Covering cap and measuring device

Abstract

A covering cap, in particular for placing on a skin analyzer, contains an end wall bounded by a circumferential edge, and a circumferential wall adjoining the circumferential edge of the end wall. At least one part of the covering cap has a thickness that is less than a thickness of the circumferential wall in a portion of the circumferential wall that lies in the region or end of the circumferential wall remote from the end wall. The end wall is of a gas-permeable configuration.

Claims

1. A cap, comprising: a front wall delimited by a circumferential edge and being gas-permeable; and a jacket wall attached to said circumferential edge of said front wall, at least part of the cap having a first thickness that is less than a second thickness of said jacket wall in a section of said jacket wall in an area or end of said jacket wall facing away from said front wall; said jacket wall in an area near said front wall, having a first thickening section following from the circumferential edge, in which a thickness of said jacket wall exceeds a thickness of said front wall; said jacket wall having an intermediate section following from said first thickening section, said first thickness of said jacket wall in said intermediate section being less than said thickness of said jacket wall in said first thickening section; said jacket wall having a second thickening section, following from said intermediate section and extending until an end of said jacket wall that is farthest from said front wall; and said second thickness of said jacket wall being greater in said second thickening section than said first thickness of said jacket wall in said intermediate section; said jacket wall having a thickness being a continuous course free of kinks or edges in an axial or radial direction; and/or a respective average thickness in respective one of said first thickening section, said second thickening section and said intermediate section of said jacket wall being deemed to be said thickness; and/or said jacket wall, with an exception of an area of said locking protrusions or said recesses, being rotationally symmetric; said thickness of said first thickening section, said first thickness of said intermediate section, and said second thickness of said second thickening section having the following ratio: 2<d1:d2<5 and/or 2<d3:d2<5 and/or 0.8<d1:d3<1.25; d1 being said thickness of said first thickening section, d2 being said first thickness of said intermediate section, and d3 being said second thickness of said second thickening section; and/or said thickness of said first thickening section, said first thickness of said intermediate section, and said second thickness of said second thickening section being set as follows: 150 μm<d1 <250 μm and/or 50 μm<d2<100 μm and/or 150 μm<d3<250 μm; a height h1 of said first thickening section, a height h2 of said intermediate section, and a height h3 of said second thickening section having the following ratio: 0.2<h1:h2<0.6 and/or 0.8<h3:h2<1.25 and/or 0.2<h1:h3<0.6; and/or said jacket wall having a height of 2-80 mm; and/or a ratio between said height and a maximum dimension, being a diameter or diagonal, of said front wall is between 0.01 and 55; said front wall being circular and having a diameter of 1-50 mm; or said front wall being square or rectangular, and side edges of said front wall having a length between 2 and 40 mm; said cap having at least one of locking recesses formed therein or locking protrusions on said end of said jacket wall facing away from said front wall for removable attachment to a measuring device; or at least one of said locking recesses or said locking protrusions each having at least one of a same normal distance from said front wall, are distributed evenly in a circumferential direction of said jacket wall, or whereby a total number of said locking recesses and/or said locking protrusions being two or four; and/or at least one of said locking recesses or said locking protrusions protruding away from said jacket wall at an angle of 5°-40° and/or no more than 2 mm.

2. The cap according to claim 1, wherein said jacket wall has at least one circumferential section, said first thickness is in said at least one circumferential section.

3. The cap according to claim 1, wherein: said front wall, at at least one point, has a thickness less than 100 μm; and said front wall has a constant thickness over its course.

4. The cap according to claim 1, further comprising a base wall continuing from said jacket wall on said end facing away from said front wall and running outward from said jacket wall parallel or at an angle of no more than 10° to said front wall, said base wall formed with a shape of a circular ring and has at least one of an outer radius between 2 mm and 50 mm, an inner radius between 1 mm and 45 mm, or a circular ring width from 0.5 to 35 mm.

5. The cap according to claim 1, wherein said jacket wall in an area of said circumferential edge of said front wall protrudes outward at an angle of 20°-95° to said front wall, whereby said jacket wall expands conically.

6. The cap according to claim 1, wherein: said front wall is penetrable by at least one of radiation, vapor, moisture, particles, or light; and/or said front wall has a number of microholes formed therein and selected from the group consisting of vapor-permeable microholes and gas-permeable microholes.

7. The cap according to claim 1, wherein: said front wall and said jacket wall are formed as one of coordinated parts or as a single piece unit, at least one of said front wall and said jacket wall formed of at least one material selected from the group consisting of a thermoplastic, a plastically deformed polymer, a deformable polymer, polyethylene terephthalate glycol (PETG), polypropylene (PP), polyethylene (PE), polycarbonate (PC), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile butadiene styrene (ABS), high density polyethylene (HDPE), low density polyethylene (LOPE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), ECOTERM S 900 T1, and PETG/Copolyester 67639; said front wall and said jacket wall further containing at least one further material selected from the group consisting of additives, stabilisers, colorants, fillers and reinforcing materials; said front wall is opaque or absorbent to visible wavelengths.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) Several exemplary embodiments of the invention will be discussed by reference to the following drawings.

(2) FIG. 1a shows a cross section of a first embodiment of a cap according to the invention. FIG. 1b shows a side view of the cap of FIG. 1a.

(3) FIG. 2 shows a cross section of a cap according to a particularly simple embodiment of the invention.

(4) FIG. 3 shows a measuring device according to the invention.

(5) FIG. 4 shows a measuring device according to the invention with a cap on. FIG. 4a shows the ejection of the cap from the measuring device.

(6) FIG. 5 shows a polymer film with which the cap is formed. FIG. 5a shows the front surface of the stamp and its substamps.

(7) FIG. 6 shows the substamps pressing into the polymer film.

(8) FIG. 7 shows the expansion of the substamps and the formation of the front surface of the cap. FIG. 7a shows the movement of the substamps to form a rectangular front surface. FIG. 7b shows the movement of the substamps to form a circular front surface.

(9) FIGS. 8 and 9 show the formation of jacket wall sections of differing thicknesses in the cap.

(10) FIG. 10 shows the finishing of the cap by separating it from the polymer film.

DESCRIPTION OF THE INVENTION

(11) FIG. 1a shows a cross section (cutting line 1a in FIG. 1b) of a first embodiment of a cap 10 according to the invention. This cap 10 is shown from below in FIG. 1b according to the cutting line 1b indicated in FIG. 1a. This cap 10 has a circular front wall 1, delimited by a circumferential edge 4. From the circumferential edge 4 of the front wall 1 follows a jacket wall 2, the end of which that faces away from the front wall 1 is continued from a base wall 3. The jacket wall 2 is expands nearly conically in the following exemplary embodiment, and deviates outward in the area of the circumferential edge 4 from the front wall 1 at an angle α of 75°.

(12) The front wall 1 has a very small thickness d.sub.S of 10 μm; advantageously, this wall thickness d.sub.S may be between 0.05 μm and 20 μm, in particular between 3 μm and 20 μm. The front wall 1 has a diameter of 5 mm in this case. Generally, this diameter may vary widely; in particular, diameters between 2 and 20 mm area advantageous, whereby, depending on the application, larger diameters of up to 100 mm certainly may be used.

(13) An alternative embodiment of the invention, not shown, has a square front wall 1 with a substantially equal surface area to the exemplary embodiment shown in FIG. 1, rather than a circular front wall 1, and has an edge length of approximately 10 mm. Alternatively, the front wall 1 may also be rectangular, square, or elliptical in shape, whereby the side edges of the front wall 1 may be approximately between 2 and 40 mm long, in particular between 5 and 8 mm long.

(14) In the exemplary embodiment shown in FIG. 1a, the jacket 2 of the cap 10 consists of three parts, and, near the front wall 1, comprises a first thickening section 7, following from the circumferential edge 4, having a thickness d.sub.1; in this exemplary embodiment, a thickness d.sub.1 between 150 and 250 μm was selected for the first thickening section. The thickness d.sub.1 of the jacket wall 2 in the first thickening section 7 exceeds the thickness d.sub.S of the front wall, and is 5 μm-8 μm in this exemplary embodiment. The first thickening section 7 is formed circumferentially, whereby the first thickening section 7 is circularly delimited on the end farthest from the front wall 1, and whereby an intermediate section 8 follows the first thickening section 7 in this boundary area.

(15) In the intermediate section 8, the jacket wall 2 has a thickness d.sub.2, that is less than the thickness d.sub.1 of the jacket wall 2 in the first thickening section 7. In this exemplary embodiment, a thickness d.sub.2 of the jacket wall 2 in the intermediate section 8 of 50-150 μm was selected. The intermediate section 8 is circularly delimited at the end farthest from the first thickening section 7, whereby this circular limit is followed by a second thickening section 9, in which the thickness d.sub.3 of the jacket wall 2 is greater than the thickness d.sub.2 of the jacket wall 2 in the intermediate section 8. In this exemplary embodiment, a thickness d.sub.3 between 150 and 250 μm was selected for the first thickening section. The second thickening section 9 here follows the end of the jacket wall 2 farthest from the front wall 1, in particular, the second thickening section 9 borders directly on the base wall 3.

(16) This special configuration gives the jacket wall 2 a circumferential section in the form of the intermediate section 8, in which the thickness d.sub.2 is less than the thickness d.sub.3 of the jacket wall 2 in the area of the end of the jacket wall 2 facing away from the front wall 1. The thickness of the jacket wall 2 constantly/continuously decreases in the axial or radial direction, from the thickness d.sub.1 in the first thickening area 7, reaching a minimal level in the intermediate section 8; the thickness of the jacket wall 2 then increases in the second thickening area 9 up to the end of the lateral surface farthest from the front wall 1.

(17) The thickness of the jacket wall 2 has a continuous course free of kinks or edges over the jacket wall 2. To the extent necessary for the following observations, the thickness of the jacket wall 2 in the respective section 7, 8, 9 of the jacket wall 2 will be understood to be the average thickness in the respective section.

(18) In order to allow for a particularly advantageous adaptation of the front wall 1 to the front surface 21 (FIG. 4) of a measuring device 20, the thickness of the jacket wall 2 in the area of the intermediate section 8 is thinner than in the other two thickening sections 7, 9. The ratio of the thickness d.sub.2 in the intermediate section 8 to the thickness d.sub.1 in the first thickening section 7 is approximately between 2 and 5. The ratio of the thickness d.sub.2 in the intermediate section 8 to the thickness d.sub.3 in the second thickening section 9 is approximately between 2 and 5. The thickness d.sub.1 of the lateral surface 2 in the first thickening section as well as the thickness d.sub.3 of the lateral surface 2 in the second thickening section 9 are roughly equal. The ratio between these two thicknesses d.sub.1, d.sub.3 is approximately between 0.8 and 1.25.

(19) In this exemplary embodiment, the jacket wall 2 has the following average thickness values in the individual sections 7, 8, 9: d.sub.1=0.18 mm d.sub.2=0.08 mm d.sub.3=0.22 mm

(20) The height h of the jacket wall 2 is 20 mm in this exemplary embodiment, but, depending on the shape and structure of the measuring device 20 to be covered, may have different values, typically between 15 and 35 mm. The ratio between the height h of the jacket wall 2 and the maximum dimension of the front wall 1 is between 0.02 and 5.

(21) The first thickening section 7 is formed in the area of the front wall 1, and has a height of approximately 4 mm in this exemplary embodiment. The other two sections of the jacket wall 2, i.e., the intermediate section 8 and the second thickening section 9, have approximately the same height, in this case app. 10 mm each. Typically, the height h.sub.1 of the first thickening section 7, the height h.sub.2 of the intermediate section 8, and the height h.sub.3 of the second thickening section 9 are in the following ratio to one another: 0.2<h.sub.1:h.sub.2<0.6; 0.8<h.sub.3:h.sub.21.25; 0.2<h.sub.1:h.sub.3<0.6

(22) A specific further configuration of the invention allows for improved handling and less susceptibility of the cap 20 to tears and breakage. In order to provide better handling, a reinforcing element is arranged in the cap 10 in the area of the second thickening section 9, or in its lower terminal area farthest from the front wall 1. Such a reinforcing element is connected with the inner or outer lining of the lateral surface 2, and is in the shape of a cuff, the surface of which corresponds to the surface of the inner or outer lining. This cuff preferably consists of reinforced plastic or a polymer having a greater rigidity than the polymer of which the cap 10 consists.

(23) The base wall 3, continuing the jacket wall 2 on the end farthest from the front wall 1, runs parallel to the front wall 1 in this exemplary embodiment. Alternatively, however, the base wall 3 could run outward at an angle of 10° to, and away from, the front wall 1. Preferably, the base wall 3 deviates outward from the jacket wall 2, whereby the normal distance of the base wall 3 from the front wall increases with increasing radial distance.

(24) The base wall 3 in this exemplary embodiment is radial in shape and parallel to the front wall 1, and has an external diameter of 21 mm and an internal diameter of 18 mm. The radial width in this case is 1.5 mm.

(25) Additionally, the cap 10 has locking recesses a on the inside of the jacket wall 2, allowing for removable attachment to a measuring device 20 (FIG. 4). In this exemplary embodiment, two locking recesses 5a are arranged such that they are opposite one another on the jacket wall of the cap 10. Alternatively, instead of locking recesses 5a, locking protrusions (not shown) may be provided. Generally, the purpose of the locking recesses 5a and protrusions is to allow for locking attachment to a measuring device 20 or with locking recesses and/or protrusions 25b arranged on the measuring device.

(26) The two locking recesses 5a are formed in this exemplary embodiment as recesses on the inside of the jacket wall 2 in the area of the second thickening section 9, and run approximately at an angle β.sub.1, β.sub.2 of 20° to the jacket wall 2. The locking recesses 5a protrude approximately 60 μm into the second thickening area 9.

(27) Alternatively, it is also possible to provide locking protrusions instead of locking recesses 5a. They protrude inward away from the jacket wall 2 at an angle β.sub.1, β.sub.2 of 10°-30°,and deviate approximately 1.5 mm inward from the jacket wall 2. The locking protrusions 5a are opposite one another at the same height, each with the same normal distance from the front wall 1, and are distributed evenly in the circumferential direction of the jacket wall 2, i.e., they are at an angle of 180° to one another in this exemplary embodiment.

(28) Alternatively, it is also possible for the locking recesses 5a or the locking protrusions to be present in greater numbers. In particular, a number of four locking protrusions or recesses 5a has proved advantageous; they are spaced respectively 90° from one another in the circumferential direction.

(29) In a particular embodiment of the invention, it may be provided for two each of the four locking elements to be formed as locking recesses 5a, and the rest as locking protrusions, whereby two locking recesses 5a each are opposite two locking protrusions by 180° in the circumferential direction. This measure allows the cap 10 to be held advantageously in a position relative to the measuring device 20 (FIG. 4), where by the jacket wall 2, in particular in the area of the intermediate section 8, is subject to elastic extension due to the small thickness d.sub.2, thus allowing for particularly good adaptation of the front wall 1 to a front surface 21 (FIG. 4) of the measuring device 20 to be covered. The degree of the extension and the elasticity of the jacket wall 2 and the intermediate section 8 depend on the polymer used and the thickness d.sub.2 of the jacket wall 2 in the area of the intermediate section 8.

(30) There is additionally the possibility of providing circumferential locking elements either on the measuring device 20 or the cap 10 in the form of locking protrusions or grooves, whereby, advantageously, a circumferential locking element is only either provided on the cap 10 or the measuring device in order to allow for optimal ejection of the cap 10 from the measuring device.

(31) In this exemplary embodiment, the entire cap 10 consists of coordinated material, specifically polymer. In this case, PETG was used, mixed with a small quantity of colourants. The use of colourants for the cap 10 allows for the distinction of different caps with different material properties, in particular different thicknesses d.sub.S of the front wall 1. However, it is also possible to make the front wall opaque or absorbent to certain wavelengths by adding colourants.

(32) Instead of PETG (polyethylene terephthalate glycol), prior-art polymers, e.g., polyethylene or polypropylene, or mixtures thereof, may be used.

(33) In alternative exemplary embodiments of the invention, the cap may consist of one of the following substances or a mixture thereof: PETG (Polyethylene terephthalate Glycol), PP (Polypropylene), PE (Polyethylene), PC (Polycarbonate), PVC (Polyvinyl chloride), PS (Polystyrene), ABS (Acrylonitrile butadiene styrene), HDPE (High Density Polyethylene), LDPE (Low Density Polyethylene), PET (Polyethylene terephthalate), PMMA (Polymethyl methacrylate), ECOTERM S 900 T1. In particular one or more of the following components may be added to the material of the cap 10: Additives, stabilisers, colourants, fillers, reinforcing agents, PETG/copolyester 6763.

(34) By the specific selection of the chain length of the individual molecule chains of the polyethylene, polypropylene, or PETG, the chemical compounds to which the front wall 1 is permeable or impermeable may be determined. Thus, it is possible to measure specific samples such as blood, urine, sweat, or faeces, as well as living samples, e.g., skin, whereby only certain substances desired for the measurement can diffuse through the front wall 1, e.g., sodium, potassium, chlorine, magnesium, vitamins, hormones, glucose, alcohol, trace elements, and water vapour, whilst other components of the sample cannot diffuse, or can only diffuse after a long period of time in the range of hours through the front wall 1, e.g., water, blood, urine, or faeces. By selecting shorter chains, holes form in the respective polymer or polymer structure, such that larger molecules may diffuse through the front wall 1. The longer the chain molecules selected, the tighter the polymer structure and the smaller the molecules must be in order to penetrate the front wall 1. Additionally, the thickness d.sub.S of the front wall 1 determines permeability, because molecules can permeate a thinner front wall 1 more easily than a thicker front wall 1. To the extent that specifications on the stability of the front wall 1 require a specific thickness, alternatively, microholes or nanoholes 6 with a diameter of 0.1 nm-5 μm, or up to 400 μm, may be formed in the front wall 1, e.g., with a microneedle or laser beam.

(35) Alternatively, chemical processes, e.g., etching, maybe used to form holes 6 in the front surface 1. In order to prevent further damage to the front surface 1, it is cleaned after forming the holes to remove the respective caustic agent, in particular rinsed.

(36) Because the molecule size of water is 0.3 nm and the molecule size of water vapour is 0.1 nm, the provision of holes having a diameter of less than 0.3 nm can prevent the penetration of the front surface by water. Starting at a hole or pore diameter of 1 nm, water gradually comes through the front surface 1 into the inside of the hygienic cap. For measurements lasting 3 seconds, the holes or pores may also be 3-4 mm, because the water diffuses more slowly through the front surface than vapour. If a cap 10 with holes having a thickness of approximately 3-4 nm is immersed front surface 1 first into water, depending on the thickness of the front surface, it will require approximately 1 min for the front surface 1 to be penetrated.

(37) Due to material coordination, the individual parts of the cap 10 have essentially the same properties. Special permeabilities for specific substances or radiations can only be obtained through the respective thickness d.sub.S of the front wall 1, the jacket wall 2, and the base wall 3. Thus, the front wall 1 may be made particularly thin during production so that it allows the diffusion or flow of certain materials, e.g., gases, liquids, atoms, molecules, compounds.

(38) The exemplary embodiment shown in FIG. 2 substantially corresponds to the exemplary embodiment shown in FIG. 1a and FIG. 1b; as such, only the differences between the two exemplary embodiments shown will be discussed in detail. The height h.sub.1 of the section following from the front wall 1 corresponds approximately to the height h.sub.2 of the thickening section 7 far from the front wall 1.

(39) The jacket wall 2 is subdivided in this exemplary embodiment into two sections 7, 8, whereby both sections 7, 8 are formed circumferentially and border on one another, and a circular boundary line runs between these two sections 7, 8, the points of which each are at the same normal distance from the front wall 1. The thickness of the jacket wall 2 continuously increases from the front wall 1 in to the end of the jacket wall farthest from the front wall 1 in the axial or radial direction.

(40) FIG. 3 shows an embodiment of a measuring device 20 according to the invention in greater detail. This measuring device 20 has a housing 26 comprising a conically tapered component 21, which is subsequently to be covered by an aforementioned cap 10 (FIG. 4). On the end of the conically tapered component 21, a front surface 22 is arranged on or behind which a sensor 23 is located. In this exemplary embodiment, the conically tapered component 21 has an opening in the area of the front surface 22, leading to the sensor 23, such that the gases and/or substances to be measured can flow directly to the sensor 23. With a cap 10 (FIG. 4) placed on the conical component 21, the sensor 23 can be kept free of contamination.

(41) A number of locking protrusions 25b is arranged on the conically tapered housing 21; alternatively or additionally, a number of locking protrusions may also be arranged on the lateral surface of the conically tapering component 21. As shown in FIG. 4, the cap 10 may be placed on the conically tapered component 21, such that the locking protrusions 25b protruding from the conically tapered component 21 engage with the locking recesses 5a of the cap 10. In order to attain this covered state of the measuring device 20, the cap 10 is advantageously gripped with two fingers in the lower thickening area 9 and placed or pressed onto the conically tapered component 21, such that the locking protrusions 25b of the conically tapered component 21 of the measuring device engage with the locking recesses of the jacket wall 2 of the cap 10. The cap 10 is adapted to the conically tapered component 21 such that the locking protrusions or recesses 5a, 25b are at corresponding positions, such that the cap or conically tapered component 21, when locked together, are arranged such that the front surface 1 is forced over the front wall 22, and the recess on the front surface 22 of the conically tapered component 21 in front of the sensor 23 is completely covered by the front wall 1. This is achieved, in particular, by subjecting the cap 10 in its respective section with low thickness d.sub.2 to particularly substantial elastic deformation, thus generating an optimal fit for the respective measuring device or its conically tapered component 21.

(42) The position of the locking recesses and protrusions 25b on the component 21 corresponds to the position of the locking recesses 5a and/or protrusions on the cap 10a. In particular, the locking recesses and protrusions 25b are each arranged at the same normal distance from the front surface 22 on the component 21, and advantageously evenly distributed in the circumferential direction. The total number of locking recesses and/or protrusions 25b is two in this exemplary embodiment. Alternatively, however, three, four, or more locking recesses and/or protrusions may be provided. The shape of the locking recesses or protrusions 25b is respectively adapted to the shape of the caps 10 or locking recesses 5a or protrusions of the cap 10. The locking protrusions deviate at an angle of 10-30°, no more than 1 mm, in particular no more than 0.5 mm, from the outer wall of the conically tapered component 21.

(43) The measuring device 20 additionally has an ejection element 24, which is arranged on the end of the conically tapered component farthest from the front wall 22. This ejection element 24 is farther from the front wall 22 than the locking protrusions 25 of the conically tapered component. The ejection element 24 in this exemplary embodiment is annular, specifically cylindrically radial, and surrounds the component 21. As can be seen from FIG. 4, the base wall 3 of the cap 10 lies flat on the ejection element 24. The application of pressure to the ejection element 24 in the direction of the front wall 22 results in pressing the cap 10 out of its locked position, whereby the cap is subject to elastic deformation in the area of the locking recess 5a whilst it is being pushed out of the locked position. Due to the angled structure of the locking recess 5a and the locking protrusion 25b, the energy expended in the elastic deformation of the cap 10 is transformed into kinetic energy of the cap 10 upon leaving the locked position, thus accelerating the cap in the direction from the ejection element 24 to the front wall 21.

(44) In this exemplary embodiment, the ejection element 24 is formed in one piece with a lever extension 27. The lever extension 27 follows from the ejection element 24 of deviates from it, allowing for movement or pivoting of the ejection element 24 in the direction of the front wall 22. The lever extension 27 is pivotably connected with the housing 26 in its central area, whereby the lever extension 27 acts as a two-armed lever. On one end of this two-arm lever, the ejection element 24 is arranged; an actuator 28 in the form of a button is arranged on the other end of the two-arm lever. If the button is pressed, the end of the lever extension 27 farthest from the ejection element 24, as shown in FIG. 4a, is swiveled in an anticlockwise direction, and the ejection element 24 is pressed towards the front wall 22 due to the pivoting movement. Due to this pressure on the cap 10, the locked recesses or protrusions leave the locked position, and the cap 10 is thrown away towards the front wall 22.

(45) By the specific articulation of the ejection element 24 due to the pivoting movement, the trajectory of the cap 10 may be set with particular precision. By the specific pivotable configuration of the ejection element 24, the combinations of locking recesses and protrusions opposite one another and corresponding to one another in this exemplary embodiment are released at different times. As a result, the cap 10 is not directly ejected, moving instead in a deviating trajectory that is directed downward and facilitates the disposal of used caps in normal handling.

(46) Another advantageous arrangement of locking recesses or protrusions may, as discussed below, be obtained by providing only two locking recesses or protrusions at the same distance from the point at which the lever extension 27 connects to the ejection element 24 or departs from it. This ensures that the locking of the cap 10 with the measuring device 20 is released at the same time for all locked recesses and protrusions and is not delayed by re-locking of another locking protrusion in a locking recess.

(47) Thus, caps can be ejected to the greatest possible distance from the respective measuring device 20. This has the benefit that the cap can be disposed of at a greater distance and the handling of the cap during disposal is improved by the greater ejection force, thus generally improving motivation for use and user satisfaction.

(48) In order to prevent premature or accidental ejection or removal of a cap from the locked position on the measuring device 20, in this exemplary embodiment, a spring 29 in the form of a wire spring is provided to bias the lever extension 27, thus pushing the ejection element 24 away from the front wall 22. Only when the pressure on the actuator 28 exceeds the biasing force generated by the spring 29 will the cap 10 be ejected. In any case, this prevents accidental ejection or removal of the cap.

(49) Alternatively, this spring 29 may also engage the part of the lever extension 27 facing the ejection element 24, or directly engage the ejection element 24 itself, pulling it away from the front wall 22.

(50) Below, an exemplary embodiment of a method according to the invention for producing a cap 10 from a polymer film 31 is described, whereby specifically the production of the embodiment of a cap according to the invention shown in FIGS. 1a and 1b is discussed.

(51) FIG. 5 shows a polymer film 31 as a raw material, with which the cap 10 is formed. The polymer film 31 originally has a thickness d.sub.f of 0.4, and consists of polyethylene terephthalate glycol (PETG).

(52) To form a front surface 1 with a thickness d.sub.S of approximately 1 μm-10 μm, a stamp 32 comprising several substamps 33 is used. In this exemplary embodiment, the stamp 32 comprises four substamps 33. The stamp 32 is cylindrical and has a circular front surface with a radius of 1 mm. Each substamp 33 has a front surface in the form of a quarter-circle with a radius of 1 mm. All substamps 33 are arranged so as to be movable and pivotable separately from one another. FIG. 5a shows a view of the substamps 33 from the polymer film 31, as indicated by the secant Va.

(53) In a first moulding step, the substamps 33 abut one another, and the quadrant-shaped front surfaces of the substamps 33 together form a circular front surface. The substamps 33 are pressed forward together into the polymer film 31 in this position. As shown in FIG. 6, this deforms the polymer film 31. A volume 39 is formed that is delimited by the polymer film 31 except for the side from which the substamps 33 penetrated into the film 31. The external shape of the shape formed out of the polymer film 31 is determined by a first countermould (not shown), abutting the outer jacket wall 2 and the front wall 1 of the cap 10 formed from the film 31.

(54) In the next step, shown in FIG. 7, the substamps 33 are moved radially outward. In this case, the film 31 is simultaneously heated to a temperature of 40° C. in the area of the substamps 33. This causes substantial pulling and thinning of the film 31 in the intermediate area between the substamps 33, resulting in a front surface with a thickness d.sub.S of approximately 4 μm.

(55) Generally, it is provided that the substamps 33 first move axially normal to the level of the film 31 (FIG. 6), and are only moved radially (FIG. 7) to form the front surface 1 once the substamps 33 have reached a final position in this direction.

(56) Alternatively, of course, it is possible to combine the axial movement normal to the level of the film 31 and the radial outward displacement of the substamps 33, such that the two movements of the substamps 33 overlap.

(57) To the extent that a rectangular or square front surface 1 is to be produced, it suffices for the individual substamps 33 each to be moved to a corner of the front surface 1 to be formed, as shown in FIG. 7a. However, to the extent that a circular front surface 1 is intended, the substamps 33 may additionally be displaced rotationally by the common axis X, as shown in FIG. 7b. The rotation is overlapped by the radial outward movement of the substamps 33. The individual substamps 33 thus move along a spiral path, whereby each of the cylindrical lateral surfaces of the substamps 33 is in contact with the film 31.

(58) As noted above with regard to the formation of rectangular or square front surfaces 1, a combined axial and radial movement of the substamps 33 is also possible when forming circular front surfaces 1. In this case, the substamps 33 execute a movement along a spiral path runs helically downward and expands in spiral fashion, forming an overlap of an axial and radial movement and a rotation about the axis X.

(59) As shown in FIG. 7, a volume 39 is formed having a height h.sub.1 relative to a notional continuation of the upper edge of the film 31. This height is determined by the feed length of the individual substamps 33 axially in the direction of the axis X. The feed rate of the substamps 33 and the determination of the temperature of the substamps 33 and the film 31 in the axial direction, the thickness of the jacket wall 2 laterally delimiting the volume 39 is determined, whereby, in particular, the thickness in the area in which the polymer film 31 transitions into the jacket wall 2 is particularly dependent on the respective feed rate and temperature.

(60) The thickness of the jacket wall 2 may be determined by the selection of the temperature of the film 31 and the substamps 33, as well as the feed rate of the substamps 33 in the axial direction. The thickness d.sub.1 of the jacket wall 2 in the jacket wall section 7 formed may be continuously examined, whereby, if the thickness d.sub.1 is too low, the feed rate of the substamps is reduced in the axial direction, or the temperature of the polymer film 31 or the substamps 33 is reduced. If, on the other hand, the thickness d.sub.1 is too great, the feed rate of the substamps 33 in the axial direction is increased, or the temperature of the film 31 or substamps 33 is increased.

(61) In this exemplary embodiment, a film 31 with a thickness of 0.4 mm is used that was heated to 40° C. during processing. The substamps 33 have a temperature of 45° C., and form a volume 39 with a height h.sub.1 of 4 mm. Then, the substamps 33, as shown in FIG. 7a, are moved radially outward, whereby a rectangular front surface is first formed with a side length of approximately 4 mm. In another step, shown in FIG. 7b, the substamps 33 are caused to rotate, and rotate about the axis X. The cylindrically radial lateral surfaces of the substamps 33 abut the inner wall of the jacket wall formed.

(62) FIGS. 8 and 9 show the formation of additional jacket wall 2 sections 8, 9 of the cap with different thicknesses d.sub.2, d.sub.3. Instead of the substamps 33, another stamp 36, or several additional stamps, are used, the external form of which corresponds to the respective cap 10.

(63) As shown in FIG. 8, the additional stamp 36 is pressed into the volume 39 formed, whereby the respective wall thickness d.sub.2 of the area of the jacket wall 2 formed in this step (‘intermediate section 8’) is thinner than the wall thickness d.sub.1 of the area of the jacket wall 2 (‘first thickening section 7’). The thickness d.sub.2 of the jacket wall 2 in the intermediate section 8, as discussed with regard to the formation of the first thickening section 7, is determined by the feed rate of the additional stamp 36 and the temperature of the polymer 31.

(64) The external shape of the part of the cap 10 formed out of the polymer film 31, in particular the intermediate section 8, is determined by a second countermould (not shown), abutting the outer jacket wall 2 and the front wall 1 of the cap 10 formed from the film 31.

(65) In this exemplary embodiment, the polymer film 31 remains during moulding at a temperature of approximately 40-50° C.; then, the additional stamp 36 is inserted into the second countermould. This second countermould is heated to a temperature of approximately 40-50° C. The intermediate area between the additional stamp 36 and the second countermould corresponds to the desired shape of the cap 10 in the first thickening section 7 and the intermediate section 8; in this exemplary embodiment, the wall thickness in the intermediate section 8 is less than in the first thickening section 7.

(66) Then, as shown in FIG. 9, the additional stamp 36 is moved further forward, whereby a second thickening section 9 is formed, the thickness d.sub.3 of which is greater than the thickness d.sub.2 in the intermediate section.

(67) The external shape of the section of the cap 10 formed out of the polymer film 31, in particular the second thickening section 9 following from the intermediate section 8, is determined by a third countermould (not shown), abutting the outer jacket wall 2 and the front wall 1 of the cap 10 formed from the film 31.

(68) In this exemplary embodiment, the polymer film 31 remains during moulding at a temperature of approximately 40-50° C.; then, the additional stamp 36 is inserted into the second countermould. The third countermould is heated to a temperature of approximately 40-50° C. The intermediate area between the additional stamp 36 and the third countermould corresponds to the desired shape of the cap 10 in the first thickening section 7, the intermediate section 8, and the second thickening section.

(69) FIG. 10 shows the finishing of the cap by separating it from the polymer film. After the forming and contouring of the entire jacket wall 2, the jacket wall remains connected to the film 31. In a final step, the film 31 is separated along a specified cutting line 37; in this exemplary embodiment, the polymer film 31 is punched out along the jacket wall. This separates the cap 10 from the rest of the polymer film 31.

(70) In this exemplary embodiment, the cutting line 37 runs circularly and coaxially along the hollow frustoconical lateral surface 2. By cutting along the cutting line 37, a base wall 3 of the cap 10 is formed that runs parallel to the front surface and radially outward from the end of the lateral surface 2 farthest from the front surface 1. Alternatively, it is also possible to form the base wall 3 facing away from the front wall 1 and deviating radially outward from the lateral surface 2 at an angle of up to 20°, in particular up to 10°, by means of an additional deformation process.

(71) After the conclusion of the moulding process, either before or after cutting the cap 10 along the cutting line 37, the polymer film 31 forming the cap 10 is heated for a specified period of 3-4 s to a temperature between 50 and 120° C. depending on the polymer used, in this case to 75° C. Over this process, the polymer forming the polymer film 31 is reshaped by the heating. The polymer film 31 loses its thermoplastic properties. By the action of heat, the molecule chains forming the polymer film 31 are split, resulting in greater permeability of the cap 10, in particular in the area of the front surface 1. The longer the heat acts on the polymer film 31, and the greater its intensity, the shorter the molecule chains forming the film 31 and the greater the permeability of the front surface 1 will be.

(72) Alternatively, instead of heating the cap, holes 6 may be formed, in this case microholes or nanoholes, preferably exclusively in the front wall 1, in order to obtain a greater permeability for molecules of a particular size. The micro- and nanoholes can be formed using a laser beam or by perforation with a heated microneedle.

(73) It is particularly advantageous if the cap 10 is particularly rigid in the area farthest from the circumferential edge 4, which serves to stabilise the cap. The rigidity of the cap 10 increases towards the centre of the jacket wall 2, whereby the jacket wall 2 is more rigid in the area surrounding the front wall 1. The elasticity of the jacket wall 4 is greatest in the area of its thinnest point or least rigid point.

(74) Preferably, the stiffness or elasticity of the jacket wall 4 is homogeneously distributed over the circumference, varying only with the distance from the front wall 1.