EP2293881B1

EP2293881B1 - Dual servo lance spray apparatus and method

Info

Publication number: EP2293881B1
Application number: EP09751362.6A
Authority: EP
Inventors: Robert P. Perez; Sylvan Praturlon
Original assignee: Rexam Beverage Can Co
Current assignee: Rexam Beverage Can Co
Priority date: 2008-05-19
Filing date: 2009-05-19
Publication date: 2014-10-22
Anticipated expiration: 2029-05-19
Also published as: WO2009143134A2; WO2009143134A3; RU2010153199A; RU2475312C2; PL2293881T3; EP2293881A2

Description

The present invention relates to an apparatus for spray coating work pieces and, more particularly, to an apparatus for spray coating surfaces of a can body.
Contact with the metal surface of a can body has been known to adversely affect the flavor of a beverage sealed within a beverage container body. Thus, one step in the manufacturing of two-piece metal beverage cans includes spraying the interior surfaces of the can body with a coating to prevent direct beverage contact with the bare surface of the can body.
The coating process typically includes one or more spray applicator devices having one or more nozzles positioned near an opening of the can body interior. Material is sprayed into the interior of the can body while the can body is rotated.
Can bodies are typically indexed through the coating apparatus on an indexer operatively connected to a cam system which controls a dwell time during which the cans pause at a spray gun while the spray gun discharges a predetermined amount of a fluid coating into the can body as the can body rotates about a central axis. Alternatively, a servo motor is provided to control the rate and dwell time of the indexer.
It is important that the entire inner surface of the can body is coated. The amount of material that is applied to a surface is usually measured in terms of coating weight. In typical known rotating coating application systems, each deposition of material onto the circumferential surface of the container body is called a wrap. In a known can coating system, a can may be coated with two or more wraps.
For example, DE 43 33 859 A1 discloses a method and an apparatus for painting the inner surfaces of tin-plated receptacles, such as cans, buckets, etc. In the method, a powder paint is applied to the inner surface by electrostatic powder spraying, and the applied powder-paint coat is sintered at a temperature of less than 230 °C. The apparatus for carrying out the method comprises a rotary table which is driven in timed sequence and contains a multiplicity of rotary plates for the rotational mounting of the receptacles to be painted. The apparatus includes at least one spray gun, which can be moved into a rotating receptacle and out of it again, and a sintering oven.
Similarly, EP 0578426 A2 discloses an apparatus for spraying powder coating material using a rotatable turret which moves articles to and from a work station. A powder spray gun is operable to spray a pattern onto each of the articles in turn while the article is at the work station. The powder flows through the spray gun as a series of pulses. A diverter assembly is operable to divert a portion of each pulse of powder away from the nozzle to more sharply define the pulse. An excess powder collector draws a flow of powder away from the work station. A virgin powder container supplies powder to a powder collector container which supplies powder to a powder feed container which supplies powder to the spray gun. Sensors associated with the virgin, collector and feed containers ensure that a predetermined quantity of powder is maintained in each container. During transport of powder from the virgin and collector containers, the containers and their associated pumps are vibrated to facilitate the flow of powder. The powder spray gun is mounted on a three axis adjustment assembly to enable the powder spray gun nozzle to be accurately positioned relative to an article at the work station.
The present invention is introduced to provide advantages and aspects not provided by prior can body coating apparatuses of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.
The present invention is directed to an apparatus for delivering a coating to an interior surface of a plurality of can bodies; the apparatus comprising: an indexing means for sequentially transferring each of the plurality of can bodies along a plurality of index positions; and a coating delivery system associated with one of the plurality of index positions; characterized in that the apparatus further comprises: a first servo motor operably connected to the coating delivery system, the first servo motor providing substantially linear movement to the coating delivery system, said substantially linear movement being substantially horizontal and perpendicular to an imaginary vertical plane defined by an opening of a can body, wherein a distance between the indexing means and the coating delivery system may be selectively reduced. The apparatus may further comprise an external programmable controller in communication with the first servo motor. The external programmable controller provides a signal to the first servo motor controlling a rate and a distance traversed by the coating delivery system in response thereto. The apparatus may further comprise a second servo motor operably connected to the indexing means for setting an index speed and a dwell time at which the indexing means pauses at each of the index positions. The external programmable controller may be in communication with the second servo motor to provide a signal to the second servo motor controlling the index speed and dwell time. The external programmable controller may be used to synchronize the first servo motor to cause the coating delivery system to traverse toward the indexing means during the dwell time.
Another aspect is directed to an apparatus for delivering a spray coating to an interior surface of a plurality of can bodies. This apparatus comprises a rotational indexing means comprising a plurality of equally spaced index positions arranged about a circumference of the rotational indexing means, a first automatically traversing coating delivery system associated with a first index position of the equally spaced index positions, and a second automatically traversing coating delivery system associated with a second index position of the equally spaced index positions. The first index position and the second index position maybe in horizontal alignment. The apparatus may further comprise a can body feeder having a chute for sequentially feeding the plurality of can bodies onto the rotational index means. The chute feeds the can bodies onto the rotational indexing means at a third index position. The third index position is offset from a 12 o'clock position of the rotational index means, typically between 30 and 60 degrees.
Optionally to this aspect, the first index position and the second index position may be horizontally offset. The apparatus may comprise a static or stationary fluid delivery system.
A second aspect of the present invention is also directed to an apparatus for delivering a spray coating to an interior surface of a plurality of can bodies, the apparatus comprising: a frame; a can body feeder supported on the frame comprising a chute for sequentially feeding a plurality of can ends into the apparatus; a rotational indexer comprising a plurality of arms radiating outwardly from a hub, each arm terminating at a vacuum chuck, each vacuum chuck in fluid communication with a vacuum pressure for attaching the vacuum chuck to one of the plurality can bodies sequentially received from the chute; and a first spray gun for delivering a first volume of a fluid coating to an interior surface of each the plurality of can bodies; characterized in that the apparatus further comprises: a first servo motor operably coupled to the rotational indexer and controlling a rate of rotation of the indexer and a dwell time wherein rotation of the indexer pauses for a predetermined length of time; a second servo motor operably coupled to the first spray gun and controlling relative movement between the first spray gun and the interior surface of each of the plurality of can bodies; and an external controller in communication with the second servo motor, the external controller providing a first signal to the second servo motor to synchronize movement of the first spray gun during the dwell time to decrease a distance between the first spray gun and the rotational indexer. This apparatus may further comprise a second spray gun for delivering a second volume of a fluid coating to an interior surface of each the plurality of can bodies, and a third servo motor operably coupled to the second spray gun and controlling relative movement between the second spray gun and the interior surface of each of the plurality of can bodies. The external programmable controller may be in communication with the third servo motor.
Also disclosed is a method of processing a plurality of can bodies through a single coating apparatus adapted to provide a fluid coating on interior surfaces of each can body wherein a first subset of the plurality of can bodies requires a first set of processing parameters and a second subset of the plurality of can bodies requires a second set of processing parameters not identical to the first set of processing parameters. The method comprises the steps of providing an external programmable controller in communication with the single coating apparatus, providing a first set of signals from the external programmable controller to a first component of the single coating apparatus, the first set of signals controlling at least a first dwell time during which each of the first subset of the plurality can bodies receives a volume of coating from the single coating apparatus, and providing a second set of signals from the external programmable controller to a second component of the single coating apparatus, the second set of signals controlling a processing parameter other than the first dwell time.
Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings.
To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a front view of a spraying apparatus with some detail removed to aid in discussion of the features of the apparatus;
FIG. 2 is a rear view of the spraying apparatus of FIG. 1;
FIG. 3 is a top view of the apparatus of FIG. 1 with dual spray guns added;
FIG. 4 is a side view of the apparatus of FIG. 1 with dual spray guns added;
FIG. 5 is a front view of an indexer having a 12-legged assembly;
FIG. 6 is a partial cross-sectional view of a vacuum chuck showing a sensor and a flag for determining proper rate of can body rotation;
FIG. 7 is a partial cross-sectional view of a feeder showing a can body stop;
FIG. 8 is a front view of a spraying apparatus of the present invention;
FIG. 9 is a magnified front view of an apparatus of the present invention, showing a 6 position indexer and servo controlled spray guns at 5 and 7 o'clock positions;
FIG. 10 is a perspective view of the apparatus of FIG. 9 outfitted with a 12 position indexer and also showing an electrical box which may contain a controller;
FIG. 11 is a side view of the apparatus of FIG. 9;
FIG. 12 is a top view of a pair of servo motors for driving a pair of coating guns along a linear path as provided in conjunction with the embodiment illustrated in FIG. 9;
FIG. 13 is a front view of a spraying apparatus illustrating a shifted feeder assembly;
FIG. 14 is a magnified front view of an indexer as provided with an embodiment having a 6 position indexer and a servo controlled spray gun at the 9 o'clock position and static spray guns at the 5 and 7 o'clock positions;
FIG. 15 is a perspective view of the apparatus of FIG. 14 outfitted with a 12 position indexer and also showing an electrical box which may contain a controller;
FIG. 16 is a magnified front view of an indexer as provided with an embodiment having a 6 position indexer and a servo controlled spray guns at the 7 and 9 o'clock positions and a static spray gun at the 5 o'clock position;
FIG. 17 is a perspective view of the apparatus of FIG. 16 outfitted with a 12 position indexer and also showing an electrical box which may contain a controller;
FIG. 18 is a magnified front view of an indexer as provided with an embodiment;
FIG. 19 is a magnified front view of an alternative indexer as provided with an embodiment;
FIG. 20 is a magnified front view of an alternative indexer as provided with an embodiment;
FIG. 21 is a perspective view of the indexer of FIG. 20; and
FIG. 22 is a cross-sectional top view of a spray gun mounted for coating application to a bottom of a can body on a transfer turret.

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.
The present invention is directed to can body coating apparatuses. The apparatuses described herein are adapted to be incorporated within a can body making facility. In other words, the disclosed can body coating apparatuses represent one step in a can body making process.
In the figures, can bodies are generally given the reference numeral 10. These can bodies typically include a one-piece construction, having a bottom portion integral with a cylindrical side wall which terminates at an open end of a reduced diameter neck. It would be understood by one of ordinary skill in the art that the can body can be a one-piece construction as shown, a two piece construction with the bottom end wall attached to the side wall, a bottle-like construction having a reduced diameter neck similar to a bottle, etc.
Due to the complexity in terms of the confined spaces in which the various components of the apparatuses are mounted, some of the standard features on coating apparatuses of this type which, taken alone, do not contribute to the patentability of the invention, are removed from the figures to illustrate the components of the apparatuses which require more detailed description.
Now, referring to FIGS 1-4, a can body coating apparatus 100 is supported by a frame 102 and generally includes a can body feeder 104, an indexing means, such as a rotational indexer 108, a fluid or coating delivery system, a transfer turret 116, and a can body delivery chute 120. A control panel 124 is electrically connected to the apparatus 100 to provide manual control over the process. An external programmable controller 128 is also connected to the apparatus, the purpose of which will become clear upon further description.
As will be described in more detail below, this type of can body coating apparatus is capable of coating an internal surface of a can body with two layers of coating in about 200 ms, or about 100 ms per spray operation. These apparatuses typically process, as in apply two coats to, 350 can bodies per minute with the capability of processing even greater numbers due to a variable nature of the various components which will be described in more detail below.
The frame 102 is suitable for supporting, and attachment to, the various components that make up the apparatus 100. Accordingly, the frame 102 has a plurality of rigid members, generally produced from a metal such as a steel, and configured to reduce movement of the machine caused by processing of can bodies.
The indexing means sequentially transfers a plurality of can bodies 10 along a predetermined fixed path through the coating process. In the apparatus illustrated in FIGS. 1-4, an indexer 108 includes a star-shaped member having a plurality of legs 136 radiating outwardly from a hub 140. Any number of legs 136 can be provided as feasibly possible. In the apparatus 100 illustrated in FIGS. 1-4, there are six (6) legs 136 forming a 60 degree index. However, Applicants are aware of the existence of indexers having twelve (12) legs forming a 30 degree index as illustrated in FIG. 5, and Applicants contemplate that the apparatuses disclosed herein maybe provided with a 30 degree index, a 60 degree index, or any other degree index. In other words, one indexing means as contemplated herein comprises a plurality of equally spaced index positions about a circumference of a rotational indexer.
One advantage of the 12-legged apparatus is that it may be used to process two can bodies simultaneously by indexing 60 degrees, thus doubling the production rate. The known machines, however, do not provided wet-on-wet capabilities, that is, the can is sprayed only once, when coating two can bodies simultaneously. As will be described below, the present invention maybe provided to simultaneously spray/coat wet-on-wet two can bodies. Furthermore, a variation of the 12-legged apparatus, which will be described in more detail below, can be used to coat/spray four can bodies 10 simultaneously using four spray guns and a 120 degree (4 hour) index.
At a terminal end of each leg 136, the indexer 108 has a vacuum chuck 144. The vacuum chucks 144 utilize a vacuum pressure to maintain the can bodies 10 in position as the indexer 108 indexes the can bodies 10 through the coating process. Thus, the vacuum chucks 144 are each in fluid communication with a source of fluid pressure. The vacuum pressure is used to attach each can body 10 to the indexer 108. The vacuum chucks 144 have been used on coating apparatuses for a number of years.
The vacuum chucks 144 are substantially free-wheeling. This enables a spinner belt 148 wound around a plurality of Idler pulleys 152 to Impart rotational movement to the can bodies 10 attached to the vacuum chucks 144. One of the idler pulleys 152 is operably joined to a spinner motor 156 which in turn drives the spinner belt 148. One or more spinner gears 158 may be provided to control the revolutions per minute of the can bodies 10.
As shown in FIG. 6, each vacuum chuck 144 is outfitted with a flag 157. As each chuck 144 moves into a dwell position, the chuck 144 pauses in front of a sensor 159. The sensor 159 counts the number of times the flag 157 passes and compares it against a preset count to insure the can body 10 undergoes the proper number of revolutions.
The indexer 108 may further include an index turret 162. The index turret comprises 2 plates, each supporting an end of the can, generally produced from a polymeric material, and having a plurality of recesses 164 associated with the terminal end of each leg 136. The recesses are arcuate in shape for supporting a sidewall of the can bodies 10 thereon. An index turret 162, 262, 362, 462, 562, and 662 with recesses 164, 264,364, 464, 564, and 664 is illustrated in conjunction with the embodiments illustrated.
The transfer turret 116 receives can bodies 10 from the indexer 108. This transfer typically occurs at the 270 degree index position in a counterclockwise cycle by the indexer 108, or the 3 o'clock position using a time clock reference. The transfer turret 116 transports coated can bodies 10 in a clockwise rotation to the delivery chute 120 at a 180 degree index position or a 3 o'clock position using a time clock reference. Can bodies 10 exit the apparatus 100 via the delivery chute 120 for further processing, packaging and delivery, filling, etc.
The apparatus 100 of FIGS. 1-4 further includes a first servo drive motor 166. The first servo drive motor 166 is operably connected to the indexer 108 via a hollow shaft 168 projecting outwardly from the indexer hub 140 into the servo motor 166. An advantage of using a hollow shaft motor is in being able to use a light weight (aluminum) shaft passing through the motor. At the front end of the shaft, the main turret can be firmly mounted and at the other end the gear that drives the transfer turret can be mounted. If the gears that drive the transfer turret were mounted next to the main turret in the front, they would be exposed to overspray. Motors having shafts extending at both ends are available, but they are usually not standard. Moreover, the mounting of the main turret would be more elaborate.
The first servo motor 166 provides many advantages over cam driven coating apparatuses. For instance, typical cam driven coating apparatuses include a mechanical intermitter including a cam arrangement to operate or transfer motion to the indexer 108. Thus, a dwell time, wherein the can body 10 is stationary for a moment during which a coating is applied to the can body 10, is created by the mechanical cam arrangement and fixed relative to the rotational speed of the indexer 108. In other words, when the speed of the rotation of the indexer 108 is increased the dwell time decreases. Therefore, when any variable of the process is changed, e.g. can size, dwell time, coating weight, indexing speed, etc., the cam arrangement must be retooled for the change in timing of the process. A cam operated system is, thus, very inflexible.
The apparatus 100 of FIGS. 1-4 does not have these drawbacks and is, conversely, very flexible. The external programmable controller 128 is in communication with the first servo motor 166 and can be used to program the first servo motor 166 to any predetermined dwell time independent of the speed of the indexer 108, which may be controlled by the controller 128, by sending a signal thereto. Thus, this apparatus 100 can be programmed based on time without mechanical intervention. This is very important as other technology improves.
One such technological improvement is spray gun technology. As spray guns are improved and capable of coating can bodies at higher rates, dwell times can be decreased via an external controller 128. In a prior art coating apparatus, the mechanical cam would have to be retuned to the new capability. The coating apparatus of the present invention requires no such retuning. Current spray gun capability is typically less than 90 to 100 ms. Thus, dwell times are typically set at 100 ms.
The servo motor 166 is further coupled to a first gear 172. The first gear 172 operates a second gear 174 which Is operably coupled to the transfer turret 116 to provide synchronized rotational movement to the transfer turret 116 with the indexer 108.
The apparatus 100 further includes coating applicators such as a pair of static spray guns 176a,b. The static spray guns 176a,b deliver a fluid coating to the interior surfaces of the can bodies. Each static spray gun 176a,b delivers one coat, a separate volume of fluid, to each can body 10. Thus, each can body 10 receives to coating of coating in a wet-on-wet application.
In the apparatus of FIGS. 1-4, the static spray guns 176a,b are fixedly mounted to the frame 102. One spray gun 176a Is mounted in an upper position, typically at the 120 degree index position or 8 o'clock position in a clock-like orientation. The second spray gun 176b is mounted in a lower position, typically at the 180 degree index position, or the 6 o'clock position in a clock-like orientation.
The apparatus 100 also includes a coating control panel 179. This panel 179 includes pressure gauges, regulators, adjustments, and the like for controlling the fluid coating applied to each can body 10. This control panel 179 is typical of coating apparatuses in use for a number of years, and one of ordinary skill in the art would readily recognize the components necessary to regulate the fluid coating.
Further to the feeding of can bodies, can bodies 10 enter the apparatus 100 via the feeder 104. Gravity acts to transfer the can bodies 10 one-by-one through an entry chute 132 which delivers the can bodies 10 to the indexer 108. This in-feed assembly allows for proper flow of the can bodies into the apparatus 100 and controls the flow with a pneumatically operated can stop 186 as illustrated in FIG. 7.
To provide a sufficient column of can bodies 10 to the indexer 108, a proximity sensor 190 is mounted on the chute 132 connected to the in-feed assembly 104. As can bodies 10 are presented to the sensor 190, a plunger 194 associated with the can stop 186 remains in its contracted inward position. This allows can bodies 10 to be received by the indexer 108 and the vacuum chucks 144. When the level of can bodies 10 in the chute 132 falls below the sensor 190, an electrical solenoid valve activates an air cylinder and the can stop plunger 194 is extended outwardly to stop the flow of can bodies 10 to the indexer 108. Upon arrival of an additional supply of can bodies 10 to the chute 132, the plunger 194 retracts, and the can bodies 10 are automatically fed via gravity one-by-one to the indexer 108. To insure that can bodies 10 are loaded into proper position on the indexer 108, a timing flag with a sensor is provided to detect a turret pocket (dwell position). When the turret 162 is in a dwell position, the timing sensor sends a signal for the can stop cylinder to retract, allowing can bodies 10 to be fed into the indexer 108 at the 12 o'clock or zero degree position.
The present invention is illustrated in FIGS. 8-12. In these drawings a coating apparatus 200 is again illustrated. Reference numerals given to the embodiment of FIGS. 8-12 are greater than 200 but less than 300. Each element described in reference to the apparatus 200 of FIGS. 8-12 is similar to each corresponding element of the apparatus 100 illustrated in FIGS. 1-4. For clarity, the last two digits of the reference numeral of the apparatus of FIGS. 8-12 are identical to the last two digits of the apparatus 100 illustrated in FIGS. 1-4. The only differences between the two apparatuses are described below.
Similar to the apparatus of FIGS. 1 -4, this apparatus 200 includes a pair of spray guns 276a,b. However, apparatus 200 includes means for providing relative movement between the indexing means of the coating delivery system wherein a distance between the indexing means and the coating delivery system may be reduced, namely at least one of the spray guns 276a,b. Preferably, at least one of the spray guns 276a,b is capable of movement relative to a can body 10 adhered to the indexer 208. More preferably, both spray guns 276a,b are capable of such relative movement. This movement is preferably a linear movement to traverse a tip 278a,b at the end of a nozzle 277a,b of each spray gun 276a,b from a first position to a second position adjacent or within the opening of the can body 10 where coating can be delivered from the tip 276a,b to the interior surfaces of the can body 10. The linear movement is illustrated by arrows and is preferably substantially horizontal. Regardless, the movement should be perpendicular to an imaginary plane defined by the opening of the can body 10. Typically, this imaginary plane is a vertical plane.
Movement of the spray guns 276a,b is accomplished by operably connecting or coupling the guns 276a,276b to one or more lancing servo motors. Preferably, each of the spray guns 276a,b is coupled to a separate lancing servo motor 280a,b such that each spray gun 276a,b is capable of movement independent of the other spray gun 276a,b. The spray guns 276a,b are each attached to guide shafts 282a,b controlled, preferably directly controlled, by its corresponding lancing servo 280a,b.
The spray guns 276a,b are mounted at the 150 degree and 210 degree index positions of the indexer 208 (the 7 o'clock and 5 o'clock positions in a clock type orientation), rather than the 120 and 180 degree positions described in conjunction with the apparatus 100 illustrated in FIGS. 1-4. Thus, the spray guns 276a,b are mounted on the same horizontal plane, at identical heights. This mounting is intended to reduce or eliminate vibrational movement caused by the traversing spray guns 276a,b. It provides the further benefit of allowing sufficient space on the apparatus 200 to mount the lancing servo motors 280a,b.
In order to accomplish the spray gun layout described, the index position of the spraying operations may be shifted by 30 degrees. One way of achieving this is by shifting the index feed position by 30 degrees. For instance, the apparatus 100 illustrated in FIGS. 1-4 receives can bodies 10 at the 0 degree or 12 o'clock position. However, due to the 30 degree shift in the coating operation, the 0 degree index position is eliminated (the indexer does not pause or dwell at that position). A linear chute 232 can be shifted counterclockwise or clockwise as illustrated in FIG. 13. The chute 232 would thus be aligned with either the 11 o'clock (30 degree) or the 1 o'clock position (330 degree) and linearly feed can bodies the indexer 208 at one of those positions.
It is possible to load the can bodies 10 with an arrangement similar that illustrated in FIGS. 1-4. Here, when a leg 236 reaches a few degrees left (counterclockwise) of the 12 o'clock position (0 degrees), the bottom of a can body 10 is pulled against a vacuum chuck 244. The can body 10 is pulled along through an offset in the chute 232. The offset is created by an angled portion 284 which is adapted, as in sized and shaped, to guide and support the can body 10 until the indexer 208 reaches a dwell position at the 11 o'clock or 30 degree index position.
In use, can bodies 10 index counterclockwise on the indexer 208 in 30 or 60 degree increments. A dwell time is established at each index position. The dwell time can be varied as desired to any predetermined duration via controller 228. The lancing servos 280a,b are programmed to cause spray gun 276a,b movement during the dwell time. This dwell time is typically restricted by the rate at which the spray guns 276a,b can complete a coating cycle. Some additional time may be added due to the traverse of the spray guns 276a,b. However, this is dependent upon the nature of the can body 10 to be coated. The expected dwell time being less than 200 ms, preferably within the range of 50 ms to 150 ms, more preferably 80 ms to 120, or any value, range or combination of ranges therein.
Further, this arrangement may be used to process two can bodies simultaneously because the spray guns 276,a,b are located at adjacent positions. This is advantageous, especially in the case of processing can bodies formed to resemble bottles. In the case of spraying can bodies formed to resemble bottles, the production rate is typically very low (150 CPM). The apparatus 200 of this aspect, may be programmed to process two can bodies at the time, thus the production time goes up to 300 CPM.
It should be understood that the apparatus 200 is programmable, and any number of dwell time preferences can be achieved on the same apparatus 200 without the need for mechanical changes to the apparatus 200 as would be required with a prior art apparatus provided with camming mechanisms to control the dwell times, indexing of the can bodies 10, and movement of the spray guns. Thus, the relative movement between the coating delivery system and the indexing means is both selective and automatic as controlled by a signal delivered from the external programmable controller 228 to one or more lancing servo motors 280a,b. Furthermore, the external programmable controller 228 can be used to selectively set a rate of travel by the spray gun(s) 276a,b as well as a distance traveled by the spray gun(s) 276a,b.
The controller 228 is capable of synchronizing the movement of the indexer 208 and the spray gun(s) 276a,b so that the spray gun(s) traverse during the dwell period.
Another embodiment is illustrated in FIGS. 14-15. In this drawing a coating apparatus 300 is again illustrated. Reference numerals given to the embodiment of FIGS. 14-15 are greater than 300 but less than 400. Each element described in reference to the apparatus 300 of FIGS. 14-15 is similar to each corresponding element of the apparatus 100 illustrated in FIGS. 1-4. For clarity, the last two digits of the reference numeral of the apparatus of FIGS. 14-15 are identical to the last two digits of the apparatus 100 illustrated in FIGS. 1-4. Differences between the apparatuses are described below.
This apparatus 300 includes three spray guns 376a,b,c. A first spray gun 376a is capable of relative movement between the can bodies 10 and the spray gun 376a. Second and third spray guns 376b,c are static or stationary, similar to the static spray guns 176a,b of the apparatus of FIGS. 1-4.
The first spray gun (not shown) is coupled to a lancing servo motor 380a. This first spray gun has identical movement capabilities as the spray guns 276a,b of the apparatus 200 of FIGS. 8-12. In the embodiment illustrated, the first spray gun is mounted at the 90 degree index location, the 9 o'clock position.
The static spray guns 376b,c are located at the 150 degree and 210 degree index positions of the indexer 308 (the 7 o'clock and 5 o'clock positions in a clock type orientation). As such, the static spray guns 376b,c are positioned on a common horizontal plane, similar to the spray guns 276a,b of the embodiment of FIGS. 8-11.
Again, in order to accomplish the spray gun layout described, the index position of the spraying operations may be shifted by 30 degrees. Similar to the embodiment of FIGS. 14-15, this is achieved by shifting the index feed position by 30 degrees. Alternatively, this can be accomplished according to the embodiments illustrated in FIG. 8-12.
In use, can bodies 10 processed on the apparatus 300 index counterclockwise on the indexer 308 in 30 or 60 degree increments. A dwell time is established at each index position. The dwell time can be varied as desired to any predetermined duration via controller 328. The lancing servo 380a is programmed to cause spray gun movement during the dwell time. This dwell time is typically restricted by the rate at which the spray gun can complete a coating cycle, the cycle of the moving spray gun requiring a longer dwell time than the static spray guns 376b,c. It follows that the expected dwell time is less than 200 ms, preferably within the range of 50 ms to 150 ms, more preferably 80 ms to 120, or any value, range or combination of ranges therein.
It should be understood that the apparatus 300 is programmable, and any number of dwell time preferences can be achieved on the same apparatus 300 without the need for mechanical changes to the apparatus 300 as would be required with a prior art apparatus provided with camming mechanisms to control the dwell times, indexing of the can bodies 10, and movement of the spray gun.
Another embodiment is illustrated in FIGS. 16-17. In this drawing a coating apparatus 400 is again illustrated. Reference numerals given to the embodiment of FIGS. 16- 17 are greater than 400 but less than 500. Each element described in reference to the apparatus 400 of FIGS. 16-17 is similar to each corresponding element of the apparatus 100 illustrated in FIGS. 1-4. For clarity, the last two digits of the reference numeral of the apparatus of FIGS. 16-17 are identical to the last two digits of the apparatus 100 illustrated in FIGS. 1-4. Differences between the apparatuses are described below.
This apparatus 400 includes three spray guns. First and second spray guns (not shown) are capable of relative movement with the can bodies 10. A third spray gun 476,c is static or stationary, similar to the static spray guns 176a,b and 376b,c of the apparatuses of FIGS. 1-4 and 14-15.
The first spray gun is coupled to a lancing servo motor 480a. This first spray gun has identical movement capabilities as the spray guns 276a,b of the apparatus 200 of FIGS. 8- 12, albeit at a different location. In the embodiment illustrated, the first spray gun is mounted at the 90 degree index location, the 9 o'clock position.
The second spray gun is also coupled to a lancing servo motor 480b. This second spray gun has identical movement capabilities as the first spray gun, albeit at a different location. In the embodiment illustrated, the second spray gun is indexed 60 degrees from the fist spray gun. Accordingly, the second spray gun is mounted at the 150 degree index location, the 7 o'clock position. Thus, the first and second spray guns are located on separate horizontal planes with the first spray gun being on a vertically higher plane than the second spray gun. Stated another way, the first spray gun is located at a height above a height of the second spray gun.
A static spray gun 476c is located at the 210 degree index positions of the indexer 408 (the 4 o'clock position in a clock type orientation). As such, the static spray gun 476c is positioned on a common horizontal plane with the second spray gun.
Again, in order to accomplish the spray gun layout described, the index position of the spraying operations may be shifted by 30 degrees. Similar to the embodiment of FIG. 13, this is achieved by shifting the index feed position by 30 degrees. Alternatively, this can be accomplished according to the embodiments illustrated in FIG. 8-12 and 14-15.
In use, can bodies 10 processed on this apparatus 400 index counterclockwise on the indexer 408 in 30 or 60 degree increments. A dwell time is established at each index position. The dwell time can be varied as desired to any predetermined duration via controller 428. The lancing servo 480a is programmed to cause the spray guns' movement during the dwell time. This dwell time is typically restricted by the rate at which the spray guns can complete a coating cycle, the cycle of the moving spray guns requiring a longer dwell time than the static spray guns 476c. It follows that the expected dwell time is less than 200 ms, preferably within the range of 50 ms to 150 ms, more preferably 80 ms to 120, or any value, range or combination of ranges therein.
It should be understood that the apparatus 400 is programmable, and any number of dwell time preferences can be achieved on the same apparatus 400 without the need for mechanical changes to the apparatus 400 as would be required with a prior art apparatus provided with camming mechanisms to control the dwell times, indexing of the can bodies 10, and movement of the spray gun.
One of the main differences between the embodiments disclosed herein and the prior art is that these embodiments use a timing to determine when to turn the spray guns on and off. The programmable controllers are programmed to control the lancing servos to traverse, stop and perform other tasks to spray the middle and bottom of the can bodies. This differs from using the position of the gun through its cycle to turn spray on and off.
The embodiments of FIGS. 8-12 and 14-15 have four servo motors in communication with a programmable controller such that the servo motors are electronically timed together. For instance, the lancing servo with control the traversing spray guns to traverse inwardly toward the can body, stop, and reverse itself outwardly.
The traversing system described herein is particularly useful for processing can bodies of larger sizes with elongated sidewalls. Such cans are very popular in the energy drink market, as well as iced teas and some alcoholic beverages, and generally exceed a typical 12 ounce (355 mL) volume, available in volumes of 16 ounces (473 mL) to 24 ounces (708 mL). Prior art sprayers sprayed inside can body from an external position, the embodiments disclosed herein can enter a containment chamber of the can body.
Referring to FIGS. 18 and 19, two additional embodiments are illustrated. In these drawings coating apparatuses 500, 600 are again illustrated. Reference numerals given to the embodiment of FIG. 18 are greater than 500 but less than 600. Reference numerals given to the embodiment of FIG. 19 are greater than 600 but less than 700. Each element described in reference to these apparatuses are similar to each corresponding element of the apparatus 100 illustrated in FIGS. 1-4. For clarity, the last two digits of the reference numeral of the apparatuses of FIGS. 18 and 19 are identical to the last two digits of the apparatus 100 illustrated in FIGS. 1-4. Differences between the apparatuses are described below.
According to FIG 18, this embodiment includes four spray guns 576a,b,c,d, preferably static or stationary, although possibly traversable, are mounted at the 10 o'clock, 8 o'clock, 6 o'clock, and 4 o'clock (60 degree, 120 degree, 180 degree, and 210 degree) positions on a six-legged indexer. This system is particularly adapted to deliver coating to longer can bodies which are smaller in diameter than the typical beverage can bodies on the market today.
According to an alternative arrangement of FIG. 19, the spray guns 676a,b,c,d, preferably static or stationary, although possibly traversable, are mounted at the 120 degree, 150 degree, 180 degree, and 210 degree (8 o'clock, 7, o'clock, 6 o'clock, and 5 o'clock) positions on a twelve-legged indexer. Likewise, this system is particularly adapted to deliver coating to longer can bodies which are smaller in diameter than the typical beverage can bodies on the market today. A further advantage of the apparatus 600 of FIG. 19 is that four can bodies 10 may be processed (sprayed/coated) simultaneously using a 120 degree (4 hour) cycle or index.
According to an alternative arrangement illustrated in FIGS. 20-21, four feed positions 604a,b,c,d can be used to load can bodies 10 onto the indexer 608. Here, the four feed positions 608a,b,c,d may be used load can bodies, for example, at the 300 degree, 330 degree, 0 degree, and 30 degree (2 o'clock, 1 o'clock, 12 o'clock, and 11 o'clock) positions. The static spray gun 676a,b,c,d could then be located at the 60 degree, 90 degree, 120 degree, and 150 degree (10 o'clock, 9 o'clock, 8 o'clock, and 7 o'clock) positions. A separate transfer assembly may be located at the 180 degree, 210 degree, 240 degree, and 270 degree (6 o'clock, 5 o'clock, 4 o'clock, and 3 o'clock) positions.
Referring to FIG. 22, another aspect is illustrated. In this drawing a coating apparatus 700 is again illustrated. Reference numerals given to the embodiment of FIG. 22 are greater than 700 but less than 800. Each element described in reference to these apparatuses are similar to each corresponding element of the apparatus 100 illustrated in FIGS. 1-4. For clarity, the last two digits of the reference numeral of the apparatus of FIG. 22 are identical to the last two digits of the apparatus 100 illustrated in FIGS. 1-4. Differences between the apparatuses are described below. This aspect, however, may be practiced with any of the other embodiments previously described.
According to this aspect, a back spray gun 776a is associated with the transfer turret 716. This spray gun 776a is preferably a static spray gun, although it may optionally be a traversable spray gun as well. This spray gun 776a deliver a coating to a bottom end wall portion of a can body 10 just prior to exiting the apparatus 700.
The present invention may be used to effectuate a method of processing can bodies of vastly different configurations without retuning a cam mechanism used to set dwell time and indexer rate and realigning spray guns on a single coating apparatus. Accordingly, the plurality of can bodies may include a first subset of the plurality of can bodies requiring a first set of processing parameters, e.g. based on size and shape of the can body, dwell time required, volume of coating required etc., and a second subset of the plurality of can bodies requiring a second set of processing parameters not identical to the first set of processing parameters. The external programmable controller provides a first set of signals to a first component of the single coating apparatus, e.g., the indexer, controlling at least a first dwell time during which each of the first subset of the plurality can bodies receives a volume of coating from the single coating apparatus. The controller is further capable of providing a second set of signals to a second component of the single coating apparatus. The second set of signals controls a processing parameter other than the first dwell time.
As used herein, the terms "first," "second," "third," etc. are for illustrative purposes only and are not intended to limit the embodiments in any way. Additionally, the term "plurality" as used herein is intended to indicate any number greater than one, either disjunctively or conjunctively as necessary, up to an infinite number. The terms "joined," 'attached," and/or "connected" as used herein are intended to put or bring two elements together so as to form a unit, and any number of elements, devices, fasteners, etc. may be provided between the joined, attached or connected elements unless otherwise specified by the use of the term "directly" and/or supported by the drawings.

Claims

An apparatus (200) for delivering a coating to an interior surface of a plurality of can bodies (10), the apparatus comprising:
an indexing means (208) for sequentially transferring each of the plurality of can bodies (10) along a plurality of index positions; and

a coating delivery system associated with one of said plurality of index positions;

characterized in that the apparatus further comprises:
a first servo motor (280) operably connected to said coating delivery system, the first servo motor (280) providing substantially linear movement to said coating delivery system, said substantially linear movement being substantially horizontal and perpendicular to an imaginary vertical plane defined by an opening of a can body, wherein a distance between said indexing means and said coating delivery system may be selectively reduced.
The apparatus of Claim 1 further comprising an external programmable controller (228) in communication with said first servo motor (280).
The apparatus of Claim 2 wherein said external programmable controller (228) provides a signal to said first servo motor (280) controlling a rate and a distance traversed by said coating delivery system in response thereto.
The apparatus of Claim 3 further comprising a second servo motor (266) operably connected to said indexing means (208) for setting an index speed and a dwell time at which said indexing means pauses at each of said index positions.
The apparatus of Claim 4 wherein said external programmable controller (228) is in communication with said second servo motor (266), said external programmable controller (228) providing a signal to said second servo motor (266) controlling said index speed and dwell time.
The apparatus of Claim 5 wherein said first servo motor (280) causes said coating delivery system to traverse toward said indexing means during said dwell time.
An apparatus (200) for delivering a spray coating to an interior surface of a plurality of can bodies (10), the apparatus comprising:
a frame (202);

a can body feeder (204) supported by said frame (202) comprising a chute (232) for sequentially feeding a plurality of can bodies (10) into the apparatus (200);

a rotational indexer (208) comprising a plurality of arms (236) radiating outwardly from a hub (240), each arm (236) terminating at a vacuum chuck (244), each said vacuum chuck (244) in fluid communication with a vacuum pressure for attaching said vacuum chuck (244) to one of the plurality of can bodies (10) sequentially received from said chute (232); and

a first spray gun (276) for delivering a first volume of a fluid coating to an interior surface of each the plurality of can bodies (10);

characterized in that the apparatus further comprises:
a first servo motor (266) operably coupled to said rotational indexer (208) and controlling a rate of rotation of said indexer (208) and a dwell time wherein rotation of said indexer (208) pauses for a predetermined length of time;

a second servo motor (280) operably coupled to said first spray gun (276) and controlling relative movement between said first spray gun (276) and the interior surface of each of the plurality of can bodies (10); and

an external controller (228) in communication with said second servo motor (280), said external controller (228) providing a first signal to said second servo motor (280) to synchronize movement of said first spray gun (276) during said dwell time to decrease a distance between said first spray gun (276) and said rotational indexer (208).
The apparatus of Claim 7 further comprising a second spray gun (276) for delivering a second volume of a fluid coating to an interior surface of each the plurality of can bodies (10).
The apparatus of Claim 8 further comprising a third servo motor (280) operably coupled to said second spray gun (276) and controlling relative movement between said second spray gun (276) and the interior surface of each of the plurality of can bodies (10).
The apparatus of Claim 9 wherein said external controller (228) provides a signal to said third servo motor (280).