GB2576754A

GB2576754A - Vehicle active surface actuation apparatus

Info

Publication number: GB2576754A
Application number: GB1814148.1A
Authority: GB
Inventors: Dowden Thomas; Lewis Jordan; Saranna Kalvin; Marchant Rob
Original assignee: Marchantcain Design Ltd
Current assignee: Marchantcain Design Ltd
Priority date: 2018-08-31
Filing date: 2018-08-31
Publication date: 2020-03-04
Also published as: WO2020044017A1; EP3844054A1; GB201814148D0

Abstract

A vehicle active surface actuation system 100 has a first drive mechanism 110 forming a first load path between an active surface 18, typically a spoiler or wing, and a vehicle, which moves between first and second conditions in which active surface 18 is respectively in first and second positions relative to the vehicle. A drive system 106, for example a motor 102 and cable drive, is engaged with and delivers mechanical power to first mechanism 100 to drive it between the first condition and the second condition. Drive system 106 is independent of the first load path in at least one condition of first mechanism 100, so that drive system 106 can be disengaged from first mechanism 100 without interrupting the first load path. Also disclosed is a system where mechanism 100 has a mechanical linkage which moves over-centre to lock the linkage in the second condition, and a system where mechanism 100 has an intermediate stop to lock the mechanism between the first and second conditions.

Description

Vehicle active surface actuation apparatus

The present invention is concerned with an actuation apparatus for a vehicle active surface. More specifically, the present invention is concerned with an apparatus for an active wing which is configured to move the wing between at least two positions relative to the vehicle body.

The term wing is used herein to refer to an aerodynamic device which is attached to the outer surface of a vehicle. Wings are used in motorsport and production vehicles. The present invention is primarily concerned with wings for production vehicles.

Typically, vehicle wings extend generally laterally across the vehicle width, and are attached to the rear of the vehicle to provide a beneficial aerodynamic effect. Rear wings tend to be attached to the upper rear surface of the boot / trunk lid in order to both provide downforce at high speeds, and to reduce drag due to the vehicle shape in this area.

It will be noted that although the term wing is used herein, the device is also commonly referred to as a spoiler. The term surface is broader than wing and applies to any moveable part of the vehicle, whether aerodynamic or for other purposes.

Some high-end production vehicles have active or dynamic wings. These wings are configured to move between at least two discrete positions, and possibly across a range of discrete or continuously variable positions therebetween. Movement of the wing can provide many benefits- most notably by matching the position of the wing to the vehicle's speed and thus providing the aerodynamic effects when required. For example, some active wings are provided in a lower or stowed configuration at low speed, where the generated downforce would be low, and only deploy above a certain speed (say 90kph).

Known active wings are often deployed using direct electric linear actuators, positioned within the stanchions supporting the wing at either end thereof. This system has certain drawbacks.

Firstly, the actuators form part of the load path between the vehicle and wing surface. As a result, they tend to be embedded in the extension / retraction mechanism. This makes servicing and replacement difficult, as the entire mechanism needs to be removed and disassembled in order to service or replace an actuator.

Secondly, the presence of the actuators in the stanchions makes the stanchions bulky. This should be avoided, as they can increase drag and thus reduce aerodynamic performance.

Thirdly, there is a requirement to balance the actuation of the two independent actuators to ensure that they deploy by the same amount at the same speed. Unequal actuation would put an undesirable torque load on the wing and may cause twisting which in turn would detrimentally affect aerodynamic performance.

Fourthly, two actuators are required, increasing the system complexity and therefore likelihood of system failure.

Fifthly, additional mechanisms need to be incorporated to counteract back-driving from the aerodynamic forces exerted on the wing in use.

Sixthly, directly linearly actuated systems can be expensive.

The applicant's co-pending patent application published as GB2533576A discloses an actuator which provides a sliding and pivoting movement for a car wing. A cable drive arrangement is provided to drive the wing between stowed, deployed and air-brake positions. The system operates by driving a carriage in a sliding track by means of a pair of Bowden cables. The inner cables are extended and retracted by means of a motor-driven drum. This solution mitigates some of the above problems, but it is to be noted that the wing-side part of the actuation system is very much integrated with the wing support 12a, and replacement / servicing of those parts would necessitate removal of the wing from the vehicle.

It is an aim of the present invention to overcome, or at least mitigate, the above problems. In particular, it is an aim of the present invention to allow replacement or servicing of the actuator without necessitating removal of the wing from the vehicle.

According to a first aspect of the invention there is provided a vehicle active surface actuation apparatus comprising:

a first actuable drive mechanism for forming a first load path between a vehicle active surface and a vehicle, the first actuable drive mechanism being configured to move between a first condition in which the vehicle active surface is in a first position relative to the vehicle, and a second condition in which the vehicle active surface is in a second position relative to the vehicle;

a drive system engaged with and configured to deliver mechanical power to the first actuable drive mechanism to drive the first actuable drive mechanism between the first condition and the second condition;

wherein the drive system is independent of the first load path in at least one condition of the first actuable drive mechanism such that the drive system can be disengaged from the first actuable drive mechanism without interrupting the first load path.

Advantageously, this allows the drive system to be removed and / or replaced without needing to remove the surface (such as a wing or spoiler).

Preferably the drive system is configured to deliver mechanical power to the first actuable drive mechanism via a rotatable drive shaft.

Preferably the drive system is can be engaged and disengaged from the first actuable drive mechanism by movement of the drive system along an axis of the drive shaft.

Preferably the drive system comprises:

a master drive subassembly comprising a motor and a master cable drum;

a first slave drive subassembly; and, at first cable arrangement configured to transfer power between the master and first slave drive subassemblies;

wherein the first slave drive subassembly is engaged with and configured to deliver mechanical power to the actuable drive mechanism.

Preferably the first slave drive subassembly comprises a first slave cable drum, and in which the first slave cable drum is configured to transfer rotational power to the first actuable drive mechanism.

Preferably the apparatus comprises:

a second actuable drive mechanism forforming a second load path between the vehicle active surface and a vehicle, the second actuable drive mechanism being configured to move between a first condition in which the vehicle active surface is in the first position relative to the vehicle, and a second condition in which the vehicle active surface is in the second position relative to the vehicle;

wherein the drive system comprises:

a second slave drive subassembly;

a second cable arrangement configured to transfer power between the master and second slave drive subassemblies;

wherein the second slave drive subassembly is engaged with and configured to deliver mechanical power to the second actuable drive mechanism.

Preferably the second slave drive subassembly comprises a second slave cable drum, and in which the second slave cable drum is configured to transfer rotational power to the second actuable drive mechanism.

Preferably the first actuable drive mechanism comprises a mechanical linkage.

Preferably the first actuable drive mechanism comprises a housing for pivotable attachment of a vehicle active surface, and in which the mechanical linkage is configured to pivot the active surface relative to the housing.

Preferably in moving from the first to the second condition of the first actuable drive mechanism, the mechanical linkage moves over-centre to lock the mechanical linkage in the second condition.

Preferably in moving from the second to the first condition of the first actuable drive mechanism, the mechanical linkage moves over-centre to lock the mechanical linkage in the first condition.

Preferably the first actuable drive mechanism comprises an intermediate stop arrangement to hold the first actuable drive mechanism in an intermediate condition between the first and second conditions.

Preferably the intermediate stop arrangement comprises a resilient stop configured to capture a part of the first actuable drive mechanism in the intermediate condition.

Preferably the intermediate stop arrangement comprises a spring clip.

According to a second aspect of the invention there is provided a vehicle active surface actuation apparatus comprising:

an actuable drive mechanism for forming a first load path between a vehicle active surface and a vehicle, the first actuable drive mechanism being configured to move between a first condition in which the vehicle active surface is in a first position relative to the vehicle, and a second condition in which the vehicle active surface is in a second position relative to the vehicle;

wherein the actuable drive mechanism comprises a mechanical linkage and wherein in moving from the first to the second condition, the mechanical linkage moves over-centre to lock the mechanical linkage in the second condition.

Preferably the intermediate stop arrangement comprises a spring clip.

According to a third aspect of the invention there is provided a vehicle active surface actuation apparatus comprising:

wherein the first actuable drive mechanism comprises an intermediate stop arrangement to hold the first actuable drive mechanism in an intermediate condition between the first and second conditions.

Preferably the intermediate stop arrangement comprises a spring clip.

According to a fourth aspect there is provided a method of installing an active surface actuation apparatus on a vehicle comprising the steps of:

providing a static vehicle delimiting an exterior and interior side of the vehicle;

providing an opening in the vehicle surface;

providing a vehicle active surface actuation apparatus according to any of claims 1 to 14;

mounting the actuable drive mechanism to the vehicle surface from the exterior side; and, engaging the drive system from the interior side by passing the drive system at least partially through the opening.

Preferably the drive system engages the actuable drive mechanism on the exterior side.

Preferably the actuable drive mechanism extends through the opening to attach to the vehicle on the interior side.

An example active wing actuation apparatus will now be described with reference to the accompanying Figures in which:

FIGURE 1 is a side view of a vehicle with an active wing and an active wing actuation apparatus according to the present invention;

FIGURE 2 is a perspective view of the active wing actuation apparatus of Figure 1, generally from the front left-hand side of the vehicle;

FIGURE 3 is a view of the active wing actuation apparatus of Figure 2 from the front of the vehicle facing rearwards;

FIGURE 4 is a view of the active wing actuation apparatus of Figure 2 from the right-hand side;

FIGURE 5 is an exploded view of a master drive subassembly of the active wing actuation apparatus of Figure 2;

FIGURE 6 is a view of the master drive subassembly of Figure 5 from the opposite angle to Figure 5;

FIGURE 7 is a view of a selection of parts of the master drive subassembly of Figure 5 from the same angle as Figure 6;

FIGURE 8 is a perspective exploded view of a part of the master drive subassembly of Figure 5;

FIGURES 9 and 10 are perspective views of a slave drive subassembly of the active wing actuation apparatus of Figure 2;

FIGURE 11 is a side view of the slave drive subassembly of Figures 9 and 10;

FIGURE 12 is a bottom view of the slave drive subassembly of Figures 9 and 10;

FIGURES 13 and 14 are exploded views of the slave drive subassembly of Figures 9 and 10;

FIGURES 15 and 16 are perspective views of a part of the slave drive subassembly of Figures 9 and 10;

FIGURE 17 is a section view of the part of Figures 15 and 16;

FIGURE 18 is a section view ofthe slave drive subassembly of Figures 9 and 10 assembled with a linkage mechanism of the active wing actuation apparatus of Figure 2;

FIGURES 19 and 20 are perspective views ofthe slave drive subassembly of Figures 9 and 10 assembled with a linkage mechanism ofthe active wing actuation apparatus of Figure 2;

FIGURES 21 and 22 are exploded views of the linkage mechanism of Figure 18;

FIGURE 23 is a perspective view of certain parts ofthe linkage mechanism of Figure 18;

FIGURE 24 is a side view of the linkage mechanism of Figure 18;

FIGURE 25a is a left-hand side view of the active wing actuation apparatus of Figure 2 in a fully deployed / air-brake condition;

FIGURE 25b is a left-hand side view of the active wing actuation apparatus of Figure 2 in an intermediate condition; and,

FIGURE 25c is a left-hand side view of the active wing actuation apparatus of Figure 2 in a stowed condition.

Referring to Figure 1, there is shown a vehicle in the form of an automobile 10 having wheels 12, body 14 and an openable boot or trunk lid 16. A wing 18 is mounted to the boot lid 16 via an active wing actuation apparatus 100 (Figure 2) which is in part contained within two stanchions 20 (only one stanchion is visible, but it will be noted that two are provided at either end of the wing 18).

For the purposes of the following description, the terms left, right, upper and lower refer to the general reference frame of the automobile 10 from an occupant's perspective, unless indicated otherwise. The direction of travel is forwards (direction D in Figure 1) for the purposes of this description.

General assembly

Referring to Figure 2 to 4, the active wing actuation apparatus 100 is shown in more detail. The apparatus comprises:

• a drive system comprising a master drive subassembly 102, two slave drive subassemblies 104, 106 and two sets of Bowden cables 112, 114;

• an actuable drive mechanism comprising two linkages 108, 110; and, • two wing mounting plates 113,115.

Master drive subassembly

Referring to Figures 5 to 7, the master drive subassembly 102 is shown in more detail. The master drive subassembly 102 comprises a housing made up of two housing parts 116,118, a rotary actuator in the form of an electric motor 120, a gearbox 122, a cable drum 124, two cable compensators 126, 128 and two sprung cable mounts 130, 132.

The first housing part 116 defines a cavity 134, a motor attachment formation 136 and three fixing bosses 138.

The second housing part 118 defines a cavity 140 which is generally cylindrical. An annular boss 142 is provided in the centre of the cavity 140, with a plurality of six tabs 144 spaced therearound. Four tangentially oriented channels 146, 148, 150, 152 extend from the cavity 140. The channels 146,148 are aligned on one side of the cavity 140, and the channels 150, 152 are aligned on the other side of the cavity. The channels 146, 148, 150, 152 are parallel to each other and extend from the cavity to respective openings 154, 156, 158, 160 in the outer surface of the second housing part. Three fixing holes 162 are provided in the second housing part 118.

The motor 120 is a 12V DC electric motor and has a power / data connection port 164 for connection to the automobile control system, typically a CAN bus. The motor 120 has a rotary output shaft (not visible).

The gearbox 122 comprises a worm drive comprising a worm (not shown) and worm gear 168. The worm 122 is configured to rotate about a worm axis W to drive the worm gear about a master drum axis X. W and X are at 90 degrees to each other (as with all worm drives). The gearbox 122 comprises a drive shaft 170 extending from the worm gear 168 and configured to rotate therewith. The drive shaft 170 defines an external splined formation 172.

The cable drum 124 is a generally cylindrical component with a plurality of helical grooves in the outer surface thereof. The cable drum 124 is a double drum inasmuch as it is configured to simultaneously extend and retract each of two pairs of cables up rotation. Rotation in a first direction retracts a first cable of each pair, and extends the second. Rotation in a second, opposite direction retracts the second cable of each pair, and extends the first.

The cable compensators 126, 128 are identical, and as such only the compensator 128 will be described here. The compensator 128 is of the type described in applicant's co-pending patent application published as EP3237768 (incorporated herein by reference where permitted). Although a detailed explanation of the structure and function of the compensator 128 can be determined from EP3237768, the following brief explanation is offered in support of the present application.

The compensator 128 is configured to act as a part of a Bowden cable sleeve. It is configured to gradually elongate to match any stretching of the inner cables of a Bowden cable pair which also offering resistance to the compressive loads experienced during normal use of the Bowden cable.

The compensator comprises a housing 174 of hollow tubular form, a central passage of which is dimensioned to slidingly receive a generally cylindrical part 176 of an adjustment member 178. The outer surface of the part 176 is provided with a thread formation 180, the surface defining the passage in the housing 174 being formed with corresponding generally helical grooves. It will be appreciated that the adjustment member 178 and housing 174 are free to undergo telescoping movement relative to one another, the engagement of the ribs 180 within the grooves requiring such telescoping movement to be accompanied by angular or rotary movement of the housing 174 relative to the adjustment member 178.

An end of the adjustment member 178 is provided with an outwardly extending flange 182. A similar flange 184 is provided on the housing 28, resilient biasing means in the form of a spring 186 being located between the flanges 182,184 and applying a biasing load to the adjustment member 178 and housing 174, urging them apart.

A first ratchet member 188 is provided at an end of the housing 174.

The adjustment member 178 includes a central through passage 190 of non-circular cross-section. Slidably received within the passage 190 is a stem 192, of cross-sectional shape matching that of the passage 190, projecting from a second ratchet member 194, the ratchet member 194 including a surface provided with ratchet teeth adapted to cooperate with the first ratchet member 188.

The ratchet member 194 defines a through passage 196. It will be appreciated that the ratchet members interengage to allow rotation of the housing 174 relative to the ratchet member 178 in one direction, limiting or resisting reverse rotation, and hence resisting contraction of the cable compensator 128.

A Bowden cable sleeve abuts the end of the ratchet member 194 and can apply axial load thereto.

This arrangement means that should the tension in the inner cable running through the compensator start to stretch, the compressive force acting through the sleeve and compensator 128 will reduce. This allows the spring 186 to push the sleeve 174 from the member 178 and thus increase the length of the compensator 128. The ratchet arrangement ensures that the compensator 128 cannot be compressed when the Bowden cable is subsequently used.

The two sprung cable mounts 130,132 are provided to reduce any shock loading on the Bowden cable sleeves as is known in the art.

The master drive subassembly 102 is assembled as follows.

The gearbox 122 is inserted into the cavity 134 of the first housing part 116. The cable drum 124 is mounted on the splined formation of the drive shaft 170 such that the worm gear 168 is co-axially mounted therewith for rotation about the axis X. The worm (not shown) is engaged with the worm gear 168 such that rotation of the former about axis W drives the latter. The motor 120 is assembled with the housing 116 such that the output shaft drives the worm. The second housing part 118 is assembled with the fits housing part 116 to encapsulate the gearbox, and mechanical fasteners (not shown) attach the two housing parts using the adjacent holes 162 and bosses 138. It will be noted that the drum 124 sits within the cavity 140 of the second housing part 118, in-line with the channels 146, 148, 150, 152.

The compensators 126, 128 and mounts 130,132 are assembled to the outside of the second housing part 118, the compensator 126 and mount 130 extending from a first side, and the compensator 128 and mount 132 extending from a second, opposite side. In other words, two compensator-mount pairs are provided facing away from each other.

It will be understood that the Bowden cables 112, 114 are assembled with the master drive subassembly, but this will be described in more detail below.

Slave drive subassemblies

The slave drive subassemblies 104, 106 are mirror images of each other, but otherwise identical. As such, only the left-hand slave drive subassembly 106 will be described here. The left-hand slave drive subassembly 106 is shown in Figures 9 to 17.

With reference to Figures 13 and 14, the left-hand slave drive subassembly 106 comprises a retaining pin 198, a boss 200, a housing 202, a drum inner 204, a drum outer 206, a grub screw 210 and cable ferrules 212, 214. A drive shaft 208 is also shown, but forms part of the linkage 110 as will be described below.

The retaining pin 198 is generally cylindrical comprising an annular outwardly projecting flange 216 at a first end and an annular groove 218 at a second end.

The boss 200 is a formed as a hollow cylinder or tube.

The housing 202 is constructed from plate material. It comprises a central plate 220 having a through bore 222. The plate 220 is a formed as a six-sided polygon (an irregular hexagon). Flanges extend from, and normal to, five of the six sides. There are two short flanges 224, 226, two long flanges 228, 230 and a single end flange 232. The long flanges 228, 230 each comprise attachment tabs 234, 236 respectively. The end flange 232 also comprises an attachment tab 238. The attachment tabs 234, 236, 238 extend outwardly from the housing 202 and are generally parallel to the plate 220. The long flanges 228, 230 each define ferrule receiving slots 240, 242 adjacent the end flange 232. The absence of a flange at the sixth side of the plate 220 forms an access aperture 243.

The drum inner 204 is generally cylindrical. It comprises an inner shaft 244 having a tapered region 246 at a first end and an annular flange 248 at a second end. The tapered region 246 comprises four spaced apart fingers 247 which extend both axially and radially inwards. The annular flange 248 extends radially outwardly from the inner shaft 244. Four axially extending fingers 250 extend from the outer rim of the annular flange 248 in the same direction as the inner shaft 244, each terminating in an outwardly extending tab 252.

The drum outer 206 is shown in detail in Figures 15 to 17. Referring to Figure 17, the drum outer 206 has an annular outer section 253 having an inner cylinder 254, an annular rib 256 and an outer cylinder 258. The outer cylinder 258 defines a helical groove 260 on its cylindrical outer surface.

On a first axial face 262 of the annular outer section 253 of the drum outer 206 there are provided a plurality of stiffening ribs 264 (Figure 15). There is also provided a cable-receiving recess 266 which joins to a first end of the helical groove 260.

On the opposite axial face 268 of the annular outer section 253 of the drum outer 206 there are provided a plurality of stiffening ribs 270 (Figure 16). There is also provided a cable-receiving recess 272 which joins to a second end of the helical groove 260.

The drum outer 206 has an inner section 274 which is generally cylindrical in shape. The inner section 274 is connected to the outer section by four arms 275 which define apertures 276 therebetween. The inner section 274 defines a tapered body 288 defining a first axial blind bore 278 having a tapered region 280 leading to a central wall 282. On an opposite side of the central wall 282 there is a second axial blind bore 284 having a radial grub screw bore 286 defined therein. The tapered body 288 defines four outer axially extending ribs 290 extending from the arms 275.

The cable ferrules 212, 214 are identical, each having a through-bore 296 and a pair of opposed side slots 298, 300.

The assembled left-hand slave drive subassembly 106 is shown in Figure 18. The boss 200 is inserted into the bore 222 of the plate 220 of the housing 202. The retaining pin 198 is inserted through the boss 200 such that the flange 216 engages the end of the boss 200 and the groove 218 extends from the boss 200. The drum inner 204 can then be mated with the boss 200 such that the boss 200 engages the inner shaft 244 of the drum inner 204. The drum inner 204 is assembled over the boss 200 until the fingers 247 of the drum inner 204 resiliently snap into the groove 218 on the pin 198. This allows secures the drum inner 204 in an axial sense, but allows rotation about a slave drum axis Y.

The drum outer 206 can be assembled onto the drum inner 204 by engaging the fingers 250 of the drum inner into the apertures 275 between the arms 276 of the drum outer 206. The fingers 250 resile inwards and snap back to engage the tabs 252 against the outer section 253 of the drum outer 206. It will be noted that the tapered region 280 of the first axial blind bore 278 is engaged by the tapered region 246 of the inner shaft 244 of the drum inner 204. In particular, the engagement prevents the fingers 247 from deforming outwardly, thus ensuring engagement between the drum inner 204 and the pin 198.

The end of the drive shaft 208 is engaged in the second blind bore 284 of the drum outer 206 and secured with the grub screw 210 to the drum outer 206 to transfer torque thereto. It will be noted that the grub screw 210 can be accessed from the access aperture 243 in the housing 202 to attached and detach the drive shaft 208 (see Figure 19).

The ferrules 210, 212 are engaged in the ferrule receiving slots 240, 242. The inner cables of Bowden cables can be fed through the bores 296 and attached to the cable-receiving recesses 266, 272 of the drum outer 206 as will be described below.

Linkages

The linkages 108, 110 are identical (mirror images) of each other, and as such only the left-hand linkage 110 will be described here.

The left-hand linkage 110 is shown in Figures 18 to 25c. The linkage 110 comprises:

• a housing 302 having:

o a first part 304; and, o a second part 306;

• an articulating mechanism 308 comprising:

o a crank 310;

o a crank connector 312 comprising two identical crank connector parts 312a, 312b;

o a link arm 314; and, o a wing link 316;

• a crank retaining clip 318; and, • a drive shaft 208 (depicted in Figures 9 to 14 and 18, but forming part of the linkage 110).

The first housing part 304 is generally flat and plate-like, defining a drive pivot bore 320, three slave drive attachment bores 322, a link arm bore 324, a wing pivot bore 326. The first housing part 304 further defines a clip flange 328 and an attachment flange 330, both of which extend normal to the main plate of the first housing part 304.

The second housing part 306 is generally flat and plate-like, defining a drive pivot bore 332, a link arm bore 334 and a wing pivot bore 336. The second housing part 306 further defines a support flange 338 which extends normal to the main plate of the second housing part 306.

The crank 310 is a flat plate component having a first bore 340 and a second bore 342 at either end.

The crank connector parts 312a, 312b are flat plate components comprising first and second sections 344, 346 which are angled to each other to form a cranked / angled shape. The crank connector parts 312a comprise respective first and second bores 348, 350 at either end.

The link arm 314 is a straight, flat plate component comprising first and second bores 352, 354 at either end and a central bore 356 midway along its length.

The wing link 316 is a unitary component comprising two flat, planar, parallel portions 316a, 316b joined by a single abutment 358 at one end. The abutment 358 keeps the flat, planar, parallel portions 316a, 316b spaced apart. The wing link comprises first and second bores 360, 362 at either end, which pass through both the portions 316a, 316b.

The crank retaining clip 318 is shown in Figure 25c and comprises a generally resilient metal body constructed from sheet material. The clip 318 has two return portions 380, 382 at either end. At the centre of the clip 318 there is provided a crank recess 384 formed between two ridges 386, 388.

The drive shaft 208 is generally cylindrical comprising an annular outwardly projecting flange 292 at a first end and a radial through-bore 294 at a second end.

The linkage 110 is assembled as follows.

The crank 310 is rotationally fixed to the drive shaft 208 at the first bore 340.

The crank 310 is pivotably connected to the crank connector 312. A pivot pin 364 is engaged with the bores 348 of the two crank connector parts 312a, 312b either side of the crank 310. The pivot pin 364 also engages the second bore 342 of the crank 310.

The other bore 350 of the crank connector 312 is pivotably connected to the central bore 356 of the link arm 314 using a pivot pin 366.

The link arm 314 is pivotably connected to the wing link 316 using a pivot pin 358 passing through the first bore 352 of the former and second bore 362 of the latter. The link arm 314 is also pivotably connected to the housing parts 304, 306 with a pivot pin 359 passing through the second bore 354 of the link arm 314 and the link arm bores 324, 334 of the housing parts 304, 306.

The assembled articulating mechanism 308 is positioned between the first housing part 304 and the second housing part 306. The crank 310 is pivotably attached to the drive pivot bores 320, 332 with the drive shaft 208 of the slave drive subassemblies 104, 106 (Figure 18). The clip 318 is attached to the clip flange 328 by wrapping the returns 380, 382 around either end of the flange such that the crank recess 384 faces inwardly.

Bowden cables

The first set of Bowden cables 112 comprises a first cable 112a and second cable 112b. Each cable has a sleeve capable of holding a compressive force and an inner cable capable of holding a tensile force as is known in the art.

The second set of Bowden cables 114 comprises a first cable 1124 and second cable 114b. Each cable has a sleeve capable of holding a compressive force and an inner cable capable of holding a tensile force as is known in the art.

Wing mounting plates

The wing mounting plates 113, 115 are identical, and as such only the left-hand wing mounting plate 115 will be described here. Referring to Figure 25c, the plate 115 is a flat component (parallel with the plane of the page) and is connected to the wing 18 along a first edge 368.

The plate 115 comprises a first bore 370 at a first end, and a second bore 372 at a second end.

A notch 374 is defined on a second side of the plate 115 opposite the first side. The notch 374 has a first surface 376 which is normal to the edge, and a second surface 378 which is angled to form a slope.

Assembly of the active wing actuation apparatus

The assembled apparatus 100 is shown in Figures 2 to 4. The first set of Bowden cables 112 is connected between the master drive subassembly 102 and the first slave drive subassembly 104.

Regarding the first set of Bowden cables 112:

The sleeve of the first Bowden cable 112a is connected to the compensator 128 at a first end, and to a first ferrule of the slave drive subassembly 104 at a second end.

The inner cable of the first Bowden cable 112a is threaded through the compensator 128 to the cable drum 124 and attached thereto at a first end. At a second end, the inner cable of the first Bowden cable 112a is threaded through the first ferrule of the slave drive subassembly 104 and connects to the drum outer at one of the cable-receiving recesses.

The sleeve of the second Bowden cable 112b is connected to the sprung cable mount 132 at a first end, and to a second ferrule of the slave drive subassembly 104 at a second end.

The inner cable of the second Bowden cable 112b is threaded through the sprung cable mount 132 to the cable drum 124 and attached thereto at a first end. At a second end, the inner cable of the second

Bowden cable 112b is threaded through the second ferrule of the slave drive subassembly 104 and connects to the drum outer at the other of the cable-receiving recesses.

Regarding the second set of Bowden cables 114:

The sleeve of the first Bowden cable 114a is connected to the compensator 126 at a first end, and to the first ferrule 210 of the slave drive subassembly 106 at a second end.

The inner cable of the first Bowden cable 114a is threaded through the compensator 126 to the cable drum 124 and attached thereto at a first end. At a second end, the inner cable of the first Bowden cable 114a is threaded through the first ferrule 210 of the slave drive subassembly 106 and connects to the drum outer 206 at one of the cable-receiving recesses 266, Til..

The sleeve of the second Bowden cable 114b is connected to the sprung cable mount 130 at a first end, and to the second ferrule 212 of the slave drive subassembly 106 at a second end.

The inner cable of the second Bowden cable 114b is threaded through the sprung cable mount 130 to the cable drum 124 and attached thereto at a first end. At a second end, the inner cable of the second Bowden cable 114b is threaded through the second ferrule of the slave drive subassembly 106 and connects to the drum outer 206 at the other of the cable-receiving recesses 266, 272.

The master drive subassembly 102 is attached to the interior surface of a vehicle panel- for example the boot or trunk lid / closure 16, approximately at the centreline of the vehicle (although this is not essential). The boot lid 16 is shown schematically in Figure 4.

The linkages 108,110 are attached such that they project from the exterior surface of the vehicle boot or trunk 16 and support the wing 18 at spaced apart positions, proximate either end. The linkages 108, 110 are concealed by stanchions 19 (Figure 4).

The linkages 108, 110 are attached to the vehicle at the attachment flanges 330, and to the wing 18 by (i) pivotably attaching the first bores 360 of the wing link 316 to the second bores 372 of the wing mounting plates 113, 115 with pivot pins 390 and (ii) pivotably attaching the wing pivot bores 326, 336 of the housing parts 304, 306 to the first bores 370 of the wing mounting plates 113, 115 with pivot pins 392. In this way, the linkages 108, 110 support the weight of the wing 18.

The slave drive subassemblies 104, 106 are attached to the first housing parts 304 ofthe linkages 108,

110. Each housing 202 is secured to the respective first housing part 304 by fastening via the attachment tabs 234, 236, 238. Mechanical fasteners are used such that the slave drive subassemblies 104, 106 can be easily removed or replaced. As each slave drive subassembly 104,106 is assembled with the respective linkage 108,110, the drive shaft 208 enters the second axial blind bore 284 ofthe inner section 274 of the drum outer 206. The drive shaft 208 is secured thereto with the grub screw 210 such that drive is transferred from the drum outer 206 to the drive shaft 208.

It will be noted that the drums of the slave drive subassemblies 104, 106 rotate on a common axis.

A key advantage of the present invention is that the linkages 108,110 (the actuable drive mechanism) can be installed from the vehicle exterior- i.e. from the top of the boot / trunk lid, and the drive system (the master and slave units and the cables) can be installed from the vehicle interior. In practice, the method of installation is as follows:

• The boot lid is provided with two openings where the linkages will be located;

• The linkages 108, 110 are mounted to the boot lid from the external surface, such that the flange 330 is on the interior side and can be attached to the boot lid and the rest of the linkages (including the articulating mechanism 308) is external to the boot lid;

• The wing 18 is attached (with pre-assembled wing mounting plates);

• The pre-assembled drive system is installed from the interior side of the boot, with the slave units being passed from the interior side, though the openings in the boot lid, to engage the linkages 108, 110;

• Stanchions 19, 20 are installed over the linkages 108, 110.

Use of the active wing actuation apparatus

The apparatus is configured to move between three discrete conditions as depicted in Figures 25a to 25c (although the skilled person will understand that movement between more conditions, or even continuous movement is possible). In these Figures, the outermost housing part of the linkage is not shown so the articulating mechanism 308 can be understood.

Movement between the conditions is effected by delivering power to the motor 120. Rotation of the motor shaft drives rotation of the worm which in turn drives the worm gear 168. This rotates the cable drum 124 in the master drive subassembly 102. Depending on the direction or rotation, either:

1. The first cables 112a, 114a in each set are wound in (placed in tension) whilst the second cables 114b, 114b are unwound (tension is released); or,

2. The second cables 112b, 114b in each set are wound in (placed in tension) whilst the first cables 114a, 114a are unwound (tension is released).

In situation 1, both of the drum outers 206 of the slave drive subassemblies 104, 106 rotate in a first, common rotational direction. In situation 2, both of the drum outers 206 of the slave drive subassemblies 104, 106 rotate in a second, opposite common rotational direction. Actuation of the slave drive subassemblies 104, 106 is simultaneous and synchronised because the drum outers 206 are of the same diameter.

Starting with Figure 25a, the wing 18 is shown in a stowed or closed condition in which it lies closest to the vehicle exterior surface. The wing mounting plate 115 is partially between the two housing parts 304, 306. The crank is in a lower position, and it will be noted that a crank axis CA between its pivots lies on a first (left hand) side of a crank connector axis CCA between its pivots. As will be seen below, in the intermediate and air-brake positions the crank axis moves to the other side of the crank connector axis. Therefore in this position the crank 310 and crank connector 312 have gone past alignment and are over parallel or over centre. In other words, the crank connector axis CCA has crossed the pivot axis Y of the crank 310 in this stowed condition. The elbow of the crank connector 312 abuts the drive shaft 208, and indeed the crank connector 312 is configured (shaped) such that this abutment occurs at an over-centre position- typically in the range of 1 to 5 degrees between CA and CCA about Y.

The crank connector 312 is in its lowermost position, and as such the link arm is at approximately 90 degrees to it. This, in turn, means that the wing link 316 is in a lower position such that the abutment 358 has entered the notch 374 and rests therein. The wing link 316 also rests on the pivot pin 366 between the crank link 312 and the link arm 314. This supports the weight of the wing 18.

When it is desired to move to the intermediate position (Figure 25b), as described above, the motor 120 is driven to drive the master drive subassembly 102. This in turn drives the slave drive subassemblies 104, 106 which rotates the drive shafts 208 in a clockwise direction about the axis Y per Figures 25a and 25b (and as shown in Figure 25b). This rotates the crank 310, which in turn pushes the crank link 312 upwards. This pivots the link arm 314 about the pin 359 and in turn pushes the wing link 316 upwards. Because the wing 18 is pivotably fixed to the housing parts 304, 306 at the front of the wing mounting plate 115, this has the effect of rotating the wing 18 about a wing pivot axis W.

As shown in Figure 25b, as the crank 310 moves towards the intermediate position, it must pass the ridge 388 of the clip 318. In order to do so, it must deform the clip 318 towards the clip flange 328. Once the end of the crank 310 passes the ridge 388, it enters the recess 384. The clip 318 resiles back into a less-deformed position as shown in Figure 25b. Now the crank 310 is positioned in the recess 384, further deformation of the clip 318 is required to move it out of position. Therefore the clip 318 holds the mechanism in this intermediate position until further significant torque is applied to the crank 310.

Moving from the condition shown in Figure 25b to the air-brake position in Figure 25c, the wing 18 is moved from a condition where downforce is increased to a condition where the wing has an aerodynamic braking effect. The motor 120 is powered, the master drive drives the slave drives and the cranks 310 are rotated further in the same direction to the position of Figure 25c.

Rotation of the crank 310, in turn pushes the crank link 312 further upwards. This pivots the link arm 314 about the pin 359 and in turn pushes the wing link 316 upwards. Because the wing 18 is pivotably fixed to the housing parts 304, 306 at the front of the wing mounting plate 115, this has the effect of rotating the wing 18 about the wing pivot axis W.

It will be noted that during this motion, the link arm 314 and the wing link 316 go over centre. The link arm 314 has a link arm axis LAA between its end pivots, and the wing link has a wing link axis WLA between its end pivots. The axes LAA, WLA become aligned (parallel) shortly before the air-brake position and travel past alignment. The axes LAA, WLA have an angle A between them in Figure 25b which is < 180 degrees. Moving from the intermediate condition of Figure 25b to the air-brake condition of Figure 25c, the angle A passes alignment at 180 degrees (and exceeds it by about 5 degrees in the air-brake condition). At this point, the link arm 314 abuts the abutment 358 on the wing link 316 preventing further articulation. The link arm 314 and wing link 316 are locked-out overcentre. The wing link arm 316, and in particular the abutment 356 is configured to lock out the two links at this over-centre position. It will be noted that this is similar to the over-centre lock on the crank 310 and crank link 312 at the stowed position.

What this means is that a rearward force on the wing 18 (F) from e.g. air resistance of the moving vehicle will not tend to try to collapse the linkage and back-drive the system. Back-driving the system could cause damage to the cables (by stretching) and worm gear / worm teeth. This is resisted instead by the lock-out between the link arm 314 and wing link 316. The force F will try to increase the angle A, which is resisted by the abutment 358. The links transfer a compressive force through the housing parts 304, 306 into the vehicle structure. Essentially, the lock-out short-circuits the load path through the rest of the active wing actuation apparatus 100.

Driving the motor 120 in the opposite direction acts to return the wing 18 to the intermediate position and stowed position.

Servicing of the active wing actuation apparatus

One significant advantage of the present invention is that the load path from the wing to the vehicle is carried entirely by the link mechanisms 108, 110. Should any part of the master-slave arrangement require replacement, this is easily achieved without any need to remove the wing 18.

To replace a slave drive subassembly, the user needs to (i) undo the grub screw 210 though the aperture 243 shown in Figure 19. This disengages the drive shaft 208 from the slave drive subassembly.

The three housing bolts can then be undone and the entire slave drive subassembly 106 removed along the shaft axis in direction R (see Figure 19).

It will be noted that because the link mechanisms 108, 110 are stable in all three positions discussed above, the slave drive subassembly 106 can be removed in any of these conditions.

Variations of the above embodiment fall within the scope of the present invention.

The grub screw 210 may be replaced with a splined connection between the drive shaft 208 and slave drive subassemblies 104, 106. This reduces the steps involved in replacing the slave drive 10 subassemblies.

The master drum may be unitary (as described above) or may be two separate drums driven by a common shaft.

Although the wing described within the present application has a single degree of freedom (rotational), the present invention can be used to move wings and spoilers through more complex 15 motion paths. For example combined rotational and translational movement.

Claims

1. A vehicle active surface actuation apparatus comprising:

2. A vehicle active surface actuation apparatus according to claim 1, wherein the drive system is configured to deliver mechanical power to the first actuable drive mechanism via a rotatable drive shaft.

3. A vehicle active surface actuation apparatus according to claim 2, wherein the drive system is can be engaged and disengaged from the first actuable drive mechanism by movement of the drive system along an axis of the drive shaft.

4. A vehicle active surface actuation apparatus according to any preceding claim, wherein the drive system comprises:

a master drive subassembly comprising a motor and a master cable drum;

5. A vehicle active surface actuation apparatus according to claim 4, wherein the first slave drive subassembly comprises a first slave cable drum, and in which the first slave cable drum is configured to transfer rotational power to the first actuable drive mechanism.

6.

A vehicle active surface actuation apparatus according to claim 4 or 5, comprising:

wherein the drive system comprises:

a second slave drive subassembly;

7. A vehicle active surface actuation apparatus according to claim 6, wherein the second slave drive subassembly comprises a second slave cable drum, and in which the second slave cable drum is configured to transfer rotational power to the second actuable drive mechanism.

8. A vehicle active surface actuation apparatus according to any preceding claim, wherein the first actuable drive mechanism comprises a mechanical linkage.

9. A vehicle active surface actuation apparatus according to claim 8, wherein the first actuable drive mechanism comprises a housing for pivotable attachment of a vehicle active surface, and in which the mechanical linkage is configured to pivot the active surface relative to the housing.

10. A vehicle active surface actuation apparatus according to claim 8 or 9, wherein in moving from the first to the second condition of the first actuable drive mechanism, the mechanical linkage moves over-centre to lock the mechanical linkage in the second condition.

11. A vehicle active surface actuation apparatus according to claim 10, wherein in moving from the second to the first condition of the first actuable drive mechanism, the mechanical linkage moves over-centre to lock the mechanical linkage in the first condition.

12. A vehicle active surface actuation apparatus according to any of claims 8 to 11, wherein the first actuable drive mechanism comprises an intermediate stop arrangement to hold the first actuable drive mechanism in an intermediate condition between the first and second conditions.

13. A vehicle active surface actuation apparatus according to claim 12, wherein the intermediate stop arrangement comprises a resilient stop configured to capture a part of the first actuable drive mechanism in the intermediate condition.

14. A vehicle active surface actuation apparatus according to claim 13, in which the intermediate stop arrangement comprises a spring clip.

15. A vehicle active surface actuation apparatus comprising:

16. A vehicle active surface actuation apparatus according to claim 15, wherein in moving from the second to the first condition of the first actuable drive mechanism, the mechanical linkage moves over-centre to lock the mechanical linkage in the first condition.

17. A vehicle active surface actuation apparatus according to claim 15 or 16, wherein the first actuable drive mechanism comprises an intermediate stop arrangement to hold the first actuable drive mechanism in an intermediate condition between the first and second conditions.

18. A vehicle active surface actuation apparatus according to claim 17, wherein the intermediate stop arrangement comprises a resilient stop configured to capture a part of the first actuable drive mechanism in the intermediate condition.

19. A vehicle active surface actuation apparatus according to claim 18, in which the intermediate stop arrangement comprises a spring clip.

20. A vehicle active surface actuation apparatus comprising:

21. A vehicle active surface actuation apparatus according to claim 20, wherein the intermediate stop arrangement comprises a resilient stop configured to capture a part of the first actuable drive mechanism in the intermediate condition.

22. A vehicle active surface actuation apparatus according to claim 21, in which the intermediate stop arrangement comprises a spring clip.

23. A method of installing an active surface actuation apparatus on a vehicle comprising the steps of:

providing an opening in the vehicle surface;

24. A method of installing an active surface actuation apparatus according to claim 23, wherein the drive system engages the actuable drive mechanism on the exterior side.

25. A method of installing an active surface actuation apparatus according to claim 23 or 24, wherein the actuable drive mechanism extends through the opening to attach to the vehicle on the interior side.