JP2889943B2 - Headrest front and rear position adjustment device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for adjusting the front / rear position of a headrest of a vehicle seat.

(Prior Art) Conventionally known Japanese Utility Model Application Laid-Open No. 59-162053 discloses a headrest operating device that uses a reaction force of a coil spring press-fitted inside a fixed drum to stop reverse rotation of an operating shaft due to a load from the headrest. Is described.

In Japanese Utility Model Application Laid-Open No. 61-60855, an operating shaft that is orthogonal to the center of a circular brake drum is rotatably provided, and an elliptical disk having a diameter smaller than the inner diameter of the brake drum is provided in the brake drum. The operating shaft is loosely fitted to the center of the elliptical disc, and the narrow portion, the wide portion, and the narrow portion are provided between the outer peripheral surface of the perfect circular disc and the inner peripheral surface of the brake drum. A space portion that gradually becomes wider as it reaches the wide portion is provided, and a left and right brake block having the same shape as the space portion is provided in the space portion except for the narrow portion and the wide portion. Describes a steplessly prepared friction brake device in which an operating plate fixed to the operating shaft is provided with an engaging projection at the tip.

(Problems to be Solved by the Invention) Among the above-mentioned known examples, the former one has a structure in which reverse rotation is prevented by using a reaction force of a coil spring press-fitted inside the fixed drum. It cannot withstand a load higher than the frictional force. Also, since a spring is mounted in the drum, assembly is troublesome.

The latter employs a structure in which an elliptical disc is provided in a regular circular brake drum, so that a total of four left and right brake blocks are used. For this reason, the structure is inevitably complicated, and two of the four left and right brake blocks are pressed by springs, so that the function of loosening the brake blocks is poor. For this reason, the adjustment sometimes became hard. In addition, the spring is subjected to permanent deformation due to long-term use, and the locking becomes uncertain.

(Object of the Invention) The present invention is an operating device using a stepless adjustable brake by two left and right brake blocks, and always operates satisfactorily and reliably.

(Means for Solving the Problems) Accordingly, the present invention provides a stay 6 having a pair of vertically long legs 7 inserted and supported on the backrest sheet 2 side, and a sub-frame 5 fixed to the stay 6. , The subframe 5
, An adjusting mechanism Y for adjusting the position of the main frame 20, and an operating shaft to which an operating dial 21 or a motor for operating the adjusting mechanism Y is attached.
A headrest provided between the operating shaft 19 and the adjusting mechanism Y, the operating device 18 transmitting rotation from the operating shaft 19 but locking rotation from the adjusting mechanism Y; A fixed circular brake drum 24 provided on the outer periphery of the operation shaft 19; a small-diameter circular disk 34 loosely fitted to the operation shaft 19 and eccentrically provided in the drum 24; The narrow portions 42, 43 on both lower sides and the wide portions 44, 45 on both upper sides formed between the outer peripheral surface of the disk 34 and the inner peripheral surface of the brake drum 24, and the narrow portion.
Side space portions 40 and 41 which gradually become wider as they reach the wide portions 44 and 45 from 42 and 43, and the narrow portions 42 and 43 and the wide portions 44 provided in the side space portions 40 and 41. , 45, and brake locks 46, 47 having the same shape as the space portions 40, 41,
An operation plate 33 having an engagement projection 32 fixed to the operation shaft 19 and engaged between the narrow portions 42 and 43;
A locking projection which is loosely fitted to and engages between the wide portions 44, 45.
A lock plate 56 having a lock 57 and an engagement member (60) which is loosely fitted to the operation shaft 19 and is fixed integrally or separately to the lock plate 56 and rotates with respect to the adjustment mechanism Y. A headrest front-rear position adjustment device, and a stay 6 having a pair of legs 7 long in the vertical direction,
A sub-frame 5 fixed to the stay 6 and having a group of engagement holes 13 in the front-rear direction on both the left and right sides, a pinion gear 12 respectively engaging with the engagement holes 13, and a shaft 11 to which the pinion gear 12 is fixed; An operating device 18 for rotating the shaft 11,
In a headrest including side frames 17, 17 and a main frame 20 attached to the shaft 11 and moving back and forth with the shaft 11, the operating device 18 includes an operating shaft 19 attached to one end of the shaft 11, Fixed round circular brake drum 24 provided on the outer periphery of operation shaft 19
A small-diameter circular disc 34 which is loosely fitted to the operation shaft 19 and is eccentrically provided in the drum 24, and between the outer peripheral surface of the circular disc 34 and the inner peripheral surface of the brake drum 24. The narrow portions 42, 43 on both lower sides and the wide portions 44, 45 on both upper sides are formed from the narrow portions 42, 43 to the wide portions 44, 45.
And the side space portions 40 and 41, which gradually become wider as
Brake blocks 46, 47 having the same shape as the spaces 40, 41, except for the narrow portions 42, 43 and the wide portions 44, 45 provided in the side space portions 40, 41, and the operation shaft 19. An operation plate 33 fixed and having an engagement projection 32 engaged between the narrow portions 42 and 43; and the wide portions 44 and 45 loosely fitted to the operation shaft 19.
Lock plate 56 with lock projection 57 engaging between
And an engagement cylinder 60 which is loosely fitted to the operation shaft 19 and is integrally or separately fixed to the lock plate 56 and integrally rotates with the shaft 11, and is fixed to an end of the operation shaft 19. A headrest front / rear position adjusting device comprising an operation dial 21 and a headrest provided with an elastic member 63 for pressing the brake blocks 46, 47 toward the narrow portions 42, 43 in the wide portions 44, 45. This is a front / rear position adjusting device.

(Embodiment) One embodiment of the present invention will be described with reference to the drawings. 1 is for a vehicle (regardless of whether it is a front seat or a rear seat), 2 is a backrest sheet of the vehicle seat 1, and 3 is a It is a headrest provided in the upper part. In FIG. 2, reference numeral 5 denotes a subframe provided in the headrest 3;
The upper part of the stay 6 is fixed to the lower surface of the backrest 2, and the pair of legs 7, 7 of the stay 6 is inserted into a pair of support cylinders provided in the backrest sheet 2 so as to be vertically adjustable.

The left and right side plates 8, 8 of the sub-frame 5 are bent so as to protrude midway in the vertical direction over the entire width to form bent portions 9, 9 (FIG. 2). Sliding members 10, 10 are fitted in the bent portions 9, 9 so as to be slidable back and forth, respectively. The sliding members 10 and 10 are formed of a synthetic resin or the like in the shape of a quadrangular prism that is long in the front-back direction. Left and right ends of a left and right shaft 11 are freely rotatably mounted at the middle portions of the sliding members 10 in the front and rear direction. Pinion gears 12 and 12 are fixed to a portion of the shaft 11 inside the sliding members 10, respectively. The pinion gears 12 and 12 are formed on the lower surfaces of the bent portions 9 and 9 by a plurality of engagements formed at predetermined intervals. Engage with one of the holes 13 group.

Outside the side plates 8, 8 of the sub-frame 5, side frames 17, 17 are attached to the sub-frame 5 so as to be movable back and forth. That is, long holes 15, 15 long in the front-rear direction are formed in the side plates 14, 14 of the bent portions 9, 9, and the sliding member 10 and the side frame 17 are formed by pins 16, 16 passing through the holes 15.
Are fixed by caulking so as to move together with the side plates 8, 8 interposed therebetween. Reference numeral 20 denotes a main frame mounted between the side frames 17, 17. In addition, side frame 1
The main frame 20 may be integrally formed with the main frames 7, 17, but this is not the gist of the present invention.

An operating shaft 19 of an operating device 18 to be described later is attached to one end of the shaft 11, and the operating shaft 19
By rotating the pinion gear 12 and the engagement hole 13, the sliding members 10, 10 are moved back and forth by rotating the pinion gear 12, the side frame 17 and the main frame 20 are moved back and forth with respect to the sub-frame 5, and the headrest Adjust the front and rear position of 3.
Therefore, an adjusting mechanism Y is constituted by the sliding members 10 and 10 for moving the main frame 20 back and forth with respect to the sub-frame 5, the shaft 11, the pinion gears 12 and 12, and the like.

The moving direction of the headrest 3 can be changed by changing the shapes of the bent portions 9 and 9 and the sliding members 10 and 10. That is, when viewed from the side, if the bent portion 9 is formed so as to be inclined lower toward the front side,
The headrest 3 can be moved diagonally forward.

Thus, the operation device 18 has an operation dial 21 attached to the outer end of the operation shaft 19, and the operation shaft 21 is provided from the operation dial 21 side.
19 can be rotated, but is locked continuously from the pinion gear 12 (adjustment mechanism Y) side so that it cannot be rotated. That is, although a load for moving the headrest 3 backward is applied, the headrest 3 is held at the adjustment position by preventing the pinion gear 12 from rotating backward due to this load.

In FIG. 2, reference numeral 22 denotes a case of the operating device 18, which is formed of a desired material such as metal or synthetic resin, and has a bottomed drum drum 24 having a horizontal tubular shape, abuttingly closed and having a bottom plate 23; A flange portion connected to the edge of the drum 24
The flange 25 is fixed to the side frame 17 by a known means such as bolting or welding. The bottom plate 23
A left and right mounting hole 26 is formed at the center of the shaft, and a serration groove shaft 27 is formed in the mounting hole 26 at the outer end of the operation shaft 19.
Is rotatably inserted, and the operation dial 21 is fixed to the serration groove shaft 27 protruding outside of the mounting hole 26 with a bolt 28. Reference numeral 29 denotes a bent portion formed at the center of the operation dial 21, reference numeral 30 denotes a through hole formed at the bottom of the concave portion 29 for inserting a bolt 28, and reference numeral 31 denotes a lid member fitted into the concave portion 29.

An operation plate 33 having an engagement projection 32 projecting in a radial direction and having a tip bent in parallel with the operation shaft 19 is formed on an inner portion of the operation shaft 19 inside the bottom plate 23.
It is formed so as to rotate within 24 (FIGS. 2 and 5).

An eccentric round disk is provided inside the operation plate 33.
Install 34. The eccentric perfect circular disc 34 is formed in a perfect circular shape by a member having a thickness on the left and right (FIG. 2, FIG. 4).
Figure). A mounting hole 35 in the left-right direction is formed at an eccentric position off the center of the eccentric circular disk 34 (FIG. 2), and the mounting hole 35 is freely inserted into the operation shaft 19 only for rotation.

A fitting groove 36 is formed on the outer surface of the eccentric regular circular disc 34 so as to extend through the center of the disc 34 and the mounting hole 35, and the operation plate 33 is fitted into the fitting groove 36. The left and right width of the fitting groove 36 as viewed from the side is formed wider than the left and right width of the operation plate 33 (FIG. 7). When the operation plate 33 is rotated, the operation is performed without first rotating the disc 34. When only the plate 33 idles and then rotates a little, the left and right sides of the operation plate 33 contact the wall surface 37 of the fitting groove 36 to rotate the eccentric perfect circular disc 34.

Thus, when the eccentric perfect circular disc 34 is fitted into the brake drum 24, between the outer peripheral surface 38 of the disc 34 and the inner peripheral surface 39 of the drum 24, when viewed from the side, Symmetrical side space portions 40 and 41 are formed (FIG. 7). Since the eccentric perfect circular disc 34 has the mounting hole 35 at an eccentric position off center as described above, the side space portions 40 and 41 have lower sides on both sides as shown in FIG. The upper portions are formed in narrow portions 42, 43, and the upper sides are formed in wide portions 44, 45 that gradually become wider.

A pair of left and right brake blocks 46 and 47 are movably fitted to the side space portions 40 and 41 (FIG. 8). The left and right brake blocks 46 and 47 are formed symmetrically to the left and right according to the shapes of the side space portions 40 and 41, and are formed in a shape in which the lower side is thinner and the upper side is thicker toward the upper side in FIG. The moving side engaging surfaces 48 and 49 are formed on the end surface on the side
(FIG. 2), lock-side engaging surfaces 50 and 51 are formed on the wide end surface (FIG. 2). Outer peripheral surface 5 of left and right brake blocks 46, 47
Reference numerals 2 and 53 are formed on an arc surface centered on the axis of the operation shaft 19, respectively. Inner peripheral surface 5 of left and right brake blocks 46, 47
Reference numerals 4 and 55 are formed on a circular arc surface concentric with the center of the circular disc 34 at a predetermined position.

Therefore, the inner peripheral surface 5 of the left and right brake blocks 46 and 47
Reference numerals 4 and 55 move (rotate) the outer peripheral surface 38 of the eccentric perfect circular disc 34 and the outer peripheral surfaces 52 and 53 of the left and right brake blocks 46 and 47 in close contact with the inner peripheral surface 39 of the brake drum 24, respectively. To prevent backlash.

The engagement protrusion 32 of the operation plate 33 is located between the movable engagement surfaces 48 and 49 formed below the left and right brake blocks 46 and 47, and the upper lock side of the left and right brake blocks 46 and 47 is locked. A lock plate 56 is provided between the engagement surfaces 50 and 51.
The lock projection 57 is positioned. A gap is formed between the lock projection 57 and each of the lock-side engagement surfaces 50 and 51 (FIG. 8). When the engagement projection 32 rotates, the gap is released and the left and right brakes are released. Only the blocks 46 and 47 are moved to release the locked state.

The lock plate 56 has a mounting hole formed at its base.
The engaging teeth 61 of the engaging cylinder 60 are engaged with the engaging grooves 59 of 58. The engagement cylinder 60 may be formed integrally with the lock plate 56. The engagement teeth 61 of the engagement cylinder 60 are inserted into the shaft 11 through the elongated holes 15 of the side frame 17. A serration groove 62 is formed on the inner peripheral surface of the shaft 11, and engagement teeth 61 are formed in the serration groove 62.
And the rotation of the lock plate 56 causes the shaft 1 to rotate.
1. Rotate the pinion gear 12 to move the headrest 3 back and forth. The inner end of the operation shaft 19 is rotatably inserted into the engagement cylinder 60. Therefore, if the operation shaft 9 and the lock plate 56 are loosely fitted to each other and the lock plate 56 and the shaft 11 rotate integrally, the engagement cylinder 60 may be provided on the shaft 11 side.

Thus, an elastic member 63 is fitted between the lock-side engaging surfaces 50, 51 of the left and right brake blocks 46, 47. The elastic member 63 is formed of a synthetic resin or the like so as to be wider than the gap between the lock-side engagement surface 50 and the lock-side engagement surface 51 so as to press the left and right brake blocks 46 and 47 against the narrow portions 42 and 43. , Resiliently contact both of the lock-side engaging surfaces 50 and 51.

64 is a spring provided between the main frame 20 and the sub-frame 5, and 65 is an undercover.

(Operation) Next, the operation will be described.

The present invention has the above-described configuration, in which the upper portion of the stay 6 is fixed to the sub-frame 5, and the left and right ends of the shaft 11 are sliding members.
10 and 10, the perforated members 10 and 10 are fitted to the bent portions 9 and 9 of the sub-frame 5, and the sliding members 10 and the side frames 17 are pinned with the sub-frame 5 therebetween. Fix with 16. Next, the main frame 20 is attached to the side frames 17, 17, and a spring 64 is provided between the main frame 20 and the sub-frame 5.
And the under cover 65 is attached from below the stay 6.

Next, the operation shaft 19 is inserted through the case 22 from the inside, the eccentric circular disc 34 is inserted into the operation shaft 19 in the brake drum 24, and the left and right brake blocks are inserted into the side space portions 40 and 41 in the brake drum 24. 4 and 47 are fitted, the engaging cylinder 60 is inserted through the operating shaft 19, the lock plate 56 is engaged and fixed to the engaging cylinder 60, and the shaft facing the long hole 15 of the side plate 14 of the bent portion 9. When the engaging teeth 61 of the engaging cylinder 60 are engaged and fixed in the serration grooves 62 of 11 and the flange 25 of the case 22 is fixed to the side frame 17, the assembly of the operating device 18 is completed, and the side A cushion material is attached to the outer periphery of the frame 17 and the main frame 20, the outer periphery of the cushion material is surrounded by a skin, and the operating shaft 19
The operation dial 21 is fixed to the serration groove shaft 27.

When the operation dial 21 is rotated by manual operation and the operation shaft 19 is rotated counterclockwise as shown in FIG. 9, the right and left widths of the operation plate 33 are changed to the fitting grooves 36 of the eccentric circular disc 34.
Are formed narrower than the left and right widths of the operation plate 33. At first, only the operation plate 33 idles,
Abuts on the moving side engagement surface 48 of the right brake block 46.

Further, when the operation plate 33 rotates left, the lock projection 57
And the lock side engaging surface 5 of the left and right brake blocks 46 and 47
Since a gap is formed between the eccentric 0 and 51, the gap serves as a clearance, and only the right brake block 46 is rotated to the left without rotating the eccentric round disk 34 (FIG. 9). Therefore, the locked state of the right brake block 46 is released.

When the right brake block 46 rotates left, the lock-side engaging surface 50 on the upper part of the right brake block 46 contacts the elastic member 63, and when the right brake block 46 further rotates, the elastic member
63 pushes the lock side engagement surface 51 of the other left brake block 47.

At the same time, the side surface of the operation plate 33 comes into contact with the wall surface 37 of the fitting groove 36 of the eccentric regular circular disk 34, and rotates the disk 34 counterclockwise.

When the operation shaft 19 rotates to the left in this way, the side space portion 40 in which the right brake block 46 is fitted is formed in a wide portion 44 that becomes wider in the direction in which the right brake block 46 rotates. After that, the right brake block 46 moves to a position where it becomes loose.

On the other hand, the left brake block 47 is pushed toward the apparently narrow portion 43 by the right brake block 46 via the elastic member 63, but earlier than the movement of the left brake block 47, and is eccentric by the side surface of the operation plate 33. Round disc
Since the 34 rotates counterclockwise, the narrow portion 43 relatively moves before the left brake block 47 and the left brake block
47 moves to the loosened position, and the right brake block 46, the left brake block 47, and the eccentric circular disc 34 rotate counterclockwise together.

Therefore, when the operation shaft 19 rotates left, the right brake block 46, the left brake block 47, and the eccentric circular disc 34 rotate together, and the rotation rotates the lock plate 56, and the lock plate 56 The rotation is performed by the engagement groove 59 of the lock plate 56 → the engagement tooth 61 of the engagement cylinder 60 →
The shaft 11 is transmitted to the serration groove 62 of the shaft 11 to rotate the shaft 11 so that the pinion gear 12
And the rotation of the pinion gear 12 causes the sliding member 10 to rotate.
Moves forward with the side frame 17 and the main frame 20, and moves the headrest 3 forward and backward.

When the operation shaft 19 is rotated clockwise by the operation dial 21, the right brake block 46 is turned off for the same reason as described above.
And the left brake block 47 and an eccentric round disk
Numeral 34 rotates clockwise together to move the sliding member 10 rearward by the rotation of the pinion gear 12, and adjusts the headrest 3 to move rearward.

In this case, an elastic member 63 is fitted between the lock-side engaging surfaces 50, 51 of the left and right brake blocks 46, 47, and almost simultaneously with the movement of the right brake block 46 via the elastic member 63, the left brake block. Since 47 is moved, the right brake block 46, the left brake block 47,
Rotation with the eccentric perfect circular disc 34 is performed smoothly.

When the hand is released from the operation dial 21 after the position adjustment, the elastic member 63 returns to its original size after being released from being pressed by the rotation of the left and right brake blocks 46 and 47. Narrow parts of brake blocks 46 and 47
Push toward 42, 43, left and right brake blocks 46, 47
To prevent backlash.

Thus, when the headrest 3 is pressed backward by the driver's head, the main frame 20, the side frames 17,
A load for rotating the pinion gear 12 in the reverse direction is applied via the shaft 11.

Therefore, the pinion gear 12 tries to rotate the lock plate 56 clockwise from the state shown in FIG. 8 through the engagement teeth 61 of the engagement cylinder 60 (FIG. 11). Then, the right brake block 46 is pushed so as to move in the direction of the narrow portion 42, and the right brake block 46 pushes the eccentric circular disc 43 in a direction to turn right.

When a force in the right rotation direction is applied to the eccentric circular disc 34, the left brake block 47 is in the same state as being pushed in a direction in which the left brake block 47 is relatively rotated left relative to the eccentric circular disc 34, and the left brake block 47 47 is also pushed in the direction of the narrow portion 43, so that the right brake block
The 46, the left brake block 47, and the eccentric circular disc 34 cooperate to apply a brake, thereby preventing the pinion gear 12 from reversing.

Therefore, the headrest 3 does not move backward even by the impact load by the occupant.

In this case, the elastic member 63 between the lock side engagement surfaces 50, 51 of the left and right brake blocks 46, 47 is, as described above,
Since both the lock side engaging surfaces 50 and 51 are constantly pressed so that the left and right brake blocks 46 and 47 move to the narrow portions 42 and 43, the lock protrusion 57 is fixed to the left and right brake blocks 46 and 47.
When one of the lock-side engaging surfaces 50, 51 is brought into contact with and pushed, both of the left and right brake blocks 46, 47 are immediately fitted in the direction of the relatively narrow portions 42, 43 as described above. Can be locked.

(Effect) The present invention provides a stay 6 having a pair of vertically long legs 7 inserted and supported on the backrest sheet 2 side, a sub-frame 5 fixed to the stay 6, and a sub-frame 5. A moving main frame 20, an adjusting mechanism Y for adjusting the position of the main frame 20, an operating shaft 19 to which an operating dial 21 or a motor for operating the adjusting mechanism Y is attached,
A headrest provided between the operating shaft 19 and the adjusting mechanism Y and having an operating device 18 that transmits rotation from the operating shaft 19 but locks a circuit from the adjusting mechanism Y, the operating device 18 includes: A fixed circular circular brake drum 24 provided on the outer periphery of the operation shaft 19; a small diameter circular disk 34 loosely fitted to the operation shaft 19 and eccentrically provided in the drum 24; The narrow portions 42, 43 on both lower sides, the wide portions 44, 45 on both upper sides, and the narrow portions 42, 43 formed between the outer peripheral surface and the inner peripheral surface of the brake drum 24.
Side space portions 40, 41 whose width gradually increases as they reach the wide portions 44, 45, and the narrow portions 42, 43 and the wide portions 44, 45 provided in the side space portions 40, 41. Brake locks 46, 47 having the same shape as the space portions 40, 41, and an operation plate 33 having an engagement projection 32 fixed to the operation shaft 19 and engaged between the narrow portions 42, 43; A lock plate 56 having a lock projection 57 which is loosely fitted to the operation shaft 19 and engages between the wide portions 44 and 45; and a lock plate 56 which is loosely fitted to the operation shaft 19 and is integral with or separate from the lock plate 56. Since the headrest front and rear position adjusting device is constituted by a fixed engaging member (60) and a rotating engaging member (60), the frame 20 moves rearward due to the load applied to the headrest 3, This movement is rotated by the adjustment mechanism Y to rotate the engagement cylinder member (60). When rotated the locking projection 57, the brake blocks 46, 47 are relatively moved toward the narrow portions 42 and 43, since brake by the wedge phenomenon,
Can withstand heavy loads.

When assembling the eccentric round disk 34 and the left and right brake blocks 46 and 47 in the case 24, the assembly is easy because no spring is used as in the known example.

Since the eccentric round disk 34 is used, the size, weight and cost are reduced.

The present invention also provides a stay 6 having a pair of vertically long legs 7, a sub-frame 5 fixed to the stay 6, and having a group of front and rear engagement holes 13 arranged on both left and right sides. A pinion gear 12 that engages with each of the holes 13;
In a headrest including a shaft 11 to which 12 is fixed, an operation device 18 for rotating the shaft 11, and side frames 17, 17 and a main frame 20 attached to the shaft 11 and moving back and forth with the shaft 11, The operating device 18 includes an operating shaft 19 attached to one end of the shaft 11, a fixed regular circular brake drum 24 provided on the outer periphery of the operating shaft 19, and a loosely fitted to the operating shaft 19 and inside the drum 24. Small diameter circular disc 34 provided in eccentric state
And the outer peripheral surface of the circular disc 34 and the brake drum
Narrow portions 42, 43 on both lower sides formed between the inner peripheral surface of 24
And the upper side wide portions 44, 45 and the side spaces 40, 41 whose width gradually increases from the narrow portions 42, 43 to the wide portions 44, 45, and in the side spaces 40, 41. The narrow portion provided
Brake blocks 46, 47 having the same shape as the space portions 40, 41 except for the portions 42, 43 and the wide portions 44, 45, and the engaging members fixed to the operation shaft 19 and engaged between the narrow portions 42, 43. An operation plate 33 having a mating projection 32; a lock plate 56 having a lock projection 57 which is loosely fitted to the operation shaft 19 and engages between the wide portions 44 and 45; and a lock plate which is loosely fitted to the operation shaft 19. The shaft 11 is fixed to the plate 56 integrally or separately.
Is a device for adjusting the front / rear position of the headrest, which comprises an engaging cylinder 60 that rotates integrally and an operation dial 21 fixed to the end of the operation shaft 19. The adjusting mechanism Y is constituted by a group of engagement holes 13 formed in the frame 5 in the front-rear direction, the pinion gears 12 respectively engaging with the engagement holes 13, and the shaft 11 to which the pinion gears 12 are fixed. Is simple, easy to assemble, lower in cost, and contributes to weight reduction.

The lock plate 56 is loosely fitted to the operation shaft 19 and
Is attached to the engaging cylinder 60 which rotates integrally,
It has a rational configuration, facilitates assembly, and is compact, lightweight,
Lower cost.

Further, the present invention is an apparatus for adjusting the front / rear position of the headrest in which the elastic members 63 for pressing the brake blocks 46, 47 toward the narrow portions 42, 43 are provided in the wide portions 44, 45. Since the elastic member 63 moves the other brake block 47 substantially simultaneously with the movement of one brake block 46,
A pair of brake blocks 46 and 47 and an eccentric round disk
34 and rotate smoothly.

After the position adjustment, when you release your hand from the operation dial 21,
The elastic member 63 presses the brake blocks 46 and 47 toward the narrow portions 42 and 43, thereby preventing the brake blocks 46 and 47 from rattling.

When the lock projection 57 pushes one of the brake blocks 46 and 47, both of the brake blocks 46 and 47 can be fitted and locked in the direction of the narrow portions 42 and 43 relatively immediately.

This has the effect.

[Brief description of the drawings]

1 is a perspective view of a seat, FIG. 2 is a perspective view of an entire assembly state of the apparatus, FIG. 3 is a perspective view of a main part assembly state, FIG. 4 is a vertical sectional front view, and FIG. 6, FIG. 6 is a cross-sectional plan view of a main part, FIG. 7 is a vertical right side view in a state where the brake block is not fitted, FIG. 8 is a vertical right side view in a free state,
9 and 10 are vertical right side views in the operating state, and FIG. 11 is a vertical right side view in the locked state. DESCRIPTION OF SYMBOLS 1 ... vehicle seat, 2 ... back seat, 3 ... headrest, 5 ... subframe, 6 ... stay, 7 ... leg, 8 ... side plate, 9 ... bend, 10 ... sliding member, 11 ... ... shaft, 12 ...
Pinion gear, 13 ... engagement hole, 14 ... side plate, 15 ... long hole, 17 ...
Side frame, 18 operating device, 19 operating shaft, 20 main frame, 21 operating dial, 22 case, 23 bottom plate,
24: brake drum, 25: flange, 26: mounting hole, 27: serration groove shaft, 28: bolt, 29: recess, 30: through hole, 31
... lid member, 32 ... engaging projection, 33 ... operating plate, 34 ... eccentric round disk, 35 ... mounting hole, 36 ... fitting groove, 33 ... wall surface,
38 ... outer peripheral surface, 39 ... inner peripheral surface, 40, 41 ... side space, 42, 43
... Narrow part, 44, 45 ... Wide part, 46, 47 ... Brake block, 48, 49 ... Moving side engaging surface, 50, 51 ... Lock side engaging surface,
52, 53 ... outer peripheral surface, 54, 55 ... inner peripheral surface, 56 ... lock plate, 57 ... lock projection, 58 ... mounting hole, 59 ... engagement groove, 60 ... engagement cylinder, 61 ... engagement tooth, 62 ... Serration grooves, 63 ... elastic members, 64 ... springs, 65 ... undercover.

Claims (3)

(57) [Claims] 1. A stay 6 having a pair of vertically long legs 7 inserted and supported on the backrest sheet 2 side, a sub-frame 5 fixed to the stay 6, and a movement with respect to the sub-frame 5. A main frame 20, an adjustment mechanism Y for adjusting the position of the main frame 20, an operation shaft 19 to which an operation dial 21 or a motor for operating the adjustment mechanism Y is attached,
In a headrest provided between the operation shaft 19 and the adjustment mechanism Y and having an operation device 18 that transmits rotation from the operation shaft 19 but locks rotation from the adjustment mechanism Y, the operation device 18 includes: A fixed circular circular brake drum 24 provided on the outer periphery of the operation shaft 19; a small diameter circular disk 34 loosely fitted to the operation shaft 19 and eccentrically provided in the drum 24; The narrow portions 42, 43 on both lower sides, the wide portions 44, 45 on both upper sides, and the narrow portions 42, 43 formed between the outer peripheral surface and the inner peripheral surface of the brake drum 24.
Side space portions 40, 41 whose width gradually increases as they reach the wide portions 44, 45, and the narrow portions 42, 43 and the wide portions 44, 45 provided in the side space portions 40, 41. Leave the space part
Brake blocks 46 and 47 having the same shape as 40 and 41, an operation plate 33 having an engagement projection 32 fixed to the operation shaft 19 and engaged between the narrow portions 42 and 43, and the operation shaft 19 A lock plate 56 having a lock projection 57 which is loosely fitted and engages between the wide portions 44 and 45; and the adjustment mechanism which is loosely fitted to the operation shaft 19 and fixed integrally or separately to the lock plate 56. A headrest front / rear position adjusting device constituted by an engagement member that rotates with respect to Y. 2. A stay 6 having a pair of legs 7 which are long in the vertical direction, a sub-frame 5 fixed to the stay 6, and having a group of front and rear engagement holes 13 arranged on both left and right sides; 13, a pinion gear 12 respectively engaged with the shaft 11, a shaft 11 to which the pinion gear 12 is fixed, an operating device 18 for rotating the shaft 11, a side frame 17 attached to the shaft 11 side and moving back and forth with the shaft 11, The headrest comprising the main frame 17 and the main frame 20;
An operating shaft 19 attached to one end of the shaft 11
A fixed regular circular brake drum 24 provided on the outer periphery of the operation shaft 19, and the drum 24
A small-diameter circular disc 34 provided in an eccentric state inside,
The narrow portions 42, 43 on both lower sides, the wide portions 44, 45 on both upper sides, and the narrow portions 42, 43 formed on the lower circumferential side between the outer circumferential surface of the circular disc 34 and the inner circumferential surface of the brake drum 24. From the side space portion 4 which gradually becomes wider as it reaches the wide portions 44 and 45.
0, 41 and the narrow portion 4 provided in the side space portions 40, 41.
The brake blocks 46, 47 having the same shape as the space portions 40, 41 and the engagement portions fixed to the operation shaft 19 and engaged between the narrow portions 42, 43, except for the space portions 40, 41 and the wide portions 44, 45. An operation plate 33 having a mating projection 32; a lock plate 56 having a lock projection 57 which is loosely fitted to the operation shaft 19 and engages between the wide portions 44 and 45; and a lock plate which is loosely fitted to the operation shaft 19. The shaft 11 is fixed to the plate 56 integrally or separately.
A headrest front / rear position adjusting device comprising an engaging cylinder 60 which rotates integrally and an operation dial 21 fixed to an end of the operation shaft 19. 3. The elastic member 63 according to claim 1, wherein said wide blocks 44, 45 press said brake blocks 46, 47 toward said narrow sections 42, 43. Headrest front and rear position adjustment device provided with.