GB2074281A

GB2074281A - Overcentre Locking Device for Collapsible Structures

Info

Publication number: GB2074281A
Application number: GB8112223A
Authority: GB
Original assignee: Wilson & Son Ltd Lawrence
Current assignee: Wilson & Son Ltd Lawrence
Priority date: 1980-04-21
Filing date: 1981-04-16
Publication date: 1981-10-28
Also published as: GB2074281B

Abstract

A locking device for a collapsible linkage structure in which a toggle linkage 40, 42, 44 serves to open and then, on moving into an over-centre position, to locks further folding linkage 10, 12, 14 in its open extended condition to form a rigid framework. The arms of the toggle linkage 40, 42 and further folding linkage 10, 12 are in two pairs which are mutually parallel in the collapsed position of the framework, the pairs of arms being in mutual contact when the rigid framework is formed. <IMAGE>

Description

SPECIFICATION Locking Device for Collapsible Structures This invention relates to locking devices for securing together two or more pivotable members in order to form a rigid frame. The invention is particularly, but not exclusively, applicable to folding frameworks in baby carriages or pushchairs.

According to the present invention, there is provided a locking device to secure a plurality of pivotable members together to form a rigid framework, said locking device including a plurality of arms which are pivotally connected to said framework and to each other through the intermediaries of linkages such that said arms may move relative to one another and to said framework, movement of said arms into an overcentre position locking said members together to form a rigid framework.

Preferably, said locking device will include two pairs of arms pivotally secured together and to the framework, a first pair of arms being adapted to be moved into said over-centre position so as to lock the members together to form a rigid framework.

Said two pairs of arms will preferably be mutually parallel in the collapsed position of the framework, and said pairs of arms will preferably be in mutual contact in the over-centre position of said first pair of arms.

Spring means will preferably extend between said arms and said framework to urge the framework to a collapsed position.

In order that the invention may be more readily understood, an embodiment thereof will now be described, by way of example, reference being made to the accompanying drawing, the single figure of which is a front elevation of a locking device according to the invention.

Referring to the drawing, there is shown mutually parallel members 2 and 4 which in the particular illustration form part of a foldable and collapsable frame of a collapsible pushchair or baby carriage. Pivotally secured to the members 2 and 4, by means of brackets 6 and 8 are members 10 and 12, the members 10 and 12 being pivotally secured together through the intermediary of a linkage 14 pivotally secured at 16 and 18 to the members 10 and 12. The members 10 and 12 are pivotally secured at second points 20 and 22 to the members 2 and 4 through the intermediaries of linkages 24 and 26 respectively, these linkages being pivotable about pivot points 24A and 26A respectively and being pivotally secured at 28 and 30 to the members 10 and 12. The brackets 6 and 8 are pivotally secured at 32 and 34 to the members 2 and 4, and rigidly secured at 36 and 38 to the members 10 and 12.

Pivotally secured to the pivot points 24A and 26A are arms 40 and 42 which are pivotally secured together through the intermediary of a bracket 44. The rear of the bracket 44 carries a stud or knob 46.

Coil springs 48 and 50 extend respectively between the pivot points 20, 28 and 22, 30, the springs being provided to assist collapse of the structure as will be hereinafter explained.

In the full line position shown, the various integers are not rigid, and the full line position indicates the state or positions of the integers during erection or collapse of the structure. When it is required to form a rigid framework, upward pressure is applied to the stud or knob 46 which causes the various integers to pivot about their respective pivot points, thus causing the members 10 and 12 to move into the in-line positions indicated by the chain lines referenced 1 0A and 12A. In this position, the members 1 0A and 1 2A lie substantially normal to the members 2 and 4.

At the same time, the arms 40 and 42 assume a substantially in-line relationship and continued upward pressure on the stud or knob 46 causes the arms 40 and 42 to pass upwardly over-centre, to the positions indicated by reference numerals 40A and 42A so as to lock together the framework formed by the members 2, 4 and 10, 12. In the locked position of the framework, the springs 48 and 50 will have been extended such that they will be in tension, and the bracket 44 and will lie against the underside of the linkage 14.

When it is required to collapse the structure, downward pressure is applied to the stud or knob 46 thus causing the various integers to return to the full line positions shown in the drawing, such movement being assisted by the release of the tension forces in the coil springs 48 and 50.

The members 2, 4, 10 and 12 are preferably formed of squaresection tubular material such as alloy or lightweight metal, the linkages preferably being formed of flat section alloy or other lightweight metal or mild steel.

As previously mentioned, the locking device according to the invention is particularly applicable to collapsible baby carriages and pushchairs, in which case the members 2 and 4 would form part of the framework of the baby carriage or pushchair, but it will be appreciated that the invention is equally applicable to other forms of collapsible structures.

Claims

1. A locking device to secure a plurality of pivotable members together to form a rigid framework, said locking device including a plurality of arms which are pivotally connected to said framework and to each other through the intermediaries of linkages which such that said arms may move relative to one another and to said framework, movement of said arms into an over-centre position locking said members together to form a rigid framework.

2. A locking device according to Claim 1, wherein said locking device includes two pairs of arms pivotally secured together and to the framework, a first pair of arms being adapted to be moved into said over-centre position so as to

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

SPECIFICATION Locking Device for Collapsible Structures This invention relates to locking devices for securing together two or more pivotable members in order to form a rigid frame. The invention is particularly, but not exclusively, applicable to folding frameworks in baby carriages or pushchairs.

According to the present invention, there is provided a locking device to secure a plurality of pivotable members together to form a rigid framework, said locking device including a plurality of arms which are pivotally connected to said framework and to each other through the intermediaries of linkages such that said arms may move relative to one another and to said framework, movement of said arms into an overcentre position locking said members together to form a rigid framework.

Preferably, said locking device will include two pairs of arms pivotally secured together and to the framework, a first pair of arms being adapted to be moved into said over-centre position so as to lock the members together to form a rigid framework.

Said two pairs of arms will preferably be mutually parallel in the collapsed position of the framework, and said pairs of arms will preferably be in mutual contact in the over-centre position of said first pair of arms.

Spring means will preferably extend between said arms and said framework to urge the framework to a collapsed position.

In order that the invention may be more readily understood, an embodiment thereof will now be described, by way of example, reference being made to the accompanying drawing, the single figure of which is a front elevation of a locking device according to the invention.

Referring to the drawing, there is shown mutually parallel members 2 and 4 which in the particular illustration form part of a foldable and collapsable frame of a collapsible pushchair or baby carriage. Pivotally secured to the members 2 and 4, by means of brackets 6 and 8 are members 10 and 12, the members 10 and 12 being pivotally secured together through the intermediary of a linkage 14 pivotally secured at 16 and 18 to the members 10 and 12. The members 10 and 12 are pivotally secured at second points 20 and 22 to the members 2 and 4 through the intermediaries of linkages 24 and 26 respectively, these linkages being pivotable about pivot points 24A and 26A respectively and being pivotally secured at 28 and 30 to the members 10 and 12. The brackets 6 and 8 are pivotally secured at 32 and 34 to the members 2 and 4, and rigidly secured at 36 and 38 to the members 10 and 12.

Pivotally secured to the pivot points 24A and 26A are arms 40 and 42 which are pivotally secured together through the intermediary of a bracket 44. The rear of the bracket 44 carries a stud or knob 46.

Coil springs 48 and 50 extend respectively between the pivot points 20, 28 and 22, 30, the springs being provided to assist collapse of the structure as will be hereinafter explained.

In the full line position shown, the various integers are not rigid, and the full line position indicates the state or positions of the integers during erection or collapse of the structure. When it is required to form a rigid framework, upward pressure is applied to the stud or knob 46 which causes the various integers to pivot about their respective pivot points, thus causing the members

10 and 12 to move into the in-line positions indicated by the chain lines referenced 1 0A and 12A. In this position, the members 1 0A and 1 2A lie substantially normal to the members 2 and 4.

At the same time, the arms 40 and 42 assume a substantially in-line relationship and continued upward pressure on the stud or knob 46 causes the arms 40 and 42 to pass upwardly over-centre, to the positions indicated by reference numerals 40A and 42A so as to lock together the framework formed by the members 2, 4 and 10, 12. In the locked position of the framework, the springs 48 and 50 will have been extended such that they will be in tension, and the bracket 44 and will lie against the underside of the linkage 14.

When it is required to collapse the structure, downward pressure is applied to the stud or knob 46 thus causing the various integers to return to the full line positions shown in the drawing, such movement being assisted by the release of the tension forces in the coil springs 48 and 50.

The members 2, 4, 10 and 12 are preferably formed of squaresection tubular material such as alloy or lightweight metal, the linkages preferably being formed of flat section alloy or other lightweight metal or mild steel.

As previously mentioned, the locking device according to the invention is particularly applicable to collapsible baby carriages and pushchairs, in which case the members 2 and 4 would form part of the framework of the baby carriage or pushchair, but it will be appreciated that the invention is equally applicable to other forms of collapsible structures.

Claims

1. A locking device to secure a plurality of pivotable members together to form a rigid framework, said locking device including a plurality of arms which are pivotally connected to said framework and to each other through the intermediaries of linkages which such that said arms may move relative to one another and to said framework, movement of said arms into an over-centre position locking said members together to form a rigid framework.

2. A locking device according to Claim 1, wherein said locking device includes two pairs of arms pivotally secured together and to the framework, a first pair of arms being adapted to be moved into said over-centre position so as to lock the members together to form a rigid framework.

3. A locking device according to Claim 2, wherein said two pairs of arms are mutually parallel in the collapsed position of the framework, and wherein in the over-centre position of said first pair of arms said pairs of arms are in mutual contact.

4. A locking device according to Claim 2 or Claim 3, wherein in the over-centre position of said first pair of arms, the arms of said second pair of arms are in a substantially in-line position relative to each other.

5. A locking device according to any of Claims 1 to 4, including spring means extending between said arms and said framework to urge the framework to a collapsed position.

6. A locking device according to any of the proceeding Claims, wherein said arms are formed of tubular material.

7. A locking device substantially as herein described with reference to and as illustrated in the accompanying drawing.

8. A collapsible structure having a locking device as herein described.

9. A collapsible structure having a locking device according to any of Claims 1 to 7.

10. A collapsible pushchair or baby carriage including a locking device according to any of Claims 1 to 7.