US3726631A

US3726631A - Device for the consecutive ignition of combustion flash-light lamps

Info

Publication number: US3726631A
Application number: US00074542A
Authority: US
Inventors: Graaf W De; P Tielemans
Original assignee: US Philips Corp
Current assignee: US Philips Corp
Priority date: 1969-10-03
Filing date: 1970-09-23
Publication date: 1973-04-10
Anticipated expiration: 1990-04-10
Also published as: ATA882970A; BE757008A; DE2046187A1; AT334201B; CH543845A; JPS5317899B1; GB1330906A; DE2046187B2; SE354563B

Abstract

In both parallel and series arrangements for the sequential flashing of flash lamps used in conjunction with camera mechanisms, accessible switching means formed as break contacts are provided which assure full utilization of all the bulbs in the arrangement in the event one or more of the bulbs fail to achieve sufficiently high resistance after ignition. The user may actuate the break contact in either series or parallel arrangement so that the remainder of the flash lamps may be utilized in the event one of the lamps fails to operate.

Description

Unite States atent 1 deGraaf et al.

[451 Apr. 10, 1973 DEVICE FOR THE CONSECUE IGNITION 0F CONBUSTION FLASH- LIGHT LAMPS Inventors: Wilhelmus Polycarpus De Graaf; Peter Andreas Waltherus Tielemans, both of Emmasingel, Eindhoven,

Netherlands Assignee: U.S. Philips Corporation, New

York, N.Y.

Filed: Sept. 23, 1970 Appl. No.: 74,542

Foreign Application Priority Data Oct. 3, 1969 Netherlands ..6915055 U.S. Cl ..431/95 Int. Cl ..F21k 5/02 Field of Search ..431/93, 95; 315/232,

[5 6] References Cited UNITED STATES PATENTS 3,532,931 10/1970 Cote et a1. ..315/240 3,518,487 6/1970 Tanaka et al.... ..315/232 3,443,875 5/1969 Herrmann ..431/95 3,458,270 7/1969 Ganser et al. .....431/95 3,544,251 12/1970 Brandt ..431/95 3,562,508 2/1971 Hofiacker ..240/1.3

Primary Examirter-Carrol1 B. Dority, Jr. Att0rneyFrank R. Trifari 5 7 ABSTRACT In both parallel and series arrangements for the sequential flashing of flash lamps used in conjunction with camera mechanisms, accessible switching means formed as break contacts are provided which assure full utilization of all the bulbs in the arrangement in the event one or more of the bulbs fail to achieve sufficiently high resistance after ignition. The user may actuate the break contact in either series or parallel arrangement so that the remainder of the flash lamps may be utilized in the event one of the lamps fails to operate.

3 Claims, 2 Drawing Figures PATENTEDAPR 1 0191s 3. 72s 631 s N\N N m m E T w w Fig.1

C22 [130 23 [131C324 25 E I 26 28 29 21 A B L A Fig.2

INVEXTORS WILHELMUS F. DE GRAAF PETER A.W. TiELENlANS -"MC, AGENT DEVIlCE FOR THE CONSECUTIVE IGNITION OF COMBUSTION FLASH-LIGHT LAMPS The invention relates to a device comprising at least two combustion flash-light lamps and means for igniting these lamps in order of succession, in which device a first circuit including an externally accessible switching element shunts a second circuit including a filament of one of these flash-light lamps, said switching element responding to the energy released in a flash-light lamp during ignition.

In a known device of the kind set forth the switching element is formed by a make contact (see, for example, US. Pat. No. 3,458,270). This known device has the disadvantage that if a lamp refuses to ignite either the whole unit with flash lamps has to be thrown away or attempts have to be made to close the make contact by means of a conductive wire or in some other way.

The invention has for its object to provide a device of the kind set forth in which this disadvantage does not occur or is at least mitigated. The invention has for its object to provide a solution both for the series combination and the parallel combination of the lamps.

In the first case a device in accordance with the invention is characterized in that the lamps are connected in series and the switching element is formed by a break contact responding to the ignition of a lamp other than that whose circuit including the filament is shunted by the switching-element circuit and in that the connection of the terminals of said other lamp has a low ohmic value subsequent to the ignition of said lamp.

In the second case the device in accordance with the invention comprising at least two parallel-connected combustion flash-light lamps and means for igniting said lamps in order of succession, in which device a circuit including an externally accessible switching element shunts a second circuit including the filament of one of these lamps, said switching element responding to the energy released in a flash-lamp upon ignition, is characterized in that the switching element isformed by a break contact which responds to the ignition of a lamp other than that whose filamenet-including circuit is shunted by the switching element and prior to the ignition of the lamps the resistance of the connection of the terminals of the device via the other lamp has a lower ohmic value that that of a further connection of the terminals and subsequent to the ignition of the other lamp the resistance of the connection of the terminals of the device via said other lamp has a higher value than that of a further connection of the terminals.

Both with the series combination and the parallel combination of flash-light lamps such a device provides the advantage that in the event of failure of a lamp the externally accessible, break-contact switching element can be actuated in a simple manner, for example, by drawing or scratching it away. This may be done by the nail or by a small knife. In this way the unit of flashlight lamps can rapidly be used further.

In the case of a series combination of flash-light lamps it is necessary for the connection of a lamp subsequent to ignition thereof to the other lamps to be of low ohmic value, since otherwise no further lamps can be ignited.

In the case of a parallel connection of flash-light lamps it is desirable to ensure, for example, by including a separate resistor in the circuit, that no connection is established via the terminals through the break contact at such low ohmic value that no further lamp can any longer be ignited. It is also desirable with this parallel combination to ensure that after ignition of a lamp the connection of the terminals of the device via this lap has a high ohmic value. This may be achieved by using lamps having a high ohmic value after ignition. It is furthermore possible to connect a further break contact in series with such a lamp, said contact responding to the lamp connected in series herewith so that after the ignition of said lamp also a high-ohmic connection is established between the mains terminals via said ignited lamp.

It is possible, for example, for the interrupting contact to respond to an increase in pressure in the ignited lamp. If this contact is arranged, for example, at a sealing area of the lamp and if it is ensured that the contact is interrupted when the lamp ignites, a device according to the invention will be obtained.

In a device according to the invention having either a series connection or a parallel connection of lamps, the switching element is preferably constructed so that it responds to the energy released in the other lamp in the form of heat, the switching element being then formed by an interrupting melting contact.

Such a solution has the advantage that the switching element is particularly simple.

In the case of a series connection of flash-light lamps the low-ohmic connection of the terminals of the other lamp. may be obtained by using lamps having a fairly low ohmic value after ignition.

In an advantageous embodiment of a device according to the invention having a series connection of flashsaid lamp, whilst the resistance of said lamp prior to ignition is about 1 Ohm and the value of the shunting resistor lies between 0.5 Ohm and 6 Ohms.

This preferred solution has the advantage that the manufacture of these lamps need not satisfy special requirements. I

In a further advantageous embodiment having a series connection of flash-light lamps the low ohmic connection of the terminals of the other lamp is established by a make contact shunting said lamp, said contact responding to the energy released by the ignition of said lamp.

Also in this case, as stated above, no further special measures are required in the manufacture of these flash-light lamps.

A device having a parallel connection of flash-light lamps may be provided with an ejecting mechanism for removing a lamp out of its holder after ignition. In this way the resistance of the terminal connection of the device according to the invention is higher after the ignition of a lamp via said lamp than that of a further connection of the terminals.

In an advantageous device embodying the invention having a parallel connection of lamps each lamp is also connected in series witha switching element associated with the lamp and formed by a break contact responding to the ignition of the lamp.

This embodiment has the advantage that the lamp need not be removed from its holder, because it is ensured by a second break contact that in fact the connection of the terminals of the device via the ignited lamp has become high ohmic because after ignition this break contact produces a void in the circuit.

The invention will be described more fully with reference to a drawing. Therein 7 FIG. 1 shows a circuitry of a device in accordance with the invention and I FIG. 2 shows a second circuitry of a further device in accordance with the invention.

Referring to FIG. 1, reference numerals l and 2 designate connecting terminals. They can be connected to a capacitor. The connection to the capacitor can be established by means of a switch which is closed for a short time upon the actuation of a shutter of a photocamera. The capacitor may first be charged in some way or other, for example, to 9 to V. The terminals 1 and 2 may, if desired, be connected to a different, suitable voltage source. The terminals 1 and 2 are connected by the series connection of two low-voltage combustion flash-light lamps 3 and 4. The lamp 3 is shunted by a resistor 5. The lamp 4 is shunted by an interrupting melting contact 6. In the non-ignited state the resistance of the lamps 3 and 4 was about l Ohm, the resistor 5 had a value of 2 Ohms. The fusible strip 6 had initially a resistance value of 0.1 Ohm. The arrangement operates as follows. When a voltage is applied to the terminals 1 and 2 first a partial current passes through the lamp 3, which is thus ignited. The ignition of this lamp results in fusion of the strip 6. Thus the short-circuit across the lamp 4 is obviated. Subsequently a voltage is again applied to the terminals '1 and 2. Then thelamp 4 is ignited, by means of a current through the resistor S. In accordance with the value of the resistance of the lamp 3 after its ignition a part of the current of the lamp 4 also passes through the ignited lamp 3. However, when the lamp 3 has got a very high resistance, the current will pass substantially completely through the resistor 5. The sequence of flash-light lamps (two lamps in FIG. 1) may be extended to a sequence of three or more series-connected flash-light lamps. In a practical case of the series combination of five low-voltage combustion flash-light lamps (each having a resistance of about I Ohm in the cold state) the first lamp was shunted by a resistance of about 0.55 Ohm, the second by an ohmic resistor of about 1 Ohm, the third by an ohmic resistor of about 2 Ohm and the fourth by an ohmic resistor of about 4.5 Ohms. The fifth lamp was, of course, not shunted by a resistor. In this practical case the second, third, fourth and fifth lamps were each shunted by an interrupting fusible contact.

FIG. 2 shows a parallel combination of flash-light lamps.

Reference numerals

20 and 21 in this Figure designate connecting terminals similar to the terminals 1 and 2 of FIG. 1. Also the

terminals

20 and 21 may be connected to a supply capacitor. FIG. 2 shows furthermore three flash-

light lamps

22, 23 and 24. The lamp 22 is connected in series with a fusible strip 25, the lamp 23 with a fusible strip 26 and a resistor 27 and the lamp 24 with a fusible strip 28 and a resistor 29. The

lamp 23 is shunted by a fusible strip 30 and the series 6 connection of lamp 24 and fusible strip 28 is shunted by a fusible strip 31.

The arrangement is such that the fusible strip 30 responds to the development of heat in the lamp 22. The fusible strip 25 also responds to heat developed in the lamp 22. The fusible strips 26 and 31 respond to heat developed in the lamp 23 and the fusible strip 28 responds to heat developed in the lamp 24. The

resistors

27 and 29 had values of 1.3 Ohms and 4 Ohms respectively. Prior to fusion the fusible strips had a re sistance value of less than 0.1 Ohm. The flash-

light lamps

22, 23 and 24 had prior to ignition a resistance value of about 1 Ohm and after ignition a resistance of more than 1000 ohms in about percent of the cases and in the remaining cases a resistance between about 0.5 and 10 Ohms.

The arrangement shown in FIG. 2 operates as followsi When a voltage is applied to the

terminals

20 and 21, first the lamp 22 will ignite, because the circuit of the

lamps

23 and 24 includes resistors (27 and 29). The ignition of the lamp 22 causes fusion of

strips

25 and 30. Owing to the fusion of the strip 25 the lamp 22 is put out of circuit. Owing to the fusion of strip 30 a short-circuit across the lamp 23 is obviated. This means that the lamp 23 is made ready for use. When again a voltage is applied to the

terminals

20 and 21 the lamp 23 is ignited. As a result the lamp 23 gets out of circuit owing to the fusion of the strip 26, whilst owing to the fusion of the strip 31 the short-circuit across the lamp 24 is obviated. When again a voltage is applied to the

terminals

20 and 21 the last lamp 24 is ignited.

When a lamp fails to ignite, both in the arrangement of FIG. 1 and in that of FIG. 2 it can be ensured simply by scratching away one or more fusible strips that the unit can be used further, so that the further lamps can be ignited.

In the case of FIG. 1 the resistor across the lamp 3 may be replaced by a make contact responding to the ignition of the lamp 3.

In a variant of the arrangement of FIG. 2 the

resistors

27 and 29 may be replaced by resistors included in the continuous conductors, forexample, at the positions A and B(see FIG. 2).

What is claimed is:

1. An arrangement for the sequential operation of combustion-type flash light lamps intended for use with a flash-operating camera mechanism comprising:

at least two combustion type lamps connected in a series circuit;

means for flashing said lamps coupled to the outer terminals of said series circuit;

a break contactswitching element being responsive to the energy released by a first lamp of said circuit, and also being connected in shunt arrange-' ment with a second lamp of said circuit, said switching element also being external to said camera mechanism and accessible to a user of said mechanism and adapted to being broken by the user in the event said first lamp fails to flash;

and means for providing a low ohmic value across the terminals of said first lamp after ignition of said first lamp, said low ohmic means being a resistor permanently shunting said first lamp.

2. The arrangement as claimed in claim 1 wherein the resistance value of the lamp prior to ignition being 1 ohm and the value of the shunting resistor being between 0.5 ohms and 6 ohms.

of said circuit, said switching element also being external to said camera mechanism and accessible to a user of said mechanism and adapted to being broken by the user in the event said first lamp fails to flash;

a resistor in series with said second leg for making said second leg of higher ohmic value than said first leg prior to ignition of said first lamp;

and switching means, responsive to the energy released by said first lamp, for opening the circuit of said first leg after ignition of said first lamp.

Claims

1. An arrangement for the sequential operation of combustiontype flash light lamps intended for use with a flash-operating camera mechanism comprising: at least two combustion type lamps connected in a series circuit; means for flashing said lamps coupled to the outer terminals of said series circuit; a break contact switching element being responsive to the energy released by a first lamp of said circuit, and also being connected in shunt arrangement with a second lamp of said circuit, said switching element also being external to said camera mechanism and accessible to a user of said mechanism and adapted to being broken by the user in the event said first lamp fails to flash; and means for providing a low ohmic value across the terminals of said first lamp after ignition of said first lamp, said low ohmic means being a resistor permanently shunting said first lamp.

3. An arrangement for the sequential operation of combustion-type flash light bulbs intended for use with a flash-operating camera mechanism comprising: at least two combustion-type lamps connected in a parallel arrangement including first and second legs; means for flashing said lamps coupled to the outer terminals of said parallel circuit; a break contact switching element responsive to the energy released by a first lamp in said first leg of said circuit and also being connected in shunt arrangement with a second lamp in said second leg of said circuit, said switching element also being external to said camera mechanism and accessible to a user of said mechanism and adapted to being broken by the user in the event said first lamp fails to flash; a resistor in series with said second leg for making said second leg of higher ohmic value than said first leg prior to ignition of said first lamp; and switching means, responsive to the energy released by said first lamp, for opening the circuit of said first leg after ignition of said first lamp.