VEHICLE SEAT ADJUSTMENT SYSTEM

Abstract: At each side of the seat is a slide mounting assembly consisting of a fixed slide (12) and a moveable slide 22 which carries independent means for controlling fore-aft sliding, front height adjustment, and rear height adjustment. That may be by electric motors (3, 5, 7) or by mechanical means controlled by a lever (107). Driving gear (Figure 3) is mounted in the enclosed space between the walls (24) of the moveable slide and includes epicyclic gearing which in an electrical embodiment, is driven through a worm (32) and worm wheel (34). Racks (40, 56, 76) are used for effecting or controlling the adjustment and are mounted within the enclosed space. A mechanical version (Figure 10) and an electrical version (Figure 7) are interchangeable.

Description: This invention relates to vehicle seat mounting systems which incorporate means for adjusting the position of the seat. Such seat mounting systems are provided for the fore-aft and height adjustment of the front seats of a motor car, or the driving seat of other types of vehicle. In a known seat mounting system there is provided a pair of slide assemblies each of which comprises a stationary member which is fixed to the vehicle floor and a movable member which supports one side of a framework onto which the seat is fixed. Fore-aft adjustment of the seat is accomplished by relative sliding, and height adjustment of the seat is provided by quadrant geared levers which are pivotally mounted at the front and rear ends of the movable slide members. The other end of each of the levers is fixed to a front or rear corner respectively of the seat supporting framework. Height adjustment at the one side of the seat is transferred across to adjust the other side by front and rear torque tubes. The mounting system described above suffers from the disadvantages that foot room for the rear passenger in a motor car is restricted by the rear torque tube. Likewise storage space under the seat is inaccessible because of both of the torque tubes. Furthermore, the mechanism is exposed within the space under the seat so that anything that is placed there would be likely to come into contact with lubricant on the rack. In EP-A- 0130275 there is disclosed a seat slide comprising two members having generally L-shaped cross-sections, one slidable with respect to the other, which define a generally square cross-section cavity therebetween. Fore-aft adjustment is provided by means of a pinion mounted on the vertical wall of the movable member meshing with a rack mounted on the horizontal wall of the fixed member, both pinion and rack being located within the cavity. EP-A-076 041, corresponding to the preamble of claim 1, discloses a vehicle seat slide comprising a pair of members, one of which is formed from two sheet material components having a space therebetween, within which a locking trigger is pivotally mounted. The locking trigger is provided with teeth which engage in slots formed in the other member to maintain the relative positions of the two members. The trigger teeth may be lifted clear of the slots by an operating handle to allow fore-and-aft adjustment of the seat. It is an object of the present invention to provide an improved seat adjustment mechanism. According to the invention a vehicle seat adjustment mechanism comprises two slides which co-operate in sliding relationship and which have a substantially enclosed space having a symmetrical cross-section therebetween one slide comprising two closely spaced parallel walls for said enclosed space arranged symmetrically about the axis of symmetry of said cross-section, characterised in that at least one adjustment member is positioned between and supported by both the walls. Preferably the said one slide comprises an inverted U-shaped channel having the closely-spaced parallel walls and the adustment member comprises a gear mounted between said parallel walls and having teeth projecting from between the walls and meshing with teeth on the other slide. Such a seat adjustment mechanism may be electrically driven by electric motors. According to another embodiment of the invention a pair of seat adjustment mechanisms according to claim 1 are provided one of which is mechanically operated and the other of which is electrically operated, and the two mechanisms have corresponding means for connection respectively to a floor or wall and to the front and rear of a seat so that the mechanisms are interchangeable and a user can choose either the electrical or the mechanical mechanism. According to a further embodiment of the invention, a seat adjustment mechanism kit comprises two similar height adjustment mechanisms according to claim 1, one for each side of the seat and each including means for independently adjusting the height of the front and the rear of the seat. There may also be interconnecting means for extending transversely to ensure angular register between corresponding components on opposite sides of the seat. According to another embodiment of the invention a seat adjustment mechanism according to claim 1 comprises a member for engagement with a floor or wall and a member for securing to a seat at front and rear includes independent front and rear height adjustment mechanisms and a single operating member which can be used to enable the occupant to adjust the height of either the front or the rear of the seat, but not the other, at the same time. According to another embodiment of the invention a fore/aft adjustment mechanism according to claim 1 for a seat having fixed and movable slides includes a rack and pinion, the pinion being mounted within one of the slides and the rack being mounted on, or part of, the other slide. The pinion may be driven by a worm, for example from an electric motor. Such a worm may drive a worm wheel which drives a planet wheel forming a component of a planetary wheel system of which the pinion is a component. According to another embodiment of the present invention a seat adjustment mechanism according to claim 1 comprises a member for engagement with the floor or wall and a member for securing to a seat at the front and the rear and includes independent front and rear height adjustment mechanisms, each mechanism having a lock for retaining the seat front or rear at a set height, and a lever for releasing either lock and arranged to prevent the other lock being released for as long as the first lock is released. The height adjustment mechanisms may each comprise a pair of engageable components one of which moves to effect height adjustment, but is immovable when engaged with the other, while the lock, until it is released, holds the two components in engagement. The lever may be positioned between and coupled to, the two locks and conveniently has a handle positioned for easy manual operation by an occupant of the seat. The engagement components can be spring biased into engagement although the spring bias can be overcome by the weight of the occupant if the corresponding lock is released. If the lever is free such spring bias means can be arranged to automatically centre the lever. A seat adjustment mechanism of that kind can be positioned at one side of the seat between the floor and the bottom of the seat and may have connection points exactly corresponding to those on the alternative electrical adjustment mechanism mentioned above. The mechanism could be duplicated at the other side of the seat. According to another embodiment of the invention, there is provided a vehicle seat adjustment system for movably supporting a seat comprising; a pair of elongate slide assemblies according to claim 1 each including: a) first and second slide members which co-operate in sliding relation with one another and together define a substantially enclosed space; b) a fore/aft adjustment gear means including a fixed gear means which is integral with or mounted on the first slide member so that it lies within the enclosed space, a drivable gear means which meshed with the fixed gear means and is mounted on the second slide member, and a gear train connected to drive the drivable gear but which cannot be driven thereby, so that by driving the drivable gear the first and second slide members are caused to slide relative to one another; c) a front height adjustment gear means including a driven gear which is arranged to support and to alter the height of a respective side of the front of the seat and a drivable gear, both of which are supported by one of the slide members in meshed contact within the enclosed space, and a gear train connected to drive the drivable gear but which cannot be driven thereby, so that by driving the drivable gear the respective slide of the front of the seat is moved, vertically, d) a rear height adjustment gear means including a driven gear which is arranged to support and to alter the height of a respective side of the rear of the seat and a drivable gear both of which are supported by one of the slide members in meshed contact within the enclosed space, and a gear train connected to drive the drivable gear but which cannot be driven thereby, so that by driving the drivable gear the respective side of the rear of the seat is moved vertically. In this system, the fore-aft adjustment gears are at least substantially contained within the space defined by the slide members, thereby removing the dangers and dirtiness of an exposed rack. Because the front and rear height adjustment means are independent on each side of the seat, the requirement of connecting torque bars is eliminated, thus making the space beneath the seat accessible. In a preferred form the invention provides a vehicle seat adjustment system which includes a first electric motor connected to the two fore-aft adjustment gear means by respective flexible drive cables and adapted to rotate them in synchronism. Preferably, the invention also provides a vehicle seat adjustment system which includes a second electric motor connected to the two front height adjustment gear means by respective flexible drive cables and adapted to rotate them in synchronism. Preferably the invention also provides a vehicle seat adjustment system which includes a third electric motor connected to the two rear height adjustment gear means by respective flexible drive cables and adapted to rotate them in synchronism. The flexible drive cables enable the electric motors to be conveniently positioned. In another preferred embodiment the invention provides a vehicle seat adjustment system according to claim 1 in which the fixed gear means and meshing drivable gear means of the fore-aft adjustment gear means is a rack and pinion. Preferably the pinion comprises an annulus carrying external teeth meshing with the rack and internal teeth meshing with a plurality of gear wheels by which in the annulus is rotatably supported on the second slide member. Preferably one of the gear wheels is rotatably mounted on the second slide member and connected via the associated gear train to the first motor whilst the remaining gear wheels are floating, all the gear wheels constituting planet wheels meshing with a central sun wheel. In another preferred form the invention provides a vehicle seat adjustment system according to claim 1 in which the gear trains for driving the drivable gears are encased in housings mounted on the sides of the respective slide members. Preferably the gear trains are worm and worm wheel gear trains. In another preferred form the invention provides a vehicle seat adjustment system according to claim 1 in which the drivable gears of the front and rear height adjustment means comprise gear sectors carried at one end of respective pivotally mounted levers. Certain specific embodiments will now be described by way of example with reference to the accompanying drawings, in which:- Figure 1 is a schematic plan view of a vehicle seat adjustment system in accordance with the invention for electrical operations; Figure 2 is a sectional side elevation taken on line II-II of Figure1; Figure 3 is a sectional end elevation of a slide member of the system taken on line III-III of Figure 1; Figure 4 is a diagrammatic view of a part of Figure 3; Figure 5 is a view on the line V-V in Figure 4; Figure 6 is a view on the line VI-VI in Figure 4; Figure 7 is a view corresponding to Figure 2 but of an alternative mechanism; The adjustment system comprises two slide assemblies 10, each of which is connected to a front and rear corner of a seat supporting framework 4, two fore-and-aft adjustment means 30, two front height adjustment means 50, two rear height adjustment means 70, and three electric motors 3, 5 and 7, each having two flexible drive cables 2. At each side of the system is an assembly of one slide pair, and one of each of the adjustment means 30, 50 and 70, arranged to be driven by one of the flexible drive cables 2. Each of the slide assemblies 10 comprises a stationary slide 12 and a moveable slide 22. The stationary slide 12 has a cross-section, as shown in Figure 3, generally in the form of a channel having a base 14, sides 16, and inwardly extending portions 18. Each end of the stationary slide 12 is adapted for fixing it to a vehicle floor, and supporting the rest of it at a height slightly raised from the floor. The base 14 has a series of apertures or windows 20 cut along its centre, which are pitched at regular intervals of about 12.5 mm and whose function will be described in relation to the fore-and-aft adjustment means 30, below. The moveable slide 22 has an inverted 'T'-shaped cross-section whose head is slidably received within the fixed slide and whose stem extends upwardly through the gap defined by the portions 18 of the fixed slide, as shown in Figure 3. The movable slide is formed by folding a sheet metal strip to define a deep inverted U-shaped channel having two closely spaced walls 24, then bending the ends of the walls 24 perpendicularly in the same sense at two positions to form two U-section channels having bases 26 and outer walls 28. The movable slide 22 is slidably supported within the stationary slide 12 by rollers 13 which run between the base 14 of the stationary slide 12 and the bases 26 of the movable slide. The slide assembly 10 is pre-loaded to prevent rattling, by ball bearings 15 which are placed in races formed between the inwardly extending portions 18 of the stationary slide 12, and the U-section channel bases 26 and the outer walls 28 of the movable slide 22. Each fore-aft adjustment means 30 is incorporated in its slide assembly 10, and comprises a worm 32 and a worm wheel 34, a planetary gear system 36 and a rack 38 and pinion 40 as shown in Figures 2 and 3. The worm 32 engages the worm wheel 34 which is fixed to a spindle 42, the whole assembly being mounted within a casing 44 on the outside of one of the walls 24 of the movable slide 22. The spindle 42 is supported by, and extends through, the walls 24 of the movable slide 22. The gear system is shown in detail in Figures 4, 5 and 6. The worm wheel 34 can turn on the spindle 42 and is fast with a sun gear 61 which protrudes through a hole in a nylon plate 63 which is formed with internal teeth defining an annulus gear 64. The plate 63 closes the open side of the worm casing 44. A planet carrier plate 62 carries four planet wheels 65, each free on an axle carried by the plate. The planet wheels mesh around the sun gear 61 and within the annulus gear 64, which is fixed, so that as the sun gear 61 is driven by the motor through the worm and worm wheel, the planet plate 62 rotates carrying the planet wheels 65 with it. The planet plate 62 is fast with a gear wheel 46 which lies between the walls 24, and thus within the stem of the movable slide 22. The gear wheel 46, in turn, meshes with internal annulus gear teeth 48 of the pinion 40 and a free wheeling sun gear 47, both of which are also located within the stem of the movable slide 22. The sun gear 47 can rotate on a shaft 49 held at its ends in the slide walls 24. Three other free wheeling planet wheels 45 are also mounted within the stem of the movable slide 22; these free wheeling planet wheels 45 together with the driven planet wheel 46 support the pinion 40. The pinion 40 has gear teeth formed around its outer circumference which mesh with the windows 20 in the base 14 of the stationary slide 12 which form the rack 38. In use the adjustment system is secured, e.g. to the floor of a vehicle and supports a seat (not shown) whose fore-aft position, height, and fore-aft angular inclination, may be adjusted. The fore-aft slide adjustment is effected by the motor 3 which drives each of the fore-aft slide adjustment means 30 by way of the two associated flexible drive cables, the paths of which are shown in chain dotted lines in Figure 1. Each drive cable drives the associated one of the worms 32. Driving of the annulus gear teeth 48 rotates the pinion 40 in relation to the rack 38 thus causing the movable slide 22 to slide in relation to the stationary slide 12. The worm gear and the two epicyclic gear arrangements, each give speed reduction and also reduce the back loading on the drive due to the force tending to move the slide. The front height adjustment means 50 are incorporated whith the slide assemblies 10 in a similar way to the fore-aft adjustment means 30. The motor 5 is connected by a flexible drive cable to a worm which meshes with a worm wheel which drives through an epi-cyclic drive a gear wheel 52 located between the walls 24 of the movable slide 22, and corresponding with the planet wheel 46 in the fore-aft drive. The epi-cyclic drive is similar to the drive 61-65 described above. However, instead of driving a second epi-cyclic gear, the gear wheel 52 meshes with an arcuate rack 54 on one end of a lever 56, which also lies between the walls 24. The lever 56 is pivoted about a spindle 57 which is supported by the walls 24 of the moveable slide 22. The other end 58 of the lever 56 extends beyond the front end of the moveable slide 22 and is pivotally connected in a slot in an arcuate movement compensation link 60, the upper end of which is pivotably connected to the seat supporting framework 4. The rear height adjustment means 70 is similar to the front height adjustment means 50. The motor 7 is connected via a cable, a worm and a worm wheel to rotate a gear wheel 72 which meshes with an arcuate rack 74 on one end of a lever 76, the components 72, 74 and 76 lying between the walls 24 of the moveable slide 22. The other end 78 of the lever 76 extends beyond the rear end of the moveable slide 22 and is pivotably connected to a link 80 which is attached to and extends from the seat supporting framework 4. Height adjustment of the seat supporting framework 4 is effected by actuation of both front and rear adjustment means 50 and 70 by motors 5 and 7. The motor 5 drives each of the front adjustment means 50 by way of the flexible drive cables, the paths of which are shown in chain dotted lines in Figure 1. Each cable drives one of the worms, thus driving the worm wheel and gear wheel 52 which causes the lever 56 to pivot about the spindle 57. Pivoting of the lever 56 results in movement of its other end 58, which movement is transmitted to the seat supporting framework 4 by the link 60. The motor 7 drives each of the rear adjustment means 70, again by way of flexible drive cables, the paths of which are shown in chain dotted lines in Figure 1, and each cable drives one of the worms, thus driving gear wheel 72 and causing the lever 76 to pivot. Pivoting of the lever 76 causes movement of its other end 78 which is transmitted by the seat supporting frame 4 through a fixed lug 80. By independent operation of either of the motors 3 or 5, the seat supporting frame can be tilted to a desired angle. Figure 7 shows a modified version in which the flat end 58 of the lever 56 is pivoted to a link 59, which is in turn pivoted to the seat framework 4.

Claims: A vehicle seat adjustment mechanism comprising two slides (12,22) which co-operate in sliding relationship and which have a substantially enclosed space having a symmetrical cross-section therebetween, one slide (22) comprising two closely spaced parallel walls (24) for said enclosed space arranged symmetrically about the axis of symmetry of said cross-section, characterised in that at least one adjustment member (45-48, 72-76, 52-56, 92,93,105,114) is positioned between and supported by both said walls (24). A vehicle seat adjustment mechanism according to claim 1 characterised in that the said one slide (22) comprises an inverted U-shaped channel having said two closely spaced parallel walls (24). A vehicle seat adjustment mechanism according to claim 1 or claim 2 characterised in that the adjustment member comprises a gear mounted between said parallel walls (24). A vehicle seat adjustment mechanism according to claim 1 or 2 characterised in that the adjustment member comprises a gear mounted between said parallel walls (24) and having teeth (40,88) projecting from between the walls and meshing with the teeth on the other slide (12). A vehicle seat adjustment mechanism according to claim 4, characterised in that said teeth on the other slide (12) are defined between apertures (20) spaced-apart along the length thereof. A vehicle seat adjustment mechanism according to any one of claims 3, 4 or 5 characterised in that the gear mounted between the walls (24) includes an annulus gear (48), a sun gear (47) and one or more planet gears (45,46). A vehicle seat adjustment mechanism according to any one of the preceding claims characterised in that drive means (32) is connected via a speed reduction gear arrangement (32,34;61-65) to the adjustment member or members (45-48,72-76,52-56,92,93,105,114). A vehicle seat adjustment mechanism according to claim 7 characterised in that the drive means (32) is driven by means of a motor (3,5,7) which is preferably an electric motor. A vehicle seat adjustment mechanism according to claim 6 characterised in that the drive means (32) is connected to the, or one of the planet gears (45,46). A vehicle seat adjustment mechanism according to any one of the preceding claims characterised in that at least one adjustment member comprises two seat height adjustment mechanisms, one (50,52-56) for the front of the seat and the other (70,72-76) for the rear of the seat, the two mechanisms being operable independently by means of a single operating handle (107). A vehicle seat adjustment mechanism according to claim 10 characterised in that the seat height adjustment members comprise toothed gear sectors (54,74) each carried at one end of respective pivotally mounted levers (56,76). A pair of vehicle seat adjustment mechanisms each according to any one of the preceding claims characterised in that one mechanism is mechanically operated and the other of which is electrically operated, and the two mechanisms have corresponding means for connection respectively to a floor or wall and to the front and rear of a seat so that the mechanisms are interchangeable and a user can choose either the electrical or the mechanical mechanism.

Inventors: BABBS, FREDERICK WILLIAM
Applicants: DUNLOP COX LIMITED
Application year: 1986
Main classification: B60N2
IPC codes: B60N2