US3387240A - Reed relay with mounting for protecting encapsulated switches and for positioning bias magnets - Google Patents

Description

J. v. KOPPENSTEINER 3,387,240 TH MOUNTING FOR PROTECTING ENCAPSULATED S AND FOR POSITIONING BIAS MAGN June 4, 1968 REED RELAY WI SWITGHE Filed May 31, 1966 INVENTOR. JAMES V. KOPPENSTEINER BY E, w

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United States Patent 3,387,240 REED RELAY WITH MOUNTING FOR PROTECT- ING ENCAPSULATED SWITCHES AND FOR POSITIONING BIAS MAGNETS James V. Koppensteiner, Chicago, Ill., assignor to Automatic Electric Laboratories, Inc., Northlake, Ill., a corporation of Delaware Filed May 31, 1966, Ser. No. 553,953 Claims. (Cl. 335-153) ABSTRACT OF THE DISCLUSURE This invention relates generally to reed relays and more particularly to reed relays which may be mounted on printed circuit cards.

Reed relays which comprise a coil wound support structure of insulating material having a center tunnel extending therethrough with reed switches placed therein close ly adjacent and side by side are known in the art; see, for example, US. Patent 3,238,327. In certain instances all or certain ones of the reed switches of the relay are to be held latched or normally closed. To accomplish this, permanent magnets are provided within the center tunnel area near the reed switch to be influenced by the magnet. To be effective, the magnet must be placed in the immediate vicinity of the reed switch to be biased, and therefore is placed in the position designed to usually accommodate an adjacent reed switch; alternatively, the width of the support structure would have to be increased to provide room for the magnet. In either case, additional width is required to contain these magnetically biased reed switch arrangements within the tunnel. Thus, the magnetic efficiency of the reed relay is reduced. Furthermore, in the case of printed circuit mounted reed relays, surface area on the printed circuit card is generally at a premium, and it therefore becomes especially important to limit the width of the reed relay package as much as possible.

Accordingly, it is a primary object of this invention to provide an improved reed relay of high magnetic efficiency which requires no more width for a permanent magnet biased reed switch arrangement than for an unbiased reed switch.

A principal feature of this invention is a reed relay, having a preferably molded support structure or bobbin of insulating material which has on one surface thereof, open-sided channels for receiving encapsulated reed switches, and on the opposite surface, a plurality of recesses for receiving permanent biasing magnets.

Another feature of the present reed relay is that the bobbin includes integral shoulder portionsbetween which encapsulated switches are supported and retained in position by pressure absorbing rods engaging external portions of the reeds of the switches so that pressure applied to the ends of the reeds will not be transferred to the envelope.

Another feature of this invention is a reed relay of the above kind which, because of its design, provides flexibil- 3,387,249 Patented June 4, 1968 ity in the combinations of make and/or break reed switches capable of being used therein.

Still another feature of this invention is a reed relay whose design lends itself to the use of miniature reed switches of both the biased and unbiased type.

Other objects and features of this invention will become more apparent by referring to the accompanying drawings, of which:

FIG. 1 is a top plan view of one embodiment of a reed relay according to the invention, with the operating coil and insulating material removed.

FIG. 2 is a cross-section view of the reed relay of FIG. 1 taken along the line 22 with the operating coil and insulating material in place.

FIG. 3 is an end view in cross-section of an alternative embodiment of a reed relay according to the invention.

FIG. 4 is an end view in cross-section of still another reed relay embodying the invention.

Referring to FIGS. 1 and 2 of the drawings, there is shown a reed relay 10 according to the invention, comprising a relatively flat molded bobbin 11 preferably of plastic insulating material, having on the top surface thereof a plurality of channels 12, each for receiving an encapsulated reed switch such as 17. The external portions 19 of reeds 18 of each of the reed switches, rest on respective shoulder portions 15 located at both ends of channels 12, thereby supporting reed switches 17 in their respective channels. As can best be seen in FIG. 2, which is a cross-sectional view taken along the line 22 of FIG. I, the insulating tube or envelope 27 of the reed switch, which is preferably of a vitreous material, does not contact the floor 28 of channel 12, and is supported only by the external reed portions 19, so as to reduce danger of damage to the envelope 27. The external portions 19 of reeds 18 are bent at a point 29 outside shoulder portions 15, and are received by apertures 16 in platform portions 14 integrally molded with bobbin 11, at each end thereof. The ends 21 of the reeds, which protrude from the bottom of platform portions 14 serve as terminals, allowing the reed relay to be plugged into a printed circuit card, not shown.

On the opposite surface of bobbin 11, and integrally molded therewith, are recesses 13, each shaped and dimensioned to receive a permanent biasing magnet 22. The location and number of recesses is a matter of choice and will be determined by the number of reed switch channels and the number of biased and unbiased reed switches required in the relay. In the relay embodiment shown in FIGS. 1 and 2, three recesses 13 are provided, one adjacent and between each outer pair of reed switches, and one adjacent the center reed switch. Thus, if a magnet 22 is provided in either or both of the outer recesses, one or both pairs, respectively, of the outer reed switches will be rendered either normally closed or latched, depending on the strength of the magnet, etc., and if a magnet 22 is provided in the center recess, only the center reed switch will be rendered either normally closed or latched. In this manner one can, by selectively placing magnets in predetermined recesses, determine which reed switch or switches are to be biased. Furthermore, this can be done without sacrificing a reed switch channel or without enlarging the relay to provide extra width for the magnet.

Placed over the external portions of reeds 18, between the ends of envelope 27, and inside shoulder portions 15, are a pair of pressure absorbing rods 23, preferably formed of a phenolic insulating material. These rods 23. as well as reed switches 17 and magnets 22, are secured in their respective positions by a layer of insulating material 24, shown in fragmentary cross-section in FIG. 2, which is preferably in sheet form and wrapped about bobbin 11. Thus, upon mounting relay 10, whether it be by plugging the relay into a printed circuit card, or by some other means, any pressure which is applied to the ends of the reeds, e.g. terminals 21, will not be transferred to the envelope-reed junction 50, but will instead be absorbed by rods 23, and therefore prevent any damage, such as cracking, etc., to the reed switch envelope, or movement of reeds 18 within the envelope.

The relay assembly is completed by an operating winding 25 wound about insulating layer 24, and if desired, over that, a second insulating layer or magnetic shield 26.

It should be noted that operating winding 25 and layers 24 and 26 have been omitted in FIG. 1 so that the important features of reed relay could be more easily shown.

FIG. 3 is an end view, in cross-section, of a reed relay according to the invention. The reed relay 30 shown in FIG. 3 is the same in all respects to the reed relay 10 of FIGS. 1 and 2 except that its bobbin 31 has only one channel 32 receiving a single reed switch 17, that accordingly each of the two platform portions (not shown in FIG. 3) of bobbin 31 has only one aperture for receiving the downwardly extending ends 21 of reeds 18; and that only one recess, designated 34, is provided in this bobbin 31 for accommodating a permanent biasing magnet designated 35 in FIG. 3. Reference numeral 33, FIG. 3, denotes one of the two pressure rods corresponding to pressure rods 23 of FIG. 2. Thus reed relay 30 of FIG. 3 provides for a single normally closed reed switch, or a single latching reed switch, if a magnet 35 is placed in recess 34, or alternatively, a single normally open reed switch if recess 34 is left vacant.

Reed relay 40 which is shown in a cross-sectional end view in FIG. 4, also is the same as reed relay 10 of FIGS. 1 and 2 except that this alternative embodiment is designed for a maximum of two reedswitches 17 which are received in channels 42. correspondingly, each of the two platform portions (not shown in FIG. 4) of bobbin 41 has two apertures therethrough for receiving the reed ends 21 of reeds 18 of the reed switches 17, and relay 40 has, as do the above-mentoned embodiments, a pair of pressure absorbing rods 43 to protect the reed switches from damage upon mounting the relay. Reed relay 40 has only a single magnet recess 44 located on the opposite surface from, and between, its two reed switch channels 42; thus if a magnet 45 is present in recess 44, either two normally closed reed switches or two latched reed switches are provided, and alternatively, if the recess is left vacant, two normally open reed switches are provided.

It is to be noted that with a reed relay according to the invention, in addition to the advantage of being able to provide alternative reed switch arrangements (e.g. normally open, normally closed, or latched), there is also the advantage that these arrangements can be provided without altering the physical size of the reed relay or without sacrificing reed switch channels therein. Furthermore, because a relay designed according to the invention requires a minimum amount of space, it is particularly suited for use with miniature reed switches, which themselvesare used in situations where space is at a premium.

Thus the invention provides a reed relay of high magnetic efliciency and of compact design which is versatile in that it can accommodate a multiplicity of reed switch combinations.

It will be obvious to those skilled in the art that changes and modifications may be'made without departing from this invention in its broadest aspects and therefore the aim in the appended claims is to cover all such changes and modifications as are within the true spirit and scope of this invention.

What is claimed is:

1. A reed relay comprising:

a bobbin having at least one longitudinal open-sided channel in one surface and at least one recess in the opposite surface, a platform portion across each end of said bobbin having at a point beyond the respective end of said channel an aperture therethrough extending in a direction normal to said surfaces, and a shoulder portion disposed between each of said platform portions and a respective end of said channel,

a permanent magnet positioned within said recess,

a reed switch of the type having an elongated envelope and a pair of reeds with a portion of each reed extending from a respective end of said envelope, the envelope of said switch being supported in said channel by positioning the external portion of each of said reeds on a respective one of said shoulder portions, each of said external portions being bent over the outer surface of its shoulder portion to extend through a respective one of said apertures to provide plug-in terminals for said relay, and

an operating coil wound about said bobbin.

2. A reed relay as claimed in claim 1, wherein said bobbin has wrapped thereabout an insulating layer about which said coil is wound; and further including pressure absorbing means urged by said insulating layer against the respective external portions of said reeds at a point inside the respective shoulder portion to absorb pressure applied to said plug-in terminals upon the mounting of said reed relay.

3. A reed relay bobbin of insulating material having integrally molded in one surface thereof, one or more open-sided channels each adapted v to receive a reed switch, and integrally molded in the opposite surface thereof in generally juxtaposed relation to said channels, one or more recesses each shaped and dimensioned for receiving a permanent biasing magnet, said bobbin having an integrally molded platform portion at each end thereof, with at least one aperture extending therethrough in a direction normal to said surfaces, and at each end of said channels a shoulder portion for supporting said reed switch.

4. A relay according to claim 3 having a plurality of channels with a plurality of reed switches mounted individually therein arranged in parallel on said one surface of said bobbin, and a plurality of recesses on said opposite surface, a plurality of permanent magnets, certain ones of said recesses being centered on said opposite surface with respect to respective ones of said channels and others of said recesses being centered between two adjacent ones of said channels to facilitate location of said magnets in selected ones of said recesses such that each of the magnets located in said one recesses bias magnetically a single adjacent one of said switches, and each of the magnets located in said other recesses bias two adjacent ones of said switches.

5. A relay according to claim 4, wherein said pressure absorbing means comprise a pair of rods transversing respective ends of said channels, the rods being pressed by said insulating layer against the respective external portions of said reeds.

References Cited UNITED STATES PATENTS 3,171,918 3/1965 Killion 335-153 3,268,686 8/1966 Wauer 335-454 FOREIGN PATENTS 1,021,870 3/ 1966 Great Britain.

BERNARD A. GILHEANY, Primary Examiner.

R. N. ENVALL, IR., Assistant Examiner.

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