Solenoid powered seat latch preferably for motor cars

Abstract: A solenoid operated interlocking motor car seat device of low cost, having a back rest latching 1) to infinite back reclining positions, 2) to a steering wheel to secure a motor vehicle against theft, 3) to programmed tilt positions; the device providing 4) the adjustment of a longitudinal transferable seat, 5) optional the reclining of a seat of the adjustment of knee positions, 6) optional an automatic off-power of the electric seat commands. The components of the device are built in a compact unit ready for the assembly to in-process seat structures. The components are preferably of injection molded engineering plastics; the eccenter discs (4, 7) apply sinusoidal latch surfaces (3B), therewith overcoming eccenter gears. Two electric push button commands, operating two solenoids (14, 16), are placed between the front seats and one, key locked, on the back, doorside.

Description: The present invention refers to an electromechanical interlocking device assembled in a compact unit for a) adjusting the longitudinal position of a seat, b) adjusting infinite reclining positions of a back rest being part of said seat, c) pre-setting infinite rearward tilt positions of said back rest, denominated tilt program, d) locking said back rest to a steering wheel, denominated anti-theft back rest latch, e) providing optional an automatic off-power of the seat commands; f) providing optional a seat for a reclining to infinite knee positions. A system arresting a backrest onto a front wheel similar to the one stated herein is disclosed in European Patent Application Nr. 83306604 (EP-A-0 108 581) and also in WO-A-8 101 121 (corresponding to the preamble of claim 1) as well as in Patent GB-A-2 082 904. The mentioned system refers to the arrest of a backrest onto fixed positions by means of a solenoid powered plunger inserting into notches, while the present invention refers to a system arresting a backrest onto infinite positions by means of a solenoid powered eccentric disc, wherein said function b) of the present device, if applied to the cited devices, would need the latter to completely change the system. The abovementioned functions of the present device are achieved by means of the technical features disclosed in claim 1. The components of the device are assembled onto and into a tube-shaped axle mounted in the axis of a back rest. Said axle with its flange fixed onto a flat triangular support is anchored to a rail sliding on a track, while the back rest is assembled to the joint of a back wheel reclining on said axle. The interlocking command of the device consists of a first and second electric push button placed between the front seats, the first achieving a longitudinal adjustment of a seat, the second a reclining of said back rest . A third push button, placed doorside upon the back rest, provides a tilt from outside. Said three commands are operating two solenoid plungers, pulled out by a spring when off-power in order to latch and pulled in when on-power in order to unlatch; wherein a back tilt onto a pre-set stop is achieved as well as a forward tilt, the latter by means of a coil-or cylindrical spring; wherein the programming of a tilt stop is achieved by engaging simultaneously both said central commands. Consequently, the program does not change when unlatching alternately the back rest or the seat. Further, the present invention provides a back rest latching onto a steering wheel when operating said doorside back command, this option being equipped with a key in order to secure a motor car against theft; optional too, is an automatic off-power of the electric seat commands, which is to be coupled with a starter lock. Said commands are set out of function when starting a motor vehicle in order to prevent hazardous seat adjustments during the ride. Known manually operated auto car back rests with a notch mechanism providing a 100% latch surface are performing a tilt or socalled discontinuing latch and, therefore, are adjustable only onto stepped positions, while toothed eccentric latch gears providing about a 30 to 40% latch do not tilt and, therefore, assure a back rest to latch continously also when reclining. Besides a lack of safety inherent in both said systems, a continuously latching backrest having a seat latching discontinuously is but a hybrid construction. Generally, back rests are mounting horizontally transferable seats with three manual commands respectively three assemblies commonly placed in three different positions; a lever or a knob for adjusting the back, placed in the axis of the back rest; a lever for the back tilt, generally used in two-door cars, placed doorside of the back and a lever for the horizontal adjustment, placed under the seat. Differently, the here described device uses a substantially cost saving single assembly furnishing five electrical seat functions accomplished by two central push buttons and one placed on the back rest. As to the state of art, known seat adjusters, contrary to the here described device, do not provide interlocking eccentric latches substantially exceeding the safety limits set by the automotive industry. The present invention, instead, uses eccentric latch discs, preferably made of engineering plastics, with sinusoidal shaped latch surfaces engaging over 70% of the surface of toothed eccentric gears. Consequently, the present device is supporting heavier load bearings and providing greater impact strength, thus providing additional safety. Further, toothed eccentric discs corresponding to the current quality standards are normally metal made, while the application of, for instance, polyammidic eccentric discs using the herein proposed curved latch surfaces is thoroughly achievable. Considering further, that only a smaller portion of the here described assembly is needed to recline a seat also for the adjustment of knee positions , said device is performing a number of functions comparable only to highly priced motorized seat adjusters. As to be seen, the inventive system differs conceptionally and functionally from known seat latch systems. In the accompanying drawings: Fig. 1 is a front view of a seat latch device, showing a solenoid 16 with a plunger 17 incorporated in an assembly axle 1, the latter mounting a back wheel 3 with a back joint 3A, said wheel having a sinusoidal shaped latch surface 3B; said axle mounting further a support 2 with the upper part fixed onto a squared flange 1C and with the lower part 1B onto a rail 18, the latter sliding in a track 19; axle 1 further mounts a toothed seat lock 8 latching onto a rack 11 within an angle "alpha" providing a cam 10 for an angular interlocking. Fig. 2 is a longitudinal section taken along the line II-II of Fig. 1, showing the device latching a back, a back program and a seat; further, axle 1 mounted in axis X1 onto a support 2, the latter fixed to said axle by screws in holes 20 and 21, said support screwed or welded onto rail 18; axle 1 is incorporating a solenoid 16 with plunger 17 and a second solenoid 14 with plunger 15, said axle is also mounting a back wheel 3 with a back joint 3A and a first eccentric disc 4 cooperating with a first tumbler spring 25 - better shown in Fig. 4 . Mounted onto said axle, too, is a first coil spring 5 fixed on one end to said back joint 3A of back wheel 3 and with the other end inserted into axle 1, said spring reclining forward the back rest. A centric back wheel 3 is cooperating with a centric ring 6 having a bracket 6A, wherein sold ring is interlocking with a second eccentric disc 7 by means of a second tumbler spring 27. A seat lock 8 mounted onto said axle interlocks within said angle alpha with a toothed rail 11 by means of a second coil spring 9 and a cam 10; further, a fastening ring 23 is inserted in a key way of said axle, thus arresting the right end of the assembly onto said axle. While back wheel 3, program ring 6 and seat lock 8 are centric reclining in axis X1 and latched when eccentric discs 4 and 7 are in axis X2 both said discs are reclining when in axis X1 as shown in Fig. 4. Fig. 3 is a front view showing; a forward reclined back wheel 3; a program ring 6 with bracket 6A, a transparent view of a first coil spring 5 fixed on one end to back joint 3A of said back wheel 3 and inserted on the other end into said axle ; back wheel 3 with program ring 6 having a bracket 6A and a flat spur spring 26; further, a sinusoidal shaped internal latch curve 6C of ring 6. Fig. 4 is a front view of a back wheel 3 latched by eccentric disc 4, a plunger 17 at off-power expelled by means of said spring biased solenoid 16, said plunger engaging said disc 4 onto its max. circumference (level X2) and disengaging the latter at a level X1 when the plunger is retracted by said solenoid on-power; wherein a disengaging of said disc 4 is assisted by said flat curved tumbler spring 25 symmetrically fixed with both ends on said disc and its center curve rotating upon axle 1 causing disc 4 to flex on said plunger from axis X2 to X1. Fig. 5 is a front view of an angular interlocking toothed seat latch 8, incorporating into a key bed 8B a second coil spring 9, wherein the latter is inserted with its one end in axle 1 and with the other end reclining the seat latch upward within an angle "alpha" when solenoid 14 is on-power; further shown is a triangular cam 10 cooperating with the plunger 15 of a second solenoid 4, said plunger 15 having an upside radial as well as a lateral conical surface 15A; wherein the lateral surface is achieving a reclining of seat latch 8 and the upside surface an interlocking of eccentric ring 7; wherein said reclining and interlocking is accomplished by said solenoid 14 on-power. As shown in Figs. 1 to 5, the herein disclosed seat device is arresting a back rest by means of a first upside radial conical plunger 17 expelled by a first spring-biased solenoid 16 built in a tube-like axle 1; wherein said plunger at off-power is elevating the eccentric disc 4 upon its maximal circumference from axis X1 to X2, thus locking the external sinusoidal latch surface onto the internal sinusoidal latch surface of back wheel 3, the latter including back joint 3A mounting the upholstery of said back rest. While back wheel 3, at on-power of solenoid 16, rotates on said axle in axis X1, disc 4 in this phase rotates synchron with said wheel on the same axis, i.e. onto a minimum circumference of plunger 17, while tumbler spring 25 cooperates in the latch system the same way as tumbler spring 27, previously described in Fig.4. Therefore, an unlatched back wheel 3 is rotating disc 4 in both directions due to the movement of said back rest, interlocking the same to infinite positions when commanding off- or on-power of first solenoid 16. In order to tilt a back rest from a forward to a pre-set rearward stop position, a program ring 6, cooperating with eccentric disc 7, latches the back by means of a bracket 6A of said ring. Unlatching said ring 6, said bracket 6A is turning disc 7 counterclockwise when a pressure is exerted against the back, reclining rearward the back rest; viceversa, reclining the same forward by means of a coil spring 5, said bracket is rotating disc 7 clockwise by means of a flat spur spring 26, fixed at one end into axle 1. The interlocking of said seat latch, shown in Fig. 5, and said program achieved by ring 6 in cooperation with eccentric disc 7, as well as the interlocking of the back rest, achieved by back wheel 3 in cooperation with eccentric disc 4 work all according to the same system. Therefore, when selecting a reclining position, back wheel 3 and program ring 6 are always interlocked simultaneously. Once the stop-position is set, a longitudinal adjustment of a seat cannot change the reclining program because wheel 3 of the back rest holds bracket 6A also when eccentric disc 8 is unlatched. Viceversa, said program cannot be changed when reclining said back rest because eccentric disc 8 latches ring 6 with bracket 6A. Consequently, a reclining program, or socalled pre-set tilt stop of a backrest can only be selected when both push buttons commands, i.e. for the seat and the backrest are being engaged simultaneously. Providing optionally a push button command of said back rest doorside with a special key lock, a motor car can be secured against theft simply reclining the back rest onto a steering wheel. Such an anti-theft reclining is provided by the present invention without adjunct costs. Further on, the herein described solenoid operated device is providing all seat commands with an automatic off-power by means of an electrical seat circuitry connected to a starter lock interrupting said commands when starting a motor car. Such an arrangement prevents a driver from hazardous seat adjustments during the ride and, consequently, results in higher road safety for passengers and pedestrians.

Claims: A solenoid operated device for interlocking a horizontally transferable seat with a reclining back rest, preferably for motor vehicles, comprising the following components: an assembly axle (1) mounted onto a support (2) in the pivot axis of said back rest, said support (2) being anchored onto a sliding structure (18, 19) of said seat; a seat lock (8), a back wheel (3) with a joint (3a) for said back rest, and a ring (6) cooperating with said back wheel, these three components (8, 3, 6) of said device reclining centric on the circumference of said axle (1) having an axis X1; a first coil spring (5) having one end fixed onto said axle; a first (16) and a second (14) solenoid built into said axle (1), both solenoids (16 resp.14) having plungers (17 resp. 15) retracting against the action of a respective spring when said solenoids are on-power; wherein all said components (1,2,8,3,6,5,9,16,14) are assembled onto said axle (1) in a single unit performing:- a reclining of the back rest and a tilt program of the same to different positions; the latching of said back rest onto the steering wheel in order to secure a motor car against theft; and the longitudinal transfer of the seat having said back rest, characterised in that a) said ring (6) comprises a bracket (6a) cooperating with said back wheel (3), both said ring (6) and back wheel (3) having internal sinusoidal curved latch surfaces; b) a first (4) and a second (7) eccentric disc having outside sinusoidal curved latch surfaces are further provided reclining on said axle (1) centric (level X1) and latching eccentric (level X2); c) a flat spur spring (26) and a second coil spring (9) are provided in addition to said first coil spring (5); d) said first solenoid (16) has an upside conical plunger (17), whereas the plunger (15) of said second solenoid (14) has an upside radial as well as a lateral conical surface (15a) in order to interlock simultaneously said second eccentric disc (7) and said seat lock (8); thereby performing reclining and tilt program of the back rest to infinite positions. The device of claim 1, wherein said back rest latches when said first eccentric disc (4) inserts into said back wheel (3) by means of a first spring-expelled conical plunger (17), the latter elevating the disc (4) onto the maximal conical circumference of said plunger; wherein, said seatback unlatches when the plunger is retracted by said first solenoid on-power operated by a first central or by a lateral push button of the back rest; wherein said eccentric disc (4) resets onto a minimum circumference of the conical plunger, assisted by a flat tumbler spring (25) fixed at both ends onto said eccentric disc (4) and the centre upon the circumference of said axle (1); wherein a reclining angle of said back rest is the angle of an open sector in said axle for the reclining of said disc. The device of claim 1 or 2, wherein said backrest is rearward tilting onto a programmed stop by means of a program ring (6), the latter turning clockwise by the force of a flat spur spring (26) having an internal end inserted in said axle and the external end pulling the program ring; wherein said operations is assisted by a bracket (6A) of the ring (6), linked to said back wheel (3), and by a first coil spring (5) pulling said wheel (3), linked to said back rest, forward; wherein said program ring is turning by means of said bracket, counterclockwise when pulling rearward the back rest. The device of claim 1, wherein a toothed or notched seat latch (8) interlocks with a rack (11), fixed onto a motor car chassis; wherein said second plunger (15) is upside conical to interlock the program but also laterally conical (15A) to interlock synchronously the seat latch, too ; wherein a cam (10) is reclining said seat latch (8) onto said rack (11); wherein a downward reclining of said cam is achieved by said lateral conical part (15A) of said plunger (15) when being expelled; wherein an upward reclining of said cam is achieved by retraction of said plunger; wherein the interlocking of said seat latch is assisted by a second coil spring (9) having one end inserted into said axle (1) and the other end upward reclining said seat latch (8); wherein the interlocking of the latter is synchron with the interlocking of the program, both operations being achieved by the central seat latch push button; wherein an interlocking arc "alpha" of said seat latch is the arc of an open sector provided in said axle (1). The device of any of claims 1 to 4, wherein a disengagement of said seat latch and said backrest is simultaneously achieved, thus permitting the latter to be pre-set to a permanent tilt stop by means of a contemporaneous command of both central push buttons; wherein said permanent tilt stop does not change when engaging alternately one or the other central or only the lateral command on the backrest, doorside. The device of any of claims 2 to 4, wherein all seat commands are off-power prior to the start of a motor car provided that the electrical circuitry of a starter lock is connected with said seat commands. The device of claim 2, wherein a latch of said backrest onto a steering wheel is achieved when engaging said lateral command, doorside; wherein the latter can be blocked using a key lock for the interruption of the circuitry, whereby a combination of said lock with an alarm device is optional. The device of claim 1, wherein said axle and said latching components are preferably made in engineering plastics, thereby improving the impact strength and safety.

Inventors: LIPOWEC WALTER A, LIPOWEC, WALTER A.
Applicants: LIPOWEC WALTER A, LIPOWEC, WALTER A.
Application year: 1989
Main classification: B60R25
IPC codes: B60R25