IMPROVEMENTS IN SPRINGS APPLICABLE TO PISTONS, PUMPS, STUFFING BOXES, VALVES, AND OTHER ANALOGOUS PUR- POSES.
Year: 1879

page_text: LETTERS PATENT to Matthew Prior, of Sheffield, in the County of York,
Engineer, for the Invention of "IMPROVEMENTS IN SPRINGS APPLICABLE TO
PISTONS, PUMPS, STUFFING BOXES, VALVES, AND OTHER ANALOGOUS PUR-
POSES.
"
Sealed the 29th July 1879, and dated the 12th April 1879.
PROVISIONAL SPECIFICATION left by the said Matthew Prior at the Office
of the Commissioners of Patents on the 12th April 1879.
MATTHEW PRIOR, of Sheffield, in the County of York, Engineer. " IMPROVE-
MENTS IN SPRINGS APPLICABLE TO PISTONS, PUMPS, STUFFING-BOXES, VALVES,
AND OTHER ANALOGOUS PURPOSES."
This said Invention has reference to certain improvements in and connected with
the construction of various forms of new spiral, helical, or volute and other cur-
vilinear springs, suitable for the rings of the pistons of motive power engines,
pumps, and other cylinders and stuffing boxes; or for the pressing out or expansion
of ordinary forms of such rings, or for the springs of safety and other valves, and
for other analogous purposes, and which improvements will make these springs
lighter and more elastic and efficient in their action, and durable, or less liable to
break than such springs have been as heretofore constructed. And the nature and
novelty of the Invention or improvements in the construction of these springs
consist all as follows:-The first and main improvement and feature of novelty
consists in making or coiling these springs out of bars or rods of spring metal
(preferably of steel or hard rolled or drawn brass) of a double or reverse kneed or
web section, with a central feather (Z), so that when coiled on a mandrel of any
desired sectional shape or form, with the central feather radial and the two edge
webs laid parallel to the axis or surface of the mandrel, the outer or higher web
will coil or lap over the inner or lower web, and form a true or nearly even surface
along the inner or outer circumference and length of the springs so coiled, and so
take up less sectional area for the amount of metal and strength in the spring, or

page_text: allow of more coils and freedom of action in the same sectional area than when
such springs are coiled out of round, oval, or rectilinear solid secțional bars, as they
have been heretofore. These new or improved springs, formed with the double
kneed and central web sectional steel or other ductile metal, may be coiled on
mandrels (in a lathe or by other driving axis) of any desired section, as other coiled
springs have heretofore been done, such as round, oval, or square or rectangular,
with the corners rounded in section, and either parallel, or single, or double,
conoidal, curvilinear, or spheroidal profile in the longitudinal direction, according
to the kind of spring desired; that is to say, as when these springs are for pressing
out the bearing rings of pistons, the springs would be coiled on a mandrel of a
section sufficiently less than the space between the rings and the body of the piston
to allow the spring after being coiled in one long length or in pieces to form a
complete coiled annular ring rather larger than the diameter of the space within
the joint rings, with free action as springs to press these out, as other forms of
springs have been heretofore secured at their joints by passing out pieces. Where
it is found necessary, as in packing rings subject to great pressures or to sudden
shocks, to strengthen the action of the above named spring or spring packing
already in use, I use an additional spring band or ring placed at the back of the said
spring or springs, made of any suitable elastic metal, preference being given to steel,
and they may be either cast or wrought, having spring loops or bends formed or
attached at intervals on its inner circumference. Such spring loops or bends may
be made angular, circular, or oval, or of other suitable form, and may be formed
from the same material as the ring of which they are part, or the looped or bent
springs may be made separate and attached to the outer or band pressing ring, in
either case openings being left or cut in this ring in the centre of the junction of
each spring loop or bend, with the outer pressing ring, which would look like a
ring of segments, with spring opening joints nearly close or open, as compressed or
expanded respectively. Where the pressures are suitable this spring may be used
separately. In such cases I make the section of the spring to suit the shape of the
packing rings to which it is to be applied, and when required I turn the spring in
a lathe.
With some shaped packing rings, such as those having a flange upon each
ring, I slightly twist the spring loops or bends while hot in alternate directions, 80
that each interval between such loops or bends projects higher and lower alter-
nately, giving the spring a double action when compressed between the packing
rings, to which it is applied. Where it is found necessary for the packing rings to
bear an extra amount of weight or thrust, as in horizontal engines and pumps,
oscillating engines and pumps, or where the packing rings work over the ports or
passages, or in such like cases, I use either separately or in combination with the
afore named springs a double or single conical or dome formed spring or springs,
made of any suitable elastic metal, preference being given to steel or brass,
of the improved sectional form described, or of any ordinary sectional form, and
made in one or more suitable lengths. When these helical springs are made of the
double conical or semi spheroidal form, the connection between the two cones,
spheres, or domes, or the frustrums of these, is made by one or more spiral coils of
the same material, and where the space for the spring or springs is not sufficiently
wide for the double springs, single, conical, or spheroidal formed springs are used;
and where the space is shallow the springs are made of an oval or other suitable
form, and formed at the ends to suit the packing rings or spring packing to which
they are to be applied, and upon which they press. And where the weight or
thrust is very great, headed props or bolts are used of the same length or nearly
the same length as the width of the space in which the springs are placed, openings
being left in the centres of the springs for the props or bolts to pass through, and
such props or bolts may have their lengths adjusted by screws or other equivalent
as the packing rings wear. These said improved single or double conical, spheroidal,
or dome springs are also applicable to steam boiler safety valves and other valves, to
which ordinary spiral springs are applicable, such as reducing valves, concussion valves,

page_text: pump valves, escape valves, and other like valves, and other analogous purposes where
ordinary spiral or helical springs are used, and they may be applied in the same manner
as those springs heretofore in use are applied. The hollow curvature or dome shape of
the springs may be made approximately to suit the curvature of the valve, and press
directly upon the same; or a dish or cup of suitable material having a stem or
spindle passing through the centre of the spring may be used, such cup or dish
being made to fit the valve and receive directly the pressure of the spring. In
applying the spring to the india rubber or other flexible valves or "lids" of air or
water pumps, in addition to or instead of the ordinary guards now in use, there is
a circular space in the centre of the spring for the pump rod to pass through, or an
attachment bolt as required, and where necessary these springs are made flat or
nearly flat, and of a volute form, preferably with the knee webs' radial or forming
the sides of the volute, with the central feather parallel to the axis, as in ordinary
watch volute springs.