Improvements in or Connected with Pressure and other similar Gauges.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
Improvements in or Connected with Pressure and other similar
Gauges.
I, WILLIAM PORRITT INGHAM of Middlesbrough, in the county of York, Engineer,
do hereby declare the nature of this invention to be as follows.-
This invention relates to improvements in pressure or other similar Gauges,
which gauges may be worked either by Steam, Compressed air, Water, or Gas-The
mechanical construction of the improvements is as follows-On the Spindle or Shaft
which caries the pointer or indicating hand (or on the spindle or shaft which
carries the Segmental Wheel) of the Gauge, is fixed a catch wheel, and working
against this catch wheel, is a pall or catch (which is pivotted on a centre) and so con-
structed that the said catch wheel can work freely one way, but cannot return or
work the opposite way, being prevented from so doing by the said pall or catch-
When it is desired to allow the catch wheel to return (and of course the pointer or
indicating hand also) to zero, the said catch or pall is lifted or disengaged from the
said catch wheel, by means of a lever and small inclined plane (a spring is employed
to bring the lever and inclined plane back to their normal position). When the catch
or pall is thus freed from the catch wheel, the pointer or indicating hand back
to zero, (e.) provided that all pressure be off the gauge-The purpose of this inven-
tion being; that the pointer or indicating hand of the Gauge shall remain at and
indicate the maximum pressure to which it has been pressed or blown, and only
return to zero when the said catch has been lifted as described-The said lever and
inclined plane, for lifting the said pall or catch may be under lock and key, so that
it cannot be worked except by the person with the key, or the lever may be arranged
to be worked by a small weight, token, or coin being allowed to fall on it, or a small
handle or stop connected to the said lever may project through the case of the
apparatus, and the lever worked by this means by the pressure of the hand or
thumb.
goes

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with Pressure or other similar
Gauges.
I, WILLIAM PORRITT INGHAM, of Middlesbrough, in the County of York, Engineer,
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
My said invention relates to improvements in or connected with pressure and other
similar gauges such as capacity gauges for measuring the pressure or quantity of
steam, compressed air, water, gas, or other fluid and in which the hand or pointer is
returned to zero by a spring or otherwise and has for its object to lock the indicating
hand or pointer at the extreme point to which it has moved thus recording the
maximum pressure attamed or quantity measured and to provide means for releasing
it and allowing it to return to its normal position.
For this purpose upon the spindle or shaft which carries the indicating hand or
pointer or upon some other suitable moving part such as the spindle or shaft which
carries the toothed segment of a "Bourdon "gauge, I fix a ratchet wheel and in connec-
tion with this ratchet wheel 1 employ a pawl or catch mounted upon a centre of
motion and preferably held in gear with the ratchet wheel by its own gravity or it
might be by a light spring. By these means the indicating hand or pointer 15
prevented from running back with the falling pressure in the ordinary way but is
locked at the extreme point to which it has moved thus recording the maximum
pressure attained
In order to disengage the pawl from the ratchet wheel at the desired times and
thus permit the indicating hand or pointer to return to zero or as far as the pressure
of the fluid will permit when there is a pressure on the gauge, I employ a lever or
pusher rod sprung into its normal position and provided with a cam or incline or other
means to act upon the pawl and lift it out of engagement with the ratchet wheel.
The lever or pusher rod for disengaging the pawl may be carried to the outside of
the case of the instrument so that it may be readily acted upon by the finger or
thumb or it desired it may terminate within the case of the instrument so as to be
under lock and key thereby rendering it impossible for an unauthorised person to cause
the indicating hand to run back or return to zero.
Or for some purposes the lever may be so arranged that a weight, token, or coin will
work it and impart the necessary movements thereto.
And in order that my said invention may be more clearly understood and readily
cairied into effect, I will proceed aided by the accompanying drawings more fully to
describe the same.
Figure 11s a rear view of part of a pressure gauge showing my invention applied
thereto
Figure 2 is a similar view illustrating a modification of the means for disengaging
the pawl from the ratchet wheel.

page_text: Figure 5. 19 a similar view mustrating the method of actuating the lever by a
weight, token or coin
Figure 4. is a plan thereof and Figure 5. is a sectional end view part being broken
away.
In the several Figures like parts are indicated by similar letters of reference.
a represents the dial plate, b¹ the indicating hand and 6 the spindle or shatt upon
which the same is fixed as is usual
According to my invention however, I also fix upon this spindle or shatt b a ratchet
wheel c and in connection with this ratchet wheel c I employ a pawl or catch c¹
which is mounted upon a centre of motion carried by the dial plate a and is
preferably held in gear with the ratchet wheel c. by its own gravity or it might be
by means of a light spring.
By these means the indicating hand, or pointer 61 is prevented from running back
with the falling pressure in the ordinary way but is locked at the extreme point
to which it has moved thus recording the maximum pressure attained.
In order to disengage the pawl c from the ratchet wheel c at the times desired
and thus permit the indicating hand or pointer 61 to return to zero or as far as
the pressure of the fluid will permit when there is a pressure on the gauge, I
employ a releasing device for acting upon the pawl c¹ the construction and action
of which I will now proceed to describe.
In the arrangement represented at Figure 1 this releasing device consists of a
bell-crank lever d. mounted upon a centre of motion d¹ fixed to the dial plate a.
and the end of the vertical arm of this lever is formed or provided with an
incline which at the times desired acts upon the pawl c¹ to disengage it from
the ratchet wheel c. and the end of the horizontal arm thereof passes through the
case of the instrument so that an upward pressure exerted theicon will cause the
inclined to act upon the pawl c¹ in the manner desired.
A spring d³ is employed to normally retain the lever d and consequently the
inclined in their non-acting position
In the modification represented at Figure 2 the parts are very similar but in this
example the incline d² is formed upon a pusher rod d. which passes through a guide d'
fixed to the dial plate a. an inward pressure upon the rod d. causing the incline d* to
act upon the pawl c¹.
In lieu of leading the lever or pusher rod d. to the outside of the case of the
instrument as herein before shown and described it may terminate within the case
so as to be under lock and key thereby rendering it impossible for an unauthorised
person to cause the indicating hand to run back or return to zero.
Or for some purposes the lever d. may be so arranged that a weight token or
coin will produce the necessary movements thereto and a device such as this is
represented at Figures 3, 4. and 5.
but
In this arrangement the incline is fixed to the pawl c¹ and is marked * and the
lever d. is provided with a projecting finger which acts upon the incline
it will be evident that these parts might be reversed
The lever d. is mounted upon a centre of motion d¹ fixed to a shoot e. which
leads the weight or coin into the instrument from a slot f¹ formed in the case f. and
the upper end of the lever d. is formed with a projection or enlargement d* which
passes through an opening e¹ in the shoot e. and normally obstructs the passage for
the weight or coin at one side thereof so that as the weight or coin is passed into the
instrument through the slot fit will move the lever d. upon its axis d¹ causing the-
finger to act upon the incline of the pawl c' and disengage it from the ratchet
wheel c. and thus permitting the indicating hand or pointer 6 to return to zero.
The lower end of the lever d. 1s formed with a projection or enlargement d³ similar
to which enters the notch or opening of the shoot e. so that the weight or coin
as it leaves the shoot e. acts upon the projection d' of the lever d. withdrawing the
finger from the incline c and causing the parts to resume their normal position
or a light spring might be employed to return the lever d. to its normal position.

page_text: It will be evident that the ratchet wheel c. may be mounted upon some moving part
other than the spindle of the indicating hand or pointer such for example as the
spindle or shaft which carries the toothed segment of a "Bourdon "
gauge and that
the lever or pusher rod d. may be modified without departing from the nature of my
invention.
I have not thought it necessary to give an example of the application of my inven-
tion to a capacity gauge, such as the gauges ordinarily employed in connection with
spirometers, but it will be readily understood that the same is equally applicable to
any such instrument in which the hand or pointer is returned or capable of being
returned to zero by a spring or otherwise and any ordinary mechanic will be able to
make the modifications necessary in existing gauges for that purpose.
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 a pressure or other similar gauge a ratchet wheel fixed upon the spindle or
shaft of the indicating hand or pointer or some other moving part connected there-
with and a pawl so disposed as to engage such ratchet wheel in manner substantially
as herein shown and described and for the purpose stated.
2 In or in connection with a pressure or other similar gauge provided with the
ratchet wheel and pawl referred to in claim 1. a lever or pusher rod for disengaging
the pawl from the ratchet wheel at the times desired in manner substantially as herein
shown and described and for the purpose stated.
3. In or in connection with a pressure or other similar gauge provided with the
ratchet wheel and pawl referred to in claim 1. a lever moved by a weight token or
coin to disengage the pawl from the ratchet wheel at the times desired the lever
being then returned to its normal position, all in manner substantially as herein
shown and described and for the purpose stated.
Dated this Fifth day of March 1889
VAUGHAN & SON,
Agents for the Applicant.