TECHNICAL FIELD
The subject matter described herein in general relates to a seat assembly of an automotive and in particular relates to a recliner assembly for reclining the seat at a desired angle. BACKGROUND
Automotive vehicles include seat assemblies for supporting occupants within the vehicle. The seat assemblies include a seat cushion and a seat back. The seat back has a front surface for supporting the occupant and an opposite rear surface. Typically, the seat back is pivotally interconnected to the seat cushion by a recliner mechanism. The recliner mechanism allows pivotal adjustment of the seat back relative to the seat cushion between a plurality of reclined position about a fixed, single pivot axis.
Disc-type recliner mechanism is commonly known to those skilled in the art. Such recliner mechanism includes a fixed plate that is fixedly secured to the seat cushion and a mobile plate that is fixedly secured to the seat back. The mobile plate is rotatably coupled to the fixed plate to allow pivotal adjustment of the seat back relative to the seat cushion. An annular rim of teeth is formed in the mobile plate. At least one sector, having teeth on the circumference, is slidably supported between the fixed and mobile plates for radial movement. A cam actuated by a lever arm pushes the sector radially outward thereby meshing the teeth of the sector with the annular rim of teeth provided in the mobile plate. When the sector is lockingly engaged with the annular rim of teeth, the seat back is held in one of the plurality of reclined position.
The recliner mechanism is further provided with a number of dump profile regions on the mobile plate inorder to provide a dump state. During the dump state, the sector is

obstructed from engaging with the teeth of the annular rim due to which a free movement of the seat is achieved. Therefore, in the dump state, the seat is having a free movement. The dump locking, as aforementioned, restricts the range of inclination of the backrest to 360 degree divided by the number of sectors used. Inorder to achieve wide range of inclination, it is desirable to reduce the number of sectors. However, the locking strength of the recliner mechanism depends directly on the number of sectors provided. More the number of sectors, greater is the locking strength of the recliner mechanism, at the same time narrower is the range of inclination of the recliner mechanism. Therefore, inorder to achieve wide range of inclination, the locking strength of the recliner mechanism has to be compromised or else to achieve the high locking strength, the range of inclination has to be compromised. Both the conditions are not desirable.
There is, therefore, a need for providing a well designed recliner mechanism that achieves a wide range of inclination without affecting the locking strength of the recliner mechanism.
SUMMARY
The subject matter described herein is directed to a recliner assembly for automotive seats for reclining the seats at a desired angle. The recliner assembly includes a lower housing, an upper housing, and a plurality of sectors disposed on the lower housing and a guide plate disposed on the upper housing. The guide plate herein guides the radial movement of the sectors thereby locking and unlocking the recliner assembly. A cam, having a plurality of cam profiles, is movably disposed on the guide plate. The cam profiles are movably in contact with the sectors, each sector having a teeth profile. One of

the sectors, called the dump sector, is provided with a dump projection. The upper housing further includes an annular rim having a teeth profile and a circular central cavity. The central cavity is provided with a dump profile.
When the dump sector reaches the region of dump profile, a condition of dump is achieved. The dump condition signifies the free movement of the recliner seat. The advantage of the present subject matter is that wide range of inclination is achieved without compromising the locking strength of the recliner assembly. Further the time and cost for manufacturing the recliner assembly is reduced.
These and other features, aspects, and advantages of the present subject matter will become better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
BRIEF DESCRIPTION OF DRAWINGS
The above and other features, aspects, and advantages of the subject matter will become better understood with regard to the following description, appended claims, and accompanying drawings where:
Fig.l illustrates a perspective view of an automotive seat assembly with a compact high strength recliner according to an embodiment of the present invention.
Fig.2 illustrates a exploded view of the recliner assembly of Fig.l.

Fig. 2(a) illustrates the detailed perspective view of the upper housing of the recliner assembly of Fig. 1.
Fig. 2(b) illustrates the cross sectional view of the upper housing of Fig. 2(a).
Fig. 2(c) illustrates the perspective view of a dump sector according to an embodiment of the present subject matter.
Fig. 2(d) illustrates the cross sectional view of a dump sector of Fig. 2(c).
Fig. 3 illustrates the detailed view of a shaft arm of the recliner assembly of Fig.l.
Fig. 4 illustrates the detailed arrangement of internal parts of the recliner assembly of Fig.l with respect to the upper housing in unlocked condition.
Fig. 5 illustrates the detail arrangement of internal parts of the recliner assembly of Fig.l with respect to the upper housing in locked condition.
Fig. 6 illustrates the dump locked condition of the recliner assembly of Fig.l.
Fig. 7 illustrates the detail arrangement of internal parts of the recliner assembly of Fig.l with respect to the upper housing with four sectors in locked condition.
DETAILED DESCRIPTION
The present describes a recliner assembly for adjusting an automotive seat in a desired position. The recliner assembly includes a lower housing and an upper housing. A plurality of sectors, having a teeth profile on the circumferential end and a wave profile on the central end, are disposed on the lower housing. One of the sectors herein is provided with a dump projection. This sector is called as the dump sector. Further, the upper housing is comprised of an annular rim having a teeth profile and a circular central cavity provided with a dump projection having a dump profile. In the dump profile region, the

dump sector is prevented from engaging with the teeth profile due to the obstruction caused by the presence of dump profile. This results in a free movement of the seat.
A guide plate is further disposed on the upper housing inorder to guide the radial movement of the sectors. A cam having a plurality of cam profiles is movably disposed on the guide plate. The cam profiles are in movable contact with the sectors. When the recliner assembly is operated, the cam rotates and is selectively engages with the sector.
The engaged sector moves with the cam thereby achieving a locked, unlocked or dump condition. During the dump condition, free movement of the recliner assembly is achieved. In the dump condition, the teeth profile of the dump sector does not mesh with the teeth profile of the annular rim. During the unlocked condition, the dump projection of the sector is not held by the dump profile. The dump projection herein is disposed in a space between the dump profile and the guide plate. The advantage of present subject matter is that a wide range of inclination is achieved. Since the dump projection is provided in one sector instead of all three sectors, the dump region in the upper housing is reduced to one. Therefore, the reclining range is increased. Further, the range of inclination is independent of number of sectors used therefore desired number of sectors is used to increase the locking strength of the recliner assembly.
According to one embodiment of the present subject matter, Fig.l exemplarily shows the perspective view of an automobile seat 100. The seat 100 includes a seat cushion 105 and a seat back 110. The seat back 110 is rotatably supported on the seat cushion 105 via recliner assembly 115 & 120. The recliner assembly 115 & 120, mounted on opposite sides of the seat 100, are joined together by a connecting rod (not shown in Fig.) for synchronizing the operation of the two recliner assemblies. The recliner assembly

115 & 120 are provided for controlling the angle of inclination of the seat back 110 relative to the seat cushion 105. The recliner assembly 115 & 120 allows selective pivotal adjustment of the seat back 110 relative to the seat cushion 105 between a plurality of reclined seating positions about the pivot axis (not shown in fig.). A lever release 125 having a slot 130 is attached to the recliner assembly 115 for controlling the functioning of the recliner assembly 115 & 120. The recliner assembly 115 acts as a master as the lever release 125 is attached with the recliner assembly 115 for controlling the recliner assembly 115 & 120. Further, the recliner assembly 120 acts as a slave to the recliner assembly 120 since the recliner assembly 120 follows the motion of recliner assembly 115 transmitted to it by the connecting rod.
Fig. 2 exemplarily shows the exploded view of the recliner assembly 115 according to an embodiment of the present subject matter. The recliner assembly 115 includes an upper housing 210 and a lower housing 205. The lower housing 205 has been provided with a slot 212. The lower housing 205 is secured to the seat cushion 105. Further, the upper housing 210 is secured to the seat back 110.. The upper housing 210 is pivotally coupled to the lower housing 205. The upper housing 210 preferably has a cup shaped configuration with an annular rim 215 having a teeth profile 217. A cover ring 220 encapsulates the upper housing 210 and the lower housing 205 together. Between the upper housing 210 and the cover ring 220 clearance is provided inorder to rotate the upper housing 210 about the axis of a shaft arm 225.
The lower housing 205 is stamped with three slots 230 such that the surface of the lower housing 205 is projected inside. Further, a plurality of circular features 235 is stamped on the upper housing 210 with a hole 240 formed at the centre. The circular

features 235 are the semi piercing features provided inorder to be used for welding with upper housing 210. The shaft arm 225 passes through the hole 240. A circular central cavity 242 is further caved inorder to provide the housing for the locking components. A dump projection 243 is provided inside the central cavity 242 and close to the teeth profile 217. Fig. 2(a) illustrates the detailed perspective view and Fig. 2(b) illustrates the cross sectional view of the upper housing 210 with a dump profile 244 in the dump projection 243.
The recliner assembly 115 includes a locking mechanism movable between locked and unlocked states. In the locked state, the locking mechanism maintains the angular position of the seat back 110 relative to the seat cushion 105 by locking the lower housing 205 and the upper housing 210. In the unlocked state, the upper housing 210 is freely pivotable relative to the lower housing 205 for allowing pivotal movement of the seat back 110 relative to the seat cushion 105. The locking mechanism is biased toward the locked state by any suitable means, such as a coil spring. The shaft arm 225 axially disposed along the pivot axis is operatively coupled to the locking mechanism for pivotal movement between unreleased and released positions for actuating the locking mechanism between the locked and unlocked positions, respectively.
The locking mechanism herein includes a cam 245, three sectors 250(a), 250(b) and 250(c), and a guide plate 255. The cam 245 has a slot 260 at the centre, three equally spaced cam profiles 265 at the periphery and three pin type projections 270 on the cam profiles 265. The cam profiles 265 are wavy in shape. Further, the sectors 250 are provided with teeth profile 275 at the outside and wave profiles 280 in the inside as shown

in Fig. 2. The wave profiles 280 are operatively coupled to the cam profiles 265. A pin type projection 285 is further stamped on each of the sectors 250. The sectors 250 are identical in all respects except the dump sector 250(c) which is provided with a dump projection 277. Fig. 2(c) illustrates the perspective view and Fig. 2(d) illustrates the cross sectional view of the dump projection 277 of the dump sector 250(c).
The sectors 250 are housed inside the slots 230 and are slidable radially. The sectors 250 are connected to the guide plate 255 through slots 290 disposed on the guide plate 255 and the projections 285. The shape of the slots 290 is provided in such a way that a part of the slots 290 is parallel to the circumference of the guide plate 255 and remaining part of the slot is inclined at an angle as shown in Fig. 2. Therefore, one end of the slots 290 is wider than the other end.
During the .operation of the recliner assembly 115 & 120, the shaft arm 225 rotates, the cam 245 which in turn moves the sectors 250 radially outward direction. Due to the movement provided by the cam 245, the sectors 250 slide in the slots 290 via the projections 285. During the locked condition, the projections 285 lie on the broader part of the slots 290 thereby pushing the sectors 250 radially outward. Alternatively, for unlocking the recliner assemlby the projections 285 slide towards the narrower part of the slots 290 i.e. move on an inclined path thereby pulling the sectors 250 radially inward. The guide plate 255 is further connected to the cam 245 via holes 295 provided on the guide plate 255 and projections 270. A hole 297 is provided at the centre of the guide plate 255. The circular central portion 242 provides the housing for the cam 245, the sectors 250 and the guide plate 255 connected together. The teeth profile 275 is faced

towards the teeth profile 217. During the locked state of the recliner assembly 115, the teeth profile 275 is engaged with the teeth profile 217.
Herein, a single dump sector is provided for which a single dump profile region is provided on the circular central cavity. Therefore, remaining region of the circular central cavity is used for setting the angle of inclination for the seat. Although, the number of sectors, without dump projection, is increased, still the range of inclination achieved is same. Simultaneously, the locking strength is increased as the locking strength is directly proportional to the number of sectors used.
Fig. 3 illustrates the detailed view of the shaft arm 225. The shaft arm 225 has a slot 305 and four steps 310, 315, 320 and 325. The slot 130 of the lever release 125 is inserted in slot 305. Further, the step 310 is passed along the hole 212. The radius of the step 315 is greater than the step 310 and the step 320. The =step 315 disposed through the slot 260 and the step 320 is passed through the hole 297. The step 325 is inserted into the hole 240 of the upper housing 210. A shaft arm spring (not shown in Fig.) is mounted on the slot 305 of the shaft arm 225. The shaft arm spring provides a permanent bias to the shaft arm 225. Operation of the lever release 125 by the occupant rotates the shaft arm 225 against the force of the shaft arm spring. It should be appreciated that the spring rate of the shaft arm spring is sufficient to bias the lever release 125 toward the initial position, but not high enough to overcome the bias of the recliner assembly 115 toward the locked state when the lever release 125 is rotated between the initial and required positions. The shaft arm 225 is operatively coupled to the cam 245.
To adjust the seat back 110 between the reclined seating positions, the shaft arm 225 is rotated counter clockwise for actuating the recliner assembly 115 to the unlocked

state. Fig. 4 illustrates the detail arrangement 400 of internal parts of the recliner assembly 115 with respect to the upper housing 210 in unlocked condition. Rotation of the shaft arm 225 in the counter clock wise direction causes the outer wave portion of the cam profile 265 to come in contact with the inner portion of the wave profile 280. The above contact causes the projection 285 to slide towards the inclined end thereby pulling the sectors 250 radially inwards and inside the slots 230 causing temporary unlocking. With the recliner assembly 115 in the unlocked state, the seat back 110 freely rotates relative to the seat cushion 105.
Once the seat back 110 has been adjusted to a desired one of the plurality of reclined seating position, the shaft arm 225 is allowed to rotate clockwise to the unreleased position as the recliner assembly 115, under its internal bias, returns to the locked state. Fig. 5 illustrates the detail arrangement 500 of internal parts of the recliner assembly 115 with respect to the upper housing 210 in locked condition. During the locked state, the cam 245 pushes the sectors 250 radially outward which are disposed inside the slots of the lower housing 205 thereby engaging the teeth profile 275 with the teeth profile 217. Due to the engagement of the teeth profiles, the lower housing 205 and upper housing 210 are locked. Once the recliner assembly 115 is returned to the locked state, the seat back 110 is locked and prevented from rotating relative to the seat cushion 105. During rotation of the shaft arm 225 between the unreleased and released positions, there is no relative motion between the lever release 125 and the shaft arm 225.
Now referring to Fig. 6, which illustrates the dump locked condition 600 of the recliner assembly 115. During the dump locked condition, the dump projection 277 comes

in contact with the profile 244 of the dump projection 243 due to which the radial movement of the dump sector 250(c) is obstructed. In this position, due to the close fit between the hole 240 of the upper housing 210 and step 320 of the shaft arm 225, no axis shift is possible between the shaft arm 225 and hole 240. But in case, sectors 250(a) or 250(b) reaches the area of dump projection 243, the sectors 250(a) or 250(b) are not obstructed by the profile 244 as the sectors 250(a) or 250(b) do not have any dump projection.
As only one sector is provided with a dump projection, the region provided for dump profile is one. Remaining region is now reserved for setting the angle of inclination for the seat. Although, the number of sectors, without dump projection, is increased, still the range of inclination achieved is same. Simultaneously, the locking strength is increased as the locking strength is directly proportional to the number of sectors used. Therefore, in the present subject matter, due to presence of only one dump region in the upper housing, the range of inclination remains constant even on increasing the number of sectorss.
According to another embodiment of the present subject matter, Fig. 7 illustrates the detail arrangement 700 of internal parts of the recliner assembly 115 with respect to the upper housing 210 with four sectors in locked condition. Herein, four sectors 250 are disposed in the lower housing 205. One of the sectors 250(c) is provided with the dump projection 277. The advantage of disposing four sectors is that the locking strength of the recliner assembly is increased.

Further, according to another embodiment of the present subject matter, any number of sectors may be used without compromising the range of inclination.
The aforementioned versions of the subject matter and equivalent thereof have many advantages, including those which are described below.
One advantage of the present subject matter is that the range of inclination is made independent of the number of sectors. Increase in the number of sectors does not change the range of inclination. This ensures that the locking strength is increased, as the locking strength is directly proportional to the number of sectors. Therefore, the range of inclination is increased without compromising the locking strength of the recliner assembly. Conventionally, the range of inclination was ±75° to ±90. But the present subject matter has achieved a wide range ±165° theoretically.
Another advantage of the present subject matter is that the time and cost of manufacturing the recliner assembly is reduced. This is because there is no need to manufacture the sectors having dump projections therefore time required for stamping the dump projection is eliminated. Further, the need for stamping the projections on the upper housing is eliminated thereby further reducing the time and cost for manufacturing.
Although the subject matter has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the subject matter, will become apparent to persons skilled in the art upon reference to the description of the subject matter. It is therefore contemplated that such modifications can

be made without departing from the spirit or scope of the present subject matter as defined.

I/We claim:
1. A recliner assembly for automotive seats, said recliner assembly comprising:
a lower housing;
an upper housing comprising,
an annular rim having a teeth profile, and a circular central cavity;
a plurality of sectors disposed on said lower housing, each of said sectors
having a teeth profile;
a guide plate disposed on said upper housing, said guide plate guides the
radial movement of said sectors;
a cam movably disposed on said guide plate, said cam having a plurality of
cam profiles, wherein said cam profiles movably contact with said sectors, characterized in that said sectors comprise a dump sector, said dump sector provided with a dump projection and wherein said central cavity is provided with a dump profile.
2. The recliner assembly as claimed in claim 1, wherein each of said sectors has a wave profile on an end in contact with said cam.
3. The recliner assembly as claimed in claim 1, wherein said dump projection is held by said dump profile in a dump condition.

4. The recliner assembly as claimed in claim 1, wherein said dump projection is
disposed in a space between said dump profile and said guide plate in an unlocked
condition.
5. The recliner assembly as claimed in claim 1, wherein said dump projection is held
against said circular central cavity by said cam in a dump condition.