DK144720B - DEVICE FOR ELECTROSTATIC CHARGES - Google Patents

Description

(19) DENMARK (^)

(12) PUBLICATION (Π) 144720 B

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

^ _ (21) Application No. 15 ^ 9/73 (51) IntCI.3 Η O5 p 3/04 (22) Filing Day 21. tnar. 1973 (24) Race day 21 Mar 1973 (41) Aim. available Dec. 1 1973 (44) Submitted May 1, 1 982 (86) International Application No. - (86) International Filing Day (85) Continuation Day - (62) Master Application No. -

(30) Priority Jun 15 1972, 8966/72, CH

(71) Applicant WALTER SPENGLER, CH-4105 Blel-Benken, CH.

(72) Inventor Same.

(74) International Patent Bureau.

(54) Device for dissipating electricity = static charges.

The invention relates to a device for dissipating electrostatic charges from the surface of poorly conductive materials by means of an electric spark discharge. Devices of this kind are known. For example, in a known from DE Provision Specification No. 1,224,848 is placed in a legane of insulating material as electrodes serving conductors which are parallel to one another, whereby neighboring conductors are placed in two different planes, and the deeper lying and sparking conductors ground potential is applied, whereas the higher located OQ can be connected to a high voltage source. In order to avoid the danger of conductor contamination and thus the propensity for short circuits between the grounded and the high-voltage electrodes on one side, and to exclude any contact. danger with high voltage conductors on the other hand, the latter are molded firmly into the f ”body of insulating material.

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A disadvantage of these known devices is that for relatively economic reasons, the relatively flat body of insulating material may tend to twist in the longitudinal and transverse directions due to temperature stresses. Therefore, its build length is limited.

Era U.S. Patent No. 3,457,405 discloses an electrostatic discharge of a flat device in which spark discharge electrodes are held taut by pressure springs so that length changes due to temperature variations can be compensated. In such a device, however, a separate rigid frame is required to protect against twisting.

In another device known for the removal of electrostatic charges from US Pat. in which capacitively coupled discharge pins are inserted. Suspension of the high voltage cable is prevented by the rigid insulating material pipe.

The object of the present invention is to provide a device of the kind mentioned initially, which can be built arbitrarily in an economical manner without twisting danger, without thereby losing the advantages of the initially known known devices.

The device for dissipating electrostatic charges from the surface of poorly conductive materials by means of an electric spark discharge, with mutually held elongated electrodes, at least one of which is a conductive rod having pronounced discharge sites and located at ground potential, and in the at least one of the others is a high voltage potential conductor, according to the invention is characterized in that the conductor rods are rigid and are disposed freely as spacers between two end plates formed as end plates and firmly connected to them at both ends, and that the electrical conductors, which are insulated, are man-shaped between and through the retaining means and at least one of the retaining means is provided with pressure springs located outside the retaining means.

Hereby a device is obtained whereby the risk of torsion due to temperature influences is avoided so that in practice it can be built arbitrarily long. It can also be made flat because a large insulating material body is not required. The device can easily be used to treat items of widely different forms, e.g. rod-shaped or web-shaped or sheet-shaped items.

Embodiments of the device according to the invention are explained in more detail with reference to the drawing, in which fig. 1 shows an embodiment of the device according to the invention for treating flat materials as paper or textile webs, seen in the direction of movement of the material to be treated; FIG. 2 is a partially horizontal view of the device according to the invention; 3 is a cross-sectional view of an embodiment of the device according to the invention for the treatment of rod or tubular materials, seen from the outside; FIG. 4 and 5 constructive details of the guide element fastening on the lateral holders of the device according to FIG. 3, in section along the line IV-IV and V-V, which simultaneously apply to further embodiments of the device according to the invention; and FIG. 6 is a partial view of a further embodiment of the device according to the invention for the treatment of tubular or casing materials, or for the treatment of web material in the area of a e.g. as a bending means designed according to the invention.

In FIG. 1 and 2, 1 denotes a frame structure, which in the special case is designed as a U-shaped channel, whereby the base plate 1 'can be used as the installation and mounting plate. Heats 2 and 2 'are designated holders between which a first rod-shaped electrode 4 is provided with tips 3 and a second electrode 5 is supported. To avoid deformations due to the length extension of the electrodes 4, the electrodes 4 are connected by frame structures with the base plate 1 * suitably only rigidly at one end, as shown in FIG. 1 and 2. On the other hand, it is advantageous to provide a relatively rigid, self-supporting body with a missing base plate 1 'by rigid connection at both ends of the electrodes 4 to the holders 2 and 2'.

The first electrode is functionally grounded and is electrically conductively connected to the holders 2 and 2 'if these are made of metal. As the second electrode, an insulated electrical conductor which is connected to a high voltage ski idea not shown, whose one pole has the ground potential and thus communicates with the first electrode 4, while the other insulated pole is connected to the other electrode. In order that the conductor forming the second electrode 5 is still tightly tensioned, even at temperature fluctuations, in order to ensure an unchanged distance on one side relative to the tips of the first electrode and on the other side relative to the surface of the the material to be treated is at least one of its support sites on the opposing holders 2 and 2 'suitably provided with an expansion compensation link. In FIG. 1 and 2, for this purpose pressure springs 6 are used on both sides which abut at one end against a disc 7 on the outside of the holders 2 and 2 'and on the other side against a collar element 8 on the electrode 5. The collar element 8 and the disc 7 consists, at least when metallic holders 2 and 2 ·, of insulating material. In the case of metallic holders, it is convenient to protect the conductor insulation on the electrodes 5 by using a casing 9 of insulating material e to cover the electrode insertion. The collar element 8 is advantageously connected to the conductor insulation, so that in case of any breakage or damage of one of the electrodes 5 only the particular conductor section in question must be repaired.

The electrodes 5, as shown, are partial stretches of a mean-shaped single conductor extending over all or a significant portion of the device electrodes 5. However, these may also be connected in series, at least in the conductor sections surface insulated with the electrodes 4, at one end. or both ends of the conductor lines are connected to the insulated pole of the high voltage shield.

It is to be understood that devices according to the invention in accordance with the embodiment of FIG. 1 can practically be built to any width individually according to the apparatus or plant to be equipped therewith. Thereby, it is not unconditionally necessary that the holders 2 and 2 'extend from one end to the other end of the device in unbroken line, since the lengths of neighboring electrodes can also be easily chosen oddly long. The base plate 1 'of the illustrated frame structure can be dispensed with, where on the apparatus or plant supporting the device there are found elements suitable for fulfilling the task of the base plate, i.e. recording of holders 2 and 21.

If the device, which can be designed in any width, must be constructed so wide that a reliable parallel guide of the electrodes 4 and 5 cannot be ensured, intermediate braces 10 which are firmly connected to the base plate 1 'or a suitable appliance or system part can be used. and which at least in the region of electrodes 4 and 5 consists of insulating material.

In FIG. 3, there is shown an embodiment of the device according to the invention in cross-section which is suitable for the treatment of rod or tubular materials. FIG. 3 shows an annular support flange 21, whose passage opening 22 provides free passage for a workpiece 23. On the flange 21, which faces a substantially identical flange at the opposite end of the device, is evenly distributed with first electrodes 24 with discharge tips 25th

The two flanges 21, together with the preferably rod-shaped electrodes 24, can form a stable, cage-shaped body which can be mounted on the flanges by means of suitable, not shown connection means on an apparatus or plant to be equipped with the device. The rod-shaped first electrodes thereby serve as spacers.

Further electrodes 26 are disposed between the first electrodes 24 and at the most equally radially removed from the longitudinal axis of the device, both the first and the additional electrodes can, as can be seen in FIG. 4 and 5, be designed like the relevant electrodes 4 and 5 in accordance with FIGS. 1 and 2. The electrodes 24 are in operation grounded and in the event that one or both of the flanges 21 are made of metal, electrically connected parallel to them. The electrodes 26 are again shown as isolated electrical conductors and are connected to the insulated pole by a high voltage source not shown during operation of the system.

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FIG. 4 schematically shows a screw connection between the electrodes 24 and one of the flanges 21, and in FIG. 5, there is shown an insertion point for a conductor serving as an additional electrode 26 through the flange 21. Provided that the flange 21 is made of metal, a sleeve 27 made of insulating material is disposed in the flange penetration bore, which sleeve on the outside of the the flange engages in a suitable insulating material consisting of abutment disc 28, on which a compression spring 29 is supported. This compression spring presses one already in connection with FIG. 1, collar member 30 extends outwardly to tightly tighten the conductor which forms the additional electrodes 26, thus ensuring a still unchanged distance with respect to the adjacent electrodes 24 and the workpiece 23.

The electrodes 26 are, like those of FIG. 1 and 2, partial sections of a mean-shaped continuous continuous single conductor. However, they may also be connected in series, at least in the conductor sections surface insulated with the electrodes 24, whereby one or both ends of conductor lines are connected to the insulated pole of the high voltage source.

The device according to FIG. 3, 4 and 5 can be built axially of any length if the stability problem can be solved. To ensure that the individual electrodes remain parallel to each other and maintain the same distance to the workpiece, intermediate stiffeners not shown can also be inserted.

In order to show further, but not exhaustive, building possibilities for the device according to the invention, FIG. 6 shows a portion of an embodiment for treating tubular or at least partially cylindrical casing shaped materials, which in a similar design may also be useful as stationary or slow moving bending means for a material web. This is as in fig. 3 shows a cross-sectional view, in which 41 denotes a section of the material to be treated, 42 a support body shown here as a flanging, and 43 and 44 the first and the further electrodes whose structure and fastening may be selected in accordance with the embodiments of Figures 1, 2 and 3.