Patent Publication Number: US-7896464-B2

Title: Printhead restraint system

Description:
TECHNICAL FIELD 
     The present disclosure relates to imaging devices that utilize printheads to form images on media, and, in particular, to printhead restraints for use in such imaging devices. 
     BACKGROUND 
     Ink jet printing involves ejecting ink droplets from orifices in a printhead onto an image receiving surface to form an image. Ink-jet printing systems commonly utilize either direct printing or offset printing architecture. In a typical direct printing system, the image receiving surface comprises a media substrate and ink is ejected from jets in the printhead directly onto the media substrate. In an offset printing system, the image receiving surface comprises an intermediate transfer surface, such as a drum or belt, and ink is ejected by the jets of the printhead onto an intermediate transfer surface, such as a liquid layer on a drum. The final receiving substrate is then brought into contact with the intermediate transfer surface and the ink image is transferred and fused or fixed to the substrate. 
     In many direct and offset printing systems, the printhead(s) are configured for movement with respect to the image receiving surface. For example, printheads may also be configured to translate across the image receiving surface as the printhead while forming images on the image receiving surface. Printheads may be also configured for movement toward and away from the image receiving surface to, for example, enable maintenance operations. When moving or transporting an imaging device that includes movable printheads, printhead movement is advantageously restrained or prevented so that the printheads of the imaging device are protected from inadvertent contact with other internal components of the imaging device should the imaging device experience a shock loading or other deleterious movement during transport. 
     Previously known printers featured a single printhead that performed a shorter range of movements. In such previously known devices, printhead restraint was enabled by bringing mechanized components in the printer into contact with the printhead. Current imaging devices, however, may include multiple printheads that are configured for a more extensive range of movements than previously known printers. Restraining the printheads in a multi-printhead system with an extensive range of printhead movement is difficult without creating interferences with the printhead range of movement and/or without increasing the cost and complexity of the restraint system. 
     SUMMARY 
     The present disclosure is directed to a printhead restraining system that is configured to lock or restrain both head-to-drum (HTD) movement and translational movement of a printhead or printhead array in an imaging device that incorporates one or more printheads or printhead arrays. In one embodiment, a system for restraining printhead movement in an imaging device includes an imaging device frame; a carriage operably coupled to the imaging device frame for movement between a print position and a retracted position; and a printhead array movably supported by the carriage for translation with respect to the carriage. The system includes a restraint system supported by the carriage. The restraint system has at least one carriage restraint pin and a printhead restraint pin. The at least one carriage restraint pin is configured for movement into and out of engagement with the imaging device frame and the printhead restraint pin being configured for movement into and out of engagement with the printhead array when the carriage is at the retracted position. 
     In another embodiment, an imaging device is provided that includes an imaging device frame, and an image receiving surface supported by the imaging device frame for movement in a process direction. A plurality of carriages is operably coupled to the imaging device frame. Each carriage in the plurality is configured for movement toward and away from the image receiving surface between a print position and a retracted position. A printhead array is movably supported by each carriage in the plurality for translation in a cross-process direction with respect to the image receiving surface. A restraint system is supported by each carriage in the plurality. Each restraint system includes at least one carriage restraint pin and a printhead restraint pin. The at least one carriage restraint pin is configured for movement into and out of engagement with the imaging device frame and the printhead restraint pin is configured for movement into and out of engagement with the associated printhead array when the corresponding carriage is at the retracted position. 
     In yet another embodiment, a method of restraining printheads of an imaging device that includes a frame that supports an image receiving surface and a plurality of carriages, each carriage configured for head-to-drum (HTD) movement with respect to the image receiving surface. Each carriage supports at least one printhead in a manner that enables the at least one printhead to be translated in a cross-process direction with respect to the image receiving surface. The method includes providing a restraint system in each carriage of the imaging device. The restraint systems each include a carriage restraint pin and a printhead restraint pin. To restrain the printhead, each carriage is moved to a restraint position. With the carriages at the restraint positions, the restraint systems are actuated in each carriage to move the corresponding carriage restraint pin into engagement with the frame to prevent HTD movement of the corresponding carriage and to move the corresponding printhead restraint pin into engagement with the at least one printhead supported on the carriage to prevent translation of the at least one printhead with respect to the carriage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic elevational view of an embodiment of an imaging device. 
         FIG. 2  is a perspective view of the arrangement of printheads in the imaging device of  FIG. 1 . 
         FIG. 3  is a side view of the printheads of  FIG. 2  in a retracted position. 
         FIG. 4  is a side view of the printheads of  FIG. 2  in a home/print position. 
         FIG. 5  is a perspective view of the printhead carriages of the imaging device showing the printhead restraint systems. 
         FIG. 6  is a perspective view of the restraint system of  FIG. 5  in the disengaged position. 
         FIG. 7  is a perspective view of the restraint system of  FIG. 5  in the engaged position. 
         FIG. 8  is a detailed view of the worm drive of the restraint system of  FIGS. 6 and 7 . 
         FIG. 9  is a perspective view of the imaging device depicting a slender tool engaging the restraint system of  FIGS. 6 and 7 . 
         FIG. 10  is a perspective view of the printhead array locking pin of the restraint system engaged with a printhead array frame. 
     
    
    
     DETAILED DESCRIPTION 
     For a general understanding of the present embodiments, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate like elements. 
     As used herein, the terms “printer” or “imaging device” generally refer to a device for applying an image to print media and may encompass any apparatus, such as a digital copier, bookmaking machine, facsimile machine, multi-function machine, etc. which performs a print outputting function for any purpose. “Print media” can be a physical sheet of paper, plastic, or other suitable physical print media substrate for images, whether precut or web fed. The imaging device may include a variety of other components, such as finishers, paper feeders, and the like, and may be embodied as a copier, printer, or a multifunction machine. A “print job” or “document” is normally a set of related sheets, usually one or more collated copy sets copied from a set of original print job sheets or electronic document page images, from a particular user, or otherwise related. An image generally may include information in electronic form which is to be rendered on the print media by the marking engine and may include text, graphics, pictures, and the like. 
     Referring now to  FIG. 1 , an embodiment of an imaging device  10  of the present disclosure, is depicted. As illustrated, the device  10  includes a frame  11  to which are mounted directly or indirectly all its operating subsystems and components, as described below. In the embodiment of  FIG. 1 , imaging device  10  is an indirect marking device that includes an intermediate imaging member  12  that is shown in the form of a drum, but can equally be in the form of a supported endless belt. The imaging member  12  has an image receiving surface  14  that is movable in a process (Y-axis) direction  16  past a printhead system  30 . The printhead system  30  is configured to form an image on the image receiving surface of the drum as the drum rotates in the process direction. A transfix roller  19  rotatable in the direction  17  is loaded against the surface  14  of drum  12  to form a transfix nip  18 , within which ink images formed on the surface  14  are transfixed onto a media sheet  49 . In alternative embodiments, the imaging device may be a direct marking device in which the ink images are formed directly onto a receiving substrate such as a media sheet or a continuous web of media. The terms “Y-axis” and “process direction” may be used interchangeably and refer to an axis or direction that is parallel to the direction of movement of an image receiving surface past a printhead, and the terms “X-axis” and “cross-process direction” may be used interchangeably and refer to an axis or direction that is perpendicular to the process direction. 
     The imaging device  10  includes an ink delivery subsystem  20  that has at least one source  22  of one color of ink. Since the imaging device  10  is a multicolor image producing machine, the ink delivery system  20  includes four (4) sources  22 ,  24 ,  26 ,  28 , representing four (4) different colors CYMK (cyan, yellow, magenta, black) of ink. In one embodiment, the ink utilized in the imaging device  10  is a “phase-change ink,” by which is meant that the ink is substantially solid at room temperature and substantially liquid when heated to a phase change ink melting temperature for jetting onto an imaging receiving surface. Accordingly, the ink delivery system includes a phase change ink melting and control apparatus (not shown) for melting or phase changing the solid form of the phase change ink into a liquid form. The phase change ink melting temperature may be any temperature that is capable of melting solid phase change ink into liquid or molten form. In one embodiment, the phase change ink melting temperate is approximately 100° C. to 140° C. In alternative embodiments, however, any suitable marking material or ink may be used including, for example, aqueous ink, oil-based ink, UV curable ink, or the like. 
     The ink delivery system is configured to supply ink in liquid form to a printhead system  30  including at least one printhead assembly. In the embodiment of  FIG. 1 , the printhead system  30  includes two printhead assemblies  32 ,  34  although the imaging device may include any suitable number of printhead assemblies. Each printhead assembly includes at least one printhead arrayed across the image receiving surface in the cross-process direction (i.e., along the X-axis). The printheads in a printhead array may be spaced from each other in the cross-process direction or butted together to form a continuous linear array. 
     As further shown, the imaging device  10  includes a media supply and handling system  40 . The media supply and handling system  40 , for example, may include sheet or substrate supply sources  42 ,  44 ,  48 , of which supply source  48 , for example, is a high capacity paper supply or feeder for storing and supplying image receiving substrates in the form of cut sheets  49 , for example. The substrate supply and handling system  40  also includes a substrate or sheet heater or pre-heater assembly  52 . The imaging device  10  as shown may also include an original document feeder  70  that has a document holding tray  72 , document sheet feeding and retrieval devices  74 , and a document exposure and scanning system  76 . 
     Operation and control of the various subsystems, components and functions of the machine or printer  10  are performed with the aid of a controller or electronic subsystem (ESS)  80 . The ESS or controller  80  for example is a self-contained, dedicated mini-computer having a central processor unit (CPU)  82 , electronic storage  84 , and a display or user interface (UI)  86 . The ESS or controller  80  for example includes a sensor input and control system  88  as well as a pixel placement and control system  89 . In addition the CPU  82  reads, captures, prepares and manages the image data flow between image input sources such as the scanning system  76 , or an online or a work station connection  90 , and the printhead arrays  32 ,  34 . As such, the ESS or controller  80  is the main multi-tasking processor for operating and controlling all of the other machine subsystems and functions, including the printhead cleaning apparatus and method discussed below. 
     In operation, image data for an image to be produced are sent to the controller  80  from either the scanning system  76  or via the online or work station connection  90  for processing and output to the printhead arrays  32 ,  34 . Additionally, the controller determines and/or accepts related subsystem and component controls, for example, from operator inputs via the user interface  86 , and accordingly executes such controls. As a result, appropriate color solid forms of phase change ink are melted and delivered to the printhead assemblies. Additionally, pixel placement control is exercised relative to the imaging surface  14  thus forming desired images per such image data, and receiving substrates are supplied by any one of the sources  42 ,  44 ,  48  along supply path  50  in timed registration with image formation on the surface  14 . Finally, the image is transferred from the surface  14  and fixedly fused to the copy sheet within the transfix nip  18 . 
     Referring now to  FIG. 2 , a more detailed view of the printhead system  30  of  FIG. 1  is shown. As depicted in  FIG. 2 , the printhead system  30  includes two printhead arrays  32 ,  34  with each printhead array having two printheads  36 . In the embodiment of  FIG. 2 , each printhead array  32 ,  34 , comprises a Staggered Full Width Array (SFWA) in which the printheads  36  of an array are spaced from each other in the cross-process direction. While forming an image, a mode referred to herein as print mode, the upper printhead array  32  and the lower printhead array  34  are staggered with respect to each other in the cross-process direction to enable the printhead system  30  to form an image across the full cross-process direction width of the image receiving surface. Each printhead array  32 ,  34  is mounted to a printhead array frame  104  that is movably supported by a carriage  108 , as depicted in  FIG. 2 . Each printhead array frame  104  is configured for cross-process (or X-axis) translation of the printhead array with respect to the carriage  108  and, consequently, the image receiving surface. Printhead array frames  104  may be operably coupled to a carriage  108  in any suitable manner that permits the requisite translational movement of the printhead array frame. 
     Each carriage  108  is movably supported in the imaging device so that the corresponding printhead array  32 ,  34  may be moved into various positions with respect to the drum, referred to herein as Head to Drum (HTD) movement. In an exemplary embodiment, the different positions to which an printhead array  32 ,  34  may be moved include at least one retracted position in which the printhead array  32 ,  34  is retracted from the drum ( FIG. 3 ) and a home/print position in which the printhead array  32 ,  34  is positioned closely adjacent the drum ( FIG. 4 ). HTD movement of a carriage between the various positions may be accomplished in any suitable manner. For example, carriages  108  may be configured for linear, pivotal, or a combination of linear and pivotal movement toward and away from the drum. In the embodiment of  FIGS. 3 and 4 , the upper printhead array  32  is configured for pivotal movement along a path P within the imaging device and the lower printhead array  34  is configured for linear movement along a path L within the imaging device. 
     Each printhead array  32 ,  34  is operably coupled to a suitable positioning system  110  that is configured to actuate and control the X-axis movement of the printhead array frame  104  with respect to the carriage  108  and to actuate and control the HTD movement of the carriage  108  between the various positions ( FIGS. 3 and 4 ). The positioning systems  110  may be under the control of controller  80 , and may include any necessary drivers, motors, pistons, sensors, and the like that enables the controller to drive and track the lateral (X-axis) movement of the printhead array frame with respect to the carriage and the HTD movement of the carriage assemblies with respect to the drum. 
     When moving or transporting an imaging device, such as the imaging device described above, printhead movement is advantageously restrained or prevented so that the printheads of the imaging device are protected from inadvertent contact with other internal components of the imaging device should the imaging device experience a shock loading or other deleterious movement during transport. Accordingly, the present disclosure proposes a printhead restraint system that includes a separate restraint system  100  housed in each printhead carriage  108  in the imaging device. Each restraint mechanism is configured to a) lock printhead array (SFWA) movement with respect to the carriage (the “X-direction”), and b) lock the movement of the entire carriage assembly against motion toward the fragile imaging drum surface. As explained below, the restraint systems are equipped with pins that lock into the imaging device side frames to prevent HTD movement. Additionally, each restraint mechanism pushes a printhead array restraint pin into the printhead array frame to lock it to the carriage. This restraint design is advantageous to a multi-head product because it is compact enough to fit within a printhead array carriage assembly and, when retracted, it will not interfere with the motion of the carriage or other marking unit systems. Since each printhead array carriage is equipped with a restraint mechanism, a head restraint solution is in place regardless of how many carriages are used in a product. 
     To facilitate the restraint locking function, each of the printhead carriages  108  is first moved to a predetermined restraint position, also referred to herein as a ship or shipping position. In one embodiment, a restraint position corresponds to the retracted position of the carriage assemblies depicted in  FIG. 3 . A restraint position, however, may be substantially any position along the respective carriages path of movement. For example, the restraint position may be any position between and including the home/print position depicted in  FIG. 4  and the retracted position depicted in  FIG. 3 . Each printhead array frame  104  mounted on a carriage  108  may also be moved laterally (X-axis) with respect to the carriage  108  to a predetermined restraint position at which the printhead array is locked to prevent lateral movement of the printhead array with respect to the carriage. The carriages  108  and printhead array frames  104  may be moved to the restraint position in response to input received by the controller  80  through, for example, the user interface of the imaging device. The controller  80  may actuate the positioning system  110  of the carriages  108  in a known manner to move each carriage and corresponding printhead array  32 ,  34  to its respective restraint position. 
     Referring now to  FIGS. 5 to 10 , the restraint system  100  in each carriage  108  includes at least one HTD locking pin  114  that is configured to extend out from the carriage  108  when the carriage is in the restraint position to engage features in the imaging device frame in order to effectively “lock” the carriage at the restraint position. As best seen in  FIGS. 6 and 7 , a restraint system  100  may include two HTD locking pins  114  that are configured to extend laterally from each end of a carriage  108 . In one embodiment, each HTD locking pin  114  is supported in the corresponding carriage for translation between a disengaged position at which the HTD locking pins  114  are retracted ( FIG. 6 ) and held within the confines of the carriage (not shown in  FIG. 6 ) and an engaged or locking position at which the HTD locking pins  114  are extended ( FIG. 7 ) beyond the lateral ends of the carriage (not shown in  FIG. 6 ). When in the restraint position, the HTD locking pins  114  are positioned to engage, for example, openings  118  in complementary positions in the imaging device frame  11 . 
     In addition to the HTD locking pins  114 , each restraint system includes an array locking pin  120 . The array locking pin  120  is supported in the corresponding carriage  108  for translation in a direction from the back of the carriage toward the printhead array mounted at the front of the carriage. The array locking pin  120  is supported for movement between a disengaged position at which the printhead array restraint pin is retracted away from the printhead array ( FIG. 6 ) and an engaged or locking position at which the printhead array restraint pin  120  is extended or pushed through an opening  124  in the carriage  108  toward the printhead array frame  104  ( FIGS. 7 and 10 ). With the printhead array frame  104  in a restraint position with respect to the carriage  108 , the printhead array restraint pin  120  is aligned with a complementarily shaped feature  138  in the printhead array frame  104 . When the printhead array restraint pin  120  translated into its locking position and the pin is pushed through the opening in the carriage, the restraint pin  120  engages the complementary feature  138  in the printhead array  104  thereby preventing lateral movement of the printhead array  104  with respect to the carriage. 
     Each restraint system  100  includes a driver that is configured to move the HTD  114  and array restraint pins  120  from their disengaged positions to their locking positions. Any suitable driving system may be utilized. In one embodiment, the locking pin drive system includes a linkage assembly  130  and a linkage driver  128 . The linkage assembly  130  is operably coupled to the locking pins  114 ,  120  in a manner such that movement of the linkage assembly imparts the translational movement to the locking pins. The linkage driver  128 , in turn, is operably coupled to the linkage assembly  130  and is configured to impart the movement to the linkage assembly  130  that causes the locking pins  114 ,  120  to be moved between the disengaged positions and the locking positions. 
     The exemplary linkage assembly  130  of  FIGS. 5-10  includes a linkage member in the form of a cam gear  130 . Cam gear  130  is rotatably supported by a pin  132  extending from the back of the carriage. The cam gear  130  of the linkage assembly is coupled to each HTD locking pin  114  by a linkage arm  134 . Linkage arms  134  are freely supported at one end by the corresponding locking pin  114  and at the other end by the cam gear  130 , and are attached to the cam gear  130  at predetermined positions along the periphery of the cam gear. Cam gear  130  is configured to rotate about pin  132  between a disengaged position ( FIG. 6 ) and an engaged position ( FIG. 7 ). When in the disengaged position, the HTD restraint pins  114  and the array restraint pin  120  are retracted to their positions within the carriage. As may be ascertained by a person skilled in the art, rotation of the cam gear  130  about pin  132  from the disengaged position to the engaged position causes a corresponding movement of the linkage arms  134  which in turn imparts linear motion to the HTD locking pins  114  to move the HTD locking pins  114  from disengaged positions to locking positions. Conversely, rotation of the cam gear  130  from the engaged position to the disengaged position causes a corresponding movement of the linkage arms  134  which in turn imparts linear motion to the HTD locking pins  114  to move the HTD locking pins  114  from the locking positions to the disengaged positions. 
     Using the exemplary cam gear linkage  130 , motion may be imparted to the array restraint pin  120  using a further cam  142  provided on a side of the cam gear linkage  130 . In this embodiment, the array restraint pin  120  is independently supported in an operable position in the carriage frame irrespective of the rotational movement of the cam gear. For example, array restraint pin  120  pin may be sandwiched between the cam gear  130  and the corresponding opening  124  that extends through the carriage  108  toward the printhead array frame  104 . Thus, rotation of the cam gear  130  does not affect the lateral position of the restraint pin  120  with respect to the carriage. A spring  140  may be used to bias the pin  120  into the disengaged position. As seen in  FIGS. 6 and 7 , the further cam  142  may comprise a protrusion from the side of the cam gear  130  in the form of a ramp, for example. The pin  120  and the further cam  142  of the cam gear  130  are positioned with respect to each other such that the further cam  142  is positioned away from the pin  120  when the cam gear  130  is in the disengaged position ( FIG. 6 ). As the cam gear  130  is rotated from the disengaged position to the engaged position ( FIG. 7 ), the protruding cam  142  engages an end of the pin  120 . Continued movement of the cam gear causes the protruding cam  142  to move under the pin  120 , thereby pushing the pin  120  through the opening  124  in the carriage toward the complementary locking feature  138  in the array frame  104  ( FIG. 10 ). Rotation of the cam gear  130  from the engaged position to the disengaged position removes the further cam  142  from engagement with the pin  120 . In the absence of contact with the further cam  142 , biasing spring  140  pushes the pin  120  toward the disengaged position ( FIG. 6 ). 
     The exemplary cam gear linkage  130  is operably coupled to a suitable linkage driver  128  that is configured to move or rotate the cam gear  130  about the pin  132  between the disengaged and engaged positions. In one embodiment, the linkage drive  128  comprises a worm drive system. With reference to  FIG. 8 , an exemplary embodiment of a worm drive system  128  is depicted. As shown, the worm drive system includes an electric motor  150  having a motor drive shaft  154 , worm  158 , gear train  160 , and output drive gear  164 . The motor  150  may be any suitable type of electric motor, and may be a variable speed motor, a reversible motor, a non-reversible motor, or the like. The motor is operably coupled to a power source (not shown) which, in turn, may be controlled by controller  80  for actuating the motor to engage or disengage the restraint systems. Drive shaft  154  has worm  158  at one end thereof. Gear train  160  includes a plurality of intermeshed gears that are operatively engaged at one end thereof with worm  158  on drive shaft  154  of motor  150  and at the other end with drive gear  164 . Drive gear  164  is, in turn, meshed with cam gear linkage  130 . 
     Each restraint system  100  in the imaging device is configured for automatic engagement and disengagement using the corresponding worm drive  128 . For example, once a carriage  108  and associated printhead array frame  104  are in their restraint positions, controller  80  may actuate the motor  150  of the worm drive of the corresponding restraint system to rotate drive shaft  154  in a first direction for engaging the restraint system. In response, drive shaft  154  causes worm  158  to rotate. Worm  158  causes rotation of gears  160  of gear train which, in turn, rotates drive gear  164 . Drive gear  164  is meshed with cam gear linkage  130  so that rotation of drive gear  164  causes rotation of cam gear linkage  130  from the disengaged position to the engaged position. When it is desired to unlock or unrestrain the printheads, controller  80  actuates the motor  150  to rotate drive shaft in the opposite direction which causes opposite motion of the worm  158 , gear train  160 , and drive gear  164  which, in turn, causes rotation of cam gear linkage  130  from the engaged position to the disengaged position. 
     The restraint systems  100  may also be configured for manual engagement and disengagement. For example, referring to  FIGS. 6 and 7 , a restraint system  100  may be equipped with a manual drive pin  168 . In the exemplary embodiment of  FIGS. 6 and 7 , manual drive pin  168  is supported in the corresponding carriage for translation between a first position ( FIG. 6 ) at which the restraint system  100  is disengaged and a second position ( FIG. 7 ) at which the restraint system is engaged. Manual drive pin  168  is coupled to cam gear linkage  130  by a linkage arm  170 . Drive pin linkage arm  170  is attached to the cam gear  130  at a predetermined position along the periphery of the cam gear  130  such that translation of the drive pin  168  from the first position ( FIG. 6 ) to the second position ( FIG. 7 ) causes the cam gear linkage  130  to rotate from the disengaged to the engaged position, which, in turn, causes the restraint pins  114 ,  120  to be moved to their respective locking positions. 
     The drive pin  168  of each restraint system is configured for external access so that the drive pin may be moved from the first position to the second position manually from outside of the imaging device without requiring disassembly of the imaging device. For example, when a carriage  108  is in its restraint position and restraint system  100  is disengaged, an end of manual drive pin  168  is positioned adjacent an access hole  174  in the imaging device. With reference to  FIG. 9 , for manual engagement, a slender tool  178 , such as a rod or screw driver, may be used to push the manual drive pin  168  from the first position to the second position. Manual disengagement may be enabled by providing an access hole  118  in the imaging device to at least one of the HTD restraint pins  114 . For manual disengagement, a slender tool may be used to directly push an HTD restraint pin  114  out of its locked position, i.e., from its locked position toward its disengaged position. Movement of the HTD pin  114  from its locked position causes a corresponding movement of cam gear linkage  130  from its engaged position to its disengaged position thereby disengaging the restraint system. The worm drive  128  is an important component in the manual operation of the mechanism. The worm drive is designed with a large enough lead angle so that it may be back-driven from a source external to the worm drive, such as drive pin, while still providing enough frictional resistance to motion that the worm drive holds its position once engaged. The design may therefore utilize the mechanical advantage of a worm drive within its limited design space, and at the same time allow manual operation without disengagement of the drive train. 
     The printhead restraint system described above may also be utilized to actuate print head thermal insulation covers (not shown). Printhead insulation covers for use with an SFWA printhead array, such as described above, are described in more detail in commonly owned U.S. Publication No. 2006/0227191 to Williams et al. entitled “System and method for insulating solid ink printheads,” which is hereby incorporated by reference herein in its entirety. Printhead insulation covers are configured to conserve energy and keep the face plate clean during the printer&#39;s sleep mode. Such a cover would need to move out of the way when the head is again needed for printing. Given the printhead restraint&#39;s close proximity to the print heads, the restraint system may be modified to perform both head restraint and cover functions using the same mechanism. The restraint mechanism contains both rotational and translational motion components, so a variety of cover actuation schemes are possible. One such arrangement would be a cover that pivots on the print head. In one embodiment, a cable may be extended between the insulative cover and the linkage assembly  130  and running over a guide or pulley. When the shipping restraint is in the engaged position, i.e., sleep mode, the print heads are retracted and the insulative cover is pivoted over the ejecting faces of the printheads. When the printhead restraint is moved from the engaged to the disengaged position, the cable pivots the cover up and out of the way the printheads. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems, applications or methods. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.