GB2153899A

GB2153899A - A band clip

Info

Publication number: GB2153899A
Application number: GB08502153A
Authority: GB
Inventors: Siegmund Zeidler
Original assignee: Rasmussen GmbH
Current assignee: Norma Germany GmbH
Priority date: 1984-02-03
Filing date: 1985-01-29
Publication date: 1985-08-29
Also published as: FR2559220A1; CH665699A5; SE8500416D0; DE3403781A1; GB8502153D0; SE455961B; FR2559220B1; SE8500416L; DE3403781C2; GB2153899B

Abstract

In a wide-band clip comprising tongue portions (11, 12) which are bent radially outwardly at the ends of the band (1), clamping jaws (11, 12) which are connected to the tongue portions and which bear against the faces of the tongue portions which face away from each other, and a clamping screw (7) which passes centrally through the clamping jaws and tongue portions and whose clamping force is transmitted to the clamping jaws (3, 4), the central regions (14) of the clamping jaws (3, 4), through which the clamping screw passes, are provided on their side which is towards the associated tongue portion (11, 12), with a radially continuous groove (15) whose width corresponds at least approximately to a third of the width of the band, and the clamping jaws (3, 4) are connected to the tongue portions on both sides of the groove. In that way, when using only one central clamping screw. the clamping forces are uniformly transmitted to the edge regions of the clip. <IMAGE>

Description

SPECIFICATION A band clip This invention relates to a wide-band clip having an annular band locatable around an item to be clipped, tongue portions formed by radially outwardly bent ends of the band, clamping jaws which are connected to the tongue portions and which bear against the faces of the tongue portions which face away from each other, and a clamping screw which passes through the clamping jaws and tongue portions in the centre and the clamping force of which is transmitted to the clamping jaws.

Wide-band clips are used as hose and clamping clips, for example for fixing rubber hoses, plastics hoses and rubber sleeves and for connecting ends of pipes, or as an intermediate position on a rubber sleeve.

In a known wide-band clip of the general kind set forth above, having only one clamping screw in the middle of the tongue portions which are formed at the ends of the band of the clip, there is the danger that, when the clip is tightened, the tongue portions may bend in their central region which is weakened by the hole for the clamping screw to pass therethrough, and the clamping force exerted in the peripheral edge regions of the clip may be lower than in the central peripheral region of the clip. This can result in leaks when connecting the ends of pipes or connecting hoses to tubular connections.

Wide-band clips having two clamping screws are also known, but they are more expensive to produce and use, because of the two clamping screws: There is thus a need for a generally improved band clip which, at low cost, ensures a better seal in th edge regions of the clip.

According to the present invention there is provided a band clip having an annular band locatable around an item to be clipped, tongue portions formed by radially outwardly bent ends of the band, clamping jaws which are connected to the tongue portions which face away from each other, and a clamping screw locatable through the clamping jaws and tongue portions and operable to transmit a clamping force to the clamping jaws, wherein central regions of the clamping jaws through which the clamping screw is locatable are provided on their side which is towards the associated tongue portion with a radially continuous groove whose width is at least approximately one third of the width of the band, and the clamping jaws are connected to the tongue portions, on both sides of the groove.

With this construction, the clamping forces of the clamping screw are completely and uniformly transmitted to the edge regions of the clip by the clamping jaws as the clamping jaws bear against the tongue portions only with their end portions which are disposed laterally of the central region which is provided with the groove. Even when joining pipes of different diameters, with the clamping jaws as a result being in an inclined position with respect to the axial direction of the pipes or the clamping screw, the clamping force of the screw is uniformly transmitted to the edge regions of the clip as the clamping jaws act virtually like different levers.

Preferably, the tongue portions extend continuously over the entire width of the band. In this arrangement, the tongue portions carry the axial forces of the clamping jaws, which occur when the clip is tightened, so that the tongue portions resist any flattening out of the middle region of the clamping jaws and spreading of the clamping jaws under the effect of high clamping forces. Correspondingly, this arrangement gives a high degree of bending strength in the clamping jaws, to resist flexing.

Furthermore, the middle region of the clamping jaws may be curved as a whole.

This provides a saving in material in comparison with a possible construction in which the clamping jaws comprise a flat plate which is only provided with the groove. Thus, the clamping jaws can easily be produced by bending a metal plate. However, it is also possible for the clamping jaws to be produced from a plastics material of suitably high strength.

The tongue portions may include an acute angle, on the sides on which the clamping jaws are enclosed, with the plane in which the radially inward edges of the tongue portions lie. Therefore, when the clip is tightened, forces which act substantially radially inwardly with respect to the clip also occur in the tongue portions so that they resist radially outward sliding movement of the clamping jaws and thus relieve the load on the connection between the clamping jaws and the tongue portions.

Then, the faces, which are towards the associated tongue portions. of the middle regions of the clamping jaws may be flat and may include an acute angle whose apex is radially outside the clip. In that way, the head of the clamping screw and a normal securing or lock nut which is possibly provided on the free end of the clamping screw bear against the clamping jaws virtually only with their radially inward edge so that the clamping force acts on the tongue portions with a corresponding short radial lever arm. The tongue portions therefore withstand higher clamping forces before they bend towards each other.

Preferably, the clamping jaws also bear against the mutually facing surfaces of the tongue portions, said clamping jaws being connected by means of cylindrical members which pass through apertured pulled-through collar portions on the tongue portions, to the clamping jaws which bear against the faces of the tongue portions which face away from each other, wherein the cylindrical members and apertured collar portions engage into apertures in the clamping jaws bearing against the faces of the tongue portions which face away from each other. This connection provides a high radial load carrying capacity for the tongue portions in the region of the aperture collar portions.

The cylindrical members may be rivets which pass through the tongue portions and the clamping jaws which bear against the tongue portions at both sides thereof. By virtue of the rivets, the frictional contact between the tongue portions and the clamping jaws which bear thereagainst at both sides is increased.

Alternatively, the cylindrical members may be catch pins which are formed on the clamping jaws which bear against one side of the tongue portions. With that arrangement, there is no need for separate production and handling of the rivets. The clamping jaws may be easily produced from plastics material.

Then, the clamping jaws which bear against a tongue portion on both sides may be connected by at least one film hinge. The clamping jaws which bear against a respective tongue portion may then be made in one piece from plastics material, the film hinge ensuring that associated clamping jaws are held together.

Also advantageous is a construction wherein at least one of the clamping jaws bearing against the faces of the tongue portions which face away from each other is provided at the edge, which is away from the tongue portion bearing thereagainst, of a through hole for the clamping screw, with a first spherical zone surface, and the end face, which is towards said spherical zone surface, of a securing nut for the clamping screw, has a second spherical zone surface which matches the first spherical zone surface. With that construction, there is a certain degree of pivotability between the respective clamping jaw and the clamping screw which extends with clearance therethrough. That avoids bending stresses as between the clamping screw and the clamping jaw through which it passes.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a perspective view of a part of a first embodiment of a wide-band clip according to the invention, Figure 2 is a partly sectioned side view of the wide-band clip shown in Fig. 1, Figure 3 is a plan view of the clip shown in Fig. 1, Figure 4 is a partly sectioned view of a part of a second embodiment of a wide-band clip according to the invention, and Figure 5 is a cross-sectional view of a modified part of the wide-band clip according to the invention.

A wide-band clip of a first embodiment of the invention shown in Figs. 1 to 3 comprises a clip band 1 of sheet metal, clamping jaws, 3, 4, 5 and 6, a clamping screw 7 and a bridge portion 8.

At its peripheral edges. the clip band 1 has radially inwardly bend flanges 9 and 10 while at its ends it has substantially radially outwardly bent tongue portions 11 and 12. Each tongue portion 11 and 12 forms an acute angle with the plane in which its radially inward edges (bending edges) are disposed, and extends in the axial direction of the clip over the entire width of the clip band 1. In the centre, the tongue portions 11 and 12 are each provided with a respective hole 13 for the clamping screw 7 to pass through.

The clamping jaws 3 and 4 also extend over the entire width of the clip band 1 and, in their middle region 14, on the side which is towards the associated tongue portion 11 and 12 respectively, are provided with a radial groove 15 whose width is at least approximately one third, in this case approximately half, the width of the clip band. The groove 15 is of substantially trapezoidal cross-section and is formed by a corresponding curvature of the central region 14. Then, the central region 14 of the clamping jaw 3 is provided with a screwthreaded bore (not shown) for receiving the clamping screw 7 and the clamping jaw 4 is provided with a through bore (not shown) for the clamping screw 7. The bores are aligned with the holes 13 in the tongue portions 11 and 12.The flat faces 16, which are remote from the associated tongue portions 11 and 12 respectively, of the middle regions 14 of the clamping jaws 3 and 4 include an acute angle whose apex is radially outside the clip (see in particular Fig. 2). That provides that the pressure of the head 17 of the clamping screw and a nut (not shown) which is possibly provided on the free end of the screwthreaded shank of the clamping screw 7 instead of the screwthread in the clamping jaw 3 acts on the tongue portions substantially as close as possible to the radially inward edge (bending edge) of the tongue portions, with a correspondingly low bending moment. Beads 19 which are formed between the central region 14 and the axially outward portions 18 of the clamping jaws 3 and 4 increase the bending strength of the clamping jaws 3 and 4. The surfaces of the clamping jaws 3 and 4 which bear against the tongue portions 11 and 12 include the same acute angle as the tongue portions 11 and 12 with a plane in which the radially inward edges of the clamping jaws 3 and 4 lie.

The clamping jaws 5 and 6 bear against the mutually facing faces of the tongue portions 11 and 12 and are form-lockingly or positively connected to the clamping jaws 3 and 4 by hollow rivets 20 in the region of the portions 18 of the clamping jaws 3 and 4. In addition, the clamping jaws 5 and 6 are integrally connected at their radially outward side to the respective clamping jaws 3 and 4 by a respective film hinge 21. The hollow rivets 20 also pass through pulled-through aperture collar portions 22 (Fig. 2) in the tongue portions 11 and 12, the portions 22 simultaneously engaging into enlarged regions of the apertures provided in the clamping jaws 3 3 and 4 for the hollow rivets 20 to extend therethrough. Corresponding collar portions may be provided at the through holes 13 in the tongue portions.Such collar portions increase the admissible bearing pressure of the through holes 1 3.

The clamping jaws 5 and 6 extend with their radially inward ends 23 radially inwardly somewhat beyond the radially inward edges of the tongue portions 11 and 12 or the clamping jaws 3 and 4 and bear with said radially inward edges 23 on the bridge portion 8 which bridges across the gap between the tongue portions 11 and 12 or the clamping jaws 5 and 6 in order to support the tongue portions 11 and 12 to resist bending thereof.

The bridge portion 8 is welded to the inside of the one end portion of the clip band 1 but may also be integrally formed on the clamping jaws 5 and 6 in the region of the edges 23.

Like the clamping jaws 3 to 6, the bridge portion possibly comprises hard-elastic glass fibre-reinforced plastics material such as polyamide.

As the central region 14 of the clamping jaws 3 and 4 does not bear against the associated tongue portion 11 and 12, the clamping force which is applied to the clamping jaws 3 and 4 in the central regions 14 when the clip is tightened by the clamping screw 7 is distributed in equal parts to the clamping jaw portions 18 on both sides of the grooves 15, those portions alone bearing against the tongue portions 11 and 12, and thus to the annular regions of the clip band 1, which are close to the peripheral edges of the clip and in which the clip is most heavily loaded when connecting the ends of pipes, with the interposition of a rubber sleeve.The uniform distribution of the clamping force to the edge regions of the tongue portions or the band of the clip is obtained even when the ends of the pipes to be connected are of somewhat different diameters and accordingly the clamping jaws 5 and 6 on one side of the clamping screw 7 are at a different spacing from the clamping jaws 5 and 6 on the other side of the clamping screw 7.

The tongue portions 11 and 12 which extend continuously between the hollow rivets 20 resist flattening of the curved central regions 14 of the clamping jaws 3 and 4 when very high clamping forces are applied as they carry corresponding spreading forces of the clamping jaws 3 and 4, such forces acting in the axial direction of the wide-band clip. In all therefore, that arrangement ensures that the fastening means afforded by the wide-band clip is highly resistant to bending.

The embodiment shown in Fig. 4 differs from that shown in Figs. 1 to 3 only insofar as, instead of the hollow rivets 20, catch pin portions 20a are formed at the inside of the clamping jaws 5a and the clamping jaw (6a) which is disposed opposite thereto but which is not shown. The pin portions 20a engage into blind holes on the inside of the clamping jaw 3a (4a). With that arrangement, there is no need for separately forming and fitting the hollow rivets.

The embodiment illustrated in Fig. 5 differs from the embodiments shown in Figs. 1 to 4 only in that the clamping jaw 3b has a through hole 24 for the clamping screw (not shown), the hole 24 being without a screwthread. The edge 25 of the clamping screw, which is remote from the tongue portion 11, is in the shape of a spherical zone surface. For the purposes of axially securing the clamping screw (not shown), the arrangement has a nut 26 whose end face which bears against the surface 25 is also in the form of a spherical zone surface 27 having the same radius as the surface 25. The diameter of the hole 24 is somewhat larger than that of the screwthreaded shank of the clamping screw so that the clamping screw which is screwed with its free end into the securing nut 26 can perform a slight pivotal movement when the clip is tightened, without the clamping jaw 3 bending.

Claims

1. A band clip having an annular band locatable around an item to be clipped. tongue portions formed by radially outwardly bent ends of the band. clamping jaws which are connected to the tongue portions and which bear against the faces of the tongue portions which face away from each other.

and a clamping screw locatable through the clamping jaws and tongue portions and operable to transmit a clamping force to the clamping jaws, wherein central regions of the clamping jaws through which the clamping screw is locatable. are provided on their side which is towards the associated tongue portion with a radially continuous groove whose width is at least approximately one third of the width of the band, and the clamping jaws are connected to the tongue portions on both sides of the groove.

2. A band clip according to claim 1, wherein the tongue portions extend continu ously over the entire width of the band.

3. A band clip according to claim 1 or claim 2, wherein the central region of each clamping jaw is generally curved.

4. A band clip according to any one of claims 1 to 3, wherein each tongue portion forms an acute angle, on the side on which the clamping jaws lie with the plane in which the radially inward edges of the tongue portions lie.

5. A band clip according to any one of claims 1 to 4, wherein a surface which faces away from the associated tongue portion of the central region of each clamping jaw is flat and includes an acute angle whose apex is radially outside the clip.

6. A band clip according to any one of claims 1 to 5, wherein some of the clamping jaws are operable to bear against the mutually facing surfaces of the tongue portions, said some clamping jaws being connected by cylindrical members which pass through apertured collar portions fitted in apertures through the tongue portions, to the clamping jaws which bear against the faces of the tongue portions which face away from each other, and wherein the cylindrical members and apertured collar portions engage in apertures in the clamping jaws bearing against the faces of the tongue portions which face away from each other.

7. A band clip according to claim 6, wherein the cylindrical members are rivets passing through the tongue portions and the clamping jaws bearing against the tongue portions on both sides thereof.

8. A band clip according to claim 6, wherein the cylindrical members are catch members formed on said some of the clamping jaws which bear against one side of the tongue portions.

9. A band clip according to any one of claims 6 to 8, wherein the clamping jaws which bear against a tongue portion on both sides thereof are interconnected by at least one film hinge.

10. A band clip according to any one of claims 1 to 9, wherein at least one of the clamping jaws which bear against the faces of the tongue portions which face away from each other is provided at an edge, which faces away from the tongue portion bering thereagainst, of a through hole for the clamping screw, with a first spherical zone surface and the end face, which is towards said spherical zone surface, of a securing nut for the clamping screw, has a second spherical zone surface which complements the first spherical zone surface.

11. A band clip substantially as herienbefore described with reference to Figs. 1 to 3, Fig. 4 or Fig. 5 of the accompanying drawings.