An Improvement in Parallel Rulers.
Year: 1897

page_text: Date of Application, 5th Feb., 1897-Accepted, 20th Mar., 1897
An Improvement in Parallel Rulers.
I, ARNULPH MALLOCK, of No. 3 Victoria Street, Westminster, in the County of
London, 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 :-
My invention relates to the construction of a parallel ruler in such a manner that
its rollers are not in contact with the paper or surface on which it can run, unless they
are depressed by acting on a knob, and that by employing two sets of rollers, with a
knob for each set, the ruler can be made to run parallel to itself in one direction when
the one knob is depressed, and can be run in a direction at right angles to the former
when the other knob is depressed.
Fig. 1 of the accompanying drawings is a plan of a parallel ruler according to my
invention provided with two sets of rollers and a knob for each set.
Fig. 2 is a plan looking from below and
Fig. 3 is a section on the line 3-3 of Fig. 2.
The body of the ruler is a shallow cup A of square outline with its edges bevelled
so that lines can be drawn along them. The bevelled faces may be graduated with
any desired scales, or with oblique protractor lines determining angles from one of
the corners. B is a central knob by which the ruler can be lifted or pushed along ;
C and D are two other knobs, by depressing the one or the other of which the
ruler is suited to roll in the one or the other direction. In the cup cavity on the
under side are arranged two sets of levers and rollers-which operate in the following
manner.
The stem c of the knob C bears on the arm of a lever which has two fulcra c¹ c³
bearing against the top plate and a middle bar c³ having its ends pivotted in two
bars terminating in gabs in which are engaged the parallel spindles cc of
two pairs of fluted rollers. In like manner the stem d of the knob D bears on
the arm of a lever which has two fulcra d¹³, and a middle bar d³ having its ends
pivotted in two bars d d³ terminating in gabs in which are engaged the parallel
spindles d d of two pairs of fluted rollers. A pair of bent springs c and d acting
on the bars and d³ press them upwards and thus keep the fluted rollers clear of
the paper or other surface on which the ruler rests. But on pressing down the
knob C and so depressing the bar and the bars c and the spindles care
urged down pressing their rollers on the paper, and, so long as the knob C is
depressed the ruler can travel on those rollers always parallel to itself.
In like manner on pressing down the knob Ď the spindles d d of the other
rollers are depressed, and then the ruler can travel in a direction at right angles
to its former direction.
I have described a parallel ruler with two sets of rollers and their knobs, suited for
running in either of two directions.
It is to be understood, however, that one of the knobs such as D and the spindles de
and d with their rollers and the intermediate connections might be dispensed with,
the ruler being then adapted to run in only one direction on depressing the remaining
knob C.

page_text: Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
-claim is':-
1. A parallel ruler having its rollers kept off the paper or surface on which it is to
run, unless they are depressed by acting on a knob, substantially as described.
2. A parallel ruler having two sets of rollers on spindles at right angles to each
-other, each set arranged as in the preceding claim, substantially as described.
Dated this 5th day of Febru 1807
ABEL & IMRAY,
Agents for the Applicant.