Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J15/00—Sealings
  • F16J15/46—Sealings with packing ring expanded or pressed into place by fluid pressure, e.g. inflatable packings

Definitions

• the present invention relates to a gasket consisting of at least one closed hose
• the invention relates particularly to a gasket intended to provide a seal between two surfaces one of which is moving.
• a purpose of the invention is to eliminate the drawbacks of previously known packings mentioned above and to provide a gasket allowing for varying distances between the surfaces to be sealed.
• the present invention relates to a gasket consisting of at least one closed hose 25 having excess inner pressure relative to one or more ambient pressures and intended to provide a seal between two surfaces, the gasket being characterised in a hose fastening line extending substantially in the longitudinal direction of the hose, on the side of the hose facing the higher ambient pressure.
• the fastening line is preferably closer to the possibly more irregular and/or stationary surface.
• the pressure within the hose is adapted such that at least an infinitesimal width of the contact surface 35 between the hose and each surface to be sealed is maintained over the entire length of the hose when complete sealing is desired.
• the gasket is intended to provide a seal between two surfaces at least one of which is moving, the pressure within the hose being adapted such that at least an infinitesimal amount of medium leaks between the hose and the moving surface when as low friction as possible between the hose and the moving surface is aimed at.
• the gasket in accordance with the invention may comprise two hoses, which, together with the surfaces to be sealed, form a closed space, as well as means for controlling pressure in the closed space.
• the hose perimeter may be adapted to the distance variations. These provisions are appropriately made as the hose is being fitted in place.
• the gasket in accordance with the invention is also able to adapt itself in shape to the distance between the surfaces to be sealed. If this distance grows, for instance due to irregularities, the inner excess pressure in the hose enables the gasket to expand in width. On the other hand, if this distance decreases, the flexible hose allows the pressure to be balanced, and the gasket becomes thinner.
• the hose fastening line may be e.g. straight, circular or elliptical.
• the gasket in accordance with the invention may be a single or double gasket intended to provide a seal e.g. between a stationary surface and a moving surface.
• the gasket in accordance with the invention may also be a double-sided gasket intended to provide a seal on either face of a moving surface, for instance.
• FIG 1 shows a cross-section of a gasket in accordance with the invention
• figure 2 shows a section along line I-I in figure 1
• figure 3 shows a cross-section of a second gasket in accordance with the invention
• figure 4 shows a section along line II-II in figure 3.
• Figures 1 and 2 illustrate a simple gasket in accordance with the invention, intended to provide a seal between a stationary surface 2 and a moving surface 3, e.g. a conveyor belt.
• the gasket consists of a hose 1.
• Hose 1 is attached to a fastener 5 along fastening line 4, the fastener being in turn anchored to the stationary surface 2.
• the distance S2 between fastening line 4 and the stationary surface 2 is smaller than the distance sj between the fastening line 4 and the moving surface 3.
• Fastening line 4 is on the hose side facing the higher ambient pressure p2-
• pressure pj is prevailing.
• hose 1 forms a substantially semi-circular surface having a radius Rj, which is half of the distance s between surfaces 2 and 3.
• the hose describes a radius R2 determined by the equation
• a desired value may be selected for the sealing width 1 j between the hose and surface 3. Sealing width I2 between the hose and surface 2 is greater than 11. When sealing width 1 is very narrow, there will be minimum friction between hose 1 and moving surface 3. Fastening line 4 of hose 1 extends in the longitudinal direction of hose 1, being circular in this embodiment.
• Hose 1 may be made of a flexible and resistant material, such as polytetrafluoroethylene (teflon). Hose 1 is connected to a pressure source, which maintains hydraulic or pneumatic inner excess pressure p3 within the hose relative to ambient pressures pj and P2- The pressure in the hose may for instance be somewhat higher than the ambient pressures.
• FIGS 3 and 4 show a double gasket in accordance with the invention, intended to provide a seal between a stationary surface 8 and a moving surface 9, e.g. a conveyor belt.
• This double gasket consists of two parallel hoses 6 and 7.
• Hose 6 is attached to a fastener 12 along fastening line 10 and hose 7 is attached to the same fastener along fastening line 11, the fastener being in turn anchored to stationary surface 8.
• the distance between fastening line 10 or 11 and stationary surface 8 is smaller than the distance between fastening line 10 or 11 and moving surface 9.
• Fastening line 10 runs on the side of hose 6 facing the higher ambient pressure P5. The same applies to fastening line 11.
• pressure P4 is prevailing
• pressure p is prevailing
• p6 may be equal or unequal to ps-
• Fastening line 10 for hose 6 extends in the longitudinal direction of hose 6, and similarly, fastening line 11 of hose 7 extends in the longitudinal direction of hose 7.
• Fastening lines 10 and 11 are straight in this embodiment.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Architecture (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• Gasket Seals (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8543509

Family Applications (1)

Country Status (3)

Citations (2)

• 1995
  • 1995-05-31 FI FI952664A patent/FI100424B/fi not_active IP Right Cessation
• 1996
  • 1996-05-31 AU AU58227/96A patent/AU5822796A/en not_active Abandoned
  • 1996-05-31 WO PCT/FI1996/000318 patent/WO1996038685A1/en active Application Filing

Patent Citations (2)

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