Switch for roof lights

A switch (1) for roof lights (2) has: a supporting frame (3); a push-button (7) slidably mounted on the frame (3); a printed circuit, which is associated to the frame (3) and defines two operative positions for a lamp-bulb; and an actuator (13), which is set between the push-button (7) and the printed circuit (8) and is moved by the push-button (7) between the two operative positions; the actuator (13) being provided with a rolling element (18), which can roll on the printed circuit (8) between the two operative positions, and an motion-imparting arm (15), which supports the rolling element (18) and is actuated by the push-button (7) for moving the rolling element (18) itself between the operative positions.

Not Applicable

FIELD OF THE INVENTION

The present invention relates to a switch for roof lights.

BACKGROUND OF THE INVENTION

In general, switches for roof lights of a known type comprise:

a supporting frame having an open end wall;

a push-button, which is supported by the frame and is mobile with respect to the frame itself for switching on and switching off a lamp-bulb supported by the frame;

an electric circuit, which is set so as to close partially and end wall and defines two operative positions for the lamp-bulb; and

an actuator, which is set between the push-button and the electric circuit and is moved by the push-button between the two operating positions.

Normally, the actuator is defined by a plate made of conductive material, which is made to slide on the printed circuit between the two operative positions, each time actuating the push-button.

The switch for roof lights of the type described above presents a drawback due to slipping of the actuator on the printed circuit and the corresponding friction, which brings about, in the long run, wearing-out of both of the components.

The purpose of the present invention is to provide a switch for roof lights which will be free from the drawback described above.

BRIEF SUMMARY OF THE INVENTION

According to the present invention, a switch for roof lights is provided, comprising: a supporting frame; a push-button slidably mounted on the frame; a printed circuit, which is associated to the frame and defines two operative positions for a lamp-bulb; and an actuator, which is set between the push-button and the printed circuit and is moved by the push-button between the two operative positions; said switch being characterized in that the actuator comprises a rolling element, which can roll on the printed circuit between the said two operative positions, and an motion-imparting arm, which supports the rolling element and is actuated by the push-button for moving the rolling element itself between the operative positions.

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIGS. 1,2, and3, the reference number1designates, as a whole, a switch for a roof light2provided with a light-bulb (of a known type and not illustrated) for lighting the inside of a motor vehicle.

The switch1comprises: a supporting frame3, which is mounted in a housing4of the roof light2and has a substantially curved front wall5and an open rear part6; and a push-button7, which is mounted through the front wall5and is able to slide along an axis A of movement between two operative positions, as will be explained more fully in what follows.

The switch1further comprises a printed circuit8, which is mounted so as to close the rear wall and in turn comprises, as illustrated schematically in plan view inFIG. 1, a first path10and a second path11, which are both made of conductive material and are set aligned to one another but separate from one another. The switch1further comprises a continuous path12made of conductive material, which is set adjacent and parallel to the two paths10and11.

Finally, the switch1comprises an actuator13, set between the push-button7and the printed circuit8and is moved by the push-button7between a first operative position, illustrated inFIG. 2, in which the push-button7is set flush with the wall5, and a second operative position, illustrated inFIG. 3, in which the push-button7projects from the wall5.

Passage of the actuator13between the first operative position and the second operative position occurs through an intermediate operative position, illustrated inFIG. 1, in which the push-button7is set in with respect to the wall5.

According to what is illustrated in greater detail inFIG. 4, the actuator13comprises: a containing body14, which is mounted so that it can slide along the axis A within the frame3and is rigidly coupled to the push-button7; and an motion-imparting arm15, which has one end16thereof pivoted on the body14, and a second end17thereof set facing the circuit8.

The actuator13further comprises a rolling element18made in the form of a rocket, which is coupled in such a way that it can turn at the end17of the arm15, is entirely made of conductive material, and is set forming a bridge between the continuous path12and the path10, in the first operative position, and between the continuous path12and the second path11, in the second operative position.

The containing body14is an open annular body extending along the axis A, and comprises two larger plane walls19set facing and parallel to one another on opposite sides of the arm15, and two substantially curved smaller walls20and21, which are transverse to the walls19, and of which the wall20has, on the side facing the circuit8, a cavity22for housing the rolling element18, whilst the wall21has, on the side facing the push-button7, a respective cavity23. The body14further comprises a rod24, which is fixed to the walls19and set transverse thereto and is set in the cavity23so as to define the fulcrum of rotation of the end16of the arm15.

Finally, the body14comprises two wedge-shaped detents25, which are fixed to the walls20and21and extend towards the outside of the walls20and21themselves to co-operate with respective detents26fixed to the frame3, thus regulating the amplitude of the return travel of the body14itself and hence of the push-button7.

The rolling elements18comprises a respective rod27slidably coupled to the end17of the arm15, and two disks28and29, which are angularly fixed to the rod27and are set on opposite sides of the arm15to roll on the printed circuit8and, in particular, to engage the path10or the path11and, respectively, the path12.

The actuator13further comprises a helical spring30compressed between a pin31, which is fixed to the end17and extends on the opposite side of the rolling element18, and a further pin32, which is fixed to the body14and extends towards the circuit7. The actuator13finally comprises a desmodromic cam33made on the outside of one of the two walls19, and a finger34, which is engaged by the cam33and is designed to run over the cam33itself with a given direction of rotation.

In particular, the desmodromic cam33is substantially heart-shaped and comprises a cusp37facing the circuit8, and two U-shaped parts38and39, the concavities of which are oriented towards the cusp37itself and which are separated by a deviating prism40having a triangular shape. The cam33further comprises a deviating tile41, which has substantially the shape of an skew V and is set facing the prism40and opened towards it. Instead, the finger34is supported, at one end42of an oscillating arm43, which is set on the outside of the wall19and a further end44of which is pivoted on the frame3.

In use, once the switch1is connected to the external electrical circuit of the vehicle, it enables turning-on of the aforesaid lamp-bulb upon opening of a door of the motor vehicle itself, or also when the actuator13is set in the position corresponding to the first operative position, or alternatively, direct turning-on of the aforesaid lamp-bulb2, or else with the actuator13set in a position corresponding to the second operative position.

The description of the operation of the switch1will be made starting from the first operative configuration with the rolling element18set astride of the paths10and11and with the finger34set facing the cusp37of the cam33.

Starting from said first operative configuration, a pressure on the push-button7brings about an axial displacement along the axis A of the push-button7itself against the resisting action of the spring30, an oscillation of the motion-imparting arm15about the rod24and a displacement of the rolling element18towards the intermediate operative position. During the displacement of the rolling element18from the first operative position towards the intermediate operative position, the finger34hits against the title37and is invited to run over the U-shaped part38which defines a top dead centre for the displacement of the finger34itself.

At this point, a further pressure on the push-button7will not have any further effect, whilst release of the push-button7will bring about, under the elastic action of the spring30, positioning of the finger34between the tile37and the prism40, raising of the push-button7outside the wall5and, above all, positioning of the rolling element18in the second operative configuration with the disk28set in contact with the path11and with the disk29set in contact with the path12.

Starting from this second operative position, a further pressure on the push-button7brings about an axial displacement along the axis A of the push-button7itself against the resisting action of the spring30, an oscillation of the motion-imparting arm15about the rod24and a new displacement of the rolling element18towards the intermediate operative position. During the displacement of the rolling element18from the second operative position to the intermediate operative position, the finger34hits against the prism40and is invited to run over the U-shaped part39, which defines a further top dead centre for the displacement of the finger34itself.

Also in this case, a further pressure on the push-button7will not have any further effect, whilst release of the push-button7will bring about, under the elastic action of the spring30, positioning of the finger34on the outside of the tile37, raising of the push-button7flush with the wall5and, above all, positioning of the rolling element18in the first operative configuration with the disk28set in contact with the path10and with the disk29set in contact with the path12.

During all the displacements described above, the rolling element18rolls on the printed circuit8reducing substantially to zero the friction with the paths10,11and12and thus practically eliminating completely the wear of the components involved and guaranteeing a longer service life of the switch1.

It is understood that the invention is not limited to the embodiment described and illustrated herein, which is to be considered purely as an example of implementation of the switch for roof lights, which may, instead undergo further modifications as regards shapes and arrangements of parts and details of construction and assembly.