Sept. 10, 1929.
`
`S, FORD
`ELECTRICAL CABLE
`
`1,727,972
`
`Filed April 18, 1924
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`ELECTRICAL CABLE
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`1,727,972
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`Filed April 18, 1924
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`Sept. 10, 1929.
`
`L. S. FORD
`ELECTRICA CABLE
`
`1,727,972
`
`Filed April 18, l924
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`2. Sheets-Sheet 2
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`Patented Sept. 10, 1929.
`
`1,727,972
`
`UNITED STATES
`PATENT OFFICE.
`
`LEROY STEARNS FORD, OF RIVER FOREST, ILLINOIS, ASSIGNOR, TO WESTERN ELEC
`TRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A. CORPORATION OF NEW
`YORK,
`ELECTRICA CABLE.
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`60
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`65
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`Application filed April 18, 1924, Serial No. 707,528.
`center, a core is formed of the first 101 pairs,
`This invention relates to improvements in
`electrical cables, particularly to the type em
`One conductor of each pair being insulated
`ployed for telephonic communication.
`with One color of paper and the other con
`ductor of a pair being insulated with a dif
`Subscribers in city districts are, in the
`5 modern telephone plant, connected to the
`ferent color, as, for instance, one wire hav
`55
`central office through lead covered cables of
`ing an insulation of white paper and the
`either the aerial or underground type. In
`other wire of red paper. Around this cen
`a typical connection the subscriber's tele
`tral core of red and white pairs are stranded
`phone set is connected by means of a twisted
`in concentric layers a second group which
`10 pair of rubber insulated drop wires with a
`may be colored blue and white. A third
`sealed chamber type of terminal located near
`group may be colored orange and white, etc.
`As the factory lengths of such cables are
`the subscriber's house. The sealed cham
`ber is provided with means for connecting
`joined together in the field, like color groups
`several subscribers’ pairs to it. From these
`are always spliced together so that from end
`to end of long cables the pairs are definitely
`15 terminals, connection is made to the main
`underground or aerial cable system by means
`separated into finite groups. Each group is
`of Small lead covered cables known as
`given a definite group of pair numbers as,
`“block' cables. A number of these block ca
`for instance, the red-white group is given
`bles bridge into the main aerial or under
`numbers from 1 to 101 inclusive, the blue
`20 ground cable which enters the central office.
`white group 102 to 202 inclusive, etc., and
`The block and main aerial or underground
`in locating an individual pair it is only nec
`cables are of the paper insulated, dry core,
`essary to ring out the pairs of the group in
`lead covered type. At the central office it
`which the sought number is located.
`is necessary to connect the paper insulated
`With the type of subscribers’ paper in
`25 conductor wires of the main cable with wires
`sulated cable above described the groups are
`suitably insulated with silk, cotton, wool, or
`arranged in concentric layers, and since
`some other suitable insulating materiai So
`each layer or series of layers constituting a
`that they may be handled in connecting them
`group does not always contain the proper
`to the terminals on what is termed a “main
`number of pairs to complete a layer, a layer
`frame' located in the central office. These
`may contain the last pairs of one group and 3C
`connecting cables between the paper insu
`the first pairs of the next group. As a con
`lated underground cable and the main frame
`sequence, although the individual Sub
`are known as tips or terminating cables.
`scriber's lines are arranged in groups in the
`The larger aerial or underground paper in
`cable, these groups are not entirely separate
`sulated cables connecting the subscriber to
`35
`and to this extent are not always well de
`the central office consist of a large number
`fined. Furthermore, in order to collect like
`of lines ranging from 606 to 1212 actual
`colored pairs into a unit group or bunch, it
`pairs.
`is necessary, except for the central group, to
`It is necessary, of course, to know each
`divide the layers and pass the pairs around
`subscriber's number at the central office.
`It
`the central core to one side of the cable, re
`would be impractical to attempt to associate
`sulting in an unhandy and awkward ar
`these large subscriber cables each pair with
`rangement in splicing and terminating the
`its terminal number. On the “main frame’
`throughout the entire circuit length by
`cable.
`An object of this invention is to provide a 95
`means of identification marks or colors. As
`cable, particularly of the type employed for
`a consequence the pairs in all of these large
`telephonic communication, consisting of a
`cables are separated into groups of pairs by
`plurality of pairs similar in appearance of
`definite color combinations. For instance, a
`individually insulated conductors arranged
`606 pair paper cable has six distinct color
`in well defined and distinguished groups, 100
`50 groups of 101 pairs each. Starting at the
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`3 5
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`40
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`

`

`2.
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`the insulation of conductors in adjacent
`groups being in contact.
`Another object of the invention is to pro
`vide a cable of the above described type, so
`constructed that when it is enclosed in a pro
`tective sheath practically all of the space
`within the sheath is utilized by the insulated
`conductors.
`Other objects and advantages of the inven
`tion will more fully appear from the fol
`lowing detailed description and will be par
`ticularly pointed out in the appended claims.
`In the accompanying drawings:
`Fig. 1 is a Schematic side elevation of part
`of an apparatus for making the improved
`form of cable;
`Fig. 2 is an enlarged vertical sectional
`view of the die for compressing the groups
`of conductors so that the cable presents a
`substantially cylindrical exterior;
`Fig. 3 is an enlarged vertical sectional
`view taken on the line 3-3 of Fig. 1;
`Fig. 4 is a vertical sectional view of a
`cable made in accordance with the inven
`tion;
`Fig. 5 is a fragmentary side elevation
`thereof;
`Fig. 6 is a schematic vertical sectional
`view of a modified form of cable made in
`accordance with the invention; and
`Fig. 7 is an enlarged view of one of the
`groups of conductors constituting the cable
`showing that the individual conductors are
`twisted into pairs.
`The improved type of cable and method
`of making the same disclosed in this ap
`plication is a modification of the cable and
`method of producing it disclosed in co
`pending application, Serial No. 677,873, filed
`November 30, 1923. In the co-pending ap
`plication just mentioned, although the con
`ductors are arranged in groups, the color
`scheme of each group is different from the
`insulation color scheme of adjacent groups;
`Whereas in the cable and method of produc
`ing it constituting the present invention the
`insulation color scheme of all the groups is
`the same, means being provided for differ
`entiating each group from the adjacent
`groups.
`it is believed that the construction of the
`improved form of cable will be understood
`by a description of the method of making
`the same.
`A plurality of copper wires insulated with
`paper, cotton, silk, or other suitable mate
`rial, usually twisted together in pairs, are
`stranded together loosely to form a group
`or bundle 5 of conductors which are held
`together in their loosely stranded condition
`by means of a suitable strand binder 6 of
`cotton or other suitable materia. The
`binder 6 is wrapped in a helix the turns of
`which are spaced widely apart as illustrated
`in Figs. 5 and 7. The group or bundle 5
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`5
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`5 5
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`5
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`1,727,972
`may be formed in any suitable manner but
`preferably by the usual and well-known form
`of strander in which, when the cable is used
`for telephonic communication the conduc
`tors are stranded in oppositely laid layers
`to eliminate cross talk.
`In the formation of a cable, a plurality
`of groups 5 are formed in the manner above
`described and then stranded together to have
`the form shown in Fig. 3. Any suitable
`type of strander may be used, such as those
`employed in the stranding of rope, the con
`struction and operation of which are well
`known to those skilled in the art.
`The insulation color scheme of each
`twisted pair of conductors is such that the
`conductors may be distinguished from each
`other; that is, one conductor of a pair may
`be white and the other red, or colored in
`any suitable manner to differentiate them
`from each other. The twisted pairs in all
`of the groups may or may not have the
`same color scheme, as desired, since means
`is provided for differentiating one group of
`conductors from adjacent groups irrespective
`90
`of the insulation color scheme of the group,
`said insulation color scheme only being nec
`essary to differentiate the conductors consti
`tuting the pair. The means for distinguish
`ing one group of conductors from the ad
`jacent groups comprises the strand wrapping
`6 which is of a different color on each
`group of conductors. Thus one group may
`have a red strand wrapping, another white,
`another blue, another orange, etc., the groups
`being so arranged that the strand wrapping
`of one group is different color from the
`strand wrapping of adjacent groups. In
`stead of having the strand wrappings of
`different colors, any suitable retaining means
`having different distinctive appearances may
`be employed.
`Means is provided for compressing the
`groups as shown in Fig. 3 into the form
`shown in Fig. 4 and for retaining the groups
`5 in the latter formation. This means com
`prises a cylindrical die 7 through which the
`stranded cable is pulled, the die serving to
`compress the groups 5 into a cylindrical
`composite which is retained in this form by
`means of a paper wrapping 8 which may be
`applied by a usual form of tape serving head
`9. The die 7 and serving head 9 are, for
`economy, preferably mounted on the ma
`chine which strands the groups 5 together.
`120
`The keystoning of the groups into a cylin
`drical composite as shown in Fig. 4 is only
`possible due to the fact that each group 5
`is loosely stranded prior to the assembly
`of these groups to form the compiete cable,
`and that the binding 3 of each group is
`Wrapped in an open spiral of long lay, so
`as not to restrict, the readjustment of the
`pairs as the units are cabled together.
`instead of maizing a cable with the “iay
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`up' illustrated in Fig. 4 in which five groups
`5 are arranged around a central group, the
`cable may be designed as shown in Fig. 6.
`In this “lay up' three groups 15 are arranged
`5 at the center constituting a core around
`which nine groups 15 are stranded. After
`the cable has been passed through the appara
`tus shown in Figs. 1 and 2, the loosely strand
`ed groups 15 assume a shape in which the
`10 three central groups 15 are compressed into
`sector shapes while the nine groups arranged
`therearound are given a shape which may
`be defined as a “sector shape’ for want of a
`better descriptive term.
`5 Where the cable is used for telephonic com
`munication it is usually enclosed within a
`protective lead sheath 10.
`By referring to Figs. 4 and 6 it will be ap
`parent that each group 5 or 15 is, in effect, a
`20 separate small cable and due to the color
`scheme employed for the strand wrapping 6
`of each group, they are clearly defined and
`readily distinguishable from each other.
`Furthermore, although the groups are read
`ily distinguishable, they are in close associa
`tion, the insulation of the outer conductors
`of each group exposed between the helical
`turns of the strand binder 6 being in actual
`engagement with the insulation of the outer
`30 conductors of adjacent groups and substan
`tially all of the space within the lead sheath
`is utilized by the individually insulated con
`ductors.
`What is claimed is:
`85
`1. In a cable for the transmission of in
`telligence electrically, a plurality of insu
`lated conductors arranged in pairs occupy
`ing substantially the same relative positions
`throughout their length, the insulation of the
`40 individual conductors forming each pair dif
`fering in color and the colors of all pairs be
`ing alike, the pairs held together on groups
`solely by a plurality of textile strands ap
`plied therearound in open spiral formation
`45 to permit the inter-engagement of the insula
`tion of conductors in adjacent groups, and
`the strands surrounding adjacent groups dif
`fering in color.
`2. In a cable for the transmission of in
`50 telligence electrically, a plurality of individ
`ually insulated conductors twisted into pairs,
`said pairs being substantially parallel to each
`other throughout their length and arranged
`in separate and distinct groups, the insula
`tion of all of the pairs of the conductors in
`the groups being similar in appearance, and
`distinctively and characteristically different
`means individual to each group Serving as a
`sole retaining means for the groups of con
`60 ductors and permitting ready and easy iden
`tification of the groups one from another
`and the separation of the conductors within
`the groups.
`-
`3. In a cable for the transmission of in
`65 telligence electrically, a plurality of insur
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`2 5
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`5 5
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`3
`1,727,972
`lated conductors arranged in twisted pairs,
`the conductors forming each pair being dis
`tinctive in appearance from each other, said
`pairs being substantially parallel to each
`other throughout their length and arranged
`in separate and distinct groups, and distinc
`tively and characteristically different strand
`binding elements individual to each group
`serving as a sole retaining means for the
`groups of conductors and permitting ready
`75
`and easy identification of the groups one
`from another and the separation of the con
`ductors within the groups.
`In witness whereof, I hereunto subscribe
`my name this 7th day of April, A. D. 1924.
`LEROY STEARNS FORD.
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