CN87200130U

CN87200130U - High safety factor electrothermal blanket

Info

Publication number: CN87200130U
Application number: CN 87200130
Authority: CN
Inventors: 丁贵生
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-01-09
Filing date: 1987-01-09
Publication date: 1988-03-02

Abstract

The utility model relates to an electrothermal blanket with high safety factor. The utility model uses an alternating-current shielded electrothermal wire as the heating element of the electrothermal blanket. Using the electrothermal blanket can completely avoid the alternating current induction electric voltage acting on the human body. Consequently the utility model eliminates the induction electric voltage to cause light electric shock phenomenon and tense mentality to the humans. When the electrothermal element generates the fault of the electrical leakage because of the insulation damage, the generation of the electric shock accident can be also prevented. In particular when the electrothermal blanket overfires, before the temperature is lifted to the ignition point of the cotton fabrics, the electrothermal blanket can also switch the power supply off. The electrothermal blanket effectively prevents the generation of the fire accident.

Description

High safety factor electrothermal blanket

The utility model relates to the safer reliable electric blanket of a kind of electrical insulation properties (cotton-padded mattress quilt).(following title " electric blanket)

Electric blanket of the prior art, although its heater element has adopted a series of insulation measures such as high insulating property engineering plastics, and DC break down voltage reaches several kilovolts and just calculates certified products, above these measures remain helpless to ac induction voltage.This is because exist electric capacity inevitably between human body and the electric blanket, and electric capacity allows alternating current to pass through, and these insulating properties with direct current have nothing to do.The electric blanket test shows qualified to multiple insulaion resistance, a people and a earth that lies on the electric blanket exists the alternating voltage that can not ignore.Stand in the hand-held electroprobe of people on the ground and remove to measure the health that lies in the people on the electric blanket, can make voltage test pencil luminous everywhere.Lie in people's alternating voltage over the ground on the electric blanket with the voltmeter measurement, can show as 40-70 volt voltage under the different situations, this has surpassed the standard of safe voltage.The existence of this voltage when making that stand in people on the ground and the person on lying in electric blanket contacts, has slight or tangible numb inductance feel under the different situations.Though the electric current that this voltage produced is unlikely to be in peril of one's life, on people, cause a kind of sense of insecurity at least concerning the people of health.Particularly to old, or the baby, or cardiopathic people is arranged, also exist potential danger really.Especially for the people of the iron railing bed of sleeping, because of human body head is often wanted the contact bed railing, this danger is just bigger.

Above-mentioned situation is not noticed by consumers in general as yet.But as manufacturer, can not think that the insulaion resistance of electric blanket is qualified, can not electrocute the people a little less than the alternating current impression electric current and just think that product is safe.We can say, the electric blanket of technology production at present, because of its induced-current (15-50 microampere) that will have ac induction voltage inevitably and form certain intensity acts on human body frequently, this can produce which type of influence, still a problem that remains long-term observation and test on earth to human body.In other words, the electric blanket that prior art is produced, its security performance is not perfect at least.

What should be mentioned in that especially is, no matter how well the heater element insulation of electric blanket is done, and always has that day of breaking down in use over a long time.And one of fault just may show as the destruction of insulation and leaks electricity.The slight electric leakage at initial stage perhaps only show as not too serious numb electrical phenomena, and this is the signal of a danger for people's safety.Above-mentioned electric blanket exists ac induction voltage and the numb electrical phenomena that causes, and making people can't distinguish this numb electricity is that alternating current impression causes, and still can cause people's insulation breakdown electric leakage desperately and cause.And correctly judge above-mentioned two kinds of situations, be vital to personal safety.

The present invention relates to a kind of with exchanging the high safety factor electric blanket that shielding heating wire and related elements thereof are made.It not only can stop the potential danger of alternating current impression electricity fully, and can insulate when destroyed at heater element, provides to people and avoids the assurance of getting an electric shock.

Fig. 1 is the interchange shielding heating wire wire schematic diagram that electric blanket is used.The 1st, flat or garden shape heating line base, the 2nd, have the heating wire of insulating barrier, the 3rd, inner insulating layer is made with high-temperature resistance plastice, and the 4th, the metal wire knitted separation net, the 5th, external insulation layer also requires to make with high-temperature resistance plastice.

This interchange shielding heating wire has increased metal knitted separation layer and external insulation layer except having kept height electrical insulation properties of the prior art. During the electric blanket practical application, be wire sheathing ground connection securely, ac induction voltage is just directly from entering ground here like this, and can not act on the user. In addition, just in case insulating, with the passing of time destroyed because using electric blanket, so because this layer metal net arranged, electric current is imported into underground, forms the short-circuit condition to power supply, thereby blows the special insurance silk in electric blanket wiring place, thereby cut off the electricity supply, provide Reliable guarantee to the safety of human body. In simulated experiment, have a mind to puncture the power line that metal net is protected with sharp instruments such as pocket knife, scissors, prove that this protection can prevent effectively that people from getting an electric shock.

In heating wire and power line link the terminal box of wiring, should enclose a special disposable quick fuse pipe, in case this fuse tube has broken, just illustrate that the insulation of heating wire goes to pot, sliver promptly can not be used again.The purpose of fuse tube sealing can not come into operation the electric blanket of existing leaky by changing fuse tube with regard to being to use the family.

This with exchanging the electric blanket that the shielding heating wire is made, the thermostatic control technology is adopted in suggestion, to guarantee the hot safety of electric blanket.The wiring of electric blanket should be used single-phase three-wire plug, seat, and should be by accompanying drawing 2 wiring.6 is flat (or circular) heating wires among the figure, the 7th, heating wire, the 8th, wire sheathing, the 9th, the single-phase three-wire latch, the 10th, have single-phase three sockets of earth terminal, the 11st, thermostatically-controlled equipment of the prior art, it can be made by electrothermal relay, also can use the IGCT radiator valve that the PTC element is made, 12 are sealed in the fuse tube in the terminal box.

Accompanying drawing 3 shows the Zapping circuit schematic diagram of quick fuse pipe, and it can make the slight short trouble near zero line side also can make fuse tube fusing rapidly.Should be understood that especially, no matter be which kind of reason makes heating wire overheated, before the burning-point that melt at plastics, temperature rises to bafta, this heating wire can both be cut off the electricity supply effectively because of short circuit, and the fire incident of fundamentally having stopped to cause because of electric blanket temperature is too high takes place.

Among Fig. 3 12 is the quick fuse pipe, and 13 are the heating wire signal, and 14 is the metal knitted screen layer signal of heating wire.15 lines of starting to exchange fire, 16 connecting to neutral lines.All the other are the Electronic Control part, should be contained in the switch control box of electric blanket.

Above-mentioned with exchanging the electric blanket that the shielding heating wire is made, preventing that getting an electric shock and stopping ac induction voltage is very effective aspect the potential danger of human body.

Claims

1, a kind of under blanket, it is characterized in that electrothermal part is by flat or circular electrothermal part line base 1, heating wire 2 around described original paper line base outside, cover on the inner insulating layer 3 of described heating wire outside, cover on the metal wire knitted separation net 4 of described inner insulating layer outside, outermost insulating barrier 5 is formed.

2, under blanket as claimed in claim 1, its feature also are to have sealed a special fuse in the leading-out terminal plastic casing of described electrothermal part.