US 2908896 A
Description (OCR text may contain errors)
Oct. 13, 1959 .Jf HOMMA TEMPERATURE RESPONSIVE MEANS 2 Sheets-Sheet 1 Filed Sept. 19, 1955 IIIIIIIIIIIIIIIIIIIIIIIIIIII Oct. 13, 1959 HOM A 2,908,896
TEMPERATURE RESPONSIVE MEANS Filed Sept. 19, 1955 2 Sheets-Sheet 2 INVENTOR. J05 Q. Q Ham ma mwmm vg United States Patent Otfice 2,908,896 Patented Oct. 13, 1959 RESPONSIVE MEANS Josef Homma, Weisbaden, Germany Application September 19, 1955, Serial No. 535,169
' Claims priority, application Germany June 1', 1955 4 Claims. (Cl. 340-227) The present invention relates to an automatic temperature responsive mechanism. More particularly the ,present invention relates to temperature responsive apparatus which can be used with fire alarm systems. i
There are many types of fire alarm systems in use today. These systems are usually operated by some temperature responsive means which can be a thermostat, a bimetallic element, a contact thermometer or any other type of themperature dependent strip element. In large industrial factories and in other commercial buildings such as theaters, sprinkler systems are provided which both respond to a fire and open valves for directing water at the fire.
It is apparent that expensive and complicated fire alarm systems cannot be installed in smaller buildings such as hotels and private houses. It is apparent that such smaller houses and hotels would not be ableto afford the initial investment cost for the more complicated fire alarm systems. On the other hand they would be able to afiord a fire alarm system which will immediately respond to the outbreak of a tire and will immediately indicate where the fire is located. Once the location of the'fire is known it would be possible to extinguish the fire with conventional hand-extinguishers.
Accordingly, the present invention provides a fire alarm system which will immediately respond to the outbreak of the fire and will send information back to a central station telling the location of the fire. The present invention can also be incorporated in apparatus wherein the alarm is given right at the apparatus itself. Accordingly it is an object of the present invention to overcome the disadvantages of' conventional fire alarm systems as described hereinabove.
A second object of the present invention is to provide a new and improved fire alarm system which is relatively cheap and easy to construct.
Another object of the present invention is to provide temperature responsive means for use with a fire alarm system.
Still another object of the present invention is to provide an apparatus which responds to the outbreak of a fire and which transmits to a central location information which identifies the location of the outbreak of the'fire With theabove objects in view the present invention mainly consists of apparatus for use with a fire alarm system including temperature responsive apparatus having a housing, switch means mounted in the housing and being movable between a first and a second position, first circuit means being deactuated when the switch is in its first position and; actuated when the switch is in its second position, second circuit means being open circuited when the switch is in its first position and actuated when the switch is in its second position, means for normally urging the switch means into its second position, and temperature-responsive means for maintaining the switch means in its first position against the action of the urging means until the temperature-responsive means reaches a predetermined temperature.
In another embodiment of the present invention, the present invention mainly consists of a fire alarm system including a plurality of alarm devices, each of the alarm devices being located in separate locations which are desired to be protected in the event of outbreak of fire, a source of operating potential for the alarm devices, a plurality of switch means, each of the switch means being located respectively in the same location as one of the alarm devices and located between the source of operating potential and its respective alarm device, each of the switches being movable between a first position wherein its respective alarm device is disconnected from the source of operating potential and a second position wherein its respective alarm device is connected to and energized by the source of operating potential, a plurality of urging means, each of the urging means being mounted in operable association with one of the switch means, respectively, for normally urging its respective switch into its second position, a plurality of signalling means, each of the signalling means being connected in circuit, respectively, with one of the alarm devices so as to be shortcircuited when its respective switch is in its first position and energized by the source of operating potential when its respective switch moves out of its first position, and a plurality of temperature responsive means, each of the plurality of the temperature responsive means being associated, respectively, with one of the switch means, for maintaining its respective switch means against the action of the urging means until the temperature responsive means reaches a predetermined temperature,
The novel features which are considered ascharacteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:
Fig. 1 is a longitudinal cross sectional view of one embodiment incorporating the principles of the present invention;
Fig. 2 is a transverse cross sectional view of the temperature responsive element used in the apparatus illus trated in Fig. 1;
Fig. 3 is a side view of apparatus incorporating the principles of the present invention showing the external appearance thereof; and
Fig. 4 is an electrical schematic diagram showing the electrical connections between the various elements of an embodiment of the present invention as incorporated in a hotel.
Referring to the drawings and more particularly to Fig. 1, it can be seen that the apparatus is mounted Within a tubular outer housing 20. Mounted on an angle bracket 8 near the top of the housing 20 is a switch 6. The switch 6 includes an axially displaceable rod 9 having a tapered central portion on which is mounted a bushing 23. On the bushing 23 is mounted a strip of electrically conductive material 5. The strip 5 contains electrical contacts which are shown mating with contacts 1 and 2 of the switch 6.
It can be seen that contacts 1 and 2 are the two lower contacts of the switch 6. The switch 6 also has upper contacts 3 and 4 respectively. The strip 5 is maintained in contact with the contacts 1 and 2 by means of a weight 16 which is conneced to the lower end of the rod 9 by means of the temperature responsive element 13 and 14.
The alloy 14 can be a low melting alloy such as Woods alloy which contains bismuth, tin, lead and cadmium in proper portions to provide a low melting alloy. In Fig. 1 it can be seen that the strips 13 are provided with notches which receive upper and lower loops. The lower loop attaches the hook of the weight-16 to the lower strip 13 while asecond' loop attaches the upper strip. 13 to a hookat the bottom end of the rod 9.
The lower endiof'the rod 9 extends through the housing of the switch 6 and has a wider flange portion9 positioned between the bushing 23 and'a'spring 7 which is located between the flange and the housing of the switch 6. Above the bushing 23 a second spring 7a is provided which abuts against a second flange of the rod 9. The rod 9 extends upwardly through the top of the switch housing and aknob 10 is at the upper end thereof. The bottom of the housing is provided with a bottom cap 11 and the top of the housing has a cap 11a which is'provided with mounting loops 19'. As illustrated in Fig. 1' the top cap 11a also may have an alarm bell 12 mounted thereon.
In operation the apparatus is normally maintained'in the position illustrated in Fig. l. The spring 7 which is a Very strong spring would normally urge the bushing 23 upwardly into contact with the contacts 3 and 4. However, the weight 16 overrides the action of this spring 7 and compresses the spring 7 by means of the rod 9 the'flange 9.
It should be noted that the bushing 23 is freely mov-.
able on the shaft 9 so that the downward movement of the shaft 9 would not normally carry the bushing 23 with the'shaft 9. However, the spring 7a which bears on the top surface ofthe bushing 23 imparts adownward motion proportional to the downward force of the weight 16 to the bushing 23. Therefore the spring 7a presses the bushing 23 and its electrically conductive strip 5 into electrical'contact with the contacts 1 and 2 of the switch 6. As will be seen later the contacts 1 and 2 are adapted to be connected in a signalling circuit and the electrically conductive member 5 prevents this signal circuit from operating. When the temperature reaches a predetermined amount due to the outbreak of a fire in the neighborhood of the fire alarm system, the temperature responsive alloy 14 will melt. At that point it no longer acts as a mechanical bond between the two strips 13.
When this occurs the weight 16 will drop to the bot-- tom of the housing 20 and will no longer acton' the rod 9. The spring 7 now urges the bushing 23 upwardly through the flange 9 into contact with the contacts 3 and 4 of the switch 6. As will be described hereinbelowthe action of the bushing 23will cause the signalling system to be actuated and the closing of the contacts 3 and 4 will actuate an alarm mechanism. The signalling mechanism will indicate which of thehousing's of the entire fire alarm system is affected and the alarm which may be mounted on'the housing itself will warn people in the immediate area that a fire has broken out.
- It can be seen that this apparatus is a fail-safe apparatus in that if the weight 16 falls on its own accord or is released for any other reason the spring 7 will immediately'place the electrically conductive member 5 of the bushing 23 into contact with the contacts 3 and 4 of the switch 6. This will simultaneously operate the signalling system and the alarm system.
Referring now to Fig. 3 it can be seen that the outer housing of the apparatus may be made of a perforated metal material 17 which may be part of a design. This apparatus can. be mounted on a bracket '21 which has a chain running through the holes .19 shown in Fig. 1. The brackets 21 may be mounted at any convenient portion of a wall 22.
Referring now to Fig. 4 an electrical schematic diagram is shown of the fire alarm system incorporating the principles of the present invention as applied to a hotel."
The hotel is diagrammatically shown as having a plurality of individual rooms indicated by numerals I, II,
HI, and IV. While only four rooms are shown it is apparent that any plurality of rooms and locations may be used. f
In the right hand portion of Fig. 4 terminals 31 and 32 are provided which represent respectively terminals of a potential source. The terminal 31 representing the positive terminal of the potential source and the terminal 32 representing the negative terminal of the potential source. It is apparent that this potential source may also be the usual house current supply. The terminal 31 is connected on conductors 33 and 34 to one side of a plurality of signal lamps G G G and G These signal lamps may be neon bulbs for example which draw very little current. The other side of the lamp'G is connected on conductors 36 and 37 to the switch contact 1 of the switch S in room I. The conductor 36 is also connected to one side of a resistor R the other side of which is connected by means of conductor 38 and conductor 39" to the negative terminal 32 of the potential source. I
The contact 2 of the switch S is directly connected to the contact'3 thereof and is also connected onconductor 41 and conductor 33 directly to the positive terminal 31 of the potential source. The contact 4 of the switch S is connected to one side of an alarm device W1 which may be a, bell for example. The other side of the alarm deviceW is connected on conductor 42; to one side of a second alarm device W the other side' of which is connected on conductor 43 to a. third alarm device W The other side of the alarm device W is connected on conductor 39 to the negative terminal 32 of the potental source.
In operation it can be seen that the member 5 in room" drawn from the potential source and accordingly this current will not represent an appreciable power loss.
' If a fire breaks out in room I the alloy 14 in the temperature responsive element will melt causing the weight in the device to fall and release the spring therein. Therefore the memberS' of the switch S will be moved in the direction of the arrow. This will open the contacts 1 and 2 and short togetheritlrec on'tacts 3 and 4 of the sWitchS t When the contacts 1 and 2 are no longer short circuited, the short circuit across" the'signal lamp G is'removed.
Therefore, the signal lamp G will be connected in series with the resistor R across the terminals 31 and 32 of the potential source. This will cause the signal lamp G to be illuminated.
When the "member 5 is in its uppermost position due to theiaction of its respective spring 7, it will short circuit the contacts 3 and 4 of the switch S This will connect the positive terminal 31 of the potential source by means of conductors 33 and 41 directly to one side of the alarm device W devices W W and W are now all connected in series across the terminals 31 and 32 of the potential source.
Therefore all three of these alarm devices will be set off.
The alarm device W will warn the occupants of the room I that a fire is present in that room. The alarm device W may be located either in the hallway of a othercentral location-at the same location where the signal lamps are provided.
Therefore by means of the apparatus incorporating It can be seen that the alarm the principles of the present invention the occupants of the hotel in the immediate vicinity are informed that a fire has broken out and can take proper action. Also the employees of the hotel will be able to respond with hand fire extinguishing apparatus to combat the fire in the room I. It should be noted that by means of the signal lamp G the location of the fire is known as soon as the fire breaks out.
It is clear that if the fire should break out in any one of the other rooms the corresponding alarm devices and signal lamps will be actuated. The alarms W and W are set off in series with the alarm device of the particular room in which the fire has broken out.
It would also be possible to have the contacts 3 and 4 operate the signal lamps as well as the alarm devices. However the present arrangement, as illustrated, provides an apparatus having the above described fail-safe feature. It should be apaprent that the present apparatus draws substantially no power from the house current and is very simple and inexpensive to construct.
In Fig. 1 a knob portion 10 is shown at the upper end of the rod 9. This knob 10 can be used when it is desired to see whether or not each of the individual apparatuses of the fire alarm system is in operating order. Merely by taking ofr the top cover of the housing and lifting the knob 10 to override the force of the weight 16, it is possible to move the bushing 23 and its electrically conductive member 5 from the contacts 1, 2 into electrical contact with the contacts 3, 4. This should operate both the signalling device as well as the alarm device. It is apparent that this test may be carried out even though the temperature responsive member 13 and 14 remains bonded together.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of fire alarm systems differing from the types described above.
While the invention has been illustrated and described as embodied in a fire alarm system for a hotel, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any Way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
What is claimed as new and desired to be secured by Letters Patent is:
1. A fire alarm system, comprising, in combination, a
. source of operating potential including two output terminals; at least one change-over switch having a first and a second pair of contacts, said switch being movable between a first position in which said first pair of contacts is closed while said second pair of contacts is disconnected, and a second position in which said first pair of contacts is disconnected while said second pair of contacts is closed, said switch including fusible means for holding at ordinary temperatures said switch in said first position but releasing it therefrom at elevated temperatures, and moving means including gravity means for moving said switch into its said second position when re leased by said holding means; first circuit means connecting said output terminals with said second pair of contacts, respectively, and including alarm signal means so that the latter are set off only when said switch is in its second position; second circuit means connecting said output terminals with said first pair of contacts, respectively, and including resistance means for limiting the current flowing constantly from said source through said resistance means while said switch is in its first position; third circuit means including auxiliary signal means of comparatively high resistance and connected in parallel with said first pair of contacts so that said auxiliary signal means is inoperative by being shunted as long as said switch is in its first position, by that portion of said second circuit means which is connected in parallel with said auxiliary means and includes said first pair of contacts, said portion of said second circuit having a resistance smaller than that of said third circuit means including said auxiliary signal means.
2. A fire alarm system as set forth in claim 1, including a plurality of said change-over switches, and one of said first, second and third circuit means associated and operatively connected With each of said switches.
3. A fire alarm system as set forth in claim 2, wherein in each of said first circuit means one of said alarm signal means is connected in close vicinity to the changeover switch in the particular circuit, and a circuit portion including additional alarm signal means is connected at one end jointly with a plurality of said first circuit means and at the other end with one of said terminals.
4. A fire alarm system as set forth in claim 3, wherein said change-over switch includes manually operable means for temporarily connecting said second pair of contacts and disconnecting said first pair of contacts so that the operative condition of the system can be tested although said fusible means are intact.
References Cited in the file of this patent UNITED STATES PATENTS 1,049,586 Koup Jan. 7, 1913 1,244,332 Hughs Oct. 23, 1917 1,720,793 Kunkle July 16, 1929 2,380,495 Banks July 31, 1945 2,389,103 Wood Nov. 13, 1945 2,459,015 Clement Jan. 11, 1949 2,472,266 Quellette June 7, 1949 2,599,623 Forrester June 10, 1952 FOREIGN PATENTS 16,595 Great Britain July 11, 1914