Hose clamp

(42) Date of commencement of the patent: 15. 4.1987 (45) Date of issue: 25.11.1987

<td>(30) Priority:</td><td>(73) Patent owner:</td>

<td>20. 6.1984 US 622765 claims.</td><td>OETIKER HANS</td>

<td>(56) Documents: US-PS 2614304 US-PS 3042436 US-PS 3082498 US-PS 4299012 US-PS 4315348 US-PS 4425781</td><td>HORNS (CH).</td>

CQ

AT 384 465 (54) CLAMP (57) An open clamp (10) resistant to very high tightening forces comprises a staple band (11) whose overlapping inner and outer band portions (12, 13) are locked against each other by a mechanical connection, the outwardly projecting hook (31, 33) near the free end of the inner band portion (12) which can engage in openings (36, 37) near the free end of the outer band portion (13). For tightening the clip after engagement at least one of the hooks (31, 33) in the associated opening (36, 37), a deformable ear (20) is provided, which has two substantially outwardly projecting legs (21) which through a Bridge (22) are interconnected, the latter comprising a reinforcement (23). At least one of the hooks is a cold-formed support hook (31) with a contact surface (32), while another hook represents a combined support and guide hook (33) with a sloping support and guide surface (34), which is formed by the rear edge, which faces away from the free end of the inner band section. The reinforcement is formed as a substantially pan-shaped recess which extends over a greater part of the length and width of the bridge (22).

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MR 0078018

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The invention relates to a clip that can withstand very high tightening forces.

Clasps of the genus of the invention normally fall into two categories, namely, endless braces and open braces. The invention particularly relates to staples of the latter type. These open clips require some sort of mechanical connection between the overlapping strap ends before the clip can be tightened over the article to be secured. The tightening of the clip can be carried out in many ways, such as by means of a so-called screw mechanism or at least one plastically deformable ear, as described in US Patent No. 2,614,304 and No. 3,082,498 and has become known under the name Oetiker ear.

In particular, the invention relates to a clamp with a mechanical connection between the overlapping band portions in the form of hooks which extend outwardly from the inner band portion and engage in openings of the outer band portion, wherein at least one so-called Oetiker ear is used to clamp to put on the object to be secured. With such brackets, there are two problems. First, any step or misalignment on the inside diameter of the clip caused by the overlapping band portions may be the cause of potential leakage when the clip is installed. However, this problem has been solved by the so-called stepless clamp according to US Pat. No. 4,315,348. The second problem associated with such clips is their sufficient holding force when the clips are installed. This depends again on the one hand on the size of the force with which the clamp can be closed by plastic deformation of the ear, without compromising the desired compensation function of the ear, and on the other hand by the resistance of the mechanical connection against the high forces with which the ear is deformed to contract the staple band. Improvements in both aspects have heretofore been achieved by reinforcing grooves in the bridges of the so-called Oetiker ears according to US Pat. No. 3,402,436. These known reinforcing grooves were - seen in the cross-sectional direction of the bridge in a plane containing the staple axis - more or less V-shaped and possessed, seen from above, more or less the shape of a canoe or small rowing boat. Although these known reinforcing grooves have proven to be extremely successful, however, the development of new plastics with ever higher hardness, such as the material sold under the name HYTRELL, which are used in practice with relatively small thickness, constantly increasing clamping forces to complete Guarantee tightness.

The ability to apply higher closing or tightening forces has been significantly enhanced by the mechanical connection of US Pat. No. 4,299,012, which has two cold formed

Traghaken and a flap-shaped guide hook describes which project from the inner band portion to the outside and can engage in corresponding openings in the outer band portion, the guide hook serves above all to lead the two band sections against each other until the cold-formed suspension hooks are effective by engage their force-transmitting contact surfaces in associated openings. However, the mechanical connection according to US Pat. No. 4,299,012 has certain drawbacks resulting from the fact that the clamps, as shown for example in FIG. 7 of this patent, normally punched out of flat brim material and transported for economic reasons as flat blanks from the manufacturing site to the place of their use, where they are brought into a substantially circular shape before being mounted on an article to be secured, s.

For example, U.S. Patent No. 4,425,781. On the automatic machines that are used to produce the flat blanks, there is always the same angle of the guide hook when using one and the same tool. This means that in the flat blank of the guide hook always assumes a predetermined angle. However, this angle changes under installation conditions, u.zw. depending on the diameter of the clip. This then requires a special one

Attention and, if necessary, compensatory measures to optimally adjust the angle of the guide hook in the installation state of the clamp. In addition, the guide hook, which is not intended to absorb any significant tightening forces, according to the above

Patent specification represents a substantially rectangular, flap-shaped element, the

No.384465 is punched out of the band material and thus leaves a corresponding opening in the band material. This in turn may cause the strip material to tend to bulge in the area weakened by the punched-out guide hook when the planar blank is bent into the approximately circular shape of the clip.

Accordingly, it is an object of the invention to provide a clamp which avoids the above disadvantages and at the same time permits the use of ever greater closing or tightening forces to ensure complete sealing of the installed clamp even with relatively thin, very hard plastic pipe materials , as used for example for axle shafts in the automotive industry n.

This is in an open, resistant to very high tightening forces clamp with a staple tape having an inner band portion and an outer band portion; a mechanical connection comprising outwardly projecting hooks near the free end of the inner band portion which can engage in apertures near the free end of the outer band portion, means for tightening the clip upon engagement of at least one of the hooks into the associated aperture, said device comprising deformable ears, each comprising two substantially outwardly projecting legs and a bridge between the legs, which has a reinforcement, wherein at least one of the hooks is formed as a cold-formed support hook with a contact surface, proposed that another hook is formed as a combined, circumferentially extending Tragund guide hook with a sloping support and guide surface, which from its free end the trailing edge is formed away from the inner band section, and in that the reinforcement is formed as a substantially cup-shaped recess, with a flat, at least 35% of the area of ​​the bridge in its non-reinforced peripheral bottom and connecting portions extending in the longitudinal and transverse direction over a greater part of the length and width of the bridge extend.

Further features and advantages of the invention will become apparent from the following description of a preferred embodiment in conjunction with the drawings. The drawings show in Fig.l a perspective view of an open bracket according to the invention prior to assembly over an object to be secured, but already preformed in a circular shape; Figure 2 is a side view of a portion of the clip of Fig.l; 3 is a plan view of the clip of Fig.l in flattened form; Figure 4 is a side view similar to Figure 2, with the inner and outer band portions shown in assembled position; Fig.5 is a plan view of the assembled staple of Fig.4.

In the drawings, like parts are given the same reference numerals.

Fig. 1 shows a clamp -10- with a staple ribbon -11- having an inner end band portion -12- and an outer end band portion -13- to overlap in an assembled position. The inner band portion -12- terminates in a tongue -15- which can engage in a trough-shaped recess which is formed by an extruded portion -16- and paragraphs -17 and 18-, thus to a stepless inner shape of the clip to as shown in U.S. Patent No. 4,315,348.

Further, the bracket -10- comprises an ear -20- consisting of two substantially outwardly projecting legs -21- which are interconnected by a bridge -22-. The latter is in turn provided with a reinforcement -23-. This has the shape of a relatively shallow, substantially pan-shaped recess with a bottom -24- and longitudinal and transverse connecting portions -25 and 26 respectively^;- connecting the floor -24- with the remaining, non-recessed section of the bridge -22-. As can be seen from the drawings, the bottom is relatively flat over at least a substantial portion of its length and width. However, if desired, the floor may have a slight curvature, in particular a concave curvature with a relatively large radius of curvature.

As is apparent from Figs. 1, 3 and 5, the longitudinal connecting portion -25- and the transverse connecting portion -26- form an angle of almost

90 ° with the ground -24- and the remaining, not recessed part of the bridge -22-.

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According to a preferred embodiment, this angle deviates by not more than about 20 ° from the right angle. The connecting portions -25 and 26- merge into the bottom -24- and the remaining, non-recessed portion of the bridge -22- via rounded corners having relatively small radii of curvature. These radii of curvature may be the same or different from each other. Also, they do not have to be of constant length for a particular corner.

The area of ​​the floor must occupy at least 35% of the area of ​​the unreinforced bridge, preferably about 40 to 60%.

By using the ear according to the invention, the length of the legs -21- can be reduced compared to the previously usual length, without impairing the retention capacity of the ear or its compensation properties in the event of temperature and / or pressure fluctuations. This is true even if the staple band is made of relatively thick material to further increase the attractive forces that can be exerted on the ear as the staple contracts.

The inventive mechanical connection -30- between the overlapping inner and outer band sections -12 and 13- comprises at least one cold-formed suspension hook -31-. In the illustrated embodiment are two such cold-formed support hooks -31-, the force-transmitting contact surfaces have -32- and their construction with the description in US Patent No. 4,299,012 match. As can be seen from this patent, each cold-formed suspension hook -31- is integrally connected on all sides with the adjacent parts of the strip material, except for the area of ​​a substantially transverse section forming the force-transmitting abutment surface -32-. The support hooks -31- can engage in rectangular openings -36- in the outer band portion, as also described in the last-mentioned patent. After Erfin25 fertil in addition to the cold-formed support hook -31- a combined, in the circumferential direction of the staple belt -11- extending support and guide hook -33- is provided which is punched out of the inner band portion -12- and pushed out and substantially extends at right angles to the outer surface of the strip material. The outer band portion -13- has a relatively narrow slot -37- for receiving the combined Trag30 and guide hook -33- on. To perform the guiding function, the trailing edge -34- of the combined support and guide hook, which faces away from the free end of the inner band portion -12-, is tilted rearwardly and outwardly toward the inner and outer band portions -12 and 13- when tightening the clamp around the object to be secured. The flap-shaped, combined support and guide hook -33- is like the slot -37- preferably in the region of the longitudinal center axis of the belt. This uneven widths of strip material to the two sides of the combined support and guide hook -33- stand, u.zw. due to the fact that the surface area is reduced on the one hand through the opening -35-, which corresponds to the surface of the stamped, combined support and guide hook -33-. The latter, for example, parallelogram grammal and leaves an opening -35- of appropriate form. It should be understood, however, that the shape and form of the combined support and guide hook may differ from the illustrated embodiment to suit specific needs, as will be apparent to those skilled in the art.

When assembling the combined support and guide hook -33- is inserted through the slit45-shaped opening -37-, whereupon the tightening of the clip begins, u.zw. by plastic deformation of the ear -20-, for example, using a pneumatic pliers, which is attached to the inner ends of the legs -21-; the process of plastic deformation of an ear is shown, for example, in Figures 1 and 2 of U.S. Patent No. 3,082,498. As a result of the resulting circumferentially occuring closing or tightening forces, the inclined support and guide surface 34- will flex the inner and outer band portions 12 and 13 against each other until, upon continuation of tightening, the cold-formed support hooks 31 become effective and tightening forces absorb, u.zw. by engaging in the associated openings. The combined carrying and guiding hook -33- thus fulfills its special purpose

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- 5 shape and construction not only guide functions, but also support functions, until the latter are supported by the cold-formed suspension hook -31-. Even after the latter take effect, the combined support and guide hook 33 continues to support the support function as it is capable of receiving longitudinal forces without deflection. In addition, the tendency to buckling in that part of the strip material, which lies in the region of the combined support and guide hook -33-, effectively prevented, u.zw. by the resistance afforded by the substantial amount of strip material remaining on one side of the combined support and guide hook.

Furthermore, the combined support and guide hook -33- provides the ability to establish a permanent mechanical connection between the open ends of the bracket, u.zw. by riveting, as described, for example, in US Pat. No. 3,286,314.

In practice, it has been possible with a particular clip to increase the closing forces of the ear using the same material, as shown in the following table:

<td>sample</td><td>dimensions</td><td>middle tensile ness^σΒ</td><td>Close - force</td><td>tightness</td>

<td>A</td><td>9 χ 0.8 mm</td><td>470 N / mm²</td><td>380 kp</td><td>from 0 to 1.8 bar</td>

<td>B</td><td>9 χ 0.8 mm</td><td>470 N / mm²</td><td>460 kp</td><td>from 0 to 2 bar</td>

<td>C</td><td>9 χ 0.8 mm</td><td>470 N / mm²</td><td>550 kp</td><td>from 0 to 2.2 bar</td>

<td>D</td><td>10 χ 1 mm</td><td>500 N / mm²</td><td>800 kp</td><td>from 0 to 3.4 bar *)</td>

*) Breakage of the bellows at 3.4 bar

The following applies to the individual samples:

Sample A is a clamp having a known reinforcing groove and mechanical connection according to U.S. Patent 4,299,012.

<td>Sample B is</td><td>a</td><td>clip</td><td>with a reinforced</td><td>ear</td><td>to</td><td>the</td><td>invention</td><td>and</td><td>one</td><td>mechanical</td>

<td>see connection</td><td>to</td><td colspan="2">U.S. Patent No. 4,299,012.</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>20 sample C is</td><td>a</td><td>clip</td><td>with a reinforced</td><td>ear</td><td>to</td><td>the</td><td>invention</td><td>and</td><td>one</td><td>Likewise</td>

<td>invention</td><td colspan="2">mechanical</td><td>Connection.</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Sample D is</td><td>a</td><td>clip</td><td>with a reinforced</td><td>ear</td><td>to</td><td>the</td><td>invention</td><td>and</td><td>one</td><td>Likewise</td>

inventive mechanical compound, u.zw. using a thicker and wider material.

As can be seen from the above table, the invention not only enables a substantial increase in the closing or tightening forces exerted on the ear and which the mechanical connection can withstand, but also allows the use of a wider and thicker strip material in turn allows a further increase in the forces acting on the ear closing forces.

In addition, the reinforced ear of the invention allows a lower ear height than was possible with known reinforcements. While the ear height for samples A and B was 6.2 mm, the height of samples C and D could be reduced to 5 mm.

Tests with clips according to the invention have shown that clips with a reinforcement according to the invention in the bridge of the ear face a strength increase of about 150%

Allow braces with known ear reinforcements.

Although only a single embodiment of the invention has been described and described above, it should be understood that the invention is not limited thereto but may be varied and adapted in many ways as will be apparent to those skilled in the art. The invention is therefore not limited to the details shown and described, but includes all such changes and adaptations.

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