Cable monitoring unit for a gate leaf

Abstract

Cable monitoring unit for a door leaf, in particular a sectional door, which is moved vertically on both sides by mechanical cables in guide rails from a closed position to an open position, these cables are each attached laterally at the lower end of the door leaf, wherein a change in the length of the cables is detected by a safety device with a microswitch, characterized in that the cables are each monitored by a sensor unit, the sensor unit detects any change in tension of the cables, for this purpose a deflection pulley (1) is mounted on an axle (5) over which the cable is guided, the axle (5) directly or indirectly exerts a force on the sensor unit via the tension of the cable.

Description

[0001] The invention relates to a suspension cable monitoring unit for a door leaf that can be moved vertically from a closed position to an open position on both sides by mechanical suspension cables in guide rails. The suspension cables are each attached to the lower end of the door leaf, with any change in the length of the suspension cables being detected by a safety device.

[0002] A safety device for a movable door leaf of a gate, in particular a sectional door, is known from DE 20 2011 000 948 U1. The door leaf is moved between an open position and a closed position via guide rails, wherein the door leaf is equipped with pull cables on the sides, which are fastened in the lower area of ​​the door leaf and each guided via deflections. The fastening of a pull cable via a safety device is designed in such a way that, when the door leaf is closed, a continuous adjustment of the pull cable length is possible. The safety device essentially consists of a fixed base part and an upper part whose position relative to the base part can be changed via a pivot axis and which has a connecting element movably mounted therein. The change in the length of the pull cable is detected by the upper part during operation of the door leaf and is detected by a microswitch.

[0003] The object of the invention is to detect without doubt any damage or change in the length of support cables in door leaves, the relative positions of which can be changed by support cables attached to the sides of the door leaf, in order to cause the drive device to immediately block the movement of the door leaf.

[0004] The object of the invention is solved by the features of claim 1. The subclaims following the main claim represent a further embodiment of the inventive concept.

[0005] The inventive idea of ​​constructing a suspension cable monitoring unit using simple, cost-effective means consists in guiding the suspension cables attached to the lower end of the door leaf over a deflection pulley. However, it is also possible for the end of at least one suspension cable to be simultaneously attached to a housing of the suspension cable monitoring unit; other attachments are also possible. In such a case, the housing is attached to the bottom of the door leaf. The deflection pulley is mounted on a translationally modified axis and, in conjunction with a spring element, loads a pressure sensor. Once the suspension cables are attached to tension, an output pressure is exerted on the pressure sensor of the sensor unit via the axis of the deflection pulley in conjunction with the spring element.This signal is fed to the drive unit, where it can quickly stop the door leaf when the pressure on the sensor decreases, thus changing its output signal. This also allows the sensor unit to continuously monitor the door leaf both during standstill and during operation. Should any deviations be detected during the measurement, the door leaf can be checked and simultaneously stopped for safety reasons, even if one of the suspension cables has not yet broken.

[0006] Such pressure sensors with diffused resistors have proven to be very effective as pressure sensors. These strain-sensitive resistors can react to deformation with positive or negative resistance changes, depending on the application of the resistors, and complement each other in the equation. The resistors, which are located on a base, thus measure forces and pressures and are suitable for detecting relatively small changes in force. To record these very small currents and changes in resistance, a so-called Wheatstone bridge is used, which can detect the smallest ohmic resistance changes. Such a Wheatstone bridge has four resistors connected together to form a closed ring and connected diagonally to a voltage source. Two resistors each form a voltage divider. This means that two voltage dividers are always connected in parallel.If a change in the resistance values ​​is detected in one of the voltage components or one of the resistors, this can be detected as an alarm signal.

[0007] In order to ensure a good initial load on the sensor device after tensioning the suspension cables, it is necessary for the suspension cable monitoring unit to be able to react to relevant pressure changes. For this purpose, a fixing unit with internal guide sides is located in or on a housing. The axis of the deflection pulley is in contact with the guide sides of a fixing unit. For this purpose, a pressure piece is located at the end of the axis, which is guided translationally within the guide sides. A pressure element is arranged below the pressure piece, which is positioned on the one hand against the pressure piece and on the other hand against a pressure plate. The fixing unit is closed on the underside so that the sensor unit can be placed between the base of the fixing unit and the pressure plate.

[0008] In order to detect a relative translational change in the position of the axis, which would result in a change in the load-bearing capacity of the suspension cables, there is a slotted hole in the housing or in the fixing unit through which the axis of the deflection pulley extends.

[0009] The invention is explained in more detail using a schematically illustrated embodiment. Fig. 1 shows a suspension cable monitoring unit in a perspective view; Fig. 2 a section through the suspension cable monitoring unit.

[0010] A substantially completely executed suspension cable monitoring unit 2 is installed in the Fig. 1. A deflection pulley 1 is arranged rotatably about an axle 5. The deflection pulley 1 can be partially wrapped with one or two supporting cables, whereby the ends of the supporting cables can be secured to an end fastening 13 of a section 4 of a housing. Within the housing 3 there is a fixing unit 6, which can also be part of the housing 3. The axle 5 penetrates the fixing unit 6 via an elongated hole 9, which is located on opposite sides of the housing 3 and on opposite sides of the fixing unit 6. The axle 5 is provided with a pressure piece 7, which generates a pressure on a spring unit 8 located underneath, which pressure is generated by the existing supporting cable tension. This can be the case, in particular, Fig.2 in a sectional view of the fixing element 6. The spring element 8 presses against a pressure plate 10, with the sensor unit located below the pressure plate 10, which, on the other hand, is positioned against a base 11 of the fixing unit 6. The pressure piece 7 slides with its lateral ends in guide surfaces 12 of the fixing element 6 and can thus reliably transmit any pressure change to the sensor element.

[0011] A strain gauge sensor unit has proven very effective in training. Strain gauges of this type are available in various designs that can be adapted to the required application. Reference symbol 1 pulley 2 suspension cable monitoring unit 3 housings 4 Fastening 5 axis 6 Fixing unit 7 Pressure piece 8 spring element 9 slotted hole 10 printing plate 11 Floor 12 guide pages 13 End fastening QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2011 000 948 U1

[0002]

Claims

[1] Support cable monitoring unit for a door leaf, in particular a sectional door, which is moved vertically in guide rails on both sides by mechanical support cables from a closed position to an open position, these support cables are each attached to the lower end of the door leaf, whereby a change in the length of the support cables is detected by a safety device with a microswitch, characterized by that the supporting cables are each monitored by a sensor unit, the sensor unit detects any change in tension of the supporting cables, for this purpose there is a deflection pulley (1) on an axis (5) over which the supporting cable is guided, the axis (5) loads the sensor unit directly or indirectly via the tension of the supporting cable. [2] Suspension cable monitoring unit according to claim 1, characterized bythat a spring element (8) is placed between the axis (5) and the sensory unit, the spring element (8) being positioned against a pressure plate (10) above the sensory unit. [3] Suspension cable monitoring unit according to claim 1, characterized by that the axis (5) has a guide projection with a pressure piece (7) which is guided laterally between guide sides (12) of a fixing unit (6). [4] Suspension cable monitoring unit according to claim 3, characterized by that the side guides (12) of the fixing unit (6) merge into a closed base (11) at the bottom. [5] Suspension cable monitoring unit according to one or more of the preceding claims, characterized by that the sensor unit is arranged between the base (11) and the pressure plate (10), wherein the pressure plate (10) is loaded by the spring element (8). [6] Suspension cable monitoring unit according to one or more of the preceding claims, characterized by that the fixing element (6) is fastened to a housing (3), wherein in the housing (3) and in the fixing unit (6) corresponding elongated holes (9) run, which are penetrated by the axis (5). [7] Suspension cable monitoring unit according to one or more of the preceding claims, characterized by that the spring element (8) is designed as a compression spring. [8] Suspension cable monitoring unit according to one or more of the preceding claims, characterized by that an end fastening (13) for at least one of the supporting cables is located on the housing (3). [9] Suspension cable monitoring unit according to one or more of the preceding claims, characterized by that one or more supporting cables are guided together over the deflection pulley (1). [10] Suspension cable monitoring unit according to one or more of the preceding claims, characterized by that the sensory unit is a pressure sensor. [11] Suspension cable monitoring unit according to one or more of the preceding claims, characterized by that the sensor unit is designed as a strain gauge sensor. [12] Gate with a gate leaf, the relative position of which can be changed by lateral support cables attached to the gate leaf, with at least one support cable monitoring unit (2) according to one or more of the preceding claims.

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