Year: 1886

page_text: Date of Application, 13th Nov., 1886.
Complete Left, 28th Feb., 1887.
Complete Accepted, 5th Apr., 1887.
I HENRY SAMUEL Spiller WatkIN of The Wilderness, Cantwell Road, Woolwich
in the County of Kent, Major Royal Artillery do hereby declare the nature of this
invention to be as follows:-
The invention relates to that class of aneroid barometer which is provided with a
large open scale and in combination with which the index hand or pointer is required
to make two or more complete revolutions.
In such class of instrument the volute spring ordinarily employed to control the
motion of the hand or pointer spindle is found to buckle and therefore to act irregularly
on the said spindle and the first part of the invention consists of means for remedying
this defect. For this purpose I according to one arrangement enclose the said volute
spring in a suitable box or case which is so proportioned as to permit of the full action
of the spring and is yet so shallow as to prevent the buckling thereof when it has
performed more than a complete turn; according to another arrangement I substitute
for the ordinary volute spring a cylindrical coiled spring surrounding the index hand
or pointer spindle and of sufficient length to enable it to make the required number of
revolutions and yet to act efficiently on the spindle according to another arrangement
I fix one end of a cylindrical coiled spring to a fixed stud whilst the other end is
connected to a thread or ligature passed several times round a spiral groove or screw
thread formed on the hand or pointer spindle and such thread or ligature is fixed to
the spindle beyond such spiral groove or screw thread which latter is formed in the
opposite direction to that around which the chain or other connection actuating the
spindle is coiled.
According to another arrangement I employ a volute spring of the ordinary form
but I fix it to and around a separate spindle which has a toothed wheel fixed thereon
which works into a toothed pinion fixed or formed on the hand or pointer spindle ;
any required number of revolutions may be given to the latter and a smaller number
to the spring spindle thereby securing the correct action of the spring upon the hand
or pointer spindle.

page_text: My invention relates secondly to improvements in the indicating mechanism of
aneroid barometers. According to one arrangement I employ two or more concentric
circles of scales and in combination therewith I employ a hand or pointer sufficiently
long to extend across all of such concentric circles and in some cases I form such hand
or pointer with as many pointers as there are circles of scales, each of such pointers
pointing to a separate circle and in order to indicate which circle of scales should be
looked at I employ an indicator connected to or operated by the rocking bar and chain
giving motion to the hand or pointer spindle in such manner as to cause it to point to
the circle of figures to be looked at, the diameter or trace of the circle being made to
correspond to the movement of the pointer for each complete turn of the index finger
or such hand or pointer is caused to point to one or other of a series of figures
indicating such circle or I form such indicator with a series of figures either of which
will be exhibited through an aperture in the dial. Or the movement of the rocking
bar or chain may cause the revolution of a finger on a small circle on the dial plate,
this circle is engraved with figures denoting which circle of graduations is to be read
under the index neeille.
Or the dial plate may be made of a thin disc of aluminium (or other material) which
being attached to the spindle will revolve in the same manner as the ordinary index
needle when the instrument is subjected to varying pressure of atmosphere. On the
disc are engraved either concentric circles of scales or a continuous spiral scale. A
flexible cord wound on two pulleys and actuated by the rocking bar and chain will
indicate where the reading of the scale or scales is to be observed.
The hand or pointer may however extend only to the inner circular scale, in which
case. employ a moveable pointer extending across all the scales and nearly meeting
the hand or pointer so that any scale can be read off by placing the said moveable
pointer in line with the hand or pointer.
H. S. S. WATKIN.
By Harris & Mills,
23, Sonthampton Buildings,
Agents.

page_text: I, HENRY SAMUEL SPILLER WATKIN of The Wilderness, Cantwell Road, Woolwich
in the County of Kent, Major Royal Artillery 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:
The Invention relates to that class of aneroid barometer which is provided with a
large open scale and in combination with which the index hand or pointer is required
to make two or more completo revolutions.
In such class of instrument the volute spring ordinarily employed to control the
motion of the hand or pointer spindle is found to buckle and therefore to act
irregularly on the said spindle. The first part of the invention consists of means for
remedying this defect and the second part relates to improvements in the indicating
mechanism of such class of barometers.
In the accompanying drawings I have represented various modes in which my
invention may be carried into effect. In all the figures like parts are indicated by
similar letters of reference.
a represents the case of the instrument, the vacuum chamber, c the counteracting
spring, d the operating lever attached to and operated by the spring e, e a link
connecting the fever d to an adjustable arm fixed on the rocking bar f, and fan
arm or lever also fixed to the rocking bar fand which has its upper end connected by
a chain g to a worm or screw h¹ formed or fixed on the spindle carrying the hand or
pointer i.
The spindle is mounted in bearings carried by the cock or bracket j.
The parts above described form no part of my present invention.
In such class of instrument it is usual to employ a volute spring 1 to control the
motion of the hand or pointer spindle h but such spring when employed in combination
with a hand or pointer which is required to make two or more complete revolutions is
found to buckle and therefore to act irregularly on the spindle h but in order to
remedy this defect I according to one arrangement as shown at Figures 1. 2. 3 and 11
enclose the said volute spring 4, in a suitable box or case m which is so proportioned
as to permit of the full action of the spring and is yet so shallow as to prevent the
buckling thereof when it has performed more than a complete turn.
According to another arrangement as represented at Figures 5 and 6 I substitute
for the ordinary volute spring 7 a cylindrical coiled spring surrounding the index
hand or pointer spindle and of sufficient length to enable it to make the required
number of revolutions and yet to act efficiently on the spindle h.
According to another arrangement as represented at Figures 7 and 8 I fix one
end of a cylindrical coiled spring 1**, to a fixed stud n whilst the other end is.
connected to a thread or ligature passed several times round a spiral groove or
screw thread formed on the spindle h and such thread or ligature A, is fixed-to the

page_text: spindle beyond such spiral groove or screw thread which latter is formed in the
opposite direction to that of the screw thread or worm h¹ around which the chain or
other connection 9 actuating the spindle in one direction is coiled. The spring 1**
may occupy the position shown by either the full lines or the dotted lines in
Figure 8.
According to another arrangement as represented at Figures 9 and 10 I employ a
volute spring of the ordinary form but I fix it to and around a separate spindle o
which has a toothed wheel o' fixed thereon which works into a toothed pinion ³ fixed
on the hand or pointer spindle whereby any required number of revolutions may
be given to the latter and a smaller number to the spring spindle o, thereby securing
the correct action of the spring upon the hand or pointer spindle k.
I would here remark that the improvements above described are equally applicable
to aneroid barometers of the character described in the Specification of Letters Patent
granted to me dated March. 11. 1886 No. 3425.
In carrying out the second part of my invention I in some cases employ a dial k
with two or more concentric circles of scales engraved thereon as represented at
Figures 2. 4. 6. 10 and 12 and in combination therewith I employ a hand or pointer i
sufficiently long to extend across all of such concentric circles and according to one
arrangement as shown at Figure 4 I form such hand or pointer. with as many
pointers as there are circles of scales, each of such pointers pointing to a
separate circle and in order to indicate which circle of scales should be looked at I
employ, according to the arrangement shewn at Figure 2 an indicator P connected
to or operated by the rocking bar and chain 9 giving motion to the hand or
pointer spindle in such manner as to cause such indicator to point to the circle
of divisions and figures to be looked at, the diameter or trace of the circle being
made to correspond to the movement of the pointer p for each complete_turn of the
index finger i. or according to the arrangement represented at Figure 6 I cause such
indicator hand or pointer p to point to one or other of a series of figures "1. 2. 3
engraved on the dial plate k to indicate which scale or circle of divisions and figures
is to be looked at or I form such indicator pas represented at Figures 3. 4 and 9. 10
with a series of figures engraved on a plate p¹ carried by a link pone end of which
is connected to the upper end of the arm and the other to the chain ; thus either
of the figures will be exhibited through an aperture in the dial according to which
circle of divisions and figures is to be observed.
22
Or the movement of the rocking bar fand chain g may as represented at Figures
11 and 12 cause the revolution of an indicator or finger p on a small circle k² on the
dial plate k, this circle is engraved with figures denoting which circle of
graduations is to be read under the index needle i. In carrying this arrangement
into effect the indicator p is mounted on an axis p³ which has fixed thereon a screw
thread p around which the chain y passes in its way from the arm to the spindle h.
In the various arrangements represented at Figures 2. 4. 6. 10 and 12 the dial plate k
has arrows, engraved thercon between the several circles of scales_in_order_to
indicate the points where the reading of one circle ends and another begins. The
hand or pointer i, may if desired extend only to the inner circular scale in which
case I employ a moveable pointer connected to a moveable ring on the case and
extending across all the scales and nearly meeting the hand or pointer i, so that any
scale can be read off by placing the said moveable pointer in line with the hand or
pointer as shown by the dotted lines in Figure 4.
i
Or as represented at Figure 13 the dial plate may be made of a thin disc * of
aluminium (or other material) which being attached to the spindle h will revolve in
the same manner as the ordinary index needle i when the instrument is subjected to
varying pressure of atmosphere.
On the disc is engraved a continuous spiral scale and a spiral slot or opening is
formed between the several parts of the spiral scale.
"Through this slot passes a band or pointer i* which is attached to the chain
connected to the lever on the rocking barf. This hand or pointer i* projects over
the spiral scale and by travelling with the chain g will traverse to and fro in the spiral

page_text: slot or opening in the disc and indicate where the reading of the scale is to be
observed.
In the last mentioned modification the scale on the disc k*, is engraved in the
reversed direction to that of the fixed dial plates in the other modifications but the
internal construction of the instrument is not changed.
I would here remark that the above described methods of carrying my invention
into effect are those I have found to answer but I do not confine myself to the precise
details herein shown and described as such may be varied without departing from the
peculiar character of my invention.
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 aneroid barometers provided with a large open scale and in which the
indicating hand or pointer is required to make two or more complete revolutions, the
various methods of securing the correct action of the spring upon the hand or pointer
spindle substantially as herein shown and described.
2. In aneroid barometers provided with a large open scale and in which the
indicating hand or pointer is required to make two or more complete revolutions the
various methods of indicating which circle of the scule is to be observed substantially
as herein shown and described.
3. In aneroid barometers provided with a large open spiral scale forming such scale
on a thin disc of aluminium or other material fixed on the spindle in lieu of the
ordinary hand or pointer and indicating the point where the reading is to be observed
on said scale substantially as herein shown and described with respect to Figure 13.
Dated this 28th day of February 1887.
. H. S. S. WATKIN.
By Harris & Mills,
23, Southampton Buildings,
Agents.