PATENT DOCUMENT

Publication Number: US-11371644-B2
Application Number: US-201916572410-A
Country: US
Kind Code: B2

Title: Dual display stand

Abstract:
A display stand has two spaced apart legs connected by a horizontal support bar that is attachable to multiple displays. Carriage assemblies allow the stand to adjust the vertical position of the displays, shuttles and rails allow the stand to adjust the horizontal positions of the displays, and a central joint on the support bar allows the stand to adjust the angle between the displays. The carriage assemblies can convert rotational movement of adjustment handles into vertical movement of the support bar that is synchronized at both legs whether the support bar is in a straight or angled configuration. Wheels on the shuttles can provide smooth, consistent contact with rails in the support bar despite changes in the nominal dimensions of the rails. The display stand provides improved smoothness, rigidity, and comfort for the user to support and use multiple displays on a single stand.

Claims:
What is claimed is: 
     
       1. A display support assembly, comprising:
 a first stand leg; 
 a first carriage assembly positioned on the first stand leg; 
 a second stand leg; 
 a second carriage assembly positioned on the second stand leg; 
 a display support bar connected to the first carriage assembly and to the second carriage assembly, the display support bar extending from a first vertical position on the first stand leg to a second vertical position on the second stand leg, the display support bar comprising:
 a first segment; 
 a second segment; and 
 a pivotable joint rotatable about a vertical pivot axis and including a fastener joining the first and second segments; 
 wherein a first longitudinal axis of the first segment and a second longitudinal axis of the second segment are configurable in an angled configuration with the first longitudinal axis and the second longitudinal axis extending from the pivotable joint in a non-coaxial configuration; 
 
 a carriage adjuster to simultaneously adjust the first and second vertical positions of the display support bar relative to the first and second stand legs by adjusting the first carriage assembly and the second carriage assembly when the display support bar is in the angled configuration and with the fastener being aligned with the vertical pivot axis. 
 
     
     
       2. The display support assembly of  claim 1 , further comprising a display support arm mounted to the display support bar at a mounting position relative to the first stand leg, wherein the mounting position is adjustable relative to the first stand leg in a vertical direction, and in a horizontal direction, and about the vertical pivot axis at the pivotable joint. 
     
     
       3. The display support assembly of  claim 1 , wherein the carriage adjuster is rotatable about at least one of the first or second longitudinal axis of the display support bar. 
     
     
       4. The display support assembly of  claim 1 , wherein the carriage adjuster is positioned at an end of the display support bar. 
     
     
       5. The display support assembly of  claim 1 , wherein the carriage adjuster comprises a first carriage adjuster positioned at a first end of the display support bar and a second carriage adjuster positioned at a second end of the display support bar. 
     
     
       6. The display support assembly of  claim 1 , wherein the first carriage assembly comprises a rack and pinion adjustable by the carriage adjuster. 
     
     
       7. The display support assembly of  claim 1 , further comprising a support arm extending from the display support bar. 
     
     
       8. The display support assembly of  claim 7 , further comprising a shuttle movable along an axis of the display support bar, the support arm being movable with the shuttle. 
     
     
       9. The display support assembly of  claim 8 , further comprising a rotatable shaft linked to the carriage adjuster, the rotatable shaft extending through the shuttle. 
     
     
       10. The display support assembly of  claim 8 , wherein the display support bar comprises a first rail surface and a second rail surface, and wherein the shuttle comprises a first wheel in contact with the first rail surface and a second wheel in contact with the second rail surface. 
     
     
       11. The display support assembly of  claim 1 , wherein the display support bar comprises a first portion, a second portion, the pivotable joint joining the first and second portions. 
     
     
       12. The display support assembly of  claim 11 , further comprising a universal joint positioned in the pivotable joint. 
     
     
       13. A display stand for an electronic device, comprising:
 a vertical support base; 
 a support bar vertically movable relative to the vertical support base, the support bar being configured to mount to an electronic display; 
 a first handle to adjust a position of the support bar relative to the vertical support base between an extreme raised position and an extreme lowered position, the first handle having a first slip clutch; and 
 a second handle to adjust a position of the support bar relative to the vertical support base between the extreme raised position and the extreme lowered position, the second handle having a second slip clutch; 
 wherein when the support bar is positioned between the extreme raised position and the extreme lowered position, rotation of the first handle or the second handle raises or lowers the support bar relative to the vertical support base; and 
 wherein when the first handle and the second handle are torqued in opposite directions, at least one of the first slip clutch and the second slip clutch slips. 
 
     
     
       14. The display stand of  claim 13 , wherein the first handle is coaxial with the support bar. 
     
     
       15. The display stand of  claim 13 , wherein the first slip clutch slips upon application of a torque to the first handle exceeding a predetermined maximum torque. 
     
     
       16. The display stand of  claim 13 , wherein the first slip clutch comprises a disk contacted by a biased pressure plate. 
     
     
       17. The display stand of  claim 13 , wherein the support bar comprises an adjustment shaft, wherein rotation of the adjustment shaft adjusts the position of the support bar between the two extreme raised and lowered positions, wherein the first handle comprises a friction engine coupled with the adjustment shaft, the friction engine applying a first amount of friction to the adjustment shaft as the handle adjusts the position of the support bar in an upward direction and applying a second amount of friction to the adjustment shaft as the first handle adjusts the position of the support bar in a downward direction, the first amount of friction being less than the second amount of friction. 
     
     
       18. The display stand of  claim 13 , wherein rotation of the first handle adjusts a pinion relative to a rack. 
     
     
       19. The display stand of  claim 18 , wherein the pinion comprises a shoulder surface having a diameter equal to a pitch diameter of the pinion. 
     
     
       20. The display support assembly of  claim 1 , wherein the pivotable joint comprises a range of deflection up to 40 degrees. 
     
     
       21. A display support assembly, comprising:
 a first stand leg; 
 a first carriage assembly positioned on the first stand leg; 
 a second stand leg; 
 a second carriage assembly positioned on the second stand leg; 
 a display support bar connected to the first carriage assembly and to the second carriage assembly, the display support bar extending from a first vertical position on the first stand leg to a second vertical position on the second stand leg, the display support bar comprising a pivotable joint configured to position the display support bar in an angled configuration with a first longitudinal axis of the display support bar and a second longitudinal axis of the display support bar extending from the pivotable joint in a non-coaxial configuration; 
 a carriage adjuster to simultaneously adjust the first and second vertical positions of the display support bar relative to the first and second stand legs by adjusting the first carriage assembly and the second carriage assembly when the display support bar is in the angled configuration; and 
 a display support arm mounted to the display support bar at a mounting position, wherein the mounting position is adjustable relative to the first stand leg in a vertical direction, in a horizontal direction, and about a vertical axis of rotation at the pivotable joint. 
 
     
     
       22. A display stand for an electronic device, comprising:
 a vertical support base; 
 a support bar vertically movable relative to the vertical support base, the support bar being configured to mount to an electronic display; 
 a handle to adjust a position of the support bar relative to the vertical support base between an extreme raised position and an extreme lowered position, the handle having a slip clutch; 
 wherein when the support bar is positioned between the extreme raised position and the extreme lowered position, rotation of the handle raises or lowers the support bar relative to the vertical support base; 
 wherein when the support bar is positioned at the extreme raised position, rotation of the handle slips the slip clutch; and 
 wherein when the support bar is positioned at the extreme lowered position, rotation of the handle slips the slip clutch; and 
 wherein the support bar comprises an adjustment shaft, wherein rotation of the adjustment shaft adjusts the position of the support bar between the two extreme raised and lowered positions, wherein the handle comprises a friction engine coupled with the adjustment shaft, the friction engine applying a first amount of friction to the adjustment shaft as the handle adjusts the position of the support bar in an upward direction and applying a second amount of friction to the adjustment shaft as the handle adjusts the position of the support bar in a downward direction, the first amount of friction being less than the second amount of friction.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This claims priority to U.S. Provisional Patent Application No. 62/855,226, filed 31 May 2019, and entitled “DUAL DISPLAY STAND,” the entire disclosure of which is hereby incorporated by reference. 
    
    
     FIELD 
     The described embodiments relate generally to stands and supports for electronic devices. More particularly, the present embodiments relate to adjustable stands for multiple computer displays. 
     BACKGROUND 
     Computer device designers often desire to control positioning of a computer monitor or similar display at whatever height and orientation are best suited for the needs of the user. A stand can position the display to accommodate users and desktop surfaces of different heights, sizes, and postures. The stand can allow the user to adjust the monitor with little expended effort. 
     While various existing display stands provide tilt, rotation, and vertical height adjustment of monitors, these features often come at the expense of being convenient and natural to use. Many require the user to deal with significant friction or hysteresis that makes adjustment difficult, awkward, and time consuming. Such issues impede the stand from having a high quality, satisfying user experience. These issues are compounded when the display stand must support more than one display. There is, therefore, a constant need for improvements to stands and supports for electronic devices. 
     SUMMARY 
     Aspects of the present disclosure can relate to a display support assembly comprising a first stand leg, a first carriage assembly positioned the first stand leg, a second stand leg, a second carriage assembly positioned the second stand leg, a display support bar connected to the first carriage assembly and to the second carriage assembly, with the display support bar extending from a first vertical position on the first stand leg to a second vertical position on the second stand leg, and a carriage adjuster to simultaneously adjust the first and second vertical positions of the display support bar relative to the first and second stand legs by adjusting the first carriage assembly and the second carriage assembly. 
     In some embodiments, the display support assembly further can comprise a display support arm mounted to the display support bar at a mounting position relative to the first stand leg, wherein the mounting position can be adjustable relative to the first stand leg in a vertical direction, in a horizontal direction, and about a vertical axis of rotation. The carriage adjuster can be rotatable about a longitudinal axis of the display support bar or can be positioned at an end of the display support bar. The carriage adjuster can comprise a first carriage adjuster positioned at a first end of the display support bar and a second carriage adjuster positioned at a second end of the display support bar. The first carriage assembly can comprise a rack and pinion adjustable by the carriage adjuster. A support arm can extend from the display support bar, and a shuttle can be movable along an axis of the display support bar, with the support arm being movable with the shuttle. A rotatable shaft can be linked to the carriage adjuster, with the rotatable shaft extending through the shuttle. The display support bar can comprise a first rail surface and a second rail surface, and the shuttle can comprise a set of wheels in contact with the first and second rail surfaces. The display support bar can also comprise a first portion, a second portion, and a pivotable joint joining the first and second portions. A universal joint can be positioned in the pivotable joint. 
     Another aspect of the disclosure relates to a display support assembly comprising a first rail having a V-shaped profile, a second rail having a V-shaped profile, with the second rail being parallel to the first rail, and a slide having a display support portion, with the slide having a set of rollers in contact with the first rail and the second rail. Contact between the set of rollers and the first and second rails can constrain movement of the slide to a single principal plane of motion, and the single principal plane of motion can intersect the first and second rails. 
     In some embodiments, the slide can comprise a body, and the set of rollers can comprise at least one roller biased into contact with the first rail or the second rail relative to the body. The set of rollers can comprise at least one roller unbiased relative to the body. The slide can comprise a body and the set of rollers can comprise a first pair of rollers at a first end of the body, a second pair of rollers at a second end of the body, and a third pair of rollers positioned between the first and second ends. The first and second rails can be positioned within a hollow elongated structure, and the slide can be movable within the hollow elongated structure parallel to the first and second rails. The first and second rails can be vertically aligned with each other, and the slide can comprise a body having a longitudinal aperture. 
     Yet another aspect of the disclosure relates to a display stand comprising a vertical support base, a support bar vertically movable relative to the vertical support base, with the support bar being configured to mount to a display, and a handle to adjust a position of the support bar relative to the vertical support base between two extreme raised and lowered positions, with the handle having a slip clutch. When the support bar is positioned between the two extreme raised and lowered positions, rotation of the handle can raise or lower the support bar relative to the vertical support, and when the support bar is positioned at one of the two extreme raised and lowered positions, rotation of the handle can slip the clutch. 
     The handle can be coaxial with the support bar. The slip clutch can slip upon application of a torque to the handle exceeding a predetermined maximum torque. The slip clutch can comprise a rotor contacted by a biased pressure plate. 
     In some embodiments, the support bar can comprise an adjustment shaft, wherein rotation of the adjustment shaft can adjust the position of the support bar between the two extreme raised and lowered positions. The handle can comprise a friction engine coupled with the adjustment shaft, with the friction engine applying a first amount of friction to the adjustment shaft as the handle adjusts the position of the support bar in an upward direction and applying a second amount of friction to the adjustment shaft as the handle adjusts the position of the support bar in a downward direction. The first amount of friction can be less than the second amount of friction. 
     In some configurations, rotation of the handle can adjust a pinion relative to a rack. The pinion can comprise a shoulder surface having a diameter equal to a pitch diameter of the pinion and rack. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  shows an isometric view of a display stand in a straight configuration. 
         FIG. 2  shows an isometric view of the display stand of  FIG. 1  in an angled configuration. 
         FIG. 3  shows an isometric breakaway view of an end portion of the display stand of  FIG. 1 . 
         FIG. 4  shows an isometric breakaway view of a shuttle in a support bar. 
         FIG. 5  shows an end section view taken through section lines  5 - 5  in  FIG. 4 . 
         FIG. 6A  is a rear view of a linking rod, a joint, and a set of racks and pinions in a drivetrain of the display stand in a straight configuration. 
         FIG. 6B  is a top view of the drivetrain of  FIG. 6A  in an angled configuration. 
         FIG. 7  is a section view of a joint as taken through section lines  7 - 7  in  FIG. 1 . 
         FIG. 8  is an isometric view of a shaft joint of a linking rod. 
         FIG. 9  is an isometric section view of the shaft joint as taken through section lines  9 - 9  in  FIG. 8 . 
         FIG. 10  is an isometric view of a rack, pinion, and linking rod. 
         FIG. 11  is a section view of a leg, linking rod, and support bar as taken through section lines  11 - 11  in  FIG. 3 . 
         FIG. 12  is an exploded isometric view of a handle and leg of the display stand. 
         FIG. 13A  is an isometric view of a clutch and linking rod. 
         FIG. 13B  is an isometric exploded view of the clutch and linking rod of  FIG. 13A . 
         FIG. 14A  is an isometric view of a friction engine. 
         FIG. 14B  is an isometric exploded view of the friction engine of  FIG. 14A . 
         FIG. 15  is a section view of the handle, linking rod, and support bar as taken through section lines  15 - 15  in  FIG. 1 . 
         FIG. 16  is a plot of torque versus displacement for embodiments of a handle, linking rod, and carriage assembly having a gas spring and/or friction engine. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     The following disclosure relates to embodiments of a support stand for multiple displays. When users use multiple displays in a workspace, the displays are generally supported by multiple different individual stands or by independently-movable arms that extend from a single support point. These individual stands or arms unnecessarily take up large spaces, are often aesthetically unpleasing, overcomplicated, and have inefficient redundant mechanisms. When multiple displays are used on independent arms, they can be difficult to align in a smooth and precise way due to inconsistent counterbalancing and arm lengths. When multiple displays are used on a single support, they cannot be effectively adjusted relative to each other about a vertical axis. 
     Aspects of the present disclosure relate to features of a display stand for providing vertical, horizontal, and center pivot degrees of freedom for multiple displays. The stand can have two legs spaced at end portions of the stand (e.g., farther apart than the mounting points of the outermost displays) that are linked by a substantially horizontal support bar. The support bar can be vertically adjustable relative to the legs by synchronized adjustment of carriage assemblies associated with each of the legs. The legs can be referred to as vertical supports or vertical support bases. The vertical position of the support bar can be simultaneously adjusted relative to each of the legs due to a linking rod extending across the length of the support bar. The linking rod can be referred to as a linking shaft or a rotatable shaft. The carriage assemblies can have rack-and-pinion features that are connected to each other by the linking rod, wherein rotation of the linking rod induces equal vertical displacement of the support bar at each leg. The rack-and-pinion features can comprise contact surfaces configured to control their spacing to remain at a pitch diameter of the mesh at all times, thereby ensuring even movement at both ends of the display stand and minimized tooth slippage or binding at the rack and pinion. 
     The horizontal support bar can include an internal space in which shuttle devices are positioned, and the shuttles can be coupled to display support arms extending laterally from the display stand. The support bar can therefore be referred to as a hollow elongated structure with an internal passage for the shuttles, hollow structure being elongated in a generally horizontal direction when the support bar is in an orientation of intended use. The shuttles can be horizontally movable relative to the support bar by using rollers or wheels that ride upon rails through the horizontal support bar. The rollers can constrain the movement of the shuttle devices along two principal planes of motion and can tolerate high moment loads about their moving axis/the longitudinal axis of the support bar. Thus, the rollers can limit movement of the shuttle devices to stay within a single principal plane of motion or to be biased to travel along a single primary axis (e.g., the longitudinal axis of the support bar). 
     The rollers can be arranged on the shuttle devices in a crossing-axis arrangement with pairs of roller wheels being spaced along the length of the shuttle to prevent twisting or turning of the shuttle caused by the weight of an attached display or caused by movement of the shuttle along the rails. At least one of the rollers can be biased into contact with the rail so that the shuttle stays in contact with the rails even if the shape or straightness of the rails vary along the support bar. The rails can have V-shaped profiles to help support the weight of the support arm and display without roller slippage or unnecessarily large biasing forces on the biased roller. 
     The support bar can also be pivotable about a vertical axis positioned between the support legs. In other words, a first portion or segment of the support bar can be pivoted relative to a second portion or segment thereof. The joint can be referred to as a support bar joint and can be a single-pivot joint. The linking rod for vertical adjustment of the support bar can extend through the support bar joint. Segments or portions of the linking rod can be joined to each other within the single-pivot joint by a universal joint that synchronizes rotation of one segment of the linking rod (e.g., a segment in the first portion of the support bar) with another segment (e.g., a segment in the second portion of the support bar). 
     A rotatable handle can be positioned at each end of the support bar, wherein rotation of the handle can adjust the support bar upward and downward along the carriage assemblies. Thus, the handle can be referred to as a carriage adjuster or a rotatable vertical position adjuster for the support bar. The handle can be connected to the linking rod and can rotate the pinion (and the linking rod attached to the pinion) relative to the rack in order to move the carriage assemblies. In some embodiments, the handle can include a slip clutch to limit or prevent over-torqueing the handle and linking rod. The slip clutch can comprise a friction-based rotor and biased plate assembly. The handle can also include a friction engine to help balance input torque required for upward or downward adjustment of the support bar. The friction engine can vary its application of friction based on whether the support bar  106  is moving upward, downward, or is static. 
     These and other embodiments are discussed below with reference to the figures. Those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. Features from one embodiment can be implemented in other embodiments. 
       FIG. 1  shows an isometric view of a display stand  100  according to an embodiment of the present disclosure. The display stand  100  can have a first leg  102  and a second leg  104  that extend at least partially upward and that are linked by a support bar  106  extending horizontally from leg to leg.  FIG. 2  shows another isometric view of the display stand  100  with the support bar  106  in a pivoted or angled configuration relative to the straight or linear position of the support bar  106  shown in  FIG. 1 . As shown in the breakaway isometric view of  FIG. 3 , the support bar  106  can contain movable shuttles  108 .  FIG. 1  shows support arms  110  that extend away from the shuttles  108  of support bar  106  to connect to a pair of separate displays  112 . 
     The display stand  100  can thereby provide support for one or more displays  112 . The displays  112  are shown in diagrammatic broken lines in the figures to show features of the display stand  100  that would otherwise be hidden behind the displays  112 . Each display  112  can comprise an electronic display such as a monitor or similar visual output device for displaying information in pictorial form. A display  112  can comprise a display device (e.g., a thin film transistor liquid crystal display (TFT-LCD) with light-emitting diode (LED) or cold-cathode fluorescent lamp (CCFL) backlighting or an organic light-emitting diode (OLED) display), circuitry, a housing or casing, and a power supply. The display  112  can be configured to connect to a computer using connectors and ports such as a video graphics array (VGA) connector, digital visual interface (DVI) connector, DISPLAYPORT® connector, THUNDERBOLT® connector, wireless electrical communications interfaces, or other related or similar electrical interfaces. 
     The display  112  can comprise a front-facing surface configured to face and display viewable information to the user. The viewable display area of the display  112  can be viewed through or at the front-facing surface. Thus, the front-facing surface can be referred to as a viewing surface. The front-facing surface can be substantially planar and flat, or it can be curved (e.g., cylindrically concave or convex). The display  112  can comprise a rear-facing surface configured to face away from the user. A support arm  110  can be positioned between the rear-facing surface and the support bar  106  or a shuttle  108 . The support arm  110  can be releasably coupled to the display  112  at the rear-facing surface or in a rear side portion of the display  112 . A mounting portion  114  of the support arm  110  can connect the display  112  to the support arm  110 . See  FIG. 1 . 
     The display stand  100  can adjust each display  112  in multiple different ways. By axially rotating one of the handles  116  positioned at the ends of the support bar  106 , the support bar  106  can be moved vertically upward or downward relative to a support surface on which the first and second legs  102 ,  104  are resting. In other words, the longitudinal axes  118 ,  119  of the support bar  106  can be moved along the Z-axis (i.e., in a Z-direction or a height adjustment direction) shown in  FIG. 1  when the handles  116  are rotated (e.g., as indicated by arrows H). Movement of the support bar  106  can also move the shuttles  108 , support arms  110 , and displays  112  that are supported by the support bar  106 , so that vertical movement of the support bar  106  can vertically move components supported by it. 
     The support bar  106  can comprise a joint  120  positioned between the first and second legs  102 ,  104 . Pivoting the support bar  106  at the joint  120 , such as, for example, by moving one of the first and second legs  102 ,  104  relative to the other leg, the display stand  100  can rotate one display  112  relative to the other about a pivot axis  122  that extends vertically through the joint  120  and that is parallel to the Z-axis.  FIG. 1  shows a configuration wherein the support bar  106  has a first segment  124  and a second segment  126  aligned along their respective longitudinal axes  118 ,  119 , and  FIG. 2  shows a configuration wherein the segments  124 ,  126  have respective longitudinal axes  118 ,  119  that are positioned at a non-zero angle and are not coaxial with each other due to pivoting of the segments  124 ,  126  about the pivot axis  122 . Pivoting the support bar  106  can be useful to position the displays  112  at an angle relative to each other (i.e., relative to the pivot axis  122 ) and to keep the lateral outer ends of the displays  112  at a substantially similar viewing distance from the user as compared to the lateral inner ends thereof. In this way, the widths of large side-by-side displays  112  can remain within a minimized range of focal distances from the user as compared to side-by-side displays  112  with viewing surfaces that are aligned in a plane in front of a user. Additionally, pivoting the support bar  106  can help fit the display stand  100  on corner desks or on otherwise curved or angled support surfaces. 
     The shuttles  108  can be movable along the longitudinal axes  118 ,  119  of their respective segments  124 ,  126  of the support bar  106 . For example, the shuttles  108  can move within the support bar  106  along axes parallel to arrows L in  FIG. 1 . The shuttles  108  can therefore be referred to as being laterally displaceable along horizontal axes  118  and  119 . The shuttles  108  can be referred to as slides, carts, or lateral adjustment assemblies. The support arms  110  can move with the shuttles  108 , thereby allowing the displays  112  to move laterally as well. Thus, the displays  112  can be laterally moved nearer toward or farther away from each other as the shuttles  108  are moved within the support bar  106 . In this manner, the displays  112  can be spaced apart to make room between each other (e.g., to serve two different nearby users) or can be approximated to make the workspaces of the displays  112  appear closer to each other and more seamless for a user. 
     The support bar  106  can comprise a generally tubular shape extending from a first end positioned at and around the first leg  102  to a second end positioned at and around the second leg  104 . The joint  120  can be positioned at a midpoint or center of the support bar  106 . In some embodiments, the joint  120  can be positioned off-center, such as nearer to one leg  102 ,  104  than the other or nearer to one end of the support bar  106  than another. The support bar  106  can include lateral slots  128  through which the shuttles  108  can be seen or through which the support arms  110  are connected to the shuttles  108 . The lateral slots  128  can be referred to as longitudinal slots since they can extend parallel to the longitudinal axes  118 ,  119 . The lateral slots  128  can extend along a portion of each segment  124 ,  126 , and the lengths of the slots  128  can correspond to the maximum range of the support arms  110  relative to the support bar  106 . In other words, the support arms  110  can contact the terminal ends of the lateral slots  128  at the ends of their range of lateral movement. In some embodiments, the shuttles  108  within the support bar  106  prevent the support arms  110  from reaching contact with the ends of the lateral slots  128 . 
     With reference to  FIGS. 3-5 , the support bar  106  is shown having a top rail  130  and a bottom rail  132 .  FIGS. 3 and 4  show the support bar  106  with portions of its tubular body  134  removed to show internal detail of the rails  130 ,  132  and shuttle  108 .  FIG. 5  is a cross-section of the support bar  106  taken through the center of the shuttle  108  at section lines  5 - 5  in  FIG. 4 . 
     The top and bottom rails  130 ,  132  can be integrally formed with the tubular body  134  of the support bar  106 . See  FIG. 5 . The lateral slots  128  can be formed longitudinally along the tubular body  134 . The tubular body  134  can have a longitudinally-oriented internal void  136  extending along the rails  130 ,  132  and in which the shuttle  108  moves. See  FIG. 5 . The support bar  106  can be oriented with the rails  130 ,  132  positioned at the vertical top and bottom of the internal void  136  (i.e., aligned with a vertical axis through the support bar  106  that is perpendicular to a horizontal plane through the lateral slots  128 ). The rails  130 ,  132  can therefore be respectively positioned at “12-o&#39;clock” and “6-o&#39;clock” positions within the support bar  106 . The purposes for the positioning of the rails  130 ,  132  is explained in further detail below. 
     As shown in  FIG. 5 , the rails  130 ,  132  can each have a generally V-shaped cross-sectional profile, wherein the V-shaped profile of the top rail  130  is pointed downward and the V-shaped profile of the bottom rail  132  is pointed upward, or wherein each profile points radially inward or toward the longitudinal axis of the support bar  106 . Thus, each of the rails  130 ,  132  can comprise at least two shuttle contact surfaces  138  facing in different directions. In some embodiments, the contact surfaces  138  are oriented about 90 degrees offset relative to each other, and in some embodiments, they are oriented about 120 degrees offset. The shuttle contact surfaces  138  can each be substantially planar along the length of the support bar  106  and can be referred to as roller surfaces, roller contact surfaces, or wheel contact surfaces. 
     A shuttle  108  can comprise a shuttle body  140  on which five static wheels  142  and one biased wheel  144  are located. See  FIGS. 4-5 . The wheels  142 ,  144  can also be referred to as rollers, drums, disks, or turnable/turning contact members. The biased wheel  144  can also be referred to as a compliant wheel, compliant roller, or a wheel on a compliant member. The wheels  142 ,  144  can comprise generally cylindrical members configured to rotate about a longitudinal axis of the cylinder shape, balls (e.g., ball bearings), or other rollable or turnable structures that minimize friction or primarily apply rolling friction between the shuttle body  140  and the rails  130 ,  132 . In some embodiments, the wheels  142 ,  144  can have a diameter of about 18 millimeters, thereby making the rolling movement of the shuttle  108  resistant to small debris, dust, sticky residues, and related substances as compared to wheels or ball bearings with about 3 millimeter diameters (or similar). The wheels  142 ,  144  shown in  FIG. 5  are shown with curved surfaces configured to contact the contact surfaces  138 . In some embodiments, the surfaces of the wheels  142 ,  144  configured to contact the contact surfaces  138  are cylindrical and therefore have a constant, “flat” radius from their axes of rotation across their width. The surfaces of the wheels  142 ,  144  can comprise plastic or another non-marking, durable material. In some embodiments, the biased wheel  144  can comprise a compressible or elastic material configured to help ensure constant contact between the wheel  144  and its contact surface  138 . 
     Two of the static wheels  142  can be positioned at a first end  146  (see  FIG. 4 ) of the shuttle body  140 , two other static wheels  142  can be positioned at a second, opposite end  148  (see  FIG. 4 ) of the shuttle body  140 , and one other static wheel  142  can be positioned at a center of the shuttle body  140  underneath the biased wheel  144 . The static wheels  142  can have individual axes of rotation that are stationary relative to the shuttle body  140 . The two static wheels  142  at the first end  146  can have axes of rotation that intersect (e.g., perpendicularly intersect) at the first end  146  (e.g., at axis  118 ), and the two static wheels  142  at the second end  148  have axes of rotation that intersect (e.g., perpendicularly intersect) at the second end  148  (e.g., at axis  118 ). In some embodiments, the intersections of these pairs of axes of rotation can be centered in the respective centers of the first and second ends  146 ,  148 . 
     The upper static wheels  142  (i.e., one at each of the first and second ends  146 ,  148 ) and the lower center static wheel  142  (below the biased wheel  144 ) can be configured to primarily bear the weight of the display  112  and support arm  110 . Those wheels  142  are urged into contact with the shuttle contact surfaces  138  when a moment M (see  FIG. 5 ) is applied to the shuttle  108  by the weight W of the display  112  and support arm  110  via an arm link  152  attached to the shuttle body  140 . The other two static wheels  142  can contact the rails  130 ,  132  as a result of the weight W (see  FIG. 5 ) of the support arm  110  and display  112  acting on the arm link  152 , thereby driving it downward, and as a result of a biasing force applied to the biased wheel  144  that drives the biased wheel  144  in direction C, which is directed at an about 45-degree angle upward relative to a horizontal plane and which is perpendicular to its axis of rotation  154  (see  FIG. 5 ). 
     The biased wheel  144  can be biased along a direction perpendicular to its axis of rotation, such as in direction C in  FIG. 5 . Thus, the outer surface of the biased wheel  144  can be biased into contact with a shuttle contact surface  138  of the top rail  130 . The force applied by the biased wheel  144  to the shuttle contact surface  138  of the top rail  130  can also urge the lower static wheels  142  at the ends  146 ,  148  into contact with the shuttle contact surface  138 . 
     As shown in  FIG. 4 , the biased wheel  144  can be mounted to a biased bar  156  that is pivotally attached to the shuttle body  140  at a pivot point  150  at a first end  160  and that is attached to an elastic device  162  at a second end  164 . The elastic device  162  can be a spring, elastomeric block, or similar structure configured to resiliently apply a force against the second end  164  that causes the second end  164  to be biased to rotate about an axis of rotation extending through the pivot point  150 . The pivot point  150  can comprise a fastener (e.g., a bolt or similar structure) having a longitudinal axis coinciding with the axis of rotation of the biased bar  156 . The biased bar  156  has the biased wheel  144  positioned along its length and accordingly moves the biased wheel  144  into the rail  130  when the second end  164  moves relative to the first end  160 . The biased bar  156  can have the elastic device  162  positioned further from the pivot point  150  than the biased wheel  144  in order to provide leverage and to magnify the force applied by the wheel  144  to the rail  130  as a result of the force applied by the elastic device  162 . 
     As the shuttle  108  moves along the rails  130 ,  132 , the rails  130 ,  132  can have variation in their straightness, their relative positioning (e.g., they are not precisely parallel), the thickness between their contact surfaces  138 , and other types of variation within tolerances and nominal dimensions. Additionally, parts of the shuttle  108  can have variation, such as the size and relative positioning of the wheels  142 ,  144 . A shuttle  108  having all-static wheels would therefore not consistently roll with all six wheels  142 ,  144  in contact with the rails  130 ,  132  because the variation of the shuttle  108  and rails  130 ,  132  would have some wheels separated at certain points along the support bar  106 . 
     The bottom rail  132  being below the three bottom static wheels  142  (that are arranged with 90-degree offset axes (as shown in  FIG. 5 )) ensures that gravity pulls those wheels  142  of the shuttle  108  into contact with both of the contact surfaces  138 . The biased wheel  144  applies a force to the contact surface  138  of the top rail  130  that makes the top two static wheels  142  also each contact a contact surface  138  of the top rail  130 . If there is variation in the rails  130 ,  132 , the biased wheel  144  can enable the shuttle  108  to accommodate for those changes by the biased wheel  144  rotating its axis of rotation about the longitudinal axis  118  to positions closer or farther from the position of axis  154  in  FIG. 5  as the shuttle  108  moves along the longitudinal axis. If the biased wheel  144  rotates, the other static wheels  142  can also stay in contact with the contact surfaces  138  due to the rest of the shuttle  108  rotating or being pulled down by gravity and by the weight W and moment M at the arm link  152 . 
     The top-and-bottom configuration of the top and bottom rails  130 ,  132  relative to the internal void  136  and tubular body  134  can also be beneficial in keeping the shuttle  108  on the rails  130 ,  132  while the weight W or moment M of the support arm  110  and display  112  are applied to the arm link  152 . The static wheels  142  on the bottom sides of the ends  146 ,  148  support the weight W when the arm link  152  is loaded. If the rails  130 ,  132  and shuttle  108  were positioned 45-degrees offset from the positions shown in  FIG. 5 , such as in a configuration wherein top rail  130  would be centrally aligned with the position shown for axis of rotation  154 , the bottom static wheels  142  at the ends  146 ,  148  would have horizontal axes of rotation and would have a tendency to slide relative to the contact surfaces  138 , especially if a moment about a vertical axis were applied to one end  146  to rotate that end  146  relative to the opposite end  148 . The biased wheel  144  would have to be very strongly biased in order to prevent movement or rotation of the shuttle  108  on the rails in that case, and a strong elastic device  162  would inefficiently take up more space and weight in the shuttle  108 . However, if the same moment about a vertical axis were applied to the embodiment as shown in  FIG. 5 , the shuttle  108  is more stable and rigid because none of the wheels  142 ,  144  have horizontal axes (i.e., axes perpendicular to the axis about which the moment is applied). The wheels  142 ,  144  can therefore be less susceptible to slipping on the contact surfaces  138 . As a result, the elastic device  162  does not need to be as forceful in order to keep the shuttle  108  properly positioned in the support bar  106 . 
     The shuttles  108  can also comprise an inner channel  166 . The inner channel  166  can extend longitudinally through the entire length of the shuttle body  140  and can have a diameter (or a width, if it is not circular in profile) larger than the diameter (or width) of linking rod  168 . The inner channel  166  can also be referred to as a longitudinal channel, a longitudinal passage, or a rod-receiving aperture. The shuttles  108  can therefore have a hollow interior channel and can translate along the length of the linking rod  168  without contacting the linking rod  168 . For this reason, the linking rod  168  can axially rotate while extending through a shuttle  108  without causing the shuttle  108  to also rotate. In other words, the rotation of the linking rod  168  can be independent of the shuttle  108 . The linking rod  168  can be used to adjust the height of the support bar  106 , as explained in further detail elsewhere herein. 
     The support arms  110  can extend from the arm links  152  on each shuttle  108 . The support arms  110  can be pivotable relative to the shuttles  108 , wherein each support arm  110  can be rotated about a pivot axis through the support arm  110  that is parallel to the longitudinal axis  118 / 119  of the shuttle  108  to which it is connected. In this manner, the vertical position of one display  112  can be adjusted independent of the other display  112 . This vertical position adjustment can differ from the vertical adjustment of the support bar  106  by way of the handles  116  because each display  112  is adjusted independently rather than all displays and the support bar  106  being simultaneously vertically moved. The support arms  110  can move longitudinally parallel to the longitudinal axis  118 / 119  of the individual segment  124 ,  126  they extend from. The support arms  110  can also comprise mounting portions  114  or other connectors configured to attach the displays  112  to the support arms  110 . A mounting portion  114  can be rotatable relative to the rest of the support arm  110  to which it is attached in order to provide tilting of the display  112  relative to the support arm  110  (i.e., rotation of the display  112  about a longitudinal axis parallel to the longitudinal axis  118 ,  119  of the segment  124 ,  126  to which it is mounted). 
     The joint  120  can be positioned at a midpoint of the support bar  106 . The joint  120  can be a single pivot joint having a single axis of rotation  122  between the two segments  124 ,  126 .  FIG. 6A  shows a side view of the joint  120  with the support bar  106  removed. The joint  120  can comprise a first joint portion  170  pivotally connected to a second joint portion  172 . In  FIG. 6A , the joint  120  is in a fully extended or linear configuration, wherein the linking rod  168 , the first and second joint portions  170 ,  172 , and the longitudinal axes  118 ,  119  are coaxial with each other. This configuration is also shown in  FIG. 1 .  FIG. 6B  shows a top view of the joint  120  with the joint  120  in a pivoted or angled configuration, wherein the linking rod  168 , the first and second joint portions  170 ,  172 , and the longitudinal axes  118 ,  119  are angled relative to each other. In some embodiments, the range of deflection of the joint  120  can be from about 0 degrees to about 40 degrees (forward or backward). 
     The tubular body  134  of each segment  124 ,  126  of the support bar  106  can be affixed to a corresponding first or second joint portion  170 ,  172 . Accordingly, the linking rod  168  can rotate within and relative to the first and second joint portions  170 ,  172 .  FIG. 7  is a front view central cross-section of the joint  120  as taken through section lines  7 - 7  in  FIG. 1 . The linking rod  168  can have a first portion  171  within the first segment  124  and within the first joint portion  170  and can have a second portion  173  within the second segment  126  and within the second joint portion  172 . The tubular body  134  of each segment  124 ,  126  can be concentric with its respective joint portion  170 ,  172  and with its respective portion of the linking rod  168 . The first joint portion  170  and second joint portion  172  can be respectively connected to a first pivot connector  174  and a second pivot connector  176 . 
     The first pivot connector  174  can have an opening  178  into which the second pivot connector  176  can be positioned and through which the first and second portions  171 ,  173  of the linking rod  168  can extend. In some embodiments, the first pivot connector  174  can have a fork-like shape with a top portion  180  and a bottom portion  182  respectively positioned above and below the second pivot connector  176  (i.e., on opposite sides of the opening  178 ). The first and second pivot connectors  174 ,  176  can rotate relative to each other about vertical axis  122  in the manner shown in  FIGS. 6A-6B . A top fastener  184  and bottom fastener  186  can join the first and second pivot connectors  174 ,  176  along the vertical axis  122 , thereby preventing the first and second pivot connectors  174 ,  176  from being laterally pulled apart from each other. 
     A set of bushings  188  can be positioned between the first and second pivot connectors  174 ,  176  and the fasteners  184 ,  186  to allow sliding relative movement of the first and second pivot connectors  174 ,  176  and the first pivot connector  174  and the fasteners  184 ,  186  while the fasteners  184 ,  186  are affixed to (and not pivotable relative to) the second pivot connector  176 . The bushings  188  can comprise a size and material composition configured to provide a predetermined amount of friction to the joint  120 . For example, the bushings  188  can comprise brass, nylon, or other common materials for joint bushings in order to ensure that joint  120  movement is smooth, reversible, and neither requiring too much nor too force little to change the angle between the first and second pivot connectors  174 ,  176 . The friction at the bushings  188  can be controlled by tightening or loosening the top fastener  184 , such as, for example, by advancing it downward or upward relative to the second pivot connector  176 . 
     A biased washer  190  or similar compression-biased structure such as a compression spring, Belleville washer, or “wavy washer” can be positioned between the top fastener  184  and the bushings  188  or the first pivot connector  174 , and the biased washer  190  can increase the magnitude of a normal force between the first and second pivot connectors  174 ,  176  at the bushings  188  that provide friction surfaces between those connectors  174 ,  176 . Accordingly, the amount of frictional resistance to pivoting the joint  120  can be controlled by the set of bushings  188  and the position of the top fastener  184  relative to the second pivot connector  176 . The friction preload on the joint  120  can be controlled independent of the rigidity of the coupling by adjusting pressure on the biased washer  190 , changing the biased washer  190  for a different one, or removing it. 
     The first and second pivot connectors  174 ,  176  can each have central openings through which the first and second portions  171 ,  173  of the linking rod  168  can extend and connect to each other at a universal joint  192 . The universal joint  192  can move without contacting the first and second pivot connectors  174 ,  176  or the fasteners  184 ,  186 . The universal joint  192  can transfer axial rotation of the first portion  171  into axial rotation of the second portion  173  at any rotated angle between the first and second portions  171 ,  173  and at a ratio of about 1:1. Accordingly, the universal joint  192  within joint  120  can transfer rotation in a manner wherein rotation of the first portion  171  (e.g., as caused by rotation of a handle  116  connected thereto) can cause equal rotation of the second portion  173 . This can be beneficial to synchronize the vertical movement of the support bar  106  at each leg  102 ,  104  using the rack and pinion features at the carriage assemblies. See  FIGS. 3, 10, and 11  and their related descriptions herein. 
     The display stand  100  can have no support pillars underneath the joint  120  and can be free-floating relative to a support surface below the display stand  100  at the ends of the segments  124 ,  126  of the support bar  106  that are coupled to each other at first and second pivot connectors  174 ,  176 . This can beneficially allow the space between the legs  102 ,  104  to be open and to take up less room on a support surface. The support surface can therefore have more space for input devices, computers, and related components connected to the displays  112 . 
     The linking rod  168  can comprise shaft joints  194  as shown in  FIGS. 3, 4, 6A, 6B, 8 , and  9 . Each shaft joint  194  can be a position at which a portion (e.g., second portion  173 ) of the linking rod  168  is connected to another portion thereof (e.g., third portion  175  in  FIG. 8 ). In this example embodiment, the second portion  173  can be referred to as a middle portion since it extends from the shaft joint  194  to the middle of the linking rod  168 , and the third portion  175  can be referred to as an end portion since it extends from the shaft joint  194  to the outer end of the linking rod  168  at the handle  116 . 
     The middle portion and end portion can be attached to each other by a pair of fasteners  196 . As shown in the section view of  FIG. 9  (which is an isometric section view taken through section lines  9 - 9  in  FIG. 8 ), the fasteners  196  can extend through the middle and end portions. Accordingly, axial rotation of the middle portion is synchronized with axial rotation of the end portion. Using two fasteners  196  can help prevent the middle and end portions from rotating relative to each other about an axis extending parallel to a longitudinal axis of a fastener  196  (e.g., axis F in  FIG. 9 ). 
     The end of the middle portion of the linking rod  168  can comprise an inverted V-shaped recess having two downward-facing sloped surfaces  198 , and the end portion of the linking rod  168  can comprise a corresponding V-shaped surface with two upward-facing sloped surfaces  200 . The sloped surfaces  198 ,  200  can contact each other when the middle portion and end portion are fastened together by the fasteners  196 . The angle between each of the downward-facing sloped surfaces  198  and the angle between each of the upward-facing sloped surfaces  200  can be substantially equal to each other to provide a mating fit as shown in  FIG. 9 . In some embodiments, the angle is about 120 degrees. The mating contact of those surfaces  198 ,  200  can keep the middle portion and end portion from moving relative to each other in a plane perpendicular to the longitudinal axis of the linking rod  168  or from rotating about an axis perpendicular to the longitudinal axis of the linking rod  168 . The mating contact between the surfaces  198 ,  200  can also be radially self-aligning. The surfaces  198 ,  200  can be formed by machining the middle and end portions of the linking rod  168 . 
     When assembling the linking rod  168 , the sloped surfaces  198 ,  200  can be placed in contact with each other before the fasteners  196  are applied, and the fasteners  196  can then be positioned through openings  202 ,  204  in the middle and end portions. See  FIGS. 9 and 13A . The middle portion and end portion of the linking rod  168  can each comprise two openings  202 / 204 . At least one pair of openings  202 ,  204  can have an elongated longitudinal dimension rather than being circular to receive the fasteners  196 . See  FIG. 13A . In some embodiments, the elongation is about one millimeter greater than the diameter of the fasteners  196 . For this reason, the axial positions of the middle and end portions (i.e.,  173 ,  175 ) can be longitudinally tuned. Fasteners  196  can be applied to keep the middle and end portions held together in a first position, or the fasteners  196  can be loosened and can slide between different longitudinal positions (within the elongated openings  202  or  204 ) to lengthen or shorten the overall length of the linking rod  168 . 
     Accordingly, moving the fasteners along the elongated openings can adjust and tune axial misalignment (i.e., improper length) of the linking rod  168  in order to ensure smooth operation of the handle  116  and universal joint  192  despite variation of the manufactured length of the linking rod  168 . Assembling the linking rod  168  rather than using a single-piece linking rod  168  can also be beneficial for streamlining manufacturing and allowing easier adjustment or maintenance of the display stand  100  after manufacturing. The fasteners  196  can also be accessed through the lateral slots  128  in the support bar  106  for adjustment of the linking rod  168  after assembly of the display stand  100 . 
     In some embodiments, the second and third portions  173 ,  175  can also have equal overall diameters adjacent to the shaft joint  194 . The fasteners  196  can be recessed into at least one of the second or third portions  173 ,  175  in order to ensure that application of the fasteners  196  do not increase the overall diameter of the linking rod  168  at the shaft joint  194 . An example set of recesses is shown in  FIG. 13A  and around the heads of the fasteners  196  in  FIGS. 8 and 9 . The maximum overall diameter of the linking rod  168  can therefore be sufficiently small enough to pass through the inner channel  166  of the shuttle  108  without contacting the shuttle body  140 . Accordingly, the shuttle  108  can move longitudinally across the shaft joint  194  without interfering with operation of (or contact between) the shuttle  108  or linking rod  168 . The shaft joints  194  can have high coupling strength in a small volume, and their coupling strength can be independent of the surface finish of the linking rod  168 . 
     The first and second legs  102 ,  104  can each comprise a carriage assembly. One carriage assembly  206  is shown within second leg  104  in  FIGS. 3 and 11 , and a similar carriage assembly (e.g., one that is a mirror image across axis  122 ) can be included in the first leg  102 . The carriage assembly  206  can include an energy storage device  208 , a bearing  210 , and a rack  212 . 
     The energy storage device  208  can comprise a spring (e.g., a gas spring, elastic coil spring, power spring, torsion spring, or constant force spring) or other energy storage structure configured to store energy and to act as a counterbalance for the movement of the weight of the support bar  106 , shuttles  108 , support arms  110 , displays  112 , and other movable components of the display stand  100 . The energy storage device  208  can therefore be configured to store potential energy as the support bar  106  moves downward (i.e., as the support bar  106  and attached components lose potential energy) and can be configured to release potential energy as the support bar  106  moves upward. In this manner, movement of the support bar  106  can require reduced force input as compared to moving the entire support bar  106  without counterbalance assistance. The energy storage device  208  can be attached to a vertically translatable portion  214  of the bearing  210 . 
     The vertically translatable portion  214  of the bearing  210  can be vertically translatable along a vertical axis through the leg  104  relative to a static portion  216  of the bearing  210  attached to the leg  104 . See  FIGS. 3 and 11 .  FIG. 11  is a top end section view taken through the leg  104  and support bar  106  as indicated by section lines  11 - 11  in  FIG. 3 . The vertically translatable portion  214  can be attached to the tubular body  134  that surrounds the leg  104 , and the vertically translatable portion  214  can therefore move with the support bar  106 . The bearing  210  can be configured to prevent movement and rotation of the vertically translatable portion  214  except along the vertical direction (i.e., along axis V in  FIG. 3 ). 
     As shown in  FIGS. 10-11 , the rack  212  can comprise a set of gear teeth  218  formed within and extending across a portion of a planar surface  220 . Each lateral side of the planar surface  220  can be a flat and smooth shoulder  222 ,  224  lacking protrusions or recesses. The rack  212  can be positioned on a rear-facing surface of the leg  104  (i.e., a surface facing away from the lateral slots  128  and generally configured to face away from the displays  112 ). Thus, the planar surface  220  can be a rear-facing surface. 
     The rack  212  can be engaged by a pinion  225  which is coaxial with and located on (or integrally part of) the end portion/third portion  175  of the linking rod  168 . The pinion  225  can comprise a gear surface comprising teeth  226  sized and shaped to engage and enmesh with the teeth  218  of the rack  212 . The pinion  225  can also have two laterally adjacent shoulder surfaces  228 ,  230  configured to engage and roll against the smooth shoulders  222 ,  224  of the rack  212 . The shoulder surfaces  228 ,  230  can be an integral part of the pinion body in which the teeth  226  are formed or can be positioned on separate parts that are combined with or assembled onto the pinion  225 . 
     Rotational movement of the pinion  225  can drive vertical movement of the linking rod  168  at each end of the linking rod  168  due to the pinions  225  at each end of the linking rod  168 , as shown in  FIGS. 6A-6B . The vertical movement of the linking rod  168  as it rotates can also induce vertical movement of the support bar  106  as a whole due to simultaneous movement of the vertically translatable portion  214  of the bearing  210  of the carriage assembly  206 . Accordingly, application of an input moment N to the linking rod  168  (see  FIG. 10 ) can cause vertical translation of the entire support bar  106 . 
     When the support bar  106  is loaded with the weight of the displays  112 , their weight can pull forward on the legs  102 ,  104  in direction P in  FIG. 11 . The pinion  225  can also be pulled into the rack  212  parallel to direction P. While this force is applied, the gear teeth  218 ,  226  can be prevented from overmeshing or undermeshing by the engagement of the rack  212  and pinion  225  being limited by contact between the shoulder surfaces  228 ,  230  and the smooth shoulders  222 ,  224 . The diameter of the shoulder surfaces  228 ,  230  can be equal to a pitch diameter of the mesh of the rack  212  and pinion  225 , and the smooth shoulders  222 ,  224  can be set to the pitch height or pitch diameter of the mesh as well. Accordingly, as the shoulder surfaces  228 ,  230  roll against the smooth shoulders  222 ,  224 , the distance between the gear teeth  218 ,  226  can be limited by the mechanical contact between the shoulder surfaces  228 ,  230  and the smooth shoulders  222 ,  224 . Furthermore, because the shoulder surfaces  228 ,  230  are pulled against the smooth shoulders  222 ,  224  by the weight of the displays  112 , they can always be at the proper distance from each other to limit slippage or binding of the gear teeth  218 ,  226  that can be caused by over- or undermeshing. 
     As shown in  FIG. 12 , a handle  116  can be attached to a terminal end  177  of the linking rod  168 . A similar handle  116  can be attached to the opposite terminal end of the linking rod  168 , as shown in  FIG. 1 . A handle  116  can comprise a clutch  232  and a friction engine  234  positioned within a shell  236  and cap  238 .  FIGS. 13A-13B  respectively show an isometric view and an exploded view of the clutch  232 ,  FIGS. 14A-14B  respectively show an isometric view and an exploded view of the friction engine  234 , and  FIG. 15  shows a side central cross-section of the display stand  100  at the handle  116  as taken through section lines  15 - 15  in  FIG. 1 . The handles  116  can support ambidextrous input, wherein operating a handle  116  on either end of the support bar  106  can raise or lower the support bar  106 . 
     The clutch  232  can be used to prevent torque applied to the shell  236  of the handle  116  from over-torqueing the linking rod  168 . For example, the clutch  232  can slip when the top or bottom of the range travel of the support bar  106  is reached and the user continues to apply a torque to respectively move the bar upward or downward. Similarly, the clutch  232  can slip when opposite handles  116  are sufficiently torqued in opposite directions. 
     As shown in  FIGS. 13B and 15 , the clutch  232  can comprise a rotor  240 , a floating plate  242 , and a backing plate  244  that are all axially aligned. The floating plate  242  can contact the outer side of the rotor  240 , and the backing plate  244  can contact the inner side thereof. The clutch  232  can also include a set of biasing devices  246  to apply a biasing force to the floating plate  242  and, in turn, to the rotor  240 . The biasing devices  246  can be springs such as, for example, Belleville springs or elastically compressible washers. The rotor  240  can be fixed to a shaft  248  that is fixed to the third end  177  of the linking rod  168  via a bearing  252 . The rotor  240 , shaft  248 , and linking rod  168  can be fixed relative to each other and can therefore have their axial rotation synchronized. 
     The floating and backing plates  242 ,  244  can frictionally engage opposite sides of the rotor  240 , and the carrier  250  can be fixed to the backing plate  244 . Accordingly, rotation of the carrier  250  can be synchronized with rotation of the backing plate  244  and rotor  240  insofar as the force of the frictional engagement between the backing plate  244  and rotor  240  is not overcome. For example, when a low input torque (along arrow H in  FIG. 1 ) is applied to the carrier  250  via the shell  236 , the entire clutch  232  can axially rotate with the linking rod  168 . As the input torque increases, a threshold torque can be reached wherein the torque overcomes the frictional engagement between the rotor  240  and the backing plate  244  and therefore causes the rotor  240  to slip relative to the backing plate  244 . As a result, the input torque does not cause rotation of the linking rod  168 . The clutch  232  can therefore be referred to as a slip clutch. 
     The threshold input torque can be dependent upon the magnitude of the force applied by the biasing devices  246  to the floating plate  242 . Accordingly, the threshold input torque can be controlled by longitudinal adjustment of a friction preload screw  254  that compresses, or allows the biasing devices  246  to expand, relative to the floating plate  242 . The clutch  232  can therefore limit over-torqueing the linking rod  168  while transferring torque below a threshold torque value that can safely rotate the linking rod  168  and can thereby adjust the vertical position of support bar  106  using the carriage assembly  206 . 
     As shown in  FIGS. 14A-14B , the friction engine  234  can include an outer carrier  256 , inner carrier  258 , a bearing  260 , a first set of plates  262 , a second set of plates  264 , a biasing device  266 , and a retaining collar  268 . The outer carrier  256  can comprise a plate protrusion retainer opening  270  in which plate protrusions  272  of the first set of plates  262  can be positioned (see  FIG. 14A ). The inner carrier  258  can have a plate protrusion retainer opening  274  to receive plate protrusions  276  of the second set of plates  264 . See  FIG. 14B . The radially-outward-extending plate protrusions  272  of the first set of plates  262  can synchronize axial rotation of the first set of plates  262  with rotation of the outer carrier  256 . The radially-inward-extending plate protrusions  276  of the second set of plates  264  can synchronize axial rotation of the second set of plates  264  with the rotation of the inner carrier  258 . The biasing device  266  can apply a biasing force that urges the first and second sets of plates  262 ,  264  into frictional engagement with each other. The retaining collar  268  can hold the biasing device  266  in place. 
     Axial rotation of the inner carrier  258  and second set of plates  264  can be synchronized with axial rotation of the bearing  252  and linking rod  168 . Axial rotation of the outer carrier  256  can be synchronized with rotation of the shell  236 . The outer carrier  256  and first set of plates  262  can rotate independent of the inner carrier  258 , subject to overcoming friction between the first and second sets of plates  262 ,  264 . Accordingly, a predetermined minimum input torque must be applied to the shell  236  in order to induce slippage between the first and second sets of plates  262 ,  264 . 
     In some embodiments, the bearing  260  can be a one-way locking needle roller bearing. Thus, when rotating the handle  116  to move the support bar  106  upward, the bearing  260  can allow free rotation of the inner bearing  252 . Thus, the friction between the first and second sets of plates  262 ,  264  can be reduced or eliminated. In a static hang configuration (i.e., rotation to move the support bar  106  downward), the bearing  260  can lock relative to the inner bearing  252 , and the second set of plates  264  can be held stationary by friction relative to the first set of plates  262 . This can provide a reaction torque to the hanging weight of the displays  112  and support bar  106 . 
     The friction engine  234  can therefore provide a friction-based minimum threshold for rotational movement of the handle  116 , and, accordingly, can also provide a friction-based minimum threshold for vertical movement of the support bar  106 . This friction-based minimum threshold can help make upward and downward movement of the support bar  106  require more similar amounts of input torque for movement in either direction as compared to a handle  116  only supported by the counterbalance of the energy storage device  208  (i.e., a gas spring). The clutch  232  and friction engine  234  can be independently adjusted respectively using the preload screw  254  and retaining collar  268 . 
     As shown in the chart  1600  of  FIG. 16 , when the friction engine  234  is used, the input torque required to start displacing the support bar  106  downward from the top of the range of its possible vertical travel can be between about 0.45 and 0.5 Newton-meters. As the support bar  106  travels downward, the input torque required can increase to about 0.6 Newton-meters upon reaching about 80 millimeters of downward displacement. When moving the support bar  106  upward from an 80-millimeter displacement position, the input torque can be between about 0.45 and 0.5 Newton-meters, and as the support bar  106  travels upward, the input torque can increase to between about 0.6 to about 0.65 Newton-meters. 
     By comparison, when the friction engine  234  is not used, and only the carriage assembly  206  is used for counterbalancing the support bar  106 , the torque required to displace downward from zero downward displacement is about 0.35 Newton-meters and gradually increases to between about 0.5 to about 0.55 Newton-meters at 80 millimeters of downward displacement. Moving the support bar  106  upward requires between about 0.45 and about 0.5 Newton-meters of torque at 80 millimeters of downward displacement that gradually increases to about 0.6 Newton-meters of torque at zero downward displacement. 
     Accordingly, at zero downward displacement, there is an about 0.25 to about 0.3 Newton-meter difference between moving the support bar  106  upward versus moving it downward when only the carriage assembly  206  is used. With the friction engine  234  being used, the difference is between about 0.1 and about 0.15 Newton-meters. Therefore, a user rotating the handle  116  does not feel as large of a difference between the torque required to move the support bar  106  upward versus downward when the friction engine is used. At 80 millimeter displacement, there is a larger difference between moving the friction engine-enhanced support bar  106  upward and downward as compared to an embodiment without the friction engine  234 , but the difference between upward and downward motion with the friction engine at 80 mm is very similar in the difference at zero millimeters (i.e., about 0.1-0.15 Nm). For this reason, a handle  116  using the friction engine  234  can feel more consistent with respect to how much torque is required to move the support bar  106  whether the support bar  106  is at a low position (e.g., 80 mm in  FIG. 16 ) or a high position (e.g., 0 mm in  FIG. 16 ). 
     This behavior can be provided because the friction engine  234  can resist vertical movement of the support bar  106 . Accordingly, a portion of the weight of the support bar  106  is supported by the friction engine  234 , and the energy storage device  208  does not need to store as much potential energy to help counterbalance and move the support bar  106 . The energy storage device  208  can therefore have a lower energy storage capacity or rating, which generally means the energy storage device  208  can be smaller in size, quieter, and easier to use in the leg  104 . 
     Additionally, in various configurations, the display stand  100  can use two displays  112 , one display  112 , or no displays. The energy storage device  208  therefore must be configured to counterbalance movement of the support bar  106  under multiple different loading conditions. The friction engine  234  can provide consistent support for the weight of the support bar  106  irrespective of the number of displays  112  held by the support bar  106  and can therefore give more similar torque profiles (as shown in  FIG. 16 ) for those different loading conditions. The user can be required to give an on-average higher, but more consistent, input torque to move the support bar  106  under various loading conditions. 
     To the extent applicable to the present technology, gathering and use of data available from various sources can be used to improve the delivery to users of invitational content or any other content that may be of interest to them. The present disclosure contemplates that in some instances, this gathered data may include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, TWITTER® ID&#39;s, home addresses, data or records relating to a user&#39;s health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other identifying or personal information. 
     The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver targeted content that is of greater interest to the user. Accordingly, use of such personal information data enables users to calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. For instance, health and fitness data may be used to provide insights into a user&#39;s general wellness, or may be used as positive feedback to individuals using technology to pursue wellness goals. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of or access to certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide mood-associated data for targeted content delivery services. In yet another example, users can select to limit the length of time mood-associated data is maintained or entirely prohibit the development of a baseline mood profile. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app. 
     Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user&#39;s privacy. De-identification may be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods. 
     Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publicly available information. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not target to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20190916
Publication Date: 20220628
Grant Date: 20220628
Priority Date: 20190531
Inventors: LECLERC, MICHAEL E.
DEGNER, BRETT W.
MCBROOM, Danny L.
NARAJOWSKI, DAVID H.
ENDISCH, DENIS H.
LAURENT, KRISTOPHER P.
TRIVETT, Simon J.
Assignee: APPLE INC
CPC Classifications: [{"code": "F16M11/425", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16M11/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16M11/046", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16M11/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16M2200/06", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16M11/045", "inventive": true, "first": true, "tree": "[]"}, {"code": "F16M11/045", "inventive": true, "first": true, "tree": "[]"}, {"code": "F16M11/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16M11/2014", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16M2200/066", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16M11/045", "inventive": true, "first": true, "tree": "[]"}, {"code": "F16M11/046", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16M11/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16M2200/066", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 73551391