Tilt adjustment kit

Abstract

A problem addressed by the present invention is to provide a reclining device wherein when a pole is in an unlocked position, the orientation of the pole is stable, and when the pole has been moved to a locked position, engagement between the external teeth of the pole and internal teeth of a first member is stable. This reclining device has at least one second cam 44 that is provided between a cam 31 and a second pole 42 and is pressed by the cam 31 to press the second pole 42. The reclining device is provided with a spring 51 for pressing the second pole 42 against a pole guide protrusion 37.

Description

Reclining device

[0001] The present invention relates to a reclining device comprising: a bottomed cylindrical first member having internal teeth formed along the circumferential direction on its inner surface and one of its faces being an open surface; a plurality of poles having external teeth that can mesh with the internal teeth; a second member stacked on the open surface side of the first member and provided so as to be rotatable relative to the first member in the circumferential direction, having a plurality of pole guides formed thereon that guide the pole between a locked position in which the external teeth mesh with the internal teeth and an unlock position in which the external teeth are separated from the internal teeth; a cam provided so as to be rotatable between the first member and the second member and moving the pole in the direction of the locked position; and at least one second cam provided between the cam and the pole and pushed by the cam to push the pole, wherein the pole is guided between the two pole guides, and when the pole is in the locked position, relative rotation between the first member and the second member is prohibited, and the second cam pushes the pole in the direction of the locked position and brings the pole into close contact with one of the pole guides.

[0002] As an example of a reclining device, there is a bottomed cylindrical first member having internal teeth formed along the circumferential direction on its inner surface and one side being an open surface; a plurality of poles having external teeth that can mesh with the internal teeth; a second member stacked on the open surface side of the first member and provided so as to be rotatable relative to the first member in the circumferential direction, and having a plurality of pole guides formed thereon that guide the pole between a locked position in which the external teeth mesh with the internal teeth and an unlock position in which the external teeth are separated from the internal teeth; a cam provided so as to be rotatable between the first member and the second member and moving the pole in the direction of the locked position; and at least one second cam provided between the cam and the pole and pushed by the cam to push the pole, wherein the pole is guided between the two pole guides, and when the pole is in the locked position, relative rotation between the first member and the second member is prohibited, and the second cam pushes the pole in the direction of the locked position and brings the pole into close contact with one of the pole guides (see, for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2014-239721

[0004] However, in the structure described in Patent Document 1, when the external teeth of the pole do not mesh with the internal teeth of the first member, that is, when the pole is in the unlock position, the pole is supported only by the pole guide. Due to reasons such as smooth movement of the pole, component accuracy of the pole and the pole guide, there is a gap between the pole and the pole guide.

[0005] Therefore, when the pole is in the unlock position, the posture of the pole is not stable. In particular, the pole pushed by the second cam has a shorter opposing surface with the guide, and is particularly unstable. And when the pole is moved to the lock position by the cam and the second cam, there is a problem that the meshing condition between the external teeth of the pole and the internal teeth of the first member is not stable.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a reclining device in which the meshing condition between the external teeth of a pole and the internal teeth of a first member is stabilized.

[0007] In order to achieve at least one of the above-described problems, a reclining device reflecting one aspect of the present invention includes: a bottomed cylindrical first member having internal teeth formed along the circumferential direction on the inner cylindrical surface and one surface being an open surface; a plurality of poles having external teeth capable of meshing with the internal teeth; a second member laminated on the open surface side of the first member and provided so as to be relatively rotatable in the circumferential direction with respect to the first member, and having a plurality of pole guides formed between a lock position where the external teeth mesh with the internal teeth and an unlock position where the external teeth are separated from the internal teeth for guiding the poles; a cam provided rotatably between the first member and the second member for moving the poles in the lock position direction; and at least one second cam provided between the cam and the poles for pushing the poles by being pushed by the cam. The pole is guided between two of the pole guides. When the pole is in the lock position, relative rotation between the first member and the second member is prohibited, and the second cam pushes the pole in the lock position direction and makes the pole adhere to one of the pole guides. The reclining device is characterized in that a spring for pressing the pole in the direction of the one pole guide is provided.

[0008] Other features of the present invention will become even clearer from the embodiments for carrying out the invention described below and from the accompanying drawings.

[0009] According to the reclining device of the present invention, by providing a spring that presses the pole in the direction of one of the pole guides, the pole's position is stabilized when the pole is in the unlocked position, and when the pole is moved to the locked position, the meshing between the pole's outer teeth and the first member's inner teeth is stabilized.

[0010] Other effects of the present invention will become even clearer from the embodiments for carrying out the invention described below and from the accompanying drawings.

[0011] This is an exploded perspective view of the reclining device of this embodiment. This is an exploded perspective view of the exploded perspective view of Figure 1, viewed from the opposite direction. This is a cross-sectional view of the assembled reclining device of Figure 1 (locked state) along the cutting line III-III. This is a cross-sectional view of the assembled reclining device of Figure 1 (unlocked state) along the cutting line IV-IV. This is a cross-sectional view of the assembled reclining device of Figure 1 (locked state) along the cutting line V-V. This is a diagram showing the unlocked state of the reclining device of Figure 5. This is a front view of the assembled reclining device of Figure 1 viewed from the direction of arrow VII. This is an end view of the section cut along the cutting line VIII-VIII of Figure 7. This is an end view of the section cut along the cutting line IX-IX of Figure 7. This is an end view of the section cut along the cutting line X-X of Figure 7. This is an end view of the section cut along the cutting line XI-XI of Figure 7. This is a configuration diagram of a seat equipped with the reclining device of this embodiment.

[0012] Embodiments will be described using drawings. First, Figure 12 will be used to describe the seat equipped with the reclining device of this embodiment. The seat 1 consists of a seat cushion 2 that supports the buttocks of the sitter, and a seat back 3 that is tiltable in the front-rear direction relative to the seat cushion 2 and supports the back of the sitter. 4 is a reclining device provided on the axis of rotation (O) of the tilt of the seat back 3, which allows / denies the tilt of the seat back 3.

[0013] Furthermore, this reclining device 4 can be tilted from a forward-tilted position to a backward-tilted position. While the tilting of the seat back 3 can be permitted / disabled between the initial locked position and the backward-tilted position, and in the forward-tilted position, the lock release holding mechanism keeps it in a unlocked and held state between the initial locked position and the forward-tilted position, allowing the seat cushion to be tilted without operating the control lever.

[0014] The reclining devices in this embodiment are provided on both the left and right sides of the seat, and their structure is the same; therefore, the reclining device 4 on one side will be described below. The reclining device 4 will be explained using Figures 1 to 11. Figure 1 is an exploded perspective view of the reclining device of this embodiment, Figure 2 is an exploded perspective view of the exploded perspective view of Figure 1 viewed from the opposite direction, Figure 3 is a cross-sectional view of the assembled reclining device of Figure 1 (locked state) along the cutting line III-III, Figure 4 is a cross-sectional view of the assembled reclining device of Figure 1 (unlocked state) along the cutting line IV-IV, Figure 5 is a cross-sectional view of the assembled reclining device of Figure 1 (locked state) along the cutting line V-V, Figure 6 is a diagram showing the unlocked state of the reclining device of Figure 5, Figure 7 is a front view of the assembled reclining device of Figure 1 viewed from the direction of arrow VII, Figure 8 is an end view of the section cut along the cutting line VIII-VIII in Figure 7, Figure 9 is an end view of the section cut along the cutting line IX-IX in Figure 7, Figure 10 is an end view of the section cut along the cutting line X-X in Figure 7, and Figure 11 is an end view of the section cut along the cutting line XI-XI in Figure 7.

[0015] The ratchet (first member) 21 provided on the seat back 3 side is a bottomed cylindrical shape formed by partially punching a disc-shaped plate material with a press, and has a circular recess 21a. Internal teeth 23 are formed on the inner circumferential surface of this circular recess 21a along the entire circumference. In addition, a through hole 21b is formed in the center of the circular recess 21a into which a shaft (not shown) is loosely inserted, which is arranged along the axis of rotation of the tilting of the seat back 3 (axis O in Figures 1 and 2). Note that the cross-sectional shape of the shaft not shown in this embodiment is not circular (in this embodiment, the cross-sectional shape is oval).

[0016] The base plate (second member) 25, provided on the seat cushion 2 side, is formed by partially punching a disc-shaped plate material by pressing, similar to the ratchet 21, and has a circular recess 25a. The diameter of this circular recess 25a is set to be slightly larger than the outer diameter of the ratchet 21. The ratchet 21 is fitted into the circular recess 25a, and the base plate 25 and the ratchet 21 are able to rotate relative to each other. In addition, a through hole 25b is formed in the center of the base plate 25 into which a shaft (not shown) is loosely inserted.

[0017] The outer circumference of the ratchet 21 and the outer circumference of the base plate 25 are held together by a ring-shaped outer ring 27, and the ratchet 21 and the base plate 25 are held to rotate relative to each other without being separated in the direction of the axis O of relative rotation. A cam 31 is positioned in the space formed by the circular recess 21a of the ratchet 21 and the circular recess 25a of the base plate 25. A hole (oval-shaped in this embodiment) 31a is formed in the center of the cam 31 into which a shaft (not shown) is fitted. The shaft (not shown) and the cam 31 rotate together as a single unit. For this reason, this shaft (not shown) acts as a transmission member that transmits the movement of the cam 31 of one of the reclining devices provided on both sides of the seat to the cam of the other reclining device. In addition, the cam 31 has two protrusions 31c that project toward the ratchet 21. Furthermore, four first protrusions 31d and four second protrusions 31e are alternately formed along the circumferential direction on the outer circumference of the cam 31. Furthermore, the cam 31 has two holes 31f into which two wire springs 51, which will be described later, engage.

[0018] A release plate 33 is positioned between the cam 31 and the circular recess 21a of the ratchet 21. The release plate 33 has holes 33a formed in it into which the two protrusions 31c of the cam 31 engage. This engagement between the protrusions 31c and the holes 33a causes the cam 31 and the release plate 33 to rotate as a single unit. Additionally, a hole 33e is formed in the center of the release plate 33.

[0019] Between the release plate 33 and the circular recess 25a of the base plate 25, four poles, namely two first poles 41 and two second poles 42, are alternately arranged along the circumferential direction centered on axis O. In this embodiment, the first poles 41 and the second poles 42 are arranged at approximately 90° intervals in the circumferential direction centered on axis O. That is, the second poles 42 are arranged diagonally.

[0020] External teeth 41a and 42a, which can mesh with the internal teeth 23, are formed on the surfaces of the first pole 41 and the second pole 42 facing the internal teeth 23. Furthermore, a second cam 44 is positioned between the second pole 42 and the cam 31. That is, the two (a pair) second cams 44 are positioned diagonally.

[0021] On the surface of the first pole 41 opposite to the surface on which the external teeth 41a are provided, there is a first contact portion 41b to which the first projection 31d of the cam 31 can abut, and a second contact portion 41c to which the second projection 31e of the cam 31 can abut. On the surface of the second pole 42 opposite to the surface on which the external teeth 42a are provided, there is a first contact portion 42b to which the second cam 44 can abut, and a second contact portion 42c to which the second projection 31e of the cam 31 can abut.

[0022] The second cam 44 has a first contact portion 44d that can contact the first projection 31d of the cam 31, a guide contact portion 44a that can contact the pole guide projection (pole guide) 37 (described later), and a first contact portion 44b that can contact the first contact portion 42b of the second pole 42. In the circular recess 25a of the base plate 25, four pole guide projections 37 are formed at 90° intervals along the circumferential direction of a circle centered on the axis of relative rotation O.

[0023] The two adjacent pole guide projections 37 allow the first pole 41 and the second pole 42 to move only in the radial direction of a circle centered on the axis of relative rotation O. That is, the pole guide projections 37 guide the first pole 41 and the second pole 42 between a locked position where the external teeth 41a and 42a engage with the internal teeth 23 of the ratchet 21, and an unlocked position where the external teeth 41a and 42a are separated from the internal teeth 23 of the ratchet 21.

[0024] On the surfaces of the first pole 41 and the second pole 42 facing the release plate 33, projections 41d and 42d are formed that protrude toward the release plate 33. The release plate 33 has a cam hole 33b into which the projections 41d of the first pole 41 and 42d of the second pole 42 engage. The cam hole 33b has an inclined surface into which the projections 41d of the first pole 41 and 42d of the second pole 42 abut. When the release plate 33 rotates in the opposite direction to the arrow T in Figures 1, 2, and 4 in the locked state, the shape is set such that the first pole 41 and the second pole 42 move along the pole guide projection 37 in a direction away from the internal teeth 23 of the ratchet 21 (towards the unlocked position).

[0025] Between the release plate 33 and the circular recess 21a of the ratchet 21, two wire springs 51, which are curved in a roughly C shape, are positioned. Two adjacent pole guide projections (pole guides) 37 are provided so as to sandwich the sides of the first pole 41 and the second pole 42, and each has a first pole guide 37a facing one side of the first pole 41 and the second pole 42, and a second pole guide 37b facing the other side of the first pole 41 and the second pole 42.

[0026] A recess 37f is formed in the first pole guide 37a facing one side of the second pole 42, creating a space between it and the one side of the second pole 42. In this embodiment, a recess 37f' is also formed in the second pole guide 37b facing the other side of the second pole 42, creating a space between it and the other side of the second pole 42.

[0027] One end of each of the two wire springs 51 has a first end 51a that is bent toward the base plate 25, and the other end has a second end 51b that is also bent toward the base plate 25. When the wire spring 51 is elastically deformed, its first end 51a passes through the hole 33e in the release plate 33 and engages with the hole 31f formed in the cam 31, and its second end 51b is inserted into the recess 37f of the first pole guide 37a.

[0028] Due to the elastic repulsive force of the wire spring 51, the first end 51a of the wire spring 51 presses against the inner wall surface of the hole 31f of the cam 31 with a force F, and the cam 31 is biased such that the first projection 31d and the second projection 31e are opposed to the first contact portion 41b and second contact portion 41c of the first pole 41, the second contact portion 42c of the second pole 42, and the first contact portion 44d of the second cam 44, respectively (in one direction).

[0029] The second end portion 51b, inserted into the recess 37f of the first pole guide 37a, presses against one side of the second pole 42, pushing the second pole 42 toward the second pole guide (one pole guide) 37b opposite the other side of the second pole 42. In this embodiment, the wire spring 51 always presses the second pole 42 toward the second pole guide 37b opposite the other side of the second pole 42, even when moving between the locked state and the unlocked state.

[0030] Furthermore, in this embodiment, the fitting (insertion) of the second end 51b of the wire spring 51 with the recess 37f of the pole guide projection 37 occurs when the second end 51b of the wire spring 51 presses and biases one side of the second pole 42. A space (gap) exists on the side of the second end 51b of the wire spring 51 opposite to the pressing surface, and when a force greater than the biasing force is applied to the second end 51b of the wire spring 51 in a direction different from the biasing force, the second end 51b can move in a direction that separates it from one side of the second pole 42.

[0031] When the first pole 41 and the second pole 42 are in the locked position, as shown in Figure 5, the second cam 44, which receives a force F from the cam 31, pushes the second pole 42 in the locked position direction with a component F' of the force F, and also presses the second pole 42 against the second pole guide 37b of the pole guide projection 37. In addition, with a component F'' of the force F, the second cam pushes the first pole guide 37a of the pole guide projection 37.

[0032] Here, the operation of the reclining device with the above configuration will be explained. Normally, as shown in Figures 3 and 5, due to the elastic repulsive force of the wire spring 51, the first pole 41 and the second pole 42 provided on the base plate 25 are in a locked position with their external teeth 41a and 42a engaged with the internal teeth 23 of the ratchet 21 via the cam 31. Relative rotation between the ratchet (first member) 21 and the base plate (second member) 25 is prohibited, and the seat back is in a state where it cannot rotate relative to the seat cushion (locked state).

[0033] When the cam 31 is operated against the biasing force of the wire spring 51 and rotated in the other direction (opposite direction to arrow T), the release plate 33 also rotates due to the engagement between the projection 31c of the cam 31 and the hole 33a of the release plate 33. At this time, the pressure applied by the first projection 31d of the cam 31 to the first contact portion 41b of the first pole 41 and the first contact portion 44d of the second cam 44 is released.

[0034] Furthermore, as the release plate 33 rotates, the inclined surface of the cam hole 33b of the release plate 33, into which the projection 41d of the pole 41 engages, moves the first pole 41, the second pole 42 (and the second cam 44) to an unlocked position in which the engagement between the external teeth 41a, external teeth 42a and the internal teeth 23 of the ratchet 21 is released. As shown in Figures 4 and 6, relative rotation between the ratchet (first member) 21 and the base plate (second member) 25 becomes possible, and the seat back becomes rotatable relative to the seat cushion (unlocked state). At this time, the second pole 42 is pressed against the second pole guide 37b by the second end 51b of the wire spring 51.

[0035] When the operating force on the cam 31 is released, the biasing force of the wire spring 51 causes the cam 31 and release plate 33 to return to their original positions, while the first projection 31d of the cam 31 presses against the first contact portion 41b of the first pawl 41 and the first contact portion 44d of the second cam 44. The external teeth 41a and 42a of the first pawl 41 and the second pawl 42 engage with the internal teeth 23 of the ratchet 21, preventing relative rotation between the ratchet (first member) 21 and the base plate (second member) 25, thus locking it again. During this time, the second pawl 42 remains pressed against the second pawl guide 37b by the second end 51b of the wire spring 51.

[0036] According to this embodiment, the following effects can be obtained: (1) The wire spring 51 always presses the second pawl 42 against the second pawl guide 37b, which is opposite the other side of the second pawl 42, even when moving between the locked state and the unlocked state. Therefore, even when the second pawl 42 is in the unlocked position, the posture of the second pawl 42 is stable, and the second pawl 42 can be moved to the locked position as is, so the meshing between the external teeth 42a of the second pawl 42 and the internal teeth 23 of the ratchet 21 is stable.

[0037] Furthermore, by having the second cam 44, when the second pawl 42 is moved to the locked position, no looseness occurs when the external teeth 42a of the second pawl 42 engage with the internal teeth 23 of the ratchet 21. In particular, in this embodiment, the second pawl 42 is pressed against the second pawl guide 37b of the pawl guide projection 37 by the second cam 44, and also pressed against the second pawl 42 of the second pawl guide 37b of the pawl guide projection 37 by the second end 51b of the wire spring 51. Therefore, the loss of force caused by the difference in the direction of pressure applied by the wire spring 51 and the second cam 44 is reduced, and the prevention of looseness when the external teeth 42a of the second pawl 42 engage with the internal teeth 23 of the ratchet 21 is stabilized. (2) Having a pair of diagonally arranged second cams 44 makes it possible to more effectively prevent looseness in the relative rotational direction of the base plate (second member) 25 when locked. (3) One end of the wire spring 51 pushes the second pole 42 in the direction of the second pole guide 37b, and the other end of the wire spring 51 is attached to the cam 31, biasing the cam 31, thus reducing the number of parts. (4) The second end 51b of the wire spring 51 is in direct contact with one side of the second pole 42, thus reducing the number of parts. Also, there is no loss of biasing force by using a separate member. (5) The fitting (insertion) of the second end 51b of the wire spring 51 and the recess 37f of the first pole guide 37a is achieved by the second end 51b of the wire spring 51 pressing and biasing one side of the second pole 42. A space (gap) exists on the side of the second end 51b of the wire spring 51 opposite to the pressing surface. When a force greater than the biasing force is applied to the second end 51b of the wire spring 51 in a direction different from the biasing force, the second end 51b can move away from one side of the second pole 42. Therefore, even if a load is applied from the second pole 42 toward one end of the wire spring 51, it does not affect the other end of the wire spring 51.

[0038] The present invention is not limited to the embodiments described above. For example, although the above embodiments were described using four poles, it is also possible to use three poles. In this case, of the three poles, two are second poles, and it is preferable that the second poles and the second cam are placed diagonally opposite each other.

[0039] Furthermore, this is also possible when there are five or more poles. In this case, there are at least two second cams, and it is preferable that one pair of second cams is arranged diagonally. In addition, in the above embodiment, the spring that biases the cam 31 (first spring) and the spring that presses the second pole 42 against one of the pole guide projections (pole guide) 37 (second spring) are the same wire spring 51, but separate springs may be provided for each.

[0040] Furthermore, in the above embodiment, the first end 51a of the wire spring 51 engages with the cam 31 and biases the cam 31, but it may also engage with the release plate 33 which rotates integrally with the cam 31.

[0041] This international application claims priority based on Japanese Patent Application No. 2018-32878, filed on 27 February 2018, the entire contents of said Japanese Patent Application No. 2018-32878 are incorporated herein by reference.

[0042] The above description of specific embodiments of the present invention is provided for illustrative purposes only. It is not intended to be exhaustive or to limit the invention to the forms described. Numerous modifications and changes are possible in light of the above description, as will be obvious to those skilled in the art.

[0043] 21 Ratchet (first component) 25 Base plate (second component) 31 Cam 37 Pole guide 41 First pole 42 Second pole 51 Wire spring