NO147331B - SPRAY EQUIPMENT FOR CLEANING APPLIANCES, PLANT PROTECTION APPLIANCES OR SIMILAR APPLIANCES. - Google Patents

Description

The present invention relates to a spraying device for cleaning devices, plant protection devices, etc. devices, comprising a hand-held device connected to a pressure and heat source through a line for delivering a liquid or vaporous agent under high pressure, with a coupling arm which during operation persists

end must be kept in the engaged position and which operates a switch that disconnects the pressure and heat source when the handpiece is released, e.g. in case of danger.

Steam jet cleaners or hot water high-pressure cleaners

or high-pressure cleaners without a heat source are used for cleaning, removing scale and degreasing surfaces, for disinfection for plant protection etc. 1. These devices contain a pressure source and mostly also a heat source. The syringe device comprising a movable hand apparatus is connected to the heat and pressure source through a line. The medium to be sprayed can also be mixed with agents for cleaning, disinfecting

tion, conservation and de-conservation or plant protection products.

The liquid or vaporous medium leaves the handpiece through a nozzle adapted to the purpose of application. Thereby, reaction forces occur in the hand tool which, together with the cutting effect of the high-pressure jet, the temperature of the medium and the added chemicals, pose a risk of accident for the operator.

With known spray devices, the risk of accidents is reduced by the fact that the outlet for the medium is blocked mechanically as soon as the spray device

one is released. In addition, these devices contain a further mechanical closure as well as a protective brace near the operating arm. In this way, an accidental opening of the spray device must be prevented.

In these devices, the closing springs and seals are exposed to high pressures and temperatures as well as aggressive additives, and therefore only have a short lifespan. Furthermore, large operating forces are required to open or keep the spray device open. If a pressure relief is provided to avoid the large operating forces, this contains movable mechanical control parts which are exposed to the liquid or steam, and on which scale or chemicals can settle. These deposits interfere with the operation of the device. Furthermore, the additional parts increase the handpiece's weight. By releasing the operating device, the sudden blocking of the medium causes a pressure shock in all pressure-carrying parts. Accidental pressure shocks do not damage the device. If, however, these pressure shocks are triggered in rapid succession, e.g. by playing with the coupling arm, this leads to rapid wear of the spray device, increasing the risk of accidents. In addition, the cleaning device's hose lines in particular are exposed to pressure shocks, which can cause the hose fittings to break loose and thus also cause accidents.

It is also known a spray device whose hand part has an electric switch, with which the pressure source and/or the heat source

plug in and out. For this, a switch operable from the handpiece's coupling arm is used, which is connected to the power supply for the pressure and heat source through an electric cable that is run parallel to the high-pressure hose. Through the switch, e.g. a protection which is arranged in the power line, pre-pressure and heat source.. When the coupling arm is released, the switch opens, thereby cutting off the supply voltage for the relay. Thereby, the relay falls out, so that the pressure and heat source becomes de-energized (DAS 2 219 514). This design requires a complicated construction of the hose between the pressure and heat source and the spray device with further installed electrical conductors. This hose consists of a hydraulic and an electric part

is unmanageable due to its shape and dimensions when operating the spray device and sensitive to mechanical damage during harsh treatment.

The task of the invention lies in further developing a spray-on arrangement of the type mentioned at the outset so that, by simple construction, a safe and quick disconnection is achieved without an expensive line containing an electric cable, whereby pressure peaks are avoided in the parts that carry or store the medium.

According to the invention, this task is solved by a transmitter arranged in the handheld device for generating high-frequency electrical signals

show electromagnetic waves with which, in a modulated or unmodulated state, a switch-on<p>rdre is transferable to a pressure-

and the heat source arranged amplifies and can be converted into a control signal with which the pressure and heat source can be switched on, whereby the pressure and heat source is switched off when the switch-on order is canceled by releasing the switching arm during standstill or can be brought into the switched-off state. By choosing correspondingly high frequencies, the electromagnetic waves can be transmitted wirelessly using antennae from the hand-held device to the pressure and heat source. Low voltages are sufficient for the transmission. There is therefore no need to re-

permanent protective measures against contact voltages. The low voltages enable the use of a switch with small dimensions. The transmitter can contain electrical connections in integrated technology. The space requirements of the electrical components which

must be placed in the handset is therefore small. In addition, these parts only have a low weight. The handling of the device is thereby facilitated. Next to the connection order. allows further orders to be transmitted by means of waves through a channel. Different orders are e.g. assigned to different frequencies which are transmitted in frequency multiplex. In addition, the orders can also be transmitted time multiplexed by modulating the carrier wave. Each order is e.g. determined by a particular combination of binary values. The two binary constants here correspond to different phases of the carrier waves. The switch-on order can be derived from the carrier itself. Different orders are often necessary when it comes to the quantity and type of chemicals to be mixed

must be changed.

Preferably, the high-frequency electrical waves are transmitted

through a wire braid in the hose which is arranged for the transport of the agent from the hand device to the pressure and heat source

one. With this device, to a large extent, out-

the radiation of electromagnetic waves to the environment. According to public regulations, only certain frequency ranges are permitted for wireless transmissions with limited performance, so that the electromagnetic waves do not cause interference on frequencies that are reserved for radio and other transmissions. The necessary precautions at the transmitter to meet these requirements can therefore be omitted with the device described above. It is e.g. not necessarily that the transmitter's frequency can only vary within narrow limits from the changing ambient conditions. The transmitter can therefore be made up of few components, whereby larger frequency variations do not affect the operation and safety of the switch-off. Furthermore, it is possible to carry out the transmission with frequencies in the kilohertz range. Thereby, small damping occurs on the hose's wire braid.

In a suitable embodiment, a metal plate is arranged in the handpiece's grip and is connected to the transmitter's outlet. The metal plate forms a conductive connection between the transmitter and the operator's hand. The conductor loop between the transmitter in the handheld device and the receiver at the pressure and heat source is formed by the wire braid in the hose and the conductive earth as well as the operator. The measures described above reduce the resistance in the second line section.

In a favorable embodiment, it is arranged in the hand apparatus

a battery to supply the transmitter. This battery can be an accumulator. Cables between the handpiece and the pressure and heat generator for the transmission of supply voltages are not needed. Furthermore, the transmitter is thus prevented from being affected by disturbance voltages that are superimposed on the mains voltage.

Another suitable embodiment is designed in such a way that an output of the transmitter and an input of the receiver are connected by means of capacitors to the wire braid of the hose and that through the wire braid which is connected to a mains device at the pressure and heat source, the transmitter is connected to a pole of a operating voltage, the second pole of which supplies the transmitter through a wire arranged on the hose. As only small currents are transmitted through this wire, its cross section is small. Because of. the low supply-like voltages, a wire with thin insulation can be used. The construction for supplying the transmitter with DC voltage from the mains at the pressure and heat source is therefore simple. The network device that is present at the pressure and heat source can simultaneously be used to supply the receiver.

In a preferred embodiment, a relay is connected after the receiver at the pressure and heat source / to control a protection relay if: switching contacts are arranged in line with the power supply lines for the pressure source's motor and the heat generator's burner.

If the handpiece is released, only the pressure and heat source is de-energized with this device. The mains device still receives supply voltage so that a reconnection is possible using the hand-held device.

Preferably, when the switch is opened, a monostable multivibrator can be touched, ■■ by whose output signal with an adjustable duration, the transmitter can be blocked against the emission of waves. After the disconnection, the pressure and heat source can only be reconnected when the monostable multivibrator's output signal is switched off. The duration of the output signal can be a few seconds. The working mode of the pressure and heat source cannot thus be disturbed by quickly following operation of the switching arm, as a certain delay time must have elapsed before reconnection.

Another favorable embodiment consists in the wire braid being connected at each of its ends with a metallic end piece which is pressed against a metal body which is separated from the end of the pipe to the heat source or the handpiece. by a body of insulating material and is connected to a conductor which is connected to the amplifier or the transmitter. With this device, the hose braid is isolated at both ends against the handpiece, respectively the pressure and heat source. Thereby, the ends of the wire braid can be easily connected to the transmitter and receiver.

Further details, features and advantages of the invention can be seen from the following description of a drawn embodiment example.

This shows:

Fig. 1 A schematic representation of a spray device,

Fig. 2 a longitudinal section through the connection point between the hose

and handheld device respectively hose and heat source,

Fig. 3 a cross-section through the hose.

A hand-held device 10 of an unspecified high-pressure cleaning device is connected to a heat source through a flexible hose 12, which heat source is located in a drivable container 16. The heat source is here a heat exchanger 14 which is heated by a burner 18, f .ex. an oil burner. The heat exchanger 14 is supplied by a high-pressure water pump 20 which is driven by an electric motor 22 .

The electric motor 22 and the burner 18 are connected through switch contacts 24, 26 to a relay 28 to a phase 30 of the alternating current network. The other connections to the motor 22 and the burner 18 are placed on the neutral conductor 32. To the phase 30 and the neutral conductor 32 is also connected the input to a mains device 34 which provides a direct voltage, e.g. of 12 volts, with which an amplifier with relay output 36 is supplied. A working contact 38 for the amplifier with relay output 36 is arranged in the course of a wire which connects the coil of relay 28 with the phase 30. The other connection to the relay coil is placed on the neutral conductors 32.

In the handheld device 10, a liquid which is under high pressure supplied through the hose 12 is led into a jet tube 40 at the end of which a nozzle 4 2 is arranged. The hand device 10, which resembles a spray gun, has a pistol grip 44. A coupling arm 46 is attached to the pistol grip for operation of the hand device. This coupling arm 46 acts on a switch -48. When the coupling arm 46 is pulled by the operator 50 in the direction of the pistol grip 44, the switch 48 is closed. After the coupling arm 46 has been released, as e.g. is under the influence of a spring not shown, the switch 48 opens again.

Inside the hand-held device 10, a transmitter 52 is arranged which emits high-frequency electrical or electromagnetic waves. The transmitter 52 can contain building elements that are made in integrated technology. Small dimensions can thereby be achieved. The transmitter 52 is supplied with the necessary operating voltage through the switch

48. One output of the transmitter 52 is connected through an unspecified wire to a metal plate 54 which is inserted into the pi-chair handle 44. The other output of the transmitter 52 is connected to a wire braid 56 in the hose 12. The ends of the wire braid are electrically isolated from the container 16 and the heat exchanger 14 as well as from the metallic parts of the handheld device 10. The end of the wire braid 56 which faces the heat exchanger 14 is connected to an input of an amplifier with relay output 36. The other input of this amplifier is grounded . E.g. this input is connected through an unspecified line to the pipe between the high-pressure pump 20 and the heat exchanger 14. Between the transmitter 52 and the amplifier 36, a current circuit is thereby connected to which the wire braid 56, the connecting wires between the ends of the wire braid. and the transmitter 52 respectively the receiver 36, the path through the floor, the operator 50, the metal plate 54 and the connecting lines between the metal plate 54 and the transmitter 52 as well as the receiver 36 and the pipeline in the container 16 belong. In this circuit, the waves produced by the transmitter 52 are transmitted by closed switch 48, which supplies the transmitter 52 with operating voltage. The operating voltage can be produced by the eti handpiece's 10 internally arranged battery, which no closer

is shown.

The electric waves produced by the transmitter 52 when the switch 48 is closed are received by the amplifier 36. This can contain an alternating voltage amplifier input stage, not shown in more detail, after which a rectifier is connected. The rectified voltage provides a control signal for the relay whose working contact 38 is arranged in the relay coil's 28 current circuit. When the control signal is present, the relay reacts so that contact 38 closes. The relay coil 2 8 is thereby applied alternating voltage. Thereby, the relay reacts in the same way whereby the contacts 24, 26 close, through which the burner 18 and the motor 22 of the high-pressure pump 20 are supplied with operating voltage. The electric waves emitted by the transmitter 52 as a switch-on order for the high-pressure pump and for the heat source consisting of the burner 18 and the heat exchanger 14 thereby reach the amplifier 36, through which the supply of mains voltage is regulated. For the start-up of the high-pressure pump 20 and the heat source consisting of the parts 14 and 18 must therefore

only the coupling arm 46 is pulled against the pistol grip 44 by the operator

50 • During operation, high-frequency current is admittedly present

small current through the operator, but this current is completely harmless.

If the operator 50 releases the coupling arm 46 e.g. in a father-

similar situation, the transmitter 52 ends the emission of electric waves. The coupling arm 46 is released, e.g. when the device 10 falls out of the operator's 50 hand. With the lack of electric boll-

ger also disappears the control signal for the relay and the following relay 28. The relay 28 thereby falls out and interrupts the power supply to the motor 22 and the burner 18. The one in figure 1

device shown enables a safe and quick disconnection of the high-pressure pump 20 and the heat source consisting of the parts 14, 18.

An additional cable for transmitting the switch-on order is not required. The receiver 36 responds to low voltages. It is therefore sufficient when the amplitudes of the waves are in the order of 10 volts. As these voltages are harmless, no complicated constructions are needed on the hand device 10 for contact protection. The space required for the parts that are arranged

in the hand-held device 10 for production, control and forwarding of the switch-on order is small. These parts are also light. The weight

and the dimensions of the handheld device 10 are therefore only insignificantly affected by the electrical parts.

It is convenient to design the transmitter 52 for one frequency

which is in the range of a few kilohertz. The attenuation of these waves on the transmission path between the transmitter 52 and the receiver 36 is only small. The device also works flawlessly when the frequency is exposed to certain variations, which may be due to e.g. variations in the supply voltage, temperature changes and aging of the components. There is thus no need for complicated constructions to produce an oscillation with small deviations from the nominal frequency.

In addition to the switch-on order, further orders can also be transmitted with the waves produced by the transmitter 52 through the hose 12. If the high-pressure cleaning system contains a device for dosed mixing of chemicals to the liquid medium, for example a valve in this device can be controlled 1 frequency multiplex operation. The frequency of the transmitter 52 can be affected by operation of a further switch connected to the hand-held device 10.

Electrical isolation of the metal braid 56 from the housing to the handpiece

10 and the heat exchanger 14 can be achieved by the arrangement shown in the figure,

2 is used. A pipe end 5 7 of the heat exchanger 14 or of the hand-held device 10 contains a threaded bore into which a cylindrical body 58 of a temperature-resistant, pressure-resistant electrically non-conducting plastic is screwed. The body 58 is equipped with a channel 60 for passage of the liquid medium. The cylindrical body 58 likewise has on its other end an unspecified threaded bore, in which a. metal body 6 2 is screwed in which contains a centric bore 64 which is arranged flush with the channel 60. On the body 62 is attached a conductor 66 which is added to the amplifier 36 or to an output of the transmitter 52. By means of a cap nut 68 which is screwed onto external threads on the body 62, the metallic end piece 70 of the hose 12 is pressed against a cone-shaped recess in the body 62. The metal end piece 70 is electrically conductively connected to the wire braid 56.

In the handheld device 10, next to the transmitter 52, a monostable multivibrator (not shown) is arranged, for example, together with the transmitter 52 on a common conductor plate. The monostable multivibrator, which is likewise supplied by the battery in the handpiece, emits a signal when the switch 48 is opened. After the opening of the switch 48, the multivibrator can be kept in operation through a capacitor buffer for a certain time. The output signal of the monostable multivibrator blocks, through a grid not shown, the input to the transmitter 52. Therefore, an immediate restart of the motor 22 and the burner 18 is not possible after the arm 46 is released. Reconnection only takes place after the expiry of a delay time set in the multivibrator. In this way, it is possible to avoid that the high-pressure cleaner

disengaged and engaged at short intervals when playing with the coupling arm 46.

Claims (8)

1. Spraying device for cleaning devices, plant protection devices etc., devices, comprising a hand device connected through a line to a pressure and heat source for releasing a liquid or vaporous agent under high pressure, with a coupling arm which must be continuously held in coupling position °9 during operation which affects a switch that when the handpiece is released, e.g. in the event of danger, switches off the pressure and heat source, characterized by a transmitter (52) arranged in the handheld device (10) for generating high-frequency, electrical or electromagnetic waves, with which, in a modulated or non-modulated state, a switch-on order can be transmitted to an amplifier (36 ) arranged at the pressure and heat source (20; 14, 18) and can be converted into a control signal, over which the pressure and' heat source (20; 14, 18) is switched on, by releasing the coupling arm (46) is put out of operation or in a disconnected state, as the pressure and heat source (20; 18, 14) is switched off when the switch-on order fails. 2. Syringe device according to claim 1, characterized in that the high-frequency electric waves are transferable through a wire braid (56) in the hose (12) which is arranged for the transport of the agent from the hand-held device (10) to the pressure and heat source (20; 14, 18) ). 3. Spray device according to claim 1 or. 2, characterized in that a metal plate (54) is arranged in the grip (44) of the hand-held device (10), the metal plate being connected to an output of the transmitter (52) and forming a conductive connection from the transmitter to the operator's hand. 4. Spraying device according to claim 1, 2, or 3, characterized in that a battery for supplying the transmitter (52) is arranged in the hand-held device (10). 5. Spray device according to claim 1, 2 or 3, characterized in that an output of the transmitter (52) and an input of the amplifier (36) are connected to the hose (12) wire braid (56) by means of capacitors, that through the wire braid (56) connected to a mains device at the pressure and heat source (20; 14, 18) the transmitter is connected to one pole of an operating direct current voltage, the other pole of which supplies the transmitter (52) through a thread arranged on the hose (12). 6. Spraying device according to one of claims 1 to 5, characterized in that after the receiver (36) at the pressure and heat source (20; 14, 18) a relay is connected through which a relay (28) can be controlled, whose connection contacts (24, 26) is arranged along the power supply lines for the pressure source (20) motor (22) and the heat source burner (18). 7. Spraying device according to one of claims 1 to 6, characterized in that when the switch (48) is opened, a monostable multivibrator is affected, by whose output signal with adjustable duration the transmitter (52) is blocked from emitting waves. 8. Spraying device according to one of claims 1 to 7, characterized in that the wire braid (56) is connected at each of its ends to a metallic end piece (70) which is pressed against a metal body (62) which is separated from the heat source (14) or the touching end (57) of the handpiece (10) by means of an insulating material body (58) and connected to a conductor (66) which is connected to the amplifier (36) or the transmitter (52).