stroller
The stroller's three-dimensional folding mechanism with a gear system ensures compact storage by synchronizing wheel support leg rotations, addressing the limitations of traditional one- or two-dimensional folding.
Patent Information
- Application Number
- JP2021538937
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2018-12-21
- Filing Date
- 2019-09-18
- Publication Date
- 2025-01-29
- Estimated Expiration
- 2039-09-18
AI Technical Summary
Existing strollers are typically folded into one or two dimensions, limiting their compactness and ease of transportation.
A stroller design with a central body that allows for three-dimensional folding, utilizing a gear system to connect forward and rear wheel support legs, enabling synchronized rotation in opposite directions for compact folding without sliding bars or turning components.
The stroller achieves a more compact folded state, enhancing ease of storage and transportation by eliminating the need for complex folding mechanisms that can trap fingers or objects, while maintaining structural integrity.
Smart Images

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Abstract
Description
[Technical field]
[0001] The present invention relates to a stroller, and more particularly to a stroller having an improved folding mechanism. [Background technology]
[0002] Strollers for carrying small children are well known, and modern strollers can also be used and adapted for carrying infants. In this application, the term stroller is intended to include what are also commonly referred to as baby carriages or buggies, and is also intended to describe a system comprising a chassis to which a seat or a removable cot or other enclosure suitable for carrying an infant or small child can be added. One desirable feature of a stroller is that it can be folded into a compact size, making it easy to transport and store in a car or other means of transport, such as a bus, train or airplane.
[0003] Many strollers are known to fold into smaller dimensions for storage, and in most cases only fold into smaller dimensions in one or two dimensions. Many examples can be found in stores and in general use.
[0004] No. 5,399,633 describes a foldable type of stroller, in this case one which can be folded into a backpack. The front legs are also foldable to help reduce the overall size.
[0005] US Patent No. 5,399,663 (Mocking) describes an arrangement having a combination of rods connected to a main support structure to provide support, the rods being slidably connected to supports to ensure the correct relationship between the support rods. [Prior art documents] [Patent documents]
[0006] [Patent Document 1] US Patent Application Publication No. 2014 / 0312599 [Patent Document 2] German Patent Application Publication No. 3147657(A) Summary of the Invention [Problem to be solved by the invention]
[0007] A drawback of known strollers is that they usually only fold and shrink in one or at most two dimensions. It is an object of the present invention to overcome at least some of the drawbacks of the known prior art by providing a stroller that folds to be smaller in all three dimensions. [Means for solving the problem]
[0008] According to a first aspect of the present invention, there is provided a foldable stroller comprising a central body assembly extending across the stroller substantially horizontally and perpendicular to the normal direction of travel of the stroller, a handle assembly connected to and extending from the central body, and at least three wheel support legs rotatable around and extending from the central body, wherein in an unfolded state, one or more of the wheel support legs extend in a forward direction from the central body and one or more of the wheel support legs extend in a rearward direction from the central body, the forward and rearward extending legs being coupled to each other to rotate in opposite directions around the central body during a folding or unfolding operation.
[0009] It is known that with many strollers, the folding action can be complicated and requires careful manipulation of various components. The present invention provides a means to ensure that components, including the wheel support legs, fold and unfold easily and smoothly.
[0010] According to another aspect of the invention, a stroller is provided with at least one forward extending leg and at least one rearward extending leg connected to one another by a gear system.
[0011] In accordance with another aspect of the present invention, in a stroller, a gear system connecting the forward extending legs and the rearward extending legs includes a main shaft, a counter shaft, and an idler shaft, all of which have spur gears mounted thereon.
[0012] According to another aspect of the invention, in the stroller, the gear system connecting the forward extending legs and the rearward extending legs includes a planetary gear system.
[0013] A particular advantage of using a gear system to connect the forward and rearward extending wheel support legs is that it allows for controlled and smooth rotation of the wheel support legs, avoiding the need for sliding bars and other supports in which the user's fingers, clothing or other objects may become caught or entangled, in addition providing a neater and more compact design than is often found elsewhere.
[0014] In accordance with another aspect of the invention, the stroller further comprises a shaft extending through the central body assembly, the longitudinal axis of the shaft being coincident with the axis extending through the central body assembly, and forward and rearward extending wheel support legs attached to the shaft.
[0015] According to another aspect of the invention, the stroller further comprises either two forward extending legs or two rearward extending legs, each of either the forward extending legs or the rearward extending legs being attached to the shaft such that the plane of rotation of the leg about the axis is not perpendicular to the axis of the shaft and such that in the folded state the ends of the wheel support legs are closer to each other than in the unfolded state.
[0016] By mounting the wheel support legs attached to the shaft in a manner that ensures that they do not rotate in a plane perpendicular to the longitudinal axis of the shaft, but rotate at an angle relative to it, the rearwardly extending legs or forwardly extending legs can be rotated into a folded position to have a smaller distance from each other than in the unfolded state, thereby providing a stroller that folds more compactly in all three dimensions than other known products.
[0017] According to another aspect of the invention, the stroller is provided with either two forward extending legs or two rearward extending legs fixedly mounted to a shaft rotatable about an axis and adapted to rotate together in the same direction, and the other of the rearward extending legs or the forward extending legs is mounted to a second shaft coaxial with the shaft, the shaft and the second shaft being connected by gear means such that the forward extending legs and the rearward extending legs rotate in opposite directions during folding or unfolding operations.
[0018] According to another aspect of the invention, a stroller according to any preceding claim has two forward extending legs and two rearward extending legs.
[0019] According to another aspect of the invention, in a stroller, a shaft is articulated at a central region of a central body assembly, and each arm of the shaft extends from the central region of the central body assembly to an outer portion of the central body assembly and is inclined relative to the horizontal to form a "V" shape, with each arm supporting one forward extending leg and one rearward extending leg.
[0020] By using an articulated shaft having an articulated "V" shape in the central region of the central body assembly, the shafts can be articulated and the wheel support legs can be attached to the shafts in a manner that results in a more compact configuration when folded than conventional arrangements.
[0021] According to another aspect of the invention, the stroller is provided with an articulated shaft, the articulation between the two parts of the shaft being either by a universal joint, or a gear system, or an elastomeric connector or a woven metal mesh of tubular construction (tubular structure) fixed to each shaft.
[0022] In accordance with another aspect of the invention, the stroller has a gear system attached to at least one of the arms of the shaft toward the distal end from the articulation connection.
[0023] The present invention will now be described with reference to the accompanying drawings. [Brief description of the drawings]
[0024] [Figure 1a] FIG. 1 shows a stroller assembly according to the present invention in an unfolded state. [Figure 1b] FIG. 1 shows a stroller assembly according to the present invention in an unfolded state. [Figure 1c] FIG. 1 shows a stroller assembly according to the present invention in an unfolded state. [Figure 1d] FIG. 1 shows a stroller assembly according to the present invention in an unfolded state. [Diagram 2] FIG. 13 shows the wheels and central folding axle assembly in an unfolded state. [Figure 3a] FIG. 2 illustrates how the stroller folds around the central axis. [Figure 3b] FIG. 2 illustrates how the stroller folds around the central axis. [Figure 4a] FIG. 2 is a perspective view of the folded stroller. [Figure 4b] FIG. 2 is a plan view of the folded stroller. [Figure 4c] FIG. 1 is a front view showing the chassis of the stroller in an unfolded state; [Figure 4d] FIG. 2 is a plan view showing the folded chassis. [Diagram 5]FIG. 13 shows the gearing used in the stroller to ensure the assembly folds. [Figure 5a] 13A-13C show different means by which a pair of shafts extending along a central axis can be coupled together. [Figure 6] FIG. 6 is a more detailed view of the gear train of FIG. [Figure 7a] FIG. 13 shows an alternative gearing for the folding mechanism. [Figure 7b] FIG. 13 shows an alternative gearing for the folding mechanism. [Figure 7c] FIG. 13 shows an alternative gearing for the folding mechanism. [Figure 8] FIG. 1 shows an example of a stroller that uses only three legs and wheels. [Figure 9a] 9 shows an alternative arrangement of the chassis of the stroller of FIG. 8. FIG. [Figure 9b] 9 shows an alternative arrangement of the chassis of the stroller of FIG. 8. FIG. [Figure 9c] 9 shows an alternative arrangement of the chassis of the stroller of FIG. 8. FIG. [Figure 10] FIG. 10 shows the chassis of FIG. 9 folded into a compact folded position. [Figure 11] FIG. 10 is a plan view showing the chassis of FIG. [Figure 12a] 13A-13D show the arrangement for the folding handle assembly of the present invention. [Figure 12b] 13A-13D show the arrangement for the folding handle assembly of the present invention. [Figure 12c] 13A-13D show the arrangement for the folding handle assembly of the present invention. [Figure 13] 13A-13D show arrangements with a linear chassis and a stroller chassis having three wheels. [Figure 14] FIG. 14 shows a folded version of the three-wheel linear chassis of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The invention will now be explained in more detail with reference to the drawings, in which:
[0026] Figure 1a shows a stroller according to the invention in an unfolded state. Figure 1b shows the backrest of the seat portion in a semi-reclined position. Figures 1c and 1d show different side views of the stroller. The stroller 10 comprises a central chassis assembly 12, forward and rearward extending legs 14 and 16, and a handle 26, all attached to the central chassis assembly 12. The forward and rearward extending legs are rotatable about an axis 12a passing through the central chassis assembly. A seat assembly 28 is attached to the handle 26 by a seat attachment means 30. As can be seen, the seat is normally in a substantially upright position, but can be at least partially reclined, as shown in Figure 1b.
[0027] 2 shows central chassis assembly 12, which can be clearly seen to be in the shape of a "V" extending across the chassis in a direction substantially perpendicular to the normal direction of travel. A forward extending leg 14 and a rearward extending leg 16 extend from a first arm of the V, and a second forward extending leg 14 and a second rearward extending leg 16 extend from a second arm of the V. For convenience and to help ensure clarity of the drawings, a handle portion is not shown here, which includes a handle 26 that would be attached to each arm of the V of central chassis assembly 12 to facilitate pushing and maneuvering the stroller.
[0028] At the end of the forward extending leg 14 is a front wheel assembly 18, and at the end of the rear extending leg 16 is a rear wheel assembly 20. The rear wheel assembly is typically positioned to allow the rear wheel 24 to rotate about a substantially horizontal axis. The front wheel assembly 18 includes a front wheel 22 that is typically capable of rotating about a horizontal axis, and the front wheel 22 is additionally positioned to be capable of rotating about a substantially vertical axis, i.e., providing a potential steering function to enhance the maneuverability of the stroller.
[0029] A particular advantage of mounting the wheel support legs to the V-shaped chassis is that it facilitates folding the stroller assembly into a smaller volume than may be possible with other known arrangements without compromising the strength or usefulness of the unfolded stroller. More specifically, it allows the stroller of the present invention to be folded such that when folded it is smaller in all three dimensions than in the unfolded state, thereby allowing it to be stored or transported more easily than similar designs in which the central chassis extends only in a straight line.
[0030] Figure 3a shows one arm of the V-shaped central chassis with the forward extending leg 14 and the rearward extending leg 16 in an unfolded position. Figure 3b shows how the two legs can rotate about axis 12a and fold down to form a compact folded configuration.
[0031] Fig. 4a shows a perspective view of the folded stroller, which as can be seen has particularly compact dimensions. Fig. 4b shows a plan view of the folded stroller. Fig. 4c shows a front view of the stroller chassis in an unfolded state, and Fig. 4d shows a plan view of the folded stroller chassis. As can be seen from the dotted lines extending from the outer tracks of the rear wheels in Fig. 4c to Fig. 4d, in the folded state the width of the folded stroller is significantly smaller than in the unfolded state. The forward extension leg 14 and the rear extension leg 16 are mounted on bearing means which enable them to rotate about an axis 12a to move between a folded position and an unfolded position which will be described in more detail below.
[0032] To ensure that the stroller folds neatly and consistently, the front and rear extending legs 14, 16 are connected to each other by gear means which ensures that they rotate in sync.
[0033] In other known foldable strollers, the folding assemblies and mechanisms rely on wheel support legs and other support or cross-bracing arms connected together by linkages engaged by pivotable and / or slidable connections to maintain the relative positions between the various arms and legs. Such complex connections between the arms and legs require careful movement, and users find that their fingers or other objects can become pinched or caught in the sliding or pivoting components. This is at the very least inconvenient, and even worse, can be painful and cause injury if the pinched item is a finger or other part of the user's body. A particular advantage of the present invention is that the folding mechanism does not use or rely on one or more sliding arms or pivoting components to assist in folding the front or rear extending legs, and such sliding arrangements are not required to maintain the strength and structural integrity of the stroller according to the present invention.
[0034] FIG. 5 shows an enlarged view of the gearing used in the stroller to ensure the folding or unfolding action of the stroller. In this particular drawing, the device comprises a planetary gear assembly, the detailed construction and operation of which is described below. The drawing shows an arrangement on one arm of a V-shaped chassis, the same type of arrangement can be used on the other arm, but is not shown for the sake of simplicity. Each arm of the chassis defines an axis of rotation 12a for the forward and rearward extending legs 14 and 16. A shaft 50 extends along the axis 12a. The shaft 50 is connected to a corresponding shaft on the other arm of the V by a universal joint or universal swivel coupling 52. A universal swivel coupling is a convenient and well-known means of coupling two shafts in the arms of the chassis, although other means may be used and envisaged. FIG. 5a shows the replacement of the swivel joint by a simple pair of bevel gears 51, each attached to one of the shafts 50, which engage to ensure the coupled rotation of the shafts. Further examples of couplings could be either flexible elastomeric material, devices of similar construction to automotive constant velocity joints, or tubes of woven metal mesh capable of transmitting torque. The forward extending leg 14 has a hub portion 54 that includes the end of the leg and is rotatably mounted on a shaft 50 that extends through the central chassis 12. The hub 54 is provided with internal spur gear teeth 58 that form an annular portion of the gear assembly. An internal chassis 60 is rotatably mounted on the shaft 50. Planetary gears 62 are mounted on the internal chassis to engage with the spur gear teeth 58 on the annular portion. The rearward extending leg 16 also has a hub portion 56 where the rearward extending leg 16 is mounted on the shaft 50 of the chassis 12. The hub portion 56 is provided with a set of outwardly directed spur gear teeth 64 that form a sun portion of the gear train that engages with the planetary gears 62. The inner chassis 60 includes a tongue 61 that extends from the inner chassis 60 in a plane substantially parallel to the axis 12a and which engages slots 63, 65 in the hubs 54 and 56, respectively, to limit rotation of the inner chassis relative to the hubs.
[0035] When assembled, it will be apparent that when the stroller is folded, the forward and rearward extending legs are connected by a planetary gear train so that the two legs rotate in opposite directions when the stroller is folded or unfolded. A cover unit 66 is provided on the end shaft 50 to protect the gear assembly. Preferably, the cover unit also provides a hub for mounting the handle 26 (not shown) extending therefrom.
[0036] Further improvement to the stroller is provided by the addition of a spring 68, which may be used to assist in folding or unfolding the stroller, depending on the configuration selected. In this embodiment, the spring shown is a coil spring, with the central axis of the coil parallel to axis 12a, if not coaxial therewith. The spring 68 has ends or arms 70, 72, each of which extends tangentially away from the central axis of the coil to provide a stabilizing or attachment arm. One of the arms 70 engages a retaining stop 74 in the hub 56, while the other arm 72 engages within a retaining slot or hole 76 in the cover assembly 66.
[0037] FIG. 6 shows a close-up view of a partially assembled planetary gear assembly, in which an inner chassis 60 sits inside the hub 54 and the planetary gears 62 engage the annulus gears 58.
[0038] An alternative form of gear assembly is shown in Figures 7a-7c.
[0039] FIG. 7a shows a cross-sectional view of an assembly using an alternative gearing with a main shaft and counter shaft arrangement. These types of gear systems are commonly found in many applications, such as automotive transmissions or gear boxes. In this case, a main shaft 80 extends along a line defined by the central axis 12a. A spur gear 82 is attached to the main shaft 80 and is fixed to or forms an integral part of the hub portion 54 of the forward extension leg 14. The spur gear 82 engages a counter shaft gear 84 that is attached to a counter shaft 86 (also known as a lay shaft) supported in a counter shaft chassis 88. The counter shaft 86 is supported by and extends through the chassis 88 and includes a second counter shaft spur gear 90 that engages an idler gear 92 on an idler shaft (not shown separately). The idler shaft is also supported in the counter shaft chassis. A second idler gear 93 is also attached to the idler shaft and engages a second spur gear 94 connected to the hub 56 of the rearward extension leg 16. With this arrangement, rotation of the forward extension leg 14 causes the countershaft gear 84 to rotate about its axis in the opposite direction to the rotating leg. This motion is transmitted through the countershaft and any gears attached thereto to idler gears 92 and 93, which are caused to rotate in the opposite direction. Idler gear 93 engages a second spur gear 94 in the hub 56 of the rearward extension leg 16, and is therefore caused to rotate in the opposite direction to that of the idler gear. Using this transmission system, rotation of one wheel support leg in one direction causes the other wheel support leg to rotate in the opposite direction.
[0040] Advantageously, the forward and rearward extending legs are on the same axis, thus providing a very compact arrangement of the chassis when folded.
[0041] For purposes of construction, whether the main shaft is connected to the hub of the forward or rearward extending leg, and which gear is connected to the idler gear, is a matter of convenience and preference of the builder, the operation and results will be the same.
[0042] Figure 7b shows this operation on a larger scale in more detail.
[0043] Figure 7c shows the design without the supporting chassis 88. In this case, the countershaft 86 and the second countershaft gear 90 can be clearly seen. The idler gears 92 and 93 and their arrangement relative to the shafts can be clearly seen.
[0044] To ensure that both the forward-extending legs and both the rear-extending legs on either side of the stroller rotate in the same direction at the same speed, shaft 50 (or shaft 80) extends through a central region of the chassis and either both the forward-extending legs are fixedly attached to the shaft and the rear-extending legs are rotatably attached to the shaft and driven by a gear system to rotate in the opposite direction to the forward-extending legs, or the rear-extending legs are fixedly attached to the shaft and the front-extending legs are rotatably attached to the shaft and driven by a gear system to rotate in the opposite direction to the rear-extending legs.
[0045] The concept of a single central chassis with forward and rearward extending legs can also be applied to a three wheel stroller design as shown in Figure 8. In this example embodiment, the stroller has one forward extending leg and two rearward extending legs. Other components have the same numbers as used in the previous description.
[0046] Figure 9a shows an example of the three wheel chassis alone, without the handle and seat attachment means, and Figure 10 shows the three wheel stroller chassis in a partially folded position.
[0047] 9b and 9c show alternative means of connecting the shafts 50 together so that both shafts 50 rotate simultaneously in the same direction. FIG. 9b shows an alternative gear system including a separate support chassis 130. A bevel gear at the end of each shaft 50 engages a bevel idler gear 132 mounted on an idler shaft 134 in the support chassis. This arrangement would be particularly suitable if a three-wheel design is selected. In the case of a three-wheel design, the central wheel support leg may be mounted on the idler shaft 134 in the support chassis 132. FIG. 9c shows a perspective view of FIG. 9b. For clarity, the central wheel support leg and wheel assembly are not shown. As will be apparent from the drawing, the central wheel support leg may be mounted on the shaft 134 to rotate with the shaft. This configuration would ensure that the central wheel support leg rotates in the opposite direction to the rearward extension leg 16.
[0048] FIG. 10 shows a perspective side view of the folded configuration of the three-wheel design.
[0049] FIG. 11 shows a top view of the folded arrangement of the three-wheel design.
[0050] Figures 12a-c show an overall view of the handle assembly. From these figures it can be seen that the handle assembly is provided with a number of articulation points which allow it to be folded to a more compact size, in particular to a narrower width, than the unfolded stroller. Figure 12a shows the handle in a fully extended position. Figure 12b shows an intermediate folded position and Figure 12c shows a second intermediate folded position.
[0051] In Fig. 12a, it can be seen that the articulation 150 extends to allow the handle to extend across the top of the stroller and to maintain the handle in a generally open position. In Fig. 12b, it can be seen that the articulation rotates the handle into a more compact arrangement when the side handle parts 154 are rotated inward as shown in the drawing. In addition, the height of the handle can be reduced. The upper handle arm 156 is arranged to telescope with the lower handle arm 158, i.e., the upper part 156 will slide into the lower part 158 during the folding process. The reverse action occurs during unfolding. Several different detailed schemes can be envisaged for the arrangement for the upper and lower parts to slidably cooperate to reduce the height of the handle assembly and to latch it into place in either or both of the upper and lower positions.
[0052] A latch arrangement may be incorporated into the handle assembly to ensure that the handle assembly remains in the folded or deployed state.
[0053] FIG. 13 shows another alternative embodiment in which the V-shaped chassis is replaced by a linear chassis with a single linear axis. This allows the gear system to be simpler for the three-legged variant and allows the use of straight shafts, thus avoiding the need for a universal swivel coupling in the chassis. In this illustration, the handle and seat assembly are not shown for convenience, but can be attached as shown in the other embodiments. Although the drawings show only a three-wheeled chassis, it will be readily apparent that this can be easily adapted to a four-wheeled design. Each of the forward-extending legs is attached to one of a pair of coaxial shafts, and the rearward-extending legs to the other of the coaxial shafts, which are connected to each other by a gear mechanism of the type described above to ensure that the legs rotate in opposite directions during folding and unfolding operations. This arrangement is particularly suited to planetary-type gear systems, which allows a particularly compact design to be employed.
[0054] FIG. 14 shows the chassis of FIG. 13 folded to a compact dimension. To ensure a compact dimension of the folded stroller, the rearwardly extending legs may be attached to the chassis such that the plane of rotation of the legs is not perpendicular to the axis of the central axle 12a. When attached in this manner, the legs do not extend perpendicularly from the axle 12, but rather splay outward at an angle to the axle 12, so that, as can be seen in FIG. 13, the track distance between the wheels in the extended position is greater than the distance between the wheels when folded. As can be seen in FIG. 14, when the legs are rotated and folded, the folded dimension of the stroller is more compact than in the unfolded state.
[0055] In a straight center chassis embodiment, no universal coupling or other means is required to connect each arm of the "V." Thus, a single main shaft extending across the width of the chassis can be used, with both forward-extending legs fixedly attached to the main shaft, or both rearward-extending legs fixedly attached to the main shaft, with the other of the two legs rotatably driven by the gear system described above to rotate in the opposite direction.
[0056] In a further alternative embodiment of the invention, it may be possible to have only one set of gears located on a portion of the chassis and connected to the legs, with rotation of each of the legs being achieved by coupling each of two coaxial shafts to the appropriate wheel support leg.
[0057] It may also be desirable for the handle assembly to be capable of folding to a width narrower than the stroller so that the stroller can be folded in three dimensions.
Claims
1. A foldable stroller defining a central axis extending substantially perpendicular to a normal direction of travel of the stroller, the stroller comprising: a central body assembly extending across the stroller; and a handle assembly connected to and extending from the central body assembly. and at least three wheel support legs extending from the central body assembly and rotatable about the central axis, wherein in a deployed state, one or more wheel support legs extend in a forward direction from the central body assembly and one or more wheel support legs extend in a rearward direction from the central body assembly; A stroller, wherein the forward extending legs and the rearward extending legs are coupled to each other so as to rotate in opposite directions about the central axis during a folding operation, or the forward extending legs and the rearward extending legs are coupled to each other so as to rotate in opposite directions about the central axis during an unfolding operation.
2. 10. The stroller of claim 1, wherein the front and rear extension legs are connected to one another by a gear system.
3. 3. The stroller of claim 2, wherein the gear system comprises spur gears attached to a main shaft, a counter shaft, and an idler gear shaft.
4. The stroller of claim 2 , wherein the gear system comprises a planetary gear system.
5. 5. A stroller as claimed in any one of claims 1 to 4, in which there are two rearwardly extending wheel support legs.
6. 6. The stroller of claim 5, wherein the rearwardly extending legs are attached to the central axis such that a plane of rotation about the central axis is not perpendicular to the central axis and such that in the folded state, the distal ends of the wheel support legs are closer together than in the unfolded state.
7. 6. The stroller of claim 5, wherein the forwardly extending legs are attached to the central axis such that a plane of rotation about the central axis is not perpendicular to the central axis and such that in the folded state, the distal ends of the wheel support legs are closer together than in the unfolded state.
8. A stroller as described in any one of claims 1 to 5, having either two forward extending legs or two rearward extending legs fixedly attached to a main shaft rotatable about the central axis, the two forward extending legs or two rearward extending legs attached to the main shaft rotate together in the same direction, and the other of the rearward extending legs or forward extending legs is attached to a second shaft coaxial with the main shaft, and the main shaft and the second shaft are connected by gear means such that the forward extending legs and rearward extending legs rotate in opposite directions during folding or unfolding operations.
9. 9. A stroller as claimed in any one of the preceding claims, having two forward extending legs and two rearward extending legs.
10. 2. The stroller of claim 1, wherein the central shaft is "V" shaped, each arm of the V comprising a shaft supporting one forward extending leg and one rearward extending leg, and wherein two of the shafts of the arms of the V are coupled together.
11. 11. The stroller of claim 10, wherein the shaft is articulated at a central region of the central body assembly, and each arm of the shaft extends from the central region of the central body assembly to an outer portion of the central body assembly, forming a "V" shape, and each arm supports one forward extending leg and one rearward extending leg.
12. 12. The stroller of claim 11, wherein the shafts are connected by universal joints.
13. 12. The stroller of claim 11, wherein the shafts are connected by a gear system.
14. 12. The stroller of claim 11, wherein the shafts are connected by elastomeric connectors secured to each shaft.
15. 12. The stroller of claim 11, wherein the shafts are connected by a woven metal mesh of tubular configuration secured to each shaft.
16. 16. The stroller of any one of claims 1 to 15, wherein the one or more forward extending legs and the one or more rearward extending legs are connected to one another so as to rotate in opposite directions about the central body assembly during folding of the stroller into a closed position adjacent the handle assembly.
17. 17. The stroller of claim 16, wherein when in the open position, the wheels are positioned to engage the ground surface and the one or more forward extending legs and the one or more rearward extending legs are coupled together to rotate upwardly and away from the ground surface to the closed position.
Citation Information
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