Field of the Invention
This invention relates to a foldable baby carriage and more particularly to a skeleton construction suitable for large-sized foldable baby carriages.
An examination of the history of change of baby carriages with attention paid to their seat sections shows that initially they were of the so-called box type and then changed to the chair type, which has since continued, and baby carriages with chair type seat sections are popular today. The reasons for switching from the box type to the chair type, included a desire for reducing the weight of the baby carriage and for making it more compact in the folded state.
Although the chair type baby carriage is convenient for use, the space allotted to its seat section is limited. As a result, the seat section is reduced in size to the extent that it has been difficult to sit or lay a baby there in a comfortable manner.
Accordingly, it has been proposed to add a function which makes the baby carriage compact in the closed state and which further increases the area of the seat section when the baby carriage is opened. For example, a function is proposed (for example, in Japanese Patent Publication No. 32067/1963; corresponding to U.S. Pat. No. 4,411,472) which makes the backrest of the seat section reclinable for placing a baby comfortably into the carriage by extending the seat portion of the seat section further forward to allow the baby to stretch his or her legs.
However, even if a backrest reclining mechanism or a seat portion extending function is added, as described above, the space available for the seat section has its limit. This is due mainly to the fact that the body of the baby carriage cannot be made so large because of the design requirement that the baby carriage be made compact when folded. For example, when the length of the seat section extending in the direction of travel of the baby carriage is increased to make it possible for a baby to be comfortably in the carriage lengthwise in the direction of travel of the baby carriage, it is necessary to lengthen the wheel base between the front and rear wheels of the baby carriage in order to stabilize the baby carriage and enhance its safety. Therefore, the members connecting these front and rear wheels are lengthened, resulting in a problem that the closed state of the baby carriage cannot be made so compact.