EP0172597A1 - Security catch for vertically closing doors - Google Patents

Abstract

The system has casings (1) fixed to the upper side of vertical guide rails. Each casing has a spindle to which a djum (2) is welded and each drum has a safety cord or belt (3). A ratchet wheel (4) is welded to the spindle and connected to a spiral spring that keeps the cord wound up. A pawl (6) engages the ratchet wheel and and stops rotation in one direction when a sensing rod (8) or an electromagnet releases the pawl allowing it to fall into the recesses (5) in the ratchet wheel. The rod or electromagnet release breaks or the cable moves (11,12). Sensing switches (15,16) control the electromagnet.

Description

The present invention relates to a fall protection device for lifting doors, hatches, lattice doors and such commercial doors with vertical or partially vertical opening and closing movements. As a result of tearing an accessory of the suspension device, such as a wire rope, a compensating spring, chain and the like, a door which is pulled up can fall, which can result in a serious accident. The legal safety regulations in accordance with the trade regulations, building laws, occupational safety and traffic jam laws can be met by attaching systems that cause the same to fall if the cable is clamped or damaged, the spring cable breaks, the cable on which the door is suspended, etc. prevent.

The present invention aims to provide suitable protection against such accidents.

The principle and function of the doors in question are described in the publication P 47 of the Dutch Trade Inspectorate and the Port Trade Inspectorate from October 1981: "Doors and movable grilles, construction and maintenance".

At least two separate steel cables or chains must be used to suspend vertically opening and closing doors. The cables are made of retracted galvanized wire ropes and they are constructed as prescribed in the standard NEN 3231: "Steel cables, parallel constructions for lifting and pulling devices".

The known fall protection devices, as shown on page 12 of the first-mentioned publication, have the disadvantage that the cables have to run in door rails which are provided with cutouts.

When the cable is taut, the spring-operated safety device runs up and down in it, whereas when the cable is no longer tensioning, cams press outwards, which jump into the recesses. According to the regulations, the distance between the cutouts is a maximum of 20 cm. So the heavy door can fall over 20 cm. In addition, a blocking of this device by clamping the spring or by jumping the cams too slowly outwards cannot be ruled out. Furthermore, this fuse is unsuitable for functioning if the spring breaks.

In addition, this type of construction cannot be installed in all cases in such a way that no other accidents can occur.

Other models shown are suitable for securing in the event of spring breakage, but not for cable breakage or slackening of cables.

Incidentally, not all models are suitable for hand-operated doors. These disadvantages are eliminated by the device according to the invention. The fall arrest device as mentioned at the outset is characterized according to the invention by housings which are fastened on one side or on both sides of the door opening, depending on the weight of the door, on the upper side of vertical guide rails on the wall or the portal construction, and in which one is mounted axle, on which a drum is welded, on the contour surface of which a securing tape is wound, and on which a locking wheel is also welded, which is connected to a self-winding flat coil spring, which exerts a force which keeps the securing tape wound while in secant shape attached recesses in the outline of this locking wheel fits a pawl from a lock holder which blocks the rotation of the axle in one direction when the pawl engages in one of the recesses in the secant direction.

This happens when the spring breaks, when the cable is slack or torn. There is a cable button on each cable, which indicates whether the cable hangs limply or is broken.

According to an embodiment of the invention, this button is provided with an electrical switch which allows the current to pass through in a neutral state. The power supply is interrupted by the action of these buttons as a result of slackening or tearing of the cables.

A tilting mechanism is mounted on each spring that is used, which is tilted by the force developed by the spring during the winding process. In the tilted state, an electrical switch is operated which allows the current to pass through.

If the spring tears or loosens, the spring will be in a neutral position, eliminating the force that should keep the tilt mechanism in a tilted position.

This causes the tilting mechanism to return to a neutral position, which means that the switch is no longer actuated and therefore no more electricity is passed through. According to one embodiment, an electromagnet is located above the ratchet wheel in the above-mentioned housings, which holds the pawl up. By connecting all cable buttons, tilting mechanisms and housings with electromagnets in series, there is a power cut of any kind the force of the electromagnet acting on the pawl is eliminated, as a result of which the pawl engages in the ratchet wheel so that it is stopped immediately. This will block the drum. The blocking for securing when the cable breaks can therefore be caused, as described, by the mechanical pushbutton device (rod with fork) towards the pawl or by an electromagnet mounted above the pawl, which no longer exerts its force when a circuit flows through a cable switch , is interrupted.

The ratchet wheel is centrally connected to the axle as it is to the drum on which the securing tape is wound. The end of the security band running out of the housing is connected to the door.

If cables or springs break or are no longer slack due to any reason, the circuit is interrupted when using electromagnets and the beginning movement of the door is immediately arrested by the safety band so that the door cannot move downwards.

A downward movement of the door is only possible again when the cable or spring is taut, a closed circuit is created again and the pawl is thus brought back to neutral.

When moving upwards, the securing band is wound onto the drum as a result of the self-winding flat spiral spring, which acts on the locking wheel, which is welded onto the mounted axle. According to the invention, reliable checking of the correct functioning of the safety device is possible manually by interrupting the circuit, which corresponds to the situation which occurs in the case of cables which are not tightly tensioned, in the event of cable breaks, spring breakage or slack springs.

The door must then not be able to be pushed down in any way. Visual control of correct functioning is possible by convincing yourself that the visible part of the securing strap is constantly taut.

• Fig.1 gibt eine Zeichnung der Vorrichtung mit Sperrklinke und mechanischem Kabeltaster in unblockiertem Zustand wieder.
• Fig. 2 zeigt diese in blockiertem Zustand.
• Fig. 3 zeigt eine Sicherungsvorrichtung in der Ausführung mit der Sperrklinke welche von einem Elektromagneten gehalten wird.
• Fig. ₄ zeigt diese Vorrichtung in blockiertem Zustand, bei Bruch einer Torsionsfeder.
• Fig. 5 zeigt diese Vorrichtung in blockiertem Zustand, bei Bruch eines oder mehrerer Kabel.

The invention is further explained with reference to the accompanying 5 drawings.

• Fig.1 shows a drawing of the device with pawl and mechanical cable switch in the unblocked state again.
• Fig. 2 shows this in a blocked state.
• Fig. 3 shows a safety device in the version with the lock jack which is held by an electromagnet.
• Fig. ₄ shows this device in the blocked state, when a torsion spring breaks.
• Fig. 5 shows this device in the blocked state, if one or more cables break.

• 1 ist das Gehäuse
• 2 ist die Trommel
• 3 ist das Sicherungsband
• 4 ist das Sperrenrad
• 5 sind die Vertiefungen im Umriss des Sperrenrades, in welche die Sperrklinke 6 eingreifen kann.
• 7 ist die Torsionsfeder
• 8 ist die Stange
• 9 ist die Sperrklinkenhalterung
• 10 ist der Elektromagnet
• 11 ist der Kabeltaster
• 12 ist der Kippmechanismus
• 13 ist ein federnder Drücker
• 14 ist ein Hebekabel
• 15 und 16 sind elektrische Schalter, wie näher beschrieben.
• 17 ist eine Zugfeder
• 18 ist ein Transformator.

The following parts are marked on it:

• 1 is the housing
• 2 is the drum
• 3 is the security tape
• 4 is the ratchet wheel
• 5 are the depressions in the outline of the ratchet wheel, in which the pawl 6 can engage.
• 7 is the torsion spring
• 8 is the rod
• 9 is the pawl bracket
• 10 is the electromagnet
• 11 is the cable button
• 12 is the tilt mechanism
• 13 is a resilient pusher
• 14 is a lifting cable
• 15 and 16 are electrical switches as described in more detail.
• 17 is a tension spring
• 18 is a transformer.

In the housing (1) there is a self-winding rotating drum (2) with a securing tape (3) wound on it. The security band is attached to the underside of the door. A locking wheel (4), with a self-winding spiral spring, is attached to the drum (2) and is provided with secant-shaped depressions (5) on the outline. Above it is a pawl (6) which is held up by an electromagnet (10) or a rod (8).

The pawl is fastened with a hinge joint in the pawl holder (9).

The electromagnet (10) is fed from a transformer 220/24 V (18). A cable button (11) is attached behind each lifting cable (14).

In the case of normally tensioned cables, this button actuates an electrical switch (15) which allows the current to pass through.

Each torsion spring (7) attached in front of the door is coupled to a tilting mechanism (12). When the spring is normally tensioned, this mechanism is tilted due to the torsional force of the spring and becomes the electric one Switch (16) actuated, which passes current in this position. If the electrical components are connected in series (Fig. 3), the electromagnet is actuated. If the resilient pusher (13) is now pressed, the pawl on the electromagnet is lifted and held in this position.

If one or more torsion springs (7) break, as shown in Fig. 4, the forces that held the tilt mechanism in the tilted position cease to exist.

The mechanism continues to return to the neutral position through the attached tension spring, as a result of which the electrical switch (16) no longer allows current to pass. As a result, the electromagnet (10) is no longer supplied with current and the pawl (6) can no longer be held up. Due to its own weight and the attached tension spring, the pawl quickly falls down and engages in one of the recesses

(5) of the ratchet wheel (4).

As a result of the spring break, the ratchet wheel (4) is immediately locked and thus also the drum (2) attached to it with the securing band (3) which is attached to the bottom of the door. The door's downward movement stops immediately.

If one or more cables are torn (see Fig. 5), the cable buttons fold outwards through the installed springs and the switch (15) stops flowing current. The circuit is then also interrupted in this case and the downward movement of the door is brought to a standstill immediately in the manner described above.

If the door is blocked by the lock, it can only be opened further by lifting it with a forklift, for example. By engaging the pawl (6), the self-winding drum (2) can only turn to the left, which means that the door can only be moved upwards. When this upward movement is stopped, the pawl immediately engages in the recess, which immediately brings the door back into the safe position.

A blocked door can only be closed by lifting the door slightly and then pressing and holding the resilient handle (13) until the forklift has lowered the door completely. When the handle (13) is released, the pawl (6) immediately engages in the recess and the door is immediately brought to a safe standstill.

Normal function of the door is only possible again when the cause of the blockage has been removed (i.e. when new springs or cables are installed).

The drum with the belt can only turn when the lifting cables and springs are taut and the circuit is closed. As an example, we would like to mention that a lifting door with a height of about 6 m. a weight of 800 kg is secured by a device according to the invention, which consists of two housings according to the accompanying figures, with the interacting parts shown therein, a flat spiral spring which engages the locking wheel from a length of about 12 m in a stretched state Stainless steel band. Other dimensions are of course possible.

For the calculation of forces, a door weight of 200 kg was assumed, the lifting being carried out by two springs.

After the calculation, the weight of the door can be increased to 400 kg. The shear stress in the recess of the ratchet wheel then becomes 2

_{25 N /} mm ² + 40% = 35 N / mm ² , and it remains significantly below the permissible maximum value of 85 _{N / mm} ² .

The surface pressure in the contact area of the pawl and the ratchet wheel then becomes 47 N / mm ² + 40% = 66 N / mm2 and this is clearly 2 below the maximum value of 200 N / mm ² .

The securing band has a tensile strength of 1571 kg. With a safety factor of 3.9, the permissible load is 400 kg.

With a door weight of 400 kg, if two springs are used, only 200 kg can be locked if one spring breaks.

The electrical installation is carried out in accordance with the requirements of NEN 1010.

The switch is a closed contactor, which has a mechanically forced interruption switching function, as specified in VDE 0660, T 206 and VDE 0113, I.E.C. 44.

The magnetic core is provided with a copper layer.

The device described is approved for this purpose by

the General Directorate of Labor Inspection under file number AI-2981. The details described above st.llen represent examples of the invention, whereby this is not, however, a limit _t.

Claims (4)

1. Fall arrest device for suspensions of lifting doors, hatches, grilles and similar commercial doors with vertical or partially vertical opening and closing movements, characterized in that housings (1) are fastened to the upper side of vertical guide rails, each with a mounted axle , on which a drum (2) is welded, on the contour surface of which a securing band (3) is wound, and on which a locking wheel (4) is also welded, which is connected to a self-winding flat spiral spring which exerts a force around the securing band (3) keep spooled, while in the recesses (5) in the outline of this ratchet wheel a pawl (6) engages, which blocks the rotation of the axle in one direction when a push rod (8) or an electromagnet (10) does not lock the pawl more outside the recess (5) stops due to the movement of a cable button (11) or a spring break button (12). 2. Device according to claim 1, characterized in that the circuit of the electromagnet (10) with switches (15) and (16) is provided, which in the normal state of the cable. let the current through when the springs are tensioned, but if the condition is not normal use a spring break button (tilt mechanism 12). Interrupt the power button (11). 3. Device for securing cables, chains or springs of partially or completely vertically moving doors, characterized in that the device consists of a housing (1) with an axle mounted therein, a drum (2) centrally mounted thereon, on the contour surface thereof a locking band (3) is partially wound, and whereupon a ratchet wheel (4) with a self-winding flat spiral spring is centrally attached, which ratchet wheel has secant-shaped recesses (5) into which a pawl held by a hinge joint in the pawl holder (9) 6) can intervene if an electromagnet (10) is no longer powered due to an open circuit or if the tension spring (17) moves on the rod (8), due to a no longer tight state of the cable. 4. vertically movable door, characterized in that it is provided with one or more fall arresting devices according to one of claims 1-3.

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