Adjustable durable hinge with cable routing

Abstract

An adjustable resistance hinge includes a first leaf assembly, a second leaf assembly, and a friction core assembly enclosed within a continuous hollow cylinder formed by the first and second leaf assemblies. The friction core assembly includes a hollow cam, a hollow shaft, and a fastener assembly. The hollow cam is prevented from rotating within the first leaf assembly by mating structures and includes a cam friction surface. The hollow shaft includes a first end inserted through the hollow cam, a second end with mating structures that prevents the hollow shaft from rotating within the second leaf assembly, and a middle portion that includes a shaft friction surface. The fastener assembly is coupled with the first end of the hollow shaft and maintains pressure between the shaft friction surface and the cam friction surface, thereby providing adjustable resistance to rotation of the cam with respect to the shaft.

Description

ADJUSTABLE DURABLE HINGE WITH CABLE ROUTINGBACKGROUND

[0001] Increasing numbers of electronic devices include electronic components separated by one or more hinges that allow the electronic components on each side of the electronic device to be closed onto one another or opened away from each other. For example, laptop computers, tablet computer cases, and even mobile phones include one or more hinges that allow one portion to be supported by, and move relative to, another portion. However, while many hinges may be primarily designed to provide a desirable range of motion, additional design considerations may be required when integrating them into electronic devices.SUMMARY

[0002] In some embodiments, an adjustable resistance hinge is provided. The adjustable resistance hinge may include a first leaf assembly comprising a first hollow cylinder that forms a first inner opening at a first end of the first leaf assembly. The adjustable resistance hinge may further include a second leaf assembly comprising a second hollow cylinder that forms a second inner opening at a second end of the second leaf assembly. In some embodiments, the first end of the first leaf assembly is pressed against the second end of the second leaf assembly to form a continuous hollow cylinder. The adjustable resistance hinge may further include a friction core assembly enclosed within the continuous hollow cylinder. The friction core assembly may comprise a hollow cam enclosed by the first hollow cylinder. The hollow cam may comprise one or more cam mating structures on an external cylindrical surface of the hollow cam that prevent the hollow cam from rotating within the first hollow cylinder and a cam friction surface perpendicular to the external cylindrical surface. The friction core assembly may further comprise a hollow shaft enclosed by the continuous hollow cylinder. The hollow shaft, may comprise a first end inserted through an interior of the hollow cam, a second end opposite the first end that is inserted into the second hollow cylinder, wherein the second end comprises one or more shaft mating structures that prevent the hollow shaft from rotating within the second hollow cylinder, and a middle portion separating the first end from the second end, wherein the middle portion comprises a shaft friction surface pressed against the cam friction surface. The friction core assembly may further comprise a fastener assembly coupled with the first end of the hollow shaft that maintains pressure between the shaft friction surface and the cam friction surface, thereby providing friction between the shaft friction surface and the cam friction surface that resists rotation of the hollow cam with respect to the hollow shaft.

[0003] In some embodiments, the fastener assembly comprises one or more springs threaded onto the first end of the hollow shaft following the hollow cam and a fastener secured to the first end of the hollow shaft following the one or more springs such that the one or more springs are compressed, thereby applying the pressure between the shaft friction surface and the cam friction surface. In some embodiments, the fastener assembly further comprises one or more washers threaded onto the first end of the hollow shaft between the hollow cam and the one or more springs. The one or more washers may comprise one or more support structures that prevent the one or more washers from rotating with respect to the hollow shaft. In some embodiments, the one or more springs comprise spring discs.

[0004] In some embodiments, a predefined torque that results in a predefined hinge tension is applied to the fastener with respect to the hollow shaft to secure the fastener to the first end of the hollow shaft. In some embodiments, cylindrical side walls of the first leaf assembly and the second leaf assembly each form a hollow cable routing from an interior of the continuous hollow cylinder to external surfaces of the first leaf assembly and the second leaf assembly. The adjustable resistance hinge may further comprise a cable assembly threaded through the hollow cable routing of the first leaf assembly, the hollow shaft, and the hollow cable routing of the second leaf assembly.

[0005] In some embodiments, the middle portion of the hollow shaft and the hollow cam each form locking tabs that prevent the hollow cam from completing a full rotation around the hollow shaft. In some embodiments, the locking tabs prevent the hollow cam from rotating more than 135 degrees from a closed position to an open position. In some embodiments, the first leaf assembly and the second leaf assembly are formed using metal injection molding.

[0006] In some embodiments, a hinged tablet computer case system is provided comprising a first portion that removably docks with a tablet computer, a second portion comprising a keyboard, and a plurality of hinges connecting the first portion with the second portion. Each of the plurality of hinges may comprise a first leaf assembly comprising a first hollow cylinder that forms a first inner opening at a first end of the first leaf assembly. Each of the plurality of hinges may further comprise a second leaf assembly comprising a second hollow cylinder that forms a second inner opening at a second end of the second leaf assembly. The first end of the first leaf assembly may be pressed against the second end of the second leaf assembly, thereby forming a continuous hollow cylinder from the first hollow cylinder and the second hollow cylinder. Each of the plurality of hinges may further comprise a friction core assembly enclosed within the continuous hollow cylinder. The friction core assembly may comprise a hollow cam enclosed by the firsthollow cylinder. The hollow cam may comprise one or more cam mating structures on an external cylindrical surface of the hollow cam that prevent the hollow cam from rotating within the first hollow cylinder and a cam friction surface perpendicular to the external cylindrical surface. The friction core assembly may further comprise a hollow shaft enclosed by the continuous hollow cylinder. The hollow shaft may comprise a first end inserted through an interior of the hollow cam, a second end opposite the first end that is inserted into the second hollow cylinder, wherein the second end comprises one or more shaft mating structures that prevent the hollow shaft from rotating within the second hollow cylinder, and a middle portion separating the first end from the second end. The middle portion may comprise a shaft friction surface pressed against the cam friction surface. The friction core assembly may further comprise a fastener assembly coupled with the second end of the hollow shaft that maintains pressure between the shaft friction surface and the cam friction surface, thereby providing friction between the shaft friction surface and the cam friction surface that resists rotation of the hollow cam with respect to the hollow shaft.

[0007] In some embodiments, the plurality of hinges comprise a left hinge and a right hinge that are mirror images of each other. In some embodiments, the fastener assembly comprises one or more springs threaded onto the first end of the hollow shaft following the hollow cam and a fastener secured to the first end of the hollow shaft following the one or more springs such that the one or more springs are compressed, thereby applying the pressure between the shaft friction surface and the cam friction surface. In some embodiments, a predefined torque that results in a predefined hinge tension is applied to the fastener with respect to the hollow shaft to secure the fastener to the first end of the hollow shaft. The predefined hinge tension may be selected to resist movement of the first portion with respect to the second portion due to a combined weight of the first portion and the tablet computer.

[0008] In some embodiments, the middle portion of the hollow shaft and the hollow cam each form locking tabs that prevent adjusting an opening angle of the first portion relative to the second portion beyond a predefined opening angle. The predefined opening angle may be 130 degrees. In some embodiments, the first leaf assembly and the second leaf assembly are formed using metal injection molding.

[0009] In some embodiments, a method of adjusting tension supplied by a hinge is provided. The method may comprise assembling a friction core assembly. The friction core assembly may comprise a hollow cam comprising a cam friction surface perpendicular to a longitudinal axis of the hollow cam. The friction core assembly may further comprise a hollow shaft comprising a first end inserted through an interior of the hollow cam, a second end opposite the first end, and amiddle portion separating the first end from the second end, wherein the middle portion comprises a shaft friction surface pressed against the cam friction surface. The friction core assembly may further comprise a fastener assembly screwed onto the first end of the hollow shaft that maintains pressure between the shaft friction surface and the cam friction surface, thereby providing friction between the shaft friction surface and the cam friction surface that results in a rotational resistance around the longitudinal axis of the hollow cam with respect to the hollow shaft. The method may further comprise testing the rotational resistance around the longitudinal axis of the hollow cam with respect to the hollow shaft. The method may further comprise adjusting a torque applied to the fastener assembly to increase or decrease the rotational resistance. The method may further comprise installing the friction core assembly within a continuous hollow cylinder formed by pressing a first end of a first leaf assembly against a second end of a second leaf assembly.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A further understanding of the nature and advantages of various embodiments may be realized by reference to the following figures. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0011] FIG. 1 A illustrates a side perspective view of an embodiment of a hinge assembly in a closed position.

[0012] FIG. IB illustrates a top view of an embodiment of a hinge assembly in a closed position.

[0013] FIG. 1C illustrates a side perspective view of an embodiment of a hinge assembly in an open position.

[0014] FIG. 2 illustrates an exploded view of an embodiment of a hinge assembly.

[0015] FIG. 3 illustrates a perspective view of an embodiment of an assembled friction core assembly.

[0016] FIG. 4 illustrates a cross-section of a front view of an embodiment of an assembled hinge assembly.

[0017] FIG. 5A illustrates a side perspective view of another embodiment of a hinge assembly in a closed position.

[0018] FIG. 5B illustrates a side perspective view of another embodiment of a hinge assembly in an open position.

[0019] FIG. 6 illustrates an exploded view of another embodiment of a hinge assembly.

[0020] FIG. 7 illustrates an embodiment of a hinged tablet computer case system in an open position.

[0021] FIG. 8 illustrates a flowchart of an embodiment of a method of adjusting the tension of a hinge.

[0022] FIG. 9 illustrates a block diagram of an embodiment of an adjustable tension hinge assembly.DETAILED DESCRIPTION

[0023] Portable electronic devices such as tablet computers often benefit from the use of an accessory device such as a tablet computer case having a keyboard. A tablet computer may be removably dockable from a tablet computer case, thereby providing the user the flexibility of using the tablet computer as an individual portable electronic device or using the tablet computer as a laptop where the tablet computer case includes a keyboard and / or trackpad feature. Aspects of tablet computer cases replicate a laptop experience and may increase user productivity.

[0024] A tablet computer case system may include a tablet computer that is removably dockable to a tablet computer case. When a tablet computer is docked to a tablet computer case, the system is more top heavy compared to a laptop having just the display module, camera, and a few other components in the lid portion. A tablet computer docked to a tablet computer case includes relatively more components, and accordingly weight, located in the lid portion of the system. Various designs for tablet computer cases include soft hinges with kickstands in order to address top heaviness and decrease the overall weight of the system. For example, a kickstand may be used to maintain relative opening angle between the tablet computer screen and the base portion of the tablet computer case. These designs are functional but use a substantially flat surface for support. Soft hinges may not be suitable for transporting the tablet computer docked to the tablet computer case in an open position.

[0025] Various designs having rigid hinges address the portability of the system but compromise the structural integrity of the tablet computer case. For example, some designs use hinges with solid cores, or pins, along the rotational axis of the hinge. As a result, electrical connections, or wires, between the base portion and the lid portion are routed around an exterior of the hinge, leaving them vulnerable to damage from repeated onening and closing of the tablet computer case,and / or from impingement between a structure of the tablet computer case and a hard surface, such as the ground, when dripped directly on the electrical connection.

[0026] An additional consideration for tablet computer case system stability is the force that the tablet computer case system is able to withstand before the lid portion deflects from its current opening angle, either towards a more open angle, or a more closed angle. For example, a user may interact with the screen of the tablet computer, thereby applying force that may result in a greater opening angle. As another example, the weight of the tablet computer case system may cause the lid portion to deflect in the direction of gravity.

[0027] A further consideration for tablet computer case systems may be the reliability and durability of the case over extended use, in harsh conditions, or when exposed to extreme mechanical forces. For example, by repeatedly opening and closing the tablet computer case during routine use, surfaces designed to resist those motions may begin to wear down, resulting in less resistance over time. As another example, exposed cables connecting electronic components in the lid portion to the base portion may be vulnerable to damage from repeated bending motions and / or from being impinged between a hinge and a hard surface, such as a tabletop or floor.

[0028] The stability of the system is related to the mechanical resistance of the hinges. The mechanical resistance of the hinges sufficient to provide stability is determined from the moment arm of the lid portion and any components coupled thereto. Various embodiments described herein address instability issues of a tablet computer case system by providing hinges with adjustable friction cores. Further embodiments described herein provide increased reliability and durability by using one or more springs to apply a constant force between friction surface as they gradually wear down against each other. Further still, embodiments described herein provide reliability and durability by routing cables through an interior of the hinges, thereby providing additional support and protection to the electronic connections between a lid portion and a base portion.

[0029] The embodiments detailed herein are focused on hinges for use in a tablet computer case. An electronic device for use with the tablet computer case is removably dockable to the tablet computer case. In some embodiments, the electronic device is a tablet computer that is a component of a tablet computer case system. Specifically, a tablet computer can serve as a home assistant device and / or hub to manage smart home devices in an environment. The tablet computer may be able to record video, communicate with a remote server system, and interact with users via spoken communications. For example, a home assistant device may provide automated control or voice control of devices, appliances, and systems, such as heating, ventilation, and air conditioning ("HVAC") system, lighting systems, home theater, entertainment systems, as well as securitysystems. Smart home networks may include control panels that a person may use to input settings, preferences, and scheduling information that the smart home network uses to provide automated control of the various devices, appliances, and systems in the home. For example, the person may input a schedule indicating when the person is away from the home, and the smart home network uses this information along with information obtained from various devices in the home to detect unauthorized entry when the user is away. The tablet computer may be left docked with a dock or a tablet computer case to charge its battery and use other features of the dock or tablet computer case, such as an integrated speaker. The tablet computer may be removed from the dock for convenience to be used or displayed at another location, such as on a tablet computer case. When not in use (whether docked, not docked, or both), photos or photo albums selected by a user may be presented by the tablet computer.

[0030] Many other types of electronic devices can benefit from adjustable hinges described herein. For example, smartphones, gaming devices, e-readers, personal digital assistants (PDAs), digital paper tablets, and smart picture frames may benefit from various embodiments an adjustable hinge as detailed herein. Furthermore, the electronic device may be an assistant device (e.g., Google® Nest® Hub; Google® Nest® Hub Max); a home automation controller (e.g., controller for an alarm system, thermostat, lighting system, door lock, motorized doors, etc.); a gaming device (e.g., a gaming system, gaming controller, data glove, etc.); a communication device (e.g., a smart phone such as a Google® Pixel® Phone, cellular phone, mobile phone, wireless phone, portable phone, radio telephone, etc.); and / or other computing device (e.g., a tablet computer such as the Google® Pixel® Tablet, phablet computer, notebook computer, laptop computer, etc.).

[0031] FIGS. 1 A - 1C illustrates different views of an embodiment of a hinge assembly 100. In particular, FIG. 1 A illustrates a side perspective view of hinge assembly 100 in a closed position and FIG. IB illustrates a top down view of hinge assembly 100 in the closed position. The description of hinge assembly 100 described in relation to FIG. 1A is applicable to the top down view of hinge assembly 100 in the closed position. Hinge assembly 100 includes first leaf assembly 104 and second leaf assembly 108. First leaf assembly 104 may alternatively be referred to as a lid leaf assembly, inner leaf assembly, or top leaf assembly. Second leaf assembly 108 may alternatively be referred to as a base leaf assembly, outer leaf assembly, or bottom leaf assembly. First leaf assembly 104 includes first leaf portion 116 and first barrel portion 120. Second leaf assembly 108 includes second leaf portion 124 and second barrel portion 128. First leaf portion 116 and second leaf portion 124 may each include one or more thicknesses 132 of a rigid or semirigid material that separates a first planar surface of the material from a second planar surface ofthe material that is opposite the first planar surface. Thicknesses 132 of first leaf portion 116 and second leaf portion 124 may be selected to provide structural support for one or more components coupled with first leaf portion 116 and second leaf portion 124, as described further herein. Thicknesses 132 may be selected to provide rigidity and resist bending or braking. Thicknesses 132 may be selected from within a range of 5 millimeters to 5 centimeters. In some embodiments, thicknesses 132 are approximately 2 centimeters. First leaf portion 116 and second leaf portion 124 may alternatively be referred to as flanges, flange areas, flange portions, or the like.

[0032] First barrel portion 120 and second barrel portion 128 may each include a cylindrical structure that defines a hollow interior space within first barrel portion 120 and second barrel portion 128, as described further herein. The length of first barrel portion 120 and second barrel portion 128 may be between 10 and 20 centimeters. In some embodiments, the length is approximately 17.375 centimeters. When assembled, there may be a gap between first barrel portion 120 and second barrel portion 128 to reduce rotational friction between adjacent surfaces. In some embodiments, the gap between first barrel portion 120 and second barrel portion 128 is between 1 millimeter and 5 millimeters wide. In some embodiments, the gap is approximately 3 millimeters wide. The outer diameter of first barrel portion 120 and second barrel portion 128 may be between 5 centimeters and 15 centimeters. In some embodiments, the outer diameter is approximately 9.45 centimeters. In some embodiments, the outer diameter is selected based on a diameter of a stylus, as described further herein. First barrel portion 120 and second barrel portion 128 may include cylindrical sidewalls that form the hollow interior space within first barrel portion 120 and second barrel portion 128. The thicknesses of the cylindrical sidewalls may be selected based on the tensile strength of the material used to form the cylindrical sidewalls. For example, the thicknesses of the cylindrical sidewalls may be selected based on a minimum thickness of the material that would resist bending, braking, cracking, or other forms of damage that may occur as a result of a hard impact with another object. Additionally, or alternatively, the thicknesses may be selected to provide a rigidity to distribute the force of an impact to other components of hinge assembly 100. In some embodiments, the thicknesses of the cylindrical sidewalls is between 1 millimeter and 10 millimeters. In some embodiments, a minimum thickness of the cylindrical sidewalls is approximately 3 millimeters.

[0033] First leaf portion 116 and second leaf portion 124 may extend tangentially from first barrel portion 120 and second barrel portion 128, respectively. In other words, the leaf portions may be joined with the barrel portions such that the planar surfaces of the leaf portions are parallel with a tangent plane on the outer cylindrical surface of the barrel portions. Further, the leaf portions may be joined with the barrel portions such that the radial distance from a longitudinalaxis of the barrel portions to a plane on the surface of the leaf portions is greater than or equal to the outer radius of the barrel portions. For example, and as illustrated, first leaf portion 116 may be joined with first barrel portion 120 via first joint portion 136 such that the radial distance is greater than or equal to the outer radius of first barrel portion 120. In some embodiments, the radial distance from the longitudinal axis of first barrel portion 120 to a plane on an inner, or bottom, surface of first leaf portion 116 is approximately 5.3 centimeters. As another example, and as illustrated, second leaf portion 124 may be joined with second barrel portion 128 via second joint portion 140 such that the radial distance is greater than the outer radius of second barrel portion 128. In some embodiments, the radial distance from the longitudinal axis of second barrel portion 128 to a plane on an inner, or top, surface of second leaf portion 124 is approximately 8.31 centimeters.

[0034] In some embodiments, the radial distances are selected such that, when the longitudinal axis of the barrel portions are aligned and the leaf portions are in parallel planes, the distance between the parallel planes is greater than or equal to a predefined distance. The predefined distance may be between 5 centimeters and 25 centimeters. In some embodiments, the predefined distance from an outer surface of second leaf portion 124 to an outer surface of first leaf portion 116 is approximately 17.5 centimeters. As described further herein, the predefined distance may be selected based on the dimensions of electronic components coupled with first leaf portion 116 and second leaf portion 124. For example, in the case of a tablet computer case, the predefined distance may be selected based on depths of a base component, such as a keyboard and / or trackpad, coupled with second leaf portion 124, and one or more lid components, such as a display or tablet, coupled with first leaf portion 116. In some embodiments, the radial distance provided by second joint portion 140 is selected to accommodate a partial depth of a base component, such as a keyboard and / or trackpad, between a top surface of second leaf portion 124 and the outer surface of second barrel portion 128. In this way, second leaf portion 124 and second joint portion 140 may be all or partially concealed by the base portion, thereby providing the appearance that the barrel portions of hinge assembly 100 float above the base portion.

[0035] Each of first leaf portion 116 and second leaf portion 124 may form one or more fastener openings 144. Fastener openings 144 may enable a fastener to couple one or more components, such as a keyboard tray or tablet dock, with the leaf portions. For example, interior cylindrical walls within the one or more fastener openings 144 may include threading that mates with the threads of a fastener, such as a screw or bolt. Additionally, or alternatively, fastener openings 144 may pass through the thickness of the leaf portions such that a fastener may pass from a firstsupport structure of a component to be coupled with the leaf portion on one side of the leaf portion to a second support structure of the component on the opposite side of the leaf portion.

[0036] As further illustrated, each of first leaf assembly 104 and second leaf assembly 108 may form cable openings 148. Cable openings 148 may allow a cable assembly, as described further herein, to pass from an exterior of the leaf portions into the hollow interior of each barrel portion. For example, when the longitudinal axes of each barrel portion are aligned as illustrated, a cable assembly may be routed from an exterior of first leaf portion 116, through the hollow interiors of first barrel portion 120 and second barrel portion 128, to an exterior of second leaf assembly 104. As such, a cable assembly may electronically connect one or more electronic components coupled to second leaf assembly 108, such as a keyboard and / or trackpad tray, with one or more electronic components coupled to first leaf assembly 104, such as a tablet dock or display.

[0037] Routing a cable assembly through an interior of hinge assembly 100 enables numerous technical and non-technical benefits. For example, by a routing cable assembly in this way, the cable assembly may be concealed from external view, thereby improving the overall look and feel of a finished product. As another example, by routing a cable assembly through an interior of hinge assembly 100, hinge assembly 100 can protect the cable assembly from damage.

[0038] First leaf assembly 104 and second leaf assembly 108 may each be made of a metal, or metal alloy, such as stainless steel, titanium, copper, aluminum, or the like. In some embodiments, first leaf assembly 104 and second leaf assembly 108 are each formed as a single piece or component. In other words, first leaf assembly 104 and second leaf assembly 108 may each be formed without joining smaller component pieces together. For example, first leaf assembly 104 and second leaf assembly 108 may each be manufactured using a metal injection molding (MIM) process in which a metal material is injected into a mold cavity. In some embodiments, cable openings 148 may be formed after the overall structure of the leaf assemblies are formed. For example, after removing an insert used to form the hollow interior of first leaf assembly 104 and / or second leaf assembly 108, cable channels 148 may be formed using a chemical solvent. Forming first leaf assembly 104 and / or second leaf assembly 108 as uniform components may improve the overall durability of leaf assemblies compared to other methods of joining substructures together, such as welding.

[0039] As described further herein, a friction core assembly may enable first leaf assembly 104 and second leaf assembly 108 to rotate relative to each other within a predefined range of angular motion between a closed position, as illustrated in FIG. 1 A and FIG. IB, and an open position. FIG. 1C illustrates a side perspective view of hinge assembly 100 in an open position. Thedescription of hinge assembly 100 described in relation to FIGS. 1A and IB is applicable to the perspective view of hinge assembly 100 in the open position. The position of hinge assembly 100 may refer to an opening angle between first leaf assembly 104 and second leaf assembly 108, as described further herein.

[0040] FIG. 2 illustrates an exploded view of an embodiment of a hinge assembly. The hinge assembly may be referred to as left hinge assembly 200. As illustrated, hinge assembly 200 includes first leaf assembly 104 and second leaf assembly 108, as described above. As further illustrated, the hollow cylindrical structures of first leaf assembly 104 and second leaf assembly 108 may form interior openings 212. When first leaf assembly 104 and second leaf assembly 108 are assembled together, interior openings 212 may be directly adjacent to each other. An interior volume defined by the hollow cylindrical structures of first leaf assembly 104 and second leaf assembly 108 pressed together may accommodate a friction core assembly, as described further herein. For example, opposing ends of a friction core assembly may be inserted into interior openings 212 of first leaf assembly 104 and second leaf assembly 108.

[0041] As further illustrated, the hollow cylindrical structures of first leaf assembly 104 and second leaf assembly 108 may form exterior openings 216 on an opposite end of the hollow cylindrical structure from interior openings 212. Once left hinge assembly 200 is assembled, exterior openings 216 may enable access to the internal components of left hinge assembly 200 without disassembling left hinge assembly 200. As further illustrated, left hinge assembly 200 includes end caps 220. End caps 220 may fit within exterior openings 216. When installed within exterior openings 216, end caps 220, first leaf assembly 104, and second leaf assembly 108 may conceal the interior structure and / or components of left hinge assembly 200. End caps 220 may further seal exterior openings 216 to prevent foreign objects, such as dust, dirt, water, oil, or the like, from entering into the interior structure and / or moving parts of left hinge assembly 200. For example, end caps 220 may include rubber gaskets, chemical sealants, or the like that are pressed between interior surfaces of end caps 220 and exterior openings 216.

[0042] Left hinge assembly 200 further includes friction core assembly 224. A portion of the hollow cylindrical structures of first leaf assembly 104 and second leaf assembly 108 extending from interior openings 212 toward exterior openings 216 may enclose opposing ends of friction core assembly 224. Friction core assembly 224 may maintain an alignment between the cylindrical axes of first leaf assembly 104 and second leaf assembly 108 while also enabling first leaf assembly 104 to move relative to second leaf assembly 108, and vice versa, around a cylindrical axis of the hollow cylindrical structures.

[0043] Friction core assembly 224 may enable first leaf assembly 104 and second leaf assembly 108 to rotate relative to each other within a predefined range of angular motion between a closed position and an open position of left hinge assembly 200. The position of left hinge assembly 200 may refer to an opening angle between first leaf assembly 104 and second leaf assembly 108. The opening angle of left hinge assembly 200 may be between less than 0 degrees to 130 degrees, inclusive, measured from first leaf assembly 104 to second leaf assembly 108. As illustrated, left hinge assembly 200 is in a closed position. A closed position may refer to a minimum opening angle between first leaf assembly 104 and second leaf assembly 108, although left hinge assembly 200 may be considered ‘closed’ at more than the minimum opening angle. The minimum opening angle may be between 0 degrees and -5 degrees, inclusive. An open position may refer to a maximum opening angle between first leaf assembly 104 and second leaf assembly 108, although left hinge assembly 200 may be considered 'open' at less than the maximum opening angle. The maximum opening angle may be 130 degrees.

[0044] Friction core assembly 224 may further provide a mechanical resistance when opening or closing left hinge assembly 200. For example, based on the mechanical resistance provided by friction core assembly 224, left hinge assembly 200 may be able to retain an opening angle and / or position within a preset range when a force, or torque, is applied to either, or both, leaf assemblies and / or the components coupled thereto. The mechanical resistance may be selected to enable rotation when a torque exceeding a predefined threshold is applied to first leaf assembly 104 relative to second leaf assembly 108, and vice versa. For example, the mechanical resistance may enable left hinge assembly 200 to transition from a closed orientation to an open orientation, and vice versa.

[0045] In some embodiments, the mechanical resistance provided by friction core assembly 224 is constant through the full range of motion provided by friction core assembly 224. For example, when opening or closing left hinge assembly 200, a predefined amount of constant force applied to either leaf assembly relative to the other leaf assembly may result in a smooth, constant, motion of each leaf assembly relative to the other leaf assembly. Additionally, or alternatively, the mechanical resistance may increase or decrease in a linear, non-linear, exponential, logarithmic, or other similar manner, across the range of motion provided by friction core assembly 224. For example, an initial resistance may be selected to prevent accidental opening or closing such that that the minimum amount of force required to begin opening left hinge assembly 200 is greater than an amount of force associated with accidental opening, such as the force of gravity pulling on a component coupled with second leaf assembly 108 when left hinge assembly 200 is supported by first leaf assembly 104. After the initial resistance is overcome, the mechanical resistance maydecrease to enable a smooth rotation throughout the remainder of the range of motion provided by friction core assembly 224.

[0046] In some embodiments, the mechanical resistance provided by friction core assembly 224 increases and decreases in intervals across the range of motion provided by friction core assembly 224. For example, a predefined threshold amount of force may be required to begin transitioning away from one or more predefined opening angles. The force required to continue opening or closing left hinge assembly 200 between each predefined opening angle may then be reduced compared to the predefined threshold amount of force quired to begin the movement until the mechanical resistance increases again at the next predefined opening angle. In some embodiments, the predefined opening angles correspond to constant opening angle intervals, such as every 5 degrees, 10 degrees, 15 degrees, or another suitable angle interval. The intervals may span the full range of motion or a subset of the range. For example, the predefined opening angles may increase in intervals of 5 degrees starting at 45 degrees, 90 degrees, 110 degrees, or another similarly suitable starting opening angle. Additionally, or alternatively, the predefined opening angles may be selected based on one or more intended modes of use and / or one or more ergonomic considerations. For example, when used to support a tablet and keyboard, the predefined opening angles may correspond to predefined viewing angles, such as a 90 degree viewing angle, a 110 degree viewing angle, and a 130 degree viewing angle.

[0047] As illustrated, friction core assembly 224 includes: shaft 226; cam 228; washers 230; spring discs 232; and nut 234. Shaft 226 may include first portion 236, second portion 238, and middle portion 240 separating first portion 236 and second portion 238. Shaft 226 may include a hollow cylindrical structure along the longitudinal axis of shaft 226 extending from first portion 236 to second portion 238. The interior surface of the hollow cylindrical structure of shaft 226 may be smooth. When assembled into left hinge assembly 200, second portion 238 of shaft 226 may be enclosed by second leaf assembly 108 and first portion 236 of shaft 226 may be enclosed by first leaf assembly 104. The external surface of second portion 238 of shaft 226 and the internal surface of second leaf assembly 108 may include one or more complementary mating structures. For example, and as illustrated in FIG. 3, second portion 238 of shaft 226 may include one or more ridges 308 protruding from the exterior surface of shaft 226 parallel with the longitudinal axis of shaft 226. The internal surface of second leaf assembly 108 may include one or more complementary grooves configured to mate with the one or more ridges protruding from second portion 238 of shaft 226. When second portion 238 of shaft 226 is inserted into second leaf assembly 108, the complementary mating structures of second portion 238 and second leafassembly 108 may prevent shaft 226 from rotating around the longitudinal axis within the hollow cylindrical structure of second leaf assembly 108.

[0048] First portion 236 of shaft 226 may include one or more physical structures that support, or otherwise hold in place, the remaining components of friction core assembly 224. For example, first portion 236 of shaft 226 may be inserted into circular, semicircular, and / or polygonal openings defined by cam 228, washers 230, spring discs 232, and nut 234. Collectively, first portion 236 of shaft 226, cam 228, washers 230, spring discs 232, and nut 234 may be enclosed by first leaf assembly 104.

[0049] The one or more physical structures defined by first portion 236 of shaft 226 may include rotating portion 242, locking portion 244, and fastener portion 246. Rotating portion 242 may extend from middle portion 240 of shaft 226 along the longitudinal axis to locking portion 244. Locking portion 244 may in turn extend between rotating portion 242 and fastener portion 246. Fastener portion 246 may extend from locking portion 244 to an end of shaft 226. Rotating portion 242 may have a smooth surface with a same, or overlapping, width as a width of cam 228.

[0050] Cam 228 may be a hollow cylinder with circular openings on both ends. The circular openings may be configured to receive first portion 236 of shaft 226. The diameter of the circular opening may be the same or larger than the diameter of rotating portion 242. For example, the diameters of the circular opening of cam 228 and rotating portion 242 may be selected such that, when cam 228 is inserted onto rotating portion 242, the only direction in which cam 228 can rotate is around the longitudinal axis of shaft 226.

[0051] The interior surface of cam 228 may be smooth. The external surface of cam 228 and the internal surface of first leaf assembly 104 may include one or more complementary mating structures. For example, and as illustrated in FIG. 3, cam 228 may include one or more ridges 304 protruding from the external surface of cam 228 parallel with the longitudinal axis of cam 228. The internal surface of first leaf assembly 104 may include one or more complementary grooves configured to mate with the one or more ridges protruding from cam 228. When second portion 238 of shaft 226 is inserted into first leaf assembly 104, the complementary mating structures of cam 228 and first leaf assembly 104 may prevent cam 228 from rotating around the longitudinal axis within the hollow cylindrical structure of first leaf assembly 104.

[0052] Middle portion 240 of shaft 226 may include shaft friction surface 248 in a plane that is perpendicular to the longitudinal axis of shaft 226. Cam 228 may include inner cam friction surface 250 that is perpendicular to the longitudinal axis of cam 228. When inserted onto first portion 236 of shaft 226, inner cam friction surface 250 and shaft friction surface 248 may be flushagainst, or otherwise directly adjacent to, each other. Inner cam friction surface 250 and shaft friction surface 248 may be pressed together by other components of friction core assembly 224, as described further herein. The normal forces of each of inner cam friction surface 250 and shaft friction surface 248 pushing against each other may provide friction. The friction, or mechanical resistance, provided by inner cam friction surface 250 and shaft friction surface 248 may contribute to some or all of the mechanical resistance of friction core assembly 224 described above.

[0053] In some embodiments, inner cam friction surface 250 and shaft friction surface 248 include one or more textures or physical features that provide additional friction or resistance. For example, inner cam friction surface 250, shaft friction surface 248, or both, may be ground or sanded to provide additional surface area for increased friction between the two surfaces. Additionally, or alternatively, inner cam friction surface 250, shaft friction surface 248, or both, may be scored with one or more grooves to provide additional rotational resistance to friction core assembly 224. Further still, inner cam friction surface 250 and shaft friction surface 248 may include one or more mating structures. For example, one or more protrusions, bumps, or the like on inner cam friction surface 250 may correspond to one or more indentations, pits, dips or the like in shaft friction surface 248, or vice versa. The one or more mating structures may provide for increased friction or rotational resistance at predefined opening angles, as further described above.

[0054] Middle portion 240 may further include shaft locking tab 252 that protrudes outward from the longitudinal axis of shaft 226 within a predefined arc angle from the longitudinal axis of shaft 226. Cam 228 may further include cam locking tab 254 that protrudes outward from cam friction surface 250 parallel with the longitudinal axis of cam 228 within a predefined arc angle from the longitudinal axis of cam 228. When inserted onto first portion 236 of shaft 226, an interior surface of cam locking tab 254 may be flush against an outer surface of middle portion 240 that is perpendicular with shaft friction surface 248. Shaft locking tab 252 and cam locking tab 254 may prevent cam 228 from making a full rotation around the longitudinal axis of shaft 226. For example, the arc angles of shaft locking tab 252 and cam locking tab 254 may be selected such that cam 228 may rotate approximately 130 degrees from a closed orientation, in which first sides of shaft locking tab 252 and cam locking tab 254 are flush with each other, and a fully open orientation, in which second sides of shaft locking tab 252 and cam locking tab 254 are flush with each other.

[0055] Washers 230 may include cylindrical structures with hollow openings configured to receive first portion 236 of shaft 226 therethrough. In some embodiments, the hollow openingsmay be formed by internal walls in the shape of a polygon, such as a triangle, square, rectangle, hexagon, octagon, or the like. As illustrated, locking portion 244 may include one or more planar walls on the external surface of shaft 226 configured to mate with the shapes formed by the internal walls of washers 230. The internal walls of washers 230 and one or more planar walls on locking portion 244 may prevent washers 230 from rotating around the longitudinal axis of shaft 226.

[0056] Washers 230 may further include washer friction surfaces on either side that are perpendicular to the longitudinal axis. Cam 228 may further include outer cam friction surface 256 on an opposite longitudinal end of cam 228 from inner cam friction surface 250. When a washer of washers 230 is inserted onto first portion 236 of shaft 226 after cam 228, a washer friction surface of the washer may be adjacent to outer cam friction surface 256. Cam 228 and washers 230 may be pressed together by other components of friction core assembly 224, as described further herein. The normal forces of each of outer cam friction surface 256 and an adjacent washer friction surface pushing against each other may provide friction. The friction, or mechanical resistance may further contribute to the mechanical resistance of friction core assembly 224 described above. In some embodiments, outer cam friction surface 256 and the washer friction surfaces include one or more textures or physical features that provide additional friction or resistance, as described above in relation to inner cam friction surface 250 and shaft friction surface 248.

[0057] FIG. 3 illustrates a perspective view of assembled friction core assembly 224. As illustrated, washers 230 and spring discs 232 may be placed on first portion 236 of shaft 226 after inserting first portion 236 of shaft 226 into cam 228. Nut 234 may be attached to fastener portion 246 of shaft 226 to secure cam 228, washers 230, and spring discs 232 to first portion 236 of shaft 226. Referring back to FIG. 2, nut 234 and fastener portion 246 may include matching threads to enable nut 234 to be secured to fastener portion 246. Nut 234 may be a hex nut, cap nut, square nut, acorn nut, or other similar nut capable of being secured to fastener portion 246. In some embodiments, nut 234 may include an opening on both sides.

[0058] Spring discs 232 may include one or more conical, or Belleville, washers. The conical shape may enable spring discs 232 to resist axial loads and / or compression. In other words, when axially compressed from their original shape between two surfaces, spring discs 232 may exert a force against the compressing surfaces. For example, spring discs 232 may be compressed between cam 228 and nut 234, either directly or via one or more washers 230, by securing nut 234 to fastener portion 246 of shaft 226. Once compressed, spring discs 232 may maintain pressure between inner cam friction surface 250 and shaft friction surface 248. Additionally, oralternatively, spring discs 232 may maintain pressure between outer cam friction surface 256 and an adjacent washer friction surface. The amount of pressure, or normal forces, between adjacent friction surfaces may result in a corresponding rotational friction between the adjacent friction surfaces, as described above. While illustrated and described as conical washers, spring discs 232 may additionally, or alternatively include one or more compression springs.

[0059] Spring discs 232 may enable a consistent pressure to be applied between inner cam friction surface 250 and shaft friction surface 248 over extended rotations between cam 228 and shaft 226. For example, as inner cam friction surface 250 and shaft friction surface 248 begin to wear down through repeated rotations, spring discs 232 may apply the same amount of force while gradually decompressing.

[0060] The number of spring discs 232 may be selected to provide a predefined amount of force, and thereby friction, between rotating surfaces of friction core assembly 224, as described above. Additionally, or alternatively, the type of materials and / or longitudinal thickness of the material may be selected to provide the predefined amount of force. In some embodiments, an amount of initial compression applied to spring discs 232 may be measured by the amount of torque force used to screw nut 234 to fastener portion 246 of shaft 226. By applying the same amount of torque force to nut 234 across an entire production lot, the mechanical resistance provided by friction core assembly 224 may be consistent between each assembled friction core assembly.

[0061] Enabling the mechanical resistance provided by friction core assembly 224 to be adjusted based on the torque applied to nut 234, and / or the number and type of spring discs 232, may lead to numerous benefits over existing hinge designs. For example, be enabling friction core assembly 224 to have a range of mechanical resistances, friction core assembly 224 can be used in multiple products with different specifications. Additionally, or alternatively, friction core assembly 224 can be used in products where the final specifications, such as weight, are as yet unknown.

[0062] Left hinge assembly 200 may further include cable assembly 258. Cable assembly 258 may include one or more electrically conductive wires and / or terminals. Cable assembly 258 may provide one or more electrical connections between an electronic component coupled to first leaf assembly 104 and another electronic component coupled to second leaf assembly 108. The one or more electrical connections may facilitate power and / or data transfer. For example, cable assembly 258 may provide electrical power from a tablet device coupled with a first end of cable assembly 258 to a peripheral device, such as a keyboard or trackpad coupled to the opposite end of cable assembly 258. As another example, cable assembly 258 may transmit data from a keyboard or trackpad, such as one or more user inputs, to a tablet for processing.

[0063] Cable assembly 258 may be threaded through an interior of left hinge assembly 200 from first cable opening 260 on first leaf assembly 104, through the hollow center of friction core assembly 224, to second cable opening 262 on second leaf assembly 108. Threading cable assembly 258 through the interior of left hinge assembly 200 may provide additional protection and prolong the useful life of cable assembly 258 compared to other methods of routing cable assembly 258 between electronic components coupled with first leaf assembly 104 and second leaf assembly 108. For example, the internal pathway of left hinge assembly 200 may prevent cable assembly from being bent, pinched, crushed, or otherwise damaged from external forces, such as an impact with a hard surface.

[0064] Left hinge assembly 200 may further include one or more bumpers 264. Bumpers 264 may include one or more shock absorbing materials, such as plastic, elastomer, rubber, or the like. Bumpers 264 may be secured to first leaf assembly 104 and / or second leaf assembly 108 to protect left hinge assembly 200 and / or one or more electronic components coupled with left hinge assembly 200. For example, bumpers 264 may be located on external surfaces of left hinge assembly 200 to reduce the amount of shock transferred to left hinge assembly 200 on impact with another object, such as the ground. As another example, bumpers 264 may support and / or protect one or more electronic components coupled to left hinge assembly 200, such as a tablet computer or the like.

[0065] FIG. 4 illustrates a cross-section of a front view of assembled left hinge assembly 200. FIG. 4 illustrates the cross-section taken along the longitudinal axis of hinge assembly 100 as shown in FIG. IB. As illustrated, the friction core assembly is partially enclosed by first leaf assembly 104 and second leaf assembly 108. As described above, spring discs 232 may be compressed between cam 228 and nut 234, either directly or via one or more washers 230, by securing nut 234 to a fastener portion of shaft 226. Once compressed, spring discs 232 may maintain pressure between an inner cam friction surface and a shaft friction surface. Additionally, or alternatively, spring discs 232 may maintain pressure between outer an cam friction surface and an adjacent washer friction surface. The amount of pressure, or normal forces, between adjacent friction surfaces may result in a corresponding rotational friction between the adjacent friction surfaces, as described above.

[0066] The number of spring discs 232 may be selected to provide a predefined amount of force, and thereby friction, between rotating surfaces of the friction core assembly, as described above. Additionally, or alternatively, the type of materials and / or longitudinal thickness of the material may be selected to provide the predefined amount of force. In some embodiments, an amount ofinitial compression applied to spring discs 232 may be measured by the amount of torque force used to screw nut 234 to the fastener portion of shaft 226. In this way, by applying the same amount of torque force to nut 234 across an entire production lot, the mechanical resistance provided by friction core assembly 224 may be consistent between each friction core assembly 224.

[0067] As further illustrated, cable assembly 258 may be threaded through an interior of left hinge assembly 200 from a first cable opening on first leaf assembly 104, through the hollow center of the friction core assembly, and out through a second cable opening on second leaf assembly 108. Threading cable assembly 258 through the interior of left hinge assembly 200 may provide additional protection and prolong the useful life of cable assembly 258 compared to other methods of routing cable assembly 200 between electronic components coupled with first leaf assembly 104 and second leaf assembly 108. For example, the internal pathway of left hinge assembly 200 may prevent cable assembly from being bent, pinched, crushed, or otherwise damaged from external forces, such as an impact with a hard surface.

[0068] FIGS. 5A and 5B illustrate different views of another embodiment of a hinge assembly. In particular, FIG. 5 A illustrates a side perspective view of hinge assembly 500 in a closed position. Hinge assembly 500 may include similar components, structures, and / or characteristics as hinge assembly 100 described above. For example, hinge assembly 500 includes first leaf assembly 504 and second leaf assembly 508. As further illustrated, first leaf assembly 504 includes first leaf portion 516 and first barrel portion 520. Second leaf assembly 508 includes second leaf portion 524 and second barrel portion 528. Each of first leaf portion 516 and second leaf portion 524 may form one or more fastener openings 544. As further illustrated, each of first leaf assembly 504 and second leaf assembly 508 may form cable openings 548.

[0069] As described above in relation to hinge assembly 100, first leaf assembly 504 and second leaf assembly 508 may rotate relative to each other within a predefined range of angular motion between a closed position, as illustrated in FIG. 5A, and an open position. FIG. 5B illustrates a side perspective view of hinge assembly 500 in an open position. The description of hinge assembly 500 described in relation to FIG. 5 A is applicable to the perspective view of hinge assembly 500 in the open position. The position of hinge assembly 500 may refer to an opening angle between first leaf assembly 504 and second leaf assembly 508, as described further herein.

[0070] In some embodiments, hinge assembly 100 and hinge assembly 500 include mirrored components and structures. Mirrored hinge assemblies may be used as a pair of hinge assemblies, with one hinge assembly, such as hinge assembly 100, acting as the left or top hinge, and amirrored hinge assembly, such as hinge assembly 500, acting as the right or bottom hinge, or vice versa. Using a pair of mirrored hinge assemblies may result in an assembled product that is visually symmetrical when viewed from an angle orthogonal to the axis of rotation of both hinge assemblies.

[0071] FIG. 6 illustrates an exploded view of an embodiment of right hinge assembly 600. As illustrated, right hinge assembly 600 includes first leaf assembly 504 and second leaf assembly 508. As described above, while first leaf assembly 504 and second leaf assembly 508 may have different shapes and orientations compared with first leaf assembly 104 and second leaf assembly 108, right hinge assembly 600 may include some of the same, or similar components as left hinge assembly 200, as described above. For example, right hinge assembly 600 may include end caps 604, friction core assembly 608, cable assembly 612, and / or bumper 616. End caps 604, friction core assembly 608, cable assembly 612, and bumper 616 may be the same, or function in similar manners, as end caps 220, friction core assembly 224, cable assembly 258, and bumper 264, respectively.

[0072] FIG. 7 illustrates an embodiment of a hinged tablet computer case system. Tablet computer case system 700 includes tablet computer 702 that is removably dockable to tablet computer case 704. Tablet computer case 704 includes first portion 706 and second portion 708. First portion 706 may alternatively be referred to as a lid or a top portion. Second portion 708 may alternatively be referred to as a base or a bottom portion. Second portion 708 is configured to move relative to first portion 706 and vice versa. First portion 706 and second portion 708 are rotationally adjustable via one or more hinges 710 such that tablet computer case 704 transitions from an open position to a closed position. As shown in FIG. 7, tablet computer case 704 is in the open position. In the closed position, the opening angle may be between 0 degrees and -5 degrees. For example, when tablet computer 702 is not docked to tablet computer case 704, first portion 706 and second portion 708 may latch together at edges opposite hinges 710. Latching first portion 706 together with second portion 708 at the edges opposite hinges 710 may result in an opening angle of -5 degrees.

[0073] Second portion 708 includes keyboard 712 and trackpad 714 for a user to provide input to tablet computer 702, in a manner which would be understood by one having ordinary skill in the art upon reading the present disclosure. For example, data and / or power may be transmitted between tablet computer 702, keyboard 712 and / or trackpad 714 via one or more cable assemblies, such as cable assembly 258 described above. Tablet computer case system 700 and / or tablet computer 702 may optionally include a stylus for a user to provide input to tablet computer 702.In some embodiments, second portion 708 includes one or more electrical connections to enable data and / or power to be transferred between a stylus, tablet computer case 704, and / or tablet computer 702.

[0074] Hinges 710 may include left hinge assembly 200 and / or right hinge assembly 600, as described above. For example, hinges 710 may be able to retain an opening angle and / or position within a preset range when a force is applied to the hinges 710 and / or the components coupled to hinges 710. In at least some embodiments, hinges 710 are set to support a maximum moment in an angle range (e.g., between 0 degrees and 130 degrees, inclusive), at 3.3 kgf / cm2+ / - 10% tolerance. One or more friction core assemblies, such as friction core assembly 224, may provide the mechanical resistance to support the maximum moment, as described above. As further described above, hinges 710 may have an outer diameter that is selected based on the diameter of a stylus. For example, the outer diameter of hinges 710 may be selected such that a stylus can be stored between hinges 710 in parallel with the rotational axis of hinges 710 at a back of second portion 708.

[0075] In various embodiments, hinges 710 are configured to withstand a tapping force of less than or equal to 125 grams, inclusive, at a top portion of tablet computer 702 when tablet computer 702 is docked to tablet computer case 704. For example, a user interacting with tablet computer 702 when tablet computer 702 is docked to tablet computer case 704 generates a force toward a top portion of tablet computer 702. Hinges 710 are configured to oppose the force when the force is less than or equal to 125 grams.

[0076] FIG. 8 illustrates a flowchart of an embodiment of method 800 of adjusting the tension of a hinge. At block 805, method 800 may begin with assembling a friction core assembly of the hinge. Block 805 may further include providing the friction core assembly. The friction core assembly may be the same, or function in a similar manner, as friction core assembly 224 described above. For example, the friction core assembly may include a hollow shaft with a first end inserted into a hollow cam. A fastener assembly may be attached to the first end of the hollow shaft after the first end is inserted into the hollow cam. Attaching the fastener assembly to the first end may include screwing a fastener, such as a threaded nut, onto corresponding threads on the first end of the hollow shaft. The fastener assembly may further include one or more washers and / or one or more springs placed between the hollow cam and the fastener. The fastener may apply pressure between friction surfaces on the hollow cam and a middle portion of the hollow shaft, thereby resulting in friction between the surfaces that provides a rotational resistance between the hollow cam and the hollow shaft. For example, by tightening the fastener onto thefirst end of the hollow shaft, one or more springs may be compressed between the hollow cam, which is pressed against the middle portion of the hollow shaft, and the fastener.

[0077] At block 810, a rotational resistance of the friction core assembly may be tested. The rotational resistance, or tension, of the friction core assembly may be a measure of the force required to rotate the hollow cam around the longitudinal axis relative to the hollow shaft. For example, the rotational resistance may be a measure of the friction between the hollow cam and one or more surfaces that do not rotate with respect to the hollow shaft, such as a shaft friction surface or a washer friction surface secured to the hollow shaft. The rotational resistance of the friction core assembly may be tested prior to, or after, installing the friction core assembly into a hinge or a larger component, such as a tablet computer case. For example, increasing amounts of force may be applied against a lid portion of a tablet computer case, as described above, while holding a base portion of the tablet computer case stationary until the lid portion moves relative to the base portion. The amount of force that resulted in the lid portion moving relative to the base portion may then be used as the measure of the rotational resistance.

[0078] At block 815, a torque applied to the fastener of the friction core assembly may be adjusted. As described above, a fastener of the friction core assembly may be screwed onto the first end of the hollow shaft to compress one or more springs against the hollow cam. The initial torque applied to screw the fastener onto the first end of the hollow shaft may be directly correlated with the rotational resistance of the friction core assembly. Thus, by tightening the fastener onto the first end (e.g., by applying a more torque), the rotational resistance of the friction core assembly may be increased. Alternatively, by loosening the fastener, the rotational resistance of the friction core assembly may be decreased.

[0079] At block 820, the friction core assembly may be installed within first and second leaf assemblies. For example, the first end of the friction core assembly, which includes the hollow cam, may be inserted into a first leaf assembly, such as first leaf assembly 104, and a second end of the friction core assembly may be inserted into a second leaf assembly, such as second leaf assembly 108.

[0080] FIG. 9 illustrates a block diagram of an embodiment of an adjustable tension hinge assembly 900. As described above, hinge assembly 900 may be installed in one or more types of devices, such as a tablet computer case, with one or more additional hinge assemblies. Hinge assembly 900 may be a left hinge assembly, a right hinge assembly, a top hinge assembly, or a bottom hinge assembly, as further described above. Hinge assembly 900 may include some or all of the same, or similar, components described above in relation to left hinge assembly 200 and / orright hinge assembly 600. For example, and as illustrated, hinge assembly 900 includes first leaf assembly 904 and second leaf assembly 908. As further illustrated, hinge assembly 900 includes friction core assembly 908. Friction core assembly 908 may be partially enclosed within first leaf assembly 904 and partially enclosed within second leaf assembly 908, such that friction core assembly 908 is totally enclosed within a continuous hollow interior formed by first leaf assembly 904 and second leaf assembly 908 when pressed together along their longitudinal axes.

[0081] As described above, one or more components of friction core assembly 908 may provide mechanical resistance, or tension, when rotating first leaf assembly 904 around a longitudinal axis relative to second leaf assembly 908, and vice versa. As illustrated, the one or more components of friction core assembly 908 include cam 928, shaft 926, and fastener assembly 936. Cam 928 and shaft 926 may be the same, or have similar physical structures, as described above in relation to cam 228 and shaft 226. For example, cam 928 may form a hollow opening through which a first end of shaft 926, up to a middle portion of shaft 926, may be inserted. As further described above, cam 928 may rotate around a longitudinal axis of shaft 926 within a predefined range of angles, such as 90 degrees, 100 degrees, 115 degrees, 130 degrees, or a similarly suited range of angles.

[0082] As further described above, fastener assembly 936 may apply pressure between respective friction surfaces of cam 928 and shaft 926 that are perpendicular to their longitudinal axes. When pressed together, friction may be created between the respective friction surfaces of cam 928 and shaft 926, thereby producing some, or all, of the mechanical resistance of friction core assembly 924. While illustrated and described as an assembly, fastener assembly 936 may comprise a single component configured apply longitudinal pressure against cam 928 toward a friction surface of shaft 926. For example, fastener assembly 936 may include fastener 934 fastened onto the first end of shaft 926 following cam 928 (e.g., by mated threads), such that the first end of shaft 926 retains fastener 934 in place against cam 928. Optionally, fastener assembly 936 may include springs 932. Springs 932 may be inserted onto first end of shaft 926 following cam 928 and compressed between cam 928 and another surface, such as fastener 934, an interior surface of first leaf assembly 904, or the like. Once compressed, springs 932 may apply a constant pressure against cam 928 toward the friction surface of shaft 926, thereby creating, or contributing to, the friction, or mechanical resistance, of friction core assembly 924. As an alternative, or additional option, fastener assembly 936 may include washers 930. Washers 930 may be inserted onto shaft 926 following cam 928. Washers 930 may include one, two, three, five, or a similarly suitable number of washers. The number of washers may be selected based on the dimensions of the first end of shaft 926 and / or the number and dimensions of other components inserted onto the first end of shaft 926. Where fastener assembly 936 includes multiple components, such as one ormore springs 932 and / or one or more fasteners 936, washers 930 may separate one or more of the components from each other. For example, one of washers 930 may separate cam 928 from one or more springs 932. As further described above, when inserted onto first end of shaft 926 following cam 928, one of washers 930 may be restricted from rotating around the longitudinal axis of shaft 926 by one or more support structures formed by the first end of shaft 926. With restricted rotation, adjacent surfaces between cam 928 and the one of washers 930 may provide additional friction for friction core assembly 908.

[0083] It should be noted that the methods, systems, and devices discussed above are intended merely to be examples. It must be stressed that various embodiments may omit, substitute, or add various procedures or components as appropriate. For instance, it should be appreciated that, in alternative embodiments, the methods may be performed in an order different from that described, and that various steps may be added, omitted, or combined. Also, features described with respect to certain embodiments may be combined in various other embodiments. Different aspects and elements of the embodiments may be combined in a similar manner. Also, it should be emphasized that technology evolves and, thus, many of the elements are examples and should not be interpreted to limit the scope of the invention.

[0084] Specific details are given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, well-known, processes, structures, and techniques have been shown without unnecessary detail in order to avoid obscuring the embodiments. This description provides example embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the preceding description of the embodiments will provide those skilled in the art with an enabling description for implementing embodiments of the invention. Various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention.

[0085] Also, it is noted that the embodiments may be described as a process which is depicted as a flow diagram or block diagram. Although each may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may have additional steps not included in the figure.

[0086] Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. For example, the above elements may merely be acomponent of a larger system, wherein other rules may take precedence over or otherwise modify the application of the invention. Also, a number of steps may be undertaken before, during, or after the above elements are considered. Accordingly, the above description should not be taken as limiting the scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. An adjustable resistance hinge comprising: a first leaf assembly comprising a first hollow cylinder that forms a first inner opening at a first end of the first leaf assembly; a second leaf assembly comprising a second hollow cylinder that forms a second inner opening at a second end of the second leaf assembly, wherein the first end of the first leaf assembly is pressed against the second end of the second leaf assembly to form a continuous hollow cylinder; a friction core assembly enclosed within the continuous hollow cylinder, wherein the friction core assembly comprises: a hollow cam enclosed by the first hollow cylinder, comprising: one or more cam mating structures on an external cylindrical surface of the hollow cam that prevent the hollow cam from rotating within the first hollow cylinder; and a cam friction surface perpendicular to the external cylindrical surface; a hollow shaft enclosed by the continuous hollow cylinder, comprising: a first end inserted through an interior of the hollow cam; a second end opposite the first end that is inserted into the second hollow cylinder, wherein the second end comprises one or more shaft mating structures that prevent the hollow shaft from rotating within the second hollow cylinder; and a middle portion separating the first end from the second end, wherein the middle portion comprises a shaft friction surface pressed against the cam friction surface; and a fastener assembly coupled with the first end of the hollow shaft that maintains pressure between the shaft friction surface and the cam friction surface, thereby providing friction between the shaft friction surface and the cam friction surface that resists rotation of the hollow cam with respect to the hollow shaft.

2. The adjustable resistance hinge of claim 1, wherein the fastener assembly comprises: one or more springs threaded onto the first end of the hollow shaft following the hollow cam; anda fastener secured to the first end of the hollow shaft following the one or more springs such that the one or more springs are compressed, thereby applying the pressure between the shaft friction surface and the cam friction surface.

3. The adjustable resistance hinge of claim 2, wherein: the fastener assembly further comprises one or more washers threaded onto the first end of the hollow shaft between the hollow cam and the one or more springs; and the one or more washers comprise one or more support structures that prevent the one or more washers from rotating with respect to the hollow shaft.

4. The adjustable resistance hinge of claim 2, wherein the one or more springs comprise spring discs.

5. The adjustable resistance hinge of claim 2, wherein a predefined torque that results in a predefined hinge tension is applied to the fastener with respect to the hollow shaft to secure the fastener to the first end of the hollow shaft.

6. The adjustable resistance hinge of claim 1, wherein cylindrical side walls of the first leaf assembly and the second leaf assembly each form a hollow cable routing from an interior of the continuous hollow cylinder to external surfaces of the first leaf assembly and the second leaf assembly.

7. The adjustable resistance hinge of claim 6, further comprising a cable assembly threaded through the hollow cable routing of the first leaf assembly, the hollow shaft, and the hollow cable routing of the second leaf assembly.

8. The adjustable resistance hinge of claim 1, wherein the middle portion of the hollow shaft and the hollow cam each form locking tabs that prevent the hollow cam from completing a full rotation around the hollow shaft.

9. The adjustable resistance hinge of claim 8, wherein the locking tabs prevent the hollow cam from rotating more than 135 degrees from a closed position to an open position.

10. The adjustable resistance hinge of claim 1, wherein the first leaf assembly and the second leaf assembly are formed using metal injection molding.

11. A hinged tablet computer case system comprising: a first portion that removably docks with a tablet computer;a second portion comprising a keyboard; and a plurality of hinges connecting the first portion with the second portion, wherein each of the plurality of hinges comprise: a first leaf assembly comprising a first hollow cylinder that forms a first inner opening at a first end of the first leaf assembly; a second leaf assembly comprising a second hollow cylinder that forms a second inner opening at a second end of the second leaf assembly, wherein the first end of the first leaf assembly is pressed against the second end of the second leaf assembly, thereby forming a continuous hollow cylinder from the first hollow cylinder and the second hollow cylinder; a friction core assembly enclosed within the continuous hollow cylinder, wherein the friction core assembly comprises: a hollow cam enclosed by the first hollow cylinder, comprising: one or more cam mating structures on an external cylindrical surface of the hollow cam that prevent the hollow cam from rotating within the first hollow cylinder; and a cam friction surface perpendicular to the external cylindrical surface; a hollow shaft enclosed by the continuous hollow cylinder, comprising: a first end inserted through an interior of the hollow cam; a second end opposite the first end that is inserted into the second hollow cylinder, wherein the second end comprises one or more shaft mating structures that prevent the hollow shaft from rotating within the second hollow cylinder; and a middle portion separating the first end from the second end, wherein the middle portion comprises a shaft friction surface pressed against the cam friction surface; and a fastener assembly coupled with the second end of the hollow shaft that maintains pressure between the shaft friction surface and the cam friction surface, thereby providing friction between the shaft friction surface and the cam friction surface that resists rotation of the hollow cam with respect to the hollow shaft.

12. The tablet computer case system of claim 11, wherein the plurality of hinges comprise a left hinge and a right hinge that are mirror images of each other.

13. The tablet computer case system of claim 11, wherein the fastener assembly comprises: one or more springs threaded onto the first end of the hollow shaft following the hollow cam; and a fastener secured to the first end of the hollow shaft following the one or more springs such that the one or more springs are compressed, thereby applying the pressure between the shaft friction surface and the cam friction surface.

14. The tablet computer case system of claim 13, wherein a predefined torque that results in a predefined hinge tension is applied to the fastener with respect to the hollow shaft to secure the fastener to the first end of the hollow shaft.

15. The tablet computer case system of claim 14, wherein the predefined hinge tension is selected to resist movement of the first portion with respect to the second portion due to a combined weight of the first portion and the tablet computer.

16. The tablet computer case system of claim 11, wherein the middle portion of the hollow shaft and the hollow cam each form locking tabs that prevent adjusting an opening angle of the first portion relative to the second portion beyond a predefined opening angle.

17. The tablet computer case system of claim 11, wherein the predefined opening angle is 130 degrees.

18. The tablet computer case system of claim 11, wherein the first leaf assembly and the second leaf assembly are formed using metal injection molding.

19. A method of adjusting tension supplied by a hinge, comprising: assembling a friction core assembly, the friction core assembly comprising: a hollow cam comprising a cam friction surface perpendicular to a longitudinal axis of the hollow cam; a hollow shaft, comprising: a first end inserted through an interior of the hollow cam; a second end opposite the first end; and a middle portion separating the first end from the second end, wherein the middle portion comprises a shaft friction surface pressed against the cam friction surface; anda fastener assembly screwed onto the first end of the hollow shaft that maintains pressure between the shaft friction surface and the cam friction surface, thereby providing friction between the shaft friction surface and the cam friction surface that results in a rotational resistance around the longitudinal axis of the hollow cam with respect to the hollow shaft; testing the rotational resistance around the longitudinal axis of the hollow cam with respect to the hollow shaft; adjusting a torque applied to the fastener assembly to increase or decrease the rotational resistance; and installing the friction core assembly within a continuous hollow cylinder formed by pressing a first end of a first leaf assembly against a second end of a second leaf assembly.

20. The method of adjusting a hinge of claim 19, wherein the fastener assembly comprises: one or more springs threaded onto the first end of the hollow shaft following the hollow cam; and a fastener screwed onto the first end of the hollow shaft following the one or more springs, wherein adjusting the torque comprises tightening or loosening the fastener to increase or decrease a compression of the one or more springs.

Images