DE20215950U1 - Spring displacement limiter unit for a damper system with a helical spring and a piston rod comprises at least two elements in the form of elastically deformable rings with a gap along their circumferences - Google Patents

Abstract

The spring displacement limiter unit (8) for a damper system (1) with a helical spring (6) and a piston rod (4) comprises at least two elements in the form of elastically deformable rings which have a gap along their circumferences. The spring displacement limiter unit (8) for a damper system (1) with a helical spring (6) and a piston rod (4) comprises at least two elements in the form of elastically deformable rings which have a gap along their circumferences. This gap allows such rings to be transversely applied to the rod, to be rotated through an angle relative to one another and then be joined to one another by means of protrusions and corresponding recesses on their contacting faces. As a result, the gaps in the rings thus joined are prevented from further opening. An independent claim is included for an element forming a part of a spring displacement limiter unit.

Description

PATENT ATTORNEYS
EUROPEAN PATENT AND TRADEMARK ATTORNEYS

Attorney file:

96 122/Wy/Bo

Graduate Physicist

DR. WALTER ANDREJEWSKI (-1996)

Graduate engineer

DR.-ING. MANFRED HONKE

Diploma in physics

DR. KARL GERHARD MASCH

Graduate engineer

DR.-ING. RAINER ALBRECHT

Graduate Physicist

DR. JOERG NUNNENKAMP

Graduate Chemist

DR. MICHAEL ROHMANN

Graduate Physicist

DR. ANDREAS VON DEM BORNE

D 45127 Essen, Theaterplatz 3 D 45002 Essen, P.O. Box IO 02 54

14 October 2002

Utility model registration

AZIMUTH INTERNATIONAL TRADING,
nameless payment
Blekerijstraat 21 A

9700 Oudenaarde BELGIUM

Spring travel limiter, mounted in a suspension,

and element for limiting the spring travel for a

such spring travel limiters

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Spring travel limiter, mounted in a suspension, and element for limiting the spring travel for such a spring travel limiter.

This invention relates to a travel limiter mounted in a suspension of the type comprising a coil spring surrounding a rod, which travel limiter comprises at least one limiting element mounted on the rod.

The suspension can in particular be a combined suspension, whereby the rod can be, for example, the piston rod of a hydraulic or pneumatic damper.

In such combined suspensions, the coil spring is installed between a seat fixed to one end of the piston rod and a seat fixed to the body of the damper, at a distance from the end beyond which the piston rod projects.

Such suspensions are used, for example, in vehicles

used, with the first seat attached to the body

and the body of the damper to a wheel suspension.

The aforementioned end of the damper body forms a stop for the seat attached to the piston rod and thus determines the maximum travel of the suspension, i.e. the distance over which the suspension can be compressed.

In some cases it may be desirable to limit this travel, and this is done by means of a travel limiter, which, depending on the size of the limitation,

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has one or more boundary elements.

These limiters must be fitted after the suspension has been fitted and must be removable afterwards. They are fitted around the rod between the coils of the coil spring.

In a combined suspension, they must also be loosely mounted around the piston rod, considering that the piston rod moves and must therefore be movable in relation to the travel limiter, which is stationary on the body of the shock absorber.

Known travel limiters consist of one or more separate open rings that are mounted above the rod. However, when the suspension is impacted, the impact can force one or more of these rings open until the opening in the ring is large enough for the ring to come free from the rod.
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The invention aims to provide a spring travel limiter which does not have these disadvantages and which is not only of simple construction, can be attached or removed in a simple and rapid manner, but also, when attached, presents practically no risk of elements thereof becoming undesirably released from the rod.

This object is achieved according to the invention by a travel limiter mounted in a suspension comprising a helical spring mounted around a rod, which travel limiter comprises at least two elements for limiting the travel of the spring mounted on the rod and each comprising a ring provided with a break which is at least locally less wide than the rod, this

·

Ring is sufficiently elastic to be able to be mounted transversely on the rod by elastic deformation, and wherein two adjacent rings with their interruption are rotated by an angle with respect to each other and wherein on both sides of the interruption of each of these rings a projection located on the end face of one of the rings projects into a recess provided on the adjacent end face of the adjacent ring, so that the projections prevent the opening of the interruptions.

Preferably, at least four projections are provided on one end face of each ring, while at least four corresponding recesses are provided in the other end face of that ring, said projections and recesses being arranged such that two projections located on either side of the interruption of each of the rings project into recesses of the other ring between which there is no interruption.

Matching recesses here mean recesses into which a projection fits and which therefore have almost the same shape and size on the inside as an external projection.

Preferably, the recesses in one end face of a ring are offset by 180° with respect to the projections on the other end face, and thus two adjacent rings with their interruption are rotated by 180°.

This means that in a ring each projection is located axially opposite a recess.

As already mentioned, the travel limiter can be mounted on the piston rod of a pneumatic or hydraulic

damper, preferably towards one end of the body of that damper from which the piston rod protrudes.

Preferably, the projections fit into the recesses with a slight clamping or snapping action.

Because the elements are held together by clamping or by a snap-in connection of the projections in the recesses, the risk of them coming loose from the rod is reduced even further.

The invention also relates to a travel limiting element intended for use in a travel limiter according to one of the aforementioned embodiments, consisting of a ring provided with an interruption and slightly elastic to temporarily increase the interruption by elastic deformation, so that it can be mounted transversely on a rod of a suspension, this ring having at least four projections and at least four corresponding recesses on both end faces together, and each projection on one end face corresponding to a recess on the other end face, which recess is rotated by an equal angle with respect to this projection.

Preferably, the recesses are then shifted by 180° in relation to the projections and located axially opposite the projections.

Preferably, at least four projections are provided on one end face of the ring, while at least four corresponding recesses are provided in the other end face of this ring, two projections being located on both sides of the interruption

and the other two are diametrically opposed.

With the aim of better illustrating the features of the invention, a preferred embodiment of a travel limiter mounted in a suspension and of an element therefor according to the invention is described hereinafter, by way of example and without any limiting character, with reference to the accompanying drawings, in which:

Figure 1 shows a suspension in which a spring travel limiter according to the invention is mounted; the
Figures 2 and 3 show in perspective and on a larger scale an element for limiting the spring travel of the spring travel limiter of Figure 1, seen from above and from below respectively;

Figure 4 is a disassembled perspective view of a travel limiter according to the invention consisting of four elements, in the position in which they are to be mounted.
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Figure 1 shows a suspension which forms a shock absorber and is a combination of a coil spring 1 and a hydraulic damper 2.

The hydraulic damper 2 may be of a known construction and is well known to those skilled in the art. Only the parts necessary for understanding the invention have been shown in Figure 1, namely the body 3 and the piston rod 4.

The coil spring 1 surrounds the piston rod 4 and is held between a spring seat 5, which is fixed by a nut 6 to the end of the piston rod 4, and a spring seat 7, which is fixed to the body 3, at a distance from the end of this body 3 from which the piston rod 4 protrudes. The coil spring 6 can either

be attached to one or both spring seats 5 and 7 or not.

The aforementioned end of the body 3 forms a stop which limits the spring travel, that is to say the movement of the spring seat 7 during compression of the coil spring 6 and the damper 2, at least when no spring travel limiter is present.

In the suspension shown in Figure 1, towards the said end of the body 3, there is indeed such a spring travel limiter 8 which, according to the invention, comprises a number of elements for limiting the spring travel, as shown in detail in Figures 2 and 3.

Each of these elements is an interrupted ring 9 made of a slightly elastic material, for example plastic, and more specifically polyurethane.

The central opening 10 in the ring 9 has a diameter which is slightly larger than the diameter of the piston rod 4. The interruption 11 in the ring 9 narrows continuously from the outside to the inside and is slightly narrower on the outer circumference than the diameter of the piston rod 4. On the inner circumference of the ring 9, the width of the interruption 11 is less than half the diameter of the piston rod 4 and is, for example, approximately 40% of this diameter.

Due to its material, the ring 9 is sufficiently elastic to be able to be attached to the piston rod 4 by deformation transversely, that is to say transversely to the longitudinal direction of the latter.

The ring 9 has a constant thickness. On one end surface it has four projections 12 in the form of round

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tenons and on the other end surface four round recesses 13, the shape and size of which correspond to the tenons.

Two of the projections 12 are located on either side of the interruption, the other two diametrically opposite.

Each of the recesses 13 is offset by 180° with respect to a projection 12, so that when two rings 9 are fitted onto one another with a rotation of 180° and with respect to one another, the projections 12 of the lower ring 9 fit into the recesses 13 of the upper ring 9. A recess 13 is located axially opposite each projection 12.

The diameter of the projections 12 is such that they fit slightly clamped into the recesses 13.

In one variant, the projections 12 are designed such that they can be snapped into the recesses 13.

The spring travel limiter described above is installed as follows:

A first ring 9 is held with both hands so that the index fingers come against the side edges of the break 11 and the thumbs against the outer circumference of the ring 9 diametrically opposite the break 11, and the ring 9 is pulled open so that its break 11 becomes larger. This elastically deformed ring 9 is forced with its break 11 between two turns of the helical spring 6 over the piston rod 4.

After releasing ring 9, it resumes its

*· 9 9 9 9 9 9 ·· ♦ ··

original shape and falls to the end of the body 3.

Subsequently, a second ring 9 is attached in an analogous manner above the first ring 9 on the piston rod 4.

However, after attachment, this second ring 9 is placed so that it is rotated by 180° in relation to this first ring 9, after which it is pressed onto the first ring 9. In this process, the projections 12 of the first ring 9 are pressed into the recesses 13 of the second ring 9.

Figure 1 shows a spring travel limiter 8 with two rings 9 mounted in this way.

Because the two projections 12 on both sides of the interruption 11 of the lower ring 9 protrude into recesses 13 of the upper ring, between which there is no interruption 11, the aforementioned projections 12 cannot move apart and the aforementioned interruption 11 cannot therefore open.

The opening of the gap 11 in the upper ring 9 is prevented in an analogous manner by two other projections 12 of the lower ring 9. This makes it impossible for both rings 9 to become undesirably free due to elastic deformation.

In order to be able to remove a ring 9, it must first be displaced in relation to the adjacent ring until its projections 12 no longer protrude into recesses 13 and its recesses 13 are empty. Only then can it be moved transversely by elastic deformation and pressed by the piston rod 4.
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Depending on the desired size of the suspension travel limitation

* .... • ·* ·« ·· • » · • ft« - ...

Additional rings 9 can be attached to the two rings 9 in the manner described above.

Figure 4 shows a spring travel limiter 8 with, for example, four rings 9, in the position which they finally assume after being attached to the piston rod 4.

It is clear that the projections 12 do not necessarily have to be round pins and the recesses do not have to be round.

The invention is in no way limited to the embodiment described above and shown in the attached figures, but rather such a spring travel limiter and such an element therefor can be realized in different variants without departing from the scope of the invention.

Claims (11)

1. A travel limiter mounted in a suspension comprising a helical spring ( 6 ) mounted around a rod ( 4 ), said travel limiter ( 8 ) comprising at least two elements for limiting the travel of the spring, mounted on the rod ( 4 ) and each comprising a ring ( 9 ) provided with an interruption ( 11 ) which is at least locally less wide than the rod ( 4 ), said ring ( 9 ) being sufficiently elastic to be able to be mounted transversely on the rod ( 4 ) by elastic deformation, and two adjacent rings ( 9 ) with their interruption ( 11 ) being rotated by an angle with respect to one another, and on both sides of the interruption ( 11 ) of each of said rings ( 9 ) a projection ( 12 ) located on the end face of one of the rings ( 9 ) projects into a recess ( 13 ) provided on the adjacent end face of the adjacent ring ( 9 ) so that the projections ( 12 ) prevent the opening of the interruptions ( 11 ). 2. Spring travel limiter according to claim 1, characterized in that at least four projections ( 12 ) are provided on one end face of each ring ( 9 ), while at least four corresponding recesses ( 13 ) are provided in the other end face of this ring ( 9 ), these projections ( 12 ) and recesses ( 13 ) being located such that two projections ( 12 ) located on either side of the interruption ( 11 ) of each of the rings ( 9 ) protrude into recesses ( 13 ) of the other ring ( 9 ), between which there is no interruption ( 11 ). 3. Spring travel limiter according to claim 1 or 2, characterized in that the recesses ( 13 ) in one end face of a ring ( 9 ) are shifted by 180° with respect to the recesses ( 12 ) on the other end face and thus two adjacent rings ( 9 ) with their interruption ( 11 ) are rotated by 180°. 4. Spring travel limiter according to claim 3, characterized in that in a ring ( 9 ) each projection ( 12 ) is located axially opposite a recess ( 13 ). 5. Spring travel limiter according to one of the preceding claims, characterized in that it is attached to the piston rod ( 4 ) of a hydraulic or pneumatic damper ( 2 ). 6. Spring travel limiter according to claim 5, characterized in that the rings ( 9 ) are mounted towards one end of the body ( 3 ) of this damper ( 2 ) from which the piston rod ( 4 ) protrudes. 7. Spring travel limiter according to one of the preceding claims, characterized in that the projections ( 12 ) fit into the recesses ( 13 ) in a somewhat clamping or locking manner. 8. Element for limiting the spring travel, intended for use in a spring travel limiter according to one of the aforementioned embodiments, consisting of a ring ( 9 ) provided with an interruption ( 11 ) and slightly elastic in order to temporarily increase the interruption ( 11 ) by elastic deformation, so that it can be mounted transversely on a rod ( 4 ) of a suspension, this ring ( 9 ) comprising on both end faces together at least four projections ( 12 ) and at least four corresponding recesses ( 13 ), each projection on one end face corresponding to a recess on the other end face, which recess is rotated by an equal angle with respect to this projection. 9. Element according to claim 8, characterized in that the recesses ( 13 ) are displaced by 180° with respect to the projections ( 12 ) and are located axially opposite the projections ( 12 ). 10. Element according to claim 8 or 9, characterized in that at least four projections ( 12 ) are provided on one end face of the ring ( 9 ), while at least four corresponding recesses ( 13 ) are provided in the other end face of this ring ( 9 ), two projections ( 12 ) being located on either side of the interruption ( 11 ) and the other two diametrically opposite thereto. 11. Element according to one of claims 8 to 10, characterized in that it is made of plastic, for example polyurethane.