Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01G—WEIGHING
  • G01G3/00—Weighing apparatus characterised by the use of elastically-deformable members, e.g. spring balances
  • G01G3/12—Weighing apparatus characterised by the use of elastically-deformable members, e.g. spring balances wherein the weighing element is in the form of a solid body stressed by pressure or tension during weighing
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01G—WEIGHING
  • G01G21/00—Details of weighing apparatus
  • G01G21/30—Means for preventing contamination by dust
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L1/00—Measuring force or stress, in general
  • G01L1/26—Auxiliary measures taken, or devices used, in connection with the measurement of force, e.g. for preventing influence of transverse components of force, for preventing overload

Definitions

• the invention relates to a load cell, preferably for an aseptic platform scale according to the preamble of patent claim 1.
• Load cells are special forms of load cells and provided for the construction of weighing devices. Such weighing devices are often used in the food supply, so they often have to comply with special hygiene rules. Therefore, it is necessary for the load cells used there that they are constructed so that no dirt or food residues can accumulate permanently on their surfaces or at least must be easily removable. Furthermore, such load cells are often horizontal surfaces, gaps and depressions that are hardly accessible and therefore difficult to clean, where then easily bacteria, viruses and fungi. Therefore, it is necessary in the use of load cells in many areas of the chemical, pharmaceutical, cosmetic and food industries that they are easy to clean and have as possible no surface areas on which dirt, food residue, chemicals, bacteria, viruses and fungi settle, penetrate or can form.
• a hermetically sealed measuring bulk sensor which constitutes a load cell, is known from DE 10 2004 047 508 B3, which is designed as a horizontally installable bending beam.
• This bending beam consists of a
• the force measuring element consists of a vertical spiral spring, which was produced by two opposing horizontal transverse bores in the middle bending beam part and on the two sides Strain gauges are applied as Scherkraftaufillon that generate a proportional electric signal at a weight load.
• Strain gauges are applied as Scherkraftaufêt that generate a proportional electric signal at a weight load.
• cup-shaped metal sheet metal parts are welded in the holes, which close the sensitive electrical measuring elements hermetically sealed. This will primarily prevent moisture and other corrosive contaminants from contacting the sensitive sensing elements, creating a long-life load cell.
• this load cell is rod-shaped and equipped with largely flat outer surfaces, but especially on the horizontally extending top surface food or liquid residues can settle, which tend in connection with moisture for propagation of bacteria or viruses. Furthermore, dirt and food components which are difficult to clean and in which fungi and bacteria could form, could also adhere to the cup-shaped depressions. Therefore, such a hermetically sealed storage cell in aseptic areas according to relevant hygiene regulations often can not be used.
• a load cell for an electromechanical platform scale which consists essentially of a cylindrical rod, of which at least pourable food and liquids by means
• one side of the bending rod is fastened to the balance housing by means of two screws, while the opposite end is connected as a flattened round rod to the weighing platform, wherein the weight force can be introduced transversely to the longitudinal direction.
• strain gauges may be applied to the load cell on the surface of the bending rod to generate the electrical measuring signals, so that such a weighing cell is not cleaned with aqueous cleaning agents can not always be used in the food industry or in aseptic areas.
• FIG. 1 Another load cell with cylindrical horizontally arranged housing is known from DE OS 28 18 140, which should be completely protected against external influences.
• a horizontal round rod is arranged in the housing body, which is fastened in a self-supporting tube at its one end region.
• strain gauges are applied to the outer surface, which generate a strain on the outer surface of the tube at a vertical force in the end point of the rod.
• the self-supporting tube is hermetically sealed by a cylindrical closure sleeve as a housing part.
• the introduction of force via a bolt in an open at least downwardly open chamber in which a force introduction loop surrounds the rod, which is movably guided in this open chamber. Since this chamber is not hermetically sealed, it can penetrate dirt and liquid residues that are hardly removable, so that this load cell is not usable in contact with food.
• a kit for a load cell which can be used in particular in the field of chemical and pharmaceutical, food and cosmetics industry.
• this kit contains a vertically arranged load cell, which is arranged between two parallel horizontally arranged mounting plates.
• the load cell is arranged sealed in a round, conically extending housing, which engages in the pressure pieces or includes this, that this kit is easy to clean and apparently has few gaps and cavities in which bacteria, viruses and fungi can form.
• the plungers as force introduction or Kraftaus Gustavsetti only loosely connected to the load cell, so that such a load cell can only be installed vertically and not firmly connected to the scale, so that always a kit is additionally required.
• the invention is therefore based on the object, a hermetically sealed load cell further so that it is easy to clean and contains no gaps, depressions and horizontal surface parts, in and on which residues, dirt, bacteria, viruses or fungi settle or multiply, so that it can also be used in aseptic environment, in particular in plants for food processing.
• the invention has the advantage that, because of the horizontal installation position, it also has only vertically sloping surface parts, so that all the foodstuffs associated therewith,
• Cosmetic or pharmaceutical ingredients are difficult to fix, whereby a fungus, virus or bacteria formation is largely prevented.
• the force measuring element be designed as a double bending beam with which advantageously very high measuring accuracies can be achieved.
• the entire weighing cell consists of a high-strength stainless steel, so that such a weighing cell even at high
• Humidity and aggressive environmental influences is used and therefore represents a very durable execution, which is not attacked by the most chemicals or pharmaceutical raw materials. It is particularly advantageous, the closed
• the m flat platform scales can be used
• the force introduction and Kraftaus effetive strains are equipped with parallel vertical or parallel horizontal mounting surfaces, so that they allow advantageously a horizontal or vertical mounting.
• the weighing cell with a protective layer which has a surface which is difficult to adhere to, so that therewith come out of contact with giant-shaped or liquid materials without residues and so even without significant cleaning measures a germ formation especially of germs is prevented.
• Fig. 1 a hermetically sealed weighing cell with vertical attachment surfaces
• Fig. 2 a hermetically sealed load cell with horizontal mounting surfaces.
• Fig. 1 of the drawing is a hermetically sealed
• Load cell shown which is rotationally symmetrical, with a double bending beam 3 is arranged in the longitudinal direction between the force introduction 1 and Kraftaus effetselement 2, which is closed by two provided at its end portions ring elements 5, 6 and a tube sleeve 4 welded thereto, wherein the ring elements 5, Contain 6 concentrically encircling thin areas as a membrane 7, 8, which connect the pipe sleeve 4 flexurally soft with the force introduction 1 and the Kraftaus effetselement 2 and the double bending beam 3.
• the load cell consists of a central longitudinal body, from which the force introduction element 1, the force diverting element 2, the double bending beam 3 and the two ring elements 5, 6 are worked out.
• Longitudinal body is preferably made of a high-quality stainless bending elastic stainless steel, on the tube sleeve 4 is slipped over in the finished state and with the two ring elements 5, 6 welded airtight.
• the central longitudinal body is preferably 120 mm long and about 40 mm in diameter between the force introduction element 1 and the Kraftaus effetselement 2 of the double bending beam 3 is arranged, which contains a cuboid center part 14.
• a horizontal recess 11 is provided This results in a cloverleaf-like cross section through four horizontal bores.
• Longitudinal axis 9 each have a ring member 5, 6 attached, whose outer diameter corresponds to the inner diameter of the Rohrhulse 4 and is greater than the diameter of the Kraftem effetselements 1 and the Kraftaus effetselements 2, and preferably about 39 mm amounts.
• the two ring elements 5, 6 are concentrically concave on the annular surface facing the double bending beam 3 and thereby form a concentrically encircling first and second membrane 8, whose thickness is preferably 0.3 mm.
• the force introduction element 1 and the force diverting element 2 are mounted laterally next to the first connecting piece 16 in the axial direction, both of which are provided by a circumferential groove 21 outside cone-shaped to preferably 38 mm in diameter, to then pass into a cylindrical shape of about 16 mm long, which then m ends a flat face 17 as a vertical mounting surface.
• both the force introduction element 1 and the force diverting element 2 are formed identically in their outer shape and both are arranged symmetrically to the longitudinal 9 and transverse axis 10.
• a central longitudinal bore 22 is provided in the longitudinal direction, which extends at least to the recess 11 and in which the leads for the strain gauges are performed. Therefore, a connection cable 18 is still sealed in the force receiving element 2, in which the connecting leads are guided sealed to the outside.
• two horizontal threaded holes 19 are mounted on the end face 17 of the force diverting element 2 and two similar threaded holes 19 are also provided on the end face of the force introduction element 1 for fastening a weighing platform.
• the two parallel end faces 17 represent vertical attachment surfaces, so that such load cells can be used not only for platform scales, but also for any other weighing devices in which the weight F perpendicular to the longitudinal axis 9 in the end face 17 of the load cell is emleitbar.
• the double bending beam is hermetically sealed by means of a sleeve tube 4 pushed over by welding to the ring elements 5, 6.
• the tube sleeve 4 is preferably also made of a high-strength stainless steel whose length corresponds to the distance between the two ring elements 5 and is welded airtight with its radial outer edges.
• the tube sleeve 4 is rigid formed, wherein the outer circumferential surface has only a small predetermined roughness, which is preferably produced by an electropolishing, so that it has a good running and easy to clean surface
• FIG 2 of the drawing an alternative embodiment of a weighing cell is shown, which differs only in the formation of the force-conducting element 1 and the Kraftaus effetselements 2 of the weighing cell of Figure 1 of the drawing.
• the storage cell is provided according to Figure 2 of the drawing for a horizontal attachment in a weighing device. Therefore, on the cylindrical surface of the Kraftem effetselements 1 above a flattening 23 and in the Kraftaus effetselement 2 below a flattening 23 as a plane horizontal
• Fixing surface 20 is provided, m the two threaded holes 19 are introduced transversely to the longitudinal axis 9 m.
• Carriage platform to be fastened horizontally.
• the force introduction elements 1 and force diverting elements 2 could also be cylindrical without flattening. Therefore, both embodiments of the load cells are essentially rotationally symmetrical and are preferably provided for horizontal installation.
• Fastening surfaces 17, 20 by fastening elements of the weighing device have both executions only downwardly inclined rounded surfaces, where trickle or liquid Good can run down because the entire surface of the cells preferably only with a small Roughness be executed, have no undercut and no narrow gaps, it can hardly adhere to flowable goods or liquids.
• a further embodiment is still provided to provide the load cells in addition to a hard-adhering surface coating such.
• a hard-adhering surface coating such.
• polytetraflouretylene (Teflon) which additionally prevents adhesion and cleaning ability is improved. Therefore, such load cells are preferably used in the food supply, with any nucleation in particular the disease germs or their multiplication must be prevented.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measurement Of Force In General (AREA)
• Apparatus Associated With Microorganisms And Enzymes (AREA)

Priority Applications (9)

Applications Claiming Priority (2)

Publications (1)

Family

ID=41720532

Family Applications (1)

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Cited By (1)

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Citations (6)

Family Cites Families (36)

• 2008
  • 2008-12-22 DE DE102008064169A patent/DE102008064169B4/de not_active Expired - Fee Related
• 2009
  • 2009-12-16 DK DK09798883.6T patent/DK2379995T3/da active
  • 2009-12-16 US US13/141,561 patent/US9255832B2/en active Active
  • 2009-12-16 BR BRPI0923585-0A patent/BRPI0923585B1/pt not_active IP Right Cessation
  • 2009-12-16 PL PL09798883T patent/PL2379995T3/pl unknown
  • 2009-12-16 EP EP09798883.6A patent/EP2379995B1/de active Active
  • 2009-12-16 WO PCT/EP2009/009004 patent/WO2010072364A1/de not_active Ceased
  • 2009-12-16 CN CN2009801129214A patent/CN101999068B/zh active Active
  • 2009-12-16 JP JP2011541196A patent/JP5714502B2/ja active Active
  • 2009-12-16 ES ES09798883.6T patent/ES2464462T3/es active Active
• 2015
  • 2015-01-16 JP JP2015006687A patent/JP5921010B2/ja active Active

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