpiece. In an embodiment, the driver mounting block  22  may be integral with the driver blade  23 . The driver mounting block  22  additionally pushes a pair of clincher linkages  42  in an outward direction away from the driver mounting block. At the end of each clincher linkage is a clincher arm that is pivotable about a pivot pin  48  on the clincher linkage  42 . The pivotable movement of the clincher arm forces clincher anvils  46  toward each other to close the clinching assembly around the staple forcing the staple legs to bend toward each other to close the staple in position within the workpiece. 
         [0033]      FIGS. 6 and 7  show the driving and clinching mechanism in a cross-sectional view, During operation, the crank arm  34  is rotated by the output shaft of the motor gearbox. The crank arm pulls a connecting rod  36 , which translates the rotation into a linear reciprocating motion of a driver mounting block  22 . The driver mounting block in turn pushes the driver  23 , which pushes the staple into the workpiece. The driver mounting block additionally pushes two clincher linkages  42  which in turn rotate two clincher arms  44  about a pivot pin  48  in order to clinch the staple legs. 
         [0034]      FIGS. 8 and 9  show the driver blade  23  and clincher arms  44 , namely clincher arm  44   a  and clincher arm  44   b,  at the bottom of the drive stroke in two different positions for driving staples of different leg lengths. In  FIG. 8 , the leg length adjustment dial  7  is set in a first setting for a first length staple leg. In  FIG. 9 , the leg length adjustment dial  7  is set in a second setting for a second length staple leg. In an embodiment, the first length staple can be shorter than a second length staple. Alternatively, in an embodiment, the first length staple can be longer than the second length staple. Long leg staples have legs that longer than the short leg staples, and allow for deeper penetration into thicker workpieces. The leg length adjustment dial  7  controls the depth of the clinch to accommodate workpieces of different thicknesses by changing the centers of rotation for the clincher arms  44 , within the tool, to be closer to the workpiece. Accordingly, when the user turns the leg length adjustment dial  7  by hand, the dial  7  rotates the lower pivot pin  48  180-degrees, which changes the centers of rotation for the clincher arms  44  vertically and horizontally via two cam lobes  56 ,  58  on the pivot pin  48 . In the long leg setting, the clincher anvils  46  extend deeper into the workpiece and come closer to each other than in the short-leg setting as a result of the centers of rotation moving lower and horizontally towards the opposite clincher arms  44 . 
         [0035]      FIGS. 10 and 11  further show the leg length adjustment mechanism described above. In  FIG. 10 , the pivot pin  48  is in a long leg setting. In  FIG. 11 , the pivot pin  48  is in a short leg setting. The pivot pin  48  has two cam lobes  56 ,  58 . The cam lobes  56 ,  58  serve as the centers of rotation for the clincher arms  44 , which clinch the staple during tool actuation. In  FIG. 10 , the cam lobes  56 ,  58  are disposed at a position higher in the tool, that is, further from the workpiece than the pivot pin  48 . The axes L1 of the cam lobes are therefore higher than the axis of the pivot pin in  FIG. 10 . Each on the respective side of its mating clincher arm  44   a,    44   b.  This causes the clincher arms  44   a,    44   b  to be positioned further within the tool with respect to the workpiece and further apart at the conclusion of the downstroke. In  FIG. 11 , the cam lobes  56 ,  58  are shown at a 180 degree difference from that of  FIG. 10 , The cam lobes in  FIG. 11  are lower in the tool, that is, closer to the workpiece than the pivot pin, The axes L2 of the cam lobes are therefore lower than the axis of the pivot pin in  FIG. 11 . Accordingly, the clincher arms are closer together at the conclusion of the downstroke. 
         [0036]      FIGS. 12 and 13  show the driver blade  23  and clincher arms  44  at the bottom of the drive stroke as the clinch tightness adjustment is made.  FIG. 12  shows the clinch adjustment knob  5  set to a loose clinch, and  FIG. 13  shows the knob set to a tight clinch. When the user rotates the clinch adjustment thumbwheel, the lower pivot pin  48  is moved vertically, which in turn moves the centers of rotation for the clincher arms  44  vertically. The effect of this movement is that, at the bottom of the drive stroke, the clincher arms  44  are closer to the driver blade  23  by a distance K2, and the clincher anvils  46  are closer together in  FIG. 13  as compared to  FIG. 12 , where the clincher arms are farther from the driver blade by a distance K1. 
         [0037]      FIGS. 14 and 15  show the clinch adjustment in a loose setting and tight setting, respectively. In a loose setting, at the bottom of the drive stroke, the clincher arms are farther apart from each other than in a tight setting where the clincher arms are closer to each other. The pivot pin  48  and the clinch adjustment thumbwheel  5  are moved. In  FIG. 15 , the pivot pin  48  is positioned higher in the tool, that is, a distance D2 that is further from the workpiece, as compared to distance D1 in  FIG. 14 . The placement of the pivot pin farther away from the workpiece causes the clincher arms  44  to pivot further inward, thus coming closer to each other during the clinching of the staple and closer to the driver blade  23  than the arrangement of the clincher arms  44  in  FIG. 14 . 
         [0038]      FIGS. 16 and 17  show the tool from the rear in a cross-sectional view as the depth of drive adjustment is made. The depth of drive adjustment dial  9  is rotated by hand, which turns a drive adjustment shaft  15 . The drive adjustment shaft  15  turns a pair of depth of drive cam lobes  60 ,  62  on each side of tool which raises and lower the housing  4  of the tool. As shown in  FIG. 16 , the depth of drive cam lobe  60  is integral with the depth of drive dial  9 . Alternatively, the cam lobe  60  can be separate from the dial  9 . The depth of drive cam lobe  62  is located at an opposite side of the shaft  15 . Raising and lowering of the housing  4  of the tool also moves the motor-gear reduction housing, the driving assembly and the clinching assembly vertically with respect to the staple magazine  10  and base  3 . 
         [0039]    The fastener driving device described here represents an improvement over stapling machines of the movable anvil type which typically require tools for the adjustment of staple size or drive characteristics. The device contains features for adjustment of the staple leg length, clinch tightness, and depth of drive which can be operated in the absence of tools. 
         [0040]    Furthermore, while aspects of the present invention are described herein and illustrated in the accompanying drawings in the context of a fastening tool, those of ordinary skill in the art will appreciate that the invention, in its broadest aspects, has further applicability. 
         [0041]    It will be appreciated that the above description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein, even if not specifically shown or described, so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims.