EP0151427B1 - Spring monitoring device - Google Patents

Description

The invention relates to a spring monitoring device for a pretensioned torsion spring of a door, a door or the like, in particular as a weight compensation spring for a one-part or multi-part overhead door leaf or a roller door curtain, to prevent the door leaf from falling if the spring breaks.

Spring monitoring devices of the type in question here - US-A-2 878 865, SE-A-341 681 and the unpublished NL-A-8 202 877 and WO-A-8 501 543 - work with a separate spring device or with a gravity-actuated release element, the force of which is released when the monitored torsion spring breaks and is stored up to that point acts on a catch element and, in the event of the torsion spring breaking, transfers it to a catch position in which the blocking device prevents the door leaf from falling. This separate energy accumulator for the actuation of the catching element causes corresponding costs and, depending on the design, harbors the risk that in the normal operating state of the torsion spring a malfunction (broken spring) of this additional intended energy accumulator will not be noticed and will not be available in the event of the torsion spring breaking.

The invention has for its object to ensure the monitoring of the torsion spring in a spring monitoring device of the type mentioned, in the simplest possible manner and in particular in the case of using the torsion spring for weight compensation of a door leaf reacting so quickly that the door leaf as soon as possible after breakage the torsion spring is blocked. This object is achieved by the features specified in claim 1.

The tension sensor provided for this purpose in the spring monitoring device according to the invention is arranged in the area which holds one end of the prestressed torsion spring. The spring presses against a stop with the force corresponding to its tension, via a bolt or the like, and flips back with this spring end when the spring breaks. If one arranges support surfaces on the holding device in both directions of movement, i.e. system under pressure with unbroken spring and movement from this system in the opposite direction in the event of spring breakage, then the pressure changes occurring there can be recorded and converted into signals, for example by using strain gauges. These change their electrical resistance at low elongation or compression and can thus transform a voltage change in the holding area into an electrical signal. In another embodiment, the movement of the spring end in the event of spring breakage can be used to trigger a mechanical transmission of movement, for example the actuation of an electrical switch, a pneumatic or hydraulic pressure transmitter or the like. This movement of the spring end in the event of spring breakage can, when the tension sensor is designed as a mechanical locking mechanism, in particular also be used directly to trigger a door leaf movement or to prevent it by a safety catch.

A particular application of the torsion springs in question here is to compensate for the weight of a door leaf which is at least partially moved vertically between the closed and open positions and which can be constructed in one or more parts, i.e. an overhead door, a roller door, a lifting door or the like. Here, if the door leaf is in danger of falling, d. H. Break in its weight compensation device or drive device, make sure that the door leaf is stopped as soon as possible in its movement. For this, slack rope monitoring devices are used, and centrifugal safety devices have also been proposed. The disadvantage of a slack rope safety device is that when arranging several torsion springs to compensate for the door leaf weight on a common continuous torsion shaft, which carries rope drums at both ends, on each of which a rope can be wound up and unwound, that with one end on the associated one Side area of the bottom edge of the door leaf or the like is fixed, the breakage of only one of the torsion springs does not sufficiently reduce the tension in the ropes in order to trigger the catching device monitoring the rope tension. Due to the breakage of one of the torsion springs, the equilibrium ratio between the spring leaf and the door leaf weight is disturbed in such a way that the door leaf moves downwards accelerated, as a result of which the falling distance from the spring break is traversed relatively quickly. At least this is undesirable. Also, centrifugal force-controlled safety devices only respond when the falling door leaf has passed a certain distance, which is usually larger than permitted.

A voltage sensor used for such purposes can be designed in such a way that the spring break determined by it is clearly used to block the door leaf movement. This can be done by utilizing a signal of the type mentioned at the outset to actuate a catch device which is provided in particular in the lower door leaf area and which is then triggered in particular electrically, pneumatically or the like. In a preferred embodiment, the voltage sensor is designed as a mechanical locking mechanism, such that the monitored spring end moves a mechanical member, such as a bolt, over a distance in the event of breakage due to reaction force, thereby releasing a catching member. which acts on another component for blocking the door leaf movement, in particular for blocking the rotary movement of the torsion shaft. For this purpose, the catch element can be designed as a spring-loaded, pivotably mounted pawl which, when released, engages under spring force in the component which is designed as a ratchet wheel and is arranged on the torsion shaft in a manner fixed against relative rotation. If the spring is not broken, this pawl is kept out of engagement with the pawl wheel in its operating position by the mechanical locking mechanism or the bolt.

Catch devices are generally constructed so that the catch member in the catch position comes into engagement with a component - for example a perforated strip - and thus prevents the closing movement of the door leaf, while the door leaf movement is not blocked in the opening direction, i. H. the catch member springs back from the catch position in this latter movement. The pawl-ratchet wheel catcher described above also works when the ratchet wheel teeth are sawtooth-shaped and therefore urge the ratchet pawl into the disengaged position in the direction of rotation associated with the opening movement of the door leaf.

For many applications or catch designs, the blocking between catch element and component in the relative movement direction between these parts corresponding to the closing movement of the door leaf is sufficient. If the torsion spring breaks, however, the positive engagement of the catch member is initiated immediately, and the positive connection between the catch member and the component or the pawl and the ratchet wheel has such an impact that counter-movement phenomena in the opening direction can occur, which cancels and detaches the catch condition a "flattem _{" of} the moving parts, possibly even causing the catch to slide into the next catch opening. If the catch device is arranged in the form of a pawl and ratchet wheel on the torsion shaft on which the drums for the supporting cables of the door leaf are arranged in a torsion-proof manner and into which the torsion spring initiates the torsional tension required to compensate for the door leaf weight, reaction movements occur in the event of spring breakage which, owing to the elasticity and inertia of the connected components, can lead to pendulum movements and thus also to back-turning movements of the cable drums Urde observed that the rope can jump from the drum or move to one of the neighboring tracks of the drum, which leads to a further lowering of the door leaf, since the drums are conical due to the balance of the force-displacement characteristics of the springs. If the door leaf is lowered on one side, it can jam, making it very difficult to move the door leaf out of this position, even if only for the provisional operation until the broken spring is repaired.

In a particularly preferred embodiment of the invention, these circumstances are taken into account by designing the attack or engagement between the catching member and the component in such a way that their relative movement to one another is prevented in both directions. This ensures that pendulum movements are kept away from the door leaf or the elements holding it. This applies both to the arrangement of the catching device or a part thereof, for example the catching member on the door leaf itself, and also in the event that the catching device is arranged on the torsion shaft near one end of the torsion spring to be monitored. The catch member can be a translationally or rotatably movable member, the component moved relative to it can be an elongated strip or a wheel. In principle, it is possible to design the catching device to work in a non-positive manner, but mostly the positive engagement between the catching member and the component is provided. If the safety gear is arranged on the torsion shaft, the rope drum, which is arranged on the torsion shaft in a torsion-proof manner, can no longer perform any movements after engagement of the safety gear in the catching position, i.e. also not in the opposite direction to the closing movement of the door leaf, thereby preventing the suspension cable from being lifted out of the drum grooves becomes.

In the case of a positive engagement, the engagement surfaces of the catch member and the component or the catch pawl and the ratchet wheel are selected so that forces exerted on these flanks act upon the catch member as far as possible into the catch position, in both possible relative movement directions. This applies to both the translational and the rotatory design of the catch element. When the catch member is designed as a pivotable catch pawl, the position of the pivot axis is to be selected so that the forces exerted on the catch pawl by the engagement in the component or the ratchet wheel result in a torque about the pivot axis which acts on the lever in the catch position

In a direction-dependent design of the catch element in such a way that the relative movement between the catch element and the component is only prevented in the direction of the closing movement of the door leaf, it is possible to lift the gate out of the catch position after a spring break and to transfer it to the open position. In contrast, a return movement to the closed position is not possible. In practice, this is often very difficult. In order to be able to move the door leaf as desired after the spring break and thus blocking of the door leaf movement both in the closing direction and in the opening direction, an unlocking device is preferably provided which enables the catching element to be brought into the operating position in a targeted manner. This can cause a broken spring a door leaf can be opened and closed until the time of repair - for example with the help of a forklift. Since only a few of the torsion springs usually provided break, in any case initially only one, it is thus possible to specifically release the catching device assigned to the broken spring.

These and further embodiments of the invention result from the subclaims, in particular in connection with the embodiment shown in the drawing, the following description of which explains the invention in more detail.

• Figur 1 eine perspektivische Ansicht eines ersten Ausführungsbeispieles ;
• Figur 2 eine Draufsicht auf ein zweites Ausführungsbeispiel - in Figur 2 bzw. 3 von oben gesehen;
• Figur 3 einen Schnitt nach der Linie 111-111 in Figur 2 mit in Betriebsstellung befindlicher Fangklinke ;
• Figur 4 einen Schnitt entsprechend der Darstellung gemäß Figur 3 mit in Fangstellung befindlicher Fangklinke.

Show it

• Figure 1 is a perspective view of a first embodiment;
• Figure 2 is a plan view of a second embodiment - seen from above in Figure 2 and 3;
• 3 shows a section along the line 111-111 in Figure 2 with catch in the operating position;
• FIG. 4 shows a section corresponding to the illustration in FIG. 3 with the catch pawl in the catch position.

FIG. 1 shows the one lateral end region of a torsion spring door leaf weight compensation device, as is used in connection with, for example, a roller door or overhead sectional door. It has to be imagined that the shaft holder attachment designated 1 is located at the other end, not shown, of the torsion shaft 2 in a mirror-symmetrical design. At least two torsion springs are held on the shaft, which are connected to the shaft in a torsion-proof manner in their area facing the shaft center. Only a region of one of the torsion springs 3 adjoining the shaft holder is shown.

This area of the torsion spring 3 is held in a manner not shown on an internal cone which has a decreasing diameter towards the end of the spring 3, not shown. The cone 4 is rotatably mounted on the shaft. In the area of the holder and thus in the lateral end area of the shaft 2, a cable drum 5 is held on the latter in a rotationally fixed manner. A rope 6 can be wound up and unwound onto this rope drum, which is fixed with its free end in a manner not shown in the lower side edge region of a door leaf, also not shown. Between the cable drum and a part of the shaft holder fastening, on which the shaft is guided, a ratchet wheel 7 is fixed in a rotationally fixed manner on the shaft 2 by means of a screw 8. The pawl wheel 7 is assigned a pawl 9 which is rotatably attached to the shaft holder 1 in an end region facing away from the pawl wheel 7. In the case shown, the pivot bearing is carried out via a screw bolt 10 which engages in a «radially elastic sleeve». This sleeve serves as a damping device in such a way that an impact load exerted on the pawl leads to radial cushioning of this sleeve, as a result of which corresponding shock absorption is achieved. Such a damping can also be achieved differently, in particular by means of a holder for the bearing screw 10 in the shaft holder 1 which can be displaced in a correspondingly damped manner.

The end region 11 of the torsion spring 3 assigned to the illustrated shaft end, which is supported by the shaft holder on both sides of the cable drum or the ratchet wheel, has, for example, an eyelet or the like on the associated end 12 of this spring 3, in which a bolt 13 in not is specified in more detail. This can be done, for example, by screwing. In the area of this end 12 of the spring, the adjacent wall of the shaft holder attachment 1 is provided with a holding area 16 which has an elongated hole 14. The bolt 13 projecting axially from the end 12 of the spring passes through this elongated hole 14 and is secured against slipping out of it by means of a holding plate 15 which is arranged on the spring 3 side of the shaft holder part having the holding region 16. As the drawing shows, the holding plate extends diametrically to the shaft diameter, so that in the lower part of the figure another slot can be provided, through which the connection to the spring can be established a further time.

The bolt 13 protrudes over the holding plate 15 in the direction of the cable drum 5 with an area 19 which, in the operating position shown, that is to say with the spring not broken, engages under the pawl nose 20 of the pawl 9 such that it cannot engage in the ratchet wheel 7. The pawl is biased by a compression spring 22 in the direction of engagement with the ratchet wheel, the compression spring being supported on a holding part 21 fixed to the shaft holder.

The opposite narrow end faces of the elongated hole 14 serve as a stop 16 or counter-stop 17 for the bolt 13, which bears under the force of the tensioned, unbroken torsion spring 3 under appropriate pressure against the stop 16 and holds the pawl 9 in disengagement. If the torsion spring 3 breaks, the reaction forces or stored forces cause the bolt 13 in the exemplary embodiment shown to be removed clockwise from its support on the stop 17 and flung against the counter-stop 18. As a result, the pawl 9 is released and moves under the force of the compression spring 22 into engagement with the ratchet wheel, whereby the shaft is prevented from further rotation and thus the downward run of the rope 6, on which the door leaf is held, is stopped. This happens after only a fraction of a revolution of the shaft, so that a very low fall height of the door leaf is guaranteed from the spring break.

Should the tension of the torsion springs be relatively low, in particular only the bias is present, one could consider to ensure the displacement movement of the bolt 13 when the spring breaks, bevel the pawl nose 20 such that under the force of the compression spring 22 then no longer by the torsion spring 3 in his Support position on the stop 17 loaded bolt 13 is moved in the direction of the elongated hole, so that the release of the pawl must be ensured in any case. Something similar can be achieved if the attack between the pawl nose and the round bolt 13 is shifted to the cylinder wall of the bolt that bulges towards the pawl, that is to say not to the jacket region that is to be regarded as the zenith with regard to the pawl design.

If the pawl engages in the ratchet wheel or a safety device is triggered in some other way so that the door leaf movement occurs as suddenly as possible in the event of a spring break, then problems arise when an electric drive unit is provided for the door leaf movement. The drive motor unit should not have to work against the catch member or the pawl device. For this reason, the actuating element of an electrical switch is installed in the path of movement of one of the parts of the voltage sensor that moves when the spring breaks, which interrupts the supply circuit of the motor unit.

The above-mentioned spring monitoring device naturally also works by controlling the door leaf movement by hand.

FIGS. 2 to 4 show a lateral end region of a torsion spring door leaf weight compensation device, such as is used in connection with, for example, a roller door or overhead sectional door. It can be imagined that the shaft holder designated 31 is located at the other, not shown, end of the torsion shaft 32 in a mirror-symmetrical design. At least two torsion springs are held on the torsion shaft, which are connected to the torsion shaft in a torsion-proof manner in their region facing the shaft center. Only a region of one of the torsion springs 33 adjoining the shaft holder is shown. This region of the torsion spring 33 is held in a manner not shown on an internal spring holding body 43 which can have a decreasing diameter towards the end of the torsion spring 33 (not shown) and thus the shape of a Has cone. The spring holding body 34 is rotatably mounted on the torsion shaft 33. In the area of the holder and thus in the lateral end area of the torsion shaft 32, a cable drum (not shown) is arranged in a torsion-proof manner. A rope, which is also not shown, can be wound up and unwound onto this rope drum, and its free end is fixed in the lower side edge region of a door leaf which is also not shown. The end 35 of the torsion spring 33 which faces the spring holding body 34 is suspended in a fastening tab 36 which in turn is fastened to the spring holding body 34 in such a way that the spring end 35 cannot free itself from this fastening on the spring holding body 34.

Between the cable drum, which has to be imagined in FIG. 2 to the right of the shaft holder 31, and the spring holding body 34, a ratchet wheel 37 is fixed on the torsion shaft 32 in a rotationally fixed manner with the aid of screws 38, as can also be seen in FIGS. 3 and 4. The ratchet wheel 37 is assigned a catch pawl 39 which is pivotably mounted about a pivot axis 40 (FIGS. 3 and 4), which is fixed at both ends in the region of the legs of a bow-shaped holder 41. The bow-shaped holder 41 is braced in its thigh region with the aid of connecting webs 42 and is firmly connected to the shaft holder 31, for example with the aid of screw connections 43 in the region of the shaft bearing of the shaft holder 31. The shaft holder 31 and the bow-shaped holder 41 are on the wall anchored above the door opening to be locked.

The swivel mounting of the catch pawl can be made impact-damped, specifically in the area of the bearing of the catch pawl itself or in the area of the holder of the swivel axis. In the illustrated embodiment, the catch pawl 39 is prestressed with the aid of a torsion spring 45, which is wound around the pivot axis, in the direction of assuming the catch position (FIG. 4). Instead of a torsion spring, another spring, in particular a helical spring, can be used, which is prevented in a known manner against lateral breaking out by means of telescopic guidance, so that it still works reliably even after a break.

The spring holding body 34, which is freely rotatably mounted on the torsion shaft, has bolts 46, for example screw bolts, in two diagonally opposite edge regions, which are designed to project axially parallel to the torsion shaft 32 towards the ratchet wheel 37 and are recessed at corresponding locations in the adjacent leg of the bow-shaped holder 41 , pass through elongated holes 57 - FIGS. 3 and 4 - which extend in the circumferential direction around the shaft. In their end region facing the spring holding body 34, the bolts 46 are each provided with a collar which engages over the edge regions of the respectively associated elongated hole. From their free end on the bolt holding plates 47 are placed, which also overlap the edge regions of the elongated holes from the other side, so that the bolts 46 are secured against sliding out of the associated elongated holes 57, with play so that they are within the slots can move. The free end portions 48 of the bolts 46 protrude so far into the space between the legs of the bow-shaped holder 41 that one of them comes to rest on a shape 49 of the catch pawl 39, as can be seen particularly in FIGS. 3 and 4 is.

Figure 3 shows the safety gear in the operating position, i. H. with existing spring tension or spring preload. When the torsion spring 33 is unbroken, the end shown is supported in a fixed manner via the spring holding body 34 and its bolt 46 in one end region of the elongated holes 57 and thus on the bow-shaped holder 41 in the installed state. The region of the leg of the bow-shaped holder 41, in which the elongated hole 57 closest to the catch pawl 39 is located, is referred to as the holding region 58. In this position, with the spring not broken, the catch pawl 39 is supported by a latching surface 59 of the projection 49 on the bolt 46 closest to the catch pawl, as shown in FIG. 3. In this operating position, the catch pawl 39 is disengaged from the ratchet wheel 37. The torsion shaft 32, the ratchet wheel 37 fixed on this and the rope pulley also attached to it can rotate under tension and relaxation of the torsion spring, so that the rope held on the rope Door leaf can move between the open and closed position, for example by a drive. If the torsion spring 33 breaks, the spring holding body 34 and thus the bolts move more or less violently due to the reaction force of the spring, depending on the spring tension, from the system shown in FIG. 3 at one end of the elongated holes to the other end thereof, as shown in FIG 4 is reproduced. The bolt 46 closest to the catch pawl 39 thus releases the latching surface 59, so that the catch pawl 39 can move under the force of the spring 45 upon engagement with the ratchet wheel 37. Due to the breakage of the torsion spring 33 and the torque that is exerted on the torsion shaft 32 via the ropes and the cable drums, the torsion shaft 32 rotates counterclockwise in the example shown until the catch pawl 39 can engage in engagement with the ratchet wheel. Due to the relatively large number of points of engagement of the ratchet wheel 37 distributed over the circumference, the torsion shaft 32 can only rotate by a relatively small angle, so that the door leaf, the weight of which is no longer fully compensated by the spring force, only by a small amount Can move downwards. The suddenly released forces in the event of spring breakage mean that the bolts 46 do not remain in their position shown in FIG. 3, but bounce back. Similarly, if the torsion spring breaks, the torsion shaft will perform more or less uncontrollable movements due to the connected components, which are also dependent on the location of the spring break. There is a risk that the rope drum stopped abruptly by the catching device can turn backwards through the door leaf springing back over the ropes, as a result of which conditions occur that the ropes jump off the associated rope drum or at least move these ropes into another track can pull themselves. This can only occur with regard to one of the ropes and the associated rope drum. The catching device of the type claimed here, however, prevents such a possibility of turning back in that the locking engagement takes place in both directions of rotation of the ratchet wheel. This can prevent the above-mentioned phenomena.

The rebounding bolt 46, which is adjacent to the catch pawl 39, must not push it back into the operating position or out of engagement with the ratchet wheel 37. For this reason, in the region of the protrusion 49 of the catch pawl 39, a baffle surface 60 pointing into the path of movement of the bolt 46 is provided, onto which the bolt 46 strikes in backward movement, specifically with regard to the geometrical arrangement such that a torque about the pivot axis of the catch pawl 40 is exercised, which acts on the catch in the catch position shown in Figure 4. Thus, once the catch position of the catch pawl 39 has been assumed, it is independent of the subsequent movements of the bolt 46.

Immediately after the spring breaks, the catch pawl is transferred from the position with the spring not broken to the catch position during the first displacement movement of the bolt 46 and a further movement of whatever kind is intercepted by the torsion shaft and thus the cable drum.

The embodiment shown here works with a voltage sensor as a mechanical locking mechanism in the form of the bolt 46 and the catch pawl 39. If the catch device is not arranged in the vicinity of the spring end to be monitored, for example in the area of the door leaf, an electrical, pneumatic and hydraulic is provided in the holding area 58 Switch arranged or a strain gauge attached, which indicates the displacement movement of the bolt 46 and converts it into a trigger signal for the safety gear. If the spring breaks, for example, the door leaf can be caught immediately.

A door leaf intercepted in the event of a spring break should still be able to be opened and closed, for example with the aid of a forklift or the like, until the spring break is eliminated. For this purpose, the pawl must be disengaged from the ratchet wheel so that it and the torsion shaft and the cable drums can be rotated. For this purpose, an unlocking device is provided which comprises a shaft 63 which is mounted on the bow-shaped holder 41 and on which a cam 62 is held against rotation in the area of the catch pawl. With the help of a handle 64, the shaft and thus the cam 62 can be pivoted. In this case, the cam 62 engages a return projection 61, which is assigned to the pawl or is formed on the pawl. As indicated by the dot-dash line in FIG. 4, the cam 62 can be pivoted against the lever 64 by pivoting it Return approach 61 move and take this, whereby the FangkJinke 39 is forced into its operating position. In most cases, more than one torsion spring is arranged on the torsion shaft. Since each of these springs has to be monitored, a corresponding number of interception devices are provided. To move the door leaf when a spring breaks, all of these catch pawls must be disengaged from the associated ratchet wheels. For this reason, the shaft 63 of the unlocking device is guided parallel to the torsion shaft 32 over all safety devices, it carries as many cams as safety catches, and of course in an appropriate assignment.

As can be seen in FIGS. 2 to 4 of the second exemplary embodiment, in particular FIGS. 3 and 4, the ratchet wheel 37 is diagonally divided into two halves, which can be assembled using connecting flanges. This makes it possible to retrofit this spring monitoring device with a safety gear. The bow-shaped holder 41 comprises the catch pawl 39 with its spring and the associated part of the unlocking device. This makes it very easy to assemble the entire monitoring device retrospectively on an existing torsion shaft. To do this, it is only necessary to detach the spring holding body 34 from its connection with the shaft holder 31 which had existed up to that point. The screw connections 43 and the bolts 46 are axially aligned with one another, so that the bolts 46 can now be inserted into the same openings in the released spring holding body which is shifted to the left in FIG. 2, via which the spring holding body has so far been connected to the shaft holder. Thereafter, the two-part ratchet wheel 37 is placed on the torsion shaft in the space thus freed between the spring holding body 34 and the shaft holder 31 and fastened and connected to the shaft in a rotationally fixed manner by means of the screws 38. Thereafter, the bow-shaped holder 41 is brought with the catch kink 39 and the ratchet wheel between them into the position shown in FIG. 2 and connected to the shaft holder or the wall at the place of attachment. The spring holding body 34 is now inserted with its bolt 46 into the elongated holes 57 and fixed there with the aid of the holding plates 47. In this state, the end region 48 of the one bolt 46 engages on the latching surface 59 of the spring catch pivoted back into the operating position. The system is now ready for operation.

As can be seen in particular in FIG. 2, the bow-shaped holder is mirror-symmetrical with respect to a plane running parallel to its legs and centrally between them. Only the arrangement of the spring 45 can be excluded. The elongated holes 57 are congruent in both legs. This bracket-shaped holder with all its parts can be used for both left-hand and right-hand attachment to the shaft holder. This means that one and the same device can optionally be used for one of the torsion springs 33 of the torsion shaft 32.

In order to ensure the positive engagement of the catch pawl 39 in the ratchet wheel 37 in such a way that no force is exerted on the catch pawl 39 from there, which points in the direction of movement into the operating position, the tooth flank surfaces 56 of the teeth 54 of the ratchet wheel are designed accordingly. and undercut either in the direction of the radius of the ratchet wheel or even better to this radial direction. In the present example, a rectangular tooth gap 55 was provided, which therefore means that tooth flank surfaces 56 run undercut with respect to the respective radial direction.

The nose 51 of the catch pawl engages in these tooth gaps, provided in a first embodiment with nose surfaces 53 which, in the catching position, run approximately parallel to the tooth surfaces 56. In the present example, the catch pawl 39 is provided with a groove-shaped recess 50, the side surfaces 52 of which in the catching state run approximately parallel to the tooth flank surfaces 56. Accordingly, a tooth 54 of the ratchet wheel 37 is received in the groove 50 of the catch pawl 39 and thus the ratchet wheel is locked against rotational movements in both directions of rotation.

Claims (29)

1. Spring control device for a pretensioned torsion spring of a gate, a door or the like, in particular as a weight-balancing spring for a one-or multi-part overhead movable door leaf or an armoured roller door, to prevent the door leaf from falling down in the event of a breakage of the spring, in which, for at least one of the two end regions (11) of the spring (3), a tension sensor (13) is provided, said tension sensor being biased by said spring in one direction in the biased condition of the spring, and in the opposite direction in the event of a breakage of the spring, solely by the reaction force of the spring, to release a locking device for the door leaf (7, 9).

2. Device according to claim 1, characterised in that the tension sensor is in the form of a wire strain gauge.

3. Device according to claim 1, characterised in that the tension sensor is in the form of an electrical switch.

4. Device according to claim 1, characterised in that the tension sensor is in the form of a mechanical member (13 ; 46).

5. Device according to claim 4, characterised in that the mechanical member (13 ; 46) is secured on the one hand, to one end (12) of the torsion spring (3 ; 33), and, on the other hand, is supported on a stop (17; 59) of a support region by the tension of the unbroken spring (3 ; 33) and is guided over a certain path away from the stop (17; 59), when the spring breaks.

6. Device according to claim 5, characterised in that the displacement path guide is formed by an elongated hole (14 ; 57) in the support region (16 ; 58).

7. Device according to any one of claims 4 to 6, characterised in that the mechanical member (13) is in the form of a catch for a catch member (9, 39) displaceably guided between an operating position and a catching position, said catch member being supported in the operating position by said mechanical member when the mechanical member (13; 46) is held on the stop (17) and, when the mechanical member (13; 46) is displaced from the stop (17) being released so as to move in the direction of the catching position, in which the catch member (9 ; 39) cooperates with a component (7 ; 37) mounted so as to be movable backwards and forwards relative to said catch member as a result of the closing and opening movement of the door leaf.

8. Device according to claim 7, characterised in that the catch member (9 ; 39) is spring-loaded (22 ; 45) so as to be biased into the direction of its catching position.

9. Device according to claim 8, characterised in that the catch member is constructed as a rotatably mounted pawl (9 ; 39), which is arranged, in the operating position, so as not to cooperate with the component which is formed as a ratchet wheel (7 ; 37) and, in the catching position, so as to cooperate with said component, thus stopping rotational movement thereof, said ratchet wheel (7 ; 37) being rotationally fixedly connected to a shaft (2; 32) on which the other end of the torsion spring (3 ; 33) is held so as to be rotationally fixed at least in the operating position.

10. Device according to claim 9, characterised in that at least one of two drums (5) is connected for rotation with the shaft (2 ; 32) a cable (6) chain or similar power transmission member, having one end connected to the door leaf or armoured roller door, preferably in the position, being windably mounted on said drum.

11. Device according to any one of claims 6 to 10, characterised in that the mechanical member is in the form of a bolt (13) connected to one end (12) of the torsion spring (3) to be controlled, said bolt passing through the elongated hole (14) in the support region (16), said bolt (13) being secured against sliding out of the elongated hole (14), on the side of the support region remote from the torsion spring (3), by a retaining plate (15) and having an end region (19) projecting therefrom, by means of which it engages under the nose (20) of the pawl (9) when the spring is unbroken.

12. Device according to any one of claims 7 to 10, characterised in that the engagement of the catch member (39) on the component (37) is formed such that the relative movement is stopped in both directions.

13. Device according to claim 12, characterised in that the catch member (39) is provided with a projection (51) engaging, in the catching position, in at least one of a row of catching recesses (55) formed in the component (37), said recesses, in the two directions of the relative movement, having catching surfaces (56) which lie opposite the respectively facing projection surfaces (53).

14. Device according to claim 13, characterised in that the catch member is formed as a pawl (39) and the component as a wheel (37) which has a castellated circumferential course of tooth (54)-tooth gaps (55).

15. Device according to claim 14, characterised in that the tooth surfaces (56) facing the circumferential direction are formed so as to extend in the diametral direction of the wheel (37).

16. Device according to claim 14, characterised in that the tooth surfaces (56) facing the circumferential direction are formed to extend in an undercut manner with respect to the diametral direction of the wheel (37).

17. Device according to claim 16, characterised in that the tooth gaps (55) of the wheel (37) are formed in the shape of a rectangle, viewed from the axial direction thereof.

18. Device according to any one of claims 14 to 17, characterised in that the projection (51) of the pawl (39) has projection surfaces (53) facing the circumferential direction of the wheel (37), said projection surfaces being formed so as to extend, in the catch position, substantially parallel to the respectively adjacent tooth surfaces (56).

19. Device according to any one of claims 14 to 17, characterised in that the pawl (39) has a groove-shaped recess (50) extending in the axial direction of the wheel (37), in which a tooth (54) of wheel (37) engages in the catching position and whose side faces (52) facing in the circumferential position are formed to extend substantially parallel to the respectively adjacent tooth surfaces (56).

20. Device according to any one of claims 12 to 19, characterised in that the catch member or the pawl (39) has a recessed part (49) having a stop surface (59) on which abuts in the operating position of the pawl (39), a mechanical member (46) of a tension sensor formed as a catch, said mechanical member being secured at one end (35) of the torsion spring (33), on the one hand, and being supported on a stop of the support region (58), when the unbroken spring (33) is stressed, on the other hand, said mechanical member being guided over a given path so as to be movable away from the stop, when the spring is broken.

21. Device according to claim 20, characterised in that the recessed part (49) has an impact surface (60) which, in the catching position of the pawl (39) lies opposite the mechanical member (46) moved away from the stop in the retrogressive direction thereof.

22. Device according to any one of claims 12 to 21, characterised in that the wheel (37) is rotationally fixedly connected to the torsion shaft (32), on which the other end of the torsion spring (33) is rotationally fixedly held, at least in the operating position, that at least one of two drums is rotationally fixedly connected to the shaft (32), a cable, chain or similar power transmission member, being connected at one end to the door leaf or roller door, preferably in the lower region in the closing position thereof, and being windably held on the drum and that the catching pawl (39) is mounted on a U-shaped holder (41) which accommodates the ratchet wheel (37) and which, viewed in the axial direction of the torsion shaft (32), lies between the torsion spring (33) and a shaft mount (31) carrying a torsion shaft bearing.

23. Device according to any one of claims 12 to 22, characterised in that the wheel (37) is formed with a diagonal division.

24. Device according to any one of claims 12 to 23, characterised in that the mechanical member is in the form of a bolt (46), said bolt being secured to an optionally conically formed spring mounting body (34) which holds the end (35) of the torsion spring (33) and is rotatably mounted on the torsion shaft (32), passing through the elongated hole (57) in the support region (58) of the U-shaped holder (41), and being secured against sliding out of the oblong hole, (57) on the side of the support region (58) remote from the torsion spring (33), by a retaining plate (47), and having a projecting end region (48), which, when the torsion spring (33) is not broken acts on the stop surface (59) of the pawl (39) while holding the latter in the operating position.

25. Device according to any one of claims 12 to 24, characterised in that a release device (61-64) is provided which is adjustable between a resting position and a release position and, in the latter, by means of a release member (62), acts on the catch member or pawl (39) transferring same into and holding same in the operating position thereof.

26. Device according to claim 25, characterised in that the release device (61-64) has a shaft (63) having at least one cam (62) as a release member which acts on a return projection (61) of the pawl (39).

27. Device according to claim 25 and 26, characterised in that in a plurality of catch members or pawls (39) each is provided with a release member (62), all the release members (62) being held on a joint actuating member (63, 64).

28. Device according to any one of claims 1 to 27, characterised in that a supply current switch for an electrical door leaf drive is provided, having an actuating member which is arranged opposite an actuating surface of the mechanical member or bolt (13 ; 46) or of the catch member or pawl (9 ; 39).

29. Device according to any one of claims 7 to 28, characterised in that the catch member or the pawl (9; 39) is mounted in an impact-dampened manner, for example over a damping bush having an annular region of rubber or the like or by a dampened displaceable mount on the component (1 ; 41) providing the support region (16 ; 58).

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