Abstract:
In one aspect, the present invention is directed to an earthquake detection and alarming apparatus, comprising: a transparent object ( 46 ) having a concave surface on the top thereof; a rollable object ( 34 ) placed on the concave surface; an apiary of light projectors ( 30 ) placed above the concave surface; an apiary of light receivers ( 38 ) correspondingly to the apiary of light projectors, the apiary of light receivers being placed below the concave surface; and circuitry for determining: (a) vibrating frequency and amplitude of the rollable object with reference to the concave surface from sensing of the receivers ( 38 ); and (b) deducing therefrom the arrival of primary waves.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The current application is a U.S. National Phase Application under 35 U.S.C. 371 of PCT International Application No. PCT/IL2009/000370, which has an international filing date of Apr. 5, 2009, and which claims the benefit of priority from U.S. Provisional Patent Application No. 61/042768, filed Apr. 7, 2008, whose disclosure is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of earthquake detectors and alarms. 
     BACKGROUND OF THE INVENTION 
     Various types of earthquake sensors are known in the patent literature. The following U.S. Patents are believed to represent the state of the art: U.S. Pat. Nos. 4,086,807; 4,262,289; 4,297,690; 4,358,757; 4,484,186; 4,662,225; 4,689,997; 4,764,761; 4,764,762; 4,789,922; 4,841,288; 4,904,943; 4,945,347; 4,978,948; 4,980,644; 5,001,466; 5,101,195; 5,248,959; 5,278,540, 5,539,387. 
     The present invention seeks to overcome the disadvantages of the prior art attempts and provides a relatively inexpensive and reliable earthquake sensor and alarm therefor. 
     Other objects and advantages of the invention will become apparent as the description proceeds. 
     SUMMARY OF THE INVENTION 
     In one aspect, the present invention is directed to an earthquake detection and alarming apparatus, comprising:
         a transparent object ( 46 ) having a concave surface on the top thereof;   a rollable object ( 34 ) placed on the concave surface;   an apiary of light projectors ( 30 ) placed above the concave surface;   an apiary of light receivers ( 38 ) correspondingly to the apiary of light projectors, the apiary of light receivers being placed below the concave surface; and   circuitry for determining (a) vibrating frequency and amplitude of the rollable object with reference to the concave surface from sensing of the receivers ( 38 ), and (b) deducing therefrom arrival of primary waves.       

     According to one embodiment of the invention, determining the vibrating frequency of the rollable object is deduced from input of the receiver of the apiary that corresponds to the lowest point ( 54 ) of the concave surface. 
     According to one embodiment of the invention, determining the vibrating amplitude of the rollable object is deduced from the larger distance between each of two receivers that indicate vibrations. 
     The apparatus may further comprise an alerting system comprising visual and/or audio alarm. 
     According to one embodiment of the invention, the visual alarm comprises a plurality of lamps ( 6 ), for indicating the intensity of an earthquake. 
     The circuitry may further corresponds detected secondary waves to Mercalli Scale. 
     Preferably, the concave surface is enclosed within a sealed space ( 48 ), thereby preventing dust entry into the space, thereby prolonging the time to next maintenance of the apparatus. 
     Preferably, the casing ( 42 ) of the apparatus is in the form of a domestic appliance (e.g., a clock), thereby diminishing the frightening connotation associated with the apparatus. 
     According to one embodiment of the invention, the projectors ( 30 ) are based on LEDs, thereby adapting the apparatus to use a negligible power supply. 
     According to one embodiment of the invention, the receivers ( 38 ) are based on LED (diodes). 
     According to one embodiment of the invention, the rollable object is a mercury drop. 
     According to another embodiment of the invention, the rollable object is a non-transparent sphere. 
     The apparatus may further comprise one or more bolts, for securing the apparatus to a wall. 
     In another aspect, the present invention is directed to a method for detecting primary waves of an earthquake, the method comprising the steps of:
         providing sensors for detecting the location of a rollable object on a concave surface;   deducing the frequency and amplitude of cyclical movement of the rolling object with reference to the concave surface; and   determining primary waves on earthquake by detecting an association of the frequency and amplitude with known frequency and amplitude that characterizes primary waves of an earthquake.       

     The foregoing embodiments of the invention are described and illustrated in conjunction with systems and methods thereof, which are meant to be merely illustrative, and not limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments and features of the present invention are described herein in conjunction with the following drawings: 
         FIG. 1  schematically illustrates an earthquake detection and alarming apparatus, according to one embodiment of the invention. 
         FIG. 2  schematically illustrates the apparatus of  FIG. 1  in a disassembled mode. 
         FIG. 3  is an exploded view of the sensing and alerting units of the apparatus of  FIG. 1 , which illustrates the structure of sensor  12 . 
         FIG. 4  schematically illustrates the apparatus of  FIG. 1  in a non-earthquake situation. 
         FIG. 5  schematically illustrates the apparatus of  FIG. 1  in an earthquake situation. 
     
    
    
     It should be understood that the drawings are not necessarily drawn to scale. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention will be understood from the following detailed description of preferred embodiments, which are meant to be descriptive and not limiting. For the sake of brevity, some well-known features, methods, systems, procedures, components, circuits, and so on, are not described in detail. 
       FIG. 1  schematically illustrates an earthquake detection and alarming apparatus, according to one embodiment of the invention. 
     The apparatus, which is marked herein by reference numeral  2 , comprises a casing  42  on which are disposed indication lamps  6 , for indicating the intensity of an earthquake, and a clock  4 . Thus, the apparatus consolidates a clock with earthquake indicators in a single device. The clock diminishes the frightening connotation of an earthquake alerting apparatus. 
     Preferably, indication lamps  6  are embodied as LEDs (Light Emitting Diode), as they provide adequate light intensity to be observed in domestic surroundings, along with negligible power consumption. 
     In order to provide indication about the intensity of the earthquake, each of indication lamps  6  is marked by a digit. The higher the digit, the higher the earthquake intensity. 
     Additionally or alternatively, the sensed intensity may be marked by intensity of the illuminating LED, a color, and so on. For example, the colors of the indication lamps may vary from yellow to red. 
     According to one embodiment of the invention, the scale of the indication lamps corresponds to the New Mercalli Scale. 
     The Mercalli Intensity Scale is a scale developed as a way of measuring the actual effects or intensity of an earthquake at a particular location, and is expressed in roman numerals from I the weakest to XII the strongest. 
     The actual intensity of an earthquake depends on the distance from the epicenter and local geological conditions. While Richter scale measures the magnitude of an earthquake independent of location, Mercalli indicates the earthquake intensity at the measured location. 
     The scale quantifies the effects of an earthquake on the Earth&#39;s surface, humans, nature, and man-made structures. Intensity I denotes a weak earthquake, and XII denotes an intensity causing almost complete destruction. 
     As the first “meaningful” intensity of Mercalli Scale is III, in the embodiment illustrated herein, the first degree is 3. Intensity 9 stands for intensity IX of Mercalli, and higher. 
       FIG. 2  schematically illustrates the apparatus of  FIG. 1  in a disassembled mode. 
     Reference numeral  20  denotes the base (chassis) on which the parts of earthquake detection and alarming mechanism are mounted. 
     Reference numeral  18  denotes a battery that supplies power to the apparatus, and reference numeral  44  denotes the housing thereof. 
     Reference numeral  12  denotes an earthquake detector (sensor), numeral  24  denotes a control circuit of the alarm of the apparatus, and numeral  26  denotes a speaker thereof. Chassis  20  is secured to a wall by bolts  22 . 
     Casing  42  is secured to chassis  20  by bolts  10  and corresponding threads  28  on the chassis. Thus, in order to separate casing  42  from chassis  20 , for example, for replacing batteries  18 , one has to unscrew bolts  10 . 
       FIG. 3  is an exploded view of the sensing and alerting units of the apparatus of  FIG. 1 , which illustrates the structure of sensor  12 . 
     A mercury drop  34  is placed on a transparent plate  36 , which has a substantially concave surface  54 . The concave surface is placed between an “apiary” of projectors  30 , and a corresponding apiary of receivers (sensors). Thus, mercury drop  34 , which is non-transparent, blocks light projected by some of projectors  30 . 
     A projector  30  may be based on a LED, as its electrical power consumption is relatively low, and as a result, it can operate using battery power instead of domestic power supply. 
     A receiver  38  may also be based on a LED, which is a diode. This subject is well known in the art, and for the sake of brevity is not detailed herein. 
       FIG. 4  schematically illustrates the apparatus of  FIG. 1  in a non-earthquake situation, and  FIG. 5  schematically illustrates the apparatus of  FIG. 1  in an earthquake situation. 
     In  FIGS. 4 and 5 , element  46  is cross-sectioned. Element  46  is a transparent cover of plate  36 . 
     In  FIG. 4 , which illustrates the situation of mercury drop  34  in a non-earthquake situation, mercury drop  34  blocks the beam projected by projector  30   a  and received by receiver  38   a.    
     In  FIG. 5 , which illustrates the situation of mercury drop  34  in an earthquake situation, mercury drop  34  blocks the beam projected by projectors  30   b  and  30   c , and received by receivers  38   n  and  38   c , respectively. 
     In  FIGS. 4 and 5 , it is assumed that the receiver  38   a  is placed under the lowest point of concave surface  54 ; however, if apparatus  2  is mounted inclined, the other receiver will be under the lowest point of surface  54 . 
     Detecting an Earthquake 
     As known to the skilled person in the art, an earthquake can be detected by identifying the arrival of primary (P) waves, that precede arrival of more destructive shear (S) and rally (R) waves (secondary waves). As the P waves travel 1.68 times faster than the S waves, the greater the distance from the epicenter of an earthquake one is, the greater would be the time elapsed between the P and S waves. 
     By identifying the P waves, an alert of tens of seconds may be provided (depending on the distance from the epicenter and the depth of the focus). This time can be used to take precautionary actions such as finding shelter, leaving a building, or stopping an elevator at the next floor, in the event of an upcoming seismic shaking. 
     P waves are characterized by, for example, their frequency and amplitude, which differ, for example, from vibrations caused by passing traffic. 
     The state of a receiver can be defined as the yes/no indication thereof, i.e., is the light beam projected from the corresponding projector received by the receiver or not. “Received” in this case means that the light intensity indicated by the receiver is higher than a certain threshold. Actually, while the wall to which apparatus  2  is secured vibrates, the absolute location of the mercury drop is steadier; however, from the viewpoint of receivers  38 , the vibrating element is mercury drop  34 . 
     Assuming that in a non-earthquake situation mercury drop  34  blocks projector  30   a  (i.e., the apparatus stands substantially vertically), in an earthquake situation, receiver  38   a  senses the frequency of the vibrations, and the rest of the receivers sense the amplitude of the vibrations. For example, in the case receivers  38   c ,  38   b ,  38   a ,  38   b ′ and  38   c ′ indicate vibrations, the amplitude is greater than in the case wherein receivers  38   b ,  38   a , and  38   b ′ indicate vibrations, as the physical distance between receivers  38   c  and  38   c ′ is greater than the distance between receivers  38   v  and  38   b′.    
     The greatest distance between two receivers that indicate vibrations can be detected by processor  40 , which can calculate the distance between each of two receivers that detect vibrations. 
     According to one embodiment of the invention, a non-transparent sphere replaces the mercury drop. 
     Receivers  38  detect only an on/off state. In order to obtain the frequency and amplitude from the on/off states of the receivers, a circuitry is required. The circuitry/electronic chip is marked herein by reference numeral  40 . 
     It should be noted that apparatus  2  has to be placed substantially vertically, i.e., may be slightly inclined. As such, it suits to be used in a domestic place, as domestic users prefer an easy installation. 
     In one embodiment of the invention, apparatus  2  comprises a setup button, for informing the internal mechanism of the apparatus that the current state is the non-earthquake state. 
     The intensity of an earthquake can be determined from the distance the mercury has shifted, from the shifting speed, a combination of this information, and so on. The analysis is carried out by an electronic chip  40 . 
     Numeral  46  denotes a transparent cover, corresponding to transparent plate  36 . Cylindrical housing  50  of a projector  30  in element  46 , and cylindrical housing  52  of a receiver  38  in plate  36  are non-transparent, thereby the projected beams from a projector to a receiver does not spread. This way, the majority of the beam from a projector reaches to the corresponding receiver thereof. 
     Furthermore, if space  48  enclosed between cover  46  and plate  36  is kept sealed, it prevents dust entry into space  48 , thereby prolonging the time apparatus  2  may operate without maintenance. 
     In the figures and/or description herein, the following reference numerals have been mentioned:
         numeral  2  denotes an earthquake detection and alarming apparatus, according to one embodiment of the invention;   numeral  4  denotes a clock;   numeral  6  denotes indication lamps, for indicating the intensity of an earthquake;   numeral  8  denotes an opening in the casing of the apparatus, for speaker  26  that plays an audio alarm;   numeral  10  denotes bolts;   numeral  12  denotes an earthquake detector;   numeral  14  denotes a platform on which is disposed a matrix of receivers  38 ;   numeral  16  denotes a platform on which is disposed a matrix of projectors  30 ;   numeral  18  denotes a battery;   numeral  20  denotes the base (chassis) on which the parts of earthquake detection and alarming mechanism are mounted;   numeral  22  denotes a bolt for securing chassis  20  to a wall;   numeral  24  denotes a control circuit of an alarm of the apparatus;   numeral  26  denotes a speaker of the alarm;   numeral  28  denotes a thread on chassis  20 , correspondingly to bolt  10 ;   numeral  30  denotes a projector;   numeral  32  denotes bores restricting the course of a light beam projected by a projector  30 ;   numeral  34  denotes a mercury drop;   numeral  36  denotes a transparent plate having concave surface, on which drop  34  is placed;   numeral  38  denotes a receiver (sensor);   numeral  40  denotes an electronic chip/circuitry, which performs relevant calculations, such as the frequency and amplitude of sensed vibrations, deducting the intensity of an earthquake from these vibrations, and so on;   numeral  42  denotes, the casing of apparatus  2 ;   numeral  44  denotes a housing of batteries  18 ;   numeral  46  denotes a transparent cover to plate  36 ;   numeral  48  denotes the space enclosed between plate  36  and the cover thereof  46 ;   numeral  50  denotes a housing of a projector;   numeral  52  denotes a housing of a receiver; and   numeral  54  denotes a concave surface.       

     The foregoing description and illustrations of the embodiments of the invention has been presented for the purposes of illustration. It is not intended to be exhaustive or to limit the invention to the above description in any form. 
     Any term of the claims that has been defined above, has to be interpreted according to this definition.