Strap adjustment mechanism

Abstract

A strap adjustment mechanism for eyeglasses having a strap for securing the eyeglasses to a user's head, the adjustment mechanism comprising: a body having an elongated shaft from which a head strap can be extended, the elongated extension of the shaft defining a longitudinal direction; a mounting portion movably attached to the body; a pawl having a cam surface facing the body and extending laterally from the mounting portion towards the shaft to a free end; and an engagement member movable between the pawl and the body, the engagement member and the cam surface of the pawl being configured to cooperate to cause the engagement member to move laterally at the free end of the pawl between an engaged position and a disengaged position, the engaged position being such that the free end can engage the strap when the shaft is extended, and the disengaged position being such that the free end is lifted off the shaft so as to disengage from the strap when the shaft is extended.

Description

[Technical field]

[0001] The present disclosure relates to an eyeglass strap adjustment mechanism and eyeglasses including the adjustment mechanism, particularly but not exclusively for use with protective eyewear used in underwater activities, such as goggles and snorkeling masks. [Background technology]

[0002] Eyeglasses are worn for a variety of purposes, including fashion, eye protection, and / or improved vision. Typically, glasses include eyepieces (i.e., formed as part of the frame) and a nose bridge to which the eyepieces connect.

[0003] In some cases, the eyepiece is secured to the user's head via an arm that protrudes from the outer side of the eyepiece and hooks over the user's ear. Other arrangements use a head strap to secure the eyepiece to the user's head. Such arrangements are commonly found in swimming goggles and masks, where it is important to create a tight seal between the eyepiece and the user's face to prevent water from entering the space between them.

[0004] Typically, the head strap takes the form of an elongated band of elastic material that is connected to and extends between the outer sides of the eyepieces, with each end of the strap often threaded through an opening in each eyepiece, and a central portion of the strap extending around the wearer's head (when worn) from one eyepiece to the other.

[0005] To ensure a secure and comfortable fit, it is important that the size of the head strap (i.e., the tension applied by the head strap) is adapted to the size and shape of the wearer's head. For this reason, it is known to have an adjustment mechanism that allows the user to adjust the length of the strap that extends between the eyepieces (i.e., around the head). In some cases, this adjustment mechanism is provided on the eyepiece (usually each eyepiece includes an adjustment mechanism).

[0006] One known type of adjustment mechanism includes a member that can selectively engage and disengage the looped portion of the strap that passes through an opening in the eyepiece to restrict or allow movement of the strap through the opening. The member can be moved by pressing a button to allow a user to disengage the member from the strap to adjust the length of the strap that extends around the eyepiece and the user's head.

[0007] Such adjustment mechanisms can be difficult to operate (e.g., requiring the user to apply significant force) and, in some cases, can be uncomfortable for the user when operating the eyeglasses while they are being worn. For example, in some known arrangements, the button that releases the strap is positioned to be pressed in the direction of the user's head when the eyeglasses are being worn (usually in the area of ​​the user's temples). When the button is pressed, the adjustment mechanism is forced against the user's head, causing discomfort.

[0008] To avoid this discomfort, buttons are placed at the top and bottom of the adjustment mechanism and the user pinches them to release the strap. When pressed, the buttons slide vertically and inwardly towards each other, engaging the top or bottom edge of the claw, respectively, to lift the claw off the strap and allow the strap to be released and adjusted. While this reduces the discomfort problem described above, such adjustment mechanisms can be difficult to use, as the user must precisely position their fingers and thumbs and then apply significant force to release them.

[0009] There is a need to alleviate at least one of the above problems. Summary of the Invention [Problem to be solved by the invention]

[0010] A first aspect provides a strap adjustment mechanism for eyeglasses, the strap adjustment mechanism including a strap for securing the eyeglasses to a user's head; The adjustment mechanism includes: a head strap having an extensible elongated shaft, the elongated extension of the shaft defining a longitudinal direction; a mounting portion movably mounted to the body, a pawl having a cam surface facing the body and extending laterally from the mounting portion toward the shaft to a free end; an engagement member movable between the claw and the body; the cam surface of the engagement member and the pawl are configured to cooperate to move the engagement member laterally at the free end of the pawl between engaged and disengaged positions; the engagement position is such that the free end is engageable with a strap when the shaft is extended; The disengaged position is a strap adjustment mechanism characterized in that the free end is lifted off the shaft so as to disengage from the strap upon extension of the shaft.

[0011] In such an arrangement, the engagement member moves (e.g., sweeps) between the pawl and the body to lift the pawl off the strap and release the strap. As can be appreciated, such a mechanism can be actuated by a single press of a button. In this manner, the mechanism is easier (and more convenient) for a user to operate than, for example, a mechanism that requires multiple buttons to be pressed simultaneously.

[0012] Similarly, the engagement portion cooperates with the cam surface to translate lateral movement of the engagement portion into a lifting motion of the pawl, and thus in at least one arrangement of the mechanism, the button is actuated vertically when worn (avoiding discomfort caused by actuating it horizontally towards the wearer's head).

[0013] Configuring the cam surface to respond to lateral movement of the engagement arm (rather than, e.g., vertical movement) can provide a more robust mechanism, for example meaning that the engagement member engages the pawl over at least a portion of the width of the pawl and therefore supports the pawl over at least a portion of its width as the pawl is moved. This can, for example, minimise twisting of the pawl as it is actuated (which can occur when a lifting force is applied to one edge and / or side of the pawl).

[0014] For the avoidance of doubt, references herein to various parts of the mechanism being in an engaged or disengaged position are references to the position of those parts when the pawls are in the engaged and / or disengaged positions.

[0015] Optional features of the present invention are now described which may be applied alone or in any combination to any aspect of the present invention.

[0016] The longitudinal direction (or axis) defined by the extension of the shaft may be substantially perpendicular to the transverse direction. The pawl may extend from the attachment portion to the free end in a direction substantially perpendicular to the shaft.

[0017] In an in-use orientation (e.g., when forming part of a pair of eyeglasses worn by a user), the longitudinal direction (or longitudinal axis) may extend substantially vertically. In such an orientation, the strap extends horizontally from the shaft and passes around the wearer's head. In use, the transverse direction may be substantially horizontal. The transverse axis (i.e., extending laterally) may be a forward and / or rearward axis in use. Similarly, in use, the free ends of the claws move in medial and lateral directions (i.e., along generally inward and / or outward axes) relative to the user's head. Thus, when the claws are lifted off the shaft, the free ends of the claws may move in an outward direction.

[0018] The mechanism may include a button operatively connected to the engagement member. The operative connection may be configured such that when the button is pressed, the engagement member moves laterally between the pawl and the body. In other words, the button may be movable between a released position, in which the pawl is in the engaged position, and a depressed position, in which the pawl is in the disengaged position.

[0019] The button may be fixedly connected to the engagement member. The button may be integrally formed with the engagement member. The button may comprise a depression surface configured to be depressed by a user to move the button from the released position to the depressed position. The depression surface may be accessible from outside the body (i.e. by a user's finger). The depression surface may be arranged to be located on the exterior of the body. The depression surface may protrude from an outer surface of the body in the engaged position. The button may be at least partially received in a recess formed in the body.

[0020] The mounting may rotatably mount the pawl to the body. The mounting may be such that the pawl rotates about an axis of rotation (e.g., a fixed axis of rotation), referred to herein as the pawl axis of rotation. The pawl axis of rotation may extend longitudinally (e.g., vertically in use). The pawl axis of rotation may be substantially parallel to the shaft (i.e., the elongated extension of the shaft) and may be laterally spaced from the shaft. In the orientation in use, the pawl axis of rotation is forward of the shaft.

[0021] The attachment portion may include a pin or recess configured to engage with a pin or recess in the body. For example, the attachment portion may have spaced apart pins or recesses aligned along the pawl axis of rotation for engaging with spaced apart recesses or pins in the body. Each recess may be in the form of an opening. In one embodiment, for example, the body is provided with two projections spaced apart along the axis of rotation, each projection provided with a recess or pin for engaging with a corresponding pin or recess in the pawl. The pawls may be configured for a snap engagement between the projections.

[0022] The engagement member may be arranged to move along a reference plane between the body and the pawl (i.e., the engagement member may move and / or rotate in a single plane). In the aforementioned in-use orientation, the reference plane may be a generally vertical plane and extend substantially forward and / or backward. In an embodiment, the body comprises a base surface, and the reference plane may be parallel and / or coplanar with the base surface.

[0023] The engagement member may be rotatably mounted to the body. The engagement member may be rotatable about an axis of rotation (e.g., a fixed axis of rotation), referred to herein as the engagement member axis of rotation. The engagement member axis of rotation may be substantially perpendicular to the pawl axis of rotation. The engagement member axis of rotation may be substantially perpendicular to the shaft. The engagement member axis of rotation may be substantially perpendicular to the longitudinal and lateral directions. In an in-use orientation (as described above), the engagement member axis of rotation may extend in an inward and / or outward direction (i.e., extending towards and / or away from the user's head).

[0024] The engagement member rotation axis may be spaced laterally from the shaft. The engagement member rotation axis may be located further from the shaft than the attachment portion of the pawl. Thus, the engagement member rotation axis may be further from the shaft than the attachment portion of the pawl.

[0025] The engagement member may be disposed between the engagement member axis and the shaft.

[0026] The engagement member may be separate from the pawl (i.e. it may be or form part of a component not connected to the pawl). The engagement member may be elongate. The engagement member may, for example, extend across substantially the width of the pawl (width being the longitudinal dimension of the pawl). The engagement member may extend more than 30% or 50% or 80% of the width of the pawl. The engagement member may extend at least across the full width of the pawl (it may extend across at least the entire pawl).

[0027] The engagement member may be substantially straight along its length (although in other embodiments it may be curved along its length). The engagement member may extend longitudinally (e.g., substantially parallel to the shaft) at least in the engaged position. The engagement member may have a proximal end proximate the button and extend to a distal end, which may be a free end.

[0028] The engagement member may comprise an engagement surface (i.e., a surface facing the pawl) that cooperates with the cam surface. The engagement surface may be inclined with respect to a direction of movement of the engagement member. That is, the inclination of the engagement surface may be oriented in a lateral extension. The engagement surface may be inclined with respect to a reference surface (and / or base surface).

[0029] The engagement surface may extend across a substantial width of the nail (width being the longitudinal dimension of the nail). The engagement surface may extend across more than 30% or 50% or 80% of the width of the nail. The engagement surface may extend across the entire width of the nail (it may extend across the entire nail).

[0030] The engagement surface may include a leading edge that leads as the engagement member moves toward the cam surface. The engagement surface may include a trailing edge that trails as the engagement member moves toward the cam surface. The engagement surface may be sloped in a direction from the leading edge to the trailing edge. The engagement surface may be sloped away from the reference surface (and / or base surface) in a direction from the leading edge to the trailing edge. Thus, the engagement member may be thicker (e.g., in an inward and / or outward direction) at the trailing edge than at the leading edge.

[0031] At least a portion of the engagement surface may be further sloped in a direction along the length of the engagement member. The engagement surface may be sloped toward the reference surface in a direction from the proximal end to the distal end of the engagement member. Thus, the thickness of the engagement member may taper inwardly in a direction from the proximal end to the distal end.

[0032] The engagement member may include a proximal portion and a distal portion (i.e., disposed at a proximal end and a distal end thereof). The engagement surface may be provided on the proximal portion. The proximal portion may thus be tapered (e.g., both longitudinally and laterally) as described above. The distal portion may have a generally continuous cross-sectional shape. When the engagement member is in the disengaged position, the pawl (e.g., a cam surface of the pawl) may rest on the distal portion.

[0033] The cam surface of the pawl may be inclined relative to the direction and / or axis of movement of the engagement member. That is, the inclination of the cam surface may be oriented in a lateral extension. The cam surface may be inclined relative to (i.e., form an angle with) the reference surface (and / or base surface). The cam surface may be inclined in a direction between the attachment portion and the free end of the pawl.

[0034] The cam surface may be inclined away from the reference surface (and / or base surface) in a direction from the attachment toward the free end. Thus, the cam surface may face the free end (and shaft) or may extend toward the free end (and shaft). The end of the cam surface toward the attachment may be closer to the reference surface (and / or body) than the cam surface end of the cam surface toward the free end. The cam surface may have a proximal end closer to the attachment and a distal end farther from the attachment. The distance between the proximal end of the cam surface and the body may be less than the distance between the distal end of the cam surface and the body.

[0035] The pawl may include a limit surface at or near the distal end of the cam surface. The limit surface may extend toward the body (e.g., may be generally perpendicular to the base surface). The limit surface may be arranged to limit movement of the engagement member. The engagement member may abut the limit surface in the engaged position (which may prevent further movement toward the shaft by the limit surface).

[0036] The free end of the claw may define a longitudinally extending free edge (i.e., a substantially vertical edge in the in-use orientation) that engages the strap in use. The free edge may be substantially parallel to the shaft. The free end of the claw may be configured to allow the strap to move in a single direction (i.e., only one direction) over the claw when in the engaged position (i.e., limiting movement in other directions). In particular, the free end of the claw may be configured to allow the strap to move over the claw in a direction away from the body (e.g., base surface). On the other hand, the free end of the claw may limit and / or prevent the strap from moving over the claw in a direction towards the body.

[0037] For example, the free end may include a tip having an asymmetric profile, i.e., the tip is asymmetric, defined by inner and outer tip surfaces (the inner surface is closer to the body than the outer surface) that are joined at the free end, and the angle between the inner tip surface and the reference surface may be greater (the inner surface may be steeper than the outer surface) than the angle between the outer surface and the reference surface.

[0038] The pawl may be biased towards the engaged position. The pawl may include a pawl biasing portion arranged to bias the pawl towards the engaged position. The pawl biasing portion may be resilient (e.g. more resilient than a portion of the pawl that extends from the attachment portion to the free end). The pawl biasing portion may include a resilient protrusion. The resilient protrusion may protrude (e.g. laterally) from the attachment portion on an opposite side of the attachment portion to the free end of the pawl. The resilient protrusion may be biased against the body (e.g. a distal end of the resilient protrusion may contact the body) at least in the disengaged position.

[0039] The resilient protrusion may be curved along its length. The resilient protrusion may be curved towards the body (e.g., concave towards the body). The resilient protrusion may be configured such that contact with the body causes the resilient protrusion to flex (e.g., straighten from a curved shape) as the pawl moves from the engaged position to the disengaged position. This flexing may move the pawl out of the disengaged position (i.e., towards the engaged position). The resilient protrusion may taper inwardly away from the attachment portion. The pawl (i.e., biasing portion) may comprise two resilient protrusions (each as previously described) spaced longitudinally along the attachment portion.

[0040] The adjustment mechanism may further comprise a biasing member configured to bias the button and / or engagement member towards the engaged position. By providing a biasing member for the button and / or engagement member and a separate biasing means for the pawl (i.e., by adjusting two different biasing means), the ability to control the force required to lift the pawl is increased. Such control may be desirable, for example, to allow the force to be tailored for different user groups (such as adults and children).

[0041] The bias member may be fixedly connected (e.g., integrally formed) with the engaging member. The bias member may be resilient (e.g., more resilient than the engaging member). The bias member may be curved along its length. The bias member (e.g., a free end of the bias member) may be biased against the body, at least in the disengaged position. The bias member may be configured to deflect when moved (by contact with the body) from the engaged position to the disengaged position. The bias member may extend in a longitudinal direction.

[0042] The biasing member may be biased against (in contact with) a raised abutment of the body (e.g., protruding from a base surface of the body) at least in the disengaged position. The raised abutment may be in the form of a (e.g., longitudinally extending) rib. The biasing member may contact a side surface of the raised abutment. The pawl biasing portion (e.g., a resilient protrusion) may be biased against (in contact with) the raised abutment at least in the disengaged position to bias the pawl. The pawl biasing portion may contact a distal end surface of the raised abutment (e.g., a surface facing outward in use). The biasing member may be disposed between the biasing portion of the pawl biasing portion and the body (e.g., a base surface).

[0043] Each of the engagement member, button and biasing member may be fixedly connected (e.g., integrally formed). The engagement member, button and biasing member may form at least a portion of an actuator of the adjustment mechanism. The actuator may include an actuator mount that rotatably mounts the actuator to the body (i.e., the engagement member is rotatably mounted to the body as described above). The actuator mount may include a recess (e.g., an opening) or protrusion for engaging a corresponding protrusion or recess in the body.

[0044] The actuator mounting portion may be connected between the button and the biasing member, i.e. the biasing member may protrude from the actuator mounting portion, such that the biasing member may be located on an opposite side of the actuator mounting portion to the button.

[0045] The actuator mounting portion may be connected to a first side edge of the button opposite a second side edge of the button from which the engagement member extends. One or both of the actuator mounting portion and the engagement member may extend from or be connected to a surface of the button opposite the pressable surface. In this manner, the actuator has a generally U-shaped configuration, with the bias member and actuator mounting portion forming a first leg of the "U" shape, the engagement member forming a second leg of the "U" shape, and the button connecting the first leg and the second leg.

[0046] A second aspect provides an eyeglass strap adjustment mechanism including a strap for securing eyeglasses to a user's head, the adjustment mechanism comprising: a body having an elongated shaft along which the head strap can be extended; a pawl having a pawl mounting portion rotatably mounted to the body and extending from the pawl mounting portion to a free end adjacent the shaft; an actuator having an actuator mounting portion rotatably mounted to the main body, The actuator is mounted for rotation along a reference plane extending between the pawl and the body such that the actuator can rotate between engaged and disengaged positions. the engagement position is such that the free end is engageable with a strap when the shaft is extended; The disengaged position is characterized by the free end being lifted off the shaft so as to disengage from the strap.

[0047] The adjustment mechanism (e.g., the body, pawl and / or actuator) of the second embodiment may be as described above with respect to the first embodiment (e.g., may include one or more of the optional features described in the first embodiment).

[0048] A third aspect provides a strap assembly, comprising: This strap assembly is A strap adjustment mechanism as described in the first and second aspects; a strap extending around the shaft of the strap adjustment mechanism; the strap having a plurality of lateral recesses spaced apart along at least a portion of the length of the strap; The strap assembly is characterized in that the recess is positioned to engage the free end of the pawl of the strap adjustment mechanism.

[0049] A fourth aspect provides a pair of glasses, comprising: These glasses are a first eyepiece and a second eyepiece connected via a nose bridge; At least one of the eyepieces is a pair of glasses having an adjustment mechanism according to the first or second aspect.

[0050] The eyeglasses may further comprise a strap extending around a shaft of the strap adjustment mechanism. The strap may comprise a plurality of transverse recesses spaced apart along at least a portion of the length of the strap. The recesses may be positioned to engage the free ends of the tabs of the strap adjustment mechanism. [Brief description of the drawings]

[0051] Hereinafter, embodiments will be described with reference to the accompanying drawings. [Figure 1A] FIG. 13 is a front view of the interior of the strap adjustment mechanism of the swimming goggles when in the engaged position. [Figure 1B] FIG. 13 is a bottom view of the strap adjustment mechanism when in the engaged position. [Figure 2A] FIG. 13 is a front view of the interior of the strap adjustment mechanism when in the disengaged position. [Figure 2B] FIG. 13 is a bottom view of the strap adjustment mechanism in a disengaged position. [Figure 3A] FIG. 13 is a perspective view of a pawl of the strap adjustment mechanism. [Figure 3B] FIG. [Figure 4A] FIG. 13 is a front view of the actuator of the strap adjustment mechanism. [Figure 4B] FIG. [Diagram 5] FIG. 13 is a perspective view of the main body of the strap adjustment mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] Aspects and embodiments will now be described with reference to the accompanying drawings, and further aspects and embodiments will be apparent to those skilled in the art.

[0053] 1A-2B show a strap adjustment mechanism 10 (only a portion of which is shown) that forms part of an eyepiece 11 of a pair of swimming goggles 12. In particular, adjustment mechanism 10 is provided on an outer side 13 of eyepiece 11 to which a head strap 14 (for securing goggles 12 to a user's head) is attached.

[0054] Strap adjustment mechanism 10 includes a body 15 formed integrally with eyepiece 11 (defining an arm extending rearwardly of eyepiece 11). Body 15 has a longitudinally extending shaft 16 around which head strap 14 is looped and secured to strap adjustment mechanism 10. Strap adjustment mechanism 10 further includes a housing (not shown) that is attached to body 15 to enclose the various components shown and described below.

[0055] The foregoing description of mechanism 10 in Figures 1A and 2A illustrates the orientation of mechanism 10 during normal use (i.e., when worn by a user). In this orientation, shaft 16 extends generally vertically (i.e., the longitudinal, or longitudinal, axis is vertical). As used herein, lateral is horizontal and extends generally along the front and / or rear axis (i.e., front is in front of the user and rear is behind the user), which is the left-to-right axis on the page. Similarly, references to inward are references toward the wearer's head (into the page) and references to outward are references away from the wearer's head (out of the page).

[0056] Although not shown, a first portion 17 of the strap 14 on one side of the shaft 15 extends to a free end, and a second portion 18 of the strap 14 on the other side of the shaft 15 extends to a further strap adjustment mechanism on the other eyepiece of the goggles 12 (i.e., the second portion 17 extends around the back of the user's head in use). The head strap 14 is in the form of an elongated elastic band. One side of the strap 14 is provided with a plurality of lateral recesses 19 (or grooves) extending across the width of the strap 14 and spaced apart along a portion of the length of the strap 14. These recesses 19 cooperate with the adjustment mechanism 10 to allow the length of the strap 14 that extends around the user's head in use to be adjusted.

[0057] In particular, the recess 19 cooperates with a pawl 20 of the adjustment mechanism 10. The pawl 20 has a mounting portion 21 that rotatably mounts the pawl 20 to the body 15 such that the pawl 20 rotates about a pawl axis of rotation that is parallel to and in front of the shaft 16 (perpendicular to and to the left of the shaft 16 as shown in FIGS. 1A and 2A). The pawl 20 extends laterally toward the shaft 16 from the mounting portion 21 to a free end 22 that engages the recess 19 of the head strap 14 (in the engaged position as shown in FIGS. 1A and 1B).

[0058] Rotation of the pawl 20 is effected by an actuator 23 of the strap adjustment mechanism 10. The actuator 23 is rotatably mounted to the body 15 via an actuator mount 24. The actuator 23 has an elongated engagement member 25 that moves between the pawl 20 and the body 15 (i.e., a substantially flat base surface 31 of the body 15) as the actuator 23 rotates. In operation, an engagement surface 26 of the engagement member 25 cooperates with a cam surface 27 on the inner side (the side facing the body 15) of the pawl 20, and lateral movement of the engagement member 24 causes the free end 22 of the pawl 20 to move between an engaged position (as shown in FIGS. 1A and 1B) and a disengaged position (as shown in FIGS. 2A and 2B). In the engaged position, the free end 22 of the pawl 20 engages a lateral recess 19 in the strap 14 to limit movement of the strap 14 about the shaft 16. In the disengaged position, the free end 22 of the pawl 20 is lifted off the strap 14 to allow movement of the strap 14 about the shaft 16 .

[0059] Thus, a user can release pawl 20 to adjust the length of strap 14 that extends between eyepieces 11 (and around the head), and then engage pawl 20 with strap 14 to fix the length of strap 14 between eyepieces 11 (i.e., secure goggles 12 to the user's head). A user can induce such movement of pawl 20 by pressing button 28, which is part of actuator 23 (and thus operably connected to engagement member 25). In particular, pressing button 28 causes engagement member 25 to move laterally such that engagement surface 26 engages cam surface 27, lifting pawl 20.

[0060] Pawl 20 is shown in detail in Figures 3A and 3B. As can be seen from these figures, for rotational mounting purposes, mounting portion 21 of pawl 20 includes two opposed cylindrical pins 29 spaced along the axis of rotation of the pawl (projecting from the top and bottom of pawl 20). Pins 29 are received in corresponding circular openings 30 formed in body 15 (shown in Figure 5).

[0061] The cam surface 27 of the pawl 20 extends from the mounting portion 21 towards the free end 22 of the pawl 20. The cam surface 27 is curved and angled relative to a plane (i.e., a reference plane) in which the engagement member 25 moves in use (i.e., in the illustrated embodiment, the reference plane is parallel to the base surface 31 of the body 15). In particular, the engagement member 25 angles away from the base surface 31 in a direction from the mounting portion 21 towards the free end 22 of the pawl 20. Thus, the proximal end of the cam surface 27 (located towards the mounting portion 21) is closer to the base surface 31 of the body 15 than the distal end of the cam surface 21 (located towards the free end 22).

[0062] As is particularly apparent from Figure 3B, cam surface 27 partially defines a recess 32 on the interior side of pawl 20. Recess 32 is also partially defined by a limiting surface 33 that extends from a distal end of cam surface 27 toward body 15. As will be further described below, engagement member 25 abuts limiting surface 33 when in the engaged position (thereby limiting lateral movement of engagement member 25).

[0063] As is evident from Figure 3B, the free end 22 of the claw 20 is configured to allow the head strap 14 to move in one direction past the claw 20. In particular, the free end 22 has an asymmetrical feature. The inner surface 34 of the free end 22 extends at a steeper angle (relative to both the base surface 31 or reference plane) than the outer surface 35. Thus, when the free end 22 of the claw engages the strap 14 (specifically, at the lateral recess 19 formed in the strap), the asymmetrical shape of the free end 22 limits the strap from loosening, but allows the strap 14 to be further tightened.

[0064] The pawl 20 is configured to be biased towards the engaged position. To achieve this, the pawl 20 includes a pawl biasing portion 36 arranged to bias the pawl 20 towards the engaged position. The pawl biasing portion 36 includes two resilient projections 37 (or projections) spaced longitudinally along the mounting portion 21. The resilient projections 37 project from the mounting portion 21 on opposite sides of the mounting portion 21 relative to the free end 22 of the pawl 20. The resilient projections 37 are formed to be curved (concave towards the body 15) along their respective lengths, with both projections 37 tapering inwardly in the direction of their extension. As will be explained in more detail below, the resilient projections 37, in operation, contact the body to bias the pawl 20 towards the engaged position.

[0065] 4A and 4B show more detailed views of actuator 23. Actuator 23 includes engagement member 25, button 28, elongated biasing member 38, and actuator mount 24 for rotatably mounting actuator 23 to body 15. These components are integrally formed into a unitary structure.

[0066] The actuator mounting portion 24 is annular and defines an opening 40 for receiving a corresponding cylindrical projection 39 extending outwardly from the base surface 31 of the body 15 (see FIG. 5). Thus, when mounted on the projection 39, the actuator 23, and thus the engagement member 25, button 28, and biasing member 38, are rotatable about the projection 39. In particular, the actuator 23 is rotatable about an axis of rotation (referred to herein as the engagement member axis of rotation) that extends inwardly and / or outwardly in the in-use orientation as shown in FIGS. 1A and 2A. The engagement member axis of rotation is substantially perpendicular to the pawl axis of rotation and the extension direction of the shaft 16.

[0067] The bias member 38 extends generally upwardly (in its in-use orientation) from a proximal end 41 adjacent the actuator mounting portion 24 to a distal free end 42 distal from the actuator mounting portion 24. The bias member 38 is arcuate (in the reference plane) and curves away from the engagement member 25. As explained further below, the bias member 38 biases the actuator 23 to the engaged position, and the arcuate shape of the bias member facilitates this function.

[0068] Button 28 is connected to the actuator mount 24 on the opposite side of the actuator mount 24 from biasing member 38. Opposite its connection to actuator mount 24, button 28 includes a pressure surface 43 that defines a lower exterior surface of mechanism 10 (when assembled to body 15) and thus can be pressed by a user (using a finger or thumb) to move engagement member 25, thereby moving pawl 20 from the engaged position to the disengaged position. Specifically, pressure surface 43 is located (accessibly) on the lower portion of eyepiece 11 (as is apparent from FIGS. 1B and 2B ).

[0069] Similar to actuator mounting portion 24, engagement member 25 is connected to the top surface of button 28 (opposite the pressable surface). Actuator mounting portion 24 is connected to the front of this surface and engagement member 25 is connected to the opposite rear of the surface. This results in actuator 23 being generally "U" shaped, with biasing member 38 and actuator mounting portion 24 forming a first leg of the "U", engagement member 25 forming the second leg of the "U", and button 28 forming the base of the "U" joining the first and second legs.

[0070] Engagement member 25 extends upwardly from a proximal end 44 (which is secured to button 28) to a distal free end 45 that is distal from button 28. Engagement member 25 is elongate and substantially straight along its length and extends longitudinally in the engaged position.

[0071] The engagement member 25 is provided with an engagement surface 46 which cooperates with the cam surface 27 of the pawl 20 (i.e., the engagement surface 46 is the surface which faces the pawl). The engagement surface includes a leading edge 47 which is forwardly disposed as the engagement member 25 moves toward the cam surface 27, and an opposing trailing edge 48 which is rearwardly disposed as the engagement member 25 moves toward the cam surface 27. The engagement surface 27 is angled relative to the base surface 31 (and thus the reference surface against which the engagement member 25 moves), and in particular, is angled away from the base surface 31 in the direction from the leading edge 47 to the trailing edge 48 (i.e., the engagement member 25 is thicker at the trailing edge 48 than at the leading edge 47).

[0072] Engagement surface 46 also slopes in a direction along the length of engagement member 25. Specifically, proximal portion 49 of engagement surface 26 slopes toward base surface 31 in the direction from proximal end 44 to distal end 45 of engagement member 25.

[0073] Opposite the engagement surface 46, the engagement member 25 includes a planar bearing surface 62 which faces and (in operation) slides across the base surface 31 of the body 15. A similar planar bearing surface 63 is provided on the inner side (facing the base surface 31) of the bias member 38 and the actuator mounting portion 24.

[0074] FIG. 5 shows the body 15 of the adjustment mechanism 10 in more detail. As previously mentioned, the body 15 defines an opening 30 in which the pin 29 of the pawl 20 is received (for rotatable mounting). Specifically, the opening 30 is formed in a projection in the form of a collar 51 that projects from a base surface 31 of the body 15 and is spaced apart in accordance with the axis of rotation of the pawl. An inner surface 52 of each collar 51 (facing the other side of the collar 51) includes a guide recess 53 located at the end of the collar 51 remote from the base surface 31. The guide recess 53 is configured to guide the pin 29 into the opening 30. In particular, the guide recess 53 facilitates snap-engagement of the pin 29 into the opening 30. That is, during assembly, the pin 29 can be received in the guide recess 53 and then the mounting portion 21 can be further pushed in to snap the pin 29 into the opening 30.

[0075] The body 15 rotatably mounts the actuator 23 in the form of a cylindrical projection 39 (described briefly above) that is laterally (forwardly) spaced from the lower of two collars 51. The cylindrical projection 39 projects outwardly from the base surface 31 and is receivable in a central opening 40 in the actuator mounting portion 24.

[0076] The shaft 16 (not shown in FIG. 5 ) is attached to the rear end of the body 15. In particular, the shaft 16 is mounted so as to be rotatable about its longitudinal axis (although in other embodiments it may be fixed). This allows for easy movement of the strap 14 about the shaft 16 (i.e., the strap 14 can be loosened or tightened). To provide this rotatable mounting, the body 15 includes axially aligned opposed holes 54 for receiving opposite ends of the shaft 16. Each hole 54 is formed in a respective arm 55 extending toward the rear of the body 15. The arms 55 are longitudinally spaced apart to define an interior opening 58 therebetween, across which the shaft 16 extends (when mounted in the holes 54). A cross member 56 connects the arms 55 (at their rearward ends). The cross member 56 is arched and defines a rearward facing opening 57 of the body 15 through which the two strap portions 17, 18 extend when worn.

[0077] At the front opposite the end of the body 15, the body 15 includes a raised abutment in the form of a rib 59 projecting outwardly from the base surface 31. The rib 59 is longitudinally elongated (i.e., extends generally parallel to the shaft 16) and includes a distal (outwardly facing) abutment surface 60 and a rearwardly facing lateral abutment surface 61. These abutment surfaces 60, 61 facilitate biasing of the actuator 23 and the pawl 20. This can be best illustrated with reference to Figures 1A to 2A. As can be seen from these figures, the distal end of the resilient projection 37 of the pawl 20 contacts the distal abutment surface 60 of the rib 59. When the button 28 is pressed to move the engagement member 25 and lift the pawl 20, the pawl 20 rotates and the resilient projection 37 abuts the rib 59, deflecting the resilient projection 37. This curvature of the protrusions 37 facilitates some of the flexing movement of the protrusions 37 (as the resilient protrusions 37 flex, they straighten out). Thus, in the disengaged position, the resilient protrusions 37 bend from their natural shape creating internal stresses that result in the protrusions 37 returning the pawl 20 to the disengaged position.

[0078] The bias member 38 operates in a similar manner. The distal end of the bias member 38 contacts the lateral abutment surface 61 of the rib (such that the bias member 38 passes under the resilient projection 37). When the button 28 is pressed to rotate the actuator (counterclockwise as shown), the bias member 38 presses against the lateral abutment surface 61, causing the bias member 38 to flex (i.e., straighten). Thus, in the disengaged position, the bias member 38 bends from its natural shape, creating internal stresses that result in the bias member 38 urging the actuator 23 back towards the engaged position (i.e., urging the actuator 23 back in a clockwise direction as shown).

[0079] The biasing member 38 not only allows the engagement member 25 to move rearwardly and the pawl 20 to move inwardly, but also ensures that the button 28 returns to its original position (protruding from the underside of the body 15). Further movement of the actuator 23 in a clockwise direction (i.e. beyond the engaged position) is prevented by engagement of the engagement member 25 with the limiting surface 33 of the pawl 20. Similarly, movement of the actuator in a counterclockwise direction beyond the disengaged position is limited by engagement of the button 28 at the bottom of a button-receiving recess 64 in the body 15 within which the button 28 is received.

[0080] The foregoing exemplary embodiments are considered to be illustrative and not limiting. Various changes can be made to the described embodiments without departing from the spirit and scope of the present invention.

[0081] For the avoidance of doubt, the theoretical explanations provided herein are provided for the purpose of enhancing the understanding of the reader, and the inventors do not wish to be bound by any of these theoretical explanations.

[0082] In this specification and the claims that follow, unless the context clearly indicates otherwise, the words "comprise" and "include", as well as variations such as "comprises", "comprising" and "including", are understood to imply the inclusion of stated integers or steps, or groups of integers or steps, but not the exclusion of other integers or steps, or groups of integers or steps.

[0083] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" with respect to numerical values ​​can be modified, for example, to mean + / - 10%.

Claims

1. 1. A strap adjustment mechanism for eyeglasses, including a strap for securing the eyeglasses to a user's head, comprising: a head strap having an elongated extensible shaft, the elongated extension of the shaft defining a longitudinal direction; a mounting portion movably mounted to the body; a pawl having a cam surface facing the body and extending laterally from the mounting portion toward the shaft to a free end; an engaging member movable between the pawl and the body; the cam surfaces of the engagement member and the pawl are configured to cooperate to allow the engagement member to move laterally at the free end of the pawl between engaged and disengaged positions; The engagement position allows the free end to engage with a strap when the shaft is extended; The disengaged position is characterized in that the free end is lifted from the shaft so as to disengage from the strap when the shaft is extended.

2. 10. The strap adjustment mechanism of claim 1, the engaging member has an engaging surface that engages the cam surface during lateral movement of the engaging member; At least one of the cam surface and the engagement surface is inclined relative to a reference plane along which the engagement member moves.

3. 3. The strap adjustment mechanism of claim 2, 10. A strap adjustment mechanism as claimed in claim 9, wherein the slope of at least one of the cam surface and the engagement surface is arranged to extend laterally.

4. 10. The strap adjustment mechanism of claim 1, The strap adjustment mechanism, wherein the attachment portion is attached to the main body so that the claw rotates around a claw rotation axis.

5. 5. The strap adjustment mechanism of claim 4, The strap adjustment mechanism, wherein the pawl rotation axis is substantially parallel to the shaft.

6. 10. The strap adjustment mechanism of claim 1, 10. A strap adjustment mechanism as claimed in claim 9, wherein the pawl includes a pawl biasing portion positioned to bias the pawl into the engaged position.

7. 7. The strap adjustment mechanism of claim 6, The strap adjustment mechanism according to claim 1, wherein the pawl biasing portion has an elastic protrusion protruding from the mounting portion on the opposite side of the mounting portion from the free end of the pawl.

8. 8. The strap adjustment mechanism of claim 7, The strap adjustment mechanism, wherein the elastic protrusion is biased against the main body in at least the disengaged position.

9. 10. The strap adjustment mechanism of claim 1, The strap adjustment mechanism, wherein the free end of the pawl is configured to allow unidirectional movement of the strap about the shaft when in the engaged position.

10. 10. The strap adjustment mechanism of claim 1, A strap adjustment mechanism, wherein the engagement member is attached to the main body so as to rotate about an engagement member rotation axis.

11. 6. The strap adjustment mechanism of claim 5, the engagement member is attached to the body so as to rotate about an engagement member rotation axis; The strap adjustment mechanism of claim 1, wherein the engagement member rotation axis is substantially perpendicular to the pawl rotation axis.

12. 10. The strap adjustment mechanism of claim 1, A strap adjustment mechanism, wherein the engagement member is elongated and extends over 30% or more of the width of the pawl.

13. 10. The strap adjustment mechanism of claim 1, A strap adjustment mechanism comprising: a biasing member configured to bias the engaging member to the engaged position.

14. 14. The strap adjustment mechanism of claim 13, The strap adjustment mechanism according to claim 1, wherein the engaging member and the biasing member are fixedly connected.

15. 14. The strap adjustment mechanism of claim 13, The bias member is disposed between the pawl and the body of the strap adjustment mechanism.

16. 14. The strap adjustment mechanism of claim 13, The strap adjustment mechanism of claim 1, wherein the bias member is biased against the body at least in the disengaged position.

17. 9. The strap adjustment mechanism of claim 8, a biasing member configured to bias the engaging member to the engaged position; the biasing member is biased against the body at least in the disengaged position; the body has a raised abutment; The strap adjustment mechanism according to claim 1, wherein the resilient projection and bias member are each biased against the raised abutment at least in the disengaged position.

18. 10. The strap adjustment mechanism of claim 1, a button operably attached to the engagement member; The strap adjustment mechanism, wherein the operable connection is configured to move laterally between the body and the pawl when the button is depressed.

19. A strap assembly comprising: a strap adjustment mechanism according to any one of claims 1 to 18; a strap extending around the shaft of the strap adjustment mechanism; the strap having a plurality of lateral recesses spaced apart along at least a portion of the length of the strap; The strap assembly, wherein the recess is positioned to engage the free end of the pawl of the strap adjustment mechanism.

20. Glasses, a first eyepiece and a second eyepiece connected via a nose bridge; 19. Eyeglasses, wherein at least one of the first eyepiece and the second eyepiece has an adjustment mechanism according to any one of claims 1 to 18.

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