GB2426231A - Pushchair or stroller with scissor folding action - Google Patents

Abstract

A pushchair is disclosed comprising at least a pair of front wheels, at least a pair of rear wheels and a folding mechanism, wherein, when folded from a usable to a folded position, the rear wheels and front wheels lie at the same end of the structure, opposite the handle end. The folding mechanism may comprise both longitudinal and lateral scissor mechanisms. Two scissors mechanisms may be linked together to form a concertina mechanism.

Description

PUSHCHAIRS OR STROLLERS

This invention relates to pushchairs. These are often referred to as strollers or buggies.

In particular, the invention relates to a foldable pushchair, stroller or buggy (hereinafter pushchair) which can be folded into a disposition where it is relatively easily carried and stowed in a car boot or trunk for example, but which can then unfold to a disposition where it can be used to carry a child. The invention refers both to single pushchairs designed to carry one seated or supine child or infant and also to tandem type pushchairs designed to accommodate two children or infants, positioned one behind the other or side by side (generally * ** known as a twin). Indeed, in theory, pushchairs accommodating more than two passengers may be within the scope of the invention.

* : * Foldable pushchairs have been in existence for many years and although :. perhaps slightly less robust than unfoldable ones, do have huge advantages in terms of portability, transportability and lightness. However, although lighter * than previous unfoldable designs, folding designs available today are still * . * 20 relatively heavy and it is undesirable to carry them for long periods. Furthermore, known designs include two or four wheels at the front and two or four wheels at the back of the pushchair. When folded, the rear wheels generally rest at one end of the folded structure, adjacent the handles, and the front wheels generally rest at the other end. This can render the device difficult to carry or manoeuvre since the wheels tend to get in the way and also does not mean that the pushchair can simply be rolled along the ground when folded up. A pushchair of this type is shown in many patent applications of MacLaren Limited and others, for example US 4,232,897.

The present invention arose in an attempt to provide an improved folding mechanism for a pushchair.

According to the present invention, in a first aspect, there is provided a pushchair comprising front wheel means, rear wheel means and a folding mechanism, wherein, when folded from a usable to a folded position, the rear wheels and front wheels lie at the same end of the structure, opposite the handle end.

Preferably, when folded, the rear and front wheel axles are generally coplanar so that all wheels can be rolled along the ground by holding the pushchair by handles at its end remote from the wheels.

Most preferably, the handle or handles always stay at generally hand level, so that when folded, the chair can be rolled along the ground when holding the * : handle at normal hand level.

* S. * The wheels may be castors but are preferably conventional wheels. * *. * S S.. *

:. According to the present invention, in a second aspect, there is provided a : foldable pushchair comprising at least one scissor type mechanism for causing * longitudinal folding and at least one scissor type mechanism for causing lateral * * 20 folding whereby the chair can be folded both lengthwise and widthwise by a single fold operation.

The pushchair may be a single, tandem, twin or multiple-occupant pushchair.

In one embodiment, the pushchair is a tandem design each side comprises two linked scissor mechanisms, formed by a first member between a front axle and a pivot point, a second member between the pivot point and a rear axle, a third member between a handle part and a second pivot point, the third member and second member being connected via a respective pivot point spaced from the ends of the members, and a fourth member connected between the second pivot point and pivotally connected to the first member whereby a forward movement on the handle member causes relative pivoting so as to draw the axles together.

Most preferably, the mechanisms on each side are connected by a further scissor mechanism substantially at right angles to these and widthwise causing the sets to be drawn together and hence the pushchair to fold laterally as it is simultaneously folded longitudinally.

The pushchair may be a three wheeler design, having one wheel at the front or rear, four wheeler, eight wheeler or have any other number of wheel means. * I* * I I

:::.: Embodiments of the invention will now be described, by way of example * 15 only, with reference to the accompanying drawings in which: * : Figure 1 shows a side view of a pushchair with seat and hood portion :. attached; : Figure 2 shows a rear perspective view of a pushchair frame; Figure 3 shows the frame in a partially folded position; * 20 Figure 4 shows a frame in a fully folded position; Figure 5 shows schematically a folded frame in side view; Figure 6 shows a side view of a tandem pushchair; Figure 7 shows the tandem pushchair partially folded; Figure 8 shows the tandem pushchair fully folded; Figure 9 shows a rear view of a tandem pushchair; Figure 10 shows a prospective view of a tandem pushchair; Figure 11 shows a plan view of the tandem; Figure 12 shows a rear view of a tandem pushchair fully folded; and Figure 13 shows a plan view of a tandem fully folded.

Referring now to the figures, Figure 1 shows a side view of a single pushchair. This is shown mounting a carrycot/car seat 1 although, of course, a chair, cot or other passenger support may instead be used. The carrycot/car seat is mountable by a mechanism (not shown) to be attachable or removable from the frame 2 so as to be affixed into a car or used on its own. A fabric hood 3 is also shown. Instead of a rigid seat 1 a flexible material may be used as a seat which can stay attached to the pushchair and fold when the pushchair frame is folded, or the seat and/or hood may be hinged so as to be foldable.

The pushchair itself comprises two respective pairs of front wheels 4, 5, each mounted one either side of a respective side frame member 6. The side frames extend from the respective axles 7 up to respective handle portions 8 and, * ,* as with other parts of the frame, may typically be made of light cylindrical metal : or plastic material, although they may have other longitudinal and cross-sectional shapes and be made of other materials as appropriate. * S. * . . ** *

*:. Respective pairs of rear wheels 9, 10 are mounted so that each pair lies either side of an axle on a further frame member 11, 12. Towards its other end, each of these respective frame members is pivotally connected to, or by a hinge * ** 20 adjacent to, a respective one of the first frame members 6, at a pivot point 13. In Figures 1 to 4, pivot point 13 is formed by a bracket 14 mounted around frame member 6 (and the other front frame member extending behind it). However, the rear leg frame members 11, 12 may also be pivotally connected directly to the front frame members in other embodiments.

Rear frames may be straight or may be, as shown, arcuate or have an elbow 15. Figure 1 shows an embodiment with an elbow and Figures 2 to 4 show an embodiment which is generally arcuate. This is convenient but not essential.

The arcuate or curved nature of the rear frame means that when the rear frame is pivoted relative to the front frame and therefore the pushchair is folded, the rear wheels move towards the front wheels and a convenient spacing is obtained, even when fully folded, so as not to trap an infants fingers for example. The frames may be pivoted together at the end of the rear frames or at a point spaced apart from the end of the rear frames.

Importantly, it will be seen that as the frame is folded, by pivoting, the rear wheels move towards the front wheels and therefore the pushchair moves from the configuration shown in Figure 2 to that of Figure 4, via that of Figure 3, so that the rear wheels move relatively towards the front wheels. The rear frames are mounted (as best shown in Figures 3 and 4) so that they lie inside the front frames. Thus, the respective outer and inner ones of each pair of rear wheels (e.g. 9a, 9b of Figure 3) lie respectively inwards spaced from the corresponding outer and inner wheel of the front wheel (e.g. 4a, 4b).

The front and rear frames are also connected by a further rear crossframe .: assembly 14. This comprises a pair of cross members, each respective cross member being pivotally connected between a point on the front frame 6 and a : * . . point on the respective rear frame 11 which is on the opposite lateral side of the pushchair. Similarly, a second cross frame member is connected between the : 20 other front frame member and the other rear frame member. These are connected towards the top end of the front frame member and a position on the lower frame member, typically at or towards its lower end but not necessarily.

These may be simple straight cross members and are pivotally connected together at a point between their ends, typically at their centres, so as to form an X-shape. Alternatively, and as shown in the embodiment of Figures 2 to 4, each cross piece is generally bent or cranked, i.e. generally Z-shaped having a generally downwardly directing portion 1 4a, then a generally laterally directed portion I 4b and then a further generally downwardly directed portion 14c, although the angles of the downwardly directed portions need not be the same. These members are pivotally connected at or towards their centres by a pivot point 15. Thus, in a folding operation, when the rear wheels and their respective frame members are brought towards the front wheels, the vertical spacing between the connection points of the cross pieces 14 and the frames increases. This therefore causes the cross frame pieces to pivot such that their top ends move towards each other and also their lower ends move towards each other. Similarly, actuation of the rear frame causes the wheels to move together. This is shown in the progression from Figure 2 through Figure 3 to Figure 4 and causes the front and rear leg frames 6 and 11 to move laterally towards each other as shown.

Thus, in a single folding operation, pivotal movement occurs to both move the wheels towards each other and therefore reduce the front to back dimension of the pushchair but also the frame itself moves inwards laterally and so the lateral widthwise dimension of the pushchair is reduced. Once in the fully folded * 15 position of Figure 4, the pushchair is easily portable. It will be noted that at this * : * position all the wheels contact the ground and therefore the pushchair may be held *:. at the handles and simply rolled along the ground by holding it with one hand at : the now close-together handles. This may be very convenient when a young child : . *: is perhaps being held in the carer's other hand.

* ** 20 The handles stay in a vertical position generally at hand height so that a user does not have to bend to push the now folded chair, or to fold or unfold the assembly.

In embodiments of Figures 2 to 4 the cross frames 14 are shown as being cranked. As described, the parts of the cross frame may instead be straight, pivoted at its middle. The cranked version is generally found to be more satisfactory and enables an attached seat to recline fully. It can also reduce the chances of finger pinching or more serious injuries. Another other configuration which generally or topographically achieves an X-frame may be used.

A cross strut 45 is shown in the figures. This is connected between the rear members and is comprised of two struts 45a and 45b pivotally connected where theyjoin. This can provide further strength and might also be part of an initiating mechanism by enabling pressure to be applied at its centre pivot point which therefore starts to cause the rear legs to move inwards and commences the folding operation which can then be manually completed. Other movement initiating means, particularly but not exclusively foot operated ones may be used, or none. Strut 45 gives rigidity and can also be used to provide a secondary lock.

Figure 5 shows a side view of a folded pushchair. It will be noted more clearly in this figure that at the end of each rear frame is a protrusion 16. This forms part of the mounting structure for a carrycot, car seat, seat or other module which may be affixed in place in the pushchair. As described, the pushchair may : .: alternatively be provided with a permanently attached seat or bed structure which * 15 may be flexible so that it folds as the pushchair is folded or which may have a * : hinged portion which hinges to accommodate the folding. As is also clearly :. shown in Figure 5, any of the pivot points may be formed by bracket portions.

: : By correctly arranging the relative positions of the wheels and frames : 20 relative to each other laterally, the pushchair is preferably (but not necessarily) arranged so that when folded the front and rear wheel assemblies overlap each other to a certain extent, as is shown in Figures 4 and 5.

Figure 6 shows a tandem pushchair. This has two mounting parts 20 and 21 for receiving respectively a front and a rear seat portion, carrycot, car seat or similar. Front 22 and rear 23 wheel assemblies are provided.

It will be appreciated that fundanientally the single type pushchair shown in Figures 1 to 5 utilises scissor mechanisms. A first scissor mechanism in one pair of parallel planes enables front and back (longitudinal) folding and a second scissor mechanism in a plane perpendicular to the first mechanism enables folding in the lateral direction. The present invention extends to any type of single, tandem or twin pushchair which utilises this concept. A plurality of scissor mechanisms may be used in each plane in other embodiments.

The tandem pushchair also uses scissor mechanisms in orthogonal planes.

The rear mechanism comprising a scissor mechanism formed by an X-frame is also present in the tandem structure, as is shown most clearly in Figures 9 and 12 for example where Figure 9 shows the rear of a tandem. Note that the rear of a single mechanism may also look similar to this. Figure 12 shows the rear of a tandem when it has been folded, illustrating how the top ends 30, 31 of the X- frame have been pulled towards each other as the spacing between the leg frame * : :* members increases.

* ** * * S. Figure 6 to 8 and 10 show more clearly the side view of a tandem design.

.: In this case, scissor mechanisms are still provided but slightly differently configured. In effect, each side comprises two side by side scissor mechanisms.

:; The front wheel assembly 22 and rear wheel assembly 23 on each side are * * 20 connected by a frame compnsing a front frame member 24 and rear frame member 25, the ends of these members remote from the axles being connected at a pivot point 26. The handles 27 are connected to a frame member 28 which pivots at a pivot point 29 with rear leg frame 25. At its end 33 remote from the handle, frame member 28 pivots with the end of a further frame member 34 which itself is then pivotally mounted to a point 34 along front leg frame member 24.

Frame members 28 and 34 bear respective mounting means 35 and 36 for rear and front seats, carrycots, etc. The rear X-frame is connected as shown between frames 28 (the left most one of this is shown in Figure 6, of course there will be a right version of all of the frame members described) and the corresponding opposite rear leg 25.

As is shown in Figures 7 and 8, in the folding operation, from a side, the frame members pivot at points 26, 29, 33 and 34 so as to bring the rear and forward wheels together, thus, this might be described as a double scissor mechanism, the scissoring action occurring at pivots 34 and 29 and further pivoting being allowed at points 26 and 33.

This causes the vertical distance between rear frame 28 and lower leg frame 25 to increase and therefore draws the frame laterally inwards.

Note that if the pushchair is a three wheeler, the side frames will be convergent towards one end. In this case, the rear X-frame will not be precisely at right angle to the side mechanism but this embodiment is still considered to be within the scope of the present invention.

The reader will also note that the end of each mounting part 35 and 36 a * : :* further X-frame member 37, 38 respectively is provided connecting the end of the :. mounting part remote from the respective pivot to either front leg frame member 24 or a lower end of handle frame member 28. These X-frames also ensure that * * the mounting parts pivot upwards as the pushchair is folded, and may be omitted, or only one of them, more than two, provided.

Another way of describing the tandem arrangement is that the frame comprises two U or V configuration frame parts, each being able to change its angle at the apex of the U or V and one of them being inverted, the two U or V- shaped frame parts being pivotally connected to each other so that respective concertina-type movement can take place, each U or V-shaped frame part being able to change the angle between its main legs, by pivot means for example, so that the frames can concertina.

Note that instead of pivots 26 and 33 the U or V-shaped parts may simply have flexible hinge joints or indeed be made of flexible material at these parts to allow flexing and change of angle between the two leg portions of the U or V. Figure 10 shows a perspective view of a tandem pushchair and illustrates the additional X-frames 37 and 38.

Note that preferably, in embodiments of the invention, the front and rear wheels longitudinally overlap when fully folded. This is shown for example in Figures 4, 5 and 8 where the rearmost part of the front wheels extends beyond the most forward part of the rear wheels when folded. This means that the wheels effectively are horizontally offset when folded and enables easier control when * : :* rolling the folded pushchair along the ground.

* 15 In some embodiments, folding may only be possible longitudinally. This * : :* is, the width of the pushchair may remain constant as the chair is folded. In this *:. case a lateral X-type frame generally will not be included.

Embodiments of the invention result in a pushchair which is light (perhaps * 20 7 kg compared to a conventional 12 kg), and very compact, particularly with tandem and twin pushchairs.

Claims (21)

1. A pushchair comprising front wheel means, rear wheel means and a folding mechanism, wherein, when folded from a usable to a folded position, the rear wheels and front wheels lie at the same end of the structure, opposite the handle end.

2. A foldable pushchair as claimed in Claim 1, comprising at least one scissor type mechanism for causing longitudinal folding and at least one scissor type mechanism for causing lateral folding whereby the chair can be folded both lengthwise and widthwise by a single fold operation.

:

3. A pushchair as claimed in Claim 2, wherein, when folded, all wheels are at . . the same end of the structure. S*a S

* : *

4. A pushchair as claimed in Claim 2 or Claim 3, wherein each scissor :. mechanism comprises two members pivotably connected so as to enable respective ends of respective members to move towards or away from each other in a folding or unfolding operation.

5. A pushchair as claimed in any preceding claim, wherein each side comprises two linked scissor mechanisms.

6. A pushchair as claimed in Claim 5, which is a tandem, twin or multiple occupant pushchair.

7. A pushchair as claimed in Claim 5 or Claim 6, wherein the scissor mechanisms are formed by a first member between a front axle and a pivot point, a second member between the pivot point and a rear axle, a third member between a handle part and a second pivot point, the third member and second member - 12 - being connected via a respective pivot point spaced from the ends of the members, and a fourth member connected between the second pivot point and pivotally connected to the first member whereby a forward movement on the handle member causes relative pivoting so as to draw the axles together.

8. A pushchair as claimed in any of Claims 5 to 7, comprising two U or V configuration frame parts, each being able to change its angle at the apex of the U or V and one of them being inverted, the two U or V-shaped frame parts being pivotally connected to each other so that respective concertina-type movement can take place, each U or V-shaped frame part being of variable angle between its main legs so that the frames can concertina.

*

9. A pushchair as claimed in any of Claims 5 to 8, wherein the mechanisms on each side are connected by at least one further generally laterally acting scissor a S 15 mechanism causing the sets to be drawn together, and hence the pushchair to fold * a. laterally as it is simultaneously folded longitudinally, and vice versa. *4. *

S a.

10. A pushchair as claimed in Claim 9, wherein the lateral mechanism is S. I :.: 20 substantially at right angles to the side mechanisms.

11. A pushchair as claimed in Claim 9 or 10, wherein a plurality of laterally acting scissor mechanisms are provided.

12 A pushchair as claimed in Claim 9, Claim 10 or Claim 11, wherein each laterally acting scissor mechanism is formed by an X-frame.

13. A pushchair as claimed in Claim 12 wherein the members of the Xframes are straight.

- 13 -

14. A pushchair as claimed in Claim 12, wherein at least one of the members of the X-frame comprise at least one bend.

15. A pushchair as claimed in any preceding claim, including a means for initiating folding.

16. A pushchair as claimed in Claim 15, wherein the initiating means is foot- operated.

17. A pushchair as claimed in any preceding claim, wherein, when folded, the front and rear wheels overlap longitudinally.

18. A foldable pushchair, comprising at least one scissor type mechanism for * causing longitudinal folding and at least one scissor type mechanism for causing I.'.

lateral folding whereby the chair can be folded both lengthwise and widthwise by : a single fold operation. S.. *

I I..

19. A pushchair as claimed in any preceding claim, wherein, when folded, all * 20 wheels can roll along the ground when the pushchair is moved.

20. A pushchair as claimed in any preceding claim, wherein, when folded and held so that the handle part lie substantially vertically above the wheels, the handle is approximately hand height.

21. A pushchair substantially as hereinbefore described with reference to, and as illustrated by, the accompanying drawings.