FR2543996A1 - IMPROVEMENTS IN ANCHORING DEVICES FOR GREASE PRE-STRESS REINFORCEMENTS - Google Patents

Abstract

THE INVENTION CONCERNS AN ANCHORING DEVICE FOR A PRE-STRESSING REINFORCEMENT 2 GREASED AND CONTAINED IN A SHEATH 5, REINFORCEMENT RETAINED BY A TRUNCONIC CROWN OF JAWS 8 IN A HOUSING 7, ITSELF RECESSED IN A PLATE 6. THE MOUTH MORE LARGE DIAMETER OF THE HOUSING CONSTITUTES THE CENTER OF A BOWL 12 WHOSE INTERNAL LATERAL FACE PRESENTS A CURVED BOTTOM 14 AND RIBS IN A CIRCLE ARC 18 AND THIS BOWL IS CLOSED BY A HOOD 21 IN PLASTIC SHOWING A CYLINDRICAL SKIRT 24 ON A THINNED EDGE 25 CLEAN TO COACT WITH THE CURVED BOTTOM 14, THE EXTERNAL FACE OF THIS SKIRT INCLUDING LOCKING SNAPS 27 SPECIFIC TO COATING AS A BAYONET WITH THE RIBS 18 AND A DAMPER AND STOP 28.

Description

Improvements to anchoring devices for reinforcements

greased prestress.

  The invention relates to anchoring devices intended to retain the ends of reinforcement put under tension and intended to ensure the prestressing of concrete elements these reinforcements being contained in sheaths filled with grease and being preferably constituted by a strand.

  More particularly, among these provisions,

  those which include on the one hand a rigid plate of

  distribution hollowed out by a tapered housing suitable for

  cevoir contiguously the end of the reinforcement to be retained surrounded by a frustoconical crown of jaws, and on the other hand a peopre cover to cover and close in a grease-tight manner the end of larger diameter of said housing ,

  the smaller diameter end of this housing being itself

  even tightly connected to the corresponding end of the sheath, in particular by means of a funnel in

plastic material.

  In the known embodiments of these devices

  anchor, the cover is a piece with a large

  mechanical assistance, generally made of metal, the base of which is screwed in with the interposition of an annular seal on a complementary threaded collar

of the plate.

  The whole of this cover and of this seal is relatively

  expensive and their installation is tedious.

  The object of the invention is, above all, to eliminate these drawbacks

nients.

  To this end, the anchoring devices of the kind in question

  tion according to the invention are essentially characterized: in that their cover is constituted by a slightly deformable plastic bell having a cylindrical skirt with thinned edge which carries on its outer face at least two locking lugs,

  and in that the portion of their own plate 3 receives

  see the cover has the shape of a bowl of revolution whose bottom of the internal lateral face has a frustoconical shape or the like suitable for interacting with the thinned edge of the skirt above so as to ensure application

  sealed mutual between this bottom and this edge, said face

  so many ribs in an arc of a circle suitable for interacting with

  above lugs so as to ensure a ball lock

clear of the hood on the bowl.

  In preferred embodiments, recourse is also had to one and / or the other of the following arrangements: the external face of the skirt carries at least one lug for coding and angular stop capable of interacting with a notch hollowed out in one of the ribs, each locking lug is delimited laterally by two parallel flat faces and externally by a projecting dihedral at an acute angle, the face disposed of the cft E of the top of the cover is perpendicular to the axis of this cover and the other face of which is slightly inclined on this axis, and the internal lateral face of the bowl comprises a frustoconical bearing capable of coacting joined with said slightly inclined face,

  * two ears molded with the cover are pre-

  seen on the external face of the bottom of this cover, the bottom of the cover comprises a flat central disc and a frustoconical neck connecting this disc to the skirt,

  the bottom of the cover is hollowed out with at least one hole for the

  grease production and is secured by means of a flexible tab with a plug suitable for closing this hole, the assembly of this tab and of this plug having come

  injection molding with the cover.

  The invention includes, apart from these main provisions, certain other provisions which are used

  preferably at the same time and which will be more explicit-

  question below. In the following, a preferred embodiment of the invention will be described with reference to the accompanying drawings.

  of course in a nonlimiting manner.

  Figure 1 of these drawings shows in axial section an anchoring device established according to the invention with its cover

cut according to I-I, figure 2.

  Figure 2 is a cross section of Figure 1

according to II-II.

  Figure 3 shows an end view of the entire plate.

  as understood by the above anchoring device and the

pot mounted on this plate.

  Figure 4 shows said cover alone-in perspective view.

  The reinforcement here considered, intended to subject a concrete element or structure 1 by prestressing by being tensioned between its two ends, is constituted by a strand 2 itself composed of wires 3 (FIG. 2) wound

  around a slightly larger central wire 4 of diameter.

  In a manner known per se, this strand is itself enveloped

  pe by a plastic sheath 5, for example poly-

  ethylene, and the volumes between this sheath and the wires

  components of the strand are filled with grease.

  Such cladding and such lubrication have the double advantage of making possible the relative sliding of

  the reinforcement relative to the sheath, after pouring the concrete above

  tower of the latter, which facilitates the tensioning of said armature, and to protect this armature against

  corrosion, caused in particular by the action of humidity.

  The anchoring device intended to retain one of the ex-

  strands of the strand 2 comprises a metal plate 6, in particular

  cast iron, thickened at its center and pierced at this center

by a frustoconical housing 7.

  This housing 7 is suitable for joint reception of the ex-

  frame end considered surrounded by a set of three -

  jaw 8 forming a ring split longitudinally at 9: cha-

  each of these jaws extends substantially over 1200 around the axis common to the strand 2 and to the housing 7 and has a cylindrical inner face suitable for matching the strand and a face

  frustoconical exterior complementary to the accommodation.

  The edge of the small-diameter mouth of the frustoconical housing 7, or more precisely that of a cylindrical flange 10 extending this mouth axially, is connected in a relatively tight manner at the end of the

  sheath 5 which sheath is interrupted below the end

  mite of the frame 2 to allow the grip of the jaws 8 on this frame by a suitable funnel 11 of plastic material of which a cylindrical end is fitted

force on said flange.

  It is essentially the closure of the other mouth of said housing 7, namely that of larger diameter, which

  is concerned with the present invention.

  The edge of this mouth appears here in the form

  me of a bowl 12 of revolution whose internal face comprises

  takes, successively connected to each other a planar transverse annular area 13 forming the bottom of the bowl, a area 14 curved in a truncated cone or quarter-toroid, a first cylindrical area 15, a tapered flared area 16,

  and a second cylindrical area 17.

  On the cylindrical surface 17 protrude three ribs 18 in an arc of a circle angularly offset between them by 1200 around the axis and angularly separated from each other

  others by intervals 19 (Figure 3).

  In addition, a notch 20 interrupts one of the three nerves.

  vures 18 at an angle of around 300.

  To close the bowl 12, the interior profile of which has just been defined, use is made of a cover 21 consisting of

  slightly deformable plastic such as poly-

  propylene, molded, in particular by injection.

  This cover is in the general form of a bell of revolution comprising, connected successively to each other

  a central circular patch 22 constituting the top

put the bell, -

  a frustoconical neck 23, and a cylindrical skirt 24 whose end edge 25 is thinned and whose outside diameter is slightly less than the inside diameter of the cylindrical area 15 above

of the bowl 12.

  The terminal thinning in question corresponds to a suppression of thickness of the skirt inside of it

and not outside.

  In other words, if a drop appears in 26

  on the inner face of the skirt, its outer face remains

  re substantially cylindrical over its entire extent while being able to be made slightly frustoconical and convergent

towards the axis at its end.

  The thickness of this thinned edge 25 is advantageously

between 0.4 and 0.6 mm.

  On the outer face of the skirt 24 project three

  locking lugs 27 and a locating and locking lug

angular head 28.

  Each locking pin 27 is here delimited laterally.

  ralement by two plane faces 29 parallel to the axis of the assembly and externally by a projecting dihedral at an acute angle comprising, on the side of the top of the cover, a plane face perpendicular to this axis and, on the other side, a face

  31 slightly inclined on said axis.

  The inclination in question is substantially equal to that

  of the frustoconical face 16 of the bowl.

  The width of each lug 27 is less than that of the

intervals 19.

  The axial distance between the transverse faces 30 of the

  said lugs and the end edge of the skirt 24 is felt

  sibly-equal to the axial distance between the flat bottom of the bowl 12 and the face of each rib 18, facing this bottom. The coding lug 28 is in the form of a prismatic pad of generatrices parallel to the axis of

  the set and semi-circular or rectangular director.

  This lug is designed so that it can penetrate axially-

  lying in the notch 20 and coming to angularly abut against

  the angular ends of this notch in view of the 1st determination

  undermining the assembly limit switches.

  Two 32 venoes ears & molding with hood make sail-

  binds on its collar 23 and facilitate manual control of its

angular displacements.

  These ears are for example flat and triangular

as clearly visible in Figure 4.

  In the bottom of the cover are hollowed out two holes 33 through

  towards which one can fill with grease or more precisely complete the filling with grease of all of the intercommunicating volumes located inside the cover 21, of the

  bowl 22, 'of the housing 7, of the funnel II and of the sheath 5.

  These holes 33 are advantageously provided at the end

  axial chimneys 34 formed in the neck 23.

  They can be closed using small plugs 35 mounted at the end of flexible tabs 36 molded, just like these plugs 35, with the entire cover: -this last measure avoids the loss of plugs in

  causes and makes these constantly available.

  To mount the cover 21 on the bowl 12, we proceed

by a bayonet movement.

  In other words, we start by orienting this cover

  in such a way that its lugs 27 and 28 are presented respectively-

  axially opposite the intervals 19 and the notch 20. These pins are then introduced axially into their

  housings at the same time as the skirt 24 in the bowl 12.

  At the end of this axial introduction, the thinned edge of the skirt 24 comes into contact with the curved surface

14 from the bottom of the bowl.

  The cover is then rotated in the direction of screwing, which angularly penetrates the pins 27 in the grooves in an arc defined between the ribs 18 and

  the frusto-conical range 16 of the bowl.

  This angular penetration is guided by a slightly oblique profiling of the faces of the ribs against which

  come to carry the lugs: this guidance has the effect of

  rer a slight wedging effect on the lugs au'fur and as they penetrate into their grooves, -which makes this penetration involuntary little reversible, and to push back slightly in an axial direction the edge 25 against the pad 14, which ensures automatically between these two elements a very intimate and therefore grease tight contact, the application in question possibly resulting in

  a slight centripetal deformation of said edge 25.

  The end of the angular displacement considered

  is ensured by the stop of the lug 28 against the end of the rib

re 18 opposite.

  The cover 21 is then secured in an extremely

  solid and rigorously tight on the bowl 12.

  For disassembly, simply execute the movement in

  balonnette reverse of that previously described.

  Following this, and whatever the mode of realization

  tion adopted, we finally get an anchoring device

  whose constitution and implementation are sufficient

ment of the above.

  This device has clear advantages over those previously known, in particular as regards the low price and the simplicity of the assembly, which does not require

  plus the use of a seal.

  As goes without saying, and as it already follows from the above, the invention is in no way limited to those of its modes of application and embodiments which have

  been more specifically contemplated; she embraces it,

milk, all variants.

Claims (6)

  1 Anchoring device for retaining one end of a prestressing frame (2) contained in a sheath (5) with grease, comprising on the one hand a rigid distribution plate (6) hollowed out by a frustoconical housing (7 ) suitable for receiving the end of the reinforcement to be joined contiguously surrounded by a frustoconical crown of jaws (8), and on the other hand a cover suitable for covering and closing with a   grease-tight end of larger diameter   tre said housing, the smaller diameter end of this   housing itself being tightly connected to the outside   corresponding part of the sheath (5), characterized in that its cover consists of a slightly deformable plastic bell (21) having a cylindrical skirt (24) with a thinned edge (25) which carries on its external face at least two locking lugs (27), and in that the portion of its plate suitable for receiving the cover has the form of a revolving bowl (12) whose bottom (14) of the internal lateral face has a frustoconical shape or the like suitable for coagulating with the thinned edge (25) of the skirt   above so as to ensure mutual application   che between this bottom and this edge, said face carrying ribs   res (18) in an arc capable of interacting with the pins (27) above so as to ensure bayonet locking from the hood to the bowl.   2 Anchoring device according to claim 1, charac-   characterized in that the external face of the skirt (24) carries at least one lug (28) of polarization and own angular stop   to coagulate with a notch (20) hollowed out in one of the ribs res (18) -   3 Anchoring device according to any one of   previous claims, characterized in that each er-   locking has (27) is delimited laterally by two parallel flat faces (29) and externally by a projecting dihedral at an acute angle whose face (30) disposed on the side of the top of the cover is perpendicular to the axis of this cover and of which the other face (31) is slightly inclined on this axis, and in that the internal lateral face of the bowl comprises a frustoconical bearing (16) capable of coagulating jointingly   with said slightly inclined face (31).   4 Anchoring device according to claim 3, charac-   terrified in that the ribs capable of interacting with the er-   locking lugs are tilted slightly so that exert a wedging effect.   Anchoring device according to any one of   previous claims, characterized in that two ear-   the (32) moldings with the cover (21) are provided   on the outer face of the bottom of this cover.   6 Anchoring device according to any one of   previous claims, characterized in that the bottom of the   cover (21) includes a flat central disc (22) and a neck   frustoconical (23) connecting this disc with the skirt (24).   7 Anchoring device according to any one of   previous claims, characterized in that the bottom of the   cover (21) is hollowed out with at least one hole (33) for the intro   fat reduction and is joined by   a flexible tab (36) with a plug (35) suitable for obtaining   ture this hole, all of this tab and this plug   having come from injection molding-with the hood.