GB2384517A

GB2384517A - Latch assembly with two latch members and a deformable track

Info

Publication number: GB2384517A
Application number: GB0201460A
Authority: GB
Inventors: Adrian Batchelor; Paul Sims
Original assignee: Britax Excelsior Ltd
Current assignee: Britax Excelsior Ltd
Priority date: 2002-01-23
Filing date: 2002-01-23
Publication date: 2003-07-30
Anticipated expiration: 2022-01-23
Also published as: GB0201460D0; GB2384517B

Abstract

A latch assembly 54, preferably for use in securing seat of pushchair or stroller, comprises a latch body with a deformable guide track 74, a primary latch 80, a secondary latch 92. Latch body has a opening 72 for receiving a connecting member 40. Primary latch 80 is slidable mounted on guide track 74 for movement between a latched position and a released position. Secondary 92 latch is pivotally mounted on latch body for angular movement between a latch position which obstructs movement of the primary latch 80, and a release position. In use, the connecting member 40 is pushed into opening 72 and displaces bulge 90 on primary latch against spring. Continued movement of connecting member 40 causes portions of front wall 64 to bend outwardly which allows connecting member 40 to move fully into opening 72. The primary latch 80 is now free to move back to its original position and the secondary latch 92 prevents disengagement.

Description

LATCH ASSEMBLY This invention relates to a latch assembly of the type having a latch body, a primary latch member for securing a connection member in engagement with the latch body and a secondary latch for resisting movement of the primary latch to a disengaged position. In order to release the connecting member, it is necessary first to disengage the secondary latch and then to disengage the primary latch. Latch assemblies of this type find particular application to the mounting of a pram body, a pushchair seat or an infant car seat on a chassis.

According to the invention, a latch for engagement with a connecting member comprises a latch body having a recess for receiving the connecting member and a resiliently deformable guide track extending transversely relative to said recess, a primary latch slidably mounted in the guide track for movement between a latched position in which it at least partially covers an outer end of the recess so as to retain such connecting member therein and a released position clear of the recess, a secondary latch pivotally mounted on the latch body for angular movement between a latched position in which a blocking formation therein obstructs movement of the primary latch into its released position and a released position in which the blocking formation allows movement of the primary latch to its released position and a heel on the secondary latch extends partially across an inner part of the recess to limit the extent to which the connecting member can enter into the recess, wherein resilient deformation of the guide tracks allows the primary latch to move outwardly from the recess sufficiently to allow the secondary latch to move to its released position while the primary latch remains in its latched position.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a pushchair

chassis having a child car seat mounted thereon; Figure 2 is a scrap perspective view of part of the assembly shown in Figure 1, taken from behind the car seat thereof, showing a latch in accordance with the invention connecting the car seat to the chassis; Figure 3 is an elevational view of the latch assembly shown in Figure 2, as seen from behind the child car seat; Figure 4 is a cross-sectional view taken on the line 4-4 in Figure 3 showing the latch disengaged from the pushchair chassis; Figure 5 is a cross-sectional view taken on the line 5-5 in Figure 4; Figure 6 is a cross-sectional view similar to Figure 4 but showing the latch during an phase of Figure 7 is a cross-sectional view similar to Figure, 5 but showing the latch in an intermediate position during movement into engagement; and Figure 8 is a cross-sectional view, similar to Figures 4 and 6, showing the. latch in a fully engaged position.

Referring to Figure 1, a pushchair chassis 10 comprises a pair of front legs 12 and 14, a pair of rear legs 16 and 18 and a U-shaped handle 20. The front legs are interconnected by a front transverse member 22 and the rear legs are interconnected by a rear transverse member 24. Respective struts 26 and 28 link the front leg 12 to the rear leg 16 and the front leg 14 to the rear leg 18 respectively. A luggage tray 30 is suspended between the front transverse member 22 and the rear transverse member 24. An operating lever 32 for a brake mechanism (not shown) extends between the bottom of the rear legs 16 and 18. This type of pushchair chassis is well known and will not be described in more detail.

Referring also to Figure 2, a U-shaped support member 34 has one side limb 36 extending between the front leg 12 and the rear leg 16, and another limb 38 extending

between the front leg 14 and the rear leg 18. In front of the front legs 12 and 14, the U-shaped member 34 has a raised central portion 40. A transverse bar 41 extends between the limbs 36 and 38 in front of the rear legs 16 and 18.

A child safety seat has a seat body 42 with a pivotally mounted carrying handle 44 and a pair of integrally moulded ribs 46 and 48 projecting from the back and bottom of the seat body 42. Each of the ribs 46 and 48 has a slot 50 near its front end for engagement with the bar 41 and a second slot 52 near its upper rear end for engagement with the raised central portion 40 of the Ushaped member 34. A latch 54 in accordance with the invention is mounted on the back of the seat body 42 between the two ribs 46 and 48 for engagement with the Ushaped member 34.

Referring to Figures 3,4 and 5, the latch assembly 54 comprises a back wall 56, side walls 58 and 60, a bottom wall 62 and a front wall 64. The upper end of the front wall 64 curves to meet the back wall 56 at a top edge 66.

An opening 68 extends across the full width of the front wall 64 in alignment with respective cut-outs 70 and 72 in the side walls 58 and 60. The opening 60 and cutouts 70 and 72 are dimensioned to receive the central portion 40 of the U-shaped member 34. A vertically extending slot 74 is formed in the front wall 64, above the opening 68. An opening 76 extends part way across the front wall 64, above the slot 74.

A primary latch 80 is mounted on a slider 82 which is of T-shaped cross-section and which engages in the slot 74. A compression spring 84 biasses the slider 82 towards the bottom end of the slot 74. When the slider 82 is at the bottom end of the slot 74, the lower end 86 of the primary latch 80 projects more than half way across the opening 68 in the front wall 64 of the housing 54.

A finger 88 is formed on the upper end of the

primary latch 80 and extends towards the upper opening 76 in the front wall 64 of the housing 54. The primary latch 80 also has a convex bulge 90 projecting from its side opposite to the housing 54, the bulge 90 serving as a camming surface during engagement of the latch and as a finger grip during release.

A secondary latch 92 is pivotally mounted on a shaft 94 which extends between the side walls 58 and 60 of the housing 54. The secondary latch 92 is in the form of a lever having a lower arm 96 extending into the space between the cut-outs 70 and 72. An upper arm of the secondary latch 92 has an elbow 98 beyond which is an end portion 100 which projects through the upper opening 76 in the top face 64 of the housing 54. A hole 102 extends through the end portion 100.

The secondary latch 92 is biassed about the axle 94 in a counter-clockwise direction by a torsion spring 104 (Figure 5). Such counter-clockwise movement is limited by abutment of the elbow 98 against the inner wall 56 of the housing 54, as shown in Figure 4. In this position, the hole 102 is in a line with the finger 88 on the upper end of the primary latch 80.

Figures 3 to 6 show the latch 54 disengaged. When the child seat body 42 is to be fitted on to the U-shaped member 34, the central portion 40 thereof presses against the bulge 90 on the primary latch 80. This displaces the finger 88 into the hole 102 against the action of the spring 84, and the central portion 40 comes into abutment with the end 96 of the lever 92, as shown in Figure 6.

Clockwise movement of the secondary latch lever 92 is prevented by the presence of the finger 88 in the hole 102, with the result that continued movement of the central portion 40 into the openings 70 and 72 causes the portions of the front wall 64 on each side of the slot 74 to bend outwardly away from the inner wall 56, as shown in Figure 7. This allows the central portion 40 to move fully into the openings 70 and 72. The primary latch 80 is now free

to move back to its original position under action of the compression spring 84 where it retains the central portion 40 in the openings 70 and 72. The outer wall 64 springs back from its outwardly bent position shown in Figure 7 to its original position shown in Figure 5, with the result that the hole 102 is no longer in alignment with the finger 88, thereby preventing disengagement of the primary latch 80, as shown in Figure 8.

When it is desired to remove the infant carrier 42 from the U-shaped member 34, it is necessary to press the outer end 100 of the secondary latch inwardly relative to the housing 54. This causes the lower end 96 of the secondary latch 92 to press outwardly on the central portion 40 of the U-shaped member 34. The resulting force on the primary latch 80 causes the upper face 64 to bend back to the position shown in Figure 70, allowing the finger 88 to come into alignment with the hole 102. The user can then push on the bulge 90 to move the primary latch 80 clear of the path of the central portion 40 out of the openings 70 and 72. The infant carrier 42 can then be removed from the U-shaped member 34, whereupon the catch returns to its original position as shown in Figures 3 to 5.

Claims

CLAIMS 1. A latch assembly for engagement with a connecting member comprises: a latch body having a recess for receiving the connecting member and a resiliently deformable guide track extending transversely relative to said recess, a primary latch slidably mounted in the guide track for movement between a latched position in which it at least partially covers an outer end of the recess so as to retain such connecting member therein and a released position clear of the recess, a secondary latch pivotally mounted on the latch body for angular movement between a latched position in which a blocking formation thereon obstructs movement of the primary latch into its released position and a heel on the secondary latch is clear of the recess, and a released position in which the blocking formation allows movement of the primary latch to its released position and the heel on the secondary latch extends partially across an inner part of the recess to limit the extent to which the connecting member can enter into the recess, wherein resilient deformation of the guide track allows the primary latch to move outwardly from the recess sufficiently to allow the secondary latch to move to its released position while the primary latch remains in its latched position.
2. A latch assembly according to claim 1, wherein the guide track comprises a slot in an outer wall of the latch body.
3. A latch assembly according to claim 2, wherein the latch body has two side walls extending perpendicular to said outer wall and the secondary latch is mounted on a shaft extending between said side walls.
4. A latch assembly according to claim 1,2 or 3, wherein the secondary latch is resiliently biased into its released position.
5. A latch assembly according to any preceding claim, wherein the primary latch is resiliently

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biased into its engaged position.
6. A latch assembly for engagement with a connecting member, substantially as hereinbefore described with reference to the accompanying drawings.