# US 11,999,272 B2 · Child safety seat > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,999,272 B2 - Document ID: US11999272B2 - Status: Granted - Kind: B2 - Application number: 18/135,675 - Filed: 2023-04-17 - Published: 2023-08-10 - Granted: 2024-06-04 - Earliest claimed: 2018-11-14 - Assignees: Wonderland Switzerland AG - Applicants: Wonderland Switzerland AG - Inventors: Xiao Song Duan - Web page: https://patentgrep.com/patent/US11999272B2 ## CPC - B60N 2/2851: {provided with head-rests} - B60N 2/2222: {the back-rest having two or more parts} - B60N 2/2227: {and provided with braking systems} - B60N 2/2872: {provided with side rests} - B60N 2002/2204: {Adjustable back-rest height or length} - B60N: SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR ## Abstract A child safety seat includes a seat portion, a backrest assembly connected with the seat portion, and a backrest adjusting system carried with the backrest assembly and including a lock. The backrest assembly including a first portion, a second portion slidably connected with the first portion, and a third portion slidably connected with the second portion. The lock includes a first latching part operable to lock and unlock the third portion with respect to the second portion, and a second latching part operable to lock and unlock the first portion with respect to the second portion, the second latching part being coupled to the first latching part so that the first and second latching parts are movable in unison relative to the backrest assembly. ## Claims ### Claim 1 A child safety seat comprising: a seat portion; a backrest assembly connected with the seat portion, the backrest assembly including a first portion, a second portion slidably connected with the first portion, and a third portion slidably connected with the second portion; and a backrest adjusting system carried with the backrest assembly and including a lock, wherein the lock includes a first latching part operable to lock and unlock the third portion with respect to the second portion, and a second latching part operable to lock and unlock the first portion with respect to the second portion, the second latching part being coupled to the first latching part so that the first and second latching parts are movable in unison relative to the backrest assembly. ### Claim 2 (depends on 1) The child safety seat according to claim 1, wherein the lock is provided on the second portion. ### Claim 3 (depends on 1) The child safety seat according to claim 1, wherein the second latching part is carried by the first latching part. ### Claim 4 (depends on 1) The child safety seat according to claim 1, wherein the lock further includes a spring connected with the first latching part and the second latching part. ### Claim 5 (depends on 1) The child safety seat according to claim 1, wherein the first latching part is pivotally connected with the second portion about a pivot axis. ### Claim 6 (depends on 5) The child safety seat according to claim 5, wherein the first latching part is configured to engage with the third portion at a first side of the pivot axis for locking the third portion with the second portion, and the second latching part is configured to engage with the first portion at a second side of the pivot axis opposite to the first side for locking the first portion with the second portion. ### Claim 7 (depends on 1) The child safety seat according to claim 1, wherein the lock has a first locking state where the second latching part locks the first portion with the second portion while the first latching part unlocks the third portion from the second portion so that the third portion is movable for adjustment relative to the first and second portions, and a second locking state where the first latching part locks the third portion with the second portion while the second latching part unlocks the first portion from the second portion so that the second and third portions are movable in unison for adjustment relative to the first portion, the first and second latching parts being movable in unison relative to the backrest assembly for switching the lock between the first locking state and the second locking state. ### Claim 8 (depends on 7) The child safety seat according to claim 7, wherein the backrest adjusting system further includes a switching actuator operable to cause the lock to switch between the first locking state and the second locking state. ### Claim 9 (depends on 8) The child safety seat according to claim 8, wherein the switching actuator is operable to cause the lock to switch from the second locking state to the first locking state via a contact with the first latching part. ### Claim 10 (depends on 8) The child safety seat according to claim 8, wherein the switching actuator is provided on the first portion. ### Claim 11 (depends on 8) The child safety seat according to claim 8, wherein the lock is carried with the second portion, and the switching actuator is provided on the first portion, a placement of the second portion at a predetermined position relative to the first portion causing the switching actuator to actuate the lock so that the lock switches from the second locking state to the first locking state. ### Claim 12 (depends on 11) The child safety seat according to claim 11, wherein the predetermined position corresponds to a most extended position of the second portion relative to the first portion. ### Claim 13 A child safety seat comprising: a seat portion; a backrest assembly connected with the seat portion, the backrest assembly including a first portion, a second portion slidably connected with the first portion, and a third portion slidably connected with the second portion; and a backrest adjusting system carried with the backrest assembly and including a lock, wherein the lock includes a first latching part operable to lock and unlock the third portion with respect to the second portion, and a second latching part operable to lock and unlock the first portion with respect to the second portion, the second latching part being disposed adjacent to the first latching part, and the second latching part being coupled to the first latching part so that the first and second latching parts are movable in unison. ### Claim 14 A child safety seat comprising: a seat portion; a backrest assembly connected with the seat portion, the backrest assembly including a first portion, a second portion slidably connected with the first portion, and a third portion slidably connected with the second portion; and a backrest adjusting system carried with the backrest assembly and including a lock, wherein the lock includes a first latching part operable to lock and unlock the third portion with respect to the second portion, and a second latching part operable to lock and unlock the first portion with respect to the second portion, the second latching part being disposed adjacent to the first latching part, wherein the first and second latching parts are disposed on the second portion. ### Claim 15 (depends on 14) The child safety seat according to claim 14, wherein the first latching part is movable to engage with the third portion for locking the third portion with the second portion, and is movable to disengage from the third portion for unlocking the third portion from the second portion. ### Claim 16 (depends on 14) The child safety seat according to claim 14, wherein the second latching part is coupled to the first latching part so that the first and second latching parts are movable in unison. ### Claim 17 (depends on 14) The child safety seat according to claim 14, wherein the second latching part is carried by the first latching part. ### Claim 18 (depends on 17) The child safety seat according to claim 17, wherein the first latching part is pivotally connected with the second portion about a pivot axis, and the second latching part is disposed at a distance from the pivot axis. ### Claim 19 (depends on 14) The child safety seat according to claim 14, wherein the lock further includes a spring connected with the first latching part and the second latching part. ### Claim 20 (depends on 14) The child safety seat according to claim 14, wherein the lock has a first locking state in which the first latching part unlocks the third portion from the second portion and the second latching part locks the second portion with the first portion, and a second locking state in which the first latching part locks the third portion with the second portion and the second latching part unlocks the second portion from the first portion. ### Claim 21 (depends on 20) The child safety seat according to claim 20, wherein the backrest adjusting system further includes a switching actuator operable to cause the lock to switch between the first locking state and the second locking state. ### Claim 22 (depends on 21) The child safety seat according to claim 21, wherein the switching actuator is operable to cause the lock to switch from the second locking state to the first locking state via a contact with the first latching part. ### Claim 23 (depends on 21) The child safety seat according to claim 21, wherein the lock is carried with the second portion, and the switching actuator is provided on the first portion, a placement of the second portion at a predetermined position relative to the first portion causing the switching actuator to actuate the lock so that the lock switches from the second locking state to the first locking state. ### Claim 24 (depends on 23) The child safety seat according to claim 23, wherein the predetermined position corresponds to a most extended position of the second portion relative to the first portion.