Improvements in Pressure Doors
Year: 1899

page_text: COMILNIE DI MULTIVATION
Improvements in Pressure Doors,
THOMAS SHAW, 109, Chatham Street, Victoria, British Columbia, Canada,
Boiler Maker, 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:
My invention relates to improvements in doors for closing apertures that are
subjected to extreme pressure, and to make such openings steam or water tight
in a very substantial and effective manner, and the object of this invention is to
provide a means of effecting a closure, where the pressure to be resisted is very
great, in a comparatively short space of time, and at a minimum of cost.
I attain this object by the mechanism illustrated in the accompanying draw-
ing, in which-
Fig. 1 is a front elevation of my door or closure.
Fig. 2 is a section of the same on the line a a, in Fig. 1, and,
Fig. 3 is a detail of one of the hinges of my door, taken on the line bb, in
Fig. 1.
Similar letters and numerals refer to similar parts throughout the several
views.
As illustrated in the appended drawings, my door is designed to close a
cylindrical opening, but it is obvious that this device may be applied to apertures
of various forms. In this case it is applied to a vessel having a cylindrical
mouth.
In describing the various parts, A indicates the vessel or opening to be closed,
and B is the door or closure. These parts do not constitute my invention, but
the mechanism by which they are secured together illustrates the construction
on which I base my claims.
The said door B is hung on the hinges 10. The fixed portions of these are
secured to a band 11, or otherwise secured to the mouth of the opening.
Arranged around the mouth of the opening, and seated in a groove 12 is a
rubber packing 13, which forms a seat for the door B.
Securely fixed to the centre of the door B is a stud 14, which is threaded on
its projecting end. Passed over the stud 14 and arranged to move thereon is
a disc 15, having a boss 15 on its inner side. Pivotally fixed to the under or
inner side of the disc. 15, and with their inner ends abutting against the boss 15"
are radial arms or bolts 16, which project beyond the outer rim of the door B,
and when these bolts are thrown out, as will be understood presently, their
ends will. pass through apertures 11ª in projecting lugs 11b, which lugs are
integral with the band 11 on the rim or edge of the aperture. These bolts 16
are arranged tangentially to the axis of the disc 15, so that as the disc is turned
or rocked back and forth the said bolts are susceptable of being withdrawn or
removed from the apertures 11" in the lugs 11b. The disc 15 is provided with
a crank and handle 15b for turning it back and forth. As shown by dotted
lines (see Fig. 1) when the crank is moved within the segment of the stops 17
the outer ends of the bolts will be passed through the apertures in the lugs 11".

page_text: To prevent the bolts from moving from their proper position, when withdrawn
from the lugs, I provide staples or clasps 18, which are rigidly fixed to the door
and act as keepers for the bolts to work therein. Around the outer side of the
door B is a raised rim or bead 19 on which the bolts 16 fulcrum; and the
opposite ends of the said bolts lie on the inner side of the disc 15 (see Fig. 2).
Encircling the stud 14, and lying between the door B and the boss 15" on the
disc, is a spiral spring 20, and on the opposite side of the said disc is a nut 21
which is turned on the threaded portion of the stud by the crank 22.
From the foregoing it is shown that the disc 15 is controlled in its position
on the stud 14 by the spring 20 on one side, and the nut 21 on the other, and
consequently, as the bolts have their inner ends pivotted to the disc, and their
outer ends fulcrumed over the rim 19, as the disc 15 forces the inner ends
towards the door, it is clear that a powerful leverage is exerted on the door,
it being firmly held on its seat and thus forms an air-tight or steam-tight
joint. The bolts 16 when forced down by the nut 21 take the place of and
become levers, and the power exerted is in proportion to the distances between
the point of fulcrum, the lugs 11b, and the pivot on the disc, and the pressure
exerted by the nut 21. It is clear, therefore, that, even the ends of steam
cylinders may be successfully closed with this device, it being merely necessary
to construct the parts sufficiently powerful to stand the strain that will be
exercised.
To provide for the door being properly forced up to its seat at the side occupied
by the hinges, the hinge-pin holes are slotted in the direction of the thrust of
the door, as 10" (see Fig. 3). This allows the door to move to and from its
seat the required distance without unnecessary strain.
Should this door be employed to close steam-boxes or retorts, for cooking
canned fish and the like, I provide rails, as 23, for the carriage, (which conveys
the matters to be cooked). This, of course, is no part of my invention, as the
closure will be the same whether the pressure to be resisted be fluid or liquid.
In the operation of my improved door, the crank 15b is turned to the position
as shown in dotted lines and the door is closed. This crank is then returned to
its depending position, which drives the points of the bolts 16 into the apertures
in the lugs 11. The nut 21 is then turned until sufficient strain is exercised on the
bolt levers 16, to rigidly secure the door against movement from the pressure
exerted against the opposite side. When the nut 21 is relaxed the spring 20
will carry out the disc, so that the outer ends of the bolts will be released from
pressing contact between the rim 19 and the lugs 11b. They may then be
withdrawn by the movement on the crank 15b.
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-
1. In a door or closure having a rubber packing arranged thereround, a door
arranged to seat upon said packing, lugs arranged at intervals around the outer
rim of said door, apertures in said lugs, in combination with a threaded stud
fixed in the centre of the said door, a disc designed to move on said stud, bolts
pivotted to the outer rim of said disc, the said bolts being tangentially placed
to the disc, a rim on the outer edge of the door to form a fulcrum for the bolts,
and means for moving the bolts in and out radially from the centre, and for
moving the centres of said bolts in and out in direction of the thrust of the door
as specified.
2. A door hinged or otherwise supported on a suitable seat around an open-
ing, lugs projecting outwards at intervals around in proximity to said door,
apertures or recesses in said lugs, in combination with a rim or bead around the
outer edge of said door, a threaded stud fixed to the centre of the door, a diso
made to move on the stud, and bolts connecting with the disc at a tangent to a
circle near its outer edge, means for turning said disc, so that said bolts will be

page_text: thrust through the openings in the said lugs, staples or keepers for holding the
arms in place, a spring interposed between the disc and the door, and a nut on
the outer end of the stud, whereby the disc, and consequently the inner ends
of the bolts will be moved in or out in the direction of the thrust of the door,
as specified.
3. A door having a raised rim or bead around its outer edge, a stud secured
to its centre having a disc to move thereon, a crank-handle secured to said disc,
radial bolts pivotted to the rim of the disc, said bolts projecting beyond the
edge of said door when the disc is turned, so that they are approximately in
line with the axis thereof, but when the disc is turned back their outer ends
will be withdrawn and their alignment will be tangential to the disc, means for
moving the disc in or outward upon the stud, whereby when the bolts are projected
forward they will be engaged by lugs or fixtures on the walls of the openings
to be closed, and by moving the disc inward on the stud the door will be held
down by the bolts acting as levers, substantially as specified.
Dotal +1: 2041 laf L 1900
W. G. TRETHEWEY,
Scant