Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
  • A47J27/00—Cooking-vessels
  • A47J27/08—Pressure-cookers; Lids or locking devices specially adapted therefor
  • A47J27/09—Safety devices
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
  • A47J27/00—Cooking-vessels
  • A47J27/08—Pressure-cookers; Lids or locking devices specially adapted therefor
  • A47J27/0804—Locking devices
  • A47J27/0815—Locking devices where vessel and lid have adapted shapes to provide for the locking action

Definitions

• the present invention relates to the technical field of overpressure safety devices for pressure cookers with a manhole, such devices being designed to prevent violent projection of steam and / or complete destruction of the cooking appliance in the event of overpressure.
• the present invention relates to an overpressure safety device for a pressure cooker with a manhole comprising a cooking vessel with an opening delimited by a reentrant rim into which a lid can be inserted to seal the vessel hermetically. intermediate a seal mounted in a substantially peripheral groove of the cover forming a rolled edge, said seal thus coming into leaktight abutment against the reentrant rim of the tank.
• Pressure cookers known as "manhole” or even with a tuck-in lid are widely known and have a number of advantages, in particular those relating to their simplicity and economy of manufacture, leading to the production of particularly simple and inexpensive products.
• Pressure cookers with a manhole are, as is well known to those skilled in the art, pressure cookers whose bowl and cover have a slightly oval shape allowing the cover to be inserted at the interior of the tank to come occupy, by means of a seal, and after rotation and fitting of the cover in the tank, a sealed closing position in which the rolled edge of the cover is at inside the tank, the seal being interposed between the rolled edge and the peripheral re-entrant edge of the tank.
• thermoplastic material It is generally a piece or patch of thermoplastic material fixed to the cover, for example by screwing. In the event of an abnormal rise in temperature and overpressure, the tablet or the piece of thermoplastic material is caused to melt and then eject from the cover, thus allowing the excess pressure to escape.
• the parts in thermoplastic material can be replaced by fusible safety devices made from easily fusible metal parts.
• the objects assigned to the invention therefore aim to remedy the various drawbacks listed above and to propose a new overpressure safety device for a pressure cooker with a manhole whose efficiency is improved and which avoids the destruction of the device in case of overpressure.
• Another object of the invention is to propose a new overpressure safety device for a manhole pressure cooker allowing normal reuse of the appliance after an abnormal overpressure cycle which has caused the triggering of the overpressure device.
• Another object of the invention is to propose a new overpressure safety device having excellent efficiency in terms of its safety while being of particularly simple design. Another object of the invention is to propose a new safety device avoiding any risk of improper handling, modification or improper assembly of the elements making it up.
• a complementary object of the invention aims to propose a new safety device making it possible to avoid mounting inappropriate parts in the device
• the objects assigned to the invention also aim to propose a new safety seal specially shaped to ensure safety at the overpressure of a pressure cooker and prevent its destruction
• an overpressure safety device for a pressure cooker with a manhole comprising a cooking vat with an opening delimited by a flange entering into which is likely to be inserted a cover for hermetically closing the tank by means of a seal mounted in a substantially peripheral groove of the cover forming a rolled edge, said seal thus coming into sealing contact against the re-entrant flange, characterized in that the seal and the re-entrant rim are shaped so that in the event of overpressure, the cover comes into abutment position against the re-entrant rim by one or more sector (s) of the periphery of the rolled edge while leaving the seal free to deform locally by substantially radial internal direction under the effect of the pressure acting through one or more clearance zone (s) outside the sector (s) so to locally break the seal and let the steam escape between the inside edge and the cover
• the objects assigned to the invention are also achieved using a seal intended to be mounted and used in a safety device to the overpressure for a pressure cooker with a manhole comprising at least one zone of weakening of its section to favor its local deformation.
• FIG. 1 shows in a longitudinal cross sectional view, a general view of a pressure cooker with a manhole according to the invention.
• FIG. 2 illustrates in a partial cross-sectional view, a detail of embodiment of the safety device according to the invention in an operating situation without overpressure.
• FIG. 3 illustrates in a view identical to Figure 2, a detail of the safety device according to the invention in an overpressure situation.
• FIG. 4 illustrates in a general perspective view, an embodiment of a pressure cooker manhole cover according to the invention.
• FIG. 5 illustrates in a top view, an exemplary embodiment of a seal according to a safety device overpressure according to the invention.
• FIG. 6 illustrates in a side view, an embodiment of a seal conforming to a safety device to overpressure according to the invention, said seal being identical to that shown in FIG. 5.
• FIG. 7 illustrates in a partial top view a detail of an area of weakness in the section of a seal according to the invention.
• FIG. 1 illustrates in general a pressure cooker with a manhole comprising a cooking tank 1 made of metallic material, with a bottom 2 from which rise the walls 3, substantially vertical, of the tank, the latter being surmounted by a re-entrant edge 4 extending over the entire periphery of the tank 1.
• the opening of the tank is delimited by the terminal edge 5 of the re-entrant flange 4.
• a re-entrant flange 4 means the upper annular end portion of the tank 1 directed towards the axis of symmetry S of the tank whatever or the angular value of the re-entrant flange 4 relative to a horizontal plane, the re-entrant flange 4 therefore overhanging part of the bottom 2.
• the pressure cooker with a manhole also comprises a cover 10 (FIG. 4), also of substantially oval shape with a domed central portion 10A and a toric flank 10B, the cover 10 being intended to be inserted into the opening of the cooking tank 1 in order to close the latter hermetically by means of a seal seal 11 mounted in a substantially peripheral groove 12 of said cover 10, said groove being formed by a rolled edge 13.
• the cover 10 can be inserted into the opening of the tank 1 at its outer periphery, by means of a handle (not shown). , by tilting it slightly and inserting it through the largest opening of the tank, then making the oval of the cover 10 coincide with the oval of the tank 1 by rotation to an angular value of approximately 90 degrees .
• the cover 10 is held against the re-entrant flange 4 by means of the upper part of the seal 11 which comes into sealing abutment against the re-entering edge 4 by means of the re-pressing of a tank handle and a cover handle not shown in the figures.
• the groove 12 delimited externally by the rolled edge 13 includes an internal edge 13A and an external edge 13B forming the rolled edge proper and intended to come into abutment against the internal face of the edge re-entering 4 by its upper end 13C as illustrated in FIG. 3, in the event of overpressure.
• the rolled edge 13B In the stop position illustrated in FIG. 3, the rolled edge 13B, according to its geometric configuration, comes into abutment on one or more angular sector (s) defined by the surface of the upper end 13C.
• the seal 11 and the re-entrant flange 4 are shaped, so that in the event of overpressure, the cover 10 comes into abutment position against the re-entrant flange 4 by one or more sector (s) of the periphery of the edge rolled 13, 13B defined by the surface of the upper end 13C while leaving the seal 11 to deform locally in a substantially centripetal direction, in consideration of the axis of symmetry S of the cooking vessel 1, under the effect of the pressure acting through one or more clearance zone (s) formed outside the contact sector (s) so as to locally break the seal and allow the pressure to escape between the re-entrant rim 4, that is to say between the end edge 5, and the cover 10.
• the concept of "overpressure” means a state of pressure internal to the pressure cooker, greater than the normal operating pressure, and for example greater than 0.9 bars.
• the clearance zone (s) which is (are) formed outside the sector (s) of contact with the returning edge 4 is (are) advantageously produced (s) in the form simple local deformations of drilling (s), cutout (s) or notch (s) 15 (FIG. 4) formed or made in the rolled edge 13B over a certain height from the end 13C, and at intervals regular or not. Thanks to this arrangement, it is thus possible to release a part of the lateral surface of the seal 11 so as to allow the pressure P to be exerted directly on the seal 11 in a substantially centripetal manner as can be seen in FIG. 3, to locally break at the level of the notch (s) 15.
• all or part of the seal 11 may locally at the level of the notch (s) 15 disappear, that is to say leave its sealing contact by simple creep or else move locally, or even more or less partially extrude between the terminal edge 5 and the cover 10.
• the safety device according to the invention may advantageously comprise on an angular sector substantially aligned with the clearance zone or zones corresponding to the notches 15, a localized clearance L situated on at least one annular sector between the side 10B of the cover 10 and the re-entrant edge 4, said localized clearance L being greater than the average peripheral clearance M existing between the cover 10 and the re-entrant edge 4 to allow the seal 11 to extrude out of the groove 12 at said localized clearance L.
• the localized clearance L will be formed by at least one local deformation of the cover 10.
• the localization deformation (s) is (are) formed by a counter 20 ( Figure 4) formed from the outer face of the cover 10 in line with a notch 15.
• Such local deformation can be obtained in a particularly simple manner by forming during the stamping operation of the cover.
• Other forms and ways of obtaining a local deformation of the cover are obviously conceivable as soon as one succeeds in obtaining a local rupture of the general shape of the sidewall 10B located at right or in radial alignment with a notch 15 allowing an increase in the leakage space of the seal 11 in the centripetal direction.
• the safety device according to the invention will comprise a pair of notches 15 of any shape and for example in diametrically opposite arc of a circle and situated at the level of the small width of the substantially oval opening of the tank. 1.
• the clearance area (s) in the form of an opening or of a bore made in the re-entrant edge 4 situated at the right of the annular zone against which the seal 11 comes to rest in the sealing position.
• the rolled edge 13B has a substantially planar upper end 13C, where the clearance zone (s) are formed (each) by a notch 15 formed in the end upper 13C.
• the safety device will be provided with means for indexing the position of the seal 11, so that the zone or zones of weakness 30 of the section of the seal 11 can be substantially radially aligned at the level or zones (s) of clearance of the cover 10, that is to say at the level of the notches 15 and of the counter 20, to favor the local deformation of said seal.
• the seal 11 can deform locally in the centripetal direction at a level of overpressure substantially lower than the level of overpressure required for a displacement or an extrusion of the seal 11 without the presence of a weakening zone 30.
• 31 may be a recess of shape substantially comparable to a rectangle quadrilateral, it being understood that any other geometric form of possible internal weakening is also possible.
• the weakening zone 30 can be made even more sensitive to deformation by associating the internal recess 31 with an external recess 32, aligned radially with the internal recess 31.
• the outer recess 32 may be formed by an outer recess 32 of shape substantially equivalent to the inner recess 31, but of smaller size, formed in the upper part of the joint.
• the external recess 32 can be completed by a complementary external recess 32A produced in the form of a substantially concave cutout extending over the entire height of the seal 11.
• a seal according to the invention could be provided with one or more weakening zones comprising an internal recess 31 or an external recess 32 or a combination of the two.
• the seal 11 according to the invention and intended for use in a device according to the invention will preferably comprise two weakening zones 30 diametrically opposite and preferably arranged at the level of the small width of the seal oval 11.
• the means for indexing the position of the seal are advantageously produced in the form of an internal bead 35, for example hemispherical, projecting radially from the internal blank of the seal and by a corresponding housing (not shown in the figures) of conjugate shape provided on the cover 10 at the level of the groove 12.
• the seal 11 may advantageously be provided with an upper peripheral rib 36 (FIG. 7), arranged for example in a substantially central manner, surmounting the rest of the body of the seal 11.
• the presence of the upper peripheral rib 36 has the advantage of improving the total tightness of the seal without reducing its propensity to centripetal deformation in the event of overpressure.
• the outer edge 13B of the rolled edge 13 is also advantageous to stiffen the outer edge 13B of the rolled edge 13 in order to avoid any deformation or crushing of said rolled edge when the end 13C comes into contact with the re-entrant edge 4. In fact if such a deformation took place the seal 11 could be pinched between the rolled edge 13 and the re-entrant edge 4 which would prevent its centripetal displacement.
• the outer edge 13B will see its mechanical strength reinforced, its height h (FIG. 2) being advantageously between 2R and 4R, and preferably substantially equal to 3R.
• the height h corresponds to the height of the rolled edge 13B extending beyond the semicircle forming the bottom of the groove 12, the value R corresponding to the mean radius of the bottom of the groove 12.
• the operation of the safety device according to the invention is as follows.
• the seal 11 seals the pressure cooker with a manhole, avoiding any passage of pressure from the interior of the tank 1 towards the exterior of the pressure cooker.
• the cover 10 comes into contact via the end upper 13C of the rolled edge 13B with the internal face of the re-entrant edge 4 (FIG. 3). Such a situation generally occurs towards a pressure zone close to 1.7 bars approximately.
• the seal 11 can then either be locally extruded by sliding and accompanying it out of the groove 12 in the counter 20, or simply creep if the safety device is provided with a thinning zone 30. In one case as in the other, the pressure can escape avoiding any explosive destruction of the pressure cooker. After moving, the seal 11 can of course be replaced and reused normally.
• the invention finds its industrial application in the manufacture of pressure cookers with a manhole and in the manufacture of safety seals intended to be mounted and used in such pressure cookers.

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• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Cookers (AREA)
• Pressure Vessels And Lids Thereof (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9548593

Family Applications (1)

Country Status (7)

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Family Cites Families (4)

• 1999
  • 1999-07-23 FR FR9909758A patent/FR2796542B1/fr not_active Expired - Fee Related
• 2000
  • 2000-07-19 AR ARP000103705 patent/AR030027A1/es unknown
  • 2000-07-21 AU AU70051/00A patent/AU7005100A/en not_active Abandoned
  • 2000-07-21 CN CNB008106207A patent/CN1139351C/zh not_active Expired - Fee Related
  • 2000-07-21 WO PCT/FR2000/002093 patent/WO2001006901A1/fr active Application Filing
  • 2000-07-21 BR BRPI0012690-0B1A patent/BR0012690B1/pt not_active IP Right Cessation
  • 2000-07-21 EP EP00958573A patent/EP1202657A1/fr not_active Withdrawn

Non-Patent Citations (1)

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