JP3353111B2 - Pole-shaped alarm device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to an alarm device, and more particularly to a collision avoidance alarm device for a telescopic mast.

[0002]

2. Description of the Related Art Telescopic masts of the type that include a plurality of extensible interconnects that are actuated by pneumatic, hydraulic, mechanical, or the like are well known to those skilled in the art. For example, such telescoping masts are widely used in the broadcasting business to raise the antenna for remote transmission of audio and video signals. Such telescoping masts have been used to repair small trucks with extension booms, including so-called "cherry pickers," used by public and private universal maintenance personnel to reach overhead power lines, cable lines, power lines, etc. Is also used. Similarly, this pole alarm can be used with ladder trucks, cranes, hoists,
It is suitable for use in other similar devices.

[0003] Telescoping masts or pole mounted remote broadcasting antennas may need to be deployed quickly under the harsh weather conditions encountered by television or radio reporters while reporting on natural disasters. Many. Similarly, the skilled worker raises maintenance personnel up to power and telephone lines in severe weather or at night,
It is often necessary to have those damages repaired.

Raising such masts in open areas with good visibility has little problem, but is especially important when encountering overhead power lines and / or physical obstacles at night or in poor visibility. Everyone's lives or equipment are susceptible to dangerous situations. In some cases, contact with power lines or collision with an imaginary obstacle can cause injury or death, or cause enormous damage to equipment.

[0005] Thus, prior to actual contact, the operator of such a telescopic mast or boom-type device is alerted of imminent contact with an overhead power line or other potential hazard. An alarm device is needed. Such an alarm reduces operator personal injury and equipment damage caused by collisions.

DISCLOSURE OF THE INVENTION [0006] In view of the various problems discussed above, the present invention contemplates that an operator of a boom truck or other telescopic mast system may provide an overhead power line or other potentially hazardous overhead It was developed to provide a pole alarm that warns of imminent contact with a structure. This pole-shaped alarm device
It can detect the electric field generated by the overhead transmission line,
A housing mounted on top of a mast or boom for monitoring, including at least two independent sensing devices capable of detecting physical obstacles within specified proximity of the housing using an ultrasonic transducer; including.

In addition, the alarm housing also includes a light source or so-called look-up light, which illuminates the intended range of movement of the mast for the pilot to operate successfully, so as to safely control the device on which the alarm housing is mounted. . In addition, the alarm device includes a plurality of tilt sensors that monitor the orientation of the mast against a desired level condition so that the mast does not extend when tilting or bending.

[0008] Upon detecting an overhead power line or a physical obstruction, the pole alarm provides audible and control feedback to a control module in the vehicle to alert the operator of impending contact. And quickly stop moving the mast or boom. The range of detection provided by this alarm device allows the operator to manually stop moving the mast or boom, and to supply a control signal to the mast's electrical controller to automatically stop moving to the danger zone. The audible alarm is designed to be activated long enough to do so.

In view of the above, it is an object of the present invention to provide a telescopic mast, such as a boom light truck, which alerts an operator of imminent contact with an overhead power line or other physical obstacle. An object of the present invention is to provide a pole alarm device used in the device. Another object of the invention is
It is an object of the present invention to provide a pole alarm having at least two independent sensor devices capable of detecting the presence of an electric field and of detecting physical obstacles using ultrasound or other technologies. It is a further object of the present invention to provide a pole alarm that includes a light source that illuminates the expected range of movement of the mast so that the operator can successfully operate the device to safely control the device. It is a further object of the present invention to provide a pole-shaped alarm device that includes a tilt sensor that can monitor the orientation of the mast with respect to level conditions in order to properly operate the device.
It is a further object of the present invention to provide audible and control feedback to alert the operator of impending contact and to automatically stop the movement of the mast to the danger zone. It is to provide an alarm device. Further objects and advantages of the invention will become apparent from a consideration of the following description, which illustrates examples of the invention described above, and the accompanying drawings.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, there is shown a view of a pole-shaped alarm housing, generally designated 100, mounted on a telescopic mast 25 of the type used for boom trucks. FIG. 2 shows a pole-shaped alarm housing 100, an antenna for an AC (alternating current) detector generally denoted by 10, a collision detector unit generally denoted by 11, a look-up light generally denoted by 12, and 13 generally. FIG. 2 shows an enlarged view of components included in a housing including an integrated control unit and the like indicated by “.”

It will be appreciated that the housing 100 is mounted at the top end of the telescoping mast 25 as shown in FIG. 1 and is oriented generally upwards in a functional position. In order for the alarm device to function properly, it is necessary that there is no obstacle to either the AC detector 10 or the collision detector 11.

The AC detector antenna 45 projects above the housing 100. Lookup light 12
The halogen spotlight bulb is disposed in the housing 100 for protection. The collision detector 11 is attached to a side surface. The control unit 13 is arranged in the housing 100 and shields and protects the circuit configuration from surrounding elements. The tilt sensor 59 is mounted inside the control unit 13 circuit board.

In another embodiment (not shown), as described above, the parallel AC and collision detectors 10 and 11 are connected to the housing by a power line or physical line on one of three axes. It is arranged to detect a target obstacle. Referring to FIG. 3, an AC detector antenna 10
FIG. 2 is a schematic diagram of a control circuit configuration such as a collision detector 11, a look-up light 12, and the like. Further, FIG.
Tilt sensor 59 arranged in housing 100
Is explained. Referring to FIG. 4, the control unit 1
3 is +1 through the main power disconnector 14 and the fuse 15
Connected to 2 volts (DC). Second power lead 1
6 is connected to the vehicle ground 17.

When the audible external alarm output 18 detects a possible safety hazard, it applies a signal to an audible device 19, here shown as a piezoelectric resonator. Status external output 20 activates lamp 21 to indicate the status of the alarm. The second lamp 22 is illuminated by a signal from the collision external output 43 when detecting an object likely to collide with the mast or boom. The third lamp 23 is illuminated by a signal from the AC external output 51 when detecting the presence of the high voltage line.

An audible device 19 and lamps 21, 22, 23
And an external switch 24 are respectively connected to a common + 12 volt (DC) output control component 25 of the control unit 13. External switch 2
4 is connected to a mast up input 26 and a mast down input 27, and controls the movement of the mast or boom 26.
When the switch 24 is actuated, the mast or boom 26
And a corresponding pneumatic or hydraulic valve 28 connected to a Valve Air output 29 and a Valve Vent output 30
Is applied as appropriate to raise or lower the mast or boom.

As described above, the control device includes the control unit 1
3 can be disconnected from the manual operation of the mast or boom 26 and stop their movement before dangerous power lines or obstacles come into contact. The control unit 13
It is connected to the AC detector 10 and the collision detector 11 through the multiple signal conductor 31.

Referring to FIG. 5, the control unit 13
3 and a more detailed diagram of the interconnection of the AC detector 10 and the collision detector 11, the tilt sensor 59 of FIG. 3, and the valve 28 of FIG. As shown in FIG.
The EMI filter 33 receives the respective signal inputs to the control unit 13, that is, the COL signal 61 and the TX 37
, Tilt 60 and AC signal 62 to minimize detection of pseudo electrical signals.

Further, FIG. 5 shows a temperature sensing element 34 having an associated voltage comparator 35 configured to signal the control unit 13 when the ambient temperature of the alarm housing 10 exceeds a predetermined level. Have been. The voltage comparator 35 is connected to the control unit 13
LAMP input 36 is connected. The serial communication data is received by the control unit 13 of the TX input 37 and transmitted to the TxD output 38.

The Zener diode and the standard diode 39 prevent the control unit 13 from being damaged from excessive or reverse polarity voltages inadvertently applied to the control unit 13.
Is provided to protect the A MOS field effect transistor (MOSFET 40) is used to interface the control unit 13 to a relay 41 which in turn supplies a control voltage to an external air or hydraulic valve 28. The status of the tilt sensor 59 is monitored through the tilt input 60.

Referring to FIG. 6, the ultrasonic collision detector 11
A preferred embodiment of the control circuit configuration for the present invention is shown.
The output from the collision detector 11 is T
Connected to X, TXFILT, + SV, COL signal terminal connectors. The ultrasonic collision detector 11 detects an object within 1 to 8 feet of the alarm housing 100 and outputs a control signal to a mast control device (not shown) of the vehicle to stop moving the mast. I do.

Such ultrasonic collision detectors as stand-alone devices are well known to those skilled in the art and do not require a detailed discussion of the same. Referring to FIG. 7, a schematic diagram of the AC detector 10 of the present alarm device is shown. AC detector 10 detects the presence of an AC (alternating current) voltage via its associated antenna 45. Such an electrostatic induction signal is transmitted to a field effect transistor (FET) 4
Amplified by 6 and filtered by multiple stages of the filter circuitry, indicated generally at 47.

In the preferred embodiment, the AC detector 10 is capable of detecting the presence of 7200 volts at 60 hertz at a minimum distance of 8 feet. This distance provides sufficient alarm for the mast or boom operator to stop moving them toward the power line or to send an electrical signal to the vehicle's mast positioning controller (not shown)
Is sufficient to automatically stop the mast movement so as not to collide. The output from the AC detector 10 is interconnected to the control unit 13 via an AC signal terminal 48.

The control of the look-up light 12 is performed by the circuit configuration shown in FIG. Negative temperature coefficient (NTC) device 49 is responsive to ambient temperature within alarm housing 100. Thermally stable resistor
The voltage resulting from the voltage division between the resister 50 and the NTC device 49 is monitored by a pair of window-like voltage comparators 35.

When the ambient temperature drops below a predetermined threshold, such as that caused by icing of the alarm housing 100, the look-up light 12 illuminates and acts as a heating element to melt the ice, causing the device to operate at any time. Keep it movable. When the ambient temperature rises above a second predetermined threshold level as caused by the elongation of the halogen light, the look-up light 12 turns off,
The housing 100 can be cooled before being damaged by excessive heat. Upon detecting an electrical or physical obstruction within range of any of the sensors, an audible and visual alarm is activated to alert the person operating the impending mast positioning device. The look-up lights 12 function to help the pilot direct the mast to a safe position.

Referring to FIG. 9, a microprocessor board, generally indicated at 52, translates the signals generated by AC detector 10 and collision detector 11 (inter).
) and responds to the signal. In a preferred embodiment, such a conventional microprocessor configuration includes an 8031 microprocessor 53, an external CMOS latch 54, and an erasable program read only memory 55.

The microprocessor 53 and its associated circuits have low voltage,
Because they are low current devices, they cannot directly drive external relays, valves, or other high current devices. Interconnection and proper drive levels are achieved by an array of additional transistors, indicated generally at 57, as shown.

A visual status indicator, so-called (AC, status, collision, tilt), is provided by a light emitting diode 56. The power-on reset for the microprocessor 53 is specifically designed to monitor the operating voltage of the microprocessor circuit board 52 and reset the microprocessor 53 necessary to initiate and maintain reliable operation. It is supplied by the monitoring circuit 58.

The basic operation of the pole-shaped alarm device and the relationship between the respective sensor operations have been described above. A housing 10 containing a sensor for operating the alarm
The 0 is located at the top of the mast or boom using hardware that is suitably mounted so that the AC detector 10 projects upward as shown in FIG. AC detector antenna 4 projecting from the side of housing 100
The absence of an obstacle in either 5 or the collision detector 11 is critical to the operation of the device.

A six-conductor shielded cable 65, not exceeding 100 feet in length and having a line gauge of 16 gauge or more, is mounted on the inside of the vehicle with a safety control module generally indicated at 66 as shown in FIG. Used to connect the pole-shaped alarm housing 100 to the housing. The safety control module 66 is mounted so that the operator can fully view the alarm indicators 68-71 while operating the mast. Needless to say, the switches and control valves for extending and retracting the mast for moving the boom,
Wired as specified in the vehicle wiring schematic.

The pole alarm has a nominal current of 12.6 volts DC (actually 1
0.6 to 20 volts). An 8 amp fuse protection circuit is provided. The pole-shaped alarm device has a power input circuit configuration (its power input input).
Some installations that have loud noise filtering on the circuit, but have extreme electrical noise from other devices, require additional filtering of the power input. It is the installer who needs to prove proper operation of the safety control module 66 under all circumstances, as the equipment changes significantly from vehicle to vehicle.

After the installation of the pole alarm device is completed, the power is turned on using the main power switch 67 of the safety control module 66. This device has approximately 8
It is designed to perform self-tests on integrated devices that require seconds. When the self-test is completed and passed, Re
ady Status (operable status) display 6
8 continuously emit "green" light. This visual indicator indicates that the device appears to be working properly and that the mast or boom is extending.

If the self test fails, an error indication code is displayed on the System Ready indicator 68. The failure codes are as follows: 1 blink every 10 seconds AC detector failed 2 blinks every 10 seconds AC detector clear failed 3 blink every 10 seconds Collision detector failed 4 blink every 10 seconds Collision detector clear failed 5 blinks every 10 seconds External switch failure

If the self-test passes, the pole alarm goes into monitoring. The look-up light 12 attached to the mast is illuminated, and the AC power indicator 69 of the control unit blinks at any time. The rate at which AC power indicator 69 flashes is a measure of the signal strength of nearby AC power supplies.
After a through inspection of the fictitious and surrounding area, the mast or boom 26 can be extended using the vehicle's mast control (not shown). During the monitoring state, this pole-shaped alarm device
Detection of a possible collision or a dangerous AC electric field triggers an alarm condition. The safety control module 66
An audible alarm is issued by the speaker 72 to indicate to the operator the cause of the alarm condition. A fast blinking AC power indicator 69 indicates the presence of a strong AC electric field. A flashing collision indicator 70 indicates a possible collision with a power line or other physical obstruction. Flashing tilt indicator 71
Indicates that the mast is unstable or that the vehicle is not level, or both. While in any of the alert conditions, the new extension of the mast or boom is automatically stopped and the System Re
The ady (device ready) indicator 68 will no longer flash.
After 5 seconds, when the fault alarm condition is cleared, the mast extension
Will be possible again. Of course, it is possible to retract the mast or boom at any time during operation.

If there is no alarm, and if the mast or boom is not raised for approximately 15 minutes, the alarm will go to a standstill. The AC monitoring continues, but the look-up light 12 turns off and the collision detector 1
The operation of 1 ends. During very cold conditions, whenever the main power switch is in the "on" position, the look-up light 12 mounted on the mast is illuminable. This illumination minimizes ice and snow build-up in the alarm housing due to elevated temperatures. The AC detector 10 and the collision detector 11 must be free of ice and snow for proper operation.

Conversely, prolonged operation of the mast-mounted look-up light 12 causes the alarm housing 100 to overheat, in which case the look-up light 12 automatically fails. When the temperature of the alarm housing returns to the predetermined normal operating temperature, light 12 is illuminated again. But A
C power or collision alerts are not affected. In view of the foregoing, the pole alarm of the present invention provides audible and control feedback to alert the operator of the imminent contact with hazardous overhead power lines or physical obstacles. It can be seen that it provides an improved method for the operator's safety of a telescoping mast or boom truck or other related equipment.

The detection range provided by the alarm device is:
An audible alarm activates with sufficient time to manually halt the movement of the mast or boom to the pilot and to provide a control signal to automatically halt the movement of the mast to the danger zone. Designed for Words such as "upper", "lower", "side" and the like are used because they are merely convenient for describing the present invention and portions thereof as directed in the figures. However, it is to be understood that these words are in no way limiting of the invention, as such inventions, when used, may be arranged in clearly different positions.

The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention. Accordingly, the present embodiments are to be considered in all respects as illustrated, and are not intended to be limiting, and all modifications that come within the meaning of the appended claims are embraced. Will be interpreted.

[Brief description of the drawings]

FIG. 1 is a diagram of a pole alarm housing of the present invention mounted on a telescopic mast structure.

FIG. 2 is an enlarged side view of the pole alert housing showing the arrangement of components within the housing.

FIG. 3 is a schematic diagram showing a circuit configuration for interconnecting an AC detector, a collision detector, a look-up light, and a tilt sensor of the alarm device.

FIG. 4 is a schematic diagram showing the interconnection of the circuit configuration of the pole-shaped alarm device to an external audible alarm, a switch, a valve, and the like.

FIGS. 5A and 5B are schematic diagrams illustrating the interconnection of a microprocessor circuit board to components within an alarm housing.

FIG. 6 is a schematic diagram of the collision detector of the device showing the components and their circuit configuration.

FIG. 7 is a schematic diagram of the AC detector of the device showing the components and their circuit configuration.

FIG. 8 is a schematic diagram of a control circuit configuration of the alarm device and components of a look-up light.

FIGS. 9A, 9B, and 9C are schematic diagrams of a microprocessor circuit board of the alarm device.

FIG. 10 is a schematic diagram of a microprocessor circuit board of the alarm device.

FIG. 11 is a front view of a safety control module of the present device.

[Explanation of symbols]

 1 AC external display 2 Status external display 3 Collision external display 4 Beeper external display 5 + 12V display Normal 6 + 12V control Normal 7 Mast rising input 8 Mast lowering input 10 AC detector, AC signal 11 Collision detector, COL Signal (collision signal) 12 Lamp 21 Lamp 22 Lamp 23 Lamp 24 Rise 24 Lower 29 Valve air 30 Valve ventilation 51 AC external display 32 Mast rise input 25 + 12V Control component COM. )

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-243670 (JP, A) JP-A-8-254576 (JP, A) JP-A 6-59139 (JP, U) JP-A 6-59139 37298 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G08B 23/00 530 H01Q 1/10

Claims (35)

(57) [Claims] 1. Combination with a telescope type mast device
UsePole alarmWherein the alarm device is
Overhead power lines and physical obstructions to the operator of the mast device
Warning the presence of thingsIs configured toThe device
But,Within a predetermined neighborhood for the mast Alternating current
Can detect the presence of voltage and output in response
Electromagnetic field detecting means for generating a signal,Within a predetermined neighborhood for the mast Physical
The presence of the structure can be detected and
A collision detection unit that generates a force signal, the electromagnetic field detection unit, and the collision detection unit.
ConnectedAnd the electromagnetic field detecting means and the collision detecting means
The output signal output from any of the detection means
Control the appropriate alarm display when the size exceeds the specified size
Signal, and based on the control signal,
The mast contacts the overhead power selective or physical obstacle
Control to interrupt the movement of the mast before
Microprocessing means, Electrically connected to the microprocessing means.
The mast and the overhead power line or the physical obstruction
The operation of the mast device indicates that imminent contact with objects
Display on the alarm display to notify the vertical
A pole alarm device including a safety control module. 2. The alarm device according to claim 1, wherein said electromagnetic field detecting means, said collision detecting means, and said microprocessing means are arranged in a housing mounted on an uppermost portion of said mast device. 3. A light source mounted within the housing and directed upward to illuminate the mast's intended course during operation of the mast at night or in other poor visibility situations. The alarm device according to item 1. 4. The alarm device according to claim 3, wherein said light source includes a halogen bulb capable of heating said alarm housing to maintain a predetermined operating temperature in cold or stormy weather. 5. The apparatus according to claim 2, further comprising a plurality of tilt detecting means electrically connected to said microprocessing means and capable of detecting a physical orientation of said mast device so as not to be placed in danger. Alarm device. 6. The alarm device according to claim 2, wherein said electromagnetic field detecting means is capable of detecting the presence of a 7,200 volt, 60 hertz electric power transmission line at a shortest distance of 8 feet. 7. The alarm according to claim 2, wherein the collision detecting means includes an ultrasonic device capable of transmitting and receiving a reflected ultrasonic wave indicating the presence of a non-electrical physical obstacle near the mast device. apparatus. 8. The alarm device according to claim 1, wherein the safety control module is mounted on a section of a driver of a vehicle where the mast is installed. 9. The control module includes a plurality of visual and audible indicators that alert an operator of the mast device of an imminent contact between a power line and a physical obstacle near the mast device. The alarm device according to claim 8, comprising: 10. The alarm device according to claim 1, wherein the control module has a self-test function, and it is possible to prove that the electromagnetic field detecting means and the collision detecting means are activated before moving the mast device. . 11. The alarm device according to claim 10, wherein the control module is capable of displaying a coded error message whenever the self-test function is not activated. 12. A safety device having one outer end and used together with an in-vehicle mast that moves the outer end so as to extend upward and downward from the vehicle or downward from the vehicle. Wherein the alarm system detects an AC voltage while the outer end is displaced upward from the vehicle, and generates a first output signal in response to the AC voltage on an outer end of the mast. A sensor provided, a second output signal responsive to an obstacle detection signal, detecting a physical obstruction on the ascending path of the outer end while the outer end is displaced upward from the vehicle. The outer end of the mast that generates
An upper detector , electrically connected to the sensor and the detector for receiving first and second output signals, and the first and second detectors;
A microprocessor for individually generating first and second control signals, respectively, when the output signal exceeds a predetermined magnitude, and a respective microprocessor for preventing the outer end from displacing upward from the vehicle. A safety device comprising: a mast control mechanism that responds to first and second control signals. 13. The safety device according to claim 12, wherein the safety device further includes first and second indicators respectively responsive to first and second control signals. 14. The safety device according to claim 13, wherein each of the first and second indicators is at least one of an audible indicator and a visible indicator. 15. The safety device of claim 1, wherein the sensor, the detector, and the microprocessor are located within a housing at an outer end of the mast.
3. The safety device according to 2. 16. The safety device according to claim 15, wherein the safety device further includes a light source for a light mounted in a housing oriented in a track direction of the outer end while moving upward from the vehicle. Safety device. 17. The light source according to claim 16, wherein the light source includes a light bulb capable of maintaining the inside of the housing at a predetermined temperature.
A safety device according to claim 1. 18. The safety device is further electrically connected to a microprocessor provided in the housing, and wherein a vertical displacement of the mast with respect to the vehicle while the outer end moves upwardly from the vehicle. And a plurality of tilt sensors for outputting a corresponding plurality of third output signals to the microprocessor indicative of the angle, wherein the microprocessor outputs the third tilt signal when the third output signal indicates an undesirable placement angle of the mast. 16. The safety device according to claim 15, wherein a control signal is generated and the mast control means is responsive to a third control signal whose outer end prevents movement upward from the vehicle. 19. The safety device according to claim 18, wherein the safety device includes first, second, and third indicators respectively responsive to the first, second, and third control signals. Safety device as described. 20. The safety device according to claim 19, wherein each of the first, second, and third indicators is at least one of an audible indicator and a visible indicator. 21. The apparatus of claim 20, further comprising a light source mounted on a housing oriented in a direction of movement of the outer end while the outer end moves upwardly from the vehicle. Safety device as described. 22. The safety device according to claim 19, wherein the first, second, and third indicators are in a control module in an operation room of a vehicle equipped with a mast. 23. The control module according to claim 22, wherein the control module includes a mechanism for confirming the operation of the sensor and the detector before the outer end of the mast moves upward from the vehicle. Safety equipment. 24. The safety device according to claim 23, wherein the control module includes a mechanism for indicating an inoperability of one of the sensor and the detector. 25. The safety device according to claim 12, wherein the sensor is an electromagnetic field sensor. 26. The electromagnetic field sensor according to claim 1, wherein the outer end of the mast is 7,200 volts 60 to a minimum distance of 8 feet.
26. The safety device according to claim 25, wherein it is possible to detect an approach to a hertz power transmission line. 27. The safety device according to claim 12, wherein the detector includes an ultrasonic transducer. 28. The safety device according to claim 27, wherein the sensor is an electromagnetic field sensor. 29. The safety device according to claim 28, wherein the sensor, the detector and the microprocessor are located within a housing at the outer end of the mast. 30. A light source mounted in a housing for directing light in a direction of movement of the outer end while the outer end moves upwardly from the vehicle. A safety device according to claim 29. 31. An output electrically connected to a microprocessor within the housing and indicating an angle of displacement of the mast from a vertical orientation with respect to the vehicle during the upward movement of the outer end from the vehicle; and A plurality of tilt sensors for outputting a corresponding plurality of third output signals to a microprocessor, the microprocessor generating a third control signal when the third output signal indicates an undesired displacement angle of the mast; The mast control means is responsive to a third control signal for preventing the outer end from moving upward from the vehicle.
The safety device according to 0. 32. The safety device according to claim 31, wherein the first, second, and third indicators are responsive to first, second, and third control signals, respectively. 33. The safety device according to claim 32, wherein the first, second, and third indicators are at least one of an audible indicator and a visible indicator. 34. The safety device according to claim 33, wherein the first, second, and third indicators are in a control module in an operation room of a vehicle equipped with a mast. 35. The control module includes a mechanism for confirming the operation of the sensor and the detector before the outer end of the mast moves upward from the vehicle, and the control module includes one of the sensor and the detector. 34. A mechanism for indicating that one operation is not possible.
A safety device according to claim 1.