IMPROVEMENTS IN SHUTTERS AND BLINDS FOR WINDOWS, DOORWAYS, AND OTHER APERTURES, AND IN THE MEANS FOR ADJUSTING THE SAME
Year: 1870

page_text: LETTERS PATENT to Frederick Hartt Knevitt, of No. 3, Sun Court,
Cornhill, in the City of London, Architect, for the Invention of
"IMPROVEMENTS IN SHUTTERS AND BLINDS FOR WINDOWS, DOORWAYS, AND
OTHER APERTURES, AND IN THE MEANS FOR ADJUSTING THE SAME,
"
Sealed the 24th May 1870, and dated the 12th January 1870..
:
PROVISIONAL SPECIFICATION left by the said Frederick Hartt:
Knevitt at the Office of the Commissioners of Patents, with his
Petition, on the 12th January. 1870.
I, FREDERICK HARTT KNEVITT, of No. 3, Sun Court, Cornhill, in the
City of London, Architect, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SHUTTERS AND BLINDS FOR WINDOWS, DOOR-
WAYS, AND OTHER APERTURES, AND IN THE MEANS FOR ADJUSTING THE SAME," to
be as follows:-
My present Invention relates partly to further improvements in the
louvering shutters and blinds described in the Specification of an Invention
for which Letters Patent have been granted to me and Henry Herbert'>

page_text: Hazard, bearing date the Seventeenth day of December, in the year of
our Lord One thousand eight hundred and sixty-eight, No. 3845, the
object of the said further improvements being to reduce the cost of
manufacture of such shutters and blinds while retaining the main
advantages designed to be secured by the said former Invention.
In carrying my present Invention into practice I use a single
stationary groove at cach side of the window, doorway, or other opening,
in which groove works a single pin or projection formed on or attached
to each end of the laths. These pins form centres about which the
laths turn in louvering. The said pins, which may be at the centre or at
or near either the inner or outer edge of the lath working in the grooves,
cause the shutter to move up and down with great smoothness and support
the same and keep it steady in any position against the action of the
wind. For the purpose of louvering or adjusting the laths on their centres
I attach either webbing or metal jointing to both the front and back
edges of the said laths, the upper ends of which webbing or jointing are
hung upon a roller of wood or metal, extending across the top of the
window or other aperture or upon pullies connected by a shaft; the said
roller or shaft is mounted in suitable bearings. When this roller or
shaft is revolved by a cord; it winds or unwinds a small portion of the
webbing or jointing and moves the same up or down sufficiently to
louvre the laths to any required angle. When the pins are placed
centrally upon the ends of the laths, the webbing or jointing at both
edges is made fast to the top of the roller crossing under the same, but
if the pins are placed at either the back or front edge of the laths the
webbing or jointing at the same edge is secured to the lintel, or soffit,
the webbing or jointing at the opposite edge only being hung upon the
roller. The shutter or blind is raised by cords or by flat chains attached
to the lower lath, which cords or chains coil upon pullies connected by a
shaft to insure their simultaneous. action. I prefer to extend the bottom
lath to receive the said cords or chains, but if desired I may pass the
said cords or chains to the bottom lath at the back of the shutter or blind.
These chains or cords (unlike those of ordinary Venetian blinds) are of
equal length and therefore not liable to unequal stretching. The blind
is therefore always kept level in whatever position it may be raised or
lowered. By attaching the cords or chains to the ends of the bottom.
lath or arranging them at the back of the shutter or blind as above set
forth we obviate the necessity of cutting holes for the passage of the cords
through the entire scries of laths composing the blind or shutter.

page_text: My Invention relates also to the use (as a substitute for, ordinary
webbing) of a strip or band of thin metal. hinges constructed in a peculiar
manner. These hinges besides being jointed together at the edge of every
lath have an additional joint midway between the laths, so that the said
hinges fold up flat as the laths close or come together in raising the blind
or shutter. The flaps of the hinges at this central joint are formed with
a stop at the outside or back, which prevents their folding. inward
between the laths, and in order that they may fold easily in. an outward
direction, I arrange the stops, so that when fully open the plates
of the hinges are slightly inclined outward towards the central joint.
The said hinges are preferably stamped out of sheet metal, doubled over
and rivetted. They are jointed to wings or flaps on each side to which
the laths arc attached by rivets or screws.
The said Invention also relates to means for balancing shutters and
blinds which are raised by cords, chains, or other connections attached
to the lower lath. For this purpose I use a compensating balance weight
of novel construction. The said weight is formed of a series of lead, iron,
or other metal plates flat or slightly curved in transverse section. These
plates diminish in width towards the lower end of the weight so that the
same is gradually tapered from the upper to the lower end. The said plates
are jointed together so as to coil upon a barrel or cylinder which is
connected by a shaft to the pulley whereon the raising chain or cord is
wound. As the shutter ascends the weight descends, and as the laths are
connected upon the lower lath in its ascent a corresponding amount of
the weight is uncoiled and suspended from the barrel. By an accurate
adjustment of the width of the plates the weight of shutter resting upon
the raising chains as well as the difference of the constantly varying
Ieverage upon the barrel and pulley may be exactly balanced in any
position, of the shutter.
i
The said Invention also relates to the attachment of the laths of
Venetian blinds to the webbing by crossing strips of webbing from
edge to edge under and over the laths instead of using sewn cross tapes
or ladders, either threading them through metal staples driven into the
edges of the laths or by passing the webs under one edge and through
longitudinal slits cut in the centres and over the other edge of the lath,
in which latter case I generally secure the laths to the webs by copper
tacks or similar fastenings. This mode of interlacing the webs with the
lathis keeps the latter securely in place, forms a very strong Venetian

page_text: blind, and allows any portion of the webbing to be easily repaired at any
time without removing the whole strip. I sometimes hang the laths
centrally upon strips of webbing or metal jointing by passing the said
webbing or jointing through holes cut in the laths, the said holes being
of such a width as to permit the free movement of the laths in louvering.
I pass through the metal jointing or webbing pin centres upon which
the laths are hung by the attachment of metal plates placed at each
side of the holes. The louvering in this case is effected by means of an
expanding groove at one or both sides of the window or opening formed
by two wooden or metal fillets arranged to work with a parallel motion
upon central pivots.
The pins or projections herein-before described are not required in this
modification of my Invention as the entire ends of the laths lie and
move within the expanding grooves. The expanding groove is operated
by a cord passing over a pulley.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Hartt Knevitt in the Great Seal Patent
Office on the 12th July 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
HARTT KNEVITT, of No. 3, Sun Court, Cornhill, in the City of London,
Architect, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of January, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Frederick Hartt Knevitt, Her special licence,
that I, the said Frederick Hartt Knevitt, my executors, administrators,
and assigns, or such others as I, the said Frederick Hartt Knevitt, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter 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 "IMPROVEMENTS IN
SHUTTERS AND BLINDS FOR WINDOWS, DOORWAYS, AND OTHER APERTURES, AND IN
THE MEANS FOR ADJUSTING THE SAME," upon the condition (amongst others) a
that I, the said Frederick Hartt Knevitt, my executors or administrators,

page_text: 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 Frederick Hartt Knevitt, 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, reference being had to the accompanying
Drawings, forming a part of this Specification:-
"
My present Invention relates partly to further improvements in the
louvering" shutters and blinds described in the Specification of an
Invention for which Letters Patent have been granted to me and Henry
Herbert Hazard, bearing date the 17th day of December, in the year of
our Lord One thousand eight hundred and sixty-eight, No. 3815, the
object of the said further improvements being to reduce the cost of
manufacture of such shutters and blinds while retaining the main
advantages designed to be secured by the said former Invention.
In carrying this part of my present Invention into practice I use a single
stationary groove at each side of the window, doorway, or other opening,
in which groove works a single pin or projection formed on or attached
to each end of the laths. These pins form centres about which the laths
turn in "louvering." The said pins which may be at the centre or at or
near either the inner or outer edge of the lath working in the grooves
cause the shutter to move up and down with great smoothness and
support the same and keep it steady in any position against the action of
the wind. For the purpose of "louvering" or adjusting the laths on
their centres I attach either webbing or jointed metal strips to both the
front and back edges of the said laths, the upper ends of which webbing
or jointed strips, are hung upon a roller of wood or metal extending
across the top of the window or other aperture or upon pulleys con-
nected so as to turn together by a shaft; the said roller or shaft is
mounted in suitable bearings. When this roller or shaft is revolved by a
cord it winds and unwinds a small portion of the webbing or jointing and
moves the same up or down sufficiently to "louver" the laths to any
required angle. When the pins are placed centrally upon the ends of the
laths the webbing or jointing at both edges is made fast to the top of the

page_text: roller, crossing under the same, but if the pins are placed at either the
back or front edge of the laths the webbing or jointing at the same
edge is secured to the lintel or soffit, the webbing or jointing at the
opposite edge only being hung upon the roller. The shutter or blind is
raised by cords or by flat chains attached to the lower lath or a raising
bar under the same, which cords or chains coil upon pulleys connected
by a shaft to insure their simultaneous action as shewn in Figure 10 of
the aforesaid former Specification. I prefer to extend the bottom lath or
raising bar at each side of the shutter or blind to receive the said cords
or chains, but if desired I may pass the said cords or chains at the back
of the shutter or blind to the bottom lath or raising bar. These chains
or cords (unlike those of ordinary Venetian blinds) are of equal length
and are therefore not liable to unequal stretching or extension. The
blind is therefore always kept level in whatever position it may hang.
By attaching the cords or chains to the ends of the bottom lath or
arranging them at the back of the shutter or blind as above set forth
I obviate the necessity of cutting holes for the passage of the cords
through the entire series of laths composing the blind or shutter.
My Invention relates also to the use (as a substitute for ordinary
webbing) of a jointed strip or band composed of thin metal hinges
constructed in a peculiar manner. These hinges besides being jointed
together at the edge of every lath have an additional joint midway
between the laths, so that the said hinges fold up or close as the latlıs
close or come together in raising the blind or shutter. The flaps of the
hinges at this central joint are so formed at the outside or back that
their edges meet each other and act as stops, which prevent the folding
inward of the hinges between the laths; and in order that they may fold
easily and without obstruction outside of the laths I arrange the stops
so that when fully open the plates of the hinges are slightly inclined
outwards towards the central joint. The said hinges are preferably
stamped out of sheet metal doubled over and rivited, or they may be in
some cases of cast metal. They are jointed on each side to plates or
strips which are attached to the laths by rivets or screws.
The said Invention also relates to means for balancing shutters
and blinds which are raised by cords, chains, or other connections
attached to the lower lath or raising bar under the same. For this
purpose I use a compensating balance weight of novel construction. The
said weight is formed of a series of lead, iron, or other metal plates, flat

page_text: or slightly curved in their transverse section. This scries of plates
deminislies in width towards. the lower or outer end of the weight, so
that the same is gradually tapered from the upper to the lower end. The
said plates are jointed together so as to coil upon a barrel or cylinder
which is connected by a shaft to the pulley whereon the raising chain or
cord is wound. As the shutter ascends the weight descends, and as the
laths are collected upon the lower lath or raising .bar in its ascent.:
corresponding amount of the coiling weight is uncoiled and suspended
from the barrel. By an accurate adjustment of the width of the aforesaid.
plates the weight of the laths of the shutter resting upon the raising
chains, and the effect of the constantly varying leverage of the weight
upon the barrel and that of the cord upon the pulleys may be exactly
balanced in any position of the shutter.
.a
The said Invention also relates to a novel manner of attaching the
laths of Venetian blinds to the webbing which connects them together.
For this purpose I cross the strips of webbing from edge to edge of and,
under and over the laths instead of using sewn cross tapes or "ladders,"
the strips being either threaded through metal staples driven into the
edges of the laths or passed under one edge and through longitudinal.
slits cut in the centre of the lath and over the other edge of the said.
lath. In the latter case I generally secure the laths to the webs by.
copper tacks or similar fastenings. This mode of interlacing the webs
with the laths keeps the latter securely in place, forms a very strong
Venetian blind, and allows any portion of the webbing to be easily repaired.
at any time without removing the whole strip. I sometimes hang the
laths centrally upon webbing or upon jointed metal strips by passing
the said webbing or metal strips through holes cut in the laths, the said
holes being of such a width as to permit the free movement of the laths
in "louvering." Through the jointed metal strips or the webbing and
through metal plates attached to the laths at each side of the holes I
pass small pin centres, and thereby support the laths upon the joints or
webbing. The "louvering ".in this case may be effected by means of an.
expanding groove at one or both sides of the window or other aperture,
such groove being formed by two wooden or metal fillets or bårs
arranged to work with a parallel motion upon central pivots. The pins
or projections on the laths herein-before described are not required in
this modification of my Invention, as the entire ends of the laths lie and
move within the expanding grooves. The expanding groove is operated.

page_text: by a cord passing over a pulley, and may be used alone as a means of
"louvering" the blind, or in combination with other devices, as herein-
after described.
"
"I will now proceed more fully to describe my said Invention by the aid
of the accompanying Drawings, in which Figure 1 is an interior elevation
of a window provided with my improved. Venetian or "louvering
blind showing the single stationary groove and the pins which work in
the said grooves formed in the centre of the ends of the laths; Figure 2
is a vertical section on the line x, x, Figure 1; Figure 3' is a horizontal
section on the line y, y, Figure 1; Figure 4 is an interior elevation of a
window showing the modification of the said blind in which the pins aro'
formed at one edge of-the laths; Figure 5 is a vertical section on the
line z, z, Figure 4; Figure 6 is a horizontal section on the line x1, x¹,
Figure 4; Figures 7 and 8 are an interior elevation and vertical section
of the upper part of a window with a blind constructed similar to that
shown in Figure 4, but with a modification of the mechanism for
"louvering" the said blind. Figures 8ª, 86, 80, 8d; illustrate modified
arrangements of my Invention in which I make use of expanding
grooves for receiving and supporting the ends of the laths. Figures 9,
10, 11, 12, and 13, shew detached portions of the aforesaid blinds and
"louvering" mechanism drawn to an enlarged scale. Figures 14, 15,
16, and 17 illustrate the construction of my improved jointed metal
strips to be used as a substitute for the webbing ordinarily employed for
connecting the laths of Venetian blinds. Figures 18, 19, and 20,'
illustrate my improved manner of attaching the laths of à Venetian
blind to the strips of webbing. Figures 21 and 22 illustrate the operation
of my improved counterbalance weight. Like letters indicate the same
parts throughout the Drawing.
-
A is a shutter or blind, which is composed of a number of parallel
laths or bars a. of any convenient size, and formed of wood or other
suitable material. In Figures. 1, 2, and 3 it will be seen that the
strips 6 whereby the laths are connected together are passed over and
attached to the roller c, which extends across the top of the window..
This roller is provided with a cord d which is extended downward to any
convenient position and secured to the tightener. It is obvious that by
the manipulation of this cord the blind can be turned or "louvered" in
either direction, and to any angle between the two positions indicated by
full and dotted lines, Figure 11. The upper lath, as shown in Figure 11,

page_text: 66
is provided with small circular segments a*, which take up the slack of
the part 6* of the webbing. In Figures 4 and 5 the webbing 6 on one
side only is shown attached to the roller, the webbing at the other side
being connected to the bar c* secured to the under side of the lintel. In
this case the small segments a* are not required. On each side of the
window and extending from the top to the bottom of the same is the
groove f, which in the arrangement illustrated in Figures 1, 2, and 3 is
in the centre of the ends of the laths a and the pins a¹, which are also
formed centrally on the said laths, work up and down freely in the said
grooves, and also turn freely therein, while at the same time they offer a
firm support to the laths against the force of the wind in any position of
the blind, and at any angle to, which the laths may be adjusted by
'louvering.” The ends of the laths may be advantageously constructed
with brass caps a² on which the pins a¹ are formed, the said caps being
attached to the laths by small rivets or other suitable fastenings. The
groove fmay be formed by placing together two pieces of angle iron f¹;
as shown in Figure 10, or I may use single bars f' of cast iron, brass, or
other suitable material with the groove cast or cut in them, as.in
Figure 12. The raising bar g, which may be of wood or metal, or wood
and metal combined, forms the bottom of the shutter or blind, and
extends into the grooves f. The said bar is connected to the lower ends
of the raising chains or bands. I prefer to use chains h constructed as
shown in Figures 9, 11, 12, and 13, as such chains are strong and
durable, while at the same time they are light, and the form of the links
offers no obstruction to their coiling around the pulleys i at the top of
the window. These pulleys are fixed upon the shaft j which is fitted to
turn freely in the hangers k secured to the lintel B. At one end of the
said shaft is another pulley or barrel 7, on which is wound the cord m
This cord is wound on the pulley in the opposite direction to that in
which the raising chains are wound on the pulleys i, so that when the
cord is pulled the blind will be raised, and when the cord is released the
blind will descend by its own weight.
•
T
In the modification of my Invention illustrated in Figures 7 and 8, the
"louvering" is effected through the medium of the lever c¹ to which the
cord d is attached, the said lever being curved to allow it to work clear
of the raising shaft.
j
My improved jointed metal strips shewn in Figures 14, 15, 16, and
17, consist of a series of hinges which, as herein-before stated, are jointed

page_text: together in such a manner that they are perfectly flexible, while at the
same time they cannot in folding get between the laths and so obstruct
the adjustment of the blind. Each of these hinges n is composed of the
pieces n', n², n³, Figure 17. These pieces are preferably made of thin
sheet iron or brass, and the parts n', n², are then doubled and rivettéd
together, as shewn in Figures 15 and 16. These two parts are connected
together by the pin o. In Figure 15 I have clearly shown the effect
of the shoulders p which prevent the inward folding of the hinges
between the laths. These latlis are formed in such a position that the
pieces n', n², instead of hanging in a straight line are inclined outward to
the middle joint, and by this slight inclination the hinges are caused to
fold outward without any obstruction. The pieces 13 arc screwed or
otherwise attached to the laths one at each side of the pieces n¹ and n², to
which they are connected by the joint pin o', which also passes through
the eyes of the part n¹ of the next hinge in the series.
The construction and operation of my improved compensating balance
weight will be readily understood by referring to Figures 21 and 22.
The weight q is composed of the plates q', which are formed of iron or
other suitable metal hinged or jointed together at q², and which it will
be observed are slightly curved, so that they will coil easily and
compactly upon the barrel r which is fixed on the spindle. or shaft j,
whereon are fixed the pulleys i of the raising cords or chains h and the
pulley or barrel for the operating cord m. By carefully adjusting the
taper or diminution in width from the inner to the outer extremity of
this weight to the weight of the blind, and the varying leverage on the
pulleys and the barrel r, the blind A will be accurately balanced in
any position, and may be raised or let down without with equal facility,
and I thus avoid the necessity for any exertion of strength or disagreeable
effort.
}
My improved method of supporting the laths upon the webbing by
crossing two strips of the same under and over cach lath is illustrated in
Figures 9, 10, 11, and also in Figures 18, 19, and 20. In the latter case
it will be observed that the strips of webbing bare passed entirely across
the surface of the laths, and are fastened at each edge by the staples",
while in Figure 11 it will be seen that the strips bare passed from one
edge over one surface of the lath as far as the slit s in the centre thereof,
then through the said slit and over the other surface to the. other edge of
the said lath, the said strips being secured by small tacks stor by.otlier

page_text: t
suitable means. When the laths a arc hung upon strips b passed
centrally through them, as shown in Figures 8ª, 8b, 8°, I prefer that
there shall be an additional strip or small cord ț at one edge to keep the
laths properly in position together. The expanding grooves, which are
also illustrated in these Figures and also in Figure 8, is formed by
connecting together, like the two sides of an ordinary parallel rule, two
bars u.
The said bars are connected by the arms w¹, which are fitted to
turn on the centre pins u² fixed in the side of the window frame. By
referring to Figure 8 it will be seen that the entire end of each lath
works in the said groove, and that the pins a¹ are not required. I may
effect the "louvering" as shewn in Figure 8 by simply opening or
closing this groove, one of whose sides u is for this purpose connected
to the cord ³. I prefer however when the expanding groove is used
to employ in combination therewith the arrangement illustrated in
Figure 8, in which the "louvering" is effected by the roller c, as
herein-before described, the groove being used merely as an effective
means of securing the blind firmly when the same is cither open or
closed. The arms u¹ arc in this case attached to the end of the
roller, and the "louvering" and adjustment of the groove are effected
simultaneously.
By the various improvements herein described I obtain many advan-
tages which are not possessed by an ordinary Venetian blind, and of
which the following may be considered the most important :—The blind
or shutter will be always held firm against the action of the wind. The
laths will always be kept level and will not present the unsightly
appearance so often presented by Venetian blinds, when from the
stretching of the raising cords one end hangs lower than the other. The
"louvering" is effected with ease and smoothness, the jerking which
takes place with an ordinary Venetian blind being entirely obviated.
The laths and connections are stronger and more durable than those of
an ordinary Venetian blind, the webbing (when used) is more durable
and more easily repaired, and the possibility of the webbing or the metal
strips getting between the laths and obstructing the working of the blind
is entirely obviated. By making the roller or cylinder c of metal and
the raising bar g of T iron of suitable strength, the widest shop front
may be provided with blinds constructed according to my Invention.
Having thus fully described my said Invention, and shown how the

page_text: same may be conveniently and advantageously carried into practice, I
wish it understood that I claim, -
First. A single pin at each end of the laths (of a louvering blind or
shutter), working in a fixed groove or channel at the side of the said
blind or shutter, substantially as set forth for the purpose specified.
Second. The roller arranged across the top of the window with the
webbing or jointed strips attached thereto, and operated to effect the
"louvering" or angular adjustment of the laths, substantially as set
forth.
Third. The jointed metal strips for connecting and supporting the 1
laths so constructed and attached to the said laths that they will fold
freely outward, but will not fold inward between them as the shutter or
blind is raised.
Fourth. The taper coiling counterbalance weight constructed and
operating in combination with a shutter or blind, substantially as herein 1
set forth.
.
Fifth. Connecting together the laths of a "louvering" shutter or
blind by strips of webbing crossed from edge to edge of the laths and
secured thereto, substantially as set forth.
.
Sixth. The expanding grooves arranged and operating in combination 2
with the laths of a "louvering" blind or shutter, substantially as set
forth and for the purpose specified.
Seventh. A."louvering." shutter or blind' with the laths constructed
and connected together as herein specified in combination with the
devices for "louvering" for raising and lowering and for supporting the 2
same, substantially as herein set forth.
In witness whereof, I, the said Frederick Hartt Knevitt, have here-
unto set my hand and seal, this Fifth day of July,
our Lord One thousand eight hundred and seventy.
in the year of
Witness,
D. L. WAGNER.
FREDERICK HARTT KNEVITT. (L.S.)