This invention relates to pushchairs. The term "pushchair" is intended to be construed widely to cover carriages for infants and young children which comprise a frame, wheels and a seat or cradle arrangement in which the child or infant sits of lies. These may also variously be known as strollers, buggies or baby carriages.

Traditionally, new born and very young babies were transported in a pram for the first few months of life and then in a separate pushchair in which the growing child could sit upright. Recently, however, the demand has grown for child carriages which can be used both for the new born and for the older child, thus offering more flexibility and economy. In order to achieve this, pushchairs are commonly available which have a seat unit which can move from a substantially lying down position for a new born to a sitting position for an older child. In all pushchairs up to now, this movement has been achieved by moving the rear of the seat backwards to increase the angle between it and the seat base, or by pivoting the seat around a generally central transverse axis.

As a child gets older and begins to become proficient at walking, he will tend to use the pushchair less and at this stage siblings may arrive who can then be accommodated in the pushchair. The older child of, say two to three years, will, however, not be able to walk for great distances without getting tired and therefore British patent application no 9301497.5 describes a pushchair in which a rear mounted platform is provided upon which an older child may stand whilst a younger child sits in the seat or cradle portion. A problem with this sort of pushchair is that it is not easy to accommodate a moveable seat since the conventional movement mechanism,

involving a generally backwards movement of the back rest portion, obstructs access to the platform and thereby does not allow an additional child to stand on a platform.

It is an object of the present invention to provide an improved movement mechanism for a pushchair seat. The invention is applicable particularly to pushchairs of the type having a rear platform but not exclusively and may be advantageously applied to any type of pushchair. According to the present invention there is provided a pushchair having a frame and a seat oveable relative to the frame, the front end of the seat being arranged to move generally forwardly and upwardly from a sitting-up to a lying back position, with respect to the frame.

Preferably, the seat is adapted to pivot about an axis at or towards the topmost part of the seat.

By the 'front end' is meant the end of the seat which is towards the normal direction of movement of the pushchair. A child will normally sit facing this direction but could alternatively sit or be facing rearwards, particularly for new born or very young infants.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows schematically a side view of a pushchair in a sitting-up position;

Figure 2 shows the pushchair of Figure 1 when the seat is moved to an intermediate position;

Figure 3 shows the pushchair of Figure 1 when the seat is moved to the furthest extent of its lie back position;

Figure 4 shows a schematic underplan view of the pushchair;

Figure 5 shows a pushchair having an alternative movement mechanism;

Figure 6 shows part of the mechanism for achieving movement of the chair of Figure 5; Figure 7 shows the mechanism in its extended position;

Figure 8 shows the mechanism when released from its extended position; and

Figure 9 shows a partial underplan view of the seat of Figure 5 showing the underside of the seat and movement/lock mechanism.

Figures 1 to 4 show schematically a version of a pushchair according to the present invention in which generally upward and forward movement is achieved by virtue of a telescopic extension mechanism. Figure 1 shows a pushchair having a frame structure 1 and wheels 2 in conventional fashion. A seat 3 is mounted upon the frame and a rearwardly mounted platform 4 is provided which enables a child to stand upon the platform whilst an additional child sits in the seat. The seat is attached, at its top end to the frame at a transverse bar 5.

Note that the lie back (lying back) position does not necessarily imply that the angle between the back rest and base of the seat of the chair varies. It merely implies that the angle of the back rest is increased relative to the vertical.

One way of achieving upwards and forwards movement is by virtue of a telescoping effect from a fixed point on the frame. This is shown in Figures 2 and 3 where a relatively small diameter rod 6 is pivotally attached at 7 to the cross member 8 of the frame. Frame member 8 generally has an elbow in it. Rod 6 is adapted to axially slide within a larger diameter hollow rod 7 which is affixed to the base of the seat 3. The seat can thereby be pivoted about point 5 so that rod 6

telescopically slides within outer rod 7 to move the front portion 9 of the seat upwards and forwards into a desired position. Figures 2 and 3 show one method of securing the seat in a desired position comprising a longitudinal groove 10 in outer rod 7 and a pin 11 protruding from rod 6 and through the groove. This may be provided with a screw thread for example and an external nut or other member be screwed on when the seat is in a desired position to securely hold the pin in that desired position and thereby the seat.

The embodiment shown in Figures 2 and 3 is a crude one and a better version is shown in Figure 4 in which two rods 6 are shown, at either side of the pushchair and the outer rod 7 is a U-shaped tubular frame forming the support for the seat base itself. Rods 6 can slide longitudinally within tube 7. Tube 7 may be provided with one or more internal pins (not shown) which are urged by a spring or other resilient means into a position where they extend radially inwards. Rods 6 are provided with a plurality of holes 12 and the pin can extend into anyone of these to lock the mechanism into any desired position. Release buttons 13 are provided which act upon the or each pin so that by depressing the lower part of each button 13 the pin is retracted from a hole, against and spring urging force and by releasing this the pin is urged radially inwards again. Thus, to alter the seat position the adjuster buttons 13 are depressed, rod 7 and thereby the seat base is moved to its desired position and the lever is released from allowing the pin to fall into the nearest appropriate hole 12. Clearly, both adjuster buttons 13 and their associated pins must be actuated to move the seat simultaneously. Mechanisms may be provided which are linked both adjuster buttons so that by a single adjustment both buttons are depressed simultaneously.

A wedge may be used, mounted on the underside of the seat or on the frame for example, with one or more push rods acted on by the wedge so that relative movement of the wedge and rod(s) causes the rods to move laterally, forcing them into and out of engagement with a lock mechanism.

It will be appreciated that many other mechanisms employing generally telescopic principles from a fixed pivot point on the frame may be used. Figure 5 shows an alternative type of movement in which, instead of pivoting with respect to the frame, a member connected to the seat slides with respect to the frame. Again, many variations on sliding mechanisms may be used. In the figure, a member 14 which is attached to the seat portion is slidably attached to frame member 8 and can slide from the position shown in solid lines to the lie back position 14' shown in dashed lines.

If desired, combinations of telescoping and sliding movement can be used. For example, cooperating rods may slide a certain distance then telescope.

Figures 6 to 9 show a mechanism for locking and locking a sliding seat movement mechanism. Figures 6 to 8 represent generally a cross-sectional view through A-A of Figure 9 which is a view of the underside of a pushchair seat and associated lock/unlock mechanism. A U-shaped tubular pushchair base support frame 14 is pivotally mounted to a bracket 15 which is arranged to slide on frame member 8 of the pushchair. Numeral 16 designates a frame member supporting the back rest part of pushchair seat and which is mounted at one end to frame 14 and at its other end to a transverse support rod 15 forming a pivot at the top end of the seat with the frame. Also pivotally mounted to bracket 15 is a lock member 17 which is pivotally mounted at a pivot 18 towards its top.

Locking member 17 is formed with a cut-out 19 forming a slot having a reduced neck portion extending inwards to a wider portion, towards its lower surface and an extension 20 forming a manually depressable knob. Knob 20 may be omitted if desired. A spring 21 is mounted between the lock member 17 and seat frame 40. The mounting point of the spring on member 17 is preferably slightly above the opening of slots 19.

A U-shaped locking rod 22 is supported underneath the seat and is attached at its free ends to each of the locking members 17, preferably just above the pivot point 18. As shown more clearly in Figure 9, release rod 22 is held loosely by brackets 23 underneath the seat and may be pulled manually towards the front of the seat. A pair of nipples 24 are mounted on the frame 8 of the pushchair, towards the front thereof and extending towards each other. Alternatively, these may be lengthened to provide a cross-bar as shown at 25 on Figure 9 and this may conveniently be used as one of the supports for a basket for the pushchair (eg a shopping basket) as is commonly provided. The nipples or cross-bar are designed to interlock with slot 19 of the locking member when the is in its lie back position.

As shown in Figure 9, the seat frame 14 may be narrowed slightly towards its front end. This may be useful in certain folding pushchair designs in order to allow the seat properly to fold down without being obstructed by the frame of the pushchair.

Figure 6 shows the mechanism when the seat is in its upright, sitting position. In order to move the seat to its lie back or new born position bracket 15 has to be slid forwardly with respect to frame 8. This can be achieved by pulling on frame member 14. It should be noted that regulations generally require that there be at least a minimum spacing between rods on pushchairs to

avoid entrapment of fingers and this is why rod 14 is shown as being spaced, via the bracket, from rod 8. Typically, this spacing may 12 mm or greater. As bracket 15, and thereby locking member 17, is moved forwardly (ie to the left in the figure) member 14 and thereby member 22 and the seat base tends to increase in angle as the other end of member 16 is pivoted and this increased angle is shown in Figure 7. Note that bracket 15 is not shown in Figures 7 and 8 for clarity. The locking member is moved forwards until it is obstructed by nipples or rod 24. Since frame 17 is free to pivot about point 18, it can lock against nipple 24 by virtue of the nipple extending into slots 19. The slot is designed such that when in the position shown in Figure 7, the frame member, and thereby the bracket and the seat cannot be moved backwards unless the frame is deliberately pivoted away. Thus, the seat automatically locks into its forward most (lie back/new born) position.

In order to disengage the seat and move it back into its upright position, release rod 22 can be pulled forward. This pulls on the top part of frame 17 which causes the lower part of the frame to move in the opposite direction, thus freeing the slot from nipples 24. Alternatively, the knob portions 20 may be manually depressed in some embodiments but this clearly requires both knobs to be depressed simultaneously whereas the mechanism of rod 22 requires only one action to simultaneously release both locking members. When release rod 22 has been pulled and lock member 17 has been released from the nipple the pushchair base may then be moved back and slid into its upright position again. Spring 21 urges frame member 17 into its position where it can again be locked into nipple 24 when desired since the spring is expanded by pulling upon rod 22 and tends to urge the locking member back again.

The embodiment of Figures 6 to 9 only has two positions for the seat, fully upright and fully lie back. It is possible to have intermediate positions by arranging for extra spring loaded or otherwise retractable nipples to be provided on the frame or on the locking member.

These may be provided in pairs for example so that one of the pair extends into the locking member while the other lies to the side of the locking member. The free member can then be depressed and this is linked to the captive member so that also depresses to free the mechanism. Many other methods of achieving intermediate positions will be apparent.