Patent Grant
7093642
1. Field of the Invention
This invention relates to the field of sealing, adhesives, and applying structural enhancements. Particularly, the invention relates to the field of applying a tape onto a work-piece by using a robot.
2. Background
It is known in the art to employ mastics, foams and expandable materials for sealing cavities and joints between metal, glass, plastic, composites, combinations of these components. Examples of metal components include metal panels such as those used in metal buildings, roofing, pipelines, aircraft, medical instruments, marine, non-automotive equipment and vehicles such as tractors, tractor trailers, golf cars, construction equipment, recreational vehicles, etc, and automotive components, among other applications wherein robot assembly is desirable. In the case of automotive components, metal is typically stamped into a desired configuration and the joint between the stamped metal components, or over/under the metal seam, is sealed (e.g., to control wind, dust, noise, water intrusion, metal bonding, structural reinforcement, and function as an adhesion promoter).
In a typical manufacturing operation, a worker seals, (including adding an adhesive, or a structural material or sound abatement material) a work-piece (e.g., stamped metal part or component), by applying a tape onto the metal component. The worker is required to maneuver a tape (e.g., a sealant) along a non-linear path, and to apply sufficient pressure to the tape in order for the tape to adhere to the underlying metal component (e.g., stamped automotive part). The metal component can also have contours that complicates such tape application. This requires a significant amount of manual dexterity on the part of the worker at various stages, laying down the tape and applying appropriate pressure to the tape in order to ensure that the tape will be fastened securely and function adequately.
Accordingly, it would be desirable to reduce the time required to perform these taping operations while retaining, or improving the level of precision of a skilled worker. In addition, it would be an advantage to provide a method of applying tape that is uniform, predictable and reproducible, using an apparatus which is cost-effective.
U.S. patent application Ser. No. 10/087,930, filed Mar. 5, 2002, discloses an applicator and method for applying two-sided adhesive tape between two plastic components; the disclosure of which is hereby incorporated by reference in its entirety.
Broadly, the invention relates to systems and methods for applying a tape and sealing with the tape. In one embodiment, the system includes a robotically controlled tape applicator, and a computerized method or process for applying the tape that includes placing the part to be sealed into a specified orientation in relation to a robotically controlled tape applicator and applying tape along a surface of the part to be sealed. The computerized method includes using the robotically controlled tape applicator to apply the tape along a predetermined path, and using computer control for operating the tape applicator and monitoring the tape.
As referred herein, a “tape” can be an adhesive, a sealant, sound abatement material, among other adhesive materials. Also, a tape can be adhesive or tacky on both sides or is capable of being rendered adhesive or tacky on both sides. Tapes can be used in automotive, industrial, among other applications. Tapes suitable for robotic application can have a wide range of chemical compositions and physical properties. Examples of suitable tapes used in automotive sealing include tapes that can be welded through and seal the welded area, tapes with mastic and a thin film (e.g., EPDM, butyl, nitrile, SBR, polybutadiene, metallic filler); tapes having a weld through film only (e.g., EMA, ethylene acrylic, epoxy); tapes having a rigid or structural film (e.g., epoxy or ethylene acrylic); tapes that are heat cured subsequent to application and become rigid or function as structural reinforcements (e.g., nitrile, ethylene acrylic, epoxy, and SBR); tapes having various degrees of temperature resistance (e.g., high temperature resistant compounds such as fluoroelastomer, polysiloxane, ethylene arylic, EPDM, and acrylic and ambient to medium resistant compounds such as butyl, polybutadiene, SPR, nitrile, neoprene and low temperature compounds such as flouro, polysiloxane); heat expandable compositions, paintable sealants, tapes that melt when heated, among other tapes used for automotive applications. Automotive tapes are available from Orbseal LLC of Richmond, Mo.
The tape can also include a general purpose material such as PVC, Mylar®, polyethylene, or similar backings on pressure sensitive mastic, that can used for barrier wrap. An example of such a material includes the laminar structure disclosed in U.S. Pat. No. 6,638,590B2; the disclosure of which is hereby incorporated by reference in its entirety. The suitable tape (including its backing material) will depend upon the end use of the tape. Examples of suitable backing material includes at least one member selected from the group consisting of polypropylene film, metallic films, glass weave, Kevlar®, Mylar®, or specially formulated films of fluoroelastomer. Tapes could also include special fillers in order to obtain certain desirable properties. Examples of suitable fillers include at least one member selected from the group of metallic (e.g., magnetic), paintable, ceramic, silicates (e.g., corrosion buffer), conductive graphite, expansion agents (e.g., an encapsulated blowing agent), UV cured or activated, among others.
The part, component, member, or work piece to be sealed or taped can have a virtually unlimited configuration and size. Examples of automotive work-pieces onto which tape can be applied by the inventive method include:
While the size of the automotive components listed above typically ranged from about 100 to 1,400 mm, the size of automotive components (as well as non-automotive components) to be sealed can range widely depending upon the size of the assembled article.
According to one embodiment of the present invention, there is provided a robotic tape applicator that includes a computer apparatus, tape applicator apparatus under the control of the computer apparatus, and a mechanism to hold a work-piece (or part to be sealed) in registration with a tape applicator apparatus such that when the computer apparatus is programmed with data respecting the shape of the work-piece and the proposed path of the tape to be adhered to the work-piece, the tape applicator apparatus is adapted to apply the tape to the work-piece along the path.
According to another embodiment of the present invention, the tape applicator apparatus includes a tape applicator head, cutting apparatus to slice the tape, and tape braking apparatus adapted to hold the tape stationary during cutting.
According to still another embodiment of the present invention, a robotic tape applicator includes a computer adapted to control a robotic arm according to a program, and the robotic arm includes a roller adapted to releasable store tape, guide apparatus to guide the tape to a tape applicator head for application to a work-piece, the tape applicator head including a nose biased to permit reciprocal motion in a direction normal to the work-piece, and cutting apparatus integral with the tape applicator head adapted to cut the tape under the control of the computer. The cutting apparatus can include any suitable mechanism such as a knife blade, rotary cutting die, among other cutting devices.
According to still another embodiment of the present invention, the tape applicator further includes tensioning apparatus located between the roller and the nose adapted to maintain a uniform tension on the tape during tape application.
According to still another embodiment of the present invention, the tape applicator further includes braking apparatus adapted to releasably restrain movement of the tape.
According to still another embodiment of the present invention, the braking apparatus includes a spring biased level adapted to releasably trap the tape.
According to still another embodiment of the present invention, the spring biased lever is adapted to release the tape under pneumatic pressure.
According to still another embodiment of the present invention, a hydraulically or pneumatically controlled piston in a compliance cylinder is adapted to maintain a constant pressure on the tape applicator head.
According to still another embodiment of the present invention, the cutting apparatus includes a knife blade that is located within the perimeter of the tape applicator head when the cutting apparatus is not in operation.
According to still another embodiment of the present invention, the tape applicator further includes a pneumatic or hydraulic blade control piston to control the knife blade operation.
According to still another embodiment of the present invention, the tape applicator further includes a knife blade sensor adapted to detect when the knife blade is fully retracted after the tape is cut and to signal the computer so that tape application can resume.
According to still another embodiment of the present invention, the tape applicator further includes vacuum ports adapted to provide sites of negative pressure against which the tape can be slideably held during application of tape to the work-piece.
According to still another embodiment of the present invention, the adhesion between the tape and the metal work-piece is improved by pretreating the work-piece. In some cases the work-piece has a film of oil (e.g., residual stamping fluid) that can reduce adhesion. The adhesion can be improved by high velocity air (including heated air), applying a cleaner, heating the work-piece, among other adhesion promoting steps.
According to still another embodiment of the present invention, the tape applicator includes an apparatus for splicing two tapes together. That is, the end of a first tape is sliced or connected to the beginning of a second tape. By splicing these two tapes, the tape application can be continuous.
According to still another embodiment of the present invention, the tape is dispensed from a cartridge that is in communication with the tape dispenser. The cartridge can be replaced as needed in order to deliver tape to the tape dispenser.
The preferred embodiments are illustrated by way of example and not limited in the following figure(s), in which:
The drawings are provided to illustrate certain embodiments of the invention and shall not limit the scope of any claims appended hereto. Referring now to the drawings, in which like numerals represent like elements,
In some cases, it is beneficial to pre-treat or clean the work-piece prior to applying the tape in order to improve or promote adhesion between the tape and the member/part to be sealed. For example, the work-piece can be cleaned in order to remove debris, residual metal working fluids, among other undesirable material. The work-piece can be pre-treated (e.g., heated), or cleaned by hand, or by an adhesion promoter which is adapted to follow the same path as the tape applicator head (e.g., refer to
Referring to
When the robotic tape applicator is placed into operation, the applicator head can proceed to the precise location dictated by its computer controller, e.g., the robot controller (shown in
The point of the tape applicator head (7) closest to the work-piece is referred to as the nose (9) which can be constructed as a nose piece capable of movement independently of the rest of the applicator head (7). In order to ensure that the tape is applied evenly without damage to the member to be sealed, the nose piece (9) is free to move reciprocally up and down in a direction normal to the surface of the work-piece. In one embodiment, a linear bearing (11) can be provided which allows the nose piece to move vertically in relation to the surface of the work-piece with a minimum of friction. Irregular motion of the tape applicator head (7) can introduce uneven tensions into the tape itself, so freedom of vertical motion for the applicator head (7) can be advantageous.
The amount of downward vertical force on the tape applicator head (7) depends upon the tackiness of the tape, surface characteristics of the work-piece, and/or other variables affecting adhesion between the tape and work-piece. If desired, a constant pressure can be maintained on the tape applicator head (7) by means of the pressure cylinder (2), which can be regulated by hydraulic or pneumatic forces. The pressure cylinder (2) can assist by providing a downward vertical force and allowing the head (7) to be in constant compliance with the work-piece. In addition, as illustrated in
In order to apply tape in a controlled fashion, it is normally useful to cut the tape while the head (7) remains in contact with the work-piece so that the tape that has been applied cannot be pulled away from the work-piece. In one embodiment, as illustrated in
When the cutting apparatus includes a knife blade (17), such blade operates under the control of a knife blade control piston (4). Referring to
If the knife blade (17) is not fully retracted before the tape is applied, the tape can be cut or scraped in a unwanted manner. Accordingly, in one embodiment, a knife blade sensor (12) is provided to ensure that the knife is fully retracted before tape application commences or recommences.
In another embodiment, the cutting apparatus includes a cutting station having a rotary die or knife as illustrated in
It is beneficial to maintain a constant tension on the tape during tape application. In one embodiment, a nip roller (25) provides a point of constant tape tension regardless of the amount of tape on the roll. As the radius of the tape on the roll decreases, the tension on the tape can vary unless such a tape tensioning mechanism is employed. The nip roller (25) mechanism (one such roller is shown in
In order to keep the tape moving completely in line with the tape applicator head (7), side guides can be provided. For instance, in one embodiment, crown guides (28) on the idler rollers (29) keep the tape moving in a straight line with the applicator head. These side guides (28) can also be covered with a non-stick coating in order to prevent the tape from dragging, thus avoiding unwanted tensions. Also, side guide plates (31) can be located at one or more locations on the head (7) of the tape applicator in order to help guide the tape. In one embodiment, the side guide plates (31) are extended down to the application area of the nose (9) as shown in
As set out above, a spring applied/air release braking apparatus (21) keeps the assembly locked during cutting of the tape in order to prevent tape movement. It is intended that the tape should remain in contact with the work-piece without any movement after it has been laid down. The pressure cylinder (2) is also locked when the braking apparatus (21) are applied.
The shape of the nose (9) can affect the efficiency of tape application. A smooth radius at the tip of the nose (9) prevents excess tension in the tape (3). If the center point (35) of the radius of the nose tip (as shown in
In another embodiment, one or more vacuum ports (37) in the applicator head (7) are provided in order to assist the tape to adhere against the surface of the tape applicator head (7) for control after the tape cutting. The vacuum assists in holding the non-adhesive backing cover of the tape to the nose (9) during the taping operation. When vacuum is being drawn, the tape is urged into contact with the tape applicator head (7) by ambient air pressure. Although this vacuum can be turned on and off as required, every such change results in a certain amount of cycling time. Since it is beneficial to reduce cycling times, a constant vacuum can be maintained if it is of a strength which allows the tape to move along its intended path while drawing it into contact with the tape applicator head (7). Further, as shown in
It should be noted that
As shown in
The tape applicator head (7) can be adapted to accommodate a wide range of tape widths. If desired, two tape heads can be dedicated to each tape width. In this way, the operator could replenish the tape supply without shutting down the process. The heads can be stored in a rack that was easy for the operator to reach from outside the cell location. According to one embodiment of the present invention, the head includes:
A new roll of tape can be removably connected to the main bracket (18). The new roll of tape can be changed manually or robotically. If desired, the tape can be dispensed from a replaceable and refillable cartridge (e.g., as illustrated in
During the tape application, the system was capable of negotiating curves as well as straight runs of tape. The tape application roller provided the normal force on the tape as it was applied. The tape was cut off at the end of each tape run by the cutting apparatus. The removable backing material is removed from the tape applicator after applying material to the work-piece. The backing material can be removed by any suitable apparatus and/or method that does not adversely affect applying material or operation of the robot (e.g., passing the backing material over rollers and then into a collection system).
The tape is drawn from the reel due to adhesion or friction between the tape and the work-piece. If desired, the tape applicator could employ a driven system to apply the sealer instead of using adhesion or friction. A driven system can allow less tension to be applied to the sealer thereby preventing unintended tape dispensing (e.g., uncut tape becomes adhered to the work-piece surface thereby causing unintended tape dispensing as the tape applicator is displaced).
In one embodiment of the invention, the method for applying the tape includes causing the tape in the tape applicator to first contact the work-piece at a predetermined location and remain at this location for a period of time sufficient to permit the tape to adhere to the work-piece. The first contact location can be at any desirable location along the path over which the tape can be applied. The adhesion or bond formed at the first contact location can increase the effectiveness of tape application (e.g., in the case of an oily work-piece the initial bond permits the tape to unreel along the application path instead of sliding across the work-piece surface without being dispensed). If desired, a downward pressure can be applied at the first contact location. This downward pressure can mimic a manual tape application. After the first contact, the tape is applied as described herein.
The tape applicator illustrated in
Referring back to
Referring now to
Referring now to
Referring now to
Referring now to
A method of monitoring the amount of tape previously dispensed could be employed. This could include an encoder counter that would count the number of inches of tape dispensed, and report that back to the robot controller for evaluation of amount of tape needed vs. amount on the reel (e.g., refer to
In one embodiment of the invention, a barcode label or magnetic strip or any other device is used to transfer information. The barcode can be used to identify the type, quantity of sealer enclosed in the cartridge, among other information. This information can be used to ensure that the appropriate tape and amount thereof is applied onto the work-piece. An example of this embodiment is illustrated in
Referring now to
The optical or vision system can also include a detector in the tape applicator head (7) to ensure the tape is being applied onto the work-piece along a predetermined path or configuration. The computer control system can modify the tape applicator direction to ensure proper tape application based on information received from the optical/vision system. The optical system can also confirm that tape is being applied onto the work-piece (as a redundant system to the system monitoring the amount of tape of the cartridge).
It should be noted that the various components, apparatuses, and systems shown in
In a further embodiment of the invention, a self-threading machine or apparatus could be used introduce tape from the reel and into the tape applicator (e.g., when the tape is not loaded into a cartridge). This could include a miniature robot that could take the sealer off the reel and thread it through the applicator head. This self-threading machine could be located on the applicator head or in a different location.
In another embodiment of the invention, the tape application is monitored by using a camera system or several sensors. This system can be used to monitor operation of at least one of the robot, applicator head, cartridge dispenser, apparatus for adhesion promotion, cutting station, among other embodiments of the invention. This system could also monitor sealer movement through each reel, tape application pressure, tape tension, among other variables associated with conducting the instant invention.
In a further embodiment of the invention, an applicator can be used to apply a die cut shape instead of a roll of tape. The die could also be used for embossing or shaping the tape prior to or during application onto the work-piece. This head can include vacuum pads placed in strategic locations to support the die cut tape in the appropriate positions that would allow a robot to apply the tape to a predetermined position.
In a further embodiment of the invention, the tape applicator head (7) can be oriented into a horizontal position when not in use. This orientation is especially useful when working with relatively soft tapes. Such relatively soft tapes can deform if the applicator is maintained in a vertical stationary position (e.g., depending upon the ambient environment, the tape can change [flow due to gravity] from a generally round configuration to an oblong dimension). The applicator head should also be in a horizontal orientation when in the reloading position, and as it is being stored prior to changeover for an empty reel.
Any suitable robot can be employed for transporting the tape applicator. The robot can be new or an existing robot can be retrofitted to receive the inventive tape applicator. An example of a suitable commercially available robot includes a Fanuc S-5th Robot was chosen for the activator and tape application due to the shape and size of the part to be taped. On many of the parts, a large reach combined with the ability to manipulate the tool at a complex tilt is required. The six-axis, articulated robot was programmed based on the nominal contours of the 3-dimensional mathematical part profile data. This was used to generate the basic tool path for the part. Any difference in shape due to moisture content and shrinkage was accommodated by the end of arm tooling. The robot has the capacity to store a multitude of robot paths.
While the above description emphasizes using the tape applicator head for applying an adhesive, a sealant, structural or sound abatement material upon an automotive component, the tape head can be used for applying tape to a wide range of automotive and non-automotive surfaces. Examples of such surfaces include steel, galvanized metal, aluminum, among other metals, glass, composites, carpets, pads, plastic, alloys and materials used in automotive construction. Examples of additional automotive and non-automotive components include: previously painted articles, exterior and interior trim articles, among other areas of an automobile; windows, doors, and other building components. In addition, the tape applicator head can be employed for applying tape to non-metallic surfaces such as plastic, foam, wood, among other materials wherein it is desirable to apply a tape. Furthermore, the tape applicator head can be used to apply or construct gaskets or weatherstrippings. Thus, the tape applicator head generally can be used to apply one or more strips of any material to any surface and along any path as desired.
Although the invention has been described with reference to these preferred embodiments, other embodiments could be made by those in the art to achieve the same or similar results. Variations and modifications of the present invention will be apparent to one skilled in the art based on this disclosure, and the present invention encompasses all such modifications and equivalents.
This application is a continuation-in-part (CIP) of the following U.S. Utility patent applications: 1. Ser. No. 10/087,930, filed Mar. 5, 2002, entitled, “ROBOTIC TAPE APPLICATOR AND METHOD;” and2. Ser. No. 10/826,506, filed Apr. 19, 2004, entitled, “ROBOTIC TAPE APPLICATOR AND METHOD.” The aforementioned utility patent applications are herein incorporated by reference in their entireties. This application claims priority to the following U.S. Utility and Provisional Patent Application: 1. No. 60/523,483, filed Nov. 19, 2003, entitled, “ROBOTIC TAPE APPLICATOR AND METHOD FOR APPLYING TAPE;”2. No. 60/535,968, filed Jan. 12, 2004, entitled, “ROBOTIC TAPE APPLICATOR AND METHOD FOR APPLYING TAPE;” and3. No. 60/623,066, filed Oct. 29, 2004, entitled, “SYSTEMS AND METHODS FOR ROBOTIC TAPE APPLICATOR.” (Attorney Docket No. FDH0006-PRO). The aforementioned utility and provisional patent applications are herein incorporated by reference in their entireties.
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| Number | Date | Country | |
|---|---|---|---|
| 20050161161 A1 | Jul 2005 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60523483 | Nov 2003 | US | |
| 60535968 | Jan 2004 | US | |
| 60623066 | Oct 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10087930 | Mar 2002 | US |
| Child | 10991853 | US | |
| Parent | 10826506 | Apr 2004 | US |
| Child | 10087930 | US |
