Abstract:
A solid ink stick configuration efficiently provides functional features for use of the ink stick in a phase change ink printer without adversely impacting the volumetric content of the ink stick and its appearance.

Description:
PRIORITY CLAIM 
       [0001]    This application is a continuation application claiming priority from co-pending U.S. patent application ser. No. 13/334,569, which was filed on Dec. 22, 2011, and was entitled “Solid Ink Stick Configuration.” This application issued as U.S. Pat. No. x,xxx,xxx on date. 
     
    
     TECHNICAL FIELD 
       [0002]    The solid ink stick delivery system disclosed below are used in phase change ink printers, and, more particularly, in phase change ink printers that have delivery systems configured for solid ink that is larger than pellets or pastilles. 
       BACKGROUND 
       [0003]    Solid ink or phase change ink printers conventionally receive ink in various solid forms, such as pellets or ink sticks. The solid ink pellets or ink sticks are typically inserted through an insertion opening of an ink loader for the printer, and the ink sticks are moved along a feed channel by a feed mechanism and/or gravity toward a melting device. The melting device heats the solid ink impinging on the device until it melts. The liquid ink is collected and delivered to a printhead for jetting onto a recording medium. 
         [0004]    Known ink sticks are variously configured with predetermined protuberances and indentations that serve a number of purposes. Some previously known solid ink stick configurations included protuberances and indentations that restrict the insertion of solid ink sticks into particular feed channel openings. In other configurations, some of the protuberances and indentations are used to guide the ink stick through a feed channel, to limit the interaction of the ink stick with feed channel structures, to interact with identification sensors within the ink loading device, or to activate sensors positioned along the feed channel to provide information regarding the position of the ink stick in a feed channel. Other protuberances and indentations provide humanly perceptible indicia that help a user identify an ink stick color or help a user correlate an ink stick with a particular printer or feed channel in a printer. In each ink stick configuration, a balance is required between ink stick esthetics, unique identification and intended usage purposes for different printer configurations and ink formulations, and the need to provide a customer with a reasonable volume of ink that will withstand manual handling and maneuvering along a feed channel to a melting device. Each configuration requires thorough and careful engineering. 
       SUMMARY 
       [0005]    A solid ink stick configuration efficiently provides functional features for use of the ink stick in a phase change ink printer without adversely impacting the volumetric content of the ink stick and its appearance, which conveys a sense of purposeful function contributing to perceived value, makes handling and loading of the ink stick intuitive, and imparts visually recognizable differences among a multitude of shapes, which are simultaneously existent in the market. The solid ink stick includes a solid ink body having a center, a first end surface, a second end surface, the first end surface and the second end surface being configured on the solid ink body to enable an axis to extend from the first end surface to the second end surface and pass through the center of the solid ink body without passing through any other surface of the solid ink body, a third surface that extends from an edge of the first end surface to an edge of the second end surface, a first pair of protuberances extending from the third surface at a first height, a first protuberance in the first pair of protuberances being positioned at a distance from the second end surface that is different than a distance from the second end surface at which the other protuberance in the first pair of protuberances is positioned, a second pair of protuberances extending from the third surface at the first height, a first protuberance in the second pair of protuberances being positioned at a distance from the second end surface that is different than a distance from the second end surface at which the other protuberance in the second pair of protuberances is positioned and each of the protuberances in the second pair of protuberances being positioned at a distance from the second end surface that is greater than either distance from the second end surface at which the protuberances of the first pair of protuberances are positioned, and a fifth protuberance extending from the third surface, the fifth protuberance being positioned at a distance from the second end surface that is different than each distance at which each protuberance in at least the first pair of protuberances is positioned from the second end surface and a volume of the fifth protuberance is greater than any protuberance in either the first pair of protuberances or the second pair of protuberances. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The solid ink stick structure configured for use in a phase change ink printer is discussed with reference to the drawings now described. 
           [0007]      FIG. 1  is a bottom view of a solid ink stick having two pairs of protuberances to provide a first function while a fifth protuberance provides a support function. 
           [0008]      FIG. 2  is a bottom view of another embodiment of the solid ink stick shown in  FIG. 1 . 
           [0009]      FIG. 3  is a bottom view of another embodiment of the solid ink stick shown in  FIG. 1  with the third surface providing the support function that the fifth protuberance provided in the embodiment of  FIG. 1 . 
           [0010]      FIG. 4  is a bottom view of another embodiment of the solid ink stick shown in  FIG. 1  with the third surface providing the support function that the fifth protuberance provided in the embodiment of  FIG. 1  and with a different shape in the protuberances of the two pairs of protuberances shown in  FIG. 1  and  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    The term “printer” refers, for example, to devices that produce images on media, such as printers, facsimile machines, copiers, and related multi-function products. Solid ink may be called or referred to in this document as ink, ink sticks, or sticks. 
         [0012]      FIG. 1  shows an example of a solid ink stick  10  having a configuration with features that emphasize visual differentiation between a multitude of earlier generation ink sticks, current printer model marketing and geographic considerations, and that enables future ink sticks to pose similar or equivalent interfaces and/or exclusionary features along with differentiating features. This configuration enables applicable usage of the ink stick to be determined by a user prior to insertion into the ink handling device of an imaging product. The solid ink stick  10  has a body  14  with a center  18 , a first end surface  22 , and a second end surface  26 . The center, as used in this document, refers to the center of gravity for the body as that term is defined in physics. The first end surface  22  and the second end surface  26  are oriented and positioned on the solid ink body  14  to enable an axis  30  to extend from the first end surface  22  to the second end surface  26  and pass through the center  18  of the solid ink body  14  without passing through any other surface of the solid ink body  14 . A third surface  34  extends from an edge  38  of the first end surface  22  to an edge  42  of the second end surface  26 . A first pair of protuberances  46  extends from the third surface  34  at a first height. The protuberance  50  in the first pair of protuberances  46  is positioned at a distance D1 from the second end surface  26  that is different than a distance D2 from the second end surface  26  at which the other protuberance  54  in the first pair of protuberances  46  is positioned. A second pair of protuberances  58  extends from the third surface  34  at the first height. The protuberance  62  in the second pair of protuberances is positioned at a distance D3 from the second end surface  26  that is different than a distance D4 from the second end surface  26  at which the other protuberance  66  in the second pair of protuberances  58  is positioned. Also, as shown in  FIG. 1 , each of the protuberances  62 ,  66  in the second pair of protuberances  58  is positioned at a distance D3, D4, respectively, from the second end surface that is greater than either distance D1, D2 from the second end surface at which the protuberances  50 ,  54  of the first pair of protuberances  46  are positioned. A fifth protuberance  70  extends from the third surface  34 . The fifth protuberance  70  is positioned at a distance D5 from the second end surface  26  that is different than each distance D1, D2 at which each protuberance  50 ,  54  in at least the first pair of protuberances  46  is positioned from the second end surface  26  and a volume of the fifth protuberance  70  is greater than any protuberance  50 ,  54 ,  62 ,  66  in either the first pair of protuberances  46  or the second pair of protuberances  58 . 
         [0013]    As used in this document, “a pair of protuberances” refers to a set or group of protuberances that have at least two protuberances, but can have more than two protuberances provided the other structural limitations of a pair of protuberances as defined by the claims in this document are met. “Protuberances” refer to the common meaning of “thrusting out from a surrounding or adjacent surface. 
         [0014]    In one embodiment, the protuberance  70  operates as a rest that supports the weight of the solid ink stick  10  on a feed channel guide feature. In another embodiment, the protuberance  70  operates as a rest that supports the weight of the solid ink stick  10  on a drive member. In both of those embodiments, the distances from the second end  26  of the ink stick body  14  of the protuberances place the protuberances at angle with respect to one another that correspond to an angle on a lead screw that is operated as a drive member to move the ink stick through a feed channel. 
         [0015]    In another embodiment, each protuberance  50 ,  54  of the first pair of protuberances  46  and the second pair of protuberances  58  has a volume approximately equal to a volume of the other protuberances in the first pair of protuberances and the second pair of protuberances. As shown in the embodiment of  FIG. 1 , each protuberance  50 ,  54  of the first pair of protuberances  46  and the second pair of protuberances  46  has a curved surface, although other linear and non-linear profiles can be used. 
         [0016]    Other embodiments of the ink stick have a fifth protuberance  70  with other characteristics. For example, in one embodiment, the volume of the fifth protuberance  70  is at least thirty percent greater than any protuberance in either the first pair of protuberances  46  or the second pair of protuberances  58 . In another embodiment, the fifth protuberance  70  extends across a width of the third surface  34  that is orthogonal to a line extending from the first end surface  22  to the second end surface  26  and also extends parallel to the axis  30  that extends from the first end surface  22  to the second end surface  26  that passes through the center  18  of the solid ink body  14 . In other embodiments, the fifth protuberance does not completely cover the width of the third surface, but is truncated on one or both ends of the protuberance in the direction that parallels the width of the third surface  34 . In yet another embodiment, the shape and/or size, including the height, of the protuberance second pair  58  can be different than the first pair  46  or such differences can apply to individuals within the pair. In any of these embodiments, the ink stick is configured in such a manner as to accomplish the intended rest, guidance, or feed function. These various configurations enhance the range of visual differentiation between individual sticks apart from the interface functions of the ink stick with the ink handling/loading device of a printer. 
         [0017]    In  FIG. 2 , another embodiment of the solid ink stick is shown with like features being identified with the same reference numbers used to identify features in the embodiment of  FIG. 1 . In this embodiment, the fifth protuberance is not a unitary structure, but rather divided into a fifth protuberance  70  and a sixth protuberance  74 . The sixth protuberance  74  extends from the third surface  34  and a sum of the volume of the fifth protuberance and a volume of the sixth protuberance is greater than any protuberance  50 ,  54 ,  62 ,  66  in either the first pair of protuberances  46  or the second pair of protuberances  58 . In this embodiment, the fifth protuberance  70  and the sixth protuberance  74  each have a surface  78  that slopes relative to a plane of the third surface  34  from a first height, which is not inset in the third surface, to a second height above the third surface. In one embodiment, the second height is greater than the first height, while in another embodiment, the second height is equal to the first height. 
         [0018]    In  FIG. 3 , another embodiment of the solid ink stick is shown with like features being identified with the same reference numbers used to identify features in the embodiment of  FIG. 1 . In this embodiment, the fifth protuberance has been removed and the third surface  34  provides support for the solid ink stick. The spacing between the first pair of protuberances and the second pair of protuberances is greater than shown in  FIG. 1 . A similar embodiment not having a fifth protuberance is shown in  FIG. 4 . As noted above, some embodiments have protuberances have linear shapes, as shown in  FIG. 4 , while other embodiments have linear shapes as shown in  FIG. 3 . 
         [0019]    Those skilled in the art will recognize that numerous modifications can be made to the specific implementations described above. For example, the size and number of rest features and the position and relative spacing of all protuberances as well as size and shape of the individual protuberance elements can vary based on both functional and visual differentiation objectives. Therefore, the following claims are not to be limited to the specific embodiments illustrated and described above. The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.