EP0491097A1

EP0491097A1 - Adjustable venetian blind

Info

Publication number: EP0491097A1
Application number: EP90313803A
Authority: EP
Inventors: Ming Nien
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-12-18
Filing date: 1990-12-18
Publication date: 1992-06-24

Abstract

A venetian blind of adjustable width includes a top frame (10), a bottom frame (20), multiple slats (30), a lifting/lowering pull cord (40), a slat rotating device (50) and a rotating rod (60). The top frame (10) includes a main rail (11) and left and right rails (12, 13) which are formed by multiple mortise and tenon blocks (16, 17) which are interfitted to one another. The number of the blocks (16, 17) can be increased or reduced to adjust the width of the blind. The slat rotating device (50) is secured in the main rail. The bottom frame (20) includes a main rod (21) and left and right rods (22,23) which are also extensible and retractable relative to the main rod to adjust the length of the bottom frame to match the top frame so that the width of the blind can be adjusted according to requirements.

Description

The present invention relates to an adjustable venetian blind, and more particularly to a venetian blind the width of which is adjustable according to particular requirements without dismantling the blind.
At present, a conventional blind is designed with a fixed dimensional specification. The width of such a blind is difficult to adjust. Especially when the blind is rigidly constructed, the top frame and bottom frame thereof are hard to modify to match the width of a specific window. As a result, only a specific blind with a corresponding rail width can be bought and used for a specific window.
If the purchaser wants to shorten a bought blind, it will be quite troublesome for the buyer or a handyman to do so, and this procedure must be done by a professional installation person.
Therefore, a blind with adjustable width and length, which can easily be modified by the owner of a house or a handyman is required.
It is an object of this invention to provide a venetian blind the width and length of which are adjustable according to actual requirements.
It is a further object of this invention to provide such a venetian blind having multiple mortise and tenon blocks which can easily be adjusted by the owner or a general handyman.
It is yet a further object of this invention to provide such a venetian blind which can be widely used and has an attractive appearance.
It is yet a further object of this invention to provide such a venetian blind wherein several protective covers can be fitted on the extending portions of the main rail and main rod to achieve an attractive appearance.
In accordance with the invention there is provided a venetian blind of adjustable width comprising a top frame, a bottom frame, multiple slats, a lifting/lowering pull cord, a slat rotating device and a rotating rod, characterised in that said top frame includes a main rail, a left rail and a right rail, said left and right rails comprising interfitting multiple blocks which are associated with one another to form said left and right rails, wherein the number of said blocks can be increased or reduced to adjust the width of said blind, the blocks being securable to said main rail, said slot rotating device being fixed in said main rail, and said bottom frame including a main rod, a left rod and a right rod.
Moreover, the slats of the blind are preferably formed with circular holes instead of conventional slots so that, when taking up the pull cord, one eliminates the shortcomings due to the slots where the pull cord is not easy to pull vertically upwards in a stable manner and the slats are apt to tilt. In addition, circular holes can be made at low manufacturing cost.
In order that the invention may be fully understood, one presently preferred embodiment of blind will now be described by way of example and with reference to the accompanying drawings, in which:

Fig. 1 is a front view of the blind of this invention;
Fig. 2 is an exploded perspective view thereof; and,
Fig. 3 is a perspective view of the adjustable mortise and tenon blocks of the blind.

Referring to Figs. 1, 2 and 3, there is shown a venetian blind 100 of this invention which includes a top frame 10, a bottom frame 20, multiple blind slats 30, a lifting/lowering pull cord 40, a slat rotating device 50 and a rotating rod 60. The top frame 10 includes a main rail 11, a left rail 12, a right rail 13 and protective covers 14, 15, 18, 19. After the dimensions of a specific window have been measured, the top frame 10 can be adjusted to match the dimensional specification. The adjustment is enabled by the extending portions of the top frame 10 being formed by interfitting blocks, here
mortise and tenon blocks 16, 17, which associate with one another to form the left rail 12 and right rail 13. When adjusting, the number of the mortise and tenon blocks can be increased or decreased as necessary to adjust the overall width of the blind. As shown, the blocks 16, 17 have dovetail shape slots and projections and are slidingly fitted together. After the adjustment, the protective covers 14, 15, 18, 19 can be fitted to the left and right rails 12, 13 according the adjusted dimensional specification to maintain the whole attractive appearance of the blind 100. The blocks 16, 17 are held in place in their positions relative to the main rail 11 by securing screws 70, 71, 72, 73.
The slat rotating device 50 includes a drive drum 52, a drum seat 54 and a rotary shaft 55 of irregular cross-section. When the slat rotating device 50 is fitted on a protective cover, the cover is secured to the main rail 11. The rotary shaft 55 is clamped by a clamp block 122 which is provided with a gear set so that the rotary shaft 60 can control the rotation of the rotary shaft 55. At this time, the drive drum 52 will pull the pull cord 53 engaged therewith. The two ends of the pull cord 53 are tied to the drive drum 52. The drive drum 52 is rotatably driven by the rotary shaft 55 to pull the pull cord 53 forwards and backwards so as to adjust the angle of the slats 30 for controlling the light entering the room and the illumination thereof.
The bottom frame 20 includes a main rod 21, a left rod 22 and a right rod 23. The manner of adjusting the left rod 22 and the right rod 23 is like the manner of adjusting the left rail 22 and right rail 23 of the top frame 10. The left and right rods 22, 23 are adjusted to match the specification and then protective covers 25, 26, 27, 28 are fitted to the left and right rods 22, 23 to maintain the beauty of the appearance.
When pulling the pull cord 40 which goes through the holes 101, 102 of the top frame 10 and the circular holes 31 of the multiple slats 30, the pull cord 40 will stably lift the blind 100. After reaching a certain position, the pull cord 40 is clamped tightly by a clamping device 41 so that the blind 100 will not come loose and drop down. At two ends of the main rod 21 of the bottom frame 20 are two hollow protuberances 24 for receiving knotted ends of the pull cord. The left and right rods 22, 23 of the bottom frame 20 can extend and retract freely without being affected.

Claims

A venetian blind of adjustable width comprising a top frame (10), a bottom frame (20), multiple slats (30), a lifting/lowering pull cord (40), a slat rotating device (50) and a rotating rod (60), characterised in that said top frame includes a main rail (11), a left rail (12) and a right rail (13), said left and right rails comprising interfitting multiple blocks (16,17) which are associated with one another to form said left and right rails, wherein the number of said blocks can be increased or reduced to adjust the width of said blind, the blocks being securable to said main rail (11), said slot rotating device (50) being fixed in said main rail (11), and said bottom frame (20) including a main rod (21), a left rod (22) and a right rod (23).
A venetian blind as claimed in claim 1, characterised in that the blocks (16, 17) are mortise and tenon blocks.
A venetian blind as claimed in claim 1 or 2, characterised in that adjustable protective covers (14, 15, 18, 19) are fitted on the outwardly extending portions of said left and right rails (12, 13).
A venetian blind as claimed in claim 1 or 2, characterised in that adjustable protective covers (14, 15, 18, 19) are fitted on the outwardly extending portions of said left and right rails (12, 13), and the length of said bottom frame (20) corresponds to that of said top frame (10).