Improvements in Telephone Call Apparatus.
Year: 1888

page_text: Date of Application, 31st Dec., 1888
Complete Specification Left, 30th Sept., 1889-Accepted, 2nd Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in Telephone Call Apparatus.
I THOMAS JOHN HANDFORD of 50 Bedford Row in the County of Middlesex
Patent Agent do hereby declare the nature of this invention which has been
communicated to me by the Western Electric Company of Chicago in the State of
Illinois, United States of America, to be as follows:-
This Invention relates chiefly to tho mode of connecting the driven wheel to the
armature shaft, and also to the arrangement of the switches pertaining to the
telephone hook.
In carrying out this Invention, the driven wheel is connected to the armature shaft
through the intervention of springs or elastic material, which will compensate the
inequalities of motion and render the action of a noiseless nature.
It is found convenient to employ two studs or projections, one on the driven wheel
and the other on the armature shaft, or on an attachment thereto, between which two
studs or projections the springs or elastic materials are placed. The springs which are
employed are preferably helical springs, but springs of any other suitable description,
or equivalent clastic material, may be employed. Similar arrangements may also be
applied to the driving instead of or in addition to the driven wheel.
The springs of the switch arm are arranged in such a manner that the force of one
set is in opposition to that of the other. The switch arm is provided with insulating
studs or projections opposite the corresponding springs. By this arrangement of the
switch, good electrical contacts and actual electrical separation, according to the
position of the switch arm, are ensured. The insulating studs or projections which
effect the electrical separation, afford a modium by which the mechanical force of the
spring or set of springs out of circuit, is utilized for producing the efficient electrical
contact of the spring or set of springs which is in circuit.
In lieu of the insulating studs or projections being placed on the switch arm, they
may be placed on the springs themselves.
D:1:1:1
1000
THOS. J. HANDFORD,
50, Bedford Row, London, W.C.
COMPLETE SPECIFICATION.
Improvements in Telephone Call Apparatus.
I, THOMAS JOHN HANDFORD, of 50 Bedford Row, in the County of Middlesex,
Patent Agent, (a communication to me from abroad by the Western Electric
Company, of Chicago, in the State of Illinois, United States of America) do hereby
declare the nature of this invention and in what manner the saine is to be performed
to be particularly described and ascertained in and by the following statement:-
In telephone call apparatus in which an electric current for ringing the call bell is
generated by revolving the armature of a small electric generator, a yielding spring
connection is according to this Invention provided between the armature shaft and a
pinion by which it is driven so that the shaft may be driven by a gear wheel which
meshes with the pinion steadily and noiselessly and preferably in either direction; and
secondly the telephone switch lever upon which the telephone is to be hung when out
of use is provided with two bearing surfaces on its under side one of insulating
material and the other of metal and a spring is caused to press upwards against these
projections. The spring and bearing surfaces are also so disposed that when the
telephone is hung upon the hook the spring bears upon the metal bearing surface and
Pine Rd 1

page_text: then completes the bell circuit and when the telephone is off the hook the spring bears
upon the surface of insulating material and the bell is then out of circuit.
A second spring is also provided and is set to press alternately against two other
similar bearing surfaces on the lever. in opposition to the underlying spring and
these serve to complete the telephone circuit when the telephone is off the hook and
to break it when the telephone is on the hook.
My invention as thus described I have shown in the accompanying drawings
embodied in a telephone call box.
Figure 1 Sheet 1 is a front view of a magneto bell or box, a portion of the door
being broken away and 'the telephone being removed from the hook, the hook or switch
lever being shown in its elevated position.
Figure 2 is a front view of the driving wheel in engagement with the pinion.
Figure 3 is a side view of the driving wheel in engagement with the pinion upon
the shaft of the revolving armature.
Figure 4 is an enlarged detailed view of the end of the shaft with the pinion in the
form of a cup mounted thereon the cap and the screw for holding the cap to the end
of the shaft being removed.
Figure 5 is an inside view of the cap.
Figure 6 is a detailed view showing the springs pressing against the shorter arm of
the switch lever as seen from section line x-x of Figure 1.
Figure 7 is a plan view of the switch as seen from section line y-y of Figure 1.
Figure 8 is a rear view of the same as seen from section line - of Figure 7.
Referring now to Figures 1, 2, 3, 4, 5 X X are fixed permanent magnets and Z
is the revolving, armature of the electric generator. is a pinion loose on the
armature shaft and a a driving wheel gearing therewith and turned in the usual
manner by a crank.
The pinion b is in the form of a cup so that when placed upon the end of the shaft
an annular space is formed in the pinion about the shaft. The stop d projects from
this cup so as to come within the annular space about the end of the shaft c. On
opposite sides of this stop d and within the annular space I insert stiff coiled
springs ef. It is these springs which furnish the yielding connection between the
pinion and the shaft.
As shown more clearly in Figure 2 the cap is secured to the shaft by the screw h
inserted through the central opening provided in the cap into the end of the shaft
which is tapped out to receive the screw. The stud provided upon the end of the
shaft projects into the hole provided in the cap and thus the cap is held rigidly upon
the end of the shaft. A stud m provided upon the cap is brought between the
springs eat n when the cap is secured to the shaft.
When the crank is turned to drive the wheel a and pinion b the stud d is forced
against spring e or spring f' according to the direction in which the crank is turned
and the spring thus compressed is forced against the stud m which is rigid with the
shaft. The shaft is thus turned with the pinion, no matter how irregular may he
the pressure upon the crank or how variable may be the attraction of the field
upon the revolving armature the teeth of the pinion wheel and driving wheel cannot
rattle. The amount that the pinion may be moved upon the shaft is determined by 4
the tension of the springs ef. 1 preferably provide strong steel springs.
Referring now to Figures 1, 6, 7 and the line wire may be considered as
permanently connected with binding post . The ground branch containing the hell
and generator may be considered as connected with contact spring o while the branch
containing the telephone may be considered as connected with spring p.
spring 9 may be considered as the local contact.
The
I have not deemed it necessary to show the circuits of the telephone call box in
detail since they are well understood.
The pivotted lever or hook is provided with a lug and a strip of insulation
upon its shorter arm. On the under side of the said lever I provide insulation s and 5
contact or lug s¹. The spring o bears against said insulations or contact ♪³ according

page_text: to the position of the switch lever. When the telephone is off from the switch the
switch takes the elevated position shown in Figure 1 and the spring o bears upon the
insulation s.
The tension of this spring o is sufficient to raise the switch lever when
the weight of the telephone is removed. Therefore, on the removal of the telephone
this spring o by its own tension raises the lever and changes its bearing upon the
switch from the contact to the insulating studs while at the same time the
springs are closed to the lug upon the shorter arm of the switch lever.
On hanging up the telephone the force of spring o is overcome and the lever is
brought down so that its electrical contacts closes upon said spring o while at the
same time the springs p q are separated from lug and closed upon insulation.
As the switch is moved back and forth the contact points have a sliding motion
upon the surface of the springs; thus the electrical connections are kept bright
and any particles of dirt that may get between them and their springs will be
worked out.
I have shown the two springs p q adapted to press against the shorter arm of the
lever; these springs may be united in one piece if desired. For convenience of
manufacture, however, I prefer two separate pieces. Since the lover is pivotted I
have provided an electrical connection around the pivot in a well known way.
In order that the lever may be carried steadily by its pivot I attach a pivot to it
in the manner shewn at Figures 9 and 10. Hitherto the hook lever has turned upon
a support screwed into a bracket or in some equivalent way.
In the present case the pivot screws into the lever and its two ends are made to
project from its two opposite sides and to turn freely on two bearings which project
from a bracket piece fixed to the casing. One end of the pivot is made of larger
diameter than the portion which is screwed into the lever so that a shoulder is formed
which can be made to bear forcibly against the side of the lever.
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. In call apparatus in which an electric current for ringing a call bell is produced
by revolving the armature of an electric generator I claim driving the armature
through a spring connection interposed between the armature shaft and a pinion by
which the shaft is driven.
2. The combination of the armature, the pinion loose on its shaft and having an
annular recess within it, the two springs lying in this recess, the stop fast with the
pinion entering between two of the adjoining ends of these springs and a stop fast on
the shaft entering between the two other ends of the springs.
3. The construction of a telephone switch lever upon one side of which are two
bearing surfaces against one of which (a metallic one) a spring bears when the
telephone is hung upon the lever and then completes the bell circuit whilst when
the telephone is off and the lever is raised by the action of the spring the spring
bears against the other surface which is of insulating material and then breaks the
bell circuit and also forming the lever with two other similar bearing surfaces against
which a second spring (or set of springs) presses alternately in opposition to the first
mentioned spring and completes the telephone circuit when the telephone is off the
lever and breaks it when the telephone is hung onto it.
4. Securing pivots to opposite sides of a telephone switch hook lever substantially
as described with reference to Figures 9 and 10.
DL: 0011 1
1000
CARPMAEL & Co.,
Agents.