FR2901881A1 - Body protection garment or equipment e.g. jacket, designing method for e.g. police force, involves designating garment or equipment as acceptable or giving structural modifications to it based on absorption and/or force attenuation values - Google Patents

Abstract

The method involves applying impacts on a target e.g. thigh, zone of a fashion model with a body protection garment or equipment e.g. bracket, and taking measurements e.g. speed measurement, provided by sensors e.g. force sensor. Values of energy absorbed and/or force attenuation by the garment or equipment is determined from the measurements. The garment or equipment is designated as acceptable in a direction of threshold values, if the values are greater than the threshold values, or otherwise structural modifications are provided to the garment or the equipment, for improving the values. An independent claim is also included for a method for approval test of a body protection garment or equipment for police force.

Description

The present invention relates generally to the design

  protective equipment for law enforcement. By protective equipment for the law enforcement forces is meant any clothing or equipment worn by the user to reduce or prevent the risk of specific bodily injury. Traditionally, protective equipment of this nature is essentially empirically designed: several prototypes are made and tested either actual conditions of wearing the equipment or close to real conditions (taking care not to exert too much stress on the person performing the test).

  The present invention aims at overcoming these limitations of the state of the art, and at proposing methods which make it possible, in particular by ensuring a precise and reproducible measurability of the protective effect of clothing or protective equipment on the human body, to facilitate the design of such clothing or equipment according to a desired protection objective, to improve its reliability and to offer users a range of clothing or equipment that can offer different degrees of protection, as needed. For this purpose, according to a first aspect, the invention proposes a method of designing a garment or body protection equipment for the police, characterized in that it comprises the following steps. - equipping a manikin with a set of kinematic and / or dynamometric sensors, - positioning an impact application device so that it can apply to at least one predetermined target zone of the impact dummy according to a kinematics reproducible determined, -apply said impacts on the target area of the dummy without clothing or protective equipment, and record the measurements provided by the sensor or sensors located in the region of said target areas, - mount a protective clothing or equipment on the manikin so as to cover the target area, - to apply said impacts to the target area of the dummy provided with the protective clothing or equipment, and to record the measurements provided by the one or more sensors, - to derive from the measurements at least one value of energy absorbed and / or attenuated by said protective clothing or equipment, and - if the value or values are greater than at threshold values, designate the garment or equipment as acceptable within the meaning of said thresholds, - if not, make structural changes to said protective clothing or equipment with a view to improving said values of absorbed energy and / or attenuation of force. It is also proposed, according to a second aspect of the invention, a method of testing the approval of a garment or body protection equipment for the police, characterized in that it comprises the following steps: - equipping a manikin with a set of kinematic and / or dynamometric sensors, - positioning an impact application device so that it can apply to at least one predetermined target zone of the manikin, likely to be protected by the garment or equipment to be tested, impacts according to a determined reproducible kinematics, - apply said impacts to the target area of the manikin devoid of the garment or equipment to be tested, and record the measurements provided by the sensor (s) located in the region of said target areas, mount the protective clothing or equipment to be tested on the manikin so that it covers the target area, - apply said impacts to the target area of the dummy provided with the said garment or equipment, and record the measurements provided by the one or more sensors, - deduct from the measurements at least one value of energy absorbed and / or attenuation of force by the said protective clothing or equipment, and if the value or values are greater than threshold values, designate the garment or equipment as approved. Some preferred, but not limiting, aspects of these methods are the following: * The impacts are applied using an orthofilar pendulum carrying a support for an impactor. the support comprises at least one kinematic or dynamometric sensor. the measurements provided by the one or more sensors selected from a group include displacement measurements, velocity measurements, acceleration measurements, force measurements, and their changes as a function of time. the impacts are applied with an impactor in the general shape of a cylinder of revolution. * the impacts are applied according to at least two different angles of incidence. * One of the impacts is usually orthogonal to the surface of the manikin at the target. * the impacts are applied with an impactor provided with a sharp edge. the method comprises measuring the depression of the impactor in the material of the garment or equipment. * Protective clothing and equipment are selected from the group consisting of leggings, thigh guards, vests, and shoulder guards, cuffs. Other aspects, objects and advantages of the present invention will appear better on reading the following detailed description of the preferred embodiments thereof, given by way of nonlimiting example and with reference to the appended drawings, in which: FIG. 1 is an overall diagram of a test equipment according to the invention. FIGS. 2a and 2b are side and end views of a first type of impactor used in the test equipment, and Figures 3a and 3b are side and end views of a second type of impactor used in the test equipment.

  (1) Definitions (a) Protective area: area of the human body covered by all clothing or protective equipment and its accessories; (b) test area: the part or area (s) of a particular clothing or protective equipment to be examined; (c) targets: anatomical regions of the human body on which a shot is aimed; among these targets: primary targets are generally considered to be the forearms, buttocks, thighs, back of the heel and instep; these are mainly areas where the masses of muscle protect the skeletal elements and which are devoid of vital organs; The secondary targets are generally considered as the back of the hands, the inside of the wrists, the joints of the elbows, the upper arms, the shoulders, the shoulder blades, the collar bone and the joints of the knees; 20 - finally tertiary targets are generally considered as each part of the face, skull, neck, backbone region and rib, the area just below the rib region, the entire liver, solar plexus, spleen, kidneys, lower abdomen, groin and coccyx. d) impact of a stroke: it is defined by the angle of attack relative to an axis normal to the general surface of the target (z axis), the value of 0 corresponding to a frontal impact; 30 (e) performance levels: the performance level of a garment or equipment is a number used to give an indication of the degree of protection afforded by the garment or equipment, as determined by performance tests such as that we will describe them later; the higher the number, the higher the degree of performance. 2) Description of the Equipment The present invention aims at designing and testing for an official or private homologation of protective clothing or equipment of the human body by proposing a test apparatus for measuring the reduction of energy. and the force of impact on such clothing or equipment, this under the effect of an impactor simulating a real shot. For example, such an impactor can simulate a hit with a baseball bat or with an ax. This test apparatus comprises in an advantageous embodiment: - a biomechanical manikin M - a test bench comprising a pendulum orthofilaire 20 P; - an impactor I (here the baseball bat or the ax) mounted on the pendulum. The manikin M simulates, within the limits of its accuracy, a male human being 175 cm tall and weighing 80 kg. It is instrumented, ie equipped with a set of force sensors, moment sensors, displacement sensors and acceleration sensors. In the present exemplary embodiment, a manikin M having the following characteristics is used: Hybrid III in front, having two channels namely a displacement sensor and an accelerometer; - five-way frontal instrumented leg, namely two force sensors, two moment sensors and an accelerometer; instrumented four-way front-end instrument according to the EuroSID-2 standard, with two force sensors, a moment sensor and an accelerometer; Four-way lateral instrumented shoulder according to EuroSID-2, with three force sensors and an accelerometer. It should be noted that these standardized definitions of mannequins resulting in particular from the legally supervised automotive crash-test activities, are accessible with all the details of implementation necessary to the person skilled in the art with the official authorities concerned (see in particular the website). Internet www.inrets.fr of the National Institute of Research on Transport and their Security). Such a manikin is equipped with the clothing or protective equipment to be tested. The test bench of the test apparatus is here an orthofilar pendulum P on which the impactor I is fixed. Such a pendulum simulates the strike on an individual using this impactor. The pendulum has a length of rope for example of 5 meters, which is advantageously adjustable. The starting position and the mass of the impactor repeatedly determine its speed of impact on the dummy, the force transmitted to the manikin and the impact energy. As noted above, the impactor may be one of two types in the present embodiment, namely a baseball bat or ax.

  In all cases, the impactor comprises a support base S or metal reinforcement (typically made of steel) equipped with an accelerometer and a speed sensor. The minimum mass of this base S is typically 2.5 kg. It is possible to fix on this base a tip of suitable shape forming the impactor proper I to simulate the desired threat, namely here a tip simulating the most corpulent part of a baseball bat or simulating the blade of an ax . In the present particular embodiment, the tip Il simulating a baseball bat is illustrated in Figures 2a and 2b. It comprises a solid steel cylindrical shaft, 200 mm in length and 50 mm in diameter, and a Rockwell hardness of 55 +/- 3 (Type C steel). The tip I2 simulating an ax blade is constituted by a bar of steel, of identical hardness, having a generally equilateral triangle section of 5 mm side and a length of 200 mm, as illustrated. in Figures 3a and 3b of the drawings. Of course, other types of impactors can also be used, including an impactor simulating the impact of a tonfa defense stick, an iron bar, etc.

  3) Description of the use of the equipment The test apparatus according to the invention is used as follows.

  Firstly, one of the two impactor models mounted on its base is placed on the orthofilar pendulum, the assembly being positioned and maintained so as to achieve the desired energy, impact speed and force. This maintenance is carried out so as to be perfectly reproducible so that the impactor can touch the target respectively equipped with its protection and without protection under the same conditions. The protective clothing or equipment to be tested is first subjected to baking for a period of 4 h at 80 C, then stored at 20 C for 48 h with a relative humidity of 65%.

  In the case where the test of the garment or the equipment must be carried out under conditions of different temperature or humidity, then it is preferably carried out within 5 minutes after destocking, and last for not more than 20 minutes.

  The protective clothing or equipment to be tested is placed on the manikin as described above, in order to reproduce the real conditions as best as possible. Typically, this garment or equipment is positioned on the manikin and brought into contact with it with a contact force of about 20 to 30 N in the case where this force can be measured or estimated. The manikin is then placed on the test bench and positioned to simulate the actual wearing of the item of clothing or equipment in law enforcement. The test procedures can then be performed, the initial choice residing in the desired values of impact velocity, impact energy and maximum force transmitted (in fact the choice of an angle of incidence) as is the case. has already indicated.

  For example one can perform tests with the baseball bat type with the following parameters. - impact speed: 5 m / s - impact energy: 120 Joules - incidence: 0 and 30 and with the ax-type nozzle with the following parameters. - impact speed: 5 m / s - impact energy: 50 Joules - incidence: 0. Furthermore, a different average transmitted force is advantageously used depending on the target envisaged, with for example a value of less than 5 kN for the elbow or the thigh, a value of less than 8 kN for the upper arm, the forearm. arm or shin, and less than 10 kN for the shoulder and knee. The tests are carried out on the different targets of the manikin and in particular: - on a mounted leggings fixed on one leg of the dummy between the knee (included) and the ankle, with targets on the top of the foot, the bottom of the shin, the middle of the tibia, upper shin and knee; - on a thigh protector attached to the thigh of the dummy between the hip and the knee not included, with targets on the lower thigh, the middle of the thigh and the upper thigh; - on a vest attached to the trunk of the manikin and equipped with articulated protective shells on the shoulders and upper arms and a bib for the pelvic area, with targets at the shoulder, on the upper arm superior, on the scleral plexus, on the kidneys, on the clavicles and on the pelvic area; - on a shoulder-mounted shoulder protector mounted on the shoulder (possibly retained by a vest as before), with targets at the corner of the shoulder and on the upper arm; - on a cuff mounted on a forearm of the manikin, with targets on the wrist, on two forearm and elbow regions.

  Of course, other tests are possible on other equipment or protective clothing. The test procedure itself consists in placing the manikin, without any clothing or protective equipment, on a test surface such as a table or more generally any other fixed support capable of holding the manikin. As indicated, the position of the manikin is adjusted to correspond to a realistic situation corresponding to the test. For example, for a legwarming test, the manikin's position simulates a standing man, and the contact pressure between the manikin's foot and the test surface is adjusted to match that which would be obtained with a man of normal weight; the sensors are calibrated in a manner known per se in the field of automotive safety tests. The position of the manikin is also adjusted so that the angle of incidence (orthogonal or oblique striking - see above) is the desired one.

  The orthofilar pendulum is then adjusted, and more precisely the starting point and the load of the impactor (mass of the moving part) are adjusted so as to obtain the desired speed, force and impact energy. A registration is performed so that this starting point, for a given series of tests, can be determined reproducibly.

  The tests on the preselected targets are then performed, first on the dummy without the clothing or protective equipment. Then the garment or equipment is placed on the corresponding area of the manikin, and the tests are performed again with the same speeds, forces and energies. Preferably each individual test, without protection then with protection, comprises a measurement of the acceleration (in m / s2) as a function of time (in s), of the effort (in daN) as a function of time (in s) and displacement (in m) as a function of time at the sensors instrumenting the manikin. Each test also includes a measurement, on the impactor, of the acceleration (in m / s2) as a function of time (in s). All of the above measures are performed with the impactor simulating a baseball bat. As indicated above, other tests with one of the impactors simulating for example a tonfa or an iron bar can be performed, with in this case a procedure similar to that used with the impactor simulating a baseball bat . The data provided by the sensors with when testing with different impactors on different targets are recorded. This provides a series of measures that allows equipment designers and clothing to gradually improve the behavior of these. More specifically, these recorded data are reprocessed, in particular by comparing the data collected during impacts directly on the dummy (without the protection) and during impacts on the protection placed on the manikin. It is thus possible to calculate in particular an energy absorption coefficient and a coefficient of attenuation of the force transmitted to the different target points. The test campaign also includes the use of the impactor simulating an ax. In this case, no measurement is taken at the sensors, but it is simply measured, manually, the depth of depression of the blade. For this purpose, the equipment or the protective clothing is positioned not on the dummy, but on a rigid and fixed anvil, and the ax-type impactor is applied with the desired force, speed and energy.

  The validation process of the design of a garment or protective equipment can be based on the comparison of these coefficients with pre-established thresholds, according to calculation rules that can be quite varied (by target, in a global way , etc.).

  The designer can play in particular on the nature and the mechanical properties of the materials involved (rigid plastics, foamed fabrics) and on their dimensional parameters, mainly in terms of thickness.

  Of course, those skilled in the art will be able to provide the invention with numerous variants and modifications.

Claims (11)

  1. A method of designing a garment or body protection equipment for the police, characterized in that it comprises the following steps. - equipping a manikin with a set of kinematic and / or dynamometric sensors, - positioning an impact application device so that it can apply to at least one predetermined target zone of the impact dummy according to a kinematics reproducible determined, - apply said impacts to the target area of the dummy without protective clothing or equipment, and record the measurements provided by the sensor (s) located in the region of said target areas, - mount a protective clothing or equipment on the manikin so that it covers the target area, -apply said impacts on the target area of the manikin provided with the protective clothing or equipment, and record the measurements provided by the one or more sensors, - deduce from the measurements at least one value of absorbed energy and / or attenuation of force by said garment or protective equipment, and - if said one or more values are greater than at threshold values, designate the garment or equipment as acceptable within the meaning of the said thresholds; if not, make structural changes to the garment or protective equipment with a view to improving the absorbed energy values and / or force attenuation.   2. A method of testing the approval of a garment or body protection equipment for the police, characterized in that it comprises the following steps. - equipping a manikin with a set of kinematic and / or dynamometric sensors, - positioning an impact application device so that it can apply to at least one predetermined target zone of the manikin, capable of being protected by the garment or equipment to be tested, impacts according to a determined reproducible kinematics, - apply said impacts to the target area of the manikin devoid of the garment or equipment to be tested, and record the measurements provided by the sensor or sensors located in the region of said target areas, - mount the protective clothing or equipment to be tested on the manikin so that it covers the target area, - apply the said impacts to the target area of the manikin provided with the said clothing or equipment, and record the measurements provided by the at least one sensor, the measurements of at least one absorbed energy value and / or the attenuation of force by said garment or protective equipment, and - if the value or values are greater than threshold values, designate the garment or equipment as approved.   3. Method according to one of claims 1 and 2, characterized in that the impacts are applied using an orthofilar pendulum carrying a support for an impactor.   4. Method according to claim 3, characterized in that the support comprises at least one kinematic or dynamometric sensor. 10   5. Method according to one of claims 1 to 4, characterized in that the measurements provided by the sensor or sensors are selected from a group include displacement measurements, velocity measurements, acceleration measurements, measurement measurements. force, and their evolutions as a function of time.   6. Method according to one of claims 1 to 5, characterized in that the impacts are applied with an impactor in the general shape of a cylinder of revolution.   7. Method according to claim 6, characterized in that the impacts are applied according to at least two different angles of incidence. 25   8. The method of claim 7, characterized in that one of the incidences is generally orthogonal to the surface of the manikin at the target.   9. Method according to one of claims 1 to 8, characterized in that the impacts are applied with an impactor provided with a sharp edge. 20   10. The method of claim 9, characterized in that it comprises the measurement of the depression of the impactor in the material of the garment or equipment.   11. Method according to one of claims 1 to 10, characterized in that the protective clothing and equipment are selected from the group comprising leggings, thigh protectors, vests, and shoulder protectors, cuffs.