Patent ID: 7309100

Claim:
A door latch device for a vehicle rear door having a front panel adjacently opposed to a rear panel of a vehicle front door in a substantially parallel condition when the front door is moved to a door closed position with respect to a vehicle body, wherein the front door is pivotally mounted on the vehicle body at its front edge part, the rear door is pivotally mounted on the vehicle body at its rear edge part, and the door latch device prevents the rear door from opening when the front door is closed and enables the rear door to be opened when the front door is opened, the door latch device comprising: an upper latch unit provided at an upper part of the rear door for engagement with an upper striker fixed onto the vehicle body; a lower latch unit provided at a lower part of the rear door for engagement with a lower striker fixed onto the vehicle body; a base plate secured on the rear door; a ratchet release lever pivotally mounted on the base plate by a first shaft, said ratchet release lever comprising a first arm connected to the upper latch unit by a first connecting means, and a second arm connected to the lower latch unit by a second connecting means; an open lever pivotally mounted on the base plate by the first shaft and connected to an open handle of the rear door; a coupling spring to resiliently link the open lever to the ratchet release lever; a door detection lever pivotally mounted on the rear door by a second shaft and rotatable in response to abutment against the rear panel of the front door when the front door is closed; and a lock lever pivotally mounted on the base plate by a third shaft and connected to the door detection lever by a third connecting means, said lock lever being displaced from an unlocked position to a locked position when the door detection lever is brought into contact with the rear panel; wherein said lock lever is configured such that rotation of the ratchet release lever can be restricted through mechanical abutment against the lock lever when the lock lever is displaced to the locked position; wherein said coupling spring includes a coiled portion disposed around the periphery of the first shaft, a first leg abutting against the open lever for urging the open lever to a first direction, and a second leg abutting against the open lever for urging the open lever to a second direction opposite to the first direction; and wherein said second leg can also abut against the ratchet release lever for urging the ratchet release lever to the second direction.