IMPROVEMENTS IN CARRIAGE SPRINGS
Year: 1877

page_text: LETTERS PATENT to John Belmer Armstrong, of the Town of Guelph, in the
County of Wellington, in the Province of Ontario, Canada, Manufacturer, for
the Invention of "IMPROVEMENTS IN CARRIAGE SPRINGS,"
COMPLETE SPECIFICATION filed by the said John Belmer Armstrong at the
Office of the Commissioners of Patents on the 6th December 1877.
JOHN BELMER ARMSTRONG, of the Town of Guelph, in the County of Wellington,
in the Province of Ontario, Canada, Manufacturer. "IMPROVEMENTS IN CARRIAGE
SPRINGS."
This Invention relates to an improved carriage spring, and consists,-
First. Of a crucible or cast steel single plate or leaf gradually tapered to each
end from or near its centre, and forming an elliptic, C, or any of the other ordinary
shaped springs used in carriages. The said springs have no holes pierced through
their plates, but are provided with suitably shaped "tits" for preventing the springs
slipping when put in place.
Secondly. Of a spring formed by two tapered plates of cast steel, cyma reversa
or ogee shape, the ends of which overlap each other, forming an eye on the outside
of one or other of the plates, as shewn in Figure 8, permitting the plates thus held
together to come in contact, commencing at their extreme ends, and closing gradually
in proportion to the weight carried.
In the Drawing,
Figures 1, 2, 3, 4, and 5 exhibit different styles of springs made in accordance
with my Invention.
Figure 6 exhibits my ogee single plate elliptic spring as it appears when carrying
a weight; and Figure 7 is a view of it as it appears when not carrying a weight.
Figure S is a detail, shewing how I connect the ends of the plates together.
By making what are commonly known in springs as the main plates of crucible
or cast steel, and tapering them from or near their centre to their ends, I produce a
[Price 4d1

page_text: light and evenly elastic spring, any desired shape and strength, without the necessity
of adding additional leaves or plates.
In all the Figures exhibited in Drawing the main plate is indicated by the
letter A, and, where shewn, the "tit" is identified by the letter B.
As there are various methods for forming and attaching the tit B, I do not
confine myself to any peculiar way for effecting this purpose, but I may state that
I usually drill a hole, say, about 1/" deep in the plate where the tit B is to be
placed, making the base of the hole larger than the mouth thereof, so that a soft
piece of wire hammered into it to form the tit B is dovetailed, and thus securely
fastened therein.
The single plate A of tapered cast steel and the tit B is embodied in all the styles
of springs shewn in Drawing, but Figures 6 and 7 exhibit my improved ogee
elliptic spring, and as I consider it of considerable importance, I shall proceed to
describe it more minutely. Owing to this ogee or cyma reversa shape, and peculiar
mode of connecting the ends of the plates together, hereafter described, the elasticity
of the thinest part of the plate is secured when a light weight is being carried, but
as the effect of a heavier weight is to close the plates together, as shewn in
Figure 6, and thus shorten the spring, its rigidity is increased in proportion to the
weight carried.
Figure 8 shows how the ends are fastened together. b, b, are the ends of the
lower plate A formed into an eye at each end and under the said plate. The
ends a, a, of the upper plate A¹ are bent to fit around the ends b, b, and a rivet C
passing through the eye thus formed completes the connection between the two
plates. The chief advantage of a connection of this description is that the rivet C
does not pass between the plates A, A¹, as in ordinary elliptic springs, and conse-
quently the faces of the said plates rest against each other, the length of the
connection being gradually increased in proportion to the weight carried, thus
increasing the rigidity of the spring as required.
I claim as my Invention,―
1st. A crucible or cast steel carriage spring made from a single plate or leaf A
tapered to each end, substantially as shewn and described.
2nd. A tapered single plate or leaf A in combination with a "tit " B, substantially
as and for the purpose specified
3rd. The carriage spring shewn in Figures 6 and 7, formed by the tapered steel
plates A, A¹, cyma reversa or ogee shape, fastened together by the rivets C or their
equivalent, passing through the eyes made by the ends a, a, and b, b, on the outside
of the said plates A, A¹, as and for the purpose specified.
In witness whereof, I, the said John Belmer Armstrong, have hereunto set my
hand and seal, the Eighth day of October, in the year of our Lord One
thousand eight hundred and seventy-seven.