AN IMPROVEMENT IN ELLIPTIC OR OTHER ELASTIC SPRINGS
Year: 1867

page_text: LETTERS PATENT to Edwin Marcus Chaffee, of the City and County of
Providence, State of Rhode Island, United States of America, Manu-
facturer, for the Invention of "AN IMPROVEMENT IN ELLIPTIC OR OTHER
ELASTIC SPRINGS."
Sealed the 9th July 1867, and dated the 11th January 1867.
PROVISIONAL SPECIFICATION filed by the said Edwin Marcus Chaffee
at the Office of the Commissioners of Patents, with his Petition, on the
11th January 1867.
I, EDWIN MARCUS CHAFFEE, of the City and County of Providence, State
of Rhode Island, United States of America, Manufacturer, do hereby declare
the nature of the said Invention for "AN IMPROVEMENT IN ELLIPTIC OR OTHER
ELASTIC SPRINGS," to be as follows:-
This Invention consists in the introduction of rubber or any of its allied
gums between the plates or "lifts" of elliptic steel springs for the purpose of
reducing or preventing the injury to the elasticity of the springs, and also the
wear and tear and other consequent results of friction between, the plates.
This improvement is applied to ordinary elliptic springs by simply raising
the ends of the lifts slightly from one another, at inserting at or near their
ends small pieces of rubber or other elastic material, fabricated or not, which
will have the effect of entirely. preventing friction between the plates..

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edwin Marcus Chaffee in the Great Seal Patent Office
on the 11th July 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWIN
MARCUS CHAFFEE, of the City and County of Providence, State of Rhode
Island, United States of America, Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of January, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edwin Marcus Chaffee, Her special licence that I, the said Edwin
Marcus Chaffee, my executors, administrators, and assigns, or such others as
I, the said Edwin Marcus Chaffee, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time, and at all
times thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Island, and Isle of Man, an Invention for "AN
IMPROVEMENT IN ELLIPTIC OR OTHER ELASTIC SPRINGS," upon the condition
(amongst others) that I, the said Edwin Marcus Chaffee, 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 performed, 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 Edwin Marcus Chaffee, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof (that is to say) :-
My Invention relates to an improvement in the common elliptic steel
springs, and consists in the introduction of rubber or any of its allied gums
between the plates or "lifts" of the spring for the purpose of reducing or
preventing the consequent results of friction between the plates.
It is well known that in elliptic springs formed from plates that the wear
upon the several plates occasioned by the constant working of one upon another
not only reduces the natural elasticity of the several plates, but wears away
the metal so rapidly that this otherwise perfect spring is rendered useless for
many purposes.

page_text: By my Invention these difficulties are entirely overcome, and to enable
others skilled in the art to construct and use my improvements I will proceed
to describe the same as illustrated in the accompanying Drawings, in which
Figs. 1, 2, and 3 are side views of elliptic springs of different construction to
which my improvements are applied.
In Fig. 1, the plates or lifts a, b, c, d, are represented as formed from thin
metal; at the centre between each of the lifts I place a metal or other plate,
as denoted in black, which raises each lift slightly off the surface of the one
below it, then at or near the points of each lift I place a piece of sheet rubber
or similar elastic substance f, fabricated or not, and at intervals on the larger
lifts other pieces i may be inserted. I find by experiment that the best sizo
for these pieces is about one-sixteenth of an inch thick, and three-eighths of
an inch wide, and of a length equal to the width of the plates.
In Fig. 2 is shown a spring of like construction, but of solid plates, having
the rubber introduced in like manner as in Fig. 1.
In Fig. 3 is represented an old spring, into which the rubber is inserted in
the following manner :-Raise the end of each lift slightly from the other,
then insert the pieces of rubber in like positions, as before described. More
or less pieces than shewn may be inserted and of different dimensions than
those herein given, but I find this arrangement to be the best for ordinary
carriage springs; larger or heavier springs would of course require increased
dimensions of the rubber. If required the pieces of rubber may be cemented
in their places, but this I do not find necessary. The rubber being thus
inserted will when the spring is compressed prevent the surfaces of the plates
coming in contact one with the other, the natural elasticity of the rubber
yielding between the two surfaces, thus the rubbing and consequent wear of
one plate against the other is wholly and entirely avoided. If after use it
should from any cause be necessary to replace the rubber simply raise one
plate from the other, remove the old rubber and insert fresh pieces; the wear
however upon the rubber is so slight that such change would be rendered
almost unnecessary. If preferred an indentation or recess may be formed in
the leaves of the spring to receive the rubber, so that the space between tho
leaves would be nearly closed.
I do not, therefore, confine myself to the precise manner of inserting the
rubber, but having fully described and ascertained the nature of the said
Invention, and the manner in which the same is or may be performed, what
I claim as new and useful and desire to secure by Letters Patent is, the
introduction of india-rubber or similar elastic substance between the leaves or

page_text: lifts of elastic springs, substantially in the manner and for the purpose herein-
before set forth and described.
In witness whereof, I, the said Edwin Marcus Chaffee, have hereunto
set my hand and seal, this Seventh day of June, in the year of our
Lord One thousand eight hundred and sixty-seven.
EDWIN MARCUS CHAFFEE. (L.S.)