JP6486869B2 - Headrest device - Google Patents

Description

  The present invention relates to a headrest device provided in a chair used in, for example, a barber / beauty facility or a medical facility.

  2. Description of the Related Art Conventionally, a chair on which a patient is seated when performing treatment at a hairdressing facility or a medical facility has a mechanism for adjusting the headrest to various positions and angles according to the posture of the patient. . As such a mechanism, there is a height and angle adjustment device for a headrest of a treatment chair described in Patent Document 1 below.

  In this device, the headrest is connected to the backrest via a headrest support. The headrest support is in the form of a long straight line with gear shafts at both ends. This gear shaft is provided with its axis directed in the lateral width direction of the headrest. Therefore, the headrest is disposed at a position where the angle changes with respect to the backrest with the gear shaft as an axis and is lowered forward by the length of the headrest support. The headrest whose position is adjusted is stopped by the gear fixed to the gear shaft. More specifically, the gear is a crown gear having a gear shaft as an axis, and is coaxially facing another gear which is another crown gear engaged with the gear. In addition, an operation lever is connected to the gear shaft, and when the operation lever is pressed, the gear shaft moves back and forth in the axial direction, and the gears are engaged or separated. That is, when the operation lever is not operated and the gears are engaged with each other, the rotation of the gear shaft is restricted, so that the movement of the headrest stops. On the other hand, when the operation lever is operated to move the gear shaft and the gears are separated from each other, the gear shaft can be freely rotated, so that the position of the headrest is freely changed. The operation lever has a longitudinal linear shape like the headrest support, and is provided on the headrest support.

Japanese Unexamined Patent Publication No. 63-130067

  However, according to the height and angle adjustment device of the headrest of the treatment chair described in Patent Document 1, as described above, the gears are coaxially facing each other, and the gears are engaged or separated from each other. Since the position of the headrest is adjusted, backlash is required as gear play. In addition, since the operation lever has a longitudinal linear shape like the headrest support, the gears may not be appropriately engaged depending on the pressed position. That is, if the operating lever is pushed straight from the gear shaft, the gear moves straight and the gears engage with each other, but if the operating lever is pushed at a position away from the gear shaft, the gear is pushed. As a result, the applied external force does not act straight on the shaft, and the gear may be eccentric. In this case, a large backlash is required for the gear eccentricity. If the backlash is large, the gears may not be properly engaged with each other, and the backlash may increase.

  The present invention has been proposed in view of the above circumstances. That is, an object of the present invention is to provide a headrest device that can reduce backlash.

  In order to achieve the above object, a headrest device according to the present invention is a headrest in which a chair backrest and a headrest are connected via a connecting portion, and the headrest is operated with respect to the backrest via the connecting portion. In the apparatus, the connecting portion is configured by a first gear and a second gear meshing on the same axis, and the interval between the tooth portions of the first gear is formed narrower on the other side than one side on the shaft, The width of the tooth portion of the second gear is formed narrower on the other side than one side on the shaft, and the locked state in which the headrest is stopped by engaging the first gear and the second gear; An operation unit for selecting a release state in which the headrest is operated by separating the first gear and the second gear is disposed away from the axis.

  The headrest device according to the present invention is characterized in that the first gear is an external gear and the second gear is an internal gear.

  According to the headrest device of the present invention, the first gear is an internal gear whose other side is reduced in diameter from one side, and the second gear is an external gear whose other side is reduced in diameter from one side. It is characterized by that.

  In the headrest device according to the present invention, the inner gear is formed on one of the backrest and the headrest, and the other is an engagement support portion that engages the other side of the external gear on the shaft. The external gear is engaged with the engagement support portion and the internal gear in the locked state, and is separated from the internal gear in the release state and is engaged with the engagement support portion. It is characterized by the fact that

  In the headrest device according to the present invention, the first gear is formed on one of the backrest and the headrest, and the other is engaged with one side of the second gear on the shaft. A support portion is formed, and the second gear is engaged with the engagement support portion and the first gear in the locked state, and is separated from the first gear in the released state, and the engagement It is characterized by being engaged with the joint support part.

  In the headrest device according to the present invention, the first gear of the backrest side connecting portion is formed on either one of the backrest portion or one end of the arm portion, and on the other side of the backrest side connecting portion, A back-side engagement support portion that engages with one side of the second gear of the back-side coupling portion on the shaft is formed, and the first gear of the headrest-side coupling portion is the other of the headrest or the arm portion. A headrest side engagement support portion that is formed on either one of the end portions and engages with one side of the second gear of the headrest side coupling portion on the axis of the headrest side coupling portion is formed on either one of the ends. It is characterized by that.

  The headrest device according to the present invention is characterized in that an elastic member is provided on the shaft, is in the locked state by the elastic force of the elastic member, and is in the released state by operation of the operation unit. And

  The headrest device according to the present invention is characterized in that the operation portion is provided in the arm portion.

  The headrest device according to the present invention is characterized in that the arm portion is formed longer than a linear distance between the backrest side connecting portion and the headrest side connecting portion.

  The headrest device according to the present invention has the above-described configuration. That is, the first gear is formed with one side wide and the other side narrow in the interval (pitch) between the first tooth portions that are teeth of the first gear, and the second tooth portion that is the teeth of the second gear. The same applies to the width of. Therefore, the backlash is formed on the other side of each gear, and the backlash is gradually reduced toward the one side. With this configuration, when the second gear is engaged with the first gear at the connecting portion, it is easily engaged by backlash on one side, and then firmly engaged on the other side. Therefore, backlash can be minimized and rattling can be prevented.

  In addition, since the operation unit is disposed at a position away from the shaft, even if the gear is eccentric when the operation unit is operated, the second gear is changed to the first gear at the connection unit. When engaged, it is easily engaged by backlash on one side and then firmly engaged on the other side. Therefore, backlash can be minimized even if the operation unit is arranged away from the axis, and rattling can be prevented.

  In the headrest device according to the present invention, the first gear is an external gear, and the second gear is an internal gear. In the external gear, in the interval (pitch) between the external gear teeth that are the teeth of the external gear, one side is formed wide and the other side is formed narrow, and the same applies to the width of the internal gear that is the teeth of the internal gear. . Therefore, the backlash is formed on the other side of each gear, and the backlash is gradually reduced toward the one side. With this configuration, when the external gear engages with the internal gear at the connecting portion, it is easily engaged by backlash on one side, and then firmly engaged on the other side. Therefore, backlash can be minimized and rattling can be prevented.

  The headrest device according to the present invention includes an internal gear whose other side has a smaller diameter than one side, and an external gear whose other side has a smaller diameter than one side. That is, the internal gear that is the first gear and the external gear that is the second gear are formed in a tapered shape from one side to the other side. Therefore, backlash can be minimized and rattling can be prevented.

  In the headrest device according to the present invention, the first gear is formed on one of the backrest and the headrest, and the other side is formed with an engagement support portion that engages with one side of the second gear on the shaft. The second gear is engaged with the engagement support portion and the first gear in the locked state, and is separated from the first gear and engaged with the engagement support portion in the released state. That is, the engagement support portion is disposed coaxially with the first gear and the second gear. Therefore, on the shaft, the second gear engages with the first gear and the engagement support portion to be in a locked state, and the first gear and the engagement support portion rotate relatively on the shaft. Regulated by the second gear. That is, the relative angle on the axis of the backrest and the headrest is fixed. On the other hand, when the second gear is separated from the first gear on the shaft, the second gear is released, and the first gear and the engagement support portion rotate relatively freely on the shaft. Therefore, the headrest can be freely operated in the released state, while the headrest can be prevented from rattling in the locked state.

  The headrest device according to the present invention includes an arm portion between the backrest portion and the headrest, and includes a backrest side connecting portion that connects one end portion of the arm portion and the backrest portion, and the other end portion of the arm portion and the headrest. The headrest side connection part to connect is provided. With this configuration, the movable range of the headrest is expanded by the amount of the arm portion, and the headrest can be adjusted to various positions and angles. Moreover, rattling can be prevented by operating the arm portion and the headrest, and the arm portion and the backrest portion via each connecting portion.

  In the headrest device according to the present invention, the first gear of the backrest side connecting portion is formed on either the backrest portion or one end of the arm portion, and on the other side, the backrest side on the axis of the backrest side connecting portion A backrest side engagement support portion that engages with one side of the second gear of the connecting portion is formed, and the first gear of the headrest side connecting portion is formed on either one of the headrest or the other end portion of the arm portion. On the other side, a headrest side engagement support portion that engages with one side of the second gear of the headrest side connection portion on the axis of the headrest side connection portion is formed. That is, on the axis of the backrest side connecting portion, the second gear engages with the first gear and the backrest side engaging support portion so that the backrest side connecting portion is locked, and similarly, the shaft of the headrest side connecting portion is In the upper part, the second gear engages with the first gear and the headrest-side engagement support portion, so that the headrest-side connection portion is locked. Accordingly, the second gear restricts the first gear and each engagement support portion from rotating relative to each other on the shaft. That is, the relative angle on the axis between the backrest and the arm is fixed, and similarly, the relative angle on the axis between the headrest and the arm is fixed.

  On the other hand, when the second gear is separated from the first gear on the axis of the backrest side coupling portion, the second gear is released, and the first gear and the backrest side engagement support portion rotate relatively freely on the shaft. Similarly, the second gear separates from the first gear on the shaft of the headrest side coupling portion to be released, and the first gear and the headrest side engagement support portion rotate relatively freely on the shaft. . Therefore, the headrest and the arm portion can be freely operated in the released state, while the headrest and the arm portion can be prevented from rattling in the locked state.

  The headrest device according to the present invention is provided with an elastic member on the shaft, is locked by the elastic force of the elastic member, and is released by the operation of the operation unit. That is, in the released state, an external force acts on the operation portion against the elastic force of the elastic member, and the first gear and the second gear are separated, whereas in the locked state, the first force is applied by the elastic force of the elastic member. The gear and the second gear are engaged. Accordingly, the unlocked state can be set only when the operation unit is operated in the locked state.

  In the headrest device according to the present invention, the operation portion is provided in the arm portion. Therefore, the practitioner can grasp the arm part with one hand and operate the operation part.

  In the headrest device according to the present invention, the arm portion is formed longer than the linear distance between the backrest side coupling portion and the headrest side coupling portion. That is, the arm portion has a shape that bypasses the linear distance between the backrest side coupling portion and the headrest side coupling portion, and is not linear. As a result, when the arm portion and the headrest are combined, a gap is created between the arm portion and the headrest by the amount of detour, so the practitioner matched the arm portion and the headrest while holding the arm portion. At that time, the practitioner's hand enters the gap. Therefore, it is possible to prevent the practitioner from putting his hand between the arm portion and the headrest.

The appearance of the headrest device concerning a first embodiment of the present invention is shown, (a) is the back perspective view seen from back, and (b) is the right side view seen from one side. The external appearance of the process of operating the headrest of the headrest device according to the first embodiment of the present invention is shown, (a) is a rear perspective view, and (b) is a right side view. The external appearance after the headrest of the headrest device concerning a first embodiment of the present invention act | operates is shown, (a) is a rear perspective view, (b) is a right view. It is a back perspective view of the important section of the headrest device concerning a first embodiment of the present invention. It is a disassembled perspective view of the principal part of the headrest device concerning a first embodiment of the present invention. The principal part of the headrest apparatus which concerns on 1st embodiment of this invention is shown, (a) is a rear view, (b) is AA side sectional drawing, (c) is a right view. It is a BB back sectional view of the locked state in the important section of the headrest device concerning a first embodiment of the present invention. It is BB back sectional drawing of the cancellation | release state in the principal part of the headrest apparatus which concerns on 1st embodiment of this invention. The principal part of the headrest device concerning a second embodiment of the present invention is shown, (a) is a front perspective view in the state where the headrest was attached, and (b) is a front perspective view in the state where the headrest was removed. It is a disassembled perspective view of the principal part of the headrest apparatus concerning a second embodiment of the present invention. The locked state in the principal part of the headrest device concerning a second embodiment of the present invention is shown, (a) is a left side view and (b) is a CC front sectional view. It is a back perspective view of the important section of the headrest device concerning a third embodiment of the present invention. It is a disassembled perspective view of the principal part of the headrest apparatus concerning a third embodiment of the present invention. It is a disassembled perspective view of a part of the principal part of the headrest device concerning a third embodiment of the present invention. The principal part of the headrest apparatus which concerns on 3rd embodiment of this invention is shown, (a) is a rear view, (b) is DD side sectional drawing. It is EE back sectional drawing of the locked state in the principal part of the headrest apparatus concerning 3rd embodiment of this invention. It is EE back sectional drawing of the cancellation | release state in the principal part of the headrest apparatus which concerns on 3rd embodiment of this invention. It is a back perspective view of the important section of the headrest device concerning a 4th embodiment of the present invention. It is a disassembled perspective view of the principal part of the headrest device concerning a 4th embodiment of the present invention. The principal part of the headrest device concerning a 4th embodiment of the present invention is shown, (a) is a rear view, and (b) is a FF side sectional view. It is GG back sectional drawing of the locked state in the principal part of the headrest apparatus concerning 4th embodiment of this invention. It is GG back sectional drawing of the cancellation | release state in the principal part of the headrest apparatus which concerns on 4th embodiment of this invention.

  Below, the headrest device concerning a first embodiment of the present invention is explained based on a drawing. 1, 2 and 3 show the appearance of the chair 1 to which the headrest device 10 according to the first embodiment of the present invention is attached. In the following description, the front side of the chair 1 is the front side, the back side opposite to the front side is the rear side, the height of the chair 1 is the upper and lower sides, and one of the widths of the chair 1 as viewed from the rear side. The side is the right side and the other side is the left side. The front side of the chair 1 may be the rear side, the back side may be the front side, one side of the width of the chair 1 may be the left side, and the other side may be the right side.

  As shown in FIGS. 1 to 3, the chair 1 includes a base 2 installed on the installation surface and a seat on which the patient (not shown) sits on the base 2. Part 3, a leg rest part 4 connected to the front end of the seat part 3 and directed downward, a backrest part 5 connected to the rear end of the seat part 3 and raised upward, The headrest 6 is mounted above the backrest portion 5 and the arm portion 19 is connected to the backrest portion 5 and the headrest 6. The headrest device 10 according to the first embodiment of the present invention operates the headrest 6 with respect to the backrest portion 5 via the arm portion 19. A connecting portion is formed at each end of the arm portion 19, and the headrest 6 is operated via the connecting portion. The headrest 6 is disposed at a low position above the backrest 5 by descending to the front side of the backrest 5.

  Here, the headrest device 10 will be described in more detail based on the drawings. FIG. 4 shows an appearance of the headrest device 10 according to the first embodiment of the present invention, FIG. 5 shows an exploded view of the headrest device 10, and FIG. 6 shows an appearance and a cross section of the headrest device 10. ing.

As shown in FIG. 4 and FIG. 5, the headrest device 10 includes the following parts. That is, the backrest side engagement support part 12 that is a part of the backrest part 5, the headrest side engagement support part 16 that is a part of the headrest 6, the backrest side engagement support part 12, and the headrest side engagement support part 16. an arm portion 19 which is connected to the bets, the backrest side connecting portion 21 for connecting the lower side and the back side engaging supports 12 which is one end portion of the arm portion 19 on the back side shaft X _1, the arm portion 19 release actuating a second end portion and the upper side and the headrest-side connecting portion 23 and a head rest side engaging supports 16 connecting on the headrest side shaft X _2, the locked state where the headrest 6 is stopped, and the headrest 6 The headrest device 10 includes the operation unit 32 for selecting a state. Here, the backrest side axis X ₁ is a rotation axis when the arm portion 19 rotates relative to the backrest portion 5, and the headrest side axis X ₂ is the rotation when the headrest 6 rotates relative to the arm portion 19. Is the axis.

The back side engagement support portion 12 is formed in an annular shape with the left-right direction as an axis, and a back side supporting internal gear 13 is formed on the inner periphery. The diameter of the back support inner gear 13 is constant in the axial direction. A protrusion 7 a that protrudes inward is formed on the upper side of the inner periphery of the back support inner gear 13. Back-side annular supporting portion 14 facing the backrest side engaging supports 12 are spaced between aligned on the back side engaging supports 12 and the backrest side shaft X _1. Each of the support portions 12 and 14 on the backrest side is formed at the upper end of the support main body portion 11 that is formed longitudinally in the vertical direction, and the backrest side engagement support portion 12 is arranged close to the right end, and the backrest side annular shape The support part 14 is arranged close to the left end. The support main body 11 is attached to the backrest 5, and the height of the support main body 11 is freely adjusted up and down with respect to the backrest 5.

The headrest side engagement support portion 16 is formed in an annular shape with the left-right direction as an axis, and a headrest side support internal gear 17 is formed on the inner periphery. The diameter of the headrest side supporting internal gear 17 is constant in the axial direction. Of the inner periphery of the headrest side supporting internal gear 17, the rear side is formed with a protrusion 7 b that protrudes inward. The headrest-side annular support portion 18 facing the headrest-side engagement support portion 16 is arranged on the headrest-side engagement support portion 16 and the headrest-side axis X ₂ with a space therebetween. Each of the headrest side support portions 16 and 18 is formed on the upper side of the rear surface side of the support plate portion 15 formed in a substantially square plate shape, and the headrest side engagement support portion 16 is arranged close to the right end. The headrest side annular support portion 18 is arranged close to the left side. The support plate portion 15 is attached to the rear surface of the headrest 6.

  In addition, the inner periphery of the backrest side engagement support part 12 and the headrest side engagement support part 16 is not limited to the internal gears 13 and 17 for support, for example, as a second gear to be described later, such as a single or a plurality of irregularities. Any shape that engages with the external gear 27 can be used.

  The arm portion 19 is formed with a gripping portion 20 that is thick enough for a practitioner (not shown) to grip it with one hand, and a backrest side connecting portion 21 is formed at the lower end of the gripping portion 20 to hold the arm portion 19. A headrest side connecting portion 23 is formed at the upper end of the portion 20. The length of the arm portion 19 is longer than the linear distance Y between the backrest side connecting portion 21 and the headrest side connecting portion 23 (see FIG. 6C). That is, the arm portion 19 has a curved shape projecting in an arc shape toward the rear. In addition, as long as the practitioner has a shape that can be easily grasped with one hand, the arm portion 19 may have a “B” -shaped shape or a “U” -shaped rectangle. From the viewpoint of design, the arm portion 19 is preferably curved. Further, the arm portion 19 is formed with such a length that the headrest 6 is disposed at a sufficiently low position above the backrest portion 5 when the headrest 6 is operated.

As shown in FIG. 5, the backrest side connecting portion 21 is composed of an internal gear 25a as a first gear and an external gear 27a as a second gear that mesh with _{each other} on the backrest axis X1. The internal gear 25 a is formed on the inner periphery of the backrest side hole 22 penetrating in the left-right direction at the lower end of the arm portion 19. The internal gear 25a has different diameters on the left and right sides. That is, the internal gear 25a, rather than the right, which is one side of the backrest side axis X _1, reduced diameter is more left which is the other side, gradually inclined toward the back side shaft X ₁ toward the left Taper shape (see FIGS. 7 and 8). Thus, the interval of internal teeth portion 26a is a tooth of the internal gear 25a (pitch) is gradually narrower toward the left, toward the left is narrower than the right in the back side axis X on ₁ ing.

The external gear 27a includes a support external tooth portion 28a formed on the right side and an engagement external tooth portion 29a connected to the left side of the support external tooth portion 28a. A cylindrical shaft-shaped portion 30a is connected to the left of the portion 29a. The diameter of the supporting outer teeth 28a is constant in the axial direction of the backrest side shaft X _1. Engaging outer teeth 29a, rather than the right side on the back side axis X _1, reduced in diameter towards the left, it is gradually inclined tapered shape toward the back side shaft X ₁ towards the left (FIG. 7 and FIG. 8). Thus, the interval of the external teeth portion 31a is a tooth of the external gear 27a (pitch) is gradually narrower toward the left, toward the left is narrower than the right side on the back side axis X ₁ ing. Of the external gear 27a, an upper side is formed with a groove 8a that is recessed inward. The supporting external tooth portion 28a may be any shape as long as it has a shape that engages with the back side support internal gear 13 of the back side engagement support portion 12, such as a single or a plurality of irregularities. If the external tooth portion 31a has the same shape as the engaging external tooth portion 29a, the supporting external tooth portion 28a is preferable because it is easy to mold.

The headrest side connecting portion 23 is composed of an internal gear 25b and an external gear 27b that mesh with _{each other} on the headrest side axis X2. The internal gear 25 b is formed on the inner periphery of the headrest side hole 24 penetrating in the left-right direction at the upper end of the arm portion 19. The internal gear 25b has different diameters on the left and right sides. That is, the internal gear 25b, rather than the right, which is one side of the head rest side shaft X _2, and reduced in diameter toward the left is the other side, gradually inclined toward the headrest side shaft X ₂ toward the left Taper shape (see FIGS. 7 and 8). Thus, the spacing of the teeth in a internal toothed portion 26b of the internal gear 25b (pitch) is gradually narrower toward the left, toward the left is narrower than the right side on the headrest side shaft X ₂ ing.

The external gear 27b is composed of a support external tooth portion 28b formed on the right side and an engagement external tooth portion 29b connected to the left side of the support external tooth portion 28b. A cylindrical shaft portion 30b is connected to the left of the portion 29b. The diameter of the supporting outer teeth 28b is constant in the axial direction of the headrest side shaft X _2. Engaging outer teeth 29b, rather than the right side of the headrest side shaft X _2, reduced in diameter towards the left, it is gradually inclined tapered toward the headrest side shaft X ₂ toward the left (FIG. 7 and FIG. 8). Thus, the interval of the external teeth portion 31b is a tooth of the external gear 27b (pitch) is gradually narrower toward the left, toward the left is narrower than the right side on the headrest side shaft X ₂ ing. Of the external gear 27b, a groove 8b that is recessed inward is formed on the rear side. The supporting external tooth portion 28b is arbitrary as long as it has a shape that engages with the headrest-side support internal gear 17 of the headrest-side engagement support portion 16, such as a single or a plurality of irregularities. If the external tooth part 31b has the same shape as the engaging external tooth part 29b, the supporting external tooth part 28b is preferable because it is easy to mold.

  As shown in FIGS. 5 and 6, the operation portion 32 is formed following the shape of the left side surface of the arm portion 19 and is attached to the left side surface of the arm portion 19. That is, it is a curved shape projecting in an arc shape toward the rear. Note that the operation unit 32 may be a “B” -shaped shape or a “U” -shaped rectangle depending on the shape of the arm unit 19. The operation portion 32 is formed with an operation pressing portion 33 at a position corresponding to the grip portion 20 of the arm portion 19, and the lower end of the operation pressing portion 33 shields the backrest side hole 22 on the right side. On the left side, a backrest side pressing portion 34 that fits in the backrest side annular support portion 14 is formed. Similarly, the upper end of the arm portion 19 is formed with a headrest side pressing portion 35 that shields the headrest side hole 24 on the right side and fits in the headrest side annular support portion 18 on the left side.

As shown in FIG. 5, elastic members 36 a and 36 b are disposed between the operation unit 32 and the arm unit 19. If detail, the elastic member 36a, b are disposed respectively on the backrest side shaft X ₁ and on the headrest side shaft X _2, the backrest side connecting portion 21 of the backrest-side pressing portion 34 and the arm portion 19 of the operation portion 32 Similarly, it is arranged between the headrest side pressing part 35 of the operation part 32 and the headrest side connecting part 23 of the arm part 19. The elastic members 36a and 36b are, for example, coil springs or the like, but may be a plate spring or an elastically deformable resin as long as it has a function of separating the operation unit 32 from the arm unit 19 on each of the axes X ₁ and X _2. . From the viewpoint of simplicity of configuration, the elastic members 36a and 36b are preferably coil springs.

  Each of the above members is connected via connecting shaft members 37a and 37b such as bolts. Here, the state where each member is connected will be described with reference to the drawings. FIG. 7 shows a cross section of the headrest device 10 according to the first embodiment of the present invention.

  As shown in FIGS. 5 and 7, the operation unit 32 is attached to the left side of the arm unit 19 through elastic members 36 a and 36 b. The elastic member 36a is locked to the left end of the internal gear 25a of the back side coupling portion 21 and is sandwiched between the internal gear 25a and the back side pressing portion 34 in a compressed state. Similarly, the elastic member 36b is locked to the left end of the internal gear 25b of the headrest side connecting portion 23 and is sandwiched between the internal gear 25b and the headrest side pressing portion 35 in a compressed state.

In this state, the lower end of the arm portion 19 is disposed between the backrest side engagement support portion 12 and the backrest side annular support portion 14, and the upper end of the arm portion 19 is the headrest side engagement support portion 16 and the headrest side annular shape. It arrange | positions between the support parts 18. FIG. To the gear 25a and the backrest side engaging supports 12 inner aligned on back side shaft X _1, is inserted the external gear 27a from the right side, the internal gear 25a and the backrest side support for the gear 13 and the external gear 27a Engage. The connecting shaft member 37a penetrates from the right side of the external gear 27a and is fastened to the backrest side pressing portion 34. Similarly, the gear 25b and the headrest side engaging supports 16 inner aligned on headrest side shaft X _2, is inserted the external gear 27b from the right side, to the internal gear 25b and the headrest in a side support wheel 17 The external gear 27b is engaged. The connecting shaft member 37 b penetrates from the right side of the external gear 27 b and is fastened to the headrest side pressing portion 35.

As shown in FIG. 6, the operation pressing portion 33 of the operation portion 32 is arranged away from the backrest side axis X ₁ and the headrest side axis X ₂ . If detail, the upper backrest side shaft X _1, is arranged backrest side pressing portion 34 of the operation unit 32, on the headrest side shaft X _2, since the headrest side pressing portion 35 of the operation portion 32 is disposed, An operation pressing portion 33 is disposed between the axes X ₁ and X ₂ .

  As described above, the headrest device 10 according to the first embodiment is configured.

  Next, operation | movement of the headrest apparatus 10 which concerns on 1st embodiment is demonstrated based on drawing. FIG. 7 illustrates a locked state in which the headrest 6 is stopped due to the engagement of the internal gears 25a and 25b and the external gears 27a and b among the changing states of the headrest device 10 according to the first embodiment of the present invention. FIG. 8 is an enlarged view of the release state in which the headrest 6 is activated by the separation of the internal gears 25a and 25b and the external gears 27a and 27b.

  As shown in FIG. 7, the operation unit 32 is pushed leftward by the elastic force (restoring force) of the compressed elastic members 36 a and 36 b. Since the external gears 27a, b are connected to the backrest side pressing part 34 and the headrest side pressing part 35 via the connecting shaft members 37a, 37b, they are brought to the left together with the operation part 32. In this state, the external gears 27a and 27b are engaged with the external gears 29a and 29b for engagement with the internal gears 25a and 25b, and the external gears for support 28a and b are the back support internal gear 13 and the headrest. The side support internal gear 17 is engaged.

  The arm portion 19 is structured to rotate with respect to the backrest side engagement support portion 12. In the locked state, the arm portion 19 includes an internal gear 25 a of the arm portion 19 and a backrest side support internal gear 13 of the backrest side engagement support portion 12. An external gear 27a is interposed between the external gear 27a and the external gear 27a is engaged with the internal gear 25a and the back support internal gear 13. Similarly, the headrest 6 (headrest side engagement support portion 16) is structured to rotate with respect to the arm portion 19. In the locked state, the headrest of the internal gear 25b of the arm portion 19 and the headrest side engagement support portion 16 is locked. An external gear 27 b is interposed between the side support internal gear 17 and the external gear 27 b is engaged with the internal gear 25 b and the headrest side support internal gear 17. Therefore, the operation of the arm portion 19 and the headrest 6 is restricted.

  In this locked state, the operation pressing portion 33 of the operation portion 32 is pushed rightward, and the operation portion 32 is pushed into the arm portion 19 to change to the release state. More specifically, as shown in FIG. 8, when the operating portion 32 is pushed against the restoring force of the elastic members 36a, 36b, the external gears 27a, 27b move to the right together with the operating portion 32. It is done. At that time, the external gears 27a and 27b are engaged with the external gears 27 and 17 and the external gears 28a and b are engaged with the internal gears 13 and 17, respectively. It moves rightward along each supporting internal gear 13 and 17 as it is.

  In the released state, the external gear 27a interposed between the internal gear 25a and the back support inner gear 13 in the locked state moves away from the internal gear 25a by moving to the back support internal gear 13 side, It is engaged only with the back support internal gear 13. Similarly, the external gear 27b interposed between the internal gear 25b and the headrest side support internal gear 17 in the locked state moves away from the internal gear 25b by moving to the headrest side support internal gear 17 side, and the headrest Only the side supporting internal gear 17 is engaged. Therefore, the arm portion 19 operates with respect to the backrest side engagement support portion 12, and the headrest 6 (headrest side engagement support portion 16) also operates with respect to the arm portion 19.

In this released state, the operation unit 32 is released to change to the locked state again. As shown in FIG. 7, the operation unit 32 is pushed and moved to the left by the restoring force of the elastic members 36 a and b. At that time, the external gears 27a and 27b move to the left along the supporting internal gears 13 and 17 while the supporting external gear portions 28a and 28b are engaged with the supporting internal gears 13 and 17, The engaging external teeth 29a, b are engaged with the internal gears 25a, 25b. Here, the internal gears 25a and 25b are formed so that the interval (pitch) between the internal gear portions 26a and 26b is gradually narrowed toward the left, and the left side is more right than the right side on each of the axes X ₁ and X _2. It is narrowly formed. With this configuration, the external gears 27a and 27b are easily engaged with each other by backlash on the right side, and thereafter, the external gear portions 29a and 29b for engaging the external gears 27a and b on the left side with respect to the internal gears 25a and 25b. Engage firmly.

  As described above, the headrest device 10 according to the first embodiment operates.

  Next, the action | operation of the headrest 6 of the headrest apparatus 10 which concerns on 1st embodiment of this invention is demonstrated based on drawing. As shown in FIG. 1, the headrest 6 is disposed at the highest position with respect to the backrest portion 5. In this state, the headrest 6 and the arm portion 19 face each other and are close to each other, but a gap is provided between the arm portion 19 and the support plate portion 15 (or the headrest 6) as much as the arm portion 19 is curved. Has occurred (see FIG. 6C).

  As shown in FIG. 6, when the practitioner grips the grip portion 20 of the arm portion 19 when operating the operating portion 32, the practitioner's finger is sandwiched between the arm portion 19 and the support plate portion 15. Without any gaps. When the practitioner pushes the operation pressing portion 33 of the operation portion 32 to change to the release state, the arm portion 19 operates with respect to the backrest portion 5 and the headrest 6 also moves to the arm portion 19 as shown in FIG. Operates against. As a result, as shown in FIG. 3, the headrest 6 is disposed at a lower position than the backrest portion 5. Since the arm portion 19 is curved, the arm portion 19 is disposed at a lower position than when the arm portion 19 is formed on a straight line. When the headrest 6 is stopped at an arbitrary position according to the head of the person to be treated and the operation unit 32 is released, the headrest 6 is fixed in a locked state.

  Next, the effect of the first embodiment will be described.

As described above, according to the first embodiment, the backrest side connecting portion 21 and the headrest-side connecting portion 23 from each respective axes X _1, X internal gear 25a that meshes ₂ over at, b and the external gear 27a, and b It is configured. The internal gears 25a and 25b have a tapered shape in which the left side is smaller than the right side on the respective axes X ₁ and X ₂ and is gradually inclined toward the backrest side axis X ₁ toward the left side. As a result, the interval (pitch) between the internal teeth portions 26a and 26b, which are the teeth of the internal gears 25a and 25b, is gradually narrowed toward the left, and is smaller than that on the right on the respective axes X ₁ and X _2. The left side is narrow. Therefore, each gear 25a, b, 27a, b is formed with a backlash on the right side and gradually reduced in the back side. With this configuration, when the external gears 27a and b are engaged with the internal gears 25a and 25b, the external gears 27a and b are easily engaged by backlash on the right side. The tooth portions 29a and b are firmly engaged with the internal gears 25a and 25b. Therefore, backlash between the external gears 27a, b and the internal gears 25a, b in the locked state is minimized, and rattling between the external gears 27a, b and the internal gears 25a, b can be prevented.

Moreover, the upper backrest side shaft X _1, is arranged backrest side pressing portion 34 of the operation unit 32, on the headrest side shaft X _2, since the headrest side pressing portion 35 of the operation unit 32 is arranged, the axes An operation pressing portion 33 is disposed between X ₁ and X ₂ . With this configuration, even when the external gears 27a and 27b are eccentric when the operation unit 32 is operated, when the external gears 27a and b are engaged with the internal gears 25a and 25b, the backlash is caused on the right side. Thus, the external gears 27a, b are easily engaged, and thereafter, the engaging external teeth portions 29a, b of the external gears 27a, b are firmly engaged with the internal gears 25a, 25b. Therefore, backlash can be minimized even if the operation unit 32 is arranged away from the axes X ₁ and X ₂ , and rattling between the external gears 27a and 27b and the internal gears 25a and 25b is prevented. Can do.

  According to the first embodiment, in the locked state, the external gears 27a and 27b are interposed between the internal gears 25a and 25b of the arm portion 19 and the support internal gears 13 and 17 of the engagement support portions 12 and 16, respectively. The external gears 27a and 27b are engaged with the internal gears 25a and 25b and the supporting internal gears 13 and 17, respectively. Therefore, the operation of the arm portion 19 and the headrest 6 is restricted. On the other hand, in the unlocked state, the external gears 27a and 27b interposed between the internal gears 25a and 25b and the supporting internal gears 13 and 17 in the locked state move to the supporting internal gears 13 and 17, respectively. Thus, it is separated from the internal gears 25a, 25b and engages only with the supporting internal gears 13, 17. Therefore, the arm portion 19 operates with respect to the respective engagement support portions 12 and 16, and the headrest 6 (headrest engagement support portion 16) also operates with respect to the arm portion 19. Therefore, the arm portion 19 and the headrest 6 can be freely operated in the released state, while rattling of the arm portion 19 and the headrest 6 can be prevented in the locked state.

According to the first embodiment, the elastic members 36a and 36b are arranged on the axes X ₁ and X ₂ , respectively, and the back side pressing portion 34 of the operation unit 32 and the back side connecting portion 21 of the arm unit 19 are connected. Similarly, it is arranged between the headrest side pressing part 35 of the operation part 32 and the headrest side connecting part 23 of the arm part 19. The operation unit 32 is pushed and moved to the left by the restoring force of the elastic members 36a and 36b. At that time, the external gears 27a and 27b move to the left along the supporting internal gears 13 and 17 while the supporting external gear portions 28a and 28b are engaged with the supporting internal gears 13 and 17, The engaging external teeth 29a, b are engaged with the internal gears 25a, 25b. Therefore, the unlocked state can be set only when the operation unit 32 is operated in the locked state.

  According to the first embodiment, the arm portion 19 is formed with a grip portion 20 that is thick enough to be held by a practitioner with one hand, and the operation portion 32 has a shape on the left side surface of the arm portion 19. It is copied and attached to the left side surface of the arm portion 19. Accordingly, the practitioner can grasp the arm portion 19 with one hand and operate the operation portion 32.

  According to the first embodiment, the length of the arm portion 19 is longer than the linear distance Y between the backrest side coupling portion 21 and the headrest side coupling portion 23, and the arm portion 19 projects in an arc shape toward the rear. The curved shape. As a result, when the headrest 6 and the arm portion 19 are brought to face each other, a gap is generated between the arm portion 19 and the support plate portion 15 (or the headrest 6) by the amount that the arm portion 19 is curved. . When the practitioner grasps the arm portion 19, the practitioner's hand enters the gap. Therefore, it is possible to prevent the practitioner from putting his hand between the arm portion 19 and the headrest 6.

  As described above, the headrest device 10 according to the first embodiment is configured. Here, it is good also as the following structures as a modification of 1st embodiment.

  That is, in the first embodiment described above, the internal gear 25a of the backrest side connecting portion 21 is formed at the lower end of the arm portion 19, the backrest side engagement support portion 12 is formed on the backrest portion 5, while the headrest side The internal gear 25b of the connecting portion 16 is formed at the upper end of the arm portion 19, and the headrest side engagement support portion 16 is formed on the headrest 6. However, in the modification of the first embodiment (not shown). The inner gear of the backrest side connecting portion is formed in the backrest portion, and the backrest side engaging support portion is formed at the lower end of the arm portion, while the internal gear of the headrest side connecting portion is formed in the headrest, and the upper portion of the arm portion A headrest side engagement support portion is formed at the end.

  In addition, an external gear may be formed on the upper and lower ends of the arm portion, and an internal gear may be formed on each of the engagement support portions 12 and 16.

  Next, a headrest device according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 9 shows the appearance of the headrest device 210 according to the second embodiment of the present invention, and FIG. 10 shows the headrest device 210 in an exploded state. In the following description, configurations different from those of the first embodiment are described, and descriptions of similar configurations are omitted as appropriate.

In the headrest device 210 according to the second embodiment, the backrest portion and the headrest are directly connected by a connecting portion without using an arm portion. Specifically, as shown in FIGS. 9 and 10, the backrest side engagement support portion 212 that is a part of the backrest portion, the headrest side engagement support portion 216 that is a part of the headrest 206, and the backrest side a connecting portion 221 for connecting the engagement supporting portion 212 and the headrest side engaging supports 216 on actuation shaft X _3, the locked state in which the headrest 206 is stopped, and for selecting the released state to operate the headrest 206 A headrest device 210 is configured from the operation unit 232. Here, actuation shaft X ₃ is the rotational axis when the headrest 206 is rotated relative to the backrest.

The back-side engagement support portion 212 is formed in an annular shape with the left-right direction as an axis, and an internal gear 225 and a locking step portion 209 are formed on the inner periphery (see FIG. 11). The diameter of the internal gear 225, a reduced diameter is left side than the right side of the operation shaft X _3, it is tapered to gradually inclined toward the operating shaft X ₃ toward the left. The locking step portion 209 protrudes from the inner periphery of the backrest side engagement support portion 212 toward the operation axis X ₃ , so that the hole of the backrest side engagement support portion 212 is larger than the internal gear 225. It is narrowed. The backrest side engagement support portion 212 is formed at the upper end of the support main body portion 211 that is formed in a longitudinal direction in the vertical direction, and is disposed substantially at the center.

The headrest side engagement support portion 216 is formed in an annular shape with the left-right direction as an axis, and a headrest side support internal gear 217 is formed on the inner periphery. The diameter of the headrest side supporting internal gear 217 is constant in the axial direction. Headrest side annular supporting portion 218 facing the headrest side engaging supports 216 are spaced between aligned on actuation shaft X ₃ headrest side engaging supports 216. Each of the headrest side support portions 216 and 218 is formed at the lower end of the curved long neck portion 219, the headrest side engagement support portion 216 is arranged close to the right end, and the headrest side annular support portion 218 is on the left side. It is arranged close to. Between the headrest side engagement support part 216 and the headrest side annular support part 218, the space | interval by which the backrest side engagement support part 212 is arrange | positioned is opened. A through hole (not shown) penetrating in the left-right direction is formed above the neck portion 219. A support plate portion 215 formed in a flat plate shape is formed at the upper end of the neck portion 219, and is attached to the headrest 206 via the support plate portion 215. Note that the axis of the through hole and the through axis X _4.

The connecting portion 221 includes an internal gear 225 and an external gear 227 that mesh with each other on the operating axis X ₃ . Since the external gear 227 has the same configuration as that of the first embodiment, description thereof is omitted.

The operation portion 232 is formed following the shape of the left side surface of the neck portion 219 and is attached to the left side surface of the neck portion 219. The operation portion 232 has a backrest-side pressing shaft portion 234 formed at the lower end of the operation pressing portion 233 and a headrest-side pressing shaft portion 235 formed at the upper end. Each pressing shaft portion 233, 234 protrudes rightward. The elastic member 236a is passed through a back-side pressing shaft portion 234 is disposed between the headrest-side annular supporting portion 218 on the actuating shaft X _3. Similarly, the elastic member 236b is passed through the headrest side pressing shaft portion 235 is disposed between the neck portion 219 on the through-shaft X _4.

  Each of the above members is connected via connecting shaft members 237a and 237 such as bolts by appropriately interposing a lid member 201a and b, a ring member 202, bush members 203a and 203b, and a connecting ring member 204. Here, the state where each member is connected will be described with reference to the drawings. FIG. 11 shows a side surface and a cross section of a headrest device 210 according to the second embodiment of the present invention.

As shown in FIGS. 10 and 11, the operation portion 232 is attached to the left side of the neck portion 219 via elastic members 236a and 236b. More specifically, the elastic members 236a and 236b are passed through the pressing shaft portions 233 and 235, respectively. The bush member 203b is attached to the through hole of the neck portion 219 from the left side. In this state, on the operating shaft X ₃ , the backrest side pressing shaft portion 234 is inserted into the headrest side annular support portion 218 on the left side, and the connecting ring member 204 is attached on the right side. The backrest side engagement support portion 212 has the bush member 203a attached from the left side and the ring member 202 attached from the right side. In this state, the backrest side engagement support member 212 is attached between the headrest side engagement support portion 216 and the headrest side annular support portion 218. The headrest side engagement support member 216 is attached with an external gear 227 from the right side, and the connecting shaft member 237a is inserted into the external gear 227 from the right side. The connecting shaft member 237a is connected to the backrest side pressing shaft portion 234. The lid member 201a is attached to the headrest side engagement support member 216. On the other hand, on the through shaft X ₃ , the connecting shaft member 237 b is inserted from the right side of the through hole and connected to the headrest side pressing shaft portion 235. The lid member 201b is attached to the right side of the through hole. Since the operation is the same as that of the first embodiment, the description is omitted.

  As described above, the headrest device 210 according to the second embodiment is configured. As a modified example (not shown) of the second embodiment, the backrest portion and the headrest are directly connected by a connecting portion. Unlike the headrest device 210, an internal gear is formed on the headrest, and the backrest side engagement support is provided on the backrest portion. The structure in which the part was formed may be sufficient. In addition, an internal gear may be formed in the operation unit, and an external gear may be formed in the headrest.

  Next, a headrest device according to a third embodiment of the invention will be described with reference to the drawings. 12 shows the appearance of the headrest device 310 according to the third embodiment of the present invention, FIG. 13 and FIG. 14 show the headrest device 310 in an exploded state, and FIG. 15 shows the appearance and cross section of the headrest device 310. It is shown. In the following description, configurations different from those of the first embodiment are described, and descriptions of similar configurations are omitted as appropriate.

As shown in FIGS. 12 to 15, the headrest device 310 is composed of the following parts. That is, the backrest side engagement support portion 312 which is a part of the backrest portion, the headrest side engagement support portion 316 which is a part of the headrest, the backrest side engagement support portion 312 and the headrest side engagement support portion 316. The arm unit 319 to be connected, the operation unit 332 attached to the right side surface of the arm unit 319 for selecting the locked state and the release state, and the backrest side pressing unit of the operation unit 332 below the arm unit 319 A backrest side coupling portion 321 that couples 334 and the backrest side engagement support portion 312 on the backrest side axis X ₅ , and a headrest side pressing portion 335 and a headrest side engagement support portion of the operation portion 332 above the arm portion 319. headrest device 310 and 316 from the headrest side connecting portion 323 which connects on the headrest side shaft X ₆ is not configured The

Headrest-side connecting portion 323, and an internal gear 325b as an external gear 327b and the second gear as a first gear that meshes on the headrest side axis X _6. The external gear 327 b is formed on the right side in the headrest side pressing portion 335 that is the upper end of the arm portion 319. The external gear 327b is constant in diameter on both sides of the left and right on the headrest side axis X _6, spacing of the external teeth portion 331b of the external gear 327b (pitch) is gradually narrower toward the left, Write left is narrower than the right side on the headrest side axis X _6. In other words, the width of the outer tooth portion 331b is gradually wider toward the left, toward the left is wider than the right side on the headrest side axis X _6.

As shown in FIG. 14, the internal gear 325 b is formed on the inner periphery of the headrest side engagement support portion 316. Internal gear 325b is on both sides of the left and right in the headrest side axis X on ₆ is a constant diameter, the width of the internal section 326b of the internal gear 325b is gradually narrower toward the left, the headrest-side axis X _{6 The} left side is narrower than the right side on ₆ . In other words, the interval of internal teeth 326b of the internal gear 325b (pitch) is gradually wider toward the left, toward the left is wider than the right side on the headrest side axis X _6.

As shown in FIG. 13, the backrest side connecting portion 321 is composed of an external gear 327 a as a first gear and an internal gear 325 a as a second gear that mesh with each other on the headrest side axis X ₅ . It is formed on the right side in the backrest side pressing portion 334 which is the lower end. The configuration of the external gear 327a and the internal gear 325a is the same as that of the external gear 327b and the internal gear 325b.

  Here, the state where each member is connected will be described with reference to the drawings.

As shown in FIG. 13, the operation unit 332 is attached to the right side of the arm unit 319 via elastic members 336 a and 336 b. If detail, the elastic member 336a, b are disposed respectively on the backrest side axis X ₅ and on the headrest side shaft X ₆ is disposed between the backrest side pressing portion 334 and the arm portion 319 of the operation unit 332, Similarly, it is disposed between the headrest side pressing portion 335 and the arm portion 319 of the operation portion 332. The elastic members 336a and 336b are sandwiched between the arm portion 319 and the operation portion 332 in a compressed state.

In this state, the lower end of the arm portion 319 is disposed between the backrest side engagement support portion 312 and the backrest side annular support portion 314, and the upper end of the arm portion 319 is the headrest side engagement support portion 316 and the headrest side annular shape. It arrange | positions between the support parts 318. External gear 327a which is aligned on the back side shaft X ₅ is engaged is inserted into the gear 325a from the left side. The connecting shaft member 337 a penetrates the backrest side connecting portion 321 from the left side of the backrest side annular support portion 314 and is fastened to the backrest side engaging support portion 312. External gears aligned on the headrest side axis X ₆ 327b and the internal gear 325b is similar.

  As described above, the headrest device 310 according to the third embodiment is configured. Next, operation | movement of the headrest apparatus 310 which concerns on 3rd embodiment is demonstrated based on drawing. FIG. 16 is an enlarged view of the locked state in which the headrest is stopped due to the engagement of the internal gears 325a and 327a and the external gears 327a and b among the changing states of the headrest device 310 according to the third embodiment of the present invention. FIG. 17 is an enlarged view of the release state in which the headrest is activated by the separation of the internal gears 325a, b and the external gears 327a, b.

  As shown in FIG. 16, the pressing portions 334 and 335 of the operating portion 332 are pushed rightward by the elastic force (restoring force) of the compressed elastic members 336a and 336b, and the external gears 327a and 327b are It is engaged with gears 325a, b. Therefore, the operation of the arm portion 319 and the headrest is restricted.

  In this locked state, the operation pressing portion 333 of the operation portion 332 is pushed leftward, and the operation portion 332 is pushed into the arm portion 319 to change to the release state. More specifically, as shown in FIG. 17, when the operating portion 332 is pushed against the restoring force of the elastic members 336a, b, the external gears 327a, b move to the left together with the pushing portions 334, 335. It is sent. At the same time, the outer gears 327a, b are separated from the inner gears 325a, b. Therefore, in the released state, the arm portion 319 operates with respect to the backrest side engagement support portion 312, and the headrest (headrest side engagement support portion 316) also operates with respect to the arm portion 319.

In this released state, the operation unit 332 is released to change to the locked state again. As illustrated in FIG. 16, the operation unit 332 is pushed to the right by the restoring force of the elastic members 336a and 336b. Here, the internal gear 325a, b are internal teeth 326a, spacing b (pitch), gradually increases is formed toward the left, the left side than the right side in the axis X _5, X on ₆ Widely formed. With this configuration, the external gears 327a, b are easily engaged by backlash on the left side, and thereafter, the external gears 327a, b are firmly engaged with the internal gears 325a, b on the right side.

  As a modification of the third embodiment, the external gear of the backrest side connecting portion is formed on the backrest portion, the internal gear is formed at the lower end of the arm portion, while the external gear of the headrest side connecting portion is formed on the headrest. An internal gear may be formed at the upper end of the arm portion.

  Next, a headrest device according to a fourth embodiment of the invention will be described with reference to the drawings. 18 shows an appearance of a headrest device 410 according to the fourth embodiment of the present invention, FIG. 19 shows an exploded view of the headrest device 410, and FIG. 20 shows an appearance and a cross section of the headrest device 410. ing. In the following description, configurations different from those of the first embodiment are described, and descriptions of similar configurations are omitted as appropriate.

As shown in FIGS. 18 and 19, the headrest device 410 according to the fourth embodiment includes the following parts. That is, the backrest side engagement support part 412 which is a part of the backrest part, the headrest side engagement support part 416 which is a part of the headrest, the backrest side engagement support part 412 and the headrest side engagement support part 416. The arm part 419 to be connected, the operation part 432 attached to the right side surface of the arm part 419 for selecting the locked state and the release state, and the back side pressing part of the operation part 432 below the arm part 419 434 and the backrest side engagement support portion 412 on the backrest side axis X ₇ , and the headrest side pressing portion 435 and the headrest side engagement support portion 416 above the arm portion 419 are connected to the headrest. headrest side connecting portion 423 which connects on the side axis X _8, the headrest apparatus 410 is configured.

Back-side connecting portion 421, and a second crown gear 425a as a first crown gear 427a and the second gear as a first gear that meshes on the back side axis X _7. The first crown gear 427 a is formed on the right side in the backrest side pressing portion 434 that is the lower end of the arm portion 419. The first crown gear 427a, the first crown teeth spacing 431a of the first crown gear 427a (pitch), is gradually narrower toward the left, the left than the right side on the back side axis X ₇ It is narrower. In other words, the width of the first crown teeth 431a is gradually wider toward the left, toward the left is wider than the right side on the back side axis X _7.

As shown in FIGS. 19 and 20, the second crown gear 425 a is formed on the inner periphery of the backrest side engagement support portion 412. Second crown gear 425a, the width of the second crown teeth 426a of the second crown gear 425a is gradually narrower toward the left, narrower left towards than the right on the back side axis X ₇ Has been. In other words, the interval of the second crown teeth 426a (pitch) is gradually wider toward the left, toward the left is wider than the right side on the back side axis X _7.

Headrest-side connecting portion 423, and a second crown gear 425b of the first crown gear 427b and the second gear as a first gear that meshes on the headrest side shaft X _8. The configurations of the first crown gear 427b and the second crown gear 425b are the same as those of the first crown gear 427a and the second crown gear 425a.

  As described above, the headrest device 410 according to the fourth embodiment is configured. In addition, about another structure, it is the same as 3rd embodiment.

  Next, operation of the headrest device 410 according to the fourth embodiment will be described with reference to the drawings. FIG. 21 shows that the headrest is stopped because the first crown gears 427a and 427b and the second crown gears 425a and 425b are engaged in the changed state of the headrest device 410 according to the fourth embodiment of the present invention. The locked state is shown in an enlarged manner, and FIG. 22 shows the released state in which the headrest is operated due to the separation of the first crown gears 427a, b and the second crown gears 425a, b. .

  As shown in FIG. 21, the operating portion 432 is pushed rightward by the elastic force (restoring force) of the compressed elastic members 436a, b, and the first crown gears 427a, b are moved to the second crown gears 425a, 425a, is engaged with b. Therefore, the operation of the arm portion 419 and the headrest is restricted.

  In this locked state, as shown in FIG. 22, when the operation portion 432 is pushed against the restoring force of the elastic members 436a, b, the first crown gears 427a, b move together with the operation portion 432 to the left. It is sent. At the same time, the first crown gears 427a and 427b are separated from the second crown gears 425a and 425b and change to the released state. Accordingly, in the released state, the arm portion 419 operates with respect to the backrest side engagement support portion 412, and the headrest (headrest side engagement support portion 416) also operates with respect to the arm portion 419.

In this released state, the operation unit 432 is released to change to the locked state again. As shown in FIG. 21, the operation unit 432 is pushed rightward by the restoring force of the elastic members 436a and 436b. Here, the second crown gear 425a, b, the second crown teeth 426a, spacing b (pitch), it is gradually wider toward the left, from the right in on each axis X _7, X ₈ The left side is also widely formed. With this configuration, the first crown gears 427a and 427b are easily engaged by backlash on the left side, and then the first crown gears 427a and 427 are firmly fixed to the second crown gears 425a and b on the right side. Engage.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited to the said embodiment. The present invention can be modified in various ways without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1 Chair 2 Base part 3 Seat part 4 Leg rest part 5 Backrest part 6,206 Headrest 7ab Protrusion part 8ab Groove part 10,210,310,410 Headrest apparatus 11,211 Support main body part 12,212,312,412 Backrest side relation Joint support portion 13 Back support side internal gears 14, 314, 414 Back support side annular support portions 15, 215 Support plate portions 16, 216, 316, 416 Headrest side engagement support portions 17, 217 Headrest side support internal gears 18, 218, 318, 418 Headrest side annular support part 19, 319, 419 Arm part 20 Grasping part 21, 321, 421 Backrest side connection part 22 Backrest side hole 23, 323, 423 Headrest side connection part 24 Headrest side hole 25ab, 225 325ab, 425ab internal gear (first gear, Two gear)
26ab, 226,326ab, 426ab Internal teeth (first tooth, second tooth)
27ab, 227, 327ab, 427ab External gear (first gear, second gear)
28a, b Supporting external teeth 29a, b Engaging external teeth 30a, b Shaft-shaped parts 31ab, 231, 331ab, 431ab External teeth (first tooth, second tooth)
32, 232, 332, 432 Operation part 33, 233, 333, 433 Operation pressing part 34, 234, 334, 434 Backrest side pressing part 35, 235, 335, 435 Headrest side pressing part 36ab, 236ab, 336ab, 436ab Elastic member 37ab, 237ab, 337ab, 437ab connecting shaft member 201ab lid member 202 ring member 203ab bushing member 204 connecting ring member 209 locking step 219 neck portion 221 connecting portion 234 backrest side pressing shaft portion 235 headrest side pressing shaft portion 425a, b Double crown gears 426a, b Second crown teeth 427a, b First crown gears 431a, b First crown teeth X ₁ , X ₅ , X ₇ Backrest side shaft (backrest side connecting shaft)
X ₂ , X ₆ , X ₈ headrest side shaft (headrest side connecting part shaft)
X ₃ actuation axis X ₄ through axis Y linear distance

Claims (7)

In the headrest device in which the backrest portion of the chair and the headrest are connected via a connecting portion, and the headrest is operated with respect to the backrest portion via the connecting portion,
The connecting portion is composed of a first gear and a second gear meshing on the same axis,
The interval between the tooth portions of the first gear is formed narrower on the other side than one side on the shaft,
The width of the tooth portion of the second gear is formed narrower on the other side than one side on the shaft,
A locked state in which the headrest is stopped by engaging the first gear and the second gear and a released state in which the headrest is operated by separating the first gear and the second gear are selected. An operation unit for disposing is disposed away from the axis ,
The first gear is formed on one of the backrest and the headrest, and on the other is formed an engagement support that engages one side of the second gear on the shaft,
The second gear is engaged with the engagement support portion and the first gear in the locked state, and is separated from the first gear and engaged with the engagement support portion in the released state. doing,
A headrest device characterized by that. In the headrest device in which the backrest portion of the chair and the headrest are connected via a connecting portion, and the headrest is operated with respect to the backrest portion via the connecting portion,
The connecting portion is composed of a first gear and a second gear meshing on the same axis,
The interval between the tooth portions of the first gear is formed narrower on the other side than one side on the shaft,
The width of the tooth portion of the second gear is formed narrower on the other side than one side on the shaft,
A locked state in which the headrest is stopped by engaging the first gear and the second gear and a released state in which the headrest is operated by separating the first gear and the second gear are selected. An operation unit for disposing is disposed away from the axis,
An arm is provided between the backrest and the headrest;
A backrest side connecting portion that is the connecting portion that connects the one end portion of the arm portion and the backrest portion, and a headrest side connecting portion that is the connecting portion that connects the other end portion of the arm portion and the headrest. Provided,
The first gear of the backrest side connecting portion is formed on either one of the backrest portion or one end portion of the arm portion, and on the other side, the backrest side connecting portion on the axis of the backrest side connecting portion A back-side engagement support portion that engages with one side of the second gear is formed,
The first gear of the headrest side connecting portion is formed on either one of the headrest or the other end of the arm portion, and on the other side, the headrest side connecting portion on the axis of the headrest side connecting portion A headrest side engagement support portion that engages with one side of the second gear is formed.
Features and to Ruhe Ddoresuto device that. The first gear is an external gear ;
The second gear is an internal gear ;
The headrest device according to claim 1 or 2 , wherein the headrest device is provided. The first gear is an internal gear whose other side is smaller in diameter than one side ,
The second gear, the other side lies outside gear der who diameter than the one side,
The headrest device according to claim 1 or 2, wherein the headrest device is provided. An elastic member is provided on the shaft;
It is in the locked state by the elastic force of the elastic member, and is in the released state by operation of the operation unit .
It headrest apparatus as claimed in claim 1, wherein any one of claims 4 to. The operating unit is found with the arm portion,
A headrest device according to any one of claims 2, 3 dependent on claim 2, claim 4 dependent on claim 2, and claim 5 dependent thereon . The arm part is formed longer than a linear distance between the backrest side connecting part and the headrest side connecting part ,
Any one of claim 2, claim 3 dependent on claim 2, claim 4 dependent on claim 2, claim 5 dependent thereon, and claim 6 dependent thereon The described headrest device.

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