a-10d are perspective views showing the attachment of the trigger housing element to the cutter housing element;
a-12e are perspective views of the cutting elements of the automatic tape dispenser of the present invention showing the cutting path of the blades;
a-13c are side elevational views showing the cutter lever sub-assembly;
a-14b are side elevational and top plan views showing elements of the cutter lever sub-assembly;
a and 17b are perspective views showing the cutter housing element in the open and closed positions;
a and 18b are side elevational views showing the trigger housing elements with the trigger released and the trigger depressed; and
Referring to the drawings and, in particular, to
In the preferred embodiment, the roll of tape 102 is attached to the cylindrical post 108 in an axial direction, as shown in
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.
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
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
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
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.
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.
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
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.
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).
The perimeters of the rollers 160, 162 extend beyond the perimeters of the drive wheels 116 (as shown in
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.
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.
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.
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.
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.
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
The cutter lever subassembly 206 (shown in
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.
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't prevent the tape 102 from being pulled out. As illustrated in
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.