Improvements relating to Mathematical Drawing Instruments, Spirit Levels, Trammels, and Callipers.
Year: 1891

page_text: Date of Application, 30th June, 1891
Complete Specification Left, 30th Mar., 1892-Accepted, 14th May, 1892
PROVISIONAL SPECIFICATION.
Improvements relating to Mathematical Drawing Instruments, Spirit
Levels, Trammels, and Callipers.
We GEORGE WILLIAM DAVIS Foreman Tool Maker & Machinist 7 Thynne
Street West Bromwich & RICHARD SOUTHERTON Machine Fitter 92 Gladstone
Road Sparkbrook Birmingham do hereby declare the nature of this invention to be
as follows:-
-
The instrument to which we direct particular attention is the compass, or
divider.
We purpose combining these together with the scale rule, and calling the
combination the "scalimeter."
We effect this by employing at the fulcrum, or joint of the instrument, (&
attached to one leg) a wheel or part thereof, the same engaging with a pinion,
which is connected to the other leg.
Upon the spindle of pinion we fix a dial, which can be graduated in any standard
whatever, such as feet & inches, metres and decimetres, or in degrees &c., which
said dial can be marked on either or both sides according to the requirements of
instruments.
Over the dial an index plate is placed to effect the reading of the instrument.
The legs of the instrument are to be made either telescopic, or lengthened by
means of tubes, or additional limbs, preferably the latter, so as to read off in various
scales, such as 1"-1 ft., or 2" scale or th full size, or full size &c., and such
scales to be marked upon the loose tubes or limbs.
The compass may be made to read in one scale only, in which case the limbs
would be made without its separate attachments.
Having adapted the requirements of the scale rule to the compass; the separate
"scale rule" may be entirely dispensed with.
We do not confine ourselves solely to the use of this device upon the "scali-
meter." as it may be employed upon a beam compass, or trammel, a spirit level,
an angle gauge, or callipers.
The method we purpose adopting for using this device upon a beam compass, or
trammel, is to have the beam or bar connecting the points, notched, or serrated
each inch or part thereof, the one point allowed to travel along the bar only in
these notches.
Upon one extremity of bar a rack is attached, and gearing with this rack is a
pinion, the spindle of which is connected with a dial, that is divided off in decimal
portions of an inch, or otherwise as desired all of which is carried along with otlier
point.
At any convenient position around this dial may be placed a vernier, to effect a
more minute reading of subdivisions than is possible without such aid.
By these means, the inches are read from the one point which travels only
in these notches, or serrations, on the bar, and the decimal portions or subdivision's
from the other point upon the dial itself.
The principle upon which we adapt our device upon a "spirit level," is to attach
to the base of the level itself a limb, such limb to be connected to spirit level at
one extremity by means of a hinge.
Connected to this moveable limb is the wheel or part thereof, and to the level
itself the pinion and dial, which dial is marked in degrees and subdivisions.
Also the moveable limb and level are connected, by a slotted link' or' other

page_text: suitable means, so that when the level is set to any desired angle they may be firmly
secured to each other by means of a screw. Around this dial a vernier is placed
similar to the "beam compass."
To attach the device upon an angle gauge, we employ two limbs, at the fulcrum
or joint of which, and connected to one limb, is the wheel or part thereof, to other
limb is connected the pinion and dial, which dial is marked in degrees and
subdivisions, and connected also to a vernier same as "beam compass" and "level."
In none of the foregoing do we confine ourselves solely to the use of one
wheel and pinion, as two or more may be used, such reason being to give a much
greater magnified measurement.
Given under our hand this-29th-day-of June 1891.
GEORGE WILL
and
DAVIS
RICHARD SOUTHERTON.
RICHARD SOUTHERTON.
RICHARD SOUTHERTON.
GOMPLETE SPECIFICATION.
Improvements relating to Mathematical Drawing Instruments, Spirit
Levels, Trammels, and Callipers.
GEORGE WILLIAM DAVIS, 7, Thynne Street, West Bromwich, Staffordshire,
Foreman Engineer & Machinist, and RICHARD SOUTHERTON 92 Gladstone Road
Sparkbrook Birmingham Machine Fitter 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:
The nature of the above invention consists in employing a dial at the end of a
suitable spindle upon a pair of compasses, to enable the operator to read off the
measurement without the aid of a scale rule.
Such dial may be graduated in any known standard, as shown in Figs. 1. 3. 4 & 6.
The various scales are obtained, either by inserting separate limbs, or by making
them telescopic, or by having a series of interchangeable dials, marked on either
or both sides, and graduated in the various required scales.
In the case of separate limbs being used, the one or both would be marked for
which scale it were intended, if separate dials were employed each dial would in
like manner be marked.
In the case of the beam compass shown at Figs. 4 & 5 the dial is actuated by
means of a rack to subdivide each division upon the bar, such as 1" or 1" etc.;
then the inches are read from the one point which travels in the notches,
(A Fig. 4) and the fractional portion upon the dial itself (B Fig. 4). The dial
can be actuated either by means of the nut C in front of dial, or by screw D on
end of bar.
With the spirit level is attached a limb B connecting with the level A at one
extremity of level by a hinge, (Fig. 6). ·
The quadrant is attached to the level while the spindle containing the pinion
and dial is carried by the loose limb as shown in Figs. 5 & 6.
With the callipers the mode of construction is same as in the compass, Figs. 1. 2
& 3, except that they would contain calliper extremities to the limbs instead of
points as shown..
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
(1st.) Any revolving dial or series of dials, or fingers upon a dial, as applied
to any of the, above mentioned instruments, for the purposes of self-registering
measurement

page_text: (2nd.) Any revolving dial or dials, or fingers upon a dial, as applied to any of the
above mentioned instruments for the purposes of self-registering measurement,
whose scale is varied by adding to, or diminishing the length of the legs of the
instrument.
Given under our hand this 30th day of March 1892.
GEORGE WILLIAM DAVIS.
RICHARD
SOUTHERTON.