Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
  • G01F23/30—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats
  • G01F23/32—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats using rotatable arms or other pivotable transmission elements
  • G01F23/36—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats using rotatable arms or other pivotable transmission elements using electrically actuated indicating means
  • G01F23/363—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats using rotatable arms or other pivotable transmission elements using electrically actuated indicating means using electromechanically actuated indicating means
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C10/00—Adjustable resistors
  • H01C10/30—Adjustable resistors the contact sliding along resistive element
  • H01C10/32—Adjustable resistors the contact sliding along resistive element the contact moving in an arcuate path

Definitions

• the invention is based on a rotational resistance according to the preamble of the main claim.
• each wiper arm grind offset from one another via the web-shaped conductor sections, that there are leading and trailing contacts with respect to the conductor sections. In this way, it is ensured that always a contact with its slider track is electrically contacted, especially in strong vibrations. It has been found that the arrangement of the web-shaped conductor sections with respect to the contacting of the slider tracks is still not optimal.
• the rotational resistance of the invention with the characterizing features of the main claim has the advantage that in a simple way an improvement in the contacting of the slider tracks is achieved by the web-shaped conductor sections of the first slider track and / or the second slider track are aligned such that their imaginary extension tangent to a circle having the same center as the associated slider track. Due to the inventive construction also the wear on the
• the circle has a radius of 2 to 20 millimeters. In this radius range results in a particularly reliable and accurate level measurement.
• first wiper arm has at least two first contacts cooperating with the first wiper track and the second wiper arm has at least two second contacts cooperating with the second wiper track since at least two contacts rubbing on the same wiper track will fail the rotational resistance signal by lifting the contacts as a result of vibration less frequently or not at all.
• the web-shaped conductor sections of the first slider track are aligned such that their imaginary extension runs tangentially to a first circle, and that the web-shaped conductor sections of the second slider track are aligned such that their imaginary extension runs tangentially to a second circle the centers of the first circle and the second circle are identical.
• the oblique position of the conductor sections effected in this way ensures that each wiper arm contacts more than one web-shaped conductor section. This will not cause signal interruptions if e.g. a conductor portion is dirty or corroded.
• the contacts can be moved with a rotational movement over the slider track with less force, so that less wear on the slider track occurs.
• the drawing shows a rotary resistance according to the invention, which is provided in particular for measuring a level in a container, for example a fuel tank.
• the variably adjustable rotational resistance is produced for example by means of thick film technology and formed on a support plate 1, which consists of a ceramic material.
• Support plate 1 of the rotational resistance two arcuate slider tracks 2 are provided, the are arranged side by side.
• Each arcuate slider track 2 has a geometric
• a first slider track 2.1 is formed similarly to a curved comb and has a plurality of web-shaped conductor sections 3.1, which extend from a main section 5 in the direction of a second slider track 2.2.
• the web-shaped conductor sections 3.1 are connected to each other via the main section 5.
• the main section 5 is electrically connected via a first connection section 8.1 with a first signal tap 9.1.
• the first slider track 2.1 has, for example, 30 to 50 bar-shaped conductor sections.
• the second slider track 2.2 is also formed similarly to a curved comb and has a plurality of web-shaped conductor sections 3.2, which extend in the direction of the first slider track 2.1. For example, 50 to 70 web-shaped conductor sections 3.2 are provided.
• the web-shaped conductor sections 3.2 are electrically connected to a resistance section 11, which acts as an electrical resistance.
• the resistance section 11 is applied, for example, via the web-shaped conductor sections 3.2 of the second slider track 2.2.
• the resistance section 11 is electrically connected via a second connecting section 8.2 with a second signal tap 9.2.
• the web-shaped conductor sections 3.1.3-2 are electrically conductive and contain, for example, gold, silver, palladium or platinum. They are, for example 0.2 mm wide and have a distance of 0.2 mm from each other. According to a further development, in each case the width of the web-shaped conductor sections 3.1.3.2 increases in the direction away from the center 4.4.1.4.2.
• the first slider track 2.1 and the second slider track 2.2 are for example via a
• Resistor 12 short-circuited, which has a resistance which is greater than the maximum resistance of the resistor portion 11th
• the slider tracks 2 is associated with a grinder 15 which interacts electrically with a first wiper arm 15.1 with the first slider track 2.1 and with a second wiper arm 15.2 with the second slider track 2.2.
• Both wiper arms 15.1, 15.2 have at least two finger-shaped contacts 16, for example, which are resiliently pressed against the associated web-shaped conductor sections 3.1, 3.2 of the slider track 2.1, 2.2.
• By providing at least two contacts per wiper arm 15 it is ensured that always one of the contacts 16 is electrically contacted with its grinding erbahn2.1,2.2, especially with strong vibrations.
• the first wiper arm 15.1 and the second wiper arm 15.2 are electrically conductively connected to each other , - A -
• the rotational resistance of the invention acts as a potentiometer, the total resistance in two
• the grinder 15 is rotatably mounted about a pivot point 17 and mechanically connected, for example, with a lever arm, not shown, but sufficiently known from the prior art.
• a lever arm On the lever arm, a float is provided in a known manner.
• the wiper 15 When changing a liquid level in a container, the wiper 15 is rotationally adjusted via the torque acting on the lever arm, whereby the angular position of the grinder 15 is changed on the conductor tracks 2 and thereby the resistance of the rotational resistance is changed.
• the web-shaped conductor sections 3.1, 3.2 of the first slider track 2.1 and / or the second slider track 2.2 are aligned such that their imaginary extension runs tangentially to a circle 6, which has the same center point 4 as the associated slider track 2.1, 2.2 ,
• the imaginary extensions of the web-shaped conductor sections 3.1, 3.2 of the first slider track 2.1 and / or the second slider track 2.2 run either tangentially to a first semicircle section 7.1 or to a second semicircle section 7.2 of the circle 6.
• the web-shaped conductor sections 3.1.3.2 of the first slider track 2.1 are aligned such that their imaginary extension runs tangentially to a first circle 6.1.
• the web-shaped conductor sections 3.1, 3.2 of the second slider track 2.2 are, for example, oriented such that their imaginary extension runs tangentially to a second circle 6.2.
• the centers of the first circle 6.1 and the second circle 6.2 are identical. However, they can also be expressly spaced from each other.
• the web-shaped conductor sections 3.1, 3.2 of the first slider track 2.1 and / or the second slider track 2.2 run with their outer ends ahead, for example, to the direction in which the electrical resistance of the resistor section 11 increases.
• the circle has a diameter of 2 to 25 millimeters, preferably 10 to 20 millimeters.
• this angle deviates from 90 degrees, whereby the shearing forces acting on the contacts 16 are reduced.

Landscapes

• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Adjustable Resistors (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2006
  • 2006-08-22 DE DE200610039401 patent/DE102006039401A1/de not_active Withdrawn
• 2007
  • 2007-08-09 BR BRPI0715706-1A2A patent/BRPI0715706A2/pt not_active Application Discontinuation
  • 2007-08-09 CN CN2007800312980A patent/CN101506628B/zh not_active Expired - Fee Related
  • 2007-08-09 EP EP07788325A patent/EP2057443A1/de not_active Ceased
  • 2007-08-09 WO PCT/EP2007/058258 patent/WO2008022927A1/de active Application Filing

Non-Patent Citations (2)

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