JP4958730B2 - Infant tricycle drive mechanism and infant tricycle - Google Patents

Description

  The present invention relates to a drive mechanism for an infant tricycle and an infant tricycle, and more specifically, includes a drive mechanism capable of switching the relationship between a drive shaft and a front wheel to three stages of fixed, idle, and shift, and the drive mechanism. It relates to a tricycle for infants.

  2. Description of the Related Art Conventionally, a drive mechanism for an infant tricycle has a drive shaft that is attached to both ends via a crankshaft and is rotatably supported at the lower end of a handle frame, and a hollow structure that is rotatably supported by the drive shaft ( It is known that the drive shaft is in a fixed state (connected state) with the front wheel so that the rotation ratio is 1: 1.

  In recent years, infant tricycles equipped with a push bar or a push frame at the rear have been provided. When the tricycle is driven by pushing the push bar, etc., the crankshaft (drive shaft) rotates together with the front wheels. However, since the infant's foot on the pedal also rotates together, it is not necessarily comfortable for the infant, and it cannot be said that there is no risk of an unexpected situation if the infant's foot comes off the pedal. Further improvement is desired.

  As a mechanism for solving such a problem, for example, mechanisms disclosed in Patent Document 1 and Patent Document 2 are known. Patent Document 1 and Patent Document 2 disclose that a mechanism capable of switching the relationship of a front wheel with respect to a crankshaft (drive shaft) between a fixed state and an idling state is housed in the front wheel.

Japanese Utility Model Publication No. 7-15492 Japanese Patent No. 2820396

  However, in the above-described conventional mechanism, the relationship of the front wheel with respect to the drive shaft can be switched to only two stages of the fixed state and the idling state, and no further function is provided.

  The present invention has been made in view of such a conventional situation, and an object of the present invention is to switch the relationship between the drive shaft and the front wheels to three stages of fixed (1: 1 rotation ratio), idling, and shifting. It is an object of the present invention to provide a novel drive mechanism improved so as to be capable of being used and an infant tricycle equipped with the drive mechanism.

In order to achieve the above object, the present invention is equipped with a drive shaft that is rotatably supported at the lower end of the handle frame and a pedal is attached to both ends of the handle frame via a pedal shaft, and is freely mounted by the drive shaft. A front wheel having an internal hollow structure, and a switching mechanism that is housed in the front wheel and switches the relationship between the drive shaft and the front wheel to each of three positions of fixing, idling, and shifting,
The switching mechanism includes an operation member for switching to each of the three stages so as to face the side surface of the front wheel,
When the operation member is in the fixed position, the front wheel is fixed with respect to the drive shaft, the rotation ratio of the drive shaft and the front wheel is 1: 1, and the operation member is in the idling position. When the front wheel is idle with respect to the drive shaft, and the operating member is in a shift position, the drive shaft and the front wheel are moved by a transmission interposed between the drive shaft and the front wheel. The present invention is characterized by being configured to be in a speed change state in which the rotation ratio changes.

According to such a configuration, when the operation member facing the outside from the side surface of the front wheel is in the fixed position, the front wheel is fixed (directly connected) to the drive shaft by the switching mechanism. As a result, in the tricycle, the front wheel rotates integrally with the drive shaft at a rotation ratio of 1: 1 with respect to the drive shaft, as in the conventional case.
When the operating member is switched to the idle position, the switching mechanism causes the front wheels to idle (separate) from the drive shaft. As a result, the drive shaft rotates idly with respect to the rotation of the front wheel.
Further, when the operating member is switched to the shift position, the transmission is operated by the switching mechanism, and the rotation ratio of the front wheels to the rotation operation of the drive shaft is changed by the operation of the transmission. For example, the rotation of the front wheels is decelerated with respect to the rotation of the drive shaft.
In addition, the switching mechanism can be provided, for example, on the outer side of the front wheel or the handle frame, but is housed inside the front wheel having an internal hollow structure. As a result, the switching mechanism is not exposed to the outside, and the appearance shape almost the same as that of the conventional tricycle can be maintained.

Moreover, although it does not specifically limit as said transmission, As a preferable aspect, it is comprised combining 2 pairs of 1st-4th bevel gears which each oppose.
The specific structure will be described. Of the pair of first and second bevel gears on the opposite one side, the first bevel gear is rotatably supported by the drive shaft, and the second bevel gear is provided. Is pivotally supported by the drive shaft so as to rotate integrally with the drive shaft, and a pair of third and fourth bevel gears on the other side are locked to the front wheel in a direction perpendicular to the drive shaft. The first to fourth bevel gears are meshed with each other so as to rotate integrally with each other by being rotatably supported by the shafts.
When in the speed change state, the first bevel gear becomes non-rotatable, and the rotation of the remaining three second to fourth bevel gears reduces the rotation ratio of the front wheel to the rotation of the drive shaft. Can be configured.
The pair of first and second bevel gears on one side are used as a first large-diameter bevel gear and a second large-diameter bevel gear, and the pair of third and fourth bevel gears on the other side are the first It is preferable that the third small-diameter bevel gear and the fourth small-diameter bevel gear are used. Thereby, the transmission comprised by combining two pairs of 1st-4th large and small bevel gears which each oppose can be built and accommodated compactly in the inside of a front wheel.
Further, when the speed change state is the speed reduction state by the combination of two pairs of first to fourth bevel gears facing each other and the selection of the number of teeth and the outer diameter, the rotation ratio between the drive shaft and the front wheels Can be configured to be 2: 1.
Further, by using synthetic resin materials as the materials of the two pairs of first to fourth bevel gears, smooth meshing that suppresses meshing noise and the like can be expected, and the intended purpose can be sufficiently achieved. Can do.

  The switching mechanism includes an engaging member that slides along the axial direction of the drive shaft in conjunction with the operation of the operating member and rotates integrally with the first bevel gear, When the operation member is in the fixed position, the engagement member engages with the front wheel and rotates together with the first bevel gear together with the front wheel, so that the rotation ratio of the drive shaft and the front wheel becomes 1: 1. When the operating member is in the idling position, the engagement between the engaging member and the front wheel is disengaged, the front wheel is idling with respect to the drive shaft, and the operating member is in the shift position. It is preferable that the engaging member is configured to engage with a lower end of the handle frame so as to be unable to rotate together with the first bevel gear and to be in the deceleration state.

  Moreover, in this invention, the tricycle for infants provided with the said drive mechanism can be included.

Since the present invention is configured as described above, the fixed state in which the front wheel is rotated at a ratio of 1: 1 to the rotation of the drive shaft that the infant puts his / her foot on the pedal and rotates, and the front wheel has It is possible to arbitrarily select and switch between an idle state in which the drive shaft idles and a shift state in which the rotation ratio between the drive shaft and the front wheels changes.
Therefore, when the tricycle is run by pushing a hand barb or the like, the infant's foot placed on the pedal does not rotate with the running (rotation of the front wheel) by selecting the idling state. Also, in the unlikely event that an infant's foot comes off the pedal, the drive shaft (pedal shaft) does not rotate, so there is no possibility of an unexpected situation. As a result, in traveling with a hand-claw or the like, safety can be improved, for example, an infant can expect a safe and comfortable traveling with a foot on the pedal.

Further, when the infant travels by stepping on the pedal, either a fixed state or a shift state (for example, deceleration) can be selected in accordance with the infant's leg strength, road inclination, and the like. This makes it possible to expect a comfortable travel for the infant even when the infant travels by stepping on the pedal.
Also, since the switching mechanism is hardly exposed to the outside of the front wheel, there is no risk that an infant will be pinched by the switching mechanism, and the appearance is almost the same as a conventional tricycle, so the design is also similar to that of a normal tricycle. It can be kept unchanged.

  Further, in the present invention, as a transmission, a gear mechanism configured by combining two pairs of first to fourth bevel gears facing each other is adopted, so that it can be accommodated inside the front wheel of the tricycle. It can be made compact and can be manufactured at a low cost, and the drive shaft and the front wheels are fixed with moderate rigidity that does not cause damage even when a large load is applied to the drive shaft. Further, it is possible to provide an improved drive mechanism that can be switched to three stages of idling and speed change.

  Further, a gear mechanism configured by combining an engaging member that slides in the axial direction of the drive shaft in conjunction with the rotation operation of the operating member, and two pairs of first to fourth bevel gears that face each other. By adopting the combination, the above-described three-stage switching operation becomes simple, and a new infant tricycle with high commercial value can be provided.

Hereinafter, an infant tricycle equipped with a drive mechanism according to an embodiment of the present invention will be described with reference to the drawings as appropriate.
FIG. 1 is a perspective view showing an infant tricycle according to the present embodiment.

≪Configuration of infant tricycle≫
As shown in FIG. 1, the infant tricycle (hereinafter referred to as “tricycle”) A is rotatably provided with a handle frame 3 equipped with a front wheel 2 on the front side of the body frame 1. Has left and right rear wheels 4 so as to be freely rotatable.
The tricycle A includes a saddle 5 in the middle of the body frame 1, and a hand bar 6 behind the saddle 5.

Further, as shown in FIG. 2, the tricycle A is provided with a shaft support portion 8 at the lower end of the handle rod 7 on both sides of the handle frame 3 by fixing means such as a pin, and the shaft support portions 8 on the both sides. The drive shaft 9 is rotatably supported so as to penetrate both end portions thereof.
Then, at both ends of the drive shaft 9 protruding outward from the shaft support portions 8 on both sides, one end sides of the left and right pedal shafts 10 formed in a substantially L shape are respectively attached to be non-rotatable by nuts or the like. In addition, left and right pedals 11 are attached to the left and right pedal shafts 10, respectively.
As a result, the drive shaft 9 and the left and right pedal shafts 10 form a crank form, and by stepping on the left and right pedals 11, a rotational force for moving the tricycle A forward and backward is transmitted to the front wheels 2. It has become.

≪Configuration of front wheel≫
FIG. 2 is an enlarged vertical cross-sectional view of the front wheel at the fixed position, and FIGS. 3 and 4 are vertical side views of the front wheel with different cross-sectional positions.
As shown in FIG. 2, the front wheel 2 includes a wheel 12 having an internal hollow structure and a tire 13 formed of an elastic material such as rubber or synthetic resin attached to the outer periphery of the wheel 12. .
In the front wheel 2, the relationship between the drive shaft 9 and the wheel 12 (front wheel 2) is fixed (normal) shown in FIG. 2, idle (free) shown in FIG. A switching mechanism for selectively switching to each of the three positions (deceleration) is provided in the wheel 12.
Further, as shown in FIG. 2, the front wheel 2 is interposed between the drive shaft 9 and the wheel 12 (front wheel 2) and an engaging member 34 described later, so that the rotation of the drive shaft 9 and the wheel 12 is performed. A transmission for changing the ratio is provided inside the wheel 12.

  As shown in FIG. 2, the wheel 12 is formed into an internal hollow structure by fitting and combining a pair of wheel constituent bodies 12a and 12b divided into two in the width direction of the front wheel 2 in the circumferential direction. It is like that.

≪Configuration of wheel structure≫
FIG. 5 is a perspective view showing a pair of wheel components, and FIG. 6 is a side view of the wheel components as viewed from the inside. Here, description will be made with reference to FIGS. 1 and 2 as appropriate.
The pair of wheel structural bodies 12a and 12b is made of a molding material such as aluminum or synthetic resin, and has a predetermined diameter (rim diameter), as shown in FIG. It is formed in a substantially U-shape (substantially a saucer shape) in a longitudinal sectional view so as to fit and overlap each other.
And a pair of wheel structure 12a, 12b is the state mutually fitted by the relationship between inside and outside, and as shown to FIG. 5 and FIG. 6, in the screw hole 14 provided in the one wheel structure 12a side. On the other hand, it is formed so as to be united by screwing with a connecting screw (not shown) from the side of the screw insertion hole 15 provided on the other wheel constituent body 12b side.
Thus, a wheel 12 that is hollow inside and on which the tire 13 is mounted on the outer periphery is configured.

Of the pair of wheel components 12a and 12b, the wheel component 12a shown in FIG. 5A and FIG. 6A includes the large-diameter hole 16 in the shaft core.
As a result, as shown in FIG. 2, the one-side shaft support portion 8 that supports the drive shaft 9 is interposed between the opening edge of the large-diameter hole portion 16 and the inner surface of the wheel structure 12 a via the lubricating ring 17. In order to face the wheel 12 in a substantially flush state, it is incorporated into the shaft core of the wheel component 12a. Further, as shown in FIG. 2 and FIGS. 11 and 12 to be described later, the shaft support 8 is provided with a lock pin 18 protruding at an appropriate height from the inward end surface of the shaft support 8 facing the wheel 12. I have to.

  The lock pins 18 are provided, for example, at three locations spaced by an arc of 120 ° on the circumferential line of the inward end surface having the shaft insertion hole of the shaft support portion 8 as an axis. Accordingly, as shown in FIG. 12 to be described later, the engagement member 34 is pivoted by removably inserting (connecting) the lock pin 18 to the lock hole 40 provided in the engagement member 34 described later. The support 8 is locked (held) so as not to rotate.

  Further, the wheel structure 12a is opened in a substantially arc shape along a circumferential line having the large-diameter hole portion 16 as an axis so as to follow a ring shape (ring diameter) of an operation member 33 to be described later of the switching mechanism. The operation window hole 19 is provided. Thereby, as shown in FIG. 1 and FIG. 11 described later, an operation knob 35 described later of the operation member 33 can be exposed to the outside from the operation window hole 19.

  In addition, as shown in FIG. 5 and FIG. 6A, the wheel structure 12a has an equal interval of approximately 120 ° on the circumferential line with the large-diameter hole portion 16 as the inner axis inside the operation window hole 19. Protrusions 20 are provided at three places.

And the wheel structure 12b is provided with the shaft hole 21 in the axial center part, as shown to (b) of FIG. Thereby, as shown in FIG. 2, the drive shaft 9 is penetrated.
As shown in FIG. 5, the wheel structure 12 b includes a gear box 22 raised in a cylindrical shape along a circumferential line having a predetermined diameter with the shaft hole 21 as an axis. As a result, as shown in FIGS. 2 and 4, the second large-diameter bevel gear 43, which will be described later on the transmission, and the gears 46 and 46 that are rotatably supported by the shafts 46 and 46 perpendicular to the drive shaft 9, respectively. A pair of third and fourth small-diameter bevel gears 44 and 45, which will be described later, are installed inside the gear box 22 and incorporated therein.
As shown in FIGS. 5 and 6B, a pair of third and fourth small-diameter bevel gears 44 and 45 are respectively provided at two locations on the inner circumferential surface of the gear box 22 that are symmetrical with respect to the axis. Shaft locking grooves 23 and 23 for fitting and locking one ends of the shafts 46 and 46 for supporting are provided from the opening edge toward the bottom of the box.

Further, as shown in FIG. 6B, the wheel structure 12 b includes pin receiving portions 24 at two locations on the outer periphery of the gear box 22 that are opposite to each other in the axial symmetry around the gear box 22. .
The pin receiving portion 24 is formed by being raised in a cylindrical shape having a predetermined height from the inner surface of the wheel constituting body 12b. Accordingly, as shown in FIG. 2, the connecting pin for connecting to the engaging member 34 in a releasable engaging relationship with the connecting hole 41 described later of the engaging member 34 at the fixed (normal) position. 25 is formed so as to be incorporated in a state in which the spring 25 is always urged in a protruding direction by the spring 26.

Further, as shown in FIG. 5 and FIG. 6B, the wheel structural body 12 b is spaced at an interval of 120 ° on the circumferential line located outside the gear box 22 including the pin receiving portion 24. Spring receiving portions 27, 27, 27 are provided at the locations.
As shown in FIG. 2, the spring receiving portion 27 is formed in a cylindrical shape or a column shape with an outer diameter and a height enough to fit and fix the lower end side of the spring 28.
As a result, the biasing head 29 incorporated so as to constantly bias the operation member and the engagement member of the switching mechanism toward the inside of the wheel constituent body 12a is arranged inside the wheel constituent body 12b as shown in FIG. They can be arranged at intervals of 120 ° on the circumference.
That is, the spring receiving portion 27 is provided on the inner side of the wheel constituting body 12b on a circumferential line substantially the same as the ring diameter of the operation member.

Further, as shown in FIG. 5 and FIG. 6B, the wheel constituting body 12b is raised from the inside into a substantially T-shape in a positional relationship facing each other with the spring receiving portions 27 provided at the three positions. Each guide frame 30 is provided.
As a result, the biasing head 29 stably biases the operation member 33 and the engaging member 34 of the switching mechanism toward the inner side of the wheel constituting body 12a without causing shaft shake or the like.

≪Configuration of biasing head≫
FIG. 7 is a perspective view showing the biasing head. Here, description will be made with reference to FIGS. 2 and 4 as appropriate.
As shown in FIGS. 2 and 7, the urging head 29 is formed in a hollow cylindrical shape with one end closed in a spherical shape using a molding material such as aluminum or synthetic resin.
The urging head 29 includes guide frames 31 and 31 at two locations on the outer circumferential surface of the cylinder that are axially symmetric. As shown in FIGS. 4 and 7, the guide frames 31, 31 are formed in a substantially elongated block shape in two rows that are paired so as to sandwich the guide frame 30 and are directed from the opening edge of the urging head 29 in the cylindrical direction. Are formed respectively.
As a result, in cooperation with the guide frame 30 and the guide frame 31 of the urging head 29, centering of the urging head 29 is suppressed, and the urging head 29 (spring 28) moves inward of the wheel component 12 a. The operation member 33 and the engaging member 34 of the directing switching mechanism are constantly biased stably.

  Further, as shown in FIG. 7, the urging head 29 includes an engaging portion 32 on a cylindrical outer peripheral surface in a direction orthogonal to a line connecting the guide frames 31 and 31. As shown in FIGS. 2 and 7, the engaging portion 32 is urged at an interval of the thickness so as to sandwich an engaging flange portion 34 a to be described later of the engaging member 34 of the switching mechanism in the thickness direction. The head 29 is formed in a substantially elongated block shape at the vertical position in the cylinder direction.

  As shown in FIGS. 2 and 4, the urging head 29 formed in this way urges the engaging member toward the inner side of the wheel constituting body 12a in an engaging relationship with the engaging member. Thus, the operation member is incorporated so as to urge the operation member toward the inner side of the wheel structural body 12a in an abutting relationship.

≪Configuration of switching mechanism≫
FIG. 8 is a perspective view showing an operation member of the switching mechanism, and FIG. 9 is a perspective view and a cross-sectional view showing an engaging member of the switching mechanism. Here, description will be made with reference to FIGS. 1 to 4 as appropriate.
The switching mechanism is driven by the operation member 33 for switching the relationship between the drive shaft 9 and the front wheel 2 to each of the three positions of fixed, idle, and speed change, and the switching operation of the operation member 33 to each position. An engagement member 34 that slides along the axial direction of the shaft 9 and is rotatably mounted on the drive shaft 9 so as to rotate integrally with a first large-diameter bevel gear 42 described later of the transmission. It is configured with.

≪Configuration of operation member≫
As shown in FIG. 2 and FIG. 3, the operation member 33 is formed in a flat plate ring shape having an outer diameter that fits inside the wheel constituting body 12 a by using a molding material such as aluminum or synthetic resin.
As shown in FIG. 8, the operation member 33 has the operation boss 35 at one place on one side of the ring surface and the push cam portions 36 at three places equally spaced in the ring direction on the other side of the ring surface. I have.

  The operation knob 35 has an appropriate shape such as a square shape or a round shape corresponding to the opening width of the operation window hole 18 provided on the wheel structural body 12a side, and has a protruding height enough to face the outside from the operation window hole 18. Is formed.

As shown in FIG. 8, the push cam portion 36 rises from the ring surface to an appropriate height on one side of the operation member 33 in the ring direction in the ring direction, and is substantially the same as the link surface on the other side. In order to be flush with each other, they are formed stepwise and gradually in a substantially slope shape from the rising top side on one side.
As a result, when the operating boss 35 is moved to each of the fixed position, the idling position, and the shift position in the operating window hole 19 of the wheel structure 12a, the pushing cam portions 36 provided at the three positions allow The engaging member 34 is moved (slided) via the biasing head 29 to the respective portions in the axial direction of the drive shaft 9 where the respective positions shown in FIG. 2 and later-described FIGS. 11 and 12 are executed. To be able to.

  The pushing cam portion 36 includes an urging head 29 so that the operation member 33 does not rotate carelessly due to vibrations at the fixed position shown in FIG. 2 and the idle position shown in FIG. In order to hold the operation member 33 using the biasing force (the elastic force of the spring 28), a fixed position portion 36a that is recessed in accordance with the shape of the top surface of the biasing head 29 and an idling position portion 36b are provided. Each is provided. As shown in FIG. 11, the lower end of the slope of the push cam portion 36 that is flush with the ring surface of the operation member 33 is used as a shift position portion 36c.

Further, as shown in FIGS. 3 and 8, the operation member 33 includes rotation restricting portions 37 that project inward at three positions at equal intervals of 120 ° in the ring direction at the inner edge of the ring. .
As a result, the relationship between the drive shaft 9 and the wheel 12 (front wheel 2) is set to the three positions of fixed (normal), idling (free), and shifting (deceleration) shown in FIGS. 2, 11 and 12, respectively. When selectively switching, the operating rotation range of the operating member 33 when switching to the fixed position shown in FIG. 2 and the shift position shown in FIG. 12 is caused by the protrusion 20 as shown in FIGS. The rotation restriction portion 37 of the operation member 33 is restricted by being received.

≪Configuration of engaging member≫
As shown in FIGS. 2 and 3, the engaging member 34 is made of a molding material such as aluminum or synthetic resin. The engaging member 34 has an outer diameter that is about two smaller than the inner diameter of the ring of the operating member 33. The bevel gear 42 is formed in a substantially U-shape (substantially a saucer shape) in a longitudinal sectional view having a depth that can be slidably accommodated in the axial direction of the drive shaft 9.
In other words, the first large diameter is an inner diameter corresponding to the outer diameter of the engagement flange portion described later formed in the first large-diameter bevel gear 42 of the transmission that is rotatably mounted on the drive shaft 9. It is formed in a substantially U-shape in a longitudinal sectional view having a depth that can surround the bevel gear 42.
As shown in FIG. 9A, the engagement member 34 includes an engagement flange 34a on the outer periphery of the opening, and surrounds the peripheral wall from the engagement flange 34a to the back surface of the closed bottom. By forming the concave and convex shape at equal intervals in the direction, engagement recesses 38 extending from the opening edge to the closed bottom are provided at equal intervals on the inner peripheral surface.
Thereby, as shown in FIGS. 2 and 3 and FIGS. 11 and 12 to be described later, the large-diameter bevel gear 42 is slidable in the axial direction of the drive shaft 9 in the engagement member 34 and the drive shaft. 9 is fitted and accommodated so as to rotate together with the engaging member 34 in the rotational direction 9.

Further, a shaft hole 39 is provided in the center of the engaging member 34 so as to be pivotally supported with respect to the drive shaft 9, and a lock hole 40 is formed around the shaft hole 39. Are opened at three equally spaced locations.
The engaging member 34 is provided with connecting holes 41 at several places at equal intervals in the circumferential direction of the engaging flange 34a. As a result, when the operation member 33 is switched to the fixed position, the connecting pin 25 provided on the wheel constituting body 12 b side is detachably inserted into the connecting hole 41 by the spring 26. That is, the wheel 12 and the engaging member 34 are connected by the connecting pin 25 and rotate integrally.

≪Transmission configuration≫
FIG. 10 is a side view showing the first large-diameter bevel gear of the transmission housed in the engaging member. Here, description will be made with reference to FIGS. 2 and 4 as appropriate.
As shown in FIG. 2 and FIG. 4, the transmission is positioned in the gear box 22 provided inside the wheel structure 12b and the engaging member 34 of the switching mechanism in a mutually opposing relationship, respectively. Are configured by combining two pairs of first to fourth large and small bevel gears 42 to 45 equipped so as to face each other.
That is, of the pair of opposing first and second large-diameter bevel gears (hereinafter referred to as “a pair of large-diameter bevel gears”) 42 and 43, as shown in FIG. 42 is rotatably supported on the drive shaft 9, and the second large-diameter bevel gear 43 is supported on the drive shaft 9 so as to rotate integrally with the drive shaft 9. A pair of opposing third and fourth small-diameter bevel gears (hereinafter referred to as “a pair of small-diameter bevel gears”) 44 and 45 are rotatably supported on a shaft 46 orthogonal to the drive shaft 9. Therefore, the large and small bevel gears 42 to 45 are configured to rotate integrally with each other, positioned between two pairs of large and small bevel gears 42 to 45 facing each other from four directions.
As a result, the large-diameter bevel gear 43 that is pivotally supported by the drive shaft 9 via the connecting plate 47 rotates in unison with the rotational speed of the drive shaft 9, thereby meshing with the large-diameter bevel gear 43. The pair of small-diameter bevel gears 44 and 45 rotate, and the large-diameter bevel gear 42 meshed with the small-diameter bevel gears 44 and 45 is configured to rotate.

As shown in FIGS. 3 and 10, the large-diameter bevel gear 42 has engagement claw pieces 48 for engaging with the respective engagement recesses 38 provided on the inner peripheral surface of the engagement member 34. , The same as the interval in the circumferential direction of each engagement recess 38, and in the same shape, provided on the outer peripheral edge.
Accordingly, the large-diameter bevel gear 42 is incorporated and accommodated inside the engagement member 34 so as to be slidable (movable) in the axial direction of the drive shaft 9 and to rotate integrally with the engagement member 43.

As shown in FIG. 2, a shaft 46 that rotatably supports the pair of small-diameter bevel gears 44 and 45 includes a bearing member 49 that is loosely supported on the drive shaft 9 and a wheel structure. Between the shaft locking groove 23 provided inside the gear box 22b of 12b, it integrates rotatably in the direction orthogonal to the axial direction of the drive shaft 9.
As a result, the shaft 46 is provided with a pair of small-diameter bevel gears 44 and 45 so as to rotate integrally with each other, as shown in FIG. The pair of large-diameter bevel gears 42 and 43 are rotatably supported in the gear box 22 in a state in which they are engaged with the tooth portions at two circumferentially opposite ends.

[Explanation of functions of tricycle]
Next, a method of using the tricycle according to the present embodiment configured as described above will be briefly described.
FIG. 11 is an enlarged longitudinal sectional view showing the front wheels when in the idle (free) position, and FIG. 12 is an enlarged longitudinal sectional view showing the front wheels when in the shifting (deceleration) position. Here, a description will be given with reference to FIG.
First, as shown in FIG. 2, when the infant is in a fixed (normal) position where he / she steps on the pedal 11 himself / herself, the operation facing the outside through the operation window hole 19 of the wheel 12 as shown in FIG. By the turning operation of the operation member 33 in one direction by the knob 35, the engagement member 34 moves away from the wheel component 12a and approaches the wheel component 12b most against the urging force of the urging head 29. It moves to the axial direction of the drive shaft 9 so that it may carry out. That is, the tip of the urging head 29 hits the fixed position portion 36a.
In this state, when the infant steps on the pedal 11 to rotate the drive shaft 9, the drive shaft 9 rotates from the large-diameter bevel gear 43 rotating integrally with the drive shaft 9 via the pair of small-diameter bevel gears 44 and 45. The engagement member 34 that is transmitted to the large-diameter bevel gear 42 and rotates integrally with the large-diameter bevel gear 42 rotates. Then, the connecting pin 25 urged by the spring 26 in a state where it abuts against the engaging flange 34a of the engaging member 34 can be freely inserted into and removed from any of the connecting holes 41 provided in the engaging flange 34a. Is inserted.
Thereby, the drive shaft 9 and the wheel 12 are in a fixed state in which they are integrally connected by the two pairs of large and small bevel gears 42 to 45, the engaging member 34, and the connecting pin 25 that face each other. That is, the infant wheel is in a fixed state in which the front wheel 2 is rotated at a ratio of 1: 1 to the rotation of the drive shaft 9 that the infant puts his / her foot on the pedal 11 to rotate. The front wheel 2 is integrated with the drive shaft 9. It rotates and the infant's own tricycle A runs.

As shown in FIG. 11, when the pusher 6 is pushed and the tricycle A is in the idle (free) position, the engaging member 34 is urged by the turning operation of the operating member 33 by the operation knob 35. The head 29 is moved in the axial direction of the drive shaft 9 so as to return to the middle part on the wheel component 12a side by the urging force of the head 29. That is, the tip of the biasing head 29 hits the idling position portion 36b.
Then, the connection state of the engagement member 31 and the wheel 12 by the connection pin 25 and the connection hole 41 is released, and the front wheel 2 is idled with respect to the drive shaft 9, so that the drive shaft 9 is rotated even if the front wheel 2 rotates. Is an unrelated relationship that does not rotate. That is, the left and right pedals 11 attached to the both end portions of the drive shaft 9 via the pedal shaft 10 do not rotate. As a result, the pedal 11 is held with the infant on the foot, so that the infant can run comfortably. Even if the infant's foot is removed from the pedal 11, the drive shaft 9 is rotating. Because it does not lead to unexpected situations, safety is improved.

Furthermore, as shown in FIG. 12, when the infant travels while stepping on the pedal 11, when the infant is in the shift (deceleration) position, the engaging member 34 is moved by rotating the operation member 33 with the operation knob 35. The drive shaft 9 is moved in the axial direction so as to return to the portion that is brought into contact with the inside of the wheel constituting body 12a by the biasing force of the biasing head 29. That is, the tip of the urging head 29 hits the shift position portion 36c.
In this state, as described in detail in the case of the fixed position, when the infant steps on the pedal 11 and rotates the drive shaft 9, the engaging member 34 that rotates integrally with the large-diameter bevel gear 42 rotates. The lock pin 18 provided in the shaft support portion 8 is removably inserted (linked) into the lock hole 40 provided in the engagement flange portion 34a.
As a result, the engaging member 34 is locked (held) to the shaft support 8 so as not to rotate. That is, the large-diameter bevel gear 42 that is rotatably supported with respect to the drive shaft 9 is locked to the shaft support portion 8 through the engagement member 34 so as not to rotate, so that the drive shaft 9 rotates once. On the other hand, the wheel 12 (front wheel 2) is in a shift state in which the rotation ratio between the drive shaft 9 and the wheel 12 is reduced to 2 to 1 so that the wheel 12 rotates halfway.
That is, when the infant steps on the pedal 11 and rotates the drive shaft 9, only the three large and small bevel gears 43 to 45, the remaining large diameter bevel gear 43 and the pair of small diameter bevel gears 44 and 45, are included. Due to the rotation, rotation is transmitted from the drive shaft 9 to the wheel 12, so that the rotation ratio between the drive shaft 9 and the wheel 12 is reduced to 2: 1.
More specifically, the rotation of the drive shaft 9 when the infant steps on the pedal 11 from the large-diameter bevel gear 43 that rotates integrally with the rotational speed of the drive shaft 9 to the large-diameter bevel gear 43. 9 is transmitted to a pair of small-diameter bevel gears 44 and 45 that are meshed with each other at two opposite positions in a direction orthogonal to the direction 9. Then, the pair of small-diameter bevel gears 44 and 45 that are respectively engaged with the wheel 12 (gear box 22) via the shafts 46 and 46 are locked so as not to rotate while receiving the rotational force from the large-diameter bevel gear 43. The large-diameter bevel gear 42 moves so as to roll in the circumferential direction along the tooth group. As a result, the rotation of the drive shaft 9 is transmitted to the wheel 12 of the front wheel 2 after being decelerated to a rotation ratio of 2: 1.
Accordingly, either the deceleration state or the fixed state in which the front wheel 2 is rotated at a ratio of 1: 1 to the rotation of the drive shaft 9 is selected in accordance with the infant's leg strength, road inclination, and the like. Therefore, when the infant travels by stepping on the pedal 11, the infant can travel comfortably.

The specific configuration of the embodiment of the present invention is not limited to the above-described embodiment, and there are design changes and the like without departing from the gist of the present invention described in claims 1 to 5. Are also included in the present invention.
For example, the two pairs of first to fourth bevel gears that constitute the transmission that are opposed to each other are not limited to those of the large and small bevel gears as in the above-described embodiment, but are two pairs that are all the same diameter and are opposed to each other. It can be configured by combining the first to fourth bevel gears. That is, by making the number of teeth of a pair of first and second bevel gears on one side the same number and making the number of teeth of a pair of third and fourth bevel gears on the other side the same number, A shift state in which the rotation ratio of the front wheels 2 is decelerated with respect to the rotation of the drive shaft 9 can be achieved.

It is a perspective view which shows an example of embodiment of the tricycle for infants which concerns on this invention. It is a longitudinal cross-sectional view which expands and shows a front wheel when it exists in a fixed (normal) position. It is the III-III line vertical side view of FIG. It is the IV-IV line vertical side view of FIG. It is a perspective view which shows a pair of wheel structure body which comprises a wheel, respectively. (A) is a side view when one wheel structure 12a is seen from the inside, (b) is a side view when the other wheel structure 12b is seen from the inside. It is a perspective view which shows a biasing head. It is a perspective view which shows the operation member which comprises a switching mechanism. The engaging member which comprises a switching mechanism is shown, (a) is a perspective view, (b) is the longitudinal cross-sectional view. It is a side view when the 1st large diameter bevel gear which comprises a transmission is seen from back. It is a longitudinal cross-sectional view which expands and shows a front wheel when it exists in a free-wheeling (free) position. It is a longitudinal cross-sectional view which expands and shows the front wheel when it exists in a speed change (deceleration) position.

Explanation of symbols

A Tricycle 1 Body frame 2 Front wheel 3 Handle frame 4 Rear wheel 5 Saddle 6 Hand rod 7 Handle rod 8 Shaft support 9 Drive shaft 10 Pedal shaft 11 Pedal 12 Wheel 12a, 12b Wheel component 13 Tire 18 Lock pin 19 Operation window hole 25 Connecting pin 26, 28 Spring 29 Energizing head 33 Operating member (switching mechanism)
34 Engagement member (switching mechanism)
35 Operation knob 42, 43 Large diameter bevel gear (first and second bevel gears, transmission)
44, 45 Small-diameter bevel gear (third and fourth bevel gears, transmission)
46 axes

Claims (5)

A drive shaft that is rotatably supported at the lower end of the handle frame, and a pedal is attached to each end thereof; and
A front wheel with an internal hollow structure that is freely mounted on the drive shaft;
A switching mechanism housed in the front wheel and switching the relationship between the drive shaft and the front wheel to each of three positions of fixing, idling, and shifting,
The switching mechanism includes an operation member for switching to each position so as to face a side surface of the front wheel,
When the operation member is in the fixed position, the front wheel is fixed with respect to the drive shaft, and the rotation ratio between the drive shaft and the front wheel is 1: 1.
When the operating member is in the idling position, the front wheel is idling with respect to the drive shaft,
When the operation member is in the shift position, the transmission interposed between the drive shaft and the front wheels is configured to be in a shift state in which the rotation ratio between the drive shaft and the front wheels changes. A driving mechanism for a tricycle for infants. The transmission is configured by combining two pairs of first to fourth bevel gears that face each other.
Of the pair of first and second bevel gears on the opposite one side, the first bevel gear is rotatably supported by the drive shaft, and the second bevel gear rotates integrally with the drive shaft. Thus, the pair of third and fourth bevel gears on the other side are rotatably supported by shafts that are locked to the front wheels in a direction perpendicular to the driving shaft. By being located between the first to fourth bevel gears, the first to fourth bevel gears are meshed so as to rotate integrally,
When in the speed change state, the first bevel gear becomes non-rotatable, and the rotation of the remaining three second to fourth bevel gears reduces the rotation ratio of the front wheel to the rotation of the drive shaft. The drive mechanism for an infant tricycle according to claim 1, wherein the drive mechanism is configured as follows.   3. The drive mechanism for an infant tricycle according to claim 2, wherein when the speed change state is a deceleration state, a rotation ratio between the drive shaft and the front wheels is 2: 1. The switching mechanism is free to rotate with respect to the drive shaft, slides along the axial direction of the drive shaft in conjunction with the operation of the operation member, and rotates integrally with the first bevel gear. An engagement member,
When the operation member is in a fixed position, the engagement member engages with the front wheel and rotates together with the first bevel gear together with the front wheel, so that the rotation ratio of the drive shaft and the front wheel is 1: 1. become,
When the operating member is in the idling position, the engagement between the engaging member and the front wheel is released, and the front wheel is in an idling state with respect to the drive shaft.
When the operation member is in the shift position, the engagement member engages with the lower end of the handle frame and is unable to rotate together with the first bevel gear so that the deceleration state is established. The drive mechanism of the tricycle for infants of Claim 2 or Claim 3 characterized by these.   An infant tricycle comprising the drive mechanism according to any one of claims 1 to 4.

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