GB2544284A

GB2544284A - Release mechanism

Info

Publication number: GB2544284A
Application number: GB1519826.0A
Authority: GB
Inventors: Hugh Wickett David
Original assignee: DAVIDHUGH Ltd
Current assignee: DAVIDHUGH Ltd
Priority date: 2015-11-10
Filing date: 2015-11-10
Publication date: 2017-05-17
Also published as: GB201519826D0

Abstract

A release mechanism for controlling the operation of a locking mechanism (24, fig.1) comprises a principal body part (32, fig.7) coupled to the locking mechanism via a mechanical linkage such as a pull-cable 34. The principal body part is movable between a first position in which the locking mechanism is locked (see figure 5), and a second position in which the locking mechanism is unlocked (see figure 6). A mode selector 30 enables a user to select a mode of operation of the release mechanism. A selectively-deployable engagement mechanism (56, fig.4) is actuatable by the mode selector. When the mode selector is in the first mode of operation, the engagement mechanism is not deployed, and when the mode selector in the second mode of operation, the engagement mechanism is deployed. When deployed, the engagement mechanism holds the principal body part in the second position, allowing the locking mechanism to remain unlocked. The release mechanism may be applied to the lock of a seat assembly or reclining chair. It allows a reclining seat to be adjusted and locked in the first mode, or moved freely without locking in the second mode.

Description

RELEASE MECHANISM

Field of the invention

This invention relates to a release mechanism for manual operation by a user, for controlling the operation of a locking mechanism to which, in use, the release mechanism is coupled.

The invention is particularly applicable, but by no means limited, for use with a seating assembly such as a recliner chair, where a locking mechanism prevents (when locked) or allows (when unlocked) a hinged or pivoted part of the seating assembly (e.g. the seat, or seat back) to move relative to a fixed part (e.g. a support structure), the release mechanism being operable by the user to control whether the locking mechanism is locked or unlocked. Other applications are also possible in which, under the control of the release mechanism, a locking mechanism prevents or allows a first component to move relative to a second component.

Background to the Invention

As mentioned above, recliner chairs may be provided with a locking mechanism which prevents (when Socked) or allows (when unlocked) a hinged or pivoted part of the chair (e.g. the seat, or seat back) to move relative to a fixed part (e.g. a base support). The locking mechanism is typically coupied to a user-operabie release mechanism by a pull-cable, although other mechanical linkages, such as one or more connecting rods, may alternatively be used to couple the release mechanism to the locking mechanism. The locking mechanism is positioned in a suitable location, typically beneath (or potentially inside) the seat. The pull-cable (or other linkage(s)) is routed (e.g. through the chair) to the release mechanism, which may, for example, be located on an armrest or on the side of the chair for ease of access and operation by a user.

The present inventor has found that pre-existing release mechanisms for use with a locking mechanism and a pull-cable (or other mechanical linkage(s)) are biased into one operational mode - usually the mode in which they cause the Socking mechanism to be Socked. Such pre-existing release mechanisms are operable to cause the Socking mechanism to unlock when the release mechanism is manipulated by a user, but, as soon as the release mechanism is released by the user, the release mechanism immediately springs back and thereby causes the locking mechanism to lock again.

The present inventor has identified that, under some circumstances, such behaviour of a release mechanism is undesirable, and that an alternative manner of operation is desired whereby, when the release mechanism is manipulated to cause the locking mechanism to unlock, the locking mechanism remains unlocked even when the user subsequently releases the release mechanism - for example to enable free movement of the hinged or pivoted part of a recliner chair relative to a fixed part for as long as the user desires - until the release mechanism is once again manipulated by the user to cause the locking mechanism to lock.

Summary of the Invention

According to a first aspect of the present invention there is provided a release mechanism for controlling the operation of a locking mechanism, the release mechanism comprising: a principal body part configured to be coupled, in use, to a locking mechanism via a mechanical linkage, the principal body part being movable by a user between a first principal position in which the locking mechanism is caused to be locked, and a second principal position in which the locking mechanism is caused to be unlocked; a mode selector for enabling a user to select a mode of operation of the release mechanism from among a plurality of modes of operation which include a first mode of operation and a second mode of operation; and a seiectively-deployable engagement mechanism actuatable by the mode selector; wherein the release mechanism is configured such that when the mode selector is set to the first mode of operation the engagement mechanism is not deployed, and when the mode selector is set to the second mode of operation the engagement mechanism is deployed; and wherein the engagement mechanism, when deployed, is able to hold the principal body part in the second principal position.

Thus, advantageously, a second mode of operation is provided in which the principal body part of the release mechanism can be held in the second principal position, thus causing the locking mechanism to remain unlocked.

The abovementioned locking mechanism and mechanical linkage are pre-existing components with which this aspect of the invention may be used. The locking mechanism and mechanical linkage do not in themselves form part of this aspect of the invention.

In presently-preferred embodiments the principal body part is rotatable, the first and second principal positions being first and second positions of angular rotation.

Further, in presently-preferred embodiments the seiectively-deployable engagement mechanism is coupled to the principal body part such that it moves with the principal body part. For example, the seiectively-deployable engagement mechanism may extend radially from the principal body part.

In presently-preferred embodiments the seiectively-deployable engagement mechanism comprises a detent-engaging member which is movable between first and second positions under the control of the mode selector; wherein, when the mode selector is set to the second mode of operation, the detent-engaging member is caused to be in the second position from which it is able to engage with a detent when the principal body part is moved into the second principal position, and when the mode selector is set to the first mode of operation, the detent-engaging member is caused to be in the first position from which it is unable to engage with said detent during movement of the principal body part.

Further, the seiectively-deployable engagement mechanism may comprise a housing which is attached to the principal body part, the detent-engaging member being movable relative to the housing.

In presently-preferred embodiments the mode selector comprises a rotatable cam arranged to set the position of the detent-engaging member (by virtue of the cam acting, directly or indirectly, on the detent-engaging member); wherein, when the cam is in a first rotational position, it causes the detent-engaging member to be in its first position, and when the cam is in a second rotational position, it causes the detent-engaging member to be in its second position.

More particularly, the detent-engaging member may be part of a subassembly having: a proximal end, against which the cam acts; and a distal end at which the detent-engaging member is situated.

The subassembly may further comprise a push-rod disposed between the proximal end of the subassembly and the detent-engaging member.

The proximal end of the subassembly may be provided with a bearing which contacts the cam and acts against a proximal end of the push-rod.

The subassembly may further comprise an adjustment screw, e.g. disposed between a distal end of the push-rod and the detent-engaging member.

Most of the subassembly may be contained with the abovementioned housing. in presently-preferred embodiments the detent-engaging member comprises a bearing, which may be spring mounted.

The release mechanism may further comprise a race along which the bearing of the detent-engaging member can travel when the detent-engaging member is in its second position, the detent being provided along said race.

In presently-preferred embodiments the rotatable cam is mounted within the principal body part. Accordingly, the mode selector may further comprise a mode switch lever attached to the rotatable cam, to facilitate operation thereof. The mode switch lever may extend radially from the rotatable cam. Further, the mode switch lever may extend through an aperture in the side of the principal body part.

The release mechanism may further comprise a release Sever attached to the principal body part, to facilitate operation thereof. In embodiments in which the principal body part is rotatable, the release lever may extend radialiy from the principal body part.

In presently-preferred embodiments the release mechanism is for use in controlling the operation of a locking mechanism of a seating assembly, although other applications are also possible, as those skilled in the art will appreciate.

According to a second aspect of the present invention there is provided a seating assembly comprising a release mechanism in accordance with the first aspect of the invention, a locking mechanism acting on a hinged or pivoted part of the seating assembly, and a mechanical linkage coupling the release mechanism to the locking mechanism.

The locking mechanism may comprise a gas spring or gas strut, for example. The mechanical linkage may comprise a pull-cable, although in alternative embodiments other linkages are possible, such as one or more connecting rods.

The hinged or pivoted part of the seating assembly may be a seat structure, which is pivotally movable relative to a support structure. For example, the seat structure may comprise a back section and a seat base section (and optionally a leg rest section), arranged so as to move as one relative to the support structure.

The seating assembly may further comprise an armrest attached to the support structure, to which armrest the release mechanism is attached.

According to a third aspect of the present invention there is provided a method of controlling the operation of a locking mechanism using a release mechanism in accordance with the first aspect of the invention, the release mechanism being coupled to the locking mechanism via a mechanical linkage.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, and with reference to the drawings in which:

Figure 1 is an overview of a recliner chair having a release mechanism for controlling the operation of a locking mechanism, the release mechanism having a release lever and a mode switch;

Figure 2 is a perspective overview of the release mechanism of Figure 1;

Figure 3 is a view of the release mechanism of Figure 2 with the housing removed for explanatory purposes;

Figure 4 is a schematic diagram focusing on the mode switch as present in the preceding drawings, the mode switch being coupled to a cam for selectively extending or retracting a spring-mounted bearing;

Figure 5 is a cut-away plan view of the release mechanism of Figures 1 to 3, with the mode switch set such that the cam causes the spring-mounted bearing to be in an extended position (in accordance with a “second mode” of operation of the release mechanism);

Figure 6 corresponds to Figure 5, but with the mode switch set such that the cam causes the spring-mounted bearing to be in a retracted position (in accordance with a “first mode” of operation of the release mechanism); and Figure 7 is an exploded diagram showing the constituent components of the release mechanism of the preceding drawings.

In the figures, like elements are indicated by like reference numerals throughout. Detailed Description of Preferred Embodiments

The present embodiments represent the best ways known to the Applicant of putting the invention into practice. However, they are not the only ways in which this can be achieved.

To illustrate an exemplary application of the present embodiments, Figure 1 shows a recliner chair 10. The recliner chair 10 comprises a pivotally-mounted reclinable seat structure 12 - in this example, having a back section 12a, a seat base section 12b and a leg rest section 12c that are formed as a unitary construction and pivot as one. The reclinable seat structure 12 is pivotally movable within, and relative to, a support structure 18, about pivot points 22. Armrests 20 are provided on the support structure 18. The underside of the support structure 18 is attached to a rotatable spindle 18, which itself is supported by a base 14. Further details of such a chair, in a general sense, may be found in PCT/GB2015/051573 (in the name of DavidHugh Limited).

Returning now to the present embodiments, the chair 10 has a locking mechanism 24 (e.g. a lockable gas spring or gas strut) that is positioned beneath the seat structure 12 and controlled by a pull-cable (34 in subsequent figures). The pull-cable is routed through the chair and coupled to a user-operable release mechanism 26 (the focus of the present work) that is mounted on the underside of an armrest 20. Thus, one end of the pull-cable is coupled to the locking mechanism 24, and the other end of the pull-cable is coupled to the release mechanism 26. The locking mechanism 24 is a readily-available pre-existing component, and those skilled in the art will be familiar with suitable models, the principles of operation and the details of practical implementation. When locked, the locking mechanism 24 prevents the seat structure 12 from pivotally moving relative to the support structure 18. On the other hand, when unlocked, the locking mechanism 24 allows the seat structure 12 to be pivotally moved relative to the support structure 18 (i.e. allowing the recline position of the seat structure 12 to be changed).

Overview of the release mechanism and its first and second modes of use The release mechanism 26 includes a user-operable release lever 28, positioned for ease of operation (e.g. by the user's thumb). As discussed in greater detail below, the release lever 28 is coupled to the pull-cable such that manipulation of the release lever 28 causes the locking mechanism 24 to lock or unlock.

The release mechanism 26 also includes a user-operabie mode switch lever 30, the configuration of which is also described in greater detail below. The purpose of the mode switch lever 30 (and the components to which it is connected) is to provide the chair 10 with two modes of operation (more particularly, modes of reclining behaviour), namely a first mode and a second mode. The mode switch lever 30 is movable by the user between a first position and a second position. When the mode switch lever 30 is in the first position, the chair 10 is put into the first mode of operation. When the mode switch lever 30 is in the second position, the chair 10 is put into the second mode of operation.

In the first mode of operation the user must pull on the release lever 28 to unlock the locking mechanism 24 and thereby enable the recline position of the seat structure 12 to be adjusted relative to the support structure 18 (such adjustment being performed, for example, by the user moving their body or redistributing their weight within the chair). When the release lever 28 is released by the user, the locking mechanism 24 (and thus the seat structure 12 of the chair) immediately locks rigid, allowing the user to move their body or redistribute their weight without the recline position of the seat structure 12 changing. This mode of operation may be considered to be equivalent to the manner of operation of conventional reciiner chairs.

As with the first mode, in the second mode of operation the user must pull on the release lever 28 to unlock the locking mechanism 24 and thereby enable the recline position of the seat structure 12 to be adjusted relative to the support structure 18. However, in the second mode, when the release lever 28 is pulled to its maximum extent (or limit of travel) the chair 10 enters a state of free movement where the locking mechanism 24 remains unlocked when the user lets go of the release lever 28, thereby enabling the recline position of the seat structure 12 to continuously move as the user moves their body or redistributes their weight. If the user so desires, this continuous free movement may be over an extended period of time, e.g. many minutes. (With a little practice, this can give the user a “floating” or “weightless” feeling while reclining in the chair.) Then, as and when the user so desires, the user can lock the locking mechanism 24 (and thus lock the recline position of the seat structure 12) with a light touch on the release lever 28, moving the release lever 28 back from its maximum extent position. The user may repeatedly unlock and relock the locking mechanism 24 whilst the chair is in the second mode, by moving the release lever 28 back toward the maximum extent position (to unlock the Socking mechanism 24) or away from the maximum extent position (to relock the locking mechanism 24).

The user can change between the first and second modes of operation with a simple fiick of the mode switch lever 30, in a reversible manner, whenever desired.

In presently-preferred embodiments the various components of the release mechanism 26 are primarily formed of a suitable metal for engineering purposes, such as steel, although those skilled in the art will appreciate that, for certain components, other materials may be used instead.

The release lever and associated mechanism

With reference to Figures 2 to 7, the release mechanism 26 will now be described in greater detail. These figures show the release mechanism 26 only (in some cases together with part of the pull-cable 34). Figure 2 shows an overview of the release mechanism 26 in an assembled state, whereas Figures 3, 5, 6 and 7 show open, cut-away or exploded views. Figure 4 shows certain components within the release mechanism 26 relating to the mode switch 30.

The release mechanism 26 comprises a release mechanism body 32 to which the release lever 28 is attached, and a housing (or cover) 42. The release mechanism body 32 is circular in shape and has a central hole 39 (Figure 7) to provide an axis for lever rotation 38. The release lever 28 is attached to the release mechanism body 32 (e.g. by means of a threaded hole 64 in the side of the release mechanism body 32 - see Figure 7) such that the release lever 28 extends radially from the release mechanism body 32.

The release mechanism body 32 incorporates an annular recess 33 (Figure 7), for receiving cam member 44 (as discussed in greater detail below) and to facilitate connection of the pull-cable 34.

More particularly, one end of the pull-cable 34 is attached to the release mechanism body 32 by means of a slot or hole provided through the side of the release mechanism body 32. Inward of the slot or hole a recess 68 is provided within the release mechanism body 32, to retain an enlarged end 35a of the inner core 35 of the puN-cable 34. The outside of the puil-cabie 34 is attached to the outside of the housing 42 by means of barrel part 34a,

The release mechanism body 32 is rotatabiy attached to housing 42 about the axis of rotation 38, by means of a countersink screw or bolt 29 which passes through the central hole 39 of the release mechanism body 32 and into the housing 42. Thread locking adhesive may be applied to ensure that the countersink screw or bolt 29 is firmly fixed in place. To promote smooth operation a washer (e.g. a leather washer) may be provided to bear against the mating surfaces of the release mechanism body 32 and the housing 42 Subsequently, for use, the housing 42 may be fixedly attached to the underside of an armrest 20 of the chair 10, as mentioned above and illustrated in Figure 1 - or conceivably to another part of the chair.

The range of angular rotation of the release mechanism body 32 relative to the housing 42, upon movement of the release lever 28 by the user, is defined by a limit screw 40 which protrudes from the release mechanism body 32 and which is located within an arcuate slot 41 within the housing 42. (The limit screw 40 may be attached to the release mechanism body 32 by means of threaded hole 66 as shown in Figure 7, for example.) More particularly, the limits of angular rotation of the release mechanism body 32 relative to the housing 42 are defined by the points at which the iimit screw 40 comes into contact with each end of the arcuate slot 41. If will be appreciated that, in alternative embodiments, protrusions other than screws (e.g. bolts, threaded cylinders, etc.) may be provided for this purpose on the release mechanism body 32, to move within such a slot (or recess). In yet further alternative embodiments, the protrusion provided for this purpose may protrude inwardly from the housing 42, toward the release mechanism body 32, and a corresponding slot (or recess) may be provided within the release mechanism body 32, defining the limits of angular rotation of the release mechanism body 32 relative to the housing 42.

As illustrated, the pull-cable 34 (more precisely, the inner core 35 thereof) applies a force in a counter-clockwise direction and pulls the release mechanism 26 to the extent of its travel where the limit screw 40 comes into contact with the end of the slot 41, Application of force to the release lever 28, e.g. from the user’s thumb, turns the release mechanism body 32 in a clockwise direction, thereby extending the pull-cable and releasing the locking mechanism 24 beneath the seat structure 12. This occurs in the first mode of operation, wherein subsequent release of the release lever 28 results in the release lever 28 immediately moving back to its original position and the locking mechanism 24 locking the recline position of the seat structure 12. (The same unlocking process also occurs in the second mode of operation, but with the difference that, in the second mode, once the locking mechanism 24 is unlocked with the release lever 28 at the extent of its travel, when the user subsequently releases the release lever 28 it remains in that position and the locking mechanism remains unlocked -- until the user chooses to move the release lever 28 and thereby lock the locking mechanism 24 again.)

The release mechanism body 32 may be considered to be a principal body part of the release mechanism 26, movable (i.e. rotatable) by the user between a first principal position (of angular rotation) in which the locking mechanism 24 is caused to be locked, and a second principal position (of angular rotation) in which the locking mechanism 24 is caused to be unlocked.

The mode switch Sever and associated mechanism

As shown for example in Figure 3, and also Figures 4, 5, 6 and 7, the release mechanism 26 also includes an annular cam member 44, the cam member 44 being rotatably mounted within the annular recess 33 (Figure 7) within the release mechanism body 32 - i.e. effectively around a central hub 37 of the release mechanism body 32. The mode switch lever 30 is attached to the cam member 44 (e.g. by means of a threaded hole in the side of the cam member 44) such that the mode switch lever 30 extends radially from the cam member 44. Further, the mode switch lever 30 protrudes through an elongate slot 31 in the side of the release mechanism body 32. During rotation of the release mechanism body 32 (by operation of the release lever 28) the cam member 44 moves (i.e. rotates) with the release mechanism body 32,

The mode switch lever 30 and its associated components function as a mode selector, enabling a user to set the release mechanism to either the first mode of operation or the second mode of operation.

Also attached to the release mechanism body 32 is a so-caiied “plunger housing” 36, which is effectively an elongate hollow/tubular member. The plunger housing 36 is attached to the release mechanism body 32 via a hole 62 (e.g. threaded) in the side of the release mechanism body 32 (see Figure 7). The plunger housing 36 extends radially from the release mechanism body 32. As the release mechanism body 32 rotates in use, by operation of the release lever 28, the plunger housing 36 moves through an arc within a “fantail” part 42a of the housing 42.

The hollow centre of the plunger housing 36 is in open communication with the annular recess 33 within the release mechanism body 32, via the hole 62 in the side of the release mechanism body 32. Further, the side surface of cam member 44 (in the annular recess 33) is situated adjacent to the inward end of hole 62 in the side of the release mechanism body 32.

The plunger housing 36 contains (at a distal end of the plunger housing 36, furthest from the release mechanism body 32) a commercially-available spring plunger 52. A distal end of the spring plunger 52 is provided with a spring-mounted bearing 54 (which, in the example illustrated, is a ball bearing, although in alternative embodiments may be another shape such as a cylinder). A proximal end of the spring plunger 52 is attached to a distal end of a push-rod 48, preferably by means of an adjustment screw 50. Further, a proximal end of the push-rod 48 is provided with a bearing 46 which effectively acts as a cam follower. In the example illustrated, the bearing 46 is a bail, although in alternative embodiments it may be another shape such as a cylinder.

Thus, passing through the plunger housing 36, there is a subassembly 56 (see Figure 4) comprising: the “cam follower” bearing 46, which acts on the push-rod 48, which in turn acts (via the adjustment screw 50) on the spring plunger 52, the spring plunger 52 terminating with the bearing 54, This subassembly 56 is longitudinally movable (as one) within and relative to the plunger housing 36, towards or away from the release mechanism body 32.

The bearing 46 of the subassembly 56 is in contact with the side surface of cam member 44, within the annular recess 33 of the release mechanism body 32, Longitudinal movement of the subassembly 56 relative to the plunger housing 36 is governed by the action of the cam member 44 against the bearing 46. Thus, dependent on the angular position of the cam member 44, the spring plunger 52 may be in either an extended position relative to the plunger housing 36 (e.g. as illustrated in Figure 5, corresponding to the second mode of operation mentioned above), or in a retracted position relative to the plunger housing 36 (e.g. as illustrated in Figure 6, corresponding to the first mode of operation mentioned above).

More particularly, the cam member 44 is profiled such that, when it is rotated by operation of the mode switch lever 30 into a position corresponding to the second mode of operation mentioned above (e.g. as illustrated in Figure 5), the distance from the central axis of the cam member 44 to the point on its side surface at which it contacts the bearing 46 is relatively large, thereby pushing against the bearing 46 and causing the spring plunger 52 to be pushed into the extended position relative to the plunger housing 36.

The cam member 44 is further profiled such that, when it is rotated by operation of the mode switch lever 30 into a position corresponding to the first mode of operation mentioned above (e.g. as illustrated In Figure 6), the distance from the central axis of the cam member 44 to the point on its side surface at which it contacts the bearing 46 is relatively small, thereby causing the spring plunger 52 to adopt the retracted position relative to the plunger housing 36. When the cam member 44 is in this position the bearing 54 of the spring plunger 52 is allowed to extend (under the effect of the compression spring within the spring plunger 52), which pushes the subassembly 56 in the direction of the cam member 44.

Thus, in the first mode of operation the spring plunger 46 is retracted relative to the plunger housing 36 (as illustrated in Figure 6). In the second mode of operation the spring plunger 46 is extended relative to the plunger housing 36 (as illustrated in Figure 5).

The inner surface of the “fantaN” part 42a of the housing 42 is provided with an arcuate race 58 against which the bearing 54 of the spring plunger 52 can run when the release mechanism 26 is in its second mode of operation and the spring plunger 52 is extended relative to the plunger housing 36, as illustrated in Figure 5. A detent 60 (e.g. a recess, in the presently-preferred embodiments) is provided at an end of the race 58, corresponding to the angular position reached by the plunger housing 36 (and more precisely the bearing 54) when the release lever 28 is pulled to its maximum extent (or limit of travel).

On the other hand, when the release mechanism 26 is in the first mode of operation, with the spring plunger 52 retracted relative to the plunger housing 36 (as illustrated in Figure 6), the bearing 54 of the spring plunger 52 is heid inwardly of the race 58, such that the bearing 54 does not interact with the detent 60 when the release lever 22 is pulled to its maximum extent (or limit of travel). As a consequence, in the first mode of operation, because the detent 60 has no effect on the bearing 54, when the release lever 22 is released by the user it immediately springs back to its original position and the locking mechanism 24 locks the reciine position of the seat structure 12.

However, when the release mechanism 26 is put into the second mode of operation (as illustrated in Figure 5), the spring plunger 52 is moved outwardly and the bearing 54 is pressed against the race 58. This also has the effect of partly retracting the bearing 54 into the body of the spring plunger 52, due to the bearing 54 being spring-mounted on the plunger 52. When the user pulls on the release lever 28, the bearing 54 of the spring plunger 52 rolls against the race 58. As the release lever 22 is pulled to its limit of travel the bearing 54 engages with the detent 60, causing the release lever 28 to be held at that position if the user removes manual pressure from the release lever 28 at that position. Accordingly, the locking mechanism 24 remains unlocked when the release lever 28 is released by the user in that position, enabling free movement of the chair for as long as the user desires.

When the user subsequently wishes to lock the locking mechanism 24, the user manually touches on the release lever 28, to move it away from its limit of travel, and overcoming the effect of the detent 60 on the bearing 54. Accordingly, the release mechanism body 32 rotates, causing the locking mechanism 24 to lock.

Without being bound by theory, in the second mode of operation it is understood that the ability of the spring plunger 52, when the bearing 54 is engaged with the detent 60, to hold the release lever 28 (and the release mechanism body 32) at the limit of its travel, and thereby hold the locking mechanism 24 in an unlocked state, is because the force from the spring plunger 52 against the detent 60 creates a clockwise moment that is slightly greater than the counter clockwise moment resulting from the force of the pull-cable 34 (more particularly the inner core 35) on the release mechanism body 32. Consequently, in the presently-preferred embodiments, a light touch onto the release lever 22 by the user is sufficient to increase the counter clockwise moment and enable the effect of the spring plunger 46 against the detent 52 to be overcome. indeed, with the presently-preferred embodiments, the finely-balanced way in which, in the second mode of operation, the spring plunger 52 cooperates with the recess of the detent 60 such as to provide sufficient force to hold the locking mechanism 24 in an unlocked state, but enables the locking mechanism 24 to be reiocked by only a light touch onto the release lever 28 by the user, is surprising, as the inventor initially thought that additional means for strengthening the action of the detent 60 would be necessary, such as a magnet to grip the bearing 54 when in the detent 60. However, whilst such a magnet may of course be included in alternative embodiments, it is not considered necessary, and thus the presently-preferred embodiments use just a recess to form the detent 60.

Again, without being bound by theory, the ability of a recess aione to provide the abovementioned detent function in the second mode of operation is believed to be as a result of the forces in the release mechanism 26 coming into alignment when the release lever 28 is pulled to its limit of travel and the bearing 54 engages with the detent 60. Consequently, when the bearing 54 is engaged with the detent 60, no turning moment is applied to the release mechanism body 32, and the locking mechanism 24 can therefore remain in the unlocked state for as long as the user desires.

The adjustment screw 50 is incorporated into the design of the subassembly 56 to accommodate manufacturing tolerances and to enable the correct balance of forces to be achieved.

Component 51 in Figure 7 is a linear bearing.

Concluding remarks

From the above discussion, it will be appreciated that the subassembly 56 within the plunger housing 36 functions as a selectively-deployable engagement mechanism, actuatable by the mode selector (more particularly, by the mode switch lever 30 and the associated cam member 44), When the mode switch lever 30 is set to the first mode of operation the engagement mechanism is not deployed. When the mode switch lever 30 is set to the second mode of operation the engagement mechanism is deployed.

Furthermore, of the subassembly 56, the bearing 54 of the spring plunger 52 serves as a detent-engaging member, movable relative to the plunger housing 36 between a first (retracted) position and a second (extended) position, under the control of the mode switch lever 30 and the associated cam member 44. When the mode switch lever 30 is set to the second mode of operation, the cam member 44 causes the bearing 50 to be in the second (extended) position from which it is ab!e to engage with the detent 60 when the principal body part (i.e. the release mechanism body 32) is moved into the abovementioned second principal position. However, when the mode switch lever 30 is set to the first mode of operation, the cam member 44 causes the bearing 50 to be in the first (retracted) position from which it is unable to engage with the detent 60 during movement of the principal body part (the release mechanism body 32).

Possible modifications and alternative embodiments

Detailed embodiments have been described above, together with some possible modifications and alternatives. As those skilled in the art wili appreciate, a number of additional modifications and alternatives can be made to the above embodiments whilst still benefiting from the inventions embodied therein.

For example, whilst in the above embodiments the mode selector is a manually-operable arrangement, operable to mechanically actuate the selectively-deployable engagement mechanism, in alternative embodiments the mode selector may be an electronic assembly operable to actuate the selectively-deployable engagement mechanism (for example electromagnetically).

Whilst in the above embodiments the mode selector enables the user to choose between two modes of operation, in alternative embodiments additional modes of operation or other functions (e.g. heating, massaging, etc.) may also be selectable using the mode selector.

Whilst in the above embodiments the principal body part (the release mechanism body 32) is rotatable, in alternative embodiments it may be movable in some other way, for example in a linear manner, between the first and second principal positions.

Whilst in the above embodiments the selectively-deployable engagement mechanism is coupled to the principal body part such that it moves with the principal body part, in alternative embodiments it may be provided elsewhere within the release mechanism, but still arranged such that, when it is deployed, it is abie to hold the principal body part in the second principal position and thereby hoid the locking mechanism in the unlocked state.

Whiist in the above embodiments a recess is used as the detent and a bearing is used as the selectiveiy-deployable detent-engaging member, in alternative embodiments other combinations of detents and detent-engaging members are possible - for example using magnetic or electromagnetic components.

Although, in the above discussion, embodiments of the release mechanism have been described in the context of controlling the operation of a locking mechanism of a seating assembly (specifically a recliner chair), other applications are also possible - e.g. for controlling, more generally, the operation of a locking mechanism which prevents or allows a first component to move relative to a second component.

Finally, throughout the above discussion, it should be appreciated that references to “clockwise” and “counter clockwise” are simply used to indicate relative (opposite) directions of rotation, and can readily be interchanged to form alternative embodiments (e.g. suitable for mounting on an opposing armrest of a chair).

Claims

1. A release mechanism for controlling the operation of a locking mechanism, the release mechanism comprising: a principal body part configured to be coupled, in use, to a locking mechanism via a mechanical linkage, the principal body part being movable by a user between a first principal position in which the locking mechanism is caused to be locked, and a second principal position in which the locking mechanism is caused to be unlocked; a mode selector for enabling a user to select a mode of operation of the release mechanism from among a plurality of modes of operation which include a first mode of operation and a second mode of operation; and a selectively-deployable engagement mechanism actuatable by the mode selector; wherein the release mechanism is configured such that when the mode selector is set to the first mode of operation the engagement mechanism is not deployed, and when the mode selector is set to the second mode of operation the engagement mechanism is deployed; and wherein the engagement mechanism, when deployed, is able to hoid the principal body part in the second principal position.

2. A release mechanism as claimed in claim 1, wherein the principal body part is rotatable, the first and second principal positions being first and second positions of angular rotation.

3. A release mechanism as claimed in claim 1 or claim 2, wherein the selectively-depioyabie engagement mechanism is coupled to the principal body part such that it moves with the principal body part.

4. A release mechanism as claimed in claim 3 when dependent on claim 2, wherein the selectively-deployable engagement mechanism extends radially from the principal body part.

5. A release mechanism as claimed in claim 3 or claim 4, wherein the selectively-deployable engagement mechanism comprises a detent-engaging member which is movable between first and second positions under the control of the mode selector; wherein, when the mode selector is set to the second mode of operation, the detent-engaging member is caused to be in the second position from which it is able to engage with a detent when the principal body part is moved into the second principal position, and when the mode selector is set to the first mode of operation, the detent-engaging member is caused to be in the first position from which it is unable to engage with said detent during movement of the principal body part.

6. A release mechanism as claimed in claim 5, wherein the selectively-deployable engagement mechanism comprises a housing which is attached to the principal body part, the detent-engaging member being movable relative to the housing.

7. A release mechanism as claimed in claim 5 or claim 6, wherein the mode selector comprises a rotatable cam arranged to set the position of the detent- engaging member; wherein, when the cam is in a first rotational position, it causes the detent-engaging member to be in its first position, and when the cam is in a second rotational position, it causes the detent-engaging member to be in its second position.

8. A release mechanism as claimed in claim 7, wherein the detent-engaging member is part of a subassembly having: a proximai end, against which the cam acts; and a distal end at which the detent-engaging member is situated.

9. A release mechanism as claimed in claim 8, wherein subassembly further comprises a push-rod disposed between the proximal end of the subassembly and the detent-engaging member.

10. A release mechanism as claimed in claim 9, wherein the proximal end of the subassembly is provided with a bearing which contacts the cam and acts against a proximal end of the push-rod.

11. A release mechanism as claimed in claim 9 or claim 10, wherein the subassembly further comprises an adjustment screw disposed between a distai end of the push-rod and the detent-engaging member.

12. A release mechanism as claimed in any of claims 8 to 11 when dependent on claim 6, wherein most of the subassembly is contained with said housing.

13. A release mechanism as claimed in any of claims 5 to 12, wherein the detent-engaging member comprises a bearing.

14. A release mechanism as claimed in claim 13, wherein the bearing of the detent-engaging member is spring mounted.

15. A release mechanism as claimed in claim 13 or claim 14, further comprising a race along which the bearing of the detent-engaging member can travel when the detent-engaging member is in its second position, the detent being provided along said race.

16. A release mechanism as claimed in any of claims 7 to 15, wherein the rotatable cam is mounted within the principal body part.

17. A release mechanism as claimed in any of claims 7 to 16, wherein the mode selector further comprises a mode switch lever attached to the rotatable cam.

18. A release mechanism as claimed in claim 1/, wherein the mode switch Sever extends radially from the rotatable cam.

19. A release mechanism as claimed in claim 18, wherein the mode switch lever extends through an aperture in the side of the principal body part.

20. A release mechanism as claimed in any preceding claim, further comprising a release lever attached to the principal body part.

21. A release mechanism as claimed in claim 20 when dependent on claim 2, wherein the release lever extends radially from the principal body part.

22. A release mechanism as claimed in any preceding claim, for use in controlling the operation of a locking mechanism of a seating assembly.

23. A seating assembly comprising a release mechanism as claimed in claim 22, a locking mechanism acting on a hinged or pivoted part of the seating assembly, and a mechanical linkage coupling the release mechanism to the locking mechanism.

24. A seating assembly as claimed in claim 23, wherein the locking mechanism comprises a gas spring or gas strut.

25. A seating assembly as claimed in claim 23 or claim 24, wherein the mechanical linkage comprises a pull-cable.

26. A seating assembly as claimed in any of claims 23 to 25, wherein the hinged or pivoted part of the seating assembly is a seat structure, which is pivotally movable relative to a support structure.

27. A seating assembly as claimed in claim 26, wherein the seat structure comprises a back section and a seat base section, arranged so as to move as one relative to the support structure.

28. A seating assembly as claimed in claim 27, wherein the seat structure further comprises a leg rest section.

29. A seating assembly as claimed in any of claims 26 to 28, further comprising an armrest attached to the support structure, to which armrest the release mechanism is attached.

30. A method of controlling the operation of a locking mechanism using a release mechanism as claimed in any of claims 1 to 22, the release mechanism being coupled to the locking mechanism via a mechanical linkage.

31. A release mechanism substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings.

32. A seating assembly substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings

33. A method of controlling the operation of a locking mechanism using a release mechanism substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings.