Mechanism for waving elements

Technical field

The present invention relates to a mechanism adapted to periodically oscillate a mechanical arm on adjustable curved trajectories. The mechanical arm allows the movement of waving elements, such as flags.

Background Art

Various types of mechanisms for supporting and moving waving elements such as flags, are currently known.

Usually, the mechanisms used for flags do not allow the trajectory of the flag to be adjusted, and therefore the visibility thereof to be increased.

Patent Application US 2008 254416 A1 describes a mechanism for oscillating a cab or a platform.

Object of the invention

It is the object of the present invention to overcome these and other drawbacks. Summary of the invention

The object of the invention is a mechanism comprising:

- a frame;

- a first and a second crank, each of which including:

• a shaft connected to said frame by means of supports so as to rotate about an axis thereof;

• an arm connected to said shaft, said shafts lying on a horizontal plane; - a motor connected to said frame;

- a drive member with one or more drive ratios, actuated by said motor, said drive member being connected to said shafts so as to transmit a rotary motion received from said motor thereto, about the respective axis thereof;

- first adjustment devices adapted to set both the lengths of said arms and a phase angle of said arms with respect to said horizontal plane, in which, according to the invention, said mechanism further comprises:

- a mechanical arm hinged, at a lower end thereof, to a further support so as to have two levels of rotational freedom about two axes, respectively, each of which different from the axis of said mechanical arm;

- for each of said cranks, a pin comprising a first end and a second end oppo site to said first end, for each of said cranks, said pin being connected, at said first end, to said arm of said crank by a rotary support so as to be rotatable about an axis thereof;

- a first rod comprising a first end and a second end opposite to the first end thereof, said first rod, at the first end thereof, being connected by means of a hinge to said pin of said first crank at said second end of said pin, said first rod, at the second end thereof, being hinged to said mechanical arm;

- a second rod comprising a first end and a second end opposite to the first end thereof, said second rod, at the first end thereof, being connected by means of a hinge to said pin of said second crank at said second end of said pin, said second rod, at the second end thereof, being hinged to said mechanical arm;

- second adjustment devices adapted to set the length of said mechanical arm;

- third adjustment devices adapted to set the length of each of said rods;

- a flywheel associated with each of said shafts, said mechanism being adapted to periodically oscillate said mechanical arm along an adjustable trajectory. According to an aspect of the invention, said shafts are perpendicularly con nected to each other by said drive member.

According to another aspect of the invention, said drive member has two right- angle outlets which ensure the perpendicularity of said shafts.

According to another aspect of the invention, said rods are locked in the rotation about an axis thereof.

According to another aspect of the invention, said further support is below said horizontal plane, said mechanical arm being hinged to said further sup port by means of a universal joint.

According to another aspect of the invention, both said second adjustment devices and said third adjustment devices comprise at least one telescopic device which allows the length of said mechanical arm and of each of said rods, respectively, to be adjusted and fixed, said telescopic device comprised in said second adjustment devices being be low the connections between said mechanical arm and said rods, and being above said universal joint.

According to another aspect of the invention, said shaft of said crank in each of said cranks is connected to said arm of said crank at one end of said shaft, for each of said cranks, said first adjustment devices comprising:

- a plurality of polygonal seats obtained in said arm of said crank;

- a polygonal profile connected to said shaft of said crank at said end of said shaft, said polygonal profile being associable with each of said polygonal seats so as to set both said phase angle of said arms of said cranks with respect to said horizontal plane and the lengths of said arms of said cranks.

The invention relates to a mechanism which causes the periodic oscillation of a mechanical arm on which a flag or a waving element is fixed.

The oscillation trajectory of the mechanical arm has radii of curvature which change according to the movement of the arm itself.

The trajectory may be set and adjusted through adjustment devices.

An advantage resulting therefrom is that the mechanism, through adjustment devices, allows the best trajectory to be set according to the geometries and dimensions of the flags or waving element, thus allowing the complete unfold ing, and therefore the increased visibility of the flag.

A further advantage is ensured by the joints and supports which allow an in creased resistance, also to stresses induced by large waving elements. Moreover, there are two flywheels, which ensure that the oscillation of the me chanical arm remains periodic also in the presence of external forces, such as wind.

Brief description of the drawings

The geometric, structural and functional features of the invention and the ad vantages thereof with respect to the prior art will be clearly comprehensible form the following description, referring to accompanying diagrammatic drawings, which show a possible industrial embodiment and a schematized model of the invention.

In the drawings:

Figure 1 is the diagrammatic depiction of a possible industrial realization of the invention.

Figure 2 is the diagrammatic depiction of the invention in a position, called initial position, in which the mechanical arm 8 is perpendicular to the horizontal plane 17; the mechanism has a specific setting which allows trajectory 13 to be ob tained.

Figure 3 is the diagrammatic depiction of the invention in a position with a movement of the mechanism with respect to the initial position, in which the mechanical arm 8 is tilted with respect to the horizontal plane 17.

Figure 4 is the top view of the mechanism, in which the positions obtained by dividing the period into eight equal parts and starting from the initial position, are depicted. Point P is on the upper end of the mechanical arm 8 which takes on the various positions of trajectory 13.

Figure 5 is the diagrammatic depiction of the invention with a specific setting which allows trajectory 14 to be obtained.

Figure 6 is the diagrammatic depiction of the invention with a specific setting which allows trajectory 15 to be obtained.

Figure 7 is the diagrammatic depiction of the adjustment device 23. Detailed disclosure of the invention and effective embodiment Mechanism 50 (Fig. 1) comprises:

- two cranks 4 and 6 associable with a frame 1 by means of supports;

- a drive member 3 with one or more drive ratios, associated with the shafts of the two cranks 4 and 6 and actuated by a motor 2;

- a rod 5 hinged at one end to the pin of crank 4, and at the other end to the mechanical arm 8;

- a rod 7 hinged at one end to the pin of crank 6, and at the other end to the mechanical arm 8;

- adjustment devices for setting the length of the mechanical arm 8, the arms of the cranks and of the rods 5 and 7;

- adjustment devices for setting the phase angle of the arms of the cranks with respect to a horizontal plane;

- a flywheel 21 associated with each crank shaft.

The shafts of the two cranks 4 and 6 preferably, but not necessarily, are ar ranged perpendicularly on a horizontal plane 17. Point A is the intersection of the axes of the two crank shafts 18 and 19.

By virtue of two preferably, but not necessarily, right angle outlets, the drive member 3 ensures the aforesaid preferred perpendicularity of the two shafts 18 and 19 of the cranks and transmits the motion received from motor 2 to the shafts themselves.

Each crank contains a pin 12 which rotates about the axis thereof; the pin is connected at one end to the crank with a rotary support 20, and the pin instead is connected at the other end to the rod by means of a hinge 11. Point B is the intersection of the axes of rod 7 and of pin 12; point D is the intersection of the axes of rod 5 and of pin 12.

Hinge 11 allows the rotation about an axis perpendicular to the axis of the pin. The rotation of rod 5 about the axis thereof is locked; the other two rotations of rod 5 instead are free.

The rotation of rod 7 about the axis thereof is locked; the other two rotations of rod 7 instead are free.

The arm of the crank connects the wheel rotation axis of the crank to pin 12. The arm of crank 4 is R and the arm of crank 6 is r.

The lower end of the mechanical arm 8 is hinged to a support below the hori zontal plane 17 by means of a universal joint 10 which allows only two rotations by the mechanical arm 8; indeed, the rotation about the axis of the mechanical arm is locked. Point E is the middle of the spider (Fig. 2).

The rods 5 and 7 are therefore articulated at one end to pin 12 and at the other end to the mechanical arm 8 in a point thereof above the cardan joint 10, by means of ball joints 9.

Obviously, the cardan joint 10 allows partial rotations about the two free rotation axes thereof, therefore the maximum angles of oscillation q and b of the me chanical arm are less than or equal to the angles allowed by the cardan joint (Fig. 3).

The adjustment device 22 is telescopic and allows the length of the rods 5 and 7 and of the mechanical arm 8 to be adjusted and fixed. There is at least one tel escopic device on the mechanical arm 8, below the connections of the rods and above the cardan joint 10.

By virtue of the arrangement of a polygonal profile 25 associable with various polygonal seats 24, the adjustment device 23 allows setting the phase angle a of the arm of the cranks 4 and 6 with respect to a horizontal plane and the lengths R and r of the arms of the cranks (Fig. 7).

The trajectory of the mechanical arm 8 is adjustable through the adjustment de vices 22 and 23 and the selection of the ratio of the drive member 3. The drive ratio defines the angular speed of the cranks 4 and 6.

In particular, the length of the crank arms R and r affects the amplitude of the oscillation.

In particular, device 22 located above the connections of the rods 5 and 7 al lows the length of the upper part of the mechanical arm 8 to be changed, and therefore the trajectory of point P to be increased or reduced.

In particular, the change in the phase angle a and the selection of the drive ratio affect the shape of the trajectory.

The trajectories 13, 14 and 15 (see drawings) are obtained with the following configurations and settings. Trajectory 13 in Figures 1 to 4 is determined by the following settings:

- ratio two of the drive member 3;

- the two crank arms in the initial position (Fig. 2) are vertical, with pin 12 in the highest position of the circular trajectory thereof; - one position, called initial position, in which the projections of the rods 5 and

7 on the horizontal plane 17 are parallel to the shafts of the cranks 6 and 4, respectively, and the axes of the rods 5 and 7 intersect in point C belonging to the axis of the mechanical arm 8 perpendicular to the horizontal plane 17; a rectangle ABCD is obtained in the top view of the initial position. Trajectory 14 in Figure 5 is determined by the following settings:

- ratio one of the drive member 3;

- a right angle offset between the two crank arms.

Trajectory 15 in Figure 6 is determined by the following settings:

- ratio three of the drive member 3; - a right angle offset between the two crank arms.