A folding collapsible stroller that includes a pair of constraint devices to hold the stroller in an operative position. The constraint devices have a sector groove and a deep blind hole at a top side thereof. A projecting portion is situated between the sector groove and the blind hole. A projecting...http://www.google.es/patents/US5718444?utm_source=gb-gplus-sharePatente US5718444 - Folding collapsible stroller
