AN IMPROVEMENT IN GYMNASTIC APPARATUSES, KNOWN AS SEE-SAWS, AND AN IMPROVED MODE OF WORKING THE SAME
Year: 1860

page_text: LETTERS PATENT to Martin Deavin, of Crystal Terrace, Rotherhithe
New Road, in the County of Surrey, Builder, for the Invention of
"AN IMPROVEMENT IN GYMNASTIC APPARATUSES, KNOWN AS SEE-SAWS, AND
AN IMPROVED MODE OF WORKING THE SAME."
Sealed the 9th April 1861, and dated the 13th October 1860.
PROVISIONAL SPECIFICATION left by the said Martin Deavin at the
Office of the Commissioners of Patents, with his Petition, on the
13th October 1860.
I, MARTIN DEAVIN, of Crystal Terrace, Rotherhithe New Road, in the
County of Surrey, Builder, do hereby declare the nature of the said
Invention for "AN IMPROVEMENT IN GYMNASTIC APPARATUSES, KNOWN AS SEE-
SAWB, AND AN IMPROVED MODE OF WORKING THE SAME," to be as follows:-
My Invention consists, first, in constructing gymnastic apparatuses, known
as see-saws, with contrivances for adjusting the same in such manner that when
the two ends of the see-saw are occupied by unequal numbers of children, or
other persons, or by persons of unequal weights, the rocking beam may be
readily brought to balance about its centre of motion. The contrivances
which I prefer to employ for this purpose consist of a rack or racks
attached to the bottom of the rocking beam, and of corresponding teeth

page_text: placed upon the axle on which the rocking beam turns, such axle being
fitted with a handle for imparting motion to it. As the handle is turned
the said beam will be caused to move in one or other direction according to the
direction in which the handle is turned. Although I prefer this arrangement
I do not confine myself thereto, as the adjustment of the balance may be
effected by many modified arrangements.
My Invention consists, secondly, in a mode of working see-saws by means of
cords or ropes attached to an upright pole forming part of the machine, or to
any other convenient object, such cords or ropes being pulled upon by the
occupant or occupants of the apparatus; I prefer in some cases to pass the
cords or ropes round a pulley or pulleys for the purpose of changing the
directions of the same, and of varying the distance through which the pull of
the occupants may be exerted, but as cords or ropes have never before been
used for the purpose of enabling the occupants of the see-saw to rock it, and
as I have discovered that the employment of them in this way is very useful
both by dispensing with an attendant, and by affording exercise to the children
or other occupants, I claim the mode of working see-saws by means of them
as part of my Invention.
In manufacturing my improved see-saws I prefer to fit a seat, or two or
more seats at each end of the rocking beam, and I place a spring upon each
end of this beam at the under side for the purpose of preventing the ends from
striking the floor or ground with violence.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Martin Deavin in the Great Seal Patent Office on the
18th April 1861.
TO ALL TO WHOM THESE PRESENTS. SHALL COME, I, MARTIN
DEAVIN, of Crystal Terrace, Rotherhithe New Road, in the County of
Surrey, Builder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of October, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Martin Deavin, Her special licence that I, the said Martin'
Deavin, my executors, administrators, and assigns, or such others as I,
the said 'Martin Deavin, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times

page_text: thereafter, during the term, therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Bri-
tain and Ireland, the Channel Islands, and Isle of Man, an Invention
for. "AN IMPROVEMENT IN GYMNASTIC APPARATUSES, KNOWN AS SEB-SAWS,
AND AN IMPROVED MODE OF WORKING THE SAME," upon the condition
(amongst others) that I, the said Martin Deavin, my executors or
administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Martin Deavin, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof; reference being. had to the Drawings hereunto annexed,
that is to say:-
My Invention consists, first, in constructing gymnastic apparatuses, known
as "see-saws," with contrivances for adjusting the same in such manner that
when the two ends of the see-saw are occupied by unequal. numbers of children
or other persons, or by persons of unequal weights, the rocking beam may be
readily brought to balance about its centre of motion. The contrivances which
I prefer to employ for this purpose consist of a rack or racks. attached to the
bottom of the rocking beam, and of corresponding teeth placed upon the axle
on which the rocking beam turns, such axle being fitted with a handle for
imparting motion to it. As the handle is turned the said beam, will be caused
to move in one, or other direction, according to the direction in which the
handle is turned. Although I prefer this arrangement I do not confine myself
thereto, as the adjustment of the balance may be effected by many modified
arrangements.
My Invention consists, secondly, in a mode of working see-saws by means of
cords or ropes attached to an upright pole forming part of the machine, or. 'to
any other convenient object, such cords or ropes being pulled upon by the
occupant or occupants of the apparatus. I prefer in some cases to pass the
cords or ropes round a pulley or pulleys for the purpose of changing the direc-
tions of the same, and of varying the distance, through which the pull. of the
occupants may be exerted.;
"
IT'
In manufacturing my improved see-saws I prefer to fit a seat,. or two or
more seats, at each end of the rocking beam, and I place a spring or springs.

page_text: upon each end of this beam at the under side for the purpose of preventing
the ends from striking the floor or ground with violence.
In the accompanying Drawing I have illustrated one method of carrying
my Invention into effect, Figure 1 being a side elevation; and Figure 2; a
plan of the under side of an apparatus made in the manner before described.
a is the rocking beam, free to oscillate about the shaft b; c, e, are toothed
racks, placed on the under side of the rocking beam, into the teeth of which
pinions d, d, take, which are mounted on the shaft b; e is a winch handle, for
communicating motion to the shaft 6; by turning this handle the pinions take
into the teeth of the rack, and consequently move the beam either to the right
or to the left according to the direction in which the handle is turned, so that
the balance of varying weights occupying the seats f, f¹, may be adjusted. The
seats ff are placed, as shewn at the end of the beam; 9, 9, are springs
beneath the seats; for preventing the beam from forcibly striking the ground or
platform on its downward motion. In order to prevent the beam shifting its
position accidentally after being once adjusted on the shaft b, I use a small
spring paul or apparatus shown detached in side and face views at Figures 3
and 4; i is a spring, connected to the side frame; it is forked at its upper end,
as shown, so as to engage in the teeth of one of the pinions; 7 is a spindle,
carrying a blade m and handle n, the blade presses against the spring i, so
that by turning the handle n the forked end of the spring is pressed out from
between the teeth of the pinion d, and allows the beam to be shifted to the
required position. In some apparatuses I make use of only one rack and pinion
for adjusting the beam; o is one of two poles connected to the apparatus for
aiding in working the see-saws. The cords connected to these poles may be
arranged in either of the modes illustrated at Figure 1, on opposite sides of
the apparatus, or in other more convenient manner; p is a cord attached to
the back of one seat, led through a ring or pulley 9 at the top of the pole down
through another ring r to the hand of the person occupying the seat f¹; sis
another cord attached to the ring q, or to another similar ring at the top of the
pole and led down to the occupant of the seat f. In some cases I fit cords
with adjustable buckles, so that their length may be easily regulated. By
pulling the cords from the seats f and f¹ a rocking motion is imparted to the
beam.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I do not limit myself to
the precise arrangements herein-before described; but what I claim as my
improvement in gymnastic apparatuses known as see-saws, and the improved
mode of working the same is,--

page_text: First, adjusting the rocking beams of see-saws, so that the ends may carry
unequal weights, substantially in the manner herein-before described and
illustrated in the accompanying Drawings.
Second, the employment of cords or ropes for the purpose of communicating.
a rocking motion to the beam of see-saws.
In witness whereof, I, the said Martin Deavin, have hereunto set my
hand and seal, this Thirteenth day of April, One thousand eight
hundred and sixty-one.
MARTIN DEAVIN. (L.s.)