MENTS IN VENETIAN BLINDS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by the said Theodor Kauffmann at the
Office of the Commissioners of Patents on the 1st April 1881.
THEODOR KAUFFMANN, of Cologne, in the Empire of Germany.
MENTS IN VENETIAN BLINDS."
"IMPROVE-
The object of this Invention is to remedy some of the defects inherent in venetian
blinds as ordinarily constructed, while increased elegance and durability are also
obtained.
The Invention consists in the use of small chains with rings fixed thereto, and
to these are fitted pins with eyelets or hooks to be fixed directly to the laths. There
is a roller with two drums, upon which the pulling up cords which are flexible and
made of metal may be rolled up, the cords being formed with an elastic core like
some wire ropes. There is also a noiseless stopping arrangement fixed laterally in
an opening made in the guides. The blind is also furnished with an expander,
which consists of the guides that are placed at the top on both sides of the window
in such a way that they may be made to revolve, and are joined together by means
of a cross piece. The laths being expanded they remain in any position in which
they may be placed. As the blind is let down a ratchet wheel is thrown out of
gear by a slight pull of a cord on one side of the window, and as the cord is
gradually relaxed the blind falls. If another cord be pulled, and the cord just
previously alluded to be relaxed at the same time the pawl of the ratchet wheel
enters into action. This arrangement may be actuated either from within or
without. For shutting up the laths cords fixed to the chains before mentioned are
used. These cords are continued and passed over the rollers in the cutting of either
the interior or exterior board are brought together over the roller and hanging
down, are furnished with a small chain. This arrangement also may be worked
either from within or from without.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Theodor Kauffmann in the Great Seal Patent Office on the
26th September 1881.
THEODOR KAUFFMANN, of Cologne, in the Empire of Germany. " IMPROVE-
MENTS IN VENETIAN BLINDS."
The construction of venetian blinds up to the present time has various defects.
Those of which the cord pass intentionally from the rollers or rings draw with
difficulty in consequence of the numerous rubbing surfaces, and those which are
mounted upon cylinders take too much space in height so that the light from above
is impeded. It is the same with regard to the arrangement of the boards or laths
now generally employed.
The object of the present improvements is to remedy these inconveniences.
In order to draw up the blind the cord k, Fig. 6, is drawn from the cylinder a,
which revolves, and the cords e, e¹, which are attached to the lower lath are wound
round the cylinder in the reverse direction as it revolves.
The cords are brought over the conducting rollers, Figs. 5, 6, and 7, in order to
lead them across the openings for which they are intended. This contrivance
admits of the arrangement of one part of the fixed or turning sash, which has
always been employed in the actual construction, and which is shown in the
Drawings of the cylinders, and between these and the laths. By these means I
get the laths so as to permit of their being raised above the cylinder, which is very
advantageous on account of the light. The conical form of the cylinder at the
parts where the cords e, e¹, are wound is very essential. This conical form prevents
the cord from winding round itself because each turn obeys the pressure from one
side of the following and slips towards the smallest end of the cone.
Another improvement is the stopping arrangement of the cylinder a, represented
in Figs. 6 and 8, and which consists of a ratchet wheel and latch, stop, or pawl.
The wheel and the stop are placed for this purpose in the opening of the guard
board in order that the laths can be drawn without impediment as high as the top
of the cylinder. It is seen by the Drawing that in raising the blind the latch falls
by its own weight, but the cylinder can be arrested in any position by drawing
the cord i, and at the same time slacking k, and so engage anew the latch with the
stop wheel. If it is desired tó lower the blind it is only necessary to draw the
cord gently in order to withdraw the stop, and the rotation of the cylinder will
then take place in the opposite direction in consequence of the weight of the blind
when the cord is slacked. The slant of the small chains differs also considerably from
the analagous arrangements in use at the present day, for by the manner of their
attachment to the small chains by means of the little tags, hooks, or eyelets, Fig. 9,
fixed thereto, it is now possible to make the little chains wind entirely upon
themselves close together when raising them.
This considerable advantage is
effected when the blind is wholly raised so that the light from above can fall more
freely. It is also to be remarked that by the arrangement described the higher
part of the sash between the cylinder and the laths the rollers [m, m',] above from
which the slant cord passes can be placed on one side and separately from the other
parts.
Another improvement is the peculiar construction of the sash, by means of
which the lowered blind, as is shown in Fig. 3, can be placed on the outside. To
the ordinary blinds the guide is firmly fixed on one side of the casement. When
there is much wind it makes an insupportable chattering in consequence of the free
space in which the chains are in the guide at the moment when they are in an
oblique position. An attempt has been made to avoid this unpleasantry by the
guides which have grooves, and of which the grooves are engaged by the tags
attached to all the principal laths. This arrangement is good as long as the wooden

page_text: rods of the guide are not worked or do not swell, which happens so much more
easily as they are weakened by the grooves. They have besides the defect of
greatly diminishing the luminous space of the window.
With the object of removing these objections I make my sashes of iron bars with
the rods backed with wood, represented in Fig. 10, and with a sloping opening.
The iron bars prevent on one side any appreciable change of the form of the guide
rods, and on the other they do not bear, so that by the guide the free space of the
window is not diminished; the side rods are tied down by a band of iron, and all
the guides can oscillate upon a button, so that it can be placed outside with the
laths [Fig. 3] by means of two bars, a spring put on one side assuring the position
of the guide when it is perpendicular. In this construction there is no necessity
for a large free space between the parts slipping one into the other, and consequently
it is sufficient if the end of the sixth lath with the guide tags lock into the grooves.
The slanting position of the boards is ordinarily made by means of a cord (p), to
the end of which there is any suitable kind of stop. The iron bars or bands
can be substituted by wood, the fibres of which should be however put across and
above the tags, hooks, or eyelets to prevent derangement.
The last of these improvements consists in the employment of metal or iron
wire cords with tapes of hemp or other elastic tape for the cords b, b'. These cords
are not only stronger than the ordinary hempen ones, but they are also not liable
to swell when they are damp, and consequently the size of the slit in reference to
the holes for the cords in the laths can be made in practice to exactly conform to
the size of the cord, which is very important for the blinds because they do not
offer too great openings to the sun as is frequently the case with blinds having
small chains.
Having now described and particularly set forth the nature of this Invention,
and the manner in which the same is or may be used or carried into effect, I
would observe, in conclusion, that I do not confine or restrict myself to the
precise details or arrangements which I have described or referred to, as variations
inay be made therefrom without deviating from the principles or main features
of this Invention; but what I consider to be novel and original, and therefore
claim as the Invention secured to me by the hereinbefore in part recited Letters
Patent is,-
Firstly. The conical form of the guide for the cords 6, 61, upon the cylinder a in
connection with the guide rollers c to wind up the cords, as herein described and
shown on the Drawings.
Secondly. The stopping arrangement, as herein described and shown in Fig. 8
of the Drawings.
Thirdly. The connection of the small chains with the laths by means of tags so
as to produce the slanting position of the laths, as herein described and shown at
Fig. 9.
Fourthly. The guide sash, of which the sides are made of iron bars or bands, or
of wood, as herein described and shown on the Drawings.
Fifthly. The employment of fine iron wire cords in conjunction with hempen
tapes or other elastic substance to raise and lower the blinds, and as herein described
and shown on the Drawings.
In witness whereof, I, the said Theodor Kauffmann, have hereunto set my
hand and seal, this Twenty second day of September, in the year of our
Lord One thousand eight hundred and eighty one.