provided in said means a groove 15 which is open towards the suction channel 14 and which is partially limited inwardly by the front end of the suction hose 12 the connection means 11 is preferably manufactured from a thermoplastic material pvc by injection moulding where at the same time at its rear end opposite to the groove 15 there is formed a lip 16 which connects to the connection means by means of a portion 17 of thinner material the lip 16 is formed with a slightly smaller width than the groove 15 and with a length exceeding the depth of the groove when the device is mounted i e when the connection means is connected to the hose 12 the lip 16 is bent into the groove as illustrated in broken lines in fig1 where after the hose 12 is inserted into the enlargement 13 the lip 16 is secured in its folded in position the connection means 11 is secured to the hose 12 preferably by gluing if the front opening 18 of the connection means 11 should be plugged up and the subpressure in the hose and the connection means increases above a certain valve the lip 16 will likewise be actuated by the suction so that it will be lifted from its cealing position against the hose 12 and will allow passage of ambient air thereby the suction power at the front opening will decrease or completely disappear in such a way that the object which is adhered by suction is released the device shown in fig3 and 4 distinguish from the device.