Joint structure for use in foldable baby carriages

Claim 1

A joint structure using ball joints for use in foldable baby carriages in interconnecting first and second members (19, 20 and 12, 13) forming portions of a foldable baby carriage in such a manner that during the folding operation of said baby carriage, they are each turnable around two axes, a first axis (47) and a second axis (48) which intersects said first axis at a predetermined angle, said joint structure being characterized in that: said ball joint comprises a socket (29, 36) and an insert (25) adapted to be received in said socket, which, when combined, constitute a ball articulation, said socket comprises a bowl-like portion (30, 37) defined by concentric hemispherical inner and outer surfaces (30, 37 and 31, 38), the upper surface of said bowl-like portion being opened, and an attaching portion (33, 49) laterally extending from said bowl-like portion, the bottom of said bowl-like portion being formed with a lengthwise extending elongated opening (34, 41) having a width smaller than the diameter of said hemispherical inner surface, said insert comprises a spherical head portion (26) formed to fit the hemispherical inner surface, and a shaft portion (27) radially extending from said spherical head portion, said socket is fixed to said first member (19, 20) through said attaching portion, while said insert is fixed to said second member (12, 13) through said shaft portion, with said spherical head portion received in the bowl-like portion of said socket and with said shaft portion extending through said elongated opening, and the rotational movement of said shaft portion around its own axis within said elongated opening brings about a turning movement around said first axis (47) and its pivotal movement brings about a turning movement around said second axis (48).