Abstract:
A portable, handheld envelope opening device is disclosed. The envelope opening device has a head portion and a handle portion. The head portion includes a slot defined by a pair of opposing walls and a base plate. The walls being spaced so as to guide the passage of an envelope and preferably are slightly angled to provide a tapered insertion end. A pair of rotary discs disposed within the head portion adjacent the base plate intersects in partially overlapping fashion along a centerline of said slot. The discs are spaced and positioned adjacent the base plate. The first disc includes a cutting edge, and the second disc is adapted to urge the envelope into engagement with the first cutting disc to sever a marginal edge of the envelope to expose the contents. A motor is coupled through a gearbox to the rotary discs to drive the discs. A switch is used to couple the motor to a battery power supply. In one embodiment, a decorative edge is applied to the envelope but the cutting disc by providing a sawtooth or undulating cutting edge on the disc.

Description:
RELATED APPLICATIONS  
         [0001]    There are no applications related to this invention anywhere in the world.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to envelope openers and, more particularly, to portable, handheld, motor-driven envelope or letter openers with grip handles.  
           [0004]    2. Description of the Prior Art  
           [0005]    Various envelope openers exist in the prior art. Some of these envelope openers, particularly those with power-driven cutting blades, are large devices intended for use on a desktop or work surface, but are unwieldy, expensive and not practical for portable use, for example, in a briefcase, desk drawer or portable computer carrier. Other openers that are more compact do not include power-driven cutting blades or lack sufficient means for gripping such a compact device.  
           [0006]    U.S. Pat. No. 2,656,889 discloses an automatically operated cutting wheel for opening envelopes. The envelope opener is placed on a table or desk in a place of business. A pair of co-acting cutting elements is disposed adjacent to a suitable cutting guide for guiding envelopes into engagement with the cutters. A motor is operatively connected thereto and the motor operates automatically by a control switch actuated by movement of an envelope through the guide slot.  
           [0007]    U.S. Pat. No. 3,597,843 discloses a device for opening envelopes. A rectangular block, sized to be held in the hands of a user, is provided with an elongated guide slot through which the edge of an envelope is directed, and a two-part rotatable cutting means journaled into the block has a cutting nip formed in the slot so that the edge of the envelope will be severed as it moves relative to the block.  
           [0008]    U.S. Pat. No. 5,127,161 discloses a cutter for cutting an envelope along an edge. An envelope is slid with its edge in contact with a sliding surface perpendicular to a floor. The envelope or other item to be cut is pressed against the sliding surface with a press means when cut with a blade edge at a given distance from the envelope edge approximately straight and parallel to the edge.  
           [0009]    Hence, there exists a need for a compact, motor-driven portable letter opener having a grip handle.  
         SUMMARY OF THE INVENTION  
         [0010]    It is an object of the present invention to provide a motor-driven envelope opener suitable for cutting an edge of an envelope to expose the contents thereof, which is both portable and compact and has a handle for gripping the device while in use.  
           [0011]    It is another object of the present invention to provide a switching means disposed on the handle portion which is operable by the user, such as by a momentary contact switch, for actuating the motor when sliding an envelope through the cutting guide.  
           [0012]    It is a further object of the present invention to provide a pair of cooperable cutting discs or wheels, one wheel having a sharp peripheral edge and the second having a peripheral traction edge, for simultaneously pulling and cutting an envelope edge.  
           [0013]    It is yet another object of the present invention to provide a battery storage chamber in a handle portion for powering an electric motor that drives the pair of cutting discs.  
           [0014]    Another object of the present invention is to provide a miniature gearbox for reducing the speed of the output shaft of the gearbox relative to the speed of the motor input shaft so as to apply the appropriate speed and torque at the cutter block for shearing an edge from an envelope.  
           [0015]    What is disclosed is a portable, handheld envelope opening device. The device includes a housing with a head portion and a handle portion. The head portion has a slot defined by a pair of opposing walls and a base plate. The walls are spaced so as to guide the passage of an envelope through the slot.  
           [0016]    A pair of rotary discs is disposed within the head portion. The discs are adjacent the base plate and intersect in a partially overlapping fashion along a centerline of the slot. Discs are spaced in close proximity to the base plate. In the preferred embodiment, the first disc includes a cutting edge, and the second disc is adapted to frictionally urge the envelope into engagement with the first cutting disc adjacent an edge of the envelope to sever a marginal edge of the envelope to open it.  
           [0017]    Drive means is disposed within the handle portion to drive the rotary discs. The drive means is coupled to the discs through a power transfer gearcase. There is also a power source to power the drive means and a switching means for coupling the drive means to the power source to energize the drive means. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 is a perspective view of the preferred embodiment of an envelope opener;  
         [0019]    [0019]FIG. 2 is a cross-sectional elevational view of the envelope opener taken along lines  2 - 2  in FIG. 1;  
         [0020]    [0020]FIG. 3 is a cross-sectional elevational view of the envelope opener taken along lines  3 - 3  in FIG. 2;  
         [0021]    [0021]FIG. 4 is a cross-sectional view taken along lines  4 - 4  in FIG. 3;  
         [0022]    [0022]FIG. 5 is an exploded view showing the assembly arrangement of the gearbox;  
         [0023]    [0023]FIG. 6 is a perspective view of the gearbox assembly with the cover detached;  
         [0024]    [0024]FIG. 7 is an alternate sawtooth-cutting blade; and  
         [0025]    [0025]FIG. 8 is an alternate wave-cutting blade. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    Referring first to FIG. 1, an envelope opening device  10  has a head portion  14  connected to a handle portion  12 . The head portion  14  contains a guide slot  16  comprising a narrow passage through which an envelope (not shown) may be passed. The guide slot  16  traverses the entire width of head portion  14  in a direction perpendicular to the direction of an axis  13  of handle portion  12 . Handle portion  12  includes a switch  60 , which can be operated by the user&#39;s thumb when gripping the handle portion  12  in one hand, thus leaving the user&#39;s remaining hand free to manipulate an envelope through the guide slot  16 . A raised collar  61  surrounds the switch  60 . The raised collar  61  projects upward slightly beyond the raised portion of switch  60 , so that the switch  60  will not be accidentally operable when laid on a surface with the switch facing down. A string  62  is attached at the distal end of handle portion  12  opposite head portion  14  providing means for attaching the envelope opening device  10  to a clip or a hook or the like (not shown).  
         [0027]    Referring next to FIGS. 2, 3,  5  and  6 , the views show a gearbox  29  and cutter discs  24 ,  26 . Four gears  34 ,  36 ,  38  and  40  are employed in the disclosed embodiment to transfer the torque from a shaft  32  of a motor  28  to the cutter blade disc  24  and nip roller disc  26 . Nip roller disc  26  preferably includes edge serrations  27  about the periphery of the disc  26  to provide frictional engagement of the envelope. Other frictional engagement means may be employed, such as a rubber rim or knurled edge, as is well known in the art. Gears  34 ,  36 ,  38  and  40  are housed within the gearbox assembly  29 . Gears  34 ,  36 ,  38  and  40  are step gears arranged along parallel axes extending from the shaft  32  of motor  28 . Step gear  34  is attached to a first axle  84 , which is seated in a socket  92 . The step portion of gear  34  engages gear  36 , which is attached to a second axle  86 , seated in a socket  90 . Step portion of the gear  36  engages gear  38 , which is coupled to axle  84  by a hexagonal center portion  85 . Axle  84  fastened directly to nip roller disc  26 . Gear  38  also engages gear  40 , which is similarly coupled to axle  86  by a hexagonal center portion  87 . Axle  86  is directly attached to cutter blade  24 . When the motor  28  is energized by operation of the thumb switch  60 , the third and fourth drive gears  38 ,  40  cause the roller disc portion  26  and cutter blade disc  24  to rotate in opposite directions. It will be recognized that the cutter blade  24  and roller disc  26  may be switched in this arrangement to achieve the same result.  
         [0028]    Motor  28  is a miniature DC motor, which is mounted to a first gearbox plate  30 . Drive gear  37  extends through first gearbox plate  30  to engage gear  34 . Drive gear  37  and motor shaft  32  are positioned off-center, as illustrated more clearly in FIG. 3. Motor  28  is also retained in place by a fastener  39 . Other arrangements of gears may be employed to effect the same or similar speed reduction and coupling between the motor  28  and discs  24 ,  26 .  
         [0029]    Power for the motor  28  is supplied from a battery compartment generally designated as  42 , which houses four AA batteries  70 ,  72 ,  74  and  76  as disclosed in the preferred embodiment. Batteries are maintained in place by retainer springs  46 ,  48  and  45 ,  47 . Each spring is mounted opposite a pressure contact  50 ,  52 ,  54  and  56  (not shown) and connected in series to provide an electromotive force (EMF) to power the DC motor. Other battery types and DC power supply arrangements will be equally useful so long as the voltage is compatible with the motor that is employed.  
         [0030]    A battery door  58  is provided. Door  58  slides retentively into position and has raised portions  64  for providing a gripping surface to frictionally disengage the door from the handle portion  12 .  
         [0031]    Referring next to FIG. 4, a sectional view taken along the lines  4 - 4  in FIG. 3 shows a sectional view of the arrangement of the cutter blade  24  and the roller disc portion  26 . A tapered mouth  66  is formed by an angled portion  65  of a second wall  20  away from a first wall  18  at guide slot  16 . The mouth provides a slightly larger entry into the slot to assist in guiding the envelope into the narrow passage of guide slot  16 . A base plate  22  of the slot  16  is spaced slightly below cutter and roller discs  24 ,  26 , which are circular and partially intersect at approximately the centerline  17  of slot  16 . The intersection of discs forms a nip  69  into which an edge of the envelope is directed. Rotation arrows  78 ,  80  display the direction of rotation of the circular discs  24 ,  26 , which enables roller disc  26  to engage the envelope and “pull” the envelope into the nip  69  and toward the discharge end of guide slot  16  while the cutting blade  24  rotating in the opposing direction of roller disc portion  26  also cuts the envelope rotating in the direction toward the discharge of the guide slot  16 . This juncture of the two discs forms a nip  69  for grasping and cutting the narrow margin of an edge of the envelope. Other combinations of discs may be employed, such as where both discs are sharpened cutter discs  24 , or both discs include frictional discs  26 .  
         [0032]    A set of electrical contacts  44  may optionally be included to sense the presence of an envelope in the slot  16 . These contacts are pressure sensitive and are designed to close by the pressure applied by the envelope against inner walls  18 ,  20  as an added precaution against leaving the unit run when not in use.  
         [0033]    Referring next to FIG. 5, there is an exploded view showing the arrangement in the gearbox assembly  29 . The frame for gearbox assembly  29  is comprised of two shell portions  29   a  and  29   b , which are fastened together with screws or equivalent fasteners. The motor  28  has the main drive gear  37  attached to the shaft (not shown) and penetrates through the gearbox assembly  29   b  through an aperture  88 . Sockets  90 ,  92  are positioned on opposite sides of aperture  88  to provide parallel mounting seats for axles  84 ,  86 . The drive gear  37  engages the teeth of the first step gear  34  at its widest diameter. A step gear has two different radii, each containing teeth about the periphery: the outermost radius engaging the drive gear  37  and the inner radius teeth engaging the outer radius of the next adjacent step gear, in this case second step gear  36 . The inner radius gear on step gear  36  similarly engages step gear  40 . Step gear  40  engages gear  38 . Gear  38  is preferably a spur gear type. Another step gear is not required at the end of the gear train. Axles  84 ,  86  project through the two parallel axes of gear trains. Axles  84 ,  86  penetrate through gearbox assembly top portion  29   a  and are coupled to cutter blade  24  and roller disc  26 . The axles  84 ,  86  are driven by the outermost gears  40 ,  38  in the gear trains to achieve the appropriate speed reduction from the motor drive shaft  37 .  
         [0034]    Referring next to FIG. 6, the assembly  29  is shown in the assembled stage with the top portion  29   a  removed for illustrative purposes. The cutter blade  24  and roller disc portion  26  are illustrated in a vertically offset, horizontally overlapping relationship so as to permit simultaneous rotation without interference, forming the nip.  
         [0035]    In an alternate embodiment, the opener  10  would cut a sawtooth edge or wavy edge (not shown) similar to pinking shears. Referring to FIGS. 7 and 8, cutting discs  82  and  82   a  are illustrated. Blade  82  is an alternative blade to a simple straight edged disc, wherein the edge of the alternate disc has an undulating wavy profile; or alternately, the cutting blade  82   a  of FIG. 8 has an edge in the profile of a sawtooth. These blades may be used in place of a straight-edged disc. The alternative blades cut an edge on an envelope similar to their profiles. After cutting the edge margin from an envelope, it is readily apparent that the envelope has been opened so that the user does not repeat the process of opening the envelope and in the process mutilating the contents of the envelope on the second or subsequent pass.  
         [0036]    With the disclosed invention, the user may easily grasp the handle portion  12  in the palm of either hand, and the thumb is free to operate switch  60 . With his or her free hand, the user directs an envelope into the mouth  66 , holding the envelope vertically against slot base plate  22 . The user then urges the envelope further into guide slot  16  into contact with the nip  69  formed by the intersection of roller disc portion  26  and cutter blade  24 . Mouth  66  is preferably tapered slightly to facilitate guiding the envelope into the slot  16 .  
         [0037]    When the thumb switch  60  is depressed, roller disc  26  and cutter  24  rotate so that they pull the envelope into the nip  69  and shear the edge of the envelope. The roller and cutter discs  26 ,  24  will rotate as long as the switch  60  is maintained in the closed position. A hair switch (not shown) may be optionally employed to sense that an envelope is present in the guide slot  16 . An envelope positioned in guide slot  16  will deflect a “hair” sensor arm causing the microswitch (not shown) to close a set of contacts in series with thumb switch  60 . In this way, in order for the motor to be switched to the “on” position, a user must have an envelope in position in guide slot  16 , while depressing the thumb switch  60 . The hair switch (not shown) may be used as a substitute for pressure sensitive contacts  44 .  
         [0038]    The use of a hair switch or a set of pressure contacts ensures that the unit cannot run, for example, if the switch is left in the on position without an envelope in guide slot  16 ; thus the accidental drain of battery power is prevented. This is merely one example of preventing the unit from running when not in use. Those skilled in art will recognize alternative means, for example, a spring-return, momentary contact switch or a latching time-out circuit, all of which are intended to be within the scope of the appended claims.  
         [0039]    The momentary-contact switch on the handle also provides a means for test operation that may be used in the original packaging. The momentary operation of the switch permits the user to operate the device  10  while still wrapped in protective packaging. A transparent thin plastic barrier (not shown) is molded around a portion of the device  10  and adhesively or mechanically attached to a backing sheet of cardboard (also not shown), with the device secured between the plastic barrier and the cardboard. The plastic is pliable so that the pushbutton on the switch may be depressed to turn on the device while on the store shelf. The switch is returned to the off position when released, thereby avoiding unintended drainage of the batteries in the packages. This feature advantageously invites people to test-operate the device.  
         [0040]    The envelope-opening device may also be adapted so that each of the discs  24 ,  26  is each slightly tilted. This way the discs are in planes intersecting at an oblique angle with the base plate so as to pull the envelope downward into contact with the base plate  22 . This adaptation tends to prevent an envelope from “slipping” from the slot before the envelope is completely open.  
         [0041]    According to the provisions of the patent statutes, we have explained the principle, preferred construction, and mode of operation of the invention, and have illustrated and described what we now consider to represent its best embodiments. However, it should be understood that within the scope of the appended claims and the foregoing description, the invention may be practiced, otherwise than specifically illustrated and described.