the filler connection is to be explained essentially by way of fig1 . a filler connection is fastened in an opening 20 of a sheet metal member 21 , the outer skin of a body , for example . consequently , the filling connection is subdivided into an outer portion 22 and an inner portion 23 . a closure lid 24 is screwed onto the outer portion . the outer and inner portions 22 , 23 essentially consist of two tubular members 25 , 26 including between them an obtuse angle , here 135 °. the tubular portion 26 possesses a flangelike abutment 27 at the outside thereof and at the free end is provided with a circumferentially extending annular nose 28 . the first mentioned member serves as an abutment for a hose 29 which is pushed onto the tubular member 26 and fastened thereat by means of a tube clip 30 . the nose 28 is meant to prevent a sliding - off movement in an axial direction . the hose 29 of which only a portion is shown leads to a fuel tank , which is not shown . the outer portion possesses a sawtooth outer thread 4 and a flange 31 in the form of a conically shaped ring of a relatively small thickness which due to the elastic property of the synthetic material develops a spring effect . the radial flange 31 is disposed in close contact with the outer surface of the sheet metal member 21 via a sealing 3 , while from the other side there are four radially outwardly pointing resilient cams coming into close contact thus securing the filler connection in the opening 20 . the filler connection is inserted into the opening 20 from outside with the edge of the opening sliding over the ramp - like cams or noses 32 which are in this operation slightly deformed radially inwardly , until it comes to snap into the recess 33 between the flange 31 and the shoulder 32a in rear of the cam 32 . the lid 24 is recessed inwardly in the center portion thereof with a gripping portion 35 in the center slightly projecting again outwardly above the outer plane of the lid 24 . the lid 24 is in addition provided with an axial flange 36 having a sawtooth inner thread formed to match the thread 4 of the filler connection portion 22 . in the last course of thread of the thread formation 37 there is an elastic annular seal 38 which comes to lie essentially axially against the end face of the portion 25 of the filler connection and the respectively adjacent portions of the lid 24 , in order to prevent escape of fuel in a liquid or gaseous form . as an alternative to the above or as an addition thereto , an annular seal 39 is arranged in the first course of thread which cooperates with the flange 31 in order to develop here a sufficient sealing effect between the lid 24 and the filler connection . the sealing rings 38 and 39 have a high inherent elasticity and are resistant to fuel . the threads 4 and 37 of the filler connection portion 22 and the lid 24 are provided with a relatively large diameter so that the gripping trough 40 of the lid 24 is fully countersunk or recessed into the filling connection which in its turn does not project above the surface of the sheet 21 which is likewise provided with an inwardly recessed trough 41 adjacent the opening 20 . the lid 24 has a rib 42 integrally formed on the inside thereof which cooperates with a rib 43 on the inside of the connection portion 25 as an abutment . in the embodiment shown the lid 24 is formed in one piece and without a lock . in case a lock is incorporated , the rib 43 may be provided as an undercut for the closing journal of the lock . in the upper region of the rear end face of the connection portion 25 there are provided two valves 44 , 45 . the valves 44 , 45 are arranged side by side coaxially with respect to the axis of the portion 25 of the filler connection . both valves 44 , 45 are designed as membrane check valves , with the valve 44 functioning as a ventilation valve and the valve 45 as a venting valve . fig1 only shows the venting valve 45 the construction of which will be described in more detail in the following . valve 44 , shown in fig2 is constructed in the same manner but is arranged in an inverted sense because of the opposed function . the valve housing consists of two halves 46 , 47 of a circular outline and frustoconical cross sectional area which are interconnected by welding , for example , with overlapping flanges and clamping a membrane 48 between themselves . the housing portion 47 is formed integrally with the pipe connection while the housing portion 46 constitutes a separate shaped member having a discharge connection 2 formed integrally thereat . a hose 49 is pushed over the discharge connection 2 which leads to the lower region of the vehicle , which is not shown . the membrane 48 is provided with a central opening cooperating with a valve ball 6 which is retained to be movable in limits laterally and inwardly through a box - like recess 50 . on the opposite side of the membrane 48 there is a pin 41 formed integrally with the housing 46 which limits the movement of the valve ball 6 in a direction towards the membrane opening . a coil spring 52 is arranged about the pin 51 which is supported at one end against the housing member 46 and at the other end against the membrane 48 . if there is an overpressure prevailing in the fuel tank and thus in the filler connection , the medium ( in this case fuel vapour and liquid fuel too ) may enter through an opening 53 in the valve housing portion 47 into the right - hand valve chamber and may flow into the left - hand chamber via the opening of the membrane through the deflection thereof , and thence into the discharge connection 2 . the hold - down pin 51 prevents the valve ball 6 from following the deflection of the membrane 48 . the valve arrangement shown becomes responsive at lowest overpressures so that dangerous overpresssures will at any rate be avoided . as already mentioned above the valve 44 is fitted with its sides disposed vice versa and thus makes possible ventilation of the filler connection and thus of the tank when fuel is being withdrawn with the internal combustion engine running . a discharge connection would of course not be necessary here . but it is suitably provided here as well in order to avoid easy contamination of the inlet opening 54 in the outer valve housing portion . furthermore , it is possible here as well to convert the valve half 46 of the valve 44 into the valve half 46 of the valve by replacement of a core . fig2 shows a cross sectional view of the ventilation valve 44 . slightly above the axis of the connection member 25 there is a discharge connection 55 formed integrally therewith over which a hose line 56 is pushed leading to the fuel tank ( not shown ) i . e . into the interior of said tank at the uppermost point thereof , in order to guarantee venting during filling . the air and fuel entrained with it re - enter the connection portion 26 through the connection 55 and an opening 57 with a wall 58 extending normal to the axis of the connection portion 25 in the upper part and in parallel with the axis of the connection portion 26 in the lower part taking care of deflection in the direction of the axis of the connection portion 26 , so that any splashing from the filler connection is avoided . the coaxial but offset arrangement of the discharge connections 2 and 55 as well as the bend of the connection portion 26 make possible an extremely space - saving arrangement of the entire connection and insertion thereof from outside during mounting . a flange - like radial projection 59 in the bent - off region between the connection portions 25 and 26 may selectively be provided determining the cross sectional area for the tank gun ( not shown ). tank guns having a diameter exceeding that of the opening formed by the flange 59 , therefore , cannot be used for filling the fuel tank . fig6 shows a representation of the configuration of the opening 20 formed in the sheet metal member 21 . it is of an essentially circular configuration but provided with four circular recesses 60 in uniformly spaced circumferential arrangement cooperating with positioning projections 61 on the outer surface of the connection thus securing the connection against rotation .