Improvements in Telephone Exchange Switch Boards.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Telephone Exchange Switch Boards.
AUGUST ECKSTEIN, Electrical Engineer, Peel Works, Adelphi, Salford, Man-
chester, and WILLIAM ARMSTRONG GUTHRIE, Electrician, Peel Works, Adelphi,
Salford, Manchester, do hereby declare the nature of this invention to be as
follows:
-:
Our invention relates to improvements in connection with telephone switch-
boards, and has for its object the simplification of the work of the operator by
a reduction in the number of motions usually necessary to perform the switching
operations for connecting and dis-connecting operator and subscribers.
By our invention we dispense with the necessity for the operator manipulating
a cam or key to speak to calling subscriber and to connect up or put in circuit
the ringing off indicator. The ordinary operations involved in attending to a
call as are now usually performed are four fold. 1st. The operator inserts answer-
ing plug into subscribers jack.
2nd. He next pulls down his cam or key to put his own instrument in circuit
to answer the call.
3rd. He then puts the connecting through plug into the called subscribers
jack
4th. He finally puts the cam or key back to its normal position to connect up
the ring off indicator.
In our improved method these several operations can be performed by two
manipulations riz.-by the insertion of the 2 plugs into the jacks, the other
necessary connections being made automatically. Another advantage our method
confers is that cams or keys being dispensed with the dimensions of the switch-
board can be reduced because no keyboard or shelf is required, and our automatic
apparatus is fixed to the plugshelf underneath.
In carrying our invention into practice, we take a bar, (preferably of metal)
pivotted at one end to a bracket, which is attached to the underside of the plug
shelf, the other end of the said bar carries an insulating piece hereinafter
described. At right angles to the bar are placed three pairs of springs, alongside
of each other, being suitably clamped, with separating and insulating material
between them so as to be insulated from one another, to a suitable non-conductive
support. The two outer springs form one pair, the inner springs a second pair,
and the two springs between these the 3rd or intermediate pair. The ends of
each of the two outer springs are bent round the ends of the adjacent springs, &
clear therefrom, so that the two inner springs forming the second pair, may in
their normal position be in contact with the said outer springs which form the
first pair, that is the right hand spring of the second pair be on the right hand
spring of the first pair, and the left hand spring of the second pair be on the
left hand spring of the first pair; the third pair of springs being in this position
clear of the others, the said normal position obtaining by virtue of one of the
plugs resting on the bar, the cord of plug going freely through a suitable hole.

page_text: therein, the cord being weighted in the usual manner, & thereby depressing the
bar. The insulating piece at the end of the bar is preferably of circular form,
or is suitably rounded and is so placed that it presses the 2nd pair of springs out-
wards when the said bar is raised, lifting them from, and breaking contact with,
the 1st pair of springs and causing them to make contact with the 3rd pair of
springs. The raising of the bar is preferably effected by a reaction spring which
comes into force when the aforesaid plug is lifted.
The outer or first pair of springs are connected up to the operators instrument
or set, the inner or second pair are connected to the plug cords, and the inter-
mediate or 3rd pair are connected with the ring off indicator.
When the operator receives a call he places the answering plug into the
calling subscribers jack, and, as the fellow plug is still resting upon the before
described bar, thereby permitting pairs of springs 1st & 2nd to be connected,
the operators set is joined up to the callers line, and the connections are from
one line of the operators set to one of the outer springs, through one of the
inner springs to one point of plug to jack, through subscribers line, subscribers
instrument & return line, the other point of plug to jack, the other outer spring
to other line of operators set, enabling the operator to ascertain the number of
subscriber wanted. He then lifts the other plug and inserts it into this sub-
scribers jack. The bar being raised by the reaction spring moves the inner pair
of springs from contact with the outer pair, cutting out the operators set, and
bringing them into contact with the intermediate pair, when the connections
are:- The subscribers are joined by the plugs & cords, thro' the jacks, and another
circuit (in parallel) is established from one side of the pair of plug cords to one
inner spring, through intermediate spring to ring off indicator, ring off indicator
to the other intermediate spring, other inner spring, & to the other side of plug
cords, so that when either of the subscribers ring off the said indicator is operated.
Dated 13th January 1899.
Improvements in Telephone Exchange Switch Boards.
We, AUGUST ECKSTEIN, Electrical Engineer, of Peel Works, Adelphi, Salford,
in the County of Lancaster, and WILLIAM ARMSTRONG GUTHRIE, of Salford, in
the County of Lancaster, Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Our invention relates to improvements in connection with telephone switch-
boards, and has for its object the simplification of the work of the operator by
a reduction in the number of motions usually necessary for connecting and dis-
connecting the operator and subscribers.
According to our invention we dispense with the necessity for the operator
manipulating a cam or key to speak to the calling subscriber, and to connect up
or put in circuit the "ringing off" indicator the operations as heretofore per-
formed are four, that is to say,
1st. The operator inserts the answering plug into the subscriber's jack.
2nd. The operator pulls down the cam or key to put his own instrument into
the circuit to answer the call.
3rd. The operator puts the connection into the circuit through a plug into
the called subscriber's jack.

page_text: 4th. The operator as a final puts the cam or key back to its normal position
so that the ring off indicator may be in circuit."
"
According to our invention these several operations may be performed by two
manipulations, viz.-by the insertion of the two plugs into the jacks, the other
necessary connections being made automatically. A further advantage is in, that
since cams and keys are dispensed with, the dimensions of the switchboard may
be reduced, because no key board or shelf is required, and the automatic contact
apparatus is fixed to the plug shelf.
At
In order that our invention may be clearly understood, we have appended the
accompanying two sheets of drawings in which Figure 1, Sheet 1--is an elevation
of the device in section, and Figure 2 upon the same sheet a plan view of of
the automatic contacts appertaining to the same Figure 3 Sheet 2 is a diagram-
matic view showing the various contacts operated by the two plugs. Similar
letters of reference indicate corresponding parts throughout the several views.
In carrying our invention into effect we use a bar A Figure 1, preferably of
metal pivotted at a to a bracket B attached to the inner side of the plug shelf
or board C. The bar A carries a trumpet shaped hollow boss T which receives
the insulated end of the plug P, which is drawn in by the counterweight W when
released from the proper plug contact at 6 in the board according to the ordinary
usage of such boards." At the end of the pivotted bar A is an insulating block c
shown more particularly by the plan view Figure 2, which operates a set of
spring contacts, and is shown in the position of depression by the plug P.
right angles to the bar A, and enclosing the insulating contact block e are
arranged three pairs of contact springs, de f, del f¹ respectively. These are
clamped together with an intervening insulating medium: the outer springs d d'
forming one pair, the inner springs e el a second pair, and the inner, or inter-
The
mediate pair f f are in immediate contact with the insulating block c.
ends of dare bent round and insulated from the intermediate springs so that
the inner springs forming the pair f f may be in electrical contact with the
outer springs dd in the normal position, ie, when the end of the plug P is
resting on the bar A by the tension of the flexible double conductor k, the ends
of being bent inwards for that purpose. The springs e e¹ are clear of contact
in this position. The insulating block c is shaped so as to press f f¹ outwards
when the bar A is released and returned to its free position by the tension of the
spring S.
Referring now to the diagram Figure 3 Sheet 2, which is similarly lettered.
When the bar A is raised the springs f f are thrown out of contact with a d
which occurs when the handle of the plug P is drawn into the orifice T by the
weight W, and when released from its contact at b; and accordingly the
springs ff and e el are put into contact by the upward movement and shape of c.
The outer contact springs d d are connected to the operator's set or instrument,
the inner set f f to the double flexible conductor connecting the two plugs P P¹
ande e are connected to the indicator or ring off" arrangement.
When the operator receives a call he places the answering plug P or P¹ into
the calling subscriber's jack, and as the other plug P or P¹ as the case may be,
is still resting upon the trumpet T on the bar A, the springs d d¹ and ƒ f¹ are
connected, and the operators set is then connected to the caller's line, and thus
the outer connections are from the line from the operators set to the jack connec-
tion through springs f f¹ and d d through the point of the plug P or P¹, thence
through subscribers line and instrument and return line and the other point 1
of plug Por P1, (the jacks not being shown since any kind of jack board with
double contact plugs may be used) to the corresponding spring contact f fl of
the other plug P or P¹ insertion, to the opposite outer spring d d' of the opposite
set, or insertion P or P¹. The operator is then enabled to ascertain the sub-
scriber's number that is called, and then lifts the other plug P, or P' as the case
may be against the weight W, and inserts it into its socket in the switch board
jack corresponding to the subscribers number. The bar A being raised by the

page_text: spring S removes the springs f f¹ from d¹ thus cutting out the operators set,
and making contact with e el when the connections are as follows, that is to say:--
The two subscribers are joined by the plugs P P1 and the jacks as herein before
described, with the connecting cord k and another circuit is established (in
parallel) from one side of the pair of plugs P P₁ through the double conducting
Hexible cord to f f¹ and e e¹ to the "ring off" indicator, and to the spring e e¹ of
the other plug P P as the case may be, and its spring f f through the con-
ductor k, so that when either of the subscribers in circuit rings off, the indicator
is operated.
We have in Figures 1 and 2 and in the diagram Figure 3 shown only one
plug contact, it being obvious that it may be multiplied upon the same basis.
Having now particularly described and ascertained the nature of our said
invention we declare that what we claim is:-
First. In telephone exchange switchboards the construction and arrangement
of plugs and jacks, and corresponding contacts, to enable a certain circuit to be
established by two movements substantially as and for the purposes as herein
described.
Second. In telephone exchange switchboards the use and construction of a
pivotted lever A depressed by a plug P and operating spring contacts d de el ffl
by an insulating block c substantially as and for the purposes as herein described
and shown by the appended drawings.
Third. The method of and means for arranging the several contacts d, e, f, by
the impact of c actuated by the bar A by the introduction or withdrawal of the
plugs P or P¹ against the tension of the spring $, substantially as herein described
and shown by the appended drawings.
Dated this 12th day of October 1899.
FREDK. WALKER,
73, St. Stephen's Road, Upton Park, London, E.,
Agent for the Applicants.