Flexible or portable closure – partition – or panel – Plural strip – slat – or panel type – Venetian blind type
Reexamination Certificate
2001-03-21
2002-06-04
Johnson, Blair M. (Department: 3634)
Flexible or portable closure, partition, or panel
Plural strip, slat, or panel type
Venetian blind type
C160S170000
Reexamination Certificate
active
06397918
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a Venetian blind, and more particularly to a Venetian blind having a tilt means with improved ladder strings, so that upper slats of the blind could be lowered to a distance below a head rail of the blind and a light transmissible area without being shielded by any slat is provided above the blind, and the lowered slats could still be deployed and tilted to adjust volume and direction of light projected through the blind.
A Venetian blind is widely welcomed because it has the functions of blocking sunrays, adjusting indoor brightness, decorating rooms, etc. As can be seen from
FIG. 1
, a conventional Venetian blind mainly includes a head rail
10
, a bottom rail
20
, a plurality of slats
30
, a lift means
40
including multiple lift cords
41
, and a tilt means
50
including multiple ladder strings
51
. Typically, the lift cords
41
are laterally symmetrically provided on the blind to balance the bottom rail
20
and the slats
30
of the blind for them to be lowered or lifted synchronously. The number of ladder strings
51
depends on an overall width of the slats
30
. The head rail
10
is fixedly attached to an upper edge
61
of a window
60
. By pulling the lift cords
41
, the bottom rail
20
and the slats
30
may be horizontally lifted or lowered relative to the head rail
10
as desired. For example, the slats
30
may be fully lowered to locate the bottom rail
20
immediately above a stool
62
of the window
60
. At this point, all the slats
30
of the blind are deployed to shield entire area of the window
60
, as shown in FIG.
2
. Alternatively, the slats
30
may be partially lowered to locate the bottom rail
20
at any desired height above the stool
62
of the window
60
. At this point, slats
30
a
at an upper part of the slats
30
are deployed while slats
30
b
at a lower part of the slats
30
are stacked on the bottom rail
20
, as shown in FIG.
3
. In either case of
FIG. 2
or
30
a
in
FIG. 3
, the deployed slats
30
a
could be tilted upward or downward within 180 degrees through operation of the tilt means
50
to adjust the ladder strings
51
. By tilting the above-mentioned slats to different angle of inclination, amount and direction of light projected into a room via the Venetian blind can be controlled and adjusted.
There may be many changes in the manner of operating the tilt means
50
and in the design of elements included in the tilt means
50
. However, most of the tilt means
50
have similar operating principle. To be more specific, a front and a rear vertical strings
51
a
,
51
b
of each ladder string
51
are fixedly connected at their respective upper ends to a top center of a tilter, such that the front and the rear vertical strings
51
a
,
51
b
are separately located at front and rear sides of the tilter to face each other. The tilter is a lever-shaped rotatable member having two opposite arms. All the tilters are fixedly mounted on and horizontally spaced along the same one rotary shaft. The arms of the tilters have the same length and extend by a predetermined distance. By turning a tilt control bar
52
of the tilt means
50
clockwise or counterclockwise, or manipulating the tilt control bar
52
in other manner, the rotary shaft could be turned in two opposite directions by 90 degrees each, bringing the tilter to rotate along with the rotary shaft from a horizontal position to a vertical position. At this point, the front and the rear vertical strings
51
a
,
51
b
of the ladder strings
51
are ascended and descended, respectively, relative to each other, causing multiple spaced transverse ladders
51
c
of the ladder strings
51
extended between the front and the rear strings
51
a
,
51
b
, as well as slats
30
a
,
30
b
associated with the horizontal ladders
51
c
, to tilt by a desired angle. To lift the lowered bottom rail
20
and the previously deployed slats
30
a
,
30
b
to locate them immediately below the head rail
10
, simply operate the lift means
40
and the tilt means
50
backward.
The lift means
40
and the tilt means
50
, either manually or electrically operated, both have various types of designs available in the market. However, all these currently available lift means
40
and tilt means
50
for the conventional Venetian blind can only allow the bottom rail
20
and slats
30
a
,
30
b
of the slats
30
to be horizontally lowered to a desired height relative to the stool
62
of the window
60
and be lifted toward the head rail
10
. That is, when the slats
30
is partially lowered, an area of the window
60
that is not shielded by any slat and is therefore completely light transmissible is always located below the bottom rail
20
and above the stool
62
. However, in many cases, people usually need the blind to shield only a lower part or a middle part of a window and leave the remaining upper part of the window in a light transmissible state. It is obvious the conventional Venetian blind could not satisfy this requirement.
U.S. Pat. No. 5,443,108 entitled “Upwardly Deployed Privacy Blind” discloses a Venetian blind in which slats are stacked above the stool of the window when the blind is not in use or is partially lifted to provide a slat-free and light-transmissible area above the blind. This type of Venetian blind includes a fixed head rail, a fixed bottom rail, and an up and down movable middle rail, and therefore has more complicated structure. Moreover, the design of stacking slats at a lower part of the blind does not meet most people's practice of lifting and stacking the slats to an upper part of the blind when the blind is not in use.
There is a commercially available top-down pleated shade that includes a fixed head rail attached to the upper edge of the window, and a movable head rail connected to an upper edge of a pleated shade body. Through manipulation of operating elements inside the fixed head rail, the movable head rail and the pleated shade body may be lowered to separate from the fixed head rail, so that an area of the window below the fixed head rail and above the pleated shade body is not shield by the shade body and is therefore light transmissible. However, the movable head rail would extend across the window and forms a visual barrier when the pleated shade is lowered. The main difference between the top-down pleated blind and the top-down Venetian Blind is that the former needs only to lower the fablic away from the top head rail while the latter owns further function of tilting the slats in different angles.
It is therefore desirable to develop a top-down Venetian blind that overcomes the drawbacks existing in the conventional Venetian blinds and the pleated shade.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a top-down Venetian blind that after the Venetian blind is fully or partly dropped, the upper portion of the slats could be lowered to a distance below the head rail of the blind and a light-transmissible area without being shielded by any slat is provided. A ladder string includes a front & a rear vertical strings connected with a plurality of horizontal ladders. Two extending cords of suitable length without horizontal ladders are connected to the tops of the front and the rear vertical strings of the ladder strings and pass through the tilting means and then wound around a reel mounted on a rotary shaft in the head-rail. The extended cords are synchronously released from the reel when the rotary shaft is turned forward, so that upper portion of slats are lowered to a distance below the head rail and a light transmissible area without being shielded by any slat is provided when the rotary shaft is turned backward the extended cords will be rewound around the reel and the upper portion of slats is lifted to the top of the blind.
Another object of the present invention is to provide a top-down Venetian blind in which the slats located below the light transmissible area but not stacked on the bottom rail would still be deployed and tilted
Dennison, Schultz & Dougherty
Johnson Blair M.
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