Key module (10) include a case (11), a movement mechanism (15) comprising a
plunger (16) and a return spring (17), wherein the
plunger (16) is movable relative to the housing (11) between a
rest position and an actuating position, a contact piece (18) fixed in the housing (11), and a
contact element (19) made of a U-shaped bent contact spring material with a first leg (20) and a second leg (21), wherein the first leg (20) is fixed in the housing (11) and the second leg (21) is arranged freely in the housing (11) opposite the
contact element (18), wherein contact piece (18) and contact
transmitter (19) cooperate in forming an electrical contact, in that in the actuating position of the
plunger (16) the second leg (21) of the contact
transmitter (19) is biased against its first leg (20) against the contact piece (18) and in the
rest position of the plunger (16) the second leg (21) of the contact
transmitter (19) is lifted by the plunger (16) against the bias from the contact piece (18) and thus the electrical contact is interrupted, characterized by the fact that the plunger (16) has a main body (22) which executes the movement of the plunger (16) and a
moving body (23), wherein the main body (22) has a bottom (24) and a top (25) opposite the bottom (24) in the direction of actuation and a recess (26) laterally between the bottom (24) and the top (25), into which the
moving body (23) is inserted and is rotatably mounted on a base (28) of the recess (26) opposite an opening (27) of the recess (26) about an axis of rotation (29) perpendicular to a provided direction of movement (30) of the main body (22), wherein the recess (26) defines a movement space (31) for the
moving body (23) with an upper stop (32) on the side of the top (25) of the main body (22) and a lower stop (33) on the side of the bottom (24) of the main body (22), in which the moving body (23) is rotatable between the upper stop (32) and the lower stop (33), wherein the plunger (16) for lifting the second leg (21) of the
contactor (19) from the contact piece (18) rests against the second leg (21) via its moving body (23), wherein the moving body (23) has a guide profile (34) which interacts with a control profile (35) of the second leg (21), wherein the control profile (35) of the second leg (21) comprises a control
cam (36) which protrudes towards the guide profile (34) of the moving body (23), wherein the guide profile (34) forms a projection (37) and on the side of the projection (37) facing the underside (24) of the main body (22) a recess (38), wherein in the
rest position of the plunger (16) the moving body (23) rests against the lower stop (33) and the control
cam (36) rests in the recess (38) on the moving body (23) and the second leg (21) of the
contactor (19) is lifted against the preload from the contact piece (18) and thus the electrical contact is interrupted, wherein when the plunger (16) moves from the rest position towards the actuating position, the moving body (23) is first moved towards the upper stop (32) and the control
cam (36) continues to rest in the recess (38) on the moving body (23) and the second leg (21) of the
contactor (19) continues to be lifted against the preload from the contact piece (18) and thus the electrical contact remains interrupted, as the plunger (16) continues to move, the moving body (23) initially rests against the upper stop (32) and the control cam (36) slides out of the recess (38) to a vertex (39) of the projection (37), and subsequently the control cam (36) passes over the vertex (39) of the projection (37), thereby abruptly moving the moving body (23) to the lower stop (33) and generating a striking
noise, and simultaneously the guide profile (34) following the vertex (39) of the projection (37) releases the control cam (36), and thus the second leg (21) of the contactor (19) rests against the contact piece (18) due to the preload and the electrical contact is closed.