WO2005024164A1

WO2005024164A1 - Safety device to prevent crushing in particular for automatic doors

Info

Publication number: WO2005024164A1
Application number: PCT/IT2003/000644
Authority: WO
Inventors: Paolo Giorgioni
Original assignee: Wittur Spa; Paolo Giorgioni
Priority date: 2003-09-08
Filing date: 2003-10-20
Publication date: 2005-03-17
Also published as: AU2003283795A1; ITPR20030077A1

Abstract

A safety device (1) to prevent crushing, in particular for automatic doors, originally comprising a motor or a gearmotor (2) fastened in rotating fashion to a support structure and integrally connected to means for actuating the opening and/or closing of the doors. The device (1) further comprises means for interrupting and/or reversing the opening or closing motion of the doors. Said means are activated by a rotation of the gearmotor (2) induced by the stopping or slowing of the motion of the doors due to the presence of an obstacle.

Description

SAFETY DEVICE TO PREVENT CRUSHING, IN PARTICULAR FOR AUTOMATIC DOORS

TECHNICAL FIELD AND BACKGROUND ART. The present invention relates to a safety device to prevent crushing, in particular for automatic doors.

In the field of automatic doors, in particular for lift and/or elevator cars, supermarkets, banks, shopping centres or other public locales, the need arises to install safety devices to prevent crushing objects and/or persons, during the closure of the doors.

In accordance with a first prior art, existing safety devices provide for the use of a pair of photoelectric cells positioned on opposite jambs or shoulders of the door to be "guarded", or positioned on wings of the door itself, for the purpose of detecting transiting objects and/or persons, by means of a single infrared beam. Specifically, a first transmitting photoelectric cell sends, an electromagnetic signal, typically an infrared beam, to a receiving photoelectric cell. If, during the closing phase, an obstacle is interposed between the two photoelectric cells, the beam is interrupted and an electronic control board, co-operating with the photoelectric cells, causes the doors to stop and/or reverse their direction of motion.

In accordance with a second prior art, existing devices for the prevention of crushing comprise a capacitive sensor fastened to a wing of an automatic door or positioned in correspondence with a jamb, to prevent crushing things or person during the closure of the doors. Said capacitive sensor is a substantially plate-like or wire-like element connected by means of electrical wires to a battery or to the mains power supply and it is arranged along a whole height development of the wing whereon it is installed. The operation of the device summarily described above is based on the fact that the capacitive sensor is able to detect changes in an electrical field, caused by contact with obstacles, such as a user's body or fingers. The safety and crush-prevention devices summarily described above, being positioned in correspondence with doors or jambs of automatic doors, have the important drawback of being visible and hence vulnerable.

Moreover, said devices, intervening as a result of the contact with an obstacle that prevents the correct opening and/or closing of the wings, are particularly prone to failures or malfunctions. DISCLOSURE OF INVENTION. An object of the present invention is to eliminate the aforesaid drawbacks, proposing a safety device to prevent crushing, in particular for automatic doors, which is able to stop and/or reverse the opening and/or closing motion of the wings, without coming into direct contact with the obstacle that prevented their correct actuation. Another object of the present invention is to propose a safety device that is easy to install, effective and reliable.

A further object is to obtain the above results within the context of a simple, economical constructive solution. Said objects are fully achieved by the safety device to prevent crushing, in particular for automatic doors, of the present invention, which is characterised by the content of the claims set out below. BRIEF DESCRIPTION OF DRAWINGS.

These and other objects shall become more readily apparent from the description that follows of a preferred embodiment shown, purely by way of non limiting example, in the accompanying drawing tables in which:

- Figure 1 shows a front view of a safety device according to the invention, in a first operative configuration;

- Figure 2 shows a front view of a safety device according to the invention, in a second operative configuration; - Figure 3 shows an enlarged view of the device shown in Figure 1;

- Figure 4 shows an enlarged view of the device shown in Figure 2.

The illustrated embodiment relates in particular to the sector of automatic doors for lift and/or elevator cars, as well as of the related floor doors. BEST MODE FOR CARRYING OUT THE INVENTION. With reference to the figures, the safety device to prevent crushing is globally designated by the number 1 and comprises, in novel and original fashion, a gearmotor 2 fastened in rotary fashion to a support structure 3 and integrally connected to means for actuating the opening and/or closing of the doors. The device 1 further comprises means for interrupting and/or reversing the opening or closing motion of the doors. In particular, said means are activated by a rotation of the gearmotor 2 induced by the stopping or slowing of the advancing motion of the door, due to the presence of an obstacle on their trajectory. In the illustrated example, the means for actuating the opening and/or closing of the doors comprise a pulley 4, called driving pulley, integrally connected to the gearmotor 2 and a transmission pulley 5, cinematically connected to said driving pulley 4.

Between the driving pulley and the transmission pulley 5 is interposed a positive drive transmission belt 6.

In accordance with two embodiment variations, not shown herein, the belt

6 can be a "V" belt or a poli-V multi-throat belt.

To the belt are cinematically connected driving carriages 7, 8, each of which is integrally fastened to a corresponding wing of the car door. In the preferred and illustrated embodiment, the means to interrupt and/or reverse the opening or closing motion of the doors comprise and electrical switch 9, activated by a pressure exerted thereon by the gearmotor 2, as a result of its rotation.

In accordance with an embodiment variation, the switch 9 may be a magnetic bistable switch, known in itself and hence not illustrated.

The electrical switch 9 serves the purpose of stopping and/or causing the driving pulley 4 to rotate in the opposite direction, relative to the direction of rotation it had when the wing contacted an obstacle.

In the illustrated example, the rotation of the gearmotor 2 takes place about a substantially horizontal axis, passing through a point of connection of the gearmotor to the support structure 3. In particular, the gearmotor 2 being preferably hinged to the support structure 3, its rotation takes place about the hinge axis.

The device 1 further comprises elastic means to maintain or bring back the gearmotor 2 in a position of normal operation, after any interruption or reversal of the opening or closing motion of the doors.

In the preferred embodiment, said elastic means are preferably constituted by a helical spring 10.

In accordance with a possible embodiment variation not illustrated herein, the elastic means comprise a torsional spring.

The operation of the invention is as follows.

With reference to Figures 1 and 3, the gearmotor 2 actuates the driving pulley 4 which starts to rotate, driving with it the positive drive belt 6 and consequently also the driving carriages 7, 8, integral with the wings of the car door.

If an obstacle, be it a person or an object, interferes with the translation trajectory of the wings, they stop, causing a counter-rotation of the gearmotor 2 which thus impacts against the electrical switch 9, activating it (Figures 2 and 4). In essence, the obstacle prevents the translating motion of the drive belt 6, which in turn stops the rotation of the driving pulley 4. Consequently, the gearmotor 2 undergoes a sort of retrograde motion, since the driving torque provided thereby is no longer transmitted to the belt 6, but acts on the gearmotor itself, causing its rotation. Said switch can command the doors to stop and/or reverse their travel.

The invention achieves important advantages.

First of all, a safety device in accordance with the present invention is able to stop and/or reverse the opening and/or closing motion of the wings, without coming into direct contact with the obstacle that prevented their correct actuation. Another advantage of the present invention is represented by the fact that such a safety device is easy to install, effective and extremely reliable. Advantageously, such a device is simple and economical to build.

Claims

1. A safety device (1) to prevent crushing, in particular for automatic doors, characterised in that it comprises: at least a motor or a gearmotor (2) fastened in rotating fashion to a support structure (3) and integrally connected to means for actuating the opening and/or closing of the doors; and means for stopping and/or reversing the opening or closing motion of the doors, said means being activated by a rotation of the gearmotor (2) induced by the stopping or slowing of the motion of the doors due to the presence of an obstacle.

2. A device as claimed in claim 1, characterised in that the means for actuating the opening and/or closing of the doors comprise: at least a pulley (4), called driving pulley, integrally connected to the gearmotor (2); at least a transmission pulley (5) cinematically connected to said driving pulley (4); at least a transmission belt (6) or chain associated to said driving and transmission pulleys (4;5); at least a driving carriage (7; 8) integrally fastened to a corresponding wing of the car door and cinematically connected to said transmission belt

(6) or chain.

3. A device as claimed in claim 2, characterised in that the means for stopping and/or reversing the opening or closing motion of the doors comprise at least an electrical or magnetic switch (9) activated by a pressure exerted thereon by the gearmotor (2) as a result of its rotation, said switch (9) stopping the driving pulley (4) or causing it to rotated in the opposite direction.

4. A device as claimed in claim 1, characterised in that the rotation of the gearmotor (2) or of the motor takes place about a substantially horizontal axis, passing through a point of connection of the gearmotor (2) to the support structure (3).

5. A device as claimed in claim 1, characterised in that it comprises elastic means for being back the gearmotor (2) and maintaining it in a position of normal operation, after any interruption or reversal of the opening or closing motion of the doors.

6. A device as claimed in claim 5, characterised in that said elastic means comprise at least a helical spring (10).

7. A device as claimed in claim 5, characterised in that said elastic means comprise at least a torsional spring.

8. A device as claimed in claim 2, characterised in that the transmission belt (6) it a positive drive belt.

9. A device as claimed in claim 2, characterised in that the transmission belt (6) is a V-belt or a poli-V multi-throat belt.

10. A lift and/or elevator installation, characterised in that it comprises at least a safety device (1) as claimed in any of the previous claims.