An Improved Electrical Chronographic Apparatus for Measuring Very Small Intervals of Time.
Year: 1891

page_text: Date of Application, 8th Sept., 1891
Complete Specification Left, 7th June, 1892-Accepted, 9th July, 1892
PROVISIONAL SPECIFICATION.
An Improved Electrical Chronographic Apparatus for Measuring
Very Small Intervals of Time.
LIONEL DE LAUTOUR WELLS Lieutenant, Royal Navy Naval and Military
Club 94 Piccadilly S.W. do hereby declare the nature of this invention to be as
follows:-
This chronograph is adapted electrically to give the very small interval of time
which occurs with each individual between the impression received by the eye and
the ultimate effect conveyed by the action of the brain.
This arrangement can be applied to any purpose where a short interval of time
is required to be measured and consists of a tuning fork actuated by an electro-
magnet which is made to register the number of vibrations between the "making
& breaking" of another electrical circuit by the operator so giving the interval
of time during the operation.
Dated this 8th day of September 1891
COMPLETE SPECIFICATION.
An Improved Electrical Chronographic Apparatus for Measuring
Very Small Intervals of Time.
I, LIONEL DE LAUTOUR WELLS, of the Naval and Military Club,
94 Piccadilly, S.W., in the County of London, Lieutenant Royal Navy, 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 has reference to a construction of electrical chronograph specially
suitable for recording the very small interval of time that usually elapses between
the reception of an impression on the retina of the eye of an observer and the
ultimate effect conveyed by the action of the brain to any desired part of the
body as for example the hand, to indicate the reception of such impression.
For this purpose the chronograph is constructed according to this invention with
an electrically operated tuning fork the vibrations of which during the interval of
time that elapses between the making and breaking of an electrical circuit or
circuits and corresponding to the electrical operation of a visual device that causes
an impression to be produced on the retina of an observer and operation by such
observer of another electrical device to indicate the reception of such impression,
are recorded by a stylus on material carried by a suitably operated carrier or
support, as I will now proceed to explain by aid of the accompanying drawings in
which
Fig. 1 is a side elevation :
Fig. 2 is a plan and
Fig. 3 is a rear elevation of an electric chronograph according to this invention.
1 is a stylus carried by one of the prongs of a tuning fork 2 fixed to a standard 3
▸ supported by a base 4. The tuning fork is caused to vibrate with a suitable
number of vibrations a second, say for example 250, by means of an electro
magnet 5 carried by a bracket 6 and the circuit of which is arranged to be
automatically completed and broken in rapid succession by a contact making and
breaking device comprising a spring 7 fixed to one of the legs of the tuning fork
and a fixed adjustable screw 8. The arrangement is such that when the circuit 9
[Price 8d.]

page_text: indicated by dotted lines in Fig. 2, of an electric generator 10 is completed through
the electro magnet 5, tuning fork-2 and contact making device 7-8 by the
insertion of a plug 11 between two insulated. contacts 12-12 forming part of such
circuit, the electromagnet will attract the prongs of the tuning fork and cause the
spring 7 to leave the screw 8 thereby breaking the circuit of the electro magnet 5
and allowing the prongs of the timing fork. to spring back and again complete the
circuit these operations being repeated-in rapid succession. so sa-to maintain the
tuning fork in constant vibration. The vibration of the tuning fork may con-
veniently be started by gently striking it. The record carrier in the example
shown, is in the form of a rotary drum 13 provided with circumferential guides 14 1
for holding a strip of smoked paper 15 upon which the vibrations of the stylus 1
can be recorded in the form of a sinuous line as shown in Fig. 2. The record
drum is fixed upon a suitably supported shaft 16 that forms the last motion shaft
of a train of clockwork enclosed within a box 17 and driven by a spring. This
spring is arranged to be wound up from time to time by a key or hand 18 that is
applied to one end of an axle 19 the other end of which is provided with a ratchet
wheel 20 with which a detent 21 engages to prevent rotation of the axle in one
direction; or the shaft may be rotated by a falling weight, each in a manner well
understood. The record drum and shaft are normally held stationary by a device
comprising a stop 22 that is carried by a rod 23 and is normally held within a 2
recess 24 formed in a disc or collar. 25 that is fast on the shaft 17, by a
spring 26 that encircles the rod 23 and bears at one end against the stop and at
the other end against a bracket or guide 26 in which the rod 23 is arranged to
slide.
The stylus is normally held out of contact with the drum and the strip of
smoked paper thereon by. a pin 27 carried by one arm.28 of a lever pivoted at 29
and the other arm 28" of which carries the armature 30 of an electro magnet 31,
the circnit 32 of which is adapted to be completed. when necessary by a push
button 33 and spring contacts 34 as indicated diagrammatically in chain-lines in
Fig. 2. 35 is an object, such for example as a sheet of white paper having thereon
one or more black spots, that can be seen.through. a conical tube 36 and-a-hole 37
in the standard 3 by a person standing in front of the apparatus. 38 is a shutter
or indicator carried by a lever 39 that is connected to a spring 40, and to the
pivoted armature 41 of an electro-nagnet 42, the arrangement. being such that the
shutter will be normally held in the raised position shown in Fig. 3, but when
the electro-magnet 42 is excited the shutter will be depressed so as to hide the
object 35 from the view of the observer looking through the tube 36 and hole.37.
43 is another electro-magnet the spring armature 44 of which carries a tongue 45
which, when the said armature is in its normal position and unattracted by the
electro-magnet 43,.holds the arm 28" of the lever 28-28 in the depressed position
shown so that the pin 27 carried by the other arm 28 of the lever will hold the
stylus 1 clear of the record drum 13 and the strip 15 of smoked paper thereon.
When. however the armature 44 is attracted by the electro-magnet 43, the
tongue 45 will be brought over the recessed or cut away end 285 of the lever
arm 28, so that the other arm 28 of the lever and.the pin 27 carried thereby,, will
descend sufficiently to enable the stylus 1 to come into contact by reason of its
elasticity, with the smoked paper 15 when the same moves underneath it with the
record drum. The circuit 46, shown diagrammatically in chain lines in Fig.1 of
the electro magnets 42 and 43 which are connected with each other, is adapted to
be momentarily completed through insulated spring contacts 47 47" by a "spring
push 48 which is depressed by the passage over it of a pin or projection 49 on,
the recording drum 13.
The operation of the apparatus is as follows:-
Assuming a person to be viewing the object 35 through the conical tube 36 and
hole 37; that the tuning fork 2 and, stylus 1 carried thereby.are set in vibration
by inserting the blue or kev 11 between the contacts 12-12"; and that the:

page_text: projection 49 on the drum passes over the spring push 48, the circuit of the electro-
magnets 42 and 43 will be momentarily completed by the spring contacts 47 47*
being pressed against each other with the result that the armature 41 of the
electro-magnet 42 will be attracted and depress the shutter 38 so as to hide the
object 35 from view, and the armature 44 will be attracted so as to partly release
the lever 28-28" and allow the stylus 1 to move into contact with the smoked
paper 15 whereon its vibrations will be recorded in the form of a sinuous line. If
now the observer depresses the push 33, the electro-magnet 31 will be excited, and
by attracting its armature 30, will cause the stylus 1 to be raised from the smoked
paper 15 so that its vibrations will immediately cease to be recorded thereon.
Thus the short interval of time that will elapse between the impression produced
on the retina of the eye by the movement of the shutter 35 over the hole 37, and
the operation by the observer of the push 33 to indicate the reception of such
impression, will be recorded on the smoke paper in the form of a sinuous or wavy
line corresponding to the vibrations of the stylus, and by reading off the number
of vibrations on the smoked paper by a suitable scale the said interval of time
can be determined. Thus if the tuning fork makes 250 vibrations a second, and
the number of vibrations recorded on the smoked paper be 50, then the interval of
time elapsing between the actions referred to will be of a second.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. An electrical chronograph in which the interval of time elapsing between the
making and breaking of an electrical circuit or circuits, serving respectively for
producing an impression upon the retina of an observer and for indicating the
reception by the observer of such impression, is recorded upon suitably operated
material such as smoked paper, by an electrically operated tuning fork carrying a
stylus that is caused or allowed to move into contact with said material upon the
making of the electrical circuit, and to move away from said material upon the
breaking of the circuit substantially as hereinbefore described.
2. My improved electrical chronograph constructed arranged and operating
substantially as described and shown for the purpose set forth.
Dated this 6th day of June 1892.
LIONEL DE LAUTOUR WELLS.
W. Lloyd Wise,
"
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.