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Title:
BACKPACK WITH ADJUSTABLE HIP BELTS
Document Type and Number:
WIPO Patent Application WO/2020/035856
Kind Code:
A1
Abstract:
A backpack has a backpack body, a driving mechanism having a vertical axis, and two hip belt units with one hip belt unit on each of two sides of said vertical axis. Each hip belt unit includes a manipulable hip belt member with a closure element attached to a distal end thereof and configured to engage with the closure element of the other manipulable hip belt member. The manipulable hip belt member is connected to the driving mechanism at a proximal end thereof for allowing the driving mechanism to move the manipulable hip belt member at least in a direction towards the vertical axis as to reduce an operational extension of the manipulable hip belt member between its distal end and the driving mechanism.

Inventors:
WINFIELD MENACHEM PINHAS (CN)
Application Number:
PCT/IL2019/050905
Publication Date:
February 20, 2020
Filing Date:
August 12, 2019
Export Citation:
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Assignee:
STARRY LTD (CN)
REINHOLD COHN & PARTNERS (IL)
International Classes:
A45F3/04; A45F3/14
Foreign References:
US9462875B22016-10-11
JP2004330975A2004-11-25
US20050279797A12005-12-22
US7600660B22009-10-13
US6053381A2000-04-25
US4976383A1990-12-11
US20170360182A12017-12-21
FR2849996A12004-07-23
CN105901895A2016-08-31
CN205126594U2016-04-06
CN103169243A2013-06-26
KR100856454B12008-09-04
Attorney, Agent or Firm:
PUGATSCH, Ena (IL)
Download PDF:
Claims:
CLAIMS:

1. A backpack comprising:

a backpack body;

a driving mechanism having a vertical axis; and

two hip belt units, one on each of two sides of said vertical axis, each unit comprising

a manipulable hip belt member having a distal end with a closure element attached thereto and engagable with the closure element of the other manipulable hip belt member, and a proximal end connected to the driving mechanism so as to allow the driving mechanism to move at least a part of the manipulable hip belt member disposed adjacent the driving mechanism, at least in a direction towards the vertical axis so as to reduce an operational extension E of the manipulable hip belt member between its distal end and the driving mechanism, if necessary, using the driving mechanism; and optionally,

a load bearing member associated with the manipulable hip belt member and configured to bear forces of weight associated with a load contained in said backpack, when the backpack is worn by a user with the closure elements engaging each other.

2. A backpack according to Claim 1, wherein the association of the manipulable hip belt member with the load bearing member is such that a length of the load bearing member is maintained unchanged when the operational extension E of the manipulable hip belt member is changed.

3. A backpack according to Claim 1 or 2, wherein said driving mechanism comprises a single rotatable shaft, to which the proximal ends of the manipulable hip belt members are connected at least indirectly.

4. A backpack according to Claim 1, 2 or 3, wherein said driving mechanism is configured to move simultaneously at least the parts of the manipulable hip belt members disposed adjacent the driving mechanism.

5. A backpack according to any one of Claims 1 to 4, wherein the driving mechanism is configured for exerting, at least indirectly, horizontal pulling forces on the parts of the manipulable hip belt members.

6. A backpack according to any one of Claims 1 to 5, wherein each manipulable hip belt member comprises the load bearing member which is movable therewith; optionally, said load bearing member having a load bearing member proximal end and a load bearing member distal end, and said manipulable hip belt member having a proximal portion associated with the load bearing member proximal end and constituting said part of the manipulable hip belt member movable by the driving mechanism, and a distal portion associated with the load bearing member distal end.

7. A backpack according to any one of Claims 3 and Claims 4 to 6, when dependent on Claim 3, wherein said part of each manipulable hip belt member comprises a windable element configured to be wound with its one end around the rotatable shaft during its rotation, and being associated at its other end with the load bearing member.

8. A backpack according to Claim 7, wherein the windable elements of the two manipulable hip belt members are configured to be wound around the rotatable shaft at different, spaced apart locations.

9. A backpack according to Claim 7 or 8, wherein the windable elements of the two manipulable hip belt members are connected to diametrically opposite locations of the rotatable shaft so as to extend away therefrom.

10. A backpack according to any one of Claims 1 to 5 and 7 to 9, when dependent on Claims 3 to 5, wherein each of the load bearing members is fixedly attached to said backpack, and the manipulable hip belt member is movably received within the load bearing member.

11. A backpack according to any one of Claims 7 to 10, wherein each of the load bearing members is formed with a passage having a passage proximal end, via which said other end of the windable element is inserted into said passage.

12. A backpack according to Claim 11, wherein the passage in the load bearing member has a passage distal end, and the distal portion of the manipulable hip belt member with its distal end protrudes distally from the passage distal end, the distal end of the manipulable hip belt member having said closure element attached thereto.

13. A backpack according to any one of the preceding claims, wherein the manipulable hip belt member comprises a first segment having a first width and a second segment having a second width larger than the first width, the first segment extending between the proximal end of the manipulable hip belt member and the second segment, and the second segment extending between the first segment and the distal end of the manipulable hip belt member.

14. A backpack according to Claim 13, wherein the first and the second segments are connected to each other within the load bearing member.

15. A backpack according to any one of the preceding claims, wherein each hip belt unit further comprises a biasing mechanism configured to move at least the movable part of the manipulable hip belt member in a direction away from the driving mechanism.

16. A backpack according to any one of the preceding claims, wherein the backpack has a back wall and the driving mechanism is mounted to the back wall.

17. A backpack according to Claim 16, wherein the backpack has a backpack interior, and the back wall has an inner surface facing said interior, an outer surface facing away from the inner surface, and a back wall interior therebetween, wherein the driving mechanism is mounted adjacent the inner surface of the back wall.

18. A backpack according to Claim 16 or 17, wherein the load bearing members are fixedly mounted to the back wall at said outer surface.

19. A backpack according to any one of Claims 16 to 18, comprising a unitary load bearing member body having a central portion at which the body is fixed to the back wall and two wing portions extending therefrom and constituting said load bearing members.

20. A backpack according to any one of Claims 17 to 19, wherein each of the manipulable hip belt members extends from its proximal end connected to the driving mechanism to its distal end with the closure element, through the back wall interior and via the corresponding load bearing member.

21. A backpack according to any one of the preceding claims, wherein the backpack comprises a control element disposed at a location spaced from the driving mechanism and connected therewith so as to control the operation of the driving mechanism.

22. A backpack according to any one of the preceding claims, wherein the driving mechanism comprises an electric motor.

23. A backpack according to Claim 9 and any one of Claims 10 to 22 when dependent on Claim 9, wherein the rotatable shaft comprises openings at said diametrically opposite locations and a passageway therethrough connecting said openings, and wherein the windable elements of the two manipulable hip belt members are connected to one another within said passageway.

24. A backpack according to Claim 19 and any one of Claims 20 to 23 when dependent on Claim 19, wherein the driving mechanism is mounted to the unitary load bearing member body.

25. A backpack according to any one of the preceding claims, further comprising an extension-control mechanism configured to stop the operation of the driving mechanism when the operational extension of at least one of the manipulable hip belt members reaches one of Emin and Emax, where Emin and Emax are, respectively, a minimal and a maximal operational extension.

26. A backpack according to Claim 25, wherein said extension-control mechanism comprises a mechanical element manipulable to at least indirectly cause the operation of the driving mechanism to stop, when the operational extension of at least one of the manipulable hip belt members reaches one of Emin and Emax.

27. A backpack according to Claim 26, wherein said driving mechanism is a motorized driving mechanism and said mechanical element is configured to move between a first position corresponding to Emin and a second position corresponding to Emax, and to ensure that a signal be sent to the motorized driving mechanism causing it to stop, when the mechanical element is disposed in one of the first position and the second position.

28. A backpack comprising a driving mechanism having a vertical axis and two hip belt members, each having at least a part, which is manipulable by the driving mechanism so as to reduce an operational extension E of the hip belt member, the driving mechanism being mounted at least indirectly to or within the backpack's back wall, optionally, to or adjacent the back wall's inner surface, which faces the backpack's interior.

29. A backpack according to Claim 28, further comprising a load bearing member associated with one of the manipulable hip belt members and configured to bear forces of weight associated with a load contained in said backpack, when the backpack is worn by a user.

30. A backpack according to Claim 29, wherein the association of the manipulable hip belt member with the load bearing member is such that a length of the load bearing member is maintained unchanged when the operational extension of the manipulable hip belt member is changed.

31. A backpack according to any one of Claim 28 to 30, wherein each of the manipulable hip belt members extends from its proximal end connected to the driving mechanism to its distal end associated with the closure element, through the backpack's back wall interior and, optionally, via the corresponding load bearing member.

32. A backpack according to any one of Claims 28 to 31, further comprising a control element disposed at a location spaced from the driving mechanism and connected therewith so as to control the operation of the driving mechanism.

33. A backpack according to any one of Claims 28 to 32, further comprising an extension-control mechanism configured to stop the operation of the driving mechanism when the operational extension of at least one of the manipulable hip belt members reaches one of Emin and Emax, where Emin and Emax are, respectively, a minimal and a maximal operational extension.

34. A backpack according to Claim 33, wherein the extension-control mechanism comprises a mechanical element manipulable to at least indirectly cause the operation of the driving mechanism to stop, when the operational extension of at least one of the manipulable hip belt members reaches one of Emin and Emax.

35. A backpack according to Claim 34, wherein the driving mechanism is a motorized driving mechanism and its mechanical element can be configured to move between a first position corresponding to Emin and a second position corresponding to Emax, and to ensure that a signal be sent to the motorized driving mechanism causing it to stop, when the mechanical element is disposed in one of the first position and the second position.

36. A backpack according to any one of Claims 28 to 35, wherein each hip belt unit further comprises a biasing mechanism configured to move at least the movable part of the manipulable hip belt member in a direction away from the driving mechanism.

37. A backpack according to any one of the preceding claims, wherein said hip belt units and the driving mechanism constitute a hip belts assembly attached to the backpack body.

Description:
BACKPACK WITH ADJUSTABLE HIP BELTS

TECHNOLOGICAL FIELD

The presently disclosed subject matter relates to backpacks having adjustable hip belts.

BACKGROUND

Backpacks are known and widely used, being convenient for allowing items to be carried in a bag worn on the back while leaving the hands free. Backpacks typically have shoulder straps to enable the backpack to be worn on the back of a user, and some backpacks also have hip belts for securing the backpack around the hips of the user. In some backpack models, the shoulder straps and/or the hip belts can be adjusted by the user to achieve a customized fit.

Examples of backpacks of the kind, to which the presently disclosed subject matter refers, can be found in US 7,600,660, US 6,053,381, US 4,976,383, US 2017/360182, FR 2849996, CN 105901895, CN205126594, CN 103169243 and KR 100856454. GENERAL DESCRIPTION

According to the presently disclosed subject matter, there is provided a backpack comprising a driving mechanism having a vertical axis and two hip belt members, each having at least a part, which is manipulable by the driving mechanism so as to reduce an operational extension E of the hip belt member. The driving mechanism and the hip belt members can constitute a hip belts assembly attached to the backpack body.

According to one aspect of the presently disclosed subject matter, each hip belt member can constitute a part of a hip belt unit, which can further comprise a load bearing member associated with the manipulable hip belt member and configured to bear forces of weight associated with a load contained in said backpack, when the backpack is worn by a user with the closure elements engaging each other and with the operational extension E of the manipulable hip belt members having been adjusted, if necessary, using the driving mechanism. The association of the manipulable hip belt member with the load bearing member can be such that a length of the load bearing member is maintained unchanged when the operational extension of the manipulable member is changed.

According to another aspect of the presently disclosed subject matter, the driving mechanism can be mounted, at least indirectly, to or within the backpack's back wall. For example, the driving mechanism can be mounted to or adjacent the back wall's inner surface, which faces the backpack's interior.

In any of the above aspects, the backpack can features described below in any combination thereof.

The load bearing members can be fixedly mounted to the back wall at its outer surface facing away from the backpack's interior. Alternatively, the load bearing members can constitute a part of a unitary load bearing member body having a central portion, at which the body is fixed to the back wall of the backpack, and two wing portions extending therefrom and constituting said load bearing members. The driving mechanism can be mounted to the unitary load bearing member body, e.g. at the central portion thereof.

The driving mechanism can comprise a single movable element, to which the proximal ends of the two manipulable hip belt members are connected at least indirectly. The driving mechanism can be configured to move simultaneously at least those parts of the manipulable hip belt members that are disposed adjacent the driving mechanism. The driving mechanism can be configured for exerting, at least indirectly, horizontal pulling forces on the parts of the manipulable hip belt members. The movable element can be, for example, in the form of a rotatable shaft.

The load bearing member of each hip belt unit can constitute a part of the corresponding manipulable hip belt member and can be movable therewith. With the load bearing member having a load bearing member proximal end and a load bearing member distal end, the manipulable hip belt member can have a proximal portion associated with the load bearing member proximal end and constituting the part of the manipulable hip belt member movable by the driving mechanism, and a distal portion associated with the load bearing member distal end. At least a portion of each manipulable hip belt member can be configured to be wound around a shaft, during operation of the driving mechanism, with a first end of said portion, and being associated at its second end with the load bearing member. The windable portions of the two manipulable hip belt members can be configured to be wound around the same shaft, e.g. the above single rotatable shaft, at different, spaced apart locations thereof. For example, the windable portions of the two manipulable hip belt members can be connected to the shaft at diametrically opposite locations so as to extend away therefrom.

Each of the load bearing members can be fixedly attached to the backpack with a portion of the corresponding manipulable hip belt member, being movably received therein, e.g. within a passage formed therein, so that the distal end of the manipulable hip belt member, together with the closure attached thereto, protrudes distally from the load bearing member.

The manipulable hip belt member can have different geometry along its length, e.g. can have a varying width. The manipulable hip belt member can comprise at least two segments of different widths which can be connected to each other within the load bearing member.

Each hip belt unit can further comprise a biasing mechanism configured to move at least the movable part of the manipulable hip belt member in a direction away from the driving mechanism. The biasing mechanism can be disposed within the load bearing member.

The driving mechanism can be mounted to or within the backpack's back wall. For example, the driving mechanism can be mounted to or adjacent the back wall's inner surface which faces the backpack's interior. The load bearing members can be fixedly mounted to the back wall at its outer surface facing away from the backpack's interior. Alternatively, the load bearing members can constitute a part of a unitary load bearing member body having a central portion, at which the body is fixed to the back wall of the backpack, and two wing portions extending therefrom and constituting said load bearing members. The driving mechanism can be mounted to the unitary load bearing member body, e.g. at the central portion thereof.

Each of the manipulable hip belt members can extend from its proximal end connected to the driving mechanism to its distal end associated with the closure element, through the backpack's back wall interior and via the corresponding load bearing member.

The backpack can further comprise a control element disposed at a location spaced from the driving mechanism and connected therewith so as to control the operation of the driving mechanism.

The driving mechanism can comprise an electric motor. The electric motor can be of a kind having a stall torque in the range of 10 - 16 kg cm.

The manipulable hip belt member's maximal and minimal operational extension, Emax and Emin, respectively, can each be in the range of 250 - 600 mm. A ratio between the load bearing member's length L along the operational extension E of the manipulable hip belt member, and E min, i.e. L:Emin, can be in the range of 0.2 - 0.9.

The backpack can further comprise an extension-control mechanism configured to stop the operation of the driving mechanism when the operational extension of at least one of the manipulable hip belt members reaches one of Emin and Emax. The extension-control mechanism can comprise a mechanical element manipulable to at least indirectly cause the operation of the driving mechanism to stop, when the operational extension of at least one of the manipulable hip belt members reaches one of Emin and Emax. The driving mechanism can be a motorized driving mechanism and its mechanical element can be configured to move between a first position corresponding to Emin and a second position corresponding to Emax, and to ensure that a signal be sent to the motorized driving mechanism causing it to stop, when the mechanical element is disposed in one of the first position and the second position.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic perspective illustration of a backpack in accordance with an example of the presently disclosed subject matter, as viewed from the rear;

Fig. 2 is a schematic illustration of the backpack shown in Fig. 1, as worn by a user and viewed from the side; Fig. 3 is a schematic illustration of a part of a hip belts assembly of a backpack in accordance with a further example of the presently disclosed subject matter, as viewed from the rear of the backpack;

Fig. 3A is a schematic close-up plan view of the rotatable shaft of Fig. 3;

Fig. 3B is a schematic close-up plan view of another example of the rotatable shaft of Fig. 3;

Fig. 4 is a schematic perspective illustration of a backpack in accordance with a still further example of the presently disclosed subject matter, as viewed from the rear of the backpack;

Fig. 5 is a schematic illustration of a part of a hip belts assembly of a backpack in accordance with a still further example of the presently disclosed subject matter, as viewed from the rear of the backpack;

Fig. 6 is a schematic illustration of a part of a hip belts assembly of a backpack in accordance with a still further example of the presently disclosed subject matter, as viewed from the rear of the backpack;

Fig. 7 is a schematic illustration of a part of a hip belts assembly of a backpack in accordance with a still further example of the presently disclosed subject matter, as viewed from the rear of the backpack;

Fig. 7 A is a schematic illustration of a close-up side view of the driving mechanism of the hip belts assembly shown in Fig. 7, as seen from within the backpack;

Fig. 8 is a schematic illustration of a backpack in accordance with a still further example of the presently disclosed subject matter, as viewed from the rear.

Fig. 9 is a schematic illustration of a part of a hip belts assembly of a backpack in accordance with a still further example of the presently disclosed subject matter, as viewed from the rear of the backpack;

Fig. 10A is a perspective view of an extension-control mechanism, which can be used in a backpack in accordance with a still further example of the presently disclosed subject matter;

Fig. 10B is a perspective view of the extension-control mechanism shown in Fig. 10A in a position different from that shown in Fig. 10A;

Fig. 10C is an enlarged view of an area II in Fig. 10A; and Fig. 11 is a perspective view of an extension-control mechanism, which can be used in a backpack in accordance with a still further example of the presently disclosed subject matter.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1, reference to which is first made, shows generally a backpack 10 according to one embodiment of the presently disclosed subject matter. The backpack

10 has a body 15, the body 15 having a back wall 12 and a bottom 14. The backpack 10 further has a backpack interior 16 within the body 15, configured to contain items constituting a load contained in the backpack 10. The back wall 12 has an inner surface

11 facing the backpack interior 16 and an outer surface 13 facing away from the interior 16. The back wall 12 furthermore has a back wall interior 18 defined between the inner surface 11 and the outer surface 13 of the back wall 12.

The backpack 10 is shown in Fig. 1 without shoulder straps, so as not to obscure elements of the backpack 10, which are relevant to the presently disclosed subject matter. However, it is to be understood that the backpack 10, as well as the other exemplary backpacks shown in the figures, have shoulder straps such as are typical in backpacks, to allow wearing of the backpack on the back of a user.

The backpack 10 further comprises a hip belts assembly 20 attached to the backpack body 15. In the example shown in Fig. 1, the hip belts assembly 20 is attached to the back wall 12, though in general it can be attached to other areas of the backpack body 15.

The hip belts assembly 20 comprises a driving mechanism 30 having a vertical axis F, and two hip belt units 40, one on each of two sides of the vertical axis Y. Each hip belt unit 40 comprises a manipulable hip belt member 50 having a distal end 56 with a closure element 54 attached thereto and engagable with the closure element 54 of the other manipulable hip belt member 50. Each manipulable hip belt member 50 further has a proximal end 52 connected to the driving mechanism 30 so as to allow the driving mechanism 30 to move at least a part of the manipulable hip belt member 50 disposed adjacent the driving mechanism 30, at least in an inward direction I toward the vertical axis F, so as to reduce an operational extension E of the manipulable hip belt member 50 between its distal end 56 and the driving mechanism 30. For example, the driving mechanism can be of the kind configured for exerting, at least indirectly, horizontal pulling forces on the parts of the manipulable hip belt members 50 disposed adjacent the driving mechanism 30.

Each manipulable hip belt member 50 has an imaginary centerline CL extending between the driving mechanism 30 and the distal end 56 of the manipulable hip belt member 50, as schematically shown in Fig. 1.

Each hip belt unit 40 further comprises a load bearing member 60 associated with the manipulable hip belt member 50. The load bearing member 60 is configured to bear forces of weight associated with the load contained in the backpack 10 when the backpack 10 is worn by a user, with the closure elements 54 engaging each other and with the operational extensions E of the manipulable hip belt members 50 having been adjusted, if necessary, using the driving mechanism 30.

In the above example, the association of the manipulable hip belt member 50 with the load bearing member 60 can be such that the length of the load bearing member 60 is maintained unchanged when the operational extension E of the manipulable hip belt member 50 is changed. A ratio of the length L of the load bearing member 60 along the centerline CL of the manipulable hip belt member 50, to its minimal operational extension Emin , i.e. the ratio of L:Emin, can be in the range of 0.2 - 0.9.

However, in general, the load bearing member 60 can have a variable length. For example, the load bearing member 60 can comprise, at least along a portion of its length, an elastic material, such that the length of the load bearing members 60 can increase due to stretching when the backpack 10 is worn by a user with the closure elements 54 engaging each other, during which a snug fit of the hip belts assembly 20 around the hips of the user is achieved.

Furthermore, in the example shown in Fig. 1, the driving mechanism 30 is mounted to the back wall 12 of the backpack 10. However, the driving mechanism can be located in any suitable position on the backpack body 15. For example, the driving mechanism can be mounted to the bottom 14 adjacent to the back wall 12. In other examples, the driving mechanism can be mounted adjacent to the inner surface 11 or the outer surface 13 of the back wall 12, or within the back wall interior 18. In yet other examples, the driving mechanism 30 can be mounted on an element disposed between the hip belt units 40 and mounted at least indirectly to the backpack body 15 though not constituting its part. It will be appreciated that the adjustment operation described above, wherein the operational extension E of each of the manipulable hip belt members 50 can be reduced by means of the driving mechanism 30, in order to tighten the hip belts assembly 20 around the hips of a user, as illustrated in Fig. 2, allows the user to spend essentially less efforts to attain a snug fit of the hip belts assembly 20 around their hips, whereby the weight associated with the load contained in the backpack 10 can be distributed more properly between the hips and the shoulders of the user and the forces exerted on the shoulders of the user can be essentially reduced.

The hip belts assembly 20 can further comprise a control element, which can be operated to control the operation of the driving mechanism 30 via its controller (not shown). The control element can be of the kind providing manual control of the operation of the driving mechanism 30, such as, e.g., a windable reel, or it can be of the kind configured to provide automatic control of the driving mechanism 30, such as a button, which can be pressed to control the operation of the driving mechanism 30.

The control element can be disposed at a location spaced from the driving mechanism 30 and connected therewith. The connection can be a wired connection, with the wires passing inconspicuously through the hip belts assembly between the location of the control element and the driving mechanism 30, or it can be a wireless connection.

One example of such a control element is shown in Fig. 2, where a control element 17 can be seen to be disposed on the load bearing member 60 of the hip belt unit 40 within easy reach of the right hand of the user of the backpack 10. The hip belts assembly 20 can be configured such that the driving mechanism 30 can be operated to reduce the operational extension E of each of the manipulable hip belt members 50 from a maximal operational extension Emax to a reduced operational extension shorter than Emax down to a minimal operational extension Emin. A ratio between Emax and Emin can be in the range of 1.1 to 1.8.

The hip belts assembly 20 can further be configured to enable at least a part of each manipulable hip belt member 50 disposed adjacent the driving mechanism 30, to be moved, directly or indirectly, in an outward direction away from the vertical axis Y, so as to restore the operational extension E of each manipulable hip belt member 50 from the reduced operational extension to an extended operational extension, where the extended operational extension is not longer than Emax. To allow such restorative movement, the driving mechanism 30 can be configured to be operated in a direction opposite to that required to perform its reductive operation, enabling the operational extensions E of the manipulable hip belt members 50 to be restored from a reduced operational extension to an extended operational extension, as described above. The restorative operation of the driving mechanism 30 can be accompanied by applying at least to proximal portions of the manipulable hip belt members 50, directly or indirectly, pulling forces directed away from the vertical axis Y. This can be done manually by pulling the manipulable hip belt members 50, e.g. by means of their distal portions adjacent to their distal ends 56, or by using a dedicated biasing mechanism.

All above length restoring options can be applicable to only one of the hip belt members 50 rather than both of them, and they can be controlled by the control element mentioned above.

The hip belts assembly 20 can further comprise means for locking the driving mechanism 30 when the operational extensions of the manipulable hip belt members 50 have been reduced and the hip belts assembly 20 has been tightened to a desired extent, and unlocking it in order to allow the restoration of their lengths. These operations can also be performed using the control element.

The backpack 10 can further comprise an extension-control mechanism, configured to override the operation of the control element, so as to stop the operation of the driving mechanism when the operational extensions E of the manipulable hip belt members 50 reach a pre-determined minimal operational extension Emin or a maximal operational extension Emax.

More specifically, the extension-control mechanism can be configured so that, (a) when the driving mechanism is operated in the direction required to perform the reductive operation, the extension-control mechanism stops the operation of the driving mechanism when the operational extensions E of the manipulable hip belt members 50 reach the pre-determined minimal operational extension Emin; and (b)when the driving mechanism is operated in the opposite direction, to perform the restorative operation, the extension-control mechanism stops the operation of the driving mechanism when the operational extensions E of the manipulable hip belt members 50 reach the pre determined maximal operational extension Emax. It will be appreciated that, when the extension-control mechanism stops the operation of the driving mechanism when the reductive operation is underway, i.e. when the operational extensions E of the manipulable hip belt members 50 are being reduced, the extension-control mechanism functions as a safety mechanism, preventing the operational extensions E of the manipulable hip belt members 50 from being reduced further than the minimal operational extension Emin , which is pre-determined to be safe for a user of the backpack.

During the operation of the driving mechanism in the opposite direction, during the restorative operation, the extension-control mechanism functions to improve the ease of use of the backpack when it stops the operation of the driving mechanism, by preventing the operational extensions E of the manipulable hip belt members 50 from being restored further than the maximal operational extension Emax. The ease of use of the backpack 10 is thus improved by prevention of a situation, in which a user of the backpack 10 could be overwhelmed by an excess of belt length liberated during the restorative operation.

In accordance with the presently disclosed subject matter, the extension-control mechanism can comprise a mechanical element manipulable to at least indirectly cause the operation of the driving mechanism to stop when the operational extensions of the manipulable hip belt members reach Emin or Emax. That is, the mechanical element can be configured such that a particular mechanical event occurs when the operational extensions of the manipulable hip belt members reach Emin or Emax, and the stoppage of the driving mechanism is triggered by the mechanical event. The mechanical event can thus cause a non-mechanical prevention of further operation of the driving mechanism, e.g. by an electronic signal transmitted to the controller of the driving mechanism, which causes the operation of the driving mechanism to stop.

It will be appreciated that the manner in which the driving mechanism is stopped as described above can be safer than that used in conventional driving mechanisms, which do not have the straightforward relationship between a specific mechanical event caused by a mechanical element and stoppage of the driving mechanism since there the stoppage is provided solely by means of electronic components.

Returning now to the exemplary backpack 10 and hip belts assembly 20 shown in Fig. 1, the driving mechanism 30 can be seen to be centrally located with respect to the width of the back wall 12 of the backpack 10. However, in general, in a backpack 10 in accordance with the presently disclosed subject matter, its hip belts assembly 20 can be configured such that the driving mechanism 30 is asymmetrically disposed with respect to the width of the back wall 12 of the backpack 10.

Furthermore, while the driving mechanism 30 as it is schematically shown in Fig. 1, is fully contained inside a boxlike housing, it can have any other housing or it can have no housing at all. The dimensions of the driving mechanism can also vary. For example, it can be higher along the vertical axis Y and/or wider along the back wall 12 of the backpack 10, than the mechanism shown in Fig. 1.

Moreover, the driving mechanism can be of any suitable type and structure. For example, it can comprise a rotatable shaft, to which the proximal ends 52 of the manipulable hip belt members 50 can be connected so as to allow the driving mechanism to simultaneously move the parts of the manipulable hip belt members disposed adjacent the driving mechanism in a direction substantially perpendicular to the vertical axis Y. It will be appreciated that the manipulable hip belt members can be attached to the rotatable shaft directly or indirectly.

In one example, the rotatable shaft can be configured to rotate about the vertical axis Y of the driving mechanism or about an axis which is substantially parallel to the axis Y. In another example, the rotatable shaft can be configured to rotate about an axis which has a substantially horizontal orientation and which is parallel to the direction of movement of the manipulable hip belt members 50.

The manipulable hip belt members can each be in the form of a single belt or multi- segment belt, in which different segments comprising the manipulable hip belt member have the same or similar width and can be made of the same or similar materials. Alternatively, the manipulable hip belt members can be multi-segment belts comprising multiple segments of varying material types and widths. For example, at least proximal portions of the manipulable hip belt members 50 terminating at their proximal ends 52 can be in the form of thin/narrow segments made of, for example, flexible wire, shoelace or ribbon material having a narrow width. Distal portions of the manipulable hip belt members 50 terminating at their distal ends 56 can be in the form of segments, which are wider than the segments of the proximal portions of the manipulable hip belt members, e.g. they can have a typical belt width suitable for connection to the closure elements 54 and for forming the closure between the two hip belt units 40. The load bearing members can be fixed to the body of the backpack, or they can be attached to the manipulable hip belt members, each on its respective side of the vertical axis Y. In the case that the load bearing members are fixed to the body of the backpack, the respective manipulable hip belt members are configured to be movable therealong. In the case that the load bearing members are attached to their respective manipulable hip belt members, when operation of the driving mechansim causes the manipulable hip belt members to move, the load bearing members move therewith.

More particularly, in the former of the above cases, each load bearing member can comprise a passage or sleeve for the manipulable hip belt member to pass through, such that its operational extension E can be adjusted while the load bearing member is fixed and does not change its length. In this case, if the proximal portions of the manipulable hip belt members associated with their proximal ends have a thin width, and the distal portions associated with the distal ends of the manipulable hip belt member have a wider width, as mentioned above, the proximal and distal portions can be connected to each other inside the passage/sleeve of the load bearing member.

Furthermore, when the load bearing members are fixed to the body of the backpack, each load bearing member can be attached separately to the backpack, for example, to a side of the backpack adjacent to the back wall. In another exemplary configuration, the load bearing members can both be a part of a unitary load bearing member body having a central portion at which the body is fixed to the back wall at its outer surface, and two wing portions extending therefrom and constituting the load bearing members.

It will be appreciated that in an example of a backpack having a unitary load bearing member body as described above, the driving mechanism can be mounted to the unitary load bearing member body, for example, at its central portion.

In case the load bearing members are configured to be moved with the corresponding manipulable hip belt members, each load bearing member has a load bearing member proximal end fixedly connected to the proximal portion of the corresponding manipulable hip belt member 50 at its end opposite the proximal end 52 of the latter member, and a load bearing member distal end fixedly connected to the distal portion of the manipulable hip belt member 50 at its end opposite the distal end 56 of the latter member. Alternatively, the proximal and/or distal portion of each manipulable hip belt member 50 can be fixed to the load bearing member 60, at one or more locations, or along portions of its length, or along its entire length, for example, by sewing.

In all the above cases, the proximal portion of the manipulable hip belt member can extend, at least along a part of its length adjacent the driving mechanism, through the back wall interior 18 of the backpack 10, and it can protrude outwardly from the back wall together with the load bearing member, being disposed therewithin.

Backpacks and hip belt assemblies of backpacks, according to specific examples of the presently disclosed subject matter and having features described above in different combinations thereof will now be described with reference to Figs. 3, 3A 4, 5, 6, 7, 7A, 8, 9, 10A, 10B, 10C and 11.

It will be appreciated that the reference numeral for the exemplary hip belts assembly 120 shown in Fig. 3 is the reference numeral used in Fig. 1 for the exemplary hip belts assembly 20 shown there, increased by 100. Similarly, exemplary backpacks and elements of backpacks shown in subsequent figures which are analogous to exemplary backpacks and elements of backpacks shown in previous figures, are designated by the reference numerals used in the previous figures, with the reference numerals in each subsequent figure increased by 100 with respect to the previous figure. With respect to the abovementioned, Figs. 3A, 3B and 7A are not taken into account, and the reference numerals in Figs. 3A, 3B and 7A are part of the series of reference numerals used in Figs. 3 and 7 respectively.

Fig. 3 shows a part of an exemplary hip belts assembly 120 of an exemplary backpack 110 (not shown), in which the driving mechanism 130 comprises a single rotatable shaft 132 configured to rotate in a counterclockwise direction around the vertical axis Y thereof, as indicated by the arrow CC. As shown in Fig. 3, each of the manipulable hip belt members 150 comprises a proximal portion 174 associated with its proximal end 152, and a distal portion 178 associated with the distal end 156, of the manipulable hip belt member 150. It will be appreciated that while the distal portion 178 of the manipulable hip belt member 150 on the left side of Fig. 3 is not shown in the figure due to lack of space, it is analogous to the distal portion 178 shown for the manipulable hip belt member 150 shown in its entirety on the right side of the figure.

As further shown in Fig. 3, the distal portion 178 of the manipulable hip belt member 150 is in the form of a relatively wide belt segment having the closure element 154 at its distal end, and the proximal portion 174 of each manipulable hip belt member 150 is in the form of a relatively narrow windable segment whose end constitutes the proximal end 152 of the manipulable hip belt member 150, which is connected to the rotatable shaft 132 so as to allow the windable proximal portion 174 to be wound around the rotatable shaft 132 during its rotation. The ends of the windable proximal portions 174, which constitute the proximal ends 152 of the manipulable hip belt members 150, can be connected to the rotatable shaft 132 at any locations of its periphery. One example of such connection is shown in Fig. 3A, where these locations are diametrically opposite one another when seen in a plan view.

A second example of such connection is shown in Fig. 3B, wherein the rotatable shaft 132 comprises openings 133 at diametrically opposite locations of its periphery, and a passageway 135 through the rotatable shaft 132 connecting the openings 133. As shown in Fig. 3B, the ends of the windable proximal portions 174 are connected to the rotatable shaft 132 by passing, each through its respective opening 133, into passageway 135, and by being connected to one another within the passageway 135 at the connection area CP. Alternatively, the ends of the windable proximal portions 174 could each be connected to an internal element within the rotatable shaft 132, e.g. an axle at the center of the rotatable shaft 132, or a spoke radiating from such an axle. In a yet additional alternative, the windable proximal portions 174 could constitute two ends of a single continuous windable element passing through the passageway 135.

The ends of the windable proximal portions 174, which constitute the proximal ends 152 of the manipulable hip belt members 150, can be connected to the rotatable shaft 132 at different locations along the axis Y. In the example shown in Fig. 3, these locations are spaced apart by the distance d along the vertical axis Y. It will be appreciated however, that the windable proximal portions 174 need not be separated from one another. It is also possible for the windable proximal portions 174 to be wound around the rotatable shaft 132 when the distance d is equal to zero, the windable proximal portions 174 in this configuration forming an interleaved spiral when wound around the rotatable shaft 132.

In operation, when the rotatable shaft 132 is caused to rotate in the counterclockwise direction, and the windable proximal portions 174 are wound around the rotatable shaft 132, a length e of each of these portions is reduced relative to their original length and the operational extension E of each manipulable hip belt member is consequently reduced. During the winding of the windable proximal portions 174 around the rotatable shaft, horizontal pulling forces at least on the distal portions 178 of the manipulable hip belt members 150, cause the manipulable hip belt members 150 to move in the direction towards the rotatable shaft 132, thereby reducing the operational extensions E of the manipulable hip belt members 150 and thus tightening the hip belts assembly 120 when the backpack is worn by a user with the closure elements 154 engaging each other.

To restore the operational extensions E of the manipulable hip belt members 150, the rotatable shaft 132 can be configured for being rotated in a clockwise direction, thereby introducing slack into each of the proximal portions 174 of the manipulable hip belt members 150. In this case, manual tugging on their distal ends 156 after disengagement of the closure elements 154 from one another, in a substantially outward direction away from the vertical axis Y, can restore the operational extension E of each manipulable hip belt member 150 from a reduced operational extension to an extended operational extension as described above.

In the exemplary backpack 210 shown in Fig. 4, each load bearing member 260 is fixedly attached to the backpack 210, and each manipulable hip belt member 250 having its proximal end 252 connected to the rotatable shaft 232 and its distal end 256 with a closure element 254 attached thereto, is slidingly received within a dedicated passage 294 formed in the load bearing member 260.

In this example, the entire manipulable hip belt member 250 is in the form of a single belt whose proximal portion 274 and distal portion 278 each extend along about a half of the maximal operational extension Emax of the manipulable hip belt member 250. The proximal portion 274 of the manipulable hip belt member 250 has an external section disposed proximally outside the passage 294 and configured to be wound around the shaft 232, and an internal section disposed distally within the passage 294, when the manipulable hip belt member 250 has its maximal operational extension Emax. The distal portion 278 of the manipulable hip belt member 250 has an internal section proximally disposed within the passage 294 and an external section disposed distally outside the passage 294, when the manipulable hip belt member 250 has its maximal operational extension Emax .

In operation, when the rotatable shaft 232 is caused to rotate in the counterclockwise direction, and the external sections of the windable proximal portions 274 of the manipulable hip belt members 250 are wound around the shaft 232, a length e of these portions is reduced relative to their original length and the operational extension E of each manipulable hip belt member is consequently reduced.

During the winding of the external sections of the windable proximal portions 274 around the rotatable shaft 232, horizontal pulling forces are exerted via their internal sections on the distal portions 278 of the manipulable hip belt members 250, causing each entire manipulable hip belt member 250 to move in the direction I towards the rotatable shaft 232, thereby reducing the operational extension E of each manipulable hip belt member 250 and thus tightening the hip belts assembly 220, with the load bearing members 260 being static.

The restoration of the operational extensions E of the manipulable hip belt members 250 in the case of this example, can be the same as explained above with respect to the backpacks 10 and 110 shown in Figs. 1 and 3, respectively.

Fig. 5 shows only one side, with respect to the vertical axis Y, of an exemplary hip belts assembly 320 of an exemplary backpack 310 (not shown), which is similar to the exemplary hip belts assembly 220 shown in Fig. 4, except for two major differences. One difference is that the proximal portion 374 of each manipulable hip belt member 350 is in the form of a relatively narrow belt segment having a first width Wl, and the distal portion 378 of each manipulable hip belt member 350 is in the form of a relatively wide belt segment, having a second width W2, and connected to the narrow belt segment within the passage 394. The other difference is that the proximal portion 374 of each manipulable hip belt member 350 is associated with a biasing mechanism 399 disposed within the passage 394 in the load bearing member 360.

It will be appreciated that the hip belts assembly 320 is shown in Fig. 5 such that the inside of the passage 394 is visible. The manipulable hip belt member 350 within the passage 394 can thus be seen, though it is actually concealed inside the load bearing member 360.

The biasing mechanism 399 of each of the manipulable hit belt members 350 comprises a length restoration element 397 having a first end 392 fixed to a wall 393 of the passage 394, and a second end 395 fixed to the internal section of the proximal portion 374 of the manipulable hit belt member 350 disposed in the passage 394. The length restoration element 397 can be in the form an elastic rope, a spring or the like, which is configured to expand when a pulling force is exerted thereon via the external section of the proximal portion 374, and to retract when the pulling force is released. In other words, the length restoration element 397 is configured to operate as a biasing member for restoring the operational extension E of the manipulable hip belt member 350 from a reduced operational extension to an extended operational extension along with a restorative operation of the driving mechanism 330 as described above with respect to the previous examples.

Thus, when the driving mechanism 330 is operated to reduce the operational extensions E of each of the manipulable hip belt members 350 by winding the external sections of the proximal portions 374 around the rotatable shaft 332, each length restoration element 397 expands, so as to cause the proximal portions 374 to become biased. When the driving mechanism 330 is operated in the restorative direction, the length restoration element 397 retracts, thereby unwinding the proximal portion 374 from the rotatable shaft 332.

Fig. 9 shows another example of a biasing mechanism 799, which can be incorporated in a hip belts assembly 720 according to the presently disclosed subject matter. In Fig. 9 only a part of the hip belts assembly 720 is shown with corresponding part of a hip belt unit 740, and manipulable hip belt member 750 configured similarly to the manipulable hip belt member 350 shown in Fig. 5 and disposed within a passage 794, wherein a main difference therebetween is in the construction of the biasing mechanism 799.

The hip belts assembly 720 is shown in Fig. 9 such that the inside of the passage 794 is visible. The manipulable hip belt member 750 within the passage 794 can thus be seen, though it is actually concealed inside the load bearing member 760.

As can be seen in Fig. 9, a proximal portion 774 of the manipulable hip belt member 750 is in the form of a relatively narrow belt segment having a first width Wl, and a distal portion 778 of the manipulable hip belt member 750 is in the form of a relatively wide belt segment, having a second width W2, and connected to the narrow belt segment within the passage 794.

The operation of the biasing mechanism 799 is similar to that described previously with respect to the biasing mechanism 399, however, the configuration of the biasing mechanism 799 is somewhat different from that of the biasing mechanism 399. Like the biasing mechanism 399, the biasing mechanism 799 comprises a length restoration element 797 having a first end 792 fixed to a wall 793 of the passage 794, and a second end 795 fixed to the internal section of the proximal portion 774 disposed in the passage 794. However, the restoration element 797 is a significantly more substantial element than the restoration element 397, having a width W3 which is nearly as wide as the width W2 of the distal portion 778 of the manipulable hip belt member 750, and a length which is more than twice the length of the vertical height HP of the passage 794. This is different from the restoration element 397 whose width is less than the width Wl of the proximal portion 374, and whose length is shorter than a vertical height of the passage 394. Furthermore, while the first end 392 of the length restoration element 397 is fixed to the wall 393 of the passage 394 at a point along its horizontally oriented length, such that the length restoration element 397 itself is oriented at an angle to the centerline of the manipulable hip belt member 350, the first end 792 of the length restoration element 797 is fixed to the wall 793 of the passage 794 at its vertically oriented opening where the distal portion 778 exits the passage 794, such that the length restoration element 797 itself is oriented coaxially with the manipulable hip belt member 750.

In the exemplary hip belts assemblies 420 and 520 shown in Figs. 6 and 7 respectively, the load bearing members 460 and 560 thereof respectively, are attached to the manipulable hip belt members 450 and 550 respectively, such that each manipulable hip belt member comprises the load bearing member on its respective side of the vertical axis Y. When operation of the driving member causes the manipulable hip belt members to move, the load bearing members move along with the manipulable hip belt members.

The exemplary hip belts assembly 420 shown in Fig. 6 is similar to the exemplary hip belts assemblies 120 and 320 shown in Figs. 3 and 5 respectively, in that the proximal and distal portions 474 and 478 of each of its manipulable hip belt members 450 are in the form of a relatively narrow belt segment having a first width Wl, and a relatively wide belt segment having a second width W2, respectively.

In addition, similarly to the exemplary hip belts assembly 320 shown in Fig. 5, the windable proximal portion 474 of each manipulable hip belt member 450 of the exemplary hip belts assembly 420 shown in Fig. 6 is connected to the distal portion 478 of the manipulable hip belt member 450, though in this example this is achieved by virtue of the load bearing members 460. It will be appreciated that while a continuous connection is shown between the windable proximal portion 474 at its end opposite the proximal end 452 of the manipulable hip belt member 450, and the distal portion 478 at its end opposite the distal end 456 of the manipulable hip belt member 450, such continuous connection might not be needed.

Rather, the windable proximal portion 474 at its end opposite the proximal end 452 of the manipulable hip belt member 450 could be connected to a proximal end of the load bearing member 460, for example, at or near the point 462 shown in Fig. 6. Similarly, the distal portion 478 at its end opposite the distal end 456 of the manipulable hip belt member 450 could be connected to a distal end of the load bearing member 460, for example, at or near the point 468 shown in Fig. 6. These connections at or near the points 462 and 468 would provide the continuity required for the manipulable hip belt member 450 to operate as a continuous belt, by virtue of the load bearing member 460, without need for a direct connection between the windable proximal portion 474 and the distal portion 478 as described above.

The restoration of the operational extensions E of the manipulable hip belt members 450 in the case of this example, can be the same as explained above with respect to the backpacks 10 and 110 shown in Figs. 1 and 3, respectively.

The hip belts assembly 520 shown in Fig. 7 differs from the hip belts assemblies previously described with reference to Figs. 3, 4, 5 and 6, in the structure of its driving mechanism 530, whose shaft 532 is rotatable about a horizontal axis X, rather than about the vertical axis Y as in the previously described examples. It is noted, however, that the vertical axis Y of the driving mechanism 530 still represents the vertical central axis with respect to the configuration and operation of the hip belts assembly 520 of the backpack 510 (not shown), as for the previous examples. Thus, each of the two hip belt units 540 are disposed on one of two sides of the vertical axis Y, and during operation, the movement of the manipulable hip belt members 550 is alternately towards and away from the vertical axis Y.

A further difference between the hip belts assembly 520 and the hip belts assemblies of Figs. 3 to 6, is that the proximal portion 574 of each of its manipulable hip belt members 550 is in the form of a plate 551 incorporated in the load bearing member 560, the plate 551 being connected to the rotatable shaft 532 by means of a threaded rod 553, which is received within and is configured to engage an internal thread formed within the plate 551. Thus, rotation of the rotatable shaft 532 in one direction causes the threaded rods 553 to pull the plates 551 with the load bearing members 560 towards the vertical axis Y, and its rotation in the other direction causes the threaded rods 553 to push the plates 551 with the load bearing members 560 away from the vertical axis Y, so as to respectively reduce or increase an operational extension E of the manipulable hip belt member 550 between its distal end 556 and the driving mechanism 530.

In Fig. 7A, which shows a side view of the driving mechanism 530 of Fig. 7, from within the backpack, it can be seen that the driving mechanism 530 comprises a single rotatable shaft 532, to which the proximal ends 552 of the manipulable hip belt members 550 are connected via the threaded rods 553, as shown in Fig. 7. The rotatable shaft 532 can be seen to be disposed adjacent to the back wall 512 of the backpack 510, partly within the back wall interior 518, and partly outside of the backpack 510 adjacent to the outer surface 513 of the back wall 512.

It can further be seen in Fig. 7A that the rotatable shaft 532 is connected via a belt 591, to a primary rotating shaft 593, which is rotatably mounted to a mounting 595 connected to the bottom 514. The belt 591 can be seen to pass from the backpack interior 516 through the back wall interior 518 to the outer surface 513 of the back wall 512 of the backpack 510. In operation, the primary rotating shaft 593 is caused to rotate, and the rotatable shaft 532 is driven by the belt 591 such that it rotates as well.

Fig. 8, reference to which is now made, shows an exemplary backpack 610, which has load bearing members 660 fixed to the backpack body 615 similarly to those of the hip belts assemblies 220 and 320 shown in Figs. 4 and 5. In the backpack 610, the fixation of the load bearing members to the back wall 612 of the backpack 610 is achieved by forming the load bearing members 660 as parts of a unitary load bearing member body 655 having a central portion 657, at which the body 655 is fixed to the back wall 612 of the backpack 610, and two wing portions 659 extending therefrom and constituting the load bearing members 660. In this exemplary backpack, the driving mechanism can be mounted on the load bearing member body 655, as shown in Fig. 8, where the driving mechanism 630 enclosed in a boxlike housing as in Fig. 1, is shown to be mounted on the central portion 657 of the unitary load bearing member body 655.

It will be appreciated that the driving mechanism in any of the above examples of the backpack 10 can comprise an electric motor, which for example, could be a DC motor having a voltage in the range of 6-12V, a current in the range of 1.2-2.0A, a 3-4 level planetary gear with a gear ratio of 185:1 to 500:1, 30-45 RPM, a stall torque of 13- 16 kg cm, and a shaft diameter of 4-6mm. It will further be appreciated that the source of power for the driving mechanism 30 can be any suitable power source, for example, a battery contained in the backpack 10, solar power panels located on the body 15 of the backpack 10, or manual power.

Figs. 10A, 10B and 11 show two examples of the extension-control mechanism generally described hereinabove, configured to stop the operation of the driving mechanism when the operational extension E of the manipulable hip belt members reaches a pre-determined minimal operational extension Emin or maximal operational extension Emax.

Both of the exemplary extension-control mechanisms shown in Figs. 10A, 10B and 11 provide an electro-mechanical solution for stopping the operation of their respective driving mechanisms when a particular mechanical event occurs. The occurrence of the mechanical event causes a signal to be sent to the controller of the driving mechanism, which stops the operation of the driving mechanism.

To this end, the extension-control mechanism comprises a mechanical element configured to move through a range of positions between a first extreme position XI and a second extreme position X2, wherein the first extreme position XI corresponds to Emin defined above, and the second extreme position X2 corresponds to Emax defined above, and wherein the arrival of the mechanical element in each of the positions XI and X2 causes the driving mechanism to stop.

The exemplary extension-control mechanism 881 shown in Figs. 10A and 10B, and the exemplary extension-control mechanism 981 shown in Fig. 11, are shown to be operational with a driving mechanism 830 and 930, respectively, having a respective rotatable shaft 832 and 932 which can be in the form of any of the rotatable shafts 132, 232, 332, 432 and 732 shown in Figs. 3, 4, 5, 6 and 9 respectively.

The driving mechanism 830 of Figs. 10A and 10B comprises a shaft housing 831, from which the rotatable shaft 832 extends, and a motor housing 837 in which the motor, which is configured to rotate the shaft 832, is disposed. Similarly, the driving mechanism 930 of Fig. 11 comprises a shaft housing 931, from which the rotatable shaft 932 extends, and a motor housing 937 in which the motor, which is configured to rotate the shaft 932, is disposed.

In the example shown in Figs. 10A and 10B, the exemplary extension-control mechanism 881 further comprises a pinion gear 841, a movable rack gear 843, and a stationary position indication switch 844. The movable rack gear 843 has two protrusions PX1 and PX2 protruding from an upper portion of the face of the rack gear 843 which faces the stationary position indication switch 844, which are configured to operate the switch 844 as explained in further detail below. As protrusions PX1 and PX2 are located on the rear face of the rack gear 843 with respect to the view shown in Figs. 10A and 10B, protrusion PX1 is not seen (although its location is indicated in Fig. 10A), and the protrusion PX2 is only partially seen, as shown in Figs. 10A and 10B. The position indication switch 844 can be seen in Fig. 10C, which shows an enlarged view of an area II in Fig. 10A with the rack gear 843 removed so as not to obscure the position indication switch 844 from being viewed.

It can further be seen in Figs. 10A and 10B that the driving mechanism 830 and the extension-control mechanism 881 are disposed in a housing 822 having a triangular shape, with the pinion gear 841 driving the rack gear 843 in linear motion along the base 822B of the triangular housing 822, where the height of the triangular housing 822 is taken to be oriented along the vertical axis Y passing through the driving mechanism 830. The rack gear 843 is configured to move alternately in the directions Dl and D2 along the base 822B of the triangular housing 822, in accordance with the direction of rotation of the shaft 832, thus moving between the first extreme position XI and the second extreme position X2 along the base 822B, in which the protrusions PX1 and PX2 respectively are disposed in the location of the position indication switch 844.

In the example shown in Figs. 10A and 10B, with respect to the view shown in the figures, when the shaft 832 rotates in the counterclockwise direction Cl, the rack gear 843 moves in the direction Dl, as shown in Fig. 10A, and when the shaft 832 rotates in the clockwise direction C2, the rack gear 843 moves in the direction D2, opposite to the direction Dl, as shown in Fig. 10B.

As seen in Fig. 10A, the rack gear 843 is in the first extreme position XI when the protrusion PX1 comes into contact with the position indication switch 844 so as to operate it, the operation of the switch 844 sending a signal to the controller of the driving mechanism 830, for example via a circuit board, causing the stoppage of the motor of the driving mechanism 830.

In Fig. 10B, the rack gear 843 is in the second extreme position X2 when the protrusion PX2 comes into contact with the position indication switch 844 so as to operate it, in a manner similar to that described above for the first extreme position XI. Like the exemplary extension-control mechanism 881 shown in Figs. 10A and 10B, the exemplary extension-control mechanism 981 shown in Fig. 11 also comprises a mechanical element configured to move through a range of positions between a first extreme position XI and a second extreme position X2, wherein the first extreme position XI corresponds to Emin as defined above, and the second extreme position X2 corresponds to Emax as defined above, and wherein the arrival of the mechanical element in each of the positions XI and X2 causes the driving mechanism to stop.

However, the exemplary extension-control mechanism 981 accomplishes this in a manner different from the exemplary extension-control mechanism 881 of Figs. 10A and 10B. As can be seen in Fig. 11, the exemplary extension-control mechanism 981 comprises, in addition to the shaft housing 931 and the motor housing 937, a base plate 971, a driving disk 979 and a stop pin 975. The base plate 971 has an opening 972 configured for the rotatable shaft 932 to pass through it, such that while the shaft housing 931 and the motor housing 937 are disposed on a first side S 1 of the base plate 971, an end portion 32E of the rotatable shaft 932 is disposed on a second side S2 of the base plate 971 opposite the first side Sl.

The base plate 971 is further configured to have a spiral groove 973 on its second side S2. The driving disk 979 has an opening 983 configured for the rotatable shaft 932 to pass through it and for the driving disk 979 to be rotated along with the rotatable shaft 932. In the example shown in Fig. 11, the end portion 32E of the rotatable shaft 932 and the opening 983 have corresponding shapes of a circle sheared off along a chord of the circle such that rotation of the rotatable shaft 932 causes the driving disk 979 to rotate as well.

The stop pin 975 is configured to be slidably sandwiched between the second side S2 of the base plate 971 and the driving disk 979 such that when the driving disk 979 rotates as a result of the rotation of the rotatable shaft 932, the stop pin is moved along the spiral groove 973 between the first extreme position XI at the center of the spiral groove 973, position SX1, in which the stop pin 975 is disposed in Fig. 11, and the second extreme position X2 at the outer edge of the spiral groove 973, position SX2. When the stop pin 975 reaches either position SX1 or SX2 at the ends of the spiral groove 973, the motor enters a stall mode due to the resistance presented by the stop pin 975 which causes the motor to work harder. The large force then exerted by the motor causes a spike in the current which functions as a signal to stop the motor. The signal can be transmitted, for example, via a circuit board associated with the extension- control mechanism to the controller of the driving mechanism 930.

It will be appreciated that when the motor is operated to rotate the rotatable shaft 932 in a first direction causing the stop pin 975 to move to one of the extreme positions SX1 or SX2, and then the motor is operated to rotate the rotatable shaft 932 in the opposite direction, the stop pin 975 moves from the extreme position at which it is disposed at one end of the spiral groove 973 to the opposite extreme position at the opposite end of the spiral groove 973.

Needless to say, the backpacks and their components described above and shown in the drawings are non-limited examples of the presently disclosed subject matter, and they can have features different from those described above.