PARKING DISSUADER

The present invention relates to a parking dissuader in accordance with the introduction to the main claim. Manual parking dissuaders exist in the state of the art, comprising a barrier element, generally an inverted U-shaped bar, hinged such as to be able to rotate between a lowered position enabling parking and a raised position preventing parking. Automatic parking dissuaders also exist, in which the barrier element is driven by a motor controlled by a remote control. A problem of automatic parking dissuaders is that they require a battery, the charge of which is of limited duration. To solve this problem, in certain cases parking dissuaders have been produced comprising solar panels, the purpose of which is to recharge the battery and hence enable a longer duration.

However these solar panels cannot operate effectively in closed places or when the automobile is parked, as the parking dissuader is completely covered by the automobile.

Another problem is that automatic parking dissuaders present considerably higher costs than manual parking dissuaders, this limiting their acceptance. Another problem is that the barrier element of an automatic parking dissuader can cause damage if operated when an automobile or a person is positioned above the lowered parking dissuader.

A further problem is to prevent or make difficult any tampering of an automatic parking dissuader. An object of the present invention is therefore to provide an automatic parking dissuader by which the said drawbacks are overcome, a particular

object being to provide an automatic parking dissuader presenting a low energy consumption, hence leading to greater battery life.

A further object is to reduce the cost of an automatic parking dissuader. Another object is to prevent damage to persons or objects lying above the parking dissuader when this receives the command to rise.

Another object is to make it difficult to tamper with an automatic parking dissuader.

Said objects are attained by an automatic parking dissuader the inventive characteristics of which are defined in the claims. The invention will be more apparent from the ensuing detailed description of one embodiment thereof provided by way of non-limiting example and illustrated in the accompanying drawings, in which:

Figure 1 shows the parking dissuader with the barrier element in a first position enabling parking; Figure 2 shows the parking dissuader with the barrier element in a second position preventing parking;

Figure 3 shows the drive device for the barrier element;

Figure 4 is a plan view of the base of the parking dissuader, of the housing provided in the base, and of barrier element drive device disposed in the housing.

With reference to the figures, these show that the parking dissuader 1 comprises a barrier element 2 movable at least between a first position (Figure

1 ) enabling parking and a second position (Figure 2) preventing parking. Said barrier element 2 is hinged to a base 12 presenting a housing 13 in which an electric motor 3 is disposed to drive the barrier element 2 via a transmission member 4, a control unit 14 and a battery 8 for powering both the motor 3 and

the control unit 14. The transmission member 4 comprises a first reducer 9, generally an epicyclic gear with a plurality of gearwheels, and a second reducer 20 comprising a worm 5 and a gearwheel 6, the worm 5 producing an irreversible movement of the gearwheel 6 and of the barrier element 2 connected to it. On rotating about its axis M, the worm 5 rotates the gearwheel 6. To provide an irreversible movement the worm comprises a thread which winds as a spiral about the worm axis M to form an inclined plane with a low angle of inclination such as to obtain an irreversible movement of the gearwheel 6, i.e. a movement which can pass from the worm 5 to the gearwheel 6, but cannot pass from the gearwheel 6 to the worm 5. In this manner the barrier element 2 can be driven by the electric motor 3, but it is not possible for a person to transmit movement to the worm 5 and electric motor 3 by acting on the barrier element 2. For this reason, once positioned for example in a raised position preventing parking, the barrier element 2 cannot be lowered manually by acting on the barrier element 2, but can be lowered automatically by operating the electric motor 3 or by a release mechanism. Total irreversibility is achieved if the angle of the spiral or the angle of the inclined plane formed by the thread is less than or equal to 5°.

From Figure 3 it can be seen that the first reducer 9 is disposed on the exit of the motor 3 and achieves a first speed reduction for example with a 1/30 transmission ratio. A further speed reduction is achieved by the second reducer 20 comprising the worm 5 and gearwheel 6 which engages it and is directly connected to the barrier element 2. This further speed reduction can present for example a transmission ratio of 1/27. Overall, between the electric motor 3 and the barrier element 2 there is a reduction with a transmission ratio of 1/810. The worm presents a rather low efficiency compared with a gear unit formed

from gearwheels with straight teeth, i.e. it presents a greater energy dissipation due to the slippage between the worm thread and the teeth of the gearwheel 6 engaging it. For this reason the worm 5 is disposed downstream of the first reducer 9 to receive its movement after the first speed reduction has been achieved by the first reducer 9, in order to obtain, together with its engaging gearwheel 6, the final speed reduction. This expedient enables a fairly slow rotation of the worm 5 to be achieved, so reducing the power required by the electric motor, and the electrical energy consumption. For this reason it is advantageous for the movement of the electric motor 3 to be transmitted from the worm 5 to the barrier element 2 via a single gearwheel 6 engaging the worm 5, i.e. so that the second reducer 20 comprising the worm is the last reducer of the transmission member 4, downstream of the first reducer 9. Advantageously the first reducer 9 is of epicyclic type so as to be coaxial with the drive shaft and present high efficiency. To obtain a low rotational speed of the worm 5 and an adequate r.p.m. reduction of the electric motor 3, a reduction of at least 40% and preferably exceeding 50% of the total is advantageously achieved at the first reducer 9. In this respect, with regard to the stated transmission ratios the first reducer 9 produces a 1/30 reduction, while the second reducer 20 produces a 1/27 reduction, with a reduction in the first epicyclic gear reducer 9 of slightly greater than 50% of the total.

As can be seen from Figure 4, the worm 5 presents a first rotation axis M about which the thread 7 winds, while the gearwheel 6 presents a second rotation axis N substantially parallel to the tangent to the thread 7 of the worm 5 at the point of contact with the gearwheel 6. This expedient allows the use of a gearwheel 6 with straight teeth which engage the worm 5. If the first and second axis M and N were perpendicular, good engagement between the worm

5 and gearwheel 6 would require a gearwheel 6 with helical teeth, definitely more costly.

To allow the barrier element 2 to be moved manually, even when the electric motor 3 is inoperable, for example when the powering battery 8 is depleated, the parking dissuader 1 comprises a release device, able to release the barrier element 2 by decoupling its movement from that of the worm 5. Said release device can be of already known form, for example it can comprise a shaft 16 inserted into the gearwheel 6 and comprising at least one radially movable engagement element to couple the rotary movement of the gearwheel 6 to that of the shaft 16. The release device would evidently have to be operable only by the parking proprietor, for example by means of a key or by a combination mechanism.

The parking dissuader 1 can be remotely controlled from the automobile. For this purpose the control unit 14 comprises a radio reception device 10 able to receive a signal causing the electric motor 3 to rotate. The remote control and the reception device could be based not on the use of radio waves but on another principle, for example infrared or ultrasound. To increase the battery life the control unit 14 comprises a switch device 11 able to interrupt and repetitively restore power to the reception device 10 in accordance with a predetermined time cycle. For example the switch device 11 switches the reception device on and off once a second (0.5 seconds on and 0.5 seconds off), while the transmission device, normally in automobile, feeds a control signal lasting one second. In this manner the transmission device feeds a control signal, which becomes superposed on the switch-on period of the reception device 10, as its duration is equal to the on and off cycle period of the

reception device 10. This expedient reduces the energy consumption of the reception device and increases battery life.

To prevent accidents or damage to persons or objects, the parking dissuader 1 according to the invention comprises a movement stoppage or reversal device to halt or reverse the movement of the barrier element 2 when the force opposing movement of the barrier element 2 exceeds a predetermined value. For example if the automobile is parked on the parking dissuader 1 and the raising command is given to the barrier element 2, the barrier element 2 rises but then, encountering the automobile, stops or reverses its movement when the force exerted by the automobile on the barrier element exceeds a predetermined value. This prevents damage to the automobile by blocking or reversing movement before the force exerted by the barrier element on the automobile produces damage. The force opposing the movement of the barrier element 2 can be measured by an amperometer which reads the current absorbed by the electric motor 3.

To make tampering difficult, the housing 13 provided in said base 12 can be sealedly closed by a cover, which can be fixed to the base 12 by at least two fixing elements, for example two screws disposed to the side of the base 12 such that one of the two screws is covered by the barrier element 2 when it lies in its lowered first position enabling parking, and the other screw is covered by the barrier element 2 when this lies in its raised second position to prevent parking.

For operation, the parking dissuader is fixed to the ground substantially in the centre of the automobile parking place to be protected. It is operated by a remote control which enables the raising and lowering of the barrier element 2 to be controlled from a distance. If the parking dissuader receives the

command to raise the barrier element when an automobile, an object or a person is positioned on it, the parking dissuader senses a resistant force greater than that of the normal weight of the barrier element and stops or reverses its movement. As the worm 5 provides irreversible movement to the barrier element 2, the barrier element 2 cannot be lowered manually. Positioning the worm downstream of the first reducer 9, which provides for at least 40% of the reduction, enables the worm 5 to have a low rotation speed, and the energy consumption to be reduced. The angle between the axis N of the gearwheel 6 and the axis M of the worm 5, to be able to use a gearwheel 6 with straight teeth, enables production costs to be reduced. The arrangement of the closure screws for the housing cover prevents easy tampering.