Improvements in Jacks for Telephone Exchanges.
Year: 1897

page_text: Date of Application, 10th Mar., 1897
Complete Specification Left, 10th Dec., 1897- Accepted, 15th Jan.,
1898
Improvements in Jacks for Telephone Exchanges.
We, SIEMENS BROTHERS & CO. LIMITED, of 12, Queen Anne's Gate, Westminster,
in the County of London, Electrical Engineers, do hereby declare the nature of
this invention (as communicated to us from abroad by Siemens and Halske, 94,
Markgrafenstrasse, Berlin, in the German Empire, Electrical Engineers) to be as
follows:-
The present invention relates to an improved construction of jacks for the con-
necting pegs of telephone exchanges, in which firstly the separate parts of the
instrument are secured together in such a manner in a vulcanite or ebonite base,
that the ends of the several springs, provided with bends and holes, are entirely
surrounded by the vulcanite, and secondly the securing of the jacks to the jack
strips is effected by a spring fastening in such manner as to allow of their ready
removal when required.
By the improved construction any lateral connection between the separate jacks
is rendered unnecessary as they possess individually sufficient rigidity to prevent
any lateral bending by the pull of the peg-cords connected thereto. And even
should any such bending occur, the fact that the lower ends of the springs are
entirely surrounded by the vulcanite would, effectually prevent any contact between
them.
For the above purposes the jacks are constructed as follows:-
The jack consists of a metal tube, one end of which constitutes the socket by
which it is fixed to the jack strip and which serves to receive the contact peg.
The other part of the tube is cut away on one side along its entire length, forming a
tongue to which the contact springs are fixed with the interposition of the insulat-
ing vulcanite block.
For this purpose the tongue as also the springs have holes formed through
which the soft caoutchouc of the block is pressed before vulcanising, s0
that when the latter is vulcanised, the springs and tongue are effectually and
strongly keyed together, in the block which entirely surrounds each part and in-
sulates it from the others. When several jacks are combined into one strip, the
arrangement can be such that they are either permanently secured together to
form one body, or that they are separately removeable.
In the former cases all the jacks can be pressed into a single block, or each one
may have a separate block to which is secured a metal plate by screws, screwing
into the part of the vulcanite that passes through the before mentioned holes of
the tongue and spring, or the blocks may be formed with a groove on the one side
and a corresponding feather on the opposite side, so that the feather of the one
jack fits into the groove of the other, thus keying them all together.
If the jacks are to be separately removeable from the jack strip, the end of the
tube forming the socket has a spring tongue formed in it by cutting two parallel
slits therein and the end of the tongue is bent outward at an angle.

page_text: The hole of the jack strip has a bevilled notch formed in its upper edge into
which the bent end of the spring tongue of the jack springs when inserted whereby
it is held securely in position when the peg is inserted; the jack can however be
readily removed by inserting into it a rod shaped key of smaller diameter and cut
away on one side by which the jack can be pushed out of the strip-hole, as the
tongue will then yield in springing inwards.
For facilitating the introduction of the jack from below a similar bevilled notch
is formed in the lower edge of the strip-hole, through which the tongue can enter.
Dated this 10th day of March 1897
We, SIEMENS BROTHERS & CO. LIMITED, of 12, Queen Anne's Gate, Westminster,
in the County of London, Electrical Engineers, do hereby declare the nature of
this invention (as communicated to us from abroad by Siemens and Halske, of 91,
Markgrafenstrasse, Berlin, in the German Empire, Electrical Engineers,) and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
The present invention relates to an improved construction of jacks for the con-
necting pegs of telephone exchanges, in which firstly the separate parts of the
instrument are secured together in such a manner in a vulcanite or ebonite base,
that the ends of the several springs, provided with bends and holes, are entirely
surrounded by the vulcanite, and secondly the securing of the jacks to the jack
strips is effected by a spring fastening in such manner as to allow of their ready
removal when required.
By the improved construction any lateral connection between the separate jacks
is rendered unnecessary as they possess individually sufficient rigidity to prevent
any lateral bending by the pull of the peg-cords connected thereto. And even
should any such bending occur, the fact that the lower ends of the springs are
entirely surrounded by the vulcanite would, effectually prevent any contact between
them.
For the above purposes the jacks are constructed as we will describe with
reference to the accompanying drawing, in which Fig. 1 shews a part sectional
front view of the jacks, Fig. 2 a cross section and Fig. 3 a top plan and Fig. 4 an
underside plan.
The jack consists of a metal tube, one end of which constitutes the socket B
by which it is fixed to the jack strip and which serves to receive the contact peg.
The other part of the tube is cut away on one side along its entire length, forming
a tongue Z to which the contact springs F are fixed with the interposition of the
insulating vulcanite block.
For this purpose the tongue Z as also the springs F have holes I, formed through
them, through which the soft caoutchouc of the block is pressed before vulcanising,
so that when the latter is vulcanised, the springs and tongue are effectually and
strongly keyed together in the block which entirely surrounds each part and
insulates it from the others. When several jacks are combined into one strip the
arangement can be such that they are either permanently secured together to form
one body, or that they are separately removable.
In the former cases all the jacks can be pressed into a single block, or each one
may have a separate block H to which is secured a metal plate by screws, screwing

page_text: into the part of the vulcanite that passes through the before mentioned holes L
of the tongue and spring; or the blocks H may be formed with a groove n on the
one side and a corresponding feather f on the opposite side, so that the feather of
the one jack fits into the groove of the other, thus keying them all together.
If the jacks are to be separately removable from the jack strip, the end of the
tube forming the socket B has a spring tongue f¹ formed in it by cutting two
narallel slits eles therein and the end of the tongue is bent outward at an angle.
The hole of the jack strip has a bevilled notch a formed in its upper edge into
which the bent end of the spring tongue of the jack springs when inserted whereby
it is held securely in position when the peg is inserted. the jack can however be
readily removed by inserting into it a rod shaped key S Fig. 5 of smaller diameter
and cut away on one side by which the jack can be pushed out of the strip hole,
as the tongue f¹ will then yield in springing inwards out of the notch a.
For facilitating the introduction of the jack from below a similar bevilled notch b
is formed in the lower edge of the strip hole, through which the tongue can enter.
The jack can then be removed from behind, as the block H thereof can be slid
out of engagement with the groove and feather of the contiguous blocks, as above
described.
Figs. 6. 7 and 8 shew respectively a front view, vertical section and cross section
of a modification in which the insulating block H is provided with a projection
upon which the jack tongue and spring are fitted with their holes, with the inter-
position of suitable insulating discs these parts being secured in that position by
screws.
On the tongue % of the jack are fixed, by screwing. the springs F with the
interposed insulating discs J, these parts being threaded with their holes on the
projection H of the block H.
The sectional form is such that it prevents any lateral displacements of the
several parts, and at the same time affords room for two fixing screws. which pre-
vent any longitudinal shifting of the caoutchouc block on the jack. The block H
is so formed on that side where the screws are inserted as to fit with a rounded
hollow on to the rounded back face of the contiguous jack tongue, as shewn_at
Fig. 8, whereby the jacks are enabled to be brought very close together. The
advantage is gained in this construction that the rounded feather that locks into
the contiguous block H is constituted directly by the cylindrical surface of the
tongue 7 of the jack socket itself and not by an interposed part of the block H
as in the previous arrangement.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
1. A jack for multiple telephone systems, wherein the several metal parts are
secured together by providing them with holes through which the mass of the
surrounding insulating caoutchouc block is pressed, so that the parts are effectually
secured without the use of screws, the insulating blocks being provided with
grooves and feathers for keving them together substantially as described with
reference to Figs. 1 to 4 of the drawings.
2. In the construction of jacks referred to in the first claim, securing the jacks
in the jack strips by forming on the socket of the jack a spring tongue f¹ so arranged
that on the insertion of the jack peg the jack will be effectually held in position by
the spring tongue while when a key of smaller size than the peg such as S is intro-
duced, the jack can he readily pushed out of the strip, substantially as described.
3. The modified arrangement of jacks such as are referred to in the first claim
wherein the metal parts of the jack are fitted with their holes over a projection of
the insulating block, with the interposition of insulating discs, and are secured
in that position by screws, substantially as described with reference to Figs. 6, 7
and 8 of the drawings.
4. In a jack constructed as set forth in the third claim, arranging the rounded

page_text: back surface of the jack tongue to constitute the key or tongue fitting into the cor-
responding hollow of the insulating block of the contiguous jack, substantially as
described.
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100%
ABEL & IMRAY,
Agents for the Applicants.