US2699538A

US2699538A - Smoke detection system and apparatus

Info

Publication number: US2699538A
Application number: US370373A
Authority: US
Inventors: Howard G Nickel
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-07-27
Filing date: 1953-07-27
Publication date: 1955-01-11
Anticipated expiration: 1972-01-11

Description

Jan. 11, 1955 H. G. NICKEL SMOKE DETECTION SYSTEM AND APPARATUS 2 Sheets-Sheet 1 Filed July 27, 1953 INVENTOI? HOWARD G. NICKEL.

ATTORNEY Jan. 11, 1955 2,699,538

SMOKE DETECTION SYSTEM AND APPARATUS Filed July 27, 1953 2 Sheets-Sheet 2 Fla; 2

/Q O Q C L D FIG. 3

46 I02 I02 7 /06 1 law- I/VVE/VTU/P HOWARD G.N/CKEL. BY

A TTOR/VE Y United States Patent SMOKE DETECTION SYSTEM AND APPARATUS Howard G. Nickel, Battle Mountain, Nev.

Application July 27, 1953, Serial No. 370,373

1 Claim. (Cl. 340-237) This invention relates to automatic alarm devices, and more particularly to an automatic system and apparatus for detecting the presence of smoke and actuating an alarm to indicate the presence of smoke.

Many lives are lost from the effects of breathing smoke, rather than due to the fire from which the smoke originated. It frequently happens that thermostatic controls which are intended to indicate the presence of a fire are not actuated by the presence of smoke, and persons subjected to the smoke perish before the thermostatic type of fire alarm is actuated. Smoke detection devices of the photoelectric type are also shown, but such systems generally use only a single light source and frequently have no means of indicating failure of the single light source or failure of the energization circuit of the photoelectric relay itself.

Accordingly, it is an object of this invention to provide a smoke detection system in which all parts of a building are in communication with a smoke detection apparatus.

It is a further object of this invention to provide an improved smoke detection apparatus of the photoelectric detection type which actuates an alarm upon the presence of smoke.

It is a still further object of this invention to provide a smoke detection apparatus using photoelectric detection means and having an emergency light source which is automatically switched into circuit upon failure of the normal light source for the photoelectric detection device.

It is another object of this invention to provide an automatic photoelectric smoke detection system in which a warning signal or trouble light is actuated whenever the normal light source for the photoelectric device fails, the photoelectric detection system becomes inoperative due to failure of the photoelectric relay.

In accordance with these objectives, this invention provides a smoke detection apparatus in which smoke is carried by ducts having inlets in various parts of the building to a housing for the smoke detection apparatus which is located at the highest level of the building, such as in the attic, for example. The smoke detection apparatus comprises a photoelectric cell and a light source which is directed toward the photoelectric cell, subject to interruption by the presence of smoke conducted through the ducts to the housing of the detection system. An emergency light source is provided which is automatically switched into circuit upon failure of the normal light source. Means are also provided to energize a warning signal, such as a trouble light to indicate either a failure of the normal light source or an operating failure of the photoelectric detection system.

The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention itself, both as to its organization and use, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a perspective view of the general arrangement of a smoke detection system in accordance with the invention, showing the housing for the photoelectric detection device and the ducts which carry the smoke to the housing;

Fig. 2 is an enlarged detail view showing a light fixture having inlets for conducting smoke to a duct which leads to the smoke detection device housing; and

Fig. 3 is an electrical circuit diagram showing the electrical control system for the photoelectric smoke detec-- tion system in accordance with the invention.

Referring now to the drawing, there is shown in Fig. 1 a housing generally indicated at 10 for the smoke detection apparatus. The housing 10 is shown in exaggerated size in the drawing for purposes of clarity and is shown positioned at the uppermost part of the building or house having the smoke detection system. Thus, in the view of Fig. 1, the smoke detection housing 10 is shown located in the attic of a house. The housing 10 is preferably divided into three compartments, one of which, indicated at 12, houses the electrical components, such as the relays which will be described hereinafter. The intermediate compartment 14 is the smoke chamber through which the smoke passes, and compartment 16, which is separated from compartment 14 by a wall 18 having an aperture 19, houses the photoelectric relay means generally indicated at 20. The housing 10 is of leak-proof construction so that any smoke passing into the smoke chamber 14 will pass out only through the outlet duct 30.

The smoke chamber 14 is connected to an inlet duct 22 which conducts anysmoke which may be present in the building or houseto the smoke chamber 14. The inlet duct 22 is connected to auxiliary ducts 24 which communicate with various parts of the building, such as, for example, each room in the house if the building is a house. The auxiliary ducts 24 may be connected in the manner shown in Fig. 2 in which an auxiliary duct 24 is shown connected to a light fixture 26 provided with circumferentially arranged port holes 28 through which duct 24 and the duct 22 due to natural draft until the" smoke finally reaches the smoke chamber 14. An outlet duct 30 to the outside atmosphere communicates with the upper portion of the smoke chamber 14, being disposed at the opposite side of the chamber to the location of the inlet duct 22 and adjacent the wall 18, so that the natural path of the smoke in passing through chamber 14 to the outlet duct 30 is from one side to the other of the smoke chamber 14. A draft regulator 32 is provided in the upper portion of the outlet duct 30 to permit adjustment of the draft as desired.

A light source is provided in the smoke chamber 14 in the form of two small electric light bulbs or

lamps

34 and 36. Lamp 34 is the normal light source and lamp 36 is the emergency light source. Each of these lamps may be, for example, 6 watt light bulbs, and may be provided with swivel masking shades which may be adjusted to control the amount of light directed from either of the

light bulbs

34 or 36 to the photoelectric relay device 20 in the compartment 16. A suitable lens 37 is positioned adjacent each of the

light bulbs

34 and 36 in the path of the rays emitted from the respective bulbs to direct the light rays toward the photoelectric relay means 20. The wall 18 which divides smoke compartment 14 from the photoelectric relay compartment 16 is provided with an aperture 19 through which light rays from either the normal light source 34 or the emergency'light source 36' pass to the photoelectric relay means 20.

It will be seen that whenever smoke occurs anywhere Within the building provided with the illustrated smoke detection system, the smoke is conducted through the

ducts

22 and 24 to the smoke chamber 14 of the housing 10. The smoke will pass out of the inlet duct 22 and pass across the chamber 14 to the outlet duct 30. In so doing, the smoke will interrupt the light rays from the normal light source 34 or the emergency light source 36.

in such manner as to affect the condition of the photoelectric cell of. the photoelectric relay means 20.

for example, may exist between

line

42 and 44, or between line 46 and line 44, with a difference of potential of 220 volts existing between the

outer lines

42 and 46.

The normal light source 34 for the photoelectric relay is connected across the

outer power lines

42 and 46 in series with the coil 50 of a relay generally indicated at 48. Relay 50 controls two normally closed

contacts

52 and 54. The circuit of the normal light source 34 may be traced as follows: from junction 56 of power line 42, through conductor 58 to one side of relay coil 50, through coil 50 through the conductor 60 to terminal 62 of the normal light source 34, from terminal 64 through conductor 66 to junction 68 of the outer power line 46.

The emergency light source 36 is connected between intermediate power line 44 and power line 46 in series with normally closed relay contact 52 which is controlled by relay coil 50. This circuit may be traced as follows: from junction 70 on intermediate power line 44, through conductor 72 to terminal 74 of normally closed contact 52, from terminal 76 of contact 52 through conductor 78 to terminal 80 of the emergency light source 36, from terminal 82 of the emergency light source through the jumper conductor 84 to conductor 66, and thence to junction 68 of power line 46.

The relay coil 50 also controls a normally closed con tact 54 which is in series with a trouble light 86 across

power lines

44 and 46. The trouble light 86 may be located at some convenient place in the building where it may be readily seen. This circuit may be traced as follows: from junction 70 on intermediate power line 44, through conductor 72 to junction 73, through conductor 88, through the trouble light 86, to the terminal 90 of relay contact 54, through contact 54 to terminal 92 of the relay contact, through conductor 94 to conductor 66 and thence to junction 68 of power line 46. This circuit causes the trouble light 86 to become lighted when the contact 54 bridges terminals 90 and 92 in its normally closed position. As will be explained in more detail later, this happens when the relay coil 50 becomes deenergized due to a failure of the normal light source 34.

The photoelectric relay generally indicated at 20 may comprise a conventional photoelectric relay arrangement having a photoelectric cell 23 whose output is communicated to an amplifier tube having a relay coil 21 in its output circuit. In the circuit arrangement shown in Fig. 3, the amplifier tube is not shown for the sake of simplicity and the relay coil 21 is shown connected directly in series with the photoelectric cell 23.

Photoelectric relay 20 is provided with an electrical input circuit across

power lines

42 and 46, this electrical input serving as a source of biasing potential for the amplifier circuit of the relay, as is well known in the art. The electrical input circuit to the photoelectric relay 20 in series with a coil 98 of a relay generally indicated at 96 which controls a normally closed contact 100. The electrical input circuit to the photoelectric relay 20 may be traced as follows: from junction 56 of power line 42 through conductor 102, to junction 106, through conductor 108 to relay coil 98, through the relay coil 98, through conductor 110 to terminal 112 of the photoelectric relay 20, from terminal 114 of the relay 20, through conductor 116, to junction 118, through conductor 66 to junction 68 of power line 46. Thus, it will be seen that the electrical in ut to the photoelectric relay 20 is connected in series with relay coil 98 across

power lines

42 and 46.

The relay coil 98 controls a normally closed contact 100 which is in series with the trouble light 86 across

power lines

44 and 46 to indicate failure of the electrical input to the photoelectric relay 20. The circuit by means of which closure of relay contact 100 energizes troub e light 86 will now be described. Closure of contact 100 completes a circuit through the trouble light as follows: from junction 70 of power line 44, through conductor 72, to junction 73, through conductor 88 to the trouble light 86, through the trouble light to junction 120, through conductor 122 to terminal 124 of contact 100, through the contact 100 to terminal 126 of the contact, through conductor 128 to conductor 116, through conductor 116 to junction 118, through conductor 66 to junction 68 of power line 46.

The relay coil 21 controlled by the output of the photoelectric cell 123 controls a normally closed contact 130, and a normally open contact 132. When the photoelectric cell 123 is energized by the uninterrupted passage of light from either of the

light sources

34 or 36 to the photoelectric'cell, the normally open contact 132 becomes closed and the normally closed contact is opened.

The normally open contact 132 controlled by the photoelectric relay 20 is in series with a relay generally indicated at 151 and comprising a relay coil 156 which controls normally

open relay contacts

153 and 154. When the normally open contact 132 becomes closed due to uninterrupted passage of light from the light source to the photoelectric cell, the following circuit is completed through relay coil 156: from junction 70 of power line 44 through power line 44 to one side of the relay coil 156, through the relay coil 156 to conductor 166, to terminal 168 of contact 132, through contact 132 to conductor 164 and thence through conductor 102 to junction 56 of power line 42. Energization of the relay coil 156 closes the normally

open contacts

153 and 154. Closure of contact 153 completes a sealing-in circuit for the relay coil 156 which may be traced as follows: from power line 44, through relay coil 156, to terminal 170 of contact 153, to terminal 172 of contact 153, thence through conductor 164 to conductor 102 to junction 56 of power line 42. Energization of relay coil 156 also closes normally open contact 154 and sets up the circuit of the alarm bell so that if and when the normally closed contact recloses due to interruption of the light beam by smoke in the smoke chamber 14, the alarm bell circuit will be completed through

contacts

154 and 130, subject to the timing device 141 as will be explained hereinafter.

The normally closed contact 130 operated by relay 20 is connected in series with the alarm bell 134 in a circuit which may be traced as follows: from junction 136 of power line 44, through conductor 138 to terminal 140 of the alarm bell 134, from terminal 142 of the alarm bell to terminal 144 of a time controlled contact 146, from terminal 148 of contact 146, through conductor 150 to terminal 152 of contact 154 controlled by relay coil 156, through contact 154 to terminal 158 of the contact, through conductor 160 to terminal 162 of the normally closed contact 130, through normally closed contact 130, through conductor 164 to conductor 102 and thence to junction 56 of power line 42.

Relay 151 also serves to hold off the alarm bell from ringing during the warming up period of the photoelectric relay 20. When the system is initially energized, a short time is required to warm up the photoelectric cell 23 suificiently to energize relay coil 21 in the circuit of the photoelectric cell. During this warming up period, normally closed contact 130 in the bell circuit is closed. However, relay coil 156 is still unenergized, since normally open contact 132 has not yet been closed by relay coil 21. Hence, normally open contact 154 in the circuit of alarm bell 134 is still open and the bell does not ring.

A further feature of the circuit arrangement shown in Fig. 3 is the provision of a time delay device 141 in parallel with the alarm bell to hold off operation of the alarm bell for a predetermined period of time, such as three seconds, for example.

As will be seen in Fig. 3, the timing device, generally indicated at 141, controls a contact 146 which bridges terminals 144 and 148 in the circuit of the alarm bell after the lapse of the predetermined interval of time. This feature prevents the bell from ringing for a predetermined period after interruption of the light beam from either of the

light sources

34 or 36 to the photoelectric cell 23. This time delay prevents the bell from ringing during the change-over period from the normal light source 34 to the emergency light source 36.

The operation of the circuit of Fig. 3 will now be explained. Assume first that the smoke detection device is operating on the normal light source 34 and that no smoke has entered the smoke chamber 14. The following conditions will then prevail: the light source 34 will be lighted and will cause light rays to pass uninterruptedly toward the photoelectric cell 23 of the relay 20. The light source 34 is electrically connected in series with the coil 50 of relay 48 across the

power lines

42 and 46, or, in other words, across the full 220 volt power supply. Since relay coil 50 is energized, the normally closed

contacts

52 and 54 will be maintained in an open position. Hence, the circuit of the emergency light source 36 which is in series with the contact 52, will be open, and the emergency light source 36 will not be lighted. Also, since normally closed contact 54 is maintained open by relay coil 50,

the trouble light 86 will not be energized through the path provided by the normally closed contact 54. Hence, the trouble light 86 will not be lighted to indicate that the normal light source 34 has failed, although, of course, it may be lighted through the alternative path provided through contact 100, which becomes closed when the energization circuit of the photoelectric relay 20 fails.

If the normal light source 34 were to fail, it would open the series circuit which includes the relay coil 50, causing the deenergization of relay coil 50. This would cause the normally closed

contacts

52 and 54 to return to their normally closed positions. The return of contact 52 to its normally closed position would cause the energization of the emergency light source 36 through the path previously described. The closure of the normally closed contact 54 would complete the circuit of the trouble light 86 through the path previously described.

Under the normal operating conditions, with power input at terminals 112 and 114 of the photoelectric relay 20, the relay coil 98 in series with the electrical input circuit of the photoelectric relay 20 is energized. Energization of relay coil 98 causes normally closed contact 100 to be opened so that an energization path for trouble light 86 is not provided through contact 100 when relay 20 is obtaining its proper input energization. However, if, for any reason, a flow of current from terminal 114 to terminal 112 of the photoelectric relay 20 should fail, relay coil 98 becomes deenergized, and thereby permits contact 100 to return to its normally closed position, which completes a circuit through the trouble light 86 from power line 44 to power line 46, as previously described.

In the event that smoke enters the smoke compartment 14 and interrupts the light passing from either of the

light sources

34 or 36 to the photoelectric cell 23 of the relay 20, the relay coil 21 becomes deenergized and permits normally closed contact 130 to return to its normally closed position. Also, normally open contact 132 is returned to its normally open position. However, since relay coil 156 has sealed itself in through its own contact 153, both normally

open contacts

153 and 154 remain closed despite the opening of contact 132 controlled by relay 20.

The return of normally closed contact 130 to its normally closed position upon the deenergization of the photoelectric relay due to the presence of smoke closes the circuit of the timing device 141, which, in turn, closes the circuit of the alarm bell, as follows: from junction 136 of power line 44, through conductor 138 to junction 139, through conductor 143 to one side of the timing device 141, through the timing device 141, through conductor 145 to conductor 150, through conductor 150 to terminal 152 of contact 154, through closed contact 154 to terminal 158, through conductor 160, through normally closed contact 130, through conductor 164 to conductor 102, and thence, to junction 56 of power line 42. The circuit of the timing device 141 is completed first by the reclosing of contact 162 and after the lapse of a predetermined interval, such as three seconds, the contact 146 controlled by timing device 141 bridges the terminals 144 and 148 to complete the circuit of the alarm bell 134.

The principal purpose of the time delay device 141 is to permit a slight time delay before ringing the bell 134 to permit the automatic change-over from the normal light source 34 to the emergency light source 36.

It can be seen from the foregoing that there is provided in accordance with this invention a smoke detection system which automatically rings an alarm bell upon the presence of smoke. In accordance with the invention, a normal light source and an emergency light source are both provided and means are provided for automatically energizing the emergency light source upon failure of the normal light source. Furthermore, signal means, which may be in the form of a trouble light, are provided to indicate failure of the normal light source, and also to indicate the failure of the energization circuit of the photoelectric relay means. It can be seen that this invention has great practical utility and may prove a valuable aid in preventing loss of life due to the presence of smoke.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the invention, and, therefore, it is aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Having thus set forth and disclosed the nature of this invention, what is claimed is:

A smoke detection apparatus comprising a photoelectric relay means including a photoelectric cell, a normally closed contact and a normally open contract controlled by said relay means, an auxiliary relay means controlled by said photoelectric relay, closure of said normally open contact by said photoelectric relay being effective to energize said auxiliary relay means, a first and a second normally open contact means operable to closed position upon energization of said auxiliary relay means, closure of said first contact means being effective to maintain said auxiliary relay means energized independently of said photoelectric relay means, said second contact means closed by said auxiliary relay being in the input circuit to an alarm device, said normally closed contact controlled by said photoelectric relay means being in series with said second contact means in the input circuit to said alarm device, reclosure of said normally closed contact upon deenergization of said photoelectric relay being effective to actuate said alarm device.

References Cited in the file of this patent UNITED STATES PATENTS 1,256,740 Steiger Feb. 19, 1918 1,469,946 Morrison Oct. 9, 1923 1,726,994 Murray Sept. 3, 1929 1,755,834 Marr et al Apr. 22, 1930 2,119,326 Grant, Ir May 31, 1938 2,537,028 Cahusac et al Jan. 9, 1951 2,636,163 Gardiner Apr. 21, 1953