Stroller With Shock Absorbing Device for Mounting a Seat Member on a Stroller Frame

1. Field of the Invention

The invention relates to a stroller, more particularly to a stroller with a shock absorbing device for mounting a seat member on a stroller frame.

2. Description of the Related Art

A conventional stroller includes a stroller frame and a seat member on the stroller frame. The stroller frame has a bottom end provided with casters, and includes a handle unit for pushing the stroller frame. Brake devices, direction guiding devices and devices for guarding against untimely folding of the strollers are usually installed to ensure safety of a child seated on the stroller. It is noted that movement of the stroller along a rough surface can cause discomfort to the child on the stroller. Therefore, some strollers have front casters which incorporate a shock absorbing device to reduce the vibrations that result when the stroller is in motion. However, the vibrations experienced by the stroller do not come entirely from the front casters. Thus, the shock absorbing effect in such conventional strollers is severely limited.

The seat member may be formed as an integral part of the stroller frame. Alternatively, the seat member may be formed as a separate device which is mounted securely on the stroller frame. Thus, the seat member cannot be conveniently disassembled from the stroller frame of the conventional stroller for cleaning purposes.

Most strollers are seldom used when the wind is blowing in a direction facing the child on the conventional stroller to prevent the child from catching a cold. This is due to the drawback that the seat member cannot be turned relative to the stroller frame to shield the child from the wind since the seat member is mounted securely on the stroller frame. However, there is a stroller frame with a modified handle unit which can be pivoted so as to extend forwardly or rearwardly according to the wind direction in order to shield the child from the wind. Unfortunately, a change in the direction of the handle unit results in a change in the positions of the front and rear casters on the stroller frame. This results in ineffective operation of the direction guiding devices on the front casters and in inconvenient operation of the latch mechanisms on the rear casters.

Therefore, the object of the present invention is to provide a stroller with a shock absorbing device that is capable of effectively absorbing shock when the stroller is in motion.

More particularly, the object of the present invention is to provide a stroller with a shock absorbing device which mounts a seat member on a stroller frame so as to effectively absorb shock when the stroller is in motion.

Another object of the present invention is to provide a stroller with a detachable seat member which can be conveniently mounted on the stroller frame in either of two opposing directions.

According to the present invention, a stroller includes a wheeled stroller frame with a handle unit for pushing the stroller frame, and a seat member mounted on the stroller frame. The stroller frame has a pair of horizontal linking plates on two sides of the seat member. A shock absorbing device includes a frame unit disposed between the linking plates and mounted swingably on the linking plates, and a spring unit. The frame unit is movable relative to the linking plates in a first direction, wherein the frame unit swings forwardly and downwardly, and in a second direction, wherein the frame unit swings rearwardly and upwardly. The spring unit interconnects the frame unit and the linking plates and biases the frame unit in the second direction. The seat member has a seat portion with a bottom side that is provided with a mounting unit for mounting the seat member on the frame unit of the shock absorbing device.

The frame unit includes parallel front and rear rod members which extend between the linking plates. Each of the front and rear rod members has a pair of bent leg portions connected pivotally and respectively to the linking plates. The frame unit further includes two side plate members, each of which has two ends connected respectively to the front and rear rod members.

The spring unit includes two extension springs, each of which has a first end connected to a respective one of the linking plates and a second end connected to the front rod member of the frame unit.

Preferably, the mounting unit on the seat portion of the seat member mounts detachably the seat member on the frame unit, and includes at least one hook unit for engaging one of the front and rear rod members of the frame unit. The mounting unit further includes a spring-loaded retaining device for engaging releasably the other one of the front and rear rod members of the frame unit.

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:

FIG. 1 is a partly exploded, perspective view of the first preferred embodiment of a stroller according to the present invention;

FIG. 2 is a partly exploded, schematic view of the first preferred embodiment;

FIG. 3 is a perspective view of a shock absorbing device of the first preferred embodiment;

FIG. 4 is a schematic view which illustrates the assembly of the shock absorbing device;

FIG. 5 is an exploded view of a spring-loaded retaining device of the first preferred embodiment;

FIG. 6 is a partly sectional, schematic view of the retaining device when in an engaging state;

FIG. 7 is a partly sectional, schematic view of the retaining device, taken along line VII--VII in FIG. 6;

FIG. 8 is a partly sectional, schematic view of the retaining device when in a disengaging state;

FIG. 9 is a partly sectional, schematic view of the retaining device, taken along line IX--IX in FIG. 8;

FIG. 10 is a schematic view which illustrates the operation of the shock absorbing device when the stroller is in motion;

FIG. 11 is a schematic view of the second preferred embodiment of a stroller according to the present invention; and

FIG. 12 is a schematic view of the third preferred embodiment of a stroller according to the present invention.

Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.

Referring to FIGS. 1 and 2, the first preferred embodiment of a stroller according to the present invention is shown to comprise a stroller frame 1, a seat member 3, and a shock absorbing device 2 for mounting the seat member 3 on the stroller frame 1.

The stroller frame 1 is foldable and is generally similar to that disclosed in U.S. Pat. No. 5,417,450 by the applicant. The stroller frame 1 includes two front support members 11, two rear support members 13, and two connectors 12, each of which connects pivotally one of the front support members 11 to one of the rear support members 13. Front and rear axles 111, 131 extend between the front and rear support members 11, 13, respectively. A caster 14 is mounted rotatably on each end of the front and rear axles 111, 131. Each of two pivot shafts 16 has a bottom end provided with a slide piece 15 which straddles a respective one of the rear support members 13. Each of two horizontal linking plates 17 has a first end connected to one of the pivot shafts 16 and a second end connected to the top end of one of the rear support members 13. The seat member 3 is to be disposed between the linking plates 17. Each of two connecting plates 161 has a first end connected to one of the front support members 13 and a second end connected to one of the pivot shafts 16. Each of the linking plates 17 has a horizontal portion 171 which extends between the rear support member 13 and the pivot shaft 16, a forwardly and upwardly inclining portion 172 which extends from a front end of the horizontal portion 171 and which is connected pivotally to the rear support member 13, and a rearwardly and upwardly inclining portion 173 which extends from a rear end of the horizontal portion 171 and which is connected pivotally to the pivot shaft 16. The stroller frame 1 further includes a handle unit 18 with lower end portions connected pivotally and respectively to the slide pieces 15. A catch mechanism 19, similar to that employed in the aforementioned U.S. Pat. No. 5,417,450, is installed to retain releasably the stroller frame 1 in an unfolded position, thereby avoiding accidental folding of the stroller frame 1.

As shown in FIG. 3, the shock absorbing device 2 is disposed between the linking plates 17 and includes a frame unit 20, a spring unit constituted by two springs 21, and two cover pieces 22.

The frame unit 20 includes parallel front and rear rod members 23, 24 which extend between and which are transverse to the linking plates 17. The front rod member 23 has a pair of bent leg portions 231, each of which is connected pivotally to a front part of the horizontal portion 171 of a respective one of the linking plates 17 by means of a corresponding rivet 25. The rear rod member 24 has a pair of bent leg portions 241, each of which is connected pivotally to a rear part of the horizontal portion 171 of a respective one of the linking plates 17 by means of a corresponding rivet 26. The frame unit 20 further includes two side plate members 28, each of which has two ends provided with a respective connector 27 for connection with one of the front and rear rod members 23, 24. Each connector 27 has a sleeve portion 271 to be sleeved on the corresponding one of the front and rear rod members 23, 24 and is formed with a slot 272 for receiving one end of the respective one of side plate members 28. Pins 281 secure the connectors 27 onto the side plate members 28.

Each of the springs 21 has a first hook end portion 211 which engages the front rod member 23 and a second hook end portion 212 which engages an intermediate part of the horizontal portion 171 of a respective one of the linking plates 17. Each of the cover pieces 22 covers a respective one of the linking plates 17 and has an inner side formed with a projection 221 that rests on top of an adjacent one of the side plate members 28. When installed, the frame unit 20 is swingable relative to the linking plates 17 in a first direction, wherein the frame unit 20 swings downwardly and forwardly, and a second direction, wherein the frame unit 20 swings upwardly and rearwardly.

Referring to FIGS. 1 to 4, the seat member 3 is installed on the frame unit 20 of the shock absorbing device 2. The seat member 3 has a seat portion 31, a backrest portion 32 connected pivotally to a rear end of the seat portion 31, and a pair of armrests 33 disposed respectively on opposite sides of the seat portion 31. A guard rail 331 has two ends connected to front ends of the armrests 33 for safety purposes. The seat portion 31 has a bottom side with a front part which is provided with a pair of hook units 311 (only one is shown) . Each hook unit 311 has a slit 312 for engaging one of the front and rear rod members 23, 24. The bottom side of the seat portion 31 further has a rear part provided with a spring-loaded retaining device 34 for engaging the other one of the front and rear rod members 23, 24. The hook units 311 and the retaining device 34 constitute a mounting unit for mounting detachably the seat member 3 on the frame unit 20.

Referring to FIG. 5, the retaining device 34 includes a housing 341 which is mounted on the rear part of the bottom side of the seat portion 31 by means of bolts 340. The housing 341 includes a rectangular base plate 3411, a surrounding wall 3412 which extends upwardly from a periphery of the base plate 3411, and a transverse partition wall 3413 which extends between front and rear portions of the surrounding wall 3412 so as to divide the space cooperatively confined by the base plate 3411 and the surrounding wall 3412 into left and right chambers 3414. Each of a pair of retaining blocks 342 is disposed in a respective one of the chambers 3414. Each of the chambers 3414 further has a first spring member 343, a press piece 344 and a second spring member 345 disposed therein.

The front portion of the surrounding wall 3412 is formed with a pair of front notches 3415 on two sides of the partition plate 3413. The base plate 3411 is formed with two pairs of slits 3416 which are parallel to and which are disposed on two sides of the partition plate 3413. Each of the slits 3416 extends rearwardly from the respective one of the front notches 3415. The surrounding wall 3412 further has opposite side portions which are respectively formed with a side notch 3417. The base plate 3411 is further formed with a pair of upwardly extending contact plates 3418, each of which is disposed adjacent to a respective one of the side notches 3417 in the surrounding wall 3412.

Each of the retaining blocks 342 has a rear portion which is formed with a blind bore 3421 and a front portion 3422 which extends through a respective one of the front notches 3415 in the surrounding wall 3412 and which has an upwardly curving bottom face 3423. Each of the retaining blocks 342 is further formed with a pair of guide projections 3424 which slidably engage a respective pair of slits 3416 in the base plate 3411. The front portion 3422 of each of the retaining blocks 342 has a top face formed with a widthwise extending groove 3425 for engaging the other one of the front and rear rod members 23, 24.

The rear portion of each of the retaining blocks 342 is further formed with a sideward hook projection 3426 that extends toward an adjacent one of the side notches 3417 in the surrounding wall 3412. The hook projection 3426 has a first inclined face 3427 and a first shoulder 3428 on an innermost end of the first inclined face 3427.

Each first spring member 343 has a first end portion which extends into the blind bore 3421 in a respective one of the retaining blocks 342, and a second end portion which abuts against the rear portion of the surrounding wall 3412.

Each press piece 344 has an engaging portion adjacent to a respective one of the contact plates 3418 and formed with a blind bore 3441. Each second spring member 345 has a first end portion which abuts against a respective one of the contact plates 3418 and a second end portion which extends into the blind bore 3441 of a respective one of the press pieces 344. Each press piece 344 further has an operating portion 3442 wider than and opposite to the engaging portion thereof. The engaging portion of each press piece 344 is formed with a second inclined face 3440 that abuts against the first inclined face 3427 of the hook projection 3426 on the respective one of the retaining blocks 342 and a second shoulder 3443 on an innermost end of the second inclined face 3440 for engaging the first shoulder 3428 of the hook projection 3426.

Referring to FIGS. 4 and 6, when installing the seat member 3 in a first direction, the seat member 3 is provided on top of the frame unit 20 of the shock absorbing device 2 and is pulled rearwardly such that the hook units 311 engage the front rod member 23. The seat member 3 is then pressed downwardly to enable the retaining device 34 to engage releasably the rear rod member 24, thereby mounting the seat member 3 on the stroller frame 1.

As shown in FIGS. 4, 6 and 7, when the seat member 3 is disposed on the frame unit 20, the rear rod member 24 initially abuts against the bottom faces 3423 of the front portions 3422 of the retaining blocks 342. Thus, when the seat member 3 is pressed downwardly, the rear rod member 24 moves along the bottom faces 3423 and pushes the retaining blocks 342 into the housing 341 against biasing action of the first spring members 343. Once the rear rod member 24 has moved past the bottom faces 3423, the first spring members 343 expand such that the rear rod member 24 is retained within the grooves 3425 in the top faces of the front portions 3422 of the retaining blocks 342.

Referring to FIGS. 6, 8 and 9, when it is desired to detach the seat member 3 from the stroller frame 1, the press pieces 344 are pressed inwardly against biasing action of the second spring members 345. At this time, the second inclined faces 3440 on the press pieces 344 move along the first inclined faces 3427 of the hook projections 3426 on the retaining blocks 342, thereby resulting in movement of the retaining blocks 342 inwardly of the housing 341 against the biasing action of the first spring members 343. The second shoulders 3443 on the press pieces 344 eventually engage the first shoulders 3428 of the hook projections 3426, and the retaining blocks 342 cease to engage the rear rod member 24. The seat member 3 can be lifted from the frame unit 20 at this time. When the seat member 3 is lifted from the frame unit 20, the rear rod member 24 once again abuts against the bottom faces 3423 of the front portions 3422 of the retaining blocks 342 and pushes the retaining blocks 342 further into the housing 341 against the biasing action of the first spring members 343. The second shoulders 3443 disengage the first shoulders 3428, thereby permitting expansion of the second spring members 345 to return the press pieces 344 to their normal positions. When the rear rod member 24 ceases to abut against the bottom faces 3423, the first spring members 343 expand to return the retaining blocks 342 to their normal positions, i.e. from the positions in FIG. 8 to the positions in FIG. 6. At this time, the seat member 3 can be mounted on the stroller frame 1 in an opposite direction, wherein the hook units 311 engage the rear rod member 24 while the retaining device 34 engages releasably the front rod member 23. The steps for mounting the seat member 3 on the stroller frame 1 in the opposite direction are similar to those described beforehand and will not be repeated herein.

Referring once more to FIG. 4, when a child is not seated on the seat member 3, the springs 21 bias the frame unit 20 in the second direction, i.e. the frame unit 20 swings upwardly and rearwardly. As shown in FIG. 10, when a child is seated on the seat member 3 and the stroller moves along a rough surface, the shock experienced by the stroller frame 1 results in swinging of the frame unit 20 about the rivets 25, 26 in the first direction. Since the springs 21 provide resistance to swinging of the frame unit 20, the shock that is transmitted to the seat member 3 by the stroller frame 1 can be minimized.

FIG. 11 illustrates the second preferred embodiment of a stroller according to the present invention. The second preferred embodiment is generally similar to the first preferred embodiment, the main difference residing in the configuration of the stroller frame 4. The stroller frame 4 includes two front support members 41, two rear support members 43, and two connectors 42, each of which connects pivotally one of the front support members 41 to one of the rear support members 43. Front and rear casters 411, 431 are mounted rotatably on bottom ends of the front and rear support members 41, 43, respectively. The two ends of a handle unit 45 are mounted on connecting seats 44 which are respectively provided at the top end of each of the front support members 41. Each of a pair of rear linking rods 46 interconnects one of the connecting seats 44 and one of the rear support members 43. Each of a pair of front linking rods 48 has a first end connected pivotally to a respective one of the rear support members 43. Each of a pair of linking plates 47 connects pivotally one of the connecting seats 44 and a second end of one of the front linking rods 48. Installation of the shock absorbing device 2 on the linking plates 47, and of the seat member 3 on the shock absorbing device 2 are similar to those of the first preferred embodiment and will not be described further.

FIG. 12 illustrates the third preferred embodiment of a stroller according to the present invention. The third preferred embodiment is generally similar to the previous embodiments, the main difference residing in the configuration of the stroller frame 6. The stroller frame 6 includes left and right frame parts 61 and a handle unit 62. Each of the frame parts 61 includes a base frame member 611, a pair of connectors 612 provided respectively on upwardly curving ends of the base frame member 611, and forwardly and rearwardly extending frame members 613, 614 connected pivotally at intermediate portions thereof. Each of the frame members 613, 614 has a lower end connected pivotally to one of the connectors 612. A linking plate 615 has two ends connected pivotally to upper ends of the frame members 613, 614. The handle unit 62 is connected to the upper ends of the rearwardly extending frame members 614 of the frame parts 61. Front and rear axles 617 interconnect the base frame members 611 of the left and right frame parts 61. A caster 618 is mounted rotatably on each end of the axles 617. Installation of the shock absorbing device 2 on the linking plates 615, and of the seat member 3 on the shock absorbing device 2 are similar to those of the first preferred embodiment and will not be described further.

Note that the specific configuration of the stroller frame is not critical to the present invention. The shock absorbing device 2 can be used with any stroller frame, as long as there are two linking plates on opposite sides of the seat member. In addition, although the retaining device 34 in the disclosed embodiments includes a pair of retaining blocks 342, a pair of press pieces 344, a pair of first spring members 343 and a pair of second spring members 345, a retaining device with only one retaining block, one press piece, one first spring member and one second spring member may be used to achieve the same purpose.

While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.