# Patent

## Title
Solid ink stick having a feed drive coupler

## Abstract

A solid ink unit enables facilitates coupling of the solid ink unit to a drive mechanism. The solid ink unit includes a meltable ink body having a longitudinal axis, a coupler support extending from the meltable ink body, and an opening in the coupler support that extends along a portion of the longitudinal axis of the solid ink body.

## Background
TECHNICAL FIELD
The solid ink units disclosed below generally relate to solid ink sticks that are melted to produce liquid ink for printing, and, more particularly, to solid ink sticks that are delivered by mechanized drives to a melting device in a solid ink printer.
BACKGROUND
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 pushed or slid 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 print head for jetting onto a recording medium.
A common goal of all printers is an increase in the number of documents generated by the printer per unit of time. As the throughput of solid ink printers increase, the demand for a continuous supply of solid ink to the melting device also increases. The increased demand for solid ink has led to the development of energized drive trains for the feed mechanisms that deliver solid ink units to a melting device. For example, a lead screw, an endless belt, and other drive mechanisms may be located in a feed channel and coupled to a motor through a drive train. Selectively energizing the motor causes the drive mechanism to move and carry a solid ink unit resting on the drive towards the melting assembly. The motorized carrier more positively urges the solid ink towards the melting unit and helps maintain a continuous supply of solid ink to the melting assembly.
Previously known feed channels have included relatively planar floors to facilitate the sliding or gravitational pull on solid ink inserted into the feed channel. The incorporation of motorized drives in feed channels has typically resulted in the drive mechanism acting as the floor of the feed channel. Thus, the drive mechanisms usually contact the bottom of the solid ink along the entire length or nearly the entire length of the solid ink. As throughput for solid ink printers has increased, the dimensions of the solid ink have also increased. Consequently, longer feed channels may be used and these longer channels may have non-linear sections that accommodate the constraints of the available space within a printer.
SUMMARY
A solid ink stick includes a drive coupler that facilitates movement of the solid ink stick through linear and non-linear feed channels. The solid ink stick includes a meltable ink body having a longitudinal axis, a coupler support extending from the meltable ink body, and an opening in the coupler support that extends along a portion of the longitudinal axis of the solid ink body. The opening may have a variety of cross-sections including a semi-circle, a V-shape, a rectilinear shape, or an irregular shape.



BRIEF DESCRIPTION OF THE DRAWINGS
Features for controlling the transportation of solid ink in a solid ink printer are discussed with reference to the drawings, in which:
FIG. 1 is a side view of a solid ink unit having a driver coupler along a portion of the solid ink body that engages a feed drive in a feed channel.
FIG. 2 is a front view of the solid ink unit shown in FIG. 1.
FIG. 3 is a bottom view of the solid ink unit shown in FIG. 1 showing the relationship of a leadscrew to a canted drive coupler.
FIG. 4 is a side view of another embodiment of a solid ink unit having a solid ink body with a curved bottom surface.
FIG. 5 is a top view of the embodiment shown in FIG. 4 negotiating a turn in a non-linear portion of a feed channel.
FIG. 6 is a side view of another embodiment of a solid ink unit having a solid ink body with a slanted bottom surface.



DETAILED DESCRIPTION
The term “printer” refers, for example, to reproduction devices in general, such as printers, facsimile machines, copiers, and related multi-function products. While the specification focuses on a system that transports solid ink through a solid ink printer, the transport system may be used with any solid ink image generating device. Solid ink may be called or referred to as ink, ink sticks, or sticks.
As shown in FIG. 1, an example of a solid ink stick 10 having a drive coupler 14 is shown in a side view. The solid ink stick 10 has a meltable body with a length L and a height H, as shown in FIG. 1, and a width W, as may be seen in the front view of the stick depicted in FIG. 2. The meltable ink body of the solid ink stick 10 may have, for example, a bottom surface 18, a top surface 20, a front surface 24, and a rear surface 28, although other body shapes providing other or different surfaces may be used. The solid ink stick body has a longitudinal axis along its length L. The drive coupler 14 in the illustrated embodiment is incorporated in a portion of the bottom surface of the ink stick that is vertically displaced from the remaining portion of the bottom surface.
As shown in FIG. 1, the coupler 14 may be offset from a surface of the solid ink body, such as the bottom surface, by a coupler support 30 that extends from one of the ink body surfaces. As shown in FIG. 1, the coupler support 30 extends from the bottom surface 18. The drive coupler 14 is incorporated within the coupler support 30 (FIG. 2). The drive coupler 14 illustrated in FIG. 2 includes a semicircular opening in the coupler support 30. The coupler is configured to receive a feed drive 40 having a circular cross-sectional core area. Thus, the opening has a circular cross-section. In other embodiments, the opening of the drive coupler 14 may be square (or other rectilinear shape), V-shaped, curved, or some other shape that is useful to engage the drive mechanism. The driver coupler opening may vary in form and/or size along its length. For example, it may be round, curved, or some other shape that resembles the feed drive and then flare. The drive coupler may also have features in or along the opening, such as a “bump” or other protuberance that may increase engagement between the portion of the ink stick body from which the support 30 extends and the drive.
In FIG. 3, the feed drive 40 is a leadscrew having a raised thread 44 that is coupled to a rotational output of a motor (not shown) and the drive coupler 14 is formed to complement the screw pitch. The rotational output of the motor may be coupled to the feed drive through a drive train to vary the speed of the screw's rotation or torque, if desired. The motor may be selectively operated to rotate the screw. In other embodiments, the feed drive may be an endless belt having, for example, a flat, elliptical, trapezoidal, circular, or rectangular cross-section. These types of drives may also include a protuberance extending from the drive towards the ink sticks carried by the drive. Such a protuberance may also include a slanted face that enables the ink stick to slide up and the drive to pass by the ink stick in the forward direction in response to the ink stick being stopped by a melting device or another ink stick in the feed channel. When the ink stick is not blocked in the channel, however, the protuberance more easily engages the opening of the coupler 14 to urge forward the portion of the ink stick from which the coupler support extends. Of course, the remainder of the ink stick body follows this portion.
As shown in FIG. 4, the opening of the drive coupler 14 may be canted at an angle to the longitudinal axis of the ink body. The angle at which the opening of the coupler is canted may be complementary to the pitch of the raised thread of the leadscrew, however, the opening may be straight in the longitudinal direction of the ink stick body depending on the screw pitch and the length of the opening. Complementary, as used in this context, means that the drive coupler does not necessarily conform to the shape of the drive identically, but rather fits the drive to facilitate engagement between the drive and the portion of the ink stick body from which the coupler support extends. An opening in the drive coupler may be contoured, for example, to match the helical form of a leadscrew or other feed drive.
The drive coupler in the illustrated embodiment enables the leadscrew to propel an ink stick through a feed channel until the stick encounters the melting device to which the solid ink is being delivered or the rear portion of another solid ink stick in the feed channel. At that point, the stick may lift slightly as the leadscrew turns and advances through the opening and past the stick since the ink cannot advance any further. As melting occurs, resistance to forward motion is reduced and the screw once again urges the ink forward in the feed channel. The specific orientation and surface depictions set forth in this description are presented to aid in understanding and visualizing the function of the drive coupler, however, the body of the ink stick may have other surface orientations as well as other longitudinal configurations. Though any orientation or feed direction is possible, pulling the stick by generating motive force closer to the front of the stick, referenced with respect to the feed direction, may be more advantageous than pushing the stick near the rear of the stick, regardless of the type of feed mechanism employed.
Another embodiment of an ink stick 100 is shown in FIG. 4 and FIG. 5. The ink stick 100 is similar to the ink stick 10 with the exception that the drive coupler is a linear relief that may be formed in a position of the ink body surface proximate the feed drive and may be formed with a radius along its top. As shown in FIG. 4, the body surface proximate the feed channel drive, which in FIG. 4 is the bottom surface 108, may be curved or in some way elevated so a portion of the surface external to the coupler support remains out of contact with the drive mechanism. Because only a portion, rather than substantially most, of the length of the ink body contacts the feed drive 120, the drive mechanism minimally influences the portion of the ink stick outside of the drive coupler. For example, as shown in FIG. 5, the curved linear relief or bottom surface that slants away from the feed drive in the longitudinal direction (FIG. 6), enables a portion of the bottom surface of the ink stick body near the rear surface 114 to move laterally through a non-linear portion of the feed channel 122 so it is not aligned or forced to track with the feed drive 120. The drive coupler 104, however, remains engaged with the feed drive so it tracks the feed drive path more closely. Consequently, the ink stick 100 is more easily able to move through the curved channel 122 than an ink stick that has substantially the entire length of its bottom surface engaged with the feed drive 120 since the sides of the stick are not forced into contact with the feed channel walls. The same benefit extends to a vertically curved or otherwise non-linear portion of a feed channel, where the relieved portion of the surface proximate to the feed drive allows the drive coupler to remain engaged with the drive while the remainder of the ink stick body is less constrained in its movement.
By locating the opening of the drive coupler 104 and the coupler support 108 in a portion of the surface proximate the feed drive and closer to the front of the ink stick as shown in FIG. 6, the ink stick is led by the feed drive through the feed channel without unnecessarily constraining the movement of the middle and rear portion of the ink stick along its longitudinal axis. While this type of movement may be conducive for some feed channel designs, other feed channels may be better accommodated by a drive coupler incorporated in a coupler support that extends from a surface of the ink body near the longitudinal middle of the ink stick. Locating the coupler and its support in this position enables the ink stick to rotate more freely at each end. This feature works equally well with a drive belt or conveyor that has periodic flairs or catch features (not shown). These flairs or features more positively urge the ink stick forward when feed motion is possible. They also slip under or raise the ink slightly to pass beyond the ink stick when feed motion is prevented.
Those skilled in the art will recognize that numerous modifications can be made to the specific implementations described above. 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.

## Claims

1. A solid ink stick comprising:
a meltable ink body having a longitudinal axis;
a coupler support extending away from only a portion of a length of a surface of the meltable ink body; and
a drive coupler positioned within the coupler support at a location that is vertically displaced from the surface of the meltable ink body to enable the drive coupler to be outside the meltable ink body.

2. The solid ink stick of claim 1, the drive coupler further comprising:
an opening in the coupler support that parallels only a portion of the length of the surface of the meltable ink body from which the coupler support extends.

3. The solid ink stick of claim 2, the coupler support extending downwardly from a bottom surface of the meltable ink body.

4. The solid ink stick of claim 2, wherein the opening is semi-circular.

5. The solid ink stick of claim 2, wherein the opening is V-shaped.

6. The solid ink stick of claim 2, wherein the opening is canted with respect to the longitudinal axis of the meltable ink body.

7. The solid ink stick of claim 6, wherein the opening is canted laterally with respect to the longitudinal axis of the meltable ink body.

8. The solid ink stick of claim 6, wherein the opening is canted upwardly with respect to the longitudinal axis of the meltable ink body.

9. The solid ink stick of claim 6, wherein the opening is canted downwardly with respect to the longitudinal axis of the meltable ink body.

10. The solid ink stick of claim 2, wherein the opening is curved with respect to the longitudinal axis of the meltable ink body.

11. A solid ink stick comprising:
a meltable ink body having a longitudinal axis;
a coupler support extending away from only a portion of a length of a surface of the meltable ink body; and
an opening located in the coupler support at a position that is vertically displaced from the surface of the meltable ink body to enable the opening to be outside the meltable ink body.

12. The solid ink stick of claim 11, the coupler support and opening extending from a position on the surface of the meltable ink body that enables pivoting movement of a portion of the meltable ink body about the coupler support.

13. The solid ink stick of claim 12 wherein the coupler support and opening extending from the position on the surface of the meltable ink body enable one end of the meltable ink body to pivot about the coupler support.

14. The solid ink stick of claim 12 wherein the coupler support and opening extending from the position on the surface of the meltable ink body enable two ends of the meltable ink body to pivot about the coupler support.

15. The solid ink stick of claim 11, wherein the opening is semi-circular.

16. The solid ink stick of claim 11, wherein the opening is V-shaped.

17. The solid ink stick of claim 11, wherein the opening is canted with respect to the longitudinal axis of the meltable ink body.

18. The solid ink stick of claim 17, wherein the opening is canted laterally with respect to the longitudinal axis of the meltable ink body.

19. The solid ink stick of claim 17, wherein the opening is canted upwardly with respect to the longitudinal axis of the meltable ink body.

20. The solid ink stick of claim 17, wherein the opening is canted downwardly with respect to the longitudinal axis of the meltable ink body.