US 2213584 A
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Description (OCR text may contain errors)
Sept 3, 1940- c. P. HuLs'r 2,213,584
EMERGENCY EXIT LIGHT Filed Aug. 19, 1937 2 sneek-sheet 1 ,e gh- 7m., u I
ATTO R N EY Sept. 3, 1940. c. P. HULST' 2,213,584
EMERGENCY EXIT LIGHT Filed Aug. 19, 1937 2 Sheets-Sheet 2 ATToRNEYS Patented Sept. 3, 1940 t UNITED STATES PATENT OFFICE EMERGENCY Exrr I .IGH'El Clarence P. Hulst, New York, N. Y. l Application August 19,1937, serial No. 159,838
This invention relates to improvements in emergency exit lighting units, and more particularly to such units in which a normal lighting apparatus is provided in a cabinet or fixture, tolgether with an .emergency lighting unit adapted to function automatically when the normal lighting unit or system fails, and to a system of such units. In certain aspects the invention constitutes an improvement over my pending application, Serial No. 30,676, led July 10, 1935, now
Patent Number 2,097,236.
It is an object of this invention to provide emergency lighting units and a system of such units adapted primarily for use in places of public assembly, such as theatres, and in public buildings in which exit lights are employed, and such that the emergency lights will be brought into action automatically upon current failure, which may happen typically in the event of fire or other catastrophe, or failure of a power plant or other source of current. It is a further object of the invention to provide such units and such a system characterized by simplicity of construction and reliability of operation and such that the emergency lighting system will not be brought into play or affected by the normal turning on and off of switches involved in the usual regulation of the normal lighting circuit or circuits.
Still further objects of the invention will be :i0 made apparent from the following full description.
With these and other objects in view, the invention consists in the features, combinations, details of construction and arrangements of parts which will rst be described in connection with the accompanying drawings and then more particularly pointed out in the appended claims.
In the drawings, Figure l is a front elevation of a cabinet or fixture embodying the invention in a 10 preferred form;
Figure 2 is a section taken on the line 2-2 of Figure 1 and on a larger scale;v
Figure 3 is a front elevation similar to Figure 1 but with the front door or cover of the fixture opened to reveal the interior parts;
Figure 4 is a schematic circuit diagram of the device of Figures 1 to 3 and showing the mode of connection of one or more of these devices with the wiring circuits of a regular lighting system;
Figure 5 is a front elevation of a modification also embodying the invention;
Figure 6 is a front elevation of the device of Figure 5 with the front door or cover opened to reveal the interior; and
Figure 7 'is a section taken on the line .'I-'I of Figure 5.
Referring now\to Figures l to 4, inclusive, the device comprises a fixture designated generally by thenumeral I and including a cabinet made up 5 of a top 2, a bottom 3, a back 4 and side walls 5. Positioned on this cabinet is a front door or cover member 6 removably secured thereto as by hinges I and provided with locking means such as staple 8 upon the cabinet body` and hasp 9 upon the door 10 6. The fixture as a whole may be fastened to a wall in any usual manner, as by screws or bolts passing through its back 4.
The doorf6 is provided with a cutout portion I0 (Figures 1 and 2) adapted to show an illuminated 15 exit sign lighted from the interior and a second cutout II, this being shown as circular in form and adapted to direct light from an emergency spotlight in a manner to be later described. In back of cutout I0 is secured a panel I2 of glass or 20 other transparent material secured to the door as by clips I3 and whichincludes clear or ground glass portions I4 forming the word Exit and is elsewhere colored red as at I5 in the usual manner. Irr back of cutout I I and held by similar 25 clips I3 is a plate I6 preferably of glass, having a clear portion I1 coinciding with cutout II to form a window and being elsewhere mirrored as at I8, for a purpose later to be described. l
Within the cabinet I and attached to side walls 30 5, as shown, are a pair of light sockets I9 which hold a pair of lights 20 operated from the normal lighting circuit and designed to illuminate the exit sign already described. These lights are connected in parallel by wires 2I to a plug 22 3.- attached to the top 2 of the casing I and are connected to external current supply wires 23 in the usual manner, as shown in the circuit Vdiagram of Figure 4.
Included also in casing I is an emergency lighting unit comprising a bulb 24 in a socket 25 provided with a mirrored reflector 26 which is advantageously of parabolic form and such as to locate the iilament of light 24 approximately at its focus. This socket 25 is mounted by means of a ball and socket or universal joint 2l on the back wall 4 of the casing and is adapted thereby to be moved in any direction. The normal position of this light and reflector is indicated in dotted lines in Figure 2 and is such as to direct light from 50 bulb 24 through cutout I I in an outward and generally downward direction. By these means the light 24 can be made to illuminate a path from six to twenty or more feet leading toward the xture and the xture will typically be placed in a 55 theatre or building so that this lighted path extends down an aisle or other passage and serves to light the way toward an exit..
In certain cases it may be desired to cast a light downward or to the side of the flxture, as where it is desired to illuminate a door, and in such event the cutout may be positioned in a side wall or the bottom of the cabinet and socket turned in the desired direction.
Current is provided for light 24 by a pair of batteries 28 connected in seriesand held inthe casing las by clips 29. The batteries 28 are connected in series with each other and with light 24 by wires 30 and are in turn in series with a snap switch 3| and a relay 32, the binding posts for the controlled circuit of this relay or circuit, which includes switch 3|, batteries 28 and light 24, being designated by numerals 33. The control or maintaining circuit for relay 32 is connected to binding posts 34 and 35 or 36. As shown, the relay is connected for D. C. operation, the wires 31, which terminate in plug 38, being connected to binding posts 34 and 35. In this mode of connection a resistance unit of about 2,000 ohms is in series with the windings of the relay, which are also of about 2,000 ohms D. C. resistance, in a well known manner so that a direct current of 110 volts will deliver about 3 watts to the relay. Plug 38 is connected through wires forming a continuation of wires 31 to the main pwel of the building, asvshown in Figure 4, and to be later described more fully. When the device is employed for 110 volt, 60 cycle A. C. operation, binding post will be used instead of binding post 36, cutting out the 2,000 ohm resistance, as the 60 cycle A. C. impedance of the relay windings themselves is designed for about 4,000 ohms.
Relay 32 is designed to open a circuit between binding posts 33 when its winding is energized and in consequence when wires 31 have current flowing through them the circuit for light 24 is open and this light is out of operation. This is the normal condition when current is being supplied to the main panel, and the regular lights 20 may be lighted so as to illuminate the exit sign. If, however, due to accidental causes, the current at the main panel is interrupted, relay 32 will be cle-energized, closing a circuit between binding posts 33 and supplying light 24 with current from batteries 28. Light 24 then serves both to illuminate the exit sign panel I4, |5, and to direct light through aperture Il in the manner reviously explained.
As indicated in Figure 2, and in phantom in Figure 3, an internal cover plate 39 held removably in grooves 40 is provided and this covers part of the wires 2| and- 30 and also the relay 32 and switch 3|. On the bottom of the'casing is positioned a reflector surface 4|, preferably mirrored and extending between batteries 28 in one direction and from the back wall 4 to the door 6 in the other direction. Mirrors I8 and 4I serve to reflect light from bulb 24 backwardly and upwardly and to assist this reflection of light the reflector 26 is preferably designed so as to form a cone of light slightly greater in diameter than aperture II and striking an. annular area of mirror I3 surrounding the same. The back wall *4, or its lower portion which is not covered by cover plate 39, and side walls 5 and cover plate 39 are preferably painted with white paint or otherwise provided with a diffuse reecting surface. In consequence of this arrangement light from bulb 24 will be reflected-by mirrors I8 and 4| and reflected and diffused by walls 4 and 5 and cover plate 4|, so as to illuminate the exit sign in a sufllciently uniform manner. If it should be desired to place the emergency light 24 out of operation for any reason switch 3| may be opened.
Important features of the fixture of this invention are the provision of mirrored and diffuse refleeting surfaces as described, resulting in a strong and suiiiciently uniform illumination of the exit light by both the regular lighting bulbs 28 and the emergency lighting bulb 24 and also the employment of the single exit sign for illumination by both the regular lighting bulbs 20 and the emergency lighting bulb 24, which results in great compactness and the elimination of surplus parts.
Apart from the various features of the cabinet or xture of the invention, considered by itself, an important phase of the invention is that having to do with the manner of connecting such a xf ture to the building circuits, and more particularly with the manner of connecting a number of such fixtures. As shown in the circuit diagram of Figure 4, the wires 23 supplying the normal lights for the' wall xture I are connected to main power lines 42, typically located at a main control panel for the building, through control means such as double pole single throw switch 43. The wires 31, which form a maintaining cireuit for the relay 32, are connected at a point beyond the control means for the normal lighting system.
In consequence of this arrangement the emergency lighting system will be unaffected by operation of the control means (switch 43) of the normal lighting system, and will be brought into operation only by current failure in the main supply Wires 42. Where a plurality of units is employed, the relay maintaining circuits of all will be connected in parallel to main supply wires 42, and the normal lighting system of all will be connected in parallel through appropriate control meansto these supply wires. This mode o f connection is sufliciently indicated by wires 31'L and 2| which are to be understood, respectively, as the relay maintaining wires and the normal lighting'system wires leading to a second cabinet similar to the cabinet As will be readily understood, the showing of a single switch 43 as the control means of the regular lighting systems of a plurality of units is merely illustrative. A number of switches for controlling banks of units or single units may be employed, the important feature being the connection of the relay maintaining circuits to the power supply lines at a point or points beyond the control means normally used for regulating the normal lighting systems of the various units. The employment o-f the circuit arrangement of the present invention results in the emergency lighting systems being unaffected by regulation of the normal lighting systems, failure of the bulbs of such systems or blowing of any fuse, circuit breakers or the like provided for such systems beyond their ultimate point of normal control. On the other hand, should a main fuse blow or should current supply for the main panel of the building be interrupted due to power-house failure, the emergency lighting systems will be brought into operation.
As is apparent from the foregoing description,
on of a current but by the interruption of a current, which is a more reliable method, and has the further advantage that the slight heat generated in the relay by a constant consumption of about 3 watts of power serves to heat the interior of the cabinet slightly, maintaining the air therein in warm condition with low relative humidity, so that frosting or the formation of mist upon transparent surfaces is avoided and the electrical apparatus within the cabinet is maintained in good condition for long periods of time.
An alternative construction of the cabinet is disclosed in Figures to 7. The lighting elements. batteries, relay and the like, in this construction may befand are shown as, generally identical with those of the embodiment of Figures 1 to 4 and are designated by the same numerals with the addition of a prime suffix. Their general mode of attachment and position is the same, the lights 20 and their sockets I9 being shown, however, as attached to back wall I' instead of to side walls 5', this location being more advantageous due to the fact that the cabinet is elongated horizontally and shallower in the vertical direction. In this construction the front door 6 is provided with a single aperture ID' and a single glass plate I2 is held in back of this aperture by clips I 3'.' Plate I2 includes clear or ground glass portions I4. defining the word Exit as before and a red coated portion I5' in which, however, is located a clear glass portion I1', no separate aperture, such as Il in Figure 1, being provided for this. As the exit sign and the clear glass portion I1' occupy practically the whole of the front door 6' in this embodiment, no mirror corresponding to mirror I8 of the embodiment of Figures 1 to 4 is provided, but a mirror 4I', similar to the mirror 4I, is employed and the walls 5', 4' and the cover 39' are of similar construction to corresponding parts of the embodiment of Figures 1 to 4 andare similarly rendered diifusely reflecting. The relay and switch therefor in the embodiment of Figure 7 and the connections between parts are not illustrated as they are largely obscured by cover plate 39' and are identical with corresponding parts and connections of the embodiment of Figures 1 to 4. y
In some cases an exit light sign is formed of clear or translucent letters surrounded by an opaque plate. As will be readily appreciated, the transparent panel of the present invention may take such form in either embodiment shown without variation in other features of the invention.
What is claimed is: p
1. An exit lighting fixture comprising a cabinet containing a light for normal operation and including a transparent front panel positioned for illumination by said light, said cabinet containing also an emergency light and batteries therefor and a relay adapted to close a' circuit from said batteries to said light when de-energized and to open said last namedlcircuit when energized, a clear window in said cabinet adapted to pass a beam of light from said emergency light, and lower reflecting surfaces within said cabinet and diffuse reflecting upper and side surfaces within said cabinet for illuminating said panel from said emergency light.
2. An exit lighting system comprising a cabinet containing a light for normal operation and an emergency light, means for turning on said emergency light upon failure of current supply to said first mentioned light, a transparent front panel in said cabinet positioned for illumination by said first named light, a clear window below said panel, means to direct light from said emergency light through and around said window in a downward direction, a mirrored surface inside said cabinet and surrounding said window and a mirrored surface on the bottom of said cabinet, and diffuse reflecting surfaces along the inner sides, back and top of said cabinet.
CLARENCE P. HULST.