WO2011075106A1

WO2011075106A1 - Cord lock

Info

Publication number: WO2011075106A1
Application number: PCT/US2009/006601
Authority: WO
Inventors: Peter Stone
Original assignee: Freelance Inventors Inc.
Priority date: 2009-12-17
Filing date: 2009-12-17
Publication date: 2011-06-23

Abstract

A cord lock for a Venetian blind or a shade disclosed has a housing having two parallel sidewalls, and spaced end walls, an inclined downwardly facing surface of one end wall in the nature of a ramp is formed with a plurality of transverse teeth or serrations. An opening is formed by the sidewalls, the end walls and the downwardly facing surface of the other end wall. A separator extends between the end walls. A pulley roller is rotatably mounted on a shaft supported in the sidewalls. A cylindrical floating roller is formed on its peripheral surface with a plurality of teeth or serrations extending in a direction parallel to own axis. A top opening is provided through which lift cords may pass freely to the pulley roller and then through the opening and then through different sides of the separator and then be completed as free hanging ends of pull cords. A pusher is placed on the housing and makes mechanical contact with the pull cords for always pushing the pull cords towards the cylindrical floating roller permanently. The pusher insures the immediate and automatic locking of the cords if the pull cords are accidentally released or dropped.

Description

CORD LOCK

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to a cord lock for a Venetian blind or a shade, such as a pleated or roll-up window shade, and more specifically to a lock for the lift cord of such Venetian blind or shade.

DESCRIPTION OF THE PRIOR ART

Well known cord locks have a stationary pulley made from either plastic material or metal, and is either rotatably mounted or is fixed in a housing, and also have a floating serrated or knurled roller, which can move up and down in slots in the housing. The cords lifting and lowering the blind or shade passes between the stationary pulley and the floating roller. When the cords are to be locked in position the floating roller engaged by the cords travel upwardly with the cords, caused by the weight of the blind, and the cords becomes wedged between the floating roller and the stationary pulley. When the cords are pulled downwardly the floating roller drops away from the stationary pulley and the blind or shade is released.

The existing cord locks are operated manually by hand by pulling on the cords. A disadvantage of existing cord locks is that they do not automatically lock the cords if the cords are accidentally released or dropped. In this case the blind slats or shade will fall down sometimes unequally. This creates unnecessary complication, may result in injury to person or damage to the cords and takes time to fix.

It is an object of the present invention to provide a cord lock for a Venetian blind or shade in which the blind slats or shade will never inadvertently fall down due to accidental release of the cords or lines.

l SUMMARY OF THE INVENTION

Accordingly, it is a primary object to provide a cord lock that does not possess the disadvantages of like prior art devices.

It is another object of the invention to provide a cord lock that will lock the cords without damaging them.

It is yet another object of the invention to provide a cord lock that is easy and convenient to use.

In order to achieve the above and other objects a cord lock includes pushing means for continuous application of biasing or permanent pushing of the pull cords towards the floating serrated or knurled roller. The pushing means will insure the immediate locking of the cords if the pull cords are accidentally released or dropped.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention, together with further aspects, features and advantages thereof will be more clearly understood by considering the following description in conjunction with the accompanying drawings in which like elements bear the same reference numerals throughout the several views.

FIG. la to FIG. lc are cross-sections taken along vertical cutting planes illustrating different stages of a cord lock according to the invention with pushing means in the form of a gravity pusher in a case when someone controls the cord for lifting/lowering a blind or shade, with exploded insets in FIGS la and lc to illustrate details of operation.

FIG. 2 is a view similar to FIG. 1 and shows how the gravity pusher operates in a case when someone accidentally releases or drops the cord while lifting lowering a blind or shade.

FIG. 3 is a perspective view of the gravity pusher shown in FIGS. 1-2. FIG. 4 is a view similar to FIG. la with a modified gravity pusher.

FIG. 5 is a perspective view of the modified gravity pusher shown in FIG. 4.

FIG. 6a to FIG. 6c are similar to FIGS, la-lc but showing different stages of a longitudinal sectional view of cord lock according to the invention with pushing means having a piston pusher and a spring in a case when someone controls the cord for lifting/lowering a blind or shade.

FIG. 7 is a view similar to FIG. 6 and shows how the piston pusher operates in a case when someone accidentally release or drops the cord while lifting lowering a blind or shade.

FIG. 8 is a perspective view of the piston pusher with the spring.

FIG. 9a to FIG. 9b is a longitudinal view and a fragmentary cross sectional view of cord lock according to the invention with pushing means in the form of a pendulum pusher.

FIG. 10a to FIG. 10b and FIG. 1 la to FIG. 1 lb is views similar to FIG. 9a to FIG. 9b and show the different stages of the locking process with the pendulum pusher.

FIG. 12 is a perspective view of the pendulum pusher.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to the drawings in detail, a cord lock 9 according to the present invention comprises a housing 10, which has two parallel sidewalls 11 and 1 Γ, an end wall 12 and an inclined downwardly facing surface 13' of an end wall or ramp 13 is formed with a plurality of transverse teeth or serrations teeth 15. A sheave or pulley roller 16 is rotatably mounted on a shaft 17 supported in the sidewalls 11 and 11 ' in proximity to an opening or passageway -18 of the end wall 12. Also disposed within the cord lock 9, there is provided a cylindrical floating roller 19 formed on its peripheral surface with a plurality of teeth or serrations 21 extending in a direction parallel to the axis of the roller. Elongated openings 41, 41 ' are provided at the top and bottom of the sidewalls 11 and 11 respectively, between the end wall 12 and the downwardly facing surface 13' of the end wall 13. A line or cord separator 22 extends between the end wall 12 and the end wall 13 of the housing 10 as shown. The cylindrical floating roller 19 has such a length that it is free to move in any radial direction between the sidewalls 11 and 11 '. The cylindrical floating roller 19 is prevented from passing through the opening 41 by the separator 22, while the constricted dimension between the pulley or sheave 16 and the upper end 14 of the wall 13, especially with the line wrapped around the sheave, prevents the roller 19 from passing through the upper opening 41.

The cord lock 9 is disposed within an opening 51 in a header channel 52 and fixed by the separator 22 which prevents the cord lock from dropping through the opening. However, any other or suitable means may be used to fix the cord lock to a header channel or other supporting member of a blind or shade.

The opening or passageway 18 is disposed slightly outwardly relative to inner edges 42 and 42' of the sidewalls 11 and 11 ' to permit lift cords 31 and 31 ' to pass freely over the pulley roller 16 and then through the opening 18 where the lift cords 31 and 3 are split by the separator 22. Pull cords 32 and 32' hang downwardly and are used for raising and lowering the blind slats or shade.

According to the present invention the cord lock 9 is provided with pushing means, which is mounted or is fixed inside or outside of the housing 10. The pushing means makes mechanical contact with the pull cords 32 and 32' in spots facing the end wall 12 of the housing 10 and always pushes or biases the pull cords 32 and 32' towards the cylindrical floating roller 19.

FIG. 1 and FIG. 2 shown the cord lock with pushing means in the form of a gravity pusher 61 which is pivotally mounted on a shaft 62 supported in the sidewalls 11 and 11 ' in proximity to the end wall 12 between the pulley roller 16 and the separator 22. The shaft 62 is placed on a lower corner 68 of the gravity pusher 61, as shown, in proximity to the end wall 12 and the separator 22. The gravity pusher 61 has such a length that it is free to move in any rotary direction between the sidewalls 11 and 11 ' about the shaft or pin 62.

If the gravity pusher 61 is in upper position as shown on FIG. la a backside 63 of the gravity pusher 61 is in mechanical contact with the end wall 12 of housing 10 and a top face corner 64 of the gravity pusher 61 forms a gap 85 with the pulley roller 16. If the gravity pusher 61 is in lower position as shown on FIG. lb the bottom side 65 is not in mechanical contact with the separator 22.

A face side 66 of the gravity pusher 61 is not a parallel to the backside 63 so there is a gap 86 between the face side 66 and the pull cords 32 and 32'. As a result the top face corner 64 is always in mechanical contact with the pull cords 32 and 32'. This creates a force moment on the pusher 61 by cords 32 and 32' shown by arrow 74 (FIG. la inset) around the shaft or pin 62, which is always counter-clockwise.

A center of gravity 71 of the gravity pusher 61 does not coincide with a center of rotation of the gravity pusher 61 around the shaft 62. As a result there is always a clockwise gravity moment shown by arrow 72 around to the shaft 62. The clockwise gravity moment 72 creates a pushing force shown by arrow 73, which always pushes the pull cords 32 and 32' towards the cylindrical floating roller 19. Usually the moment 74 of tension on pull cords 32 and 32' is hundreds time more than the gravity moment 72. With tension on the cords 32 and 32' the gravity pusher 61 will always be in upper position as shown on FIG. la.

If the free hanging ends of the pull cords 32 and 32' are pulled down to raise the blind slats by the lift cords 31 and 3 the cylindrical floating roller 19 is in the position shown on FIG. la. In this condition the blind slats or shade can be moved up and down (as shown by two sides arrow 91).

If the free hanging ends of the pull cords 32 and 32' are pulled to one side in the direction of the roller 19 (as shown on FIG. lb by arrow 92) and then the tension on the these cords is released slightly to allow the slats to fall a short distance under the effect of gravity (as shown by arrow 93), engagement of the pull cords 32 and 32' with the cylindrical floating roller 19 will cause that roller to engage the surface 13' of the end wall 13 and the resulting rotation of the cylindrical floating roller 19 will in turn cause it to move upwardly along that end wall towards the upper portion 14 by virtue of the engagement of the teeth or serrations 21 on the cylindrical floating roller 19 with the teeth or serrations 15 on the surface of the end wall 14 (as shown by arrows 94 and 95 respectively). Such upward movement will continue until the cylindrical floating roller 19 is in the position shown in FIG. lc in which it serves to clamp the pull cords 32 and 32' between the pulley roller 16 and the cylindrical floating roller 19. This then prevents any further upward movement of the pull cords 32 and 32' and consequently any further lowering of the blind slats (not shown).

Different action will accrue inside of the cord lock with gravity pusher 61 if in unlocked cords position shown on FIG. la the pull cords 32 and 32' are accidentally released or dropped. In this case there is no tension on the pull cords 32 and 32' and pusher force 73 (FIG. la inset) will be the only force, which will push the pull cords 32 and 32' towards the cylindrical floating roller 19 as shown on FIG. 2. It is inevitable that the slats will fall a short distance (as shown by arrow 96) under the effect of gravity to wedge the pull cords 32 and 32' between the pulley roller 16 and the cylindrical floating roller 19 as shown on FIG. lc. This will be done automatically.

As shown on FIG. lc the contact surface between the pull cords 32 and 32' and the pulley roller 16 and the cylindrical floating roller 19 and the top corner 64 and the top face side 66 of the gravity pusher 61 will be increased compared with the contact surfaces used in the prior arts cord locks. As a result a damage of the cords will be reduced since the stresses will be distributed over a longer length of line.

The gravity pusher 61 shown in FIG. 3 can be modified by adding parts 79 and 79' to the bottom side 65 that are spaced from each other to form a gap 82 as shown on FIG. 5. As shown on FIG. 4 there is a gap 87 between the end wall 12 and the parts 79 and 79' for any position of the modified gravity pusher 61 '. A gravity moment 72 'and a pushing force 73' of modified gravity pusher 6 are greater than ones for the gravity pusher 61.

To increase the sensitivity of the modified gravity pusher 61 ' the friction between the gravity pusher and different parts of the housing 10 during any motion may be reduced, the length of the gravity pusher 6Γ and a distance between the sidewalls 11 and 11 ' and the diameter of the separator 22 and a size of the gap 82 being-chosen so that the gravity pusher 61 ' has mechanical contact with the separator 22 only. Preferably the material that can be used for the gravity pusher is metal such as bronze or steel. However, other suitable materials can be used.

FIG. 6 and FIG. 7 show a cord lock with pushing means having a piston pusher 101 and a spring 104, which is moveably mounted on the separator 22 in proximity to the end wall 12 under the pulley roller 16. As shown on FIG. 8 the piston pusher 101 consist of a tube 102 and a piston plate 103 as one solid body. One end 105 of the spring 104 is in mechanical contact with the piston plate 103 and another end 106 with the end wall 12 of the housing 10. The piston plate 103 and the tube 102 has such a shape and sizes that the piston pusher 101 is free to move along the separator 22 between the sidewalls 11 and 11 ' under the pulley roller 16. The piston pusher 101 is in mechanical contact with the pull cords 32 and 32' and always pushes them towards the cylindrical floating roller 19 (as shown by arrow 107 in FIG. 6).

The level of pushing force and action of the piston pusher is generally the same as for the gravity pusher 61.

FIG. 9 to FIG. 11 show a cord lock with a pushing means in the form of a pendulum pusher 109, which is pivotally mounted on a pin 114 outside of the cord lock 9. The pendulum pusher 109 has a plate 111 and a finger 112. The finger 112 is attached to the plate 111 in a bottom corner 116 of a side 117 of the plate 111. As shown on FIG. 12 a hole 114' to engage with the pin 114 is placed on the same side 117 but in a top corner 118 of the plate 111. The finger 112 is designed to always be in mechanical contact with the pull cords 32 and 32'. A center of gravity 113 of the pendulum pusher 109 does not coincide with a center of rotation the pendulum pusher 109 around the pin 114. As a result of the tendency of the plate 111 to rotate (in a clockwise rotation in FIG. 12) there is always a clockwise pendulum moment shown by arrow 121 around to the pin 114. This moment creates a pushing force shown by arrow 122, which always pushes the pull cords 32 and 32' towards the cylindrical floating roller 19. A part of 115 of the plate 111 stabilizes a rotating motion of the pendulum pusher 109. The plate 111 and the finger 112 can be made as one solid body as well.

Preferably, the materials that can be used for the pendulum pusher include metal like bronze or steel. However, other suitable materials can be used. The level of the pushing force and an action of the pendulum pusher acting is the same as for the gravity and piston pushers.

While the invention has been described with reference to illustrative embodiments, it is not intended that the novel device be limited thereby, but that modifications thereof are intended to be included within the broad spirit and scope of the disclosure and the following claims and the appended drawings.

Claims

I claim:

1. A cord lock for a Venetian blind or a shade comprising: a housing having two parallel sidewalls, spaced first and second an end walls, said second end wall being provided with an inclined a downwardly facing surface relative to said first end wall and formed with a plurality of transverse teeth or serrations; openings is being formed by said sidewalls^ and said first end wall and said downwardly facing surface of said second end wall; a separator extending between said first end wall and said downwardly facing surface of said second end wall; a pulley roller rotatably mounted on a shaft supported on said sidewalls in proximity to said first end wall; a cylindrical floating roller formed on its peripheral surface with a plurality of teeth or serrations extending in a direction parallel to own axis and to said shaft of said pulley roller and having a length, which allows said cylindrical floating roller to moves freely in any radial direction between said two sidewalls; said lift cords being freely movable over te said pulley roller and then through said opening proximate to said pulley roller and then through different sides of said separator and then be completed as free hanging ends of pull cords; and pushing means placed on said housing and arrange to always provide mechanical contact with said pull cords and always pushing said pull cords towards said cylindrical floating roller.

2. A cord lock as defined in claim 1, wherein said pushing means comprising a gravity pusher pivotally mounted on a shaft supported in said sidewalls in proximity to said end wall between said pulley roller and said separator, and having a center of gravity, which does not coincide with said shaft, and having a length, which allows it to freely move in any rotary direction between said sidewalls, and having a mechanical contact with said pull cords,

3. A cord lock as defined in claim 2, wherein said gravity pusher comprising a top face corner, forming a gap with said pulley roller when said gravity pusher is in its upper position, and providing mechanical contact with said pull cords when said gravity pusher is in it any position, a backside being in mechanical contact with said first end wall when said gravity pusher is in it upper position, a bottom side having no mechanical contact with said separator when said gravity pusher is in it lower position.

4. A cord lock as defined in claim 3, wherein said gravity pusher comprising two parts attached to said bottom side with a gap between said two parts more then a diameter of said separator, said length of said gravity pusher, said distance between said sidewalls, said diameter of said separator and said gap between said two parts having parameters which allows said gravity pusher to freely move in any rotary direction between said sidewalls and said separator.

5. A cord lock as defined in claim 1, wherein said pushing means comprising a piston pusher and a spring both moveably mounted on said separator in proximity to said first end wall so that one end of said spring is in mechanical contact with said first end wall, another end of said spring being in mechanical contact with said piston pusher, and said piston pusher being arranged to always be in mechanical contact with said pull cords.

6. A cord lock as defined in claim 5, wherein said piston pusher comprises a tube and a piston plate as one solid body, said tube and said piston plate having such a shape and sizes that allows said piston pusher to freely move along said separator between said sidewalls under said pulley roller.

7. A cord lock as defined in claim 1, wherein said pushing means comprising a pendulum pusher pivotally mounted on a pin outside of said housing and having a center of gravity^ which is does not coincide with said pin, and being arranged to always make mechanical contact with said pull cords.

8. A cord lock as defined in claim 7, wherein said pendulum pusher comprising a plate, a finger placed on a side bottom corner of said plate and arranged to make contact with said pull cords, a hole to engage with said pin placed on a top corner of said side of said plate, an additional plate on said top corner of said side of said plate, wherein said plate, said finger and said addition plate being made up as one solid body.