GB2134212A

GB2134212A - A roller bellows for pneumatic vehicle suspensions

Info

Publication number: GB2134212A
Application number: GB08333438A
Authority: GB
Inventors: Konrad Muller; Hartwig Voss
Original assignee: Continental Gummi Werke AG
Current assignee: Continental AG
Priority date: 1982-12-16
Filing date: 1983-12-15
Publication date: 1984-08-08
Also published as: GB8333438D0; IT1166541B; GB2134212B; IT8323701A0; DE3246599A1

Abstract

Roller bellows for pneumatic suspension systems of road vehicles are generally in the form of simple tubular bodies 1 having end beads 11, 12 for securing and sealing purposes. In order to facilitate their assembly, whilst simultaneously protecting the upper end bead from dirt penetration, since such end bead is otherwise particularly exposed above the rolling fold, the upper end bead 12 is provided with a metallic connecting disc which is directly attached to the vehicle component (not shown), said connecting disc 4 sealing the bellows interior. The rim of the disc 4 is bent round the bead 12 to secure it in place. The other bead 11 is detachably held on the hollow plunger 3, by friction, and has a tapered contact surface. <IMAGE>

Description

SPECIFICATION A roller bellows for pneumatic vehicle suspensions The present invention relates to a roller bellows for pneumaticvehicle suspensions which is in the shape of a tubular body and is made of rubber or rubber-like plastics materials having reinforcing plies embedded therein, said tubularbodyterminating in end beads at either end and being supported, in its installed position, againstthe outer casing of a rolling cylinder which is open in the direction ofthe bellows interior and is sealingly enveloped by the lower end bead of the tubular body, such an arrangement producing a rolling fold in the lower region of said tubular body.

Roller bellows which are used in the suspension systems of road vehicles, for example, are usually interchangeable, as interchangeable components, and installed between the body ofthe vehicle and the chassis or an axle, their end beads serving to achieve both a non-detachable securement and the sealing of the bellows interiorfrom the outside atmosphere.

Experience has shown that, without producing any adverse effects, it is possible to secure the lower end bead on the rolling cylinder solely due to its inherent tension associated with the influence ofthe internal pressure and, in consequence, no mechanical securing means are needed, such lower end bead lying adjacentthe rolling fold but not being directly affected by its movements. However, it is necessary to have an additional mechanical securing meansforthe securement ofthe upper end bead. According to known proposals (e.g.German Auslegeschrift No. 1 285792), a loose clamping disc which engages overthe bead is inserted into the bellows forthis purpose and, in turn, the disc is secured on thevehicle componentto be cushioned by means of suitably mounted screws, whereby the adjacent bead is pressed from inside againstthe opposing surface ofthe supporting or load-bearing vehicle component. As a resu It of this, however, it is labour-intensive and time-consuming to assemblethe roller bellows and also to remove a damaged bellows.An additional disadvantage ofthe known means to secure the bellows is its tendency to attract dirt and the consequential damage since it is impossible, during travelling operation, to prevent sand, dust and other extraneous bodies from being deposited on the wall portion abutting the underside ofthe car body, said wall portion changing its surface size with the spring or resilient movements of the roller bellows, and such deposits causes premature corrosion.

Accordingly, the invention seeks to simplify and accelerate the work associated with installing and removing the roller bellows by providing means for securing the bellows at both ends without impairing their stability and pressure density, and the invention also seeks to largely overcome the danger of possible dirt penetration which reduces the service life ofthe roller bellows.

According to the present invention there is provided a roller bellows for pneumatic vehicle suspensions, said bellows being in the shape of a tubular body which is made of rubber or rubber-like plastics materials having reinforcing plies provided therein, said tubular body terminating in end beads at either end and being supported, in its installed position, against the outer casing of a rolling cylinder which is open in the direction of the bellows interior and is sealingly enveloped by its lower end bead, such an arrangement producing a rolling fold in its lower region, in which the upper end bead carries a metallic connecting disc, which directly supportthe bellows against the vehicle component to be cushioned and seals the bellows interiortowards the outside, said disc being non-detachably and form-fittingly connected, and the lower end bead being provided with a circular sealing surface which is detachably and frictionally connected and abuts the outer casing of the rolling cylinder, In such a case, the form4itting connection is advantageously achieved by bending-back the rim portion oftheflatconnecting disc overthe outer periphery ofthe upper end bead of the bellows in the direction ofthe centre ofthe disc.

By joining the two different types of securing means to one and the same roller bellows, the invention produces some surprisingly advantageous results.

Due to the bellows being previously provided with the rigid connecting disc, it is not necessary to insert such disc subsequently into the bellows. Since the roller bellows are already supplied with the disc rolled or bent round the upper end bead so as to be connected in a form-fitting and pressure-tight manner, the roller bellows can be placed in situ immediately without any additional work being necessary before hand, and they can be secured by subsequently tightening the screws provided for the connecting disc. The lower end bead therefore slides substantially automatically, withoutanyfurtherassistance, onto its seat on the outer casing of the rolling cylinder. Any installation workwhich may be necessary can therefore be done very easily and rapidlywithoutany possibility of errors occurring.When the rim ofthe disc is bent round the outer periphery of the end bead crosssection, such an arrangement raises the bead from its direct mounting on the underside of the car body and therefore no longer permits extraneous bodies from accumulating, so that the damage to the surface ofthe bellows walls, which always occurred in this region in the past, is eliminated. Finally, the securing means according to the invention also permits the open connection to be maintained between the bellows interior and the rolling cylinder, such open connection being desirableto utilisethe additional volume.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawing, in which the single Figure schematically illustrates a pneumatic suspension roller bellows in its installed position, the right-hand portion ofthe drawing being a lateral view and the left-hand portion ofthe drawing being an axial sectional view, wherein, for clarification purposes, individual vehicle components have not been shown.

The illustrated rollerbellows 1 isintheformofa smooth-walled, truncated-cone-shaped tubular body made, for example, from a synthetic rubber mixture having textile reinforcing plies (not shown more fully) and having end beads of different diameters. The lower, smaller end bead 11 abuts against a supporting attachment member 2 ofthe rolling cylinder 3 by means of a sealing surface 13 which is tapered at an acute angle, relative to the axial direction, whilst the upper, large end bead 12 carries a connecting disc4 with a rim edge which is rolled into said end bead 12, the connecting disc 4 being metallic and being moulded,forexample,from sheet steel.The bellows 1 is supported by its lower portion, adjacent the end bead 11, againstthe outer casing ofthe rolling cylinder 3 and forms a rolling fold 14 in the transition region between the different diameters, said rolling fold 14 being upwardly and downwardly displaced in synchronism with the resilient movements.

The rolling cylinder3 rests on the non-cushioned vehicle subframe or chassis (not shown) and forms, within theframework of the suspension system, an additional air container which is in constant, open connection with the bellows interior. The connecting disc 4, which is attached to the upper end bead 12 in non-detachable connection and simultaneously carries a connection piece 5 forthe supply of compressed air, is fitted so as to be directly attached to the underside ofthe car body (not shown) and is provided, for this purpose, with a plurality of screw bolts 6, pin-typescrews, stud bolts or similar securing means distributed over a graduated circle.

Claims

1. Arollerbellowsforpneumaticvehiclesuspen- sions, said bellows being in the shape of a tubular bodywhich is made of rubber or rubber-like plastics materials having reinforcing plies provided therein, said tubular bodyterminating in end beads at either end and being supported, in its installed position, againstthe outer casing of a rolling cylinderwhich is open in the direction ofthe bellows interior and is sealingly enveloped by its lower end bead, such an arrangement producing a rolling fold in its lower region, in which the upper end bead carries a metallic connecting disc, which directly supportsthe bellows againstthevehicle componentto be cushioned and seals the bellows interiortowards the outside, said disc being non-detachably and form-fittingly connected, and the lower end bead being provided with a circular sealing surface which is detachably and frictionally connected and abuts the outer casing of the rolling cylinder.

2. A roller bellows as claimed in claim 1, in which the rim portion oftheflat connecting disc is beingback over the outer periphery ofthe upper end bead of the bellows in the direction of the centre of the disc.

3. A roller bellows as claimed in claim 1 or2, in which the connecting disc is provided with a connection piece for the supply of compressed air, said connection piece being open in the direction ofthe bellows interior.

4. A roller bellows as claimed in claim 1,2or3, in which the lower end bead, which has a smaller diameterthan the upper end bead, is provided with a sealing surface which conically tapers in the direction ofthe bellows interior.

5. A roller bellows for pneumatic vehicle suspen- sions, substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawing.