JP2000355237A - Seat lifter and ratchet type lever mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability and simplify a configuration. SOLUTION: A drive means 18 is formed as a ratchet type lever mechanism capable of selecting rotation direction of an output under turn operation of a single driver lever 54 and obtaining its rotation output. Up and down gears 44-u, 44-d with one-way clutch which differ in lock direction of outer ring gears 44b-u, 44b-d for inner mechanism parts 44a-u, 44a-d are arranged around a support shaft 46 while the support shaft is inserted and fixed in bearings 45-u, 45-d of the inner mechanism parts, respectively, to form a group of ratchet gears 44. The down gear 44-d is formed in such a way that it has the small diameter outer ring gear 44b-d having less number of teeth than the outer ring gear 44b-u of the up gear 44-u.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of driving a seat, which is supported by front and rear lifter links so as to be liftable and lowerable, by an arbitrary rotation operation of a lifter link by driving means.
The present invention also relates to a seat lifter that can be raised and lowered by braking a lifter link by a brake unit and that can be held at an arbitrary height, and a ratchet-type lever mechanism that can be applied as a driving means therefor.

[0002]

2. Description of the Related Art For example, a seat lifter that can secure the height of a seat according to the body shape and preference of a seated person and the height of a viewpoint suitable for driving, etc., under arbitrary adjustment, It is mounted on a seat of an automobile or the like as a seating posture control device.

[0003] The seat lifter has, for example, front and rear lifter links for supporting the seat so as to be able to move up and down. A drive means having a handle, a lever, and the like as a drive member is operatively connected to front and rear lifter links via a brake unit, a reduction gear mechanism, or a transmission mechanism including a combination of various gears. This type of seat lifter is configured so that the seat can be raised and lowered under the synchronized rotation of each link accompanying the operation of (1).

However, in the seat lifter, the seat on which the occupant is seated is the object to be moved by the driving means, and the load is large. Therefore, the handle and the lever are heavy and the operation is not easy.

Therefore, a so-called ratchet type lever mechanism, in which a driving member is a driving lever and which can output only a rotational force due to rotation of the driving lever in one direction arbitrarily selected, is applicable to a seat lifter or the like. It is provided as a driving means. This type of ratchet lever mechanism is
It is configured to be able to transmit only the rotational power of the drive lever in any one direction from the ratchet claw to the ratchet gear, and to output a rotational force in the corresponding direction from the output end of the ratchet gear, thereby moving a movable body such as a seat. It is possible to move in the corresponding direction.

According to such a ratchet-type lever mechanism, since the driving lever is rotated, the operating force is reduced by the principle of leverage. Then, under the reciprocating drive (reciprocating rotation) of the drive lever, a rotational force in any one direction can be output, that is, the lifting and lowering of the sheet can be obtained under the reciprocal drive of the drive lever. Therefore, the driving operation can be simplified.

[0007]

Here, in the known ratchet type lever mechanism, switching of the rotation direction of the ratchet gear, that is, the output rotation direction by a dedicated lever or button, is generally performed. A lever, a button, and the like for switching the output rotation direction are usually arranged at a position adjacent to the drive lever. However, in a seat lifter such as an automobile, a driving unit is often provided in a relatively narrow space such as a door side or a wall side, and an operation of a lever or a button for switching is performed. Since it is required to perform groping, it is inevitable that the operability of a known ratchet-type lever mechanism provided in a seating posture control device such as a seat lifter is reduced.

Since the switching operation is performed by groping without visual observation, it is conceivable that the output rotation direction of the ratchet gear may be erroneously selected. In this case, the driving operation is actually noticed only when the driving lever is actually operated, and after the driving lever has been noticed, the driving lever has to be selected again by using a button or the like, so that the driving operation tends to be complicated. Therefore, also in this respect, a decrease in the operability of the driving means is inevitable.

Further, in such a ratchet type lever mechanism, it is necessary to provide a switching mechanism using a lever, a button, or the like, so that the configuration is inevitably complicated.

In a known seat lifter,
Since the rotation of the driving means can be transmitted to the front and rear lifter links via the reduction gear mechanism, the transmission mechanism, and the like, the overall configuration of the seat lifter is likely to be complicated from this point. Since the reduction gear mechanism, the transmission mechanism, and the like easily cause rattling due to clearance between the gears, there is no denying the possibility of reducing the stability of the seat.

An object of the present invention is to provide a seat lifter and a ratchet-type lever mechanism for improving operability and simplifying the configuration.

[0012]

According to the present invention, a drive means for rotating the front and rear lifter links in an arbitrary direction is formed as a ratchet type lever mechanism. . In this ratchet type lever mechanism, a gear with an up one-way clutch in which the locking direction of the outer ring gear with respect to the inner mechanism part is different, and a down one way having a small diameter outer ring gear having fewer teeth than the outer ring gear of the up gear. The clutch-equipped gears are arranged around the support shaft as a group of ratchet gears with the support shaft being inserted into and fixed to the bearing of the inner mechanism. Then, the ratchet pawl integrally having the up and down claw pieces that can mesh with the up gear and the down gear of the ratchet gear group at positions separated from each other at an angle returns one of the claw pieces. Under the rotation of the spring against the biasing force of the spring, the gear is pivotally supported so as to be selectively meshable with the corresponding gear, and the drive lever is rotatably connected and engaged integrally with the ratchet pawl. I have.

Further, one of the front and rear lifter links is formed in a bell crank shape having an integral crank portion, and meshes with the crank portion of the bell crank link and the pinion gear at the output end of the brake shaft of the brake unit. By connecting the rotatable sector gear to the pivotable sector gear via a link, the seat lifter can apply any rotation power to this lifter link by a ratchet-type lever mechanism and generate a braking force on the brake shaft of the brake unit. The rotation of the lifter link can be restricted under the braking force.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, in a seat lifter 10 according to the present invention, a seat 12 is supported to be able to move up and down by front and rear lifter links 14 and 16 disposed on an inner side and an outer side, respectively. It is possible to apply any power to this lifter link,
The drive means 18 is configured and connected, and the rotation of the lifter link can be restricted under the braking force of the brake unit 20.

In the embodiment of the present invention, a runner (also referred to as an upper rail) 24 of the seat slide device 22 is provided.
The seat lifter 10 is formed on the basis of the front and rear lifter links 14, 16 in this embodiment.
However, this runner and a seat-side member, for example, an inner, an outer
Being pivoted. Then, by connecting any of the front and rear lifter links 14 and 16 to the brake shaft output end 28a of the brake unit 20 in an interlockable manner, and connecting the brake shaft input end to the output end of the drive means 18, The seat lifter 10 is configured to be able to apply any rotational power to the lifter link from the driving unit and to restrict the rotation of the lifter link under the braking force of the brake unit.

The structure of the brake unit 20 having the brake shaft is well-known, and the structure itself is not the purpose of the present invention, and will not be described in detail here.

Here, as shown in FIG. 1, the brake shaft output end 28a of the brake unit 20 is usually formed as an integral pinion gear, and is provided via a corresponding gear having teeth that can mesh with the pinion gear. , Its rotation is front,
It can be transmitted to and added to the rear lifter links 14,16.

In one embodiment of the present invention, one of the front and rear lifter links 14 and 16, for example, the rear lifter link 16 is connected to the crank portion 30.
Is formed into a bell crank shape with
Brake unit pinion gear (brake shaft output end) 28a
The sector gear 32 meshable with the seat mount bracket 26 serves as a gear for transmitting and outputting the rotation of the pinion gear.
By pivotally connecting the crank portion of the bell-crank link and the sector gear so as to be able to interlock with each other by the connection link 36, the operating force from the drive means is transferred to the rear lifter link, The seat lifter 10 according to the present invention is configured so that can be transmitted to and provided to a front lifter link.

Further, in the seat lifter 10 of the present invention, the driving means 18 is formed as a ratchet-type lever mechanism. As shown in FIGS. And a unit base 42 composed of an outer plate 40 as a base.

This ratchet type lever mechanism (driving means)
In FIG. 18, the gear 44-u with the one-way clutch for up and the gear 44-d with the one-way clutch for down are different in the locking direction of the outer ring gears 44b-u, 44b-d with respect to the inner mechanism portions 44a-u, 44a-d. However, as the ratchet gear group 44, the support shaft 46 is inserted around and fixed to the bearings 45-u and 45-d of the inner mechanism section around the support shaft. Then, a support shaft 46 is erected and supported between the unit bases 42, that is, between the inner plate 38 and the outer plate 40, thereby raising and lowering the gears 44-u, 44- of the ratchet gear group 44.
d is placed and supported.

One end 46a of the support shaft 46 is formed, for example, as a serration shaft, and is fitted and engaged with a braking shaft input end 28b formed as a corresponding serration bearing. The support shaft and the brake shaft 28 of the brake unit 20 are integrally rotatably connected.

The support shaft 46 is also formed, for example, as a serration shaft, and the bearings 45-u and 45-d are formed in corresponding shapes, so that the inner mechanism portions 44a-u and 44a of the up and down gears. -d is connected and fixed to the support shaft so as to be integrally rotatable.

The up-gear 44-u and the down-gear 44-d, which are gears with a one-way clutch, are a combination of inner mechanisms 44a-u, 44a-d and outer ring gears 44b-u, 44b-d, respectively. A one-way clutch mechanism (not shown) built in the inner mechanism portion sets one direction as a lock direction in which the inner mechanism portion and the outer ring gear are integrally rotated, and the other direction controls rotation of the outer ring gear with respect to the inner mechanism portion. The slip direction to be guaranteed is specified respectively. The up-gear 44-u and the down-gear 44-d are arranged so that the lock direction matches the up direction and the down direction required for the pinion gear 28a of the brake unit.

The principle and basic structure of the one-way clutch mechanism in the one-way clutch gear are known, and commercially available one-way clutch gears can be used as the gears 44-u and 44-d. The detailed description of is omitted.

Here, as shown in FIGS. 2 and 3, in the present invention, the down gears 44-d of the ratchet gear group are used.
However, it is formed as a form having a small diameter outer ring gear 44b-d having fewer teeth than the outer ring gear 44b-u of the up gear 44-u, and an up gear and a down gear that can mesh with the up gear and the down gear, respectively. A ratchet pawl 48 integrally having pawls 48-u, 48-d at angularly separated positions corresponds to one of the pawls under its rotation against the biasing force of the return spring 50. It is pivotally supported between the unit bases 42 by an integral support shaft 52 so as to be selectively meshable with the gear (see FIGS. 4 and 5). As can be seen from FIGS. 2 and 3, the drive lever 54 is connected and engaged via the connection end 52a of the spindle 52 of the ratchet pawl so as to be rotatable integrally with the ratchet pawl. I have.

As the return spring 50, for example, a spiral spring disposed around the spindle 52 of the ratchet pawl between the inner plate 38 and the ratchet pawl can be used. And the terminal 50 of the return spring 50 composed of this spiral spring
a is arranged so as to hang continuously on the locking piece 38a protruding from the inner plate 38 and the engagement end 48a of the ratchet pawl,
Locked.

In the case where the ratchet type lever mechanism 18 is provided in the seat lifter 10 shown in FIG. 1, as can be seen from FIG. 3 in addition to FIG. Since the up direction and the clockwise direction are the down direction, the ratchet claw piece 48-u is formed on the up direction side, and the down claw piece 48-d is formed on the down direction side, respectively. Correspondingly,
The up gear 40-u of the ratchet gear group 44 is arranged so that the locking direction matches the clockwise direction in the figure, and the down gear 40-d is arranged so that the locking direction matches the counterclockwise direction in the figure. I have. Then, the up gear 40- in the locking direction accompanying the rotation of the drive lever 54 in the corresponding direction.
u, the seat 12 can be raised and lowered under any rotation of the down gear 40-d.

In the neutral position of the drive lever 54 which is biased and held under the biasing force of the return spring 50 as shown in FIG. 3, the ratchet pawl 48 moves the up gears 44-u and the down gear 44-u of the ratchet gear group 44. Claw piece 48 for gear 44-d
-u and the down claw piece 48-d are maintained at the non-meshed position where they do not mesh.

From such a state, the drive lever 54 is moved, for example, in the upward direction against the biasing force of the return spring 50,
In other words, when the lever is turned counterclockwise in the drawing, the up claw piece 48-u of the ratchet claw is meshed with the up gear 44-u of the ratchet gear group 44 with the rotation of the drive lever. The rotation direction (clockwise in the drawing) of the up-gear 44-u interlocked with the rotation of the drive lever 54 and, consequently, the ratchet pawl 48 in the up-gear direction is determined by the inner mechanism 44a-u
And the outer ring gear 44b-u, as shown in FIG.
44b-u, with the inner mechanism 44a-u, and eventually the spindle 46,
It is rotated in the corresponding direction, that is, in the up direction by an amount corresponding to the corresponding amount, that is, the amount of rotation of the drive lever.

As described above, when the up gear 44-u of the ratchet gear group 44 is rotated in the corresponding direction under the turning operation of the drive lever 54, the corresponding rotation amount is changed from the support shaft 46 to the brake unit. Brake shaft 28, and thus the pinion gear 28a
Output through the pinion gear to the sector gear 32
(See FIG. 1). Then, the seat 12 is raised by a corresponding amount under the rotation of the rear lifter link 16 accompanying the rotation of the sector gear 32 and the rotation of the front lifter link 14 accompanying the rotation of the sector gear 32.

As shown in FIG. 4, the rotation range of the drive lever 54 is defined, for example, as the movable range of the projecting piece 48b of the ratchet claw 48 with respect to the notch 56 of the outer plate 40, and when the rotation limit position is reached. When the operating force of the drive lever is released, the drive lever and the ratchet pawl are biased and held at the neutral position in FIG.

When the ratchet pawl 48 returns to the neutral position, the outer gear 44b-u of the up gear is used.
Rotation direction coincides with the sliding direction without the inner mechanism portion 44a-u, so that even if the outer ring gear rotates under the return of the ratchet pawl, the rotation of the support shaft 46 does not occur at all. .

When the drive lever 54 is again rotated in the up direction from the neutral position shown in FIG. 3, the inner mechanism 44b-u of the up gear and the support shaft 46 are moved by a corresponding amount in the same manner as described above. Since the seat 12 is rotated in the same direction, and the seats 12 are lifted by the rotation of the front and rear lifter links 14 and 16, the operator repeats this operation to raise the seat to a desired height. (See FIG. 1).

Since the rotational power of the front and rear lifter links 14 and 16 acting in the downward direction is blocked by the rotational braking of the brake shaft 28 of the brake unit, the seat 12 is not operated when the drive lever 54 is not operated. The descent is reliably prevented.

When the seat 12 is lowered, an operation opposite to the above-mentioned operation, that is, an operation of rotating the drive lever 54 from the neutral position in the down direction (clockwise direction in FIG. 3) is performed. Nail piece 48 for nail down
If the -d is engaged with the down gear 44-d of the ratchet gear 44 group and rotated, as shown in FIG. 5, the inner mechanism portions 44a-d of the down gear and the support shaft 46 interlocked with this drive lever. Under rotation, the seat can be lowered.

As described above, the seat lifter of the present invention
In 10, the ratchet type lever mechanism 18 is used as driving means. The ratchet type lever mechanism 18 is configured to select the rotation output direction as the rotation operation direction of the drive lever 54 and to obtain the rotation output of the brake shaft output end 28a of the brake unit under this rotation operation. Therefore, the selection of the rotation direction of the output and the securing of the rotation output can be obtained under a single operation of the drive lever in the direction corresponding to the elevation of the seat 12.

That is, according to the present invention, the drive lever 54
By rotating the seat 12 in a direction corresponding to the lifting and lowering of the seat 12, the driving can be obtained, so that the switching operation of the rotation output direction by a dedicated lever, a button, or the like as in the related art is not required. Therefore, the driving operation of the ratchet type lever mechanism 18 is simplified, and the operability is improved.

In addition to the necessity of switching the rotation output direction using a dedicated lever, button, or the like, the operation direction of the drive lever 54 coincides with the desired movement direction of the seat 12. The drive lever, that is, the operability of the ratchet lever mechanism 18 is improved.

Since a switching mechanism using a dedicated lever, button, or the like can be omitted, a ratchet-type lever mechanism is provided.
The structure of 18 is sufficiently simplified.

Further, in the seat lifter 10 of the present invention, a sector gear 32 meshable with the pinion gear 28a of the brake unit is pivotally connected to the seat mount bracket 26, and this sector gear and the rear lifter link 16 are connected by a connection link 36. By doing so, the rotational force of the ratchet type lever mechanism 18 can be reduced by using the front and rear lifter links 14,1.
Since it is possible to transmit and add to 6, the overall configuration of the seat lifter is sufficiently simplified by reducing the number of parts. The reduction in the number of parts surely improves workability during assembly.

Further, since a reduction gear mechanism, a transmission mechanism, and the like are not required, a portion where play is caused due to clearance between gears is reliably reduced. That is, the occurrence of backlash is sufficiently suppressed, so that the sheet 12 is easily and sufficiently stabilized.

In the embodiment of the present invention,
The sector gear 32 is connected to the rear lifter link 16 to rotate the pinion gear 28a to the front and rear lifter links 1.
It can be transmitted to 4,16. However, the present invention is not limited to this. For example, a configuration may be adopted in which a sector gear is connected to a front lifter link. In this case, it goes without saying that the front lifter link 14 is formed in a bell crank shape.

As shown in FIG. 3, in the present invention, the outer ring gear 44b-d of the down gear is formed as a small diameter outer ring gear having fewer teeth than the outer ring gear 44b-u of the up gear. . In this configuration, the operating lever
The amount of rotation of the gears 44-u, 44-d with respect to the same operation amount (operation angle) of 54 is different, and the down gear 44-d having a small diameter rotates over a wider range than the up gear 44-u.

That is, since the amount of lowering of the operation lever 54 in one operation is greater than the amount of raising of the sheet 12, a quick and easy lowering operation of the sheet is sufficiently secured according to the present invention. It becomes possible, and the operability is reliably improved by reducing the number of lever operations at the time of getting off.

The down gear 44-d is connected to the up gear 44-d.
Since the diameter is smaller than -u, the operation force of the operation lever 54 when rotating in the down direction is slightly heavier than when up. However, when the seat 12 is lowered, the load from the occupant acting downward functions as a support force for lowering the seat, so that the operation lever 54 can be smoothly moved without a support member such as a spring. Operation can be secured sufficiently. Therefore, the speed of lowering the seat 12 can be increased without adversely affecting the operability of the operation lever 54 and without complicating the configuration.

The up gear 44-u is a down gear.
Since the diameter is larger than that of 44-d, the operating force of the operating lever 54 at the time of the up is sufficiently reduced. Therefore, the operability at the time of the up can be secured sufficiently high.

Here, the up gear 44-u is a down gear.
Since the diameter is larger than that of 44-d, the rising amount of the seat 12 for the same operation amount of the operation lever 54 is smaller than the lowering amount. However, since the amount of elevation of the seat 12 for one operation of the operation lever 54 is small, fine adjustment of the seat height can be easily performed. Can be secured sufficiently high.

In the present invention, the diameter of the outer ring gears 44b-d of the down gear is expressed as a smaller diameter compared to the outer ring gears 44a-u of the up gear. However, since this is an expression based on the up gear 44-u, the outer ring gear 44 of the up gear is referenced based on the down gear 44-d.
A configuration in which the diameter of bu is large compared to the outer ring gears 44b-d of the down gear can also be uniquely derived from the configuration of the present invention, and it goes without saying that it is included in the present invention.

In the embodiment of the present invention, the sector gear 32 and the rear lifter link 16 are connected via a connecting link 36 so as to be interlocked. But,
The invention is not limited to this, and the sector gear 32 may be formed integrally with the rear lifter link 16 as shown in FIG. According to such a configuration, the rotation of the pinion gear 28a is transmitted to and imparted to the rear lifter link 16 or the front lifter link 14 without the need for a connecting link. Further simplification is achieved.

The ratchet type lever mechanism of the present invention
Since the unit 18 is formed as a unit having a unit base 42 composed of a pair of an inner plate 38 and an outer plate 40 as a base, the unit 18 can be easily attached to the seat 12, that is, the seat mount bracket 26. In addition to being formed as a unit, the rotation of the up gear 44-u and the down gear 44-d of the ratchet gear group 44 is
By taking it out from 46, it can be used as a moving force of the movable body, so it is not limited to the seat lifter 10, but as a driving means for another seating posture control device, for example, a reclining device or a seat sliding device, etc. A ratchet-type lever mechanism may be used.

The embodiments of the present invention described above are intended to explain the present invention, and do not limit the present invention in any way. Modifications, alterations, etc., within the technical scope of the present invention may be made. It goes without saying that all are included in the present invention.

[0053]

As described above, according to the seat lifter of the present invention, the ratchet type lever mechanism is used as the driving means, and the ratchet type lever mechanism is
The drive is obtained by rotating the drive lever in a direction corresponding to the lifting and lowering of the sheet, so that there is no need to switch the rotation output direction other than by operating the drive lever. Therefore, the drive operation of the drive lever and, consequently, the drive means is simplified, and the operability is improved.

Further, in addition to the fact that the switching operation of the rotation output direction is not required, the operation direction of the drive lever coincides with the desired sheet movement direction. .

Since the switching mechanism in the ratchet type lever mechanism can be omitted, the configuration is sufficiently simplified.

Further, since it is sufficient to pivotally connect a sector gear that can mesh with the pinion gear of the brake unit and connect this sector gear to one of the front and rear lifter links by a connection link, the number of parts can be reduced to reduce the number of parts. The overall configuration is greatly simplified. The reduction in the number of parts surely improves workability during assembly.

Further, since only the gears to be meshed are the pinion gear and the sector gear, the occurrence of the play caused by the clearance between the gears is reliably reduced. In other words, the occurrence of backlash is sufficiently suppressed, so that the sheet can be easily and sufficiently stabilized.

Further, when the sector gear is formed integrally with either the front or rear lifter link, the number of parts is further reduced, and the structure is further simplified.

Since the ratchet lever mechanism of the present invention is formed as a unit having the unit base as a base, it can be easily attached to a seat.
Further, in addition to being formed as a unit, the rotation of each gear for raising and lowering the ratchet gear group is taken out from its support shaft, so that it can be used as a moving force of the movable body, so it is not limited to a seat lifter. It can also be used as a driving means for another sitting posture control device. Therefore, a ratchet-type lever mechanism excellent in versatility can be provided.

Further, in the present invention, since the outer ring gear of the down gear is formed as a small diameter outer ring gear having a smaller number of teeth than the outer ring gear of the up gear, the seat lowering amount per one operation of the operating lever is reduced. Becomes larger than the rising amount. Therefore, quick and easy lowering of the seat
According to the present invention, it is possible to sufficiently secure the operability, and the operability is surely improved by reducing the number of times the lever is operated when getting off the vehicle.

Since the up-gear has a larger diameter than the down-gear, the operating force of the operating lever during up-shifting is sufficiently reduced. Therefore, the operability at the time of the up can be secured sufficiently high.

Further, since the amount by which the sheet is raised for one operation of the operating lever is smaller than the amount by which the sheet is lowered, fine adjustment of the sheet height is easily possible, and the certainty when setting the sheet height is improved. According to the present invention, a sufficiently high level can be ensured.

[Brief description of the drawings]

FIG. 1 is a schematic side view, partially cut away, of a seat lifter according to the present invention as viewed in a longitudinal section.

FIG. 2 is a schematic exploded perspective view of a ratchet type lever mechanism.

FIG. 3 is a schematic front view of the ratchet-type lever mechanism as viewed from an inner side, showing a state in a neutral position.

FIG. 4 is a schematic front view similar to FIG. 3 of the ratchet-type lever mechanism at an up-direction rotation limit position;

FIG. 5 is a schematic front view similar to FIG. 3 of the ratchet-type lever mechanism at a rotation limit position in the down direction.

FIG. 6 is a schematic side view, partially broken away, of a seat lifter similar to FIG. 1, showing another embodiment.

[Explanation of symbols]

10 Seat lifter 12 Seat 14,16 Front and rear lifter links 18 Ratchet lever mechanism (drive means) 20 Brake unit 30 Lifter link crank 32 Sector gear 36 Connecting link 42 Unit base 44 Ratchet gear group 44-u, 44 -d Up / down gear (gear with one-way clutch) 46 Support shaft 48 Ratchet pawl 48-u, 48-d Up / down pawl 50 Return spring 54 Drive lever

Claims (3)

[Claims] 1. A front and rear lifter link supports a seat so as to be able to move up and down, a predetermined drive means can apply an arbitrary rotation power to the lifter link, and a braking force generated on a brake shaft of a brake unit. And a support shaft rotatably supported integrally with the brake shaft of the brake unit; and a different lock direction of the outer ring gear with respect to the inner mechanism. The gear with a one-way clutch for up and the gear with down one-way clutch having a smaller diameter outer ring gear with fewer teeth than the outer ring gear of this up gear can be used to insert and fix the support shaft to the bearing of the inner mechanism. And a ratchet gear group arranged around the support shaft; and an up gear and a down gear of the ratchet gear group. Integral up / down pawls are integrally located at angularly separated positions so that either pawl can be selectively engaged with the corresponding gear under its rotation. A pivoted ratchet pawl; a return spring for biasing and retaining the ratchet pawl to an unengaged neutral position; and a drive lever integrally rotatably connected to and engaged with the ratchet pawl. The above-mentioned driving means is formed as a ratchet type lever mechanism that can output only the rotational force of each gear for up and down in the locking direction accompanying the rotation of the drive lever from the support shaft to the brake shaft of the brake unit. In addition, one of the front and rear lifter links is formed in a bell crank shape having an integral crank portion, and the crank portion of the bell crank link and the braking shaft of the brake unit Sheet lifter, characterized in that the rotatable sector gear which is meshed with the pinion gear to be Chikaratan were operatively coupled via a connecting link. 2. A front and rear lifter link supports a seat so as to be able to move up and down, and a predetermined driving means can apply an arbitrary rotating power to the lifter link, and a braking force generated on a braking shaft of a brake unit. And a support shaft rotatably supported integrally with the brake shaft of the brake unit; and a different lock direction of the outer ring gear with respect to the inner mechanism. The gear with a one-way clutch for up and the gear with down one-way clutch having a smaller diameter outer ring gear with fewer teeth than the outer ring gear of this up gear can be used to insert and fix the support shaft to the bearing of the inner mechanism. And a ratchet gear group arranged around the support shaft; and an up gear and a down gear of the ratchet gear group. Integral up / down pawls are integrally located at angularly separated positions so that either pawl can be selectively engaged with the corresponding gear under its rotation. A pivoted ratchet pawl; a return spring for biasing and retaining the ratchet pawl to an unengaged neutral position; and a drive lever integrally rotatably connected to and engaged with the ratchet pawl. The above-mentioned driving means is formed as a ratchet type lever mechanism that can output only the rotational force of each gear for up and down in the locking direction accompanying the rotation of the drive lever from the support shaft to the brake shaft of the brake unit. And one of the front and rear lifter links is formed integrally with a sector gear meshable with a pinion gear serving as a brake shaft output end of a brake unit. Lifter. 3. A unit base comprising a pair of an inner plate and an outer plate; and one end having a connection end engageable with an input end of a brake shaft of a brake unit and engageable,
A rotatable support shaft rotatably supported between the unit bases; a gear with a one-way clutch for up in which the locking direction of the outer ring gear to the inner mechanism is different, and a small-diameter outer ring having fewer teeth than the outer ring gear of the up gear. A ratchet gear group in which a down gear with a one-way clutch having a gear is arranged around the support shaft with the support shaft inserted into and fixed to the bearing of the inner mechanism; an up gear and a down gear for the ratchet gear group Each of the up and down pawls that can be engaged with the gear are integrally provided at positions separated from each other at an angle, and one of the pawls can be selectively attached to the corresponding gear under its rotation. A ratchet pawl pivotally supported between the unit bases so as to mesh with the ratchet pawl; and a latch for biasing and holding the ratchet pawl to a neutral position which is a non-meshing position with respect to the ratchet gear group. A drive lever integrally rotatably connected to and engaged with the ratchet pawl; and formed as a unit having a unit base as a base, and in a locking direction accompanying rotation of the drive lever. For up,
Ratchet-type lever mechanism that can output only the torque of each down gear from the support shaft to the brake shaft of the brake unit.