WO2000063043A1

WO2000063043A1 - System for coordinating electrical actuation with the opening of a mechanical lock for vehicle parts

Info

Publication number: WO2000063043A1
Application number: PCT/US2000/010640
Authority: WO
Inventors: Kevin N. Tribbett; Donald T. Heckel, Jr.; Scott Stiffler
Original assignee: P.L. Porter Co.
Priority date: 1999-04-20
Filing date: 2000-04-19
Publication date: 2000-10-26
Also published as: AU4474900A; CA2367478A1; EP1175311A1

Abstract

The system for controlling the position of vehicle seat parts includes a mechanical lock and a power actuator (40). The actuator uses a rotating lead screw (42) to translate a threaded nut (54). Rotation within a coupler is directed through a rotating cable to rotate the lead screw. Rotation within the coupler also translates a mechanism that unlocks the mechanical lock as the power actuator translates the threaded nut. The threaded nut moves or pivots a vehicle part.

Description

SYSTEM FOR COORDINATING ELECTRICAL ACTUATION ΠΉ THE OPENING OF A MECHANICAL LOCK FOR VEHICLE PARTS

BACKGROUND OF THE INVENTION

1. Field of the Invention: The present invention relates to mechanisms used primarily in vehicles that move or pivot seat parts relative to each other and lock the parts together.

2. General Background and State of the Art: Mechanical locks allow parts to move or pivot relative to each other and to lock them together when necessary. Vehicle seats commonly use mechanical locks to control seat elevation, tilt angle and recline. Porter and Sem- ber, U.S. Patent No. 3,874,480 (1975), "Friction Brake Mechanism," Porter, U. S. Patent No. 4,577,730 (1986), "Mechanical Lock," and Stringer, U.S. Patent No. 5,819,881 (1998), "Dual

Locking Linear Mechanical Lock For High Loads," are three examples of such locks.

For one form of mechanical lock, an elongated housing attaches to a fixed part of an automobile. For example, in Patent No. 5,819,881, a rod translates within a housing that is fixed in the vehicle. One end of the rod attaches to a movable or pivoting automobile part such as a seat back that is locked and unlocked. One or two coil springs encircle the rod. One spring end is fixed in the housing, and the other spring end attaches to a lever. Each spring's normal inside diameter is less than the rod's outside diameter. Therefore, the springs normally grip the rod. When a driver or passenger moves the handle, the spring uncoils slightly. That action increases the springs' inside diameter enough to release the rod. Mechanical locks such as the one described in Patent No. 5,819,881 typically operate manually. The user directly operates a handle that connects to the spring lever, or he or she operates a handle that connects remotely to the spring lever through a cable or other connector.

In most systems that use mechanical locks, when the user releases the lock, the user provides the manual force or a spring provides force to move or pivot a vehicle part. For example, the user releases the lock and pushes against the spring-loaded seat back to recline the seat. When a user wants to tilt the seat back forward, he or she leans forward and a spring maintains the seat back against the user's back.

Most manual seat recline mechanisms use two mechanical locks. The seat back typically has two upright arms along the sides and within the seat. A portion of each arm extends below the seat back's pivot point, and a mechanical lock attaches to each portion. To recline a seat back, both mechanical locks must release their rod.

More expensive vehicles use motors for seat positioning and recline. So-called "power seats" have become a selling point. The power actuator for one motor system uses a motor to drive a lead screw. A threaded fitting on the lead screw translates along the lead screw as the lead screw rotates. By anchoring the motor to the vehicle and the threaded fitting to a seat part that moves or pivots, lead screw rotation translates the fitting to move or pivot the seat part, which customers and users often want.

Power seats have several advantages. First, their controls can be mounted in many locations. The controls for tilt, recline, and horizontal and vertical positions can be located along the side or front of the seat, on the door or elsewhere. Second, power seat controls have a luxurious feel.

INVENTION SUMMARY

One object of the present invention is to disclose and provide a system for opening mechanical locks remotely through an electrical switch. Another object is to combine a power actuator with the mechanism for opening a mechanical lock. Another object of the present invention is coordinating the opening of the mechanical lock with initial movement of the power actuator.

The system for controlling the position of vehicle seat parts of the present invention includes a mechanical lock. The lock comprises a housing having one end connected to a first part of the vehicle. A rod translates within the housing. One end of the rod attaches to a movable part of the vehicle. A locking mechanism on the housing selectively prevents movement of the rod or releases the rod to permit movement of the vehicle parts relative to each other. The system also includes power actuator. The actuator comprises a lead screw having one end connected to a part of the vehicle. A nut on and translating relative to the lead screw connects to another part of the vehicle. A motor causes relative rotation between the nut and the lead screw. A coupler extending between the motor and the mechanical lock re- leases or secures the mechanical lock in response to activation of the motor.

The coupler includes a threaded shaft connected to the motor. A threaded gear, which is threaded on the threaded shaft, moves along the shaft. Movement of the threaded gear along the threaded shaft releases or secures the mechanical lock. An output gear meshes with the threaded gear, and the threaded gear can move along the output gear. Load on the output gear prevents its rotation as the threaded gear moves along the output gear. A stop in the path of the threaded gear blocks movement of the threaded gear along the output gear. When the threaded gear cannot translate, it overcomes the load and rotates with the threaded shaft. That causes the threaded gear to rotate the output gear. The output gear connects to the actuator to provide relative rotation between the lead screw and the nut. These and other objects will be evident from the detailed description of the preferred embodiments and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of an exemplary embodiment of the system of the present invention shown mounted on a vehicle seat. FIG. 2 is a plan view of the actuator of the present invention.

FIG. 3 is a cross-section of a mechanical lock that could be used with the present invention.

FIG. 4 is a sectional view of a power actuator that the present invention also can use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The system for controlling position of vehicle seat parts comprises three major subsystems, which mount on and affect vehicle parts. In the exemplary embodiment of FlG. 1, the system mounts on a vehicle seat 10 and is used to recline the seat. The system can affect other seat parts too. The system includes a mechanical lock 20, power actuator 40 and a coupler 60. Seat 10 has a seating surface 12 and a seat back 14. Seat arms (not fully shown) run along the sides and within the seat back. The lower portions 16 and 17 of the seat arms extend below the seat back pivot points 18. Mechanical lock 20 and power actuator 40 coordinate their actions. Therefore, though the application describes the mechanical lock and power actuator separately, they work together. Thus, the application may discuss how mechanical lock 20 releases the seat back, but unless the power actuator 40 also acts, releasing the mechanical lock has a limited or no effect. Coordination comes from the coupler 60 in a manner described below. The mechanical lock 20 can have many different designs. The previously mentioned

Stringer Patent No. 5,819,881 is an example of one design, and its disclosure is incorporated by reference. The mechanical lock includes a housing 22. One end 24 of the housing attaches to a first part of the vehicle. In the exemplary embodiment, end 24 attaches to a fixed support (not shown) in the seat 10. A rod 26 translates within the housing. The left side (Fig. 3) of the rod remains within the housing. The other (right) end of the rod projects out of the housing and attaches to a second part of the vehicle. A compression spring 39 urges rod 26 out of housing 22. In the exemplary embodiment, the rod attaches to lower portion 17 of a seat arm (FIG. 1). As rod 26 moves outward from the housing 22, lower portion 17 of the seat arm pivots clockwise about pivot point 18. That action pivots the seat forward. Likewise, to re- cline the seat, rod 26 moves into the housing 22.

In one form, which FIG. 3 shows, the mechanical lock includes a pair of wound locking springs 30 and 31 fixed in the housing around the rod. The normal inside diameter of the spring coils is less than the rod's outside diameter. Consequently, the spring coils normally grip the rod. Because each spring is fixed within the housing, the springs prevent longitudinal movement of the rod. To fix each locking spring in the housing, each spring has a fixed tang

32 and 33, which seats in a corresponding notch in housing bushings 34 and 35. Each spring also has a second end tang 36 and 37, each of which fits in a groove in lever 38. Rotating the handle applies a force on the spring tangs attached to the lever. That uncoils the spring slightly, which increases their inside diameter of the spring coils enough to release the rod.

For some applications, a handle that the user can reach connects directly to the coil spring lever 38. Moving the user handle directly moves the spring lever 38 to uncoil the springs. Other systems, including the present one, move the spring lever remotely.

Instead of the mechanical lock that uses coil springs to grip or release a translating rod, the present invention can use many other mechanical locks. D.T. Heckel, U.S. Patent No. 5,689,995, "Actuator That Adjusts to Side Loads Automatically by Pivoting Internally," which is incorporated by reference, describes a lock having a gear nut within a housing. A lead screw on which the gear nut is threaded traverses the housing. As the lead screw moves axially, the gear nut rotates. When a manually controlled part projects into castellations on the outside of the gear nut, the gear nut cannot rotate. That prevents translations of the lead screw.

J. Zhuang and K. Tribbett, Application Ser. No. 09/088,212, filed May 29, 1998, "Mechanical Lock with a Cam-Driven Locking Pawl," describes another mechanical lock.

The application is incorporated by reference. It includes a toothed rack mounted in a stationary housing. The housing also carries a pivoting pawl that has teeth to engage the rack teeth. A cam pivots the pawl in one direction to disengage the pawl teeth from the rack teeth, which allows the rack to translate within the housing. The pawl is spring loaded. When a user stops applying force on the cam, the spring returns the pawl to the position where the pawl teeth engage the teeth on the rack to lock the rack against translation within the housing.

The system of the present invention also comprises a power actuator 40. In the exemplary embodiment, the power actuator includes a lead screw having one end connected to part of the vehicle. FIG. 4 shows an exemplary embodiment of the power actuator 40, but the FIG. 1 schematic is discussed first to show the actuator's environment. As FIG. 1 shows, one end 44 of lead screw 42 attaches to lower seat arm 16. A powered gear nut within housing 46 surrounds lead screw 42. The housing is fixed to part of the vehicle, In the exemplary embodiment, the housing attaches to a fixed support (not shown) in the seat. As explained be- low, coupler 60 operably connects to and rotates the gear. That rotation rotates lead screw 42 which pivots lower arm 16 to pivot seat back 14.

The application refers to the mechanical lock 20 being attached to first and second parts of the vehicle and power actuator 40 being attached to third and fourth parts of the ve- hide. Those of ordinary skill will appreciate that those parts may be at the same location. In the exemplary embodiment of FIG. 1, the mechanical lock and power actuator are spaced apart approximately the width of the seat, but in other applications, one or bothrejϊds of each^" - may be attached to the same part.

The FlG. 4 embodiment of the power actuator differs from the actuator described in FlG. 1. In FlG. 4, the power actuator 40 includes a worm 48 inside the housing 50. In a manner described below, coupler 60 rotates the worm. The worm meshes with gear 52, which attaches to the lead screw 42. Therefore rotation of worm rotates gear 52 and lead screw 42. A threaded nut 54 is threaded onto the lead screw. The distal end 58 of the lead screw is a flange that has a bore 56 extending through the flange. A pin or bolt (not shown) extends through the bore and attaches to part of the vehicle or elsewhere on the seat. As the lead screw rotates, the threaded nut translates along the lead screw and moves the part of the vehicle to which it attaches. Housing 50 also has a flange 51. A bolt extends through bore 53 in the flange to attach the housing to another part of the vehicle.

Refer next to FlG. 2 for the construction of the coupler 60. A pair of bearings 64 and 66 supports a threaded shaft 62. Motor 61 (shown schematically) connects to and rotates the threaded shaft. A threaded gear assembly is threaded on the threaded shaft for movement along the threaded shaft. In the exemplary embodiment the threaded gear assembly comprises a pair of gears 68 and 70. A shaft 72 attaches the two gears together so that they translate and rotate together. The gears straddle a flange 74 on rack 76. The motor 61 connects electrically to a switch 63 accessible to the driver or a passenger. As the motor rotates the threaded shaft 62, gears 68 and 70 translate along the threaded shaft. Outside gear teeth 80 on gears 68 and 70 mesh with teeth 84 on output gear 82. This meshing permits gear 68 and 70 to translate along output gear 82 with the teeth of the gears meshed together. Output gear 82, which is support on bearings 86 and 88, connects to a flexible output oable 90. The flexible output cable attaches to worm 48_of the power actuator 40 (Fig. 4). That connection puts a load on output gear 82.

As motor 61 rotates the threaded shaft 62, gears 68 and 70 translate along the threaded shaft instead of rotating output gear 82 because of the load on the latter gear. As the threaded gears 68 and 70 move in one direction, for example, to the left in FlG. 2, gear 70 reaches a stop 92 at the end of the threaded shaft. In the exemplary embodiment,^" the stop-js- adjacent bearings 66, but it is not required to be in that location. The stop can be a fixed ring around the threaded shaft. The stop also may be a member projecting from the housing 94 and in the path of threaded gears 68 and 70. When the threaded gears reach the stop, they cannot translate along shaft 62. Consequently, they can only rotate with rotation of the threaded shaft. That rotation provides sufficient torque to overcome the load on output gear

82. Consequently, the output gear rotates.

Because the flange 74 on rack 76 is between the two threaded gears 68 and 70, as the gears move along the threaded shaft, they translate the rack teeth 96 on rack 94. Rack teeth

96 engage teeth 100 on half gear 98. Translation of the rack, therefore, rotates half gear 98 about its axis 102. A cable 104 attaches to flange 106 at the bottom of half gear 98. As rack

96 moves to the left (FlG. 2), half gear 98 rotates counterclockwise. This rotation pulls on cable 104. The cable extends to the mechanical lock 20 (FlG. 1) and attaches to its lever 38 (FlG. 3). Therefore, the aforementioned movement of cable 104 moves lever 38 to uncoil the locking springs 30 and 31 (FlG. 3) to release rod 26. As cable 104 opens the mechanical lock

20, threaded gears 68 and 70 reach stop 92 so that the output gear 82 begins rotating. That rotation also rotates the output cable 90 which begins powering the worm 48. Consequently, the power actuator 40 begins driving the lead screw to pivot the seatback. When the seat back is properly angled, the user releases switch 63 (FlG. 2) and stops power to motor 61. Spring forces such as those from the spring 39 on the mechanical lock (FlG. 3) urge half gear 98 towards its neutral position shown in FlG. 2. Torque from half gear 98 acting on rack 76 and its flange 74 urges translation gears 68 and 70 to their neutral (FlG. 2) position. A clutch 65 between motor 61 and threaded shaft 62 permits the threaded shaft to rotate under the urging of threaded gear 68 and 70. Therefore, when motor 61 receives no power, the coupler 60 returns to its position shown in FlG. 2. In that position the mechanical lock is locked and the power actuator 40 is not active. To pivot the seat back 14 (FlG. 1) in the opposite direction, the switch 63 signals motor 61 to operate in reverse. Rotations of threaded shaft 62 moves the threaded gear 68 and 70 to the right until gear 68 reaches stop 93. When that occurs, output gear 82 rotates _ output cable 90 in the direction opposite its first-discussed direction. Likewise, the half gear rotates clockwise. A different type of connection from flange 106 of half gear 98 'could move the handle when the half .gear rotates in either direction.

^' Although the coupler 60 is shown between mechanical lock 20 and power lock actuator 40 in FlG. 1, the coupler may be mounted in the same housing or immediately adjacent to the mechanical lock or power actuator. Further, though the exemplary embodiment also shows a flexible cable for transferring rotation from output gear 82, many other types of ro- tation transfer devices can be used. Depending on the distance, a differential gear train or belt drive can provide the rotation. Moreover, rather than having a cable 104 extend to the mechanical lock from the coupler, many other types of connectors are possible.

While the specification describes particular embodiments of the present invention, those of ordinary skill can devise variations of the present invention without departing from the inventive concept.

Claims

We claim:

. A system for controlling position of vehicle seat parts comprising: a) a mechanical lock comprising: i) a housing having one end connected to a first part of the vehicle; ii) a rod translating within the housing and having two ends, one end of the rod attaching to a second part of the vehicle, which is movable relative to the first part of the vehicle; iii) a locking mechanism for selectively preventing movement of the rod in the housing and releasing the rod to permit movement of the first and second parts of the vehicle relative to each other; b) an actuator comprising: i) a housing having one end connected to a third part of the vehicle; ii) a lead screw rotating relative to the housing; iii) a nut on and translating relative to the lead screw having one end connected to a fourth part of the vehicle; c) a coupler extending between the actuator and the mechanical lock for releasing or securing the locking mechanism in response to rotation of the lead screw.

2. The system of claim 1 wherein the coupler further comprises: a) a motor; b) a threaded shaft operably connected to the motor; c) a threaded gear threaded on the threaded shaft for movement along the threaded shaft; d) the threaded gear being operably connected to the mechanical lock and re- leasing the rod as the threaded gear translates.

3. The system of claim 2 further comprising: a) an output gear connected to the threaded gear and permitting movement of the threaded gear along the output gear; b) the output gear having a load such that the output gear does not rotate as the threaded gear moves along the output gear; c) a stop in the path of the threaded gear along the output gear for blocking movement of the threaded gear along the output gear, the threaded gear rotating with the threaded shaft when the threaded gear contacts the stop, the threaded gear rotating the output gear; d) the output gear operably connected to the actuator to provide relative-rota.- tion between the lead screw and the nut.

4. A system for controlling position of vehicle seat parts comprising: a) a mechanical lock comprising: i) a lock housing having one end connected to a first part of the vehicle; ii) a rod translating within the lock housing and having two ends, one end of the rod attaching to a second part of the vehicle, which is movable relative to the first part of the vehicle; iii) a locking mechanism on the lock housing for selectively preventing movement of the rod in the lock housing and releasing the rod to permit movement of the first and second parts of the vehicle relative to each other; iv) a release mechanism operably connected to the locking mechanism for releasing the locking mechanism; b) an actuator comprising: i) an actuator housing connected to a third part of the vehicle; i) a rod projecting out of the actuator housing and having one end connected to a fourth part of the vehicle; ii) drive means connected to the rod for driving the rod relative to the actuator housing; c) a motor operably connected to the actuator for driving the drive means; d) a coupler extending between the motor and the release mechanism of the mechanical lock for releasing or securing the release mechanism in response to activation of the motor.

5. In a system for controlling a mechanical lock, wherein the mechanical lock comprises a housing and a rod projecting out of the housing and translating relative to the housing; a securing mechanism for securing the rod against translation and a release mechanism for releasing the securing mechanism to permit rod translation, the improγ.ement_com-- prising: a) a motor connectable to a switch; b) an output member driven by the motor; c) a connection between the output member and the release mechanism for releasing the release mechanism in response to activation of the motor.