Abstract:
A portable hand-held power stapler with an outer housing contoured to fit comfortably within the grip of a hand, said stapler having an improved actuation system comprising a manually operated power switch that will actuate the stapling mechanism when a paper-sensing arm positioned in a document insertion slot is brought into contact with the inserted edge of a document, thereby completing the electric circuit to the power source of the electric motor driving the stapling mechanism, said actuation system further having a manually actuated reverse switch to engage a reverse function of the stapling mechanism to clear a paper or staple jam.

Description:
RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Patent Application No. 60/506,113, entitled “Powered Stapler,” filed Sep. 26, 2003. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to electric staplers. 
   2. Description of the Prior Art 
   Electric staplers are known in the prior art. Such prior art staplers typically have an electric motor that is automatically activated by a switch when the operator inserts an item to be stapled into a slot in the stapler. Once the item is inserted, the motor is activated, and the stapler immediately punches a staple through the item. This mode of operation frequently results in the staple being placed in an unintended location, for instance, covering part of a word or number, since the operator has no opportunity to adjust the position of the item once the switch is closed by insertion of the item. 
   SUMMARY OF THE INVENTION 
   It is an objective of the present invention to provide a powered stapler that allows the operator to adjust the position of the item to be stapled before the stapler punches a staple through the item, thus permitting greater precision in the placement of the staples. This objective is realized by providing a powered stapler that requires two conditions to be met before the motor is activated. First, the item to be stapled must be inserted in the stapler. Second, a button on the stapler housing must be pressed to activate the stapler motor. 
   Accordingly, the invention provides a battery-powered stapler having a housing with a battery chamber in the rear end and a slot for receiving items to be stapled at the front end. The rear end of the housing forms a contoured handle. A stapling mechanism contained within said housing includes: a staple carriage containing a large number of U-shaped staple pins and having a staple punching outlet at the front; a staple biasing means within said staple carriage for urging said staple pins toward said staple punching outlet; a punching arm having a staple punching plate at the front end thereof, which punching arm is vertically moveable in order to punch out staple pins in the staple carriage through the staple punching outlet; and a matrix anvil for bending a staple pin punched out through said staple outlet. The housing also contains an arm drive means including an electric motor for driving said punching arm up and down and a control circuit for controlling the operation of said motor. Two switches must be actuated to cause the stapler to operate. First, a paper-sensing switch is actuated by insertion of an item to be stapled into the stapler. Then, once the operator determines that the item is properly positioned and ready to be stapled, the operator manually actuates the second switch, activating the motor and causing the stapler to staple the item. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded rear perspective view of a battery-powered stapler of the present invention. 
       FIG. 2  is top plan view showing the internal components of a stapler of the present invention. 
       FIG. 3  is a front perspective view showing the internal components of a stapler of the present invention. 
       FIG. 4  is an elevational view showing the right side of the internal components of a stapler of the present invention. 
       FIG. 5  is an elevational view showing the left side of the internal components of a stapler of the present invention. 
       FIG. 6  is a bottom plan view showing the internal components of a stapler of the present invention. 
       FIG. 7  is a front perspective view of a stapler of the present invention. 
       FIG. 8  is a perspective view showing a stapler of the present invention in a sealed package designed to permit operation of the stapler in the package. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , there is shown an exploded view of a stapler of the present invention having a left housing piece  1 , a right housing piece  2 , a top housing piece  3 , and a bottom housing piece  5 , which fit together to form a housing to contain the internal components. Referring to  FIG. 7 , the front portion of the housing forms a slot  62  for receiving items to be stapled. In a preferred embodiment, the housing pieces are molded of ABS plastic. Referring again to  FIG. 1 , an optional hanging loop  32  protrudes from the rear end of the housing through adjoining surfaces of the top housing piece  3  and bottom housing piece  5  when the two pieces are brought together. The rear portion of the housing forms a contoured handle. In the preferred embodiment shown, the rear portion of bottom housing piece  5  includes an integrally molded battery compartment  42  to hold the batteries  44  that power motor  6 . A removable battery door  4  snaps over the opening to battery compartment  42  to retain batteries  44  in said battery compartment  42 . However, it is not an essential feature of the invention that batteries power the stapler. An alternative embodiment, not shown, may be powered by alternating current via a power cord plugged into an electrical outlet. Another alternative embodiment, not shown, may include batteries as well as an optional AC adapter to provide alternating current from an electrical outlet. 
   Referring to  FIGS. 1 ,  2 ,  3 ,  4 , and  5 , contained within the housing is a stapling mechanism comprising a staple carriage  12  accommodating a large number of U-shaped staple pins, not shown, arranged in a sheet-like row in a groove slidable toward a staple punching outlet at the front end of the groove; a staple biasing means, not shown, within said staple carriage  12  for urging the staple pins in the staple carriage  12  toward the staple punching outlet; a punching arm  13 , having a staple punching plate  52  at its forward end, vertically movably supported to punch out the staple pins in the staple carriage  12  one after another through the staple punching outlet; a pair of semicircular cam receivers  31  mounted on either side of the punching arm  13 ; and a matrix anvil  14  for bending a staple pin punched out through the staple outlet. 
   The up and down motion of the punching arm  13  by which staples are punched through the staple punching outlet is driven by an arm drive means comprising a reversible motor  6  and a series of gears, as follows. Referring to  FIGS. 1 ,  2 ,  3 ,  4 , and  5 , motor  6  has a motor shaft  54  disposed toward the front end of the stapler. A pinion  17  fixedly mounted on said motor shaft  54  meshes with a crown gear  18  rotatably mounted on a first gear shaft  19 . A first gear  20  formed integrally with the crown gear  18 , meshes with a second gear  21  rotatably mounted on a second gear shaft  22 . A third gear  23  formed integrally with the second gear  21  meshes with a fourth gear  24  rotatably mounted on the first gear shaft  19 . A fifth gear  25  formed integrally with the fourth gear  24  meshes with a sixth gear  26  rotatably mounted on the second gear shaft  22 . A cam mounting gear  27  rotatably mounted on a third gear shaft  28  meshes with the sixth gear  26 . A cam mounting wheel  30  is rotatably mounted on the third gear shaft  28  near the end opposite the cam mounting gear  27 , and a cam  29  is eccentrically mounted between the cam mounting gear  27  and the cam mounting wheel  30  by attachments to the cam mounting gear  27  and the cam mounting wheel  30 . The gears are preferably manufactured of Nylon/Acetal. The gear shafts are successively located forward of the output shaft of the motor substantially at the same level as the latter and fitted and supported in bearings which are provided on the inner wall surfaces of the left housing piece  1  and right housing piece  2 . The third gear shaft  28  passes through the semicircular openings formed by the cam receivers  31 , so that the cam receivers  31  are positioned between the cam mounting gear  27  and the cam mounting wheel  30 , with the cam  29  passing through the openings formed by the cam receivers  31 . 
   In the preferred embodiment shown, the motor  6  is connected to the batteries  5  and controlled by a circuit board  16 , a power switch  7 , a paper-sensing switch  15 , a stop switch  10  and a reverse switch  11 . In the stapling operation, the operator inserts the item to be stapled in the space between staple carriage  12  and the matrix anvil  14 . As the item to be stapled is inserted, it pushes against paper-sensing arm  9 , causing paper-sensing arm  9  to press against and close paper sensing-switch  15 . At this point, prior art electric staplers automatically staple the item, sometimes resulting in placement of the staple pin in a location that the operator did not intend. To avoid this problem, the present invention requires a second step. Once the operator is satisfied that the item to be stapled is properly positioned, the operator presses the power button  8 . Pressing power button  8  closes power switch  7 , which completes the electrical circuit and activates motor  6 . Rotation of the pinion  17  on the motor shaft  54  causes the series of gears to rotate, resulting in a circular revolution of cam  29 . Before commencement of the stapling operation, cam  29  is at the top position, as shown in FIG.  1 . In the first half of its revolution, cam  29  moves downward, pressing against the top of punching arm  13  and causing the staple punch plate  52  to punch out a staple pin through the staple outlet. In the second half of the revolution, cam  29  moves upward, abutting against cam receivers  31 , thereby lifting the latter upward to return the punching arm  13  to the initial resting position. At this point, a structure, not shown, on cam mounting wheel  30  presses against stop switch  10 , causing motor  6  to stop. 
   In the preferred embodiment shown, power button  8  is located at the top and toward the front of the housing to make it easy for a user holding the stapler in one hand to press power button  8  with the thumb of the same hand. In the preferred embodiment, the housing also forms a raised collar  60  around power button  8  to help prevent accidental activation of the motor  6 . However, alternative embodiments may have the power button located elsewhere and may not include a raised collar. 
   While the preferred embodiment requires actuation of both a paper-sensing switch and a manually actuated power switch to initiate the stapling action, it is possible within the scope of the invention to provide an alternative embodiment having no paper-sensing switch, so that the stapling operation will commence whenever the user presses the power button, regardless of whether a sheet of paper has been inserted in the stapler. 
   Referring to  FIGS. 1 and 8 , in a preferred embodiment, the stapler, with batteries  44  installed but without any staple pins in the staple carriage  12 , is packaged for sale in a sealed package  70  comprising a thin transparent barrier  72  of thermoformed plastic or the like. The barrier is pliable, so that a consumer can press power button  8  to actuate motor  6  in order to activate the stapling mechanism. The sealed package includes an insert piece  74  made of paper, paperboard, cardboard, or the like inserted into slot  62  so that paper-sensing arm  9  is continuously engaged in order to allow repeated activation of the stapling mechanism. Unlike prior art electric staplers that can perform the stapling operation only once each time a paper is inserted into the stapler, the control logic of circuit board  16  allows repeated activation of motor  6  without the need to remove and reinsert the piece of paper or the like in slot  62 . This combination of features advantageously permits prospective purchasers to try the stapler in the package multiple times before purchasing it. 
   In the event that the punching arm  13  is stopped in the middle of its stroke due to jamming of a staple pin in the staple outlet or paper, the operator can actuate a reverse switch  11 , which causes the motor  6  to operate in the reverse direction. By the reversed rotation of the motor  6 , the punching arm  13  is moved upward, thereby allowing the jam to be cleared. In the preferred embodiment shown, reverse switch  11  is accessible through an opening in bottom housing piece  5 , although it should be understood that reverse switch  11  may be located at any convenient position on the stapler. In a preferred embodiment, the reverse switch  11  is also mechanically linked to the staple carriage  12  so that if there is no staple jam, actuating the reverse switch  11  does not cause the motor  6  to operate, but releases the staple carriage  12  to allow the staple supply to be replenished. 
   In an alternative embodiment, not shown, the housing may include an optional compartment for holding an optional staple remover. 
   The descriptions set forth herein describe and explain the principle, preferred construction, and mode of operation of the invention, and illustrate and describe what we now consider to represent its best embodiments. However, it should be understood that various changes in the details, materials, and arrangements of parts or the method described herein may be made by those skilled in the art within the principle and scope of the invention.