AN IMPROVED SPRING TENSION REGULATOR
Year: 1864

page_text: LETTERS PATENT to George Haseltine, of the "International Patent
Office," No. 12, Southampton Buildings, Chancery Lane, in the County
of Middlesex, Civil Engineer, for the Invention of "AN IMPROVED SPRING
TENSION REGULATOR."-A communication from abroad by Thomas Silver,
PROVISIONAL SPECIFICATION left by the said George Haseltine at the
Office of the Commissioners of Patents, with his Petition, on the 10th
August 1864.
I, GEORGE HASELTINE, of the "International Patent Office," No. 12, South-
ampton Buildings, Chancery Lane, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of the said Invention for "AN
IMPROVED SPRING TENSION REGULATOR," a communication, to be as follows:-
The nature of my Invention consists in the employment of a peculiar me-
chanical device for the purpose of diminishing or increasing the unequal or
variable resistance of a spring, and more especially for securing throughout its
action a uniform tension.
The intensity of the force applied to a simple spring in drawing out or comI-
pressing the same must be constantly increased, which prevents it in many
instances from being advantageously substituted for a weight, whose resistance

page_text: is uniform. It is therefore important to have some simple manner for modi-
fying the natural action of a spring, that it may be used as a substitute for a
weight, where the latter may become unreliable in its action from extraneous
motion or other causes, said modification of the action of a spring being
intended to increase its usefulness in various employments to which it may be
adapted.
To obtain this result is the chief object of my Invention, though it may be
desirable in some applications of the spring to increase the usual inequality of
its resistance. With a spring of any known form is combined an adjustable
excentric through which the power is transmitted in such a manner that the
first resistance of the spring is exerted against a radius, which, when uniform
resistance is required, is shortened by turning of said excentric. When it is
required to increase the inequality of resistance the radius is lengthened. The
end of the spring having motion is connected by a chain or cord, said chain or
cord being also made fast to the excentric and then passing over or partially
around the excentric, is attached to the object to which the force of the spring
is to be applied. The excentric is made adjustable by means of a set screw
passing through it in a line with which its leverage-force is to be changed,
so that by turning the set screw right or left, the effective tension of the spring
In order to avoid
may be regulated or controlled in any desired manner.
friction as much as possible, the axis of the excentric may be fixed upon a
moveable bearing, but in such case is maintained in its position by pins or
points of the axis turning in short slots and the force of the spring. In order
to adjust the general force of the spring to any determined resistance a set
screw or nut and rod controls the fixed end or part of the spring so that it
may be drawn down or released as desired, the rod having on its outer end a
pointer, which when the screw is turned will traverse over a dial, the form of
which may be circular or elongated according to the form of the spring to be
used, and so marked that it will indicate the pressure or resistance required.
When it is desired to avoid the use of levers or the like, compensating for the
superior forces that may operate against the spring, as would probably be the
case in its application to a safety valve, a small drum or roller may be placed
.upon the axis of the excentric and turning with it, the latter being connected
with the spring by one chain, and the drum or roller with the opposing force by
.another chain, or in other cases two excentrics may be used on separate axes
both being adjustable as in the former case, but geared into, each other. I
preferred, a spring may be used in a winding or unwinding action; the spring
in such case working around an axial position with one end. connected with
the excentric and the opposite to a positive or fixed support, being adjustable

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Haseltine in the Great Seal Patent Office on the
10th February 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HASELTINE, of the "International Patent Office," No. 12, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of August, in the year of our Lord One
thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Haseltine, Her special licence that I, the said George
Haseltine, my executors, administrators, and assigns, or such others as I, the
said George Haseltine, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 Islands, and Isle of Man, an Invention for "AN IMPROVED
SPRING TENSION REGULATOR," & communication, upon the condition (amongst
others) that I, the said George Haseltine, 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 George Haseltine, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Sheet of Drawings making
a part of this Specification:-
The nature of my Invention consists in the employment of a peculiar
mechanical device for the purpose of diminishing or increasing the unequal
or variable resistance of a spring, and more especially for securing throughout
its action a uniform tension.

page_text: The intensity of the force applied to a simple spring in drawing out or com-
pressing the same must be constantly increased, which prevents it in many
instances from being advantageously substituted for a weight, whose resistance
is uniform. It is therefore important to have some simple manner for modi-
fying the natural action of a spring, that it may be used as a substitute for a
weight, where the latter may become unreliable in its action from extraneous
motion or other causes, said modification of the action of a spring being
intended to increase its usefulness in various employments to which it may be
adapted.
To obtain this result is the chief object of my Invention, though it may be
desirable in some applications of the spring to increase the usual inequality of
its resistance.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a view of the spring tension regulator, partly in elevation and
partly in section; Figure 2 is a view of a portion of a marine safety valve box,
with the regulator applied, also partly in elevation and partly in section;
Figure 3 is an end elevation of the same; Figure 4 is a plan of the safety
valve box, showing also the position of the base of the casting or frame sup-
porting the regulator; Figure 5 is a view of a portion of a lever for raising
the valve spindle, in order to set the spring balances at the desired pressure.
Like letters designate corresponding parts in the several Figures. The springs
may be constructed of any suitable form.
The spiral spring A, Figure 1, is connected at its upper end to a cord or
chain B in any convenient manner. This cord is firmly attached to one point
on the circumference of the excentric or circular disc C, and passing over or
partially around said excentric is attached to the object to which it is desired
to apply the force of the spring A. The excentric or disc C is made adjust-
able by means of a set screw D, passing through its moveable bearing or
centre a. The said centre travels in the slot formed in the excentric, so that
by turning the set screw D right or left the effective tension of the spring
may be regulated or controlled to any desired extent. In order to lessen fric-
tion the bearing or centre a may be placed upon moveable bearings.
As shown in Figure 1, the circular disc C has a central bearing a, in which
position said disc will not modify the natural action of the spring A. When
desired to equalize the tension of said spring the set screw D is turned from
right to left, carrying the centre a away from the head of the screw D, thus
shortening the leverage on the opposite side of the disc C. By applying a
given weight at b, greater than would be required to commence the expansion

page_text: of the spring A if the circular disc were on a central bearing (as the disc C
turns on its eccentric bearing a), the weight acts by a gradually increasing
leverage and thus exerts a constantly increasing mechanical efficiency, which
overcomes the increasing resistance of the spring A.
In order that the nature of this Invention may be better understood, I show
in Figures 2 and 3 an application of my spring tension regulator to the safety
valves of marine engine boilers in place of the weights ordinarily used, and
from which much inconvenience is often experienced.
The eccentric or circular disc C, Figure 2 and 3, with its moveable centre a,
is shown fixed in a frame E, which slides in a groove formed in the sides of
the frame or casting F at c. The set screw D is made with a flat head,
which, when the screw is in a vertical position, fits into a slot cut in the
base of the corresponding screw D¹, which passes through the frame E, and
the
upper part of the screw turns freely, but without vertical motion, in the
bar d, which forms a part of the frame or casting F. When the screw D' is
turned to the right or left by means of the milled nute it imparts & corre-
sponding motion to the set screw D, and gives an upward or downward move-
ment to the frame E and the centre or bearing a. The centre a is thus
removed as far. from the centre of the disc C as may be required to overcome
the unequal resistance of the spring, and without altering the position of the
circular disc C. The disc or eccentric C is formed for two cords or chains
B, B, Figure 3, and connected by the bars f,f; a slot g is cut in the face of
the circular discs to admit the flat portion of the bearing or centre a, whose
conical euds project beyond each disc. The bearing or centre a moves
vertically in this slot by the action of the screw D'. The casting F is
attached to the cover h of the valve box G, the latter being shown reduced in
height. A stuffing box i is fixed in the base of the casting F to admit the
valve spindle j, which is made considerably longer than usual. The upper
part of the spindle j passes through the top of the casting F, and has at it's
extremity a cap k with a bearing 1 projecting on either side of the same. A
spring balance II, which may be of any desired form and strength, is attached
to the casting F by the screw pin m and the nuts n, n¹. The balance is
adapted for a certain diameter of valve. That shown in Figure 2 and 3 is
supposed to be for a five-inch one, whose area equals 19-635 inches, and it is
graduated on the right-hand side of the pointer o to indicate a pressure of from
ten to thirty pounds upon the square inch; and on the left-hand side is
shown the resulting pressure upon the whole area of a five-inch valve, and the
desired pressure is regulated by raising or lowering the pin m by means of the
nuts n, n. A. similar balance I is placed upon the valve spindle j and its

page_text: :
pressure regulated by the nut p. This balance may be shorter at its lower
extremity than its corresponding one H. The two balances are connected by
the chains B, B, which pass partly round the adjustable eccentric C, and are
attached at one point of the circumference of the same by the pins q, q. These
chains are fastened at an extremity to loops which are hung upon the centres
r, r, said centres forming part of a ring or boss within the balance I. The
said ring or boss with the centres r, r, slides freely upon the spindle j, and
carries the pointer 8, and the centres ", r, move in a groove formed on
either side of the balance I; the othe extremity of the chains B, B, is
connected to the flat piston J, which carries the pointer o. K is a forked
lever working in bearings, which bearings form a part of the frame or casting
F. The forks of the lever being under the bearings when the lever L is
placed upon the square part t of the lever K, the valve spindle j can be readily
raised (whatever may be the pressure put upon it by the balance H) for the
purpose of accurately adjusting the various parts as hereafter shown. M is
the lever ordinarily used for raising one of the valves whenever required.
This lever instead of being under the weights as usual bears under the project-
ing piece u formed on either side of the boss w, which is firmly secured to the
valve spindle j; N is the safety valve, shown in position. Suppose, for
instance, that the bearing a is in the centre of the adjustable excentric C,
then in order to place a desired pressure of, say, twenty pounds per square
inch upon the safety valve N, the spring balance H and I would be adjusted
by means of the nuts n, n¹, and p, until the pointer of each balance indicates
twenty pounds upon the right-hand side of the balance. In this state the
valve would lift a very small distance immediately the pressure of steam in the
boiler equalled twenty pounds per square inch, but it would be impossible
without a very great additional pressure to lift the valve the distance necessary
to allow a space for the discharge of the steam equal to the whole area of the
valve should this or any considerable part of this area be required.
To obtain this object by this apparatus the screw D', which actuates the
corresponding screw D, is turned towards the left by means of the milled nut e
until the bearing or centre a is elevated or removed sufficiently from the
centre of the disc C to give a leverage to compensate for the greatly increased
resistance of the balance H, when the eccentric C is carried partly round by
the upward movement of the valve spindle j. By means of the lever L and
the forked lever K the balances can be accurately adjusted without any
extraneous assistance. At the same time the scale on the left-hand side of
each balance corresponds with the total pressure in pounds upon the whole
area of a five-inch valve, whether worked at ten or up to thirty pounds, so

page_text: that at any time weights could be hung from a loop attached to the end of
either balance and thus ascertain that they are working perfectly correct. If
the bearing or centre a be not elevated sufficient to give the necessary increase
of leverage on the outer circumference of the adjustable eccentric C, then
when the valve spindle j is raised by the levers K and L, the centres r, r,
with the pointer s would remain stationary after a short movement, and the
balance being carried upwards with the spindle j, the pointer s would
indicate a higher pressure than the twenty pounds. This would at once
denote that the bearing or centre a required elevating still more out of the
centre of the disc C, thus giving a corresponding increase of leverage. In this
manner the balance may be adjusted perfectly accurate, which will be proved
by the pointer s of the balance I being carried upwards with said balance
without moving from the position indicated on the scale. If, on the contrary,
the bearing or centre a had been too much elevated, then upon raising the
valve spindle j as described, the centres r, r, with the pointer s would rise
more rapidly than the valve spindle j, and indicate a lower pressure than
twenty pounds upon the scale of the balance I.
The application of my Invention to a safety valve as herein-before described
is made merely for the purpose of illustrating more clearly its nature and
advantages.
This regulator may be employed advantageously for various purposes and
may be modified as regards the form of the spring and other parts employed
without departing from the spirit of the Invention, I therefore wish it under-
stood that I do not confine myself to the application described and illustrated
or to the details herein set forth, but I claim regulating or controlling the
action of a spring by means of an adjustable eccentric for the purposes and
substantially in the manner described.
In witness whereof, I, the said George Haseltine, have hereunto set
my hand and seal, this Second day of February, in the year of our
Lord One thousand eight hundred and sixty-five.
GEORGE HASELTINE. (L.B.)