Such a frictional clutch serves for creating drive adjustment for a take-up reel of a hand-held device for transferring a film from a backing tape onto a substrate, said take-up reel being driven so forcedly that the backing tape portion being supplied to the take-up reel is always slightly tensioned. In doing so, the frictional clutch ensures that the predetermined tension is not exceeded and the backing tape does not rupture.
A frictional clutch as indicated in the foregoing is described in document DE 4217295A1. In said previously-known embodiment, the frictional clutch is disposed between a supply reel and a rotating member, which is connected with the supply reel of an appertaining device by rotational drive connection. The frictional clutch comprises a sleeve-like spring element in the form of an open spring ring, which is disposed in a ring slot between two coaxially disposed sleeve-like bearing members and thereby constitutes a bearing member whose inner generated surface is on the outer generated surface of the inner bearing member, while the outer bearing member is on the outer generated surface of the sleeve-like spring. By radial bending, the spring ring presses elastically against the cylindrical inner generated surface of the outer bearing member, as a result of which the frictional clutch is formed due to cumbersome running.
In said previously known frictional clutch, it is difficult to manufacture the spring ring in a form and size so as to form a circular ring-shaped bearing surface on which the reel can slide over a large surface. There is a danger of the spring ring to relieve primarily into two opposite directions, so that it cannot offer a bearing surface in circular form to the reel located thereon. As a result thereof, support of the reel can be impaired, for instance, by excessive movement clearance due to wear of the relatively small bearing surface portions. As a result thereof, chattering can occur upon rotation of the reel, which is undesirable.
USPTO Backgrounds
USPTO Backgrounds