DE1905305A1 - Filament photo flash bulb - Google Patents

Description

PATENT ENGINEERS FW HEMMERICH GERD MÖLLER- D. GROSSE 21

D ÖSS ELDORF 10 HO MBE RGER STR AS SE 5 190530R January 31, 1969

bhibi

-El-

TOKYO SHIBAURA ELECTRIC CO. LTD., Kawasaki-shi / JAPAH Filamentless photo flash light bulb

A present invention is concerned with a photo flash bulb. It deals in particular but with a filament-free flashlight bulb in which a primary substance is produced by discharge or by a Discharge process is ignited.

There are already some filament-free photo flash lamps available which work according to the discharge principle. Such a photo flash bulb consists of a Hermetically sealed envelope or a hermetically sealed pear flask in which there is combustible Material, a gas filling that promotes combustion, primary Ignition material and a pair of electrodes arranged at a certain distance from one another are located. The primary substance or the primary ignition material is ignited by the discharge taking place and then brought about from an explosive combustion the combustible material to ignite.

In one of the previous flash light bulbs that worked according to the discharge principle, at least one was the Provide both supply wires with a layer of porous insulating material. Both lead wires were through bridges the primary ignition material. To get this photo flash bulb to ignite, between the a voltage pulse of more than 10 kV is applied to both supply lines. Through this voltage connection would ignite the primary material or the primary ignition material between the porous insulating material of the with this Insulated-coated feed wire and the

909836/1329 Bad on *. *. *. - ^{E 2} -

21 508

bh.bi

- E 2 -

Primary substance or the primary ignition material caused spark discharges. In this earlier version however, with a photo flash bulb it was difficult to completely cover the feed line with one layer to be coated with insulating material, and the occurrence caused by the activation of the cooking voltage pulse a discharge between the two supply lines prevented a reliable ignition of the primary substance or the primary ignition material.

With another already existing Photo-Blitzlicht- ™ pear, which works according to the discharge principle, was at least one of the supply lines with insulating material coated. V / eil at least part of the aforementioned insulating material as a primary material or as a primary ignition material was used, the combustible material formed an electrically conductive path or path between the. Primary layer or between the layer of primary applied to one of the supply lines Ignition material and between the other supply line. To ignite the photo flash bulb of this earlier one Execution, but rather to ignite the primary igniter, was between the two supply lines fc a voltage pulse of 200 to 500 volts is applied. With this ^ hoto flash bulb of the earlier version, but even with the design mentioned above, it was difficult to make the feed line completely with one layer made of insulating material, so that the supply line is provided with a layer of primary ignition material tended to short-circuit with the other supply line, and thus reliable ignition of the Primary substance or the primary ignition material prevented.

In yet another earlier version of the photo

909836/1329 - E- 3 -

21 508

1905305 January 31, 1969

bh.hi

- E 3 -

Flashlight bulb, which works according to the discharge principle, were the two supply lines by means of one Primary material or primary sin material bridged directly. There was also the one with the other photo flash bulbs existing coating of the supply lines with insulating material omitted. Between the feeder lines were then used to ignite the primary substance or the primary trigger material a voltage pulse of several hundred volts switched on. With this photo flash bulb the earlier execution it often happened a short circuit between the supply lines, which then ignites the primary substance or the primary Ignition material resulted.

In each of the aforementioned photo flash bulbs of the prior art, there was an ignition of the primary material or the primary ignition material uncertain, which then led to the extremely poor lightning reliability, so that Even today the photo flash light bulb, which works according to the discharge ignition principle, is not used very much will.

The present invention therefore aims at ^ one that works on the principle of discharge ignition To create a flashlight bulb at which the ignition is also performed in a reliable manner.

According to the present invention, at least one is of the two arranged at a certain distance from one another Electrodes at their end with a layer of electrically insulating primary material or primary ignition material Mistake. The distance between the primary ignition material and the other electrode, which is filled with a filling is provided with a combustion-promoting gas atmosphere, is limited in width to 0.05 mm to 0.8 mm, whereby

909836/1529

- F 4 - ORIGINAL BATHROOM

21

- E 4 -

then the energy required for ignition is reduced, but at the same time the flash reliability is increased will. The composition of the primary substance is also within the scope of the present invention or the primary ignition material has been improved, thereby significantly reducing the required Bring about energy.

To that falling within the scope of the present invention and according to the principle of discharge ignition working photo flash bulb include: a hermetic one sealed and radiating bulb, in which there is combustible material, a gas filling that encourages combustion as well as two feed lines arranged at a certain distance from one another. Some of these lead wires extend out of the butt of the pear. The part of the supply wires located inside the bulb is arranged in relation to one another in such a way that two electrodes are created, one of which is provided with the primary substance or with the primary ignition material. The distance between the electrodes is 0.05 to 0.8 mm. Between the electrodes is the primary ignition material arranged and given a filling of the aforementioned combustion-promoting gas.

-Gl-

909836 / 1.3 2 9

21 508

bh.bi

-Gl-

The present invention, its objects and characteristics, may be better understood when added to the following given description and the drawings accompanying this patent application are used as an aid will. In detail is:

Fig. 1 is a partially sectioned view of a in the frame of the present here Invention of falling photo flash bulb. '

Fig. 2 shows a characteristic curve in which the ratio of the (marked with G) distance between the electrode coated with the primary ignition material to the other electrode as a function the energy required for the ignition of the primary ignition material is applied. That Ignition material based on the embodiment according to FIG. 1.

Fig. 3 is a graph showing the relationship between the composition of the primary ignition material and represents the energy required for its ignition.

The following is a preferred embodiment of the subject matter of the invention will be described with reference to Fig. 1 and Fig.2. With the photo flash bulb shown here it is a flashlight bulb of the AG-I version. This photo flash bulb sets is composed as follows: from a hermetically sealed and radiating envelope 1, which is preferably designed as a glass bulb, dimensions: 12 mm diameter and 34 mm length; enclosed in this wrapper the combustible material 2, for example shredded

909836/1329 - G 2 -

21 508

bh.bi

- G 2 -

Zirconium foil, and also a gas atmosphere that is conducive to combustion, for example oxygen at a pressure of 4.5 atmospheres, as well as an ignition device or a Ignition mechanism 3. During manufacture, the combustible material 2 and the electrode end holder 3 or Ignition device 3 in the glass bulb 1, (v / which originally had an opening at the lower end) inserted. That The open end of the glass bulb 1 is closed by placing the glass bulb 1 flat and firmly on the electrode holder or the ignition device 3 is pressed. The next process is then evacuation or evacuation of the glass bulb 1 as well as the filling of the combustion f ordering gas. This is done through the evacuation pipe. Then the evacuation tube is melted, so that there is a baseless photo flash bulb results.

The ignition mechanism or the electrode holder 3 consists of the two supply lines 5a and 5b, which extend into the glass bulb 1 and are guided airtight through the pinch foot part 4 of this glass bulb. Get to the ignition mechanism or to the electrode holder 3 continue to hear the two electrodes 6a and 6b, which are arranged at a certain distance from one another, which from the most distant parts of the supply lines are shaped. At least one of the two electrodes - (in the execution of the subject matter of the invention the electrode 6b) - is with the electrically insulating primary ignition material 7 coated. A glass bead 8 bridges the two supply lines and combines them and thereby keeps the two electrodes at their assigned and prescribed distance from one another. the Electrode 6b extends slightly beyond the upper surface of the glass bead 8, the opposite electrode 6a

909836/1329 - g 3 -

BAD ORiOiNAi

21 508

1905305 January 31, 1969

bh.bi

however, is led far beyond the glass bead 8, then bent in the shape of an inverted U so that it from above at a certain distance from the primary ignition material layer 7 opposite the electrode 6b. The end is to facilitate the discharge process the electrode 6a is pointed. Between the electrodes 6a and the primary ignition material 7 of the electrode 6b is the discharge path G with a filling of gas atmosphere that promotes combustion.

The photo flash bulb according to FIG. 1 works as follows: A high voltage pulse is generated between the lead wires 5a and 5b of, for example, 8 kV. This voltage is called a piezoelectric device or Entoramen a capacitor discharge device, Bei When such a voltage is applied, the primary ignition material applied to the electrode 6b becomes dielectric destroyed, and / the combustion-promoting gas in the discharge path begins to discharge. the Current heat released during the discharge causes the surface of the primary ignition material 7 to be the ignition point reached, which in turn gives rise to an explosive scattering of the primary ignition material 7, and in such a way that the combustible material 2 enclosed in the glass bulb 1 is ignited and burns vigorously begins and emits bright flashes in the process.

For the method falling within the scope of the present invention, the formation is the one already mentioned Discharge path G, which is related to the ignition To increase sensitivity is essential. With the photo flash light bulb, in which the distance between the Electrodes or the discharge path between the electrodes set to values between 0.1 mm and 0.5 mm

909836/1329 -GH-

BAO ORIGINAL

21 508

bli.bi - G if -

Is at the. the electrodes are directly bridged by the primary ignition material, an energy or power of approximately 0.3 mW is required to ignite the primary ignition material. In contrast, in the context of the present invention, in which the electrodes are not directly bridged by the primary ignition material ₉ even if at least one of these electrodes is provided with a layer of primary ignition material, in which the electrodes form the aforementioned discharge path G, in the case of a resulting improvement in ignition sensitivity, the energy or power can be reduced to below 0.3 mW without failure being expected. The reason for this is presumed to be in the fact mentioned below: The heat capacity of the primary ignition material is greater than that of the combustion-promoting atmosphere, so that a discharge through the primary ignition material has a greater heat transfer loss. In contrast, where the discharges take place in a gas phase, the temperature of the pointed pole face of the primary ignition material increases slightly with regard to the discharge output, which in turn leads to reliable ignition of the primary ignition material. If the gas phase is still under increased pressure, the discharge taking place in it has a smaller cross-section, which leads to a better concentration of the resulting energy or power and enables the primary ignition material to ignite properly.

If, as will be described below, the composition of the primary ignition material is correctly selected, both electrodes are provided with a layer of primary ignition material, layer thickness approximately

- G 5 909836/1329

21 508

I JUboOo January 31, 1969 bh.bi

- G 5 -

0.2 mm, the discharge distance between these two primary material layers is set to about 0.3 mm, then the required ignition energy or ignition power is reduced to 0.15 mW. Even where only the Electrode 6b, as is the case in the exemplary embodiment of the present invention, with a Layer 7 of primary ignition material is provided where the discharge gap between the other electrode 6a and the primary ignition material 7 is set to 0.3 mm, an ignition energy or ignition power is only less than 0.1 mW required.

For the purpose pursued in the context of the present invention, the aforementioned distance Π or the aforementioned discharge path G is limited to a width of 0.05 mm to 0.8 mm. Hit Fig. 2 shows the relationship between the discharge path in mm and the required energy or the required power in mW. In this case, the primary ignition material consists of a mixture of 100 parts by weight of zirconium powder, 100 parts by weight of potassium chlorate, not steep, and of 10 parts by weight of nitrocellulose. From FIG. 2 it can be seen that as the discharge gap G becomes smaller, the required ignition energy odex> ignition power also becomes smaller. But if G = 0, ie if the two electrodes 6a and 6b are bridged by the primary ignition material and connected to one another, then the aforementioned energy or power increases sharply to 0.3 mW. Therefore, a Entladtungsstrecke G, which is designed to be small liullwertes possible by eliminating preferable for submitting a reliable Bliczens "The reduction of the charge ¹ Ent s gap G to a value which is less than 0.05 · mm, is counter-

"C 6 -

bhobi -GS-

This is difficult to achieve in production and is also unsuitable for mass production ₃ because such a small distance or such a small discharge path could lead to the igniting primary material 7 likely touching the electrode 6a. If, on the other hand, the discharge gap 6 is _{now designed to be greater than O e} 8, then the required ignition energy or ignition power increases to more than 0.15 mW and no longer fulfills the practical purpose. From the standpoint of the production of photo flash light bulbs, the most preferable discharge path distance should therefore be in the range of 0.3 to 0.6 mm.

The composition of the primary ignition material or the primary substance 7 will now be described below. As mentioned above, the correct selection of the primary ignition material composition noticeably reduces the required ignition energy or the required ignition power and at the same time increases the reliability with which the photo flash bulb emits the flashes. The primary ignition material is usually composed of zirconium powder to which oxides and nitrocellulose ψ have been added.

The smaller the specific heat and the trad of heat transfer, the easier the primary Heat ignition material 7 and ignite. For this purpose, however, there is a dielectric breakdown for the ignition discharge necessary, which is why the primary ignition material 7 should have a high dielectric constant ο If the primary ignition material 7 has a low resistance, then this is the penetration of its insulation better. But if this resistance is too small, then the temperature rise is off

909838/13 23

- P, 7 - BAD ORIGINAL

bh.bi

-U-

The reasons for the heating of the current do not have to be great, so that there are difficulties in igniting the primary ignition material 7 is coming. For this reason it is preferable that the resistance of the primary igniter 7 is large to a certain extent "

We investigated _s how the mixing ratios of zirconium "oxides and 'nitrocellulose behave in insight for the demands for igniting the primary ignition material handy ignition or ignition. The oxides used in the experiments included potassium perchlorate CKClO ,,), potassium chlorate (KClO ₀ ), lead dioxide (PbO ,,) and sodium chlorate (NaClO ₀ ). The trial result

i. Ä

Acts are shown in the tables below reproduced. For Tables i to 4, the parts by weight of these oxides are based on 100 parts by weight Zxrkonxumpulver and 10 parts by weight of nitrocellulose turned off. The one required for the ignition Liche energy or power is given in the unit mW. In all tests, the discharge distance was G about 0.3 mm.

Table 1 potassium perchlorate

Weight proportions Required ignition energy (mW)

60 0.23

75 0.15

100 0.09

125 0.07

150 0.08

175 0.10

200 0.14

210 0.17

220 0.19

909836/1329 - G 8 -

bh.bi - 6

Table 2 Potassium Chlorate (KClO ₃ )

Pevv ^T i cht s part e le Required ignition energy (mW)

75 0.18

100. 0.12

125 '0.08

150 0.10

175 0.13

200 0.16

225 0.20

Table 3 Lead DioX3 ^ d (PbO ₀ )

Weight fraction Required ignition energy (mW)

75 0.28

100 0.10

125 0.055

150-0.055

175 0.08

200 0.13

225 0.15

250 0.20

Table 4 'Sodium Chlorate (NaClO-)

Weight proportions Required ignition energy (mW)

75 0.16

100 0.08

125 0.07

150. 0.07

175 0.085

200 0.14

²²⁵ 0.18

909836/1329

- G 9 -

21

bh.bi

It can be clearly seen from the tables mentioned above that the energy or power required to ignite the primary ignition material 7 changes with the proportions by weight of the oxides added. The characteristic curve from FIG. 3 is compiled according to the values in these tables. The characteristic indicates _s that need to be added in 75 to 200 parts by weight for lowering the necessary ignition energy or ignition to about 0:15 mW or less the addition of beating of potassium perchlorate (KClO ^), potassium chlorate (KClO ₃₎ and Natriumchlorate (HaClO ₃₎ and lead dioxide (PbO ₂ ) in parts by weight of 8 7 to 2 00, on a basis of 100 parts by weight of zirconium. If the addition of oxides exceeds the upper limit values or if it falls below the lower limit values, then the ignition energy or ignition power applied from outside to ignite the primary ignition material 7 will always increase in an undesirable manner,

Ignition material, primary ignition material, of the aforementioned specific compositions became a round. Shaped disk, the thickness of which was 0.M- mm and the diameter of which 1.5 mm. The resistance was measured after applying a voltage of 500 V and was so high that its value is several tens to hundreds of MOhm fraud. This high resistance value is due to the high one Oxide surcharge. It helps to ensure that the dielectric breakdown occurs in a concentrated manner, (The breakdown of the primary ignition material did not occur at many points).

As already mentioned, within the scope of the present invention, according to the principle of discharge

- G 10 909836/1329

BATH ORIGINAL

bh.bi ft -3 10

ignition working photo flash bulb created, which can be easily manufactured and is also reliable in flashing. In addition, the Ignition energy to be switched on from the outside for the flashing through the correct selection of the composition of the primary Ignition material lowered considerably.

- A 1 -

909836/13 2 9

Claims (5)

TOKVO SHIHAURA ELECTRIC CO. LTD., Kawasaki-shi / JAPAM claims 1) Line Photo Rlitzlichtbirne, consisting of a radiating cover (1) with combustible material (2 ^{) inside it, with a combustion promoting r} : c * s (3) souie pit a pair of electrodes arranged at a certain distance from one another and a primary ignition material . Characterized in that at least one; of the aforementioned electrodes (6a) and (6b) is provided at .ihrem inner end with a layer of the aforementioned primary ignition material (7), in such a way that a discharge path C is distorted, which is designed for distances of 0.05 to 0.3 mm and is filled with the already mentioned combustion promoting oas. The Photo-Dlitz- • 1 i chtb irne weiteiii in cad u ν c L, da.C belongs to the above-mentioned primary ignition material a Ftofi ι ixt a 1-ohen electrical resistance. - A 2 - 909836/1329 ORIGINAL BATHROOM 21 bh.bi - A 2 - 2) A photo flash light bulb according to claim !, characterized in that that the aforementioned primary ignition material is composed of a mixture of 100 parts by weight Zirconium, from 10 parts of nitrocellulose and from 75 to 200 parts by weight of potassium perchlorate, all parts being made up of parts by weight. 3) A photo flash bulb according to claim 1, characterized »that see the above-mentioned primary ignition material composed of a mixture of 100 parts Zirconium, from 10 parts nitrocellulose and from 75 to 200 parts potassium chlorate, all parts are to be regarded as proportions by weight. k) A photo flash light bulb according to claim 1, characterized in that the aforementioned primary ignition material is composed of a mixture of 100 parts of zirconium, 10 parts of nitrocellulose and 75 to 200 parts of matrium chlorate, all parts being to be regarded as parts by weight. 5) A photo flash light bulb according to claim 1, characterized in that that the aforementioned primary ignition material is composed of a mixture of 100 parts Zirconium, from 10 parts nitrocellulose and from 87 to 200 parts lead dioxide, all parts are to be regarded as proportions by weight. - late 909836/1329 Blank page