Improvements in Telegraph-keys.
Year: 1890

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COMPLETE SPECIFICATION.
Improvements in Telegraph-keys.
I, ARTHUR FOSTER PURDY, of Lawrence, in the County of Santa Clara and State
of California, United States of America, a Managing Telegraph Operator for the
Western Union Telegraph Co., and Agent to the Southern Pacific R. R. Co., do
hereby declare the nature of my invention for IMPROVEMENTS IN TELEGRAPH-KEYS,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates to telegraph-keys; and it consists in the novel constructions
hereinafter fully described, and specifically pointed out in the claims. The general
object of my invention is to provide a simple and effective device of this class.
Particular objects and advantages will be hereinafter set forth.
Referring to the accompanying drawings for a more complete explanation of my
invention,
Figure 1 is a perspective view of my key.
Figure 2 is a detail showing the conical contacts in section.
A is the bed plate or frame of the key, having extending downwardly from it the
bolts a, provided with washers and thumb-nuts a', whereby the key is adapted to be
secured to the table.
B is the lever of the key, having at its outer end the usual button b. This lever is
mounted as follows: Rising from the frame A are standards C, in which is journaled
the pivot-pin of the lever. On each edge of these standards is secured in any
suitable manner, as by small rivets, pins, screws or by soldering, a steel plate D, which
projects inwardly far enough beyond the inner surface of the standards to come up
closely to the sides of the lever, and thereby form for it guides, which firmly hold the
lever, and, while permitting its free up-and-down movement, avoid and prevent any
lateral play. The inner surfaces of the standards do not come up close to the lever,
so that there is only a small frictional surface due to the guides. These guides, being
of steel, do not wear, but will hold the lever firmly in its position, as described.
In the rear arm of the bed-plate A is mounted the spring-adjusting screw E, the
lower end of which is in contact or connection with the adjusting-spring F, the lower
end of said spring being properly seated in the extreme rear end or portion of the
lever B.
G is the limiting or stop screw of the lever, the lower end of which bears on the
bed-plate.
His the small switch-lever having on its outer end a button h, by which it is
turned and adapted to form an electrical connection with the contact-spring I of the
bed-plate.
Under the main lever is one of the contact-points, designated by J. This is of a
conical shape, having its point a perfect apex. The opposing point K is also
conical.
It will be seen that the entire key is neat and simple. It is narrower than keys
generally used, while at the same time it is no longer and no higher. This is of
advantage where many keys are used in one office.

page_text: The adjusting-spring F being arranged at the extreme back or rear end of the lever'
the full effect is obtained, and it can be adjusted to suit the taste of the sending-
operator. There is no side motion of the main lever, and its pivotal connection is of
such a character as to be very desirable and is not liable to get out of order. The
strips of steel on either side hold it perfectly rigid and avoid or reduce friction by
projecting inwardly beyond the surface of the standards, so that the sides of the key
have but small frictional surface to bear against.
It will be noticed that, instead of the usual pins which form the contact points of
ordinary keys, I make my points conical with perfect apices. These apices coming
together give the finest and most perfect contact. The advantage of the perfect
contact is in avoiding what is known as "sticking." By this is meant the jumping,
as it were, of the current from point to point when they are open. To fully realize
this advantage, the points should have perfect apices, for if they be truncated to even
the slightest extent they become no more and have no other effect than the ordinary
blunt-ended pins; but where the apices are perfect the contact between the two points
is of the finest nature and effects as good a result, as far as not sticking is concerned,
as very fine-pointed pins would, but without the disadvantage of such pins, of rapidly
wearing out.
It is common in using the ordinary keys to stop from time to time and set the points
farther apart before continuing; but with my key the points may be set so close
together that there will scarcely be any perceptible motion, and yet there will be no
sticking.
The main lever may be made either heavy or light, as the operator may wish. The
lighter ones are usually preferred; but the heavier ones are sometimes desired.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a telegraph-key, the bed-plate having the side standards, in combination with
the key-lever pivoted in said standards and the guide-strips on the edges of the
standards, their inner surfaces projecting beyond the inner surfaces of said standards
and bearing against the sides of the key-lever, whereby lateral motion is prevented
and wear avoided. substantially as herein described.
2. In a telegraph-key, the combination of the bed-plate, the key-lever pivoted
thereon, the adjusting-spring seated in the rear end of the lever, and the set-screw
for regulating said spring, substantially as herein described.
3. In a telegraph-key, opposing contact-points, each conically-shaped with perfect
apices, one of said points being smaller than the other. substantially as herein
described.
4. In a telegraph-key, the combination of the bed-plate, the key-lever pivoted in
the bed-plate, the conical contact-point on the bed-plate, and the smaller conical
contact-point on the key-lever, both of said contact-points having perfect apices,
substantially as herein described.
5. A telegraph-key consisting of the combination of the bed-plate having the
standards, the key-lever pivoted in said standards, the guide bars or strips on the
edges of the standards bearing against the sides of the lever, the adjusting-spring at
the rear end of the lever, the set-screw for controlling the spring, the switch-lever
under the key-lever, the contact-spring of said switch-lever, and the conical contact-
points of the bed-plate and key-lever, substantially as herein described.
Dated this 15th day of November 1890.
F. W. BARKER,
Applicant's Agent.