IMPROVEMENTS IN SPRINGS FOR BUFFERS AND DRAW BARS FOR RAILWAY AND ANALOGOUS PURPOSES
Year: 1884

page_text: I ALFRED SLATER of Gloucester in the County of Gloucester Assistant Manager
to the Gloucester Wagon Company Limited do hereby declare the nature of said
Invention for "IMPROVEMENTS IN SPRINGS FOR BUFFERS AND DRAW BARS FOR
RAILWAY AND ANALOGOUS PURPOSES" to be as follows:-
The object of my Invention is to provide light strong and cheap springs for
buffers and draw bars for Railway and analogous purposes which will prevent the
sudden and injurious jars and concussions at present occuring when the ordinary
steel springs or metal stops are employed-According to my Invention the spring
is made of India rubber or analogous elastic material or compound the longitudinal
section of the said spring presenting an arched curved semi-elliptical or conical or
partly conical form on the exterior and on its interior or reversed curve or form of
the same nature in this case forming a kind of trumpet-mouth This form gives
spaces between both the interior and the exterior of the spring and the parts in
which the spring is enclosed into which spaces the material of the spring is
accommodated when the buffer is compressed the resistance gradually increasing
during compression--The said spring formed as described is well calculated to
resist pressure and the maximum range of motion of the buffer or draw bar is
obtained with a minimum of substance in the spring and the said spring cannot
break and is not injured by grinding or cutting against the sides of the Cylinder.
When used as a draw bar spring it will be perforated for the passage of the
draw bar.

page_text: I ALFRED SLATER of Gloucester in the County of Gloucester Assistant Manager
to the Gloucester Wagon Company Limited do hereby declare the nature of my
invention for "IMPROVEMENTS IN SPRINGS FOR BUFFERS AND DRAWBARS FOR
RAILWAY AND ANALOGOUS PURPOSES" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
The object of my Invention is to provide light strong and cheap springs for
buffers and drawbars for railway and analogous purposes which will prevent many
of the existing defects.
It is found in practice that the plain rings or Cylinders of India Rubber hitherto
used as springs, expand when under compression beyond their limit of elasticity,
hence they break or become otherwise damaged-It is also found that when they
have expanded they are forced against the side of the case in which they are
enclosed, and during the stroke of compression they are rubbed against it and
become cut and otherwise damaged; it is also found that it is necessary to put a
rod through a hole in the centre of the rings, in order to keep them in the central
position, this rod not only prevents expansion and thus militates against the utility
of the spring, but the rings being pressed up against it, become cut and otherwise
damaged. Metal rings and stops of special form have been tried to prevent such
damage, but without satisfactory results as the metal rings or stops are very liable
to damage when the blow is arrested by them, besides which they arrest the blow
suddenly.
According to my Invention the spring is made of India rubber or analogous
Elastic material or compound, and it is formed on the principle of the arch and the
inverted arch, the longitudinal section of the said spring presenting an arched,
curved, semi-elliptical, or conical, or partly conical form on its exterior, and on its
interior one or more curves or forms of similar nature forming a kind of trumpet
mouth. The said forms or their equivalents may be made up of any number of
simple or compound lines either straight or curved, giving in section the aforesaid
forms or their practical equivalents as hereinafter defined, This form gives spaces
between both the interior and the exterior of the spring, and the parts in which
the spring is enclosed, and between the spring and the rod (if any) which passes
through the spring, into which spaces, the material of the spring is accommodated
when it is compressed, the resistance gradually increasing during compression. The
said spring formed as described is well calculated to resist pressure, and the
maximum resistance and range of motion is obtained with a minimum of substance
in the spring, and the said spring cannot break, and is not injured by the bar or
by the sides of the Cylinder, against which there is no grinding or cutting action
calculated to do any damage. Figures 1 to 12 of the accompanying drawings
illustrate forms of springs from which the principle of my Invention and some
of the possible variations will be readily understood.
When desirable a ridge or ridges as at B, figure 2, may be provided to support
or assist in supporting the spring when being fixed or put in its place in the case,
and a groove or grooves may be provided if desired to permit the passage of air,
or for other purposes when the spring is being fixed or put in its place in the
Cylinder or case as at C, figure 3, or an air hole may be left in the apex of the
cone as at A, figure 1-Or the two methods may be used in the same spring.
Figure 13 shews one method of application to a buffer having external
fastenings.

page_text: Figure 14 shews one method of application to a buffer having a pin or bolt
fastening, or rod passing through the spring space.
Figure 15 shews one method of application to a draw bar.
An examination of these figures and methods of application in figures 13, 14
and 15 will shew that as the Buffer or draw bar is pressed homewards, the material
of which the spring is composed is pressed against the sides and bottom of the case
or Cylinder, and particularly into the internal spaces D, E, F and also against the
moving plunger and rod (if any) and is not damaged by its sides being ground
against any part of the metal case or rod and therefore is subjected to a strain of
compression combined with a limited expansion.
If desirable the apex of the cone and the edges around the base of the cone
may be hardened or made of different compound or material in order to render
them more durable.
A spring made according to my Invention is very strong and has great elasticity
at the commencement of stroke and a high ultimate resisting power, the resistance
increasing rapidly but gradually, as more area or surface of the spring presents
itself during the stroke until the spring becomes a solid or nearly solid mass;
there is therefore no shock or sudden jerk (although the force of the blow may
exceed the limit of elasticity of the spring), thus avoiding the shock or jerk which
is the case with any steel spring or any kind of spring which brings metal to metal
at the end of the range of stroke, such shock or jerk very frequently breaking the
springs or other parts, or causing injury to the Vehicle or article to which they are
attached, or with which they come in contact.
A spring made in these forms is of less weight and has a much greater resistance
than many steel or other springs of similar cost, range, or power, it is less liable
to damage, and also much more durable, and is therefore very economical in
maintenance or repairs.
The recoil of the spring is not so great as with other springs of equal ultimate
resistance, and there is therefore less strain on the fastenings of the cases.
These springs may be applied to Railway buffers or draw bars, to ordnance, or to
any analogous use where it is required to reduce or prevent shocks, or to arrest any
rapid motion.
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
Springs for Railway Buffers and drawbars, or for similar purposes, formed
substantially as hereinbefore described of India rubber or analogous elastic
compound or material, and so as to prevent injurious contact of the sides thereof
with the casings or bars, and also so as to avoid the necessity of metal stops, at the
same time providing a sufficient range of action.