FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to backpacks and, in particular, it concerns an over-the- shoulders strap positioner for backpacks or other carriers.

When walking with a backpack, its weight pulls the shoulder straps down. This causes pressure on the shoulder bones. The structure of the shoulder bones, which are not padded with muscles from above, does not allow to train the bone surface for high resistance to point pressure.

In order to prevent pain or discomfort, it is desired to redirect the pressure loads to the trapezius muscles, close to the user’s neck. These muscles are strong, and can be strengthened more easily to allow prolonged use.

Currently, to perform this action, a component that usually comes as part of the backpack and is attached to the straps in the front and is called the “chest strap.” The chest strap is made up of two parts. One part of the strap is connected to each of the shoulder straps and they are provided with male and female buckles, thus allowing the straps to be connected together.

When using the chest strap to determine the position of the shoulder straps, it should be positioned around the chest and can be adjusted until the user feels comfortable.

While using the chest strap, the shoulder straps’ position can be adjusted at any time by adjusting the buckles to change the length of the chest strap. Upon tightening, the shoulder straps get closer to the user’s neck and slide to the top of the trapezius muscles.

Upon its release, due to the backpack weight pulling downwards, the pressure of the chest strap will be released and the shoulder straps will slide off the trapezius muscles and move away from the user’s neck towards the shoulder bones. This action can be repeated as needed throughout the use of the chest strap.

Although the chest strap is a simple and effective solution for positioning the shoulder straps, it has significant shortcomings. During heavy exertion, and particular on hiking treks at altitude where the air is thinner and/or carrying significant loads, the tension of a chest strap across the chest can limit the user’s ability to take full deep breaths. Additionally, the external pressure applied by the chest strap is bothersome to some users, even when not exerting themselves heavily. Additional discomfort may be felt particularly by women as a result of the pressure of the chest strap on the chest, because of the chest being more prominent in women than in men, and making it more difficult to close the strap. In addition, the aesthetic discomfort stemming from the strap pressure on the chest should not be ignored.

SUMMARY OF THE INVENTION

The present invention is a system for maintaining a desired spacing between shoulder straps of a pack worn by a user.

According to the teachings of an embodiment of the present invention there is provided, a system for maintaining a desired spacing between a right shoulder strap and a left shoulder strap of a pack worn by a user, the system comprising: (a) a first positioning arm configured for extending over a right shoulder of the user and extending downwards to a distal portion for association with the right shoulder strap; (b) a second positioning arm configured for extending over a left shoulder of the user and extending downwards to a distal portion for association with the left shoulder strap; and (c) an adjustment mechanism associated with both the first positioning arm and the second positioning arm so as to be located at least in part behind a neck of the user, the adjustment mechanism assuming an open state in which the distal portions of the first and second positioning arms are spaced apart to facilitate putting on and taking off the pack, the adjustment mechanism assuming at least one proximity-maintaining state in which the distal portions of the first and second positioning arms are brought together so as to maintain a state of proximity between the right and left shoulder straps of the pack.

According to a further feature of an embodiment of the present invention, the adjustment mechanism is configured such that the at least one proximity-maintaining state is one of a plurality of proximity-maintaining positions in which the user can selectively deploy the system.

According to a further feature of an embodiment of the present invention, the adjustment mechanism is configured such that the at least one proximity-maintaining state is one position in a continuum of proximity-maintaining positions in which the user can selectively deploy the system.

According to a further feature of an embodiment of the present invention, the adjustment mechanism is configured to retain the first and second positioning arms in the at least one proximity-maintaining state with a retaining force limited to a defined threshold such that manual application of a force greater than the defined threshold is effective to displace the first and second positioning arms out of the at least one proximity-maintaining state towards the open state.

According to a further feature of an embodiment of the present invention, the adjustment mechanism includes a locking mechanism having a locking state for retaining the first and second positioning arms in the at least one proximity-maintaining state and a released state for allowing displacement of the first and second positioning arms out of the at least one proximity-maintaining state towards the open state, the locking mechanism being manually or otherwise deployable from the locking state to the released state.

According to a further feature of an embodiment of the present invention, the locking state is a directional locking state which allows displacement of the first and second positioning arms from the open state to the at least one proximity-maintaining state while opposing displacement of the first and second positioning arms from the at least one proximitymaintaining state towards the open state.

According to a further feature of an embodiment of the present invention, the adjustment mechanism defines a motion of the first positioning arm as a rotation about a first axis and a motion of the second positioning arm as a rotation about a second axis.

According to a further feature of an embodiment of the present invention, the first and second axes are substantially horizontal.

According to a further feature of an embodiment of the present invention, the first and second axes are substantially parallel.

According to a further feature of an embodiment of the present invention, the adjustment mechanism further comprises a transmission interconnecting between the first and second positioning arms, the transmission configured to link motion of the first and second positioning arms such that rotation of the second positioning arm about the second axis occurs equally to, but in an opposite direction from, rotation of the first positioning arm about the first axis.

According to a further feature of an embodiment of the present invention, the adjustment mechanism further includes a locking mechanism for selectively locking the transmission so as to retain the first and second positioning arms in the at least one proximitymaintaining state, the locking mechanism having a released state for allowing displacement of the first and second positioning arms out of the at least one proximity-maintaining state towards the open state, the locking mechanism being manually or otherwise deployable from the locking state to the released state. According to a further feature of an embodiment of the present invention, a first region of the first positioning arm is rotatably mounted so that the first axis is aligned with an extensional direction of the first region of the first positioning arm and wherein a second region of the second positioning arm is rotatably mounted so that the second axis is aligned with an extensional direction of the second region of the second positioning arm.

According to a further feature of an embodiment of the present invention, the first and second axes are substantially vertical.

According to a further feature of an embodiment of the present invention, the adjustment mechanism interconnects between the first positioning arm and the second positioning arm at a single axis of rotation.

According to a further feature of an embodiment of the present invention, the adjustment mechanism includes a telescopic configuration which can be shortened or extended to transition between the open state and at least one proximity-maintaining state.

According to a further feature of an embodiment of the present invention, the telescopic configuration is a linear telescopic configuration.

According to a further feature of an embodiment of the present invention, the telescopic configuration is an arcuate telescopic configuration.

According to a further feature of an embodiment of the present invention, the adjustment mechanism includes a first arrangement for controlling a position of the first positioning arm and a second arrangement for controlling a position of the second positioning arm, the first and second arrangements being rigidly interconnected.

According to a further feature of an embodiment of the present invention, the adjustment mechanism is integrated into a pack.

According to a further feature of an embodiment of the present invention, the adjustment mechanism is configured for mounting externally to the pack.

There is also provided according to the teachings of an embodiment of the present invention, a system for maintaining a desired spacing between a right shoulder strap and a left shoulder strap of a pack worn by a user, the system comprising: (a) a first positioning arm configured for extending over a right shoulder of the user and extending downwards to a distal portion for association with the right shoulder strap; (b) a second positioning arm configured for extending over a left shoulder of the user and extending downwards to a distal portion for association with the left shoulder strap; and (c) a rigid bridging portion mechanically associated with both the first positioning arm and the second positioning arm so as to be located at least in part behind a neck of the user, wherein each of the first and second positioning arms is formed from a plurality of rigid segments, and has a plurality of mutually- parallel hinges interconnecting between successive of the rigid segments and/or between one of the rigid segments and the bridging portion, the bridging portion, the rigid segments and the hinges being configured such that the system assumes a body-fitting state in which the positioning arms extend over the user’s shoulders and downwards across a chest of the user so as to maintain a state of proximity between the right and left shoulder straps of the pack, and wherein upward flexing of at least one of the positioning arms at the hinges facilitates putting on and taking off the pack.

According to a further feature of an embodiment of the present invention, each of the positioning arms has an extensional direction, and wherein the positioning arms are mechanically associated with the rigid bridging portion so that the extensional directions diverge.

According to a further feature of an embodiment of the present invention, each of the positioning arms has an extensional direction, and wherein the positioning arms are mechanically associated with the rigid bridging portion via an adjustable connection configured to allow adjustment of an angle of divergence between the extensional directions.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:

FIGS. 1A and IB are isometric views of a pack with a system, constructed and operative according to an embodiment of the present invention, for maintaining a desired spacing between shoulder straps of a pack worn by a user, the pack being shown with the system in an open state and a proximity-maintaining state, respectively;

FIGS. 2A and 2B are front views corresponding to FIGS. 1A and IB, respectively;

FIGS. 3A and 3B are isometric views of the system of FIG. 1A for maintaining a desired spacing between shoulder straps of a pack worn by a user, the system being shown in an open state and a proximity-maintaining state, respectively;

FIGS. 3C and 3D are rear views corresponding to FIGS. 3 A and 3B, respectively;

FIG. 4A is an enlarged isometric view of a linear telescopic element from the system of FIG. 3A;

FIG. 4B is a vertical axial cross-sectional view taken through the linear telescopic element of FIG. 3A; FIG. 5 is a vertical cross-sectional view taken through a shoulder strap of a variant implementation of the pack of FIG. 1A, where a positioning arm is integrated into a shoulder strap;

FIGS. 6A and 6B are views similar to FIGS. 3A and 3B illustrating a variant implementation of the system where the linear telescopic element is replaced by a cord-based actuator;

FIG. 7A is a view similar to FIG. 3A illustrating a variant implementation of the system employing a gear arrangement;

FIG. 7B is a rear isometric view of the system of FIG. 7 A cut-away on a vertical plane passing along a central axis for a shaft of the gear arrangement;

FIGS. 8A and 8B are views similar to FIGS. 1A and IB, respectively, illustrating a variant implementation of the system based on a curved torsion linkage;

FIG. 9A is an enlarged isometric view of the curved torsion linkage from the embodiment of FIG. 8A;

FIG. 9B is a view similar to FIG. 9 A cut-away on a horizontal plane passing through the curved torsion linkage;

FIGS. 10A and 10B are views similar to FIGS. 1A and IB, respectively, illustrating a variant implementation of the system based on two separate rotary mounts;

FIG. 11 A is an enlarged isometric view of one of the rotary mounts of FIG. 10A;

FIG. 11B is an enlarged isometric view of the rotary mount of FIG. 11A cut-away along a vertical plane passing along a central axis of the rotary mount;

FIGS. 12A and 12B are views similar to FIGS. 1A and IB, respectively, illustrating a variant implementation of the system employing linkages with vertical swivel axes;

FIGS. 13A and 13B views similar to FIGS. 3 A and 3B illustrating a variant implementation of the system employing a linkage with a single vertical swivel axis;

FIGS. 14A and 14B are isometric views of a directionally-locking swivel joint for use in the implementations of FIGS. 12A-12B and 13A-13B, shown in a locking state and a released state, respectively;

FIGS. 15A and 15B are front views of a further implementation of a system, constructed and operative according to an embodiment of the present invention, for maintaining a desired spacing between shoulder straps of a pack worn by a user, the system employing a linear telescopic mechanism shown in an open state and a proximity-maintaining state, respectively;

FIG. 15C is an isometric view of the system of FIG. 15 A; FIGS. 16A and 16B are isometric views of a further implementation of a system, constructed and operative according to an embodiment of the present invention, for maintaining a desired spacing between shoulder straps of a pack worn by a user, the system employing an arcuate telescopic mechanism shown in an open state and a proximitymaintaining state, respectively;

FIGS. 16C and 16D are plan views corresponding to FIGS. 16A and 16B, respectively;

FIGS. 17A and 17B are isometric views of a further implementation of a system, constructed and operative according to an embodiment of the present invention, for maintaining a desired spacing between shoulder straps of a pack worn by a user, the system employing positioning arms formed from a series of segments interconnected at mutually- parallel hinges, the system shown in a straightened state and a deployed state, respectively;

FIG. 17C is an isometric view of the system of FIG. 17B deployed on the shoulders of a user;

FIG. 17D is a view similar to FIG. 17A after adjustment of an angle of divergence of the positioning arms;

FIGS. 18A and 18B are isometric views of the system of FIGS. 17A and 17B deployed on a pack in a straightened state and a deployed state, respectively;

FIGS. 19A and 19B are front views of a variant implementation of the system of FIG. 17B, illustrated in an increased width configuration and a decreased width configuration, respectively;

FIG. 19C is a side view of the system of FIG. 19 A;

FIG. 20 is a rear isometric view of a variant implementation of the system of FIG. 19A without a width adjustment arrangement;

FIG. 21 A is an isometric view similar to FIG. 1A illustrating a variant implementation employing multiple hinged segments in each positioning arm; and

FIG. 2 IB is an enlarged view of the region of FIG. 21 A designated by rectangle XXI in FIG. 21 A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is a system for maintaining a desired spacing between shoulder straps of a pack worn by a user.

The principles and operation of systems according to the present invention may be better understood with reference to the drawings and the accompanying description. Overview

The present invention provides a range of systems for maintaining a desired spacing between shoulder straps of a pack worn by a user without requiring the use of a chest strap. Instead, the various systems of the present invention maintain a desired spacing between the shoulder straps by providing positioning arms, either incorporated into the shoulder straps or linked thereto, which are supported by a structure that is located at least in part behind the neck of the user.

A range of implementations are disclosed herein, as non-limiting examples of the range of options that falls within the scope of the present invention as claimed. For explanatory purposes, the disclosed implementations can be subdivided into two broad groups. A first group, described with reference to FIGS. 1A-16D, provides systems in which an adjustment mechanism allows reconfiguration of the positioning arms between an open state in which distal portions of the positioning arms are spaced apart to facilitate putting on and taking off the backpack, and a proximity-maintaining state in which said distal portions of the positioning arms are brought together so as to maintain a state of proximity between the right and left shoulder straps of the backpack. A second group of implementations, described with reference to FIGS. 17A-20, provides a similar system employing a rigid bridging element without a useroperated adjustment mechanism. In order to facilitate putting on and taking off of the backpack, a series of parallel hinges in each positioning arm provides directionally-limited flexibility, allowing the positioning arm to be lifted away from the body to open up accessibility for putting on and taking off the backpack, while resisting lateral displacement so as to maintain the desired spacing between the shoulder straps during load-bearing use. The two aforementioned groups are not mutually exclusive, in the sense that embodiments including adjustment mechanisms may also employ positioning arms with internal hinges, and implementations without a user-operated adjustment mechanism may still provide some degree of adjustability, such as for personalized fitting of the system to the user’s size and body shape. All of the above will become further clarified in view of the following description and the accompanying drawings.

Implementations with Adjustment Mechanism

Referring now to the drawings, FIGS. 1A-16D illustrate certain exemplary embodiments of the present invention provides a mechanism for adjusting a spacing between shoulder straps 10a, 10b of a pack 12 (exemplified herein as a backpack, but equally applicable to front-worn packs such as front child-carrier packs) so as to position them according to the user’s preference, such as on the trapezius muscles, and allowing displacement of the shoulder straps outward (increased separation) when desired, for example, for putting on and taking off the pack.

Thus, an aspect of the present invention provides a system 100, 200, 300, 400, 500, 600, 700, 800, 900 for maintaining a desired spacing between right shoulder strap 10a and left shoulder strap 10b of pack 12 worn by a user, including a first positioning arm 14a configured for extending over a right shoulder of the user and extending downwards to a distal portion 16a for association with the right shoulder strap 10a; (b) a second positioning arm 14b configured for extending over a left shoulder of the user and extending downwards to a distal portion 16b for association with the left shoulder strap 10b; and (c) an adjustment mechanism associated with both positioning arms 14a and 14b so as to be located at least in part behind a neck of the user. The adjustment mechanism assumes an open state (see FIGS. 1A, 2A and 3A, and the first drawing of each subsequent embodiment) in which the distal portions of the first and second positioning arms are spaced apart to facilitate putting on and taking off the backpack, and at least one proximity-maintaining state (see FIGS. IB, 2B and 3B, and the second drawing of each subsequent embodiment) in which the distal portions of the first and second positioning arms are brought together so as to maintain a state of proximity between the right and left shoulder straps of the backpack.

Although referred to herein for convenience as a “backpack”, the invention is also applicable to all sorts of packs, backpacks and other load-carrying devices in which a load is supported at least in part by shoulder straps, whether mounted on the back or on the front of the body. Another such example is a front-worn infant carrier pack. In the case of a front-worn device, the adjustment mechanism is located at least in part on the far side of the neck from the straps, which would be at the front of the user for a front-mounted baby carrier, where the straps are behind the user. This may also be considered “behind” the neck relative to the position of the straps.

Most preferably, although not necessarily, the adjustment mechanism provides a range of proximity-maintaining positions, which may be a plurality of distinct positions in which the user can selectively deploy the system or a continuum of positions within which the user can stop at any desired position.

The functionality of the adjustment mechanism and how the user interacts with the adjustment mechanism to change the separation of the positioning arms can be chosen according to the intended application. In one set of preferred implementations, the adjustment mechanism is configured to retain the first and second positioning arms in the at least one proximity-maintaining state with a retaining force limited to a defined threshold such that manual application of a force greater than the defined threshold is effective to displace the first and second positioning arms out of the at least one proximity-maintaining state towards the open state. In other words, the relative spacing between the positioning arms, and hence the shoulder straps, may be changed by the user pushing them towards each other or apart, and this force overcomes the retaining force and changes the spacing as the mechanism “clicks” into the next position. Such an implementation is particularly simple and intuitive to use. The threshold of force required to overcome the retaining force and to change the spacing between the shoulder straps is chosen so as to be sufficient to hold the straps in place during normal use while not being overly difficult to adjust when manual force is applied directly inwards or outwards on the shoulder straps. Mechanisms for providing a threshold resistance to motion are well-known in the art, and may be based on various principles such as, for example, spring- biased bearings that engage in corresponding recesses. One non-limiting example of such a mechanism is illustrated below with reference to FIGS. 10A-1 IB.

In an alternative set of preferred implementations, the adjustment mechanism includes a locking mechanism having a locking state for retaining the first and second positioning arms in the at least one proximity-maintaining state and a released state for allowing displacement of the first and second positioning arms out of the at least one proximity-maintaining state towards the open state, the locking mechanism being manually or otherwise deployable from the locking state to the released state.

In a first subset of this set of implementations, the locking state is a directional locking state which allows displacement of the first and second positioning arms from the open state to the at least one proximity-maintaining state while opposing displacement of the first and second positioning arms from the at least one proximity-maintaining state towards the open state. This functionality is similar to, and can be implemented using, a ratchet arrangement, which allows a pawl or other locking element to ride over directional teeth in one direction while opposing motion in the opposite direction. A similar functionality can be implemented using other mechanisms, such as a hydraulic or pneumatic cylinder and piston with a one-way valve, or a friction clamping arrangement. The pawl, or the valve, is then released by operation of a user control (a “neutral” state) to allow reverse movement (or free movement in both directions) when desired.

In a second subset of this set of implementations, the locking state is locked against motion in either direction. In this case, the mechanism can be manually or otherwise released to a “neutral” state which allows adjustment of the positions of the positioning arms both inwards and outwards. When the desired position is achieved, the release mechanism can be reengaged to fix the position.

In any of the cases with a “neutral” state to allow adjustment, the neutral state can optionally be a stable state which can be selected or deselected by the user, e.g., using a pull- on/pull-off mechanism similar to a push-button retractable ballpoint pen mechanism, such as in US Patent No. 3288115, which can readily be adapted to this purpose. The stable neutral state allows the user to select whether the shoulder strap positioning mechanism is active or deactivated.

The adjustment mechanism may be either a free-standing mechanism which is external to the backpack, or may be integrated into a backpack. In some cases, the adjustment mechanism may include two separate arrangements for controlling a position of the respective first and second positioning arms, where the two arrangements rigidly interconnected, either by the adjustment mechanism or by integration into a rigid structure of the backpack.

The form of the relative motion between the first and second positioning arms is typically defined by the adjustment mechanism, and can take a wide range of forms. Various non-limiting but particularly preferred examples are illustrated in the attached drawings.

In certain particularly preferred implementations, the adjustment mechanism defines a motion of the first positioning arm 14a as a rotation about a first axis 18a and a motion of the second positioning arm 14b as a rotation about a second axis 18b. In one group of implementations of particular interest exemplified by systems 100, 200, 300, 400, 500, these first and second axes 18a and 18b are substantially horizontal and substantially parallel. Substantially horizontal in this context preferably refers to angles which approximate to a horizontal axis during use, although the exact orientation of the pack may vary during use depending on the physiology of the user and how the pack is worn. As a rough indication, “substantially horizontal” can be assumed herein to be at an angle of 90°±20° to a plane defined by back contact surfaces of the pack. “Substantially parallel” in this context preferably refers to axes which are parallel to within about ±30°, and more preferably within ±20°. Precise parallelism is typically not required, such that optimal solutions may include divergence or convergence of up to about 10 or 15 degrees.

In the particularly preferred examples illustrated in FIGS. 1A-11B, a region of the first positioning arm 14a is rotatably mounted, such as in a tubular rotary mounting 20a that provides a horizontal-axis swivel joint, so that the first axis 18a is aligned with an extensional direction of the corresponding region of the first positioning arm 14a and wherein a region of the second positioning arm 14b is rotatably mounted, such as in a tubular rotary mounting 20b, so that the second axis 18b is aligned with an extensional direction of the corresponding region of the second positioning arm 14b. The parts of the positioning arms further from the mounting region then curve downwards to their distal portions 16a, 16b, following the shape of the shoulder straps 10a, 10b, corresponding also to the shape of the user’s body. The motion of positioning arms 14a and 14b when rotated about respective axes 18a and 18b results in an overall adjustment motion as illustrated in successive pairs of drawings from FIG. 1A through FIG. 3D. This form of motion has been found to be particularly effective, since there is minimal motion of the arms in the region over the shoulders, so there is no interference with the user’s neck, while the distal portions 16a, 16b of the positioning arms perform an effective motion inwards or outwards near the chest of the user. In this context, it should be noted that the “distal portions” 16a, 16b of the positioning arms are regions sufficiently far from the axis of rotation to provide the required motion, but are not necessarily at the extremities of the arms. The “distal portions” may be alternatively referred to as “chest portions” due to their location at the chest region of the user (front or back, according to the application), and are typically between 7 cm and 30 cm below the highest point of the shoulders, and most preferably at least 10 cm below the highest point.

Optionally, in this and other embodiments of the present invention, the positioning arms may include one or more pivot axis oriented to allow the positioning arms to be positioned as closer-fitting or further spaced from the chest of the user, for example, to accommodate users of different body shape and weight, while being relatively rigid in the lateral direction so as to maintain effective positioning of the shoulder straps. The pivot axes are thus typically roughly lateral to the body, thereby providing anterior/posterior flexibility in a sagittal plane while maintaining lateral rigidity. For example, each of the first and second positioning arms 14a, 14b may be formed from a plurality of rigid segments 22 sequentially interconnected via a plurality of mutually-parallel hinges (pivot joints) 24 oriented laterally and transverse to the lengths of the segments. In the examples of FIGS. 1A-6B, two pivot joints 24 are present, while FIG. 21A-21B illustrate a variant implementation with multiple smaller segments sequentially interconnected at pivot joints.

Association of the positioning arms with the shoulder straps can be achieved in many ways. In certain cases, some or all of the length of the positioning arms may be integrated with the shoulder straps, such as by insertion into an elongated pocket extending along at least part of the shoulder straps, as illustrated schematically in FIG. 5, where positioning arm 14b is sandwiched between layers of cloth 26a, 26b making up shoulder strap 10b. Alternatively, a majority of the length of the positioning arms may be external to the shoulder straps, with only a distal (or other) positioning region being anchored to the shoulder strap, such as by insertion in a small pocket or by linking with a tether, snap-connector or other connector. Advantageously, the interconnection may be via a pivotal connector 28. Although the other exemplary embodiments illustrated herein do not specifically show the option of positioning arms integrated into the shoulder straps, it should be noted that both options of external positioning arms and integrated positioning arms are explicitly relevant to all embodiments.

Turning now to details of various specific implementations of the adjustment mechanism, FIGS. 1A-5 illustrate a first preferred but non-limiting example in which a portion of each positioning arm 14a, 14b (or an extension thereof) beyond the rotary mountings 20a, 20b is curved or otherwise deflected off-axis to form a lever 30a, 30b, respectively, and a linear telescopic element 102 controls a distance between the ends of levers 30a, 30b, and hence also the angle of the positioning arms 14a and 14b. The geometry of this mechanism is seen more clearly in FIGS. 3A-3D, and an exemplary structure of linear telescopic element 102 is shown in FIGS. 4A and 4B. In this non-limiting example, linear telescopic element 102 is implemented as a notched rod 104 which slides within a cylinder 106. A displaceable tooth or pawl 108 is deployed to engage the notches of rod 104, and can preferably be selectively disengaged therefrom using a release cord (not shown) which displaces the tooth 108 to a disengaged state (FIG. 4A).

The properties and functionality of this mechanism can be varied by appropriate choice of the shape of the notches, the shape of tooth 108, the strength of a spring (not shown) biasing tooth 108 into engagement, and the provision of a release mechanism. If ratchet (directional) notches are provided in rod 104 and tooth 108 is a correspondingly shaped pawl, closing of the positioning arms from the open position of FIG. 3C towards the proximity-retaining position of FIG. 3D (or any intermediate position between these two extremes) can be achieved freely by pushing together the shoulder straps to the desired positions, where they are retained by the system until the release mechanism is actuated to disengage tooth 108, then allowing the shoulder straps to be opened apart.

Alternatively, if the notches and tooth 108 are configured to have a non-locking slope in both directions, operation of the system may be bidirectional retention (also referred to as “frictional locking” even where friction is not necessarily the primary physical process governing the retention), where the mechanism is always retained in its current position and can be manually adjusted by applying sufficient force to bring the shoulder straps together or apart, thereby causing the tooth 108 to ride up over the walls of the notch and jump to the next notch, providing tactile and/or audible feedback of successive “clicking” between positions. The force that needs to be applied in order to move between positions is determined by the gradient of the sides of the notches and/or of tooth 108 together with the force of a bias spring that biases them into engagement. Optionally, by using asymmetric notches and/or an asymmetric tooth 108, different levels of resistance may be provided to oppose closing and opening of the mechanism, with closing preferably having lower resistance than opening. Even in this case, a release mechanism may be provided in order to neutralize the clicking resistance, such as for fast and convenient opening of the mechanism for taking off the pack.

In a still further alternative, rectangular or other bidirectionally-locking notches may be provided, thereby locking the mechanism bidirectionally in any current position. In this case, both closing and opening require operation of a release mechanism to temporarily unlock the mechanism while the shoulder straps are moved to their desired (open or closed) position, where the tooth 108 is allowed to reengage and lock the mechanism bidirectionally.

Although levers 30a and 30b are shown here as continuations of the curvature of the positioning arms and thus lie in the same plane, this is not necessarily so, and the shape and orientation of the levers may be chosen according to design requirements of a particular product. In the embodiments illustrated here, since the levers curve downwards, closing of the positioning arms corresponds to bringing together levers 30a and 30b and shortening of telescopic element 102, whereas opening of the positioning arms corresponds to lengthening of telescopic element 102. In an embodiment in which levers 30a and 30b project upwards, the opposite is true.

In this and certain other mechanisms described herein, the mechanism defines a spacing between the ends of levers 30a and 30b, but does not positively lock the rotational positions of the positioning arms. As a result, there is typically some coupled freedom of motion between the positioning arms, allowing, for example, slight displacement of the left positioning arm outwards to the left when it is accompanied by a corresponding motion of the right positioning arm to the left, and without significant variation in the spacing between them. More precisely, the pivot connections between the two ends of telescopic element 102 and levers 30a and 30b and rotary mountings 20a, 20b effectively define a four-bar linkage in which the exact form of freedom of motion will be determined by the current length of telescopic element 102. The spacing and orientation of rotary mountings 20a, 20b is maintained by a rigid bridging portion 32, which may be separate from pack 12 or may be integrated therewith. This freedom of motion allows the adjustment mechanism and associated backpack to tilt while the positioning arms maintain roughly constant spacing, which may be valuable in certain applications, particularly such as rock climbing, accommodating significant flexing of the torso. Turning now to FIGS. 6 A and 6B, these illustrate a system, generally designated 200, for maintaining a desired spacing between right shoulder strap 10a and left shoulder strap 10b of pack 12 worn by a user. System 200 is a variation of the system 100 described above, with equivalent elements labeled similarly. In this case, the telescopic element is replaced by a cord mechanism which selectively applies tension between the ends of levers 30a and 30b so as to displace the positioning arms towards their closed (proximity-retaining) positions.

In the example illustrated here, a cord 202 is tied or otherwise anchored at the end of lever 30b and extends around a pulley 204 that is mounted on the end of lever 30a. The cord then continues, typically via various guide elements to a handle 206 which can be pulled by the user to actuate the mechanism and bring the shoulder straps together. The guide elements preferably include a clamp which maintains tension in the cord once it is pulled until the clamp is manually released. Carious types of such clamps are well-known and commercially available, such as those used for keeping drawstrings closed. A narrow guide element which applies frictional clamping to the cord when seated in a narrow slot may also serve this purpose.

In all other respects, the structure and operation of system 200 is identical to that of system 100 described above, and will be fully understood by analogy to that description and the accompanying drawings.

Turning now to FIGS. 7A and 7B, these illustrate a system, generally designated 300, for maintaining a desired spacing between the shoulder straps of a pack worn by a user. System 300 is a further variation of the system 100 described above, with equivalent elements labeled similarly. In this case, a gear-based transmission is employed to control motion of the positioning arms. Specifically, at or near rotary mounts 20a, 20b, each positioning arm is provided with a bevel gear 302a, 302b which are engaged with complementary bevel gears 304 at opposite ends of a shaft 306. This links motion of the first and second positioning arms such that rotation of the second positioning arm 14b about the second axis 18b occurs equally to, but in an opposite direction from, rotation of the first positioning arm 14a about the first axis 18a.

In order to lock the positioning arms in a desired position, a locking mechanism is provided, typically associated with shaft 306 so as to lock it against rotation. In the nonlimiting example illustrated here, a locking tooth 308 selectively engages a gear wheel 310 which is mounted on shaft 306 so as to lock the shaft against turning, thereby also locking the positioning arms in place. The locking mechanism preferably has a released state, in this case achieved by pulling on a cord 312 which disengages the locking tooth 308 against a spring bias (not shown) so as to allow displacement of the first and second positioning arms 14a, 14b out of the at least one proximity-maintaining state towards the open state. In the example illustrated, as in the first implementation described above, the locking mechanism may be implemented as either a bidirectional lock or as a one-way lock (ratchet), depending on the shape of the teeth of the gear wheel and of the pawl/locking tooth.

In the implementation illustrated here, the position of each positioning arm in the locked state is fixed by the rotational position of shaft 306, without the freedom of motion described above in relation to the earlier implementations. If such freedom of motion were required, it could be achieved by splitting shaft 306 and incorporating a differential therein, as will be clear to a person having ordinary skill in the art.

As shown in some of the other embodiments, the mechanism requires various additional rigid bridging elements to maintain the required relative positioning of the illustrated components during use. In all other respects, the structure and operation of system 300 is identical to that of system 100 described above, and will be fully understood by analogy to that description and the accompanying drawings.

Turning now to FIGS. 8A-9B, these illustrate a system, generally designated 400, for maintaining a desired spacing between right shoulder strap 10a and left shoulder strap 10b of pack 12 worn by a user. System 400 is a variation of the system 300 described above, with equivalent elements labeled similarly. System 400 is functionally equivalent to the gear-based transmission of system 300, but replaces the bevel gears and shaft with a single arcuate torsion drive linking between first and second positioning arms 14a, 14b. This approach may be implemented using a torque-transferring cable to link between the positioning arms. In a nonlimiting but preferred implementation as illustrated here, the arcuate torsion drive between the positioning arms is implemented as a sequence of torque-transfer segments 402 interlinked using a ball-hex and hex-socket engagement. This approach has been found to provide enhanced rigidity to ensure that equal and opposite angular displacement occurs for the two positioning arms. As in system 200, locking of the position can be achieved by engagement of a locking tooth (not shown) with a gear wheel 404 integrated with one of the segments, all in a manner fully analogous with that described above in the context of system 300. In all other respects, the structure and operation of system 400 is identical to that of system 100 described above, and will be fully understood by analogy to that description and the accompanying drawings.

Turning now to FIGS. 10A-11B, these illustrate a further non-limiting implementation of a system 500 for maintaining a desired spacing between right shoulder strap 10a and left shoulder strap 10b of pack 12 worn by a user. System 500 is similar in geometry to systems 100, 200, 300 and 400 described above in that it provides motion of two positioning arms 14a and 14b about substantially horizontal substantially parallel axes 18a and 18b extending front- to-back across the shoulders of the user. Unlike the embodiments described thus far, motion of each positioning arm is controlled by a separate mechanism 502a and 502b.

This implementation is typically best suited to a case where the positioning arms are resiliently retained in position but can be relocated by force above some threshold value which displaces the arms so as to “click” through successive positions. This avoids the need for a release mechanism linked to both parts of the mechanism.

One non-limiting exemplary implementation of mechanisms 502a, 502b is illustrated in FIGS. 11A and 11B. The mechanism is a modification of the tubular rotary mounting 20a, 20b described above, but where the mounting is formed with an end surface 504 with a set of axially-facing teeth, and the positioning arm is formed with a radially-projecting flange 506 having a complementary set of teeth. A spring (not shown) biases the positioning arm axially so that the teeth of flange 506 engage the teeth of end surface 504, thereby retaining the positioning arm against rotation. When sufficient torque is applied to the positioning arm, the teeth ride up against each other to overcome the spring bias, thereby allowing the positioning arm to “click” to the next position. The angular spacing between adjacent positions is preferably in the range of 2-10 degrees, and most preferably in the range of 3-6 degrees.

While the horizontal front-to-back rotation axes of the positioning arms as per the above embodiments are believed to be advantageous, various alternative implementations are also useful, and may themselves has particular advantages for certain implementations. FIGS. 12A and 12B illustrate an exemplary system 600 for maintaining a desired spacing between right shoulder strap 10a and left shoulder strap 10b of pack 12 worn by a user. System 600 has positioning arms 14a and 14b mounted pivotably about two separate axes 602a, 602b, which are substantially vertical (using similar definitions to those above, namely, within about ±20° from parallel to a plane defined by the back-contact surfaces of the pack). Each positioning arm 14a, 14b is shown here supported by a curved support rod 604a, 604b such that, when closed together, ample room remains between the arms for the neck of the user. Preferably, an addition pair of swivel joints 606a, 606b allow the orientation of the arms to remain constant to fit against the internal or external surfaces of the shoulder straps 10a, 10b.

FIGS. 13A and 13B illustrate an exemplary system 700 for maintaining a desired spacing between shoulder straps of a pack worn by a user. System 700 differs from system 600 primarily in that the required motion is provided by a single substantially-vertical axis of rotation 702 interconnecting positioning arms 14a and 14b. Optionally, system 700 may use a pair of curved rods and swivel joints similar to elements 604a, 604b, 606a and 606b described above. Alternatively, as illustrated here, a neck-clearance profile is provided incorporated into the form of positioning arms 14a and 14b themselves, and a rounded cross-sectional profile is used to minimize the impact of rotation of the positioning arms relative to the shoulder straps. Only the mechanism is illustrated here, but the integration of the mechanism with a pack and shoulder straps will be clearly understood by reference to the prior-described embodiments.

FIGS. 14A and 14B illustrate a selectively-releasable ratchet pivot joint 750 suitable for use in both system 600 (for the pivot joints at axes 602a and 602b) and in system 700 (pivot joint at axis 702) to provide a locking effect. Each side of the pivot joint is formed with a complementary toothed disk 752, 754 which are normally biased into engagement so as to define a one-way rotary ratchet configuration, allowing displacement of the positioning arms in a closing direction (towards the sternum in the center of the thorax) while retaining them against being opened laterally outwards. A release control, which may be implemented simply as a button 756 on the pivot joint or actuated remotely via a cord (not shown), acts against the spring bias to separate the disks sufficiently to disengage the teeth and allow free displacement of the positioning arms outwards.

FIGS. 15A-16D illustrate further options for implementation of a system 800 or 900 for maintaining a desired spacing between shoulder straps of a pack worn by a user. In this case, the adjustment mechanism is essentially a telescopic configuration which can be shortened or extended to transition between the open state and at least one proximity-maintaining state. In the case of system 800, the telescopic configuration is a linear telescopic configuration which is structurally similar to the linear telescopic element of FIGS. 4 A and 4B, but here forms a direct mechanical interconnection between positioning arms 14a and 14b. Thus, system 800 includes a notched rod 802 which is received telescopically within a hollow cylinder 804 and engaged by a tooth 806 to lock its position. The various options described above regarding shapes of the notches and the locking tooth, and corresponding functionality of the mechanism and a release mechanism described above, are all relevant here. This results in a linear lateral displacement between the positioning arms between an open (more spaced apart) state of FIG. 15A and a closed (less spaced apart) state of FIG. 15B. A preferred ergonomic form of the positioning arms is best seen in the isometric view of FIG. 15C.

FIGS. 16A-16D show an implementation of a system 900 which is structurally and functionally very similar to system 800, but in which the telescopic configuration is an arcuate telescopic configuration. Thus, system 900 includes an arcuate notched rod 902, associated with second positioning arm 14b, which is received telescopically within an arcuate hollow cylinder 904, associated with first positioning arm 14a. A pin-in-slot interengagement (not shown) or other alignment features may be required to ensure that no twisting motion occurs between the rod and the cylinder. Notches of notched rod 902 are engaged by a tooth 906.

In the implementation illustrated here, the most “shortened” position of the telescopic mechanism (i.e., maximum overlap), together with any further fixed curvature of the positioning arms, extends around at least 180 degrees about the center of curvature of the arcuate telescopic configuration. As a result, in this case it is extension of the mechanism which achieves bringing together of the positioning arms 14a and 14b, as best seen in the plan views of FIGS. 16C and 16D. This motion thus achieves bringing together of the two shoulder straps without in any way constricting the space around the neck of the user. Conversely, shortening of the telescopic mechanism achieves opening of the mechanism.

Systems 700, 800 and 900 have all been illustrated without showing the pack and shoulder straps, but their structural interaction with the pack and shoulder straps as well as their function will be clearly understood by analogy to the earlier embodiments.

Implementations without Real-Time Adjustment

According to a further aspect of the present invention illustrated in FIGS. 17A-20, a system 1000, 1100 or 1200 for maintaining a desired spacing between a right shoulder strap 10a and a left shoulder strap 10b of a pack 12 worn by a user includes a first positioning arm 14a configured for extending over a right shoulder of the user and extending downwards to a distal portion 16a for association with the right shoulder strap 10a, and a second positioning arm 14b configured for extending over a left shoulder of the user and extending downwards to a distal portion 16b for association with the left shoulder strap 10b. A rigid bridging portion 50 is mechanically associated with both the first positioning arm 14a and the second positioning arm 14b so as to be located at least in part behind a neck of the user.

Each of the first and second positioning arms 14am 14b is formed from a plurality of rigid segments 22, and has a plurality of mutually-parallel hinges 24 interconnecting between successive rigid segments 22 and/or between one of the rigid segments and bridging portion 50. Bridging portion 50, rigid segments 22 and hinges 24 are configured such that the system assumes a body-fitting state (FIGS. 17B, 17C and 18B) in which the positioning arms extend over the user’s shoulders and downwards across a chest of the user so as to maintain a state of proximity between the right and left shoulder straps of the backpack (FIG. 18B), and wherein upward flexing of at least one of the positioning arms at the hinges (FIG. 18 A) facilitates putting on and taking off the backpack. In certain particularly preferred implementations, as illustrated here, positioning arms 14a and 14b are mechanically associated with rigid bridging portion 50 so that their extensional directions 52a, 52b (when straightened, as in FIG. 17A) diverge away from the bridging portion. The angle of divergence a relative to a central plane of symmetry 54 is preferably no more than 60 degrees, and most preferably in a range of between about 15 degrees and about 45 degrees. As seen in FIGS. 17B and 17C, due to the arched shape formed by the positioning arms formed from segments and parallel hinges when they conform to the shape of the user’s body, the divergence of the positioning arms behind the neck turns into a convergence on the anterior side of the body (or the reverse for a front-mounted pack). As a result, when conforming to the shape of the user’s body, the distal portions 16a, 16b of the positioning arms are effective to maintain proximity between the shoulder straps 10a, 10b to which they are linked (FIG. 18B). As before, linkage of distal portions 16a, 16b to shoulder straps 10a, 10b may be via a pivotal connector 28, or via integration into the shoulder straps in a manner analogous to FIG. 5 above.

To facilitate taking off and putting on the pack, positioning arm 14a and/or 14b are raised so as to open up a larger gap between them. Where the positioning arms are external to the shoulder straps, this may be done by implementing connector 28 as an easy-release connector, allowing the positioning arms to be raised away from the shoulder strap. Alternatively, and particularly for the case of positioning arms integrated into the shoulder straps, the shoulder straps themselves may be provided with quick-release connectors (not shown), allowing an entire shoulder strap to be raised for easily putting on and taking off the pack.

According to a further optional feature best illustrated in FIGS. 17A and 17B, positioning arms 14a and 14b are mechanically associated with rigid bridging portion 50 via an adjustable connection configured to allow adjustment of the angle of divergence a. In the nonlimiting example illustrated in FIG. 17B, bridging portion 50 includes a pivot aperture 56 and a series of alignment apertures 58 deployed in an arc about pivot aperture 56. By fixing each positioning arm 14a, 14b to the pivot aperture 56 and to a selected one or more of the alignment apertures 58, by use of a suitable arrangements of pins, screws and/or bolts or the like, it is possible to fix each positioning arm at a desired angle of divergence relative to bridging portion 50. This adjustment is typically a one-time adjustment to fit the positioning arms to the geometry of the user’s trapezius muscles. FIG. 17D illustrates a case where the angle of divergence has been set to smaller than in FIG. 17A. Here and elsewhere in this document, both in the description and claims, the term “rigid” is used to refer to an element which has sufficient resistance to change in shape that, under normal operating conditions, the element does not significantly change shape, and maintains the spatial relationship between various other components attached thereto. Thus, a “rigid” element according to this definition may in some cases be made from polymeric materials which, if taken in hand, can be flexed, but which provide sufficient structural stability to maintain the spatial relationship between the associated components, joints or hinges during use.

Specifically in the context of a sequence of segments making up one of the positioning arms, the segments should have sufficient resistance to torsional deformation that, under normal conditions of use, they do not twist sufficiently to reorient the hinges in a manner that would allow undesired spreading apart of the shoulder straps.

FIGS. 19A-19C illustrate a system 1100 which is a variant of system 1000, with equivalent components labeled similarly. As illustrated here, the “mutually-parallel hinges” 24 are not necessarily precisely parallel, and their angles may be varied somewhat, for example, to enhance conforming of the positioning arms to the shape of the user’s body, while maintaining sufficient rigidity in the lateral direction to maintain proximity between the shoulder straps during use. Most preferably, the inclination of the hinge directions relative to an extensional direction of each positioning arm remains below 30 degrees, and more preferably below 20 degrees. Similarly, successive hinges of this embodiment maybe be considered substantially parallel if they are rotated relative to the adjacent hinges by less than 30 degrees, and more less than 20 degrees. Notwithstanding this example, certain particularly preferred implementations of the “mutually-parallel hinges” have successive hinges parallel to a higher degree of accuracy, preferably differing by no more than about 10 degrees from the neighboring hinges, and preferably with a cumulative variation along an operative length of the positioning arm of no more than 30 degrees. In certain particularly preferred implementations, parallelism of successive hinges is maintained to the extent that the hinges appear visually to be parallel (e.g., variations of no more than about 3 degrees).

The above discussion of the “mutually-parallel hinges” relates only to the region of the device which plays a role in maintaining proximity of the shoulder straps during use. In some cases, such as for aesthetic reasons or in order to maintain the “feel” of the lower part of the shoulder strap, the positioning arms may extend downwards beyond what is needed for the positioning function (which typically occurs in the mid- to upper-chest). Any part of the positioning arms which extend beyond the functional region may have hinges at any angle desired for aesthetic or ergonomic purposes and/or may be implemented with reduced rigidity.

The implementation of FIGS. 19 A and 19B does not provide angular adjustment, but illustrates a different form of adjustability, namely, width of the bridging portion. Specifically, the bridging portion is here formed from a first part 50a and a second part 50b which can be fastened together with different degrees of overlap. Fastening together of the two parts of the bridging portion may be achieved by a wide range of standard fastening arrangements, and is illustrated here by way of a non-limiting example as lines of overlapping apertures which are fastened with a desired degree of overlap by use of a suitable arrangements of pins, screws and/or bolts or the like. This allows deployment of the bridging portion with a relatively large width (FIG. 19 A) or a relatively narrow width (FIG. 19B), for optimizing the fit to the body of the user.

Although illustrated separately, the bridging portion width adjustability of system 1100 can readily be integrated into system 1000 in combination with the angular adjustability described there to provide further enhanced personalization of the fit of the system to each user.

FIG. 20 illustrates a system 1200 which is fully equivalent to system 1100 described above, but without the width adjustment arrangement, thereby providing a particularly simple and low-cost solution which is suitable for a majority of the population.

The implementations of FIGS. 19A-20 are illustrated here without a pack, but their structure and function will be fully understood by analogy to system 1000 described above, as well as by analogy to the earlier embodiments.

Referring finally to FIGS. 21A and 21B, as mentioned earlier, the features of the various embodiments described above are not mutually exclusive. By way of one non-limiting example, FIGS. 21 A and 2 IB illustrate a system 100a which is structurally and functionally equivalent to system 100 described above, but which employs positioning arms that are implemented with multiple short segments 22 sequentially interconnected at parallel hinge joints 24, in a manner conceptually similar to system 1000 of FIGS. 17A-18B.

It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims.