JP2014227129A - Caster for baby carriage and baby carriage mounted with the caster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a caster for a baby carriage which is excellent in smoothness of rotation.SOLUTION: A caster 40 includes a caster shaft 50 which is fixed to a caster fixing body 41 and extends downward from the caster fixing body 41, and a caster rotating body 60 which is rotatable with respect to the caster shaft 50. The caster rotating body 60 has a cylindrical part 61a through which the caster shaft 50 penetrates, and a resin bush 65 which is inserted into the cylindrical part 61a from above. The resin bush 65 has a cylindrical shaft part 65a which is located inside the cylindrical part 61a, and an expanded flange 65b which is provided at an upper end of the shaft part 65a to cover an upper end surface of the cylindrical part 61a. The caster fixing body 41 has a metallic washer 44 which is provided at a part facing the expanded flange 65b.

Description

  The present invention relates to a caster for a baby carriage, and more particularly to a caster for a baby carriage excellent in rotational smoothness. The present invention also relates to a baby carriage to which a caster for the baby carriage is attached.

  The caster for the baby carriage not only rotates the wheel about the rotation axis, but also rotates the wheel so that the wheel and the axle holding the wheel can rotate about the caster axis extending across the rotation axis. Used as a holding mechanism for holding. The caster for the baby carriage rotates the wheel and the axle about the caster axis line according to the direction of the propulsive force applied to the baby carriage from the operator. As a result, the baby carriage can be turned as intended by the operator.

  For example, as disclosed in Patent Document 1, a caster for a baby carriage is fixed to a leg of the baby carriage, and supports a wheel rotatably and rotates with respect to the fixed part about a caster axis. And a possible rotating part.

JP 2005-014894 A

  By the way, in consideration of maneuverability and running stability of the baby carriage, it is preferable that the rotation operation around the caster axis of the fixed portion and the rotating portion constituting the caster is smooth. In the current caster for baby carriages, a lubricant is applied at the time of assembly, and regular lubrication is recommended to the user when using the baby carriage. However, it is troublesome for the user to lubricate regularly. It is also considered effective to interpose a bearing between the fixed portion and the rotating portion in order to ensure rotational smoothness. However, the use of a bearing is not preferable because it increases the manufacturing cost of the baby carriage. That is, there is a need for a caster technique that can ensure smoothness of rotation around the caster axis without using a bearing.

  The present invention has been made in consideration of the above points, and an object thereof is to provide a caster having excellent rotational smoothness.

A caster for a baby carriage according to the present invention is:
A caster fixing body fixed to the leg of the baby carriage,
A metal caster shaft extending downward from the caster fixed body;
A caster rotating body rotatable about the caster shaft about an axis extending in the axial direction of the caster shaft;
A wheel holder connected to the caster rotor,
A wheel rotatably held by the wheel holder,
The caster rotor is
A rotating body main body having a cylindrical portion through which a caster shaft extending downward from the caster fixing body passes;
A resin bush inserted from above into the cylindrical portion, the cylindrical shaft portion disposed in the cylindrical portion of the rotating body main body, and the upper end surface of the cylindrical portion provided at the upper end of the shaft portion A resin bush having a diameter-expanding collar to cover,
The caster fixing body has a metal washer provided at a portion facing the enlarged diameter collar of the resin bush and extending around the caster shaft,
The caster fixed body and the caster rotating body come into contact with each other only by contact between the metal washer and the resin bush.

  In the caster for a baby carriage according to the present invention, the length of the cylindrical shaft portion in the axial direction may be longer than the width of the diameter-expanded collar along the radial direction of the cylindrical shaft portion.

  In the caster for a baby carriage according to the present invention, the length of the cylindrical shaft portion in the axial direction may be longer than the width of the metal washer along the radial direction of the cylindrical shaft portion.

  In the caster for a baby carriage according to the present invention, the resin bush may be press-fitted into the cylindrical portion of the rotating body main body.

  In the caster for a baby carriage according to the present invention, the metal washer may be insert-molded together with a resin portion that supports the metal washer of the caster fixing body.

  In the caster for a baby carriage according to the present invention, the cylindrical portion is provided on the rotating body main body so as to extend upward, and the caster fixing body accommodates the cylindrical portion of the rotating body main body therein. In this case, an annular groove that receives the outer periphery of the metal washer may be formed in an upper portion of the accommodation cylinder part.

  In the caster for a baby carriage according to the present invention, the accommodating tube portion may be separated from the rotating body main body.

  In the caster for a baby carriage according to the present invention, the caster fixing body includes a mounting adjuster fixed to a leg of the baby carriage, a shaft holding body fixed to the mounting adjuster, including the metal washer, and holding the caster shaft. You may have.

  In the baby carriage caster according to the present invention, a cushion material is provided between the caster rotating body and the wheel holding body, and the caster shaft and the cushion material are displaced when viewed from the axial direction of the caster shaft. It may be arranged.

The baby carriage according to the present invention is:
A caster for a baby carriage having any one of the above characteristics;
A baby carriage main body to which a caster for the baby carriage is attached.

  According to the present invention, it is possible to improve the rotational smoothness of casters.

FIG. 1 is a perspective view showing a baby carriage for explaining an embodiment of the present invention. FIG. 2 is a side view showing the baby carriage of FIG. FIG. 3 is a perspective view showing a caster according to an embodiment. FIG. 4 is a partial vertical sectional view showing the caster shown in FIG. 3 from the side. FIG. 5 is a partially enlarged view showing an essential part of the caster shown in FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIGS. 1-5 is a figure for demonstrating one Embodiment of the baby carriage and caster by this invention. Among these, FIGS. 1 and 2 show the overall configuration of the baby carriage 10. The stroller 10 shown in FIGS. 1 and 2 includes a stroller body 11 and a caster 40 attached to the stroller body 11. Among these, the baby carriage main body 11 includes a baby carriage main body 11 having a frame portion 20 having a pair of front legs 22 and a pair of rear legs 24, and a handle 26 that is swingably connected to the frame portion 20.

  A caster 40 which will be described in detail later is attached to the lower ends of the pair of front legs 22. On the other hand, a wheel holder 38 is attached to the lower ends of the pair of rear legs 24. As shown in FIG. 1, the caster 40 attached to the front leg 22 not only holds the wheel 75 rotatably about the rotation axis La, but also centers on the caster axis Lb extending across the rotation axis La. The wheel 75 and the wheel holder 70 that holds the wheel 75 can be rotated. On the other hand, the wheel holding body 38 attached to the rear leg 24 holds the wheel 39 rotatably while keeping the direction of the wheel 39 constant.

  In the baby carriage 10 of the present embodiment, the handle (26) is held by the operator (guardian) from the back side of the infant and the baby carriage 10 is operated by swinging the handle 26 with respect to the frame portion 20. , Running the baby carriage 10 so that the infant faces forward in the direction of travel (the state shown in FIG. 1 and the state shown by the two-dot chain line in FIG. 2), and the position on the front leg side where the operator faces the infant Then, the baby carriage 10 is steered by gripping the handle 26 and the baby carriage 10 is allowed to travel such that the rear leg side of the baby carriage 10 is in front of the traveling direction (state shown by a solid line in FIG. 2). ing. That is, the handle 26 is configured to be releasably fixed at a facing pressing position indicated by a solid line in FIG. 2 and a back pressing position indicated by a two-dot chain line in FIG.

  In such a baby carriage 10, the wheel holding body 38 attached to the rear leg 24 may be configured as a so-called caster so that the direction of the wheel 39 can be changed. In such a baby carriage 10, with respect to the casters attached to the legs located forward in the moving direction of the front legs 22 and the rear legs 24, the wheels and the wheel holders can be rotated around the caster axis. From the viewpoint of maneuverability of the baby carriage 10, it is preferable that the casters attached to the legs positioned rearward in the moving direction be restricted from rotation of the wheel and the wheel holder around the caster axis.

  A configuration in which the handle 26 is swingable with respect to the frame member 20 and a configuration in which the rotation of the wheel and the wheel holding body about the caster axis is automatically restricted according to the position of the handle 26 are known. A configuration, for example, the configuration disclosed in JP2008-254688A described above can be employed. Therefore, further detailed description is omitted in this specification.

  Moreover, in this Embodiment, the baby carriage 10 is comprised so that folding is possible so that it may prevail widely. As a configuration that allows the baby carriage 10 to be folded, a known configuration, for example, the configuration disclosed in JP2008-254688A described above can be employed. Therefore, further detailed description is omitted in this specification.

  Next, the caster 40 attached to the front leg 22 of the baby carriage body 11 will be described mainly with reference to FIGS. FIGS. 3 and 4 are a perspective view and a side sectional view, respectively, showing a caster 40 in one embodiment. FIG. 5 is a partially enlarged view showing an essential part of the caster shown in FIG. In addition, casters 40 for front legs are respectively provided at the lower ends of the pair of front legs 22. The two front leg casters 40 are configured identically or symmetrically to each other.

  As shown in FIG. 3, the caster 40 has, as an overall configuration, a caster fixing body 41 fixed to the leg of the baby carriage 10, a caster rotating body 60 that can rotate with respect to the caster fixing body 41, and a caster rotating body. The wheel holding body 70 connected to 60, and the wheel 75 rotatably held by the wheel holding body 70 are provided. As shown in FIGS. 4 and 5, a metal caster shaft 50 extends downward from the caster fixing body 41 inside the caster 40. The caster rotating body 60 is supported so as to be rotatable with respect to the caster shaft 50 around an axis extending in the axial direction of the caster shaft 50. More specifically, the caster rotating body 60 has a rotating body main body 61 including a cylindrical portion 61a. The cylindrical portion 61a is penetrated by the caster shaft 50 so as not to drop off, so that the caster rotating body 60 is supported so as to be rotatable about the axial direction of the caster shaft 50. Further, the wheel holder 70 holds the wheel 75 rotatably via the axle 74.

  In the caster 40 having the above schematic configuration, the wheel 75 is rotatable with respect to the wheel holding body 70 about the rotation axis La that coincides with the axial direction of the axle 74. Further, the caster rotating body 60 has a caster fixed body 41 fixed to the baby carriage main body 11 and a caster shaft 50 supported by the caster fixed body 41 around the caster axis Lb that coincides with the axial direction of the caster shaft 50. It can be rotated.

  As shown in FIG. 4, the rotation axis La extends substantially along the horizontal direction, and the caster axis Lb extends substantially orthogonal to the traveling surface (road surface) of the baby carriage 10. Further, the rotation axis La and the caster axis Lb are arranged so as to be shifted along the traveling surface of the baby carriage 10. Therefore, by adjusting the direction of the propulsive force applied to the baby carriage 10 from the operator, the caster rotating body 60 rotates with respect to the caster fixing body 41 and the caster shaft 50, and the baby carriage 10 can be turned.

  Hereinafter, each component of the caster 40 will be described in detail. First, the caster fixed body 41 and the caster shaft 50 will be described. Then, the structure which rotates with the caster rotary body 60 centering | focusing on the caster axis line Lb with respect to the caster rotary body 60, the caster fixed body 41, and the caster shaft 50 is demonstrated.

  As described above, the caster fixing body 41 is fixed to the leg of the baby carriage body 11 and supports the caster rotating body 60 via the caster shaft 50. In the present embodiment, the caster fixing body 41 includes an attachment adjuster 42 that is fixed to the leg of the baby carriage 10, and a shaft holding body 43 that is fixed to the attachment adjuster 42 and holds the caster shaft 50.

  As shown in FIG. 4, the attachment adjuster 42 has a leg housing cylinder portion 42 a that opens upward, and a shaft holder housing cylinder portion 42 b that opens downward. The lower end portion of the leg 22 to which the caster is to be attached is inserted into the leg housing cylinder portion 42a. Therefore, the leg accommodating tube portion 42 a has a shape corresponding to the shape of the leg 22. In the illustrated example, the leg 22 and the leg accommodating tube portion 42a are fixed via a pin 45 that extends in a direction orthogonal to the longitudinal direction of the leg 22 and penetrates the leg 22 and the leg accommodating tube portion 42a in common. Yes. As shown in FIG. 4, the shaft holding body accommodating tube portion 42 b of the attachment adjuster 42 accommodates the upper part of the shaft holding body 43 that constitutes the caster fixing body 41 together with the attachment adjuster 42.

  Next, the shaft holder 43 will be described. In the present embodiment, the shaft holder 43 is formed as a hollow member that opens downward. The shaft holder 43 has a caster shaft housing cylinder 43a that opens downward. The caster shaft housing cylinder portion 43a extends along the caster axis Lb defined by the caster shaft 50, and houses the upper part of the caster shaft 50 therein. The caster shaft accommodating cylinder portion 43a is arranged in the shaft holding body accommodating cylinder portion 42b of the attachment adjuster 42. As shown in FIG. 4, a pin 46 penetrating these three components is provided at a position where the mounting adjuster 42, the shaft holding body 43, and the caster shaft 50 overlap in the direction along the caster axis Lb. The pin 46 extends in a direction perpendicular to the caster axis Lb, and fixes the attachment adjuster 42, the shaft holding body 43, and the caster shaft 50 to each other.

  As shown in FIG. 5, the shaft holder 43 has a housing cylinder portion 43 b that expands from the lower end surface 43 a 1 of the caster shaft housing cylinder portion 43 a and further extends downward. The accommodation cylinder part 43b is larger than the caster shaft accommodation cylinder part 43a in both the inner dimension and the outer dimension. Therefore, as shown in FIG. 5, the lower end surface 43a1 of the caster shaft housing cylinder portion 43a forms a step surface that forms a step between the inner surface of the caster shaft housing tube portion 43a and the inner surface of the housing tube portion 43b. . The caster fixing body 41 further includes a metal washer 44 that annularly covers the lower end surface 43a1 of the caster shaft housing cylinder portion 43a. The metal washer 44 is held such that the surface thereof is orthogonal to the caster axis Lb.

  In the example shown in FIG. 5, the outer peripheral portion of the metal washer 44 is disposed at the upper portion of the accommodating cylinder portion 43 b, more strictly, at the boundary between the accommodating cylinder portion 43 b and the lower end surface 43 a 1 of the caster shaft accommodating cylinder portion 43 a. A receiving annular groove 48 is formed. The metal washer 44 is supported by the shaft holder 43 by the engagement between the outer peripheral portion of the metal washer 44 and the annular groove 48. In the present embodiment, the shaft holder 43 is made of resin with respect to the washer 44 made of metal. The metal washer 44 is supported by being engaged with the annular groove 48 by insert molding together with a resin portion that supports the caster shaft 50 of the caster fixing body 41, that is, the shaft holding body 43. In this case, the metal washer 44 can be easily and reliably fixed to the housing cylinder portion 43 b of the caster fixing body 41.

  Next, the caster shaft 50 will be described. The upper part of the caster shaft 50 is inserted into the caster shaft housing cylinder portion 43 a of the shaft holding body 43 and is held by the shaft holding body 43. As shown in FIGS. 4 and 5, the caster shaft 50 extends further downward from the caster shaft housing cylinder portion 43a so as to leave a gap between the caster shaft 50 and the housing cylinder portion 43b. Therefore, the caster shaft 50 extends through the annular metal washer 44. In other words, the ring-shaped metal washer 44 extends around the caster shaft 50.

  Further, a portion of the caster shaft 50 that extends from the caster shaft accommodating tube portion 43 a extends through the tube portion 61 a of the rotating body main body 61. As well shown in FIG. 5, the caster shaft 50 has a drop-off preventing collar 51 having a large diameter at its lower end. In the present embodiment, caster shaft 50 is made of metal.

  Next, the caster rotating body 60 will be described. As described above, the caster rotating body 60 includes the rotating body main body 61 including the cylindrical portion 61a. The caster shaft 50 extends into the cylindrical portion 61a from above, and the lower end surface of the cylindrical portion 61a faces the fall prevention collar 51 of the caster shaft 50 in the vertical direction. As well shown in FIG. 5, the cylindrical portion 61a of the rotating body main body 61 has an inner diameter through which the drop prevention collar 51 cannot pass. As a result, the caster rotating body 60 is interposed via the cylindrical portion 61a. The caster shaft 50 and the caster fixed body 41 fixed to the caster shaft 50 are rotatably supported.

  Further, as shown in FIG. 4, the caster rotating body 60 further includes a resin bush 65 inserted into the cylindrical portion 61 a of the rotating body main body 61 from above. The resin bush 65 is disposed in the cylindrical portion 61 a of the rotating body main body 61, and is provided on a hollow cylindrical shaft portion 65 a that surrounds the outer periphery of the caster shaft 50 and an upper end of the shaft portion 65 a. And an enlarged collar 65b covering the upper end surface of the portion 61a. In the present embodiment, the resin bush 65 is press-fitted into the cylindrical portion 61 a of the rotating body main body 61. That is, in a state before the shaft portion 65a of the resin bush 65 is inserted into the cylindrical portion 61a, the outer diameter of the shaft portion 65a of the resin bush 65 is larger than the inner diameter of the cylindrical portion 61a of the rotating body main body 61. It has become.

  In the caster 40, the inner peripheral surface of the shaft portion 65 a of the resin bush 65 slides on the outer peripheral surface of the caster shaft 50, so that the caster rotating body 60 can move with respect to the caster shaft 50 about the caster axis Lb. Can be rotated. Further, in order to enable relative rotation between the caster rotating body 60 and the caster shaft 50, a slight play is provided between the shaft portion 65a of the resin bush 65 and the caster shaft 50.

  As shown in FIGS. 4 and 5, in the present embodiment, the diameter-expanded collar 65b of the resin bush 65 extends outward from the upper end of the cylindrical shaft portion 65a in the radial direction of the shaft portion 65a. The diameter-expanded collar 65b is formed in a hollow disc shape in which a portion corresponding to the inside of the shaft portion 65a is hollowed, and the caster shaft 50 passes through the hollow space. The outer diameter of the enlarged collar 65b is as shown in the illustrated example so that the upper end of the cylindrical part 61a of the rotating body 61 can be completely covered from above by the enlarged collar 65b. It is preferable that the outer diameter of the cylindrical portion 61a is equal to or larger than the outer diameter of the upper end surface of the cylindrical portion 61a. As an example, the diameter of the expanded diameter collar 65b can be formed to be approximately the same as the thickness of the shaft portion 65a in consideration of formability.

  As shown in FIGS. 4 and 5, the diameter-increased collar 65 b of the resin bush 65 covering the cylindrical portion 61 a of the rotating body main body 61 comes to face the metal washer 44 of the caster fixing body 41 in the vertical direction. When the baby carriage 10 is used, the caster rotating body 60 and the caster fixed body 41 are pressed against each other in the vertical direction by the weight of the baby carriage 10 and the baby riding on the baby carriage 10. Therefore, when the caster rotating body 60 rotates with respect to the caster fixing body 41, the diameter-expanded collar 65b of the resin bush 65 and the metal washer 44 are rubbed.

  The resin bush 65 can be formed using various resin materials. However, the material forming the resin bushing 65 is more resistant to wear and lower friction than the resin material forming the rotating body 61 in relation to metal, particularly the metal used for the metal washer 44 and the caster shaft 50 ( A resin material excellent in smoothness is preferable.

  The shaft holder 43 has a housing cylinder portion 43b that extends downward from a position where the metal washer 44 is provided. The housing cylinder portion 43b extends along the caster axis Lb while leaving a gap with the caster shaft 50. The cylindrical portion 61a and the resin bushing 65 of the rotating body main body 61 are covered from the outside in a circumferential shape by the accommodating cylindrical portion 43b, and are not substantially exposed to the outside. In addition, the accommodation cylinder portion 43 b in the present embodiment does not contact any part of the caster rotating body 60. 4 and 5, the caster fixing body 41 and the caster rotating body 60 are brought into contact with each other only by the contact between the metal washer 44 and the enlarged collar 65b of the resin bush 65. .

  As shown in FIG. 5, in the present embodiment, the outer diameter of the metal washer 44 is larger than the outer diameter of the enlarged collar 65 b of the resin bush 65. Accordingly, even if the rotation axis of the caster rotor 60 with respect to the caster shaft 50 is slightly inclined from the originally intended caster axis Lb due to play between the shaft portion 65a of the resin bush 65 and the caster shaft 50, The state in which the caster fixing body 41 and the caster rotating body 60 are in contact with each other only through the diameter-expanded collar 65b of the resin bush 65 and the metal washer 44 can be stably maintained.

  In the present embodiment, the length of the cylindrical shaft portion 65a of the resin bush 65 in the axial direction (that is, the direction parallel to the caster axis Lb) is along the radial direction of the cylindrical shaft portion 65a. It is longer than the width of the expanded collar 65b. The length of the cylindrical shaft portion 65a of the resin bush 65 in the axial direction is longer than the width of the metal washer 44 along the radial direction of the cylindrical shaft portion 65a. Such a configuration is preferable from the viewpoint of stabilizing the rotation of the caster rotating body 60 with respect to the caster shaft 50 and the caster fixed body 41, as will be described later.

  Further, the caster rotating body 60 shown in FIGS. 3 and 4 further includes a lock member 69 for restricting the relative rotation of the caster rotating body 60 with respect to the caster fixing body 41. The rotating body main body 61 further includes an extending portion 61b extending in a direction away from the cylindrical portion 61a that supports the caster shaft 50. The lock member 69 is swingably supported by the extending portion 61 b of the rotating body main body 61 via a pin 67. As shown in FIG. 3, a recess 47 is formed in the shaft holding body 43 of the caster fixing body 41. The lock member 69 has a convex portion 69 a that can be fitted into the concave portion 47 of the shaft holding body 43 by swinging with respect to the rotating body main body 61. By operating the lock member 69 to engage or disengage the convex portion 69a and the concave portion 47, the rotation of the caster rotating body 60 relative to the caster fixing body 41 can be restricted or released.

  Next, the wheel holding body 70 and the wheel 75 connected to the caster rotating body 60 will be described. The wheel holding body 70 holds the wheel 75 rotatably via the axle 74. In the present embodiment, a hole 73 is formed in the wheel holder 70, and an axle 74 that rotatably holds the wheel 75 is inserted into the hole 73.

  The wheel holding body 70 is operatively connected to the caster rotating body 60, and a cushion material 77 is provided between the caster rotating body 60 and the wheel holding body 70. In the illustrated example, a penetrating pin 63 extending in parallel with the rotation axis La defined by the axle 74 extends through both the caster rotating body 60 and the wheel holding body 70. The caster rotating body 60 and the wheel holding body 70 can swing relative to each other about an axis line that coincides with the axial direction of the through pin 63. The cushion material 77 is elastically deformed by relative swinging between the caster rotating body 60 and the wheel holding body 70. The cushion member 77 can exhibit a suspension function of absorbing an impact by being deformed. As a result, it is possible to provide a comfortable ride for the infant riding in the baby carriage 10.

  Next, the operation of the caster 40 having the above configuration will be described.

  When propulsive force is applied to the baby carriage 10 from the operator, the caster rotating body 60 rotates about the caster axis Lb with respect to the caster shaft 50 and the caster fixed body 41 according to the direction of the propulsive force. As described above, the caster shaft 50 supported by the caster fixing body 41 extends in the cylindrical portion 61 a of the rotating body main body 61 of the caster rotating body 60. A resin bushing 65 is inserted into the tube portion 61a from above, the inner surface of the tube portion 61a is covered with the shaft portion 65a of the resin bushing 65, and the upper end surface of the tube portion 61a is expanded to the resin bushing 65. It is covered with a diameter collar 65b. Therefore, when the inner peripheral surface of the shaft portion 65a of the resin bush 65 slides on the outer peripheral surface of the caster shaft 50, the caster rotating body 60 rotates with respect to the caster shaft 50 about the caster axis Lb. be able to.

  At this time, the caster rotating body 60 and the caster fixing body 41 are pressed toward each other in the vertical direction according to the weight of the baby carriage 10 and the baby riding on the baby carriage 10. As shown in FIGS. 4 and 5, the diameter expansion collar 65 b of the resin bush 65 covering the cylindrical portion 61 a of the rotating body main body 61 faces the metal washer 44 of the caster fixing body 41 in the vertical direction. . Therefore, when the caster rotating body 60 rotates relative to the caster fixing body 41, the diameter-expanded collar 65b of the resin bush 65 and the metal washer 44 rub against each other. In particular, in the present embodiment, the caster fixing body 41 and the caster rotating body 60 come into contact with each other only by the contact between the metal washer 44 and the resin bush 65.

  Therefore, in the present embodiment, when the caster rotating body 60 rotates with respect to the caster fixed body 41 and the caster shaft 50, the caster rotating body 60 is connected to the caster fixed body 41 and the caster shaft 50 via the resin bush 65. To touch. If the caster 40 is continuously used, the rubbing part may be worn. In this respect, in this embodiment, both the washer 44 and the caster shaft 50 of the caster fixing body 41 are formed of a metal that is generally excellent in resistance to friction. On the other hand, the caster rotating body 60 contacts the metal washer 44 and the caster shaft 50 only through the resin bush 65.

  Therefore, only the resin bush 65 of the caster rotating body 60 is formed of a resin that can exhibit high self-lubrication, that is, smooth rotation and excellent wear resistance with respect to the metal washer 44 and the caster shaft 50. As long as this is done, wear over time in the caster 40 can be effectively suppressed. That is, instead of forming the entire caster rotator 60 from a special material that tends to be expensive, the resin bush 65 is attached to the rotator main body 61 to realize a practical manufacturing cost as a caster for a baby carriage. However, excellent wear resistance and smoothness can be imparted to the portion of the caster rotor 60 where friction occurs. Thereby, the frictional resistance at the time of the relative rotation of the caster rotating body 60 with respect to the caster fixing body 41 can be kept low, and the caster rotating body 60 can be smoothly rotated with respect to the caster fixing body 41 and the caster shaft 50. In addition, in order to reduce wear between the caster rotating body 60 and the caster fixed body 41, it is possible to avoid applying lubricant during assembly of the casters and forcing the user to periodically lubricate (maintenance). It is also possible to do.

  In particular, the contact between the caster rotating body 60 and the caster fixed body 41 or the caster shaft 50 is a contact between the resin part and the metal part. Therefore, since the frictional resistance tends to be reduced as compared with the case of contact between resin parts or contact between metal parts, the relative rotation of the caster rotating body 60 with respect to the caster fixing body 41 is performed more smoothly. In addition, wear can be reduced.

  By the way, in order to enable relative rotation between the caster rotating body 60 and the caster shaft 50, play is inevitably provided between the shaft portion 65a of the resin bush 65 and the caster shaft 50. However, when this play increases, the deviation between the axial direction of the caster shaft 50 and the axial direction of the shaft portion 65a of the resin bush 65 may increase depending on the road surface condition on which the baby carriage 10 travels. In this state, when the caster rotating body 60 rotates with respect to the caster fixing body 41, a wobble phenomenon in which the caster rotating body 40 slightly vibrates with respect to the caster fixing body 41 and the caster shaft 50 may occur. If such a phenomenon occurs, there is a possibility that the traveling stability of the baby carriage 10 is lowered, and further, it is difficult to travel in a straight line. Therefore, in the present embodiment, in order to suppress the inclination of the caster rotating body 40 with respect to the caster shaft 50, the length that the shaft portion 65a of the resin bush 65 and the caster shaft 50 can contact along the axial direction is relatively long. Secured for a long time.

  As an example, the length in the axial direction of the cylindrical shaft portion 65a of the resin bush 65 is the radial direction of the cylindrical shaft portion 65a (that is, the direction orthogonal to the axial direction of the shaft portion 65a, FIG. It is formed so as to be longer than the width of the diameter-expanded collar 65b along the horizontal direction in the drawing. In this case, the length that the shaft portion 65a of the resin bush 65 and the caster shaft 50 can contact along the axial direction can be secured relatively long. As another example, the axial length of the cylindrical shaft portion 65a of the resin bush 65 is longer than the width of the metal washer 44 along the radial direction of the cylindrical shaft portion 65a. It may be formed. In this case, the shaft portion 65a of the resin bush 65 and the caster shaft 50 are further connected to each other while ensuring that the caster rotating body 60 contacts the caster fixing body 41 only through the resin bush 65. The length of contact along the direction can be ensured relatively long. According to these structures, it can suppress that the axial direction of the axial part 65a of the resin bushes 65 inclines with respect to the axial direction of the caster shaft 50. As a result, it is possible to improve the stability of the traveling of the baby carriage 10 and the maneuverability of the baby carriage 10 and improve the riding comfort of the baby carriage 10.

  Further, according to the present embodiment, the resin bush 65 is press-fitted into the cylindrical portion 61 a of the rotating body main body 61. In this case, the resin bush 65 can be easily fixed to the cylindrical portion 61a of the rotating body main body 61, and the caster rotating body 60 can be smoothly rotated with respect to the caster fixing body 41 and the caster shaft 50. .

  Furthermore, according to the present embodiment, the annular groove 48 that receives the outer peripheral portion of the metal washer 44 is formed in the upper portion of the accommodating cylinder portion 43b. In this case, the metal washer 44 can be stably fixed by the accommodating cylinder portion 43 b of the caster fixing body 41. As a result, the caster rotating body 60 can be smoothly rotated with respect to the caster fixing body 41. Further, according to the insert molding, such a configuration can be easily realized. Thereby, the caster rotating body 60 can be smoothly rotated with respect to the caster fixing body 41 and the caster shaft 50.

  Further, according to the present embodiment, the cylindrical portion 61a of the rotating body main body 61 is provided on the rotating body main body 61 so as to extend upward, and the caster fixing body 41 is provided with the cylindrical portion 61a of the rotating body main body 61. The housing includes a housing cylinder portion 43b that extends downward so as to be housed therein. According to this accommodating cylinder part 43b, it can avoid effectively that a foreign material etc. mix in the contact area | region of the caster rotary body 60, the caster fixing body 41, and the caster shaft 50.

  Further, according to the present embodiment, the housing cylinder portion 43 b of the shaft holder 43 is separated from the rotating body main body 61 of the caster rotating body 60. Thereby, when the caster rotating body 60 rotates with respect to the caster fixing body 41 and the caster shaft 50, it is possible to prevent the accommodating cylinder portion 43 b of the caster fixing body 41 from contacting and rotating with the rotating body main body 61. it can.

  Further, according to the present embodiment, the caster fixing body 41 has the attachment adjuster 42 and the shaft holding body 43. According to such a configuration, only the mounting adjuster 42 for connecting the shaft holding body 43 to the leg of the baby carriage 10 is changed according to the configuration of the baby carriage 10, and the rotational smoothness and wear resistance according to the present embodiment are excellent. The caster 40 can be applied to the baby carriage 10 having various configurations. That is, if a caster unit comprising the shaft holder 43, the caster shaft 50, the caster rotor 60, the wheel holder 70, and the wheel 75 is produced, the caster unit can be configured in various configurations only by changing the mounting adjuster 42. It can be applied to the baby carriage 10. More specifically, the caster 40 can be attached to the front legs or the rear legs of various baby carriages by simply changing the shape of the leg accommodating tube portion 42a of the attachment adjuster 42 as appropriate. Thereby, the versatility of the caster 40 can be improved.

  Furthermore, according to the present embodiment, the caster shaft 50 and the cushion material 77 are arranged so as to be displaced when observed from a direction parallel to the caster axis Lb. In other words, the cushion material 77 is not disposed on the extension of the caster shaft 50 along the caster axis Lb. That is, when the baby carriage 10 is placed on the traveling surface, the caster shaft 50 and the cushion material 77 are positioned so as to be shifted in a direction parallel to the traveling surface. Accordingly, the length of the caster shaft 50 and the length of the shaft portion 65a of the resin bush 65 are ensured as compared with the case where the cushion material 77 is disposed on the extension of the caster shaft 50 along the caster axis Lb. It becomes easy. As a result, it is possible to ensure a relatively long length in which the shaft portion 65a of the resin bush 65 and the caster shaft 50 are in contact with each other along the axial direction, so that the caster rotating body 60 is relative to the caster fixed body 41. When rotating, it is possible to effectively suppress the occurrence of a phenomenon (wobble phenomenon) in which the caster rotating body 60 slightly vibrates together with the wheel holding body 70 holding the wheel 75.

  Note that various modifications can be made to the above-described embodiment. For example, the illustrated configuration of the baby carriage main body 11 is merely an example, and various modifications can be made. For example, in the illustrated baby carriage 10, an example is shown in which the handle 26 is configured to be swingable between a back pushing position (rear position) and a facing pushing position (front position). It may be configured such that it cannot be swung from the back pushing position.

DESCRIPTION OF SYMBOLS 10 Stroller 11 Stroller body 20 Frame part 22 Front leg 24 Rear leg 40 Caster 41 Caster fixing body 42 Attachment adjuster 43 Shaft holding body 43b Housing cylinder part 44 Metal washer 48 Annular groove 50 Caster shaft 51 Fall-off prevention collar 60 Caster rotation body 61 Rotation Body body 61a Tube portion 65 Resin bushing 65a Shaft portion 65b Expanded collar 70 Wheel holder 74 Axle 75 Wheel 77 Cushion material

Claims (10)

A caster fixing body fixed to the leg of the baby carriage,
A metal caster shaft extending downward from the caster fixed body;
A caster rotating body rotatable about the caster shaft about an axis extending in the axial direction of the caster shaft;
A wheel holder connected to the caster rotor,
A wheel rotatably held by the wheel holder,
The caster rotor is
A rotating body main body having a cylindrical portion through which a caster shaft extending downward from the caster fixing body passes;
A resin bush inserted from above into the cylindrical portion, the cylindrical shaft portion disposed in the cylindrical portion of the rotating body main body, and the upper end surface of the cylindrical portion provided at the upper end of the shaft portion A resin bush having a diameter-expanding collar to cover,
The caster fixing body has a metal washer provided at a portion facing the enlarged diameter collar of the resin bush and extending around the caster shaft,
The caster for a baby carriage, in which the caster fixing body and the caster rotating body are in contact with each other only by contact between the metal washer and the resin bush.   The caster for a baby carriage according to claim 1, wherein a length of the cylindrical shaft portion in an axial direction is longer than a width of the diameter-expanded collar along a radial direction of the cylindrical shaft portion.   The caster for a baby carriage according to claim 1 or 2, wherein a length of the cylindrical shaft portion in an axial direction is longer than a width of the metal washer along a radial direction of the cylindrical shaft portion. .   The caster for a baby carriage according to any one of claims 1 to 3, wherein the resin bush is press-fitted into the cylindrical portion of the rotating body main body.   The caster for a baby carriage according to any one of claims 1 to 4, wherein the metal washer is insert-molded together with a resin portion that supports the metal washer of the caster fixing body. The cylindrical portion is provided in the rotating body main body so as to extend upward,
The caster fixing body includes an accommodating cylinder portion extending downward so as to accommodate the cylindrical portion of the rotating body main body therein.
The caster for baby carriages according to any one of claims 1 to 5, wherein an annular groove that receives an outer peripheral portion of the metal washer is formed in an upper portion of the housing cylinder portion.   The caster for a baby carriage according to claim 6, wherein the housing cylinder part is separated from the rotating body main body. The caster fixed body is
A mounting adjuster fixed to the pram leg;
The caster for a baby carriage according to any one of claims 1 to 7, further comprising: a shaft holding body that is fixed to the mounting adjuster, includes the metal washer, and holds the caster shaft. A cushion material is provided between the caster rotor and the wheel holder,
The caster for baby carriages according to any one of claims 1 to 8, wherein the caster shaft and the cushion material are arranged so as to be displaced from each other when viewed from an axial direction of the caster shaft. A caster for a baby carriage according to any one of claims 1 to 9,
A baby carriage comprising: a baby carriage body to which a caster for the baby carriage is attached.