The Improvement of Spring Bow Dividers and such like Dividing Instruments.
Year: 1887

page_text: Date of Application, 1st Mar., 1887.
Complete Left, 25th May, 1887.
Complete Accepted, 28th June, 1887.
The Improvement of Spring Bow Dividers and such like Dividing
Instruments.
I, FRANCIS OBRÉ FERGUSON of Gothic Cottage Goldhawk Road Hammersmith in
the County of Middlesex Architect; assisting in the Estate Office of the London and
North Western Railway Company at Euston, N.W. do hereby declare the nature of
this invention to be as follows:-
My invention is designed to improve the method of using Spring bow dividers and
such like instruments. And in order that my object may be understood reference is
made in the following Specification to the accompanying drawings forming a part of
Figure 2 represents a spring bow dividers about half full size and
A Figure 1 is an enlargement of A Figure 2.
the same.
I have shewn on the drawings a specimen of my invention but I do not confine
myself to any particular shape, as changes may be made in the form and still embody
the peculiar character and object of my invention.
.
In order to carry out my invention into practical effect I provide a small cup shaped
piece of brass or steel or some suitable material (and as shewn at A on the drawing
Figure 1) which has a hole pierced through its centre to receive the top part or end
of handle of dividers which is clamped so as to prevent the cup A parting from the
dividers and also constructed to allow of the said cup A being held fixed while the
rest of the instrument is made to revolve, or the cup A may have a leg fixed to its
centre and allowed to revolve in a hole made to receive it in the upper part of
instrument. The upper edge of the cup is milled to prevent its slipping under the
thumb. When using the instrument the thumb should be pressed upon the top of the
cup A and the rest of the instrument operated in the usual way with the first and
second fingers only.
I claim the improvement of spring bow dividers and such like instruments by
designing and contriving a piece of brass or suitable material to revolve on the upper
part or handle of same.

page_text: COMPLETE SPECIFICATION.
The Improvement of Spring Bow Dividers and such like Dividing
Instruments.
1 FRANCIS OBRÉ FERGUSON of Gothic Cottage Goldhawk Road Hammersmith in
the County of Middlesex Architect assisting in the Estate department of the London
and North Western Railway Company at Euston Station 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 :-
The figures on the attached drawings illustrate some of the drawing instruments
for which my invention is intended but I do not confine myself to them only they
shew how my invention is to be applied and carried into effect. My invention is
more particularly shewn by figures 67 and 8 but I do not confine myself to the
precise forms shewn which may be varied at pleasure. I now refer to the drawings
in the following description of my invention.
I prefer to perform my invention in the forms shewn at A and E figures 6, 7, and 8
A represents a cup of brass or any suitable material milled on top and of any con-
venient size or form. E represents the handle or upper part of an instrument. It is
fluted vertically and E figure S shews a horizontal section of same. The handle E
may be of any convenient size or length to suit the kind of instrument as required.
A figure 6 is pierced through its centre and fits loosely upon a pin forming a part
of E and clamped on top so as to prevent it falling away from E. Or A may be
fitted to E by means of a small screw passing through the hole in A and let into E
which is formed for its reception and as shewn on figure 7, in both ways A is free to
revolve on E.
Figure 1 shews the application of A and E to a large size dividers or compass.
Figure 2 their application to a medium size pencil bow compass. Figures 3, 4 and 5
their application to a set of spring bow compasses. E will be fixed to the main part
of instrument in all cases. The instruments may be used in practice by placing the
thumb or finger upon the cup A and the handle E turned by the remaining
fingers.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is
In spring bow dividers compasses and such like drawing instruments a cap or
head A formed on the extremity and in combination with the handle E and as set
forth and described.
1000