Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/08—Characterised by the construction of the motor unit
  • F15B15/10—Characterised by the construction of the motor unit the motor being of diaphragm type
  • F15B15/103—Characterised by the construction of the motor unit the motor being of diaphragm type using inflatable bodies that contract when fluid pressure is applied, e.g. pneumatic artificial muscles or McKibben-type actuators

Definitions

• the invention relates to a fluid-operated contraction drive, with a contraction hose extending between two head pieces, which experiences a length contraction when fluid is applied to the hose interior delimited by it and exerts axial tensile forces acting on the head pieces in the sense of a mutual approximation, the contraction hose on at least a headpiece is fastened in that it is clamped with its relevant end section in an annular clamping gap, which between clamping surfaces which are at least partially inclined with respect to the longitudinal axis of the contraction tube, of a first clamping unit equipped with force tapping means for external tapping and a relative to the first clamping unit axially displaceable second clamping unit is defined.
• a contraction hose extends between two head pieces, each of which is equipped with two clamping units which are screwed together in the manner of a union nut.
• An annular clamping gap is defined between the clamping units, in which the contraction tube is clamped with its associated end region. If the tube interior of the contraction tube is filled with pressure medium under a certain actuation pressure, the contraction tube expands radially and simultaneously pulls the two head pieces towards one another. On In this way, external structures or components, which are fixed to the force tapping means of the head pieces, can be displaced relative to one another and / or clamped together.
• the two clamping units have been made adjustable relative to each other in the longitudinal direction of the contraction drive, and the clamping surfaces have been designed in such a way that a certain entrainment effect is achieved due to the frictional forces between them and the contraction hose, which has the consequence that when the contraction hose is acted upon, a automatic amplification of the clamping effect occurs between the two clamping units.
• tensioning means which are provided between the two clamping units and are provided in addition to the contraction tube and which the clamping units in Apply to reduce the width of the clamping gap.
• the end section of the contraction tube sitting in the clamping gap remains securely clamped even when the hose material develops a tendency to creep due to material fatigue or for other reasons, which would reduce the predetermined clamping force by default.
• the two clamping units are automatically adjusted by the tensioning means to the extent that the wall thickness of the clamped end section of the contraction tube is reduced, so that the desired clamping force can be maintained permanently and even under unfavorable environmental influences.
• clamping devices In principle, it would be possible to design the clamping devices in such a way that they only become effective or only during certain events, for example when the ambient temperature exceeds a certain level. Such a design could be realized by using so-called memory metal.
• a solution in which the clamping means are designed in such a way that they are always effective is considered to be simpler and at least currently less expensive. This can be achieved in particular by using tensioning means which have resilient inherent shadows, in particular in the form of a structure corresponding to a mechanical spring device.
• a mechanical spring device which is composed of a plate spring assembly, promises particularly compact dimensions.
• the clamping surfaces within the clamping gap run inclined to one another in such a way that their distance from the longitudinal axis of the contraction tube to the outer end region of the relevant head piece axially opposite the contraction tube increases.
• the ring diameter of the annular clamping gap then preferably increases gradually towards the outer end region of the head piece.
• the headpiece in question is expediently provided with holding means which serve to clamp the two clamping units together in order to obtain a basic clamping of the contraction tube, regardless of the fluid loading state of the tube interior.
• the holding means can be implemented, for example, by a threaded connection which is provided between a clamping nut and the force-tapping part of the first clamping unit.
• a particularly compact arrangement results if the person responsible for the active clamping of the contraction tube Chen clamping devices are in an area that is located within the contraction tube.
• an advantageous safety aspect can also be realized. Since the contraction tube is prevented from slipping out of the headpiece by the secure fixation and automatic adjustment of the clamp attachment, the effect occurs with increasing overuse that the tube material becomes slightly porous in the thinning clamping area.
• the contraction drive shown contains two spaced-apart first and second head pieces 2, 3, only one of the head pieces 2 being shown completely in the drawing for the sake of simplicity.
• the two head pieces 2, 3 are firmly connected to one another via a linearly extending contraction tube 4.
• the contraction hose 4 At least in the deactivated state of the contraction drive, the contraction hose 4 has a shape similar to a hollow cylinder.
• the longitudinal axis of the contraction drive which also represents the longitudinal axis of the contraction tube 4, is indicated at 9.
• the contraction tube 4 expediently has a material made of rubber-elastic properties.
• the material used is preferably rubber or an elastomer material with comparable properties.
• Embedded in the material of the hose body 5 is a strand structure 1, indicated only by dash-dotted lines, which is expediently completely surrounded by the hose body material and which has an arrangement which is coaxial with the hose body 5.
• the structural design of the contraction tube 4 can correspond in particular to that described in DE 29906626 U1 or in EP 0 161 750 B1.
• the contraction tube 4 is fixed with its two axial end sections 10 to the respectively assigned head piece 2, 3 in such a way that on the one hand there is a fluid-tight connection between the tube body 5 and the relevant head piece 2, 3, and on the other hand the strand structure 1 is able to Exercise tensile forces on the respective head piece 2, 3.
• the strand structure 1 instead of the strand structure 1, other measures suitable for transmitting axial tensile forces can also be taken.
• the contraction tube 4 delimits in its interior a tube interior 13 which is closed at the end by the two head pieces 2, 3. At least one fluid channel 14 opens into the hose interior 13 and, in the exemplary embodiment, preferably passes through the completely shown first head piece 2 coaxially.
• the fluid channel 14 can be connected to a fluid line, not shown, which leads to a pressure medium source.
• the contraction drive is preferably operated with gaseous pressure medium, in particular compressed air. However, it is also suitable for operation with a nem hydraulic fluid, for example with oil or with water.
• Each head piece 2, 3 is equipped with force tapping means 17 at an externally accessible location.
• these are formed by a threaded section of the relevant head piece 2, 3 and enable the relevant head piece 2, 3 to be fastened to a component (not shown).
• a component not shown.
• the contraction drive is suitable for practically all applications that make it necessary to move or clamp two components relative to one another.
• connection to the corresponding component can take place directly via the force tapping means 17 or with the interposition of an adapter part, not shown in more detail, which is fixed to the force tapping means 17.
• a pressure medium under a predetermined operating pressure is fed into the hose interior 13 via the fluid channel 14. Due to this overpressure, the wall of the
• the contraction tube 4 is acted upon radially outwards from the inside, so that an application in the sense of a radial expansion of the contraction tube 4 takes place.
• This has the consequence that the contraction tube 4 is acted upon simultaneously in the sense of an axial contraction, the axial tensile forces caused by the contraction tube 4 acting on the head pieces 2, 3 in the sense of a mutual approximation.
• This leads to the fact that the force tapping means 17 of the two head pieces 2, 3 specified components are directed towards each other.
• this goes hand in hand with a more or less strong mutual axial approach of the two head pieces 2, 3, wherein the distance traveled here by the head pieces 2, 3 relative to each other can be referred to as a stroke.
• the pressure medium is at least partially discharged from the hose interior 13.
• the contraction tube 4 then stretches back into the starting position, so that the head pieces 2, 3 return to the starting position. If necessary, this return movement can be promoted by additional support measures, for example by return springs.
• the special movement and deformation behavior of the contraction tube 4 is ensured in the exemplary embodiment by the strand structure 1.
• the associated structure can correspond, for example, to that explained in German utility model DE 29906626 Ul or in EP 0161750 B1.
• the strand structure 1 preferably contains a multiplicity of flexible, but flexible, single-strand or multi-fiber strands extending between the two head pieces 2, 3, a construction in which the strands are helically spiraling in the direction of the Extend the circumference of the hose body 5 between the head pieces 2, 3 and are arranged in particular in a crossover configuration, so that diamond-like lattice areas are formed.
• the internal pressure applied to the contraction tube 4 causes a shift in the diamond angle, which ultimately leads to axial tensile forces being established on the strand structure in the region of the end sections 10 of the contraction tube 4, which are transmitted to the head pieces 2, 3.
• the power transmission to the head pieces 2, 3 is realized in that the contraction tube 4 is firmly clamped at its end sections 10 in the respectively assigned head piece 2, 3.
• the head pieces 2, 3 are equipped with a particularly advantageous clamping device 18, which is expediently constructed identically in both head pieces. However, it is also possible to equip only one of the head pieces with such a clamping device 18.
• the clamping device 18 is a direct component of the head piece 2, 3 in question. It contains a first clamping unit 22, which is equipped with the force tapping means 17, and also has a second clamping unit 23, which is separate from the first clamping unit 22 and has no force tapping means 17.
• the two clamping units 22, 23 engage in one another coaxially, a first clamping surface 24 provided on the first clamping unit 22 being radially opposite a second clamping surface 25 provided on the second clamping unit 23.
• the two clamping surfaces 24, 25 are oriented transversely to the longitudinal axis 9 and face each other.
• the two clamping units 22, 23 define an annular clamping gap 26 between the two clamping surfaces 24, 25. This is open towards the inner end face of the relevant head piece facing the other head piece, the contraction tube 4 being concentric with its end section 10 from the open side engages in the clamping gap 26.
• the two clamping units 22, 23 are firmly clamped to one another in such a way that they clamp the wall of the end section 10 between them with a clamping force referred to as basic clamping.
• the clamping surfaces 24, 25 lie on the one hand on the inner surface and on the other hand on the outer surface of the hose body 5, against which they are firmly prestressed.
• the end section 10 of the contraction tube 4 is enclosed on the outside by the first clamping unit 22.
• the second clamping unit 23 plunges coaxially into the contraction tube 4 from the front side.
• the second clamping unit 23 is formed by a cone-like element, the lateral surface of which forms the second clamping surface 25, at least over a partial length and preferably at least approximately over the entire length, tapering towards the contraction tube 4.
• the second is
• Clamping surface 25 is expediently not designed to be smooth, but rather has a wavy cross-sectional contour. This results in an outer surface with an axial succession of alternating annular elevations and depressions.
• the first clamping unit 22 is of multi-part design and has a force tapping part 28 equipped with the force tapping means 17 and a tension nut 29 which is in threaded engagement therewith and which is designed as a union nut 33 of the second clamping unit 23, the bearing recess 33 expediently is formed by a stepped passage opening 34 which penetrates the second clamping unit 23 over its entire length.
• the force tapping part 28 also has an axial through bore 35 which, together with the longitudinal section of the passage opening 34 adjoining the bearing extension 32, forms the fluid channel 14 and which is provided with the force tapping means 17 as an internal thread.
• the two clamping units 22, 23 are designed to be movable relative to one another in the longitudinal direction of the contraction tube 4, the possible direction of movement 36 being indicated by a double arrow.
• the bearing recess 33 forms an axial displacement guide together with the bearing extension 32 engaging in it.
• the clamping nut 29 has a sleeve-like structure with a clamping section 42 which defines the inwardly oriented first clamping surface 24 and an axially adjoining fastening section 43 which overlaps the force-tapping part 28 in the region of a flange-like section.
• Holding means 44 are provided between the clamping nut 29 and the force-tapping part 28, which define a screw connection that makes it possible to vary the axial relative position between the two components. Instead of the screw connection, other holding means having the same effect could also be selected.
• the first clamping surface 24 provided on the clamping nut 29 has the same inclination as the second clamping surface 25 facing it. It is preferably designed with a smooth surface or with only slight roughness.
• the inclined course is selected so that the distance to the longitudinal axis 9 increases with increasing Approach to the outer end region of the head piece 2 axially opposite the contraction tube 4 is enlarged.
• the diameter of the annular clamping gap 26 thus widens axially outward from the axially inner end of the head piece 2.
• the clamping device 18 contains effective clamping means 45 which are able to act on the two clamping units 22, 23 in the sense of a reduction in the width B of the clamping gap 26.
• the clamping means 45 have resilient properties and are formed by a mechanical spring device which is arranged coaxially between the second clamping unit 23 and the force-tapping part 28 of the first clamping unit 22.
• the tensioning means 45 are preferably a plate spring assembly.
• the tensioning means 45 in the exemplary embodiment are located in an area which is located within the contraction tube 4. They sit in a loading space 46, which is located in front of the positioning extension 32 towards the second clamping unit 23, it being defined by an enlarged section of the passage opening 34.
• the loading space 26 is delimited by two axially opposite loading surfaces 47, 48, the first loading surface 47 being provided on the end face of the bearing extension 32 and the second loading surface 48 opposite on the second clamping unit 23.
• Radially on the outside, the loading space 46 is directly delimited by the second clamping unit 23, which engages over the bearing extension 32 like a hat.
• the clamping means 45 act simultaneously on the two loading surfaces 47, 48 and thus press the second clamping unit 23 away from the force-tapping part 28, in the sense of an approximation of the second clamping surface 25 to the first clamping surface 24.
• the pressurizing space 46 is also in constant communication with the hose interior 13 via the passage opening 34.
• the second clamping unit 23 is first attached to the bearing extension 32 of the force-tapping part 28.
• the clamping nut 29 has not yet been installed.
• the end section 10 of the contraction tube 4 is pushed onto the second clamping unit 23 until it abuts a stop 52.
• the contraction tube is expanded like a trumpet.
• the clamping nut 29 which has already been placed on the contraction tube 4 is pushed over the unit comprising the force-tapping part 28 and the second clamping unit 23, so that the second clamping unit 23 comes to lie coaxially within the clamping nut 29.
• the clamping nut 29 is now screwed onto the force tapping part 28, the first clamping surface 24 pressing from the outside against the contraction tube 4, which is supported on the inside on the second clamping surface 25.
• the supporting force of the second clamping surface 25 comes from the clamping means 45, which are supported between the two clamping units 22, 23.
• the clamping nut 29 is now tightened until the desired basic clamping of the contraction tube 4 is reached.
• the second clamping unit 23 coaxially pushed onto the bearing extension 32, the tensioning means 45 lying between them being compressed at the same time, so that a restoring force builds up which is always effective and which provides the counterforce for clamping the contraction tube 4.
• the contraction tube 4 is now firmly anchored in the clamping gap 26, the tube material having deformed in accordance with the shape of the clamping surfaces 24, 25.
• the clamping means 45 prevent the clamping force from being reduced below the preselected basic clamping. Any reductions in the wall thickness of the contraction tube 4 within the clamping gap 26 are immediately and automatically compensated for by the second clamping surface 25 being adjusted by the force of the clamping means 45. The clamping gap then becomes a little narrower, the clamping forces are nevertheless retained. Even in unfavorable circumstances, this will result in a
• the installation of separate clamping means 45 provided in addition to the contraction hose 4 has the advantage of being highly effective in all operating conditions and also during the course the time-changing material properties of the hose body 5.
• a secure hold of the contraction tube 4 is achieved by the clamping device 18, even if the wall thickness decreases sharply due to material deformation.
• the fact that there is no fear of the contraction tube 4 bursting even with a rapidly decreasing wall thickness is due to the fact that fine holes are created in the thin tube material migrating out of the clamping gap 26, which allow the excess pressure to be blown off. This way, with the design of the invention also takes into account a certain safety aspect.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Supports For Pipes And Cables (AREA)
• Clamps And Clips (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Actuator (AREA)
• Pipe Accessories (AREA)
• Infusion, Injection, And Reservoir Apparatuses (AREA)

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• 2002
  • 2002-04-11 DE DE20205719U patent/DE20205719U1/de not_active Expired - Lifetime
• 2003
  • 2003-02-21 US US10/498,405 patent/US7222887B2/en not_active Expired - Fee Related
  • 2003-02-21 AT AT03708119T patent/ATE339618T1/de not_active IP Right Cessation
  • 2003-02-21 ES ES03708119T patent/ES2268333T3/es not_active Expired - Lifetime
  • 2003-02-21 DE DE50305035T patent/DE50305035D1/de not_active Expired - Lifetime
  • 2003-02-21 MX MXPA04009945A patent/MXPA04009945A/es active IP Right Grant
  • 2003-02-21 WO PCT/EP2003/001781 patent/WO2003085271A1/fr active IP Right Grant
  • 2003-02-21 EP EP03708119A patent/EP1492958B1/fr not_active Expired - Lifetime

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