Patent Application
20120298772
1. Field
The disclosed concept relates generally to machinery and, more particularly, to machines, such as for example, machines used to apply and/or repair coatings used on can ends in the food and beverage packaging industries. The disclosed concept further relates to spray assemblies and spray heads.
2. Background Information
Typically, can bodies for food or other products are provided with easy open can ends that are characterized by having a pull tab attached to the can end, which is used to fracture a tear panel on the can end defined by a score line on the can end. For example, the pull tab may be lifted to depress the tear panel in order to provide an opening in the can end for dispensing the contents of the container.
Likewise, many food products are sold in can bodies provided with full open easy open can ends that are characterized by having a pull tab attached to the can end, which is used to fracture a score line that circumscribes the circumference of the end panel to define an opening panel. For example, the pull tab may be lifted to fracture the score line. After the score line is fractured, the pull tab may be pulled upward from the container to sever the remainder of the score line in order to remove the entire opening panel for dispensing the contents of the container.
In the manufacture of an easy open can end, a pre-converted can end, commonly referred to as a shell, is conveyed to a conversion press. In the typical operation of a conversion press, the shell is introduced between upper and lower tool members, which are in the open, spaced apart position. A press ram advances the upper tool member toward the lower tool member in order to perform any of a variety of tooling operations such as rivet forming, paneling, scoring, embossing, and final staking After performing a tooling operation, the press ram retracts until the upper tool member and lower tool member are once again in the open, spaced apart position. The partially converted shell is then transported to the next successive tooling operation until an easy open can end is completely formed and discharged from the press. As one shell leaves a given tooling operation, another shell is introduced to the vacated operation, thus continuously repeating the entire easy open can end manufacturing process. Examples of easy open can ends can be found, for example, in U.S. Pat. Nos. 4,465,204 and 4,530,631. Conversion presses can operate at speeds that manufacture in excess of 500 can ends per minute per lane, with some presses having four lanes of tooling thereby manufacturing up to 2000 converted can ends, or more per minute.
Steel sheet stock used in the manufacture of can ends has a coating that protects the metal by inhibiting oxidation, corrosion or rust from forming on the surface of the metal. During the conversion process, damage to the protective coating typically occurs while forming the score line that defines the tear panel or opening panel of the can end. As noted above, in the conversion of a shell into a can end with openable features thereon, tooling is employed to form the aforementioned score line. The score line is the most likely location where damage is caused to the protective coating. Any oxidation, corrosion or rust on the surface of the can end that could result from such damage to the protective coating represents an unattractive product appearance to the consumer and is generally unacceptable to canmakers. Accordingly, as a precautionary measure to prevent oxidation, corrosion or rust from appearing on the can end, many canmakers apply a fluid, repair agent, lacquer or paint to coat the scored area of the can end by spraying the can end. This process is generally referred to as score repair or post repair.
The spray heads for known spraying apparatus and methods for score repair typically employ a single spray gun, which is rotated at relatively high speed (e.g., about 1000 rpm) in order to enable the spray gun to make one complete revolution around the can end during the spray portion of the machine cycle. Commonly assigned U.S. Pat. No. 7,622,002 discloses a spray machine, which employs a low-pressure solid stream spray head and method to reduce over spray or spray beyond the scored surface of the can end, and allow for improved machine efficiencies, for example, due to reduced downtime associated with routine cleaning and maintenance.
There is room for improvement in post repair machines, and in spray assemblies and spray heads therefor.
These needs and others are met by embodiments of the disclosed concept, which are directed to a spray assembly for a post repair machine. Among other benefits, the spray assembly includes an oscillating spray head, which enables the efficient and effective application of a coating of fluid, repair agent, lacquer or paint to numerous can ends of varying sizes.
As one aspect of the disclosed concept, a spray head is provided for a spray assembly structured to apply a coating to a plurality of can ends. The spray assembly includes a power source and a motion control mechanism. The spray head comprises: a mounting member; a pivot member including a first end movably coupled to the mounting member, and a second end disposed opposite and distal from the first end; a gun assembly comprising a plurality of spray guns coupled to the pivot member proximate the second end; and a transfer mechanism structured to transfer a predetermined motion that is induced by the motion control mechanism from the motion control mechanism to the pivot member. Each of the spray guns is structured to apply the coating to a corresponding portion of each can end in accordance with the predetermined motion.
The pivot member may be a pivotal shaft, and the second end of the pivotal shaft may include a first mounting portion and a second mounting portion disposed opposite the first mounting portion. The plurality of spray guns may be a first spray gun coupled to the first mounting portion and a second spray gun coupled to the second mounting portion. The pivotal shaft may have a longitudinal axis of rotation, and the gun assembly may further comprise a number of spacers. Each of the spacers may be disposed between one of the first and second mounting portions and a corresponding one of the first and second spray guns, thereby offsetting the spray gun with respect to the longitudinal axis of rotation.
The predetermined motion may be an oscillating motion comprising the following sequential steps: (a) an acceleration of the spray guns in a first direction to begin a spray cycle; (b) rotation of the spray guns at a constant predetermined rotational velocity in the first direction as a first can end is sprayed; (c) deceleration of the spray guns in the first direction to a complete stop; (d) acceleration of the spray guns in a second, reverse direction; (e) rotation of the spray guns at a constant predetermined rotational velocity in the second direction as another second can end is sprayed; and (f) deceleration of the spray guns in the second direction to a complete stop, thereby ending the spray cycle.
The spray guns may rotate about a central axis. A first one of the spray guns may begin the spray cycle at 0 degrees with respect to the central axis. The spray gun may accelerate in the first direction from 0 degrees to about 45 degrees with respect to the central axis. From about 45 degrees to about 225 degrees the spray gun may rotate in the first direction at the constant predetermined rotational velocity. From about 225 degrees to about 270 degrees the spray gun may decelerate. The spray gun may stop at about 270 degrees. From about 270 degrees to about 225 degrees the spray gun may accelerate in the second, reverse direction. From about 225 degrees to about 45 degrees the spray gun may rotate in the second direction at the constant predetermined rotational velocity. From about 45 degrees to 0 degrees the spray gun may decelerate. The spray gun may stop at about 0 degrees to end the spray cycle.
The motion control mechanism may be a cam box. The cam box may include an input shaft, an output shaft, and a number of cams. The power source may be a motor, wherein the motor moves the input shaft, thereby moving the cams to induce the predetermined motion as an oscillating motion of the output shaft. The transfer mechanism may be a number of belts, wherein the belts transfer the oscillating motion to the pivot member, thereby oscillating the spray guns.
A spray assembly and a machine employing a number of the aforementioned spray heads, are also disclosed.
The spray assembly may include a plurality of spray heads. The machine may include a plurality of lanes each delivering a plurality of can ends to a corresponding one of the spray heads.
The plurality of spray heads may be a first spray head and a second spray head, the plurality of lanes may be a first lane and a second lane, and the plurality of can ends may include a first plurality of can ends being transported by the first lane to the first spray head, and a second plurality of can ends being transported by the second lane to the second spray head. The first plurality of can ends may have a first diameter, and the second plurality of can ends may have a second diameter different from the first diameter.
A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
The specific elements illustrated in the drawings and described herein are simply exemplary embodiments of the disclosed concept. Accordingly, specific dimensions, orientations and other physical characteristics related to the embodiments disclosed herein are not to be considered limiting on the scope of the disclosed concept.
As employed herein, the terms “can” and “container” are used substantially interchangeably to refer to any known or suitable container, which is structured to contain a substance (e.g., without limitation, liquid; food; any other suitable substance), and expressly includes, but is not limited to, food cans, as well as beverage cans, such as beer and soda cans.
As employed herein, the term “can end” refers to the lid or closure that is structured to be coupled to a can, in order to seal the can.
As employed herein, the term “can end shell” is used substantially interchangeably with the term “can end.” The “can end shell” or simply the “shell” is the member that is acted upon and is converted by the disclosed tooling to provide the desired can end.
As used herein, the term “pull tab” or “tab” refers to an opening device (e.g., opener) made from generally rigid material that has undergone one or more forming and/or tooling operations, and which is structured to be suitably affixed to a can end for the purpose of being pivoted to sever a score line and open at least a portion of the can end.
As employed herein, the statement that two or more parts are “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts.
As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality).
Each spray head 200 (see also spray head 300 of
In the example shown and described herein, the pivot member is a pivotal shaft 204, wherein the second end 208 of the pivotal shaft 204 includes first and second opposing mounting portions 218,220. A first spray gun 212 is coupled to the first mounting portion 218, and a second spray gun 214 is coupled to the second mounting portion 220, as best shown in
Referring again to
The predetermined motion of the spray head and, in particular, the spray guns 212,214 thereof, will be further appreciated with reference to the schematic illustration of
It will be appreciated that the foregoing spray cycle may repeat such that the spray guns 212,214 oscillate back-and-forth as the can ends 400 are coated or repaired. In one non-limiting embodiment the spray guns 212,214 oscillate back-and-forth up to about 250 times per minute, or more. It will further be appreciated that, in accordance with one non-limiting example embodiment, the spray guns 212,214 can accelerate from 0 rpm to about 500 rpm, and then rotate at the aforementioned constant predetermined rotational velocity, which is about 500 rpm. The spray guns 212,214, then decelerate from about 500 rpm to 0 rpm. Accordingly, it will be appreciated that an additional benefit of the disclosed concept is that the spray head 200 and, in particular the spray guns 212,214, operate (e.g., move; rotate) at a relatively slower speed (e.g., without limitation, 500 rpm) as compared to known spray head designs, wherein the single spray gun typically operates (e.g., rotate) at about 1,000 rpm. Among other benefits, this enables the coating to be accurately and efficiently applied to the area of the can end 400 desired, with little waste (e.g., without limitation, minimal overspray). It also provides for additional time for the spray guns 212,214 to provide a thorough and complete repair coating to the can ends 400 and, in particular the score lines 402 thereof.
Continuing to refer to
The spray assembly 100 will now be further described in connection with
More specifically, the cam box 104 further includes an input gear 112 suitably coupled to the input shaft 106, and an output gear 114 suitably coupled to the output shaft 108. The electric motor 102 also includes a shaft 116 to which a motor gear 118 is suitably coupled. Accordingly, in the example of
It will be appreciated that the machine 2 and spray assembly 100 could be configured in a wide variety of alternative arrangements other than those which are shown and described herein, without departing from the scope of the disclosed concept. For example and without limitation, while the example spray assembly 100 includes two spray heads 200,300 for spraying can ends 400,500 having different diameters 404,504, respectively, any known or suitable alternative number, type and/or configuration of spray heads (not shown) could be employed to spray (e.g., coat; repair) a wide variety of different can ends having the same or different sizes and/or shapes.
By way of example, and without limitation, the machine 2 (shown in simplified form in phantom line drawing) of
It will be appreciated, therefore, that the disclosed spray assembly 100 and spray heads (e.g., without limitation, 200,300) can be set up in a wide variety of configurations, for example and without limitation, for use with a plurality of different lanes (e.g., without limitation, first lane 4, second lane 6) wherein each lane may contain can ends (e.g., without limitation, can ends 400; can ends 500) having any known or suitable diameter (e.g., without limitation, diameter 404; diameter 504) or shape. Additionally, the spray heads (e.g., without limitation, 200,300) themselves can be relatively quickly and easily configured and/or reconfigured, for example and without limitation, by employing a different number and/or configuration of spacers 224,226 (best shown in
While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.
