Improved Low-water Safety-valve Apparatus.
Year: 1892

page_text: Date of Applicat on. 19th May, 1892
Complete Specification Left, 18th Nov., 1592-Accepted, 31st Dec., 1892
PROVISIONAL SPECIFICATION.
Improved Low-water Safety-valve Apparatus.
We, JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the firm of
J. Hopkinson & Co., of Huddersfield, in the County of York, Engineers, do hereby
declare the nature of this invention to be as follows:-
This invention relates to low-water safety-valves of the kind or class well known
as Hopkinson's compound safety-valves, and its object is to so arrange and construct
the valve appurtenances that the valve will be more sensitive and free in its action
of opening and closing at the required pressure, the friction will be reduced, and in
other respects the valve will be more efficient than heretofore.
Such valves have been heretofore so constructed and arranged that the rod or
spindle, forming the connection betwixt the valve and the lever and by which the
force or weight is brought to bear on the valve so as to load it to the required
pressure, does not move rectilinearly. It is necessary therefore to provide an
aperture in the crown of the dome or bonnet sufficiently large to allow of lateral
morement of the valve rod or spindle. This arrangement has serious objections
inasmuch as the spindle having no guide is tilted by the lifting and working of
the lever and is sometimes bent considerably out of the straight line and thus
tends to jam the valve between the guide pins, thereby preventing the valve
blowing freely.
By inventions recently patented by us we have endeavoured to obviate any
objections which may arise from this cause in the Hopkinson compound safety-
valve. One important improvement which we made was the addition of an improved
guard and guide for the valve and spindle which guide also acts as a stop to limit
the lift of the valve. We have found in practice that with the ordinary mode of
connecting the valve spindle to the lever in consequence of the angular movement
of the said lever about its fulcrum which causes the valve spindle to cant when the
lever lifts, lateral pressure was caused on the guide, producing unnecessary friction
and impairing the efficiency of the valve.
Now according to our present invention we so arrange the connection of the
valve spindle to the lever that the hole provided in the top of the valve guard,
or in the crown of the dome, or both, or in a projection thereon, may be used to
guide the spindle in its upward and downward movement in a truly straight
line, whilst we so arrange the connection of the spindle and lever as to permit.
the use of such guide which ensures the rectilinear movement of the spindle whilst.
the point of connection with the lever moves in the arc of a circle.
One mode of carrying our invention into effect is by the use of a joint made in
two pieces one of which is fixed to the upper end of the valve spindle and the other
of which is pivoted to this piece and also to the lever so that while the first named
piece moves rectilinearly with the spindle the point of attachment of the second
piece to the lever moves in the arc of a circle.
Dated this 10th dor of May 1899
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improved Low-water Safety-valve Apparatus.
We, JOIN ADDY HOPKINSON, and JOSEPH HOPKINSON, both of the firm of
J. Hopkinson and Co., of Huddersfield, in the County of York, Engineers, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to low water safety valves of the kind or class well known
as Hopkinson's compound safety-valves, and its object is to so arrange and construct
the parts of the apparatus that the valve will be more free and sensitive in its action
of opening and closing at the required pressure, the friction will be reduced, and in
other respects the valve will be more efficient than heretofore.
30
Such valves have been heretofore so constructed and arranged that the rod or
spindle forming the connection betwixt the valve and the lever and by which the
force or weight is brought to bear on the valve so as to load it to the required
pressure does not move rectilinearly. It was necessary therefore to provide
aperture in the crown of the dome or bonnet sufficiently large to allow of lateral
movement of the valve rod or spindle. This arrangement has serious objections
inasmuch as the spindle having no guide is tilted by the lifting and working of the
lever and is sometimes bent considerably. The load therefore pushes the valve
against the guide pins, causing undue friction, and also tends to cant the valve and
jam it between the said pins, thereby preventing it from working freely and
properly.
By inventions recently, patented by us we have endeavoured to obviate any
objections which may arise from this cause in the Hopkinson compound safety-valve.
One important improvement which we made was the addition of an improved guard
and guide for the valve and spindle which guide also acts as a stop to limit the lift
of the valve. We have found in practice that with the ordinary mode of connect-
ing the valve spindle to the lever in consequence of the angular movement of the
said lever about its fulcrum which causes the valve spindle to caut when the lever
lifts, lateral pressure was brought to bear on the guide producing unnecessary
friction and impairing the efficiency of the valve.
Now according to our present invention we so arrange the connection of the
valve spindle to the lever that the hole provided in the top of the valve guard, or
in the crown of the dome, or both, or in a projection on the dome, may be used to
guide the spindle in its upward and downward movement in a straight line, and we
so arrange the connection of the spindle and the lever as to permit the use of such
guide which ensures the rectilinear movement of the spindle whilst the point of
connection with the lever moves in the arc of a circle.
In order that our invention may be better understood we have shown in the
accompanying drawing a vertical central section of a Hopkinson compound safety-
valve, having our present improvement applied thereto.
A is the valve; B is the valve spindle; C the valve guard; D the dome or
bonnet, which is securely attached to the seating block; E the weighted lever;
and F the fulcrum stud, carrying a pin Fupon which the lever E is pivoted. We
prefer to make this stud vertically adjustable in the bonnet by screwing the same
therein and providing external and internal locking-nuts F2, F whereby it can be
locked in any position to which it may be set.
We connect the lever E to the valve spindle by means of a joint consisting of
two pieces G, H. The piece G is preferably formed solid with the valve spindle B,
and the piece H is pivoted at its upper end at G¹ to the piece G and at its lower
end at H to the lever E. We preferably provide a gun metal or brass busb D' in
the top of the dome or bonnet which bush is bored to properly fit and guide the
spindle. The valve spindle is in some cases also made an easy sliding fit in the

page_text: neck or necks C¹ of the valve guard and is guided thereby so as to move in a
straight line when rising and falling. It is obvious from this construction that the
valve spindle is not in any way put under lateral constraint by the lever E but is
quite free to move in a straight line as controlled by the guides in the valve guard
or bonnet or both. That is to say, the pin G' is free to move, and does move in a
straight line, while the pin H₁ is free to move in the arc of a circle about the
pivot F¹ of the lever.
We do not wish to confine ourselves to the precise construction or arrangement
of the parts herein shown or described, as it is obvious that the same may be varied
or modified to some extent without departing from the essential features of our
invention.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
1. In a Hopkinson compound safety-valve, the combination, with the valve and
its weighted fever, of a rectilinearly moving spindle, for the purpose specified.
2. In a Hopkinson compound safety-valve, the combination of the valve lever,
fulcrum stud, the joint connecting the spindle with the lever, the valve spindle, and
the guides for the same, so that while the pin H' moves in the arc of a circle, the
valve spindle moves rectilinearly, for the purpose specified.
3. In a Hopkinson compound safety-valve, the combination, with the valve
spindle, of a guide for the same in the top of the dome or bonnet, for the purpose
specified.
4. A Hopkinson compound safety-valve constructed substantially as described
with reference to the drawing, and operating as specified.
Dated this 18th day of November 1892.
..
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.