Well-known valve connectors (e.g. GB-B-977,139) can only be connected to the Dunlop-Woods valve type and/or the Sclaverand valve type, or the Schrader valve type.
A well-known connector for a Schrader valve is of the type, where a rubber cylinder is tightly squeezed against the stem by means of a lever, which axially compresses the rubber cylinder. Consequently, the rubber cylinder is squeezed radially against the stem. With reference to different valve diameters, it is necessary, that auxiliary equipment (nut 6) is screwed onto or out of the valve thread to reduce or increase the internal diameter in advance to ensure the establishment of a connection from the valve connector to other valve diameters. Loose parts can disappear and can be loosened when used, if the pump hose is turned, so that the connection is no longer air-tight. The disadvantage of this connector type is that the user has to apply much strength when using the lever. It is necessary to use both hands to stabilize the (dis)connection.
GB patent application No 39808/77 shows an universal valve connector which can be screwed on all valve types. The thread (4) corresponding to 8V1 also keeps the bushing (26) in position. The bushing (26) has an internal thread (30) corresponding to 5V2 for Sclaverand or Dunlop-Woods valves. The plug pin of the Schrader valve is opened mechanically by means of a stationary pin indicated with (12). The disadvantage of this connector type is that the bushing (26) with a 5V2 thread has to be removed before connecting to a Schrader valve, and also that the bushing (26) must be mounted again before connecting to a Dunlop-Woods or Sclaverand valve. Also in this case loose parts are used. They can disappear and loosen when used, if the pump hose is turned, resulting in an untight connection.
From DE-B 38 19 771, a universal connector on a handpump with two coupling holes is known: one for Dunlop-Woods and Sclaverand valves and one for Schrader valves of which the plug pin is opened mechanically. The disadvantage of this way of coupling is firstly, that it cannot be fastened to a valve and secondly, that it can only be used in a certain position, where the coupling hole is turned almost vertically upwards, and finally that the user has to find out which of the two holes to use for the valve in question.
Another well-known universal valve type, which, apparently, does not exist in the patent literature, is of the same type as the one of the above mentioned GB patent application No. 39808/77. This rubber cylinder consists of two adjacent parts of different diameter and length, fitting on 5V2 and 8V1 threads, respectively. Axially, proximally staggered on the centre line of the holes it is possible to mount a means, which can open the plug pin of a Schrader valve. The disadvantage of this coupling is partly that both hands must be used to stabilize the (dis-)connection of Dunlop-Woods or Sclaverand valves and partly that the rubber cylinder must be taken out of the housing and turned upside down to make connection to valves with different thread types possible, so that the coupling place for connecting the valve is always positioned closest to the opening of the coupling hole. Also, the pin which mechanically opens the Schrader valve has to be turned in the above-mentioned operation. This is a problem for the ordinary user, as both means must be positioned correctly in relation to each other in order to be able to connect the coupling to a valve: combinatorily, there are four possibilities to select from, which can only be done correctly if a user manual is available. Apart from that, the above-mentioned means can be lost, loosened or disappear in the said operation.
From WO-A-92/22448 it is known to provide a sealing means, which is placed in a single level, and from GB-B-977.139 a valve connector operated by a lever cam is known. Common to both prior art references is that they can only be used together with a Schrader valve, and that neither Sclaverand type nor Dunlop-Woods type valves can be served by this type of connector, as the sealing means only show one diameter fitting e.g. the Schrader valve.