GB2168891A

GB2168891A - Lockable steering structure

Info

Publication number: GB2168891A
Application number: GB08432705A
Authority: GB
Inventors: Ho Huang Young
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-12-28
Filing date: 1984-12-28
Publication date: 1986-07-02
Also published as: GB8432705D0

Abstract

A lockable steering structure suitable for the front wheels of a push chair for children includes a grooved block 4 slidable upon T shaped rails 13, 32 attached to both a support frame 1 and a wheel mount 3 so that in a locked position the block engages both rails, so locking the wheel mount to the support frame, and in an unlocked position the block engages only one rail. The block is mounted in the unlocked position by a stud 131 which is snap engageable with a recess (411) on the block. <IMAGE>

Description

SPECIFICATION A lockable steering structure The present invention relates to a lockable steering structure for a hand propelled vehicle and particularly but not exclusively for a push chair for children.

Steering structures are known for attaching steerable wheels to a hand propelled vehicle, as for example in the front wheels of a push chair for children. It is also known to make such structures selectively lockable so that the wheels of the vehicle are then fixedly aligned to adapt to conditions under which steerable wheels are undesirable.

A known steering structure includes a support frame for attachment to the vehicle, a wheel mount pivotally connected to the support frame and locking means for selectively locking the wheel mount relative to the support frame.

Such locking means have hitherto either been of a complex construction or of simple but unreliable construction.

According to the present invention a lockable steering structure includes a support frame for attachment to a vehicle, a wheel mount pivotally connected to the support frame, and locking means for selctively locking the wheel mount relative to the support frame wherein the locking means comprises a first rail of T shape cross section upon the support frame, a second rail of corresponding cross section upon the wheel mount, and a block having a T shaped groove cooperating with the rails and slideable thereupon between a locked position in which the block engages both rails and an unlocked position in which the block engages a single rail.

In a preferred embodiment the locking means includes securing means operative between the block and at least one of the rails whereby accidental movement of the block is resisted.

Conveniently the securing means comprises a stud projecting from a rail and a recess in the block with which the stud is snap engageable. The block thereby is held in position until positively moved by an operator.

In a preferred embodiment the stud projects from the uppermost portion of the first rail and the corresponding recess in the block is adjacent its uppermost portion so that the block encounters the stud only near to its limit of travel and therefore the stud does not otherwise restrict movement of the block.

Advantageously the block has gripping means for ease of hand gripping and preferably has an indentation for thumb engagement.

Preferably the wheel mount comprises a retainer mount pivotally connected to the support frame about a steering axis and a wheel support defining a rolling axis of one or more wheels attachable thereto and hinged to the retainer mount to allow reciprocating vertical movement of the wheels.

This vertical movement is damped by a resilient cushion operative between the retainer mount and wheel support so that the cushion is compressed under loading of the vehicle.

Advantageously the rolling axis is perpendicular to and spaced from the steering axis to thereby provide self steering in the unlocked position. A specific embodiment of the invention will now be described with reference to the accompanying drawings of which Figure 1 is a three-dimensional analytical perspective of a steering structure according to the present invention for use in a push chair; Figure 2 is a three-dimensional assemblage perspective of the steering structure of Figure 1, and Figure 3 is a partial cross-section view of the steering structure of Figures 1 and 2.

Referring to Figure 1 a steering structure has a support frame 1, a wheel mount comprising a wheel support 5 and a retainer mount 3, a pivot 2, a block 4, and a cushion 6. The steering structure is particularly useful for the front wheels of a baby cart or pushchair.

A bearing 11 is provided on the support frame 1 to permit fitting of the pivot 2. A hollow, rectangularly formed member 12, integrated to the support frame 1, extends at an upward angle to permit insertion of a leg (not shown) of a push chair, there being provided two pairs of holes 121, 121A and 121 B, 121C on both sides of the hollow member 12, such that the support frame 1 may be fixed to the leg. A first T shape rail 13 is provided on the support frame 1 with a stud 131 on its uppermost portion. The block 4 may be retained in the unlocked position by snap engaging the stud 131 with a recess 411 on the block.

On one upward end of the pivot 2 a round flange 21 is provided which will bear against the outer rim 111 of the bearing 11. The downward tip of the pivot 2 is penetrated by a hole 22 allowing hinged attachment of the wheel support 5 by a hinge pin 511.

The retainer mount 3 is provided with a hole 31 on one end to accommodate fitting of the pivot 2.

A T shape rail 32 is provided on the retainer mount corresponding to the T shape rail 13 provided on the support 1.

The block 4 is provided with a T shape groove 41 to be slideable on the T shape rails 13, 32 such that a change in the position of the block 4 will be sufficient to lock the support frame 1 and the retainer mount 3 together. A recess 411 is provided at the uppermost end of the groove such that recess 411 will be in a position to accommodate the stud 131 as provided on the terminal section of T shape rail when the block 4 slides to reach the terminal end of T shape rail 13 whereupon the block 4 will become fixed to the frame support 1. A thumb grip 42 is provided thereupon to facilitate manual movement of the block.

The wheel support 5 is composed of two symmetrically structured linked brackets and by virtue of a pair of corresponding holes 51, 51A provided on either bracket, a bolt pin 511 can secure the brackets to the outside of the retainer mount 3 by penetration therethrough to reach hole 22 provided on the terminal end of pivot 2 across the axial hole 33 relative to the support frame 3.

The wheel support 5 may thereby be hinged to the retainer mount 3 whilst another pair of corresponding holes 52, 52A are also provided for receiving an axle and thereby defining a rolling axis.

The cushion 6 is made of supple but sufficiently tough material, fitted between the retainer mount 3 and the wheel gear 5 to absorb shock.

The rolling axis is spaced from the pivot 2 so as to provide automatic steering of the wheel mount in the unlocked position as the pushchair changes direction.

In use, when it is desired to fix the direction of progression of the front wheel, an operator engages the block 4 across both the T shape rails 13 and 32 as shown in Figure 3A so that the support frame 1 is united with the retainer mount 3. When this takes place, then the wheel support 5 is secured to the retainer mount 3 and will be aligned in a fixed steering direction. Where it is desired to allow the front wheel to steer freely, an operator displaces the block 4 to the terminal end of the T shape rail 13 associated with frame support 1 in order that the stud 131 is engaged into the recess cavity 411 incorporated in the block 4 as shown in Figure 3B.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

1. A lockable steering structure including a support frame for attachment to a vehicle, a wheel mount pivotally connected to the support frame, and locking means for selectively locking the wheel mount relative to the support frame wherein the locking means comprises a first rail of T shape cross section upon the support frame, a second rail of corresponding cross section upon the wheel mount, and a block having a T shaped groove cooperating with the rails and slideable thereupon between a locked position in which the block engages both rails and an unlocked position in which the block engages a single rail.

2. A lockable steering structure as claimed in claim 1 wherein the locking means includes securing means operative between the block and at least one of the rails whereby accidental movement of the block is resisted.

3. A lockable steering structure as claimed in claim 2 wherein the securing means comprises a stud projecting from a rail and a recess in the block with which the stud is snap engageable.

4. A lockable steering structure as claimed in claim 3 wherein the stud projects from the uppermost portion of the first rail and the corresponding recess in the block is adjacent its uppermost portion.

5. A lockable steering structure as claimed in any preceding claim wherein the block includes gripping means adapted for hand gripping of the block.

6. A lockable steering structure as claimed in claim 5 wherein the gripping means includes an indentation on the block for thumb engagement.

7. A lockable steering structure as claimed in any preceding claim wherein the wheel mount comprises a retainer mount pivotally connected to the support frame about a steering axis and a wheel support defining a rolling axis of one or more wheels attachable thereto and hinged to the retainer mount to allow reciprocating vertical movement of the rolling axis.

8. A lockable steering structure as claimed in claim 7 wherein vertical movement of the rolling axis is damped by a resilient cushion operative between the retainer mount and the wheel support.

9. A lockable steering structure as claimed in claim 7 wherein the rolling axis is perpendicular to and spaced from the steering axis to thereby provide self steering in the unlocked position.

10. Baby cart front wheel steering structure of a type to consist essentially of a frame support, rotation shafts, bearing mounts, blocks, and wheel gear, characterised in the provision of a penetration hole on the frame support associated with a projectingly provided T shape rail, the penetration hole permitting fitting in full by a rotation shaft limited by a bearing mount incorporating similarly structured T shape rail on that end thereof extending exposed onto the bearing support, such that a block having complementary T shape rail may be engaged to such a T shape rail to assume control of the frame support in relation to the bearing mount, both united together or else set apart thereby, serving to transmit the wheel gear that is locked to the bearing mount to steer freely or else be bound in a fixed direction of progression in reinforced stability and security as distinguished from all known type of executions of baby carts industry.

11. Baby cart front wheel steering structure of a type substantially as identified in claim 1, characterised in that a bulging nose is provided on the terminal section of the T shape rail associated with the frame support, which nose will be brought to engage into a recess cavity provided at the bottom of the T shape groove as dependent on the block as the block sets the terminal section of the T shape rail structured projectingly on the frame support to displacement, so that the block may be checked steadfast in position, the whole production schedule as well as assembling procedure proven to be much more time and labour saving than does any other known heretofore in the industry.

12. A lockable steering structure as hereintofore described with reference to the accompanying drawings.