The invention relates to a rescue system, comprising a ring-shaped neck brace comprising an accommodation for at least one inflatable and foldable hollow body, a gas storage for filling the hollow body with gas, wherein the gas storage can be triggered in an automated manner by means of a circuit.

A plurality of rescue systems, which can also be provided with self-triggering gas storages, is already known from the prior art. It is known, for example, in this context that a triggering mechanism includes a pill or capsule-shaped triggering body, which triggers upon contact with water, wherein the gas storage is released after triggering the triggering body, so that the hollow body fills automatically. Such a rescue system is mostly offered in the form of a life vest.

Further options for triggering a rescue system in an automated manner in order to generate additional buoyancy are known from WO 2014/076685 A1 . Position sensors, motion sensors, pressure sensors, temperature sensors and pulse sensors, for instance, are known from this publication. All of these sensors, however, determine the contact with water only indirectly, for example via a temperature change, a pressure change or a change in position. Such changes, however, can also occur independent from contact with water.

For the most part, rescue systems are embodied in the form of life vests, which at least partially cover breast and back of the person wearing them. Even though such life vests can also be embodied so as to be compact, they are always an encumbrance to the person wearing the life vest. This is why the intended use of such rescue systems is limited to use in emergencies and uses, in which the user already wears clothing, for example while sailing. Such rescue systems, however, are not suitable for swimming or taking a bath.

However, accidents happen more and more frequently when taking a bath or swimming, in particular to inexperienced persons. The so-called silent drowning as a result of a circulatory collapse is particularly critical thereby. Persons, who do not yet know how to swim, in particular children, furthermore often also have an accident while taking a bath.

The invention is based on the object of providing a rescue system, which, on the one hand, only limits the users insignificantly and which, on the other hand, triggers reliably in emergency situations.

This object is solved by means of the features of claim 1 . The subclaims refer to advantageous embodiments.

To solve the object, at least four sensors for detecting the electrical

resistance, which are arranged so as to be distributed across the

circumference of the neck brace, are assigned to the circuit, wherein the sensors detect the change of the electrical resistance, when water instead of air is located between the sensors. According to the invention, the neck brace thus comprises at least four conductivity sensors. They continuously detect the resistance or the

conductivity, respectively, of the medium arranged between the two sensors. Two conductivity sensors thereby form a sensor pair in each case, so that the neck brace comprises at least two sensor pairs of conductivity sensors. In the upright position, thus when the user's head and neck projects out of the water, only air is located between the two sensors. In swimming position, thus when the user's neck and head are partially submersed in the water, water as well as air is located between the sensor pairs. The conductivity sensors use the characteristic that the electrical resistance of air is extremely high, whereas the electrical resistance of water is measurably small. The specific electrical resistance of water is approximately 2 x 10 ⁸ Ohm x mm ² / m and the specific electrical resistance of seawater is approximately 5 x 10 ⁵ Ohm x mm ² / m.

If air is thus located between the sensor pairs at least in sections, as it is the case according to the invention in the upright position and in the normal swim position, the electrical resistance between the two sensors is very high or the electrical conductivity between the sensors is very low, respectively. Once the user submerses completely below the surface of the water, only water is located between the sensor pairs. The electrical resistance decreases substantially in this case or the electrical conductivity increases substantially, respectively. This change of the electrical resistance between the sensor pairs is detected in the circuit and the gas storage is triggered, if applicable, after a preselected time has lapsed, so that the hollow body fills with the gas from the gas storage. The buoyancy of the rescue system thus increases significantly and the user is moved to the surface of the water.

The sensors of a sensor pair are preferably arranged adjacent to the neck brace. The distance between the sensors is thus small, so that only little auxiliary energy is required to be able to detect a change of the conductivity between the sensors.

It is problematic, however, in the case of this embodiment that individual drops of water, which wet the neck collar, can possibly already effect a triggering of the gas storage. To prevent this, at least two sensor pairs are present according to the invention, wherein the second sensor pair is preferably spaced far away from the first sensor pair. In an advantageous embodiment, the sensors are linear-shaped and can be arranged on a circumference of the neck brace. In this embodiment, two linear-shaped sensors are arranged parallel to each other on the neck brace. Advantageous is here that the conductivity gradually changes with increasing use of the sensors with water. Furthermore, the triggering time, depending on the circumstances, can be variated by determining different values as a threshold for the conductivity. The linear-shaped sensors can lie within an angular range of 120° until 150°, preferably 135°. In this embodiment, the sensors are preferably arranged on the neck brace in a way that they point in the direction of the shoulder area of the user, when the rescue system is being equipped. The sensors can consist of a metallic and water-resistant metal and can be embedded in the neck brace in a way that the sensors are in flush with the surface of the sensors. Alternatively, the sensors can consist of a conductive plastic. In this connection, preferably thermoplastic plastics, elastomers or silicones provided with metal or graphite particles can be taken into account. By using these thermoplastic materials and silicones, the housing of the neck brace with the sensors can be produced in one piece by means of

two-component injection molding.

The auxiliary energy for the operation of the conductivity sensors is provided by means of batteries or accumulators. Batteries in the form of button cells, which are arranged in a water-tight manner in a housing together with the circuit, are thereby preferably used. The housing is preferably embodied in once piece and of the same material from the neck brace and can be closed by means of a cover, which closes in a water-tight manner.

The energy provided by the battery or the accumulator is preferably also used to trigger the gas storage. In an advantageous embodiment, the circuit comprises a triggering device, wherein the gas storage is triggered by means of a mechanical triggering device.

The mechanical triggering device is embodied as bolt, for example, which is pretensioned by means of a spring and which perforates the metallic cover of the gas storage when being triggered. The release of the mechanical triggering device is prompted by the circuit. For this purpose, the bolt can be released, for example by moving a lever or the like. Only a small amount of auxiliary energy is necessary in this case. The mechanical triggering device can furthermore be operatively connected to a manual triggering device, which provides for a manual triggering of the gas storage by the user.

The manual triggering device can be embodied as a knob or a handle, which is pulled out of the neck brace for triggering. The knob or handle can comprise recessed grips or the like for better handling.

Due to the fact that the rescue system is embodied in the form of a ring- shaped neck brace, which is worn around the neck of the user, the head of the user is conveyed safely above the surface of the water when being triggered. Due to the density of the person, which is comparable to water, only a comparatively small buoyancy is necessary hereby in order to safely convey the user above the surface of the water. Depending on the body weight of the user, the necessary buoyancy is between 40 Newton and 80 Newton. This is attained by means of a gas-filled hollow body comprising a volume of between 3.5 dm ³ and 7 dm ³ .

Due to the fact that only a small amount of additional buoyancy must be exerted, the hollow bodies can be embodied so as to be compact. It is thus possible to produce a neck collar, which is embodied so as to be compact, which can be worn with few restrictions for the user.

In an advantageous embodiment, the gas storage is embodied as CO2 cartridge. A CO2 cartridge, also identified as CO2 cartouche, is a standardized cartridge, which is available for a wide variety of intended uses in a cost- efficient manner. A standard CO2 cartridge contains between 8 g and 16 g of CO2. The weight of such a CO2 cartridge is only between 25 g and 50 g with a length of between 65 mm and 80 mm and a diameter of between 16 mm and 20 mm. Such CO2 cartridges are sufficient for creating a hollow body comprising a volume of between 4 dm ³ and 8 dm ³ . A single CO2 cartridge is thus sufficient for safely conveying a person in need of being saved to the surface of the water.

In an advantageous embodiment, the CO2 cartridge consists of a cylindrical metal container and is closed by means of a perforable metallic cover on the front side. Depending on the embodiment of the neck collar, it is possible for the CO2 cartridge to have an alternative shape.

The rescue system is thereby embodied in such a manner that the rescue system can be regenerated easily by exchanging the CO2 cartridge. The hollow bodies can also be emptied after use and can be folded back into the accommodation. It is thus possible to use the rescue system several times. The gas storage is preferably arranged in the housing and is covered by means of a cover, which can be opened easily and which can be closed in a water-tight manner.

The circuit preferably triggers the gas storage in a time-delayed manner after detecting a change of the electrical resistance. The user is thus able to make dives, without the rescue system triggering immediately. It is furthermore possible to also use the rescue system when waves are present, in response to which it might happen that the rescue system is temporarily wetted with water completely, so that only water is temporarily located between the sensors, and the electrical resistance decreases. The time delay can preferably be preselected. It is possible in particular in this context for the user to be able to preselect a time of 30, 60 or 90 seconds, for example. Depending on the preselected time, the rescue system is only triggered when the sensors determine a change of the electrical resistance and the preselected time has lapsed. Longer dives are thus also possible for the user when desired, for snorkeling, for example. For this purpose, the rescue system is equipped with a simple rotary switch or the like. The rotary switch makes it possible to preselect the time delay. A confirmation of the preselected time delay can be made by means of a corresponding LED display.

In an advantageous embodiment, provision is made for a manual triggering device, which, in addition to the automated triggering, provides for a manual triggering by the user. For this purpose, a push button or a lever is arranged on the outer circumference of the neck brace, preferably in the area of the housing. The manual triggering device can be alternatively embodied as a knob or a handle, which is pulled out of the neck brace for triggering. The knob or handle can comprise recessed grips or the like for better handling. Once the user recognizes his own emergency situation, he can activate the push button or the lever and thus trigger the gas storage. When the push button is pushed, the triggering occurs via the circuit. The lever can effect a purely mechanical triggering of the gas storage and can act independently from the circuit in this regard. The lever, knob or handle can engage directly with the mechanical triggering device for this purpose.

In an advantageous embodiment, two sensor pairs are arranged so as to be located opposite one another on the neck brace. In this embodiment, the sensor pairs are spaced apart from one another such that, independent from the position of the sensors relative to the user, a change of the electrical resistance can only be determined when the neck brace is below water. An accidental premature triggering can be prevented through this. According to an advantageous further development, provision is made for four sensors pairs, which are distributed evenly across the circumference of the neck brace, for detecting the electrical resistance. Due to the multi-redundant set of sensor pairs, the safeguarding against failure is improved. A plurality of triggering options is provided in this case. In a first embodiment, a triggering occurs when only one of the sensor pairs determines a decrease of the electrical resistance. In a second embodiment, however, the circuit can also be designed in such a way that the possibility of an accidental triggering is minimized in that a triggering only occurs when all sensor pairs determine a decrease of the electrical resistance within a predetermined time span. It is advantageous thereby, when the sensor pairs are in each case activated individually and consecutively. In the case of this embodiment, error currents are prevented and auxiliary energy is saved.

It is possible for the neck brace to be equipped with up to eight sensor pairs. They are arranged so as to be distributed across the circumference of the neck brace. The neck brace can be provided with a size-adjustable snap closure. This makes it possible to put on the neck brace in a simple and secure manner. The neck brace can furthermore also be removed easily after taking a bath or after swimming, respectively. The snap closure is preferably arranged opposite the housing, in which the circuit, the battery and the gas storage are arranged.

The neck brace preferably consists of an elastomeric material. It is in particular possible in this context for the neck brace to be made of a silicon material. Such materials are water-resistant or seawater-resistant,

respectively, and can be worn comfortably.

The neck brace can also be a part of a piece of clothing, for example of a wetsuit or of a T-shirt. The neck brace comprising the rescue system according to the invention is incorporated into the piece of clothing in this case and is fixedly connected thereto. In the alternative, the neck brace can also be provided with fastening means, for example snaps, which make it possible to fasten the neck brace in a piece of clothing.

An acoustic and/or optical device, which signalizes that the gas storage is triggered to fill the hollow body after a predetermined time, can be assigned to the circuit. The user is hereby notified early on that the triggering of the gas storage is imminent. The user is thus able to get to the surface of the water independently. An inadvertent triggering of the gas storage can be prevented through this.

In addition to the above-described sensors for changing the electrical resistance, provision can be made for further sensors. In particular pressure sensors and temperature sensors are possible in this context. The risk of an accidental triggering can be minimized once again through this.

Some of the embodiments of the rescue system according to the invention will be explained in more detail below by means of the figures. In each case schematically

Fig. 1 shows a rescue system with emptied hollow bodies;

Fig. 2 shows a rescue system with an open cover;

Fig. 3 shows a rescue system with filled hollow bodies;

Fig. 4 shows a rescue system with linear-shaped sensors.

Figures 1 and 2 show a rescue system 1 in the form of a ring-shaped neck brace 2. The neck brace 2 consists of an elastomeric material, in this embodiment on the basis of silicon. For easy opening and closing, the neck brace 2 is provided with a size-adjustable snap closure 7. The neck brace 2 can be made in different sizes, so that the user can select the optimal size.

The neck brace 2 is provided with an accommodation for at least one inflatable and foldable hollow body 3. In this embodiment, provision is made for two hollow bodies 3, each of which are arranged in a pocket 8 molded into the neck brace 2. The hollow bodies 3 are thus integrated completely into the neck brace 2. In the alternative, it is possible to embody a circumferential hollow body. The pockets 8 are provided with sealing lips 9. The latter consist of elastomeric material and close the pockets 8 in such a manner that only a line-shaped opening remains. The accidental engagement with the pockets 8 can be avoided through this. The elastic sealing lips 9 simultaneously provide for an unhindered unfolding of the hollow bodies 3. The pockets 8 are arranged located opposite one another on the neck brace 2.

The hollow bodies 3 are embodied in a sack-shaped manner and consist of a plastic fabric, which is coated in a substantially air-tight manner and which has a conspicuous coloring in a signal color, for example neon yellow or neon orange, so as to find it more easily. The hollow bodies 3 are filled via a gas storage 4, which is arranged in a housing 10, which is integrally molded into the neck brace 2. The gas storage 4 is embodied as CO2 cartridge and is fixed in the neck brace 2 by means of an adapter so as to be capable of being exchanged. The adapter can be embodied as screw adapter. To exchange the gas storage 4, a cover is opened and the gas storage 4 is unscrewed and is replaced with a new or regenerated gas storage 4, respectively. A connection between gas storage 4 and hollow body 3 is established by means of triggering and the hollow bodies 3 are filled abruptly. The hollow bodies 3 unfold thereby and push out of the pockets 8. The triggering occurs by means of a mechanical triggering device, comprising a spring-loaded bolt, which perforates the metallic cover of the gas storage 4 after the triggering. The mechanical triggering device, in turn, is triggered by means of an electromechanical component.

The monitoring of the sensors 6 and the triggering occurs by means of an electric circuit 5, which is integrated into the neck brace 2 and which provides for an automatic independent triggering. The electromechanical component is also integrated in the circuit 5. The circuit 5 is arranged in the housing 10, which is integrally molded in the neck brace 2. In addition to the circuit 5 and the gas storage 4, the housing 10 also accommodates the battery 1 1 , which is required for operating the circuit 5 and for providing the auxiliary energy for the sensors 6. The housing 10 is closed in a water-tight manner by means of a removable cover 12. A lever 13, which provides for a manual triggering of the gas storage 4 by the user, is integrated in the cover 12. The lever 13 is in operative connection with the mechanical triggering device. Alternatively, the handle 13 can be embodied as a knob or handle, whereby the manual triggering occurs by pulling out the knob or handle. The knob or the handle can comprise recessed grips. In the case of the embodiment at hand, two sensor pairs 6, which are arranged so as to be distributed across the circumference of the neck brace 2, for detecting the electrical resistance are assigned to the circuit 5. Two sensors 6 are in each case combined to form one sensor pair in the case of this embodiment. In the case of the embodiment at hand, two sensor pairs are in each case attached to the neck brace 2 so as to be located opposite one another. The sensor pairs 6 thereby detect a change of the electrical resistance, if water instead of air is located between the sensor pairs 6. In the case of the embodiment at hand, the circuit 5 triggers the gas storage 4 only when all sensor pairs determine a significant decrease of the electrical resistance simultaneously or at last within a short time interval. This is only the case, however, when the neck brace 2 is wetted with water completely.

The sensors consists of an injection-molded and conductive plastic and is in flush with the surface of the neck brace 2 by means of two-component injection molding.

To prevent a premature triggering of the gas storage 4, the circuit 5 is provided with a time delay. The latter causes the circuit 5 to trigger the gas storage 4 in a time-delayed manner after detecting a change of the electrical resistance. The time delay can be preselected thereby. A rotary switch, by means of which a time delay of 30, 60 or seconds can be adjusted, is located on the neck brace 2 for this purpose.

An acoustic and optical device 8, which signalizes by means of an acoustic or light signal that the gas storage 4 is triggered to fill the hollow body 3 after a predetermined time has lapsed, for example 15 seconds after the beginning of the signal, is assigned to the circuit 5. In the alternative, the circuit 5 is provided with an acoustic or an optical device 8. In addition to the sensors 6 for determining the electrical resistance, provision can be made for further sensors, such as pressure sensors, temperature sensors and pulse sensors. Pulse sensors, for example, make it possible to trigger the gas storage 4 as a function of the state of the user and

independent on the water position. A particularly simple tapping of a pulse signal is possible in connection with the neck brace 2.

Figure 3 shows the rescue system 1 described in Figure 1 , wherein the gas storage 4 was triggered and the hollow bodies 3 are filled and generate buoyancy. After rescue has taken place, the rescue system 1 can be regenerated, in that the 3 hollow bodies are folded into the pockets 8 and a new gas storage 4 is screwed in. A decrease of the electrical resistance is detected only when the rescue system 1 is wetted with water completely or is submersed in water completely, respectively, and the gas storage 4 for filling the hollow bodies 3 is triggered. The unfolded hollow bodies 3 generate sufficient buoyancy to bring the swimmer safely to the surface of the water and to hold the swimmer's head above water.

Figure 4 shows a rescue system 1 according to the previous figures. In this embodiment, the sensors are linear-shaped and two sensor pairs 6 are each arranged parallel to each other on one side of the neck brace 2. The linear- shaped sensors lie within an angular range of 135°. Thereby, the sensor pairs 6 detect a change of the electrical resistance, if there is air instead of water located between the sensor pairs 6 and if a given threshold of conductivity is exceeded by wetting the sensor pair 6 with water. In the present embodiment, the circuit 5 only triggers the gas storage 4, if all sensor pairs detect a significant drop of the electrical resistance within a short time interval.

However, this is only the case, if the neck brace 2 is completely wetted with water. The sensors consist of an injection-molded and conductive plastic and are inserted into the neck brace 2 in flush with the surface of the neck brace 2 by means of two-component injection molding.