EXHAUST PIPE CONNECTOR
The present invention relates to a device for connecting a suction hose of an exhaust gas extraction device for motor vehicles to an exhaust pipe on the vehicle, comprising a connector of flexible material which can be pushed on to the exhaust pipe and which is provided with a clamping device for fastening the connector on to the exhaust pipe.
A variant of previously known exhaust pipe connectors of this type, so-called simple connectors, are fixed by means of spring clips, which grip against the exhaust pipe, or by means of tongs, which clamp the connector to the exhaust pipe. These simple connectors must be manually detached from the exhaust pipe and there is a high risk of damage both to the exhaust pipe and to the bodywork.
Another variant is formed with double rubber walls. When the space between the walls is filled with compressed air, the inner wall is pressed against the outside of the exhaust pipe, so that the connector is fastened to the pipe. In order to obtain a reliable clamping action in relation to the exhaust pipe, the connector must be pushed on relatively far, so that the air bladder of the rubber sleeve is securely situated well behind the end of the exhaust pipe. Otherwise there is a risk that the connector will slip off, since there is no gripping capacity present in the mouth of the connector. Here too, there is a risk of damage or scratches to the bodywork. Nor can a connector of this type be applied to twin exhaust pipes. A further disadvantage is that the rubber sleeve air bladder bears directly against the exhaust pipe and is thereby exposed to wear with the risk of leakage.
An object of the invention is to provide an improved device of the generic type specified, which is easy to handle and
is more reliable and less potentially damaging in use together with commonly occurring exhaust pipe arrangements .
This is possible in that the device according to the invention has fingers, which at a first end are each pivotally suspended inside the joining part of the connector and are each extended to their other end, which is connected to a corresponding notch situated right out in the mouth part of the connector, and in that the clamping device has an activation device situated between the joining part and the mouth part, the activation device serving to move each finger between a rest position, in which the fingers are essentially parallel to one another and the connector can be pushed on to the vehicle exhaust pipe, and a working position, in which the mouth part of the connector is fastened to the exhaust pipe by means of the other ends pressed against the exhaust pipe by the activation device.
Preferred embodiments and advantageous developments and enhancements of the invention are set forth in the description and the independent claims .
The device according to the invention combines the advantages of inflatable connectors and so-called simple connectors of known type, while at the same time substantially eliminating several disadvantages of these types of connector.
The invention will be described in more detail below with reference to diagrams attached, which show preferred embodiments of the invention.
Fig. 1 shows a first embodiment of an exhaust pipe connector in a partially sectional side view, with gripping fingers of the clamping device in the rest position,
Fig. 2 shows the exhaust pipe connector in Fig. 1 without bend, with the gripping fingers in the working position, Fig. 3 shows a direct front view of an embodiment of the mouth of the exhaust pipe connector according to
Fig. 1, Fig. 4 shows a direct front view of a second embodiment of the mouth of the exhaust pipe connector, and Fig. 5 shows a direct front view of a third embodiment of the mouth of the exhaust pipe connector.
Fig. 1 shows a first embodiment of an exhaust pipe connector 2, which has an essentially circular cross-section, in a partially sectional side-view. The exhaust pipe connector 2 has a joining section 4 and a connector section 6, which is preferably made of a flexible material, such as rubber, plastic or the like. A lifting grip 7 is connected to the exhaust pipe connector 2 in the transitional section between the joining section 4 and the connector section 6, in order to facilitate handling thereof. For the sake of simplicity, the connector section 6 will henceforward be referred to as the connector 6. The joining section 4 to an exhaust gas hose (not shown) is advantageously formed as a 60° bend with a conventional hose connection piece 8 at one end and at the other end is non-positively and positively connected in a known manner to the connector by means of a sleeve 10. Both the joining section 4 and the sleeve 10 may be suitably made of non-rusting material, such as aluminum, stainless steel, hard rubber or plastic. The sleeve 10 is straight at its end, suitably connected to the connector 6 by an adhesively bonded joint or by means of a clamped connection, but at its end connected to the joining section 4 has an external annular flange 12. In the assembled state the parts are held together in that the sleeve 10, by way of the annular flange 12, is retained in the other end of the joining section 4 by means of an internal annular collar 14 situated
therein. The sleeve 10 together with the connector 6 is thereby connected to the joining section 4 so that the sleeve is rotatable about its longitudinal axis. This makes it possible, as can best be seen from Fig. 3, to selectively rotate the connector by 90, 180 or 270°, for example, depending on the design of the tail pipe or pipes in the exhaust system in question.
A clamping device 16 integrally formed with the connector 6 has a fixing plate 18, which is firmly anchored, suitably by welding, inside the sleeve 10 and in Fig. 1-3 is vertically aligned, and on which fingers 20 of elongated design for fastening the connector on to the exhaust pipe are pivotally suspended around bearing points 22. In Fig. 1 the clamping device 16 is shown in the rest position, in which the fingers 20 are essentially parallel to one another.
Each finger 20 is formed with its relatively wide base plate 24, which is free to pivot about its bearing point 22 close up to and along the plane of the fixing plate 18, at a first end 23, and gradually tapers towards an intermediate section of the fingers 20. Control of the plane of the fixing plate 18 is achieved in that each base plate 24 moves close up to that plane. From the intermediate section with the base plate 24, the finger 20 continues in the form of a pressure plate 26 which has an arched shape conforming to the diameter of the sleeve and which in turn merges into a pin 30 extending to a finger tip 28 at the other end 28 of the finger. Each finger 20 thus constitutes a single-arm lever 20 extended from the bearing point 22 to the finger tip 28. The connector 6 has a joining part 32 and a mouth part 34, in which notches 36 matching the finger tip 28 of each pin 30 are arranged in such a way that the pin 30 is positively interlocked and encapsulated in the mouth part with the finger tip 28 situated right out in the mouth part 34. The flexibility of the connector 6, which also in the mouth part
endeavors to assume its original open shape imparted by the manufacturing process, means that the camping device 16 will assume the rest position shown in Fig. 1, with the fingers 20 essentially parallel to one another. For adaptation to the shape of the tail pipe or pipes of the exhaust system in question, the mouth part 34 may be formed with either a circular or essentially circular cross-section or with an oval cross-section.
An activation device 38 inflatable with compressed air, for example, is arranged approximately in the middle of the connector 6, on a level with pressure plates 26 of the fingers, and comprises an airtight pocket 40 arranged between the joining part 32 and the mouth part 34 of the connector 6. The pocket '40 is formed between a wall 42 of the connector designed for the purpose and a casing tube 44 enclosing the wall. The casing tube 44 is fixed at both ends to the connector 6, for example by means of hose clamps or clips (not shown) . Alternatively, the connector is formed with grooves 46 conforming to both ends of the tube and in which the casing tube 44 is fixed. A compressed air connection 48 is fitted on the casing tube 44 and is connected to the pocket 40 by an opening in the casing tube 44.
By means of the inflated activation device 38 it is possible to act upon the pressure plates 26 of the fingers with an inwardly directed force FI, which brings the fingers towards one another with a force F2 directly proportional to the force Fl . The magnitude of the force Fl that is developed depends in a known manner on the air pressure and the area with which the wall 42 of the activation device 38, inflated radially inwards, acts on each pressure plate 26. The force with which the connector is squeezed together in turn depends in a similarly known manner on lever ratios of the fingers 20 and corresponds to the force F2 in the mouth of
the connector 6. Experiments have shown that an air pressure P of 1 bar is sufficient to produce a reliable fastening of the connector 6 to the most common exhaust pipes with dimensioning of the constituent parts of the connector 6 designed to match these.
According to the embodiment shown in Fig. 3 the mouth part 34 of the connector 6, viewed directly from the front, is designed like a figure eight, comprising a larger, first circumference 50 and a smaller, second circumference 52. This embodiment is intended for connection to exhaust pipes with different dimensions, which can vary from approximately 50 to 65 mm in diameter. This also includes twin exhaust pipes and oval exhaust pipes with circumferences corresponding to the circular pipes. This makes it possible to attach the connector 6 to vehicles with up to seven different exhaust pipe dimensions. Larger oval exhaust pipes or exhaust pipes with rectangular tail pipe are gripped in that the fingers 20, by way of their finger tips 28, or by way of the positively interlocked encapsulation of each finger tip 28 right out in the mouth part 34, press directly against the exhaust pipe thereby fixing the connector.
In this embodiment the connector 6 is provided with two fingers 20, which as described previously are pivotally suspended via bearing points on the vertically oriented fixing plate 18. The notches 36 for the other ends or tips 28 of the fingers are here situated in the centre section 54 of the mouth part 34 formed as a waist of the figure of eight. The connector 6 may be provided with a limit stop 56, anchored or formed at the end of each fixing plate 18 preferably facing the mouth part 34, in order to prevent the connector 6 being pushed up too far on to the exhaust pipe. When the activation device 38 is inflated with compressed air, the tips 28 of the fingers are brought towards one
another and the waist or middle section 54 is compressed, which leads to a corresponding reduction of both the first circumference 50 and the second circumference 52. The mouth part 34 of the connector will thereby be fastened, as appropriate, by the first circumference 50 around a larger exhaust pipe, and by the second circumference 52 around a smaller exhaust pipe, or by both circumferences 50, 52 around a twin or oval exhaust pipe . When the connector is connected solely to a larger or smaller exhaust pipe, the mouth not in use is left open. Ambient air is thereby drawn into the extraction device, which may be advantageous in that an additional quantity of cooling air is supplied. The flow is adjusted by regulating the fan of the extraction device .
According to the second embodiment shown in Fig. 4, the mouth part 34 viewed directly from the front is of circular shape with a third circumference 58 and the fixing plate 18 is replaced by a second fixing member 60, which carries three fingers 20, which are designed and suspended in the same way as in the preceding embodiment . Three corresponding notches 36 for the other ends or tips 28 of the fingers 20 are equally spaced around the third circumference 58. When the activation device 38 is inflated with compressed air, the tips 28 of the fingers are brought radially inwards towards the centre line of the mouth part 34 and the exhaust pipe is gripped in that the fingers 20, by way of their finger tips 28, or by way of the positively interlocked encapsulation of each finger tip 28 right out in the mouth part 34, press directly against the exhaust pipe thereby fixing the connector.
According to the third embodiment shown in Fig . 5 , the mouth part 34 viewed directly from the front is of circular shape with a fourth circumference 62 and the fixing plate 18 is replaced by a third fixing member 64, which carries four
fingers 20, which are designed and suspended in the same way as in preceding embodiments. Four corresponding notches 36 for the other ends or tips 28 of the fingers 20 are likewise equally spaced around the fourth circumference 62. When the activation device 38 is inflated with compressed air, the tips 28 of the fingers are brought towards one another and the exhaust pipe is gripped in that the fingers 20, by way of their finger tips 28, or by way of the positively interlocked encapsulation of each finger tip 28 right out in the mouth part 34, press directly against the exhaust pipe thereby fixing the connector. The fixing plate 18 with only two fingers 20 may also be applicable to the second or third embodiments, although in this case with a reduced gripping action.