IMPROVEMENTS IN VACUUM BRAKE GUAGES, OR INDICATORS
Year: 1885

page_text: Improvements in
I, CHARLES SPENCER MADAN of Mansfield Chambers, St Ann's Square Man-
chester, in the County of Lancaster, Engineer, do hereby declare the nature of my
invention for IMPROVEMENTS IN VACUUM BRAKE GUAGES, OR INDICATORS, to be
as follows:-
My Invention relates to an improved combination and construction of Vacuum
Brake Guages, or Indicators, for informing the officials in charge of trains fitted
with any form of vacuum brake as to the condition of the brake apparatus, and as
to the vacuum necessary for the correct working of the brake.
The improvement consists in an arrangement by which the guage or Indicator,
in addition to shewing the vacuum by means of a pointer and dial, and moving a
shutter conspicuously placed to warn the officials in charge of any accident to the
brake apparatus, also automatically winds up an alarum which rings whenever the
vacuum falls below a certain point, drawing their attention to the position of
the pointer and shutter.
The guage or indicator consists of a vacuum chamber connected by a pipe to the
brake system, and a casing containing the necessary machinery fixed to the upper
side of the vacuum chamber, a bell being placed above the casing for the alarum to
ring upon.
The movement is effected in the following manner :-
The pointer is actuated by a rack and pinion, the rack being connected by a rod
to a plate free to move vertically up and down in the vacuum chamber, the plate
being fixed to a diaphragm, and being forced by the pressure of the air against a
suitable spring when the air is exhausted from the lower side of the diaphragm,
thus indicating the vacuum. The connecting rod also by means of pins suitably
placed moves the shutter on the face of the dial.
The alarum is of the ordinary escapement description having a pinion on the
main arbor into which a rack is fitted connected by a rod with a second plate fixed
to the diaphragm in the vacuum chamber. This plate is drawn vertically down-
wards when the vacuum is formed by the exhaustion of the air from the lower side
of the diaphragm, thus turning the main arbor, and winding up the alarum.
A suitable catch is provided for holding or releasing the alarum according to the
position of the pointer. The striker of the alarum is carried through the casing
and vibrates inside the bell.

page_text: Improvements in Vacuum Brake Gauges or Indicators.
I CHARLES SPENCER MADAN of Mansfield Chambers Saint Ann's Square
Manchester in the County of Lancaster, Engineer, do hereby declare the nature
of my invention for IMPROVEMENTS IN VACUUM BRAKE GUAGES OR INDICATORS,
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 an improved combination and construction of Vacuum
Guages or Indicators for use in connection with Vacuum Brakes or other apparatus
where it is necessary that those in charge should have the state of the vacuum
prominently indicated.
The construction of my improved instruments will be best understood by a
reference to the drawings attached hereto.
The views A and B shew the part of my invention which is devoted to the
visible indication of the vacuum by means of a pointer and dial, and a tell tale
shutter.
The views C and D shew the arrangement by which an alarum is made to ring
as required, the motive power being the pressure of the air on a diaphragm when
a vacuum is formed.
The view E shews a combination of these two portions which however may be
made and used as separate instruments when required.
I will first describe the contrivance shewn in views A and B.
It consists of a circular casing provided with a dial, and a vacuum chamber with
a suitable connection for a pipe. In this vacuum chamber is a diaphragm provided
with a plate to which is attached the rack which works the pointer and tell tale
shutter. When combined with the alarum arrangement shewn in C and D the
chamber is divided into two portions by a midfeather, and the diaphragm is
fastened to the midfeather, thus dividing the chamber into two distinct parts, and
is provided with two plates for working the pointer, telltale and alarum all as
shewn in the views A. B. C. D.
The diaphragm, or portion of the diaphragm which works the pointer and
telltale is attached by means of the plate in it to the rack, the upper end of which
is attached to one end of a light spiral spring, the other end of the spring being
attached to the top of the case.
The
The rack and diaphragm are thus held by the spring in their highest position
when the apparatus is not in action. The lower part of the vacuum chamber is
provided with a spring so placed that when the vacuum is formed the diaphragm,
plate, and rack, above described, are drawn down by the pressure of the air on the
upper side, the spring being compressed according to the amount of vacuum.
telltale shutter is formed of a piece of brass or other suitable material bent to an
angle so as to form two faces with trunions at the two ends fitting into carriers
fixed to the dial, on the inside. A suitable orifice is cut in the dial to permit the
shutter to be seen.

page_text: There is a projection on the rack, and a corresponding one on the shutter so that
when the rack is moved, the shutter turns round on the trunions. The pointer is
mounted on an arbor provided with a pinion into which the rack works, thus every
movement of the rack is indicated on the dial. When the Indicator is at rest there
is a suitable space between the diaphragm and the spring in the lower part of the
vacuum chamber, so that when the vacuum is formed the downward movement of
the diaphragm and rack is opposed only by the light spring at the top, and the
movement is thus very rapid, the pointer moving round a considerable portion of
the dial, and the shutter turning, so as to bring its other face into view almost
instantaneously. The diaphragm then comes into contact with the spring in the
lower part of the vacuum chamber, and the pointer indicates the vacuum on a
divided scale on the dial, the shutter remaining stationary until the vacuum goes
off, when the action described above is reversed.
The alarum arrangement in views C and D is constructed as follows :―
The arrangement is placed in a casing with a vacuum chamber either for it's own
working or divided into two parts when in combination with the arrangement
shewn in A and B as before described. On the casing is placed a bell for the
alarum to ring upon. The casing may be provided with a dial or not, and the
alarum may be combined with either the pointer and dial and shutter arrangement,
or with either, as may be suitable for the purpose to which it is to be applied.
The alarum is of the ordinary escapement description provided with a spring
and pinion on the main arbor.
A rack is fitted into the pinion and attached to the diaphragm in the vacuum
chamber so that when the vacuum is formed, the rack and diaphragm are. drawn
down, and the pinion on the main arbor set in motion. The alarum may be
arranged to ring either when the vacuum is being formed, or when it goes off, or at
both times, as may be found convenient. In the case in which the alarum is
combined with the moving shutter only, the shutter is operated by the downward
movement of the winding rack, when the vacuum is formed.
Both the indicating and alarum arrangements are provided with suitable guides
for the racks, and brackets for the arbor centres, as shown. In the combination
arrangement shewn in the view E, when the vacuum is formed the pointer flies
rapidly round the dial from left to right till the arrow head reaches the graduated
part, at the same time turning the shutter so as to shew the other face, after which
the shutter remains stationary while the pointer indicates on the graduated part
the amount of vacuum. Simultaneously the alarum is wound up. When the
vacuum goes off, the pointer and shutter return to their normal position, and the
alarum rings.
The respective actions may be varied as before described, according to the
purpose to which the instrument is to be applied.
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 Vacuum Guages or Indicators, the use of arrangements for producing a
rapid movement of the pointer in combination with a moving telltale shutter
arranged and constructed and operated substantially as and for the purposes
herein before described and illustrated by the drawings A. B.
2. In Vacuum Guages or Indicators, the use of arrangements for winding and
sounding an alarum arranged constructed and operated substantially as and for the
purposes herein before described and illustrated by the drawings C. D.
3. In Vacuum Guages or Indicators the use of a divided vacuum chamber
arranged and constructed substantially as and for the purposes hereinbefore
described and illustrated by the drawings.
4. In Vacuum Guages or Indicators, the combination of a pointer with rapid
initial movement, and dial, and an alarum arranged in a casing, the whole being

page_text: constructed and operated substantially as and for the purposes herein before
described.
5. In Vacuum Guages or Indicators the combination of an alarum and a telltale
shutter, arranged in a casing, the whole being constructed and operated sub-
stantially as and for the purposes herein before described.
6. In Vacuum Guages or Indicators the combination of arrangements for pro-
ducing rapid initial movement of the pointer, a telltale shutter, and an alarum,
arranged in a casing, the whole being constructed and operated substantially as
and for the purposes hereinbefore described and illustrated by the drawings A. B.
C. D. and E.