US3460077A

US3460077A - Multiple contact miniature diaphragm relay

Info

Publication number: US3460077A
Application number: US596673A
Authority: US
Inventors: Edward Ronald Myatt; Ernest Frederick Loveland; Harry Stanley Woodhead
Original assignee: International Standard Electric Corp
Current assignee: International Standard Electric Corp
Priority date: 1963-05-13
Filing date: 1966-11-23
Publication date: 1969-08-05
Anticipated expiration: 1986-08-05
Also published as: FR91558E; DE1564205A1; DE1564205B2; AT280400B; BE691102A; GB1119126A; NL6617539A; CH505457A

Description

Filed Nov. 23, 1966 Aug. 1969 I a. a MYATT ETAL 3,460,077

MULTIPLE CONTACT MINIATURE DIAPHRAGM RELAY 2 Sheets-Sheet 1 E. R. MYATT ETAL MULTIPLE CONTACT MINIATURE DIAPHRAGM RELAY Filed Nov. 23, 1966 Aug. 5, 1969 2 Sheets-Sheet 2 QEW US. Cl. 335-152 2 Claims ABSTRACT OF THE DISCLOSURE A multiple contact electromagnetic relay suitable for mounting on a printed wiring board, primarily for crosspoint switching, has a number of scaled contact units mounted magnetically in series. In the embodiment described the contact units are of the so-called diaphragmrelay type. This arrangement results in a narrow spread of operating characteristics, i.e. narrower than the spread found with the individual single contact units.

This invention relates to multiple contact light current electromagnetic relays incorporating sealed contact devices, i.e. devices having contact making members hermetically sealed inside an enclosure. The invention also relates to such relays which are suitable for incorporation in crosspoint switching arrays, such as can be used in telephone switching equipment, and to crosspoint switching arrays incorporating such relays.

According to the invention there is provided a multiple contact light current electromagnetic relay including two or more sealed contact devices arranged so that the main magnetic flux paths through all the devices are in series, and one or more energising coils arranged to operate the sealed contact devices.

According to the invention there is further provided a multiple contact light current electromagnetic relay including two or more sealed contact devices, in which each sealed contact device includes a hermetically sealed enclosure, a flat resilient plate of electrically and magnetically conductive material sealed into the enclosure around a peripheral area and having an inwardly extending integral armature which forms a movable contact member, and a fixed member of magnetically and electrically conductive material sealed into the enclosure to provide a contact member and magnetic pole piece co-operating with the movable contact member, in which the sealed contact devices are arranged so that the main magnetic flux paths through all the devices, that is through the fixed contact member and the movable contact member of each device, are in series, and in which one or more energising coils, external to the enclosures, surround the fixed contact members.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a sectioned side view of a sealed contact device,

FIG. 2 shows a perspective view of the sealed contact device shown in FIG. 1,

FIG. 3 shows a plan view of a flat plate with an inwardly extending integral armature forming a movable contact, which plate is part of the sealed contact device shown in FIGS. 1 and 2.

FIG. 4 shows a diagrammatic view of one form of multiple contact light current electromagnetic relay in- United States Patent ice corporating a pair of scaled contact devices of the type shown in FIGS. 1 and 2,

FIG. 5 shows a diagrammatic part-sectioned side view of another form of relay incorporating two pairs of scaled contact devices,

FIG. 6 shows a diagrammatic part-sectioned plan view of a form of relay incorporating two pairs of scaled contact devices in a different arrangement to that shown in FIG. 5 and mounted on a printed wiring board,

FIG. 7 shows a side view of the relay and printed wir ing board shown in FIG. 6,

FIG. 8 shows a diagrammatic part-sectioned side view of a form of relay incorporating two pairs of scaled contact devices in yet another arrangement different from those shown in FIGS. 4 to 7, and

FIG. 9 shows a diagrammatic part-sectioned view of a relay including a pair of scaled contact units arranged differently to the pairs shown in FIGS. 4 to 8.

Referring now to FIGS. 1, 2 and 3, a mild steel annulus 10 has a nickel-iron tube 11 secured within its central aperture by an annular seal 12, for example, of glass. The tube 11 provides a fixed contact member and magnetic pole-piece, with its annular end face 13 forming one of two co-operating contacts. The other, movable, contact is formed by an inwardly extending armature integral with a flat resilient plate 14 of electrically and magnetically conductive material, such as a nickel-iron alloy, which is secured at its periphery to the annulus 10 by means of a cap 15 which is itself sealed around its periphery to the annulus 10. A spring ring 16 ensures that when the plate 14 is in the unstressed state a suitable iso lating gap remains between the central contact-making area of the plate 14 and the co-operating end face 13 of the tube 11. The plate 14 is provided with a number of slots 17, of length much greater than their width, that serve to increase the resiliency of the plate and thus to reduce the stress necessary to distort it to make contact with the co-operating contact surface 13. The slot 17 are in the form of arcs of circles and are so interconnected that the central contact-making area 18 of the plate 14 is connected with its peripheral area 19, by which it is secured to the annulus 10 by three tongues of metal 20', of width small relative to their length. The cap 15 may be made of an insulating material (e.g. ceramic) or-metal. It is preferable to make it of ferromagnetic material, e.g. ferrite or a magnetic metal, as this will serve to increase the effective flux in the air gap between the armature and the fixed contact and so improve the efficiency of the device. The tube 11 is sealed off at the end 21 remote from the contacts. The sealing-off of the tube 11 may be performed at any stage during the manufacturing process. The terminals of the device consist of contact pins (not shown) afiixed to and projecting from the annulus 10 and the tube 11.

The device described above thus includes a hermetically sealed enclosure which is partly in the shape of a shallow circular cylinder, in which the plate 14 and the tube 11 are sealed into the enclosure, the plate 14 being in a diametrical plane of the cylinder and the tube 11 being on the axis of the cylinder. This type of sealed contact device is described in our British Patent Application No. 10571/65 (H.S. Woodhead, Case 4). Corresponding to US. Patent No. 3,331,040.

FIG. 4 shows a pair of sealed

contact devices

41, 42 of the type shown in FIGS. 1 and 2 arranged with the two respective fixed contacts parallel and adjacent to each other. A single energising coil 43 surrounds both fixed contacts and a C-shaped magnetic yoke 44 completes the magnetic circuit for the two sealed contact devices as shown. The main magnetic flux paths through the two devices, that is through the fixed contact and the movable contact of each device, are in series, and the magnetic yoke couples the movable contacts of the two devices. A

FIG. 5 shows two pairs of sealed contact devices, each pair arranged with the two respective fixed contacts coaxial and the two pairs arranged end to end. Two

energising coils

51, 52 each surround one of the pairs of fixed contacts and are connected in series. The sealed contact devices and the coils may be held together in the arrangement shown in a moulding, and contact pins 53 may be used for mounting the relay e.g. on a printed wiring board. The main magnetic flux paths through all four devices are in series.

Referring now to FIGS. 6 and 7 two pairs of scaled contact devices are arranged side by side with the two respective fixed contacts of each pair coaxial. Two

energising coils

61, 62 each surround one of the pairs of fixed contacts and are connected in series although parallel connection is also possible. Two

plates

63, 64 of low reluctance magnetic material each lie alongside the circular face of the enclosure, opposite the fixed contact member, of one of the sealed contact devices of one pair and the corresponding face of the enclosure of one of the sealed contact devices of the other pair. If these circular faces of the enclosures are not made of electrically insulating material then the

plates

63, 64 must be electrically insulated from the circular faces by other means. Each plate magnetically couples the movable contacts of two of the sealed contact devices as shown. The relay may be held together by the two plates being stuck to the sealed contact devices, or the plates and the sealed contact devices may be held together in a moulding.

FIGS. 6 and 7 illustrate how the relay just described can be employed in a crosspoint switching array such as can be used in telephone switching equipment. A number of relays are arranged in a co-ordinate matrix and mounted on :a printed wiring board on which is printed some of the wiring required for multiplying the crosspoints. It is assumed that a four-wire path through the matrix is to be established at each switching operation. The printed wiring board has parallel contuctors printed on one side in groups of five and the relays are mounted on the other side of the board in rows, each row associated with one group of five conductors. FIGS. 6 and 7 show a portion of the printed wiring board 70, with one group of five parallel conductors 71 on one side and one relay, the one described in the previous paragraph, mounted on the other side by contact pins extending from the two ends of the double energising coil, from the four fixed contacts and from the four plates carrying the movable contacts. The four contact pins 72 from the four fixed contacts extend through the board and are soldered to four of the five parallel conductors 71 on the other side of the board which are the input conductors to the row of relays. In each row, the sealed contact devices of the relays occupying the same numerical position are connected to the same conductor 72. The four contact pins 73 from the movable contacts extend through the board and are connected one to each of four output conductors (not shown) which may be in the form of conventional wiring or ribbon cable. The relays occupying the same numerical position in each row are connected to the same group of four output conductors. A contact pin 74 from one 0nd of the double energising coil extends through the board and is soldered to the fifth one of the five parallel conductors 71 on the other side of the board. This end of the double energising coil for each relay in the same row is connected to the same conductor. A contact pin 75 from the other end of the double energising coil extends through the board and is connected to a conductor in the form of conventional wiring or part of the same ribbon cable carrying the four output conductors. The double energising coils of the relays occupying the same numerical position in each row are connected to the same wire or ribbon cable. As an alternative to the use of conventional wiring or ribbon cable, it would be possible for the board to have printed wiring on both sides and provide all the conductors necessary for the switching arra FIG. 8 shows two pairs of scaled contact devices, each pair arranged with the two respective fixed contacts coaxial, and the two pairs arranged end to end. A single energising coil surrounds both pairs of scaled contact devices. The sealed contact devices and the coil may be held together in the arrangement shown in a moulding and connected to contact pins 81 which may be used for mounting the relay e.g. on a printed wiring board. It will be seen that this arrangement is similar to that of FIG. 5 apart from the coil arrangement.

In the relays described so far, the pair or pairs of sealed contact devices have each been arranged with the two fixed contacts next to each other so that a single energising coil can surround both fixed contacts. It would be possible, however, to have the sealed contact units facing the other way round. FIG. 9 shows a pair of scaled contact units arranged with the enclosures back-to-back. There are two energising coils 91, 92, one for each device, and a C-shaped magnet yoke 93 coupling the two fixed contacts.

The arrangements of sealed contact devices in a multiple contact relay which have been described above, whereby the main magnetic flux paths through all the devices, that is through the fixed contact member and the movable contact of each device, are in series, benefit the operating characteristics of the relay. One advantage of this arrangement is that the operation of the most sensitive contact device reduces the reluctance of the magnetic circuit of the relay and thereby increases the magneto-motive force available for the operation of the remaining devices. The result is cumulative and results in a narrow spread of operating characteristics, narrower than the spread found with the individual single contact devices. There is a similar improvement in the release characteristics. The first device to release increases the reluctance of the magnetic circuit and thus assists the release of the more sensitive devices.

The sealed contact devices used in relays according to this invention need not be the same as the device shown in FIGS. 1 to 3. Contact devices which are the most suitable should have the following general characteristics. A hermetically sealed enclosure, a flat resilient plate of electrically and magnetically conductive material sealed into the enclosure around a peripheral area and having an inwardly extending integral armature which forms a movable contact member, and a fixed member of magnetically and electrically conductive material sealed into the enclosure to provide a contact member and magnetic pole piece co-operating with the movable contact member. Other examples of this type of scaled contact device are described in our British application Nos. 18874/63 (C. H. Foulkes 33), 37923/63 (E. R. Myatt 15-1). 32741/65, 32742/65 and 32743/65 (E. R. Myatt 15-1 Div. A, Div. B and Div. C). It is preferable, but not essential, with this type of sealed contact device to have part of the hermetically sealed enclosure formed by a cap of ferromagnetic material which covers one side of the flat plate and provides a further flux carrying non contact making member for increasing the effective flux in the air gap between the armature and the fixed contact.

Within the scope of this type of sealed contact device, it is most suitable for the purposes of this invention to have the sealed enclosure wholly or partly in the shape of a shallow circular cylinder, with the flat plate in a diametrical plane of the cylinder, and the fixed contact member on or parallel to the axis of the cylinder. The sealed contact device shown in FIGS. 1, 2 and 3 has the enclosure partly in the shape of a cylinder and a tube on the axis of the cylinder which completes the enclosure. Certain of the sealed contact devices described in the applications mentioned in the previous paragraph have a sealed enclosure wholly in the shape of a cylinder with the fixed contact member being a solid rod sealed into one wall of the cylinder and on the axis of the cylinder; in devices of this type the contact area of the movable contact need not necessarily be at the centre of the fiat plate and so the fixed contact member could be parallel to the axis of the cylinder rather than on the axis.

It is to be understood that the foregoing description of specific examples of this invention is made by way of example only and is not to be considered as a limitation on its scope.

What is claimed is:

1. A multiple contact light current electromagnetic relay including a plurality of sealed contact devices; each sealed contact device including a hermetically sealed enclosure at least partly in the shape of a shallow circular cylinder; a fiat resilient plate of electrically and magnetically conductive material sealed into the enclosure around a peripheral area and having an inwardly extending integral armature which forms a movable contact member in a diametrical plane of the cylinder; at fixed member of magnetically and electrically conductive material sealed into the enclosure in parallel to the axis of the cylinder to provide a contact member and a magnetic pole piece cooperating with the movable contact member; said sealed contact devices including at least one pair of sealed contact devices arranged so that the main magnetic flux paths through all the devices, that is through the fixed contact member and the movable contact member of each device,

are in series, each pair of contact devices being arranged so that the two respective fixed contact members are parallel; a magnetic yoke which couples the movable contact of one sealed contact device in a pair of sealed contact devices; and at least one energizing coil, external to the enclosures, surrounding the fixed contact members.

2. A relay as claimed in claim 1 in which a first and second pair of sealed contact devices are arranged side by side with the fixed members of the first pair parallel to the fixed contact members of the second pair, in which an individual energizing coil surrounds each pair of fixed contact members, and in which there are two plates of low reluctance magnetic material, each plate lyin-g alongside the circular face of the enclosure, opposite the fixed contact member, of one of the sealed contact devices of the first pair and the corresponding face of the enclosure of one of the sealed contact devices of the second pair and magnetically coupling the movable contacts of these two sealed contact devices.

References Cited UNITED STATES PATENTS 3,293,502 12/1966 Beierle 335152 X 3,331,040 7/1967 Woodhead 335-154 X BERNARD A. GILHEANY, Primary Examiner R. N. ENVALL, 111., Assistant Examiner