An Improvement in Compasses.
Year: 1890

page_text: Date of Application, 5th June, 1890
Complete Specification Left, 30th July, 1890-Accepted, 30th Aug., 1890
PROVISIONAL SPECIFICATION.
An Improvement in Compasses.>
I, JOHN HOкWOOD, of 5 Myrtle Street, Hoxton, N., in the County of Middlesex,
Mathematical Drawing Instrument Maker, do hereby declare the nature of this
invention to be as follows:—
My invention relates to spring bows and consists in providing two fittings, one in
each side of the bow, which move with the bow as it is closed and opened, the bolt
working through the fittings in each side with right and left handed thread. The
instrument closes and opens in half the time that is required to operate with the ordinary
bow compass.
Dated this high dose of June 1800
JOHN HORWOOD,
Applicant.
COMPLETE SPECIFICATION.
An Improvement in Compasses.
I, JOHN HORWOOD, Mathematical Instrument Maker, of 5 Myrtle Street, Hoxton, N.,
in the County of Middlesex, 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 spring bows and consists in providing two fittings, one in
each side of the bow, which move with the how as it is closed and opened, the bolt
working through the fittings in each side with right and left handed threads.
The advantage of my invention is that the instrument cioses and opens in half
the time that is required to operate with the ordinary bow compass now in common
use.
And in order that my invention may be thoroughly understood, I now proceed
to describe the accompanying drawings thereof reference being had to letters and
figures marked thereon.
Figure is a front elevation of the spring how compass, with a portion of the
block c in section.
Figure 2 is a side elevation of the block c and a portion of the spring bow a.
с
figure is broken off for want of space.
This
This invention is constructed with a spring bow a, a, with a block con each side
and the usual legs or points. In each block 1 pierce a hole d and insert a nut e, this
said nut I fix by centre pins, so as to allow the nuts e to oscillate. The bolt
has fixed in the centre a knurled wheel b, the said bolt being screwed with a right
hand thread and a left hand thread g.
By the method and construction herein shown and described, I am enabled by the
operation of the knurled wheel to close or open the instrument in half the time
required to operate with the ordinary bow compass.
The object of this invention is that when the bolt is in motion either to open or
close the bow, the nuts oscillate in the hole d, to permit both the right and left hand
threads to operate at the same time.
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-
1. The combination of the bolt with right and left handed threads, and the wheel b,
with the nuts e, e, oscillating on centre pins, in the holes d, for the purpose of closing

page_text: or opening the bows a, substantially as herein described and according to the
accompanying drawing.
2. claim to attach this device to a pencil, ink, or divider bows, of any size,
substantially as described and for the purpose herein set forth.
Dated this 30th day of July 1890.
J. P. BAYLY,
18, Fulham Place, W., Agent for the Applicant.