US2002804A - Circuit controlling device - Google Patents

Description

' May 28, 1935.

C. F. WALLACE CIIRCUIT CONTROLLING DEVICE Original Filed Aug. 29, l92'7// 3 Sheets-Sheebl I; A TTORNEY May 28, 1935. c. F. WALLACE CIRCUIT CONTROLLING DEVICE Original Filed Aug. 29, 1927 3 Sheets-Sheet 2 1.3, QTTOR-NEY y 8, 1935. c. F. WALLACE 2,002,804

CIRCUIT CONTROLLING DEVICE- Original Filed Aug. 29, 1927 5 Sheets-Sheet 3 QHYVENTUR I; A TTORNE Y Patented May 28, 1935 UNITED STATES PATENT OFFICE CIRCUIT CONTROLLING DEVICE Original application August 29, 1927, Serial No.

216,080. Divided and this application August 11, 1933, Serial No. 684,631

4 Claims.

This invention relates to circuit controlling devices, and more particularly to devices for intermittently closing and opening an electric circuit, such, for example, as the feed circuit of a lamp used in a signal device of flash-beacon type.

It is an object of the present invention to provide simple but reliably operative means for causing periodic circuit closure with a minimum of surface friction and with a minimum net loss of energy in the actuating means.

As many flash-beacon signals are located in remote places where they are dependent on battery operation, and frequently on dry batteries, it is important that the apparatus be constructed to operate with a low consumption of current. In the flash-beacon of my application Serial No. 216,080, filed August 29, 1927, of which this is a division, the duration of each flash is very short, and as the actuating devices or circuit controls operate with small demand on the source of electrical energy, the apparatus may stand in operation for long periods of time without attention. The present invention is, therefore, particularly suited to meet the requirements of flash-beacon signals, although, obviously, it may serve other purposes.

To demonstrate the relation of the general principle of the invention to a specific condition, the invention is shown in the drawings and is hereinafter described in connection with the electromagnetic pendulum control of the flashing-light signal system of my said application Serial No. 216,080.

In the drawings:

Fig. 1 is a back elevation of a signal device embodying the invention, with the back cover broken away;

Fig. 2 is a side elevation with the casing sectioned on the line 2-2 of Fig. 1 and its rear portion cut away;

Figs. 3, 4 and 5 are enlarged detail views showing the positions of the pendulum and trip bar shown in Fig. 1 at various different times during the operation of the device;

Fig. 6 is a side elevation of the light carrier which is shown from the other side in Fig. 2;

Fig. 7 is a plan View of the light carrier partly sectioned on the line 1| of Fig. 6;

Figs. 8 and 9 are enlarged fragmentary back elevations showing different positions of the switch operating mechanism shown in Fig. 1;

Fig. 10 is a diagram of the electric connections of the device; and

Fig. 11 (on Sheet 1) is an enlarged fragmentary vertical section taken on the line l|-ll of Fig. 6 showing the lamp contact mechanism.

The signal device illustrated in Figs. 1 to 11 has a casing It] provided with a removable back cover H. In the upper part of the front wall of the casing is a window l2 behind which is a parabolic reflector [3 having a vertical slot 14 in its central portion. The working parts of the device are supported from a main bracket 15 which is rigidly held in the central portion of the casing by bars I6 secured to posts I! projecting inwardly from the front wall of the casing.

The signal device is provided with a movable 'lamp carrier 20, which can be made to carry any desired number of incandescent electric lamps Zia, Zlb, etc. A pair of electric terminals 22, 23am so arranged that the movement of the carrier 20 causes the electric lamps to be successively connected in a lighting circuit. The carrier 20 is in the form of a wheel having a shaft 24 journaled in two posts 25 rising from the top of the main bracket [5. The shaft 24 and the inner portion 26 of the wheel are of conducting material, while one side and the periphery of the wheel are made of insulating material 21. Lamp sockets 28 are secured about the periphery of the portion 21, and the inner terminal 29 of each socket is insulated from the side wall of the socket and is connected by a screw with the conducting portion 26 of the wheel and is thus grounded through the shaft to the bracket, so that in this instance the terminal 23 is the grounded metallic portion of the wheel 20. To the peripheral portion of each socket is connected a wire 30 which extends radially inward along the insulated face of the wheel. The wire 30 of each lamp comes in contact with the spring terminal 22 when the lamp is positioned at the focus of the reflector 13. Thus, when the lamp carrier 20 is rotated, the lamps are successively brought into the focus of the reflector and into circuit between the terminals 22 and 23.

The device has an oscillating member, which most desirably and as shown is a magnetic pendulum 40 formed by a U-shaped bar 4| magnetized in its lower central portion as indicated on Fig. 1 and supported by a transverse bar 42, which has secured at its center a thin upwardly projecting plate 43 by which the pendulum is suspended from staples 44 projecting downwardly from a plate 45 secured to the top of the main bracket 15, the staples passing through openings in the plate 43. The bearing provided by the staples 44 in the plate 43 is located above the center of gravity of the pendulum but considerably below its upper end, the pendulum being a compound pendulum and being proportioned according to the period of oscillation desired.

A fixed coil bil surrounds the lower magnetized part of the bar l! of the pendulum, and the ends El, 52 of this coil are connected respectively with the terminals'22 and 23 (see Fig. 10) The end 5i of the coil is secured to a binding post 53 mounted on an insulating bar 54 carried by the main bracket, and this post is connected by a conductor 55 to the terminal'ZZ. The end 52 of the coil is grounded to the main bracket, and is thus connected to the grounded lamp terminal 23. Consequently, when the filament of theelectric lamp 2m is intact, the coil 55 is in a closed circuit. Under these circumstances, the oscillae tion of the pendulum ii; moving the magnet bar M to and fro through the coil generates a flow of electric current through the coil and its close circuit, and the energy thus dissipated is, of course, fdrawn from "the kinetic energy of the pendulum. Consequently, when a small properly timed force is applied to the pendulum tosustain its-oscillation, the amplitude of its oscillation is less when the circuit containingrthe coil 59 is closed than when the coil is open-circuited.

With the magnetic" pendulum it and the damping coil 59 in series with the active lamp are combined means for utilizing the large amplitude oscillation of the pendulum, which occurs when the damping coil 50 is open-circuited by the burning out of the filament in the lamp for the purpose of removing the burned out lamp and replacing it with a new one whose filament is intact.

Such means include,in the form shown, a rigid double bar 6!! depending from the cross-piece 52 ofthe pendulum, and carrying a projecting pin '55, and ale'ver 62 pivoted on a pin 63 extending between the main bracket and a vertical plate fi fixed on posts 65 secured to the main bracket. The lever 62 has at its free end a hanging trip bar 66 provided with a shoulder 6? which is at a lower level than the pin 61 when the bar hangs vertically. A rod 58 limits downward turning of the lever 62. The trip bar E6 hangs close to the pin 6! projecting from the depending bar 68, as shown in Fig. 1, and the shoulder Bl is so positioned .that'with only a normal amplitude oscillation of the pendulum, such as occurs when the coil5fl is in closed circuit, the pin 6! does not move under the shoulder 61 but merely strikes the side of the trip bar 66 as shown in Fig. 3.

' When, however, the filament of the lamp burns out, open-circuiting the coil 51], and the amplitude of the oscillation of the pendulum becomes greater, the pin 6! in its left-hand swing moves far enough to enter under the shoulder El as shown in Fig. 4, so that as the pendulum and pin start back towards the right, the pin raises the shoulder 6'5, thereby lifting the trip bar 66, and tipping up the free end of the lever 62 as shown in Fig. 5.

" The tipping up of the lever 62 may be used in various difierent ways to actuate the lamp carrier 29 so as to move the burnt out lamp away from the terminal 22, and to bring the next lamp into contact with it. In the form shown in Fig. l,'the lever 62 is connected by the rod with a leveri 59 pivoted on the shaft 2d and having a downwardly extending arm 69' abutting a pin til" projecting from the post 25. The

. lever $9 carries a pawl lilwhich engages a ratchet wheel lljiixed on the lainpcarrier 2d. The movements'of the leverjfiz, which occur on the large 1 amplitude swings-of the pendulum'after the fila- 6? and the movement of the carrier 26 stops.

The carrier then remains stationary until the filament of the active lamp is burnt out or broken.-

A part of the abovedescribed means for damping the oscillation of the pendulum may be utilized-as a means for sustaining the oscillation of the pendulum 3Q. This is accomplished by caus-.

ing a momentary flow of electric current through the coil 59 on each oscillation of the pendulum in such a direction that the action of the coil as a solenoid tends to accelerate the movement which the pendulum has at the time. A source of electromotive force, such as the: battery 89 shown diagrammatically in Fig. '10, has one of its terminals connected by a wire 8! to the binding post 53 and thus'to the end 5! of the coil 5%. The other terminal of the battery is grounded to the main bracket i5 through a wire 82, binding post 83, wire 86 and switch 35, so that when the switch is closed this terminal of the battery is connected through ground to the end 52 of the coil 55. The switch 85 has a fixed insulated con tact 86, and a movable contact 8'! formed by a leafspring fixed at its outer end" in a block il mounted on the plate 54 and thus grounded to the main bracket. The binding post 33 is mounted on theinsulating bar 5 5.

The switch 85 is closed at a predetermined point of eachoscillation of the pendulum'through the engagement ofthe spring contact 8? by a quadrant-shaped member 90 carried on the lower end of the 'double bar 6!) of the pendulum. The quadrant-shaped engaging member at is pivot ally mounted to turn freely on an axis 9i extending across the lower end' of the doublebar 6E and is normally held in the position shown in Figlby a light coiled spring ElZ. each swing of the pendulum toward the left in Fig. l, the concentrically curved edge 93. of the member engages the upwardly turned end of the leaf spring 8? and then, as the movement of the pendulum continues, the member 95 turns on its pivot without changing its point of contact with the end of the spring and depresses the spring into contact with the fixed contact member 86, as shown in Fig. 9. There is thus no rubbing frictionbetweenthe pendulum and the movable contact member -of the switch, and the retardation of the pendulum which would result from such rubbing contact is avoided. The energy expended by the pendulum in depressing the spring through the rolling contact of the member 9!] with the end ofthe spring is, at least largely, returned to the'pendulum by the pressure of the end of the spring against the member 953 after the axis of the member 9!] has passed beyond the line extending from the end of the spring at right angles tothe direction of movement of said axis.

\Whell' the continued movement of the pendulum spring without depressing it, and, because of the very light force exerted by the coil spring 9!, this engagement of the member 59 with the end of the contact spring oifers very little resistance to the movement of the pendulum.

The source of electromotive force and the switch are used to cause flashing of the lamp which is in operating position. This is accomplished by means of the connections already described, since when the switch is closed, one terminal of the battery is connected with the terminals 29 of the lamp sockets through wires 82 and 84, the switch the main bracket and t re metallic portion of the lamp carrier which forms the grounded lamp terminal 23, while the other terminal of the battery is permanently connected with the lamp terminal 22 through the wire L-l and conductor 55. Therefore, when the switch 85 is closed, current from the battery flows through both the coil 55 and the lamp filament in parallel. The coil is of relatively high resistance compared. to the lamp, so that only a small part of the current flows through the coil.

The battery or other source of electromotive force may be of higher voltage than that for which the filament of the lamp is intended and the application of this voltage to the lamp be cut ofi so quickly that the filament is not heated beyond its normal operative temperature. The use of the higher voltage reduces the time required to heat the lamp filament to the desired brilliancy, and the total period of time during which the current flows through the lamp is extremely short. I have ascertained that by this expedient the normal length of life of both the lamp and the battery may be increased, while at the same time the flashes although very brief may be of strong intensity so as to serve as an eifective signal. A very high efficiency is thus secured, a d sired signal light being secured at a very low lamp and battery cost. Regulation of the length of time during which the switch 85 is closed on each oscillation of the pendulum is accomplished in the construction shown by adjustment of the position or" the fixed contact 85 of the switch. To provide for such adjustment, the contact 85 is made in the form of a screw set in threaded openings in two tabs extending from an insulated plate 9.5. in order that the contact screw shall be held in its position of adjustment, the tabs 9% after their openings are tapped are slightly relatively upset before the contact screw is inserted.

If the voltage of the battery drops due to use, the pendulum will swing at a smaller amplitude and lower speed and the switch member 8? will be held closed for a longer period, thus compensating for the lower voltage applied to the lamp and preventing the drop in brilliancy oi flash which would otherwise result from the drop in voltage of the battery.

It will be seen that the invention provides an electric circuit control which is particularly suited to use with battery-operated flash beacons and especially those employing a dampened pendulum action. On the other hand, it will be obvious that the controlling device may be of general application serving to make and interrupt a circuit with slight demand on the power source and in a manner which regulates itself favorably to the de-. crease in energy at said source.

What is claimed is:

1. A circuit controlling device, comprising a normally open switch having a movable member, an oscillating member, and an engaging member pivotally mounted on the oscillating member and shaped and normally positioned to engage the movable switch member and to turn while in engagemcnt therewith to maintain a fixed point of engagement with the switch member and to move the switch to close the switch on the movement of the oscillating member in one direction and on engagement with the switch member on the movement or" the oscillating member in the other direction to turn and pass over the switch men: or without moving it to close the switch.

2. A circuit controlling device, comprising a normally open switch having a movable member, an oscillating member, a quadrant-shaped engaging member pivotally mounted on the oscillating member, and a light coiled spring tending to hold the engaging member in position such that its concentric surface comes into engagement with the movable switch member on the movement of the oscillating member in one direction and one a of its radial surfaces comes into engagement with the movable switch member on the movement of the oscillating member in the other direction, the en aging member being free to turn in either direction against the light resistance of its spring from its normal position in which the spring tends to hold it.

3. In a circuit controlling device, the combination with an oscillating member and a movable switch member to be operated thereby, of an engaging element pivotally mounted on one of said members, and a spring normally positioning said engaging element to engage the other member when the oscillating member is swinging in one direction, the engaging parts being shaped and relatively positioned to cause pivotal movement of the engaging element and bodily movement of the movable member while maintaining a fixed point of engagement between them during con tinned swing of the oscillating member in said direction, and said engaging element being freely pivotally movable to turn and pass said other member without moving it when the oscillating member swings in the opposite direction.

4.. In a circuit controlling device, the combine. tion with a moving member and a movable switch member, of an engaging element pivotally mounted on one of said members and shaped and yieldingly held on its pivot normally in position to engage the other member and being free to turn in engagement with said other member to maintain a fixed point of engagem nt therewith, thereby to move the movable member during continued movement of the moving member.

CHARLES F. WALLACE.

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