Abstract:
An automatic tape dispenser for automatically dispensing and cutting a length of adhesive tape or other spooled material having adhesive on one or both sides stored on a roll by a user operating the dispenser single-handedly is provided, the dispenser comprising a housing including a cylindrical post for loading and receiving the roll of tape, at least one drive wheel for advancing the roll of tape, means for preventing the tape from jamming, and means for safely cutting the tape comprising a pair of scissor-like blades disposed at the opening of the housing through which the tape is dispensed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to an improved device for dispensing adhesive tape, and more particularly to such a device for automatically dispensing adhesive tape or other similar materials stored on a roll, and even more particularly to such a device including means for advancing, dispensing and cutting said adhesive tape using one hand. 
         [0003]    2. Description of the Prior Art 
         [0004]    Tape or adhesive dispensers of various forms have long been known in the art. The most common examples of such dispensers comprise plastic disposable hand-held dispensers and desktop dispensers. Automatic dispensers and “tape guns” of the type having a spindle upon which a roll of tape is attached, at least one roller and guide for rolling out the tape, and a handle or grip for holding the dispenser are also known, although less common. Such dispensers are designed to allow a user to dispense a length of tape relatively automatically using one hand by affixing the start of the tape to an object, using the adhesion of the tape to the object to unspool the desired length of tape, then cutting the tape by biasing a saw-like cutter against the tape. 
         [0005]    Such devices are relatively simple to operate in principle, although in practice managing the tape and cutting it at the desired length is quite difficult, often resulting in the tape folding upon itself or adhering to the object in an undesired location or position, or even damaging the object. Furthermore, such dispensers have traditionally been used for rolls of tape having large diameters and widths, and not for smaller rolls of tape. An example of such device is shown in U.S. Pat. No. 6,540,002, which issued to Edwards, et al. on Apr. 1, 2003 for “Apparatus for dispensing mesh drywall tape,” which patent discloses a mesh drywall tape dispensing apparatus including a chassis with a pistol grip for one-hand operation, a tape reel, a tape guide roller mounted within the chassis, and a tape pressure roller mounted adjacent a front end of the chassis. 
         [0006]    Smaller hand-held devices capable of housing smaller rolls of tape have also been developed. For example, U.S. Pat. No. 3,725,182, which issued to Regan on Apr. 3, 1973 for “Tape dispenser” discloses a hand-held dispenser including a tape guide adjacent a cutting edge for enabling the application of tape with the guide being movable to move the tape against the cutting edge after dispensing. 
         [0007]    Alternative means for cutting the tape are also known in the prior art. For example, U.S. Pat. No. 4,630,765, which issued to Samuelson, et al. on Dec. 23, 1986 for “Dispenser for tape with a stretchable backing,” discloses a tape dispenser for pressure sensitive adhesive coated tape having a stretchable backing including a housing comprising having a cover defining a socket adapted to receive a portion of a user&#39;s thumb so that the user may grasp the dispenser in one hand with his fingers around the base and his thumb in the socket and with one hand alone move the cover and base between their open and closed positions leaving his other hand free to pull tape from the dispenser. Similarly, U.S. Pat. No. 4,826,557, which issued to Fu, et al. on May 2, 1989 for “Tape dispenser” discloses an improved tape dispenser having a gun-shaped housing and operated by a trigger in operative association with a number of interconnected links so that a cutting blade disposed at the gun point can be actuated to laterally move for cutting off the rolled tape and smoothly dispensing the same simultaneously. Another example of an automatic cutter is shown in U.S. Pat. No. 4,762,586, which issued to Wilkie on Aug. 9, 1988 for “Combination tape applicator and tape dispenser,” and which discloses a combined tape dispenser and hand-held tape applicator wherein tape is mounted on a tape carrier normally biased to an extended tape-applicating position and manually retractable to expose a normally guarded cutting blade for severing the tape, and further wherein the tape carrier is movable toward its retracted position either by a trigger adjacent a handgrip or by pivotal movement of the handgrip substantially to its retracted position. 
         [0008]    It is also well-known in the art to provide means for automatically advancing the tape using a trigger or similar device. For example, U.S. Pat. No. 4,643,059, which issued to Phillips, et al. on Feb. 17, 1987 for “Tape dispenser” discloses a tape dispenser having a hollow body to receive a supply of medicated tape to be dispensed in predetermined lengths into the mouth of an animal, the tape dispenser being trigger operated and provided with a barrel along which a delivery head moves, whereby a predetermined length of tape is delivered into the barrel and severed from the supply by said delivery head, which predetermined length is then delivered into the mouth of the animal via the terminal end of the barrel. Another example of an automatic dispenser is shown in U.S. Pat. No. 5,910,227, which issued to Mistyurik, et al. on Jun. 8, 1999 for “Hand-held labeler” discloses a hand-held labeler having a gear driven print head wherein the print head is situated on an upper housing section and the print head is actuated from a lower housing section such that the upper housing section can be moved to an open position without interfering with the maintenance of the drive connection with the print head or the advance of a label carrying web through the labeler. 
         [0009]    The combination of the automatic tape advancing feature and the automatic cutter is a relatively recent innovation. An example of an automatic tape dispenser including both features is shown in U.S. Pat. No. 6,065,519, which issued to Lee on May 23, 2000 for “Automatic drawing and cutting device for adhesive tape dispenser,” which discloses an adhesive tape dispenser including a case body for containing an adhesive tape and having a detachable cover, a drawing means for automatically drawing the adhesive tape from the case body in a desired length, and a cutting means for automatically cutting the adhesive tape drawn by the drawing means. Similarly, U.S. Pat. No. 6,176,409, which issued to Lee on Jan. 23, 2001 for “Adhesive tape dispenser” discloses an adhesive tape dispenser which includes a gun-shaped case body having a detachable cover, a drawing portion for drawing an adhesive tape from the case body, and a trigger handle protruded outwardly from one side of the case body and a pair of drums rotating with the trigger handle, and a cutting portion for cutting the adhesive tape which is drawn by the drawing portion from the dispenser, and having a handling member mounted on a gunbarrel portion of the case body, a lever interlocking with the handling member and a cutter mounted at a front end of the lever, so that an user may draw the adhesive tape as long as necessary by pulling the trigger handle without pulling it with hand, an adhesive strength of the adhesive tape is kept in good state, and an adhesion state of the adhesive tape is clean, since the adhesive tape is cut clean by a cutter. 
         [0010]    Prior designs use sharpened knife blades to skewer and slice the tape. In order to function, these blades must be extremely sharp and pointed, which makes them very dangerous if they are exposed to the user in any way. 
         [0011]    As shall be appreciated, the prior art fails to specifically address either the problem or the solution arrived upon by applicant. 
       SUMMARY OF THE INVENTION 
       [0012]    Against the foregoing background, it is a primary object of the present invention to provide an automatic tape dispenser that is operable with one hand. 
         [0013]    It is another object of the present invention to provide such a tape dispenser that allows a user to easily and automatically apply any length of tape from a roll to an object. 
         [0014]    It is but another object of the present invention to provide such a tape dispenser that allows a user to easily and automatically advance the tape to a desired length. 
         [0015]    It is still another object of the present invention to provide such a tape dispenser that allows a user to easily and automatically cut the tape once the desired length is reached. 
         [0016]    It is yet a further object of the present invention to provide such a tape dispenser that is easily loaded and unloaded. 
         [0017]    It is yet another object of the present invention to provide such a tape dispenser that may be used with a variety of different types and lengths of tape. 
         [0018]    It is a further object of the present invention to provide such a tape dispenser that is inexpensive to manufacture. 
         [0019]    It is also an object of the present invention to provide such a tape dispenser that is easy to manufacture. 
         [0020]    It is another object of the present invention to provide such a tape dispenser that cuts the tape in a fashion more analogous to a pair of scissors. 
         [0021]    It is still another object of the present invention to provide such a tape dispenser that includes two metal cutting elements whose edges are not particularly sharp or pointed which can be exposed to the user with no danger. 
         [0022]    It is a further object of the present invention to provide such a tape dispenser that may be used to dispense a wide variety of tapes having adhesive on one side, including clear tapes, masking tapes, surgical tapes, double-sided tape and the other materials that are stored in a roll on a spindle. 
         [0023]    To the accomplishments of the foregoing objects and advantages, the present invention, in brief summary comprises an automatic tape dispenser for automatically dispensing and cutting a length of tape by a user operating the dispenser single-handedly, said dispenser comprising housing including a cylindrical post for loading and receiving the roll of tape, at least one drive wheel for advancing the roll of tape, means for preventing the tape from jamming, and means for safely cutting the tape comprising a pair of scissor-like blades disposed at the opening of the housing through which the tape is dispensed. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is an exploded perspective view of a roll of tape and a simple housing for the automatic tape dispenser of the present invention; 
           [0025]      FIG. 2  is an exploded perspective view of a roll of tape and another example of a simple housing for the automatic tape dispenser of the present invention; 
           [0026]      FIG. 3  is an exploded perspective view of a roll of tape and yet another example of a simple housing for the automatic tape dispenser of the present invention; 
           [0027]      FIG. 4  is an exploded perspective view of a roll of tape and still another example of a simple housing for the automatic tape dispenser of the present invention; 
           [0028]      FIG. 5  is a perspective view of a roll of tape, drive wheels and guide post of the automatic tape dispenser of the present invention showing the direction of motion of the elements; 
           [0029]      FIG. 6  is a simple side elevational view showing a portion of tape and the drive wheel of the automatic tape dispenser of the present invention; 
           [0030]      FIG. 7  is a simple side elevational view showing the elements of  FIG. 5  as well as center roller; 
           [0031]      FIG. 8  is a partially-exploded perspective view of the automatic tape dispenser of the present invention; 
           [0032]      FIG. 9  is an exploded perspective view of the trigger housing element of the automatic tape dispenser of the present invention; 
           [0033]      FIGS. 10   a - 10   d  are perspective views showing the attachment of the trigger housing element to the cutter housing element; 
           [0034]      FIG. 11  is a side elevational view of the trigger housing element of  FIG. 9 ; 
           [0035]      FIGS. 12   a - 12   e  are perspective views of the cutting elements of the automatic tape dispenser of the present invention showing the cutting path of the blades; 
           [0036]      FIGS. 13   a - 13   c  are side elevational views showing the cutter lever sub-assembly; 
           [0037]      FIGS. 14   a - 14   b  are side elevational and top plan views showing elements of the cutter lever sub-assembly; 
           [0038]      FIG. 15  is an exploded perspective view showing elements of the cutter housing element; 
           [0039]      FIG. 16  is a perspective view showing the cutter lever sub-assembly and roller; 
           [0040]      FIGS. 17   a  and  17   b  are perspective views showing the cutter housing element in the open and closed positions; 
           [0041]      FIGS. 18   a  and  18   b  are side elevational views showing the trigger housing elements with the trigger released and the trigger depressed; and 
           [0042]      FIG. 19  is a cut-away perspective view showing the means for attaching the trigger housing element to the cutter housing element for the automatic tape dispenser of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0043]    Referring to the drawings and, in particular, to  FIG. 1  thereof, the automatic tape dispenser is provided and is referred to generally by reference numeral  10 . The dispenser  10  comprises a housing  100  within which the roll of tape  102  is inserted and housed. In the preferred embodiment, the housing  100  comprises a pair of complementary housing elements  104  which cooperate to form a chamber  106  in the housing  100  within which the roll of tape  102  is stored. The housing has an “opened” and “closed” position, the former being used to insert or remove the roll of tape  102 , the latter being used for the actual dispensing of the tape  102 . In the preferred embodiment, opening and closing the housing  100  requires the user to bias the housing elements  104  relative to each other. The device  10  accepts a new roll of tape  102  by opening the housing  100  and inserting the roll of tape  102  onto a cylindrical post  108 . 
         [0044]    In the preferred embodiment, the roll of tape  102  is attached to the cylindrical post  108  in an axial direction, as shown in  FIG. 1 . However, in certain other embodiments, particularly those without axles such as those shown in  FIGS. 2 and 3 , it may be advantageous to have an opening in the side of the chamber  106  so that the user can install the tape  102  by moving it in a direction perpendicular to its axis, as is shown in  FIG. 4 . 
         [0045]    The housing elements  104  may be removably attached to each other by various means, such as by frictional attachment or by means of snaps or the like. In the preferred embodiment, however, the housing elements  104  share a common axis as the cylindrical post  108 , and the housing elements  104  are separated by first rotating the two housing elements  104  relative to each other about the cylindrical post  108  in a scissor-like motion, then by pulling the two elements  104  apart axially relative to the cylindrical post. The housing elements  104  are attached by reversing this process. 
         [0046]    The cylindrical post  108  is sized so as to fit through the hole  110  in the roll of tape  102 . It is also possible to locate the tape  102  by containing it within a chamber  106  that is somewhat larger than the tape  102  and has an opening  112  in one wall of the chamber  106  to allow the tape  102  to exit the chamber  106  (as shown in  FIG. 1 ). This chamber  106  can be a substantially closed cylinder, but it need not be cylindrical ( FIG. 3 ), or even mostly enclosed ( FIG. 2 ) to function. For instance, a series of posts  114  could surround the roll of tape  102  and allow it to rotate, but still locate it well. 
         [0047]    A pair of rotating wheels  116  is provided for advancing the tape  102 . The adhesive side  118  of the tape  102  sticks to the outside surfaces of the wheels  116 , and as the wheels  116  turn they serve to pull more tape  102  off the roll and into adhesion with themselves. A guide post  120  is disposed within the housing  100  to encourage the adhesion of the tape  102  to the wheels  116  (as shown in  FIG. 7 ). The guide post  120  serves to pull the tape  102  down from its natural path to the rotating wheels  116 , therefore increasing the area of attachment between the tape  102  and the rotating wheels  116 . Flex arm  122  is also provided to force the tape  102  into contact with the wheels  116  when tape  102  is installed. It should be appreciated that flex arm  122  can serve the same function as guide post  120 , thereby rendering the guide post  120  superfluous. 
         [0048]    The wheels  116  are rotated by means of a user-operated trigger  124  interconnected with said wheels  116 . The trigger  124  is pulled back by the user to drive the wheels  116 . The trigger  124  moves within a fixed angle of travel (as shown in  FIGS. 18   a  &amp;  18   b ), and is returned to its original position by means of a torsion spring  126  which is located on a shaft  128  integral to the trigger  124  and coaxial with the wheels  116  and the trigger  124  rotation. This torsion spring  126  acts between the trigger  124  and mounting bracket  130 . 
         [0049]    Rotation of the wheels  16  is provided by means of the interaction between a ratchet pawl  132  connected to the trigger  124  and the corresponding inwardly facing ratchet teeth  134  on each wheel  116 . A second ratchet pawl  136 , connected to the bracket  130  mounting the wheel  116 /trigger  124  assembly to the housing  100  of the device  10 , also engages the ratchet teeth  134  in the wheels  116 . The ratchet pawl  132  on the trigger  124  serves to rotate the top surface of the wheel  116  forwards, advancing the tape  102 , and the second ratchet pawl  136  on the housing serves to prevent the wheel  116  from rotating backwards and thereby pulling the tape  102  back and potentially jamming the device  10 . 
         [0050]    In the preferred embodiment, the ratchet pawls  132 ,  136  are plastic features integrally molded onto other parts. In the case of the trigger pawl  132 , it is molded as one piece with the trigger  124 . The housing pawl  136  would similarly be integrally molded into the bracket  130 . The ratchet pawls  132 ,  136  are shaped and manufactured from a material that allows them to flex but also have an elastic restorative force to keep them in contact with the ratchet teeth  134  to properly work as ratchets. By integrating the ratchet pawls  132 ,  136 , the preferred embodiment has fewer parts and can be manufactured more economically than existing designs. 
         [0051]    After the roll of tape  102  is inserted into the device  10 , a length of tape  138  must be separated from the roll  102  and placed across the wheels  116  in order for the wheels  116  to operate properly and advance the tape  102 . The tape  102  can be placed directly on the wheels  116  by pulling out a length of tape  138  and dragging it across the wheels  116 , in much the same was as 35 mm film is loaded onto the take up wheels of a camera (as shown in  FIGS. 10   a  through  10   d ). As discussed, the length of tape  138  is forced to take on a serpentine shape (as shown in  FIGS. 7 and 11 ) in order to exit the roll  102 , bend backwards around the post  120  and then curve the opposite way to go around the wheels  116 . In the preferred design, the housing element  104  upon which the post  120  is mounted is first translated axially relative to the roll of tape  102  previously placed on the housing element  104  holding the wheels  116 , and then rotated into its final position (as shown in  FIGS. 10   a  through  10   d ). 
         [0052]    A female keying feature  140  on one housing element  104  accepts a mating male keying feature  142  on the other housing element  104  to ensure that the two housing element  104  halves can only be inserted together in such an orientation that ensures the tape  102  will not be struck during the axial movement. The fact that the male keying feature  142  is elongated prevents the rotation of the housing  104  until the axial movement is complete. Once rotated, a pair of edges  144  on the female keying feature  140  tuck under the bumps  146  of the male keying features  142  to prevent axial movement. A pair of ears  148  on the trigger housing  150  includes small undercuts  152  which engage matched recesses  154  in the cutter housing  156  to provide a detent fit to keep the housings  104  from rotating relative to each other. 
         [0053]    Once the tape  102  has been loaded, started, and advanced, it must detach from the wheels  116  and exit the housing  100  so it can be used. The challenge then becomes to strip the tape  102  from the wheels  116  and transport it to the exit orifice  158  of the housing  100  without getting it hung up or stuck to something. The wheels  116  provides the motive force for moving the tape  102  and any resistance to the movement of the tape  102  that occurs after the wheels  116  will put the tape  102  into compression. Many types of tape  102  are very prone to buckling, and cannot tolerate the compression forces developed when the sticky side of the tape  102  adheres to a surface. Actually stripping the tape  102  from the wheels  116  is accomplished by locating a pair of small rollers  160  on either side of each drive wheels  116 . A center roller  162  is also disposed between the two wheels  116  (while the small rollers  160  are located just to the outside of each wheels  116 ). 
         [0054]    The perimeters of the rollers  160 ,  162  extend beyond the perimeters of the drive wheels  116  (as shown in  FIG. 11 ), which tends to push the tape  102  off the drive wheels  116 . It is important that the rollers be located close to the surfaces on the drive wheels  116  to which the tape  102  is so as to be most effective at breaking the adhesive bond between the tape  102  and the drive wheels  116 . It has been observed that if they are too far away, the lack of stiffness in the tape  102  would result in the tape  102  merely bending instead of releasing from the drive wheels  116 . 
         [0055]    Another important factor is the extent to which the rollers extend beyond the perimeter of the drive wheels  116 , and the radial position on the perimeter of the drive wheels  116  where they do so. The goal is to get the tape  102  to release from the drive wheels  116 , and then stay high so the non sticky side of the tape  102  encounters the boundaries of the exit orifice  158  and the sticky side of the tape  102  does not touch anything.  FIG. 11  illustrates the tape end  164  situated high up against the top limit of the exit orifice  158  in the optimal position for the tape  102  to move. Another factor found to help manage the disposition of the tape  102  as it comes off the wheels  116  is to make the center roller  162  extend further beyond the perimeter of the wheels  116  than the outer rollers  160 . 
         [0056]    In the preferred embodiment, the rollers  160 ,  162  are made of a non-adhering material such as silicone. Teeth  166  are provided on the perimeter of the rollers  160 ,  162  to reduce the surface area of contact with the tape  102  and thereby further reduce the adhesive force. As a precaution against the sticky side of the tape  102  getting caught on something, the preferred design further includes a silicone spike pad  168  with a bed of spikes  170  located just after the wheels  116 . The spikes  170  serve to reduce the contact area possible for the tape  102 . This spike pad  168  acts as a backup method of avoiding buckling of the tape  102  due to adhesion after it is stripped from the wheels  116 . If tape  102  does make its way down to that area despite the effects of the rollers  160 ,  162 , then the spike pad  168  will help prevent adhesion. Another reason for the spike pad  168  is that it can help pop the tape after a cut. The tips of the spikes  170  are actually a bit higher than the lower blade cutting edge, so the tape  102  is forced down onto the front row of spikes  170  during a cut. The spring back of the spikes  170  and tape  102  helps pop it off the lower blade. It has been observed that if the cut edge of the tape  102  remains stuck to the lower blade cutting edge in any way it can lead to a jam. 
         [0057]    Two notches  172  may be provided in the spike pad  168  just ahead of the adhesion surfaces of the wheels  116 . It has been observed that with certain soft and sticky tapes, removing material from this area helped prevent tape hang ups. It has also been observed that with the soft and sticky tape, the tape  102  can be more difficult to strip from the wheels  116  and the tape  102  can be pulled down between the stripper rollers  160 ,  162  creating dents in the tape  102  which would dip down low enough and contact the silicone spike pad  168  with sufficient force to cause the tape  102  to hang up. Removing the material from the notches  172  allows more room for the tape to dip without adverse effects. 
         [0058]    In the preferred embodiment, the tape is cut by means of a pair of cutting blades  174 ,  176  disposed in such a way as to create a scissor-type cutting action that is much safer than existing designs using sharpened blades. In fact, in the preferred design, the cutting blades  174 ,  176  are made from thin sheet metal that has been stamped or laser cut with no secondary sharpening required. The included angle of the cutting edge is roughly 90 degrees and presents a fairly blunt edge to the user. 
         [0059]    In order to operate effectively, such a scissor cutting approach demands precise alignment of the blades  174 ,  176 , as well as a certain amount of force to keep the blades  174 ,  176  in contact during cutting. One blade  174  must be made to pass across the other 176 in a progressive fashion such that point contact is maintained between the linear cutting edges throughout the movement. A conventional pair of scissors uses a fixed pivot between the two cutting blades. The current design demands a solution where the two cutting blades  174 ,  176  can be completely removed from each other to load tape  102  into the device  10  and to allow tape  102  to dispense, but then be aligned for a cut. 
         [0060]    The proper cutting motion at the blade interface is created by holding the blades  174 ,  176  independently, yet still achieving the precise alignment and force application required for a good cut. The lower blade  174  is held fixed relative to the trigger housing assembly  150  depicted in  FIGS. 8   a  and  9 . The blade  174  is located by a hook feature  178  which engages a slot  180  in the mounting bracket  130 , and a hole  182  in the blade  174  locates on a corresponding pin  184  molded into the bracket. A screw  186  fixes the lower blade  174  to the bracket  130 . The upper blade  176  is mounted to a cutting lever  188 . The cutting lever  188  pivots at one end on a shaft feature  190  which engages the cutter housings  192 ,  194  of the device  10 , and the other end of the lever  188  holds the upper blade  176 . The upper blade  176  is held in place by ears  196  on the blade  176  which engage pockets  198  in the lever  188  which are formed in such a way that, referring to  FIG. 13 , the blade  176  can be inserted perpendicular to its final position ( FIG. 13   a ), such that when rotated to its final position ( FIGS. 13   b  &amp;  13   c ) it is held securely. For assembly purposes a positive stop  200  located on the lever  188  holds the upper blade  176  in place against the force of a spring  202 . In this fashion, the blade location is stabilized prior to mounting this sub-assembly into the cutter housings  192 ,  194  (as shown in  FIGS. 15 and 17 ). The pockets  198  in the lever  188  which accept the ears  196  on the blade  176  are staggered, so that one is further from the axis of the pivot axle  204  of the lever  188  than the other. This forces the blade  176  into the angled orientation (see  FIG. 14   b ) that is required in order to engage the lower blade  176  in point contact during cutting (as shown in  FIGS. 12   a - 12   e ). 
         [0061]    The cutter lever subassembly  206  (shown in  FIG. 14 ) comprising the cutter housings  192 ,  194  and cutting parts is installed into the cutter housing element  156  (as shown in  FIGS. 16 &amp; 17 ), a positive stop  208  in the front cutter housing  192  supersedes the positive stop  200  on the lever  188  in determining the limit of motion (in a direction towards the lever pivot  204  of the upper blade  176 . This carefully placed stop  208  ensures that the leading tip of the upper blade  176  will contact the sloped surface of the lead-in tab on the lower blade  174 . This is the “parked” position for the upper blade, and it leaves ample room for tape  102  to be dispensed between the blades.  FIG. 12   b  shows the leading tip of the upper blade  176  as it makes contact with the lead-in tab  210  of the lower blade  174 . The purpose of the lead-in tab  210  is to allow for the inevitable misalignment between the upper and lower blades  174 ,  176 . The lead-in ramp  210  “catches” the leading tip/cutting edge of the upper blade  174  and guides it towards the cutting edge of the lower blade  176 . It supersedes the stop  208  as the feature that determines the position of the upper blade  176 . Once past the lead-in ramp, the upper blade&#39;s cutting edge begins to run across the cutting edge of the lower blade  176  (as shown in  FIG. 12   c ), starting the cut. Now the point contact between the cutting edges of the upper and lower blades  174 ,  176  determines the position of the upper blade  176 . All the while, the tension spring  202  prevents the upper blade  176  from moving any further away from the pivot  204  than it must. As the upper blade  176  moves past the lower blade  174  (as shown in  FIG. 12   d ) the upper blade  176  rotates forward, stretching the tension spring  202 . This action ensures a constant pressure at the point of contact between the upper and lower blades  174 ,  176 , leading to a clean cut.  FIG. 12   c  depicts the end of the cutting motion in a full cut. Operation of the cutter lever sub-assembly  206  is effected by depressing the cutter button  209 . It has been observed that the operation of the cutter button  209  by depressing the button  209  is far more efficient and ergonomic than a slide-type cutter mechanism. 
         [0062]    It has further been observed that the tape  102  can jam on the lower cutter blade  174  if the tape is allowed to drift left and right in its path, particularly depending on how the user holds the device  10 . In the preferred embodiment, therefore, ribs  212  are provided on each side of the tape path to center the tape  102 . These ribs  212  are disposed just before the drive wheels  116 , as it has been found that putting the ribs  212  after the drive wheels  116  results in the ribs  212  acting as obstacles to the motion of the tape  102 , potentially causing a jam. It is at this point before the drive wheels  116  that the tape  102  is under tension, as opposed to after the drive wheels where the tape is being pushed or compressed. In the preferred embodiment, these ribs  212  comprise a pair of raised protrusions on either side of the tape path. 
         [0063]    It should be appreciated that instead of dispensing short individual pieces of tape  102 , the dispenser  10  of the present invention can also be used much like a tape gun commonly used to dispense packing tape. The ratchets  132  on the wheels  116  don&#39;t prevent the tape  102  from being pulled out. As illustrated in  FIG. 16 , a cylindrical roller  212  with an axle shaft that is located by bosses in the housings  192 ,  194  is situated on the front of the device  10  just above where the tape  102  exits. If one advances a certain amount of tape  102 , the tape end  164  can be adhered to the object to be taped by pressing and rolling the roller  212  in such a manner that it pushes the tape  102  into the object. Moving the device  10  while keeping it pressed down to the object can serve to reel out more tape  102 . The blades  174 ,  176  still operates normally in this application. 
         [0064]    Having thus described the invention with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications can be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.