WO2019089036A1

WO2019089036A1 - Carriage repositioning

Info

Publication number: WO2019089036A1
Application number: PCT/US2017/059771
Authority: WO
Inventors: Gareth Ryan Kelly
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2017-11-02
Filing date: 2017-11-02
Publication date: 2019-05-09

Abstract

In one example, a carriage repositioning device can include an aperture to receive a stop tab coupled to a carriage of a printing device, a mounting tab within the aperture to couple the carriage repositioning device to the stop tab of the carriage of the printing device, and an interaction surface to interact with a carriage backbone to limit a rotation of the carriage in a particular direction.

Description

CARRIAGE REPOSITIONING Background

[0001] Inkjet printers can deposit quantities of printing fluid onto a printable medium (e.g., paper, plastic, etc.). In some examples, the printing fluid can be deposited utilizing a number of nozzles and/or pens. In some examples, inkjet printers can utilize a carriage to align the number of nozzles and/or pens with the printable medium, in some examples, a misalignment of the number of nozzles and/or pens can result in an image that has a relatively lower image quality compared to when the number of nozzles and/or pens are aligned.

Brief Description of the Drawings

[0002] Figure 1 illustrates an example carriage repositioning device consistent with the present disclosure.

[0003] Figure 2 illustrates an example system for a carriage repositioning device consistent with the present disclosure.

[0004] Figure 3 illustrates an example system for a carriage repositioning device consistent with the present disclosure.

Detailed Description

[0005] A number of systems and devices for carriage repositioning devices are described herein. In some examples, a carriage repositioning device can include an aperture to receive a stop tab coupled to a carriage of the printing device, a mounting tab within the aperture to couple the carriage repositioning device to the stop tab of the carriage of the printing device, and an interaction surface to interact with a carriage backbone to limit a rotation of the carriage in a particular direction. [0008] In some examples, the carriage repositioning devices can be utilized in a printing device. For example, the carriage repositioning devices can be utilized in an inkjet printing device. An inkjet printing device can include a print zone or print area to deposit a printing fluid on a print medium. The print zone of the inkjet printing device can deposit the printing fluid to generate partially dried Inkjet media. In some examples, the print zone can include a carriage that includes a carriage backbone, a number of print nozzles, a number of print pens, among other devices to align the number of print nozzles or print pens with the print medium when depositing the printing fluid on the print medium. In some examples, the carriage can be coupled to the carriage backbone such that the carriage backbone can alter an angle of rotation of the carriage to adjust and align the number of print nozzles or print pens with the print medium, in some examples, the carriage can include a stop tab that interacts with the carriage backbone to prevent misalignment of the carriage, which can cause a misalignment of the number of print nozzles and/or print pens.

[0007] In some examples, the carriage repositioning devices described herein can be coupled to the stop tab of a carriage to alter an interaction point of the stop tab. For example, the stop tab of the carriage can interact with a carriage backbone at a first interaction point when the carriage repositioning device is not coupled to the stop tab. in this example, the stop tab of the carriage can interact with the carriage backbone at a second interaction point when the carriage repositioning device is coupled to the stop tab. In this example, an interaction surface of the carriage repositioning device can interact with the carriage backbone when the carriage repositioning device is coupled to the stop tab of the carriage.

[0008] In some examples, the interaction point of the stop tab can be a functional interaction point (e.g., interaction point that provides a particular image quality, etc.) when the printing device is in an area with a first acceleration due to gravity, but may not be a functional interaction point when the printing device is in an area with a second acceleration due to gravity. For example, the interaction point of the stop tab can be a functional interaction point when the printing device is on the surface of the Earth and experiencing an acceleration due to gravity around 9.8 meters per second squared (m/s²). However, in this example, the interaction point of the stop tab may not be functional when the printing device is not on the surface of the Earth and experiencing a different acceleration due to gravity (e.g.,

approximately 0 m/s², etc.). In some examples, the carriage repositioning devices can alter the interaction point of the stop tab to provide a functional interaction point even when the printing device is experiencing a different acceleration due to gravity.

[0009] The figures herein follow a numbering convention in which the first digit corresponds to the drawing figure number and the remaining digits identify an element or component in the drawing. Elements shown in the various figures herein may be capable of being added, exchanged, and/or eliminated so as to provide a number of additional examples of the present disclosure. In addition, the proportion and the relative scale of the elements provided in the figures are intended to illustrate the examples of the present disclosure, and should not be taken in a limiting sense,

[0010] Figure 1 illustrates an example carriage repositioning device 100 consistent with the present disclosure. The carriage repositioning device 100 can be a single piece of material that includes an aperture 102, an interaction surface 108, and/or a mounting tab 104. In some examples, the material can be a nylon materia! or other type of material with a relatively low friction level and/or a relatively high resistance to wear. For example, the carriage repositioning device 100 can comprise a po!yamide (e.g., polyamide-12, polyamide-12 glass bead, etc.).

[0011] In some examples, the carriage repositioning device 100 can be utilized to alter a size and/or shape of a stop tab that is coupled to a carriage of a printing device. As described herein, the carriage repositioning device 00 can be coupled to the stop tab of the carriage to alter an interaction point of the stop tab. In some examples, the altered interaction point can be utilized to align print nozzles or print pens coupled to the carriage with print medium that is receiving deposited printing fluid from the print nozzles or print pens.

[0012] In some examples, the carriage repositioning device 100 can include an aperture 102. in some examples, the aperture 102 can be utilized to receive the stop tab of a carriage. For example, the stop fab of the carriage can be inserted into the aperture 102. In some examples, the carriage repositioning device 100 can surround the stop fab of the carriage. For example, the aperture 102 can include a top portion, a bottom portion and two side portions that surround the stop tab of the carriage. In this example, the top portion, bottom portion, and two side portions can provide an increased area for the stop tab of the carriage and alter an interaction point of the stop tab. [0013] In some examples, the aperture 102 can include a mounting tab 104. In some examples, the mounting tab 104 can be utilized to couple the carriage repositioning device 100 to the stop tab of the carriage. For example, the stop tab can include an indentation or receiving tab to receive the mounting tab 104. In some examples, the mounting tab 104 can include a protrusion that can be received by the indentation of the stop tab. For example, the mounting tab can couple to the indentation of the stop tab when the stop tab is positioned within the aperture 102.

[0014] In some examples, the carriage repositioning device 100 can include an interaction surface 106. In some examples, the interaction surface 106 can interact with a carriage backbone to limit a rotation of the carriage in a particular direction. In some examples the interaction surface 106 can interact with the same or similar location on the carriage backbone as the stop tab when the carriage repositioning device 00 is not coupled to the stop tab. For example, the stop tab can interact with a ledge or flat surface of the carriage backbone, in this example, the interaction surface 106 can interact with the same ledge or fiat surface of the carriage backbone.

[0015] In some examples, the interaction surface 106 can alter an angle of rotation of a carriage coupled to the carriage backbone. For example, the carriage of the printing device can rotate in a particular direction via a rotatable connection (e.g., shaft, bearing, etc.) with a carriage backbone, in this example, the carriage of the printing device can be coupled to the carriage backbone by a shaft (e.g., cylinder, pin, etc.) and/or bearing that allows the carriage to rotate on the shaft or bearing, in some examples, the interaction surface 106 can interact with a portion of the carriage backbone when the carriage is rotating beyond a particular rotation angle. In some examples, the interaction surface 106 can physically interact with the carriage backbone to prevent the carriage from exceeding a threshold rotation angle in a particular direction.

[0016] In some examples, the interaction surface 06 can be in contact with the carriage backbone when the nozzles and/or printing pens of the carriage are aligned with the print medium. For example, the interaction surface 106 can increase a size of the stop tab coupled to the carriage to decrease an angle of rotation in the particular direction. In some examples, the carriage repositioning device 00 can increase an area of the stop tab when the carriage repositioning device 100 is coupled to the stop tab. For example, the height and width of the carriage repositioning device 00 can provide an area or size that is greater than the area of the stop tab. in this example, the area of the stop tab can be the area within the aperture 102 and the area of the stop tab coupled to the carriage repositioning device 100 can be the exterior of the carriage repositioning device 100. in some examples, the interaction surface 106 can be in contact with the carriage backbone to maintain a pen to paper spacing (PPS) and an orthogonality of a plane of a pen with the print medium. As used herein the PPS can be a distance between a surface of the print medium and a location of a pen coupled to the carriage. As used herein, the orthogonality of the plane of a pen with the print medium can include an angle between surface of the print medium and the location of a plurality of pens coupled to the carriage.

[0017] In some examples, the PPS and the orthogonality of the carriage can correspond to a print quality of an image or text printed on the print medium. For example, the image quality can decrease when the PPS and/or the orthogonality of the carriage are outside corresponding threshold values. In some examples, the PPS can include a threshold range with an upper threshold value and a lower threshold value. For example, the threshold range of the PPS can be a range between 1 ,6 millimeters (mm) and 1.8 mm. In this example, the lower threshold value can be 1.6 mm and the upper threshold value can be 1.8 mm.

[0018] In some examples, the interaction surface 106 can allow the carriage to rotate for maintenance of the carriage or storage when the printing device is not in use. In some examples, the carriage repositioning device 100 can prevent the carriage from over rotating or rotating beyond a particular threshold, but the interaction surface 106 can allow the carriage to be moved along the carriage backbone and rotate when maintenance is being performed on the carriage. For example, the carriage repositioning device 100 can allow the carriage to be moved to a maintenance area and allow the carriage to rotate such that the pens can be capped or replaced. In this example, the printing device can include instructions to move the carriage to a maintenance area such that a capping function can be performed without having to remove the carriage repositioning device 100.

[0019] Figure 2 illustrates an example system 220-1 , 220-2 for a carriage repositioning device 200 consistent with the present disclosure. In some examples, the system 220-1 can illustrate a stop tab 210-1 that is not coupled to a carriage repositioning device 200. In some examples, the system 220-2 can illustrate a stop tab 2 0-2 that is coupled to a carriage repositioning device 200.

[0020] As described herein, the stop tab 210-1 can be utilized to prevent a carriage 212-1 from rotating beyond a threshold rotation angle when, as illustrated by the system 220-1 , the carriage repositioning device 200 is not coupled to the stop tab 210-1. For example, the stop tab 210-1 can interact with a portion of a carriage backbone 214-1. In this example, the stop tab 210-1 can move in a downward direction as illustrated in Figure 2 and can make contact with the portion of the carriage backbone 214-1 to stop the carriage 212-1 from rotating past a particular threshold rotation angle. In some examples, the system 220-1 can rely on a gravitational force to move the carriage 212-1 within a particular PPS range as described herein. For example, the stop tab 210-1 can prevent the carriage 212-1 from rotating beyond a threshold rotation angle, but the gravitational force can move the carriage 212-1 such that the stop tab 210-1 moves in an upward direction as illustrated in Figure 2. In some examples, the gravitational force can be

approximately 9.8 m/s² when the system 220-1 is on a surface of the Earth.

[0021] In some examples, the gravitational force can position the carriage 212-1 such that a distance 216 exists between the stop tab 210-1 and the portion of the carriage backbone 214-1. In some examples, the distance 216 can correspond to a particular PPS and/or orthogonality of the carriage 212-1. For example, the distance 216 can correspond to the PPS being within a range of approximately 1.6 mm and 1.8 mm. Thus, the system 220-1 can rely on a particular gravitational force to align the nozzles and/or printing pens of the carriage 212-1 with print medium.

[0022] In some examples, the stop tab 210-1 can include an indentation 213. in some examples, the indentation 213 can be coupled to a mounting tab (e.g., mounting tab 104 as illustrated in Figure 1 , etc.) of the carriage repositioning device 200. For example, the carriage repositioning device 200 can include a mounting tab within an aperture that corresponds to the indentation 213, In this example, the mounting tab of the carriage repositioning device 200 can couple the carriage repositioning device 200 to the stop tab 210-1 as illustrated in system 220-2.

[0023] The system 220-2 can illustrate when the carriage repositioning device 200 is coupled to the stop tab 220-2. in some examples, the system 220-2 can be utilized to maintain a PPS and/or orthogonality of the carriage 212-2 despite a gravitational force applied to the system 220-2. For example, the system 220-2 can provide an acceptable PPS and/or orthogonality of the carriage 212-2 when the system 220-2 is on the surface of the Earth and/or when the system 220-2 is at a location that is less affected by the gravitational force of the Earth (e.g., outer space, space station, greater than 330 kilometers from the surface of the Earth, etc.). For example, the system 220-2 can utilize the carriage repositioning device 200 to maintain a distance 218. in this example, the distance 218 can be the same or similar distance as distance 216 when the system 220-1 is on the surface of the Earth and affected by a particular gravitational force.

[0024] In some examples, the carriage repositioning device 200 can surround an area of the stop tab 210-2. For example, the stop tab 210-2 can be positioned within an aperture (e.g., aperture 102 as illustrated in Figure 1). In this example, the carriage repositioning device 200 can alter an interaction point of the stop tab 210-2 by replacing an interaction surface of the stop tab 210-2 with the interaction surface 206 of the carriage repositioning device 200. In some examples, the interaction surface 206 can be a surface of the carriage repositioning device 200 that can physically interact or make contact with the portion of the carriage backbone 214-2. in some examples, a distance 218 can be provided when the interaction surface 206 is in contact with the portion of the carriage backbone 214-2. As descried herein, the distance 218 can correspond to a particular PPS and/or orthogonality that is within a particular PPS range and/or orthogonality range. For example, the distance 218 can provide a nominal rotation angle (e.g., angle the provides a PPS range and/or orthogonality range that is within a threshold range, etc.) that provides a particular pen to paper spacing and a particular orthogonality of the printer carriage with a relative gravitation of zero.

[0025] In some examples, the carriage repositioning device 200 can include a separation tab 219 that can be positioned between the printer carriage 212-2 and the carriage backbone 214-2. In some examples, the separation tab 219 can prevent the printer carriage 212-2 from moving in a particular direction. In some examples, the separation tab 219 can be utilized to prevent the printer carriage 212-2 from contacting the carriage backbone 214-2. in some examples, the separation tab 219 can be positioned to contact a surface of the carriage backbone 2 4-2 when the interaction surface 206 is in contact with the carriage backbone 2 4-2,

[0028] In some examples, the system 220-2 can include a printer carriage 212-2 coupled to a carriage backbone 214-2. In some examples, the system 220-2 can include a stop tab 210-2 coupled to the printer carriage 212-2 to interact with the carriage backbone 214-2 to prevent rotation of the printer carriage 212-2 over a first rotation angle. For example, the first rotation angle can be the rotation angle provided when the stop tab 210-1 is not coupled to the carriage repositioning device 200 and the stop tab 210-1 makes contact with the carriage backbone 214-1. In some examples, the system 220-2 can include a carriage repositioning device 200 that includes a mounting tab to couple the carriage repositioning device 200 to the stop tab 210-2. In some examples, the repositioning device 200 can include an interaction surface 206 to prevent rotation of the printer carriage 212-2 over a second rotation angle when the carriage repositioning device 200 is coupled to the stop tab. in some examples, the second rotation angle can correspond to an angle of the carriage 212-2 when the distance 218 is provided.

[0027] As described herein, the system 220-2 can be utilized to provide a particular PPS and/or orthogonality of a carriage 212-2 despite a gravitational force on the system 220-2. The system 220-2 can be utilized on the surface of the Earth and provide a particular PPS and/or orthogonality of the carriage 212-2 and also be utilized beyond 330 kilometers from the surface of the Earth and provide the particular PPS and/or orthogonality of the carriage 212-2. In this way, the system 220-2 can be utilized independent of a gravitational force.

[0028] Figure 3 illustrates an example system 330-1 , 330-2 for a carriage repositioning device 300 consistent with the present disclosure. In some examples, the system 330-1 can illustrate portion of a printing device. In some examples, the system 330-1 can illustrate a portion of a printing device in zero gravity or when the printing device is in a location that is less affected by Earth's gravitational force compared to a surface of the Earth. In some examples, the system 330-1 can illustrate a stop tab 310 that is not coupled to a carriage repositioning device 300. In some examples, the system 330-2 can illustrate when the stop tab 310 is coupled to the carriage repositioning device 300 as described herein.

[0029] In some examples, the system 330-1 can include a printer carriage 342-1. In some examples, the printer carriage 342-1 can include a print area 334-1. in some examples, the print area 334-1 can include a number of print nozzles and/or print pens as described herein. For example, the print area 334-1 can be an area where the system 330-1 can deposit printing fluid on a print medium 340-1. In some examples, the printer carriage 342-1 can rotate on an axis of rotation. For example, the printer carriage 342-1 can rotate on a shaft 343-1. In this example, the printer carriage 342-1 can rotate in a clockwise direction and/or a counterclockwise direction. As illustrated in Figure 3, the print area 334-1 can move further away from the print medium 340-1 when the printer carriage 342-1 moves in a counterdockwise direction and the print area 334-1 can move closer to the print medium 340-1 when the printer carriage 342-1 moves in a clockwise direction around the shaft 343-1.

[0030] In some examples, the printer carriage 342-1 can be coupled to a bracket 312-1. in some examples, the printer carriage 342-1 and the bracket 312-1 can be a single device or element. For example, the bracket 312-1 can be part of the printer carriage 342-1 , In some examples, the bracket 312-1 of the printer carriage 342-1 can include a stop tab 310. As described herein, the stop tab 310 can interact with a carriage backbone 314-1 to prevent the printer carriage 342-1 and/or bracket 312-1 from rotating beyond a threshold rotation angle on the shaft 343-1. For example, the stop tab 310 can physically hit or make contact with the carriage backbone 314-1 and stop the printer carriage 342-1 from rotating further in a counter clockwise direction as illustrated in Figure 3.

[0031] As described herein, the position of the stop tab 310 can correspond to a position of the printer carriage 342-1 and/or a print area 334-1 in relation to the print medium 340-1. For example, the position of the stop tab 310 can alter a distance 336, 338 between the print area 334-1 and the print medium 340-1. In some examples, the system 330-1 can rely on a gravitational force to move the printer carriage 342-1 in a clockwise direction as illustrated in Figure 3. For example, the gravitational force can decrease the distance 338, 338 such that the print area 334-1 has a particular PPS and/or orthogonality as described herein. In some examples, the particular PPS for a relatively high image quality on the print medium can correspond to a particular distance between the stop tab 310 and the carriage backbone 314-1. However, as described herein, the system 330-1 can rely on gravity to provide the particular distance between the stop tab 310 and the carriage backbone 314-1. Thus, the stop tab 310 can be in contact with the carriage backbone 314-1 in zero gravity and a corresponding PPS and/or orthogonality may be outside a threshold PPS and/or threshold orthogonality when the system 330-1 is in an area with a relatively lower gravitational force than the surface of the Earth, [0032] In some examples, the distance 336 or the distance 338 can exceed a threshold distance. For example, the distance 336 and/or the distance 338 can be greater than 1.8 mm. In some examples, the orthogonality of the print area 334-1 with the print medium 340-1 can correspond to a difference between the distance 336 and the distance 338. For example, the absolute value of the difference between the distance 336 and the distance 338 can represent the orthogonality of the print area 334-1 with the print medium 340-1. In some examples, the threshold orthogonality can be an absolute value that is less than 0.5 mm of the difference between the distance 336 and the distance 338. In some examples, the difference between 336 and the distance 338 can have an absolute value that is 1.8 mm when the system 330-1 is in zero gravity. Thus, the value that represents the orthogonality can be greater than the threshold value when the system 330-1 is in zero gravity.

[0033] In some examples, the system 330-2 can include a print carriage 342-2 comprising a number of printheads and corresponding pen nozzles (e.g., print area 334-2, etc.) to deposit printing fluid on a print medium 340-2. In some examples, the system 330-2 can include a carriage backbone 314-2 coupled to the print carriage 342-2 to alter an angle of the print carriage 342-2. in some examples, the system 330-2 can include a stop tab (e.g., stop tab 310) coupled to the print carriage 342-2 or bracket 312-2 that interacts with a portion of the carriage backbone 314-2 to prevent the print carriage 342-2 from exceeding a first rotational angle around the shaft 343-2. In addition, the system 330-2 can include a carriage repositioning device 300 coupled to the stop tab (covered by the carriage repositioning device 300). In some examples, an interaction surface (e.g., interaction surface 106 as referenced in Figure 1 , etc.) of the carriage repositioning device 300 coupled to the stop fab interacts with the carriage backbone 314-2 to prevent the print carriage 342-2 from exceeding a second rotational angle, in some examples, the first rotation angle is represented in system 330-1 and the second rotation angle is represented in system 330-2.

[0034] In some examples, the carriage repositioning device 300 can provide a distance between the stop tab and the carriage backbone 314-2. As described herein, the distance between the stop tab and the carriage backbone 314-2 can be provided by an interaction surface, in some examples, the interaction surface of the carriage repositioning device 300 can alter the rotation angle of the print carriage 342-2 when the interaction surface is in contact with the carriage backbone 314-2. Thus, the system 330-2 does not have to rely on gravity to rotate the print carriage 342-2 in a clockwise direction to achieve a particular PPS and/or orthogonality as described herein.

[0035] As described herein, a distance 337, 339 can be a distance between a surface of the print area 334-2 and the print medium 340-2. In some examples, the carriage repositioning device 300 can provide a distance between the stop tab and the carriage backbone 314-2 such that the distance 337, 339 are within a particular threshold range. For example, the distance 337 and the distance 339 can be within a distance range of 1 .6 mm to 1.8 mm. As described herein, the distance 337 and the distance 339 can correspond to a PPS of the print area 334-2. in some examples, the carriage repositioning device 300 can provide a particular orthogonality of the print area 334-2 with respect to the print medium 340-2. For example, the carriage repositioning device 300 can provide a distance between the stop tab and the carriage backbone 314-2 such that the absolute value of the difference between the distance 337 and the distance 339 is less than 0.5 mm.

[0038] In some examples, when the PPS and orthogonality are within a threshold range, the print area 334-2 or print carriage 342-2 can be in a nominal rotational angle. In some examples, the nominal rotational angle can be less than the second rotational angle (e.g., rotational angle generated by the spacing of the carriage repositioning device 300) to align the number of printheads and

corresponding pen nozzles of the print area 334-2 with a plane of the print medium 340-2. In some examples, the carriage repositioning device 300 can interact with the carriage backbone 314-2 to provide the nominal rotational angle without gravitational assistant (e.g., without a gravitational force, etc.).

[0037] In some examples the carriage repositioning device 300 can prevent the stop tab from contacting the carriage backbone 314-2 when the carriage repositioning device 300 is coupled to the stop tab. As described herein, the print area 334-2 can be out of alignment (e.g., PPS and/or orthogonality are outside a corresponding threshold value, etc.) when the stop tab is contacting the carriage backbone 314-2 as illustrated in system 330-1. Thus, the carriage repositioning device 300 can prevent the print area 334-2 or print carriage 342-2 from being misaligned in zero gravity by preventing the stop tab from contacting the carriage backbone 314-2.

[0038] In some examples, the carriage repositioning device 300 may not prevent the carriage 342-2 from entering a maintenance area or from rotating to perform a number of maintenance operations. For example, the carriage

repositioning device 300 can allow the carriage 342-2 to move along the carriage backbone 314-2 to a maintenance area, in some examples, the carriage

repositioning device 300 can allow the carriage 342-2 to rotate to a capping rotation angle. For example, when the system 330-2 is in a particular state, the printer pens or nozzles of the print area 334-2 can be capped to prevent damage to the printer pens, in this example, the carriage 342-2 is capable of rotating on the shaft 343-2 to allow the printer pens to be capped during a capping process.

[0039] The above specification, examples and data provide a description of the method and applications, and use of the system and method of the present disclosure. Since many examples can be made without departing from the spirit and scope of the system and method of the present disclosure, this specification merely sets forth some of the many possible example configurations and implementations.

Claims

What is claimed:

1. A carriage repositioning device, comprising:

an aperture to receive a stop tab coupled to a carriage of a printing device;

a mounting fab within the aperture to couple the carriage repositioning device to the stop tab of the carriage of the printing device; and

an interaction surface to interact with a carriage backbone to limit a rotation of the carriage in a particular direction.

2. The carriage repositioning device of claim 1 , wherein the carriage

repositioning device increases an area of the stop tab when the carriage

repositioning device is coupled to the stop tab.

3. The carriage repositioning device of claim 1 , wherein the mounting tab is coupled to an indentation of the stop tab.

4. The carriage repositioning device of claim , wherein the interaction surface allows the carriage to rotate for maintenance of the carriage.

5. The carriage repositioning device of claim 1 , wherein interaction surface interacts with the carriage backbone to maintain pen to paper spacing and an orthogonality of a plane of a pen with print medium.

6. A system, comprising:

a printer carriage coupled to a carriage backbone;

a stop tab coupled to the printer carriage to interact with the carriage backbone to prevent rotation of the printer carriage over a first rotation angle; and a carriage repositioning device comprising:

a mounting tab to couple the carriage repositioning device to the stop tab; and

an interaction surface to prevent rotation of the printer carriage over a second rotation angle when the carriage repositioning device is coupled to the stop tab.

7. The system of claim 6, wherein a nominal rotation angle range for the printer carriage is less than the second rotation angle.

8. The system of claim 7, wherein the nominal rotation angle provides a particular pen to paper spacing and a particular orthogonality of the printer carriage with a relative gravitation of zero.

9. The system of claim 8, wherein the interaction surface allows movement of the carriage along the carriage backbone in a first direction and a second direction that is opposite the first direction. 0. The system of claim 8, wherein the carriage repositioning device includes a separation tab that is positioned between the printer carriage and the carriage backbone.

1 . The system of claim 6, wherein the printer carriage is serviceable when the carriage repositioning device is coupled to the stop tab.

12. A printing device, comprising:

a print carriage comprising a number of printheads and corresponding pen nozzles to deposit printing fluid on a print medium;

a carriage backbone coupled to the print carriage to alter an angle of the print carriage;

a stop tab coupled to the print carriage that interacts with a portion of the carriage backbone to prevent the print carriage from exceeding a first rotational angle; and

a carriage repositioning device coupled to the stop tab, wherein an interaction surface of the carriage repositioning device coupled to the stop tab interacts with the carriage backbone to prevent the print carriage from exceeding a second rotational angle.

13. The printing device of claim 12, wherein the carriage repositioning device prevents the stop tab from contacting the carriage backbone when the carriage repositioning deice is coupled to the stop tab,

14. The printing device of claim 12, wherein a nominal rotational angle is less than the second rotational angle to align the number of printheads and

corresponding pen nozzles with a plane of the print medium.

15. The printing device of claim 13, wherein the carriage repositioning device interacts with the carriage backbone to provide the nominal rotational angle without gravitational assistant.