Improvements in Compasses, Calipers, and other similar Measuring Instruments.
Year: 1895

page_text: Date of Application, 8th Oct., 1895
Complete Specification Left, 8th July, 1896-Accepted, 8th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in Compasses, Calipers, and other similar Measuring
Instruments.
I, WILLIAM CHARLES SHARPE, of Bridlington House, Hainton Street, Grimsby
in the County of Lincoln, Sanitary Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to improvements in that class of measuring instru nents
which commonly consist of two straight or curved legs jointed or hinged together
and provided with more or less sharp points such as compasses and calipers for
example.
In using compasses for measuring from one point to another of a plan for
example, the pointed end of one leg of the compasses is placed on one point on the
plan and the other leg is then opened or closed sufficiently to bring its pointed end
on to the other point on the plan. The compasses are then removed in that
condition from the plan and placed on a graduated scale or rule and the distance
from point to point is thereby ascertained.
The object of my invention is to provide means whereby the distance contained
at any time between the two pointed ends of the compasses or calipers may be
ascertained at sight without applying the said points to a scale or rule.
For this purpose I provide in connection with one of the legs of the compasses
for example, at its head or part where it is hinged to the other leg, a suitably
graduated dial, the index of which is connected to and moved proportionately with
the movement of the other leg. This movement of the dial and index in relation
to one another may be effected by any suitable or convenient arrangement of
mechanism, such for example as a toothed sector on the head of one leg, gearing
with or without intermediate gear with a toothed wheel on the arbor of the index.
The dial may be provided with two faces and indices, one being adapted for
drawings made to one scale and the other for drawings made to a different scale or
several scales may be marked on one dial.
I prefer to provide suitable means for the protection of the points of the
compasses when not in use in order to keep them perfectly true.
Dated this 8th day of October 1895.
COMPLETE SPECIFICATION.
Improvements in Compasses, Calipers, and other similar Measuring
Instruments.]
I, WILLIAM CHARLES SHARPE, of Bridlington House, Hainton Street, Grimsby,
in the County of Lincoln, Sanitary Engineer, do hereby declare the nature of this
invention, and in what manner the saine is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to improvements in that class of measuring instruments
21

page_text: which commonly consist of two straight or curved legs jointed or hinged together,
and provided with more or less sharp points, such as compasses and calipers for
example.
In using compasses for measuring from one point to another of a plan for
example, the pointed end of one leg of the compasses is placed on one point on the
plan and the other leg is then opened or closed sufficiently to bring its pointed end
on to the other point on the plan. The compasses are then removed in that
condition from the plan and placed on a graduated scale or rule, and the distance
from point to point is thereby ascertained.
The object of this invention is to provide means whereby the distance contained
at any time between the two pointed ends of the compasses or calipers may be
ascertained at sight without applying the said points to a scale or rule.
The accompanying drawings illustrate my invention as applied to a pair of
compasses, Figure 1 being a front view, Figure 2 a similar view but with the dial
plate removed, and Figure 3 a sectional elevation taken on a plane at right
angles to that of Figures 1 and 2.
I provide in connection with one of the legs a of the compasses at its head, or
part where it is hinged to the other leg, a suitably graduated dial 6 the index c of
which is connected to and moved proportionately with the movement of the other
leg d. This movement of the dial 6 and index c in relation to one another may be
effected by any suitable or convenient arrangement of mechanism, such for example
as a toothed sector e on the head of the leg d gearing with or without intermediate
gear, with a toothed pinion fon the arbor of the index c. Each side of the head of
the compasses may be provided with a dial and index so that a reading may be
taken from either side of the compasses. The dials bare preferably so arranged
that they may be easily removed and others substituted, thus allowing plans of
various scales to be read by means of the same pair of compasses. Or several
scales may be marked upon one dial.
When not in use the poirts of the compasses may be enclosed in a screw or other
cap for the purpose of protecting them and preserving the truth and accuracy of
the instrument.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
First. In compasses, calipers and other similar measuring instruments, the
employment of indicating mechanism whereby the distance apart of the pointed
ends of the two legs may be read at sight on a dial, substantially as described with
reference to the drawings.
Second. In compasses, calipers, and other similar measuring instruments the
combination with the legs of such an instrument, of indicating devices consisting
of a graduated dial, an index and gearing actuating the same, substantially as
described.
Dated this 8th day of July 1896