EP0710343A1

EP0710343A1 - Spring band

Info

Publication number: EP0710343A1
Application number: EP94921614A
Authority: EP
Inventors: Martin Fitz
Original assignee: Dipl-Ing Henn Gesmbh & Cokg; Henn GmbH and Co KG
Current assignee: Dipl-Ing Henn Gesmbh & Cokg; Henn GmbH and Co KG
Priority date: 1993-07-17
Filing date: 1994-06-18
Publication date: 1996-05-08
Also published as: DE4324055A1; WO1995002780A1; AU1240195A

Abstract

Described is a spring band (1) consisting of a continuous elastic strip (2) of material with cut-outs (3-5) located symmetrically within the strip and along its edges, making it possible for the strip (2) to stretch in the longitudinal direction (6, 7) with uniform distribution of the resulting stress in the material making up the strip.

Description

F E D E R B A N D

The invention relates to a spring band according to the preamble of claim 1. Such spring bands are usually designed as flat tension bands and should have good spring properties. It is known here to make such spring bands from a plastic material, a metal material or other tensile materials, such as To train leather, textile or plastic-impregnated textile.

Such spring bands are used for hose clamps or tension clamps, as has become known, for example, from EP 0 203 921 B1 or DE 30 18 383 C2.

In EP 0 203 921 B1 the spring band essentially consists of a two-part body, namely an inner spring band which can be tensioned with the aid of a turnbuckle and which rests on the outer circumference of a two-part clamp. When the turnbuckle is tensioned, the spring band is pulled together under the action of a tensile force and thus pulls the two-part clamp together in order to achieve a corresponding clamp connection on a pipe or hose.

The disadvantage of this arrangement is that a two-part design, namely a spring band and a two-part clamp, is complex and, moreover, it has been found that the meandering spring band has practically no spring action because it is continuously stretched when a tensile force is exerted and not more deformed back to its original shape. With DE 30 18 383 C2 a further spring band has become known in which there is a one-piece construction, according to which the spring band itself is designed as a clamp. In this known spring band, double T-shaped punched-outs are in the area of the band body, which are arranged one after the other at a mutual distance in the band body. This spring band is pulled apart in the transverse direction by its own subsequent deformation process, so that the double-T-shaped recesses overlap one another and thus overlap one another in the middle in the form of a scale. This is intended to achieve a desired spring property in the longitudinal direction of the spring band. However, it has been shown that a spring action is only insufficiently achieved and that the spring band is permanently deformed when relatively high tensile forces are applied. With DE-32 46 542 AI a further spring band in the form of a hose clamp has become known, in which the spring effect is to be achieved in that radially outwardly directed features are arranged in the band body, which have the disadvantage that a relatively large material consumption is given because the characteristics must have a height of about 3-5 mm in order to give the spring band sufficient spring elasticity. In addition to the high material consumption, it is also relatively difficult to apply such features without simultaneously weakening or thinning the material cross section of the spring band. Therefore, there is a risk that the spring band on the bending edges of the stampings cannot be subjected to high loads and, overall, can only be subjected to a low tensile stress.

In addition, there is a high space requirement in the radial direction, because the characteristics - as shown above - Must have a relatively large height. The same criticism also applies to DE 1 775 913, in which also radially outward-pointing features are arranged in the area of the band body, which are intended to give the band body a certain spring elasticity in the longitudinal direction.

The invention is therefore based on the object of developing a spring band of the type mentioned at the outset in such a way that an excellent spring action in the longitudinal direction is achieved at a significantly lower space requirement in the radial direction at low production costs.

To achieve the object, the invention is characterized by the technical teaching of claim 1.

An essential feature of the invention is that the spring band consists of a series of recesses, which recesses are arranged in such a way that the spring band can expand elastically in the longitudinal direction, these recesses preferably being arranged in the form of club-shaped recesses which, due to their club shape, claimed the claimed shape Achieve spring elasticity in the longitudinal direction of the spring band.

When a tensile stress acts in the longitudinal direction on the spring band, the lobe-shaped recesses can expand correspondingly in the longitudinal direction and contract again when the tensile stress ceases, which results in the spring property of the spring band being said. The following advantages are achieved:

the spring band consists of only one part it is simple and inexpensive to manufacture

the elasticity of the material is used to the maximum

the spring action is e.g. with a stainless steel strip of 14 mm width, 0.8 mm thickness and a resilient length of 150 mm at least 5.5 mm with tensile forces in the strip of approx. 700 N (this would correspond to approx. 3%)

Various materials, including stainless steel, can be used for this

A wide variety of closure and connection types and mechanisms are possible.

To work this out, the applicant used the finite element analysis, by means of which the stress distribution and the elongation of such spring bands can be calculated and displayed on the computer.

In a preferred embodiment of the present invention, it is provided that with respect to the longitudinal and transverse axes of the spring band there is a cross-shaped inner recess which is mirror-symmetrical with respect to these longitudinal and transverse axes, which inner recess accordingly has 4 arms due to its cross shape, exactly mirror-symmetrical to the longitudinal and central axes of the spring band.

It is also essential that more kidney-shaped in the outer region of this cruciform inner recess Internal recesses are present, which consist of double lobes, which lobes are separated from one another by corresponding constrictions.

The longitudinal axis of these kidney-shaped or double-lobe-shaped inner recesses is inclined at an angle to the horizontal in order to achieve an optimal tension distribution in the spring band.

Due to the chosen shape of the cruciform

Internal recesses and the distribution of the kidney-shaped inner recesses, which is symmetrical with respect to the cruciform inner recess, have shown that high stress values occur only in the regions of the inner curvatures of the club arms of the kidney-shaped inner recesses and the cruciform inner recesses, the stress distribution being very low in the other regions and is very even.

The following advantages are achieved:

Optimal, even voltage distribution:

The specially designed contour and the punched-out sections in the clamp band ensure that even with high tensile forces, a uniform stress distribution occurs across the entire band cross-section and the spring properties of the material are thus optimally utilized.

Minimized wing load by design of the support surface:

The dimensionally very small punched-out areas prevent the material to be penetrated in the case of soft chip material (Protection of the surface and minimization of friction), and a very even surface load on the chip is guaranteed.

Edges gentle on the chip material:

When used as a tensioning element, the outer edges can also be rounded off in the punching direction in order to prevent the cutting or notching effect of the outer edges of the strip on the material to be tensioned (e.g. a hose).

Various connection, fastening or locking mechanisms or techniques are possible:

By means of a connection, fastening or locking mechanism (e.g. worm screw, tensioning lever ...) the tension band is tensioned around the material to be tensioned, for example, until the necessary tension force is reached in the band. The spring is tensioned (e.g. 5.5 mm travel with 700 N tractive force). For other applications, any type of connection, such as Tightening, clamping, welding and. Like. m. in question.

Compensation of dimensional deviations:

When used as a tensioning element, this band is able to bridge manufacturing tolerances of the material to be tensioned (eg different hose diameters). Furthermore, temperature-related expansions or shrinkages of the goods can be compensated for by this spring action. If, for example, the material to be clamped ages here (eg a "creeping away" of the elastomer material under the clamping band) or the like occur, the spring action of the belt can compensate for this to a high degree without any problems.

Sufficiently long travel:

There is still sufficient spring tension reserve available, since normally only a fraction of the possible spring travel is used for the re-tensioning.

A hose fastening clamp is proposed as a possible application example.

With this spring band, hose clamps can be produced which have a fantastic spring action without additional parts and therefore without additional costs. This means that with hose connections that are exposed to strong temperature, pressure and vibration loads and fluctuations, guaranteed tightness over the entire service life can be guaranteed without the need for maintenance and manual re-tensioning. Depending on the locking mechanism, this spring action can also compensate for manufacturing-related tolerance deviations and thus reduce the error and reject rate in the user's production.

The special shape prevents damage to the hose and the elasticity of the spring compensates for the temperature-related stretching and shrinking of the rubber.

A fastening and suspension element is proposed as a further exemplary embodiment.

This drawstring could be a stable yet vibration-isolating or damping suspension of ceilings, beams or the like can be created, which can be produced at almost the same cost as the perforated sheet metal strips or threaded rods currently used.

The subject matter of the present invention results not only from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another. All of the information and features disclosed in the documents, including the summary, in particular the spatial configuration shown in the drawings are claimed to be essential to the invention insofar as they are new to the prior art, individually or in combination.

In the following, the invention is explained in more detail with reference to drawings showing several possible embodiments. Here, from the drawings and their description, further features and advantages of the invention that are essential to the invention emerge.

Show it:

Figure l: top view of a spring band in a first embodiment of the invention;

FIG. 2: the spring band according to FIG. 1 in its design as a pipe clamp,

FIG. 3: the spring band according to FIG. 1 in its design as a suspension element,

FIG. 4: section through a spring band according to FIG. 1 when used as a hose clamp, FIG. 5: strain-tension diagram of a spring band according to FIG. 1,

FIG. 6: enlarged plan view of a spring band according to FIG. 1,

FIG. 7: a further embodiment of a spring band,

FIG. 8: a third embodiment of a spring band,

FIG. 9: a further embodiment of a spring band,

Figure 10: another embodiment of a spring band.

The spring band according to FIGS. 1 to 4 essentially consists of a band body 2 made of a tensile material, such as a metal material, a light metal material, any metal alloys, plastic-coated textile, paper, cardboard, leather and the like materials.

For the sake of simplicity, the following description assumes that the spring band is made of a metal material.

It is important that the spring band 1 according to the drawings of FIGS. 1-4 consists of a flat band body 2 which has a thickness that only corresponds to the material thickness of the band body 2. A series of recesses 3-5 are arranged in the band body 2, with lobe-shaped edge recesses 3 being provided in accordance with FIGS. 1-3 and 6-9, the lobes of which are open towards the edge and are exactly mirror-symmetrical to the transverse axis 19 of the band body 2. In the following, the term "lobe" also means for the other recesses that there is an arched inner area which merges into a neighboring area via a narrowing.

In this case, cruciform inner recesses 4 are provided in the inner region of the band body, which can also be described as club-shaped arms 30, 31 (see FIG. 6).

In this case, kidney-shaped or double-lobe-shaped inner recesses 5 are arranged symmetrically to the longitudinal center axis 18 in the edge region of the band body 2, the longitudinal axis 33 (FIGS. 6, 8 and 9) of which is directed obliquely at an angle 34 to the horizontal.

Because of this special shape, superior spring properties result when a tension is applied to the spring band 1 in the arrow directions 6, 7.

FIG. 2 shows the design of the spring band 1 as a pipe clamp 8, the spring band being integrally connected in a manner known per se to band regions not having the recesses 3-5, a tension lock 9 being arranged on one band region and being associated with an associated one Teeth 10 cooperates in the other band area.

In Figure 3, the spring band 1 is shown as a suspension element, which carries a pipe clamp 11, which is thus suspended on the spring band 1 in a resilient and vibration-damped manner. FIG. 4 shows that the edge areas of the spring band 1 preferably form an angle 14 to the horizontal in order to prevent these edge areas from cutting into a rubber-elastic material of a tubular rubber 12 when the spring band 1 is now used as a pipe clamp 8 creates a tubular rubber 12 and thereby forms a recess 13.

FIG. 5 shows a spring characteristic of a spring band 1, the elongation in mm being shown on the ordinate and the tensioning forces in N being shown on the abscissa.

The upper curve shows the elongation 15 and means the total elongation which this spring band 1 experiences under the specified force.

With a clamping force of e.g. 680 Newtons an elongation of about 7 mm is achieved.

The curve 17 shows the suspension, which is defined as the difference between the elongation 15 and a deformation residue 16. If the tension is removed, the curve 16 remains as a deformation residue, and the difference between these two curves 15 and 16 represents the pure suspension 17 of this spring band.

With a force of 680 Newtons, a pure spring action of 5 mm is achieved over a length of about 150 mm.

FIG. 6 shows a preferred embodiment of a spring band. It can be seen here that the cruciform inner recess 4 consists of a total of mirror There are lobes 30, 31 arranged symmetrically to the longitudinal and transverse axes 18, 19, the lobes being directed outwards in each case and having inner curvatures 24 which taper inwards in the direction of a constriction 37 and then into the center of the cross shape of the inner recess 4 pass.

The kidney-shaped inner recesses 5 are designed as double lobes and have two lobes 32, 35 which are separated from one another by a respective constriction 27.

The longitudinal axis 33 of the lobes 32, 35 is oriented at an angle 34 obliquely to the horizontal, so that these double lobes 32, 35 are fitted obliquely symmetrically in the edge regions left free by the cruciform inner recess 4.

Thus, starting from a transverse web 36, which is defined by the previously described, outwardly open, club-shaped edge recess 3, arms 20, 21 are formed in the material of the band body 2, which have the described spring properties. Areas 22, 29 are formed in the intermediate space between the arms 20, 21, which force transfer into the arms 20, 21.

The arched or wedge-shaped outer curvature 23 reinforces the area 29 in order to ensure that force is applied to the arms 20, 21.

The outer curvatures 25 arranged on the arms 21 are designed such that they correspond approximately to the inner curvatures 26, so that an arm cross section 21 with a relatively constant thickness results. Otherwise, it is characteristic of the present embodiment that, starting from the bearing point, namely the area 22, the arms taper and narrow in the direction of the inner curvatures 26, 28.

As a result, this uniform stress distribution is achieved and it has been shown that stress peaks only occur in the area of the inner curves 26, 28 and the associated inner curves 24, while the other areas, in particular the areas 22 and the arms 20, 21 have a low tension at the same time - Have moderate stress distribution.

FIG. 7 shows a spring band 1, the cruciform inner recesses 4 of which also have the constrictions 27, but the inner recesses 5 of which are rectangular. In addition, the outer curvatures 23 are missing in the cross region of the cruciform inner recesses 4. The force is then applied equally to the arms 20 and 21.

FIG. 8 shows an embodiment of the spring band 1 in which the cruciform inner recesses 4 also have no constrictions. In addition, the longitudinal axes 33 of the rectangular inner recesses 5 are inclined at an angle 34 to the longitudinal axis 18 of the spring band 1. The outer curvatures 23 correspond to those in FIG. 6.

Another embodiment of the spring band 1 is characterized in that there are club-shaped edge recesses 3 both in the cross region of the inner recesses 4 and in the web region 36. In FIG. 9, in which this further development of the spring band 1 according to FIG 6, in particular the cruciform inner recesses 4 are redesigned in such a way that approximately the same material widths are realized between the kidney-shaped inner recesses 5 and the edge recesses 3 including the transverse webs 36. This creates rectangular internal recesses 4 with two symmetrical, semicircular constrictions. The exemplary embodiment in FIG. 10 contains only cruciform inner recesses 4 and extended edge recesses 3. The enlarged ones

Edge recesses were obtained by removing the arms 21 in FIG. 6. The edge recesses 3 are thereby given the shape of a rectangle open on one side with constricted sides 39.

Drawing legend

I spring band 26 inner curvature 2 band body 27 narrowing

3 edge recess 28 inner curvature

4 inner recess 29 area (cruciform)

5 inner recess 30 club (kidney-shaped)

6 Arrow direction 31 club

7 arrow direction 32 club

8 pipe clamp 33 longitudinal axis

9 turnbuckle 34 angle 10 toothing 35 club

II pipe clamp 36 crossbar

12 tube rubber 37 constriction

13 recess 38 semicircular. Egg tying

14 Angle 39 cut into an arc. Page 15 Elongation

16 deformation set

17 suspension

18 longitudinal axis

19 transverse axis 20 arm

21 arm

22 area

23 outer curvature

24 inner curvature 25 outer curvature

Claims

PATENT CLAIMS

1. Spring band, dadurchgekennzeich¬ net that symmetrical inner and Randaus¬ recesses (3-5) are introduced in a one-piece elongated elastic band body (2), which with a possible elastic expansion in the longitudinal direction (6,7) of the Band body (2) cause a uniform stress distribution in the material surrounding them.

2. Spring band according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the edge recesses are arranged symmetrically to the transverse axis (19) of the band body (2) and have a club shape open to the outside.

3. Spring band according to claim 1 to 2, d a d u r c h g e k e n n z e i c h n e t that inner recesses (4) are present which have a mirror-symmetrical cross-like shape with respect to the longitudinal axis (18) and transverse axis (19) of the elastic band body (2).

4. Spring band according to claim 1 to 3, characterized in that in addition to the cross-shaped inner recesses (4) there are further rectangular or kidney-shaped inner recesses (5) in the edge region of the band body (2) which are symmetrical to the cross-shaped inner recesses (4). are arranged.

5. Spring band according to claim 4, characterized in that the rectangular or kidney-shaped inner recesses (5) are inclined to the longitudinal axis (18).

6. Spring band according to claim 1 to 5, so that the band body (2) has kidney-shaped edge recesses (3) and cruciform inner recesses (4) which are adapted to the shape of the band body (2) determined by the kidney-shaped edge recesses (3).

7. Spring band according to claim 1 to 7, that the edge region of the band body (2) is angled to the horizontal.

8. Spring band preferably according to claim 1, d a d u r c h g e k e n n z e i c h n e t that known fittings (9, 10, 11) are present at the end regions in the longitudinal direction (18) of the band body (2), which allow use for a special use as a spring element.

9. Spring band according to claim 8, characterized in that on one end region in the longitudinal direction (18) of the band body (2) a turnbuckle (9) and on the other end region a toothing (10) for the use of the spring band (1) as a tension ¬ clamp is present.

10. Spring band according to claim 8, d a d u r c h g e k e n n z e i c h n e t that for use as a suspension element one end region in the longitudinal direction (18) of the band body (2) is fixed to a device on the other end region, a pipe clamp (11) is present.