Improvements in Anemometers.
Year: 1894

page_text: Date of Application, 6th Jan., 1894
Complete Specification Left, 5th Oct., 1394-accepted, 10th Nov., 1894
TROYINIONAT
Improvements in Anemometers.
I, JOHN HALL, of 32 Trinity Road, East Finchley, in the County of Middlesex,
Manufacturer of Scientific Instruments, do hereby declare the nature of this
invention to be as follows:-
This invention has reference to improvements in anemometers, and it has for
object to enable all the hands of such instruments to be readily and quickly
returned to zero after each operation and reading of the instrument, so as to thereby
obviate the,necessity, when the hands do not, for a given test, start from zero, of
writing down a number of figures, in order to deduct the last reading of the
instrument from the previous one to arrive at the correct reading for the last test
made, and which, under some circumstances, as when the instrument is used in
mines, is troublesome and inconvenient.
The
For this purpose I provide in conjunction with the train of wheels and hands or
pointers used for indicating the number of revolutions of the fan spindle of an
anemometer, a supplementary toothed wheel adapted to be put in gear with the
said train and capable of being rotated by hand, from the exterior of the wheel-
case either directly, or indirectly through another toothed wheel or wheels.
supplementary toothed wheel may advantageously be carried by a support connected
with the catch or stop ordinarily used for disconnecting the said train of wheels
from the worm on the fan spindle, the arrangement being such that when the said
train is put out of gear with the fan spindle, the supplementary toothed wheel will
be put in gear with one of the wheels of the said train and vice versa.
An arrangement for this purpose is as follows:-
The supplementary wheel is carried by a lever pivoted to a pin fixed to the
movement plate, and jointed to a lever arm or extension carried by the lever used
for operating the pin or arm ordinarily used for putting a worn wheel that forms
the first wheel of the train of wheels, in and out of gear with driving worm, the
spindle of the said supplementary toothed wheel extending through a slot in the
movement plate to the exterior thereof where it is provided with a milled wheel or
button adapted to be readily turned by hand. The arrangement is such that when
the catch lever is operated to put the train of wheels out of gear with the fan
spindle, the lever carrying the supplementary wheel will be moved so as to put this
wheel automatically in gear with one of the wheels, say the hundreds wheel of the
indicating mechanism, so that the direction of movement of this mechanism can
then be readily reversed, by turning the milled wheel or button, in order to bring
all the hands back to the zero point on the corresponding dials, and upon afterwards
placing the train of wheels again in gear with the fan spindle, the said supplementary
wheel will be automatically put out of action. The milled wheel or button may
be acted upon by a spring to prevent it turning too freely.
The pinion on the spiudle of the worm wheel may, in some cases, be made of
such length that, when the worm wheel is disconnected from the fan spindle it
passes out of gear with the wheel of the train with which it normally gears.
Usually, however, the said pinion will be of such length as not to pass out of gear
with the said wheel at the time mentioned.
Dated this 6th day of January 1894.

page_text: Improvements in Anemometers.
I, JOHN HALL, of 32 Trinity Road, East Finchley, in the County of Middlesex,
Manufacturer of Scientific Instruments, 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 improvements in anemometers, and it has for
object to enable all the hands of such instruments to be readily and quickly
returned to zero after each operation and reading of the instrument, so as to thereby
obviate the necessity, when the hands do not, for a given test, start from zero, of
writing down a number of figures, in order to deduct the last reading of the
instrument from the previous one to arrive at the correct reading for the last test
made, and which, under some circumstances, as when the instrument is used in
mines, is troublesome and inconvenient.
For this purpose I provide in conjunction with the train of wheels and hands
or pointers used for indicating the number of revolutions of the fan spindle of an
anemometer, a supplementary toothed wheel adapted to be put in gear with the
said train and capable of being rotated by hand, from the exterior of the wheel-
case either directly, or indirectly through another toothed wheel or wheels.
The
supplementary toothed wheel may advantageously be carried by a support
connected with the catch or stop ordinarily used for disconnecting the said train of
wheels from the worm on the fan spindle, the arrangement being such that when
the said train is put out of gear with the fan spindle, the supplementary toothed
wheel will be put in gear with one of the wheels of the said train and vice versa.
Setting mechanism to operate in the manner described can be constructed in
various forms.
In the accompanying drawings,
Fig. 1 shows in plan, and with the top plate removed, so much of the indicating
mechanism and adjacent parts of an anemometer as is necessary to illustrate the
application thereto of mechanism according to this invention for quickly setting or
returning the indicating hands or pointers to zero. The indicating mechanism is
shown in gear with the fan spindle and the setting mechanism out of gear.
Fig. 2 is a corresponding vertical section, to an enlarged scale, of part of the
indicating mechanisin.
Figs. 3 & 4 are similar views to Figs. 1 and 2 respectively, but showing the
indicating mechanism out of gear with the fan spindle and in gear with the setting
mechanism.
Fig. 5 is an enlarged detail view.
The setting mechanism shown in these figures comprises a supplementary toothed
wheel 1 journalled in a lever 2 that is pivoted to a pin 3 fixed to the movement
plate 4, and is jointed to a lever arm or extension 5 pivoted to the catch or stop
lever 5 used for operating the pin or aım 6 ordinarily used for raising and releasing
a spring plate or bridge 7 that serves to put the worm wheel which forms the
first wheel of the train of wheels, in and out of gear with the driving worm 9 on
the fan spindle 10. The spindle 1 of the said supplementary toothed wheel 1,
extends through a slot 4* in the movement plate 4, to the exterior or underside of
the said plate where it is provided with a milled wheel or button 11 adapted to be
readily turned by hand. As will be seen the arrangement is such that when the
catch or stop lever 5 is moved from the position shown in Fig. 1 to that shown in
Fig. 3, in order to lift the spring plate 7 and worm wheel 8 and put the train of
wheels out of gear with the fan spindle Fig. 4, the lever 2 carrying the supple-
mentary wheel 1 will be moved so as to put this wheel automatically in gear
through an intermediate or idle wheel 12, with one of the wheels, say the centre

page_text: wheel 8 of the indicating mechanism, so that the direction of movement of this
mechanism can then be readily reversed, by turning the milled wheel or button 11
in order to bring all the aforesaid hands or pointers back to the zero points on the
corresponding dials, and upon afterwards placing the train of wheels again in gear
with the fan spindle by moving the catch or stop lever 5 in the opposite direction,
the said supplementary wheel will be automatically put out of action. The milled
wheel or button 11 may be acted upon by a spring or springs to prevent it turning
too freely. In the arrangement shown in Fig. 5, two dished spring plates 13, 13
are shown for this purpose, one of them being arranged between the wheel or
button and the underside of the movement plate 4 and the other between the upper
side of this plate and a cross pin 14 extending through the spindle 1 of the
supplementary toothed wheel 1.
The pinion 8 on the spindle 8* of the worm wheel 8, may, in some cases, and as
shown in Figs. 2 and 3, be made of such length that, when the said worm wheel is
disconnected from the worm 9 on the fan spindle 10 it will pass out of gear (Fig. 4)
with the centre wheel 8 of the train with which it normally gears (Fig. 2), so
as to thereby lessen the friction when setting the hands back to zero. Con-
veniently, this may be effected by cutting away the teeth of the pinion 8b at the parts
thereof that would be opposite the centre wheel 8 when the spindle 8° is raised
by the spring plate or bridge 7. The said pinion 8b may however, if desired,
be of such a length as not to pass out of gear with the said centre wheel at
the time mentioned, though I do not consider this to be so advantageous a
construction as that shown. 15 is the usual spring fixed to the upper side of
the top plate 16 and serving to return the spindle 8* with worm wheel 8 and
pinion 8 to their normal positions, when the catch lever 5 is moved to put the
train of wheels in gear with the fan spindle.
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. An anemometer constructed with supplementary mechanism adapted to be
put in and out of gear with the train of wheels connected with the hands or
pointers used for indicating the number of revolutions of the fan spindle, and
capable of being operated from the exterior of the wheel case so as to quickly
re-set the said hands or pointers to zero substantially as herein before described
for the purpose specified.
2. In an anemometer, the combination with the train of wheels therein and the
catch or stop used for disconnecting the said train from the worm on the fan
spindle, of a supplementary toothed wheel capable of being operated from the
exterior of the wheel case and connected with the said catch or stop, in such a
manner that when the said train of wheels is put out of gear with the fan spindle,
the supplementary toothed wheel will be directly or indirectly put in gear with
one of the wheels of the said train and vice versa, substantially as hereinbefore
described for the purpose specified.
3. An anemometer provided with supplementary mechanism constructed arranged
and operating substantially as herein before described with reference to and shown
in the drawings annexed, whereby the indicating hands or pointers can be quickly
returned to the zero positions on the dials as set forth.
Dated this 5th day of October 1901
J. HALL.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.