Improvements in Telephone Switch Operating Mechanism.
Year: 1893

page_text: Date of Application, 19th Sept., 1893--Accepted, 28th Oct., 1893
COMPLETE SPECIFICATION.
Improvements in Telephone Switch Operating Mechanism.
I, THOMAS WOOD NESS of No. 749 Craig Street, in the City of Montreal,
in the District of Montreal and Province of Quebec, Dominion of Canada,
Electrician, 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 :----
This invention relates to the switch mechanism of warehouse or local telephone
systems in which each department or office has a segmental key-board with an
independent axially mounted spring key or switch bar adapted to be shifted by hand
from a normal resting point or line terminal segment to any of the other line
terminal segments or points of the key-board to secure the necessary line connection
with other departments or offices of the system, the object of the invention being to
provide an automatic return for such key or switch after the user has finished
talking so as to avoid all chances of the key not being returned, as is required by
the nature of such systems.
For full comprehension however of the invention, reference must be had to the
annexed drawings forming a part of this Specification in which like symbols indicate
corresponding parts. and wherein
Figure 1 is a front view of the usual box or casing carrying the key-board.
telephone hook wire terminals, hell &c., all of which with the exception of the key
board, the key and telephone hook are not shown since they form no part of my
invention; Fig. 2 is an interior view of such box or casing and Fig. 3 a vertical
section thereof on the linear Fig. 2.
The key-board is as usual composed of the several line terminals 1, 2, 3 &c., and
calling or battery circuit bar a. B is the switch key mounted on a rotatable axis
or spindle e which passes through the usual door of the box A and has a bearing
therein as well as in an arm d carried on the inside of such door.
The key or switch bar B is rigidly secured to the outside end of such spindle and
in being moved to its different points from the normal position in which it is shown
in Fig. 1 and where it fits into a spring, or yielding check X serves to rotate such
spindle and this being the case I have found that by connecting with such spindle
a controllable yielding resistance device having a permanent tendency to rotate such
spindle in the direction required to return the key to its normal position, I am able
through a detent and releasing device such as the usual telephone hook mechanism
to control such yielding resistance device and consequently secure an automatic
return of the key to its normal position through such medium.
The yielding resistance used is preferably in the form of a spiral spring C
encircling the spindle c and having one end attached thereto while the other end is
screwed to the arm d, and the controlling mechanism for such spring comprises in
addition to the telephone hook mechanism when such is used preferably the
following parts:-
A. ratchet wheel D, mounted rigidly on the spindle c, a pivotted pawl-lever E,
normally engaging such ratchet and provided with a projection e, whereby a yielding
pressure dog, pivotted in the forked end of the inner arm of the pivotted
telephone hook or lever F and thrown normally outward by a spring 1, can operate
such pawl lever E to disengage it from the ratchet D whenever the outer end of
such hook is depressed as by hanging the telephone T upon it; the pawl-lever, and
the yielding pressure dog y acting in conjunction with the telephone hook as detent
mechanism to control the parts which act to return the key to its normal position
after having been moved to, say, the point 6, shown by dotted lines in Fig. 1.
The outer end of the telephone hook F is automatically elevated in the usual
way by a spring such as F¹.

page_text: As an auxiliary or safeguard against the detent mechanism accidentally locking
the yielding resistance or parts acting to return the key before this latter is returned
to its normal position, I use a spring detent m secured to the door. of the box at one
end and carrying on its free end a projection n adapted when the pawl lever E is
disengaged from the ratchet D to be projected in front of and so retain it until a
lateral projection p on the side of the ratchet wheel D comes in contact with and
presses the spring m backward thus freeing the pawl in order that it may re-engage
the ratchet.
The operation of the device is as follows:-
:-
The normal position of the parts is shown in full lines Fig. 2 the telephone being
hung on and depressing the hook F so that the upper side of the dog y is by the
elevation of the inner arm of such hook located above the projection e on the pawl
lever E and the free end of this latter thrown into engagement with the ratchet
wheel D by the spring e or other arrangement by force of gravity if desired.
The switch key is free to be moved to the direction of any of the terminal
points 1, 2, 3 &c., and the yielding pawl lever E being normally engaged with the
ratchet wheel D while allowing of its rotation in either direction will hold the key,
through such ratchet wheel, at whatever point it is moved to until the pawl lever is
disengaged from the ratchet.
After the key is moved to the required point for connection with another
department the telephone is naturally taken off the hook and the inner arm of this
latter is consequently drawn down by the spring and passing the projection e on
the pawl lever the dog yields or is forced backward against the pressure of the
spring which acts to throw it forward again, as soon as the projection e is passed,
to the position shown by dotted lines in Fig. 2 and with its upper side g¹ beneath
the projection e so that when the telephone is replaced on the hook and the inner
arm thereof elevated the dog will bear against the projection and as the pressure
will be in line with or against the pivotted point of the dog and not against the
spring the pawl lever will be forced out of engagement with the ratchet wheel D
and the yielding resistance parts being freed will return the switch key to its
normal position.
By means of this automatic return of the switch key all chance of its being left
in a position which would interfere to some extent with the working of the system
is avoided.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The combination of the key board of a warehouse or local telephone system
an independent switch key therefor, and the telephone hook mechanism, with
means whereby said independent switch key is, after being moved to the several
points of such key board by hand, automatically returned to its normal position.
2. In combination with the key board of a warehouse or local telephone system,
having an independent switch key adapted to be moved to the several points of
such key board by hand, a detent, a releasing device and automatic return for such
switch key.
3. In combination with the key-board of a warehouse or local telephone system,
the independent switch key thereof, and the telephone hook mechanism, an automatic
return for such key or switch under the control of said telephone hook mechanism,
as set forth.
4. In combination with the key-board of a warehouse or local telephone system,
the independent switch key thereof and the telephone book mechanism, a con-
trollable yielding resistance device acting to return said key or switch to its normal
position after effecting a line connection, as set forth.
5. In combination with the key-board of a warehouse or local telephone system,
the independent switch key thereof and the telephone hook mechanism, a yielding
resistance device tending to return said key to its normal position after effecting

page_text: a line connection, and detent mechanism acting to control such yielding resistance
device, as set forth.
6. In combination with a key-board, of a warehouse or local telephone system,
the switch key B; the rotatable axis or spindle c thereof and suitable bearings
for same; the telephone hook mechanism; the spring C; ratchet wheel D; a
yielding pressure pawl lever engaging said ratchet wheel, and a yielding pressure
contact dog g on the inner end of said telephone hook, all substantially as and for
the purposes set forth.
7. In combination with the key-board of a warehouse or local telephone system,
the switch key B; the rotatable axis or spindle c thereof and suitable bearings for
same; the telephone hook mechanism; the spring C; ratchet wheel Ď; a
yielding pressure pawl lever engaging said ratchet wheel, and a yielding pressure
contact dog on the inner end of said telephone hook, detent m and means on
said ratchet wheel for operating same, all substantially as and for the purposes
set forth.
Dated this 10th 1
1000
T. W. NESS,
By L. W., per W. C.