DE2435686A1 - LOAD MEASURING AND LOAD DISPLAY SYSTEM FOR CRANE DEVICES - Google Patents

Description

lawyers

Olpl.-Ιης ·. Martin light

Dr. Reinhold Schmidt

Dlpl.-Wirtsch.-Ing. Hansmann

Dipl.-Phys. Seb. Herrmann

Β MUNICH 2 Yheresienstrasse 33

Munich, July 24, 1974

FORNEY INTERNATIONAL, INC.

6434 Maple Avenue Dallas, Texas
V. St. A.

"Debit measurement and debit note system for crane devices "

In lifting equipment, including cranes and crane scaffolding, there is a real need for accurate, resilient, reliably working systems for processing signals in analog form, which means not only continuously the actual weight of a load moved by the lifting device is displayed, but also that Pediatricians are warned if the strain affects one

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reached a certain value, since then the safety of the operating personnel and other people in the company can be at risk. For example, when the permissible load limit in the case of jib cranes overturn the entire lifting device. With heavy loads and There is thus a considerable potential hazard for long booms. The present invention allows this Operating personnel to adjust the arrangement to a certain permissible load, and a warning buzzer or a Warning lights are automatically put into operation when the load limit is reached, whereby the operating personnel is made aware and the dangers resulting from overloads can be eliminated.

There is a need in particular to "an analog-warning system of simple design _t that can be easily read and repaired quickly and at low cost. The present system meets these requirements, as it comprises a single card with a printed circuit for the entire analog scarf tkreis , including sub-circuits for supplying power with a regulated, constant output voltage for the other transistorized circuits in the system.

If several load cables are used in the crane device

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devices must be used to multiply the tensile stress caused by the stress in a cable by "the Total number of cables used to be provided. ' In addition, devices must be used to automatically compare the actual Load with a 'selectable load limit are provided so that the warning device when reached the load limit is put into operation. In the present case, these processes take place in suitable integrated circuits instead, which are integrated into the printed circuit and connected to external, manually adjustable digital switches with which the number of load cables and the desired load limit (in kilograms) can be set.

There is also a need for a simplified procedure for quick checking of the load-indicating instrument when the lifting device is not in the process of being lifted a load is used. According to the invention, this is done in a relay test circuit operated by a push button switch, which is operated manually and switches on the printed circuit in such a way that it depends on the actual load generated signal is switched off, and that one of a simulated number of cables and a simulated load lead the corresponding signal to the deflection of the display instrument.

Furthermore, is e? expedient to create a system in which the digital switch in one of the display unit

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separate power pack are housed, so that the two units at convenient locations for the operator can be mounted. According to the invention, the display unit can be in front of the operator in the driver's cab of the crane system be attached, and the power supply mounted within easy reach of the operator.

A universal display system is desired, such as a system that utilizes a single load cable or used with multi-cable hoists or jib cranes, crane gantries, or other lifting gear in which a load is suspended from a cable. The present invention can be advantageous in all of these Machines are used, with only three units needing to be assembled, namely one inserted in a cable Load cell, a display unit and a power supply unit.

When using jib cranes, the operator must of the crane always have knowledge of the angle that the jib forms with the horizontal (jib angle) to prevent the crane from tipping over. This is particularly important when moving heavy loads and in the In the case of a small boom angle, i.e. when the boom is almost in a horizontal position. To be effective and reliable Operation of the crane, the display device for the boom angle must also very much in the entire angular range of the boom work precisely, i.e. in most cases in one area

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of about 90 °.

Previous attempts, a completely satisfactory, simple, effective, reliable, resilient and compact Providing an indicating device of the boom angle have not given satisfactory results. The present Invention overcomes significant difficulties associated with known crane boom angle indicators by creating a transistorized system that can be built in a compact form and at the same time works precisely and reliably. Simple construction is achieved by using only two units, which include a new type of transmitter for the boom angle, as well as a control unit with a new type printed circuit to control the whole system and with a printed circuit to stabilize the power supply. The power pack is supplied by the battery housed in the crane, to which the circuits are isolated via an Cables to be connected.

In known potentiometer pendulum transformers for the boom angle, difficulties arose with the analog signal, which was not accurate over the entire angular range of 90 °. According to the invention, this problem is solved by a novel transformer that produces an extremely accurate, positive output voltage; this output voltage changes uniformly in direct proportionality to the actual

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common boom angle over the entire angular range of 90 °. This is achieved by arranging the potentiometer in the Transformer and by connecting the power supply from the printed circuit.

So far it has been proposed that a potentiometer used as a transmission element to determine the Convert the boom angle obtained analog signal into digital form and then convert it back into an analog signal for the boom angle indicator. According to the invention this complicated transformation is made possible by a new, extremely precise processing circuit of analog signals avoided. All circuits of the present invention are designed for analog signals, which simplifies the structure of the system.

An important point of view for crane operation are those difficult operating conditions, i.e. operation in extreme heat or very cold, in dust-laden ambient air or when the crane vibrates heavily. Such operating conditions usually reduce the life of instruments and affect the accuracy of their puncture. According to the invention, such conditions are largely taken into account by using a display system for the Long service life jib angle, even in the case of jib cranes.

Systems that can be used in crane arrangements must

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i'erner ranch can be checked for a possible Failure of external power supply; the whole system can be easily checked in terms of the boom angle gauge and warning indicators, so that the operator knows if the system works flawlessly ..

The warning display when the permissible angle is reached must be visible and audible so that the operator can A warning is given with safety even if she is busy operating the crane. In the present case, uses a simple, foolproof system that the The operator warns with a flashing light and a buzzer or horn as soon as one of the limit angles of the boom is achieved. The border angles can be quickly and simply by moving the range switch to the appropriate position and turning the appropriate potentiometer while observing the instrument to display the boom angle. The warning indicator when the limit values are reached, it can easily be set to any desired high or low value.

The system must also be easy to maintain, especially since maintenance is normally carried out at the crane's site is carried out. According to the present invention this is achieved by the card with a printed circuit which quickly replaced if a component of the circuit fails

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- 3 -

can be. The printed circuit board of the present invention also withstands and is operational failure
less susceptible to vibrations than known circuit arrangements.

In the system according to the invention, a transformer is used for the boom angle, which is expediently attached to the boom of the crane. A control and display unit is housed in the crane operator's cab. The system can be powered by the crane's battery,
which is connected to the housing of the
Control unit is connected. A connection between the
Transformer and the control display unit is via a
shielded cable made. The control display unit contains a card with a printed circuit which includes an integrated circuit for the power supply, which in turn results in a constant GI calibration voltage source of +15 volts with a center tap. The circuit for the constant voltage supply is connected to the end connections of a
bent potentiometer resistor connected in the transformer of the boom angle, so that the with the boom
occurring angular movement of the resistance leads to
that the resistance slides over a pendulum-like hanging tap, the axis of rotation of which corresponds to the movement of the resistance. When the boom is in the horizontal position, the tap in relation to the counter

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stood in the middle position. The resistance goes through an arc of 90 when the boom also goes through an arc runs from 90 °. The potentiometer, which is in the middle between -15 V = and +15 V =, runs from zero YoIt direct current to 7.94 V = in direct proportionality to the angular displacement from -0 ° to 90 °. The control display unit also includes a faceplate on which an analog display instrument for the boom angle, the knob of a range switch, and two adjustment knobs for potentiometers Setting the limit angle are attached, in addition to warning lamps for the angle limitation and a cooperating with it audible alarm device. A test switch is mounted and included on one side of the control display unit an acoustic alarm device that is switched on when the high or low limit angle is reached. The unit for control and display has rear lighting and an on / off switch for the supply Battery voltage attached.

The power pack is printed on a card or board that is housed in the control display unit is. This printed circuit controls almost the entire system that comes with a stabilized voltage from one on the The sub-circuit printed on the card is supplied. In addition to the power supply circuit If the card includes a test circuit, which with the corresponding warning device cooperates, as well as

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a circle for the display instrument '. The latter circle has high impedance, so that the potentiometers for setting the limit angle are not loaded when the limit angle are displayed. Also, the circuit for the gauge works to be either positive or negative Voltage is displayed because the voltages for setting the critical angle are those of the actual signal voltage the critical angle have opposite polarity.

The test circuit includes a capacitor that is normally is discharged through the test switch. When operating the test switch, the input becomes the amplifier of the transmitter signal separated from the transformer and connected to the capacitor. There is also a resistor across the capacitor connected so that the latter is slowly charged by the supply circuit with +15 V =. It thus arises a slowly increasing test voltage signal on the amplifier circuit. This signal simulates a slow change in the position of the angle transmitter from 0 ° to 90 ° and enables it is the operator, the operation of the display instrument as well as the use at the alarm points with high or lower angular position to follow.

The printed circuit is reliable and compact, but can still be easily replaced in the event of failure will. The system is very simple, extremely effective and easy to install or replace.

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The transformer is also extremely compact, but it generates a very precise analog signal that changes the boom angle during operation is directly proportional. The system can also be easily connected to the battery of the crane with which the system works, connect or disconnect from it. The entire signal processing in the system is done in analog form, so that none Conversion of the signals in digital form in the system is necessary "..

An exemplary, to explain the features and Embodiment used in the present invention includes a billing system and an IT power supply with a card with printed circuits. The printed circuit boards comprise an integrated circuit for a DC voltage source that generates a constant, regulated output voltage for the entire system.

A first integrated amplifier circuit is designed so that it is connected to the output signal of a circuit for the load cell attached to the cable can be connected; the latter circuit is energized by the. DC voltage supplied by a sub-circuit, the output voltage being proportional to the load attached to a cable is.

A second integrated amplifier circuit is connected to the first integrated amplifier circuit to its To automatically multiply the output signal with a signal,

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that of the total number used to suspend the load Cable corresponds; there is also an integrated circuit for comparing the load limit with the actual load provided, the corresponding signals are automatically compared with one another.

A switch for setting the number of cables used and the load limit is assigned to the power supply unit; the Switch includes numbered devices for setting the number of cables used to suspend the load and the load limit.

The switching devices are connected to the printed circuit via lines connected to corresponding sub-circuits the printed circuit are performed. The output signal generated in these sub-circuits corresponds to the actual one load occurring on the cable. Furthermore, an output warning signal is generated in the comparison circuit when the load limit is reached generated.

The display unit comprises an instrument indicating the load to which the one corresponding to the actual load Output signal is applied, furthermore a red warning light and a buzzer responsive to the warning signal, the indicates the occurrence of the limit load in the cable.

The exemplary embodiment used to illustrate Utilizing the characterizing features and advantages of the present invention further includes a display system

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the boom angle with an indicator and warning devices for the high and low boom angles, which indicate operation at the upper and lower limit, respectively. A transistorized power supply unit is connected to the transformer and operates the display instrument and the warning devices depending on the boom angle. Furthermore, devices are provided with the upper limit and lower limit of the boom operation can be adjusted.

The foregoing brief description and other objects, features, and advantages of the present invention are apparent in detail from the following detailed description of a preferred one which is particularly suitable for explanation Embodiment with reference to the accompanying drawings.

Figure 1 is a top plan view of a jib crane in which the debit reporting system of the present invention is used will.

Figure 2 is a perspective view of a transducer referred to as a nuisance.

Figure 3 is a perspective view of the debit indicator unit.

Figure 4 is a perspective view of the power supply.

Figure 5 is a circuit diagram of the switch for setting the cable section used and the switch to limit the load in the power supply unit.

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-H-

FIG. 6 is a circuit diagram of the display unit shown in FIG.

FIG. 7 is the circuit diagram of the load transmitter shown in FIG.

Figure 8 is a circuit diagram of the overall system.

Figure 9 is a block diagram of the system.

Figure 10 is an elevation of the crane in which the invention Transformer is used for the boom angle.

Figure 11 is an enlarged front elevational view of the transmitter for the crane shown in Figure 10, with parts for clarity the arrangement inside are shown cut open.

Figure 12 is a longitudinal cross-section through the transmitter the line denoted by 3-3 in Figure 11 «

FIG. 13 is a front view of the control display unit for the crane shown in FIG.

FIG. H is a side view of that shown in FIG S expensive display unit »,

FIG. 15 is the circuit diagram of part of the for the in Figure 10 shown crane provided system,

FIG. 16 is a circuit diagram of another part of the system provided for the crane shown in FIG.

Finally, FIG. 17 is a block diagram of the for the in the crane provided system shown in Figure 10.

The crane 10 shown in FIG. 1 is provided with a cable 12

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and an attached crane hook 14 provided with the a load, not shown, can be raised when boom 16 is raised or lowered and cables 18, 19> 20 are wound or unwound on drums 22, 24. At at least one of the. The cable used to transport the load is a tension meter or tensiometer or an on the load facing away from the cable end attached compression transmitter is used, which in each case is shown in Figure 2 Load cell 30 includes. Load cell 30 can also be used with other devices for measuring cable stress but pull knives or a compression transducer attached to the side of the cable facing away from the load are preferable. each comprising the load cell 30.

The tension meter is used to measure the tension occurring in the cable, regardless of the cable parts used. The tensile stress in the cable is measured in terms of the force acting on load cell 30. For example Load cell; 30 used as a tension meter when cable 19 is subjected to tensile stress.

Other load transducers can be used in the present system provided that their output is proportional to the cable load and consists of a DC voltage. As can be seen from Figure 7, includes Load cell 30 has essentially four resistors 40 of the same Resistance value that are suitable for strain measurements and

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lie in a bridge circle. Connections are made to the bridge 42, 44 a constant voltage is applied and a variable output voltage is taken from the output terminals 46, 48. The device works in such a way that an output signal is generated when the load cell is compressed or tensioned, that occurs at output terminals 46, 48 and is proportional to the load is.

As can be seen from Figure 4, power supply 50 comprises the single printed circuit board 52 shown in Figure 8, on which the transistorized network circuit for the system is arranged. Furthermore, power supply 50 includes the two-digit Switching register 54 with knurled adjusting screws (Figure 5) for manual preselection of the ones used for transporting loads Cable parts, and a six-digit switch register 56 with knurled adjusting screws for preselecting the desired Load limits. Power supply 50 is with insulated cable 58 to the power supply of the vehicle, for example a battery 60 for 12 V or 24 V direct current, connected (Figure 8). Finally, shielded line cable 62 connects power supply 50 to the display unit shown in FIG 64. Power pack 50 is connected to load transmitter 30 (Figure 7) via a shielded line cable 66, which contains the insulated lines 42, 44, 46 and 48. Display unit 64 and load transmitter 30 are electrical with power supply 50 and with card 52 with the printed circuit

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connected (Figure 3). A fuse 63 for protecting the power supply unit is attached to the front panel of the power supply unit 50.

The display unit 64 shown in FIG. 3 Housed lamp 70 is used to illuminate the analog display instrument 72, which shows the load in kilograms, the scale 74 of the instrument is divided by 100 graduation marks subdivided, so that when operating in the low range the scale is 0 - 10000 kg and when operating in the high range 0 100 000 kg (10 000 kg χ 10). The range switching is done manually using button 76 on the front panel 78 of unit 64.

The unit 64 also includes a red warning lamp 80, a warning buzzer 82 and a push-button switch 84 which is covered with a protective cover 86. As can be seen from FIG. 6, the mains switch 90 and the range switch 94 are actuated with button 76, which can be switched either to a high resistance 96 or to a low resistance (corresponds to the measuring range 100,000 kg or 10,000 kg of the display instrument 72) . The operation of the test switch 100 operated by push button switch 84 is explained below. When the pushbutton switch 84 is pressed, switch 100 is closed in the depressed position and the circuit in the device can then be checked by observing the display instrument 72 while a constant, simulated load is applied. Of the

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The pointer 73 of the instrument 72 is in the full deflection position when the button 76 is in the "high" position is switched.

As can be seen in FIG. 3, the printed circuit board 52 includes a signal amplifier 102 for the load cell or transmitter which consists of an integrated circuit 101 and other associated circuits. The lines 46, 48 in the shielded cable 66 go from the transformer 30 (FIG. 7) to the inputs 104 and 106 of the amplifier 101, to which a differential signal amounting to a few millivolts is thereby applied. This signal is amplified by the amplifier IC1. Potentiometer R2 is set to the output signal "Hull" of the transformer, which occurs when there is no load; the gain of the amplifier IG1 is set with a potentiometer R12. The output of the amplifier 101 for the signal given by the transmitter is proportional to the tension in the cable created by the load carried by the crane.

An auxiliary integrated circuit 110 for direct current is part of the printed circuit board 52 and is connected to the battery of the vehicle via insulated lines 108, 109 in the cable 58. The output connections c, + V and -V are used to take constant, stabilized positive and negative voltages for the system; Terminal c is neutral and via line 112 to the negative pole

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10 ': connected to battery 60 and thus grounded. Auxiliary circuit 110 cur power supply supplies the supply> vun £ S voltage for the load cell transformer 30 and supplies it also amplifier IC1.

The printed circuit also includes a cable number amplifier 114 made up of integrated circuit 102 and other associated circuits. In this circuit, the signal generated by the cable load is amplified and multiplied by the number of cables set on drum switch 54 (FIG. 5). In cooperation with resistor 11Lj, the output signal is proportional to the total load. Lines 117, 11 δ, 119, 120, 121, 122 and 123 from switch 54 (Figure 5) are connected to the corresponding circuits on the printed circuit board 52 (Figure 8), the output of the amplifier 114 for the number of cables is via circuit 126 applied to the range resistors 96 and (Figure 6) of the indicating instrument 72, which then indicates the weight of the load lifted by the crane. The display instrument 72 is a voltmeter which is calibrated in such a way that, together with the connection of the series resistors via range switch 94 (FIG. 3), it displays the load in kilograms. The gain of the amplifier 114 for the number of cables can be changed by connecting the capture resistors RH - R20 of the resistor set 115 in parallel with the aid of the drum switch 54 for the number of cables (Fig

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The printed circuit also includes a comparison circuit I30 for establishing the load limit; these Circuit consists of an integrated circuit IÖ3 and associated circuits. The total signal generated by the load is applied to resistor R24, whereby a current flows into input terminal 3 of amplifier 103. A stream that the setting of the switch 56 for the load limit (Figure 4) is proportional, flows from input terminal 3 of the integrated circuit IC3 (Figure 8) through one or more of the resistors R28 - R38 in set 116, which are made up of the common Circuit 133 using switch 56 as required can be switched on. If the current corresponding to the limit load is greater than that of the total load corresponding current, then current flows from input 3 of the amplifier IC3. This becomes the output of the comparison stage 130 negative and transistor Q1 is turned off. If that The opposite is the case, i.e. if the current corresponding to the total load is greater, current flows into the input of the amplifier IC3. This turns the output of the comparison circuit I30 positive and turns on transistor Q1. The red warning lamp 80 and the warning buzzer 82 (Figures 3 and 6) are triggered via trigger line 132 (Figure 8). actuated.

In the test mode of the present system, a known

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Load signal simulated on the load cell, which means Set a specific reading on the display instrument 72 got to. When you press the push button switch shown in Figure 4 84 becomes switch 100 (Figure 6) in circle 134 (Figure 8) with relay coil 136 of relay RL1 closed. Current flows through coil 136 and switch 138 is switched from contact 140 to contact 142. In the normal position of switch 138, contact 140 of line 117 is connected to switch 54 (Figure 4). If test relay RL1 is energized, contact HO-interrupted and at the same time switch 139 closes contact 142, making a connection to the circuit containing resistor R53 for replication of the cable section is produced. The resistance value of the resistor R53 represents a simulation of a fixed one Number of cables. For example, simulating a load of 5000 kg and 20 cable sections there is a full deflection of 100,000 kg on the display instrument 72 in its "high" measuring range.

As can be seen from the block diagram of the system (Figure 9), the circuit of the transformer 30 with a constant Voltage supplied from stabilized power supply circuit 110 on printed circuit board 52. One of the Load on the cable proportional signal sent to signal amplifier 102, which is also stabilized by the Voltage source 110 is supplied. The supply circle

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in turn receives power from battery 60 via the on-off switch 38. The amplified, from the load measurement with a The single wire generated signal normally goes through test switch 138 for relay RL1-2 and through wire set switches 54 to the amplifier 114 for the number of cables, the signal corresponding to the load on a single cable multiplied by the number of cables used, which have been adjusted on Sehalter 54 to set the number of cables is. This results in that corresponding to the total load Signal which is applied to the comparison circuit 130 together with that corresponding to the permissible limit load Signal, in turn with switch 56 for the limit load was discontinued. The signal corresponding to the actual load is applied to display instrument 72 via Range setting stage 126 so that the display instrument shows the actual weight in. Kilograms of the load.

To test the system, a test switch is activated via push button 84 100 actuated, whereby through the coil 136 of the test relay RL1 current is sent. RL-1-1 switch 146 closes then connect the simulation circuit 143 of the load to the input of the amplifier 102. At the same time connects RL1-2 switch 138 Load simulation circuit 143 (with resistor R53, see Figure 8) with amplifier 114 for the number of cables that is connected to it sends the corresponding replica signal directly to instrument 72 via range setting stage 128. The instrument

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indicates whether the system is working according to its calibration.

The load measuring system according to the invention shows continuously the actual load and is suitable for use in cranes, crane lists, lifting devices and the like. The load transmitter can be any suitable transmission device, provided that the output signal is a DC voltage acts that of the tensile stress in one of the load bearing Cable is proportional.

The power supply includes: 1) the single card with the printed circuit board for the system; 2) the two-digit Drum switch for manual preselection of the cable portion used; 3) the six-digit drum switch for manual preselection of the permissible load limit.

The display unit comprises: 1) the analog voltmeter, which is calibrated to display the load in kilograms (in conjunction with with the range setting); 2) the red warning light, which is switched on automatically as soon as the measured load exceeds the manually preselected load limit; 3) the on / off switch for the system; 4) the load switch for the indicating instrument; 5) the acoustic Alarm device that sounds when the red warning lamp is switched on; 6) the push button switch to check the on the Is mounted on the top of the unit and gives a simulated load signal when pressed, so that a full

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impact of the instrument occurs in the "high" measuring range.

From the power supply of the crane vehicle (usually a battery for 12 or 24 V DC), from the display unit and Cables going out from the load transmitter are connected to the power supply unit or connected to the printed circuit contained in it.

As can be seen from FIG. 8, the amplifier for the load transformer consists of the integrated circuit 101 and assigned circles. This amplifier has the task of a differential signal emitted by the load transmitter from some Amplify millivolts. Potentiometer R2 is used to control the output signal of the load transmitter in the unloaded To adjust the state to zero; Potentiometer R12 is used for Adjustment of the gain level, The output signal of the Amplifier for the load transmitter is proportional to the im Cable tension occurring.

The amplifier for the number of cables consists of an integrated circuit IC2 and associated circuits. This amplifier amplifies the signal received from the loaded cable according to the cable preselection, so that the output voltage is proportional to the total load. The output signal is applied to the instrument indicating the load. The display instrument provides a display in one of the two areas, depending on which series resistor was connected with the switch on the front panel. The gain of the amplifier for the number of cables is regulated by parallel

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switching of input resistors RH- R20 by means of the Cable adjustment switch.

The comparison level for determining the load limit consists of integrated circuit IC3 and associated circuits. The signal corresponding to the total load is on Resistor R24 is applied and causes a current to flow in input to terminal 3 of integrated circuit IC3. A Current proportional to the preselected load limit flows from input terminal 3 through one or more of the resistors R28 - R38, which are switched on with the switch for setting the load limit. If the one of the selected The current corresponding to the load limit is greater than the current corresponding to the total load, a current flows out Input terminal 3 of the integrated circuit IC3 «thereby the output of the integrated circuit IC3 becomes negative and transistor Q1 is turned off. If the reverse is true occurs, i.e., if the current corresponding to the total load is larger, a current flows into the input terminal of the integrated circuit IG3. This makes the output of the integrated circuit IC3 positive, creating transistor Q1 is turned on, which in turn turns on the alarm and lights up the red warning light.

The test circuit generates a signal corresponding to a known load at the input terminals of the load transmitter, with a specific display on the instrument must result if the system is working properly. By pressing

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of the test button, relay RL1 is energized. Contact RL1-1 sets the signal corresponding to the load when the relay is energized. Contact RL1-2 also disconnects the number of cables determining the cable setting switch and connects to resistor R53, which has a certain number of Kaböl sections simulated. For example, a load of 5000 kg and 20 cable sections can be simulated, which must then lead to a full deflection of 100,000 kg in the "high" area of the display instrument.

The load cell shown in Figures 2 and 7 is expedient constructed from a thick cylinder, on which in the longitudinal direction two of the resistors 40 in the form of strips a metal alloy are glued on; the other pair of resistors is used for temperature compensation. Serve for example Resistors RC for temperature compensation, while resistors RS are strain gauges on the cell cylinders address the tension exerted.

Figure 10 shows another embodiment of the present invention, the parts being denoted by reference number η of Series 200 and 300 are marked.

The crane 210 shown in FIG. 10 comprises a crane operator's cabin 212 and a boom 216 which is mounted on pivot point 218 at the front of the cab 212 and can be pivoted through an angle of approximately 90 °. Boom 216 and cab 212 can be one rotate vertical axis passing through the center of the horizontal

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Ring 20 goes under the cab 212, as is common in the art. At a suitable A transducer 222 is mounted in place of the boom 216 which generates an output signal corresponding to that between the boom 216 and the horizontal axis of the crane 210 spanned angle is proportional. As can be seen from Figure 13, is a transformer 222 for the boom angle via a shielded cable 224 to the control display unit 226 in the crane operator's cabin 212 ' connected. An insulated cable 228 provides an electrical connection between the unit 226 and that shown in FIG 24 V battery 230.

As can be seen from Figure H, a display instrument 234 for the boom bracket attached; next to it are the lamps 236 and 238 for indicating that the critical angle has been reached the "low" or "high" critical angle. These lights are attached directly via the corresponding adjustment knobs 240 or 242 for manual adjustment of the potentiometers 244 or 245 (Figure 17). These potentiometers are mounted in the box of unit 226 (Figure 14). A push button switch 248 for testing purposes is attached to the top 250 of the unit. A test switch 252 (FIG 16), which represents part of the test circuit belonging to the power supply unit 256 (FIG. 18). PSU 256 is as printed Circuit attached to card 258, which is included in the control display

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Unit 226 is inserted (Figure 14). Next to the test switch 252 for the system are associated with printed circuit board 256 (Figure 16) an integrated circuit 258 for signal amplification, integrated circuits 260 and 262 for voltage comparison (Figure 17), a circuit 266 for the meter and an integrated circuit 268 for generating a stabilized supply voltage (Figure 16).

The power supply circuit 268 is connected to the battery 230 via lines 270, 272 in the cable 228. In line 270 a fuse 274 is inserted, and in line 272 a On-off switch 276. A lamp 278 for illuminating the front panel 234 of the control display unit 226 (Figure H) is inserted in circuit 279 which contains switch 280 applied to output circuits 270,272. Lines 336 and 338 connect the positive pole of the battery 230 to the positive connections of the lamps 236, 238 (FIGS. 14 and 17). The integrated circuit 268 for the stabilized voltage supply (Figure 16) generates +15 V = between the center tap connection (c) 286 and the output terminal 288 for the positive pole of the stabilized DC voltage, as well as -15 V = between the center tap connection 286 and the terminal 290 for the negative pole of the stabilized DC voltage · center tap connection 286 is to the negative input terminal 292 of circuit 268 via ground line 294.

As can be seen from FIGS. 12, 13 and 16, the

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Load transmitter 222 a pendulum 296, which is attached to a horizontal Shaft 298 is attached. Shaft 298 is mounted in suitable, in the center of a diagonal rod 300 attached Bearings and at the other end on the rear wall 302 of the housing 304. Shaft 298 is at the radial center tap 306 a bent resistor 308, which forms the potentiometer 310 of the transformer 222. The ends of the resistance 308 (Figure 16) are connected to leads 312, 314 in cable 224 to the negative pole and the. positive pole 290 or 288 connected. The tap 306 is connected to the center connection of the power supply 268 via ground line 316. Daa The housing (FIG. 13) has a front plate 318 which is pressed firmly against the edge of the housing 304 with the aid of a seal 320 is. A small calibration lamp 322 is mounted in the housing 304.

In the present system, the boom angle transducer 22 is used to generate an accurate, analog DC voltage signal that is proportional to the angular deflection « As can be seen from FIG. 11, the transmitter 222 is mounted directly on the boom 216, which pivots. TTm the To facilitate calibration, transmitter 222 is conveniently mounted so that its X and Y axes are parallel to their respective ones The X and Y axes of the boom 216 are. If . Cantilever 216 from the perfectly horizontal position to the completely vertical position is transferred, the pendulum 296 remains due to the action of gravity in the position, in

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which its Y-axis is perpendicular to the ground. At a 90 ° Rotation of boom 216 will also turn potentiometer 310 around rotated a 90 ° angle around its own Z-axis. Axis 298 of potentiometer 310 is firmly connected to pendulum 296. Therefore, if potentiometer 310 is rotated around its Z-axis, while its axis 298 (Figure 13) is held by pendulum 296, the output voltage of the potentiometer increases 310 proportional to the increasing angular deflection. As previously mentioned, both ends of potentiometer 310 are in Transformer 222 is connected to the temperature-independent voltage supply 268 (FIG. 16). This is an end of the Potentiometer 310 connected to connection 288 for +15 V =, while the other end is connected to terminal 290 for -15 V =.

Potentiometer 310 can be rotated through an angle of 340 ° will. The output voltage of the potentiometer 310, which is between the common C-terminal 286 of the power supply 268 and the solenoid 306 of the potentiometer 310 is measured, can therefore vary between -15 V = and +15 V =. in the In the present system, transmitter 222 is attached to cantilever arm 216 so that zero output voltage is generated, when boom 216 is in the horizontal position, wiper 306 then being located in the middle between -15 V = and +15 V =. With a subsequent 90 ° rotation of the boom 216, the grinder 306 is also turned 90 ° to the +15 V = side of the

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Resistance 308 turned off. The output signal changes therefore by 9O / 17O (+15 V =) or by 7.94 V =, which is directly proportional is the change in angle from 0 ° to 90 °.

As previously mentioned, the control display unit comprises the following components: a) an analog display instrument 234 for displaying the boom angle; b) a switch handle 243 for manual range switching of the desired high and low limit angles (with a "1T" position for normal operation); c) two potentiometers 244, 245 (Figure 17) with buttons 240, 242 for setting the low and high limit angles; d) low and high angle warning lights 236, 238; e) a warning buzzer 239 which is activated when either the high or the low limit angle is reached;

f) a manually operated on-off switch 276 (Figure 16);

g) light 278 and switch 280 (Figure 15); and

h) a test switch 252 for testing the circuit. In addition, two separate connector plugs 324, 326 are provided, with which the display unit 226 is connected to the transmitter 222 of the boom angle and to the power source 230 of the vehicle can be. A single card 258 with a printed circuit board and the transistorized circuits 256 for the system is contained in unit 226.

The transistorized circuit 256, shown in detail in FIGS. 16 and 17, operates in FIG following way.

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The signal emitted by transmitter 22 goes through test switch 252 to amplifier 258, in which it is amplified that a shift of 90 ° of a signal voltage of 10 volts is equivalent to. Amplifier 258 is a voltage follower stage with a certain gain, so that a load on the potentiometer 310 is avoided. That from Amplifier 258 picked up, amplified signal is transmitted over line 259 (FIG. 17) at comparison stage 260 for the lower limit, at comparison stage 262 for the upper limit, and at circle of the display instrument via position 2 of the range switch 247 created. The input signals arriving at comparator 260 for the lower limit are the actual angles corresponding signals; Another input signal is a voltage of opposite polarity coming from the potentiometer 245 is taken for the preselection of the lower limit angle and is proportional to the desired lower limit angle. At the inputs of the comparison stage 262 for the high limit value receive the signal corresponding to the actual angle and a voltage of opposite polarity taken from potentiometer 245 for setting the upper limit and is proportional to the desired upper limit angle.

As long as the signal corresponding to the actual angle is greater than the lower limit voltage and less than that high limit voltage, the outputs of the two comparison stages 260, 262 are negative, causing transistors Q1, Q2 and Q3

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stay switched off. Palls the actual angle under the lower limit angle decreases or rises above the upper limit angle, the output signal of the corresponding comparison stage positive. This causes a base current to pass through diodes D5 or D6 to transistor Q3, which turns it on and the acoustic alarm device 239 sounds " A positive output signal of the comparison stage generates a Counter voltage on diode D7 or D8, whereby blinker circuit 5 supplies a base current to transistor Q1 or Q2. Since the Output signal of the flashing circuit 5 to a pulsating current transistors Q1 and Q2 are alternately switched on and off, causing the warning lamps 236 and 238 to flash leads. The supply circuits of the lamps 236, 238 (FIG. 17) comprise positive lines 236 and 238, respectively, which are connected to the positive Circle 270 are connected (Figure 16). Through this circle, the positive pole of battery 230 is aligned with the positive Input terminal 339 of DC supply circuit 268 tied together.

Potentiometers 244, 245 for setting the lower or upper limit angle are turned while the corresponding. Output signals on the display instrument 234 for the angle are displayed via positions 1 and 3 of the range switch 247. Position 2 corresponds to the normal (N) position of switch 247.

Since the input impedance of circuit 266 for the display

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instrument is high, this circle can have two punctures fulfill. On the one hand, circuit 266 does not load the potentiometers 244, 245 for setting the limit values during this Limit values are displayed. In addition, circle 266 indicates either positive or negative voltages, which is necessary because the limit value voltages have a polarity opposite to the actual angle signal to have. A full-wave rectifier circuit 267, which consists of four diodes D1, D2, D5, and D4, is used for this purpose. These diodes are like that arranged that current flows to the terminals of the instrument 234 from plus to minus when switch 247 is in normal Position 2 and in position 1 or 3.

During normal operation, the capacitor discharges 01 (Figure 16) via test switch 252 instead. When the test switch is closed by hand, the input to amplifier 258 is disconnected from transformer 222 and to capacitor 01 laid. At the same time, resistor R1 is connected to capacitor 01 and then slowly charges it, creating a gradually increasing input to amplifier 258 is generated. This signal represents a replica of one slow change of the angular position from zero to 90 ° in the transmitter 222. The operator can thus operate Track through the display of the instrument 234 for the angle and also determine the use at the lower and upper warning point.

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24356ΘΘ

Those protruding over the top 250 of the unit 226 Switches 252 and 276 are provided with rubber covers 249 and 277, respectively, for protection. The range switch handle 243 can be used to switch switch 247 to the positions 1 or .3 used for setting from the normal (U) position 2 bring. Fuse 274 is in the right side wall 275 of the unit 226 next to the buzzer 239 for the acoustic Alarm inserted. Unit 226 is compact but clearly visible to the operator. Lights 236 or 238 flash and buzzer 239 sounds when the corresponding high or low limit angle to which the system has been set, has been reached by boom 216. This exposes the operator to potentially dangerous operating conditions made aware and can then adjust the boom angle to avoid accidents.

As can be seen from the block diagram in FIG. 18, to set the system to the high and low limit angles of the boom, the range switch 247 is first turned to position 1 and, while observing the display instrument 234, the potentiometer 244 for the high limit value is adjusted until am Display instrument 234 the desired value is displayed. Similarly, the low limit is obtained. Switch 247 is then switched to the Endsttllung, and crane 210 is operated in the usual way has been to one of two limiting positions reached. In

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This Pall sounds the acoustic alarm buzzer 239 and the corresponding warning lamps 236 or 238 flash. this shows the operator of possible hazards resulting from the inclination of the boom 216.

During normal operation of the system, i.e. when the crane's battery 230 is connected to power supply 256, transmits Transmitter 222 sends an analog signal to circuit 256 and the instrument 234 shows the actual boom angle, which changes continuously as the crane 210 is operated. As long as the angular position assumed by the boom is within the predetermined high and low limit values, the alarm device will not respond. To ensure that the To check the system, push button switch 252 is manually operated and the system automatically powers the meter 234, the display of which changes slowly until the desired simulated limit values are reached. Warning system 237 then responds, whereby the desired operating conditions have been simulated.

A wide variety of possible changes and exchanges must be taken into account; in certain cases it can be appropriate to certain distinguishing features of the invention on their own without the corresponding use of others Feature · to be applied. The following patent application is therefore comprehensive and formulated in a way that meets the objectives and takes into account the scope of the invention.

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Claims (1)

2Ά3568Θ PATENT CLAIMS I 1.Improved system for load measurement and load display for a crane device working with several cables, characterized by devices "which respond to the tensile stress occurring in at least one crane cable transporting the load, with a transmitter (load cell) (30) assigned to the cable; a Power supply (268) for generating a stabilized DC voltage for the system; a first amplifier (102) connected to the transformer (30) which generates a signal proportional to the tensile stress generated in the cable; a second amplifier (114) for multiplication of the signal with a signal corresponding to the number of cables used to lift the load; a switch (54) for selecting the cable sections in order to generate a signal corresponding to the number of cables to be multiplied by the signal from the second amplifier (114) is proportional; a third amplifier (130) for comparing the total output of the second ver amplifier (114) with a signal corresponding to the load limit; a limit load selection switch (138) with which a signal corresponding to the desired load limit is selected; one on the third Ver stronger (130) responsive trigger circuit, dl · produces an output signal when there · corresponding to the actual load applied to the third amplifier · Signal to 509807/0352 The value of the signal corresponding to the limit load has been reached; a display unit (64) with an instrument (72) connected to the third amplifier (130) for displaying the actual load corresponding output signal of the third amplifier (130), a warning lamp (80) and a acoustic indicator (82) from trigger always is then excited when the actual load reaches the desired load limit, with the improvement consists of: relay (136) which normally connects the first amplifier (102) to the output of the load transmitter (30) and the switch (54) for the number of cables and which interrupt the connections when they are excited and an input test signal to the first amplifier and the Apply the output of the first amplifier to the input of the instrument (72); a test circuit for energizing the relays and to apply the one corresponding to a known load Signal to the first amplifier (102). 2. System according to claim 1, characterized in that the cable setting switch (54) and the switch (56) for setting the load limits enclose manually operated switches provided with digital numbers, which are used to select the number of cables lifting the load and the load limits serve, whereby an associated output signal is generated which corresponds to the number of cables and the maximum load carried by the cable. 509807/0352 3. System according to claim 1, characterized in that the display unit (64) includes a changeover switch circuit for the indicator instrument (72) comprising: a manually operated switch (76) having different switching positions and certain resistances in the circuit, wherein the switch is selectively is connected to the circle of the indicating instrument (72) so that the indicating instrument shows the load in the desired area. 4. The system of claim 1, characterized in that the test devices comprise: a first switch for applying the test signal simulating a load to the first amplifier (102); a second switch for manually disconnecting the signal corresponding to the number of cables from the second amplifier and for simultaneously applying a test signal simulating a certain number of cables on the basis of the simulated, known load signal in order to energize the display instrument (72). 5. Improved display system of the crane boom angle and warning system, characterized by a transmitter (222 ) for the boom angle, which generates an output signal proportional to the angular position of the boom (216) in analog form, a display instrument (72) for the boom angle, the one visual indication of the jib position over an angular range ron 90 ° from the completely vertical to completely horizontal position of the boom covers; one 509107/0352 Warning device for pre-selected upper and lower limit angles of the boom (216), the corresponding upper and lower Show the limits of the boom pitch, which means that a permissible The working area of the boom is defined; main circuit connected to the transformer (222), warning devices to excite the same and connected to the warning device, manually preselectable devices for setting of the upper and lower limits, the improvement comprising: a test circuit connected to the main circuit and can be connected to the transformer and generates a slowly rising signal that corresponds to a simulated transformer output signal instead of the actual output signal corresponds to the display instrument (72) the entire Operating range including the upper and lower limit angles of the boom to be covered so that the crane operator can observe the operation of the gauge (234). 6. System according to claim 5 »characterized in that the transformer (222) generates a positive output voltage signal which is directly proportional to the boom angle ron 0 ° to 90 °; that the variable devices for the manual setting of the operating limits can be adjusted manually · potentiometers (244, 245), with * · * · η the upper and lower limit values can be adjusted, so that one in relation to the other transmission output 501107/0352 reversed voltage, corresponding to the lower or upper limit, arises; and that the display instrument (234) responds to positive as well as negative input voltages. 7. System according to claim 6, characterized by a Range switch with at least three positions, the normal, the high and the low boom pitch. correspond, with the range switch used in the circuit of the indicating instrument for the boom angle is that in the normal position the boom angle and the limit positions preselected by the potentiometers (244, .245) are displayed when switching to the high or low positions. 8. System according to claim 7, characterized in that the main circuit has an impedance circuit with respect to each potentiometer used to set the limit angle (244, 245) has high impedance, so that the load is reduced while the limit values from the display instrument (234) are displayed; and that the meter shows the positive and negative voltages as required on the display instrument applies. 9. System according to claim 8, characterized in that the main circuit (256) has one in it instead of the transformer (222) Usable test circuit (143) comprises, with which a slowly varying voltage can be generated, the one Simulation of the transformer output voltage from 0 ° to 90 ° 509807/0352 so that the operator can operate the meter (234) including high and low Can observe deployment points. 10. System according to claim 8, characterized in that the main circuit (256) is a manually operated, double-pole changeover switch (252) to switch the transformer output and of the associated circle belongs to the main circle. 11. System according to claim 5, characterized in that the warning device (237) comprises: flashing lamps (236, 238) to indicate that the upper or lower operating limit has been reached and an acoustic warning indicator (82), which is activated when Reaching the upper or lower limit becomes effective. 12. System according to claim 10, characterized in that the main circuit (256) on a single circuit board (258) is appropriate. 13 · System according to claim 12, characterized in that the main circuit comprises: ■ integrated comparison circuits for the high and the low limit value, with an input voltage of the comparison circuits being the actual Angle associated with the transformer output signal, while the other input voltage corresponds to a negative voltage from the corresponding potentiometer (24-4, 245), in the case of an angle assumed between the high and low limit values, the output signal of the corresponding Comparative level (130) is negative and the 509807/0362 Remote devices remain off while in the event an actual angle exceeding the limit values, the output signal of the corresponding comparison stage is positive is, whereby the acoustic warning device as well as the corresponding warning lamp must be put into operation. 14. System according to claim I3, characterized in that the main circuit (256) further comprises: an integrated circuit for generating a constant DC voltage (268) with a grounded center tap (286) as input terminal, a + 15V output terminal (283) and a -I5 V output terminal (290); a battery (230); an on-off switch (88) for the negative pole of the battery; an on-off switch (276) for the negative input terminal of the circuit for equal voltage generation; and one over a switch small lamp connected to the positive input terminal of the circuit for generating direct voltage, which also has the negative pole of the battery is connected to indicate the connection of the same. 15 · System according to · Claim 14, characterized in that the circuit of the meter (234 *) comprises: an integrated amplifier with one output terminal, one with the center tap (286) of the circuit (2 * 8) * r DC voltage generation connected earthing clergy, and with a Input terminal that is connected to the selector switch, the impedance arrangement being a full wave rectifier (D1-D4) 50SI07 / 0352 includes whose output terminals to the terminals of the indicating instrument (234) are placed, while the input terminal η are connected to the output terminals of the amplifier or the ground terminal. I60 system for angle display according to claim 11, characterized by a board (258) with a printed circuit (256) and a control display unit containing the board (226) with a front plate on which the display instrument (234) for the boom angle, warning light for the high and low critical angle, one knob each for the potentiometers (244, 245) for the high ones and lower limit values and a three-stage range switch are attached, the board for the printed circuit is provided with appropriate terminals for connection to the output terminals of an external battery (230), with the transformer (222) for the boom angle, with the adjustment potentiometers attached to the unit (244, 245) for the high and low limit, with the instrument for the boom angle, with the range switch, and with the indicator lamps (278). 17. System according to claim 16, characterized in that the circuit board with the main circuit (256) a contains integrated circuit for generating a constant DC voltage for the entire system, as well as a Center tap trained earth line and positive and 509807/0352 negative terminals, one of which is in relation to the center tap the same 15 V signals can be supplied. 18. System according to claim 17, characterized in that the board (258) with the integrated circuit (256) devices for connecting the transformer to the + and terminals the DC voltage generation circuit comprises; that the transformer consists of a pendulum-like grinder (306) and a curved resistance element (308) which rotates with the boom and rotates with the grinder in Contact is; that the resistance element is connected in parallel to the circuit for DC voltage supply; that this curved resistance element of the transformer (222) can be moved through an angle of 340 °; that the output voltage of the potentiometer varies between -15 V = and +15 V =; and that the wiper is in its middle position in the curved resistance element of the output Hull of the transformer (222) results. 19. System according to claim 18, characterized in that the output of the transmitter (222) is zero in the event the horizontal boom position and +15 V = in the case of the vertical boom position varies. 20. System according to claim 11, characterized in that the warning device has a flasher stage for operating the lights (236, 233) when one of the limit positions is reached includes. 509807/0352 Read 1 1 e