FR2559220A1 - WIDE BAND TIGHTENING COLLAR WITH IMPROVED MARGINAL SEALING SYSTEM - Google Patents

Abstract

A WIDE BAND CLAMP INCLUDES LEGS 11, 12 BENDED TO THE ENDS OF BAND 1; TIGHTENING JAWS 3, 4 CONNECTED TO THESE LEGS AND APPLIED AGAINST THE SURFACES OF THE SAID MUTUALLY OPPOSED LEGS; AS WELL AS A TIGHTENING SCREW 7 THROUGH CENTRALLY THE JAWS AND THE LEGS, AND WHOSE TIGHTENING FORCE IS TRANSMITTED TO THE SAID JAWS 3, 4. OF THE CENTRAL REGIONS 14 OF THE JAWS 3, 4 THROUGH THIS SCREW PRESENT, FROM THE SIDE TURNED TOWARDS THE LEG CONSIDERED 11, 12, AN UNINTERRUPTED RADIAL NOTCH 15 OF A WIDTH CORRESPONDING TO AT LEAST THIRD OF THAT OF THE BAND. JAWS 3, 4 ARE CONNECTED TO LEGS 11, 12 ON BOTH SIDES OF NOTCH 15.

Description

WIDE BAND TIGHTENING COLLAR WITH SYSTEM

  The present invention relates to a necklace of

  wide band clamping including curved radiating tabs

  Lement outwards at the ends of the strip, clamping jaws connected to these legs and applied against the surfaces of said legs which are turned opposite to each other, as well as a clamping screw passing right through in their center the clamping jaws and the legs, and whose clamping force

is transmitted to said jaws.

  Wide band clamps are used as connecting elements for flexible pipes and clamps, for example for fixing flexible rubber or plastic pipes and rubber sleeves, and for connecting ends of pipes. tubes, or even as an intermediate lining for a

rubber sleeve.

  In a known wide band collar of the aforementioned type, having only one clamping screw in the center of the

  tabs formed at the ends of the strip, it is

  dre that said legs flex during tightening

  in their central region weakened by the through hole

  intended for the clamping screw, and that the clamping force applied to the circumferential marginal zones of the collar is less than in the central peripheral zone of this collar. This may result in leaks when joining the ends of the tubes, or when connecting flexible pipes to fittings

tubular.

  Collars with wide bands are also known

  with two clamping screws. Manufacturing and handling

  However, these necklaces are more complicated

255922 O

because of the two clamping screws.

  The object of the invention is to provide a wide band clamp of the aforementioned type which guarantees, with less complexity, better sealing in the marginal areas of this collar. According to the invention, this object is achieved by the fact that the central regions of the clamping jaws traversed by the clamping screw have,

  on their face facing the associated tab, a swap

  radially unbroken crust whose width represents

  feels at least approximately one third of the width of the strip; and by the fact that the clamping jaws are connected to the tabs on either side of

said notch.

  With this solution, the tightening forces exerted by the screw are transmitted fully and uniformly to the marginal zones of the collar via the clamping jaws, since these jaws

  bear against said legs only by their sections

  extreme lessons located on the side of the central region provided with the notch. Even in the case of a connection of tubes having different diameters and when, consequently, the clamping jaws occupy an inclined position relative to the axial direction of the tubes or of the clamping screw, respectively, the clamping force applied by this screw is uniformly transmitted to the marginal areas of the collar, since the clamping jaws act practically as differential levers.

  Preferably, the legs extend without interruption.

  over the entire width of the strip. These legs absorb

  bent then the axial forces of the clamping jaws manifested during tightening, so that said tabs act against a flattening of the central region of said jaws and against a spacing

  of these jaws in the presence of large clamping forces.

  As a result, there is a high flexural rigidity of the clamping jaws, which

prevents their sagging.

  In addition, the central region of the clamping jaws can be generally rounded. This implies a saving of material by comparison with a possibility of making the clamping jaws from a plate.

  flattened, which is only provided with the notch.

  So the clamping jaws can be produced

  in a simple way, by bending a metal plate

  than. However, it is also possible to manufacture the clamping jaws from plastic, with a

great corresponding robustness.

  With the plane in which their radially internal edges are arranged, the tabs can form an acute angle on the sides on which the clamping jaws are located. During tightening, it therefore also manifests in the legs

  forces which act substantially radially inward

  laughing with respect to the collar, so that they prevent the clamping jaws from skidding radially outwards, and thus relieve the connection between

those jaws and legs.

  Furthermore, the surfaces of the central regions of the clamping jaws, which are turned away from the associated tabs, may be planar and form an acute angle, the apex of which is located radially outside the collar. In this way, the head of the clamping screw and a common locking nut, possibly

  provided on the free end of this screw, do not exert

  it is only pushed against the clamping jaws by their radially internal edge, so that the clamping force acts on the legs with a consequently weak radial lever arm. Therefore, said legs withstand large clamping forces before bending

towards each other.

  Preferably, it is further arranged that clamping jaws are also applied against the surfaces of the legs which are turned towards each other, these jaws being connected, by means of cylindrical parts passing right through the furs of said legs, with the clamping jaws applied against the surfaces of said legs which are turned opposite to each other, said cylindrical parts and said furs engaging in holes made in the clamping jaws which are applied against the surfaces of the legs facing away from each other. This connection gives the legs great resistance to stress

  radial in the vicinity of the through furs.

  The cylindrical parts can consist of rivets which pass right through the legs and the clamping jaws carrying on either side of these

  paws. Said rivets strengthen the assembly by fric-

  between the legs and the clamping jaws

  applied on both sides against these legs.

  Alternatively, the cylindrical parts may consist

  ter in stop pins which are formed integrally on the clamping jaws applied against one of the faces of the tabs. This removes the need for a

  separate manufacture and handling of the rivets.

  The clamping jaws can, in a simple manner,

  be made of plastic.

  In addition, the clamping jaws bearing

  on either side of a leg can be connected by the inter-

  medial of at least one film hinge

  cular. Thus, the clamping jaws applied against a respective tab can be produced in a single piece of plastic, the hinge joint with film ensuring the cohesion of associated clamping jaws.

  In an embodiment, moreover,

  geuse, at least one of the clamping jaws applied against the surfaces of the legs, turned away from each other, has a first hemispherical surface area on the edge, turned away from the adjoining leg, a through hole intended for the clamping screw, while the end face of a locking nut of this clamping screw, facing towards said hemispherical surface zone, comprises a second zone

  hemispherical surface adapted to the first zone.

  This embodiment results in a certain capacity for articulation between the clamping jaw considered and the clamping screw which crosses it right through with play. This avoids, in this way, bending stresses between the clamping screw and the clamping jaw

that she crosses.

  The invention will now be described in more detail by way of non-limiting examples, with reference to the appended drawings in which: FIG. 1 is a perspective view of part of a first embodiment of the broadband collar according to the invention; Figure 2 is a side elevation with partial section of the collar according to Figure 1;

  FIG. 3 is a fragmentary plan view of the neck

  link from Figure 1; Figure 4 is a fragmentary view with section

  partial view of a second embodiment of a collar

  link broadband according to the invention; and Figure 5 is a fragmentary cross section of an alternative embodiment of part of the collar to

wide band according to the invention.

  The wide band collar according to Figures 1 to 3

  includes a strip 1 of sheet steel, clamping jaws

  rage 3, 4, 5 and 6, a clamping screw 7 and a piece of

connection 8.

  The band 1 of the collar has on its circumferential edges

  of wings 9 and 10 bent radially inward and, at its ends, legs 11 and 12

  bent substantially radially outwards.

  Each of the tabs 11 and 12 forms an acute angle with the plane in which its radially internal edges are located (bending edges), and it extends over the entire width of the strip 1, in the axial direction of the collar. The legs 11 and 12 are pierced centrally with a respective through hole 13 allowing passage

of the clamping screw 7.

  The clamping jaws 3 and 4 also extend over the entire width of the band 1 of the collar and they are provided in their respective central regions 14, on the side facing the tab 11 or 12 respectively associated, with a radial notch 15 the width of which represents at least approximately one third of the width of the strip (approximately half of this width in the example considered). The notch 15 is of substantially trapezoidal section s and it is formed by a corresponding bulging of the central region 14. In addition, the central region 14 of the clamping jaw 3 is pierced with a tapped hole (not shown) to receive the clamping screw 7, a hole (not shown) ensuring the through passage of this screw 7 being

  formed in the clamping jaw 4. These holes coincide

  coincide with the holes 13 formed in the legs 11 and 12. The central regions 14 of the clamping jaws 3 and 4 have surfaces 16 of planar embodiment, turned away from the leg 11 or 12 respectively associated, and forming an angle acute whose top is relegated radially to the outside of the collar (see in particular Figure 2). We obtain in this way that the pressure exerted by a head 17 of the clamping screw - and by a nut not shown, possibly provided in place of the thread of the jaw 3 on the free end of the threaded rod of the screw 7 , acts, on the legs, essentially as close as possible to the radially internal edge (bending edge) of these

  legs, with a consequently weak bending torque.

  Chords 19, produced between the central regions 14 and axially external zones 18 of the jaws of

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  tightening 3 and 4, increase the rigidity of these jaws 3 and 4 in bending. The surfaces of said jaws 3 and 4 applied against the legs 11 and 12 register the same acute angle as these legs 11 and 12 with a plane in

  which are the radially internal edges of the

say jaws 3 and 4.

  Clamping jaws 5 and 6 are applied

  against the surfaces of the legs 11 and 12 which are turned

  born towards each other, and they are assembled by conformation with the clamping jaws 3 and 4, by means of hollow rivets 20, in the vicinity of the

  zones 18 of said jaws 3 and 4. In addition, these jaws

  res 5 and 6 are connected in one piece on their radially external face to the jaws 3 and 4, through

  of a respective articulation 21 with a film hinge.

  Furthermore, the hollow rivets 20 pass through furs

  22 (Figure 2) housed in the legs 11 and 12, these four-

  rures 22 simultaneously engaging in large areas

  Gies of holes provided for the through passage of said hollow rivets 20 in the jaws 3 and 4. Furs

  can be provided in the through holes

  slopes 13 of the legs. These furs increase the admissible diametral pressure exerted on the wall

through holes.

  Clamping jaws 5 and 6 are slightly sail-

  radially inwards, by radially internal ends 23, beyond the edges radially

  internal legs 11, 12 or jaws 3, 4, res-

  pectively, and they are supported by these radially internal ends 23 on the connection piece 8 crossing the gap between said legs 11, 12 or said jaws 5, 6, respectively, so as to form a support preventing bending of said legs 11 and 12. The connecting piece 8 is welded to the internal face of one of the end sections of the band 1 of the collar, but it can also be formed in one piece on the clamping jaws 5 and -6, neighborhood

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  ends 23. Optionally, this connecting piece

  string 8 consists, like clamping jaws 3 to 6, of a hard elastic plastic

  and reinforced with glass fibers, like a polyamide.

  Since the central region 14 of each of the clamping jaws 3 and 4 does not bear against the associated tab 11 or 12, the clamping force, exerted during tightening by the screw 7 on the jaws 3 and 4 in the central regions 14, is evenly distributed

  on the zones 18 of said clamping jaws applied

  quées only against the legs 11 and 12, on either side of the notches 15, and in this way on the annular zones of the band 1 of the collar which are located near the circumferential edges of this collar and in which said collar undergoes the strongest constraint during the joining of ends of

  tubes with interposition of a rubber sleeve.

  There is also a uniform distribution of the clamping force on the marginal regions of the tabs or the band of the collar, respectively, when the ends of the tubes to be connected have appreciably different diameters and that, therefore, the jaws of clamping 5 and 6 are spaced apart, on one side of the clamping screw 7, by a distance other than the clamping jaws 5 and 6 on the other side of said

screw 7.

  Legs 11 and 12 of continuous production

  between the hollow rivets 20 act against a flatness

  weaving of the convex central regions 14 of the clamping jaws 3 and 4 in the presence of very large forces

  tightening, because they absorb spreading forces

  ment corresponding to said jaws 3 and 4 acting in the axial direction of the collar. Overall, this results in a locking of this wide band collar which has

  very good flexural rigidity.

  The example of embodiment according to FIG. 4 differs from that of FIGS. 1 to 3, only by the fact that stop pins 20a replacing the hollow rivets 20 are produced integrally on the internal face of a jaw of clamping Sa and of another jaw (6a) not shown and opposite to the aforementioned jaw, these nipples penetrating into blind holes on the internal face of a clamping jaw 3a (4a). We can then dispense with the separate production and assembly

hollow rivets.

  Compared to the exemplary embodiments according to FIGS. 1 to 4, the exemplary embodiment according to the figure is distinguished only by the fact that a clamping jaw 3b has a non-tapped through hole 24 intended for the clamping screw not illustrated, and whose edge turned opposite the tab 11 has the shape of a hemispherical surface area 25. To axially lock the clamping screw not shown, a nut is used

  26 whose end face applied against the super zone

  hemispherical 25 also presents the

  shape of a hemispherical surface area 27 accumulated

  sant the same radius as said area 25. The diameter of the hole 24 is substantially larger than that of the threaded rod of the clamping screw, so that this screw,

  introduced by its free end in the lock nut

  cage 26, can perform a slight pivoting during

  tightening, without any bending of the jaw 3b.

  It goes without saying that many modifications can be made to the clamp described and shown,

  without departing from the scope of the invention.

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Claims (10)

  1. Wide band hose clamp including   legs curved radially outward at the ends   tees of the strip, clamping jaws connected to these tabs and applied against the surfaces of said tabs which are turned opposite to each other, as well as a clamping screw passing right through in their center said jaws and said legs, and whose clamping force is transmitted to said jaws, collar characterized in that the central regions (14) of the clamping jaws (3, 4; 3a, 4a; 3b) traversed by the clamping screw (7) have, on their face facing the associated tab (11; 12), a radially uninterrupted notch (15) whose width represents at least approximately one third of the width of the band of the collar; and by the fact that the clamping jaws are connected to the tabs (11, 12) on the one hand and on the other of the notch (15).   2. Clamp according to claim 1, characterized in that the tabs (11, 12) extend   without interruption over the entire width of the strip.   3. Clamp according to one of the claims   1 and 2, characterized in that the central regions (14) of the clamping jaws (3, 4; 3a, 4a; 3b) are globally domed.   4. Clamp according to any one of   Claims 1 to 3, characterized in that the   legs (11, 12) form, with the plane in which their radially internal edges are arranged, an acute angle on the sides on which the jaws of tightening (3, 4; 3a, 4a; 3b).   5. Clamp according to any one of   Claims I to 4, characterized in that the   surfaces (16) of the central regions (14) of the clamping jaws (3, 4; 3a, 4a; 3b), which are turned opposite the associated legs (11, 12), are planar and form an acute angle whose the top is relegated J]   radially outside of said collar.   6. Clamp according to any one of   Claims 1 to 5, characterized in that   clamping jaws (5, 6; Sa; 5b) are also applied against the surfaces of the tabs (11, 12) which are turned towards each other, these jaws being connected, by means of cylindrical parts (20; 20a) passing through right through the furs (22) of said legs, with the clamping jaws (3, 4; 3a, 4a; 3b) applied against the surfaces of said legs (11, 12)   which are turned opposite to each other, the-   said cylindrical parts (20; 20a) and said -   furs (22) engaging in holes made in the clamping jaws (3, 4; 3a, 4a; 3b) bearing against said surfaces legs turned opposite each other.   7. Hose clamp according to claim 6, ca-   characterized by the fact that the cylindrical parts consist   tent in rivets (20) which pass right through the tabs (11, 12) and the clamping jaws (3, 4;, 6) bearing on either side of these tabs. 8. Clamp according to claim 6,   characterized by the fact that the cylindrical parts   exist as stop pins (20a) which are formed in one piece on the clamping jaws (Sa, 6a)   applied against one of the faces of the legs.   9. Clamp according to any one of   Claims 6 to 8, characterized in that the   clamping jaws (3, 5; 4, 6) bearing on both sides   on the other side of a tab (11; 12) are connected by the inter-   - medial of at least one articulation (21) with a film hinge. 10. Clamp according to any one of   Claims 1 to 9, characterized in that at least   one (3b) of the clamping jaws (3b; 4) applied   against the surfaces of the legs (11, 12), turned opposite   sewn from each other, has a first hemispherical surface area (25) on the edge, facing away from the adjoining tab (11), of a through hole (24) intended for the clamping screw (7), while the end face of a nut (26) for locking said screw, facing towards said hemispherical surface area   (25), has a second hemispherical surface area   risk (27) adapted to the first zone.