Abstract: A warning device comprised of an electrochemical cell which detects the concentration of toxic gas that is passing through a housing holding the cell to a face mask. The cell produces a signal corresponding to the concentration level of toxic gas present. The signal is received by a threshold switch which is set to produce a signal only when a signal from the cell equals or exceeds a predetermined level. The signal from the threshold switch activates a visual signal means and acoustical signal means to indicate that a gas filter, connected to the warning device, is exhausted.

Abstract: The invention is a spacer of a respirator bag to be carried in front of the chest. Inside the respirator bag an oxygen producing chemical cartridge is positioned. On the outside of the respirator bag facing the body of the carrier, a spacer body open at its top and bottom, is positioned as a spacer between the carrier and respirator bag.

Abstract: A respirator hood designed as an emergency escape hood and air filter device. A head protector is provided, which is simultaneously designed as a packing and stand-by container. The crown area of the respirator hood is provided as an impact-resistant head protector with the respirator hood being an integral component thereof. The respirator hood in its unused state is packed and stored under moisture-proof conditions within the head protector.

Abstract: The invention describes a closing device for the gas-tight closing of an ever-ready container consisting of two shells for respirators. The closing device is arranged on one shell part and has essentially trapezoidally designed tension bands on whose longer side of the trapezoid hook-shaped parts are arranged which engage in correspondingly defined counter parts on the other shell part. A tension lever with unequal legs holds the tension bands together under tension.

Abstract: Mounted in the front wall region of a hood is a curved replaceable facepiece lens. In order to obtain a gas-tight joint between the rigid component constituting the facepiece lens and the flexible garment material, as well as obtaining a distribution of the stresses which occur in the region of the junction between the facepiece lens and the garment material, a spherically-bent frame is enclosed by an overlapping cloth frame in the region of the opening for the facepiece lens and forms a firm connecting rim. Located as a seal between the said connecting rim and the rigid facepiece lens is an elastic coupling gasket.

Abstract: An air conveyor for gas test tubes used in the detection of foreign gases or suspended matter in air having an instrument body in the form of a handle and including a channel therethrough. The body has at one end a sealing element for connecting the gas test tube to the channel and at its other end a suction element in the form of a bellows. A base plate is included to which the suction element is mounted and has an air outlet valve therethrough and in communication with the bellows. A counter ring means is mounted to and rotatable about said body and including a spring biased locking element. A control rod is connected to the base plate and positioned for guided movement in the channel, said control rod being arrestable when said suction element is empty and releasable to initiate a suction stroke of said suction element by rotation of such counter ring.

Abstract: Ambiguous measurement results can be obtained in the measurement and indication of high concentrations obtained in air of combustible gases when employing the thermal effect principle. In order to prevent such ambiguities from arising, the measuring range is, in accordance with the invention, limited to the linear part of the characteristic curve of the measuring sensor and displayed digitally.

Abstract: A closed cycle respirator includes a breathing bag, the bottom of which is in communication with a canister containing a chemical that binds carbon dioxide and water vapor and liberates oxygen. Inside the breathing bag there is a distributor that guides the regenerated respiratory air flowing up from the canister laterally in the direction of the breathing bag's side walls but keeps that air largely away from the side of the bag that lies against the chest of the wearer. The reason for directing the air through the bag in this manner is to reduce the temperature of the air before it is inhaled again.

Abstract: A circuit arrangement for an apparatus for measuring and analyzing gases which emits a signal when a specified gas concentration is exceeded and which is capable of recalling the maximum value of gas concentration measured. A binary counter acted upon by an oscillator is connected to a digital-analog converter via a digital storage, and a digital-comparator compares the binary values of the counter output from the binary counter and the input to the digital-analog converter. An analog comparator receives the measured value input from a gas measuring device and the maximum value output from the digital-analog converter, and the digital storage is opened via a logic section when the voltage at the measured value input is greater than the voltage at the maximum value output and the digital storage also has equal signals at the input and output thereof.

Abstract: An electronic circuit for processing measured values obtained from a vortex sequence produced by a Karman vortex path, wherein the ultrasonically sensed signals are processed both digitally in a first circuit branch for a computer and analogously in a second circuit branch for the connection of a two-channel continuous recorder. An adjustable frequency transforming arrangement is serially connected in the computer branch for balancing the circuit, and an additional frequency-voltage converter and and integrator are serially connected in the recorder branch along with a control logic circuit inserted between the two branches for starting the recorder after activation of the computer only when signals which can be evaluated are present.

Abstract: A filtering respirator in the form of a mask has an outer casing and a filter layer inside the casing. The edge of the filter liner is sealed to the casing and the rest of the filter layer is spaced from the casing to provide an interspace between them which is connected with the outside atmosphere by an opening in the casing so that exhaled air will leave the mask at a velocity sufficient to prevent inhaling of the exhaled air.

Abstract: A switching circuit for monitoring the switching state of switching elements wherein the switching state of the switching element is detected and a corresponding signal is generated and this signal is compared to the input signal initially provided for switching the switching element from one switching state to another whereby a fault signal is produced when the switching state monitor signal indicates that the switching element is in one switching state and the input signal indicates that the switching element is or should be in another switching state.

Abstract: A ring-shape connecting member is disposed in an opening in the bottom of a breathing bag, where it is encircled and tightly engaged by an elastic sleeve secured to the bag around its opening and projecting downwardly out of the bag. A chemical cartridge is provided with an upwardly extending ring-shape flange projecting up into the elastic sleeve in sealing engagement with it, and the top of the cartridge within said flange is provided with an opening communicating with the connecting member.

Abstract: A pair of nose pads are connected to the ends of a spring clip that presses the pads against the sides of the nose of the wearer. The connection between the spring and pads is such that the pads can tilt freely relative to the spring clip to avoid discomfort.

Abstract: Exposed components, including an exhalation valve, of a respirator mask are protected from extremely cold temperatures by a bag containing them, with its open end held in sealing engagement with the portion of the mask adjacent the components by means of a flexible collar. The bag is provided with an air inlet and with air outlets isolated from the inlet for escape of exhaled air from the bag. When one of the mask components in the bag is a filter, its inlet side is covered by an air-permeable base portion of the bag, and the rest of the bag is made of air-impermeable material, with the junction of the two parts of the bag sealed against the filter.

Abstract: The outlets of an oxygen liberating canister and a carbon dioxide absorbing canister are connected with a breathing bag that has an outlet connected to an inhalation tube. An exhalation tube is connected with the canister inlets. A valve system controls the proportion of exhaled air flowing through each canister, from 100% to zero, the system being actuated by the breathing bag as the bag is inflated and deflated.

Abstract: A device for monitoring and indicating the operational readiness of a gas-measuring instrument fitted with a built-in chargeable battery has visible luminescent diodes that emit different colors when energized and which are disposed in an electrical flip-flop circuit with rheostats for adjusting the switchover values of the circuit which is provided with a pair of input leads for connecting a chargeable battery to the circuit.

Abstract: One of two parts of a protective covering for a person has an opening therein facing the other part, and one edge of an elastic band secured to the one part around that opening extends away from it and around a portion of the other part. The free edge of the band is thickened and provided with a continuous groove in its inner surface extending around the thickened portion and receiving one of a plurality of laterally spaced ribs encircling the surrounded portion of the other part of the protective covering to hold the two parts of the covering together.

Abstract: A respirator canister provided with openings for flow of air therethrough is filled with a chemical that removes water vapor and carbon dioxide from the air and liberates oxygen into it. A breathing tube communicates with one of the canister openings, and an expandable breathing bag or equivalent has an opening communicating with the other canister opening. A spring or the like resists expansion of the bag during exhalation through the breathing tube and canister in order to maintain the air in the respirator under positive pressure to prevent toxic air from leaking into the respirator.

Abstract: A canister provided with openings for flow of air therethrough contains a chemical that removes water vapor and carbon dioxide from that air and liberates oxygen into it. After a period of time the flow of air through the canister is reversed.