US 3594748 A
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Description (OCR text may contain errors)
United States Patent 1,815,941 7/1931 Blair et al. 340/277 UX 3,440,636 4/1969 Sliman 340/280 FOREIGN PATENTS 277,848 9/1951 Switzerland 340/277 Primary Examiner lohn W. Caldwell Assistant ExaminerDavid L. Trafton Attorney-Richards & Geier ABSTRACT: A portable radio transmitter for personal protection wherein the energizing circuit contains a tilt-responsive switch and a pressure-sensitive switch, both switches normally held in an open circuit condition by the manner in which the transmitter is carried.
PATENTEB JULZOIHYI 3, 594', 748
IAN 01707? A. E-rotjah ai -LL? TTORNEE PMENTED JUL20 I97! SHEET 2 OF 2 INVENTOR TTORNEBG DESCRIPTION The inventionrelates to an alarm signalizer with a miniature transmitter, which can be carried by a personor used in connection with an object to be protected and which can be released via a gravity-responding switch and via a selection switch responding to pull or pressure.
It is an object of the invention to provide an alarm signalizer which releases an alarm signal in all feasible cases requiring the protection of a person or an object and particularly in such cases in which the person to be protected is unable to actuate the device.
Another object is to provide an alarm signalizer which for the protection of an object is released as soon as this object is exposed to interference from outside.
Still another object of the invention is to constructthe alarm signalizer in such a size that it may easily be carried by the person to be protected or joined with the object to.be protected.
According to the invention, the alarm signalizer, which is provided with a miniature transmitter, has a gravity-responding switch which is provided as an annular mercury contact tube, one circumferential half of which accommodates a midpositioned contact which is in direct connection with a supply of electric current and two external parallel contacts which are connected 'to the miniature transmitter. In the opposite circumferential half of the annular tube two additional contacts are provided which are in parallel connection with the contacts of the first-mentioned half.
The annular mercury contact tube consists of an annular glass tube the sectional diameter of which depends on the surface or skin stress of the mercury; in the initial or resting position of the device the cohesion of the mercury is stronger than its adhesion to the inside wall of the glass tube. lf'thequantity of mercury approximately equals half the volume of the annu- I lar tube, the mercury fills up the whole of the cross section of the tube and half its circumference when the tube is in horizontal position. The other circumferential half is in this case void of mercury and therefore an alarm cannot be released. By a minimum of vibration, the surface or skin stress of the mercury is eliminated and the mercury is distributed over the whole circumference of the annular tube, wetting its contacts and closing the electric circuit for the release of an alarm signal.
The contacts of the second-mentioned circumferential half of the tube, which are in parallel connection with the contacts of the first-mentioned half, are preferably designed as dampening elements for the mercury filling and advantageously consist of discs of smaller diameters than the inside diameter of the annular tube.
An annular mercury contact tube of this type will always close an alarm-releasing contact if the person carrying the device raises his arms at his sides or over his head. The combination of the mercury contact tube with the selective switch, which responds to pressure or relief of pressure, enables protection of objects of any kind: the object concerned may, for
instance, be laid on the alarm signalizer, the selection switch of which is adjusted to respond to relief of pressure, which causes a contact to be closed and the alarm signal to be released if the object concerned is removed from the device.
Another feature of the invention is to provide a changeover switch which is connected in series with the above-mentioned selective switch or reverser and can be locked in its end positions. By this changeover switch the action of said selective switch or reverser can be adjusted selectively to respond to pressure exerted on the device or to relief of pressure.
In a preferred embodiment of the invention, the selective switch or reverser of the device may be actuated by a lid or cover member of the casing in which the miniature transmitter and the control means are accommodated, which lid can be turned about an axis. This causes a contact of the reverser to be closed and the release of an alarm signal even when a minimum of movement or displacement of the person or object to be protected takes place.-Altern'atively,the actuation member of the reverser may have the shape of a head or plate screwed on its axis or of any other suitable design. The device according to theinvention therefore offers a versatile and reliable means of protection for persons and objects in all cases one might think of.
Other objects and advantages of the invention will be explained in the following more detailed description, in which reference is made to the accompanying drawings, in which a preferred embodiment of the invention 'is illustrated. In the drawings,
FIG. 1 is a top view ofthe alarm signalizer with open lid;
FIG. 2 is a side elevation ofthe alarm signalizer of FIG. 1;
FIG. 3 is a partial sectional view taken along the line III-III of FIG. 1;
FIG. 4 is a circuit diagram;
FIG. 5 is'a side view of the annular mercury contact tube in a vertical position;
FIG. 6 is a tope view of the annular mercury contact tube in a horizontal position;
. FIG. 7 is a section taken through the annular tube 7 in the direction of the contacts 14 and 16.
With reference to FIG. 1, a switch combination, which will be described further below, is together with a dry cell battery 6 and a miniature transmitter 5 accommodated in a casing l of size and shape similar to a cigarette box. At one end of the rectangular casing I a cover lid 3 is pivotally mounted on an axle journal 4, the two ends of which project over the edges of the casing. Said lid 3 is under the action of a pressure spring 8. The lateral edges of lid 3 overlap the edges of casing I.
Within the casing I, a miniature transmitter 5 is mounted underneath the axle journal 4 and, when connected with the battery 6 which is underneath the transmitter, transmits a constant frequency. The transmitted frequency is selectively received by a nearby receiver, which is not shown in the drawing, and by an integrating circuit is conveyed to release the alarm. The integrating circuit may, for instance, consist of a condensor which is loaded via a rectifier and is connected with a rapid discharge circuit in such a manner that interruption of the transmitted frequency causes an immediate rapid discharge of the condensor. Therefore alarm signals can be released only by emission of a frequency of a certain duration, e.g. 4 seconds. Experience has shown that such circuit arrangement is sufficient to prevent to necessary extent unwanted release of alarm signals.
As will be seen from the circuit diagram in FIG. 4, a contact device responding to gravity is provided by an annular mercury contact tube 7 interposed in the circuit between the battery 6 and the miniature transmitter 5. Said contact tube consists of an annular evacuated glass tube 7, half of its volume being filled with mercury 9. The sectional diameter of tube 7 is in conformance with the surface or skin stress of mercury and has a length of approximately 6 mm. A glass tube of such a diameter causes the cohesion of the mercury to be stronger than its adhesion to the smooth inside wall of tube 7. Consequently, in the horizontal position of tube 7, the mercury 9 fills up the whole of the section of tube 7 in half its circumference, as shown in FIG. 6 of the drawings. The other half of circumference of tube 7 is not wetted with any mercury.
In one circumferential half of annular tube 7, which is the upper one in the drawings, two interior contacts 13 which are joined with each other and two exterior contacts 14 and 15 which are connected in parallel with each other, are provided. These contacts l3, l4, 15 have the shape of rectangular electrodes as is apparent from the sectional drawing of FIG. 7. The opposite half of the circumference of tube 7 houses two contacts 16 and 17, the circuiting of which is shown in FIG 4, and which (see FIG. 7) are in the shape of radially arranged discshaped electrodes, which together with the inside wall of the tube 7 form an annular passage for the mercury filling 9 and act as dampening elements. Dampening of the mercury liquid is of particular importance where the device is used for the protection of objects, as will be explained later.
According to the circuit diagram of FIG. 4, in parallel connection with the mercury tube 7 is a selective switch or reverserll which responds to tension or pressure on the lid 3 of the casing. In a corner of casing 1 remote from the axle journal 4 a circuit breaker 2 is arranged in the part of the circuit leading from the two parallel contacts, l4, 15 to the miniature transmitter 5. The circuit breaker 2 may be operated from outside (cf. FIG. 1). Arranged in the opposite portion of easing 1 is a changeover switch which may also be operated from the outside and may be locked in its end positions. The changeover switch 10 connects one of two spring contacts of reverser 11 with the miniature transmitter 5. A second circuit breaker 18 is provided in the lead connecting the contacts 13 with contact 17.
The pressure spring 8 acting on the casing lid 3 is arranged in the center of the annular mercury contact tube 7 and is I designed as a screw spring, in place of which one may use with the same advantage a leaf spring or a torsion spring wound around axle journal 4 to prop the casing lid 3.
The reverser 11 is actuated by an internal shoulder 12 of casing lid 3. Depending on the position of the changeover switch 10, one or the other contact of reverser 1 1 is connected with the miniature transmitter 5.
The alarm signalizer operates in a manner described in the following:
If the signalizer is used for protection of things the changeover switch 10 is shifted into the position which in FIG. 4 is shown by full lines and reverser 11 is in dependence of the position of switch 10 adjusted to respond to pressure or pull exerted on lid 3.
The circuit breaker 2 is in the position represented in the drawing switched on. Therefore, all the contacts of the annular mercury contact tube 7 are in operation.
For protection of persons the casing 1 has a basically vertical position in which the person to be protected may carry it, for instance, at his upper arm or in a pocket. In this vertical position, the mercury filling 9 of annular tube 7 fills the space shown in FIG. 5. In this case the two contacts 16 and 17 are short circuited by the mercury filling 9. As soon as the person makes a movement, for instance raises his arms, or the position of the annular tube 7 is in any other way altered, the mercury 9 fiows from the midposition of FIG. 5 to one or the other side and closed either contact 14 or contact 15, which causes the alarm-releasing circuit to be closed.
Where objects are to be protected the device is placed on or beneath the object in question. The mercury filling 9 will then fill up only one circumferential half of annular tube 7, which will be in horizontal position, as indicated in FIG. 5. The other circumferential half containing the contacts 13 and 14 and 15 is void of mercury because, due to its surface or skin stress, the mercury is retained in the other circumferential half of the tube. When any vibration or change of position occurs the surface stress of the mercury filling 9 is overcome and the mercury liquid spreads over the whole circumference of tube 7, as shown in FIG. 7. This causes the electric circuit to be closed through the contacts 13, 14, and 16 and releases the alarm signal.
Additionally, displacements of the lid 3 of the casing cause, depending on the position of the changeover switch 10, one of the contacts of the annular mercury tube to be by the reverser 11 connected to the circuit of battery 6 and transmitter 5. There is, therefore, a multitude of possible ways of actuation of the miniature transmitter 5.
The alarm signalizer according to the invention can be operated if the casing lid 3 is either pressed on or relieved from pressure. An alarm-releasing circuit is also closed if the position of casing 1, and, together therewith, of the annular mercury contact tube 7 is altered or if casing l is subjected to vibrations. In this case, the provision of the contacts 16 and 17, which act as throttle plates, avoids unwanted alarm signals to be caused by excessive movement of the mercury filling 9 due to vibration, for instance of travelling vehicle.
A particular advantage of the device 15 tn that electric current is needed, only for the transmission of an alarm signal over a period of some seconds, which gives the battery 6 a long useful life.
Having described my invention, it is apparent that the embodiment shown in the drawing is only an example of the invention and alterations and other combinations of parts are fully within the scope of the invention and the appended claims.
1. An alarm signalizer for the protection of persons and objects, comprising a casing adapted to be attached to the person and the object to be protected, a cover lid movably mounted upon said casing, a miniature transmitter located within said casing, a source of electric current located within said casing, an alarm-releasing circuit located with said casing and connected to said transmitter and said source, said circuit including a gravity-responding switch and a pressure-responding switch means, and means engaging said cover lid and said pressure-responding switch means and operating said pressure-responding switch means depending upon pressure or relief from pressure exerted upon said cover lid.
2. The alarm signalizer according to claim 1 wherein an annular mercury contact tube in a circumferential half is provided with a midpositioned contact directly connected to a dry cell battery and two external paralleled contacts connected with said miniature transmitter.
3. The alarm signalizer according to claim 2 wherein the circumferential half of said annular tube which is opposite to said first group of contacts is provided with a second group of two contacts in parallel connection with said contacts.
4. The alarm signalizer in accordance with claim 3 in which the contacts are adapted to form dampening elements for the mercury filling ofsaid annular tube.
5. The alann signalizer according to claim 4 wherein the contacts are formed as disclike electrodes of a diameter smaller than the internal diameter of said annular tube.
6. The alarm signalizer as claimed in claim 2 wherein the annular mercury contact tube consists of an annular glass tube the sectional diameter of which is dependent on the surface stress of the mercury filling, which in the resting position causes the cohesion of the mercury to exceed its adhesion to the inside wall of said glass tube.
7. The alarm signalizer according to claim 2 wherein the quantity of mercury filling corresponds to half the volume of the annular tube.
8. The alarm signalizer according to claim 1 in which a changeover switch is in parallel connection with the reverser, which responds to pressure or relief of pressure exerted to the cover of the device and is lockable in its end Jsitions.
9. An alarm signalizer according to claim 1 wherein a lid of the casing, in which the miniature transmitter is housed, is pivoted to an axle journal and forms an actuation member for the reverser.