No.

767,303, PATENTED AUG, 9, 1904,

W
Witnesses: Avalendor
2 23/24 Horace G/Martin,
1246-2-1-(2--- 4/6(2,... f6-7fe/ Attys.
 No. 767,303. Patented August 9, 1904.

UNITED STATES PATENT OFFICE.

SPECIFICATION forming part of Letters Patent No. 767,303, dated August 9, 1904.
Application filed May 7, 1904, Serial No. 206,795, (No model.)
To all, Luhon, it may concern: movement of said key, and thrown out of Op
Beit known that I, HoRACE G.MARTIN, a citi eration by the interruption of such current.
Zen of the United States, residing at Brooklyn, I have found that this plan is in many respects
in the county of Kings and State of New York, the most reliable and effective; but I have
have invented certain new and useful Im also devised another way of carrying out the 55
provements in Telegraphic Transmitters, of invention in which a circuit-controller hav
which the following is a specification, refer ing a predetermined period of its own is di
ence being had to the drawings accompanying rectly controlled by the movement of the
and forming a part of the same. key-that is to say, is mechanically released
O In a patent granted to me on June 30, 1903, or set in operation and restrained or pre
No. 732,648, I have shown and described a vented from its normal operation of sending
novel form of telegraphic transmitter the es successive short impulses over the line by the
sential features of which are a key, a vibra disengagement and engagement there with of
tor, and suitable electrical connections by the key itself. Such a device may be made
means of which a movement of the key in one more cheaply and is more simple in construc
direction closes the circuit continuously to tion; but for many purposes it is a very de
line, while a movement of the key in the op sirable instrument and secures the main ad
posite direction closes the line-circuit through vantages of my novel System. This form of
the vibrator, which operates to send a suc transmitter, which I designate as 'semi-auto
cession of impulses continuing as long as the matic,” is exemplified in any combination of 7o
lkey remains in such position. a key which by a movement in one direction
Briefly stated, the object of the invention is sends an impulse to line proportional in length
to enable operators to send Morse signals by to the duration of the contact thus effected
means of a key, but by a very greatly-reduced and an automatic circuit breaker or control
25 number of movements of the latter, and thus ler of the general nature of a vibrator or 75
to provide a simple and effective method of buzzer” which operates to make and break
sending that avoids the intense nervous strain the circuit at a substantially uniform but com
involved in the operation of the ordinary paratively rapid rate and which is normally
Morse key in rapid work. Inasmuch as the restrained from operation by the key, but
nature, object, and advantages of this system released by the movement of the latter in a
are dwelt upon at length in my patent re direction opposite to that utilized for sending
ferred to, it is unnecessary to repeat them dashes. Obviously many forms of vibrator,
herein, it being Sufficient now to point out mechanical and electrical, may be utilized for
that the first of the above-described move this purpose; but in illustration of the gen
35 ments of the key which effect prolonged clo eral principle I have shown in the accompany
sures of the line is used to send the dashes, ing drawings a device in the nature of a pen
while the movement in the opposite direction, dulum which by the engagement of the key
which closes the line through a vibrator, sends is normally held at such a point in its path of
the dots of the Morse code. The length of swing that when released by the withdrawal
the spaces and dashes and the number of the of the key it will be free to vibrate. This
dots are thus under the direct control of the vibrator is utilized to make and break a cir
operator, while the length of the dots and cuit and send dots over the line, the number
their rapidity of succession is determined by sent in succession being determined by the
the adjustment of the period of vibration of length of time the key is held out of engage
45. the vibrator. In the several forms of instru ment with the pendulum. In connection with 95
ments shown in my said patent in illustra the pendulum I may use an electromagnet the
tion of the principle of the invention the vi circuit of which is controlled by the Oscilla
brator-magnet is in a circuit controlled by tions of the pendulum itself; but this is not
the key, is set in operation by the current essential in any case in which, as with a pen
5O which is caused to flowin its circuit by a given dulum released at some point to either side of OO
 2 767,303

the center of Oscillation, the device possesses the pendulum-lever is of conducting material 65
in itself the capability of movement which or the spring 14 not insulated from it.
may be utilized to periodically make and break In Fig. 2 substantially the elements are
a circuit. shown, and the operation is not materially
Referring now to the drawings, Figure 1 is affected by the modifications introduced. The
a plan view of the instrument, showing the cir key-lever in this figure is shown as seated on
cuit connections. Figs. 2 and 3 are similar two spiral springs 16', inserted in recesses in
views of modifications of the same, and Fig. the post 2 on opposite sides of the fulcrum of
4 is a detail showing the key-lever in section. the key. These springs take the place of the
IC) As a convenient, form of key I use a plate flat spring 3 of Fig. 1. I have shown in this
or bar 1, held against the flat surface of an figure also an electromagnet 17 in the circuit 75
arm or post 2 by means of a flat spring 3 and of the pendulum and stop 15. When the pen
a spiral spring 4, which surrounds a stud 5. dulum has been released by the key and closes
The key bar or lever 1 contains a slot through the circuit between the spring 14 and stop 15,
15 which the stud 5 passes, and the compression the magnet 17 is energized and exerts an at
of the spring 4 is regulated by a screw-nut 6 traction for the pendulum, which ceases the
on the end of the stud. By this means the instant the circuit is broken by the separa
key-lever is held in its central or normal po tion of the contact-points. This imparts a
sition, but may be readily moved from side to more positive swing to the pendulum and
side about the point 24 as a fulcrum. A hard maintains the amplitude of its vibrations. A
rubber plate 7 and a head 8 are secured to the short circuit around the magnet, maintaining
key-lever and are of any form which makes a resistance 18 and switch 19, may be used to
it convenient for the operator to grasp them cut the magnet out when so desired.
between the thumb and fingers. The key The arrangement shown in Fig. 3 differs
lever 1 is bent at its free end at right angles from that of Fig. 2 only in having a local cir
and carries a set-screw 9. The end of this cuit 20 for energizing the magnet 17. This
Screw lies in the path of a vibrator which in circuit contains a local battery 21 and is
this case consists of a rod or bar 10, Support made and broken by an additional spring 22
ed by a flat spring-plate 11 on a stud 12. A on the pendulum and a stop 23. This arrange
3O weight or bob 13 is adjustably attached to the ment takes the magnet 17 out of the main or
bar 10 to vary its period of vibration. In its sending circuit. . 95
normal position the key-lever holds the pen From the above description of the con
dulum-bar to one side of its normal center of struction and mode of operation of the form
Oscillation, with the spring 11 under light of transmitter to which my present applica
35 tension. If the key be shifted so as to suddenly tion relates it will be obvious that the vi
withdraw the set-screw from engagement brator and the specific means for engaging IOO
with the pendulum, the latter will at once and releasing the same by the key may both
start vibrating and will continue in motion be varied in many details without departure
for Some time. This movement is taken ad from the invention.
4C) Vantage of to make and break either of the What I claim is
line or a local circuit by attaching to the bar 1. In a telegraphic transmitter, the combi
a light contact-spring 14, which touches a con nation with a circuit - controller capable of
tact-stop 15 when the bar Swings over suffi making and breaking a circuit at a uniform
ciently to that side. The circuit connections rate, of a key normally engaging said con
45 to the bar 10, stop 15, and key-lever 1 are troller and preventing it from operating, and
made in any suitable and well-known way, so a contact for said key, the key being capable IO
that when the key is shifted by the operator of two movements from its normal position,
to the right the vibrator will send dots over one of which withdraws it from engagement
the line, but when the key is turned to the left with the controller, while the other brings it
it will come in contact with a stop 16 and send into engagement with its contact, as set forth.
a prolonged impulse to line. A convenient 2. In a telegraphic transmitter, the combi I 15
arrangement of circuits for this purpose is nation with an automatic circuit-controller
shown in Fig. 1, in which 25 is a wire leading capable of making and breaking a circuit at
from a battery 26, and 27 is the line-wire. a uniform rate, of a key normally engaging
55 The wire 25 is connected to the stop 15 and said controller and preventing it from oper
also to the key-lever, while the line-wire is ating, means for holding said key in its nor
connected to stop 16 and also to the pendulum mal position of engagement with the control
lever 10. By this means the battery-currents ler, and a contact-stop for said key, the key
will be sent to the line from either the stop being capable of movement in opposite direc
15 or the key-lever 1, according as contact is tions from its normal position, by One of .
made between stop 15 and spring 14 or be which it releases the controller and by the I 25
tween the key-lever and stop 16. The screw other of which it engages the contact-stop, as
stop 9, carried by the lever 1, is of insulating set forth.
material or insulated from the lever in case 3. In a telegraphic transmitter, the combi
 767,303 8

nation with an automatic vibrating circuit- whereby the latter is permitted to intermit
controller having a defined period of oscilla- tently make and break the circuit, and by the Io
tion, of a key normally engaging the control- other of which it engages with the contact
ler, and preventing it from vibrating, and a stop, as and for the purposes set forth.
5 contact-stop for said key, the key being capa- HORACE G. MARTIN.
ble of movement in opposite directions from Witnesses:
its normal position, by one of which it is with- M. LAWSON DYER,
drawn from engagement with the controller, S. S. DUNHAM.