CN116806330A - Hinge assembly of foldable device - Google Patents

A hinge assembly (1) for a collapsible device (2). The hinge assembly (1) is movable between a closed position (P1) and an open position (P2) when the device (2) is folded or unfolded. The hinge assembly (1) comprises a first pivot element (3) configured to pivot about a first pivot axis (A1) and a second pivot element (4) configured to pivot about a second pivot axis (A2). The first pivoting element (3) and the second pivoting element (4) are configured to pivot simultaneously in opposite rotational directions by a first angle (alpha). The first support surface (5) is configured to pivot with respect to the first pivot element (3) and the second support surface (6) is configured to pivot with respect to the second pivot element (4). The first support surface (5) and the second support surface (6) are configured to simultaneously pivot in opposite rotational directions by a second angle (β) after a pivoting movement of the first pivot element (3) and the second pivot element (4) by the first angle (α). The space formed by the pivoting member and the surface may enable the display of the device to take on a teardrop shape that is accommodated within the device without increasing the thickness of the device and without requiring complex arrangements.

Hinge assembly of foldable device

Technical Field

The present invention relates to a hinge assembly for a foldable device, the hinge assembly being movable between a closed position and an open position when the device is folded or unfolded.

Background

The size of a device such as a tablet or smart phone is an important consideration in the device design process. Users often want the external dimensions of the device to be as small as possible while the display still remains as large as possible.

This problem may be solved by a foldable device or the like comprising one or more supports interconnected by hinges and supporting the display. One or more of the support and the display may be folded together to provide a device that is as small as possible and/or in which the display is protected from external influences such as impact. Accordingly, the size of the display is as large as possible when the device is deployed. In other words, the foldable device is configured to have a variable width that is minimized or maximized.

One problem associated with such foldable devices is how to provide a device that can be folded to a minimum width without increasing the thickness of the device too much. Another problem is associated with the hinge structure, which is often very complex and takes up a lot of space within the device with the folding display.

Disclosure of Invention

It is an object of the present invention to provide an improved hinge assembly for a foldable device, such as a portable electronic device. The above and other objects are achieved by the features of the independent claims. Other implementations are apparent from the dependent claims, the description and the drawings.

According to a first aspect, there is provided a hinge assembly for a foldable device, the hinge assembly being movable between a closed position and an open position when the device is folded or unfolded. The hinge assembly includes a first pivot element configured to pivot about a first pivot axis and a second pivot element configured to pivot about a second pivot axis. The first pivot element and the second pivot element are configured to pivot simultaneously in opposite rotational directions by a first angle. The first support surface is configured to pivot relative to the first pivot element and the second support surface is configured to pivot relative to the second pivot element. The first and second support surfaces are configured to simultaneously pivot a second angle in opposite rotational directions in response to the pivotal movement of the first and second pivot elements through the first angle.

This helps to create a space between the pivot element and the support element that accommodates the folded area of the display when the display is folded. When the display is folded, the fold areas do not fold rapidly, but rather form tear drops, i.e. the fold areas of the display have a thickness which is greater than, for example, the edge areas of the display which can extend directly next to each other when the device is folded. On the other hand, the folded area of the display is folded with a radius, i.e. the corresponding parts of the display are separated by a gap, the size of which is reduced and eventually disappears, so that the edge areas of the display are in direct contact. The space created by the present solution allows such a teardrop shape of the display to be accommodated within the device without increasing the thickness of the device and without requiring complex arrangements.

In a possible implementation manner of the first aspect, the first support surface and the second support surface are configured to extend on a common plane when the hinge assembly is in the open position, and the first support surface and the second support surface extend at a third angle when the hinge assembly is in the closed position. Such that the hinge assembly supports the display in an open position and accommodates the folding display in a closed position.

In another possible implementation of the first aspect, the first and second pivot elements are configured such that when the first and second pivot elements pivot the first angle towards the closed position, a recess is formed between the first pivot element and the first support surface, a recess is formed between the second pivot element and the second support surface, the recess accommodating any deformation of the first and second support surfaces when the first and second support surfaces pivot the second angle simultaneously.

In another possible implementation manner of the first aspect, the first angle is between 0 ° minimum and 80 ° maximum and 100 °, preferably 90 °.

In another possible implementation manner of the first aspect, the second angle is between 0 ° minimum and 1 ° maximum and 45 ° maximum.

In another possible implementation of the first aspect, the first pivot element includes an inner end and an outer end, wherein the inner end is disposed adjacent the first pivot; the second pivot element includes an inner end and an outer end, wherein the inner end is disposed adjacent the second pivot; the first support surface includes an inner end and an outer end; the second support surface includes an inner end and an outer end; the outer end of the first support surface is configured to pivot relative to the outer end of the first pivot element and the outer end of the second support surface is configured to pivot relative to the outer end of the second pivot element, wherein the inner end of the first support surface extends adjacent to the inner end of the second support surface when the hinge assembly is in the open position;

the outer end of the first support surface extends adjacent the outer end of the second support surface when the hinge assembly is in the closed position.

In another possible implementation of the first aspect, the inner end of the first support surface is spaced from the inner end of the second support surface by a first gap when the hinge assembly is in the open position; the inner end of the first support surface is spaced from the inner end of the second support surface by a second gap when the hinge assembly is in the closed position, wherein the second gap is larger than the first gap, freeing up space to accommodate the folded and deformed display.

In another possible implementation of the first aspect, the outer end of the first support surface is separated from the outer end of the second support surface by a combined total width of the first support surface, the second support surface, and the first gap when the hinge assembly is in the open position.

In another possible implementation manner of the first aspect, the second pivot axis extends parallel to the first pivot axis, and/or the first support surface extends parallel to the first pivot axis, and the second support surface extends parallel to the second pivot axis.

In another possible implementation of the first aspect, the first support surface and the second support surface are configured to support a foldable display of the foldable device, the recess forming a cavity that accommodates a folded portion of the foldable display. The hinge assembly is thus as uncomplicated as possible and does not significantly increase the number of parts of the device.

In another possible implementation of the first aspect, the hinge assembly further comprises a housing configured to guide the first and second pivot elements during the pivoting movement, wherein the inner ends of the first and second pivot elements are operatively connected to the housing. The housing both guides and protects the hinge assembly and also retains it in one assembly set.

In another possible implementation of the first aspect, the inner end of the first pivot element and the inner end of the second pivot element are configured to overlap along a central axis of the housing when the hinge assembly is in the open position such that the hinge assembly occupies as little space as possible.

In another possible implementation of the first aspect, the outer end of the first support surface and the outer end of the second support surface are configured to be spaced apart by a third gap when the hinge assembly is in the closed position, wherein the second gap is greater than the third gap. This facilitates that the display portions extend parallel to and adjacent to each other when the hinge assembly is in the closed position, and thus the device is folded.

In another possible implementation of the first aspect, the inner end of the first pivot element and the inner end of the second pivot element are configured to slide within the housing during the pivot movement, wherein the sliding movement is limited in a direction perpendicular to the first pivot axis and the second pivot axis.

In another possible implementation of the first aspect, the sliding movement is limited by a first set of grooves accommodating the inner ends of the first pivoting elements and a second set of grooves accommodating the inner ends of the second pivoting elements.

In another possible implementation manner of the first aspect, the first pivot element and the second pivot element pivot simultaneously at the same angular velocity.

In another possible implementation of the first aspect, the inner end of the first pivot element includes a protrusion configured to engage the inner end of the second support surface when the hinge assembly is in the open position, the inner end of the second pivot element includes a protrusion configured to engage the inner end of the first support surface; the protrusion is configured to disengage the first and second support surfaces when the hinge assembly is in the closed position. This helps to reduce the number of components while still providing adequate support for the display when the hinge assembly is in the open position.

In another possible implementation of the first aspect, the housing is configured to partially engage the first and second support surfaces when the hinge assembly is in the open position, providing a hinge assembly that is more stable even when in the open position.

In another possible implementation of the first aspect, the hinge assembly further comprises a guiding structure, wherein the guiding structure is configured to ensure that the inner ends of the first and second support surfaces are away from each other when the hinge assembly is moved to the closed position, ensuring that the two halves of the hinge assembly are securely and reliably opened and closed.

In another possible implementation of the first aspect, each guiding structure comprises a fixed element extending from the housing or one of the first and second support surfaces and a movable element extending from one of the first and second support surfaces or the housing. This reduces the need for separately operated guide members.

In another possible implementation of the first aspect, the fixed element comprises a pin and the movable element comprises a groove or surface configured to slide over the pin in response to the pivoting movement, the sliding movement forcing the first support surface or the second support surface to move in a direction towards or away from the other of the first support surface and the second support surface. These elements are readily part of other hinge assembly components.

In another possible implementation of the first aspect, each guiding structure comprises a spring element extending between the housing and the first or second support surface.

According to a second aspect there is provided a foldable device movable between a closed position and an open position, the device comprising at least one hinge assembly, a foldable display and a foldable body according to the above, wherein the foldable body comprises a first body portion and a second body portion, each body portion comprising a display backlight surface supporting a portion of the foldable display, the first body portion and the second body portion being interconnected by the hinge assembly such that the display backlight surfaces of the first body portion and the second body portion extend in parallel when the device is in the closed position, and the display backlight surfaces of the first body portion and the second body portion extend in a common plane when the device is in the open position.

This facilitates folding of the device while still preventing the surface layer (e.g. a display of an electronic device) from becoming wrinkled and/or permanently deformed due to the folding. Furthermore, the hinge assembly provides a stable open position as well as stable folded and closed positions, which prevents accidental folding beyond the mechanical limits of the device.

In a possible implementation manner of the second aspect, the outer end of the first pivoting member is fixedly connected to an inner surface area of the first body portion, the outer end of the second pivoting member is fixedly connected to an inner surface area of the second body portion, and each inner surface area extends at a fourth angle > 0 ° to the display backlight surface.

This and other aspects will be apparent from the embodiments described below.

Drawings

In the following detailed portion of the invention, aspects, embodiments and implementations will be explained in more detail with reference to exemplary embodiments shown in the drawings in which:

FIG. 1 is a schematic side view of a hinge assembly provided by one embodiment of the present invention, wherein the hinge assembly is in an open position;

FIG. 2 is a schematic side view of a foldable device provided by one embodiment of the present invention, with the device deployed and the hinge assembly in an open position;

FIG. 3 is a schematic side view of the hinge assembly shown in FIG. 1, with the hinge assembly in a closed and folded position;

FIG. 4 is a partial side view of the foldable device shown in FIG. 2, wherein the device is closed and folded and the hinge assembly is in a closed position;

FIG. 5 is a partial cross-sectional view of a hinge assembly provided in accordance with one embodiment of the present invention, wherein the hinge assembly is in a closed position;

FIG. 6 is a partial cross-sectional view of a foldable device provided in one embodiment of the present invention, wherein the foldable device is closed and folded, with the hinge assembly in a closed position;

FIG. 7 is a partial cross-sectional view of the hinge assembly shown in FIG. 5, with the hinge assembly in an open position;

FIG. 8 is a partial cross-sectional view of the foldable device shown in FIG. 6, with the foldable device open and unfolded and the hinge assembly in an open position.

Detailed Description

Fig. 1 to 4 show a hinge assembly 1 for a foldable device 2, the hinge assembly 1 being movable between a closed position P1 and an open position P2 when the device 2 is folded or unfolded. The closed position P1 is shown in fig. 2 and 4 and the open position P2 is shown in fig. 1 and 3. The foldable device 2, such as a tablet or a smart phone, or any mobile communication device, such as a mobile phone, a desktop computer, or the like, may also be movable between a closed position P1 and an open position P2, in other words, both the hinge assembly 1 and the foldable device 2 are located in the closed position P1 or the open position P2, or are simultaneously movable between the closed position P1 and the open position P2.

As shown in fig. 2, the device 2 includes a hinge assembly 1, described in more detail below, a foldable display 10, and a foldable body including a first body portion 16a and a second body portion 16b. The first body portion 16a and the second body portion 16b may be two separate portions as shown in fig. 2, or two portions of a single piece body (not shown). The first body portion 16a and the second body portion 16b may be interconnected by the hinge assembly 1 or by other additional folding elements.

Each body portion 16a, 16b includes a display backlight surface 17a, 17b, which display backlight surfaces 17a, 17b respectively support a portion of the foldable display 10, such as a portion of the display 10 that does not extend directly adjacent the hinge assembly 1.

The first and second body portions 16a, 16b are interconnected by the hinge assembly 1 such that the display backlighting surfaces 17a, 17b of the first and second body portions 16a, 16b extend in parallel when the device 2 is in the closed position P1 (not shown) and the first and second body portions 16a, 16b extend in parallel when the device 2 is in the open position P2, as shown in fig. 2.

As shown in most detail in fig. 1 and 3, the hinge assembly 1 includes a first pivot element 3 configured to pivot about a first pivot axis A1 and a second pivot element 4 configured to pivot about a second pivot axis A2. As shown in fig. 3, the second pivot axis A2 may extend parallel to the first pivot axis A1.

The first pivot element 3 and the second pivot element 4 are configured to pivot simultaneously in opposite rotational directions by a first angle α, optionally at the same angular velocity. This helps the main part of the first pivoting member 3 and the main part of the second pivoting member 4 to pivot substantially away from each other when the device 2 is folded and closed, and to move substantially away from each other when the device 2 is unfolded and opened. The first angle α may be between 0 ° and 80 ° and 100 °, preferably 90 °. For example, the first angle α may have a minimum of 0 ° when the hinge assembly 1 is in the open position P2, and a maximum of 80 ° to 100 °, preferably 90 °, when the hinge assembly 1 is in the closed position P1.

The hinge assembly further comprises a first support surface 5 configured to pivot relative to the first pivot element 3, and a second support surface 6 configured to pivot relative to the second pivot element 4. The first support surface 5 extends parallel to the first pivot axis A1 and the second support surface 6 extends parallel to the second pivot axis A2.

The first and second support surfaces 5, 6 are configured to simultaneously pivot in opposite rotational directions by a second angle β in response to a pivoting movement of the first and second pivot elements 3, 4 through the first angle α. The second angle β may be between a minimum of 0 ° when the hinge assembly 1 is in the open position P2, and between a maximum of 1 ° and 45 ° when the hinge assembly 1 is in the closed position P1, for example. When the device is open and the hinge assembly 1 is in the open position P2, both the first angle α and the second angle β may be minimal, e.g. 0 °. Accordingly, when the device is folded and the hinge assembly 1 is in the closed position P1, both the first angle α and the second angle β may be at a maximum, for example at 90 ° and 45 °, respectively.

When the hinge assembly 1 is in the closed position P1, the first support surface 5 may extend to the second support surface 6 at a third angle γ, as shown in fig. 3. The first and second support surfaces 5, 6 may be configured to extend on a common plane when the hinge assembly 1 is in the open position P2, as shown in fig. 1 and 2, i.e. the third angle γ is 180 °.

When the first and second pivot elements 3, 4 are pivoted towards the closed position P1 by the first angle α, the first and second pivot elements 3, 4 may be configured such that a recess 19a is formed between the first pivot element 3 and the first support surface 5 and a corresponding recess 19b is formed between the second pivot element 4 and the second support surface 6. The recesses 19a, 19b are shown in fig. 1. The recesses 19a, 19b accommodate any deformation or movement of the first support surface 5 and the second support surface 6 when the first support surface 5 and the second support surface 6 are pivoted simultaneously through the second angle β.

The first pivot element 3 may comprise an inner end 3a and an outer end 3b, wherein the inner end 3a is arranged adjacent to the second pivot axis A1. The inner end 3a may be an outer peripheral edge or area of the first pivot element 3, and the inner end 3a may extend parallel to the first pivot axis A1. The outer end 3b may be a peripheral edge or peripheral area of the first pivot element 3, and the outer end 3b may extend parallel to the first pivot axis A1. The first pivot axis A1 may be coplanar with the inner end 3a and/or the outer end 3b when the hinge assembly 1 is in the open position P2.

Accordingly, the second pivot element 4 may comprise an inner end 4a and an outer end 4b, wherein the inner end 4a is arranged adjacent to the second pivot axis A2. The inner end 4a may be an outer peripheral edge or area of the second pivot element 4, and the inner end 4a may extend parallel to the second pivot axis A2. The outer end 4b may be an outer peripheral edge or outer peripheral region of the second pivot element 4, and the outer end 4b may extend parallel to the second pivot axis A2. The second pivot axis A2 may be coplanar with the inner end 4a and/or the outer end 4b when the hinge assembly 1 is in the open position P2.

As described above, the device 2 may include a collapsible body including a first body portion 16a and a second body portion 16b. The first body portion 16a may include an inner surface region 18a and, correspondingly, the second body portion 16b may include an inner surface region 18b. Each inner surface area 18a, 18b extends to the display backlight surface 17a, 17b at a fourth angle delta greater than 0 deg., i.e. at an angle delta to the common plane. This helps to create a space between the body portions 16a, 16b and the display 10 that allows any raised portions or other deformed display areas to be accommodated within the device 2 when the device 2 has been folded, as shown in fig. 4. Furthermore, the outer end 3b of the first pivot element 3 may be fixedly connected to the inner surface area 18a of the first body portion 16a, and the outer end 4b of the second pivot element 4 may be correspondingly fixedly connected to the inner surface area 18b of the second body portion 16b.

The inner end 3a of the first pivot element 3 may extend adjacent the inner end 4a of the second pivot element 4, optionally overlapping the inner end 4a of the second pivot element 4, when the hinge assembly 1 is in the open position P2 and/or in the closed position P1. When the hinge assembly 1 is in the open position P2, the outer end 3b of the first pivot element 3 may be at a maximum distance from the outer end 4b of the second pivot element 4.

The first support surface 5 may comprise an inner end 5a and an outer end 5b, the inner end 5a and the outer end 5b may be oppositely extending peripheral edges or peripheral regions of the first support surface 5. The second support surface 6 may comprise an inner end 6a and an outer end 6b, the inner end 6a and the outer end 6b may be oppositely extending peripheral edges or peripheral regions of the second support surface 6.

The outer end 5b of the first support surface 5 may be configured to pivot relative to the outer end 3b of the first pivot element 3 and the outer end 6b of the second support surface 6 may be configured to pivot relative to the outer end 4b of the second pivot element 4, as shown in fig. 1 and 3 and fig. 2 and 4, respectively.

When the hinge assembly 1 is in the open position P2, the inner end 5a of the first support surface 5 extends adjacent the inner end 6a of the second support surface 6, as shown in fig. 1 and 2. When the hinge assembly 1 is in the closed position P1, the outer end 5b of the first support surface 5 extends adjacent the outer end 6b of the second support surface 6, as shown in fig. 3 and 4.

When the hinge assembly 1 is in the open position P2, the inner end 5a of the first support surface 5 may be spaced from the inner end 6a of the second support surface 6 by a first gap 7, as shown in fig. 1 and 2. When the hinge assembly 1 is in the closed position P1, the inner end 5a of the first support surface 5 may be spaced from the inner end 6a of the second support surface 6 by a second gap 8, wherein the second gap 8 is larger than the first gap 7.

The outer end 5b of the first support surface 5 and the outer end 6b of the second support surface 6 may be configured to be spaced apart by a third gap 9 when the hinge assembly 1 is in the closed position P1, wherein the second gap 8 is larger than the third gap 9, as shown in fig. 3.

Furthermore, when the hinge assembly 1 is in the open position P2, the outer end 5b of the first support surface 5 is separated from the outer end 6b of the second support surface 6 by the combined total width of the first support surface 5, the second support surface 6 and the first gap 7, preferably seen in a common plane, and shown in fig. 1 and 2.

The first support surface 5 and the second support surface 6 may be configured to support the foldable display 10 of the foldable device 2, the recesses 19a, 19b forming cavities accommodating folded portions of the foldable display 10, the folded portions optionally having a tear drop shape.

The hinge assembly 1 may further comprise a housing 11 configured to guide the first pivot element 3 and the second pivot element 4 during a pivoting movement of the first pivot element 3 and the second pivot element 4. The inner end 3a of the first pivot element 3 and the inner end 4a of the second pivot element 4 may be operatively connected to the housing 11. The housing 11 and the inner ends 3a, 4a may comprise corresponding semi-circular portions facilitating the pivoting of the first and second pivot elements 3, 4 within the housing 11.

The inner end 3a of the first pivot element 3 and the inner end 4a of the second pivot element 4 may be configured to slide within the housing 11 during the pivoting movement, the sliding movement being limited in a direction perpendicular to the first pivot axis A1 and the second pivot axis A2. The sliding movement can be limited by a first set of grooves 13a accommodating the inner ends 3a of the first pivoting elements 3 and a second set of grooves 13b accommodating the inner ends 4a of the second pivoting elements 4. The first and second sets of grooves 13b may limit the movement of the first and second pivot elements 3, 4 to pivotal movement about the first and second pivots A1, A2 in a plane extending perpendicular to the first and second pivots A1, A2.

When the hinge assembly 1 is in the open position P2, the inner end 3a of the first pivot element 3 and the inner end 4a of the second pivot element 4 may be configured to overlap along the central axis A3 of the housing 11, as shown in fig. 1 and 2. The inner end 3a of the first pivot element 3 and the inner end 4a of the second pivot element 4 may also be configured to overlap, but to a lesser extent, when the hinge assembly 1 is in the closed position P1 (not shown).

The inner end 3a of the first pivot element 3 may comprise a protrusion 14a, which protrusion 14a is configured to engage the inner end 6a of the second support surface 6 when the hinge assembly 1 is in the open position P2. Accordingly, the inner end 4a of the second pivot element 4 may comprise a protrusion 14b configured to engage the inner end 5a of the first support surface 5. When the hinge assembly 1 is in the closed position P1, the protrusions 14a, 14b are configured to disengage the first and second support surfaces 5, 6.

When the hinge assembly 1 is in the open position P2, the housing 11 may be configured to partially engage the first and second support surfaces 5, 6, as shown in fig. 1 and 2.

The hinge assembly may further comprise a guiding structure 15 configured to move the inner ends 5a, 6a of the first and second support surfaces 5, 6 away from each other when the hinge assembly 1 is moved towards the closed position P1. The guiding structure is shown in more detail in fig. 5 to 8.

Each guide structure 15 may include a fixed element 15a and a movable element 15b, the fixed element 15a extending from the housing 11, the first support surface 5 or the second support surface 6 shown in fig. 5 to 8. The movable element 15b extends from the first support surface 5, the second support surface 6 or the housing 11 shown in fig. 5 to 8, respectively, such that the fixed element 15a and the movable element 15b are connected to different components, facilitating the guiding of said components with respect to each other. In one embodiment, one fixation element 15a extends from the first support surface 5 and the other fixation element 15a extends from the second support surface 6, each fixation element 15a interacting with a movable element 15b extending from the housing 11.

As shown in fig. 5-8, the fixed element 15a may comprise a pin and the movable element 15b may comprise a groove or surface configured to slide over the pin 15a in response to the pivoting motion. The sliding movement forces the first support surface 5 or the second support surface 6 to move in a direction towards or away from the other of the first support surface 5 and the second support surface 6. The movable element 15b may be any type of element including curved surfaces configured to facilitate pivoting of the first and second support surfaces 5, 6 within the housing 11 while restricting movement to follow a desired path, for example, to avoid the display 10 being misfolded or sandwiched between elements. The movable element 15b may form a closed loop together with the support surfaces 5, 6 such that the fixed element 15a is substantially surrounded by the movable element 15b, the movable element 15b being pivoted such that the fixed element 15a is located at one end of the loop when the hinge assembly 1 is in the open position P2 and at the opposite end of the loop when the hinge assembly 1 is in the closed position P1.

Each guide structure 15 may also or alternatively comprise a spring element extending between the housing 11 and the first pivot element 3 or the second pivot element 4, between the first body portion 16a and the first support surface 5 or between the second body portion 16b and the second support surface 6 (not shown).

Furthermore, the first pivot element 3 may be part of the first body portion 16a, while the second pivot element 4 may be part of the second body portion 16b, such that they are not fixedly connected, but extend from each other.

Various aspects and implementations have been described herein in connection with various embodiments. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject matter, from a study of the drawings, the invention, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality of elements or steps. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The reference signs used in the claims shall not be construed as limiting the scope. Unless otherwise indicated, the drawings (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) should be read together with the specification, and should be considered a portion of the entire written description of this invention. Since the particular drawings are presented to the reader, the terms "horizontal," "vertical," "left," "right," "upward" and "downward" as used in the specification, as well as adjectives and derivatives of the words (e.g., "horizontal," "rightward," "upward," etc.), refer to the directions of the structures shown only. Similarly, the terms "inwardly" and "outwardly" generally refer to the direction of a surface relative to its axis of extension or axis of rotation, as the case may be.