Improvements in Air-tight Doors and Frames, Hinges and Fastenings therefor.
Year: 1899

page_text: Date of Application, 19th Sept., 1899-Accepted, 19th May, 1900
COMPLETE SPECIFICATION.
Improvements in Air-tight Doors and Frames, Hinges and Fastenings
therefor.
:
I, S. PRICE STEVENSON, of No. 321, Broomall Street, in Chester, County of
Delaware, State of Pennsylvania, United States of America, Lumber Merchant,
do hereby declare the nature of my said 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 doors and shutters for air tight chambers, and especially
to those required for refrigerators and cold storage apartments, and embraces
the doors and frames therefor, and the hinges and latches or locks for connecting
and fastening the doors and frames, and has for its object the production of such
frames and doors with the connecting parts, as a commercially merchantable
article of trade, of easy applicability to refrigerating and other chambers required
to be air tight, and with a facility of adjustment to automatically compensate for
any defects of form that may develope either in the door, or in the wall of the
chamber to which the door or frame is applied and facility of closing, latching
and opening that permits such functions with the least care and exertion of
force.
To effect these several desiderata, this invention consists in a door having two
rigid upright sides or edges united by flexible inside and outside sheathing, and
upper and lower rails, and a frame and casing into which the door fits, said frame
and casing being adjustably applicable to door openings in walls, hinges of special
construction elastically connecting the door with the frame and a special construc-
tion of latch and lock, by which the momentum of the closing motion of the door
is utilized in clamping the door tightly in shut position and whereby the unlatch-
ing and opening of the door is greatly facilitated, the whole being arranged and
constructed as hereinafter described and shown in the accompanying drawing, in
which:
Figure 1 is a front elevation of a door-frame (with the door in open position,)
embodying this invention;
Figure 2 is a front elevation thereof with the door closed;
Figure 3 is a vertical section;
Figure 4 is a side elevation:
Figure 5 is a horizontal section in closed position.
Figure 6 is a like section in open position;
Figure is an enlarged perspective view of a portion of the gasket packing;
Figure 8 is an enlarged perspective view of the latch and lock;
Figure 9 is an enlarged view of one of the hinges;
Figure 10 is an enlarged view of a modified form of hinge.
Figure 11 shows a front elevation of the lock and latch with the keeper therefor,
as applied to a door and door-jamb or stile, embodying this invention;
Figure 12 is a rear elevation of the lock and latch with the back plate removed;

page_text: www pas
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side of Figure 11;
Figure 14 is a detached side elevation of the keeper as viewed in the same direc-
tion as in Figure 13;
Figure 15 is a vertical section in the plane indicated by the dotted line Y Y
in Figure 12;
Figure 16 is a vertical section in the plane indicated by the dotted line z z
in Figure 12;
Figure 17 shows the inner side of the back plate of the lock and latch case;
Figure 18 is a perspective view of the latching lever and handle;
Figures 19 and 20 show modifications of the form of the lever handle of the
latch;
Referring to the drawing, a represents the wall of a refrigerating chamber to
which this invention is applied, is the frame to which is fitted and hung the
door c; d is the front casing of the frame b; the frame b consists of stiles e, and
rails or strips f connecting them; these parts e and f are rigid edge-wise and
lengthwise but susceptible of torsionally bending to an extent and for a purpose
that will hereinafter appear; c is the door consisting of an upright g to which
the hinges are attached by screws or rivets and a rigid stile i having the lock
and latch attached in like manner; the stiles g and i are connected at the top
and bottom by strips or rails k and 7 (as shown in Figures 3, 5 and 6).
The inner face in of the door is formed of sheathing, grooved and tongued
together, so as to be air tight, and whilst slightly flexible torsionally, as a plane,
is stiff edgewise.
The outer face n of the door c is made to project as a rim over the front
casing, it may be made of strips grooved and tongued like the inner face m
or panelled, according to taste, it should be stiff edgewise, and have some flexibility
torsionally from a plane surface.
The frame of the door c, consisting of the stiles g and i and strips and /,
fits easily within the frame b and casing d, the outer face n overlaps the casing
forming a flange or rim 1 and has a gasket o attached thereto, which contacting
with the casing d seals the joint air-tight.
The gasket o (shown in Figure 7) consists of a soft round core p, preferably
of spun hemp, covered with a flexible fabric or cloth q, the edges of the cloth
lap upon each other and form a flange r, by which it is tacked to the door, so
that the elasticity of the core p is not obstructed by the tacks.
The gasket o is compressed and slightly flattened and held clamped between
the casing d and the rim 1 of the door c, by the combined action of the hinges h
and the latch 3 hereinafter described.
The hinges h hereinafter described are attached to the door c by screws s and t
as shown in Figures 2, 4, and 6.
Horizontal strips are placed in the door c into which the screws s enter and
the screws t hold in the stile g.
The portion marked v, of the straps of the hinges h, between the screws t and
the pivots w, is made elastically flexible horizontally but is stiff vertically.
The bearing of the pivots w are fastened by screws y to the front casing d
as shown in Figure 4.
The elastic portion of the hinges h are made tapering in width as shown in
Figure 9, with the greater breadth at the place where it is attached to the
stile and front n of the door c by the screws and are of sucli proportions that
the flexure of the plates is as nearly uniform as may be throughout these parts,
the object of the tapering form being to distribute the flexure evenly in the
plates and avoid permanent bending or set at any point, thereby impairing the
elasticity of the hinge-plates. The same effect can be attained, but in a less
satisfactory manner, in the form shown in Figure 10, wherein the hinge plate z
is of equal breadth throughout but tapered in thickness.
The distance between the pivots of the hinges h and the point of attachment

page_text: to the door c is such as to provide ample elasticity to the hinges, and at the same
time operates to leave the door-way unobstructed by the thickness of the door c
when opened at right angles to the frame b.
In applying the door and frame to a door opening for use, the frame is placed
in the door opening in the wall, with the casing overlapping on the outer surface
of the wall, the frame is then strained or twisted, as may be required to contact
the casing d of the frame with the rim 1 on the door, strips 27 are then applied
closely to the inner edge of the frame and fastened to the wall in close contact
therewith, and other strips 28 are fastened to the wall in close contact therewith
and with the outer edges of the casing d, as shown in Figures 5 and 6.
The latch 2 is applied to the side of the door c opposite the hinges h at or
near the mid-length of the door, and engages a keeper 3 secured to the casing d;
both the latch 2 and keeper 3 are specially designed and adapted for use with
such doors and are important elements in the efficient working of this invention.
This is shown fully in all its details in Figures 11 to 20 of the drawing, and is
constructed and operates as follows: 4 represents the case of the lock (see
Figures 11 and 12) 5 the back plate thereof; 6 the latching hook formed as a
lever arm integrally with the cross bar or rock shaft 7, and looped lever handle 8;
the rock shaft 7 rests in notches 9 in the box 4 and is held therein by the back
plate 5; 3 is the keeper in which the latch engages, this is secured to the casing d
and has an inclined surface 10, upon which the latching hook 6 slides until it
reaches the angle 12 on which it hooks.
13 is a projection or short-lever-arm on the rock shaft 7, against which the upper
end of the spring 14 presses forcing the hook 6 upward, and the looped lever-
handle 8 toward the door. The spring 14 is forced into contact and is held in
position with the arm 13 by a projection 15 on the inner side of the back plate 5:
the back plate 5 is secured to the box by a screw 18, fitting in a boss 19, formed
in the box 4. The spring 14 is a straight, elastic plate and fits in the recess 20
in the box 4, so that it cannot be displaced. A lever-arm 26 is formed integrally
with, and projects downwardly from, the rock shaft 7, in such position as to clear
a projection 22 on a bolt 23 when the latch is fastened or unfastened; and when
the bolt 23 is locked, the lever 26 rests on the projection 22 and prevents motion
of the lever 26, rock shaft 7 and handle 8, and the unlatching of the hook 6 from
the angle of the keeper 9. The bolt 23 is operated by a key and may have
tumblers or any of the usual attachments for obstructing unauthorized unfastening.
As shown in Figures 19 and 20, a lever-handle 24 extending through an aper-
ture 25, in the case 4, is substituted for the looped handle 8 which construction
is found more convenient for large sizes.
Constructed as above described, the momentum of the door in closing suffices
to latch it, and the simple pulling of the lower end of the looped handle 8
serves to unlatch and open the door. From the construction of the parts of the
lock they are easy of production by casting, and require little or no fitting to
assemble them for use the spring is of cheap production, and easily renewed
without any considerable degree of skill, the parts of the lock and latch are.held
together when assembled, by the screw 18 and when applied to a door for use the
screws by which it is fastened to the door, firmly hold the plate 5 in position,
by clamping it between the box 4 and the door c. As a consequence of the torsional
flexible qualities of the door and frame, and the means of continuously exerting
elastic pressure at the hinges and the lock, without any special attention, such
doors remain air-tight continuously, with a minimum of strain and labor. The
door in closing by its weight and motion acquires considerable momentum, this
is greatest near the latch, and as it is arrested is expended, first in latching, and
in compressing the gasket o and flexing the straps of the hinges h then the elastic
re-action of the hinges makes a constant closing pressure on the gasket and. per-
manently seals the closed door.
It is obvious that the frames and doors can be made as described, and sold
separately, as may also the hinges and latch, and afterwards assembled and put to

page_text: use; each of these parts are of novel and useful construction, and adapted to co-
operate with each other, but are separately saleable, and therefore are made the
.subject of separate claims.
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. A. door for airtight compartments consisting of rigid stiles united by rails
susceptible of torsion, a flexible inner sheathing, a flexible outer sheathing having
a rim projecting beyond the stiles and rails, and a compressible gasket secured
to said projecting rim, in combination with elastic hinges and a lateh so pro-
portioned as to exert equal pressure upon the gasket in all parts between the-rim
of the door and a casing surrounding the door opening as set forth.
2. A combined frame and casing for the door openings of refrigerating chambers,
consisting of stiles and rails rigid in the direction on their breadth and length,
and susceptible of torsional flexure, in combination with a front casing secured
thereto, adapted to contact with the gasket of the door opposed thereto, the whole
arranged and adapted to be adjustably applied thereto, substantially as set forth.
3. In a door for airtight compartments, rigid stiles united by rails susceptible
of torsion, and a flexible inner sheathing attached to said frame, in combination
with a flexible outer sheathing, also secured to said stiles and rails, and provided
with a rim projecting beyond the stiles and rails, adapted to overlap and by
Hexure apply closely to the casing of the door opening substantially as set forth.
4. In a frame for doors of airtight compartments, stiles and a lintel and a
sill rigid in lengthwise direction, and torsionally flexible, in combination with a
torsionally flexible casing attached to the front of said frame, and adapted to be
adjusted by torsion to fit the deviations from a flat plane of a door applied thereto,
substantially as set forth.
5. In a combined airtight door and frame for refrigerating and like chambers,
a door having rigid stiles, rails connecting with said stiles susceptible of torsional
flexure, an inner sheathing susceptible of torsional flexure, an outer sheathing
projecting beyond the stiles and rails, also torsionally flexible, and a frame having
all parts rigid in the direction of their depth, a casing secured to said frame, a
gasket applied to said outer sheathing to contact with said casing, in combination
with elastic hinges and a latch, proportioned and arranged to press said door
upon said gasket uniformly in all parts against said casing, with continuous
pressure, as and for the purpose set forth.
6. Doors having rigid edges and torsionally flexible faces in combination with
elastic hinges and fastenings, arranged and adapted to apply the edges to con-
tact with casings liable to variably deviate from flat planes, as and for the purpose
set forth.
7. A door in combination with hinges, and fasteners, arranged to convert the
momentum of the door in closing into a constant elastic force, to maintain pres-
sure upon a gasket applied between the door and the margin of the door opening as
set forth.
8. In a door for air tight enclosures, a doorway frame, a flexible door fitted to
overlap the front margin of said frame, elastic hinges applied to the edge of said
door an automatic fastening applied to the opposite edge of the door, and arranged
to elastically enforce contact between the margin of the frame and the margin of
the door, substantially as set forth.
-
9. In a door for air tight apartments, a torsionally flexible frame formed of
rigid stiles and rails, an inner and outer torsionally flexible sheathing secured
thereto, said outer sheathing projecting as a rim beyond the frame and provided
with a compressible gasket adapted to contact closely with the casing of a door
frame, substantially as set forth.
10. The latch for doors of air tight structures, embracing an inclined surfaced
keeper, having angles adapted to engage a hooked latch, a rock shaft and hooked

page_text: latch, a lever handle practically at right angles to said latch, and an arm adapted
to engage a plate spring, all formed integrally with said rock shaft, in combination
with said spring, and an enclosing case, a projection therein and means of press-
ing said spring on said projection, all arranged to operate substantially as
set forth.
11. In a locking latch for air tight doors, a keeper, a lock case having bearings
to support a rock shaft, and bearings for a locking bolt formed therein, in com-
bination with a rock shaft having a hooked latching arm adapted to engage said
keeper, an arm adapted to engage a plate spring, an arm adapted to engage a
locking bolt, and a lever handle practically at right angles to said latching arm,
all formed integrally with said rock shaft, and a locking bolt, and a spring and
means of forcing said spring against one of said arms, substantially as set forth.
12. In hinges for air tight doors an elastic strap having graduated varying
thickness or breadth and flexure between the pivotal end and the point of attach-
ment to the door for the purpose of avoiding permanent set or bending and pro-
viding greater range of elastic motion as and for the purpose set forth.
Dated Town September 1000.
S. PRICE STEVENSON.
By George Downing & Sons,
Chartered Patent Agents, 8, Quality Court, London, W.C.