US1996520A - Sign flasher - Google Patents

Description

April 1935. w. H. MARSHALL, JR 1,996,520

SIGN FLASHER Filed April 12, 1930 2 Sheets-Sheet 1 W/ZZ/AM h- NAPS/74411 auioznuqs April 2, 1935. w MARSHALL, JR 1,996,520

SIGN FLASHER Filed April 12, 1930 2 Sheets-Sheet 2 m; Min

W/ZZ/A/V H MARSH/Ml Patented Apr. 2, 1935 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to means for intermittently flashing an electric sign or the like.

One object of this invention is to provide an improved simplified device for supplying electric current to a sign or other electrical apparatus at regular intervals.

Other objects are to provide a device of this type operated by the current which feeds the sign, and one which is readily adaptable for use with either direct or alternating current; to reduce the moving parts to a minimum; to utilize an electric discharge device as a timing element, and to provide means for adjusting the duration of the current flow and of the intervals therebetween.

Other objects'relating to details of construction and assembly and economies of manufacture will appear hereinafter.

In the accompanying drawings:

Fig. 1 is a circuit diagram of the improved device arranged for operation with direct current.

Fig. 2 is a circuit diagram arranged for operation with alternating current.

Fig. 3 is an elevation of the improved device showing the assembly thereof on a panel.

Referring to Fig. 1 of the drawings, the reference numerals I0 and I I designate, respectively, the positive and the negative input terminals which are adapted to be connected to a direct current supply line such as is ordinarily used to illuminate signs. The main circuit passes directly from the terminals I0 and I I through the fixed and movable contacts I2 and I3, respectively of a relay I4, to the output terminals I5 which are connected to a sign, illustrated diagrammatically as a plurality of incandescent lamps I6.

The relay I4 is controlled through the medium of an electric discharge device I1, illustrated herein as a two element space discharge valve having a filament I8 and a plate IS. The filament circuit is connected to the terminals I0 and II, the negative side directly and the positive side through the contacts I2 and I3 of the relay and a resistance 20 which reduces the line voltage to the correct value for proper operation of the valve IT. The positive side of the plate circuit passes through the windings of the relay I I to the positive input terminal III, the negative side of the filament circuit completing the plate circuit. A variable resistance 2| of any suitable type, illustrated diagrammatically as a rheostat, is shunted across the windings of the relay I4, and a second rheostat 22 is placed in series with the relay windings.

The movable contact I3 of the relay is normally held in circuit closing position against the fixed contact I2 by gravity or a spring of any suitable type. Preferably a condenser 23 is connected across the contacts I2 and I3 to reduce sparking.

When the input terminals I0 and II are connected to the supply line, current flows through the relay contacts I2 and I3 to the sign lamps l6, and through the resistance 20 to the filament l8 of the valve. As the filament heats up, space current begins to fiow to the plate I9 and through the windings of the relay I4. When the space current reaches a predetermined valve, the relay I4 retracts the movable contact l3 and breaks the sign and filament circuits. The plate circuit, however, is unaffected by the relay and the space current continues to flow as the filament cools until, at a pre-determined minimum value, the movable contact I3 returns to circuit closing position and starts another cycle of operations. As shown in Fig. 3, the movable contact I3 of the relay is carried by a spring arm 24 connected to a pivoted armature 25. The fixed contact I2 is carried by a screw 26 mounted on the base for adjustment toward or away from the relay magnets. The spring mounting of the contact I3 prevents flickering of the sign when the circuit is broken, since the initial weak space currents, which may move the armature slightly, do not interrupt the circuit.

The force required to hold the armature in raised position is less than the force required to initially lift the same, since the efiect of the magnetic flux varies inversely as the square of the distance. This difierential measures the time during which the sign circuit is broken, and can be adjusted as desired by varying the position of the fixed contact I2 with respect to the relay magnets. The rheostat 22 controls the resistance of the plate circuit, and the rheostat 2| controls the proportion of the space current which passes through the relay windings. Adjustment of these rheostats varies the length of time the sign circuit is closed and the interval between flashes. It will thus be seen that the timing of the device can be adjusted at will within wide limits.

Fig. 2 illustrates the circuit diagram of the device designed for operation on alternating current. In this form the input terminals ID are connected through the relay contacts I2 and I3 to the sign lamps I6 as in Fig. 1.

l8 of the valve I1 is fed at the proper voltage by the secondary windings of a step-down transformer 21, the primary windings of which are connected to the input terminals I0 through the contacts I2 and I3. The plate circuit passes The filament r vice is facilitated, since the through the windings of the relay [4 to one side of the supply line, and through a center tap on the secondary of the transformer 21 to the other side of the supply line. Since the relay contacts l2 and I3 carry alternating current, the condenser 23 is connected across the relay windings, instead of across the contacts.

In this form of the device, the valve H rectifies the space current to provide direct current for operating the relay. In other respects the operation is substantially identical with the operation of the direct current circuit illustrated in Fig. 1.

In manufacturing the devices the elements are preferably assembled on a suitable base or panel, as illustrated in Fig. 3. In the alternating current type the transformer 21 is installed in place of the resistance 26 and the wiring rearranged slightly to accommodate the transformer and connect the condenser 23 across the-relay windings. It will accordingly be seen that the manufacture and assembly of the two types of the departs are largely interchangeable. I

An important feature of the invention resides in the fact that the direct current circuit, as

shown in Fig. 1, may also be operated satisfactorily by alternating current, since the resistance 20 will reduce the voltage of either direct 'or alternating current. Where alternating current 1s to be employed exclusively, however, the

transformer is preferable, being less subject to heating and occupying less space than the resistance. I g

Although the foregoing description is neces- V sarily of a detailed characterin order that the invention may be fully set forth, it is to be understood that various modifications and rearrangements of parts may be resorted to without departing from the spirit or scope of the invention as defined in the following claims.

I claim:

1. In a sign flasher arranged to intermittently make and break the electric current for a sign or the like and to be actuated by such current, the combination of a relay having windings and armature controlled contacts, a sign load circuit passing through the contacts of said relay, an electrical discharge device including a filament with an appreciable temperature lag and an' anode, a circuit for heating said filament passing :through the contacts of said relay, a circuit passing through the windings of said relay and between said filament and said anode, all of said circuits being in parallel to receive current from a single source.

2. In a sign flasher arranged to intermittently make and break the electric current for a sign or the like and to be actuated by such current, the combination of a relay having windings and an armature controlled circuit breaker, a sign load circuit passing through the circuit breaker of said relay and adapted to be connected to a source of electric current, an electrical discharge device having an anode and a filament cathode with an appreciable temperature lag, a cathode heating circuit passing through the circuit breaker of said relay, and an anode-cathode circuit passing through the windings of said relay, and an adjustable resistor shunted across the windings of said relay to control the proportion of current in the anode-cathode circuit which passes through the windings of the relay.

3. In a sign flasher arranged to intermittently make and break the electric current for a sign or the like and to be actuated by such current, the combination of a relay having windings and an armature controlled circuit breaker, a sign load circuit passing through the circuit breaker of said relay and adapted to be connected to a source of electric current, an electric discharge device having an anode and a filament cathode with an appreciable temperature lag, a cathode heating circuit passing through the circuit breakerof said relay, and an anode-cathode circuit passing through the windings of said relay, and an adjustable resistor in series with the windings of said relay for varying the resistance thereof.

4. In a sign flasher arranged to intermittently make and break the electric current for a sign or the like and to be actuated by such current, the combination of a direct current relay having windings and an armature controlled circuit breaker, a sign load circuit passing through the circuit breaker of said relay and adapted to be connected to a source of alternating current, an

electric discharge device having an anode and a filament cathode with an appreciable temperature lag, a circuit for heating said cathode energized by said source of alternating current in parallel with said load circuit and passing through the circuit breaker of said relay and an anodecathode circuit passing through the windings of said relay and connected to said source of alternating current to rectify the same to actuate said relay.

5. In a sign flasher arranged to intermittently make and break the electric current fora sign or the like and to be actuated by such current, the

combination of a relay having windings and arma-

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