Patent Application
20160288484
The present disclosure relates generally to end caps for defining web tension of a printing substrate roll during a printing operation. In particular, end caps having a curved outer wall for defining a first component of the total web tension and a central protuberance for defining a second component of the total web tension are described.
It is desirable that unrolling of a rolled printing substrate through a printer during a printing operation has a smooth feed and a steady unwind pressure. Specifically, it is desirable that tension on the printing substrate (i.e., web tension) remain low enough to allow unrolling, but be high enough to prevent over-unrolling. Typically, the printing substrate roll includes end caps attached at opposing ends. Web tension is regulated via friction between the end cap and a saddle with a spring member, which is configured to receive and releasable retain the end cap. Specifically, friction between an inner wall of the saddle and an outer curved surface of a protrusion of the end cap, as well as pressure applied on a face of the protrusion by the spring member, creates the web tension required to regulate unrolling of the printing substrate.
Known end caps are not entirely satisfactory for the range of applications in which they are employed. For example, web tension produced by existing end caps is defined by dimensions of the protrusion. Accordingly, if length of the protrusion is increased or decreased, a height of the outer cursed surface is similarly increased or decreased. Thus, control over and/or regulation of web tension is limited and can result in undesired unrolling characteristics during a printing operation. In some cases, these undesired rolling characteristics can cause misprinting.
In addition, it is desirable to label and/or tag rolls of paper on the end caps for identification of the printing substrate roll, however, conventional end caps are difficult to label. Normally, the protrusion is surrounded by a conical wall. Thus, the most convenient and/or readable location to place a label and/or tag is on the face of the protrusion. Specifically, the label and/or tag can be adhered to the flat surface of the face in order to be easily read by a user and/or a scanner. Contact between the spring member and the face during rotation of the printing substrate roll will likely destroy the tag. Alternatively, the tag can be placed on the conical wall, which may be more difficult for the tag to adhere to and/or make the tag more difficult to read.
Thus, there exists a need for printing substrate roll end caps that improve upon and advance the design of known printing substrate roll end caps. Examples of new and useful printing substrate roll end caps relevant to the needs existing in the field are discussed below.
Disclosure addressing one or more of the identified existing needs is provided in the detailed description below. Examples of references relevant to printing substrate roll end caps include U.S. Patent References: U.S. Pat. No. 6,634,814, U.S. Pat. No. 7,063,470, and U.S. Pat. No. 7,664,257. The complete disclosures of the above patents are herein incorporated by reference for all purposes.
The present disclosure is directed to end caps for printing substrate rolls that are configured to engage with a print roll retaining mechanism of a printer in order to regulate total web tension of a printing substrate during a printing operation. Each of the end caps has a cylindrical boy including an attachment mechanism for attaching the end cap to the printing substrate roll; a continuously curved outer wall longitudinally aligned with the cylindrical body and configured to define a first component of the total web tension; and a central protuberance that is concentric with the continuously curved outer wall and longitudinally aligned with the cylindrical body, an outer face of the central protuberance being extended beyond an outer lip edge of the curved outer wall, the central protuberance configured to define a second component of the total web tension.
The disclosed printing substrate roll end caps will become better understood through review of the following detailed description in conjunction with the figures. The detailed description and figures provide merely examples of the various inventions described herein. Those skilled in the art will understand that the disclosed examples may be varied modified, and altered without departing from the scope of the inventions described herein. Many variations are contemplated for different applications and design considerations; however, for the sake of brevity, each and every contemplated variation is not individually described in the following detailed description.
Throughout the following detailed description, examples of various printing substrate roll end caps are provided. Related features in the examples may be identical, similar, or dissimilar in different examples. For the sake of brevity, related features will not be redundantly explained in each example. Instead, the use of related feature names will cue the reader that the feature with a related feature name may be similar to the related feature in an example explained previously. Features specific to a given example will be described in that particular example. The reader should understand that a given feature need not be the same or similar to the specific portrayal of a related feature in any given figure or example.
With reference to
End cap 100 further includes a circular lateral wall 120 encompassed by curved outer wall 112. In other words, lateral wall 120 and outer wall 112 form a recess 122. Recess 122 is configured to receive an identification tag and/or label. For example, an RFID tag can be attached to the circular lateral wall within the recess.
End cap 100 functions to allow control, regulation, and/or refinement of web tension during a printing operation. Specifically, dimensions of the continuously curved outer wall wall and dimensions of the central protuberance are independent of each other. Therefore, tension caused by friction between the continuously curved wall and the inner wall of the saddle can be independently regulated from tension caused by friction and/or pressure of the spring member on the central protuberance.
For example, a height of the wall can be selected to be increased or decreased to correspondingly increase or decrease the first component of the total web tension. In another example, a length of the central protuberance can be selected to be increased or decreased to correspondingly increase or decrease the second component of the total web tension. In even another example, width of the central protuberance can be selected to be increased or decreased and correspondingly increase or decrease the second component of the total web tension.
Additionally or alternatively, as described above, the circular lateral wall can be used for attachment of an identification label and/or tag.
End cap 100 addresses many of the shortcomings existing with conventional end caps. For example, web tension can be more tightly controlled, regulated, and/or optimized because dimensions of the curved outer wall and the central protuberance are independently selectable to cooperatively define the total web tension. In other words, dimensions of the curved outer wall define a first component of the total web tension and dimensions of the central protuberance define a second component of the total web tension. The first component and the second component can be independently selected to refine the web tension of a printing operation, which can be optimized for specific printing conditions (e.g., a type of printing substrate, an amount of remaining substrate on the roll, a speed of printing, etc.). In another example, wear on an identification label and/or tag is limited as it is protected within the recess. Further, the identification label and/or tag is easily readable by a user and/or scanner.
As shown in
It will be appreciated that in alternate examples the attachment mechanism can have a different configuration for attachment of the end cap to the printing substrate roll. In one alternate example, the attachment mechanism can be a smooth insertable arm (i.e., an arm lacking fins on an exterior surface. In another alternate example, the attachment mechanism can include three or more prongs that are slightly compressible in order to be fitted within the printing substrate roll. In this example, the prongs can each include a flange at the distal end (i.e., interior-most end) of the prong for additional gripping of the interior surface of the printing substrate roll. It will be further appreciated that the attachment mechanisms described above are mere examples and the end cap can include any attachment mechanism known or yet to be discovered.
Returning to
As can be seen in
Circular lateral wall 120 is encompassed by curved outer wall 112 and is disposed inwardly relative to an outer lip edge 154 of curved outer wall 112 (shown in
Also shown in
Turning now to
As stated above and shown in
Specifically, friction between the curved outer wall of the end cap and the inner wall of the saddle and surface area of the curved outer wall define the first component of the total web tension. Accordingly, a height of the continuously curved outer wall (i.e., the height c) and a diameter of the curved outer wall (i.e., the width d) are selectable to define the first component of the total web tension. Further, the surface area of the continuously curved outer wall has a direct relationship with the first component of the total web tension. For example, the surface area (e.g., the height, the diameter of the circle, etc.) of the continuously curved outer wall is selectable to be an increased value to correspondingly increase the first component. In another example, the surface area (e.g., the height, the diameter of the circle, etc.) of the continuously curved outer wall is selectable to be a decreased value to correspondingly decrease the first component.
The second component of the total web tension is defined by a degree of flex of the spring member and friction between the spring member and the face of the central protuberance. Accordingly, a height (i.e., the height a) and a width (i.e., the width b) of the central protuberance are each selectable to define the second component of the total web tension. Further, the length of the central protuberance and the width of the central protuberance each have a direct relationship with the second component of the total web tension. In one example, one or more of the length of the central protuberance and the width of the central protuberance is selectable to be an increased distance to correspondingly increase the second component. In another example, one or more of the length of the central protuberance and the width of the central protuberance is selectable to be a decreased distance to correspondingly decrease the second component. In other words, a greater degree of flex of the spring member (i.e., a greater distance between the spring member and the saddle main body) and/or a greater degree of surface area contact between the spring member and the face of the central protuberance results in an increase in the second component of the web tension.
It will be appreciated that in some examples web tension can be regulated or defined by a material comprising or disposed on the outer surface of the curved outer wall and/or the face of the central protuberance. Both the first component of web tension and the second component of web tension are affected and defined by friction (e.g., friction between the curved outer wall and the inner wall of the saddle and friction between the face and the spring member, respectively). Accordingly, low-friction materials (e.g., polished plastic, polished metal, grease, etc.) can comprise or he coated on the outer surface of the curved outer wall to decrease the first component of the total web tension and high-friction materials (e.g., textured plastic, textured metal, rubber, etc.) can comprise or be coated on the outer surface of the curved wall to increase the first component of the total web tension. Similarly, low-friction materials (e.g., polished plastic, polished metal, grease, etc.) can comprise or be coated on the face of the central protuberance to decrease the second component of the total web tension and high friction materials (e.g., textured plastic, textured metal, rubber, etc.) can comprise or be coated on the face of the central protuberance to increase the second component of the total web tension.
In some examples, a printing system can include a plurality of end caps. The plurality of end caps can have a variety of dimensions for the curved outer wall and the central protuberance. Additionally or alternatively, the plurality of end caps can include end caps having a variety of materials disposed on or comprising the outer surfaces the curved outer walls and/or the faces of the central protuberances. Pairs of end caps can be selectively used to convey and/or generate a specific web tension during a printing operation. Accordingly, the web tension can he optimized for specific printing conditions (i.e., type of printing substrate, a size of the roll, a speed of the printing operation, etc.).
The disclosure above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in a particular form, the specific embodiments disclosed and illustrated above are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed above and inherent to those skilled in the art pertaining to such inventions. Where the disclosure or subsequently filed claims recite “a” element, “a first” element, or any such equivalent term, the disclosure or claims should be understood to incorporate one or more such elements, neither requiting nor excluding two or more such elements.
Applicant(s) reserves the right to submit claims directed to combinations and subcombinations of the disclosed inventions that are believed to be novel and non-obvious. Inventions embodied in other combinations and subcombinations of features, functions, elements and/or properties may be claimed through amendment of those claims or presentation of new claims in the present application or in a related application. Such amended or new claims, whether they are directed to the same invention or a different invention and whether they are different, broader, narrower or equal in scope to the original claims, are to be considered within the subject matter of the inventions described herein.
