The present invention refers to a cartridge rotary damper suitable to be interposed between two hinged elements and to apply a braking force in at least one direction of rotation of one element relative to the other.

More precisely, the present invention has as its object a cartridge rotary damper comprising an elongated housing having a first and a second end, said housing having a screw thread formed on an inner surface thereof,

a rotor rotatable relative to the housing, which protrudes axially outwards from the first end of the housing,

a slider mounted for reciprocal sliding movement within the housing, said slider being rotationally integral with the rotor and being connected with helical coupling to the inner surface of the housing, and

a linear shock-absorber mounted within the housing, said linear shock-absorber comprising a base containing a viscous fluid, a piston movable by reciprocal sliding movement relative to the base, damped by the viscous fluid along at least one direction of the reciprocal sliding movement, and elastic means configured to bias the piston towards a maximum advance position relative to the base,

wherein, in a direction of the reciprocal sliding movement of the piston, the piston is thrust by the slider against the action of said elastic means.

Preferred embodiments of the invention are defined in the dependent claims, which are intended as an integral part of the description.

Further features and advantages of the cartridge rotary damper according to the invention will become more apparent in the following detailed description of an embodiment of the invention, made with reference to the accompanying drawings, provided purely to be illustrative and non-limiting, wherein:

- figure 1 is a perspective view of a cartridge rotary damper according to the invention;

- figure 2 is an exploded view of the cartridge rotary damper in figure 1 ; - figures 3 and 4 are cross-sectional views of the cartridge rotary damper in two different operating positions;

- figure 5 is a cutaway view of the cartridge rotary damper in a different operating position from the one in figure 1;

- figures 6-9c represent the steps of assembling a door on a glove compartment of a dashboard, with the cartridge rotary damper in figure 1 ;

- figure 10 is a perspective view of the cartridge damper in figure 1; and

- figures 1 la and 1 lb are perspective views of a control rod of the damper, according to a modified embodiment.

With reference to figures 1-5, a cartridge rotary damper according to the invention is indicated collectively at 1. The damper 1 comprises an elongated tubular housing 10 (represented in transparency in figure 1), comprising a first end 11 and a second closed end 12. In the example shown, the second end 12 of the housing 10 has a bottom portion that forms a single piece with the side wall of the housing. The first end 11 is closed by a cover 13 mounted on the housing 10, e.g. snap-mounted.

In proximity of the first end 11, the housing 10 has an inner thread 14 on one of its inner side surfaces. The inner thread 14 has at least two starts, and preferably has a square thread profile, i.e. a profile wherein the sides of the thread are substantially perpendicular to the axis of the thread.

The damper further comprises a rotor 20 rotatably mounted relative to the housing 10 and which protrudes axially outwards from the first end 11 of the housing 10 (e.g. through a hole made in the cover 13).

The rotor 20 comprises a drive portion 20a located within the cavity of the housing 10 and a protruding portion 20b protruding outside the housing 10. The drive portion 20a of the rotor 20 has a prismatic shape provided to achieve a prismatic coupling with a slider, as will be explained hereinafter. The rotor 20 further comprises a flange portion 20c interposed between the drive portion 20a and the protruding portion 20b and provided to anchor the rotor 20 to the housing 10 axially. In the example shown, the first end 11 of the housing 10 exerts an axial retention action on the rotor 20, due to the cover 13. However, other ways of closing the first end 11 of the housing 10 are possible.

The rotary damper contains an inner slider 30 driven in rotation by the rotor 20, the rotary movement of which being transformed into roto-translational motion by means of a screw coupling (helical coupling) between the slider and the housing. Such rotary damper is compact in size and, with the right choice of materials, has a high degree of resistance and is able to provide a high counter-torque.

The slider 30 has an inner cavity 31 which has a cross-section corresponding to the shape of the drive portion 20a of the rotor 20. Such drive portion 20a is inserted into the cavity 31 of the slider 30, thus creating a prismatic coupling between the rotor 20 and the slider 30. The slider 30 is thus rotationally integral with the rotor 20, but slidable along the drive portion 20a of the latter. According to alternative embodiments of the invention (not illustrated), the prismatic coupling between the rotor and the slider may be obtained with a reversed male/female relationship relative to the example illustrated, and thus with a protruding part of the slider inserted in a corresponding cavity of the rotor.

The slider 30 comprises a side surface with an outer thread 32 suitable to engage the inner thread 14 of the casing 10, and the configuration of which is thus complementary to such inner thread 14.

By means of the inner thread 14 of the housing and the outer thread 32 of the slider, a helical coupling is made between the slider 30 and the housing 10, which makes it possible to transform the rotary movement of the rotor 20 into the roto-translational movement of the slider 30.

Next to the slider 30 there is a connection element 40, the function of which is described below. The connection element 40 comprises an appendage 41, which protrudes laterally outwards through an opening 15 through the side wall of the housing 10. At the bottom wall of the housing 10, a linear shock-absorber 50 of a type known per se is disposed. The linear shock-absorber 50 comprises a base 51 and a movable piston 53 with reciprocal sliding movement relative to the base 51, damped in at least one direction of the reciprocal sliding movement. In particular, the linear shock-absorber 50 is of the type containing a viscous fluid inside a cavity obtained in the base 51, the fluid of which, by means of conventional valve means also disposed inside the base 51, affects the dynamic behavior of the piston 53, damping its reciprocal sliding movement relative to the base 51 in at least one direction.

The linear shock-absorber 50 further comprises elastic means, for example a helical spring 55, configured to bias the piston 53 toward a maximum advanced position relative to the base 51 (shown in figures 4 and 5).

The linear shock-absorber 50, the connection element 40, the slider 30 and the rotor 20 are held between the bottom of the housing 10 and the cover 13.

In the direction of the sliding movement of the piston 53, which goes from the first end 11 toward the second end 12 of the housing 10, the piston 53 is thrust towards the maximum retracted position thereof by the slider 30 (figures 1 and 3), which advances against the action of the spring 55. In the direction of the sliding movement of the piston 53, which goes from the second end 12 toward the first end 11 of the housing 10, the piston 53 is carried to its position of maximum elongation by the spring 55, due to the fact that the slider 30 retracts. At least in this latter direction of movement, it is provided that the linear shock-absorber acts by braking the movement of the piston 53.

The housing 10 further comprises an extension 16 extending from the second end 12 of the housing 10. An electrical switch 60 is fixed, e.g. snap-fitted, on the extension 16 of the housing 10. The electrical switch 60 comprises a moving member 61, for example a button, which is used to close and alternatively open an electric circuit incorporated in or connected to the switch 60 (not shown). Such an electrical circuit may, for example, be a power supply circuit for a light source. A control rod 70 is mounted on the extension 16 of the housing 10 for an alternative sliding movement. In the example shown, the control rod 70 is inserted into a guide made partly on the side surface of the housing 10 and partly on the extension 16. The control rod 70 comprises a first end 71 and a second end 72. At least at the second end 72, the control rod 70 is configured for a prismatic coupling with the bottom of the guide formed on the extension 16 of the housing.

The first end 71 of the control rod 70 is configured to receive the movement from the slider 30, in particular through the connecting element which is held between the slider 30 and the piston 53 of the linear shock-absorber 50. For this purpose, the first end 71 of the control rod 70 is fixed, e.g. snap-fitted to the appendage 41 of the connection element 40.

The second end 72 of the control rod 70 is configured to control the movable member 61 of the electrical switch 60.

The switch 60 and the control rod 70 are in particular arranged on opposite sides of the extension 16 of the housing 10. The movable member 61 of the electrical switch 60 protrudes on the side of the extension 16 of the housing 10 turned toward the control rod 60 through a window 17 made on the extension 16 of the housing 10.

A window 73 is further located on the control rod 70. As may be seen in figures 3 and 4, the window 73 of the control rod 70 has an edge 74 facing toward the movable member 61, which is ramp-shaped.

By virtue of the configuration described above, the movable member 61 of the switch 60 is able to assume a first operating position (figure 3) when the window 73 of the control rod is positioned above the movable member 61, and a second operating position (figure 4) when the window 73 of the control rod is moved away by the movable member 61. With reference to the stroke between the maximum retracted position and the maximum advanced position of the piston, the point at which the switching of the movable member 61 occurs depends on the position of the edge 74 of the window 73 along the control rod 70. Figures 1 and 3 show the rotary damper according to the invention in the maximum retracted position of the piston, while figures 4 and 5 show the damper in the maximum advanced position of the piston.

In the positions shown in figures 1 and 3, the window 73 of the control rod 70 is disposed over the movable member 61 of the electrical switch 60, which is thus in the first operating position. Such operating position may be, for example, a position in which a light source connected to the switch 60 is off.

If there is a relative rotation between the rotor and the housing of the damper, this is converted into a roto-translational movement of the slider 30.

As a result of the retraction of the slider 30, the connection element 40 and the piston 53 are moved towards the first end 11 of the housing 10, due to the thrust of the spring 55. The overall movement of the system is damped by the damping devices provided for in the linear damper 50. The control rod 70 moves integrally with the connection element 40, thus bringing the edge 74 of the window 73 to engage the movable member 61 of the electrical switch 60. The movable member is then moved into the second operating position. Such operating position may be, for example, a position in which a light source connected to the switch 60 is on.

The rotational movement of the rotor is interrupted once the maximum advanced point of the piston (corresponding to the maximum retracted point of the slider), shown in figure 4, is reached.

If there is a relative rotation between the rotor and the housing of the damper (contrary to the one described above), it is converted into a roto-translational movement of advancement of the slider 30.

As a result of the advancement of the slider 30, the connection element 40 and the piston 53 are moved toward the second end 12 of the housing 10, due to the thrust of the slider 30. The control rod 70 moves integrally with the connection element 40, thus bringing the window 73 over the movable member 61 of the electrical switch 60. The movable member is then moved into the first operating position.

The rotational movement of the rotor is interrupted once the maximum retracted point of the piston (corresponding to the maximum advanced point of the slider), is reached, shown in figure 3.

With the present invention it is possible to make small-sized rotary dampers, able to operate also in the presence of high external loads, and that allow all the functions (elastic thrust, damping effect) to be integrated on the hinge axis between two elements between which the damping function is to be obtained.

With reference to figures 6-9c, a stationary structure 80 of a dashboard of a motor vehicle is illustrated, within which there is a glove compartment 81.

A pair of supports 85 are disposed on an edge 83 of the glove compartment 81, which define an axis of rotation y for a door. On the edge 83 there is also a spline 87 extending from the edge 83.

The damper 1 is placed close to the edge 83, so that the spline 87 passes into a space between the second end 12 of the housing 10 and the switch 60 (figures 7a and 7b).

The damper 1 is then moved parallel to the edge 83 of the glove compartment 81 so as to bring the anti-rotation spline 87 into a slot 19 (shown in figure 10) made on a front surface of the second end 12 of the housing 10 (figures 8a and 8b). The damper 1 is now mounted on the edge 83 of the glove compartment 81, between the two supports 85, and with the rotor 20 disposed coaxially with the axis of rotation y defined by such supports. Other mounting configurations are of course possible, such as configurations in which the male (spline) and female (slot) parts are reversed relative to the one described above, or configurations in which there is a coupling between a side surface of the housing and the edge of the glove compartment. A door 90 is then coupled to the stationary structure 80, by means of a pair of pins 88 inserted in the supports 85 and in corresponding supports obtained on the door 90. One of the two pins 88 is shaped to make a prismatic coupling with the door 90 and the rotor 20 of the damper 1. In this way, the hinging of the door 90 to the stationary structure 80 is obtained, with the rotor 20 made integral with the door 90 and the housing 10 made integral with the stationary structure 80. However, it is possible to conceive of an alternative embodiment (not illustrated), wherein the rotor is made integral with the stationary structure, and the housing is made integral with the door. With reference to figures l la and l lb, a modified embodiment provides for the possibility of adjusting the point at which the switching of the movable member 61 of the switch 60 is obtained. Such adjustment may be made by changing the position of the window 73 and the edge 74 relative to the first end 71 of the control rod 70. In the example shown, this is achieved by assuming that the control rod 70 comprises a first rod section 70a and a second rod section 70b separated and coupled together by coupling means 70c (e.g. gearing) which define a plurality of mutual longitudinal positioning arrangements of the two sections 70a and 70b. Obviously, other configurations of the control rod 70 are conceivable, which similarly allow the adjustment of the position of the window 73.