WO2016131085A1

WO2016131085A1 - Locking assembly

Info

Publication number: WO2016131085A1
Application number: PCT/AU2016/000050
Authority: WO
Inventors: Alirio E GUERRA
Original assignee: Rollease Acmeda Pty Ltd
Priority date: 2015-02-20
Filing date: 2016-02-18
Publication date: 2016-08-25

Abstract

A cam member for a blind system, the cam member being moveable relative to a pin in an extension direction and a retraction direction, the cam member including a cam pathway transverse to the extension direction and the retraction direction, the cam pathway including cam surfaces to translate relative movement between the cam member and the pin in the extension direction or the retraction direction into transverse relative movement; the cam pathway including at least a locked position for the pin at which relative movement between the cam member and the pin is prevented in the retraction direction an entry pathway for the pin to enter the locked position from one side of the cam pathway; and an exit pathway for the pin to exit the locked position to the other side of the cam pathway.

Description

LOCKING ASSEMBLY FIELD

[0001 ] The present invention relates generally to a lock assembly for a blind system. It will be described with particular reference to tensioning the fabric of a roller blind, but the invention is not limited to that application.

BACKGROUND

[0002] In this specification where a document, act or item of knowledge is referred to or discussed, this reference is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of the common general knowledge; or known to be relevant to an attempt to solve any problem with which this specification is concerned.

[0003] The functional and decorative use of blinds dates back over two thousand years to times when glass windows were not available for architectural applications. In modern times, the use of blinds has become commonplace, as both external and internal coverings, and in both residential and commercial settings.

[0004] A blind system typically includes a sheet of fabric (referred to herein as a blind or screen) which is mounted to the top or side of a window or other opening. The blind can be extended to cover the opening, or retracted to the top or side to reveal the opening when desired.

[0005] In many circumstances (particularly in external blind systems), it is desirable to maintain tension in the screen. Accordingly, both wire guided and track guided systems are commercially available. [0006] In these guided systems, the end of a blind is typically (although not necessarily) provided with a draw bar (also called a weight bar). The ends of the draw bar are (in a wire guided system) connected to wires running along opposed sides of the opening, or (for a track guided system) engaged in tracks running along opposed sides of the opening. This enables tension to be maintained across the width of the screen.

[0007] It is also desirable for a user to be able to secure the draw bar to keep the screen in position - particularly in the case of a spring biased system, which may automatically retract if the draw bar is not secured. Accordingly, a locking mechanism may be provided at the bottom of the guide track. However, the design of such a locking mechanism faces a number of challenges.

[0008] One challenge is to make operation of the system simple for the user, and in particular to simplify the process of engaging the locking mechanism. It is generally desirable to minimise the actions required in order to engage the locking mechanism.

[0009] Some current blind systems simplify operation by having the locking mechanism automatically engage when the draw bar reaches the locking position. However, in these systems, if the draw bar is drawn past the desired locking position (i.e. over-runs or over- travels), generally this means that the entire locking cycle needs to be repeated (accurately) for the locking mechanism to engage.

[0010] Furthermore, in some of these systems, disengagement of the lock is not as simple as the initial engagement process.

[001 1] It is therefore desired to reduce or ameliorate one or more of the above issues, or at least provide a useful alternative to existing locking mechanisms. SUMMARY

[0012] According to one aspect of the present invention, there is provided a lock assembly for a blind system, comprising: a pin; a cam assembly including a cam member to engage the pin, the pin and the cam assembly being moveable relative to each other in an extension direction and a retraction direction; the cam member including a cam pathway transverse to the extension direction and the retraction direction, the cam pathway including cam surfaces to translate relative movement between the cam member and the pin in the extension direction or the retraction direction into transverse relative movement; the cam pathway including at least: a locked position for the pin at which relative movement between the cam member and the pin is prevented in the retraction direction; an entry pathway for the pin to enter the locked position from one side of the cam pathway; and an exit pathway for the pin to exit the locked position to the other side of the cam pathway.

[0013] One of the pin and cam assembly may be fixed to a blind (and in particular to a draw bar of a blind), and the other mounted to a support. Accordingly, the extension or retraction of the blind will result in relative movement between the pin and the cam assembly. The blind may be biased (e.g. by a spring) to move in the retraction direction. Accordingly, when the pin is in the locked position to prevent blind retraction, this will maintain tension in the blind. [0014] The cam member may have a variety of shapes, including being (substantially) planar or cylindrical. In the case of a cylindrical cam member, the cam pathway may extend around an outer or inner surface of the cam member, and relative transverse movement between the cam member and the pin may be achieved by rotation of the cam member.

[0015] The cam pathway may further include an entry position at which the pin enters the entry pathway and begins to engage the cam member, in response to relative movement between the cam assembly and the pin in the extension direction.

[0016] The cam pathway may further include an exit position at which the pin exits the exit pathway and disengages from the cam member, in response to relative movement between the cam assembly and the pin in the retraction direction. In some embodiments (e.g. where the cam member is rotatable), the entry and exit positions may be the same position - that is, the cam pathway may extend a full rotation around the cam member, between a single entry/exit position.

[0017] The entry pathway may comprise: a first entry cam surface which translates relative movement between the pin and cam member in the extension direction into transverse relative movement, to move the pin toward the locking position, followed by a second entry cam surface which translates relative movement between the pin and cam member in the retraction direction into transverse relative movement, to move the pin into the locking position.

[0018] The exit pathway may comprise: a first exit cam surface which translates relative movement between the pin and cam member in the extension direction into transverse relative movement, to move the pin out of the locking position, followed by a second exit cam surface which translates relative movement between the pin and cam member in the retraction direction into transverse relative movement, to move the pin away from the locking position.

[0019] The entry pathway may include an intermediate seat between the first entry cam surface and the second entry cam surface. Similarly, the exit pathway may include an intermediate seat between the first exit cam surface and the second exit cam surface.

[0020] Alternatively, the exit pathway may include an intermediate exit position, and/or the entry pathway may include an intermediate exit position. In either case, the pin may exit the entry pathway or exit pathway and disengage the cam member at the intermediate exit position, in response to relative movement between the cam assembly and the pin in the extension direction. The pin may re-enter the respective entry or exit pathway through the intermediate exit position, in response to relative movement between the cam assembly and the pin in the retraction direction.

[0021 ] The cam pathway may further include one or more other locked positions, and relative movement of the pin relative to the cam assembly may move the pin between these locked positions. In these embodiments, the multiple locked positions may be used to identify different functions or configurations of the blind system.

[0022] In a second aspect of the present invention there is provided a cam assembly for a blind system including a cam member to engage a pin, the pin and the cam assembly being moveable relative to each other in an extension direction and a retraction direction, the cam member including a cam pathway transverse to the extension direction and the retraction direction, the cam pathway including cam surfaces to translate relative movement between the cam member and the pin in the extension direction or the retraction direction into transverse relative movement; the cam pathway including at least: a locked position for the pin at which relative movement between the cam member and the pin is prevented in the retraction direction; an entry pathway for the pin to enter the locked position from one side of the cam pathway; and an exit pathway for the pin to exit the locked position to the other side of the cam pathway.

[0023] In a third aspect of the present invention, there is provided a blind system for covering an opening comprising: a blind; a draw bar mounted on an end of the blind; at least one track mounted on a side of the opening, an end of the draw bar slidingly located in the track; a pin assembly comprising a pin; a cam assembly, including a cam member to engage the pin, one of the pin assembly and the cam assembly being mounted to the draw bar and the other being mounted relative to the track, such that the pin assembly and the cam assembly are moveable relative to each other in an extension direction when the blind is extended and a retraction direction when the blind is retracted; the cam member including a cam pathway transverse to the extension direction and the retraction direction, the cam pathway including cam surfaces to translate relative movement between the cam member and the pin in the extension direction or the retraction direction into transverse relative movement; the cam pathway including at least: a locked position for the pin at which relative movement between the cam member and the pin is prevented in the retraction direction; an entry pathway for the pin to enter the locked position from one side of the cam pathway; and an exit pathway for the pin to exit the locked position to the other side of the cam pathway.

[0024] In a fourth aspect of the present invention, there is provided a cam member for a blind system, the cam member being moveable relative to a pin in an extension direction and a retraction direction, the cam member including a cam pathway transverse to the extension direction and the retraction direction, the cam pathway including cam surfaces to translate relative movement between the cam member and the pin in the extension direction or the retraction direction into transverse relative movement; the cam pathway including at least: a locked position for the pin at which relative movement between the cam member and the pin is prevented in the retraction direction; an entry pathway for the pin to enter the locked position from one side of the cam pathway; and an exit pathway for the pin to exit the locked position to the other side of the cam pathway.

[0025] A detailed description of one or more embodiments of the invention is provided below, along with accompanying figures that illustrate by way of example the principles of the invention. While the invention is described in connection with such embodiments, it should be understood that the invention is not limited to any embodiment. On the contrary, the scope of the invention is limited only by the appended claims and the invention encompasses numerous alternatives, modifications and equivalents.

[0026] For the purpose of example, numerous specific details are set forth in the following description in order to provide a thorough understanding of the present invention. The present invention may be practiced according to the claims without some or all of these specific details. For the purposes of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the present invention is not unnecessarily obscured.

[0027] For the purposes of providing a clear description of the present invention, terms such as "up", "down", "left" and "right" are used in the below descriptions. This terminology will be understood to be for illustrative purposes only, and does not limit the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various embodiments/aspects of the invention will now be described with reference to the following drawings in which,

[0029] Figure 1 is a perspective view of a lock assembly according to an embodiment of the present invention.

[0030] Figure 2 is a top view of the lock assembly of Figure 1. [0031 ] Figure 3 is a front view of the lock assembly of Figure 1. [0032] Figure 4 is section A- A of the lock assembly of Figure 3. [0033] Figure 5 is a perspective view of a pin assembly according to an embodiment of the present invention.

[0034] Figure 6 is a top view of the pin assembly of Figure 5.

[0035] Figure 7 is a perspective view of a cam assembly according to an embodiment of the present invention.

[0036] Figure 8 is a top view of the cam assembly of Figure 7.

[0037] Figure 9 depicts a cam pathway for a cam member according to an embodiment of the present invention.

[0038] Figure 10 depicts an alternative cam pathway for a cam member according to another embodiment of the present invention.

[0039] Figure 1 1 depicts an alternative cam pathway for a cam member according to another embodiment of the present invention.

[0040] Figure 12 depicts an alternative cam pathway for a cam member according to another embodiment of the present invention.

[0041 ] Figure 13 depicts a series of views of a rotatable cam member according to an embodiment of the present invention, as the cam member is rotated.

[0042] Figure 14 depicts a series of views of an alternative rotatable cam member according to another embodiment of the present invention, as the cam member is rotated. [0043] Figure 15 is a front view of an alternative rotatable cam member according to another embodiment of the present invention.

[0044] Figure 16 shows a pin member according to an embodiment of the present invention.

[0045] Figures 17 and 18 sequentially depict the operation of the pin member of Figure 16 and the cam member of Figure 13.

[0046] Figures 19 to 21 sequentially depict the operation of a pin member according to an alternative embodiment of the present invention and the cam member of Figure 15.

[0047] Figure 22 depicts a blind system according to an embodiment of the present invention.

[0048] Figure 23 is an exploded view of a cam assembly according to a further embodiment of the present invention.

[0049] Figure 24 is an exploded view of the pin assembly of a further embodiment of the present invention.

DETAILED DESCRIPTION

[0050] Figures 1 to 4 depict a lock assembly 100 for a blind system 400 (shown in Figure 22) according to an embodiment of the present invention. The lock assembly 100 comprises a pin assembly 200 and a cam assembly 300.

[0051] For convenience, the lock assembly 100 will be described with reference to the configuration shown the blind system 400 of Figure 22. A draw bar 500 is located at the end of the blind 600. The ends of the draw bar 500 run in tracks 700 mounted on either side of the window opening. The blind 600 may be configured to automatically retract (e.g. under the force of a spring) unless it is locked in a particular position (e.g. at the bottom of the window opening) by a lock assembly 100 of the present invention.

[0052] A pin assembly 200 is mounted on each end of the draw bar 500, and a cam assembly 300 is mounted at the bottom of the track 700 on either side of the window opening. This configuration means that, as the blind 600 is extended or retracted, each pin assembly 200 moves relative to the respective cam assembly 300, which remains stationary. Locking of the blind 600 in the closed position is achieved by engaging the pin assembly 200 with the respective cam assembly 300 in a locking position, thereby securing the draw bar 500 in position. However, other configurations are also possible - for example, only one lock assembly 100 may be provided, on one side of the window opening. Another alternative configuration may comprise a pair of cam assemblies 300 mounted to the draw bar 500, and a pair of pin assemblies mounted to the track 700.

[0053] These variations do not alter the general concept of the lock assembly 100 of the present invention, which operates merely on relative movement between the cam assembly 300 and the pin assembly 200.

[0054] The pin assembly 200, shown in Figures 5 and 6, includes a housing member 210 and a pin 220 which protrudes from the housing member 210. As described above, the pin assembly 200 may be mounted to a draw bar 500, such that as the draw bar 500 is extended or retracted, the pin assembly moves in an extension direction or a retraction direction.

[0055] The cam assembly 300, shown in Figures 7 and 8, comprises a body member 310 (shown as transparent in Figure 1 to 8), a shaft 320, and a cam member 330. In this embodiment, the cam member 330 is a rotatable cam member 330. The cam member 330 is rotatably mounted on the shaft 320, which is fixed in position in the body member 310. The shaft 320 defines the axis of rotation of the cam member 330. [0056] The cam member 330 includes a cam pathway 340 that runs transverse to the direction of extension and retraction of the blind. When the draw bar 500 is drawn down such that the lock assembly 100 is engaged, the pin 220 is received into cam pathway 340. As the draw bar 500 is drawn down, a cam surface in the cam pathway 340 translates this relative axial movement into relative transverse movement, such that the cam member 330 rotates and the pin 220 therefore moves within the cam pathway 340 (i.e. the cam pathway 340 moves relative to the pin 220 as the cam member 330 rotates, such that the pin 200 traverses the cam pathway 340).

[0057] The cam pathway 340 will now be described in more detail with reference to Figures 9 to 12, which show four variations of a cam pathway 340 for a lock assembly 100 according to the present invention (although other variations may be possible). Figure 9 depicts a "single lock" cam pathway 340, Figure 10 depicts a "thru to lock" cam pathway, Figure 1 1 depicts a "thru to unlock" cam pathway, and Figure 12 depicts an indexing cam pathway 340 for use with an auto-retracting/extending pin application.

[0058] The cam pathways 340 shown in Figures 9 to 12 are shown on a planar cam member, but conceptually they are equally applicable to a rotatable cam member 330. Although the present invention has broader application, for simplicity the variations shown in Figures 9 to 12 will be described in the context of: a. a cam assembly 300 that is stationary (along the vertical for a vertical blind 600) but is free to translate along the horizontal (for a planar cam member 330) or rotate around its axis (for a cylindrical cam member 330). b. a pin assembly 200 that moves downwards or upwards relative to the cam assembly 300; the pin 220 itself is depicted as a solid circle in Figures 9 to 12. c. a start location and end location of the pin 220 along the cam pathway 340. "Single Lock" Cam

[0059] Figure 9 depicts a "single lock" cam pathway 340. The cam pathway 340 includes an entry position 350 (at which the pin 220 first begins to engage the cam member 330), a locked position 360 and an exit position 370 (at which the pin 220 begins to disengage the cam member 330). An entry pathway 380 enables the pin 220 to move from the entry position 350 to the locked position, and an exit pathway 390 enables the pin 220 to move from the locked position 360 to the exit position 370.

[0060] The entry pathway 380 includes a first entry cam surface 382, which is the angled lower surface on the left hand side of entry pathway 380 as shown in Figure 9. As the pin 220 is moved downward (i.e. in the extension direction), it will slide along this first entry cam surface 382, until it reaches an intermediate seat 384. At the intermediate seat 384, downward travel of the pin 220 is stopped. If the pin 220 is then allowed to move upward (in a retraction direction - e..g by a spring), the pin 220 will engage a second entry cam surface 386, which is the angled upper surface on the right hand side of entry pathway 380 as shown in Figure 9. Further retraction of the pin 220 will result in the pin 220 moving into locking position 360. The intermediate seat 384 is therefore placed at a transition point between the first entry cam surface 382 and the second entry cam surface 386. It should be noted that these cam surfaces 382, 386 overlap in the transverse dimension (at the point of the intermediate seat 384), so as to facilitate a transition between the first and second entry cam surfaces 382, 386 upon the transition from downward movement of the pin 220 (extension) to upward movement of the pin 220

(retraction).

[0061] At the locked position 360, the pin 220 is fully engaged with the cam member 330 such that further retraction of the pin 220 (and therefore blind 600) is prevented. Assuming there is some retracting force still being applied (e.g. from a spring), the lock assembly 100 will therefore hold the blind 600 in a state of tension. [0062] To release the pin 220 from the locked position 360, it is pushed downward again so as to move into the exit pathway 390. The exit pathway 390 includes a first exit cam surface 392, which is the angled lower surface on the left hand side of exit pathway 390 as shown in Figure 9. As the pin 220 is moved downward (i.e. in the extension direction), it will slide along this first exit cam surface 392, until it reaches an intermediate seat 394. At the intermediate seat 394, downward travel of the pin 220 is stopped. If the pin 220 is then allowed to move upward (in a retraction direction - e..g by a spring), the pin 220 will engage a second exit cam surface 396, which is the angled upper surface on the right hand side of exit pathway 390 as shown in Figure 9. Further retraction of the pin 220 will result in the pin 220 moving out of the exit position 370 and disengaging from the cam member 330. The intermediate seat 394 is therefore placed at a transition point between the first exit cam surface 392 and the second exit cam surface 396. It should be noted that these cam surfaces 392, 396 overlap in the transverse dimension (at the point of the intermediate seat 394), so as to facilitate a transition between the first and second exit cam surfaces 392, 396 upon the transition from downward movement of the pin 220 (extension) to upward movement of the pin 220 (retraction).

[0063] In the planar embodiment shown in Figure 9, a return function may be used to shift the cam member back to its original position, after the pin 220 has been disengaged. This make take the form of a spring return activated when the pin 220 leaves via the exit position 370. Alternatively, a further cam pathway may be provided above the cam pathway 340 shown in Figure 9, joining the entry and exit positions 350, 370.

[0064] Although a planar embodiment is shown in Figure 9 for simplicity, the cam member 330 may be cylindrical as shown in Figure 13, while still maintaining the same effective cam pathway. In this embodiment, the entry and exit positions are the same position - entry/exit position 350A. The pin 220 enters the cam pathway 340 through the entry/exit position 350A (and angled cam surfaces are provided above the entry/exit position 350A, to align the pin 220 with the entry/exit position 350A, as the pin 220 is lowered relative to the cam member 330). The pin 220 traverses a full rotation of the cam member 330 as it travels through the locked position 360 and back to the entry/exit position 350A, so as to disengage the pin 220 from the cam member 330.

[0065] In Figures 17 and 18, the movement of a simplified pin member 200 is shown. Figure 17 shows the pin 220 traveling from the entry/exit position 350A into the locked position 360. Figure 18 shows the pin 220 travelling from the locked position through the exit pathway 390 and back to the entry/exit position 350A.

"Thru to Lock" Cam

[0066] Figure 10 shows an alternate cam pathway 340 in an alternate embodiment of the present invention. In this embodiment, the cam pathway is the same as shown in Figure 9, except that there is an intermediate exit/entry position 384A at the transition point between the first entry cam surface and the second entry cam surface. The Thru to Lock Type may be the most common variant of the present invention.

[0067] At the transition point between the first and second cam entry surfaces 382, 386, an intermediate exit/entry position 384A is provided. This allows the pin member 200 to either continue to move downward (i.e. in the extensions direction) and disengage from the cam member 330, or to move upwards (i.e. in the retraction direction) and transition into the locked position 360. The advantage of this configuration is that a number of cam assemblies 300 can be arranged at different heights (for a vertical blind 600), so that a pin 220 mounted to the draw bar 500 can be secured by a cam assembly 300 at a desired height, or can pass through to another cam assembly 300 at a different height.

[0068] Although a planar embodiment is shown in Figure 10 for simplicity, the cam member 330 may be cylindrical as shown in Figure 14, while still maintaining the same effective cam pathway. [0069] Of course, although Figures 13 and 14 show cylindrical cam members with external cam pathways, it is also possible to have an internal cam pathway. Figure 15 depicts a cylindrical cam member 330 of the "thru to lock" configuration, having an internal cam pathway 340.

[0070] By way of example, Figures 19 and 20 show a simplified pin member 200 which may be kept stationary as a blind 600 is retracted or extended. A cam member 330 with an internal cam pathway 340 may be attached to the ends of a draw bar 500.

[0071] Figure 20 shows the pin 220 traveling from the entry/exit position 350A into the locked position 360, as the cam is lowered (i.e. moved in the extension direction). Figure 21 shows the pin 220 travelling from the locked position through the exit pathway 390 and back to the entry/exit position 350A , so as to disengage the pin 220 from the cam member 330.

[0072] Finally, it will be seen that Figure 10 depicts, in dashed lines, that a deeper intermediate seat 394B may be provided. This seat 394B allows additional axial movement (over-travel) of the pin 220 to ensure that it has moved far enough along the exit pathway 390 to overlap the second exit cam surface 396.

"Thru to Unlock" Cam

[0073] Figure 1 1 shows an alternate cam pathway 340 in an alternate embodiment of the present invention. This embodiment is similar to the embodiment of Figure 10, except that an intermediate exit/entry position 394A is provided in the exit pathway 390 rather than in the entry pathway 380. This results in slightly different functionality.

[0074] In a vertical blind system having a plurality of "thru to lock" cam assemblies 300 at different heights, the blind 600 can be drawn straight down to the desired height as the blind 600 is extended. However, when the blind is retracted, it will first enter the locking position 360 of each cam assembly 300.

[0075] In contrast, in a vertical blind system having a plurality of "thru to unlock" assemblies at different heights, the blind 600 will lock at each lock assembly 100 as the blind is extended. However, when the blind is retracted, it will pass straight through each lock assembly 100 without passing through the respective locking position 360.

"Indexing" Cam

[0076] Figure 12 shows an alternate cam pathway 340 in an alternate embodiment of the present invention. The cam pathway of Figure 12 effectively provides a plurality of locking positions -three locking positions are shown , comprising a central locking position 360 and other locking positions 360A, 360B. These may be arranged at differing heights (see position 360C marked in Figure 10).

[0077] A cam member 330 having this type of cam pathway may be used when the lock assembly is used as part of an auto-retractable pin mechanism. The basic principle is to trap the pin 220 and cam member 330 relative to each other, at different states.

Assembly of Components

[0078] Figures 23 and 24 show a more complex lock assembly 100 according to an embodiment of the present invention. The pin assembly 200 (Figure 24) and cam assembly 300 (Figure 23) of this embodiment enable a number of different configurations to be adopted using the same pin and cam assembly components.

[0079] With respect to Figure 23, it will be seen that the cam assembly 300 of this embodiment comprises a cam body 310, a shaft 310, and two fasteners 312 to mount the cam assembly 300. Cover plates 314 cover the fasteners in use. In this design, the cam member 330 is made up of two-pieces 330A, 330B, which simplifies part manufacture and tool complexity. The cam assembly may be located on the shaft for left-hand operation, or cam member 330 may be reversed (i.e. placed upside-down) for right-hand configuration.

[0080] With respect to Figure 24, the pin assembly 200 of this embodiment comprises a pair of housing members 210, 211 , and a pin holder 216. Fasteners 212 and cover plates 214 are provided similar to those shown in Figure 23. In this embodiment, the pin 220 locates in the pin holder 216, which may be placed in the housing member 210 in one of two orientations - either as shown in Figure 24 for left-hand operation, or upside-down for right-hand operation.

[0081] In this embodiment, a spring reset via spring 218 is also provided, which means that the pin 220 is retractable. This helps to avoid damage to the assembly, in the case of misalignment of the cam assembly 300 and pin assembly 200 - for example, such that a lock on only one side of a draw bar 500 engages. It also allows the possibility that a user can release the draw bar 500 from a locked/engaged state of the lock assembly 100.

[0082] The lock assembly 100 of the present invention provides advantages over existing locking mechanisms. For example, the design allows for the draw bar 500 to over-travel in the locking process, without resulting in unwanted disengagement of the pin assembly 200 from the cam assembly 300. Furthermore, if "thru to lock" or "thru to unlock" assemblies are used, the present invention can be used to allow tensioning of the blind fabric 600 at various heights along the side channels 700.

[0083] The word 'comprising' and forms of the word 'comprising' as used in this description and in the claims does not limit the invention claimed to exclude any variants or additions.

[0084] Modifications and improvements to the invention will be readily apparent to those skilled in the art. Such modifications and improvements are intended to be within the scope of this invention. Furthermore, the invention is not limited to track guided blind systems, and may be used in various other blind systems (including wire guided blind systems).

Claims

1 A cam member for a blind system, the cam member being moveable relative to a pin in an extension direction and a retraction direction, the cam member including a cam pathway transverse to the extension direction and the retraction direction, the cam pathway including cam surfaces to translate relative movement between the cam member and the pin in the extension direction or the retraction direction into transverse relative movement; the cam pathway including at least: a locked position for the pin at which relative movement between the cam member and the pin is prevented in the retraction direction; an entry pathway for the pin to enter the locked position from one side of the cam pathway; and an exit pathway for the pin to exit the locked position to the other side of the cam pathway.

2 A cam member according to claim 1 , wherein the cam member is substantially cylindrical and relative transverse movement between the cam member and the pin is achieved by rotation of the cam member.

3 A cam member according to claim 2, wherein the cam pathway extends around an outer surface of the cam member.

4 A cam member according to any preceding claim, wherein the cam pathway further includes an entry position at which the pin enters the entry pathway and begins to engage the cam member, in response to relative movement between the cam assembly and the pin in the extension direction.

5 A cam member according to claim 4, wherein the cam pathway further includes an exit position at which the pin exits the exit pathway and disengages from the cam member, in response to relative movement between the cam assembly and the pin in the retraction direction.

6 A cam member according to claim 5, wherein the entry position is the same as the exit position.

7 A cam member according to any preceding claim, wherein the entry pathway comprises: a first entry cam surface which translates relative movement between the pin and cam member in the extension direction into transverse relative movement, to move the pin toward the locking position, followed by a second entry cam surface which translates relative movement between the pin and cam member in the retraction direction into transverse relative movement, to move the pin into the locking position.

8 A cam member according to any preceding claim, wherein the entry pathway comprises: a first exit cam surface which translates relative movement between the pin and cam member in the extension direction into transverse relative movement, to move the pin out of the locking position, followed by a second exit cam surface which translates relative movement between the pin and cam member in the retraction direction into transverse relative movement, to move the pin away from the locking position.

9 A cam member according to claim 7, wherein the entry pathway comprises an intermediate seat between the first entry cam surface and the second entry cam surface. 10 A cam member according to claim 8, wherein the exit pathway includes an intermediate seat between the first exit cam surface and the second exit cam surface.

1 1 A cam member according to claim 7, wherein the entry pathway includes an intermediate exit position between the first entry cam surface and the second entry cam surface, at which the pin may exit the entry pathway and disengage the cam member, in response to relative movement between the cam assembly and the pin in the extension direction, and re-enter the entry pathway in response to relative movement between the cam assembly and the pin in the retraction direction.

12 A cam member according to claim 8, wherein the exit pathway includes an intermediate exit position between the first exit cam surface and the second exit cam surface, at which the pin may exit the exit pathway and disengage the cam member, in response to relative movement between the cam assembly and the pin in the extension direction, and re-enter the exit pathway in response to relative movement between the cam assembly and the pin in the retraction direction.

13 A cam assembly for a blind system including a cam member as claimed in any one of claims 1 to 12.

14 A cam assembly for a blind system according to claim 13, when dependent on claim 2, further comprising a shaft for rotation of the cam member.

15 A lock assembly for a blind system, comprising: a pin; a cam assembly including a cam member to engage the pin in accordance with claim 13 or 14.

16 A blind system for covering an opening comprising: a blind; a draw bar mounted on an end of the blind; at least one track mounted on a side of the opening, an end of the draw bar slidingly located in the track; and a pin assembly comprising a pin; and a cam assembly as claimed in claim 13 or 14, wherein one of the pin assembly and cam assembly is mounted to the draw bar, and the other of the pin assembly and cam assembly is mounted relative to the track.

17 A blind system as claimed in claim 16, wherein the blind is biased to move the pin assembly and the cam assembly relative to each other, in the retraction direction.