1992-09-30
1994-09-06
Oberleitner, Robert J.
Brakes
Strand
66146, 66168, 242150R, B65H 5916, D04B 3532
Patent
active
053439830
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to a thread brake with two preferably disc-shaped or plate shaped brake elements which are resiliently pressed against each other by load means and between which at least one thread to be braked can be led through. The brake elements are mounted on bearings having a common bearing axis and are acted upon by a device which sets them in oscillatory motions.
BACKGROUND
In such thread brakes which are widely used in practice, for example, in the form of so-called disc or plate brakes, the brake discs or plates forming the brake elements are usually rotatably mounted on a guide bolt having at one end a thread on which there is screwed an adjustment nut which forms the abutment of a compression spring which presses the two brake discs or plates elastically against each other. These have the inherent, fundamental disadvantage that lubricants (paraffins, bobbin oil etc.) adhering to the surface of the thread running off form deposits on the brake discs or plates and dirt particles and fluff settling in these produce a sticky, pasty mass which penetrates progressively between the brake discs or plates. In the course of time, these deposits which build up further and further during operation cause the brake discs or plates to be held apart, which makes them less and less able to exert their braking action on the thread passing through. An irregular braking effect also occurs and results in undesired fluctuations in the thread tension. In addition, the brake plates or discs are impeded in their moveability by this sticky mass, which causes the passing thread to start cutting into the brake surfaces of the brake plates or discs, a danger which is very pronounced particularly with synthetic threads. Once the braking surfaces are damaged to the extent that quite deep grooves or flutes are cut in them, the thread passing through also suffers damage.
These difficulties make it necessary for the thread brake to be cleaned and freed from undesired deposits or even exchanged altogether at certain time intervals.
To remedy this, it is known to make the brake discs or plates be driven via a gearing (German patent 27 58 334), but this involves relatively high expenditure and is only suitable in certain cases of use. Another known measure (German published patent application 30 29 509, German patent 29 30 641, to which U.S. Pat. No. 4,313,578, Van Wilson et al, corresponds) consists in using an ac-excited electromagnet instead of the conventional compression spring to press the two brake discs or plates against each other in the axial direction and simultaneously cause vibrations or oscillatory motions with twice the excitation frequency of the electromagnet to be imparted to the brake discs or plates consisting of magnetic material by the magnetic ac field. These oscillatory motions occur in the direction of the bearing axis and, independently of the oscillatory behaviour of the brake discs or plates, can result in non-uniform braking action on the thread passing through, which causes corresponding fluctuations in the thread tension. Also, in principle, such a thread brake is dependent upon an electric ac supply which, however, in many cases is not available.
THE INVENTION
It is an object of the invention to produce a thread brake which is distinguished by improved self-cleaning action, i.e., effectively prevents the occurrence of undesired deposits of lubricant etc. and simultaneously ensures uniform thread braking over long periods of operation.
Briefly, the brake elements can be set by the invention in that the brake elements can be set by the oscillation generating device in oscillatory motions which are oriented essentially transversely to the bearing axis.
Practical experience has shown that this measure not only ensures smooth working of the discs or plates over long operating times but does, in fact, effectively prevent buildup of undesired deposits.
In a preferred embodiment, the brake elements are mounted on an elongated guide element containing the bearing axis, wit
REFERENCES:
patent: 3991954 (1976-11-01), Schwartz
patent: 4202511 (1980-05-01), Koslowski
patent: 4209881 (1980-07-01), Blore
patent: 4313578 (1982-02-01), Van Wilson et al.
Fecker Josef
Horvath Atila J.
Schmodde Hermann
Memminger-Iro GmbH
Muratori Alfred
Oberleitner Robert J.
LandOfFree
Thread brake does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thread brake, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thread brake will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1324186