GB2452956A

GB2452956A - Swivel lock for a castor

Info

Publication number: GB2452956A
Application number: GB0718375A
Authority: GB
Inventors: Shun-Min Chen; Ru-Yi Li
Original assignee: Wonderland Nurserygoods Co Ltd Taiwan
Current assignee: Wonderland Nurserygoods Co Ltd Taiwan
Priority date: 2007-09-20
Filing date: 2007-09-20
Publication date: 2009-03-25
Anticipated expiration: 2027-09-20
Also published as: GB0718375D0; GB2452956B

Abstract

A steering lock mechanism for a castor comprises a rotatable seat 21 to be mounted with a castor; a fixed seat 12 disposed on a leg [101, Fig. 3] of a moving device, e.g. a stroller; and a sliding locking latch 13 housed within a slide slot 22 formed on the rotatable seat 21. The locking latch 13 includes a latch body 131 and a resilient biasing means 132 projecting from the latch body 131. The locking latch 13 can be slid between a locking state [as shown in Fig. 11] where the latch body 131 is biased by the resilient portion 132 to extend into and engage a positioning slot [126, Fig. 11] of the fixed seat 12, and a release state [as shown in Fig. 7] where the latch body 131 is removed from the positioning slot so as to allow for rotation of the rotatable seat 21 relative to the fixed seat 12. The slide slot 22 has a neck portion [23, Fig. 7] which cooperates with the resilient portion 132 to maintain the locking latch 13 in the locking state.

Description

1 2452956

STEERING LOCK MECHMISM FOR A CASTER

This invention relates to a steering lock mechanism, and more particularly to a steering lock mechanism for use with a caster of a moving device for carrying a baby.

Referring to Figs. land 2, a caster assembly 9 disclosed in U.S. Patent No. 6,163,924 may be used on a stroller (not shown) . The caster assembly 9 has a steering lock mechanism including a fixed seat 92, a rotatable seat 91 sleeved rotatably on the fixed seat 92, a rotary lever 93 connected pivotally to the rotatable seat 91, and a spring-biased lug 94 disposed in the rotatable seat 91.

The fixed seat 92 is connected to a leg 901 of the stroller, and is formed with a downwardly facing notch 921. The rotatable seat 91 is formed with an aperture 911 for receiving a wheel axle (not shown) When no external force is applied to the rotary lever 93, a free end of the rotary lever 93 is in an upper limit position shown in Fig. 1. In this state, the lug 94 is spaced apart from the notch 921 in the fixed seat 92 to allow for rotation of the rotatable seat 91 relative to the fixed seat 92. Said differently, rotation of a caster of the caster assembly 9 about a vertical axis is allowed.

With particular reference to Fig. 2, when a downward force is applied to the free end of the rotary lever 93 by the user (e.g., by stepping on the rotary lever 93), a lug operating cross member 95 moves the lug 94 upwardly to engage the notch 921 in the fixed seat 92. As a result, the rotatable seat 91 is locked against the fixed seat 92 to thereby prevent rotation of the caster about the vertical axis.

The aforesaid caster assembly 9 suffers from the following disadvantages: (1) The steering lock mechanism is complicated in construction.

(2) To convert the rotatable seat 91 from a released state shown in Fig. 1 into a locked state shown in Fig. 2, it is necessary to apply a large force to the rotary lever 93.

(3) The operation of the rotary lever 93 imparts a feeling of discomfort to the baby, and may even pose a safety risk (i.e., overturning of the stroller due to the large force required to operate the rotary lever 93).

An object of this invention is to provide a steering lock mechanism for a caster, which is simple in construction.

Another object of this invention is to provide a steering lock mechanism for a caster, which can be operated by applying a small force so that the steering is locked automatically when a rotatable seat is rotated to a position.

Still another object of this invention is to provide a steering lock mechanism for a caster of a stroller, which does not, when operated, impart a feeling of discomfort to the baby carried on the stroller nor cause overturning of the stroller.

According to an aspect of this invention, a steering lock mechanism is adapted to be mounted on a moving device.

The moving device includes at least one leg and a caster.

The steering lock mechanism comprises; a fixed seat adapted to be disposed on the leg and formed with a positioning slot extending along an axial direction; a rotatable seat disposed rotatably on the fixed seat and adapted to be mounted with the caster, the rotatable seat being formed with a slide slot that extends along the axial direction and that has a neck portion, the rotatable seat being rotatable relative to the fixed seat so as to align the slide slot with the positioning slot along the axial direction; and a locking latch convertible between a locking state and a release state and including a latch body movable within the slide slot in the rotatable seat to extend into and retract from the positioning slot in the fixed seat, and a resilient portion projecting laterally from the latch body; wherein, when the locking latch is in the locking state, the resilient portion is disposed above the neck portion of the slide slot in the rotatable seat so as to bias the latch body to engage the positioning slot in the fixed seat; wherein, when the locking latch is in the release state, the latch body is removed from the positioning slot.

According to another aspect of this invention, a stroller comprises: a frame having a plurality of legs; a plurality of casters; and a plurality of steering lock mechanisms disposed respectively on the legs, each of the steering lock mechanisms including a fixed seat disposed on a corresponding one of the legs and having a positioning slot extending along an axial direction, and a rotatable seat disposed rotatably on the fixed seat and mounted with a corresponding one of the casters, the rotatable seat being formed with a slide slot that extends along the axial direction and that has a neck portion, the rotatable seat being rotatable relative to the fixed seat so as to align the slide slot with the positioning slot along the axial direction, and a locking latch convertible between a locking state and a release state and including a latch body movable within the slide slot in the rotatable seat to extend into and retract from the positioning slot in the fixed seat, and a resilient portion projecting laterally from the latch body; wherein, when the locking latch is in the locking state, the resilient portion is disposed above the neck portion of the slide slot in the rotatable seat so as to bias the latch body to engage the positioning slot in the fixed seat; wherein, when the locking latch is in the release state, the latch body is removed from the positioning slot.

These and other features and advantages of this invention will become apparent in the following detailed description of a preferred embodiment of this invention, with reference to the accompanying drawings, in which: Fig. 1 is a schematic side view of a caster assembly disclosed in U.S. Patent No. 6,163,924 when a rotatable seat is released from a fixed seat; Fig. 2 is a schematic side view of the caster assembly shown in Fig. 1 when the rotatable seat is locked against the fixed seat; Fig. 3 is an assembled perspective view of the preferred embodiment of a steering lock mechanism according to this invention, which is connected to two casters; Fig. 4 is an exploded perspective view of the preferred embodiment; Fig. 5 is a bottom perspective view of a fixed seat of the preferred embodiment; Fig. 6 is a perspective view of a locking latch of the preferred embodiment; Fig. 7 is a schematic front view of the preferred embodiment when the locking latch is in a release state; Fig. 8 is a schematic front view of the preferred embodiment, illustrating the transition of the locking latch from the release state to a locking state; Fig. 9 is a fragmentary sectional view of the preferred embodiment, illustrating the transition of the locking latch from the release state to the locking state; Fig. 10 is a schematic front view of the preferred embodiment when the locking latch is in the locking state; and Fig. 11 is a fragmentary sectional view of the preferred embodiment when the locking latch is in the locking state.

Referring to Figs. 3 and 4, the preferred embodiment of a steering lock mechanism 1 according to this invention is mounted to a moving device, such as a stroller. The moving device includes a frame having a plurality of legs 101 (only one is shown in Fig. 3), and a plurality of casters 102. With particular reference to Fig. 3, two of the casters 102 are mounted on one of the legs 101 by the steering lock mechanism 1. The steering mechanism 1 may be mounted to any one, each, or any combination of two or more of the legs 101 of the stroller.

The steering lock mechanism 1 includes a fixed seat 12, a rotating unit 11 sleeved rotatably on the fixed seat 12, and a locking latch 13 disposed movably within the rotating unit 11.

With further reference to Fig. 5, the fixed seat 12 includes a housing 120, an insert tube 122, and a cap portion 124 disposed around the insert tube 122 and having a bottom end formed with a positioning slot 126 extending along an axial direction (A) (see Fig. 7). The cap portion 124 has an oval top wall 128 extending radially and outwardly from a top end of the insert tube 122, a surrounding wall 121 extending downwardly from a periphery of the top wall 128, and a lug 123 extending upwardly from the top wall 128.

The surrounding wall 121 has a distal wall portion 1210 and a proximate wall portion 1219 that is disposed nearer to the insert tube 122 than the distal wall portion 1210.

The positioning slot 126 is defined by two ribs 127 extending from the distal wall portion 1210 of the surrounding wall 121 toward the insert tube 122 and spaced apart from the insert tube 122.

The rotating unit 11 includes a rotatable seat 21, a shock-absorbing member 26, and a hub-connecting member 27.

With further reference to Figs. 7, 8, and 9, the rotatable seat 21 has an upwardly opening sleeve tube portion 215 sleeved rotatably on the insert tube 122 of the fixed seat 12, a top wall 211 extending radially and outwardly from an annular outer surface of the sleeve tube portion 215, a skirt portion 212 extending from a periphery of the top wall 211, and a slide slot 22 (see Fig. 9) . The slide slot 22 extends along the axial direction (A), and has a neck portion 23. The skirt portion 212 has a distal portion 2120, a proximate portion 2129 disposed nearer to the sleeve tube portion 215 than the distal portion 2120, and two aligned pivot holes 218 formed respectively in two opposite sides of the skirt portion 212 and disposed in proximity to a bottom end of the skirt portion 212.

The slide slot 22 is defined between the proximate portion 2129 of the skirt portion 212 and the sleeve tube portion 215. The top wall 211 is formed with a top-wall opening 210 (see Fig. 4) that is in spatial communication with the slide slot 22 and that allows the locking latch 13 to project upwardly from the top wall 211 therethrough.

The skirt portion 212 is formed with a skirt opening 217 that, in this embodiment, is in spatial communication with the slide slot 22 and that has an upper end in spatial communication with the top-wall opening 210 in the top wall 211. The neck portion 23 is defined by two triangular projections 231 that extend toward each other from an annular inner wall surface 222 of the rotatable seat 21 defining the slide slot 22. Each of the projections 231 has an upper inclined side 223 and a lower inclined side 224. A distance between lower ends of the lower inclined sides 224 is greater than that between upper ends of the same. A distance between upper ends of the upper inclined sides 223 is greater than that between lower ends of the same. The neck portion 23 is defined between the upper ends of the lower inclined sides 224 and the lower ends of the upper inclined sides 223.

The hub-connecting member 27 has a top end formed with an accommodating chamber 271 for receiving the shock-absorbing member 26, and a bottom end formed with a horizontal through hole 272 allowing for extension of an axle (not shown) therethrough. The axle has two ends connected respectively to the two casters 102 (see Fig. 3). The hub-connecting member 27 has a top end portion disposed between the pivot holes 218 in the rotatable seat 21. A pivot pin (not shown) extends through the top end portion of the hub-connecting member 27 and the pivot holes 218. The shock-absorbing member 26 is disposed within the accommodating chamber 271 in the hub-connecting member 27 between the top wall 211 of the rotatable seat 21 and the hub-connecting member 27. The shock-absorbing member 26 is made of an elastic material, such as rubber. As such, when a load or a shock is applied to either the rotatable seat 21 or the hub-connecting member 27, it is buffered by the shock-absorbing member 26.

The sleeve tube portion 215 of the rotatable seat 21 is inserted between the insert tube 122 and the cap portion 124, and is rotatable about the insert tube 122. The leg 101 is inserted into the insert tube 122 of the fixed seat 12. A lock pin or lock bolt (not shown) extends through the lug 123 and the leg 101 so as to anchor the leg 101 within the insert tube 122.

With further reference to Fig. 6, the locking latch 13 includes a latch body 131 and a retaining reed 130. The latch body 131 is hollow and elongated, and is formed with an accommodating space 131' for receiving the retaining reed 130, two lateral openings 133 disposed respectively at two opposite sides of the latch body 131 and in spatial communication with the accommodating space 131', and a bottom end opening 134 in spatial communication with the lateral openings 133. The latch body 131 is further formed with an actuation portion 135 in the form of a horizontal plate, which extends from a middle portion thereof arid which projects from the rotatable seat 21 via the skirt opening 217 for operation by the user. The retaining reed 130 is generally inverted U-shaped, and has two bent arms 136 each having a V-shaped resilient portion 132. The resilient portions 132 of the bent arms 136 project respectively and laterally from the lateral openings 133 in the latch body 131.

The latch body 131 is movable within the slide slot 22 in the rotatable seat 21 so as to convert the locking latch 13 between a release state shown in Fig. 7 and a locking state shown in Fig. 10.

When the locking latch 13 is in the release state, the resilient portions 132 of the retaining reeds 130 are disposed between the lower inclined sides 224 of the projections 231, and the latch body 131 is spaced apart from the positioning slot 126 in the fixed seat 12. In this state, the rotatable seat 21 is rotatable relative to the fixed seat 12. Said differently, the casters 102 are rotatable about a central axis of the leg 101.

When it is desired to limit the moving direction of the casters 102, an upward force is applied to the actuator of the latch body 131 to move the locking latch 13 upwardly from the position shown in Fig. 7 along the slide ii slot 22 in the rotatable seat 21. When the locking latch 13 is moved to a transition position shown in Fig. 8, where the resilient portions 132 of the retaining reed 130 come into contact with the lower ends of the upper inclined sides 223 of the projections 231, respectively, due to the return farce of the resilient portions 132, a top end of the latch body 131 is biased by the retaining reed 130 to press against a bottom edge of the surrounding wall 121 of the fixed seat 12, as shown in Fig. 9. In this state, when the rotatable seat 21 is rotated to a position whereat the latch body 131 is aligned with the positioning slot 126 in the fixed seat 12, the top end of the latch body 131 is biased by the retaining reed 130 to engage the positioning slot 126, as shown in Figs. 10 and 11. Hence, the rotatable seat 21 is locked automatically against the fixed seat 12 to thereby prevent rotation of the casters 102 about the central axis of the leg 101.

Subsequently, when it is no longer necessary to limit the moving direction of the casters 102, the actuation portion 135 of the latch body 131 is moved downwardly to remove the top end of the latch body 131 from the positioning slot 126 in the fixed seat 12. When the resilient portions 132 of the retaining reed 130 come into contact with the lower inclined sides 224 of the projections 231, respectively, removal of the top end of the latch body 131 from the positioning slot 126 in the fixed seat 12 can be maintained, thereby allowing for rotation of the rotatable seat 21 relative to the fixed seat 12.

The steering lock mechanism 1 of this invention has the following advantages: (1) The number of components of the steering lock mechanism 1 is reduced, as compared to that disclosed in u.S. Patent No. 6,163,924.

(2) To convert the locking latch 13 from the release state into the locking state, it is only necessary to apply a small force to the actuator portion 135 of the latch body 131. In other words, the steering lock mechanism 1 can be operated with ease.

(3) Since a small force is sufficient to operate the steering lockmechanism 1, tipping, vibration, and overturning of the stroller can be prevented.

(4) In a state where the resilient portions 132 of the retaining reed 130 are in contact with the upper inclined sides 223 of the projections 231, respectively, when the latch body 131 is rotated to align with the positioning slot 126 in the fixed seat 12, the latch body 131 is biased by the retaining reed 130 to engage the positioning slot 126. Thus, the operation of the steering lock mechanism 1 is convenient.

Claims

CLIMS: 1. A steering lock mechanism adapted to be mounted on a moving device, the moving device including at least one leg and a caster, the steering lock mechanism comprising: a fixed seat adapted to be disposed on the leg and formed with a positioning slot extending along an axial direction; a rotatable seat disposed rotatably on the fixed seat and adapted to be mounted with the caster, the rotatable seat being formed with a slide slot that extends along an axial direction and that has a neck portion, the rotatable seat being rotatable relative to the fixed seat so as to align the slide slot with the positioning slot along the axial direction; and a locking latch convertible between a locking state and a release state and including a latch body movable within the slide slot in the rotatable seat to extend into and retract from the positioning slot in the fixed seat, and a resilient portion projecting laterally from the latch body; wherein, when the locking latch is in the locking state, the resilient portion is disposed above the neck portion of the slide slot in the rotatable seat so as to bias the latch body to engage the positioning slot in the fixed seat; wherein, when the locking latch is in the release state, the latch body is removed from the positioning slot.
2. The steering lock mechanism as claimed in Claim 1, wherein the locking latch further includes a retaining reed having two bent arms, the latch body being formed with an accommodating space for receiving the retaining reed, and two lateral openings disposed respectively at two opposite sides of the latch body and in spatial communication with the accommodating space, portions of the bent arms of the retaining reed projecting respectively from the lateral openings in the latch body and constituting respectively the resilient portions.
3. The steering lock mechanism as claimed in Claim 1, wherein the rotatable seat has an upwardly opening sleeve tube portion, atop wall extending radially and outwardly from an annular outer surface of the sleeve tube portion, and a skirt portion extending from the top wall and spaced apart from the sleeve tube portion, the slide slot being disposed between the skirt portion and the sleeve tube portion.
4. The steering lock mechanism as claimed in Claim 3, wherein the top wall is formed with a top-wall opening that is in spatial communication with the slide slot and that allows the latch body to project upwardly from the top wall therethrough, the skirt portion being formed with a skirt opening in spatial communication with the slide slot, the locking latch further including an actuation portion connected to the latch body and projecting from the rotatable seat via the skirt opening for operation by the user.
5. The steering lock mechanism as claimed in Claim 1, wherein the rotatable seat has a sleeve tube portion, and the fixed seat includes an insert tube inserted into the sleeve tube portion of the rotatable seat, and a cap portion disposed around the insert tube and having a bottom end formed with the positioning slot.
6. The steering lock mechanism as claimed in Claim 1, wherein the neck portion of the slide slot is defined by two projections, the projections extending from an annular inner wall surface of the rotatable seat defining the slide slot toward each other.
7. The steering lock mechanism as claimed in Claim 6, wherein each of the projections has an upper inclined side and a lower inclined side, a distance between lower ends of the lower inclined sides being greater than that between upper ends of the lower inclined sides, a distance between upper ends of the upper inclined sides being greater than that between lower ends of the upper inclined sides.
8. The steering lock mechanism as claimed in Claim 1, further comprising a hub-connecting member, and a shock-absorbing member disposed between the rotatable seat and the hub-connecting member, the hub-connecting member being adapted to be mounted with the caster.
9. A steering lock mechanism substantially as hereinbefore described with reference to and illustrated in Figures 3 to 11 of the accompanying drawings.
lO.A stroller comprising: a frame having a plurality of legs; a plurality of casters; and at least one steering lock mechanism disposed on one of the legs, the steering lock mechanism including a fixed seat disposed on a corresponding one of the legs and having a positioning slot extending along an axial direction, a rotatable seat disposed rotatably on the fixed seat and mounted with a corresponding one of the casters, the rotatable seat being formed with a slide slot that extends along an axial direction and that has a neck portion, the rotatable seat being rotatable relative to the fixed seat so as to align the slide slot with the positioning slot along the axial direction, and a locking latch convertible between a locking state and a release state and including a latch body movable within the slide slot in the rotatable seat to extend into and retract from the positioning slot in the fixed seat, and a resilient portion projecting laterally from the latch body; wherein, when the locking latch is in the locking state, the resilient portion is disposed above the neck portion of the slide slot in the rotatable seat so as to bias the latch body to engage the positioning slot in the fixed seat; wherein, when the locking latch is in the release state, the latch body is removed from the positioning slot.
11. The stroller as claimed in Claim 10, wherein the locking latch further includes a retaining reed having two bent arms, the latch body being formed with an accommodating space for receiving the retaining reed, and two lateral openings disposed respectively at two opposite sides of the latch body and in spatial communication with the accommodating space, portions of the bent arms of the retaining reed projecting respectively from the lateral openings in the latch body and constituting respectively the resilient portions.
12.The stroller as claimed in Claim 10, wherein the rotatable seat has an upwardly opening sleeve tube portion, a top wall extending radially and outwardly from an annular outer surface of the sleeve tube portion, and a skirt portion extending from the top wall and spaced apart from the sleeve tube portion, the slide slot being disposed between the skirt portion and the sleeve tube portion.
13. The stroller as claimed in Claim 12, wherein the top wall is formed with a top-wall opening that is in spatial communication with the slide slot and that allows the latch body to project upwardly from the top wall therethrough, the skirt portion being formed with a skirt opening, the locking latch further including an actuation portion connected to the latch body and projecting from the rotatable seat via the skirt opening for operation by the user.
14.The stroller as claimed in Claim 10, wherein the rotatable seat has a sleeve tube portion, and the fixed seat includes an insert tube inserted into the sleeve tube portion of the rotatable seat, and a cap portion disposed around the insert tube and having a bottom end formed with the positioning slot.
15. The stroller as claimed in Claim 10, wherein the neck portion of the slide slot is defined by two projections, the projections extending from an annular inner wall surface of the rotatable seat defining the slide slot toward each other.
16. The stroller as claimed in Claim 15, wherein each of the projections has an upper inclined side and a lower inclined side, a distance between lower ends of the lower inclined sides being greater than that between upper ends of the lower inclined sides, a distance between upper ends of the upper inclined sides being greater than that between lower ends of the upper inclined sides.
17. The stroller as claimed in Claim 10, further comprising a hub-connecting member, and a shock-absorbing member disposed between the rotatable seat and the hub-connecting member, the hub-connecting member being adapted to be mounted with the caster.
18. A stroller substantially as hereinbefore described with reference to and illustrated in Figure 12 of the accompanying drawings.