A COLLAPSIBLE PUSH CHAIR

Abstract: First and second moulded plastic structural components, respectively comprising a back rest portion (1) with integral front legs (3, 3) and a seat portion (2) with integral rear legs (4, 4), are connected for pivotal movement about a first horizontal axis (7) with the second structural component (2 and 4, 4) disposed between the front legs (3, 3) of the second structural component (2, 4 and 4). An inverted 'U'-shaped handle member (5 and 6, 6) has a cross-piece (5) and two side shafts (6, 6) respectively connected to opposite sides of the back rest member (2) for pivotal movement about a second parallel horizontal axis (8). Links (11) extend respectively between the rear legs (3, 3) and the side shafts (6, 6) for pivotal movement about third and fourth parallel horizontal axes (12 and 13). Stops (9) formed integrally in the sides of the back rest portion (1) and releasable hooks (10) are provided for holding the side shafts (6, 6) in a first position in which they extend away from the front legs (3). The links (11) cause the push chair to collapse when the side shafts (6, 6) are folded from their first position to a second position in which the front legs (3, 3) and the side shafts (6, 6) lie along opposite sides of the rear legs (4, 4).

Description: A Collapsible Push Chair Field of the Invent ion The invention reWlat t!.% to a collapsible push chair constructed for e,asf of conversion between its erected and collapsed conditions. In particular, although not exclusivc'ly, the invention relates to a collapsible push chair which is substantially wholly constructed from moulded plastic structural components. Background Art It is knokn to provide collapsible push chairs which each comprise a back rest portion a seat portion pairs of front and rear legs supporting the back rest and seat portions, and handle means. By constructing these components in the form of pivotally interconnected frame members, it is possible to convert the push chair between erected and compactly collapsed conditions but this mode of manufacture involves relatively high fabrication costs. One f'orm of construction devised in order to minimise this high cost of fabrication is disclosed in British Patent Specification No. 1 216 476. This method involves the moulding of a single plastic structure in which the various components of the push chair are permanently interconnected by integral film hinges. Conversion of the push chair between its erected and collapsed conditions is effected by folding the component parts about their film hinges. However. this is a relatively complicated operation requiring the use of two hands by at least one person and so is unsuitable for use by a person holding a small child in one hand. Disclosure of the Invention It is intended. by means of the present invention. to provide a push chair in which these knout disadvantages are at least alleviated. In particu7 ar, it is an object of the invention to provide a push chair which can be easily converted between its erected and collapsed conditions and which lends itself to construction substantially solely from moulded plastic components. According to the invention there is provided a collapsible push chair comprising a back rest portion, a seat portion, pairs of front and rear legs supporting the seat and back rest portions, and handle means, the front legs and back rest portion being formed as an integral plastic moulding comprising a first structural component in which the legs project from the back rest portion,the rear legs and seat portion being formed as an integral plastic moulding comprising a second structural component in which the legs project from the seat portion the first and second structural components being interconnected so that the pair of legs of one of the first and second structural components straddle the other of the first and second structural components for pivotal movement, about a first horizontal axis, between first and second configurations respectively corresponding to erected and collapsed conditions of the push chair, in which the front legs extend, respectively, alongside the rear legs and diverge downwardly from the rear legs the handle means having at least one shaft connected to the back rest portion for pivotal movement about a second horizontal axis substantially parallel to the first horizontal axis between first and second positions, respectively corresponding to the erected and collapsed conditions of the push chair, in which said shaft extends, respectively, away from the front legs and alongside the rear legs positioning means being provided for releasably locking the shaft relative to the back rest portion when the push chair is in its erected condition; and link means extending between pivotal connections with said shaft and at least one of the rear legs for pivotal movement about third and fourth horizontal axes which are substantially parallel to the first and second +^Leantal axes so that movement of the shaft between its first and second positions effects movement of the first and second structural components between their first and second configurations corresponding to erected and collapsed conditions of the push chair. Thus, when the push chair is in its collapsed condition, resting on wheels provided on the front and rear legs which lie alongside each other, erection is simply effected by swinging the handle means from their second position, alongside the rear legs into their first position, extending away from the front legs. The front legs and rear legs roll apart and the push chair is locked in its erected condition by releasably 1Ockint7 the positioning means. Stop surfaces are conveniently provided on the first and second structural compnents for engagement when the first and second structural components arx in their first configuration so that the push chair provides a rigid support when in its erected condition. T}e legs of the structural .component which straddle the other structural component constitute out-er legs haing outer wheels respectively laterally offset from the axes of said outer legs and the legs of the other structural component constitute inner legs having inner wheels respectively aligned with the inner legs so as t.o be laterally inside the outer wheels so as to allow the front and rear legs tc. approach each other when the push chair is moved into its collapsed condition. The handle means preferably comprise an inverted "U" -shaped member having a cross-piece and two side shafts respectively connected to opposite sides of the back rest portion for pivotal movement about the second horizontal axis between its first and second positions. This arrangement leaves the underside of the back rest unobstructed so that it is possible to s1r.g a receptacle fran the back rest, between the side shafts of the inverted "U7"-shaped member. This provides a convenient storage space for small items which can be stowed inside the wheelbase of the push chair so as to avoid instability. In a preferred embodiment of the invention the first structural component may include an integrally formed foot rest extending between the front legs. Similarly, an integral brace may also be moulded so as to extend between the rear legs forming parts of the second structural component. Wo return the push chair to its collapsed condition, it is merely necessary to release the positioning means and then to swing the handle means from their first position to their second position so that the lint cause the front and rear legs to roll towards each other'. Tr-iis can be done siifnpl v b! grasping the top of the push chair and biting the push chair ofi' its supporting surface. Thi moulded plastic construction facilitates fabrication in that the first and second structural components may be integrally formed with the fittings necessary for int erentaoement with each other and with other components of the push chair. Thus the pivotal interconnect ion between the first and second structural components may be provided by pins formed integrally in one of these components for reception in apertures formed in the other of these components. Similarly, the wheels may be mounted on axles for receipt in complementary apert-ures in bifurcated portions of the front and rear legs. In addition one or both of the first and second structural components may be provided on both sides with locations for bosses for the reception of coupling members for coupling push chairs side by-side for acocssnodating two or more children in interconnected push chairs. The moul ded construct ion of the first and second structural components permits the integral formation of fittings for the attachment of canopies for protection from rain or sunlight and for the attachnent of seat and back rest padding, of hooks for the suspension of a receptacle below the back rest and of bosses for the attachment of other fittings such as "bumper bars" and trays. Similarly, the positioning means for releasably locking the handle means in their first position may include integral stop means formed in the sides of the back rest portion and both the seat portion and the back rest portion may be moulded to provide aestheticalls- pleasing and comfortably shaped structural components. An embodiment of the invention is hereinafter described, by way of example only, kith reference to and as illustrated in the accompanying drawings. Brief Description of the Drawings Figure 1 is a perspective view of a push chair in accordance wit-h thc present invention in its erected condition: Figures 2 to 4 are side, front and rear elevational views of the push chair shown in Figure 1, with external fittings removed, and Figures 5 and 6 are side and front elevational vies of the push chair shown in Figures 2 to 4 disposed in its collapsed condition. Mode for Carrying Out the invention As shown in the drawings. the push chair has a first moulded structural component comprising a back rest portion 1 and two front legs 3, and a second moulded structural component. comprising a seat portion 2 and two rear legs 4 extending from opposite sides of the seat portion 1, disposed between the two front legs z of the first moulded structural component. These two structural components are pivotally interconnected by means of integrally moulded projections on the insides of the front legs 3 which define a first horizontal axis 7 and are received in apertures formed in the sides of the seat portion 1. Both structural components are moulded from polypropylene mixed with up to 405 chalk filler, together kith colouring material. As shown in Figure 1. a receptacle in the form of a plastic bag 18 is slung below the back rest portion 1 by means of hooks integrally moulded kith the remainder of the back portion 1. In addition, shaped cushions 20 and 21 are secured to the upper surfaces of the back rest portion 1 and the seat portion 2 to improve the comfort of the push chair. Comfort is also improved by utilising large wheels 16 and 17 having tyres of soft resilient material such as foamed poly (ethylene vinyl acetate). In order to enable the front and rear legs 3, 3 and 4, 4 to approach each other when the push chair is in its collapsed condition as shown in Figure 5, outer wheels 16 fitted to the front legs 3, 3 are disposed laterally outside inner wheels 17 fitted to the rear legs 4. 4. Thus, as shown in Figure 4, the inner wheels 17 are fitted swithin bifurcations 23 extending syrrinetrically on opposite sides of. the axes of the rear legs 4. The inner wheels 17 are rotatably mounted in the bifurcations 23 by means of integrally mounted on axles (not shown which seat in internal recesses formed in the bifurcations 23 and fabrication is facilitated by providing moulded slots with lead-in ramps which enable the bifurcations 23 to be temporarily sprung apart before the inner wheels 17 are snapped into position. The outer wheels 16 are mounted in a similar manner, but in this case, as shown in Figure 6, the outer wheels 16 are mounted in laterally offset bifurcations 22 which are dimensioned such that, when the push chair is in its collapsed condition, as shorn in Figure 5 the inner wheels 17 are disposed between the outer wheels 16. An inverted 8 shaped aluminium handle member of extruded boxsection has a cross-piece 5 and two side shafts 6 which are pivotally connected to the sides of the back rest portion 1 by means of pivot pins defining a second horizontal axis S extending parallel to the first horizontal axis 7. The side shafts 6 are connected to the rear legs 4 by means of two links 11 by means of pivot pins aligned on third and fourth horizontal axes 12 and 13 extending parallel to the first and second horizontal axes 7 and S. Stop surfaces 14 and 15 respectively formed on the front and rear legs 3, 3 and 4, 4 come into abutting engagement when the push chair is in its erected condition so as to prevent the front and rear legs 3 and 4 from spreading further apart. Similarly, stops 9 formed in opposite sides of the back rest portion 1 prevent the side shafts 6 of the handle member from moving upwardly beyond a first position which the handle member occupies when the chair is in its erected condition. Spring loaded hooks 10 are mounted on the stops 9 for releasable engagement vith extensions of the pivot pins defining the third horizontal axis 12 for locking the handle member in its first position and thereby locking the posh chair in its erected condition. Although only shown schematically, one of the hooks 10 latches automatically when the handle member is in its first position and the other hook must be latched manually, in accordance with British Standards Institute safety regulations. To collapse the push chair, it is merely necessary to release the manually latched hook 1Q and then the automatically latched hook 10 and, thereafter, to &commat; grasp the upper end of the back rest portion 1 and lift the push chair off its supporting surface. The front and rear legs 3, 3 and 4, 4 swing towards each other under their own weight and, during this movement, links 11 cause the side shafts 6 of the handle member to move until they lie alongside the rear legs 4. The collapsible posh chair is then free-standing on its four wheels and can be conveniently stored in a small space. To re-erect the push chair, it is merely necessary to swing the handle member 5 and 6. upwards from its second position, in which the side shafts 6 lie alongside the rear legs 4, 4, to its first position and then to engage the hooks 10. This can be done with one hand when the otherhand is being used to hold a child to be placed into the e:ected push chair. Lateral stability is improved by the provision of a foot rest 19 extending between the front legs 3, 3 and forming an integral part of the first structural component. A similar effect may be achieved by providing a stiffener which extends between the rear legs 4 4 and is formed integrally with the remainder of the second structural component. As shown, the back rest portion 1, the seat portion 2, the foot rest 19 and the stiffener 25 may be of slotted configuration in order to save moulding material and avoid unnecessary weight. An aperture 26 may also be formed in the back rest portion 1 in order to facilitate lifting and folding of the push chair into its collapsed condition. The moulded construction of the first and second structural components also lends itself to the formation of nonuniform cross-sections so that the more heavily loaded parts of these structural components may be dimensioned accordingly. Similarly, the seat portion 1 may be moulded with integral side edges and the sides of the back rest portion 3 may be formed with outwardly flared "wings". It is also possible to form the moulded plastic parts wsth slots 27, as shown in Figure 6, but omitted from the other figures for clarity. Integrally moulded lugs 28, may also he provided on the back rest portion for supporting a receptacle 15 as shorn in Figure 1.

Claims: Claims 1. A collapsible push chair comprising a back rest portion, a seat portion, pairs of front and rear legs supporting the seat and back rest portions, and handle means, characterised in that: the front legs (3, 3) and back restpztion (1) are formed as an integral plastic moulding comprising a first structural component (1 and 3, 3) in which the legs (3, 3) project from the back rest portion (1); the rear legs (4, 4) and seat portion (2) are formed as and integral plastic moulding comprising a second structural component (2 and 4, 4) in which the legs (4, 4) project from the seat portion (2) the first and second structural components (1 and 3, 3, and 2 and 4, 4) are interconnected so that the pair of legs (3, 3 or 4, 4) of one of the first and second structural components (1 and 3, 3, or 2 and 4, 4) straddle the other of the first and second structural components (2 and 4, 4 or 1 and 3, 3) for pivotal movement, about a first horizontal axis (7), between first and second configurations respectively corresponding to erected and collapsed conditions of the push chair, in which the front legs (3, 3) extend, respectively, alongside the rear legs (4, 4) and diverge downwardly from the rear legs (4, 4); the handle means (5 and 6, 6) comprise at least one shaft (6) connected to the back rest portion (1) for pivotal movement about a second horizontal axis (8) parallel to the first horizontal axis (7) between first and second positions, respectively corresponding to the erected and collapsed conditions of the push chair, in which said shaft (6) extends, respectively, away from the front legs (3, 3) and alongside the rear legs (4, 4); positioning means (9, 10) are provided for releasably locking said shaft (6) relative to the back rest portion (1) when the push chair is in its erected condition; and link means (11, 11) extend between pivotal connections with said shaft (6) and at least one of the rear legs (4, 4) for pivotal movement about third and fourth horizontal axes (12 and 13) which are parallel to the first and second horizontal axes (7 and 8) so that movement of said shaft (6) between its first and second positions effects movement of the first and second structural components (1 and 3, 3 and 2 and 4, 4) between their first and second configurations corresponding to erected and collapsed conditions of the push chair. 2. A collapsible push chair according to Claim 1, in which stop surfaces (14 and 15) are provided on the first and second structural components (1 and 3, 3 and 2 and 4, 4) for engagement when the first and second structural components (1 and 3, 3, and 4, 4) are in their first configuration. 3. A collapsible push chair according to Claim 1 or Claim 2, in which the legs (3, 3 or 4, 4) of said one of the first and second structural components (1 and 3, 3 or 2 and 4, 4) are provided with outer wheels (16) respectively laterally offset from the axes of said legs (3, 3 or 4, 4) and the legs (4, 4 or 3, 3) of said other of the first and second structural components (2 and 4, 4, or 1 and 3, 3) are provided with inner wheels (17) respectively aligned with the legs (4, 4 or 3, 3) of the other of the first and second structural components (2 and 4, 4 or 1 and 3, 3) so as to be laterally inside the outer wheels (16). 4. A collapsible push chair according to any preceding claim, in which the handle means comprise an inverted "U"-shaped member (5 and 6, 6) having a cross-piece (5) and two side shafts (6) respectively connected to opposite sides of the back rest portion (2) for pivotal movement about the second horizontal axis (8) for movement of each said side shaft (6) between its first and second positions. 5. A collapsible push chair according to Claim 4, in which a receptacle (18) is slung from the back rest portion (1), between the side shafts (6) of the "U"-shaped member (5 and 6, 6). 6. A collapsible push chair according to any preceding claim, in which the first structural component (1 and 3, 3) includes an integrally-formed foot rest (19) extending between the front legs (3, 3).

Inventors: DAYKIN, KEVIN JOHN BOLBERRY HOUSE, MORTIMER, FRANK RADCLIFFE
Applicants: ANDREWS MACLAREN LIMITED
Application year: 1984
Main classification: B62B7
IPC codes: B62B7