Test Head for Protective Mask Testing and Test Head System |
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申请号 | EP09158681.8 | 申请日 | 2009-04-24 | 公开(公告)号 | EP2123330B1 | 公开(公告)日 | 2015-04-22 |
申请人 | Dräger Safety AG & Co. KGaA; | 发明人 | Eiwen, Roland; Ehler, Björn; | ||||
摘要 | |||||||
权利要求 | |||||||
说明书全文 | The invention pertains to testing devices for personal protective gear and in particular to the testing of breathing masks. The invention provides a test head for protective mask testing and test head system as well as a method of testing a breathing mask. Breathing masks have been used for a long time for civil and military applications. These breathing masks protect the user from nuclear, biological and chemical substances, smoke, aerosols, gases and other substances in the ambient air. It is therefore extremely important that these breathing masks be tested properly in order to ensure that they will protect the user from these life-threatening substances. The following tests are performed on the breathing masks:
Test heads for testing full masks are used. Test heads support the mask for testing of sealing as well as filtering and respiration systems and other mask characteristics. The testing is done via a testing device, on which the test head is mounted. The testing device may be supplied with compressed air or another pressurized source (e.g., bellows, rotary compressor, hand ball pump, etc.) for various purposes including the tests as noted and for Closed Circuit Breathing Apparatus (CCBA) or Self Contained Breathing Apparatus (SCBA) for an inflatable test head for testing a full face mask and testing chemical protection suits. The lung demand valve and the nozzle, which inflates the chemical protection suits, may be fed through plug-in couplings. From It is an object of the invention to provide a test head that can be easily removed from and mounted on the testing device by means of a mechanism. It is a further object, according to another aspect of the invention to provide a test head to simulate a human face as realistically as possible in order to thus recognize defects of the sealing of the mask even better and, on the other hand, to guarantee the use of different sizes of breathing masks. The invention is related to Self Contained Breathing Apparatus (SCBA) testing, Close Circuit Breathing Apparatus (CCBA) testing, Self Contained Underwater Breathing Apparatus (SCUBA) testing, Lung Demand Valve (LDV) testing and mask testing. The test head is necessary for testing face masks. According to the invention a soft face front (SFF) is provided for the test head. The SFF is also referred to herein as a gel front and as further described below is used as a replaceable face, which is used on test heads for testing masks. The gel face should be placed as a kind of layer on a fixed face front and attached. The mechanical requirements include allowing a shock and pressure stress of the mask and straps only in which the mechanical stresses are relatively low. Shear stresses should occur to a low extent. The SFF allows for abrasion as breathing masks are placed on the test head up to 50 times a day. The overall service life for the SFF should be at least e.g., 1 year. The materials encountered in testing may include the material of the head straps:
Further general requirements of the SFF relate to the material simulating the properties of a human face. A certain stretching (approx. 5% to 10%) of the material should be possible in one direction. The gel face is easily replaceable and fixable. The gel front is not able to be detached too easily during use after fixing. According to a preferred embodiment the test head is similar externally to a human head. The SFF simulates the human skin/face so that mask testing is more realistic. Parts of the test head additionally simulate the consistency (in terms of elasticity, frictional surface and surface characteristics) of a human face. The test head comprises a hard head part, which simulates the back of the head and the face. The hard head part may especially be metallic or made of a hard synthetic or plastics material. The SFF is provided of a defined thickness. The SSF is the surface with which the seal of the mask will be in contact. The SSF is bonded to the hard face of the hard head part. A polyurethane compound or similar material may be provided as an SFF. The SFF simulates the human face. The rear side may be self-adhesive, and the front side or face side is covered with a resistant film. Such an SFF may be replaceable or mounted permanently. The SFF head area forms part of the overall test head and is fixed to the hard head part. The thickness of the SFF may acceptably be in the range of 4mm to 25mm. The thickness of a preferred embodiment of the SFF is approximately 10mm, as the SFF may have different thicknesses. The thickness of the SFF may be about 8 mm in the forehead area. The thickness of the SFF may be about 12 mm at the chin area. Besides the polyurethane compound or similar material provided as the SFF, the material could any material which meets the requirements noted. This may also be for example a siloxane, or a foam. All adhesives are available which allow for easy removal of the SFF and replacement by a new SFF while not allowing the SFF to slip on the hard head part during use. As noted, the SFF may have self-adhesive properties that allow for it to easily be removed while the sticky mass of the polyurethane of a preferred embodiment is very strong in its self adhesion to the hard head part. The resistant foil or resistant film that forms the outer surface (mask sealing surface) of the SFF may likewise be a polyurethane compound. The resistant film protects the SFF against mechanical stress. Other materials that meet the requirements enough may also be used. Due to the special shape of the gel front and of the head and the special head and face form, it is possible to test all mask sizes. Masks of various sizes and of various sources will fit on the test head according to the invention. Due to the simulation of the human face by the SFF, sealing is facilitated for the operator of the testing device when the mask is put on. Damage to the seal of the mask is recognized more easily than in case of other usual testing methods. According to another aspect of the invention a breathing mask testing system is provided with a testing device and a test head. The test head can be rotated about its longitudinal axis in predefined increments and locked by means of a rotational position fixing mechanism. The test head is placed on a head adapter, which protrudes from the housing of the testing device. The breathing adapter includes two respiration tubes and a test head surface. The adapter includes a casing. The mechanism may be based on the adapter having uniformly distributed holes or engagement locations provided at maximum distances of e.g., 90° and a shoulder, on which the head is placed, located on one front side of the head adapter. A hole, in which a securing pin as well as a compression spring are mounted, is located in the support surface of the test head (the base of the hard head part). This securing pin is pushed into the holes of the tube because of the spring force. If the securing pin is pulled, it is possible to rotate the tube and to let it lock in one of the holes. A rotatable test head considerably facilitates handling for the user of the testing device. The mask can thus be inspected from all sides during testing. When testing Closed Circuit Breathing Apparatus (CCBA) or Self Contained Breathing Apparatus (SCBA), testing is likewise facilitated considerably by rotating the test head to one side. A preferred embodiment of the breathing mask testing system according to the invention makes possible the simple mounting with rotational fixing means and allows easy removal of the test head from the head adapter, which protrudes from the housing of the testing device. No sensor lines have to be connected or disconnected when mounting or dismounting or turning the head. The respiration tube of the test head may be guided by the holding tube portion of the adapter. The respiration tube is inserted into the holding tube. Two seals at the end of the respiration tube keep free a pressureless space in the holding tube, in which the pressure of the sensor line (conduit to the sensing location) can be picked up. The connection between the sensor line and the measuring point does not have to be established separately during the mounting of the test head on the testing device. The removal of the head makes possible, on the one hand, an even easier transport of the testing device. On the other hand, the head can thus also be retrofitted without greater effort. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
Referring to the drawings in particular, In an advantageous embodiment as shown, a polyurethane compound or similar material is provided as the SFF 14. The SFF 14 simulates the human face. In case of replaceability, no special capabilities or tools are needed to replace the gel front or SFF 14. The rear side may advantageously be self-adhesive, and the front side or face side is covered with a resistant film. The self-adhesive nature can be based on adhesive or based on the frictional contact between the hard face of the hard head part 12 and based on the hard face contour 24 of the hard head part 12 engaging a corresponding inner side face contour of the SFF 14. Based on the matching contours, and based on the materials used, a significant self-adhesive effect may be achieved. If necessary, besides adhesive bonding, other fixing means can be employed. The hard head part 12 includes an opening 26 leading to a respiration tube 50 ( Due to the simulation of the human face by the SFF 14, including surface characteristics such as smoothness/texture, frictional characteristics and elasticity, sealing is facilitated for the operator of the testing device 32 when the mask 70 is put on the test head 10. Damage to the seal 72 of the mask 70 is recognized more easily than in case of other usual methods. A rotatable test head considerably facilitates handling for the user of the testing device 32. The mask 70 can thus be inspected from all sides during testing. When Closed Circuit Breathing Apparatus (CCBA) or Self Contained Breathing Apparatus (SCBA), testing is likewise facilitated considerably by rotating the test head 12 to one side. With the connection by the mechanism including holes 34 on the adapter 30 and compression spring 42 and securing pin 40 a rotational position fixing means is formed to provide a removable test head based on a quick release. The test head 10 may be quickly connected to the adapter 30 of the testing device 32 and the test head 10 may be oriented appropriately based on the rotational fixing aspect of the mechanism. The principle described with reference to The SFF 14 is removable and may advantageously be self-adhesive. The SFF 14 seals on the eye region due to an oversize fitting with tube 50a and the sensor at the eye location 60. The self-adhesive property is brought about by the material polyurethane. Experiments have revealed that the adhesive action of the polyurethane SFF 14 according to the invention is very strong and will very likely be sufficient for fixing the soft face front 14. To rotate or remove the entire test head 10, the spring bolt must be pulled. The test head 10 can now be rotated into another position (depending on the positions of the fixing holes) or removed. The holding tube is mounted sealingly, directly into the adapter holding tube 30. Tube 50b is joined during the insertion of the test head 10 into the head adapter holding tube 30. Two seals 52 and 54 are provided at the end of the respiration tube 50b to create a sealed air flow from the simulated lung, e.g. driven by a bellows or a compressed air source, to the mouth opening 28 (and into the space of the mask being tested) and back. An output hole 64 for low pressure at the lower end of tube 50b provides communication between the space 66 and the flexible tube 62 for the low pressure. The same pressure (low pressure) that is present in the low-pressure flexible tube and in the eye location - the sensor location or sensing location 60 prevails in the space 66 between tube 50b and the holding tube 30. This space 66 is created by the shoulder 61 in tube 50b, designated as a smaller diameter in the embodiment shown in The testing device 32 simulates respiration with exhaled and inhaled air. This may be done with an artificial lung in the testing device 32. The artificial lung has a hole for the output and input of air. The head adaptor 30 is connected to the hole of the artificial lung so that the exhaled and inhaled air goes through the head adaptor 30. Air provided from the testing device 32 flows through the head adapter 30 and the respiration tubes 50a, 50b. Pressure sensors inside the testing device 32 detect the pressure of exhaled and inhaled air. When testing a breathing mask, a mask is mounted on the test head. All valves of the mask are closed. The artificial lung inhales and creates a pressure inside the mask. The sealing of the mask is correct when the pressure inside the mask stays at the same level during a certain time. The pressure inside the mask will also be inside the sensor line 62, the space 66 and the hole 67. The pressure can be measured at the hole 67. The removal of the head 10 from the adapter 30 makes possible, on the one hand, an even easier transport of the testing device. On the other hand, the head 10 can be retrofitted without great effort. While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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