GB2388629A

GB2388629A - Power actuator assembly

Info

Publication number: GB2388629A
Application number: GB0211313A
Authority: GB
Inventors: Paul Moore
Original assignee: ArvinMeritor Light Vehicle Systems France SA; Meritor Light Vehicle Systems UK Ltd
Current assignee: Inteva Products France SAS; ArvinMeritor Light Vehicle Systems UK Ltd
Priority date: 2002-05-17
Filing date: 2002-05-17
Publication date: 2003-11-19
Also published as: GB0211313D0

Abstract

An actuator assembly comprises: a power actuator 12,130; a rotatable driven member 16,160 provided with a "Y-shaped hole 45 defining three notches 46,47,48, 148; an output element 20, 120; a coupling 57,157, which is displaceable within the notches and which connects the output element to the driven member; and a guide means 160 which guides the coupling along a longitudinal axis of the output element and which provides 'tight' control 182 over lateral movement of the coupling when the coupling is positioned within one of the notches, and provides 'loose' control 184 over lateral movement of the coupling when the coupling is positioned between two adjacent notches. Also disclosed is an actuator which comprises a stop means 22 which acts at the end of power rotation of the driven member 16 to stop the driven member, and an actuator which comprises an interlock means which acts between a chassis 14 and the driven member to actively ensure that the coupling 57 remains proximate a notch end during part of a powered actuation of the driven member.

Description

P301 23SGB

Actuator Assembly The present invention relates to actuator assemblies, and in particular actuator assemblies for rise in vehicle doors to provide for vehicle door functions such as lockJunlock, superl,ck on/superlock off and child safety on/child safety off.

lower actuators are known, for example from UK patent application number GB9822025.4 and also UK patent application number GB9521790.7.

Both these known actuator assemblies include a power actuator mounted on a chassis of the actuator assembly. The power actuator drives a power driven driver in the form of a worm wheel which in turn moves an output element via a coupling means. A head of the coupling means is biased towards a notch of the driver, and during powered actuation, the coupling means remains in the same notch.

l lowever, during manual actuation of the output element, the power driven driver remains stationary and the coupling means moves from one notch end to an adjacent notch end.

Furthermore both of these known actuators include stops which limit the rotational movement of the driver during powered operation. In the first case (GB9822025.4), the stop acts between the coupling means and the driver, and in the second case ((Rob) 175().7) the stop acts between the coupling means and the chassis.

F:urthennore in both cases an interlock acts to retain the head of the coupling means at the nctcl1 end during powered operation. However, the interlock functionally operates between the compiling means and the driver. Furthermore, in both cases the coupling means and the interlock are partially formed on opposite ends of the same component. As such they are not independent of each other.

Adclitionally the stop means and coupling means are again formed on opposite ends of the same component and again are not independent of each other.

These known actuators have various problems including jamming under certain circumstances, poor positional control and poor interlock control.

An object of the present invention is to provide an improved form of actuator assembly which solves or at least mitigates one or more of the above problems and other problems.

Thins according to the present invention there is provided an actuator assembly including a power actuator, an actuator chassis, a power driven driver, coupling means, and an output element, tile actuator assembly having a first and second condition, corresponding to a first and second position of the output element, lie power driven driver being rotatably mounted on the chassis and having at least three circumferentially spaced notches having notch ends, the power driven driver further including an equivalent number of teeth, each tooth having a tooth tip, with each tooth tip being positioned circumferentially between adjacent notch ends, tile coupling means being positioned proximate a notch end with the actuator assembly in the first or second condition, the power actuator being capable of causing the power driven driver to rotate to drive bloc output element between the first and second positions via the coupling means, manual actuation of the output element causing the coupling means to move from one otcl end. past a tooth tip, to another notch end, us which during manual actuation of the output element between the first and second positions, the coupling means is guided relative to the output element by a guide means along a longitudinal axis of the output element, wherein with the coupling means positioned proximate a notch end, lateral movement of the coupling means relative to flee axis is relatively tightly controlled, and with the coupling means proximate a tooth tip, lateral movement of the coupling means relative to the axis is relatively loosely controlled.

Accorcling to a further aspect of the present invention there is provided an actuator assembly including a power actuator, an actuator chassis, <, power driven driver, a coupling means, anal m1 output element, the actuator assembly having a first and second condition, corresponding to a first and second position of the output element, the power driven driver being rotatably mounted on the chassis and having at least three crcumferentially spaced notches having notch ends, the power driven driver further including an equivalent number of teeth, each tooth having a tooth tip, with each tooth tip being positioned circumferentially between adjacent notch ends, Ile coupling means being positioned proximate a notch end with the actuator assembly in the first or second condition, the power actuator being capable of causing the power driven driver to rotate to drive the output element between the first and second positions via the coupling means, manual actuation of the output element causing the coupling means to move from one blotch end, past a tooth tip, to another notch end, the assembly further including a stop means acting between the driver and the chassis at (lie end of power rotation of the driver to stop the driver.

According to a further aspect of the present invention there is provided an actuator assembly including a power actuator, all actuator chassis, a power driven driver.

' coupling means, and an output element, the actuator assembly having a first and second condition, corresponding to a first and second position of the output element,

else power driven driver being rotatably mounted on the chassis and having at least three crcmferentially spaced notches having notch ends, the power driven driver further including an equivalent number of teeth, each tooth having a tooth tip, with each tooth tip being positioned circumferentially between adjacent notch ends, the coupling means being positioned proximate a notch end with the actuator assembly i n the fir st or second condition, die power actuator being capable of causing the power driven driver to rotate to drive the output element between the first and second positions via the coupling means, manual actuation of the output element causing the coupling means to move from one notch end, past a tooth tip, to another notch end, the assembly includes a stop means independent of the coupling means, acting at the enct of power rotation of the driver to stop the driver.

According to a further aspect of the present invention there is provided an actuator a.ssemlly including a power actuator, an actuator chassis, a power driven driver, a coupling means, and an output element, flee actuator assembly having a first and second condition, corresponding to a first and accord position of the output element, lie power driven driver being rotatably mounted on the chassis and having at least three circumterentially spaced notches having notch ends, the power driven driver further including an equivalent number of teeth, each tooth having a tooth tip, with each tooth tip being positioned circumferentially between adjacent notch ends, bloc coupling means being positioned proximate a notch end with the actuator assembly the first or second condition, flee flower actuator being capable of causing the power driven driver to rotate to drive lie outpost element between the first and second positions via the coupling means, n.nral actuation of the output element causing the coupling means to move from one latch end, past a tooth tip, to another notch end,

Else assembly includes an interlock means to actively ensure the coupling means r cmains proximate the notch end during at least a part of the powered actuation of the driver. the interlock acting between the coupling means and the chassis.

Tile invention will now be described, by way of example only, with reference to the accompanying drawings' in which: Figure I is an exploded view of an actuator assembly according to certain aspects of the present invention, Fissure 1 A shows a plan view of the actuator housing of figure I, I?Llre I B shows an enlarged view of part of figure 1 Figure 2 is an isometric view of the assembled components of figure 1, I'i,ures 3 and 4 are plan views of the actuator assembly of figure 2 shown in a first (nloclied) and second (locked) condition, Figure 4A shows a further plan view of the actuator assembly of figure 2 shown in a second (locked) condition, Figure 5 is an isometric exploded view of the actuator assembly of figure 1 shown from below, I:igre SA shows an enlarged view of part of figure 5 I Igures 5B and 6 are views of the actuator assembly of figure 2 shown from below in an nlocl;ed and locked position, I'itres 7 to 10 show a further embodiment of an actuator assembly according to certain Inspects of the present invention shown in various positions, and ['i allures I 1 A to I I E show a schematic plan view of the worm wheel and interlock means of figure 1 in various positions.

With rct'erence to figures I to 6, there is shown an actuator assembly 10 having a power tctuator 12, an actuator assembly chassis 14 (shown in figure IA and schematically in l'igLre I)' a power driven driver 16 in the form of a worm wheel, a coupling means 18 in the torm of a pin and an output element 20 in the form of a pivotable lever.

Also shown in figure I is a switchable stop 22, an interlock means 24, a leaf spring 26 and a helical spring 28.

Leal spring 26 is generally W-shaped and includes a central region 26A for mounting the spring on the chassis (see below). Leaf spring 26 further includes anns 26B and 26C.

Power actuator 12 is in the form of a DC electric motor 30 having an output shaft 31 in driving connection with worm gear 32. The power actuator 12 is mounted in the chassis.

Figure 1 A shows part of the chassis 14 which includes a circular recess 34 in which sits the worm wheel 16. The circular recess 34 includes a base surface 35 and a central pivot pin GIG. Projecting upwards (out of the plane of the paper) from base surface 35 is an arcuate portion 37 having ends 37A and 37B.

Figure I A also shows the position of the electric motor 30 and associated worm gear 32.

The chassis 14 further includes three mounting pins 27 situated in a space between arcuate portion 37 and the edge of the circular recess 34. Pins 27 project upwardly from the base surface 35. It can be seen that leaf spring 26 is mounted non rotatably on the chassis via pins 27.

I he worm wheel 16 includes teeth on its outer periphery for engagement with teeth of the worm gear 32.

The worm wheel 16 includes an upper surface 40 projecting from which are three circunterentially equispaced arrow head shaped projections 41, 42 and 43. Each arrow head projection includes a stop abutment on its lateral side (when considering the axis of tle arrow) 41 A, 41 B. 42A, 42B, 43A and 43B.

the upper surface 40 includes a Y-shaped hole 45, with each leg of the Y being circumfercntially positioned at 120 relative to adjacent legs of the Y. Furthermore, each leg of Flee Y is positioned between corresponding adjacent arrow head shaped projections.

Fact let of the Y defines a notch 46, 47 and 48, with each notch having a notch end 46A, 47'48A.

Tl-e notches are deemed by teeth 50, 51 and 52 having teeth tips 50A, 51 A and 52A.

N<,te tight in further embodiments, the notches can be defined by surfaces other than those provided by the teeth and teeth tips.

In the bottom of the worm wheel there is a recess 54 having a recess wall 55. The recess wall 55 is generally cylindrical but includes six projections 56 grouped as three pairs 56A, 56B d 56C.

Tlic lain 18 includes a cylindrical upper head 57, a cylindrical flange 58 and a cylindrical louver head 59. all being concentric with each other.

he lever 20 is pivotally mounted about axis A (see figure 3) on the chassis and includes a slot ((1 and a switching abutment 61 on its lower surface. It can be seen that slot 60 is curved and therefore the axis of slot 60 is similarly curved.

Mated within slot 60 proximate axis A is a pin 62 over which is mounted helical spring 28 (see especially figure 3).

Switchable stop 22 is generally planar with a stop pivot pin 64 projecting therefrom and heing pivotally mounted in a hole 38 (see figure IA) of the chassis.

Sitol 00 includes abutment surfaces 65 and 66. Furthermore resilient leaf springs 67 and 68 l rolect Tom the switchable stop. In this case the leaf springs 67 and 68 are integrally firmed with the stop, which is made from a plastic material.

l he interlock means 24 is generally planar having an interlock abutment 70 projecting from the general plane of the interlock means.

Interlock means further includes a pivot hole 71, in use mounted on pivot pin 36, abutments 72 and 73, in use for engagement with ends 37A and 37B of arcuate portion 37 anal feat spring 74.

1 eat spring 74 acts in a radially outward direction in use when considering the axis B of pivot pin 36 (and hence the axis of hole 71). Leaf spring 74 is generally arcuate and codes a radially outwardly orientated abutment 75 at its free end.

The components are assembled as follows: l'terlock means 24 is mounted via pivot hole 71 on pin 36 of the chassis with the abutment 72 atoll 73 being positioned between end 37A and 37B of arcuate portion 37, with abutment 7() facing away from base surface 35.

l he worm wheel 16 is mounted over the interlock means and within circular recess 34 of the chassis, the interlock means being positioned within recess 54.

I lie lower actuator 12 is arranged as shown in figure 1A such that worm gear 32 engages worn wheel 16.

Stop Pivot pin 64 is engaged in hole 38 of the chassis such that abutment surfaces 65 and (( can come into engagement with appropriate stop abutments of the arrow head shaped F,rrjcctions 41, 42 and 43, and the resilient leaf springs 67 and 68 can come into engagement with switching abutment 61 of lever 20.

lain 18 is mounted such that lower head 59 sits within the Y shaped hole with the lower surface of flange 58 resting against the upper surface 40 of the worm wheel. The pin upper lltatl 57 is positioned within slot 60 of the lever 20 and is biased towards end 60A of slot (() he- helical spring 28.

()ler.tion of the actuator is as follows:

\ ilk r eterence to figures 3 and 5 the actuator assembly is shown in a first condition, in this chic corresponding to an unlocked condition of an associated latch (not shown). Note Tut: Pin I X is positioned proximate the electric motor 30.

1 cower head 59 is biased into engagement with notch end 48A by helical spring 28.

Allotment 66 of the switchable stop 22 does not engage stop abutment 42B. By analogy allotment surface 65 of switchable stop 22 is in engagement with stop abutment 43A of a' r ow head shape projection 43 (this engagement being hidden in figures 3 and 5).

Switching abutment 61 of lever 20 is in engagement with the free end of resilient leaf Glaring G8 of the switchable stop 22. Thus, it can be seen that the switchable stop 22 is lend eased in a clockwise direction when viewing figure 5 (and anticlockwise direction vole viewing figure 3.

h1 Girder to power operate the actuator to move it to its second (locked) condition as shown i figures 4 and 6 (where the pin 18 is remote from electric motor 30), the electric motor is actuatccl (for a predetermined short time) such that the worm wheel 16 is caused to move in Ion antclockwise direction when viewing figure 3. The edge of notch 48 drives the lower head 59 of the pin 18 in an arc through 120 . Since the pin upper head 57 is engaged in slot ((). the lever 20 is also caused to move in an anticlockwise direction about axis A, in this case througl1 approximately 20 , to the position shown in figure 4.

lt shotild be noted that during the anticlockwise rotation of the worm wheel 16, the arrow head shaped projection 42 and in particular edge 42C initially sweeps past abutment srl;.lce 66 (without contacting it) and then subsequently engages and sweeps past surface (.') ( see figure 4) of the switchable stop 22. This engagement between surface 69 and edge 42C causes the switchable stop to switch to the position shown in figure 4, i. e. to rotate clockwise when compared with figure 3. Thus, it can be seen that the stop means is switchahle between the first and second positions shown respectively in figures 3 and 4.

F;urtl1ermore, it can be seen that it is the worm wheel (power driven driver) and in particular edge 42C that is responsible for this switching.

When considering figure 4, it is apparent that the switching of the stop causes abutment surface 66 (hidden in figure 4) to be positioned in the path of stop abutment 41B (also hidden in figure 4) Upon engagement of stop abutment 41B with abutment surface 66, the motor Is caused to stall momentarily following which the power to the motor ceases after the Egregiously mentioned predetermined time.

it call be seen that the switchable stop 22 acts functionally between the worm wheel and the chassis and hence is better able to control the stop position of the worm wheel relative to the chassis in view of the reduced tolerance stack when compared with the prior art.

lit order to power operate the actuator assembly from the second (locked) position to the first (unlocked) position, the power to the electric motor 30 is reversed and the lever 20 moves from the position shown in figure 4 to the position shown in figure 3.

(2,nsiclering the position of the various components as shown in figure 3, it is possible to manually actuate the lever 20 and rotate it approximately 20 anticlockwise. However, derring this movement the worm wheel 16 remains stationary and the lower head 59 slides out 1 slot 48, past tooth tip 52, into slot 60 and into abutment with slot end 46 (as shown i', fi,rue 4B). In particular the differing positions of arrow head shaped projection 43 (and Horace Else dillering positions of the worm wheel 16) should be contrasted between figures 4 phi 43.

: It should also be noted that the manual actuation of lever 20 has caused the switchable stop 2? to rotate clockwise (in fact to the same position as shown in figure 4). However, in this c,se. the movement was caused by switching abutment 61 of lever 20 disengaging resilient loll Alarms 68 of the switchable stop 22 and engaging resilient leaf spring 67 resulting in the anticlockwise pivotable movement of the switchable stop 22 as the lever is manually rovecl from a position shown in figure 3 to the position shown in figure 4B.

It should be noted that in both figure 4 and figure 4B, the switchable stop means is being resiliently biased to the position shown, by engagement between the switching abutment 61 and resilient leaf spring 67, though the method by which the switchable stop 22 is rotated cl,clwise when moving between the positions shown in figures 3 and 4 differs from the netho1 when moving between the position shown in figures 3 and 4B.

()peration of the interlock means 24 can best be understood by consideration of figures 1 l A to I 1E. These figures are schematic plan views of the worm wheel 16, interlock means 24 and coupling means (pin) 18.

l he six pro jections 56 can be seen grouped as three pairs 56A, 56B and 56C. Pair 56A has l'rther been defined as projection 56A' and 56A".

Allotment 75 of the interlock means 24 has been indicated schematically as an arrow head.

The position of the components as shown in figure I IA equate to the position as shown in fissure 2, i.e. in an unlocked condition.

-I lie loose lion of the components in figure HE equate to their position as shown in figure 4, i.e. ill a locked position.

I:inre 11A to HE shows how the actuator assembly is moved from the unlocked to the locked condition by powered operation of the electric motor.

IS previously mentioned, powered operation of the actuator causes the worm wheel 16 to rt;te uticlockwise through 120 to the locked position (the figures showing progressive ()0 incremental rotation of the worm wheel).

>.s Fiche the projections 56, Y shaped hole 45 and pin 18 are all rotated through 120 anticlockwise. In particular please note that pin 18 remains in notch 48.

As sown in figure llA projection 56A' is positioned to the right of abutment 75.

l urtllenllore interlock abutment 70 does not obstruct notch 48. Thus, if manual locking is rewired from the position shown in figure 11A, the output element 20 can be manually beloved such that pin 18 moves out of notch 48 and into notch 46 as described above. In lnticular interlock abutment 70 does not prevent this movement.

As \vorm wheel 16 rotates anticlockwise under powered operation, projection 56A' of the W()nll wheel pushes abutment 7S of the interlock means 24 anticlockwise as shown in l-r,ure I IB and I 1C, thus also causing the interlock means 24 to rotate anticlockwise with Bloc wor m wheel.

Ho\vever, once the interlock means 24 has achieved the position as shown in figure 1 IC, abutment 7, (figure 1) of interlock means 24 engages end 37B (figure 1A) of arcuate pi 37 of the chassis 14, thus preventing further anticlockwise rotation of the interlock ecllls. I lIUS. continued anticlockwise rotation of the worm wheel causes the projection 56A' to resiliently deform leaf spring 74 allowing projection 56A' to ride over abutment 75 resulting, in abutment 75 being positioned between projections 56A' and 56A" as shown in figure I 11:).

(.ti''ccl anticlockwise rotation of the worm wheel causes projection 56A" to also ride o>'cr pro jection 75 such that the components achieve the position as shown in figure I IE.

In particular it should be noted that no relative rotation occurs between the interlock means 24 and the worm wheel 16 when considering figures I IA, 1 IB and I IC. However, when considering figures llD and llE, the worm wheel 16 has been rotated anticlockwise relative to the (now stationary) interlock means 24.

I bus it can be seen that powered operation results in interlock abutment 70 being positioned as shown in figure llD such that radially inward movement of pin 18 is prevented (by contact between lower head 59 and the interlock abutment 70). This ensures that the coupling means (pin 18) remains proximate notch end 48A during the latter part of the powered actuation of the worm wheel.

Tt would be appreciated that during an initial movement of the worm wheel (figure I IB and figure 11C) no interlock occurs since interlock abutment 70 is not obstructing notch 48.

()nly during the latter part of movement (figure LID) does interlock occur.

Consideration of the relative positions of the centre of rotation of the worm wheel and the centre of rotation (A) of the output lever 20, together with consideration of the frictional forces involved as the worm wheel drives lever 20 via pin 18' and in particular consideration of the direction of friction forces, shows that: a) As the worm wheel is driven from the position shown in figure IIA to the position show1 in figure I I B. forces on the pin 18 act to pus it towards notch end 48B. Thus, in the event that pin 18 (incorrectly) is positioned part way along notch 48 when the worm wheel is in the position shown in figure I IA, driving of the wonn wheel to the position shown in figure I 1 B will result in friction forces which will force pin 18 to the position shown in figure I 1B (i.e. to its correct position). Under these circumstances it is beneficial that no interlock occurs since the frictional forces involved beneficially act to move pin 18 from an incorrect position part way along notch 48 to the correct position at the end of notch 48 as shown in leisure JIB.

b) As the worm wheel is driven past the position shown in figure 11D, the frictional forces involvel tend to force pin 18 out of notch 48, and thus beneficially this is the position at which the interlock is functioning.

It should be noted that in further embodiments the relative positions of the centre of rotation of lever 20 and worm wheel 16 could be such that frictional forces cause pin 18 to slide out of slot 48 during an initial movement of the worm wheel but be forced towards the end of slot 48 during a final movement of the worm wheel. Under these circumstances the interlock means can be caused to operate during the initial movement and can be caused to not operate during a final movement.

[n particular the interlock means 24 acts between the coupling means (pin 18) and the chassis 14, since the interlock means 24 is mounted via its pivot hole 71 on pivot pin 36 of the chassis.

It would also be appreciated that the interlock means 24 is moved between the position shown in figure 11A and the position shown in figure 1 IF by the power driven driver (worm wheel).

As mentioned above, leaf spring 26 is mounted non rotatably relative to the actuator assembly chassis 14. Since the worm wheel is caused to rotate during powered actuation, the worm wheel rotates relative to leaf spring 26 during powered operation. However, since the worm wheel remains stationary during manual operation, no rotation of the worm wheel occurs relative to the leaf spring 26 during such manual operation.

( In fact it can be seen that arms 26B and 26C of leaf spring 26 rest upon corresponding line jcctons 56 when the actuator is in the rest position (see figure 5B and figure 6). Due to flee slrng loading of the leaf spring 26, it provides an initial high talk requirement to start rotation of worm wheel 16. Once worm wheel 16 has started to rotate the arm 26B and 2(1(' r' longer engage appropriate projections 56 and the tension in the leaf spring is relaxed therefore reducing friction between the leaf spring and the edge of the circular recess 34. Thus, it can be seen that the leaf spring acts to provide a high initial turning torqtie for the worm wheel to ensure that the worm wheel does not inadvertently rotate during manual operation of the actuator.

Fi,:,ures 7 to 10 show a second embodiment of an actuator assembly 1 10, with components Multivalent to those in actuator assembly 10 being labelled 100 greater.

I-loweven in this case slot 160 is not of constant width. Slot 160 has a relatively wide rci,n lR0 separated from a relatively narrow region 182 by a transition region 184.

l nnsiton region 184 provides for a smooth transition between the relatively wide portion 180 and the relatively narrow portion 182. It can be seen that the pin upper head] 57 is a relati vely snug fit in narrow region 182 but a relatively loose fit in wide region 180.

l issue 7 shows the components in an unlocked position.

Manual actuation of the lever 20 in a clockwise direction moves the components to the lo.sti,n as shown in figure 8. However, under certain circumstances incomplete manual acttaton is achieved and, for the purposes of this example, we can assume that the conponelts are only manually moved to the position as shown in figure 8 (i.e. incomplete mural actuation).

As sucll, and in view of the helical spring 128 (only shown in figure 7) acting on the pin l 18. upon release of the lever 120, it moves to the position as shown in figure 9 i.e. it rotates anticlockwise slightly until such time as the edge of the wide portion 180 of slot I ( () engages the pin.

llecause pin 118 is exactly aligned with tooth tip 151A, the pin is in a "dead centre" position relative to the tooth tip and thus remains positioned as shown in figure 9, in spite ill bloc bias action of the spring 128. Subsequent powered actuation of the electric motor to effect unlocking, causes the worm wheel to rotate in a clockwise direction resulting in pin I l X moving off its "dead centre" position relative to tooth tip 151A and reengaging in tcl 1 48.

11 can be seen that with pin 1 18 positioned proximate tooth tip 15IA (as shown in figures 8 and 9) i.e. within the relatively wide region 180 of slot 160, lateral movement of the lever l 2() (with respect to the longitudinal axis of slot 160) is relatively loosely controlled.

('onversely when pin 118 is positioned proximate notch end 148A, as shown in figures 7 arid 10. lateral movement of the lever 120 is relatively tightly controlled by virtue of the tact that pin 1 18 sits snugly in the relatively narrow portion 182. I he applicant is the first to realise, that under certain circumstances,

for example complete manual actuation of the actuator, the actuator can subsequently jam, for example during subsequent powered operation. By providing for a slot of differing widths, 1 in particular providing a relatively wide slot when the pin is in a dead centre position elative to a tooth, allows for the pin to be positioned off the axis of the slot 160 (as shown Arc 9) and this reduces the likelihood of jamming.

It should be appreciated that further embodiments of the present invention can be cuisaged by those skilled in the art. In particular it is not necessary for the coupling needs to be a pin moving in a slot of the output element (lever). For example pin upper heacl 157 could be replaced by a fork arrangement with each fork prong being positioned on Opposite sides of a longitudinal rail of the output element.

l:urllermore embodiments can be envisaged by those skilled in the art wherein the relative Alar positions of the slot ends and teeth can be reversed i.e. the teeth can be positioned radially outboard of the notch ends.

Emhodiments of a present invention have been described using words such as upper, lower 1 base for ease of explanation, clearly the invention encompasses actuator assemblies orientated in any direction.

Claims

Claims

1 An actuator assembly including a power actuator, i 'ctuator chassis, a power driven driver, coupling means, and an output element, the actuator assembly having a first and second condition, corresponding to a first and second position of the output element, flee power driven driver being rotatably mounted on the chassis and having at least three c rcuferentially spaced notches having notch ends, the power driven driver further including an equivalent number of teeth, each tooth having a tooth tip, with each tooth p l eing positioned circumferentially between adjacent notch ends, the coupling means being positioned proximate a notch end with the actuator assembly in the first or second condition, the power actuator being capable of causing the power driven driver to rotate to drive Alit output element between the first and second positions via the coupling means, natal actuation of the output element causing the coupling means to move from one owl end, past a tooth tip, to another notch end, Rich during manual actuation of the output element between the first and second -scions, the coupling means is guided relative to the output element by a guide means along a longitudinal axis of the output element, wherein with the coupling, means positioned proximate a notch end, lateral movement of the coupling means relative to {lltWxis is relatively tightly controlled, u,<:l with the coupling means proximate a tooth tip, lateral movement of the coupling means relative to the axis is relatively loosely controlled.

2. An actuator assembly as defined in claim I in which the guide means is arranged such fleet a smooth transition is provided between the relatively tight control of the coupling means and the relatively loose control of the coupling means.

An actuator assembly as defined in claim I or 2 in which the notch ends are positioned Lilly outboard of the tooth tips.

4 All actuator assembly as defined in claim I or 2 in which the notch ends are positioned radially inboard of tooth tips.

s. actuator assembly as defined in any preceding claim in which the guide means is in i he i orm of a slot in the output element in which a head of the coupling means moves.

(.. An actuator assembly as defined in claim 5 in which the slot has a relatively narrow portion and a relatively wide portion.

7. An actuator assembly including lower actuator, cur actuator chassis, power driven driver, ' coupling means, d all output element, Clue actuator assembly having a first and second condition, corresponding to a first and secontt position of the output element, flee power driven driver being rotatably mounted on the chassis and having at least three c'cLimferentially spaced notches having notch ends, the power driven driver further including an equivalent number of teeth, each tooth having a tooth tip, with each tooth fin l sing positioned circumferentially between adjacent notch ends, Else couplhlg means being positioned proximate a notch end with the actuator assembly in the first or second condition, Alec power actuator being capable of causing the power driven driver to rotate to drive to utpt element between the first and second positions via the coupling means, .'mal actuation of the output element causing the coupling means to move from one notch end. past a tooth tip, to another notch end, Alec.,sscmbly further including a stop means acting between the driver and the chassis at to end of power rotation of the driver to stop the driver.

S. An actuator assembly including a Flower actuator, all actuator chassis, power driven driver, coupling means, find an output element, file actuator assembly having a first and second condition, corresponding to a first and second position of the output element, lie power driven driver being rotatably mounted on the chassis and having at least three crcumferentially spaced notches having notch ends, the power driven driver further including an equivalent number of teeth, each tooth having a tooth tip, with each tooth tip being positioned circumferentially between adjacent notch ends, the coupling means being positioned proximate a notch end with the actuator assembly in the first or second conditions the power actuator being capable of causing the power driven driver to rotate to drive flee otitput element between the first and second positions via the coupling means, manual actuation of the output element causing the coupling means to move from one blotch end, past a tooth tip, to another notch end, the reassembly includes a stop means independent of the coupling means, acting at the elltl of power rotation of the driver to stop the driver.

9. Aft actuator assembly as defined in claim 7 or 8 in which the stop means is switchable between a first and second stop position to stop rotation of the driver in a first and second rotational direction.

I () An actuator assembly as defined in claim 9 in which the stop means is switchable by the driver during powered rotation of the driver.

1 1 An actuator assembly as defined in claim 9 or 10 in which the stop means is switchable lay disc output element during manual movement of the output element.

12. An actuator assembly as defined in claim l O or l I in which the stop means is resiliently retained in the first or second stop position by biased means acting on the stop means find re-acting against the output lever.

I. An actuator assembly including a power actuator, an actuator chassis, a power driven driver a coupling means, and an output element, flee actuator assembly having a first and second condition, corresponding to a first and second position of the output element, the power driven driver being rotatably mounted on the chassis and having at least three circumferentially spaced notches having notch ends, the power driven driver further including an equivalent number of teeth, each tooth having a tooth tip, with each tooth fill being positioned circumferentially between adjacent notch ends, Alec coupling means being positioned proximate a notch end with the actuator assembly in the first or second condition, Alec power actuator being capable of causing the power driven driver to rotate to drive lie output element between the first and second positions via the coupling means manual actuation of the output element causing the coupling means to move from one blotch end, past a tooth tip, to another notch end, (lie assembly includes an interlock means to actively ensure the coupling means wins proximate the notch end during at least a part of the powered actuation of the driver the interlock acting between the coupling means and the chassis.

14. An actuator assembly as defined in claim 13 in which the interlock is switchable let\veen a first and second interlock position.

I 5. I\n actuator assembly as defined in claim 14 in which the interlock means is switchable lay tle driver during power rotation of the driver.

I (I Ail actuator assembly as defined in any one of claims 13 to 15 in which the interlock means does not interlock during initial powered movement of the output element from lee first or second position but does act to interlock as the output element nears the t her of the first and second positions.

17 An actuator assembly as defined in any preceding claim in which the coupling means is leased towards a notch end when the actuator assembly is in the first or second contition.