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
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/11—Hoses, i.e. flexible pipes made of rubber or flexible plastics with corrugated wall

Definitions

• the present invention relates to a hose for an operating fluid circulating circuit.
• hoses with reinforcing ribs are known to be used, as described in Italian Patent Application n. TO93U000113 filed on 21/5/93 by the present Applicant.
• known hoses comprise a number of separate intercalated circumferential ribs in respective planes perpendicularly to the hose axis; and a number of longitudinal ribs inserted between the circumferential ribs to limit elongation of the hose.
• hoses of the above type involve several drawbacks. Firstly, the longitudinal ribs, and more specifically the arrangement of the longitudinal with respect to the circumferential ribs, result in a variation in the flexural rigidity of the hose along the hose axis, in the sense that the flexibility of the various portions of the hose differs according to the presence or absence of the longitudinal ribs. Secondly, the presence of circumferential ribs extending perpendicular to the flow direction of the operating fluid results in localized load losses, in turbulence due to the fluid striking the circumferential ribs, and inevitably in undesired noise. DISCLOSURE OF INVENTION
• a hose for an operating fluid circulating circuit comprising at least one corrugated portion; characterized in that said corrugated portion comprises at least one continuous rib extending along a substantially helical path.
• Figure 1 shows a partially sectioned side view of a hose in accordance with the present invention
• Figure 2 shows a section along line II-II in Figure 1.
• Hose l has a longitudinal axis A, and comprises a central corrugated portion 2, and two smooth lateral portions 3.
• corrugated portion 2 comprises four identical, contiguous, continuous ribs 4 extending along respective substantially helical paths P, so that corrugated portion 2 is in the form of a common screw comprising a thread with a number of starts 4a, 4b, 4c, 4d ( Figures 1 and 2).
• corrugated portion 2 When undeformed, corrugated portion 2 comprises a number of identical turns 5 with respective equal winding angles ⁇ ; and, in longitudinal half section, corrugated portion 2 comprises an undulated profile defining a succession of alternating, mutually connected outer crests 6 and depressions 7.
• each outer crest 6 is hollow, substantially U-shaped, and tapers outwards. More specifically, each outer crest 6 comprises a substantially flat intermediate portion 6a parallel to longitudinal axis A; and two substantially flat lateral portions 6b, 6c converging towards each other and towards intermediate portion 6a.
• Each depression 7 is substantially V-shaped, and comprises a rounded vertex 7a.
• Corrugated portion 2 is preferably a multilayer portion comprising an inner layer 2a of material resistant to high temperature and pressure of the operating fluid, e.g. polythene or polyethylene; an outer layer 2b of material resistant to corrosion, e.g. nylon; and an intermediate layer 2c connecting inner and outer layers 2a and 2b, and made, for example, of amide material capable of establishing strong chemical bonds with adjacent layers 2a and 2b.
• an inner layer 2a of material resistant to high temperature and pressure of the operating fluid e.g. polythene or polyethylene
• an outer layer 2b of material resistant to corrosion e.g. nylon
• an intermediate layer 2c connecting inner and outer layers 2a and 2b, and made, for example, of amide material capable of establishing strong chemical bonds with adjacent layers 2a and 2b.
• hose 1 The advantages of hose 1 are as follows. Firstly, by virtue of featuring continuous helical ribs 4, the flexibility of hose 1 is constant along the whole of longitudinal axis A, thus enabling hose 1 to adapt easily to different applications, regardless of the assembly route involved. Secondly, as compared with known solutions, the operating fluid flows more smoothly along hose 1 by being guided along the helical paths P defined by continuous ribs 4, thus reducing load losses and the noise level of the fluid inside hose 1.
• outer crests 6 and depressions 7 may be shaped differently; hose 1 need not necessarily be a multilayer hose; and corrugated portion 2 may comprise a number of continuous ribs 4 other than that described. In particular, corrugated portion 2 may comprise a single continuous rib 4.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rigid Pipes And Flexible Pipes (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11414219

Family Applications (1)

Country Status (2)

Cited By (3)

Citations (3)

• 1996
  • 1996-04-16 IT IT96TO000082 patent/IT239716Y1/it active
• 1997
  • 1997-04-16 WO PCT/IT1997/000084 patent/WO1997039270A1/en active Application Filing

Patent Citations (3)

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