Textiles: cloth finishing – Expanding device for textile webs – Spreader
Patent
1997-01-14
1998-07-21
Vanatta, Amy B.
Textiles: cloth finishing
Expanding device for textile webs
Spreader
26 93, D06C 304
Patent
active
057819742
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a magnetic tenter lever actuating device.
Tenter lever actuating devices, that is to say so-called tenter openers/closers, are used in transport devices for moving material webs, in particular in stretching systems for plastic film webs.
In the production of plastic film, transverse stretching systems, longitudinal stretching systems and also simultaneous stretching systems are known, the material web being gripped at the opposite outer edges and held clamped in movable tenters. Normally, tenters or tenter carriages on which there are seated pivotable tenter levers hold the edge of the material web clamped in relation to a tenter table.
In the region of the clamping point, the tenter levers must be closed and must be opened once more at the end of the transport device, in particular of the stretching system.
For this purpose, mechanical opening and closing systems, in which the tenter lever strikes against a rail and is in each case turned over in the opening or closing direction, are known. Such systems are subject to high wear. The primary disadvantage is also the abrupt beginning of the opening or closing movement and the undamped end of the tilting movement of the tenter levers, also designated as knife flaps below, which strike fully against the respectively provided stops.
Magnetic tenter lever actuating are known.
DE-B 1 114 460 discloses a machine for treating fabric webs, of which the control elements for pivoting the tenter levers or tenter holders include magnetic rails at the relevant sections of the circulation track. The holder levers or tenter levers are in this case configured such that, during their circulation, they pass, at least with an attachment provided on them, as magnet armatures into the region of the magnetic field of the magnetic rails, with the result that the pivoting movement is forcibly carried out under their action.
According to this prior publication, provision is made for the magnetic rail for pivoting the tenter levers to run linearly and parallel to the circulation path of the tenters. In addition, a further pivoting device, which can be actuated by means of a magnetic coupling, is provided, specifically for pivoting the tenter table cooperating with the respective tenter levers. The further magnetic rail is aligned helically with its helix axis parallel to the circulation path, with the result that in the relevant region the tenter table, which is held via a pivoting lever, is pivoted between two end positions as a function of the forward movement of the tenter carriages (that is, of the chain circulation track).
A magnetic coupling device has also been disclosed by the British GB 99 12 45 A1. However, according to this prior publication, provision is made for the tenter levers, which grip the film web and hold it in relation to the tenter table, to be pivoted into the open position by means of a curved track representing a stop. Only in its final open position is the tenter lever held by a magnet. For the purpose of closing, a lever holding the magnet is pivoted into an open position by running onto a wheel, the magnetic coupling being forcibly cancelled thereby and the tenter lever falling down onto the tenter table because of its dead weight. The particular disadvantage here is the opening and closing process, which actually proceeds mechanically, as a result of which the severe mechanical stresses outlined at the beginning lead to the disadvantages listed there.
A horizontal stretching machine for clamping or tensioning the edges of a plastic film web by means of a magnetically actuable tenter lever device has also been disclosed by EP 0 410 494 B1. In order to open and close the clamping levers (tenter levers), permanent magnets are provided here on the tenter lever, opposite the clamping point. For the purpose of closing or opening the tenter levers in accordance with the opening or closing curve of the tenter levers, stationary magnets are arranged in the inlet and in the outlet region of the stretching machine along a corresponding rai
REFERENCES:
patent: 1119824 (1914-12-01), Hayward
patent: 2350961 (1944-06-01), Haskins
patent: 2945280 (1960-07-01), Liebert
patent: 3054159 (1962-09-01), Mohring
patent: 3180002 (1965-04-01), Nash
patent: 4193175 (1980-03-01), Richter
patent: 4473929 (1984-10-01), Green
patent: 5072493 (1991-12-01), Hommes et al.
Breil Jurgen
Lindner Paul
Sieber Bernd
Bruckner Maschinenbau GmbH
Vanatta Amy B.
LandOfFree
Magnetic tenter lever actuating device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetic tenter lever actuating device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic tenter lever actuating device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1637144