Improvements in Dry Pipe Valves and Alarm Attachments for Automatic Fire Extinguishing Systems.
Year: 1899

page_text: Date of Application, 30th May, 1899-Accepted, 22nd July, 1899
COMPLETE SPECIFICATION.
Improvements in Dry Pipe Valves and Alarm Attachments for
Automatic Fire Extinguishing Systems.
We, JOHN HARPER DERBY, of Richmond Court, Draughtsman, and KATILARINE
MABEL CROSBY, of 57, Monmouth Street, Gentlewoman, both in Brookline,
Massachusetts, United States of America, 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 :-
-
Our invention relates to valves and alarms for that class of automatic fire
extinguishing apparatus known as dry-pipe sprinkling systems, the function of
a dry-pipe valve being normally to keep the water out of the system of sprinkling
pipes, and to open automatically in case of fire to admit water to said pipes.
It has been a common practice to keep these dry-pipe valves closed by forcing
air into the system of pipes until its pressure is sufficient to hold the valve closed
against the pressure of the water in the supply pipe, the compressed air being
automatically liberated upon the occurrence of a fire and the valve being there-
upon forced open by the water pressure. Inasmuch as the pressure of the water
supply per square unit of area is often considerably greater than it is desirable
to give to the air in the pipe system, the valve in such case must be provided
with some means whereby the normal effect of the air pressure may be increased,
and one feature of our invention relates to means whereby this result may be
accomplished. Our invention in its preferred form also operates to lock the
valve against closing after it has once been opened, this being desirable for
reasons hereinafter set forth. It is also desirable in most cases that the opening
of the valve shall cause an alarm to be given, and another feature of our invention
relates to devices for accomplishing this result.
A preferred form of our invention, embodying the features above referred to
together with certain others hereinafter described, is illustrated in the accompany-
ing drawings, in which Figure 1 is a central, vertical section of the valve casing
and contained parts; Figure 2 is a cross section on the line -- in Figure 1;
Figure 3 is a central, vertical section of an alarm attachment adapted to be
operated by the escape of some of the compressed air from the sprinkler system
when the main valve opens: and Figure 4 is a central, vertical section of a
supplementary alarm attachment adapted to be operated by the flow of water
from the valve casing.
So far as the automatic valve-operating mechanism of our valve is concerned,
the valve casing may be of any desired construction, so long as it provides for
the proper operation of said mechanism. We prefer however to employ the
casing shown in the drawings, which comprises an outer casing 2 and an inner
casing 3, the latter being suspended within the former to provide a passage
between the two for the water to flow through when the valve is open. The outer
casing 2 has substantially the form of a cylinder flattened on one side, said flat
portion consisting of a removable cover 4 detachably bolted to the body of the
casing as shown, and covering an aperture of sufficient size to permit of the

page_text: S
insertion and removal of the inner casing through the same. The casing 2
has also a water inlet 5 at one end and an outlet 6 at its other end, and is flanged
at both ends so that it may conveniently be bolted to the water supply pipe and
to the system of sprinkling pipes. The inner casing 3 is also substantially
eylindrical in shape and is suspended from the casing 2, preferably by means
of a flange 7 at its upper end which is held within a semi-circumferential groove
of corresponding dimensions formed in the casing 2, and is retained in said groove
by means of a screw 9, as shown. The screw 9 should be provided with a packing
washer 10, to prevent any possibility of leakage of the compressed air normally
contained in the casing. The casing 3 is thus rigidly suspended within the
casing 2 but may be removed therefrom after the cover 4 has been taken off.
Large apertures 11 are provided in the side walls of the casing 3 below the
flange 7, for the passage of the water, and below said apertures the top of the
casing 3 is closed, for a purpose which will presently appear. A removable hand
plate 12 gives access to the interior of the casing 3 when desired.
The valve proper, by which the water inlet 5 is normally closed, preferably
consists of a circular plate 13 seating against a valve seat 14 and guided in its
opening and closing movements by a triangular rod 15 secured to the bottom
of the plate 13 and arranged to slide in a circular perforation formed in a spider 16
secured to the valve seat 14. The purpose of making the rod 15 triangular and
the perforation circular is to secure a three point contact" guide, the corrosive
action of the water being much less in such a construction than where considerable
areas of the moving parts are in sliding contact with each other. The valve
seat 14 is tapered upwardly to a narrow, rounded edge, which makes contact
with a rubber ring 17 confined in a groove formed in the plate 13, thus providing
a yielding contact between said plate and its seat and insuring a tight closure
of the valve. Since rubber and metal tend to adhere to each other after they
have been in contact for some time, we interpose between the rubber ring 17 and
the seat 14 a strip or sheet 18 of very thin metallic copper, which is so soft and
flexible that it will not interfere with the compressibility of the ring 17. The
edges of the strip 18 are turned upward and confined between the edges of the
rubber ring 17 and the walls of the groove in which it is secured, and the upper
part of said groove is preferably enlarged laterally, to provide room, as at 19,
for the lateral expansion of the ring 17 when it is compressed on its bottom face.
It will be understood that while the specific valve plate just described forms one
of the lesser features of our invention, other valves may be used in connection
with the remaining features of our invention.
The operating mechanism for the valve plate 13 is contained within the easing 3,
and one of its elements is a movable plate 20, which is in communication with
the system of sprinkling pipes on one of its sides only, its other side being
exposed to the normal atmospheric pressure by means of a pipe 21 led through
a packing box 22 into a chamber provided in the casing 3 and normally
closed by the plate 20. Thus when the sprinkling pipes contain compressed air,
its pressure is operative upon the movable plate 20, and is transferred thence
to the valve proper 13 by means of suitable intermediate mechanism, which may
consist of links 24 each pivoted at one end between a pair of ears 25 attached to
the plate 20 and at the other end to a lever 26. The levers 26 are preferably
two in number and are pivoted on a cross bar 27 which forms a part of the bottom
of the casing 3, in such manner that the free end of each lever 26 will normally
bear upon the top end, near its edge, of a stem 28 attached to the valve proper 13
and extending upwardly therefrom into the casing 3 through an aperture in its
bottom. The air pressure in the system of which the casing 2 is a part is given
access to the under side of the plate 20 through suitable connectious with sail
system, such as openings 29 formed in the bottom of the casing 3.
It will be seen that with the construction above described the air pressure in
the sprinkler system acts not only on the area of the valve proper 133 but also
on an additional area furnished by the movable plate 20, its effect on both these

page_text: areas being combined to hold the valve closed, thus permitting the use of a less
pressure per square inch in the air system than is opposed thereto in the inlet 5.
If a still further reduction of the working air pressure be desired, the levers 26
may be so pivoted (as shown) that their respective arms which bear against the
valve stem 28 shall be shorter than their arms which are pivoted to the links 24,
and their multiplying effect may be increased in this manner to any desired
extent. In fact, the valve 13 may be held closed wholly by means of the pressure
transmitted to it through these levers 26, in case the valve casing for any reason
be so constructed that the valve proper is not itself subjected directly to the air
pressure in the system.
In order that a slight movement of the plate 20 may suffice to withdraw the
free ends of the levers 26 from the path of the valve stem 28 and permit the valve
to open, the pivots 30 on which said levers rock should be offset from the longi-
tudinal axis of the levers, as shown, it being obvious that the greater the amount
of this offsetting, the less the angular movement necessary to be given to the
levers 26 in order to withdraw them from the valve stem 28. The bearings
formed in the levers 26 and links 24 for the pivots on which said parts turn are
preferably channelled, as shown at 31, to provide a two point contact bearing,
for the reason stated in describing the valve guide 15.
Inasmuch as the movable plate 20 forms in effect a second valve, which must
normally be held tightly closed, said plate is provided with a knife edge 32
seating accurately against a soft metal ring 33 held in a groove formed in the
top of the casing 3. In order to insure the accurate contact of the plates 13
and 20 with their respective seats simultaneously with a firm pressure of the
levers 26 on the valve stem 28, we provide for an adjustment of these parts as
follows. The valve stem 28 is made hollow, and is provided at its lower end with
a head 34 rounded to conform to a cup-shaped depression formed in the plate 13.
The stem 28 can thus exert a downward pressure only on said plate 13 and will
have no tendency to tilt it or otherwise impair its contact with its seat 14.
Complete separation of the stem 28 and the plate 13 is prevented by means of
a collar 35 surrounding said stem above its headed end and screwed into the
plate 13, as shown. A bolt 36 passes through the stem 28, said parts being
screw-threaded at any convenient point, so that by turning the bolt 36 its end
may be made to project beyond the lower end of the stem 28 and bear against
the plate 13, whereby the stem 28 may be raised into the 'contact with the levers 26
required for accurate adjustment. A set screw 37 may be used to lock the bolt 36
against accidental changes of adjustment.
After the valve 13 has once been opened, it is desirable that it shall be positively
locked open in order to prevent water-columning, i.e., the accidental closing of the
valve and the holding of it closed by the weight of the water column in the
system of sprinkling pipes after they have been filled, and we are able to accom-
plish this result in our valve by simply reducing the diameter of the valve stem 28
a short distance below its top end, as at 38, the reduced diameter being not
greater than the distance between the ends of the levers 26 when in the position
shown in Figure 1. Thus, as will appear from the description of the operation
of the valve hereinafter given, the levers 26 may engage the stem 28 either on
its top to hold the valve closed or below its top to hold the valve open.
The operation of the parts above described is as follows. Said parts are
normally in the position shown in Figure 1, the system of sprinkling pipes.
including of course the casing 2 and all of the casing 3 below the plate 20, being
filled with air sufficiently compressed to hold the valve 13 closed against the
pressure of the water in the inlet 5, in the manner above set forth. If now, by
reason of a fire at the sprinklers or from any other cause, the air in the system
be allowed to escape, its pressure will quickly be diminished so much that the
water pressure acting against the valve 13, and thence transmitted through the
stem 28, levers 26 and links 24 to the plate 20, will draw said plate downward
a sufficient distance to permit the stem 28 to pass upward between the ends of

page_text: the levers 26, thus opening the valve 13 and admitting water to the system.
The water thus entering will flood the lower part of the casing 3 through the
openings 29 and its pressure acting on the bottom of the plate 20 will force said
plate upward into its normal position, and thereby cause the free ends of the
levers 26 to enter the groove 38, thus preventing the valve stem 28 from dropping
and locking the valve 13 open.
The plate 20 is held firmly pressed upward by the water pressure until it is
released from pressure by turning off the water supply and draining the system
through an outlet such as a pipe 39, which also serves as a leakage drain and is
connected with an alarm attachment hereinafter described. When the system
has been drained, the plate 20 will fall of its own weight and thus allow the
valve 13 to close, after which, by suddenly admitting compressed air to the
system, the plate 20 is again raised to its seat and caused to lock the main valve
closed.
The remaining features of our invention relate to attachments for giving an
alarm when the valve 13 opens, or in case of an excessive leakage from the
system. The attachment shown in Figure 3 comprises a casing 40 provided with
a cover 41 having a downwardly projecting guiding flange 42. The casing 40
is secured to the end of the pipe 21 which leads from the chamber 23, and is
further provided with a cap 43 which carries two depending metallic contacts 44.
separately clamped to an insulating block 45. Wires 46 and 47 lead from said
contacts respectively through insulating bushings 48 to an electric bell 49 or
similar device, a battery 50 being included in the circuit. The cover 41 is
provided with a screw-threaded perforation 51, into which is screwed, at its ends,
a narrow strip 52 carrying a metallic headed pin 53, extending upward directly
below the contacts 44 and normally a short distance therefrom. A pipe 54 is
screwed at its upper end into the perforation 51 and passes loosely through a hole
in the bottom of the casing 40. We prefer to cover the projecting end of said
pipe 54 by a cap 55 detachably secured to the casing 40 and perforated below
the end of the pipe 54.
The alarm attachment just described is thus operated. The movable plate 20
is preferably made to have a three point contact with the casing 3, as shown in
Figure 2, and in any case there will be left a sufficient space between said plate
and casing to permit of the escape of compressed air into the chamber 23 when
the plate 20 first moves downward when it releases the valve 13. Thus when
the valve 13 opens, a puff of air will simultaneously be transmitted through the
pipe 21 to the casing 40, where it will act to raise the loose cover 41 and thereby
carry the pin 53 between the contacts 44, whereby the electric circuit through
the bell 49 will be completed and an alarm will be given. The contacts 44, being
bent into the shape shown in Figure 3, will act as springs to hold the pin 53
in the position of contact, from which it may be released by unscrewing the cap
and drawing the cover 41 downward by means of the pipe 54, which also serves
to drain off any water which may reach the top of the plate 41, after the opening
of the valve 13, before the plate 20 has closed the chamber 23 and thus cut off
the escape of water at that point. Any water which may reach the casing 40 below
the cover 41 will escape through the hole through which the pipe 54 passes.
55
The alarm attachment shown in Figure 4 is connected to the outer end of the
pipe 39, and is so constructed as to operate whenever a sufficient quantity of water
flows through said pipe from the casing 2. This attachment comprises a vertical
casing 56, preferably cylindrical, into the top of which the pipe 39 leads. Thus
said pipe and casing form in effect an extension of the casing 2 and are subject
to the air pressure therein. The casing 56 contains a suitable float such as a
closed cylindrical drum 57 of somewhat less diameter than the casing 56 and
guided to move vertically therein by means of two sets of three point contact
guides 58, each secured to or made integral with a horizontal ring 59 secured to
the inside of the casing 56. The sides of the float 57 extend a short distance
below its closed bottom and are provided with apertures 60, whereby water

page_text: flowing into the casing 56 will flow freely around and beneath the said float.
A horizontal baffle-plate 61 is hung below the top of the casing 56, leaving a
space 62 at the edge of said plate, whereby water entering the casing will be
deflected to its circumference, thereby protecting the metallic contacts 63, which
are hung from the bottom of the baffle-plate 61 and are insulated therefrom, as by
being clamped between blocks 64 of suitable material. The contacts 63 may be
of the same form as the contacts 44 used in the air alarm, and the wires connected
to them will be led out of the casing 56 through two air-tight, insulating bush-
ings 65, and may then be joined in parallel with the similar wires leading from
the air alarm, thus operating the same bell 49. A headed metallic pin 66 is
secured to the top of the float 57, and whenever said float rises sufficiently will
be carried between the contacts 63 and complete the electric circuit through the
bell 49. It will thus be apparent that although the casing 56 is normally filled
with air under a considerable pressure, yet such pressure will have no effect on
the alarm mechanism contained in said casing. If however any water enters the
valve casing 2, whether by leakage or by reason of the opening of the valve 13,
it will at once flow through the pipe 39 into the casing 56, and when a sufficient
quantity has thus collected in said casing it will raise the float 57 and cause the
bell 49 to ring. This aların attachment thus supplements the air alarm by acting
simultaneously with it upon the opening of the main valve 13, and also serves
to give warning of a water leakage into the system as soon as such leakage has
reached a predetermined amount.
A cock 67 is provided in the bottom of the casing 56, through which water
may be drained from said casing, thus allowing the float 57 to fall by its own
weight and break the circuit through the terminals 63. It is an important
feature of this device that said casing 56 may be drained at any time without
disturbing the conditions existing in the valve casing 2, because when the
cock 67 is opened no air can escape through it until the water in the casing 56
has first been blown out by the air pressure above it, when the cock may be
instantly closed. Thus said casing may be drained to stop a leakage alarm with-
out danger of causing the main valve 13 to open.
The entire sprinkling system may be drained when necessary through the
cock 67, but it is better to provide the pipe 39 with an independent cock for
that purpose, which cock is of course kept closed at all other times.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. In a dry-pipe valve, a valve proper having a stem, pivoted levers arranged
to bear against said stem to hold the valve closed, said levers being disconnected
from said stem and having their pivots offset as described, and a pressure-
operated plate positively connected to said levers, whereby the pressure on said
plate is directly opposed to the pressure on the valve proper,
2. In a dry-pipe valve, the combination with a valve proper of locking mechanism
arranged to lock said valve proper against closing after it has once been opened,
and means actuated by the pressure of the entering fluid for positively operating
said locking mechanism.
3. In a dry-pipe valve, a valve proper having a recessed stem, one or more
locking levers arranged to engage said stem when the valve proper is open, and a
movable plate exposed to the pressure of the entering fluid and connected to said
lever or levers to operate the same.
4. In a dry-pipe valve, the combination of a valve proper, a movable plate
subject to the air pressure in the system when said valve proper is closed and
to the pressure of the entering fluid when said valve proper is open, and one or
more levers connected to said plate and arranged to engage the valve proper to
lock the same in either its closed or its open position.
5. In a dry-pipe valve, a valve proper having a headed stem, pivoted levers

page_text: arranged to bear against said head either above or below the same and having
their pivots offset, and a pressure-operated plate connected to said levers to
actuate the same.
6. In a dry-pipe valve, a casing containing the valve proper, a second casing
provided with a chamber communicating with the external air, a movable plate
forming one wall of said chamber and exposed to the air pressure in the system,
and locking mechanism for said valve proper actuated by said plate when under
pressure.
7. In a dry-pipe valve, the combination of an outer casing provided with a
valve proper, an inner casing suspended within said outer casing and communi-
cating therewith, a chamber in said inner casing communicating with the external
air, a movable plate normally closing said chamber on one side and exposed to
the pressure in the casings, and valve-locking mechanism connected to said
movable plate.
8. In a dry-pipe valve, the combination of an outer and an inner casing spaced
apart as described, the outer casing being provided with an inlet and an outlet,
a valve proper adapted to close said inlet and having a stem extending into the
inner casing, said stem having a groove or recess for the purpose set forth, levers
mounted on offset pivots in said inner casing and arranged to engage said valve
stem, and a pressure-operated plate contained in said inner casing and connected
to said levers to operate the same.
9. In a dry-pipe valve, an outer casing having an inlet and an outlet and
provided with a valve proper, a removable plate closing one side of said casing,
and an inner casing adapted to contain valve-controlling mechanism and provided
with means whereby it may be detachably secured within the outer casing in
such manner as to provide a free space between the two casings.
10. In a dry-pipe valve, a valve proper comprising a plate having a com-
pressible bearing ring, a hollow stem bearing loosely against the top of said
plate and extending upward therefrom, a retaining collar surrounding said stem,
and an adjusting bolt passing through said hollow stem and having a threaded
connection therewith, for the purpose set forth.
11. In a dry-pipe valve having a chamber normally closed by a movable plate
subject to the air pressure in the system, an alarm attachment connected with
said chamber by a pipe and comprising a casing, a loose cover resting thereon
and provided with guiding flanges, a perforation in said cover in which is secured
a pipe passing loosely through the bottom of said casing, a cap mounted on said
casing and carrying two insulated contacts electrically connected with an alarm,
and a contact pin secured to said cover and movable therewith to complete the
circuit through said alarm.
12. In a dry-pipe valve, an alarm attachment comprising a casing in communi-
cation with the sprinkler pipe system near the main valve, a float movable
vertically in said casing and carrying a contact pin, two insulated contacts secured
to the interior of said casing and electrically connected with an alarm, and a
drainage cock in the bottom of said casing.
Dated this 30th dow of W 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.