Two degree of freedom oscillator system

Oscillator system (1) comprising:- a substantially planar frame (3);- a first sub-oscillator (5), a second sub-oscillator (7), a third sub-oscillator (9), and a fourth sub-oscillator (11), each sub-oscillator (5, 7, 9, 11) comprising a substantially rigid support (5a, 7a, 9a, 11a) carrying at least one inertial mass (5f, 5g, 7f, 7g, 9f, 9g, 11f, 11g) and being joined to said frame (3) by means of a respective flexure pivot (5b, 7b, 9b, 11b) defining a corresponding axis of rotation (5c, 7c, 9c, 11c), wherein:- the first sub-oscillator (5) is coupled to the second sub-oscillator (7) by means of a first coupler link (17), these sub-oscillators (5, 7) and said first coupler link (17) being arranged such that these sub-oscillators (5, 7) are constrained to rotate synchronously in opposite directions of rotation as said first coupler link (17) translates along a first axis of translation (17t);- the third sub-oscillator (9) is coupled to the fourth sub-oscillator (11) by means of a second coupler link (19), these sub-oscillators (9, 11) and said second coupler link (19) being arranged such that these sub-oscillators (9, 11) are constrained to rotate synchronously in opposite directions of rotation as said second coupler link (19) translates along a second axis of translation (19t) which is substantially orthogonal to said first axis of translation (17t);- said oscillator system (1) further comprises a driving block (25) arranged to be driven in a circular or oval pathway by means of a crank, said driving block (25) being coupled to said first coupler link (17) by means of a third coupler link (21) and to said second coupler link (19) by means of a fourth coupler link (27);and wherein said frame (3), said substantially rigid supports (5a, 7a, 9a, 11a), said flexure pivots (5b, 7b, 9b, 11b) and said coupler links (17, 19, 21, 27) are coplanar.