An Implement for Measuring Limited Lengths and Automatically Calculating certain Fractional Parts of such Lengths.
Year: 1899

page_text: Date of Application, 4th Mar., 1899-Accepted, 8th Apr., 1899
An Implement for Measuring Limited Lengths and Automatically
Calculating certain Fractional Parts of such Lengths.
A communication from JOHN LAURENCE BROWN, Junior, of Bowenfeld, in the
Colony of New South Wales, Accountant.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
In making measurements that comprise the fractions of integers, it requires a
considerable mental effort on the part of uneducated men to find, say, the halves
or thirds, or doubles, or trebles, of these fractional parts. This implement has
been specially devised for the express purpose of making the calculations auto-
matically.
The invention is an adaptation of the principle shewn in the implement known
as the slide rule and consists of three or more slides which work together, the
slides being connected to one another by gearing. On the faces of the slides are
line markings proportionate to one another, thus; No. 1 slide will be marked to
normal inches, No. 2 slide will be marked to a scale of 2 to 1 and No. 3 slide will
be marked to a scale of 3 to 1. Or, if desired, all the slides may be marked alike.
Each slide will be provided with a rack, above which, at one end of the slide is
a pinion, the number of teeth in the three pinions being proportional, thus the
pinion gearing with No. 1 slide will have a certain number of teeth. The pinion
gearing with No. 2 slide will have half that number of teeth and the pinion gear-
ing with No. 3 slide will have one third the number of teeth that there are on
the pinion No. 1. The three pinions are keyed on to the same axis so that when
No. 1 slide is pulled out, No. 2 and No. 3 slides will be forced out by their respec-
tive pinions, No. 2 slide to a distance one half that of No. 1 and No. 3 to a distance
one third that of No. 1.
But in order that the invention may be properly understood reference is made
to the accompanying sheet of drawings, in which:-
Fig. 1 is a cross section of the implement, the pinions being shewn in elevation.
Fig. 2 is a longitudinal section taken on the line 1-2 of Fig. 1.
A is No. 1 slide, A² is No. 2 slide, and A³ is No. 3 slide. Racks B1, B2, B3 are
arranged longitudinally upon the slides and immediately above the racks are
the pinions C, C2, C3 the pinions being all keyed upon the common shaft D
which runs in bearings E E at each end. The shaft D may be provided with a
thumb screw F by which it may be rotated. The pinions and shaft are preferably
enclosed in a box G so that they will be less liable to be in the way. The box G
will be attached to the frame H in which the slides are mounted.
The slides A1, A2, A3 should project slightly beyond one end of the frame H
and be provided with projections to afford a finger hold on the slides whereby
either one of them may be pulled out by hand. The box containing the pinions

page_text: is preferably near the extremity of the implement from whence the ends of the
slides project. By placing the pinions in this position the slides will be less liable
to jam in their grooves and the operation of pulling out the slides will be facili-
tated.
The implement is worked in the following manner. A measurement is taken
by pulling out slide (A) to a distance of say 73 inches, at the same time this
will have the effect of projecting A2 slide 37 inches and A³ slide 27/12 inches.
The line markings upon the slides which give the measurements may be either
upon the tops of the slides or on the bevels and different markings may be given
on either bevil or on each side of the slide. The markings may also be made so
as to suit the requirements for which the rule is intended.
Having now particularly described and ascertained the nature of the said in-
vention, as communicated to me by my foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is :-
are
1. A measuring and calculating implement consisting of slides which
operated by pinions of different diameters whereby when one slide is pulled out
the other slides shall be forced out distances proportional to the distance that the
slide has been pulled out, such distances being regulated by the relative diameters
of the pinions.
2. The general arrangement construction and combination of parts in my
implement for measuring limited lengths, and automatically calculating certain
fractional parts of such lengths as and for the purpose herein specified.
Dated this 4th day of March 1899.
"
BOULT & WADE,
Agents for the Applicant.