Leg folding mechanism and a push chair
There is provided a leg folding mechanism, such as a leg folding mechanism for a push chair, the leg folding mechanism comprising a core member having a longitudinal axis and, preferably, first and second axially spaced core guides; a first leg member rotatably mounted on the core member, preferably at the first core guide; a second leg member rotatably mounted on the core member, preferably at the second core guide a shuttle disposed within the core member and moveable within the core member to cause movement of the legs as the shuttle moves within the core.
1 . A leg folding mechanism for a push chair, the leg folding mechanism comprising a core member having a longitudinal axis and first and second axially spaced core guides;
a first rotatable hub for connection to a first leg member and rotatably mounted on the core member at the first core guide;
a second rotatable hub for connection to a second leg member and rotatably mounted on the core member at the second core guide;
a shuttle disposed within the core member and axially translatable relative thereto;
wherein a first engagement portion from one or other of an internal surface of the first hub and an external surface of the shuttle engages with the first core guide to matingly engage with a corresponding first surface on the other of the internal surface of the first hub and the external surface of the shuttle, and a second engagement portion from one or other of an internal surface of the second hub and an external surface of the shuttle engages with the second core guide to matingly engage with a corresponding second surface on the other of the internal surface of the second hub and the external surface of the shuttle, such that in response to axial translation of the shuttle the first and second hubs are caused to rotate.
2 . The leg folding mechanism according to claim 1 , comprising an actuator configured to urge the shuttle to translate within the core member.
3 . The leg folding mechanism according to claim 1 , wherein the shuttle is arranged to move relative to the core having an axial component of movement.
4 . The leg folding mechanism according to claim 3 , in which the shuttle is disposed within the core member and is longitudinally axially translatable but rotationally fixed relative thereto.
5 . The leg folding mechanism according to claim 3 , wherein the shuttle includes at least one longitudinal rib on an exterior surface thereof and the core member includes at least one corresponding longitudinal groove in an internal surface thereof, or vice versa, to allow axial translation of the shuttle.
6 . The leg folding mechanism according to claim 1 , wherein the first and second surfaces are substantially helical surfaces on the shuttle and comprise respective first and second slots in the exterior surface thereof, and the corresponding matingly engaging internal surfaces of the hubs comprise respective first and second pegs and, wherein the first and second substantially helical slots are oriented oppositely, whereby axial translation of the shuttle causes the first hub to rotate in an opposite direction to the second hub.
7 . The leg folding mechanism according to claim 6 , wherein the first and second substantially helical slots include at least one straight end portion, parallel to the longitudinal axis.
8 . The leg folding mechanism according to claim 6 , wherein the first and second substantially helical slots each comprise an S-shaped curve between end portions thereof.
9 . The leg folding mechanism according to claim 1 , wherein the core member is substantially tubular and the first and second core guides are core slots and are circumferential slots, which are preferably rotationally offset from one another.
10 . The leg folding mechanism according to claim 1 , wherein the shuttle is substantially tubular.
11 . The leg folding mechanism according to claim 2 , wherein the actuator comprises a drive shaft at least partially housed within the shuttle and the core member and engaged with an internal portion of the shuttle, whereby rotation of the drive shaft is converted into axial translation of the shuttle within the core member and, wherein the drive shaft is the drive shaft of a motor fixedly connected to the core member.
12 . The leg folding mechanism of claim 2 , further comprising:
a third axially spaced core guide on or extending through a surface of the core member in a plane perpendicular to the longitudinal axis;
a third hub for connection to a third leg member and rotatably mounted on the core member at the third core guide; and
a third projection from one or other of an internal surface of the third hub and an external surface of the shuttle, which engages with the third core guide slot to matingly engage with a corresponding third surface on the other of the internal surface of the third hub and the external surface of the shuttle, such that the axial translation of the shuttle as the actuator is operated is also converted into rotation of the third hub member.
13 . The leg folding mechanism according to claim 1 , in which any or all of the engagement portions comprise a cam and a cam follower.
14 . The leg folding mechanism according to claim 13 , in which a rib is provided on the shuttle and the cam follower is provided on the internal surface of each hub, the cam followers arranged to follow the rib on the shuttle as it translates.
15 . A folding push chair comprising:
a subframe;
a handle assembly connected to the subframe for maneuvering the push chair; and
a seat assembly connected to the subframe;
wherein the subframe comprises a leg folding mechanism according to claim 1 .
16 . The folding push chair according to claim 15 , wherein upon operation of an actuator in a first direction the leg folding mechanism is urged to rotate the legs from an open configuration to a folded configuration upwardly away from the ground towards the seat assembly and wherein operation of the actuator in a second direction, opposite to the first, the leg folding mechanism is urged to rotate the legs from the folded configuration to the open configuration downwardly away from the seat assembly towards the ground.
17 . A folding push chair comprising:
a subframe;
a handle assembly connected to the subframe for maneuvering the push chair; and
a seat assembly connected to the subframe;
wherein the subframe comprises:
a first leg folding mechanism according to claim 1 ;
a first leg having a proximal end connected to the first hub and having a first wheel assembly mounted at a distal end;
a second leg having a proximal end connected to the second hub and having a second wheel assembly mounted at a distal end;
a second leg folding mechanism according to claim 1 ;
a third leg having a proximal end connected to the first hub of the second leg folding mechanism and having a third wheel assembly mounted at a distal end;
a fourth leg having a proximal end connected to the second hub of the second leg folding mechanism and having a fourth wheel assembly mounted at a distal end;
wherein the second and third legs extend forwardly away from the handle assembly (or vice versa) and the first and fourth legs extend rearwardly (or vice versa) beneath the chair assembly when in an open configuration for the respective wheel assemblies to engage the ground; wherein upon operation of an actuator in a first direction the leg folding mechanism urges rotation of the legs from the open configuration to a folded configuration upwardly away from the ground towards the seat assembly and optionally wherein operation of the actuator in a second direction, opposite to the first, urges the leg folding mechanism to rotate the legs from the folded configuration to the open configuration downwardly away from the seat assembly towards the ground.
18 . The folding push chair according to claim 17 , wherein the seat assembly is collapsible and wherein the first and fourth legs rotate in a first direction whilst the second and third legs rotate in an opposite direction, whereby when in the folded configuration the seat assembly is disposed in a collapsed condition between the first and fourth legs on a rearward side and the second and third legs on the forward side.
19 . The folding push chair according to claim 15 , wherein the first and second leg folding mechanisms are arranged symmetrically.
20 . The folding push chair according to claim 3 , wherein the axes of the first and second core members are co-axially arranged or wherein the first and second leg folding mechanisms are disposed in a V-shaped arrangement.
21 . A leg folding mechanism, comprising:
a core member having a longitudinal axis and first and second axially spaced core guides;
a first leg rotatably mounted on the core member at the first core guide;
a second leg member rotatably mounted on the core member at the second core guide; and
a shuttle within the core member and moveable within the core member to cause movement of the legs as the shuttle moves within the core member.
22 . The leg folding mechanism according to claim 21 , in which the first and second core guides are provided as slots in the core member.
23 . The leg folding mechanism according to claim 22 , wherein the first and second slots are helical and oriented oppositely, whereby axial translation of the shuttle causes a first hub for connection to the first leg member to rotate in an opposite direction to a second hub for connection to the second leg member.
24 . The leg folding mechanism according to claim 21 , further comprising a drive shaft of a motor fixedly connected to the core member.
25 . The leg folding mechanism according to claim 21 , wherein the shuttle includes an S-shaped rib on an exterior surface thereof.
26 . The leg folding mechanism according to claim 21 , further comprising an actuator configured to urge the shuttle to translate within the core member, wherein operation of the actuator in a second direction, opposite to a first, urges the leg folding mechanism to rotate the legs from a folded configuration to an open configuration.