Clamp structure e.g.for hoses

(54) DESCRIPTION Clamp design, especially hose clamp (56) PUBLICATIONS Cited: FR A 1 069 204, US A 4 299 012 (24-19) (57) SUMMARY:

Clamping construction with an open-ended clamping strap and a mechanical connection of the open-ended strap comprising at least two outwardly facing hooks (20, 23) in the inner strap portion adapted to engage with openings (22) for the outer strap portion. At least one of the hooks is a cold-deformed latch (20) and another of the hooks is a substantially peripherally extending combined guide and support hook (23). having an inclined guide and support surface arranged to initially engage with corresponding aperture (26) in the outer belt portion for the purpose of guiding the inner and outer belt portions towards each other and at the same time absorbing peripherally directed tightening forces until the cold-deformed support hook (20) becomes effective for absorbing tightening forces by engaging its abutment surface with corresponding opening (22).

ALLF 138 β 122 AA

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The numbers in brackets indicate international identification code, INID code Letters in clamps indicate international document code

460 987

The present invention relates to a clamp construction, in particular hose clamp.

So-called open clamp structures are known, which can be installed radially around the object to be fastened. Prior to tightening such open clamp structures, their open ends are connected by a mechanical connection. The clamping structure can be tightened by means of various devices, such as screw-type tightening devices, so-called Oetiker 'ears or by any other construction.

Two main sources of leakage occur in such types of open clamp structures. On the one hand, leakage may occur due to discontinuities due to abutments or the like along the inner circumference of the belt construction. Such problems have been effectively solved by a so-called non-clamping construction, which is described in US Patent 4,315,348. The other possible source of leakage is the inadequacy of the tightening force with which the clamping structure is closed. As relatively high hardness plastic materials such as HYTRELL become available, which are used in the automotive industry in connection with storage boxes, there is in particular a need for ever-increasing tightening forces. The mechanical connection disclosed in US Patent 4,299,012 provides an effective solution to the problem of the holding capacity of the mechanical connection using protruding, cold deformed hooks, which take over the power take-off function after a tab-like, transverse paddle controls the inner and outer band portions. to each other during tightening of the clamping structure. However, although the mechanical connection of US Patent 4,299,012 shown to be quite satisfactory, it did present some disadvantages. The open clamp construction shown, for example, in Fig. 7 of US Patent 4,299,012, is normally stamped from flat strip material and is transported, for economic reasons, as flat blanks from the manufacturing site to the place of use, e.g. an assembly path in an automobile traffic, where they are preformed into substantially circular shape prior to mounting over the object for attachment, as described, for example, in U.S. Patent 4,425,781. Since the hooks are normally formed using the same shape in the automatic machines producing the flat blank, , the angle of the guide hook, which thus has a predetermined angle in the flat blank, will vary in the Installed state, depending on the curvature of the clamping belt, i.e. its diameter. This, in turn, requires special prior attention and measures to maintain optimal conditions for the angle of the guide hook 1 the mounted

460 987 state of the clip. In addition, the guide hook, which is not intended to absorb any significant tightening forces, is formed of a substantially rectangular tab-like element which is punched from strip material, thereby leaving an opening in the strip material corresponding to the area of ​​the punched guide hook. This, in turn, can lead to a tendency for the strip material to bend within the region where the strip material has been reduced through the punched guide hook as the flat blank bends to the approximately circular shape of the clip.

Accordingly, it is a principle of the present invention to provide a mechanical connection for an open clamp structure which avoids the aforementioned disadvantages of prior art joints and which will allow the use of ever-increasing tightening forces for the clamp structure without danger of damage to the mechanical connection.

The underlying problems are solved according to the present invention in the manner of claim 1. Thus, the mechanical connection comprises at least two hooks, one of which is a cold deformed support hook, while the other is a combined guide and support hook. The combined guide and support hook is formed by a tab-like element which is pressed out of the inner strip portion and extends in the longitudinal direction (circumferential direction), which element is arranged to engage in a relatively narrow slot-like opening arranged in the outer strip portion and also extends in the outer strip portion. the longitudinal direction of the belt (circumferential direction). The guide and force engagement surface of the combined guide and support hook is thereby formed by the inclined edge of the tab-like element facing away from the free end of the inner band member. As a result, the combined guide and support hook will initially steer the inner and outer band portions towards each other while simultaneously absorbing peripherally directed tightening forces until the cold deformed hook or hooks begin to act by engaging with their respective, opening or openings, whereby the combined guide - and the bracket will continue to have a force-absorbing function, which helps the cold deformed brackets absorb the tightening forces.

The thus-designed tab-like combined guide and support hook is capable of absorbing considerable forces in the circumferential direction without danger of bending during tightening of the clamp. In addition, the probability of curvature of the band material in the area of ​​the combined guide and support hook is effectively excluded since the combined guide and support hook provides rigidity through its construction and thus effectively prevents curvature. In order to further improve the resistance to curvature and buckling, the combined guide and support hook is thereby arranged so that a greater amount of tape material is left on its

460 987 one side than the other side, which includes the opening remaining after the punched combined guide and support hook. Thus, by placing the combined guide and support hook and its corresponding slot-like opening substantially centrally in the inner and outer band portions, the holding capacity of the mechanical connection is significantly increased as the combined guide and support hook substantially contributes to the mechanical connection's retention in its holding.

These and other objects, features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, which, for purposes of illustration only, illustrate an embodiment of the present invention and in which:

Fig. 1 is a perspective view of an open clamp structure with a mechanical connection according to the present invention, showing the clamp structure in its preformed, unmounted state;

Figure 2 is a side elevational view of the inner band portion of Figure 1; Figure 3 is a longitudinal section through the inner band portion of Figure 1;

Fig. 4 is a plan view of the inner band portion of the clamp structure of Fig. 1, showing the parts in the flattened state;

Fig. 5 is a section in the direction of the arrows VV in Fig. 2; and Fig. 6 is a cross-section in the direction of the arrows VI-VI in Fig. 2. In the drawing, the same reference numerals have been used in the different views to denote equal parts. With particular reference to Fig. 1, the open clamp structure generally designated 10 comprises inner and outer overlapping strip portions 11 and 11, respectively. 12, which may be made of single-piece strip material 13 or of several parts joined by suitable joints, such as mechanical joints, as is known to those skilled in the art. After being mounted over the object to be fastened, the clamping structure can be tightened by any known device, such as, for example, by contracting a generally designated ear 14, which may be a "Unethical ear, consisting of two leg portions joined by means of a bridge portion provided with reinforcing devices, or by the construction of FIGS. 11 and 12 of US Patent Application 446503.

The clamping structure is preferably of the so-called impactless construction type and comprises a tongue portion 15 at the free end of the inner band portion 11 arranged to engage with an opening formed by an extruded portion 16 and a shoulder or step 17, as further described in U.S. Patent 4,315 348th

The mechanical connection of the present invention comprises one or more cold deformed hooks 20, in the illustrated embodiment two such cold deformed hooks 20 which have force engaging abutment surfaces 21 and are

460 987 constructed in a similar manner to U.S. Patent No. 4,299,012. As described therein, each calf 1 deformed support hook 20 is integrally formed with connecting portions of the tape material on all sides, except within the range of the substantially transverse recesses, resulting in the force engaging surface 21.

The support hooks 20 are arranged to engage with rectangular openings 22, also described in the latter patent. Furthermore, in addition to the cold deformed support hooks 20, there is a combined guide and support hook 23 which is punched and extruded from the inner band portion 11 and extends substantially at right angles to its outer surface (Fig. 6). The outer band portion 12 is provided with a relatively narrow slot 26 for receiving the combined guide and support hook 23. To perform the guide function, the rear edge of the combined guide and support hook 23, which faces from the free end of the inner band portion 11, slopes outwardly so that it guides the inner and outer band portions 11 and 12 towards each other as the clamping structure is tightened if attachment intended object. The tab-like combined guide and support hook 23 as well as the slot 26 are preferably located within the region of the longitudinal center axis 27 of the belt (Fig. 4). Oetta leaves different amounts of tape material on the two sides of the combined guide and support hook 23 due to the fact that the area 28 is reduced by the presence of the opening 24 compared to the area 29 on the opposite side of the combined guide and support hook 23. The combined guide and support hook 23 for example, the support hook is shaped as a parallel log frame and leaves an opening 24 of a corresponding shape. It is to be understood, however, that the design of the combined guide and support hook 23 may deviate from what appears in the drawing to suit particular requirements, as is well known to those skilled in the art.

During assembly, the combined guide and support hook 23 extends through the slit-like opening 26, whereupon tightening of the clamp begins. As a result of the circumferentially tightening forces, the inclined guide and force engaging surface 25 causes the inner and outer band portions 11 and 12 to move towards each other until, with continued tightening, the cold-formed support hooks 20 begin to act to absorb the tightening force by engaging their respectively, openings 22. Thus, due to such special shape and construction, the combined guide and support hook 23 has not only a guide function but also a support function until its support function is supported by the cold deformed support hooks 20. However, after the cold deformed support hooks 20 begin to operate combined guide and support hooks 23 to continue supporting the support function as it is capable of absorbing longitudinally directed forces without bending. Furthermore, the probability of curvature or buckling within regions 28 and 29 is effectively excluded because of the resistance provided by the considerable amount of tape material within region 29.

460 987