US2929964A

US2929964A - Construction of electrical apparatus

Info

Publication number: US2929964A
Application number: US574122A
Authority: US
Inventors: Rhys-Jones John Emyr
Original assignee: Plessey Co Ltd
Current assignee: Plessey Co Ltd
Priority date: 1955-03-29
Filing date: 1956-03-27
Publication date: 1960-03-22
Anticipated expiration: 1977-03-22
Also published as: FR1148694A

Description

March 22, 1960 E. RHYHONES 2,929,964

CONSTRUCTION OF ELECTRICAL APPARATUS Filed March 27, 1956 12 Sheets-Sheet 1 F/GZ.

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CONSTRUCTION OF ELECTRICAL APPARATUS Filed March 2'7, 1956 12 Sheets-Sheet 11 I I 3/0 JIO\ March 22, 1960 J. E. RHYS-JONES CONSTRUCTION OF ELECTRICAL APPARATUS l2 Sheets-Sheet 12 Filed March 27, 1956 United States Patent CONSTRUCTION OF ELECTRICAL APPARATUS John Emyr Rhys-Jones, Iver, England, assignor to The Plessey Company Limited, llford, England, a British company Application March 27, 1956, Serial No. 574,122 Claims priority, application Great Britain March 29, 1955 Claims. (Cl. 317-101) This invention relates to the construction of electrical apparatus of the type comprising components such as resistors, capacitors and inductors in their various forms, amplifying or transducing devices such as valves or transistors, and circuit elements such as switches, plug and socket connectors or the like, which are interconnected by means of appropriate conductors. There are many examples of apparatus of this type, especially in the field of telecommunications; it is convenient to identify such apparatus, in general, as electronic apparatus.

At the present time, electronic apparatus is usually constructed with a metal support, or chassis, upon which the components are mounted by hand, and connections between the various circuit elements are made individually by hand. With the object of reducing or eliminating the large amount of manual work required in making an electronic apparatus in this way, suggestions have been made in the past for methods of construction by which a measure of automaticity in production can be achieved; one example of such a construction is the socalled printed circuit. However, so far as we are aware no methods have been suggested which have not at least one of the disadvantages of high initial installation cost of the apparatus involved, delay and/or high cost in changing from an apparatus of one circuit design to another, and danger of bad connections, leading to a high reject rate or the need for further human supervision of construction.

The present invention is concerned with an improved method of manufacturing electronic apparatus, and the apparatus made thereby. In one method of carrying the present invention into effect which will be described hereinafter, use is made of a carrier for the components of the apparatus, having recesses or the like to locate the connection terminals, such as metal wires or strips emerging from the components, in a predetermined spaced relationship in a line or series of lines; as will appear an advantageous relationship is for the terminals to be located at regular intervals, or multiples of such intervals, in two or more equidistant and preferably straight lines. The connections between the elements are effected by a series of connectors each of which has parts which follow a line of the successive terminals. In consequence, the connectors can be of generally elongated or linear shape, with means for making engagement with the separate component terminals. The advantage of this arrangement lies in the fact that it becomes possible to make the connectors more easily, and, as will appear below, can be made into multiple connector units, which facilitates assembly.

It is therefore an object of the invention to provide a method of constructing electronic apparatus which lends itself to a high degree of automaticity.

It is a further object of the invention to provide a method of constructing electronic apparatus in which components of the apparatus can be arranged and located in predetermined positions, and the desired connections between them established by a composite conductor as- 2,929,964 Patented Mar. 22, 1960 2 sembly which is prepared in accordance with a predetermined programme.

Another object is to provide electronic apparatus in which a substantial part of the wiring is contained in a pair of terminal bars each having terminals along one edge, and wherein wire ended components extend each between two terminals on said respective bars, and which apparatus can be conveniently and economically manufactured.

A still further object is to provide improved terminal bars for use in such apparatus.

It is also an object of the invention to provide a novel method of manufacturing connector elements for incorporation in such bars, which method shall be capable of economical performance even when only relatively small series of identical bars are to be produced thereby.

More specifically the invention provides a method of manufacturing an electronic apparatus comprising a plurality of circuit components having conductive terminals thereon, which includes the step of forming in accordance with a predetermined programme a sequence of electrical connectors, assembling said connectors in overlapping relation to form a series of electrically separate connectors with parts thereof arranged at predetermined intervals, locating said components with said terminals arranged in at least two lines and connecting said parts to said terminals.

The invention also includes a method of manufacturing an electronic apparatus comprising a plurality of circuit components having conductive terminals thereon, which includes the step of locating said circuit components with said terminals arranged at predetermined intervals in at least two lines, forming from conductive material and in accordance with a predetermined programme a plurality of electrically separate electrical connectors having parts thereof arranged at predetermined intervals, assembling said connectors in overlapping relation, and connecting the said parts to the said terminals.

The invention further comprises an electronic apparatus comprising a plurality of circuit components having conductive terminals thereon, and an insulating carrier on which said components are located with the said terminals arranged at predetermined intervals, in at least two lines, and at least one electrical connection means consisting of a plurality of electrically insulated connectors in stacked overlapping relation.

The invention further comprises an electronic apparatus comprising a plurality of circuit components having conductive terminals extending therefrom, an insulating carrier having therein recesses or the like to receive and locate said terminals, said recesses or the like being arranged in at least two lines, and at least one electrical connecting means consisting of a plurality of fiat electrically insulating connectors in stacked overlapping relation, and mounted on said carrier on a surface thereof adjacent said recesses or the like, said connectors engaging said terminals.

The invention will be better understood, and features and advantages of it will appear, from the following description of embodiments thereof, given by way of example, in conjunction with the accompanying drawings in which:

Figure 1 is a side elevation of one form of carrier;

Figure 2 is a plan of the carrier of Figure l with some of the components in position;

Figure 3 is an example of one of the connectors;

Figure 4 is a diagram showing the initial connector stock before slitting;

Figure 5 is a diagram showing the general arrangement of one form of the composite connector forming machine;

Figure 6 is a diagram showing the general arrangement of one form of machine for inserting components, soldering connectors and testing;

Figure 7 is a diagram showing the general arrangement of a supplementary conveyor system;

Figure 8 is an underneath view of a valve holder using multiple integral terminals; Figure 9 is a side view of a different form of carrier with some of the components attached thereto, and without the connectors;

Figure 10 is a transverse cross section on the line 1010 of Figure 9;

Figure 11 is a cross section through another form of carrier, in a preliminary stage of manufacture;

Figure 12 shows another form of connector strip stock material for connectors;

Figure 13 is a diagrammatic elevation of a form of construction of a radio receiver;

Figures 14a to 14d are diagrams showing the arrangement of parts in a specific embodiment of the invention;

Figure 15 is a circuit diagram of the parts shown in Figure 14;

Figure 16 is a partly diagrammatic side elevation of a machine for manufacturing apparatus in accordance with the invention; I V Figure 17 is a plan view, also partly diagrammatic, of

the same machine;

' Figure 18 is a fragmentary cross section through one of. the selectively operable punches in its nonoperated position;

Figure 19 is a corresponding section of the punch in its operated positions;

Figure 20 is a diagrammatic sectional view showing the means for stacking and sealing together and to the carrier the connectors of an assembly and Figure 21. is a simplified block schematic diagram showing the manner of controlling and interlocking the operation of parts of the mechanism.

In the first embodiment shown in Figures 1 to the electronic apparatus comprises a carrier presenting two parallel spaced edges; it is made from two strips of insulating material of the synthetic resin bonded paper type of the same shape and size, which are held parallel to each other about an inch apart by spacers 11. Two

adjacent longer edges of the strip are notched at regular intervals as at 10a; the notches are of'special shape, as shown, but at present it is sufficient to describe them as V-shaped, with an enlargement at the base of the V.

Many of the components. used'in electronic apparatus such as resistors and fixed capacitors have two terminals in the form of wires or the like emerging from opposite ends of the body of the component; the terminals of notches, with one terminalin each notch. High frequency coils or transformers such as 15, 16, or

valve sockets

17, 18 and 19 can be mounted in this way, by the addition of connecting wires to the existing terminals if necessary. The components are mounted with the body of the component which lies between the strips, so that when the terminals are inserted in the notches along the 'top edges of the strips the components will be inverted.

In this way alarge proportion of the components required in, say, a conventional radio receiver canv be mounted on the strips. Larger or heavier components, such as loudspeakers and iron-core components can be omitted from this part of the assembly.

The terminals of the components are thus located. in the notches in the carrier, and it is necessary to provide connectors between the terminals to complete the circuit. The connectors are in the form of strip conductors, .of whichone is shown. at20 inFigure 3, which are adapted a r 4 each to lie along an edge of one of the strips, adjacent the bases of the notches, and at each point where it is desired to make connection to the terminal lying in a notch the connector is formed with a small lateral projection such as 20a, which is inserted into the notch. One

connector can have as. many lateral projections as required, but it will be seen that the projections of the connectors will all occur at regular intervals, or multiples of regular intervals, corresponding to'the regular intervals between the notches.

It will occur that some of the connectors 20 will overlap; for example one connector might be required to make connection to terminals lying in the first, second, fifth and eighth notches along the edge of one strip, a second connection to make connection with terminals in the third, fourth and sixth notches, and a third with terminals in the seventh and ninth notches. To obviate short-circuit between the respective connectors, the under face of each of them is covered with an insulating layer, so that they can be brought close together into a sandwich of alternate layers of conductor and insulator. In this way, and by causing them to adhere together, all the connectors to be applied to'one side ofjthe strips can thus be made into a preformed unit, and the insertion of the wiring thus reduces to the inserting of the projections of two such' composite connectors into the appropriate notches, which is obviously a very simple operation.

The sequence of making an electronic apparatus is thus to attach the connectors to the carrier, preferably in the composite form, then to insert the components in the notches, and finally to effect a permanent connection between each terminal and projection in a notch. It is to be observed that it is not necessary to insert more than one projection in any notch and so that problem of making the permanent connection is no more than making connection between one projection and one terminal in each slot. It is preferred to efiect this by a soldering operation.

The apparatus this far described could be assembled manually, and when so made would have the advantages of being compact and easy to assemble, but the outstanding advantage of the construction is that assembly can be very largely 'mechanised; moreover, suitable machines for this purpose are not exceptionally complicated or expensive.

Assembly, when mechanised, takes place in three stages; the preparation of the composite connectors and their insertion in the carriers, the positioning of the components in the; carriers, and the final soldering of the connections. It is advantageous to include as a stage of the manufacturethe automatic testing of the apparatus.

In thisparticular embodiment of the invention, in

making the composite connector, the individual connectors are first made separately; for ease of handling it is preferred to make thesefrom continuous material. Connector strip stock is first prepared; this consists of an insulating base, such as polythene, to one surface of which is applied a conducting layer. Such a layer can be a metal foil made to adhere to the base, or a metal coating deposited directly upon the base, as by spraying or painting, aconductive material.

The connector stock has the'shape of a narrow strip with lateral projections along one side, the projections dividual connectors by cutting it into appropriate lengths 5 and removing those projections which are not required; For this purpose the'stock 30 is fed intermittently under the control of a control unit 31 to a machine 32 which crops out the unwanted projections and one 33 cuts the stock to length; the nature of the material is very suitable for intermittent feed in this way. It is arranged that sequence of operation of the cropping and cutting tools effected by control unit is controlled by a programming device 34, so that the different connectors required for a composite unit are successively prepared.

As the individual connectors are cut off, they are received by a movable indexing tray 35, the location of which is controlled by the programming device 34 in conjunction with control unit 31. This tray has locating means, such as partition walls on the bottom of the tray, and is moved so as to receive the individual connectors in the relative positions which they will have in the finalassembly. When all the connectors of a composite connector have been loaded into the tray, the tray is moved to a station 36 at which all the connectors are made to adhere together, as by the use of a pressuresensitive or thermal adhesive applied to one side of the connectors, and applying heat and/or pressure to the assembly. 7 The composite connectors are inserted into the carriers; since it is desirable that the connectors should be inspected at this stage it is convenient for the inspector to insert the connectors by hand in the carriers, but otherwise the-connectors can be so inserted automatically. The connectors can be coloured-coded, to make it easier to perceive that they are inserted on the correct side, and the right way up, in the carriers. This assembly is indicated at the left hand end of Figure 6, which shows again diagrammatically the general arrange! ment of the apparatus for effecting the second and third stages of manufacture.

The second stage is the insertion of the components in thenotches of the carriers. As indicated in Figure 6, the carriers are accurately positioned on a conveyor 40, the motion of which is controlledby a further control unit 41. Components are carried in a series of hoppers '42, each hopper containing components of one kind only, or a selection of components in order with the delivery chute of each hopper "positioned above the carriers on the conveyor. The delivery of a component is controlled, preferably electrically, from the control unit and the latter, by a programme inserted into it from a programme unit 43, ensures that when the appropriate notches of a carrier are below the appropriate chute a component emerges from that chute and drops into a predetermined one of the notches.

The carriers as they leave the second stage of the machine have the components loosely in position, and it is necessary to make connection between the terminals of the components and the respective projection of the connectors as they lie together at the bottom of each notch. To this end, the carriers 10, still on conveyor 40. as shown, or if desired, after transfer to a further conveyor, are moved past a station 50 where a pair of soldering irons enter the notches and solder the parts together. Flux-cored solder is fed to the irons as necessary. It is desirable that the irons and the carriers should not move relatively during soldering, so that the conveyor and/or the soldering iron motions are effected accordingly. It is to be noted that the use of soldering irons permits the soldering to be effected at high temperature, in contrast to methods relying on dip-soldering where the temperature used is a compromise between effective soldering and thermal damage to insulating materials. The use of a high temperature for soldering reduces the tendency to dry joints.

As mentioned above, it is convenient to arrange that when the soldered connections have been made they are automatically tested, preferably while still on the same conveyor, for example as at station 50 in'Figure 6. It

is to be observed that apparatus made by the construction described can be tested more easily than conventional constructions of electronic apparatus. Thus, a suitable testing apparatus may include testing prods which applied to the terminals or connector projections (if any) in the successive notches, and comparing the impedance between the test prods to the impedance between the corresponding points of a standard apparatus. The successive tests are carried out as the apparatus moves step by step past the test prods. When abnormal impedance of the apparatus under test is detected by dissimilarity of impedance, a paint mark or the like can be applied to the apparatus to indicate the abnormal point. It can also be arranged that when abnormal impedance occurs at a given point in a number of successive apparatuses, indicating a constructional fault rather than a mere component fault, the machine is stopped automatically, through the intermediary of control unit 41.

In view of the physical size of the hoppers which limits the closeness with which the delivery chutes can be disposed, and the number involved, which requires the use of a long conveyor system, a supplementary conveyor system can be used for the individual components before they are placed in the notches of the carriers, for example as indicated diagrammatically in Figure 7. The supplementary conveyor is arranged below the delivery chutes of the hoppers from which, under the control of the programme unit 43 and control unit 41, the components are placed upon the supplementary conveyor in the order in which they are required to be inserted in the carrier. The components are transferred in turn from the supplementary conveyor to a common delivery chute 72, beneath which the carrier 10 on conveyor 40 is located to receive them. The supplementary conveyor can run at any convenient speed, and it is necessary only that the carrier should be moved appropriately each time a component is delivered to it and that delivery from it is synchronised with the positioning of the carrier beneath chute 72. Several supplementary conveyors can be used in this way.

One of the main advantages of the construction described above arises from the fact that the nature of the electronic apparatus produced is determined solely by the

programmes

34 and 43 of the connector forming and component-inserting stages, and given only that the carriers are of suflicient size a machine can be changed from the manufacture of one type of apparatus to another merely by change of the programmes.

This degree of flexibility is attainable by using a large number of component inserting stages, but in practice it is more efficient to use the minimum number of such stages, with the object of achieving a high production speed. Accordingly, in changing from one type of apparatus to another it is preferred to change also the magazine of the component inserting mechanisms, but in either case it will be seen that changes can be made rapidly and very much more rapidly than in known printed circuit techniques.

The programme determining device can be formed as a circuit selector of the plugboard type. Such a plugboard will determine one cycle of operation of the machine so that if desired one programme can be used to produce, in one cycle of the machine, a number of the same or of different apparatuses, The great practical advantages of such an arrangement is obvious.

The construction described above can be varied or supplemented in a number of ways. In particular the carrier itself can be formed not only as described but also as a channel member (for example as described hereinafter) or other suitable shape, so long as it permits the notches or other recesses to be disposed in pre determined and, most conveniently, regular spacing. The notches or the like can be arranged along more than one edge of the strip, this arrangement being adopted in an embodiment of the invention described hereinafter,

andmore than one pair of notches can be used. For example, four insulating strips with notches along their edges can be secured together in two pairs, parallel and side by side, with the two inner strips closer together. The components are located in notches in the respective pairs of strips, as described above, and interconnections can be made by connectors, or a composite connector, lying between the two pairs and having lateral projections on both sides.

It is clearly desirable to make use, as far as possible,

of components which are as made, or supplied by individual manufacturers; normally, components with wire terminals have widely differing lengths or" such terminals. It is preferable that the terminals should not project unduly from the sides of the carriers, and so must be trimmed. This can be done beforethe components are placed in the hoppers, butit is better to insert them in the carriers with the varying lengths of terminals and then after soldering at station 59 and before testing the projecting ends can be cut off by two trimming blades or saws, one each side of the carrier. 7 If the trimming is done in this way, it is possible to facilitate construction in another way; components which have two or more terminals to be inserted in notches on one side of the carrier can have a multiple integral terminal, for example as shown in Figure 8. In this figure the valve holder 89 is shown as having two

multiple terminals

81, 82. Such multiple terminals can be stamped out easily and can be formed integrally with the sockets for the valve pins, thus greatly simplifying assembly. When the edges of such a multiple contact are trimmed off after soldering, as described above, the separate terminals will remain.

The insulating carriers can also be used to support other components which it is not convenient to support solely by their terminal wires. Such other components can be fastened independently to the carriers, or one of the strips forming the carriers, before the main assembly takes place. The terminals of such components can enter the notches, so as to be ready for attachment .to the connectors as described. It is preferred to mount large or heavy components as a separate assembly, with connection made by plug and socket or soldered flexible 7 connections to the apparatus made as described.

The notches or recesses can be variously shaped. All the notches can be of the same shape; this has the advantage that the carrier strips can be made automatically in long lengths and cut as needed, and permits difierent designs of apparatus to be made merely by programme changes, but differently shaped notches can be used if desired, for example to accommodate the terminals of components of different sizes. The shape of slot shown .in Figure 1 has a wide opening at its upper end to facilitate the entry of the terminal, and tapering downwardly and leading to a rectangular enlargement which receives the lateral projection of the connector, but as will appear hereinafter a simple V-notch can be used.

The connectors can be substantially flat, as described above, but it is also suitable for the projections to be bent at right angles to the main part of the connector. In this-case in use the main part of each connector will lie against the side of the carrier. The inner ends of the projections can be bent over at its tip so as to engage the inner face of the carrier, though this may introduce a risk of undesired contacts when metal-cased components are used. It is also possible, though not preferred, to use connectors on both sides of one of the strips of a carrier.

In a further embodiment of the invention, illustrated in Figures 9 to 13 and now to be described, some of" these modifications are adopted. Thus, in the construction of carrier shown in Figures 9 and 10, the carrier is fabricated from three

strips

90, 91, 92 of insulating material, such as synthetic resin bonded paper or fabric. The-two

side strips

90, 91 are similar in shape and have notches 93 at regular intervals along their upper and lower edges. The strips and 91 are held spaced and parallel by the third strip 92 which thus forms a platform between them; strip 92 has side lugs 94 which enter holes 95 in the side strips. The strips are held together. by adhesive during assembly, ultimately they are also held together by the components.

A carrier of shape generally similar to that shown in Figures 9 and 10 can be made in other ways. For'exg ample, an extruded H-shaped insulating material, such as hard polyvinyl chloride can be used, the notches being punched or otherwise cut out afterwards. A suitable carrier can also be made by deposition of a fibrous mate rial from a water suspension, by suction over a wire gauze former, the deposit being afterwards compacted by heat and pressure and if desired, after impregnation or coating with a synthetic resin. A deposit whichin section is initially as shown at 96, Fi ure 11 can be used; the parts 97 can be pressed together and before the resin is hardened. A fibreglass material can also be used if desired. a I

The platform 92 is used to support components of the apparatus, and in particular valve holders 98 or high frequency coils or transformers in screening cans '99.- It is advantageous .to mount valve holdersnear lugs 94, since. the insertion and removal of valves imposes some load on the platform.

As described above notches 93 receive terminal wires from the valve holders 98 and trans-formers or coils in cans 99,'and also from resistors and small capacitors which are laid in the notches. The connections between the terminal wires in the notches are effected, also in the manner described in the prior application, by connector assemblies which are secured to the face of

strips

90 and 91. In the present embodiment, the connectors are prepared from a punched strip, shown in Figure 1 2. The strip is of copper or other high conductivity, solderable material, and is punched to form a central part 10! from which extend upper and lower extensions 101. Towards its outer end each projection has an enlarge.- ment 152. This connector strip can be punched in long lengths; to prepare a connector to make connections between the terminal wires in some only of the notches, in accordance with the desired circuit connections, the strip is passed to a programme-controlled punching machine, to remove the unwanted extensions 101.

A series of connectors so punched, are assembled with interposed layers of insulating material. There is a considerable variety of materials which can be used for such insulating strips; kraft paper is suitable for many purposes, but materials with special properties can be used when circumstances require them. Material with a high insulation resistance, such as fibreglass cloth, polystyrene or nylon, can be used, or material with a high permittivity can be used to increase'the capacity between adjacent connectors. Different materials and/or materials of different thicknesses, can be used in the-same assembly. a

When the appropriate connectors have been assembled, the outermost edges of the connector strip are removed, and the enlargement 102 are all bent outwardly, or all inwardly, and then the assemblies are secured in correct position on the sides of the carrier. The enlargements will then all lie in the bottom of the corresponding notches, if the enlargements have been bent inwardly, or adjacent them if they have been bent outwardly.

The carriers are fed through a machine where the remaining components are placed with their terminal .wires innotches 9-3 and are soldered to the enlargements 102, in the manner described in our prior application. The completed carrier can also be tested as previously described.

While the notches in the edges of the carriers are advantageous in that it is easy to locate the componeiits in the notches as the component are delivered from to the connectors, carriers until the soldered connections have been made.

9 hoppers, the notches are not essential. In a modified form of the apparatus the strips are unnotched and during the process of assembling the components on the carriers and making the necessary soldered connections to the connectors, separate locating guides can be used. In one such arrangement, similar to

strips

90, 91 but not notched are used; the connector assemblies are secured in correct position on the carrier when components are assembled on the carrier temporary guides, which are notched as shown in Figure 9 are located with respect and are held fixed in relation to the They can be removed and reused; a number of them can be used in rotation ason an endless conveyor. It will be understood that if the notches in the carrier are omitted, it is still desirable to maintain the predetermined or regular spacing of the terminal wires.

Some components which it may be desired to use in an apparatus in accordance with the invention are made conventionally with all the terminal wires at one end; intermedite frequency transformer, for example, are so made. For the purpose of the present invention it may be more convenient to make the wire terminals emerge at both ends, and to dispose the component lengthwise across the carrier.

As mentioned in the earlier application, in an apparatus such as a radio receiver it may be preferable to assemble some of the heavier and/or larger components on a separate sub-assembly or by more conventional assembly method. Figure 13 shows diagrammatically a construction which has proved. satisfactory. One assembly 104 includes the valves, transformers and the major part of the circuit; an insulating or metal strip 105 carries the tuning capacitor 106 and coils 107; a further insulating or metal strip 108 carries a gain control potentiometer 109 and output transformer 110. Another strip 111 supports a smoothing capacitor 112 and voltage-dropping resistor 113. The strips 105, 108 and 111 can be engaged by tongue and slot connections to each other and to the ends of platform 92. A loud speaker 114 is secured in a panel 115, which provides a comparatively rigid structure for the whole.

A specific construction forming one embodiment of the invention is shown in more detail in Figures 14a to 14d, and 15. This construction is of a simple radio receiver, the circuit diagram of those parts of the receiver shown in Figure 14 being given in Figure 15. Figure 1411 is a plan view of the construction and Figure 14d is an underplan; Figure 14a is an exploded diagram showing the individual connectors of the assembly which is applied to the face of the chassis of the construction shown uppermost in Figure 14b and lowermost in Figure 14d, whilst Figure 14c is a similar view of the connector assembly applied to the lower face of the chassis shown in Figure 14b of the upper-face of that shown in Figure 14d.

The construction makes use of carrier 130 of H-shape in cross section, and made of extruded hard polyvinyl chloride. This carrier is similar in cross section to the carrier shown in Figure and the edges of the carrier are notched in the same way as are those of the carrier of Figures 9 and 10.

The individual connectors of the assembly are made from stock of the type shown in Figure 12, and in Figures 144 and 140 the individual connectors are shown by a horizontal line representing the length of the connection with shortvertical strokes extending laterally from it; each vertical stroke is intended to connect to one terminal of a component lodged in a notch of the carrier. Connectors of the assembly of Figure 14a shown with a downward stroke will therefore connect to that terminal of a component which rests in a notch in the upper surface of the carrier as shown in Figure 14b, whilst an upward stroke will effect a connection to a terminal lodged ina notch in the lower surface of the carrier shown in Figure 14d. In similar fashion, connectors of the assembly 10 of Figure shown with an upward stroke will malce connection to terminals in a notch of the surface immediately above them in the carrier Figure 14b and with a downward stroke to the terminals in notches in the surface of the carrier of Figure 14a immediately below them.

In Figure 15 the apparatus includes four valves V1, V2, V3, V4 arranged in a superheterodyne circuit, and in cluding a valve operating as a supply rectifier. Valve V1 is a combined oscillator and frequency changer, the intermediate frequency output of which is coupled by transformer IFT1 to the input of valve V2. Valve V2 acts as an intermediate frequency amplifier and also has diode electrodes for demodulation; a second transformer IFTZ. couples the output of the amplifier to the diodes. The rectified diode output is applied to the input of valve V3 which is a multiple valve the first, triode, section of which is used as a low frequency amplifier and the output, tetrode, section of which is used to supply a load device such as a loudspeaker.

In addition to the components mentioned, the circuit makes use of resistors R1 to R16 and capacitors C1 to C14. The circuit as shown is incomplete inasmuch as it does not include a signal frequency tuning device, which is adapted to be applied to the input of valve V1 through capacitor C1, nor a local oscillator frequency tuning cir cuit adapted to be coupled to the triode section of valve V1 through capacitor C3. Further, a gain control p0: tentiometer is required to be connected between terminals 131 and the earth connector of the receiver and the primary winding of the output transformer feeding the loud speaker is intended to be connected to terminals 132.

Except for these omissions, the circuit shown in Figure 15 will be recognized by those skilled in the art as conventional and it is not therefore considered necessary to refer in detail to the functions of the individual components.

Components identified by these references in Figure. 15 are identified by the same references in Figure 14. In Figure 15 the various connections necessary to complete the circuit between these components are'identified'by references K1 to K34 and each of these connections if formed by that one of the connectors of the two as? semblies shown in Figures 14a and 140, which bears the same reference in Figure 15.

For example, in Figure 15 a connection K2 is required between the right-hand terminal of capacitor C1 and the control grid of the input section of valve V1, and one terminal of resistance R3. This connection is made by connector K2 which appears at the lower left-hand end of Figure 14c. It will be seen that connector K2 is shown as having three downward strokes indicating connection to terminals in the first, third and fourth notches on the upper surface of the carrier as' shown in Figure 14d. Capacitor C1 is located in the first pair of notches of the carrier, resistor R3 in the third pair and a connection from the grid contact of a valve holder for valve V1 is made to the fourth notch on this surface. Connector K2 will clearly make the desired connections.

It will be seen that connector K1 is used to make connection to the left-hand terminal of capacitor C1, but is not shown to make any other connection. It is useful to employ a connector such as K1 because it anchors the terminal wire of C1 shown lowermost in Figure 14d .so to retain the capacitor on the carrier and also provides a point to which an external tuning circuit can be readily atached by soldering and secured more effectively than if the connector K1 were omitted.

Following this example, it is not considered necessary to describe in detail the way in which all the remaining connectors are used and the'individual connections are made will be readily apparent by comparison of Figures 14 and 15. However, some further minor points arise in the method of using the connectors. For example, it will be seen that the anode supply to the three valves nebtorsKS and "K9; K is shown in the assembly of Figure 140 and K9 in that of Figure 14a. To join these connectors use is made of the simple insulated wire connection W which is lodged in one pair of the notches of the carrier. In this way it is possible to make cross connections from one side to the other of the carrier.

It will also be seen that a single connection is 'made toconnector K11 shown in Figure 14a. This connector .is however connected to an earthy point of the circuit and is used to act as an electrostatic screen for a lead such as that provided by connector K15 which might otherwise give rise to instability in the receiver.

The receiver of Figures 14 and 15 can be completed in the manner described above in conjunction with Figare 13.

In Figures 16 and 17 is shown a machine which can be used for making electronic apparatus, and in particular an apparatus'such as that shown in Figures 14 and 15. This machine forms the subject of copending application Serial No. 619,081, filed October 29, 1956, now abandoned.

Before proceeding to a description of this machine it may be pointed out that as described above it is necessary to ensure the individual connectors of the assembly are in the correct relative position, one arrangement for effecting this is described above in connection with Figure 5. In the machine of Figures 16 and 17 a different expedient is adopted: strip stock is first prepared, in the form shown in Figure 12 and then there are removed some of the portions 101, to leave a series of connectors corresponding to the individual connectors but joined to form a self 'supporting unit by the marginal portions of the strip. Insulating material is applied to the whole face of the strip, and thereafter the margins are removed, vto leave the discrete connectors insulated from each other. All the strips thus formed can be cut to precisely the same length, making it much easier to stack them in the correct relative positions.

The machine shown in Figures 16 and 17 takes a copper strip 310, which can be pre-tinned at least along the edges of one major face, and/or may have a coating of soldering flux at these parts. The strip has a width equal to that of the strip shown in Figure 12 and is fed from a drum at 311 by means of pairs of feed rolls 312 and 313. Between these feed rolls the strip is punched, the strip being advanced intermittently. A number of punches are used, but all the punches are operated from a common head 14 which is depressed after each moveineht of the strip. There is a separate die for each punch but the dies are mounted on a common support plate 315. The first four punches 316 are fixed, and operated on every stroke ofthe head of the press. These punches are used to remove material so as to leave the strip as shown in Figure 12; the punch separation is greater than that of theapertures, but the advance of the strip is controlled so that on leaving this first group of four punches, the strip is as desired.

The second group of punches 317, in this case 12 in number, are selectively operable punches. These punches are used to remove parts such as 100 or 101 in Figure 12 which are not required in any individual particular connector strip. A number of ditferent connector strips are required for each connector assembly, and it is by selective operation of punches 17 that the different strips can be made in succession.

The way in which each punch can be made operative or inoperative is indicated in Figures 18 and 19. Each punch is carried on a plunger 318 attached in turn to a piston 319 moving in afcylinder formed in'block 320. Each piston is biased upwardly by a coil spring 321, and compressed air can be admitted to the space above the piston through a port 322.

--,-If compressed air is not admitted to this space the piston assumes the position, relative to the block, as

sesame shown in Figure '18; when air is "admitted, the'piston moves to therelative position shown in Figure 19. When head 314 is depressed the tip of the punch will thus pierce strip 310 only if compressed air has been admitted to port 322. p

i The admission of air to all the separate ports 322 is controlled by a series of electrically operated air valves, controlled from a programme device, described hereinafter.

' The punches 17 do not remove the extreme edges of the strip so that the connector strips although almost completely punched are still retained in a continuous coherent strip by the marginal portions, so that it can still be handled conveniently.

' The strip so formed has applied to its upper and lower surfaces a strip of thin insulating sheet material, kraft paper about .005 inch thick being suitable. Thepaper strips are fed from an upper roll 323 and lower roll 324, and are secured to the metal strip, and to each other through the openings in the metal strip, by a layer of adhesive applied to it. The adhesive is applied from spreading baths, of which one is shown at 315. The upper surface of the upper paper strip is also given a coating of adhesive, from spreading bath 326. I

The composite strip is fed through a heating chamber 327, heated in infra-red lamps 328, to produce an initial pro-curing setting of the adhesive so that it can be subsequently fullyhardened by a single application of heat and pressure. Once the paper insulation has been 'attached to the connector strip in this way, the supporting margins of the strip are cut away, so maintaining a continuous and easily handled element despite the fact that the connector strips are at this time electrically independent.

It is arranged that the tool that removes the margins of the strips also bends at right angles the tag portions 102 of the strips, as shown in the Figure 12. This tool is shown at 329 in Figure 16; the first part of the motion of the tool cuts otf the margin, and the second part "bends down the tags.

' The composite strip is next cut into lengths, being fed by feed rolls 330 past a cropping tool 331. The Cut lengths of strip rest on top of a guide rail of rectangular cross section, shown at 332 in Figure 5. When each strip has been deposited on the rail the rail is raised and the strip is forced into a shaped retainer 333, where it is held by shoulders 334 which engage the tips of the terminal lugs of the strip. There is sufiicient resiliency of the lugs to hold the strip in position. The further strips are assembled in the retainer 333 in the same way.

When all the lengths of composite strip necessary for one connector assembly have been stacked in retainer 333, the guide rail 332 moves upwardly an increased distance, forcing the stack into a transfer retainer 334. This latter retainer is carried by a pair of arms 335 pivoted about an axis at 336.

In the meantime, carriers 337, corresponding to the carriers shown'in Figures 9, 10 or 14 are brought by a main cross conveyor 338 and are transferred to a further conveyor 339. By this latter they are brought to the position shown inFigure 20, so that when the transfer retainer 334 swings upwardlythe contact assembly can be pressed against the side of the carrier with heat and pressure applied by a platen 340, thereby curing the adhesive layers of the assembly.

As connector assemblies have to be applied to both sides of the carrier, a second connector assembly is prepared by duplicate apparatus (except for the appropriate operation of the punches) alongside the first, as shown in Figure 19. The transfer retainer for the second assembly is arranged on the opposite side of the carrier and so that the two platens are applied simultaneously to op posite sides of the carrier.

The carriers are transferred to a component loading station; components are-loaded from a series of hoppers 341, in each of which components are stored in a continuous belt 342. The belt is formed by two edge strips between which the individual components extend at intervals, ladder fashion. The'belts can be on drums or can be stored folded concertina-wise. The belts pass over driver rollers 343 so that they are advanced, as necessary, in synchronism with the motion of conveyor 339. When the wire ends of the component are in position in the notches the wires are cut by a cropping wheel 344 and the wires are soldered to the lugs by a battery of soldering irons 345, each with an automatic solder feed.

On leaving the soldering station, a carrier has all the components secured on its upper edge, and it is moved to a transfer device 346, where it is taken from conveyor 339, inverted, and deposited on a conveyor 347. Components are likewise secured on the other edge of the carrier, and the carrier is removed by a further cross conveyor 348.

If desired a testing station can be included after soldering the components on conveyor 339, and/ or one on conveyor 347 before the carriers are removed.

As mentioned above, testing can be carried out by applying test prods to pairs of terminals, and comparing the impedance between the prods with the impedance between the corresponding points of a corresponding, stand ard apparatus. The motion of the carrier through the testing station is synchronised with the movements of the earlier stages of assembly; a carrier can be moved through the testing stage a distance corresponding to one notch at a time, in which case one pair of test prods only are required, or alternatively the carrier can be moved less frequently and a larger number of pairs of test prods used. In the latter case, a stepping switch or the like can be used, to initiate the tests between successive pairs of prods. The movement of this stepping switch or the like can then be initiated in synchronism with the movements of the remainder of the machine, but once started the tests can proceed as rapidly as may be. The progress of the carrier from the testing station can then be made dependent upon the completion of the sequence of tests. By such an arrangement of a sub-cycle of operation, it can be arranged that the operation of the whole of the machineneed not be slowed by reason of one operation, 'which takes longer than the others, provided that the average time for each operation of the sub-cycle does not exceed the normal time of an operation of the machine. This principle can be otherwise applied in the machine.

The heated platens must also be in contact with the composite strips for a period suflicient to cure the adhesive, and so the mechanical interlock switch such as 369 which is associated with the platen and is operated when the platen engages the composite connector, is arranged to start a timing device 372 hold open interlock contacts at 364 included in the circuit of the air control valve controlling the removal of the platen.

As mentioned above, the stepping speed' of the step by step motion is determined by the adjustable timer 360. While any suitable devices such as relay circuits, or time constant circuits can be used for this purpose, an advantageous arrangement is to include on one of the parts of the machine suitably operated switch and to control the running speed of this part of the machine by the admission of the air supply. For example, in this embodiment, a switch is operated by the form tool at the bottom of its stroke and this switch causes the uniselector to step. Arestrictor valve is included in the air supply of the form tool, and it is this valve which determines the interval at which the next stroke will take place, and hence the interval at which the uniselector will next step.

This arrangement has the advantage that it is easier to control the stepping of the uniselector; in general, the uniselector must not step until the previous operation is '14 complete, and this can be eifected by controlling the operation of the form tool.

Itwill be understood that while the invention has been described in relation to certain embodiments it is not limited thereto, and that various modifica ions are possible, as will be apparent to those skilled in the art. One modification involves dispensing with a separate carrier as such, and using the composite connector as the carrier in this case a connector such as that described in connection with Figures 12 and 14 can be used, except that the paper strips, and with them the connector strip stock, are made wider and pairs of extensions such as 101 and 102 are made to emerge from the opposite sides of the assembly at each point where it is desired to make connection to a component the terminals of which are then attached directly to the pairs of pairs 102.

Again, it is possible to form a composite connector of other than fiat conductor material and to form the connector as a coherent assembly by embedding the conductors in a hardenable material such as a resin.

.1 claim:

1. A method of producing a plurality of connector elements each comprising a linear conductor element of conductive sheet material having at least two integral transverse extensions spaced from each other by integer multiples of a common modulus, the spacing of two such extensions of at least one element being difierent from the spacing of two such extensions on at least one other element, the method comprising blanking from conductive sheet material pre-form elements each comprising a linear conductor element provided with integral transverse extensions spaced by distances equal to said common modulus over a length equal at least to the maximum distance of any two extensions on any of the connector elements to be prepared, and preparing the individual connector elements from such pre-forms by cropping oif the unwanted parts.

2. In a method as claimed in claim 1, the steps of providing a roll of conductive strip material, blanking said roll progressively from end to end to produce a continuous length of linear conductor having integral transverse extensions spaced throughout said continuous length by distances equal to said modulus, and subdividing said continuous conductor to produce the'individual pre-forms.

3. A method in accordance with claim 2 and including the step of passing said continuous linear conductor to a combination of tools selectively operable to remove parts thereof, and selectively operating said tools to remove from said linear conductor parts thereof and synchronising the movement of said linear conductor with the operation of said tools to form a succession of a plurality of dissimilar connector elements.

4. A method in accordance with claim 3, and comprising the step of setting a programme device to control the sequence of operation of said tools.

5. An electronic apparatus comprising a plurality of wire-ended circuit components extending between two spaced composite terminal bars, each said bar comprising a stack of superimposed sheets of insulating material and a plurality of electrical conductor elements extending longitudinally of said bar and respectively separated from each other by at least one of said sheets, said co11 duetor elements being each provided with at least two integral terminal portions extending along such sheet transversely of said element, the individual extensions of each conductor element being spaced longitudinally of said element by distances which are all integer multiples of a common modulus, such distances in at least two of the connector elements being different from each other, and at least some of said components having their wire ends conductively attached to one terminal each on said two bars respectively.

6. An electronic apparatus in accordance with claim 5, wherein said components are retained in said located r is positionsonly'bythe attachment of said parts to said terminals. a

7. Anelectronic apparatus in accordance with claim 5, wherein said carrier presents a substantially flat platform serving as a support for at least some'of said components, the said recesses or the like lying without the plane of said platform.

8. An electronic apparatus in accordance with claim 7, wherein said carrier is of H-shape in cross section.

9. An electrical terminal bar for electronic apparatus, comprising a plurality of strips of insulating material each having a longitudinal edge of equal shape, said strips being superimposed with said edges coinciding, and a plurality of connector elements superimposed in alternation with said strips so as to be electrically insulated from each other by said strips, each said connector element comprising a linear conductor element extending longitudinally of said bar at a distance from said edge and provided with at least two integral terminal extensions projecting from said strip along the surface of "one of 20 said layers to points beyond said edge, the extensions of each conductor element and of the various conductor 'tudinally of the bar and each provided with at least two transversely projecting terminal extensions spaced by 10 integer multiples of said common modulus.

References Cited in the file of this patent UNITED STATES PATENTS 1,718,993 Wermine July 2, 1929 15 2,244,009 Hiensch June 3, 1941 2,399,753 McLarn May 7, 1946 2,444,037 Fritschi June 29, 1948 2,508,030 Karns May 16, 1 950 2,596,237 Gross May 13, 1952 FOREIGN PATENTS France Jan. 18, 1950