DE1088121B - Vacuum-tight bushing for electrical lines - Google Patents

Description

For the vacuum-tight passage of electrical conductors through metal parts, in particular wall parts of metal housings, So-called pressure glass feedthroughs are often used, which consist of a conductor enclosing the conductor There are glass bodies on which the outer metal body enclosing the glass body constantly exerts an inward pressure. These glass feedthroughs manufactured according to the pressure glass principle are known to have very good mechanical strength and great resistance to temperature changes the end.

Glass feedthroughs in which the conductor, glass body and surrounding metal materially overlap are coordinated so that a vacuum-tight closure due to the similar expansion behavior of these parts, but without any noteworthy against the central point of the implementation. Compression is achieved, are known. In the case of pressure glass bushings, it is known to have a purely concentric or a centrically symmetric one Execution of the arrangement of the conductor, the glass body and the surrounding metal frame. Two forms of such known pressure glass feedthroughs are in Figs. La and Ib of the drawing shown. The well-known case of a pressure glass bushing with a circular glass body and some conductors arranged in one plane is shown in Fig. 1c.

However, manufacturing difficulties arise when deviating from the aforementioned forms will. So far it has not been possible to produce a pressure glass leadthrough in which, according to FIG. 2, a rectangular cross-section having a feedthrough conductor in a plate-shaped round one (Fig. 2 a) or an elongated shape (Fig. 2 b) having a pressure glass body or in accordance with the 3, several conductors of round shape through a pressure glass body having an elongated shape (Fig. 3 a) or rectangular cross-section (Fig. 3 b and 3 c) are carried out. Of these latter embodiments are, especially, those according to FIGS. 3 a and 3 c valuable if they, for example according to FIG. 4 multiplied, serve as detachable plug connections, with the leadthrough conductors themselves as plug pins serve and over a metal housing soldered to the outer metal border the entire airtight therein enclosed electrical apparatus, e.g. B. a multiple relay wear. Attempts to push through the glass Manufacture in a manner similar to FIGS. 2 and 3, failed because within the pressure glass body Hairline cracks formed, for the occurrence of which, however, a regularity was not recognizable.

The present invention has set itself the task of eliminating these difficulties and creating pressure glass bushings in which the glass vacuum-tight bushing
for electrical lines

Applicant:
Electrovac Hacht & Huber o. HG, Vienna

Representative; Dr.-Ing. F. Wuesthoff, Dipl.-Ing. G. Pulse and Dipl. 'Chem. Dr. rer. nat. E. Frhr. v. Bad luck man,

Patent Attorneys, Munich 9, Schweigerstr. 2

Ing.Alfred Wurmb, Vienna,

and Josef Fischer, Munich,

have been named as inventors

body and / or the conductor can have a boundary line deviating from the circular shape. Through this there is the possibility of flawless, the designs according to FIGS. 2 and 3 or variants thereof to produce corresponding Druekglasdurchführung, so in terms of shape and number of through a single glass body allows a considerable amount of design freedom let what specifically in connection with the pursuit of downsizing electrical appliances and associated therewith also with a desirable reduction in size of the bushings, considerable advantages offers.

. It should be noted that bushings in which, as already mentioned above, glass and metal parts their thermal expansion behavior are matched to one another, has already become known in designs are which those of Fig. 2 and 3 are similar. However, these bushings require expensive special alloys and therefore, in terms of their price, cannot match pressure glass bushings, which are mass-produced must be designated, must be compared. So there was still a need Pressure glass bushings corresponding to the forms shown in FIG. 2 and particularly from FIG. 3 in one such mass-produced items are fair price range.

Through detailed tests it has now been found that you can get perfect pressure glass bushings of the type just mentioned of technically completely satisfactory quality, if one adheres to certain dimensioning rules when using known building materials.

The present invention is therefore concerned with a bushing for electrical lines in which

009 589/327

Claims (1)

in a plate-shaped pressure glass insulating body of * In Figs. 6 to 11 are some practical designs round shape one or more leadthroughs approximately examples of pressure glass leadthroughs according to of elongated cross-section (Fig. 2) or shown schematically in one of the invention. The Fig. 6 Compression glass insulating body of elongated shape either and 7 (the former a section along the line II-II of a single conductor of elongated cross-section (Fig.2b) 5 Fig. 7) reveal the metal plate 10, the four or several conductors of round or rectangular bushings 11 of conventional type and three Has cross-section in a row-wise arrangement side by side through-holes 12 according to the invention. (Fig. 3a and 3c) are combined. The invention consists. The distances d do not give rise to any difficulties. in that pressure glass insulating body and the or the occasion, the distances e, however, have to take into account the selected material of the metal plate under return lead-through conductors with regard to their dimensions be chosen so large that a sufficient are in tune: pressure effect on the glass body of the bushing a) K ₁ is equal to or greater than ¹ Zs K ₂ , where K ₁ is secured to gene 12. in the direction of the greater extension of the conductor or, in the embodiment of FIG in the case of a plurality of conductors, the metal plate 13 in the direction 15 in addition to conventional bushings the maximum conductor extension measured, carried out between 11 three quadruple feedthroughs 14 each see conductor and periphery of the glass body BE correspond to the embodiment according to Fig. 3a, standing distance and K ₂ the perpendicular thereto The embodiment according to FIGS. 9 and 10 (the latter measured corresponding distance between a section along line III-IV of Fig. 9) is used Means conductor and periphery of vitreous; ao a large number of round glass bodies 15 each with b) a: a _x is smaller than 1:15, where α is the larger or a lead-through conductor 16 with a rectangular transverse maximum and C _{1 is} the smaller conductor extension (cf. FIG. 2 a) and FIG. 11 indicates lead-throughs 17; especially great length, the topmost of which with c) a: d _max is within the limits of 1: 1.1 to 1: 2.5, single lead-through conductor 18, the following one with where d _{max is} the largest existing diameter 25, _two conductors 19 and finally the lowest with five of the pressure glass insulating body means. narrow ladders 20 is provided, which have a right From these ratios it can be seen that the cross-sections have an angular cross-section. Dimensioning of the pressure glass leadthrough fixed - The straight side boundary of the glass body is laid. For the quality of a pressure glass bushing 12, 14 and 17 has advantages with regard to production. These are the distances K ₁ and K ₂ , the ratio of 30 is surprising that it can be used at all, from the point of view of strengthening the ladder extension in relation to d _{max, if it is important.} One is tempted to expect that taking into account that the radial pressure in the corners of the conductor (or conductors) and their spacing of the flattened areas of the vitreous wall will not be the same from the outer vitreous boundary with regard to any notch effects as in the more curved ones will be of importance, 35 end regions of the vitreous. There is also that, but experience has shown that in this outward possibility, instead of the straight line limitation, there are difficulties in using such a woman with curvature, for example in order not to fear sioning. an implementation with an elliptical circumference of the If the present invention also does not come to pressure glass insulating body.
Spruch raises that the above-mentioned relationships between the sizes a, a _v K ₁ , K ₂ and d _max apply to the theoretically possible sizes of the pressure glass composition known for printing glass penetrations. Such a known joint implementation and for any maximum conductor settlement is, for example, the following:
have extension validity, but they apply for an outer metal part, the size ratios encountered in practice is used non-alloy steel 45 whose coefficient of expansion about and permit each final dimensions is 130 · 10 ^7; this coefficient has to be determined considerably for the desired printing glass feedthrough. greater than that yet that is the Druckglasisolierkörpers, which is about to be noted under elongate transverse 95 · 10. ⁷ This pressure glass insulating body is cut across the conductor, including those with a square cross-section, preferably in the sintering technique made of soft glass, which can be understood as a borderline case. For the central implementation task (s). Head turns out to be an alloy of nickel, iron In FIGS. 5 a and 5 b, a Druckglasdurchfüh- and chrome is suitable, their coefficient of expansion tion shown according to the invention, in which one of the glass body is adapted.
Ziger conductor 1 of rectangular cross-section in one
Pressure glass body 2 is arranged. The width a of the 55 Ladder is called a larger or maximum ladder extension.
kung, whereas the thickness Ci _{1 is} the smaller Ladder extension is. The largest diameter of the vacuum- tight bushing for electrical Lei glass body "is denoted by d _max , the direction in which the distance between the conductor and 60 glass insulating body of round shape or the periphery of the glass body measured in a plate-shaped pressure of α is K ₁ , the corresponding distance between the lead section or in a pressure glass insulating body from the glass body and the periphery of the glass body, measured vertically several lead-through conductors, is K ₂ Cross-section or meh- (see Fig. 5b) whose several, ία to ie, are present 65 rere conductors of round or rectangular cross-section (which are united with one another a substantially under-cut in rows next to each other taking into account creepage distances established, thereby marked that the iso ingestion), it is considered maximum e ladder extension lierkörper and the lead-through (s). the total extension of all conductors with a b is indicated by the following values with regard to their dimensioning. 70 ratios are matched to one another: a) K ₁ is equal to or greater than ¹ ZsK ₂ , where K _{1 is} the distance between the conductor and the periphery of the glass body, measured in the direction of the greater length of the conductor or, in the case of a plurality of conductors, the distance between the conductor and the periphery of the glass body, and K _{2 is} the means the corresponding distance measured perpendicularly between the conductor and the periphery of the glass body; is smaller than 1:15, where α is the larger a: or maximum and
extension means; the smaller conductor c) a: d _max lies within the limits of 1: 1.1 to 1: 2.5, where d _max denotes the largest existing diameter of the pressure glass insulating body.
5 Considered publications:
Journal »Glas- und Hochvakuumtechnik«, 1952, Issue 7, pp. 123 to 134; French patents No. 1 126 427,
ίο 1 125 712, 1 046 326, 943 681, 780 206; U.S. Patents
291 660. No. 2,558,876, 2,457,535, 1 sheet of drawings © 009 589/327 8.60