Year: 1887

page_text: Date of Application, 5th Feb., 1887
Complete Left, 12th Sept., 1887
Complete Accepted, 4th Feb.. 1888
I, FREDERICK AUGUST LEHMANN, of No. 9, Grimm Strasse, Berlin, S. in the
German Empire Gentleman, do hereby declare the nature of this invention to be
as follows:-
This invention has reference to Venetian blinds or shutters made with slats having
spaces between them to admit light and air, such slats being carried by metal chains
with cross-links resembling (and hereinafter called for distinction) ladders, whereby
the positions of the slats may be changed, and being provided with cords for raising
and lowering the slats.
The ladders are of peculiar construction, each comprising two chains composed of a
number of separate links, and a series of cross links connecting the two chains, and
made like frames with the inner faces of the two longer sides in different planes a
distance apart corresponding approximately to the thickness of the slat, which enables
the slat to be readily inserted. The links of the side chains are made each with
a longitudinal slot or hole, and with a tongue or projection approximately of T shape
at one end, the head of the tongue or T being in a different plane to the main body
of the link so that it may be readily caused to engage with and support an adjacent
link and be easily disengaged therefrom by turning the links to approximately right
angles to one another, and drawing the tongue of the one through the slot of the
other. The upper end of each link is formed with a hook-like or curved part to
engage with a suitably formed cylindrical part at the end of the cross-link. The
lowermost link of each side chain is formed with a long eye or guide, and each
engages with a loop of which there is one at each side near each end of the lower-
most slat.
With the above construction of parts, as will be readily understood, what I have
called a "ladder" of any desired length may be readily formed, by putting together the
requisite number of links; and with two such ladders, and the required number of
slats, a Venetian blind or shutter can be quickly put together. Cords are provided
for drawing up such a blind or shutter, as well understood, such cords being secured
to the lowermost slat, and passing up through the cross links and through holes in
the slats.

page_text: The distance between the two eyes at each end of the lowermost slat is greater than
the length of the cross-links, and the arrangement is such that when the cords before
referred to are pulled to raise the blind or shutter, the lowermost slat will be moved
upward, its eyes travelling along the loops or guides of the lowermost links to the
upper ends of the same; as the said slat is further raised, the lowermost links will
slide over the tongues of the next pair of links of each ladder, and so on in succession,
the links overlapping one another with their lower ends farther apart than their upper
ends. The arrangement and action described are such as to prevent jamming of the
several links, and consequently to render the pulling of the cords less liable to break
them. However, should a cord break through wear (which cannot be prevented,) the
lateral flexibility is such as to prevent other injury to the blind or shutter.
Dated this 5th day of February 1887
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.

page_text: Improvements in Venetian Blinds or Shutters.
I, FREDERICK AUGUST LEHMANN, of No. 9 Grimm Strasse, Berlin, S., in the
Gerinan Empire, 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 has reference to Venetian blinds or shutters made with slats having
spaces between them to admit light and air, such slats being carried by metal chains
with cross-links resembling (and hereinafter called for distinction) ladders, whereby
the positions of the slats may be changed, and being provided with cords for raising
and lowering the slats.
The ladders are of peculiar construction, each comprising two chains composed of
a number of separate links, and a series of cross links connecting the two chains, and
made like frames with the inner faces of the two longer sides in different planes a
distance apart corresponding approximately to the thickness of the slat, which enables
the slat to be readily inserted. The links of the side chains are made each with a
longitudinal slot or hole, and with a tongue or projection approximately of T shape at
one end, the head of the tongue or T being in a different plane to the main body of the
link so that it may be readily caused to engage with and support an adjacent link and be
easily disengaged therefrom by turning the links to approximately right angles to one
another, and drawing the tongue of the one through the slot of the other. The
end of each link is formed with a hook like or curved part to engage with a suitably
formed cylindrical part at the end of the cross-link. The lowermost link of each side
chain is formed with a long eye or guide, and each engages with a loop of which there is
one at each side near each end of the lowermost slat.
upper
With the above construction of parts, as will be readily understood, what I have
called a ladder of any desired length may be readily formed, by putting together the
requisite number of links; and with two such ladders, and the required number of
slats, a Venetian blind or shutter can be quickly put together. Cords are provided
for drawing up such a blind or shutter, as well understood, such cords being secured
to the lowermost slat, and passing up through the cross links and through holes in
the slats.
The distance between the two eyes at each end of the lowermost slat is greater than
the length of the cross-links, and the arrangement is such that when the cords before
referred to are pulled to raise the blind or shutter, the lowermost slat will be moved
upward, its eyes travelling along the loops or guides of the lowermost links to the
upper ends of the same; as the said slat is further raised, the lowermost links will
slide over the tongues of the next pair of links of each ladder and so on in succession,
the links overlapping one another with their lower ends farther apart than their upper

page_text: ends. The arrangement and action described are such as to prevent jamming of the
several links, and consequently to render the pulling of the cords less liable to
break them.
However, should a cord break through wear (which cannot be prevented,) the
lateral flexibility is such as to prevent other injury to the blind or shutter.
The manner in which this invention is to be carried into effect is clearly illustrated
in the sheets of drawings hereto annexed of which the following is a description.
Figs. 1 and 2 illustrate the parts of a link of the chain.
Figs. 2, 3, 4, 5 and 6 show the links combined together to form the chain with the
slats seen inserted in them, in Figs. 3, 4, 5, & 6.
Figs. 7 and 8 illustrate the blind or shutter with the slats placed at an angle in an
inclined position..
Fig. 9 illustrates a shutter in which the pull up has broken.
Each single link of the chain is composed of two similar side pieces A (Figs. 2. 2ª
and 4) and a crosspiece B (Fig. 1, 2ª and 4).
Each side piece A consists of a frame stamped out of one piece, having at its lower
end a flat tongue c (Figs. 2 and 2) projecting behind and into the lower side piece
(Figs. 2, 2, 2) and at its upper end a bent portion 6 (Fig. 2) for the purpose of
receiving the cross piece B (Figs. 2ª and 6.)
The cross-piece B is also a closed frame stamped out in a single piece the longer
sides of which are bent or turned in opposite directions, (Figs. I and 2) to allow of
the insertion of the slats C (Figs. 1, 4,6).
By this arrangement the slats can be readily inserted or removed, and they are
secured when in position in a durable manner against the warping or twisting of the
wood. By the special construction of the cross-piece B the slat which is inserted
in it, and clamped along its whole width is made to follow exactly the movements of B.
Two links A are then attached to the shorter ends d of the cross piece B, by bending
the part around the cylindrical ends of the frame B (Figs. 2° 4) and thus a single
link of the chain is constituted.
The joining together of the separate links to form the chain is effected without any
further appliances, by inserting the tongue e into the opening of the adjacent side-
piece (Fig. 2).
The tongue c is then situated with its side-projections behind the side-piece A and
is guided therein by inwardly bent over guide rims A¹ (Figs. 2, 2b,) formed during
the stamping.
The metal chain or ladder constructed in the manner above described, can be drawn
together with the greatest facility, and it also possesses an extraordinary lateral
flexibility which is of essential influence in increasing durability of the whole shutter
or blind.
The pull cords D pass through the openings of the crosspieces B and through
corresponding holes in the slats (Fig. 6).
The pull cord D is fastened to the lowest slat E which is connected to the
end-link A² (Fig. 6). The slat E (Figs. 5 and 6) is provided with two side
wire loops e e in which the side pieces A2 of the end link are guided by the
longitudinal guide loops f,, which extend nearly the whole length of the same." The
loops are farther apart than the length of the cross piece B, consequently the
end link in its ascent through the loops, spreads out and takes up the position shown
in Fig. 6. This position of the end link and the position of all the links above it
resulting therefroin as they are pushed one over the other when the blind is drawn up,
prevents the several links from jamming, the blind is thus rendered very free to raise
and lower and the pull cord is saved from breaking readily which accident is very
liable to happen in blinds constructed so as to jam when raised or lowered.
Should however a cord break from natural wear, and which cannot be prevented,
the lateral flexibility of the ladders prevents the mechanism from being destroyed.
Fig. 9 illustrates such a case; it is clearly seen that the chains have a lateral
flexibility sufficient to allow of such an accident without damage.

page_text: A* A* are chains which serve normally to support the upper ends of the
chains A A as shown in Fig. 4. F is a chain (or it may be a cord) secured at one
end to the upper part of one of the chains A its other end being led over rollers
of which one is shown at G and then downwards to a hook fastened on the side of the
window frame. By pulling this chain F (or cord,) the several links of the said
chain A will be raised and the cross pieces B and slats C will be caused to assume
inclined positions such as shown in fig. 8 in which positions they may be retained by
placing one of the links of the chain F¹ over the hook secured to the window frame.
The above described links and cross pieces as also the guide pieces for the lowest
links of the ladder or chain may be made in any suitable manner as by stamping
folding or cutting-and they may be made of any suitable material such for example
as steel, iron, brass or other suitable metal, and the parts may be finished in any
desirable manner as by painting bronzing lacquering or by any other kind of
ornamentation.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :---
1. For a ladder or chain of a venetian blind or shutter a side link such as A
consisting of a frame which has at its upper end a part hinge 6 and at its lower end
a tongue c adapted to engage and form a hinge with a cross piece such as B having
its longer sides bent in opposite directions and different planes for the reception of slats
substantially as described.
2. The arrangement of bottom slat E with side loops e e and guides ff connected
with end links of a ladder or chain so as to cause the several links of such ladder or
chain to spread out when the blind or shutter is raised substantially in the manner and
for the purpose set forth.
3. My improved venetian blinds and shutters substantially as hereinabove described
and illustrated.