IMPROVEMENTS IN MEASURING GAUGES
Year: 1886

page_text: I, JOHN KIRK of Chantery Road, Woodseats, Sheffield in the County of York
Clerk do hereby declare the nature of my invention for IMPROVEMENTS IN
MEASURING GAUGES and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement that is
to say :-
My invention relates to the construction of a Gauge for measuring the thickness
of metals, or other articles or substances, and so arranged that the measurements
(and if desired their foreign equivalents) may be read with ease by the naked eye
to very minute subdivisions.
And in order that my invention may be clearly described and fully understood
I annex a sheet of drawings of a gauge made according to my invention, and
intended to measure up to one English inch.
Fig. 1. is an elevation of the front side of the Gauge.
Fig. 2. is a section through the line y. x.
The instrument is made in two principal parts the one marked A being broad
and flat, and upon which the various English and Foreign measurements are
marked, the other part B being a moveable arm, connected to the part A, by a
spring joint C, the tendency of which is to open the jaws as shown.
This arm is curved on its lower edge D, the said curve being a segment of a
circle, the diameter of the said circle being varied when required to suit special
purposes.
Both the parts A and B, are provided with a "knife-edge" jaw, a and b, which
mect when the two parts of the instrument are passed together; these jaws if
preferred may be made with an adjusting movement so as to compensate for wear.
A slide E is fitted to the part A, preferably by means of a projection fitting into
a groove F, and retained by any means usually employed for such a purpose; in
the drawing I have shown the part A, made with a wood back G-provided with
a large longitudinal groove seen in the sectional figure 2, and faced with a metallic
plate H, on which the scales are marked, and in which a slut or groove F is cut;
through the slot an oblong projecting slide-bit attached to the back of the slide E,
is passed, and has a spring secured to it which bears against the back of the metallic
plate, preventing any shake in the slide, yet allowing it to be readily moved from
end to end of the slot F as desired.

page_text: The object of this invention as before mentioned is chiefly to enable minute
parts of measurements to be read with ease and rapidity, and to accomplish this,
the scales upon the part A are enlarged, say for example to four times the actual
size, thus the subdivisions of an inch, enlarged to four inches could be easily read
by the naked eye up to 200ths.
In this case I make the curve of the lower edge of B of the segment of a circle
the radius of which is twice the length of the distance from the centre of spring
joint C to the jaw.
The article to be gunged is placed between the jaws a, b, which are then firmly
closed upon it, the slide E is then moved back until it comes in contact with the
curved edge of B, which is then released, the spring of the joint C at once releases
the gauge from the article, and the measured size can be at once read off upon the
various scales from the edge of the slide E, thus if the article is half an inch dia
the slide moves two inches at which point the scale is marked half an inch. All
the measures or scales are enlarged in the same proportion and may be subdivided
to any desired extent, and may be so placed that they can all be read off at a
glance from the edge of the slide.
A "Vernier" may be carried on the bottom edge of the slide as shown by which
the most minute divisions may be read.
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. The measuring Gauge, substantially as hereinbefore described and illustrated.
2. In measuring Gauges, the use of a curved arm B, in combination with a
slide E, moving in a groove F, formed in a straight arm A, and the jaws a, b, for
the purpose specified, and substantially as shown.