Patent Application
20060037689
The present invention relates to a method and apparatus for applying decorative tape to glass and, more particularly, the present invention relates to an automated method and apparatus for applying decorative ductile tape to glass.
Various types of tape have been developed that have a decorative appearance when applied to glass. For example, U.S. Pat. No. 4,192,905 to Scheibal describes a transparent strip of polymeric material used to imitate a beveled edge. The transparent strip has a wedge-shaped cross-section having an angle similar to a beveled edge. The transparent strip has adhesive on one side for affixing the strip to the glass to produce a beveled edge appearance. U.S. Pat. No. 5,840,407 to Futhey et al. describes an optical film for simulating beveled glass. The optical film has a structured surface for providing a simulated beveled appearance. The structured surface is formed of a plurality of spaced parallel grooves that form a plurality of facets that simulate beveled glass.
Various applicators have been developed for applying tape to a surface. For example, U.S. Pat. No. 6,571,849 to Erickson et al. discloses a tape applicator that includes a tape head having a base, a tape roll holder attached to the base and a tape application roller for applying a tape to a surface attached to said base, where the tape applicator includes a tape path from the tape roll holder to the tape application roller. The tape applicator includes a x-axis actuator operatively connected to the tape head for moving the tape applicator in the x-axis direction and a y-axis actuator operatively connected to the tape head for moving the tape applicator in the y-axis direction.
The present invention concerns a method and apparatus for applying a ductile decorative tape to a glass surface, such as a window lite. One aspect of the invention is a tape applicator for applying a tape having a curved profile to a glass surface. The tape applicator includes a tape head, an x-axis actuator, and a y-axis actuator. The tape head includes a base, a tape roll holder attached to the base, and a tape application roller having a circumferential concavity that corresponds to the curved tape profile for applying the tape to the glass surface. The x-axis and y-axis actuators move the tape head along an x-axis direction a y-axis direction respectively.
In one embodiment, the application roller circumferential concavity is configured to apply more pressure to edges of the curved tape than a central portion of the curved tape. Quick release collars may be used to attach the tape application roller to the tape head.
Another aspect of the present invention is a tape applicator for applying a ductile tape to a glass surface in a curved pattern. The tape applicator includes a tape head, an x-axis actuator, a y-axis actuator, and a rotary actuator. The tape head includes a base, a tape roll holder attached to the base, and a tape application roller. The tape application roller presses the tape against at least two points of the glass surface along a line of tangency that extends from a first edge of the tape to a second edge of the tape. The rotary actuator for rotates the base about an axis of rotation. The axis of rotation intersects a midpoint of the line of tangency.
In one method of automatically applying a curved tape segment to a glass surface, a tape head is moved along a path stored in a controller memory. The tape head is controlled to dispense the tape to the glass surface. A midpoint of a tape application roller carried by the tape head is aligned with an axis of rotation of the tape head. The tape is pressed against the glass surface with a tape application roller carried by the tape head. The tape application roller is rotated about the axis of rotation as the tape head is moved along the path.
One aspect of the present invention is a tape applicator that limits bending of ductile tape as the ductile tape is applied to a glass surface. One such tape applicator includes a frame, a tape spool rotatably mounted to the frame, a drive roller rotatably mounted to the frame, an idler roller in communication with the drive roller, and a platen that defines a line of travel of the tape. The tape spool, drive roller, idler roller, and platen define a tape path of travel from the tape spool, between the drive roller and idler roller, and over said platen along the line of travel. The platen, drive roller and idler roller are positioned such that a line connecting a drive roller axis of rotation and an idler roller axis of rotation is perpendicular to the line of travel of the tape defined by the platen. In one embodiment of the tape applicator, that limits bending of the ductile tape, the path of travel from a point where the idler roller and the drive roller pinch the tape to an end of the platen is a substantially straight line.
Another aspect of the present invention is an assembly for cutting lead tape applied by an automatic tape applicator. The assembly includes a stationary blade, a linear bearing, a moveable blade, and an actuator. The stationary blade is coupled to an applicator frame. A first linear bearing component is coupled to the applicator frame. A second linear bearing component is coupled to the first linear bearing component such that the second linear bearing component is constrained to linear movement with respect to the first linear bearing component. The moveable blade is fixed to the second linear bearing component such that the moveable blade is constrained to linear movement with respect to the fixed blade. The actuator is coupled to the moveable blade and the frame for moving the moveable blade along a linear path with respect to the fixed blade to cut the lead tape.
Additional features of the invention will become apparent and a fuller understanding obtained by reading the following detailed description in connection with the accompanying drawings.
The present disclosure is directed to patterns 10 of decorative tape applied to glass sheets 12, such as window lites, to a decorative tape 22 that is configured to overly a second type 16 of decorative tape, to a tape head 100 for applying decorative ductile tape 14 to glass sheets, and to a tape applicator 200 for applying aligned decorative patterns 10 to opposite sides of a glass sheet 12.
Since the third strip 22 overlies the first and second strips 18, 20, the first decorative and second decorative tape strips are applied to the glass surface first. The third decorative tape strip 22 is then applied at least partially between the first and second decorative tape strips.
In the illustrated embodiments, the base portion cross-section is rectangular and the outer surface of the decorative portion is arcuate. In one embodiment, the base portion 44 is approximately 0.010″ thick or slightly thicker than 0.010″, corresponding to 0.010″ decorative tape. In the embodiment illustrated by
In the embodiment illustrated by
Lead tape is very ductile. This makes it more difficult in some respects to apply to glass sheets and to cut than relatively more stiff tapes, such as ACCENTRIM™ tape. For example, bends in the lead tape that occur as the lead tape travels through the tape head tend to be retained when the tape is applied to the glass sheet. The blades of traditional cutoff tools included in tape dispensing heads are spread apart by the thicker, ductile lead tape. The ductile property of lead tape also makes it possible to apply curved patterns to the glass sheet. One aspect of the present invention is an improved tape head 100 that includes features that allow smooth lengths of ductile tape 22 to be applied, that facilitate cutting of thicker, ductile tape and/or that allow curved segments of ductile tape 22 to be applied to glass sheets 12. These features are described below in detail in the context of an overall tape applicator 200.
The tape applicator 200 includes a tape head 100 and a tabletop 52. With the use of actuators, the tape head 100 moves to different locations on the tabletop 52 to apply tape to an article on the tabletop 52, such as a sheet of glass 12. The tape head 100 applies lengths of tape to a sheet of glass 12 to create decorative patterns. The tape applicator 200 is especially useful for applying decorative tape including lead tape that simulates the appearance leaded glass and optical film that simulates an etched, grooved, or beveled appearance. One such optical film is described in U.S. Pat. No. 5,840,407. Such tapes having the optical film disclosed in U.S. Pat. No. 5,840,407 are commercially available as 3M™, Accentrim™ Tape, from 3M Company, located in St. Paul, Minn. These tapes are referred to herein as ACCENTRIM™ tapes.
The tape applicator 200 preferably includes a frame 54 for holding the tabletop 52. The tabletop 52 is preferably tilted to allow a user to easily place a sheet of glass 12 on the tabletop 52. In the exemplary embodiment, the tabletop 52 includes a first home position fixture 56 located on one side of the tabletop and a second home position fixture 58 located on an opposite side of the tabletop. Referring to
The tabletop 52 defines an x-axis and an y-axis in the plane of the tabletop and a z-axis perpendicular to the tabletop 52. The tape applicator 200 includes a x-axis actuator 68, a y-axis actuator 70 and a z-axis actuator 72 for supporting, moving, and positioning the tape head 100 at different locations on the tabletop 52. The y-axis actuator 70 includes a support arm 74 that extends in the y-axis direction of the tabletop 52. The y-axis actuator 70 is moved in the x-axis direction by the x-axis actuator 68. Referring to
The y-axis actuator 70 is similar to the x-axis actuator 68. The y-axis actuator also includes a motor 33, a ball screw (hidden by the support arm), an end block 61 that contains a bearing for the ball screw and a car 90 for moving the tape head 100 along support arm 74 in the y-axis direction of the tabletop 52. The tape head 100 is attached to car 90. As the motor 33 turns the ball screw 88, the car 90 moves in the direction of the y-axis of the tabletop 52. As the car 90 moves, the tape head 100 moves with the car 90 along the support arm 74. One acceptable y-axis actuator is a Linear System Actuator sold under the trade name Thomson, which is commercially available from Thomson Industries, Inc., located in Port Washington, N.Y., sold under part number 2RBM160DMKL1300. The motor 33 for the y-axis actuator is preferably a step motor. An example of a suitable step motor is a step motor sold under the trade name Compumotor, which is commercially available from Braas Company located in St. Paul, Minn., sold under the part number CP*S57-51-MO-25.
The rotary actuator 72 for rotating the tape head 100 around an axis A that is parallel to the z-axis. Any commercially available rotary actuator may be used. An example of a suitable step motor is sold under the trade name Compumotor, which is commercially available from Braas Company located in St. Paul, Minn., sold under the part number S83*135-MO-S.
The tape head 100 is illustrated in
The tape head 100 also includes a drive roller 110, a pinch roller 118, a pivotal platen 122, the cutting mechanism 116, an application roller 120, and a liner take-up roller 136, all attached to the lower base portion 106b. In the exemplary embodiment, the guide rollers 108, 110, the drive roller 110, the pinch roller 118, the pivotal platen 122, the application roller 120, and the liner take-up roller 136 are all mounted using a quick connect collars 103. The quick connect collars 103 allow different sizes and types of tape 14 to be easily mounted and removed from the tape head 100.
Referring to
In the exemplary embodiment, the tape 14 moves along the following tape head path:
In one embodiment, the tape head 100 is configured to minimize bending of the tape 14 along the path of travel between the drive roller 110 and the tape application roller. This reduces visible defects in the ductile tape, such as lead tape, applied to the glass surface. Lead tape has a high degree of bend memory. That is, when lead tape is bent it tends to stay bent. Bends retained in the lead tape produce visual defects. In this embodiment, the drive roller 110, the pinch roller 118, the pivotal platen 122 and/or the application roller 120 are configured to minimize bending of the tape between the drive roller 110 and the application roller 120.
Referring to
Referring to
The pivotal platen 122 separates the liner 15 from the tape 14, as the tape 14 passes over the platen 122. After the liner 15 is separated from the rest of the tape 14, the liner winds around the pinch roller 118 and is taken up by the liner roller 136 (see
When loading a new roll of tape 14 into the tape head 100, the tape is initially threaded through the tape head 100 according to the tape path outlined above. Referring to
The tape 14 includes an adhesive layer 28 and a liner 15 covering the adhesive layer. Examples of tape that can be applied by the disclosed tape head 100 are ACCENTRIM™ tape and lead tape. Referring to
Referring to
In one embodiment, the tape head 100 is adapted to apply curved patterns 183 of ductile tape to glass sheets. Referring to
In one embodiment, curved tape segment patterns that are stored in a controller memory are automatically applied to a glass surface. The tape head is moved along a path stored in a controller memory. The controller controls the tape head to dispense curved patterns of tape onto the glass surface. This is facilitated by aligning the midpoint of a tape application roller carried by the tape head with an axis of rotation of the tape head.
In the exemplary embodiment, the cutting mechanism is adapted to cut a thick, ductile tape, such as a tape that provides the appearance of leaded glass when applied.
The cutting mechanism 116 cuts the tape 14 transversely when the air cylinder 150 actuates to force the moveable blade 114 to move along a linear path and contact the fixed blade 112. Referring to
To apply the second end 151 of the tape 14, the tape head 100 continues moving relative to the sheet of glass to allow the application roller 120 to press the remaining tape 14 against the glass sheet 12. The air cylinder 150 moves the moveable blade 114 again to move the moveable blade 114 out of contact with the fixed blade 112. At the same time the moveable blade 114 moves out of contact with the fixed blade 112, the pivotal platen 122 rotates clockwise under the force of the biasing spring to move the platen toward the blades 114, 116 of the cutting mechanism 116, between the blades 114, 116 to allow the tape 14 to pass through the cutting mechanism 120 when the tape advances.
To operate the x-axis actuator 68, y-axis actuator 70, and rotary actuator 72 to move the tape head 100, the tape applicator 200 preferably includes a computer processor/controller 300 for sending signals to the actuators 68, 70, 72 to move the tape head 100 relative to the tabletop 52. The computer processor and controller then determines which way to direct the actuators 68, 70, 72 to move the tape head 100 to apply the tape to the glass and to cut the tape. In one embodiment, the computer processor and controller is an “open loop” system, which calculates where the tape head 100 is located on the tabletop 52, based on a known series of moves. For example, the ball screw in either the x-axis actuator 68 or y-axis actuator 70 will move the tape head 100 a known distance per one rotation of the ball screw. If the computer processor knows the initial location of the tape head 100, like the first home position, or the second home position, it can determine the final location of the tape head 100, based on how many rotations the ball screws actually rotated. The computer processor will send a signal to the x-axis and y-axis actuators 68, 70 to turn the ball screws a calculated number of rotations to move the tape head 100 a certain distance in a given direction. The computer processor also sends signals to the rotary actuator 72 to rotate the tape head 100 relative to the z-axis of the tabletop 52. A suitable controller 300 is a controller sold under the trade name Compumotor, which is commercially available from Braas Company located in St. Paul, Minn., sold under part number 6K4. In another embodiment, the computer processor is a “closed loop” system, which calculates where the tape head 100 is at all times on the tabletop 52.
In the exemplary embodiment, the controller is programmed for quick tooling changes. The changeover from one size or type of tape is done with quick release collars. A software offset library is stored in a memory of the controller. The software offset library retains settings that are specific to the set of parts (guide rollers, drive roller, pinch roller, platen, application roller) that correspond to each size/type of tape. As a result, it is not necessary to mechanically alter one set of parts to respond similarly to other sets of parts. The software offset library is used to adjust the application settings of the head 110, to apply different sizes/types of tape in a similar fashion. The controller is also programmed to allow one set of parts to operate in more than one way. For example, the controller is programmed to use the same set of parts to apply a straight tape strip and a curved tape strip.
To determine the initial location of the tape head 100 on the tabletop 52, the actuators 68, 70, 72 preferably include sensors to determine the location. Suitable sensors for the actuators 68, 70, 72 are Prox Sensors sold under the trade name Omron, which is commercially available from Braas Company located in St. Paul, Minn., sold under part number E2E-X1R5E1-M1-N.
In one embodiment, the tape applicator 200 is adapted to apply aligned decorative patterns 10 to opposite sides of a glass sheet 12. Referring to
In the illustrated embodiment, the first home position fixture 56 is used to align the first corner C1 of the glass sheet when the first side 60 is accessible to the tape application head to determine the position and orientation of the first corner. The second home position fixture 58 is used to align the first corner C1 of the glass sheet when the second side 62 is accessible to the tape application head to determine the position and orientation of the first corner. In the illustrated embodiment, the controller is programmed to automatically apply a first tape pattern to the first side of the glass sheet with the tape head by referencing the first home position fixture and to automatically apply a second tape pattern to the second side of the glass sheet with the tape head by referencing the second home position fixture.
In an alternate embodiment, the position and location of the corner C1 when the sheet is on the first side may be determined by detecting edges of the sheet with a sensor, such as an optical sensor. The glass sheet is then flipped over to apply the tape to the other side. The position and location of the corner C1 when the sheet is on the second side may again be determined by detecting edges of the sheet with a sensor, such as an optical sensor.
In one embodiment, a second tape type pattern is applied to one of the sides of the glass sheet. For example, the aligned patterns on the opposite sides of the sheet may be patterns of lead tape and a pattern a pattern of tape that provides the appearance of a bevel may be applied to only one side of the sheet.
Applying lead tape strips to both sides of the glass requires that they are directly on top of each other so that the glass appears to have been actually leaded. An offset of the lead strip on the inside and outside surfaces will create a visual defect. If the same home position on the table is used as the reference point, a different corner of the glass sheet will be referenced when the glass sheet is flipped. If the glass size is different than the desired (programmed) size, an offset will occur between the inner and outer lead strips. Use of a second home position on the table so that the same corner on the glass sheet is referenced eliminates this chance of error.
Although the present invention has been described with a degree of particularity, it is the intent that the invention include all modifications and alterations falling within the spirit or scope of the appended claims.
