WO2014021582A1

WO2014021582A1 - Pumping device for adjusting seat height and apparatus for adjusting seat height for motor vehicle having the same

Info

Publication number: WO2014021582A1
Application number: PCT/KR2013/006689
Authority: WO
Inventors: Tae Heon Kim
Original assignee: KM&I CO Ltd; KM and I Co Ltd
Current assignee: KM&I CO Ltd; KM and I Co Ltd
Priority date: 2012-07-30
Filing date: 2013-07-25
Publication date: 2014-02-06
Anticipated expiration: 2015-01-30
Also published as: KR101361520B1; KR20140016064A

Description

PUMPING DEVICE FOR ADJUSTING SEAT HEIGHT AND APPARATUS FOR ADJUSTING SEAT HEIGHT FOR MOTOR VEHICLE HAVING THE SAME

The present invention relates to a pumping device for adjusting a seat height for a motor vehicle, and more particularly, to a pumping device for adjusting a seat height capable of minimizing rotational damage of a shaft by separately configuring a rotation unit for rotating the shaft for adjusting the seat height and a fixing unit for fixing the shaft, and an apparatus for adjusting a seat height for a motor vehicle having the same.

In general, a seat installed in a motor vehicle includes several convenience apparatuses for the purpose of providing comfort to passengers. As an example, there are a sliding function moving the seat toward a front or a rear depending on a leg length of the passenger, a reclining function adjusting a slope between the seat and a back of the seat for the purpose of an arm length or comfortable position of the passenger, or the like. In addition to this, the seat further includes a seat ascent and descent function adjusting a height of the seat by ascending or descending the seat according to a seating height of the passenger.

An apparatus for adjusting the seat height for implementing the seat ascent and descent function as described above has various schemes according to an operating scheme thereof, and includes a pumping device referred to as a pumping ball type, as an example.

The pumping device adjusts the seat height by delivering force toward a link mounted on the seat using an up or down operation of a lever provided at a side of the seat. The above-mentioned pumping device is generally configured of a clutch unit and a brake unit, wherein the clutch unit delivers an up or down input of the lever toward the link of the seat and the brake unit maintains a fixed state of the link completing the operation thereof.

Due to a characteristic of the clutch unit delivering an external input as described above, since the clutch unit needs to effectively deliver the external input toward the link and to flexibly maintain the operation, many parts are operated to be associated with one another in order to effectively deliver the force.

As an example, the above-mentioned type of clutch unit is a roller type of clutch unit having a force delivering path for releasing brake force at a brake unit side in a circumferential direction.

When the roller type of clutch unit pushes a roller arranged on a coaxial in the circumferential direction by a rotation through the lever, the roller causes a wedge operation with an inner wall of the clutch unit receiving the roller, thereby rotating the clutch unit. The rotation of the clutch unit as described above is converted into rotation force of the brake unit.

A rotation of the brake unit rotates a shaft and allows a sector gear at the link side engaged with a pinion gear to be a forced rotating state, such that the height of the link is adjusted by the above-mentioned rotation of the sector gear.

In addition, when the clutch unit is returned to an original position by tension, the roller is also returned to an original position by the tension and the brake force of the brake unit is restored. By restoring the brake force, the shaft is fixed at the rotated state and maintains a state adjusting the seat height by the link.

In order to completely fix the shaft by producing the maximum brake force by the brake unit in a configuration of the pumping device as described above, the roller requires a predetermined rotation interval so as to be firmly fitted into a clutch drum and a cam of the shaft. Here, in the case in which the clutch unit directly controls the roller, a loss (hereinafter, referred to as a lever angle loss) in a rotation angle of the clutch unit to a rotation angle of the shaft is produced due to the rotation interval of the roller.

A development of the pumping device capable of minimizing the lever angle loss while maintaining the maximum brake force of the brake unit by the roller is demanded.

An object of the present invention is to provide a pumping device for adjusting a seat height having a roller configured so as to be fitted between a brake block and a shaft by providing the brake block capable of moving in a circumferential direction between a clutch part and a brake part in order to directly deliver rotation force of the clutch part to the shaft and to produce maximum brake force of the brake part, and an apparatus for adjusting the seat height for a motor vehicle having the same.

In one general aspect, a pumping device for adjusting a seat height, includes: a housing coupled to a mounting bracket to form an inner space; a shaft received in the housing so as to be rotated in a shaft direction and adjusting the seat height by a rotation thereof; a lever mounting point for receiving rotation force applied from an external lever; a clutch part received in the housing and having the lever mounting point formed on one surface thereof so as to be rotated in the shaft direction according to the rotation force applied from the lever; and a brake part allowing the shaft to be rotated by fixing the shaft by a wedge operation for the housing and releasing the wedge operation by a rotation through the clutch part, wherein the clutch part is directly connected to the shaft so as to rotate the shaft in the shaft direction by the rotation after releasing the wedge operation of the brake part.

The housing and the mounting bracket may each have a through-hole formed in the shaft direction, such that the clutch part and the brake part may be disposed at a center of the shaft direction.

The pumping device may further include a shaft cam rotated integrally with the shaft and forming at least one first receiving space spaced apart from an inner peripheral surface of the housing by a predetermined distance in a circumferential direction, wherein the brake part may be configured of: a brake roller part received in the first receiving space and locking or unlocking a rotation of the shaft cam according to whether or not compression is made in the circumferential direction; a base compressing the brake roller part in the circumferential direction by a rotation produced by interworking the rotation of the clutch part; and brake blocks provided between the inner peripheral surface of the housing and the brake roller part and between the brake roller part and the base, and delivering compressing force in the circumferential direction of the base to the brake roller part.

The clutch part may have a return unit so as to be returned to a predetermined reference position after rotating the base in one direction or the other direction.

The brake roller part may be configured of a plurality of rollers received in the respective first receiving spaces and an elastic member interposed between the plurality of rollers to compress the respective rollers toward both end portions of the first receiving space; and the base may have a base protrusion, wherein the base protrusion may be interposed between the brake roller part and a neighboring brake roller part to compress the rollers adjacent to each other toward a center portion of the first receiving space by the brake block.

The base may receive rotation force of the clutch part through one surface thereof and the base protrusion formed on the other surface of the base may be in contact with the brake block and a base groove formed at the shaft cam, such that rotation force of the base may be delivered to the brake block and the shaft cam, and a spaced distance between the base protrusion and the brake block may be shorter than a spaced distance between the base protrusion and the base groove.

One surface of the base may have a clutch receiving space of an annular shape formed along a circumference of the base, the clutch part may further include a lever cam rotated integrally with the clutch part and forming at least one second receiving space spaced apart from an inner peripheral surface of the clutch receiving space by a predetermined distance in a circumferential direction; and the brake part may further include a clutch roller part received in the second receiving space and locking or unlocking a rotation of the base according to whether or not compression is made in the circumferential direction.

The clutch part may include a lever bracket having the lever mounting point formed thereon, the housing may be provided with a plurality of lever bracket guide grooves limiting a rotation angle range of the lever bracket in order to prevent the lever bracket from being rotated at a predetermine angle or more in a rotation direction of both sides based on the reference position; and the lever bracket may be provided with a lever bracket guide protrusion fitted into the lever bracket guide groove so as to be rotated.

In another general aspect, an apparatus for adjusting a seat height for a motor vehicle includes the pumping device as described above.

The pumping device for adjusting the seat height and the apparatus for adjusting the seat height for the motor vehicle having the same according to the configuration as described above may increase the rotation angle of the shaft to the rotation angle of the lever as compared to the related art by minimizing the lever angle loss while maintaining the maximum brake force of the pumping device.

Therefore, the convenience of the passenger may be increased by reducing the number of repetitively operating the lever in order to adjust the seat height.

The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

FIG. 1 is an overall perspective view of a pumping device according to an exemplary embodiment of the present invention;

FIG. 2 is an exploded perspective view of the pumping device according to an exemplary embodiment of the present invention;

FIG. 3 is a perspective view of a housing according to an exemplary embodiment of the present invention;

FIG. 4 is an exploded perspective view of a clutch part according to an exemplary embodiment of the present invention;

FIG. 5 is a front view of one side of the clutch part according to the exemplary embodiment of the present invention;

FIG. 6 is an exploded perspective view of a brake part according to an exemplary embodiment of the present invention;

FIG. 7 is a perspective view of a bottom of a base of according to an exemplary embodiment of the present invention;

FIG. 8 is a perspective view of a shaft according to an exemplary embodiment of the present invention;

FIG. 9 is a front view of the other side of the brake part according to the exemplary embodiment of the present invention;

FIG. 10 is an operating view of FIG. 9 (when the shaft is rotated);

FIG. 11 is an operating view of FIG. 9 (when the shaft is fixed); and

FIG. 12 is a perspective view of a mounting bracket according to an exemplary embodiment of the present invention.

[Detailed Description of Main Elements]

PD : pumping device LMP : lever mounting point

Shaft : shaft CP : clutch part

BP : brake part 100 : housing

210 : stopper 220 : lever bracket

230 : return spring 240 : lever guide

250 : bushing 260 : lever cam

310 : clutch roller part 320 : base

330 : brake roller part 340 : brake block

400 : shaft 410 : shaft axis

420 : pinion gear 430 : shaft cam

500 : mounting bracket

FIG. 1 shows an overall perspective view of a pumping device (PD) according to an exemplary embodiment of the present invention. As shown in FIG. 1, the pumping device (PD) is configured in a cylindrical form, and has a lever mounting point (LMP) coupled to a lever and a shaft coupled to a seat height adjusting link and ascending or descending a seat by a rotation thereof, wherein the lever mounting point (LMP) is formed on one surface of the pumping device (PD) and the shaft is formed on the other surface thereof. A lever bracket having the level mounting point (LMP) formed thereon is configured so as to be rotated at a predetermined angle in a clockwise direction or a counterclockwise direction, the shaft is rotated by interworking with the rotation of the lever bracket in the clockwise direction or the counterclockwise direction, and a seat height is adjusted by a link connected to the shaft. In this case, the lever bracket is returned to an original position thereof by a return member after being rotated at a predetermined angle, and the shaft is fixed at a rotated position after being rotated at a predetermined angle. By the configuration as described above, as an example, when the lever is ascended at a predetermined height, the seat is fixed at a state which is ascended at the predetermined height by the pumping device (PD) and the lever is returned to an original position thereof. In addition, when the lever is descended at a predetermined height, the seat is fixed at a state which is descended at the predetermined height by the pumping device (PD) and the lever is returned to the original position thereof. Therefore, a user may adjust the seat height by repetitively driving the lever to a desired height. Therefore, the most important function of the pumping device (PD) is that the shaft may need to be flexibly rotated by a manipulation of the lever and the shaft may need to be firmly fixed in a state in which it is rotated.

According to the related art, in order to firmly fix the shaft as mentioned in the foregoing background art, since a rotation angle of the shaft is small as compared to a displacement of the lever mounting point (LMP), an ascending or descending manipulation of the lever needs to be repeated several times in order to adjust the seat to a certain height, which is troublesome.

The present invention provides a pumping device (PD) having a configuration as described below in order to solve the above-mentioned problems. Hereinafter, the pumping device (Pd) according to an exemplary embodiment of the present invention as described above will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, the pumping device (PD) according to the exemplary embodiment of the present invention is configured of a housing 100, a clutch part (CP), a brake part (BP), a shaft 400, and a mounting bracket 500. The clutch part (CP) is configured of a stopper 210, a lever bracket 220, a return spring 230, a lever guide 240, a bushing 250, and a lever cam 260, and the brake part (BP) is configured of a clutch roller part 310, a base 320, a brake roller part 330, and a brake block 340.

A description will be made by defining a side at which the clutch part (CP) is positioned as one side and a side at which the brake part (BP) is positioned as the other side.

Referring to FIG. 3, the housing 100 is configured in a cylindrical shape having one surface closed and the other surface opened. The inside of the housing 100 has the clutch part (CP), the brake part (BP), and the shaft 400 received therein rotatably in a shaft direction and the opened surface of the housing 100 is configured to be closed by the mounting bracket 500. The closed surface has through-hole 101 formed therein. One side part of the lever bracket 220 is protruded through the through-hole 101 so that the lever mounting point LMP of the lever bracket 200 is exposed through the through-hole 101. The through-hole 101 has lever bracket guide grooves 102 formed at a circumference thereof in order to prevent the lever bracket 220 from being rotated at a predetermined angle or more. A pair of lever bracket guide grooves 102 may be formed so as to face each other. A plurality of stopper fixing holes 103 for fixing the stopper 210 are radially formed at a circumference of the closed surface of the housing 100. A plurality of housing fixing holes 104 for fixing the pumping device (PD) are formed at a circumference of the other side end of the housing 100.

Referring to FIGS. 4 and 5, the stopper 210 is configured in an annular shape in which a through-hole 211 is formed. The stopper 210 is fitted so that one surface thereof is in contact with an inner surface of the closed surface of the housing 100. The stopper 210 has a plurality of stopper fixing protrusions 213 protrudedly formed on one surface thereof so as to be fitted into the stopper fixing holes 103. The stopper 210 has a pair of first spring fixing protrusions 212 downwardly protruded toward the other surface so as to face each other. The first spring fixing protrusion 212 is fixed with an end in the counterclockwise direction of a return spring 230 described below. The through-hole 211 of the stopper 210 is fitted with the lever bracket 220.

The lever bracket 220 is configured in a disk shape. A plurality of lever mounting points (LMP) for coupling to the lever are formed on one surface of the lever bracket 220 so as to be depressed. The through-hole 221 is formed at a center of the lever bracket 220 and a pair of lever bracket guide protrusions 222 formed so as to face each other are formed at a circumference of the lever bracket 220 so as to be fitted into the lever bracket guide grooves 102 and to be rotated.

The return spring 230 is configured of a coil spring forming an arc so as to be disposed along an inner peripheral surface of the housing 100. The return spring 230 is configured of a first spring 231 and a second spring 232 so that restoration elastic force is each provided when the clutch part (CP) is rotated in the clockwise direction or the counterclockwise direction. Ends of the counterclockwise direction of the first spring 231 and the second spring 232 are fixed to the pair of first spring fixing protrusions 212, respectively, and ends of the clockwise direction are fixed to a pair of second spring fixing protrusions 243 of the lever guide 240 described below, respectively. Therefore, when the lever guide 240 is rotated in the clockwise direction, the return spring 230 is tensioned, thereby returning the lever guide 240 in the counterclockwise direction by the restoration elastic force, and when the lever guide 240 is rotated in the counterclockwise direction, the return spring 230 is compressed, thereby returning the lever guide 240 in the clockwise direction by the restoration elastic force.

The lever guide 240 has one surface coupled to the other surface of the lever bracket 220. The lever guide 240 includes a through-hole 241 and a plurality of lever cam fixing grooves 242 for fixing the lever cam 260 is radially formed at a circumference of the through-hole 241. A pair of second spring fixing protrusions 243 for fixing the end of the clockwise direction of the return spring 230 are formed so as to face each other at an outside of a circumferential surface of the lever guide 240. The lever guide 240 delivers the restoration elastic force of the return spring 230 to the lever bracket 220.

The bushing 250 has an annular shape in which a through-hole 251 is formed. The bushing 250 is fitted between the return spring 230 and the base 320, thereby serving as a guide so that a behavior of the return spring 230 may be flexibly operated through one surface, and serving to prevent a separation when the return spring 230 is compressed. In addition, the bushing 250 is configured so that the other surface thereof closes a clutch receiving space 322, thereby preventing a separation of the clutch roller part 310.

The lever cam 260 has an annular shape in which a through-hole 261 is formed. The lever cam 260 is configured so that one surface thereof is in contact with the other surface of the bushing 250, and a plurality of lever cam fixing protrusions 262 radially and protrudedly formed on one surface of the lever cam 260 are fitted into the lever cam fixing grooves 242, such that the lever cam 260 is fixed to the lever guide 240. A cam 263 is formed at an outer peripheral surface of the lever cam 260. Therefore, the clutch part (CP) is configured so that when the lever cam 260 is rotated in the clockwise direction or the counterclockwise direction, it releases the brake force of the clutch roller part 310 fixing the base 320 described below, thereby rotating the base 320, and when the lever cam 260 is returned, it restores the brake force of the clutch roller part 310, thereby making it possible to fix the base 320 in a state in which the base 320 is rotated.

The clutch part (CP) having the above-mentioned configuration rotates the lever bracket 220 at a predetermined angle in the clockwise direction or the counterclockwise direction when external force enough to overcome the elastic force of the return springs 231 and 232 is generated, and the lever guide 240 and the lever cam 260 are rotated by interworking with each other, accordingly. When the external force is removed, the lever guide 240 is returned to an original position by elasticity of the return springs 231 and 232, and the lever bracket 220 and the lever cam 260 are returned to an original position by interworking with each other, accordingly.

Referring to FIGS. 6 to 9, the base 320 has an annular shape in which the through-hole 321 is formed and has a clutch receiving space 322 formed on one surface thereof in which the lever cam 260 and the clutch roller part 310 are received. A plurality of base protrusions 323 for rotating the brake part 300 and the shaft 400 are radially formed on the other surface of the base 320.

A plurality of clutch roller parts 310 may be radially disposed so as to correspond to a shape of the cam 263 of the lever cam 260. As the clutch roller part 310, a typical roller spring having an elastic member 313 provided between one side roller 311 and the other side roller 312 may be applied. The clutch roller part 310 delivers the rotation force of the cam 263 to the base 320 and serves to fix the base 320 in a state in which the base 320 is rotated, when the cam 263 is returned.

The brake roller parts 330 may be radially disposed between the base protrusion 323 of the base 320 and an adjacent base protrusion 323, respectively. As the brake roller part 330, the typical roller spring having an elastic member 333 provided between one side roller 331 and the other side roller 332 may be applied. The brake roller part 330 releases the brake force of the shaft 400 by the rotation force of the base 320 and restores the brake force of the shaft 400 when the base 320 is fixed.

In this case, the present invention is configured to include the brake block 340 so that the rotation force of the base 320 may be directly delivered to the shaft 400 while maximizing the brake force of the brake roller part 330. The brake block 340 is disposed so that an inner side thereof is in contact with the brake roller part 330 and an outer side thereof is in contact with the inner peripheral surface of the housing 100. The brake block 340 is configured of a first block 341 corresponding to one side roller 331 and a second block 342 corresponding to the other side roller 332. The brake block 340 is configured so that it has a first roller groove 341b formed at an inner side of the first block 341 so as to fit one side roller 331, and one side surface 341a corresponds to the other side surface 323a of the base protrusion 323. The brake block 340 is configured so that it has a second roller groove 342b formed at an inner side of the second block 342 so as to fit the other side roller 332, and the other side surface 342a corresponds to one side surface 323b of the base protrusion 323.

Referring to FIG. 8, the shaft 400 is configured to include a shaft axis 410, a pinion gear 420, and a shaft cam 430. The shaft cam 430 has a cam 432 formed at a circumferential surface thereof and a plurality of base grooves 431 are radially formed to be depressed along the circumference of the shaft cam 430 so that the base protrusions 323 are fitted. The shaft cam 430 is configured so as to be in contact with the other surface of the base 320, and the base protrusion 323 is fitted into the base groove 431. In this case, it is preferable to form a width of the base groove 431 to be wider than a width of the base protrusion 323 so that the base groove 431 and the base protrusion 323 have clearance therebetween. The clearance is preferably a degree capable of rotating the shaft cam 430 by being in contact with the base groove 431 in a state in which the base protrusion 323 moves the brake block 340 to release the brake force of the shaft 400. According to the configuration as described above, the lever angle loss is minimized which may be produced when rotating the shaft by the brake roller in a state the base protrusion according to the related art moves the brake roller part to release the brake force. The pinion gear 420 is engaged with the link of the apparatus for adjusting the seat height and delivers the rotation of the shaft cam 430 to the link, thereby ascending or descending the seat.

By the configuration as described above, as shown in FIG. 9, the brake blocks 341 and 342 are disposed between the base protrusion 323 and the base protrusion 323, and the brake roller part 330 is disposed between the pair of

brake blocks

341 and 342. That is, the counterclockwise direction side 341a of the first block 341 is configured so as to be adjacent to the clockwise direction side 323a of the base protrusion 323 and one side roller 331 is configured so as to be adjacent to the first roller groove 341b of the first block 341. In addition, the clockwise direction side 342a of the second block 342 is configured so as to be adjacent to the counterclockwise direction side 323b of the base protrusion 323 and the other side roller 332 is configured so as to be adjacent to the second roller groove 342b of the second block 342.

The brake roller part 330 is fitted into the cam 432 of the shaft cam 430, and the first roller groove 341b and the second roller groove 342b of the brake blocks 341 and 342. The brake blocks 341 and 342 are fitted so that the

sides

341a and 342a thereof are in contact with the

sides

323a and 323b of the base protrusion 323 and the outer surface thereof are in contact with the inner peripheral surface of the housing 100. In this case, a predetermined clearance is formed between the brake blocks 341 and 342 and the base protrusion 323 so that the maximum brake force of the brake roller part 330 is produced, and a clearance wider than the clearance between the brake blocks 341 and 342 and the base protrusion 323 is also formed between the base protrusion 323 and the base groove 431.

Hereinafter, an operation state in which the shaft axis 410 is rotated by the rotation of the base 320 will be described in detail with reference to the drawings. For convenience, the description will be made by defining the clockwise direction as the other side surface and the counterclockwise direction as one side surface.

Referring to FIG. 10, when the base protrusion 323 is rotated in the clockwise direction, the other side surface of the base protrusion 323 first is in contact with one side surface of the first block 341 to rotate the first block 341 in the clockwise direction and as the first block 341 moves, one side roller 331 of the brake roller part moves in the clockwise direction, thereby releasing the brake force of the shaft cam 430. Next, the other side surface of the base protrusion 323 is in contact with the base groove 431 of the shaft cam 430, thereby rotating the shaft cam 430 in the clockwise direction.

Referring to FIG. 11, when the base protrusion 323 is fixed, one side roller 331 of the brake roller part is returned in the counterclockwise direction by the elasticity of the elastic member 333 and compresses the first block 341 and the shaft cam 430 to fix the shaft cam 430.

Referring to FIG. 12, a mounting bracket 500 has a disk shape in which a through-hole 501 is formed. The mounting bracket 500 is configured so as to close the opened surface of the housing 100. The mounting bracket 500 may be fitted into the housing 100 by a plurality of coupling protrusions 503 formed at a circumferential surface of the mounting bracket 500. A plurality of mounting bracket fixing holes 504 for fixing the pumping device (PD) are formed at a circumference of the other side end of the mounting bracket 500.

The pumping device PD according to the embodiment of the present invention as described above is mounted on the apparatus for adjusting the seat height for the motor vehicle capable of adjusting the seat height by a typical rotation, thereby making it possible to adjust the height of the seat.

The present invention should not be construed to being limited to the above-mentioned exemplary embodiment. The present invention may be applied to various fields and may be variously modified by those skilled in the art without departing from the scope of the present invention claimed in the claims. Therefore, it is obvious to those skilled in the art that these alterations and modifications fall within the scope of the present invention.

Claims

A pumping device for adjusting a seat height, comprising:

a housing coupled to a mounting bracket to form an inner space;

a shaft received in the housing so as to be rotated in a shaft direction and adjusting the seat height by a rotation thereof;

a lever mounting point for receiving rotation force applied from an external lever;

a clutch part received in the housing and having the lever mounting point formed on one surface thereof so as to be rotated in the shaft direction according to the rotation force applied from the lever; and

a brake part allowing the shaft to be rotated by fixing the shaft by a wedge operation for the housing and releasing the wedge operation by a rotation through the clutch part,

wherein the clutch part is directly connected to the shaft so as to rotate the shaft in the shaft direction by the rotation after releasing the wedge operation of the brake part.
The pumping device for adjusting the seat height of claim 1, wherein the housing and the mounting bracket each have a through-hole formed in the shaft direction, such that the clutch part and the brake part are disposed at a center of the shaft direction.
The pumping device for adjusting the seat height of claim 1, further comprising a shaft cam rotated integrally with the shaft and forming at least one first receiving space spaced apart from an inner peripheral surface of the housing by a predetermined distance in a circumferential direction,

wherein the brake part is configured of:

a brake roller part received in the first receiving space and locking or unlocking a rotation of the shaft cam according to whether or not compression is made in the circumferential direction;

a base compressing the brake roller part in the circumferential direction by a rotation produced by interworking the rotation of the clutch part; and

brake blocks provided between the inner peripheral surface of the housing and the brake roller part and between the brake roller part and the base, and delivering compressing force in the circumferential direction of the base to the brake roller part.
The pumping device for adjusting the seat height of claim 3, wherein the clutch part has a return unit so as to be returned to a predetermined reference position after rotating the base in one direction or the other direction.
The pumping device for adjusting the seat height of claim 3, wherein the brake roller part is configured of a plurality of rollers received in the respective first receiving spaces and an elastic member interposed between the plurality of rollers to compress the respective rollers toward both end portions of the first receiving space; and

the base has a base protrusion, the base protrusion being interposed between the brake roller part and a neighboring brake roller part to compress the rollers adjacent to each other toward a center portion of the first receiving space by the brake block.
The pumping device for adjusting the seat height of claim 4, wherein the base receives rotation force of the clutch part through one surface thereof and the base protrusion formed on the other surface of the base is in contact with the brake block and a base groove formed at the shaft cam, such that rotation force of the base is delivered to the brake block and the shaft cam, and

a spaced distance between the base protrusion and the brake block is shorter than a spaced distance between the base protrusion and the base groove.
The pumping device for adjusting the seat height of claim 4, wherein one surface of the base has a clutch receiving space of an annular shape formed along a circumference of the base,

the clutch part further includes a lever cam rotated integrally with the clutch part and forming at least one second receiving space spaced apart from an inner peripheral surface of the clutch receiving space by a predetermined distance in a circumferential direction; and

the brake part further includes a clutch roller part received in the second receiving space and locking or unlocking a rotation of the base according to whether or not compression is made in the circumferential direction.
The pumping device for adjusting the seat height of claim 4, wherein the clutch part includes a lever bracket having the lever mounting point formed thereon,

the housing is provided with a plurality of lever bracket guide grooves limiting a rotation angle range of the lever bracket in order to prevent the lever bracket from being rotated at a predetermine angle or more in a rotation direction of both sides based on the reference position; and

the lever bracket is provided with a lever bracket guide protrusion fitted into the lever bracket guide groove so as to be rotated.
An apparatus for adjusting a seat height for a motor vehicle comprising the pumping device of any one of claims 1 to 8.