Abstract:
An adhesive tape dispenser is provided that is operable by a single hand, and is applicable to a variety of adhesive tapes. The provided adhesive tape dispenser overcomes the problem of jamming due to tape accumulation behind the blade by providing a switchable double cam system that allows adhesive tape to be dispensed, the cutter blade to be urged suddenly downward to cut the tape, and then the cutter blade suddenly retracted during one rearward motion of the tape-cutting button.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/365,957, filed Jul. 20, 2010, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     FIELD 
     The present disclosure relates to adhesive tape dispensers and more particularly adhesive tape dispensers that include a switching dual cam and can dispense adhesive tape with one hand operation. 
     BACKGROUND 
     Adhesive tape dispensers are well known devices. For example, U.S. Pat. No. 4,097,328 (Urushizaki) teaches an adhesive tape dispenser used to apply cellophane adhesive tape and to automatically cut it. The tape dispenser includes a spring-loaded swing member, a tape press roller mounted on the bottom of the swing member, and a blade-carrying disc mounted to be rotatable as the swing member is pivoted up and down. U.S. Pat. No. 7,320,351 (Chern) teaches an adhesive tape dispenser that includes a housing comprising a rear spring, a forward opening, and a forward tape press roller; a tape dispensing unit urged by the spring and comprising a tape mount with an adhesive tape roll rotatably put thereon; a push member projected from the opening; and a cutter unit pivotably mounted in the housing comprising a front cutting blade and a top ridge. Placing the cutter on a surface to be sealed with the tape slightly projected from the opening and adhered on the surface and sliding the cutter will press the tape against the surface by the tape press roller for adhering thereto. After dispensing a desired length of the tape, pushing the push member will cause it to press down and pass over the ridge and press the blade to cut the tape off its roll with the spring being compressed. This adhesive tape dispenser is capable of being operated with one hand. 
       FIG. 1  is a perspective view of a tape cutter (adhesive tape dispenser) disclosed in U.S. Pat. No. 7,320,351 (Chern) with the side plate removed. The cutter comprises a housing  101  consisting of two mated side plates. Within the housing  101  there is provided at least one tab at one side plate, each tab adapted to snugly insert into a hole (not shown) at the other side plate for fastening both side plates together, bar  113  projected forwardly from a rear end, a first shaft  111  at a forward opening with tape press roller  115  rotatably mounted thereon, and second shaft  112  projected laterally from one side plate. 
     The cutter further comprises tape dispensing unit  102  including tubular tape mount  121  with an adhesive tape roll to be rotatably put thereon, push member  122  projected from the opening, a tape guide below push member  122  for pressing onto a tape (not shown), and platform  123  a proximate tape guide. The platform  123  and a tape guide are adapted to facilitate the pulling of tape out of the cutter. 
     The cutter further comprises coil spring  104  put on bar  113  and biased between an inner wall of the cutter and a rear recess of tape dispensing unit  102  such that tape dispensing unit  102  is able to move closer to the inner wall of the cutter by compressing spring  104  in a tape cutting operation after dispensing a tape as detailed later. The cutter further comprises cutter unit  103  having a rear tubular portion rotatably mounted on second shaft  112  and including front cutting blade  131 , mounting plate  132  for fixedly fastening blade  131  onto a front end of a block member, and top ridge  134  disposed proximate push member  122 . 
     Referring to  FIG. 1 , in operation, the cutter is placed on a surface to be sealed with an open end of adhesive tape roll  105  slightly projected from the opening and adhered on the surface. Next, the cutter is made to slide on the surface with tape  105  pressed against the surface by tape press roller  115  for adhering tape  105  to the surface. When a desired length of tape  105  has been put thereon, a user may push member  122  rearward to press down and pass over ridge  134  until ridge  134  is stopped by an edge of the opening. Also, blade  131  is pressed to cut tape  105  off its roll with spring  104  being compressed. 
     Occasionally, during operation of one-handed adhesive tape dispensers, such as the one discussed above, tape can jam inside of the dispenser causing an inconvenience to the end user. The end user then has to take apart the two halves, rethread the dispenser, and start again. The problem can occur when the end user does not complete the full stroke of the applicator button. When this happens, the blade may still come in contact with the tape and the tape tears. As result, the tape can accumulate behind the blade. When the applicator button is released, the tape can spring forward and hit the blade before it is retracted causing the tape to jam inside of the dispenser. 
     U.S. Ser. No. 61/327,125 (Hagglund et al.), filed on Apr. 23, 2010, discloses a tape dispenser for single hand operation that overcomes some of these disadvantages. The disclosed tape dispenser resists jamming due to tape accumulation behind the blade by providing a pivotable lever arm on the blade holder assembly that can be urged suddenly downward by contact with a wedge, an upper pin, and a lower pin attached to a back plate when a push button assembly attached to the back plate is urged rearward by a user. The provided adhesive tape dispenser delays contact of the blade with the adhesive tape when the pushbutton assembly is urged rearward compared to the prior art and then quickly cuts the tape. The delayed, quick downward motion of the cutting blade allows for fast cutting action of the blade on the adhesive tape while minimizing the contact time of the blade or parts of the blade assembly with the tape. The minimized contact time can significantly reduce tape jamming inside of the dispenser. However, the disclosed tape dispenser for single handed operation does not completely eliminate tape jams which can occur from blade-tape interference after the tape is cut. 
     Thus, there is a need for adhesive tape applicators that can be operated with one hand, are simple to operate and manufacture, and which resist jamming due to tape accumulation behind the blade. There is also a need for tape applicators that can eliminate blade-tape interference after the tape is cut. 
     SUMMARY 
     The provided adhesive tape dispenser has the advantages of being safe to the user in operation, being operable by a single hand, and being applicable to a variety of adhesive tapes. Additionally, the provided adhesive tape dispenser overcomes the problem of jamming due to tape accumulation behind the blade by providing a switchable double cam system that allows adhesive tape to be dispensed, the cutter blade to be urged suddenly downward to cut the tape, and then the cutter blade suddenly retracted during one rearward motion of the tape-cutting button. Unlike the prior art, the provided adhesive tape dispenser, with its one motion down and up blade operation, significantly reduces the contact of the blade with the adhesive tape, thus significantly reducing, if not eliminating, blade-tape interference after the tape is cut. 
     In one aspect, an adhesive tape dispenser is provided that includes a lower housing having a perimeter, the lower housing comprising an inner edge, an inner wall, at least two alignment features, a forward tape press roller, a pivot post, at least two forward lateral ridges defining a forward recessed groove, and at least two rear lateral ridges defining a rear recessed groove, wherein the inner edge substantially surrounds the perimeter of the lower housing except for one section that defines a forward opening, and wherein the forward tape press roller, the pivot post, and the forward lateral ridges project inwardly from the inner wall of the lower housing; a back plate assembly comprising a back plate having a inner side and an outer side, the inner side that includes a tape unwind spool, a push button attached to and projecting inward from the back plate, at least one forward and one rear tab that each slideably engage the forward recessed groove and the rear recessed grove of the lower housing, respectively, and a slide pin projecting inward from the back plate; an outer cam assembly that includes a lever arm having a proximal end and a distal end, a pivot cylinder on the proximal end of the lever arm, and a cutting blade mounted on the distal end of the lever arm, the pivot cylinder rotatably engaging the pivot post on the lower housing, wherein the lever arm includes an outer cam opening towards the distal end which engages the slide pin of the back plate assembly; and an inner cam assembly that includes a pivot arm having a proximal end and a distal end, a pivot cylinder on the proximal end of the pivot arm, a switching bar attached to the outer side of the pivot cylinder, and a pusher at the distal end of the pivot arm, wherein the pivot cylinder rotatably engages the pivot post on the lower housing on the inside of the outer cam assembly lever arm, and wherein the pusher at the distal end of the pivot arm extends outwardly into the outer cam opening of the outer cam assembly. The provided tape dispenser can include an upper housing that can be aligned with the inner housing at least two alignment features. After alignment, the upper housing and the lower housing can substantially encase the backplate assembly, the outer cam assembly and the inner cam assembly. 
     In another aspect, a method of cutting and adhesive tape is provided that includes the use of a provided adhesive tape dispenser. The cutting blade on the outer cam assembly cuts though the adhesive tape and returns to its precut position when the push button, which can be in a forward or rearward position is urged rearward. The push button can be returned to its forward or precut position by a spring. 
     In this disclosure: 
     “cam” refers to a device or device feature that translates one type of motion into another type of motion, for example, circular motion into reciprocating or oscillating motion; 
     “forward” or “front” refers to the direction towards the dispensing end of the tape dispenser; 
     “rearward” or “rear” refers to the direction away from the dispensing end of the dispenser; 
     “inner” refers to the direction or side facing towards the inside of the tape dispenser or upward (towards the observer) in  FIG. 2  and  FIGS. 3   a - 3   e ; and 
     “outer” refers to the direction or side facing away from the inside of the tape dispenser. 
     The provided adhesive tape dispenser differs from previous adhesive tape dispensers in that it can be operated with a single hand and, after a desired amount of tape has been dispensed, the tape can be cut by moving a push button from a forward position to a rearward position. During this single motion, the switching dual cam mechanism of the provided tape dispenser forces the cutting blade down through the tape and then immediately raises the cutting blade back into its original position. This quick cutting and return stroke can eliminate blade-tape interference after the tape is cut. 
     The above summary is not intended to describe each disclosed embodiment of every implementation of the present invention. The brief description of the drawings and the detailed description which follows more particularly exemplify illustrative embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a tape cutter disclosed in U.S. Pat. No. 7,320,315 with the side plate removed. 
         FIG. 2  is an exploded perspective view of an embodiment of a provided adhesive tape dispenser. 
         FIGS. 3   a - 3   e  drawings, that are sequential in time, illustrating the operation of a provided adhesive tape dispenser. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, reference is made to the accompanying set of drawings that form a part of the description hereof and in which are shown by way of illustration several specific embodiments. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense. 
     Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. 
     The provided adhesive tape dispenser features a switching dual cam mechanism to allow the desired quick cutting and return stroke to occur during a single unidirectional motion of the push button. The switching dual cam mechanism includes a stationary slide pin and two cam assemblies—an outer cam assembly and an inner cam assembly. Both the outer cam assembly and the inner cam assembly are rotatably attached to the same pivot post at their rearward ends. The outer cam assembly provides an opening that defines the path that the slide pin travels when the push button is moved rearward. The inner cam assembly includes a wedge-shaped template (pusher) that, when down, forces the slide pin to the top of the opening in the outer cam, which in turn forces the outer cam arm with cutting blade attached downward, cutting the tape. As the push button is continued to be moved rearward, a switching tab attached to the push button pushes against a switching bar on the rotatable pivot section of the inner cam assembly. This drives the lever arm or the inner cam assembly upward out of the way of the slide pin and in doing so also pushes against the arch of the opening in the outer cam assembly to raise the cutting blade. Thus, the provided adhesive dispenser includes a switching mechanism (interaction between the push button and the inner cam assembly), and two cams. One cam is provided by the outer cam opening and the other cam is provided by the pusher. 
     Referring to  FIG. 2 , an exploded perspective view of an embodiment of a provided adhesive tape dispenser is illustrated. The dispenser comprises lower housing  200  designed to fit together with an upper housing (not shown). At least two alignment features (not shown) in the upper housing fit into at least two alignment features in the lower housing. In the embodiment shown in  FIG. 2 , the alignment features in lower housing  200  include at least two alignment holes  222  and corresponding alignment features in the upper housing (not shown) include at least two location pins. When the lower housing is mated with the upper housing, the upper housing and lower housing  200  substantially contact each other along inner edge  202  of lower housing  200  and a corresponding inner edge on the upper housing. Other alignment features such as, for example, ridges and grooves, interfacing surface features, tabs, recesses, and the like are also contemplated. 
     The provided adhesive tape dispenser includes lower housing  200 , back plate assembly  230 , outer cam assembly  260 , and inner cam assembly  280 . As discussed above, the provided adhesive tape dispenser can also include an upper housing that comprises an inner edge and at least two alignment features, wherein the inner edge upper housing makes contact with the inner edge of the lower housing thereby substantially encasing the back plate assembly and the blade assembly unit. 
     Lower housing  200  includes inner wall  204  and has inner edge  202  that substantially surrounds the perimeter of lower housing  200 . Inner edge  202  matches a similar inner wall on the upper housing to substantially enclose the adhesive tape dispenser working parts to be described herein when the lower housing is mated to the upper housing. Inner edge  202  includes forward opening  206  through which tape can be dispensed and through which push button  244  of back plate assembly  230  can protrude. Lower housing  200  includes pivot post  212  and forward tape press roller  208  projecting inward substantially perpendicular from inner wall  204 . Forward tape press roller  208  is located within forward opening  206  and functions to press adhesive tape exiting the dispenser onto a substrate. Lower housing  200  also includes forward lateral ridges  214  that define forward recessed groove  214   a , and rear lateral ridges  216  projecting inward from inner wall  204 . Forward lateral ridges  214  and rear lateral ridges  215  and  216  that define rear recessed grooves  215   a  and  216   a  respectively. Forward lateral ridges  210  and rear lateral ridges  215  and  216  are substantially parallel. Forward lateral ridges  214  extends substantially from forward opening  206  to rear lateral ridges  215  and  216  as shown in  FIG. 2 . Rear lateral ridges  215  and  216  extend rearward in a substantially parallel fashion. Forward tab  248  on back plate assembly  230 , engaged with a coil spring (not shown), fits into forward recessed groove  214   a . Similarly, two rear tabs  252  and  253  on back plate assembly  230  fit into rear recessed grooves  215   a  and  216   a . Back plate assembly  230  slides on top of forward and rear lateral ridges  214 ,  215 , and  216  and the tabs and grooves confine the sliding motion of back plate assembly  230  into a lateral forward and rear sliding motion. Slide stops (forward slide stop  218  and rear slide stop  219 ) define the forward and rear slide limits of back plate assembly  230  during operation of the dispenser as illustrated in  FIGS. 3   a - 3   e.    
     Back plate assembly  230  is slideably engaged in lower housing  200  has described above and can slide forward (towards forward opening  206 ) or rearward (away from forward opening  206 ) during operation which is described further within. Back plate assembly  203  includes flat base plate  232  upon which all other features described herein are mounted. Push button  244  is attached to the upper forward part of base plate  232  and protrudes towards the inside of the tape dispenser in a direction substantially normal to base plate  232 . Push button  244  protrudes through forward opening  206  of lower housing  200  when back plate assembly  230  is slideably engaged into lower housing  200 . Back plate assembly  203  also includes tabs  252  and  253  normal to base plate  232  and protruding outwardly behind base plate  236  as described above. Back plate assembly includes tape spool  234  also mounted in a direction normal to the inner surface of base plate  232  upon which rolls of pressure-sensitive adhesive tape are be mounted. Switching tab  236  is mounted normal to the inner surface of base plate  232  upon back plate assembly  230  rearward of push button  244  and, when the provided adhesive tape dispenser is assembled, contacts and pushes against switching bar  284  of inner cam assembly  280  when back plate assembly is urged rearward. Its operation is more fully described later on. Back plate assembly also includes slide pin  238  that is mounted inwardly normal to base plate  232 . Slide pin  238  slideably engages outer cam opening  268  of outer cam assembly  260  when the provided tape dispenser is fully assembled. Back plate assembly  230  also includes tape hold down roller  246  also mounted normal to base plate  232  that has a cylindrical opening that fits around roller pin  242  so that it can rotate freely when tape is being dispensed. Tape hold down roller  246  holds tape down when cutting action is employed. Finally, back plate assembly  230  includes tape guide  240  over which tape is dispensed. Tape guide  240  is mounted normal to base plate  232 . The function of tape guide  240  is to guide the tape through forward opening  206  of lower housing  200  and to hold the tape during the cutting operation described herein. 
     The provided tape dispenser also includes outer cam assembly  260 . Outer cam assembly  260  includes pivot cylinder  262  and lever arm  266 . Lever arm  266  includes outer cam opening  268  (described later on) as a part of lever arm  266  and also includes cutting blade  264  mounted on the end or distal portion of lever arm  266 . When the provided tape dispenser is assembled, outer cam assembly  260  is mounted inwardly from back plate assembly  230  so that pivot cylinder  262  of outer cam assembly  260  is mounted on pivot post  212  of lower housing  200  and slide pin  238  on back plate assembly  230  fits into outer cam opening  268  as shown in  FIGS. 3-5 . 
     The provided tape dispenser also includes inner cam assembly  280 . Inner cam assembly  280  includes a pivot cylinder (not shown but underneath pivot cylinder cap  282 ), switching bar  284 , inner cam lever arm  286  and pusher  288 . Pusher  288  is on the forward end of inner cam lever arm  286 . Pusher  288  has recessed cut  290  on its outer side (the side towards the lower housing). Recessed cut  290  is illustrated compared to the upper outer end of pusher  288  which is shown as  291 . Recessed cut  290  extends from the upper outer end of pusher  288  down the rearward side of pusher  288  and allows for passage of slide pin  238  during operation of the dispenser. This is further illustrated in the description of  FIGS. 3   a - 3   e . When the provided tape dispenser is assembled, inner cam assembly  280  is mounted inward of outer cam assembly  260 . Pivot cylinder of outer cam assembly (not shown) is also mounted on pivot post  212  of lower housing. Pusher  288  (described herein) is slideably engaged inside of outer cam opening  268  and either over or under slide pin  238  of back plate assembly  230  depending upon position of switching bar  284 . 
     The operation of the provided switching dual cam tape dispenser is herein described for one embodiment of the provided adhesive tape dispenser. The operation of the dispenser is based upon a back plate assembly that can be slideably urged forward and rearward in a lower housing by a rigidly attached push button. In some embodiments, the push button can be fabricated as a contiguous part of the back plate assembly. A slide pin is also a part of the back plate assembly. When the push button is urged rearward after dispensing a desired amount of tape, the slide pin moves from start position, over an inner cam and pushes down on an outer cam. The outer cam has a cutting blade bonded to its forward surface. Once the slide pin moves over the top of the inner cam, the outer cam is at its lowest position and the cutting motion is complete. As the push button is urged further rearward, a switching tab on the push button engages a switching bar on the arm of the inner cam thus urging the inner cam upwards. When the inner cam reaches the arch of the outer cam, it pushes the outer cam arm (with cutting blade attached) upwards to its starting position, thus ending the cutting stroke and moving the blade out of the way of the tape&#39;s returning route. 
     The slide pin moves underneath the inner cam in a direct route towards its starting position when the push button is returned to its forward position either by the user or via an optional spring. As soon as the slide pin clears the inner cam, a pusher on the inner cam lever arm pushes the inner cam back to its starting position as the slide pin returns to its starting position, thus completing the return stroke. The whole operation is best illustrated by referring to  FIGS. 3   a - 3   e . The reference numbers used in  FIGS. 3   a - 3   e  correspond to the same numbers and parts referred to above for  FIG. 2 . 
       FIG. 3   a  is a schematic view of an embodiment of a provided adhesive tape dispenser in its pre-cut position. Tape spool  234  has tape roll  250  mounted thereon. Adhesive tape  241  is unwound from tape roll  250 , passes over tape hold down roller  246 , between cutting blade  264  (shown in its upward position) and tape guide  240 , and then emerges from the adhesive tape dispenser and passes under forward tape press roller  208 . In this position, tape can be applied to a substrate (not shown) using a single hand by drawing the adhesive tape dispenser rearward (in the left hand direction as illustrated) while pressing down on the adhesive tape dispenser which puts pressure on forward tape press roller  208 . In its pre-cut position, push button  244  (attached to back plate assembly  230 ) is in its forward position against forward slide stop  218 , slide pin  238  is in its most forward position in outer cam opening  268  and inner cam lever arm  286  is located in the rearward position of outer cam opening  268  in its downward position. Outer cam opening  268  has a flat bottom edge and is narrow at its forward end (just large enough to allow slide pin  238  to freely slide within it) but has an enlarged opening at its rearward end (that allows pusher  288  which is engaged in outer cam opening  268 ) to be in a downward position (as shown in  FIG. 3   a ) or an upward position (against the top of the enlarged opening). Both outer cam assembly  260  and inner cam lever arm are rotatably mounted on pivot post  212  of the lower housing. 
     When a desired amount of tape has been applied to the substrate, push button  244  is urged rearward and passes through a position captured by  FIG. 3   b . In this position, cutting blade  264  is still in its pre-cut position as shown. As push button  244  is urged rearward, slide pin  238  travels on the flat bottom edge of outer cam opening  268  until it encounters pusher  288 . Pusher  288  forces slide pin  238  towards the top of the enlarged opening of outer cam opening  268  as push button  244  is urged farther rearward. 
       FIG. 3   c  illustrates further rearward urging of push button  244 . In this illustration, pusher  288  has forced slide pin  238  into the upward part of the enlarged opening of outer cam opening  268 . Since outer cam assembly  260  is rotatably mounted on pivot post  212  and slide pin  238  is in a relatively fixed position (attached to back plate assembly  230  and thus, push button  244 ), outer cam assembly  260  is forced downward by slide pin  238  (which is against the roof of enlarged opening of outer cam opening  268 ) and pusher  288  (that has recessed cut  290  on its outer side to allow passage of slide pin  238 ). This downward motion of outer cam assembly  260  forces cutting blade  264  downward cutting the adhesive tape. 
     Further rearward motion of push button  244  puts it into its most rearward position, against rear slide stop  219  as illustrated in  FIG. 3   d . In this position, switching bar  284  (connected to inner cam lever arm  286 ) has been forced rearward by contact with switching tab  236  attached to push button  244 . Since inner cam lever arm  286  is attached to switching bar  284 , this action forces pusher  288  upward which in turn forces outer cam assembly upward until slide pin  238  is against the rearward most portion of the flat bottom edge of outer cam opening  268 . This action lifts cutting blade  264  up into its pre-cut position as shown. 
       FIG. 3   e  is an illustration of the provided adhesive tape dispenser as push button  244  is urged forward again (by a user, a spring, or a combination thereof). As push button  244  is urged forward, slide pin  238  now travels the whole distance from its most rearward position ( FIG. 3   d ) to its most forward position ( FIG. 3   a ) against the flat bottom edge of outer cam opening  268 . Pusher  288  remains it its upward position as slide pin  238  keeps it in its upward position. This keeps outer cam assembly also in its upward position and keeps cutting blade  264  also in its upward position. 
     Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that this invention is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the invention intended to be limited only by the claims set forth herein as follows. All references cited in this disclosure are herein incorporated by reference in their entirety.