IMPROVEMENTS IN CALIPERS FOR GAUGING VARIATIONS OF THICKNESS IN PIPES, TUBES, . PLATES AND OTHER MATERIALS."
Year: 1880

page_text: LETTERS PATENT to Andrew Scott, of the City Road, Finsbury Square, in
the County of Middlesex, Civil Engineer, for an Invention of "IMPROVEMENTS
IN CALIPERS FOR GAUGING VARIATIONS OF THICKNESS IN PIPES, TUBES, .
PLATES AND OTHER MATERIALS."
PROVISIONAL SPECIFICATION left by the said Andrew Scott at the Office.
of the Commissioners of Patents on the 6th December 1880.
ANDREW SCOTT, of the City Road, Finsbury Square, in the County of Middlesex,
Civil Engineer.
"IMPROVEMENTS IN CALIPERS FOR GAUGING VARIATIONS OF
THICKNESS IN PIPES, TUBES, PLATES, AND OTHER MATERIALS."
My Invention is designed for the purpose of gauging the thickness of gas, steam,
and water pipes, steam cylinders, girders, plates, and any other material where it
may be requisite to detect variations in thickness.
My apparatus consists of two long arms of brass or other suitable and durable
material which terminate at one extremity in two gauging points, one on each
arm, and projecting towards one another at right angles to the length of the
arms.
These gauging points are made of a hard material, such as steel, and are adjust-
able by screw thread so that they can be accurately adjusted to the reading scale
before a measurement is taken.
One of these gauging points is also fitted to a sliding rod adjustable in the arm
by a set-screw. At the opposite ends of the arms to that of the gauging points
the arms are connected by two pivoted links forming a parallel motion.
As then the gauging points are brought together on the metal that has to be
measured the whole arms must move together in a parallel manner, so that the
distance between the gauging points is accurately shown by the distance between
the upper ends of the arms.
A finely divided scale is attached to one of the upper ends of the arms projecting
at right angles to the arms, and passing conveniently through a slot in the other
arm

page_text: Upon this scale, in conjunction with which a vernier may be used if desired,
the spacing of the upper arms and thus of the gauging points is accurately
indicated.
The length of the gauging arms may be made of any desired length so as to
reach at least half way down any special pipe or bend or other material of which
it is desired to gauge the thickness.
One or more projections may be conveniently spaced upon one of the arms to be
in contact at several points in the length of the arm to aid the operator in con-
veniently applying the calipers.
On the reading end a handle is designed to facilitate the handling of the instru-
ment, and a suitable clip is provided to secure the two parts firmly together when
out of use.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Andrew Scott in the Great Seal Patent Office on the 4th June
1881.
"
°
ANDREW SCOTT, of the City Road, Finsbury Square, in the County of Middlesex,
Civil Engineer.
IMPROVEMENTS IN CALIPERS FOR GAUGING VARIATIONS IN
THICKNESS IN PIPES, TUBES, PLATES, AND OTHER MATERIALS."
My Invention is designed for the purpose of gauging the thickness of gas, steam,
and water pipes, steam cylinders, girders, plates, and any other material where it
may be requisite to detect variations in thickness.
My apparatus consists of two long arms of brass or other suitable and durable
material which terminate at one extremity in two guaging points, one on each arm,
and projecting towards one another at right angles to the length of the arms.
These gauging points are made of a hard material, such as steel, and are adjustable
by screw threads so that they can be accurately adjusted to the reading scale
before a measurement is taken. One of these gauging points is also fitted to a
sliding rod adjustable in the arm by a set screw. At the opposite ends of the arms
to that of the gauging points the arms are connected by two pivoted links forming
a parallel motion.
.
As then the gauging points are brought together on the metal that has to be
measured, the whole arms must move together in a parallel manner, so that the
distance between the gauging points is accurately shown by the distance between
the upper ends of the arms.
A finely divided scale is attached to one of the upper ends of the arms projecting
at right angles to the arm, and passing conveniently through a slot on the other
arm.
Upon the scale, in conjunction with which a vernier may be used if desired,
the spacing of the upper arms and thus of the gauging points is accurately
indicated.
The length of the gauging arms may be made of any desired length, so as to
reach at least half way down any special pipe or bend or other material of which
it is desired to gauge the thickness.
One or more projections may be conveniently spaced upon one of the arms to be
in contact at several points in the length of the arm to aid the operator in con-
veniently applying the calipers.
On the reading end a handle is designed to facilitate the handling of the instru-
ment, and a suitable clip is provided to secure the two parts firmly together when
out of use.
And in order that my Invention may be the better understood I now proceed to
describe the Drawings hereto annexed, reference being had to the letters and
figures marked thereon, that is to say,―
Figure I. is a sectional elevation of my improved caliper, and Figure II. is a
sectional elevation of an alternative arrangement; Figure III. is a detail of the
connecting rod; Figure IV. a detail of the side parallel links B showing the
manner in which they are fitted, and Figure V. is a detail of the scale fitted as
sledge link in alternative arrangement.
In Figure I., A, is one main arm of the calipers carrying the fixed gauge point C
and travelling on the parallel links B, B, by which it is attached to the other
arın D.
This arm D carries a sliding gauge point E which is moved longitudinally with
the arm by means of the inner tube F and the pin G; this pin receives its motion
from the sledge link K which travels by roller bearings L, L, one of which
embraces the arm like a strap so as to keep the sledge link in its place on the
arm.

page_text: This sledge link K and consequently the gauge point E is caused to travel
simultaneously with the upper arm A by means of the pin L¹ which is capable of
sliding motion in the hole M of the arm A, which therefore carries the sledge link K
along with it in a longitudinal direction.
The links B, B, oblige the arm A to travel outwards from the other arın D in a
truly parallel manner, and the amount of such travel corresponding to the distance
of the gauge points C and E from one another may be accurately ascertained from
the scale N which passes through slots in the arms A and D.
The gauge point C although fixed in the arm A is capable of adjustment
transversely to the arm A and towards the other gauge point E by means of a
thumb set screw O.
In Figure II. the sliding gauge point E is fitted in a stronger form upon the
inner tube F. In this arrangement the pin L' and the sledge link K are
dispensed with, the reading scale N fitting in its slots in the arm A answering the
purpose for communicating the longitudinal motion of the arm A to the sliding
gauge point E. The scale N is fitted with rollers K', K', on each side of the arm D
on which it runs so that it is rigidly held in its position. It is screwed to the loop
link P of the inner tube F of the gauging point E, such loop being necessary to
allow motion past the fixed pin Q of the parallel link.
And having now fully described and ascertained the nature and object of my
Invention and the manner in which it is to be performed, be it understood that
what I consider novel and useful and desire to protect by my Letters Patent is,-
I. the construction of an improved caliper by the combination of two arms
adjustable lengthwise with gauging points at one extremity connected by links
forming parallel motion to adjust the spacing between the gauging points, so that
the gauge at the points is correctly reproduced at the reading end, as and for the
purposes substantially herein before described.
II. The combination with my said improved caliper of a divided scale sliding
through one of the arms with or without a vernier, as and for the purposes
substantially herein before specified.
In witness whereof, I, the said Andrew Scott, have hereunto set my hand
and seal, this Thirtyeth day of May, in the year of our Lord One thousand
eight hundred and eighty one.
In the presence of
SAM. P. WILDING,
23, Rood Lane,
London E.C.,
Patent Agent.
AND. SCOTT. (L.S.)