WO1998021437A1

WO1998021437A1 - Venetian type blinds

Info

Publication number: WO1998021437A1
Application number: PCT/US1996/017747
Authority: WO
Inventors: Ren Judkins
Original assignee: Ren Judkins
Priority date: 1996-11-11
Filing date: 1996-11-11
Publication date: 1998-05-22
Also published as: EP0954672B1; EP0954672A1; DE69628343D1; DE69628343T2; AU7669596A

Abstract

An improved venetian type blind has slats (6) having a pair of slots (7, 9) disposed on an outside edge or inside edge of the slats. The slots in each pair are laterally spaced apart. A first ladder having opposite cord type rails (11, 12) and rungs (13) extends therebetween, is positioned with the rails outside of the slots and is connected to the bottom rail (4, 5). One rail of each ladder is adjacent to a lift cord (81, 82) running through slots in the inside edge or outside edge of the slats.

Description

TITLE VENETIAN TYPE BLINDS

FIELD OF INVENTION The invention relates to a Venetian type blind.

BACKGROUND OF THE INVENTION

Venetian type blinds have a series of slats hung on ladders which extend

from a headrail to a bottomrail. In most Venetian blinds a pair of lift cords is provided

each having one end attached to the bottomrail and then passing through elongated

holes in the slats up to and through the headrail. A cord lock is usually provided in the

headrail through which the lift cords pass. The cord lock allows the user to maintain

the blind in any desired position from fully raised to fully lowered.

The slats rest on rungs between rails of the ladders. The blind is in an

open position when the rungs are horizontal. To close the blind one lifts one rail while

allowing the other to either remain in place or be lowered. This raises one end of each

rung tilting the slats. Thus, when the blind is closed there is typically tension on one

rail while the other rail of the ladder is not in tension.

The rails originally used for Venetian blinds consisted of a fabric tape

typically from one to two inches in width. The rungs were also made of fabric strips.

Conventionally, the lift cords pass through holes in the slats which were aligned

between the rails of the ladder. When the blind was closed, the fabric rails covered the

holes. Consequently, there was no concern about light passing through the holes when

the blind was in a closed position. Walker in United States Patent No. 2,572,224 discloses slats for a

Venetian type blind having a tape type ladder system and two lift cords. One lift cord

passes through notches on the inside edges at one end of the slats. The second lift cord

passes through notches on the outside edge of the other end of the slats. Each lift cord

is positioned behind one of the tape-type ladders. Walker does not disclose any lift

mechanism inferring that a standard lift mechanism could be used. In a blind made

with Walker's slats the lift cords play no role in maintaining the slats in alignment when

the blinds are closed. Rather, the tape-type rails of the ladders maintain the slats in

alignment.

Very few tape type ladders are used in blinds today. Rather, the art has

adopted ladders formed of cord rails having cord-type rungs between them. Typically,

the rungs are multiple strands of cord. However, a single strand of cord has also been

used. Frequently, a braided cord is used for the ladder rails. The conventional lift cord

arrangement in which the lift cord passes through elongated holes in the slats is used.

The lift cords are aligned to be between the rails of the ladders which are provided near

opposite ends of the blind. When this type of blind is closed light can pass through the

holes in the blind slats. This is readily apparent to anyone looking at the closed blind.

In pleated shades efforts have been made to prevent light from passing

through the cord holes by making the holes to be a diameter very close to the diameter

of the cord. This is not possible in a Venetian type blind where the holes must be

elongated to allow the slats to tilt properly.

In the Venetian blinds which utilize a cord-type ladder the blinds are

opened and closed by lifting or lowering one of the ladder rails relative to the other. In most blinds the lateral position of the ladder rails relative to one another remains

unchanged at the headrail. Thus, there will be slack at the top of one of the ladder rails

and the center of gravity shifts forward or back when the blind is tilted.

Venetian blind slats are conventionally made of aluminum, plastic or

wood. Cord route holes are normally punched into the slat one at a time while the

length is cut. Wood slats are usually cut to length by saws so that punching or

machining of the holes is done one unit at a time. Moreover, punching of holes through

wood slats sometimes causes splintering and the areas around the holes are very

difficult to paint or seal. After the cord holes have been drilled, lift cords are passed

from the bottomrail through the cord holes to the headrail to complete the assembled

blind. After the blind has been assembled in this manner it is not possible to remove

the slats from the blind without removing the lift cords making it very difficult to clean

the slats in the area of the route holes. Thus, it is a major task to clean or paint the slats

in this type of blind. Since the lift cords pass through each slat they prevent tight

closure when the blind is tilted to a closed position. Further, the route holes weaken the

slats dramatically so that bending more easily occurs at the route holes.

There is a need for a Venetian type blind having no holes through the

slats. The Venetian must operate easily and the slats must maintain alignment when the

blind is open and closed and most particularly when the blind is raised and lowered.

SUMMARY OF THE INVENTION I provide a Venetian type blind having a bottomrail, headrail and

plurality of slats positioned therebetween. The slats are notched to form slots on their

inside edge and outside edge to accommodate lift cords. At least four lift cords pass from the bottomrail to the headrail each passing through a slot on the inside edge or

outside edge of each slat. At least two preferably cord-type ladders are provided to

hold the slats. The ladders are aligned such that the rails of the ladders are adjacent the

lift cords and outside the slots cut in the slats.

A tilt mechanism to close the blind is provided within the headrail which

preferably moves the rails together as the tilt mechanism lifts one rail and lowers the

other rail relative to one another. Therefore, the center of gravity of the blind is in the

same plane throughout the tilt range.

A tube lift may be provided for the lift cords or a cord lock can be

provided within the headrail or on the cords outside of the headrail.

Other objects and advantages of the present invention will become

apparent from a description of the present preferred embodiments shown in the

drawings.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a front view of the present preferred embodiment of my

Venetian type blind shown in a lowered open positioned.

Figure 2 is a front view similar to Figure 1 showing an upper portion of

the blind when the blind in a raised position.

Figure 3 is a sectional view taken along the line 111-111 of Figure 1.

Figure 4 is a sectional view similar to Figure 3 taken along the line IV-

IV of Figure 2. Figure 5 is a perspective view of a portion of the embodiment shown in

Figure 1 taken around the line V-V of Figure 1 to show the base of a pair of lift cords

and adjacent ladder.

Figure 6 is a fragmentary view showing the right end of the portion of

the raised blind shown in Figure 2 wherein the front panel of the headrail has been

removed.

Figure 7 is a sectional view taken along the line VII- VII in Figure 1.

Figure 8 is a fragmentary view showing the front portion of the blind

near the line VII-VII in Figure 1.

Figure 9 is a perspective view similar to Figure 5 showing an alternative

routing for the lift cords.

Figure 10 is a rear view of one end of the headrail with the back panel

removed to show the top portion of the alternative lift cord routing of Figure 9.

Figure 11 is a sectional view taken along the line XI -XI of Figure 1.

Figure 12 is a sectional view taken along the line XII-XII of Figure 1

with the lift cords removed.

Figure 13 is a sectional view similar to Figure 12 showing the blind in a

closed position.

Figure 14 is a fragmentary view similar to Figure 6 showing a second

preferred embodiment that utilizes a tube lift.

Figure 15 is a sectional view taken along the line XV-XV of Figure 14. DESCRIPTION OF THE PREFERRED EMBODIMENTS The first present preferred embodiment is comprised of a headrail 2, two

piece bottomrail 3 and 4 and set of slats 6 extending therebetween. If desired, a one

piece bottomrail could be used. For purposes of illustration only six slats are shown.

However, the blind could have any number of slats and likely would have many more

slats than are shown. The slats of this embodiment are symmetrical to a horizontal

plane passing through the front and back edges of the slat. Crowned slats may be used

in place of these flat slats if desired. The slats are suspended on a cord type ladder 10.

The ladder has a front rail 11, rear rail 12 and series of rungs 13 extending therebetween

on which these slats rest. As shown most clearly in Figure 7, the bottom ends of the

ladders are knotted within the bottomrails 4 and 5 and covered by plugs 42. Cord 40 is

provided to tie the bottomrails 4 and 5 together and prevent them from flaring out. At

least two front slots 7 are provided on the front edge of each slat 6. A corresponding

set of rear slots 9 have been cut into the back edge of slat 6 opposite slots 7. I prefer to

have the slots 7 and 9 directly opposite one another as shown in Figure 5. However,

one slot could be to the left or right of the other slot. The slots are sized so that lift

cords 81, 82, 83 and 84, which are generally identified by reference number 8, and ends

of rungs 13 can loosely fit therein. Tilt ladders 10 are positioned near the ends of the

blind so that the rails 11 and 12 are adjacent the lift cords. A third tilt ladder is

provided at the center of the blind where no lift cords are needed. Slots 7 and 9

preferably have a depth such that only the lift cords 8 and ends of rungs 13 can

completely fit therein. Thus, the rails 11 and 12 can never be fully within the slots. For

purposes of illustration the lift cords 8 are shown in chain line in some of the figures so as to distinguish them from the adjacent rails of the tilt ladders or other structures.

Because lift cords travel within slots 7 and 9 provided in the slats 6 there are no cord

holes in the slats. As can be seen in Figure 3 the slats 6 rest on rungs 13 of the tilt

ladder 10 and can easily be lifted from the rungs for cleaning or repainting.

The number of lift cords that are used will vary according to the size of

the blind and the cording arrangement. In every embodiment lift cords 8 should be

positioned near either end of the blind in slots on both the front and rear edges of the

slats. In the embodiment of Figure 1 four lift cords extend from the bottomrail through

the headrail. As shown most clearly in Figures 1 through 6, lift cords 81 and 83 extend

from the front bottomrail 4 through slots 7 in the front edge of slats 6. Lift cords 82

and 84 extend from the rear bottomrail 5 through slots 9 in the rear edge of slats 6. The

lift cords 81, 82, 83 and 84 pass through the headrail 2 exiting on the front right side as

shown in Figures 1 and 2. The lift cords 81, 82, 83 and 84 are threaded through the

headrail over pulley 38 and into a cord lock 26 provided in the headrail 2. Support

plate 36 is provided to attach the cord lock 26 to the headrail 2. The pulley 38 is held in

place by support 37. The cords extend through the cord lock to a position outside and

at one end of the blinds. Preferably, the cord lock is always engaging the lift cords

unless the blind is being raised or lowered. The distal end of the lift cords may be tied

together in a ball connector 33. If desired a pull cord 34 having a tassel 35 may be

connected to the ball connector 33. If the bottomrail is supported by the tilt ladders, as

in the embodiment of Figure 1, the weight of the lift cords extending out of the headrail

and the attached tassel can provide sufficient tension to hold the slats in place.

Moreover, a weight can be placed in the tassel 35 or connector 33 if needed. If the bottomrail is supported only by the lift cords, the weight of the bottomrail maintains the

lift cords in tension. Tension in the lift cord prevents lateral motion of the slats.

An alternative cording arrangement shown in Figures 9 and 10 utilizes

two lift cords and pulleys in the bottomrail 14. The distal end of each lift cord 85 and

86 is attached to the headrail via the tilt disk 18 through hole 17. (See Figure 4) The

lift cord 85 and 86 is routed from the headrail down the front of the blind, through the

front slats 7, over pulleys 88, across the bottomrails 3, 4, under pulley 89 and up the

back of the blind through back slots 9 to the headrail. The lift cords can be threaded

through the ladder rungs 13 as shown or be alternately laced with the ladder rungs. The

cords 85, 86 pass through a cord lock 90 and out of the headrail as shown in Figure 10.

One could also provide a pulley arrangement in which four cords are used and each

cord goes up and down in the same set of slots. Yet another arrangement would affix

one lift cord at the disk away from the cord lock and route it down the front of the blind

through the front bottomrail to the other end of the bottomrail, up the front of the blind,

and through a cord lock at the other end of the headrail. A second lift cord would start

at the disk near the cord lock and pass through the headrail to the disk at the opposite

end and follow a similar path as the first cord back to the disk near the cord lock where

it is affixed. A comparable pair of cords travels through the backside of the blind. In

all of those cord routing patterns the lift cords are in tension at all times preventing

lateral motion of the slats.

While the lift cords are always in tension, the rails of the tilt ladders are

only in tension when the blind is fully lowered. Since the rails are on the outside edges

of the slats they can fold neatly across the front of the blind when the blind is raised to the position shown in Figure 2. Although such neat folding generally occurs, I prefer to

assure that such neat folding always occurs by treating the rails with a permanent

pleating or other treatment to provide a memory in the rails so that they will fold in the

desired manner.

A tilt mechanism 16 is provided to move the rails 11 and 12 of the tilt

ladder 10 relative to one another to open and close the blind and also moves the lift

cords at the same time. The present preferred tilt mechanism can be seen most clearly

by referring to Figures 4, 3, 7, 8, 11, 12 and 13. The tilt mechanism in the preferred

embodiment is comprised of a disk 18 to which the rails 11 and 12 of the tilt ladder 10

are connected. There is one disk for each tilt ladder 10. The disks 18 are mounted on

tilt rod 19 so that rotation of the tilt rod will turn the disks in unison. The tilt rod is

suspended above the base 20 of the headrail by cradles 22. I prefer to provide a bridge

23 on each cradle to prevent the lift cords from getting caught on the cradles. As

shown in Figure 14, a right angle drive or worm gear drive 24 is provided at one end of

tilt rod 19. The drive extends through the headrail 2 to provide a handle 25 which is

turned to open and close the blind. Rotation of the disk 18 in either direction lifts one

rail 11 or 12 and associated lift cords relative to the other and moves the rails 11 and 12

toward one another. If a two piece bottomrail is used, the front bottomrail will move

relative to the rear bottomrail. The same center of gravity should be maintained for the

blind through the tilt cycle.. The disks can be rotated 100 degrees. As can be seen in

Figures 12 and 13, the blind slats 6 will be in a nearly closed position after the disks 18

have been rotated through approximately 90 degrees. As disks 18 are rotated the lift

cords 8 and the rails 11 and 12 of the tilt ladders 10 are constantly in tension. This contains the slats and prevents them from slipping laterally.. The number of tilt ladders

which are used will vary according to the width of the blind.

As can be most clearly seen in Figures 3, 4 and 6 the lift cords are routed

through pivot holes 17 in the disks 18 located at the point of attachment of the ladder

rails 11 and 12. Consequently, rotation of the disk shifts the lift cords transversely and

vertically in tandem with the ladder rails and keeps the lift cords under tension. An

alignment arm 27 extends from tilt rod 19 through which the lift cords pass to prevent

the lift cords from getting caught on the cradles and to present the cords for a uniform

entry into the cord lock independent of the tilt angle of the slats.

In the first preferred embodiment the lift cords 8 pass through the

headrail. An alternative is shown in Figures 14 and 15 wherein the lift cords are wound

about a tubular drive mechanism 30. The drive mechanism includes an axle 29 around

which the lift cords 8 are wound. Winding is done such that the lift cord extending

from the front is wound in one direction whereas the lift cord extending from the rear is

wound in the opposite direction as shown in Figure 15. Thus, turning of the drive axle

29 will raise or lower the lift cords in the front and back at the same time. A tube lift

mechanism such as is disclosed in United States Patent No. 5,184,660 can be adopted

for the Venetian blind shown in Figures 14 and 15.

There are many hardware systems by which the lift cords can be tilted in

tandem with the rails of the tilt ladder 10. For example, a set of parallel cradles can be

combined with straps or cables and cord locks to form a parallelogram that moves in

tandem with the tilt ladder. In another possible arrangement, the disks could be

combined with a tilting bar or rotating beam. Although I have shown and described certain present preferred embodiments of my Venetian blind it should be distinctly

understood that the invention is not limited thereto but may be variously embodied

within the scope of the following claims.

Claims

,, «I claim:

1. A Venetian blind of the type having a headrail, a bottomrail, at least

two cord ladders each having substantially parallel rails, lift cords extending between

the headrail and the bottomrail and a plurality of slats carried on the ladders, each slat

having a first end and a second end and an inside edge and an outside edge,

characterized by:

each slat having at least a first slot on the outside edge or the inside edge

proximate the first end of the slat, the first slots forming a first vertically arrayed set of

slots, and a second slot on the inside edge or the outside edge proximate the second end

of the slat and laterally spaced apart from the first slot, the second slots forming a

second vertically arrayed set of slots such that a first ladder is positioned proximate the

first ends of the slats so that one ladder rail is positioned near the first set of slots, and a

second ladder is positioned proximate the second ends of the slats so that one ladder rail

is positioned near the second set of slots;

the lift cords comprising a first pair of lift cords adjacent to the first

ladder and connected to the bottomrail, one of the first pair of lift cords running through

the first set of slots and a second pair of lift cords adjacent to the second ladder, one of

the second pair of lift cords running through the second set of slots; the first pair of lift

cords being engaged with substantially each of the rungs of the first ladder and the

second pair of lift cords being engaged with substantially each of the rungs of the

second ladder, such that the rails of the ladders fold substantially in a plane parallel to

the edges of the slats when the lift cords draw the slats together; and a tilt mechanism attached to the headrail to which the first and second

ladders are attached, such that when the blind is changed from an open position to a

closed position the rails of each of the ladders will move relative to one another.

2. The Venetian blind of claim 1 wherein each slat has a third slot

opposite the first slot and a fourth slot opposite the second slot, a second one of the first

pair of lift cords runs through the third slot of each slat and a second one of the second

pair of lift cords runs through the fourth slot of each slat.

3. A Venetian blind of the type having a headrail, a bottomrail, at least

having a first end and a second end and an inside edge and an outside edge,

characterized by:

the at least two ladders comprising a first ladder having opposite cord

type rails and rungs extending therebetween, the rails positioned near the first pair of

slots and connected to the bottomrail, and a second ladder having opposite cord type

rails and rungs extending therebetween, the rails of the second ladder positioned near

the second pair of slots and connected to the bottomrail;

the lift cords comprising a first pair of lift cords adjacent to the first

ladder, and connected to the bottomrail, one lift cord running through slots in the inside

edge of the slats and one lift cord running in the slots on the outside edge of the slats,

and a second pair of lift cords adjacent to the second ladder, and connected to the bottomrail, one lift cord running through slots in the inside edge of the slats and one lift

cord running though slots in the outside edge of the slats; and

a tilt mechanism attached to the headrail to which tilt mechanism the lift

cords are connected and to which tilt mechanism the first and second ladders are

attached wherein the tilt mechanism moves rails of the ladders and the lift cords in each

pair of lift cords together and in opposite directions at the tilt mechanism and adjacent

the slats when the blind is changed from an open position to a closed position.

4. The Venetian blind of any previous claim wherein the ladder rails

have a dimension greater than the opening of the slots.

5. The Venetian blind of any previous claim wherein the engagement of

the lift cords with the ladder rungs comprises the alternate lacing of lift cords with the

ladder rungs.

6. The Venetian blind of any previous claim wherein the engagement of

the lift cords with the ladder rungs comprises each of the lift cords passing through at

least one of the ladder rungs.

,, -

7. The Venetian blind of any previous claim wherein the bottomrail is

comprised of two spaced apart parallel rails and where one lift cord of each pair of lift

cords is attached to one rail and a second lift cord of each pair of lift cords is attached to

the other rail.

8. The Venetian blind of any previous claim also comprising a tube lift

attached to the headrail and to which the lift cords are connected.

9. The Venetian blind of any previous claim also comprising four

pulleys within the bottomrail and positioned so that one lift cord passes over each

pulley.

10. The Venetian blind of any previous claim also comprising a cord

lock through which the lift cords pass wherein the cord lock is always engaged unless

the lift cords are being operated.

11. The Venetian blind of any previous claim wherein the lift

mechanism is compromised of a first cylindrical member to which the rails of the first

ladder are attached; a second cylindrical member to which the rails of the second ladder

are attached; an axle attached between the first cylindrical member and the second

cylindrical member; and means for rotating the axle and attached cylindrical members. 1 0

12. The Venetian blind of claim 11, wherein at least one of the lift cords

passes through at least one of the cylindrical members.

13. The Venetian blind of claim 11 wherein the means for rotating the

axle and attached cylindrical members is one of a right angle drive and a worm drive.

14. The Venetian blind of any of claims 1 through 10 wherein the tilt

mechanism is comprised of:

a first disk to which the rails of the first ladder are attached;

a second disk to which the rails of the second ladder are attached;

an axle attached between the first disk and the second disk; and

means for rotating the axle and attached disks.

15. The Venetian blind of claim 14 wherein at least one of the lift cords

passes through at least one of the first disk and the second disk.