US3733598A

US3733598A - Vibration-responsive apparatus

Info

Publication number: US3733598A
Application number: US00210994A
Authority: US
Inventors: T Kato
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-12-27
Filing date: 1971-12-22
Publication date: 1973-05-15
Anticipated expiration: 1990-05-15

Abstract

A vibration-responsive apparatus having means for detecting a vibration and producing a signal in response to the detected vibration, and electric circuit means operating in response to the vibration when it lasts for more than a certain period of time and the signal corresponding thereto is produced a predetermined number of times, the electric circuit means being adapted to actuate a desired device connected thereto.

Description

Write ates atent [19] Kato [11] 3,733,598 51 May 15, 1973 VIBRATION-RESPONSIVE APPARATUS inventor: Tomezo Kato, 172 Motoderakoji,

Sendai, Japan Filed: Dec. 22, 1971 Appl. No.: 210,994

Related US. Application Data Continuation of Ser. No. 887,211, Dec. 22, 1969, abandoned.

Foreign Application Priority Data [56] References Cited UNITED STATES PATENTS 3,261,009 7/1966 Stetten et al. ..340/261 Primary ExaminerDavid L. Trafton Attorney-Hill, Sherman, Meroni, Gross, Simpson 57 ABSTRACT A vibration-responsive apparatus having means for detecting a vibration and producing a signal in response to the detected vibration, and electric circuit means operating in response to the vibration when it lasts for more than a certain period of time and the signal corresponding thereto is produced a predetermined number of times, the electric circuit means being adapted to actuate a desired device connected thereto.

4 Claims, 2 Drawing Figures DELAY SW/TCH/IVG m/aam MAIN ALARM V/BflAT/O/V 05750709 AMPLIFIER CILLATOR A 5 D E F (T l l I l R/ G COZNTER (ALARM l DELAY ALARM SWITCH/N6 c pcu r Patented May 15, 1973 2 Shoots-Shoot 1 VIBRATION-RESPONSIVE APPARATUS This is a continuation, of application Ser. No. 887,21 1, filed Dec. 22, 1969 now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a vibration-responsive apparatus for use with an object to be protected such, for example, as a safe, and more particularly to a vibrationresponsive apparatus which, for example, gives an alarm upon detection of vibrations through air, a solid or the like which are caused by an intruder who is going near the safe or the like.

2. Description of the Prior Art Almost all the conventional alarm devices of this type raise an alarm in response to only one vibration. Consequently, these prior art devices the disadvantage that vibrations caused by a person other than an intruder, for example, noises and accidental touch on the safe or the like to be guarded lead to a false alarm.

SUMMARY OF THE INVENTION Accordingly, a primary object of this invention is to provide a vibration-responsive apparatus which is capable of giving an alarm in response to a vibration which is produced intermittently for more than a predetermined period of time or produced intermittently a predetermined number of times.

Another object of this invention is to provide a vibration-responsive apparatus which is simple in construction and inexpensive but capable of responding to only specific vibrations to raise an alarm.

Other objects, features and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows in block form a vibration-responsive apparatus of this invention; and

FIG. 2 is a circuit connection diagram showing one example of the vibration-responsive apparatus depicted in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the drawings one example of this invention will hereinafter be described in detail. Reference character A designates a vibration detector or vibration-sensitive element, which is a pressuresensitive element such as a so-called piezoelectric element formed of Rochelle salt, ceramic or the like. In this case, it is preferred to use a pressure-sensitive element which has a frequency characteristic such that it detects only vibrations or sound waves of relatively high frequencies but does not pick up gentle vibration of the safe itself due to, for example, earthquake shock or the like. The pressure-sensitive element may be substituted with, for example, an electromagnetic, movingcoil type or like microphone, which is desired to have a characteristic such that it picks up sounds (vibrations) of relatively high frequencies but does not respond to vibrations of very low frequencies. In the event of using a pressure-sensitive element designed for detecting vibrations of a wide frequency range, suitable means such as a high-pass filter which cuts off a lowfrequency range of, for example, less than 30 Hz is provided on the output side of the pressure-sensitive element. The pressure-sensitive element A is mounted on the door of the safe or on the inside thereof or disposed in a room where the safe is placed. The electric output of the detector A corresponding to a vibration picked up thereby is amplified by an amplifier B and is then applied to a delay switching circuit C. The delay switching circuit C produces a signal of a constant duration irrespective of the duration of the signal fed thereto. Namely, even when supplied with a signal of a short duration of less than 4 seconds produced corresponding to a vibration detected by the detector A, the circuit C produces a signal of a constant duration of, for example, about 4 seconds and, further, when supplied with a signal of a relatively long duration, the circuit C produces a desired number of signals, each having the predetermined duration (about 4 seconds).

The delay switching circuit C drives a trigger circuit D which is preferred to be actuated by a relay and its contacts operated by the delay switching circuit C. The trigger circuit D is a circuit which supplies in pulse form an output signal corresponding to the number of vibrations picked up by the detector A or a signal representative of the duration of the number of vibrations. On the output side of the trigger circuit D there is disposed a ring counter E for reading out the number of the vibrations. The output of the trigger circuit D is counted by the ring counter E. Namely, when the detector A picks up a predetermined number of vibrations the ring counter E counts the number and when the detector A picks up a signal of a relatively long duration the vibration is converted by the delay switching circuit C into signals of a predetermined duration and the number of the resulting signals is counted by the ring counter E and a main alarm oscillator circuit F is selectively activated in accordance with the number of the outputs of the ring counter E. Thus, an alarm signal is transmitted to a predetermined location to operate an alarm device G, for example, a bell or the like which is located, for instance, in a guardmans room remote from the safe or the like to be protected. It is preferred to provide a circuit I which raises a warning signal at every detection of such a vibration as previously mentioned. In the case where the setting operation of this apparatus is likely to produce a vibration to cause accidental actuation of the device, it is desirable to set the apparatus to initiate its operation a certain period of time after the setting of the apparatus. To this end, it is preferred to employ a delay switching circuit H in association with the trigger circuit D.

A description will be made in connection with one example of the circuit construction embodying this invention.

Referring to FIG. 2, a description will be given first of one example of the delay switching circuit C. Namely, the output of the amplifier B is rectified by a diode D and its rectified output is applied to a transistor Q A transistor Q is connected to the transistor Q the collector of which is connected through a capacitor C to the base of the transistor Q which is connected to the negative electrode of a power source J through a resistor R and a switch Sb described later. The transistors Q and Q; are designed to constitute a kind of a bistable multivibrator and the capacitor C and the resistor R form a time constant circuit of the bistable multivibrator. Namely, the transistors Q and Q are interconnected in a manner to be alternately switched on and off to produce rectangular waves m at regular time intervals as shown at the top of the figure. Connected to the output side of the transistor Q, is a relay Ya, whose contacts a, and a are adapted to be opened and closed under the control of the transistor Q,. The relay Ya and its contacts a, and a correspond to the trigger circuit D previously described with FIG. 1.

The operation of the delay switching circuit C will be described. When a signal derived from the amplifier B is rectified by the diode D to make the right-hand side of the capacitor C, negative relative to its left-hand side, the transistor Q, is switched on and the transistor O is switched off. This switching is determined by a time constant circuit consisting of the capacitor C and the resistor R, and the rectangular wave current indicated by m is applied to the relay Ya to achieve makeand-break of its contacts a, and a in accordance with the curve m.

In the event that a signal of a short duration is fed to the delay switching circuit C to switch the transistor 0,, the relay Ya conducts at least for a period of time corresponding to the duration of a first one of the rectangular wave signals m to close the contacts a, and a thereby to constitute a closed circuit of a power source J a buzzer Z, the contact a,- the power source 1,, causing the buzzer Z, to raise an alarm. Namely, even in the case of a signal whose duration is shorter than that of one rectangular wave m, the buzzer Z, is made to ring for a period of time corresponding to the duration of one rectangular wave m.

When the delay switching circuit C is supplied with a signal of a sufficiently long duration, the transistors Q, and Q serve as a bistable multivibrator for a period of time corresponding to the duration of the signal, that is, they are alternately switched on and off to produce an output such as indicated by the curve In to activate the relay Ya intermittently in accordance with the curve m, causing its contacts a, and a, to make and break correspondingly.

The ring counter E used in this invention may be a usual one. In the present example, however, the ring counter E is made up of four active elements such as thyristors SC, to SC and at every arrival of a pulse the ring counter E repeats conduction and nonconduction as usual. In this case a thyristor SC,, is connected to the stage preceding the thyristor SC, of the ring counter so as to ensure that the first thyristor SC, is caused to initiate its operation by a first signal and that the following thyristors are sequentially controlled to be conductive and non-conductive. To this end, there are provided a capacitor C and a resistor R the capacitor C being charged by the power source J, when a power source switch Sb for closing the circuit of the power source J, is closed and the resistor R passing therethrough the charging current. When the capacitor C is charged in accordance with the time constant determined by the capacitor C and the resistor R a pulse n depicted in the figure is applied to the control electrode of the thyristor SC to switch it on first.

Namely, when the relay contact a is closed only one differentiated pulse is generated through the capacitor C and the resistor R to trigger only the thyristor SC thus ensuring that counting starts from the thyristor SC Any one of the thyristors other than SC,,, for example, SC, cannot be triggered by a signal which is integrated by a resistor R, and a capacitor C attenuated by resistors R, and R,, and leaking from a differentiation circuit consisting of a capacitor C and a resistor R,,. Under such conditions, the capacitor C is not charged but the capacitor C remains charged and the cathode of a diode D is in a reverse biased condition. Consequently, when an input trigger voltage is lower than the value of the reverse bias. the diode D can conduct but the thyristor SC, is conducts to cause the voltage drop across the resistor R,, to be zero, so that the input pulse is fed through the diode D, and the capacitor C to the thyristor SC, to cause it to conduct. At the instance that the thyristor SC, becomes conductive, a differentiated pulse is generated across the resistor R connected in common to the cathodes of the thyristors to instantaneously make the cathode of the thyristor SC positive and the thyristor SC by having its anode held at zero potential is reversely biased and turned off. The thyristor next to SC, is also turned off. In this manher, the counting advances one step in response to one input pulse. Subsequently, the thyristors sequentially conduct at every arrival of an input pulse and when the thyristor SC, has become conductive a relay Yb is energized to close its contact b and hence provide a closed circuit of a power source 1;, to the buzzer Z through the contact b to ring the buzzer Z The operation of the present device may be summa rized as follows.

When a vibration of a relatively high frequency is picked up by the detector A, an electric signal corresponding to the vibration 1S supplied to the switching circuit C to cause it to actuate the relay Ya as above described. In this case, however short the vibration may be, an output signal corresponding to it is derived from the delay switching circuit C for the time corresponding to one rectangular wave m to actuate the relay Ya, causing the buzzer Z, to raise a preliminary alarm and turning off the thyristor SC,, and on that SC,. Similarly, the present apparatus operates at every occurrence of vibration and when the vibration has occurred four times the main alarm oscillator circuit G operates to sound the buzzer 2,.

in the event that a signal of a long duration is applied to the delay switching circuit C, an intermittent signal of a rectangular wave m is derived from the circuit C to ring the buzzer Z, and turn on and off the contact 0 at every occurrence of the intermittent signal and when the intermittent signal produces four or more pulses or when the signal continues for a period of time of more than four pulses the buzzer Z is similarly caused to ring to give an alarm for an intruder. Even when the signal does not continue for such a period of time, if it continues for a time long enough to actuate any one of the thyristors SC to SC.,, the main buzzer Z is not actuated immediately but it is operated later when the signal is produced so many times or for so long a time as to operate the thyristor SC.,.

in short, once the four stages of the thyristors SC to SC. have been turned on and off in a sequential order, the buzzer Z is rung to raise an alarm irrespective of whether the incoming signal is a series of shortduration signals or a continuous signal. Otherwise, the buzzer Z, is energized to give a preliminary alarm at every changing over of each thyristor.

In order to avoid accidental operation of this invention apparatus which might be caused by vibrations during the setting operation of the apparatus, an operator's walking or other accidental vibrations, it is preferred to employ a delay switching circuit H.

Referring to FIG. 2, one example of the delay switching circuit H will hereinbelow be described. Reference characters S, indicates a manual switch having connected in series thereto a relay Yb which is connected to the minus side of the power source J The relay Yb serves to operate the power source switch Sb. The delay switching circuit H includes a kind of bistable multivibrator with transistors Q and Q and in this case the circuit H is adapted not to actuate the relay Yb immediately when the switch S is turned on. The time constant of the bistable multivibrator is determined by a capacitor C and a resistor R which are interposed between the transistors Q and 0,. Reference characters R and R designate bias resistors for the base of the transistor Q R, a resistor incorporated in the circuit for charging the capacitor C, and R,, a resistor interposed between the emitters of the transistors Q and Q and the plus side of the power source J,. The operation of the above circuit will hereinbelow be outlined. In the steady state of the circuit H, the transistor Q, is in the off state and the base current of the transistor Q flows but when the manual switch S remains open the collector current of the transistor 0., does not flow. The capacitor C,, which is coupled with the resistor R to determine the delay time, is always charged through the base and emitter of the transistor 0,. Further, the emitter voltage of the transistor O is held a little negative by the resistor R so as to ensure that the transistor is turned off. Closing the manual switch S a negative voltage is applied to the base of the transistor Q, to turn it on. When the transistor 0;, is turned on, its collector current flows to cause a voltage drop across the resistor R and this voltage change is applied through the capacitor C to the base of the transistor Q, to hold it at a positive potential, so that the transistor Q. is turned off and no current is fed to the relay Yb. While, the base of the transistor Q is supplied with a higher negative voltage and this voltage is maintained at the moment of reversal of the operation of the bistable multivibrator. The capacitor C is discharged through the collector and emitter of the transistor 0:, to make the base of the transistor Q negative. Immediately when the base of the transistor 0., is rendered negative, the operation of the circuit is reversed and the relay Yb operates to return the collector potential of the transistor O to its saturated potential, thereby turning off the transistor Q With this delay switching circuit H, the apparatus of this invention initiate its operation about 15 seconds after setting.

Consequently, the relay Yb does not operate immediately after the closing of the switch S, but initiates operation after a certain period of time, for example, approximately 15 seconds to turn on the power source switch Sb. This leads to the normal operation of this invention apparatus described above, so that if the operator leaves the apparatus within about l seconds after setting, no accidental actuation of the apparatus occurs due to vibrations caused by him.

As has been described in the foregoing, the apparatus of this invention is designed to pick up mechanical vibrations or sound waves caused when an intruder approaches or touches the safe or enters a room where the safe is placed and to raise an alarm when the numher and the duration of the vibrations have reached certain values, thus ensuring the protection of the safe from theft.

Although the present invention has been described in connection with the case where an alarm is given when the number and the duration of mechanical vibrations caused by an intruder have reached a certain value, the invention is not limited specifically to the above but the vibration-responsive apparatus of this invention may be designed to achieve a desired operation or control other device when vibrations caused at unspecific times continue by a certain number of times or for a certain period of time. Accordingly, the present invention provides a control device adapted not to respond to a vibration caused less than a certain number of times, for example, four times or for a shorter period of time than a predetermined one but to achieve various operations such as previously described when vibrations are caused a predetermined number of times. Further, since the apparatus of this invention is designed to initiate operation after a long period of time within which an operator can leave from the place where the apparatus is located, care need not be taken to prevent vibrations during setting of the apparatus.

Although the present invention has been described as applied to the alarm device which gives an alarm in response to vibrations caused four times or a signal continuing for a time corresponding thereto, it is needless to say that this number may be altered as desired.

It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts of this invention.

I claim as my invention:

1. A vibration responsive apparatus for detecting mechanical vibrations propagated through a solid or fluid comprising:

means for detecting said mechanical vibrations and producing an electrical output signal when said mechanical vibrations occur;

a first electrical wave generator receiving the electrical output signal from said detecting means and producing a pulse of standard time length each time an electrical output signal is received from said detecting means and producing a series of standard time length pulses if said electrical output signal from said detecting means persists longer than said standard time length, said first electrical wave generator comprising a multivibrator including a pair of transistors with a period equal to said standard time length;

a pulse generator connected to the output of said first electrical wave generator and producing a pulse each time a standard time length pulse is generated by said first electrical wave generator;

a second electrical wave generator receiving the output of said pulse generator and comprising a ring counter for counting said pulses; and

an output warning device connected to the output of said second electrical wave generator and producing an alarm if a predetermined number of standard time length pulses are produced by said first electrical wave generator.

2. A vibration responsive apparatus according to claim 1 wherein said pulse generator comprises a relay connected to the output of said first electrical wave generator and closed each time a pulse of standard length is received, a first silicon controlled rectifier with its output connected to said electrical wave generator, a voltage source, a capacitor connected between said voltage source and the gate electrode of said first form a ring counter with the gate of the first of said cascaded silicon controlled rectifiers connected to said first silicon controlled rectifier and the gates of succeeding cascaded silicon controlled rectifiers connected to the outputs of preceding silicon controlled rectifiers and the last of said cascaded silicon controlled rectifiers connected to said output warning de- VlCe w: 1: I: I

Claims

1. A vibration responsive apparatus for detecting mechanical vibrations propagated through a solid or fluid comprising: means for detecting said mechanical vibrations and producing an electrical output signal when said mechanical vibrations occur; a first electrical wave generator receiving the electrical output signal from said detecting means and producing a pulse of standard time length each time an electrical output signal is received from said detecting means and producing a series of standard time length pulses if said electrical output signal from said detecting means persists longer than said standard time length, said first electrical wave generator comprising a multivibrator including a pair of transistors with a period equal to said standard time length; a pulse generator connected to the output of said first electrical wave generator and producing a pulse each time a standard time length pulse is generated by said first electrical wave generator; a second electrical wave generator receiving the output of said pulse generator and comprising a ring counter for counting said pulses; and an output warning device connected to the output of said second electrical wave generator and producing an alarm if a predetermined number of standard time length pulses are produced by said first electrical wave generator.

2. A vibration responsive apparatus according to claim 1 wherein said pulse generator comprises a relay connected to the output of said first electrical wave generator and closed each time a pulse of standard length is received, a first silicon controlled rectifier with its output connected to said electrical wave generator, a voltage source, a capacitor connected between said voltage source and the gate electrode of said first silicon controlled rectifier, and a switch connected across said capacitor and controlled by said relay.

3. A vibration responsive apparatus according to claim 2 including a resistor connected between the gate of said first silicon controlled rectifier and said second electrical wave generator.

4. A vibration responsive apparatus according to claim 2 wherein said ring counter includes a plurality of cascaded silicon controlled rectifiers connected to form a ring counter with the gate of the first of said cascaded silicon controlled rectifiers connected to said first silicon controlled rectifier and the gates of succeeding cascaded silicon controlled rectifiers connected to the outputs of preceding silicon controlled rectifiers and the last of said cascaded silicon controlled rectifiers connected to said output warning device.