Improvements in and connected with Keys or Switches for Multiple Switchboards.
Year: 1898

page_text: Date of Application, 7th Apr., 1898
Complete Specification Left, 13th Dec., 1893-Accepted, 1st Apr.,
1899
[Communicated from abroad by ACTIEN-GESELLSCHAFT MIX & GENEST, Electrical
Engineers, of 67, Bulow Strasse, Berlin, W., in the German Empire.]
Improvements in and connected with Keys or Switches for Multiple
Switchboards.
Street,
I. HERMANN OPPENHEIMER, Electrical Engineer, of 55. Redcross
Barbican, London, E.C., do hereby declare the nature of this invention to be
as follows:-
The switches hitherto used in multiple switchboards for telephone exchanges,
have more or less been subject to the disadvantage of imperfect contact, and of
being of a size incommensurately large to their purpose.
In the tracing enclosed herewith, I show a switch which fulfils the requirements
of a perfect contact combined with condensed size. Fig. 1 is a side view, Fig. 2
bottom view, and Fig. 4 is back view, while Fig. 3 shows an alternative arrange-
ment of the bottom view.
The switch consists principally of a frame G, the 6 contact springs f¹, f², ƒ³, and
the switch lever II, the latter being pivotted to the frame, carrying at its lower
end the ball K or K¹; which rests between the contact springs, and is insulated
therefrom, or which is made of insulating material as in Fig. 3.
All contact springs are fixed to the outer side of the head pieces A¹, A2, A3,
and A. Four of the contact springs however, f¹, and f, are bent backwards
between the side walls of the frame in such a manner that always two are acting
against each other, as shown by dotted lines in Fig. 3. In consequence of this
arrangement, the springs f¹, and f, are in intimate contact with each other, thus
forming direct contact during the time the lever H is at rest, or normal.
This arrangement further allows to shorten the lever, and make it more suitable
for its purpose. The springs f¹, which encircle the ball K or K¹ respectively of
the lever, are preferably so shaped as to allow the lever H to take 2 or 3 different
positions always being retained in the various respective positions by such springs,
i.e. a normal position when in centre, and a side position as shown in Fig. 2, or a
normal position, and 2 side positions as shown in Fig. 3.
For such purpose the springs f¹, of Fig. 2. are provided on one side with wedge-
shaped insulating pieces e. As soon as the ball K of the lever is pushed between
the straight surface of the 2 insulating pieces, the contact is established between
springs fl. and f, which will last as long as the ball remains between the straight
surface of the insulating piece.
In order to re-establish contact between springs f¹, and f2, a slight push of
the lever to the left is sufficient to cause the ball to slide down the incline of
the wedge-shaped insulating piece. thus bringing back spring f' to its normal
position by which contact is established between f¹, and f, and whereby the lever
regains its normal position. In this- normal or rest position the lever.is retained
h the springs fl

page_text: The construction as shown in Fig. 3 however, shows the springs f¹, having
2 indents n¹ & ne facing the other spring f. By this means 2 curved surfaces are
created between which the ball K¹ made of insulating material, is moving.
If the lever is moved either to the right or to the left, two different switching
arrangements may be obtained, and the re-establishment of the normal: position is
as in the former case, also here done automatically.
In order to re-establish a contact between spring f¹, and f³, an insulating piece h
is provided, which gives a firm support to the contact springs.
Improvements in and connected with Keys.or Switches for Multiple
Switchboards.
I, HERMANN OPPENHEIMER, Electrical Engineer, of 55, Redcross Street,
Barbican, in the City of London (communication from abroad from Actien-Gesell-
schaft Mix & Genest, of Bulow Strasse, 67, Berlin, W., in the Empire of Germany),
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:
·
The switches hitherto used in multiple switchboards for telephone exchanges,
have more or less been subject to the disadvantage of imperfect contact, and of
being of a size incommensurately large to their purpose.
In the drawing filed with my Provisional Specification, I show a switch which
fulfils the requirements of a perfect contact combined with condensed size. Fig. 1
is a side view, Fig. 2 a bottom view, and Fig. 4 is a back view, while Fig. 3
shows an alternative arrangement of the bottom view.
The switch consists principally of a frame G, the G contact springs f¹‚ f², ƒ³, and
the switch lever H, the latter being pivotted to the frame, carrying at its lower
end the ball Kor K¹, which rests between the contact springs, and is insulated
therefrom, or which is made of insulating material as in Fig. 3.
All contact springs are fixed to the outer side of the head pieces a¹, a², a³, and at.
Four of the contact springs, however, f¹, and f³, are bent backwards
between the side walls of the frame in such a manner that always two are acting
against each other, as shown in Fig. 3. In consequence of this
arrangement, the springs f', and f2, are in intimate contact with each other, thus
forming direct contact during the time the lever H is at rest or normal.
This arrangement further allows to shorten the lever and make it more suitable
for its purpose. The springs f', which encircle the ball K or K', respectively of
the lever are preferably so shaped as to allow the lever H to take 2 or 3 different
positions, always being retained in the various respective positions by such springs,
i.e. a normal position when in centre as shown in Fig. 3, or a normal position and
2 side positions as shown in Fig. 3, by K', n¹, and n².
For such purpose the springs fi, of Fig. 2 are provided on one side with wedge-
shaped insulating pieces e. As soon as the ball K of the lever is pushed between
the straight surface of the 2 insulating pieces, the contact is established between
springs f, and f, which will last as long as the ball remains between the straight
surface of the insulating piece.
In order to re-establish contact between springs f¹, and f2, a slight push of
the lever to the left is sufficient to cause the ball to slide down the incline of
the wedge-shaped insulating piece, thus bringing back spring f¹, to its normal

page_text: position by which contact is established between f', and fa, and whereby the lever
regains its normal position. In this normal or rest position the lever is retained
by the springs f¹.
The construction as shown in Fig. 3 however, shows the springs f¹, having
2 indents N facing the other spring f. By this means two curved surfaces are
created, so that the movement of the lever either to the left or to the right, will
push the ball K', made of insulating material, into these indents, thus causing
the switching-off in either direction. The re-establishing of the normal position
is, as in the former case, also here done automatically.
In order to re-establish a contact between spring f', and f², an insulating piece h
is provided, which gives a firm support to the contact springs.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. A switch, the contact springs of which are fixed on the opposite external
sides of the frame, bent into the inside of the latter, substantially as and for the
purpose specified.
2. A switch with contact springs bent into the inside of the frame-work in
which case two of such contact springs have each other a slanting insulating
piece, or have each two curves, substantially as and for the purpose specified.
3. A switch with contact springs bent into the inside of the frame, in which
between two such contact springs, an insulating piece is arranged, substantially
as and for the purpose specified.
Dated this 2nd day of December 1898.