# Patent

## Title
Drive belt systems including belt stretch management apparatus and methods thereof

## Abstract

Drive belt systems and methods thereof are disclosed. Drive belt systems and methods thereof include driving a continuous belt around a drive pulley member and an idler pulley member by the drive pulley member and transporting a transport unit and/or reciprocating carriage unit coupled to the continuous belt in a first direction away from the drive pulley member. Drive belt systems and methods thereof also include applying at least a force to the belt in a traverse direction thereto to direct a portion of the belt about the drive pulley member by a belt stretch management apparatus coupled to the transport unit and/or reciprocating carriage unit.

## Background
BACKGROUND
Drive belt systems move a belt about pulley members to transport a transport unit attached to the belt. The transport unit may include a reciprocating carriage unit to hold a printhead. Periodically, the belt may stretch and enter a slack state such that a slack loop may form in the belt and a wrap angle of the belt about a pulley member may decrease.



BRIEF DESCRIPTION OF THE DRAWINGS
Non-limiting examples of the present disclosure are described in the following description, read with reference to the figures attached hereto and do not limit the scope of the claims. In the figures, identical and similar structures, elements or parts thereof that appear in more than one figure are generally labeled with the same or similar references in the figures in which they appear. Dimensions of components and features illustrated in the figures are chosen primarily for convenience and clarity of presentation and are not necessarily to scale. Referring to the attached figures:
FIGS. 1A and 1B are schematic views illustrating a drive belt system in a slack state without a belt stretch management apparatus thereof according to examples.
FIG. 2 is a block diagram illustrating a drive belt system according to an example.
FIG. 3A is a schematic view illustrating the drive belt system of FIG. 2 in which a belt is moving in a first direction according to an example.
FIG. 3B is a schematic view illustrating the drive belt system of FIG. 2 in which the belt is moving in a second direction according to an example.
FIG. 4 is a perspective view illustrating a belt stretch management apparatus of the drive belt system of FIG. 2 in an uninstalled state according to an example.
FIG. 5 is a block diagram illustrating a drive belt system usable with an image forming apparatus according to an example.
FIG. 6 is a perspective view illustrating a reciprocating carriage unit of the drive belt system of FIG. 5 according to an example.
FIG. 7 is a schematic view illustrating the drive belt system of FIG. 5 in which a belt is moving in a first direction according to an example.
FIG. 8 is a flowchart illustrating a method of managing belt stretch in a drive belt system according to an example.



DETAILED DESCRIPTION
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is depicted by way of illustration specific examples in which the present disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.
Drive belt systems move a belt about pulley members to transport a transport unit attached to the belt. The transport unit may include a reciprocating carriage unit to hold a printhead. Periodically, under drive loads the belt may stretch and enter a slack state such that a slack loop may form in the belt and a wrap angle of the belt about a pulley member may decrease. A slack state may also be due to an effective increase in belt length, for example, by flexing of structure such as pulley members supporting the belt and a bending of a cantilevered drive motor shaft under load. Thus, a center-to-center spacing between the respective pulley members is decreased.
Belt stretch is an effective increase to a length of a belt due to an application of forces and/or a reduction of a distance between respective pulley members. The slack state of the belt, for example, due to belt stretch gives rise to a decrease in a respective belt wrap angle. The decrease in the respective belt wrap angle reduces an amount of force a drive belt system can transmit and/or support. If such a force is less than a force being applied by a driving element such as a drive motor, skipping and/or slippage of the belt may occur. Consequently, inadequate management of belt stretch may lead to unwanted slippage and/or skipping of the belt on the respective pulley member.
Some belt tension devices may increase tension forces to address increased weight loads of the transport unit in a loaded state. Such increased tension forces, however, may contribute to system motor failures and use of expensive motors and drive electronics. Some spring-loaded rollers may address unwanted belt slippage and skipping. Such spring-loaded rollers, however, may increase cost and maintenance due to an increase amount of moving components. Accordingly, a cost-effective and low maintenance solution to manage belt stretch to reduce a potential for a drive belt system to enter a slack state resulting in belt skipping and slippage is desired.
In examples, the drive belt system includes, among other things, a belt stretch management apparatus coupled to a transport unit. The belt stretch management apparatus applies at least a first force to a belt in a traverse direction thereto to direct a portion of the belt about a drive pulley member. The first force directs the portion of the belt around the drive pulley member in response to formation of belt stretch corresponding to transportation of a transport unit along with the belt stretch management apparatus in the first direction. That is, the formation of belt stretch to a drive-side belt portion (e.g., portion of the belt between the transport unit and the drive pulley member) is managed by reducing a potential of a wrap angle about the drive pulley member to decrease due to belt stretch and the drive belt system to enter a slack state.
The belt stretch management apparatus may include a unitary spring member that applies minimal forces to the belt. Such minimal forces for example, maintain or increase the wrap angle about the respective pulley member when primary tension forces established by the respective pulley members are weakened in localized sections of the belt due to belt stretch. Such minimal forces generally do not interfere with the primary tension forces absent the presence of belt stretch. Consequently, the belt drive system provides a cost-effective and low maintenance solution to manage belt stretch to reduce a potential for a drive belt system to enter a slack state resulting in belt skipping and slippage. Additional slack may be created by an effective increase in a length of the belt due to a reduction of a center-to-center distance between the drive pulley member and the idler pulley member. Such a reduction in the distance between the respective pulley members may be due to structural deflections such a bending of a drive motor shaft, and the like (not illustrated).
FIGS. 1A and 1B are schematic views illustrating a drive belt system in a slack state without a belt stretch management apparatus thereof according to examples. Referring to FIGS. 1A and 1B, a drive belt system 100 includes a drive pulley member 10 having a drive axis 10a, an idler pulley member 12 having an idler axis 12a, a belt 14, and a transport unit 16. The idler pulley member 12 may be a fixed position idler pulley, a spring-loaded idler pulley, and the like. Referring to FIG. 1A, the belt 14 is moving the transport unit 16 in a first direction d1. Referring to FIG. 1B, the belt 14 is moving the transport unit 16 in a second direction d2. Periodically, the belt 14 may stretch, for example in response to belt stiffness, acceleration, and/or flexing caused by the transport unit 16 and enters a slack state due to inadequate management of belt stretch. In some examples, additional idler pulley members and/or drive pulley members may be used.
The slack state may correspond to a formation of slack loop 14a1, 14a2 and 14a3 in the belt 14 resulting in a decrease in an amount of wrap angle of the belt 14 about a respective pulley member 10. That is, a wrap angle αd2 about the drive pulley member 10 after the formation of belt stretch is less than a wrap angle αd1 about the drive pulley member 10 before the formation of belt stretch. In some examples, the belt 14 may tend to stretch to form a slack loop 14a1 on a drive-side belt portion 14b during movement of the belt 14 in the first direction d1 as illustrated in FIG. 1A. In some examples, the belt 14 may tend to stretch to form a slack loop 14a2 on an idler-side belt portion 14c and an extended belt portion 14d (e.g., a portion of the belt 14 disposed opposite the transport unit 16 and between the drive pulley member 10 and the idler pulley member 12) during movement of the belt 14 in the second direction d2 as illustrated in FIG. 1B.
Such belt stretch may result in a portion of the drive-side belt portion 14b to move away from the drive pulley member 10 reducing an ability of the drive belt system to handle the provided torque. Thus, the lack of adequate management of belt stretch may lead to unwanted slippage and/or skipping of the belt 14 on the respective pulley member 10 due to the drive belt system 100 entering a slack state. Such slipping and/or skipping may degrade the respective pulley member 10, degrade the belt 14, stall the transportation of the transport unit 16, and/or emit objectionable noises.
FIG. 2 is a block diagram illustrating a drive belt system according to an example. FIGS. 3A and 3B are schematic views illustrating the drive belt system of FIG. 2 in which a belt is moving in a first direction (FIG. 3A) and a second direction (FIG. 3B), respectively, according to examples. Referring to FIG. 2, in some examples, a drive belt system 200 includes a drive pulley member 10 having a drive axis 10a, an idler pulley member 12 having an idler axis 12a, a belt 14, a transport unit 16, and a belt stretch management apparatus 28.
Referring to FIGS. 3A and 3B, in some examples, the drive pulley member 10 rotates about the drive axis 10a thereof. The idler pulley member 12 rotates about the idler axis 12a thereof. The belt 14 forms a continuous loop and moves about the drive pulley member 10 and the idler pulley member 12 in response to rotation by the drive pulley member 10. For example, a drive motor (not illustrated) may be connected to the drive pulley member 10 to rotate the drive pulley member 10 about the drive axis 10a. The transport unit 16 may be transported in a first direction d1 away from the drive pulley member 10 as illustrated in FIG. 3A and in a second direction d2 towards the drive pulley member 10 as illustrated in FIG. 3B. The transport unit 16 is coupled to and transported by the belt 14. In some examples, the transport unit 16 may include a reciprocating carriage unit 56 (FIG. 6).
Referring to FIG. 3A, the belt stretch management apparatus 28 is coupled to and moves with the transport unit 16. The belt stretch management apparatus 28 applies at least one force to the belt 14 in a transverse direction thereto to direct a portion of the belt 14 about at least one of the drive pulley member 10 and the idler pulley member 12 in response to a formation of belt stretch to the belt 14. For example, the belt stretch management apparatus 28 may manage belt stretch (e.g., an effective increase to a length of the belt 14 by an application of forces and/or a reduction of distance between the drive pulley member 10 and the idler pulley member 12) by applying at least a first force f1 to the belt 14 to direct a portion of the belt 14 about the drive pulley member 10. That is, a formation of belt stretch to the drive-side belt portion 14b is managed by further wrapping a portion of the drive-side belt portion 14b about the drive pulley member 10. Thus, the potential for the wrap angle αd about the drive pulley member 10 to decrease due to the belt stretch and the drive belt system 200 to enter a slack state is reduced.
Referring to FIG. 3B, in some examples, the belt stretch management apparatus 28 may also manage belt stretch by applying at least a second force f2 to the belt 14 to direct a portion of an idler-side belt portion 14c (e.g., portion of the belt 14 disposed between the transport unit 16 and the idler pulley member 12) about the idler pulley member 12 in response to the formation of belt stretch due to the transportation of the transport unit 16 in the second direction d2. That is, a formation of belt stretch to the idler-side belt portion 14c is managed by further wrapping a portion of the idler-side belt portion 14c about the idler pulley member 12.
Additionally, in some examples, adequate use of increased belt length due to belt stretch by the second arm member 28b of the belt stretch management apparatus 26 results in the respective wrap angle αd about the drive puller member 10 before and after the formation of belt stretch being approximately equal. For example, in some examples, belt stretch may correspond to an increase amount of belt length corresponding to a length b plus a length c minus a length a. Due to adequate use of the belt stretch by the belt stretch management apparatus 58, a length of the extended belt portion 14d (e.g., a portion of the belt 14 disposed opposite the transport unit 16 and between the drive pulley member 10 and the idler pulley member 12) may remain the same (e.g. length d) before and after the formation of belt stretch.
In some examples, the forces f1 and f2 applied to the belt 14 by the belt stretch management apparatus 28 may be minimal. Such minimal forces f1 and f2 may be to direct the respective portions of the belt 14 about the respective pulley members 10 and 12 and not to provide primary tension forces to the belt 14 which are generally provided by the setting of the respective pulley members 10 and 12. Accordingly, in some examples, the minimal forces f1 and f2 applied by the belt stretch management apparatus 28 may offset the periodic formation of belt stretch.
Referring to FIG. 3A, in some examples, the belt stretch management apparatus 28 includes a first arm member 28a, a second arm member 28b and a middle member 28c. The middle member 28c is coupled to the transport unit 16 such that the middle member 28c is disposed between and connected to the first arm member 28a and the second arm member 28b. The first arm member 28a extends from the transport unit 16 to a drive-side belt portion 14b disposed between the transport unit 16 and the drive pulley member 10. The first arm member 28a is in contact with the drive-side belt portion 14b. 
The first arm member 28a may apply the first force f1 approximately perpendicular (e.g., an angle in a range from about eighty to about one hundred degrees) to the drive-side belt portion 14b that it contacts to direct a portion of the drive-side belt portion 14b about the drive pulley member 10 in response to the formation of belt stretch to the belt 14 due to transportation of the transport unit 16 in the first direction d1. The first arm member 28a reduces the potential of the wrap angle αd about the drive pulley member 10 to decrease due to belt stretch by maintaining or increasing an amount of the respective wrap angle αd that existed prior to the formation of belt stretch. Thus, the potential for the drive belt system 200 to enter a slack state is reduced.
Referring to FIG. 3A, in some examples, the second arm member 28b extends from the transport unit 16 to an idler-side belt portion 14c disposed between the transport unit 16 and the idler pulley member 12. The second arm member 28b is in contact with the idler-side belt portion 14c. The second arm member 28b may apply the second force f2 approximately perpendicular (e.g., at an angle in a range from about eighty to about one hundred degrees) to the idler-side belt portion 14c that it contacts to direct a portion of the idler-side belt portion 14c about the idler pulley member 12. For example, the second arm member 28b may direct the portion of the idler-side belt portion 14c about the idler pulley member 12 in response to a formation of belt stretch to the idler-side portion 14c due to transportation of the transport unit 16 in the second direction d2.
Referring to FIG. 3B, the second arm member 28b reduces the potential of the wrap angle αi about the idler pulley member 12 to decrease due to belt stretch by maintaining or increasing an amount of the respective wrap angle αi that existed prior to the formation of belt stretch. Additionally, in some examples, the maintaining of the respective wrap angle αd about the drive puller member 10 before and after formation of belt stretch approximately equal keeps the amount of wrap of the belt 14 about the drive pulley member 10 approximately unchanged. Thus, the potential for the drive belt system 200 to enter a slack state is reduced.
FIG. 4 is a perspective view illustrating the belt stretch management apparatus of the drive belt system of FIG. 2 in an uninstalled state according to an example. As illustrated in FIG. 4, in an uninstalled state, the belt stretch management apparatus 28 is not coupled to the transport unit 16 and does not engage the belt 14. As illustrated in FIGS. 3A and 3B, in an installed state, the belt stretch management apparatus 28 is coupled to the transport unit 16 and engages the belt 14. Referring to FIG. 4, in some examples, the belt stretch management apparatus 28 is a unitary spring member, for example, formed of sheet metal. In some examples, the belt stretch management apparatus 28 may be in a form of a multi-piece apparatus. The belt stretch management apparatus 28 may include a first arm member 28a, a second arm member 28b and a middle member 28c. The middle member 28c is disposed between and connected to the first arm member 28a and the second arm member 28b. The middle member 28c forms an angle with each one of the first arm member 28a and the second arm member 28b. 
As illustrated in FIGS. 3A and 3B, in the installed state, the middle member may be coupled to the transport unit 16, the first arm member 28a may extend from the transport unit 16 to a drive-side belt portion 14b disposed between the transport unit 16 and the drive pulley member 10, and the second arm member 28b may extend from the transport unit 16 to an idler-side belt portion 14c disposed between the transport unit 16 and the idler pulley member 12. Also, in the installed state, the first arm member 28a may contact the drive-side belt portion 14b to apply the first force f1 in an approximately perpendicular direction thereto and the second arm member 28b may contact the idler-side belt portion 14c to apply the second force f2 in an approximately perpendicular direction thereto.
The first arm member 28a may include a first end arm portion 28d to contact the belt 14 and the second arm member 28b may include a second end arm portion 28e to contact the belt 14. The first end arm portion 28d may form an angle with an other portion of the first arm member 28a and the second end arm portion 28e may form an angle with an other portion of the second arm member 28b. For example, the first end arm portion 28d and the second end arm portion 28e may provide a smooth rounded surface for the belt 14 against which to move. In some examples, the first end arm portion 28d and the second end arm portion 28e may include a roller (not illustrated).
FIG. 5 is a block diagram illustrating a drive belt system usable with an image forming apparatus according to an example. Referring to FIG. 5, in some examples, a drive belt system 500 includes a drive pulley member 10 having a drive axis 10a, an idler pulley member 12 having an idler axis 12a, a belt 14, a reciprocating carriage unit 56, and a belt stretch management apparatus 58. The drive belt system 500 may be usable with an image forming apparatus (not illustrated).
FIG. 6 is a perspective view illustrating a reciprocating carriage unit of the drive belt system of FIG. 5 according to an example. Referring to FIG. 6. For purposes of clarity of illustration only, the belt stretch maintenance apparatus 58 is not illustrated in FIG. 6. Referring to FIG. 6, in some examples, a reciprocating carriage unit 56 may removably receive a printhead 56c in a loaded state. The reciprocating carriage unit 56 may also include at least one removable ink supply container (not illustrated) to supply ink to the printhead 56c. The printhead 56c may be disposed in the reciprocating carriage unit 56 in a loaded state thereof to selectively eject ink onto media to form images thereon. In some examples, the reciprocating carriage unit 56 may include at least one of a coupling member 56a, compliant isolator members 56d, a carriage member 56b, and a printhead 56c. The carriage member 56b may removably receive the printhead 56c. The coupling unit 56a may couple the carriage member 56b to the belt 14. The compliant isolator members 56d, for example, may be mounted between the coupling member 56a and the carriage member 56b to reduce or filter vibrations from being passed, for example, from the drive motor to the carriage member 56b via the belt 14.
Referring to FIGS. 6 and 7, the z-axis represents an axis about which the coupling member 56a may tend to rotate, for example, in response to a first arm member 58a applying the one force fo against the drive-side belt portion 14b and absent an application of the other force fa (e.g., stabilizing force) to the idler-side belt portion 14c by a second arm member 58b as illustrated in FIG. 6. The printhead 56c may be removably held in the carriage member 56b. In some examples, the carriage member 56b may include a plurality of printheads disposed in the carriage member 56b. In some examples, the belt 14 may be directly coupled to the carriage member 56b. The reciprocating carriage unit 56 may slide on and be guided by surfaces such as sheet metal, cylindrical rods, and the like.
FIG. 7 is a schematic view illustrating the drive belt system of FIG. 5 in which a belt is moving in a first direction according to an example. Referring to FIGS. 5 and 7, in some examples, the drive pulley member 10 rotates about the drive axis 10a thereof. The idler pulley member 12 rotates about the idler axis 12a thereof. The belt 14 forms a continuous loop and moves about the drive pulley member 10 and the idler pulley member 12 in response to rotation by the drive pulley member 10. For example, a drive motor (not illustrated) may be connected to the drive pulley member 10 to rotate the drive pulley member 10 about the drive axis 10a. The reciprocating carriage unit 56 is coupled to and is transported by the belt 14 in a first direction d1 away from the drive pulley member 10 and in a second direction d2 toward the drive pulley member 10. The reciprocating carriage unit 56 may removably receive a printhead 56c. The reciprocating carriage unit 56 or the printhead 56c may removably receive ink supply containers (not illustrated). Accordingly, the printhead 56c may be disposed in the reciprocating carriage unit 56 in a loaded state thereof to selectively eject ink onto media to form images thereon.
Referring to FIGS. 5 and 7, the belt stretch management apparatus 58 may be coupled to the reciprocating carriage unit 56. The belt stretch management apparatus 58 may apply at least one force fo to the belt 14 in a traverse direction thereto to direct a portion of the drive-side belt portion 14b (e.g., portion of the belt 14 between the reciprocating carriage unit 16 and the drive pulley member 10) about the drive pulley member 10 in response to a formation of belt stretch to the belt 14 due to transportation of the reciprocating carriage unit 56 along with the belt stretch management apparatus 58 in the first direction d1.
For example, the belt stretch management apparatus 58 may manage belt stretch by applying at least one force fo to the belt 14 to direct a portion of the drive-side belt portion 14b about the drive pulley member 10. That is, a formation of belt stretch to the drive-side belt portion 14b is managed by further wrapping the portion of the drive-side belt portion 14b about the drive pulley member 10. Thus, the potential of the wrap angle αd about the drive pulley member 10 to decrease due to belt stretch and the drive belt system 500 to enter a slack state is reduced by maintaining or increasing an amount of the respective wrap angle αd that existed prior to the formation of belt stretch.
Referring to FIG. 7, in some examples, the belt stretch management apparatus 58 may include a first arm member 58a, a second arm member 58b and a middle member 58c. In an uninstalled state, the belt stretch management apparatus 58 is not coupled to the reciprocating carriage unit 56 and does not engage the belt 14. As illustrated in FIG. 6, in an installed state, the belt stretch management apparatus 58 is coupled to the reciprocating carriage unit 56 and engages the belt 14. The middle member 58c may be disposed between and connected to the first arm member 58a and the second arm member 58b. The middle member 58c may form an angle with each one of the first arm member 58a and the second arm member 58b. 
Referring to FIG. 7, in the installed state, the middle member 58c may be coupled to the reciprocating carriage unit. 58c, the first arm member 58a may extend from the reciprocating carriage unit 56 to the drive-side belt portion 14b disposed between the reciprocating carriage unit 56 and the drive pulley member 10, and the second arm member 58b may extend from the reciprocating carriage unit 56 to an idler-side belt portion 14c disposed between the reciprocating carriage unit 56 and the idler pulley member 12. Also, the first arm member 58a may contact the drive-side belt portion 14b and the second arm member 58b may contact the idler-side portion 14c. 
In the installed state, the first arm member 58a may apply the at least one force fo to the drive-side belt portion 14b that it contacts in an approximately perpendicular direction (e.g., an angle in a range from about eighty to about one hundred degrees) thereto to direct a portion of the drive-side belt portion 14b about the drive pulley member 10. The first arm member may direct the portion of the drive-side belt portion 14b about the drive pulley member 10 in response a formation of belt stretch to the drive-side belt portion 14b due to transportation of the reciprocating carriage unit 56 along with the belt stretch management apparatus 58 in the first direction f1.
The potential of the wrap angle αd about the drive pulley member 10 to decrease due to belt stretch and the drive belt system 500 to enter a slack state is reduced by maintaining or increasing an amount of the respective wrap angle αd that existed prior to the formation of belt stretch. In the installed state, the second arm member 58b may apply at least an other force fa onto the idler-side belt portion 14c. The at least other force fa may act as a stabilizing force to counter balance the application of the one force fo with respect to the reciprocating carriage unit 56 to minimize a net torque from the belt stretch management apparatus 58.
That is, a coupling member 56a, for example, coupled to compliant isolator members 56d may be susceptible to rotation about a z-axis (FIG. 6) due to the first arm member 28a being in contact with and applying the one force fo to the drive-side belt portion 14b that it contacts, The other force fa counter balances the rotational tendency of the coupling member 56a. Accordingly, the at least other force fa may reduce rotation of the coupling member 56a of the reciprocating carriage unit 56 in a loaded state thereof, for example, when the one force fo is applied by the first arm member 58a. In some examples, the belt stretch management apparatus 58 may be a unitary spring member, for example, formed of sheet metal.
FIG. 8 is a flowchart illustrating a method of managing belt stretch in a drive belt system according to an example. Referring to FIG. 8, in block S81, a continuous belt is driven around a drive pulley member and an idler pulley member by the drive pulley member. For example, a drive motor (not illustrated) may be connected to the drive pulley member to rotate the drive pulley member about the drive axis. In block S82, a transport unit coupled to the continuous belt is transported in a first direction away from the drive pulley member and in a second direction towards the drive pulley member. In some examples, the transport unit may include a reciprocating carriage unit to removably receive at least one printhead, for example, as previously disclosed with respect to FIG. 6.
In block S83, at least one force is applied to the belt in a traverse direction thereto to direct a portion of the belt about the drive pulley member by a belt stretch management apparatus coupled to the transport unit in response to a formation of belt stretch to the belt due to transportation of the transport unit in the first direction. For example, a formation of belt stretch to the drive-side belt portion is managed by further wrapping a portion of the drive-side belt portion about the drive pulley member. In some examples, the method also includes applying at least an other force to the belt in a traverse direction thereto to reduce rotation of the transport unit or a portion thereof. The belt stretch management apparatus may include a unitary spring member, for example, formed of sheet metal as previously disclosed with respect to FIG. 4.
It is to be understood that the flowchart of FIG. 8 illustrates an architecture, functionality, and operation of an example of the present disclosure. If embodied in software, each block may represent a module, segment, or portion of code that includes one or more executable instructions to implement the specified logical function(s). If embodied in hardware, each block may represent a circuit or a number of interconnected circuits to implement the specified logical function(s). Although the flowchart of FIG. 8 illustrates a specific order of execution, the order of execution may differ from that which is depicted. For example, the order of execution of two or more blocks may be scrambled relative to the order illustrated. Also, two or more blocks illustrated in succession in FIG. 8 may be executed concurrently or with partial concurrence. All such variations are within the scope of the present disclosure.
The present disclosure has been described using non-limiting detailed descriptions of examples thereof that are not intended to limit the scope of the present disclosure. It should be understood that features and/or operations described with respect to one example may be used with other examples and that not all examples have all of the features and/or operations illustrated in a particular figure or described with respect to one of the examples. Variations of examples described will occur to persons of the art. Furthermore, the terms “comprise,” “include,” “have” and their conjugates, shall mean, when used in the disclosure and/or claims, “including but not necessarily limited to.”
It is noted that some of the above described examples may include structure, acts or details of structures and acts that may not be essential to the present disclosure and which are described for illustrative purposes. Structure and acts described herein are replaceable by equivalents, which perform the same function, even if the structure or acts are different, as known in the art. Therefore, the scope of the present disclosure is limited only by the elements and limitations as used in the claims.

## Claims

1. A method of managing belt stretch in a drive belt system, the method comprising:
driving a continuous belt around a drive pulley member and an idler pulley member by the drive pulley member;
transporting a transport unit coupled to the continuous belt in a first direction away from the drive pulley member and in a second direction towards the drive pulley member; and
applying at least one force to the belt in a traverse direction thereto to direct a portion of the belt about the drive pulley member by a belt stretch management apparatus coupled to the transport unit, the belt stretch management apparatus including a first arm member extending from the transport unit to the belt at a first angle and a second arm member extending from the transport unit to the belt at a second angle.

2. The method according to claim 1, wherein the belt stretch management apparatus comprises:
a middle member coupled to the transport unit such that the first arm member extends from the middle member in a direction including the first direction and the second arm member extends from the middle member in a direction including the second direction.

3. The method according to claim 1, wherein the belt stretch management apparatus comprises:
the first arm member extending from the transport unit to a drive-side belt portion disposed between the transport unit and the drive pulley member, the first arm member in contact with the drive-side belt portion to apply the at least one force to the belt in an approximately perpendicular direction to a length of the belt; and
the second arm member extending from the transport unit to an idler-side belt portion disposed between the transport unit and the idler pulley member, the second arm member in contact with the idler-side belt portion to apply at least an other force to the belt in an approximately perpendicular direction to a length of the belt.

4. The method according to claim 1, wherein the belt stretch management apparatus is a unitary spring member formed of sheet metal, the unitary spring member having a first end portion and a second end portion each contacting the belt.

5. The method according to claim 1, wherein the transport unit comprises a reciprocating carriage unit to removably receive at least one printhead.

6. A drive belt system usable with an image forming system, the drive belt system comprising:
a drive pulley member having a drive axis to rotate thereabout;
an idler pulley member having an idler axis to rotate thereabout;
a belt to form a continuous loop and to move about the drive pulley member and the idler pulley member in response to rotation by the drive pulley member;
a reciprocating carriage unit coupled to and transported by the belt in a first direction away from the drive pulley member and in a second direction toward the drive pulley member, the reciprocating carriage unit to removably receive at least one printhead; and
a belt stretch management apparatus coupled to the reciprocating carriage unit, the belt stretch management apparatus to apply at least one force to the belt in a traverse direction thereto to direct a portion of the belt about the drive pulley member, the belt stretch management apparatus including a first arm member extending from the transport unit to the belt in a direction including the first direction and a second arm member extending from the transport unit to the belt in a direction including the second direction.

7. The drive belt system according to claim 6, wherein the belt stretch management apparatus comprises:
the first arm member extending from the reciprocating carriage unit to a drive-side belt portion disposed between the reciprocating carriage unit and the drive pulley member, the first arm member in contact with the drive-side belt portion such that the first arm member applies the at least one force to the drive-side belt portion in an approximately perpendicular direction to a longitudinal axis of the belt.

8. The drive belt system according to claim 6, wherein the belt stretch management apparatus comprises:
the first arm member extending from the transport unit to the belt at a first angle and the second arm member extending from the transport unit to the belt at a second angle.

9. The drive belt system according to claim 6, wherein the belt stretch management apparatus comprises:
the second arm member extending from the reciprocating carriage unit to an idler-side belt portion disposed between the reciprocating carriage unit and the idler pulley member, the second arm member in contact with the idler-side belt portion such that the second arm member applies at least an other force to the idler-side belt portion in an approximately perpendicular direction to a longitudinal axis of the belt.

10. The drive belt system according to claim 6, wherein the belt stretch management apparatus further comprises:
a middle member coupled to the reciprocating carriage unit such that the first arm member extends from a first end of the middle member and the second arm member extends from a second end of the middle member.

11. The drive belt system according to claim 6, wherein the belt stretch management apparatus is a unitary spring member formed of sheet metal, the unitary spring member having a first end portion and a second end portion each contacting the belt.

12. A drive belt system, comprising:
a drive pulley member having a drive axis to rotate thereabout;
an idler pulley member having an idler axis to rotate thereabout;
a belt to form a continuous loop and to move about the drive pulley member and the idler pulley member in response to rotation by the drive pulley member;
a transport unit coupled to and transported by the belt; and
a belt stretch management apparatus coupled to and to move with the transport unit, the belt stretch management apparatus to apply at least one force to the belt in a transverse direction thereto to direct a portion of the belt about at least one of the drive pulley member and the idler pulley member in response to a formation of belt stretch to the belt,
the belt stretch management apparatus including a first arm member extending from the transport unit to the belt at a first angle and a second arm member extending from the transport unit to the belt at a second angle, the first angle and the second angle each including an angular component extending along a length of a portion of the belt.

13. The drive belt system according to claim 12, wherein the transport unit is transported in a first direction away from the drive pulley member and in a second direction towards the drive pulley member.

14. The drive belt system according to claim 13, wherein the belt stretch management apparatus comprises:
the first arm member extending from the transport unit to a drive-side belt portion disposed between the transport unit and the drive pulley member such that the first arm member is in contact with the drive-side belt portion; and
wherein the first arm member applies a first force approximately perpendicular to the drive-side belt portion to direct a portion of the drive-side belt portion about the drive pulley member in response to the formation of belt stretch to the belt due to transportation of the transport unit in the first direction.

15. The drive belt system according to claim 13, wherein the belt stretch management apparatus comprises:
the first arm member extending from the transport unit to the belt in a direction including the first direction and the second arm member extending from the transport unit to the belt in a direction including the second direction.

16. The drive belt system according to claim 13, wherein the belt stretch management apparatus comprises:
the second arm member extending from the transport unit to an idler-side belt portion disposed between the transport unit and the idler pulley member such that the second arm member is in contact with the idler side belt portion; and
wherein the second arm member applies a second force approximately perpendicular to the idler-side belt portion to direct a portion of the idler-side belt portion about the idler pulley member in response to the formation of belt stretch to the belt due to transportation of the transport unit in the second direction.

17. The drive belt system according to claim 12, wherein the belt stretch management apparatus further comprises:
a middle member coupled to the transport unit such that the first arm member extends from a first end of the middle member in a first direction and the second arm member extends from a second end of the middle member in a second direction.

18. The drive belt system according to claim 12, wherein the belt stretch management apparatus is a unitary spring member formed of sheet metal, the unitary spring member having a first end portion and a second end portion each contacting the belt.

19. The drive belt system according to claim 12, wherein the transport unit comprises a reciprocating carriage unit to removably receive at least one printhead.

20. The drive belt system according to claim 19, wherein the reciprocating carriage unit further comprises:
a carriage member to receive the at least one printhead;
a coupling member to couple the carriage member to the belt; and
at least one compliant isolator member coupling the coupling member to the carriage member.