The present invention provides a wave generating apparatus for generating waves in for example beds, chairs and the like. The apparatus can be constructed to include a motor and crank assembly connected to a flexible sheet and a stationary inertial member. In one aspect of the invention there is provided an apparatus for generating wave motion, comprising a flexible member an oscillatory drive means attached to said flexible member, said oscillatory drive means including a crank assembly having an axis of rotation at least two link members each having opposed first and second end portions, the at least two link members being spaced apart a first pre-selected distance from each other and each being rigidly attached at their respective first end portions to said flexible member and at least one elongate beam, said at least two link members being pivotally attached to the at least one elongate beam, and the elongate beam being attached to the crank assembly, for imparting oscillatory motion to the at least one elongate beam so that when the oscillatory drive means is engaged the at least one elongate beam undergoes oscillatory motion which produces transverse waves along the flexible member.Linvention concerne un dispositif de production de mouvement ondulatoire servant à produire des mouvements ondulatoires, par exemple dans des lits, chaises et analogue. Le dispositif peut être conçu de manière à comprendre un ensemble moteur et bielle connecté à une feuille flexible et à un élément inertiel fixe. Un aspect de linvention concerne un dispositif permettant de produire un mouvement ondulatoire, qui comprend un élément flexible, des moyens dentraînement oscillants fixés à lélément flexible, ces moyens incluant un ensemble bielle présentant un axe de rotation au moins deux éléments articulés comportant chacun des première et deuxième parties dextrémité opposées, ces éléments étant espacés par une première distance présélectionnée, et chacun étant fixé fermement, à sa pre