GB1584834A

GB1584834A - Cord lock

Info

Publication number: GB1584834A
Application number: GB3053977A
Authority: GB
Original assignee: PERMA SYSTEM AB
Current assignee: PERMA SYSTEM AB
Priority date: 1977-07-20
Filing date: 1977-07-20
Publication date: 1981-02-18

Description

(54) IMPROvEMENTS IN OR. RELATING TO A CORD LOCK (rl) ) We, AB PERMA SYSTEM, a- Swedish Company, of Box 150* S-560 42 Mùllsjö, Sweden, do hereby declare the invention, for which we pray that a patent may be granted to us,-- and the method by which it is to be performed, to be particu larly described in and by the following statement: - The present invention relates to a cord lock and more particularly to a lock for a roller blind, which blind is equipped with an operating cord comprising a plurality of balls spaced along a cord. A cord of this type is herein described as a ball cord As prior proposed ball cord lock is adapted to be connected to and to support one end of a roller blind spindle. - The wind-up and unwinding of the roller blind takes place by the aid of a ball cord, that is to say a cord having balls threaded thereon and secured in position at spaced intervals, arranged in the ball cord lock and which hangs down from the ball cord lock and is manually operated.

One such - prior proposed ball cord lock is described in US patent specification 2,577,046, which illustrates and describes a ball cord lock including a lock housing which is adapted to be mounted on a wall and in which a cord pulley is turnably journalled. The cord pulley supports a ball cord having a loop which can be lockably engaged with a U-shaped portion or recess in the lock housing. In order to obtain a self-locking function of the ball cord the lock housing is provided with an inwardly bent portion which deflects the ball cbrd from the vertical in a- direction towards the recessed portion resulting in the locking of the ball cord. In order to release the ball cord froin the locked position the ball cord is moved out of the U- shaped portion to a broader portion allowing clearance for the balls of the ball cord.

However, the above described unlocking movement must be carried out in connection with the wind-up as well as the unwind ing of the roller blind, which is a drawback. Further, the device as described in the U.S. Patent Specification is complicated: and the shape thereof is not suitable for use with a new known type of roller.

blind spindle which. is not provided with the conventional centrifugal clutch and windup- spring.

According to this invention, there is pro-- vided- a cord lock for use with a roller blind,.

said fock comprising a cord' pulley mounted for rotation in a vertical plane within a housing, an endless loop of cord. arranged around said pulley, a run of cord depending from each side of the pulley and extending beyond the- housing, said cord- having a plurality of balls secured. thereon at spaced intervals, the cord or.balls or both being adapted to engage the pulley, one run of cord passing throu-gh an opening in the housing, which opening has a broad portion.

through which the run of cord together with the attached balls may pass freely and a constricted portion through which only the cord and not the balls may pass, the portions of the housing defining the constricted portion having an upper surface which when viewed in a vertical section inclines downwardly towards said broad portion, the arrangement of the lock being such that when a run of the cord lies within the constricted portion of the opening the run of cord is retained, to prevent the run of cord being wound onto the pulley, by engagement of one of the balls with the part of the housing defining the constricted portion of the opening, the arrangement of the lock also being such that when the. run of the cord lying within the constricted portion is pulled away from the pulley to cause rotation of the pulley a ball on the cord engages and slides along said inclined surface thus causing the cord to move from the constricted portion to the broad portion to permit free movement of the cord.

Preferably, said narrower portion is immediately adjacent the cord pulley and conveniently the pulley has an axially extending stub axle adapted to engage one end of a roller blind spindle.

Advantageously, the housing is formed of two substantially identical housing halves, and preferably the housing is mounted on a bracket adapted to be secured to a wall or the like, said bracket having means thereon to engage and retain a decoration or embellishment on said housing.

A cord lock in accordance with the invention may be provided with mounting means for mounting the cord lock on a wall or the like in such a way that part of the endless loop of the ball cord remote from the wall passes through the broad portion of the opening and the part of the endless loop of the ball cord closest to the wall normally passes through the narrower portion of the opening.

This invention also relates to a roller blind provided with a ball cord lock in accordance with the invention.

In order that the invention may be more readily understood and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings, in which: - Figure 1 is a side view of a ball cord lock in accordance with the invention; Figure 2 is a front view of the ball cord lock of Figure 1; Figure 3 is an underneath view of the ball cord lock of Figure 1 having the ball cord removed; Figure 4 is a side view of the ball cord lock corresponding to Figure 1 but having one of the halves of the lock housing removed; and Figure 5 is a side view of a decorative end knob intended to be mounted upon the ball cord lock in accordance with the invention.

Figures 1 and 2 show a ball cord lock comprising a cord pulley 1 having an extending stub axle 2 connected thereto, a portion of a ball cord 3 in the form of an endless loop having balls 4 attached thereto and arranged around the cord pulley 1, a lock housing 5 enclosing the cord pulley 1 and which consists of two lock housing halves 5a and 5b respectively, and a bracket 6 connected to the lock housing 5 and which is in turn connected to a wall. The cord pulley 1 is shaped with a peripheral groove having recessed portions. Said portions correspond to the shape of the balls on the ball cord and thus when the balls engage the recesses there is a secure connection between the ball cord and the cord pulley. The stub axle 2 is, in this embodiment, provided with a hexagonal crosssection but other cross-sections, such as triangular or square, could be utilised. The stub axle 2 is intended to be inserted into an opening of corresponding section in one end of a roller blind spindle so that an engagement connection between the cord pulley and the roller blind rod is established. Thus, by pulling on one or other of the two downwardly hanging portions or runs of the ball cord shown in Figure 1 the roller blind spindle may be caused to rotate in either direction.

The bracket 6 is made from a metal sheet blank and has an outwardly flared flange 7 extending adjacent the lock housing on the side of the lock housing 5 faced away from the stub axle 2. Said flange 7 is intended to engage and retain a decoration or embellishment such as and end knob shown in Figure 5. The right hand end of the knob shown in Figure 5 is hollow and may be located on the flange 7. The end knob, the cord pulley 1, the stub axle 2 and the lock housing 5 are made of a plastics material and the diameter of the exterior of the right hand end of the end knob corresponds to the diameter of the lock housing whereby a smooth joint between the end knob and the lock housing is formed which gives the assembled roller blind an attractive appearance. The ball cord 3 should, for reasons stated below, be of a comparatively stiff material. In this embodiment a cord made of a polyester for example, TERYLENE (Registered Trade Mark), having balls made of a plastics material moulded thereonto is used.

Figure 3 shows an opening 9 formed in the lower portion of the lock housing through which opening a portion of the ball cord extends. The opening has a first broad portion 10 which allows the run of the ball cord located furthest from the wall on which the housing is mounted to run freely up to the cord pulley, and a narrower constricted portion 11 for locking the cord, the restricted portion being dimensioned to receive only the cord portion of the ball cord and not the balls of the ball cord. The cord locking constricted portion 11 is arranged immediately below the right-hand periphery of the cord pulley, as shown in Figure 4, and lies in the region which would be occupied by the ball cord if the run of the cord nearest to the wall were to hang freely from the pulley 1. In this embodiinent the cord locking portion 11 is intended to catch and retain part of the run of the ball cord closest to the wall to prevent rotation of the cord pulley in one direction. If a locking of the run of the ball cord located furthest away from the wall should be desired, the lock housing can either be turned around its axis or be turned half a revolution in relation to the bracket whereby the constricted portion will be located adjacent the peripheral edge of the cord pulley faced away from the wall.

Figure 4 shows the transverse shape of the opening 9 in one of the lock housing halves 5a. The lock housing halves 5a, 5b are mirror images and thus the opposite lock housing half 5b has a corresponding shape.

The ball cord 3 is shown by continuous lines in the locked position and by broken lines in the position which it adopts when a pulling force is applied to the run of the ball cord closest to the wall.

From Figure 4 it is clear that the broader portion 10 extends around a substantial part of the lower peripheral portion of the cord pulley 1. The cord locking portion 11 which is seen from the side, extends from the broader portion 10 to a plane which extends vertically downwardly from the righthand edge of the pulley. The portions of the housing 5 that define the locking portion 11 are substantially triangular in side elevation as can be seen in Figure 4, the lowest side being curved to follow the perimeter of the housing 5 and the longest side facing, and inclining downwardly towards, the broader portion 10. As a result of this shape of the cord locking portion 11 there is formed a slip plane 12 along the longest side of the triangle for the balls 4 of the ball cord.

The operation of the illustrated and described ball cord lock is as follows: the cord pulley 1 is subjected to a counterclockwise directed torque in Figures 1 or 4, for example from a completely or partially wound-up blind supported on the spindle.

The run of the ball cord located closest to the wall will, in this situation, be located within the cord locking portion 11 and one of said balls will be retained against the lower peripheral surface of the lock housing as a result of the applied torque. If it is desired to unwind or lower the blind further the ball cord 3 is moved out of the cord locking portion 11 by grasping the portion of the ball cord closest to the wall, and moving that portion forwardly away from the wall so that said portion is inclined at an angle to the vertical so that the ball cord passes through the broader portion 10 onto the pulley 1. Whilst the ball cord is retained at said angle, the cord is permitted to move round the pulley until the blind has reached a desired position whereafter the ball cord is released. The ball cord is then caught by the cord locking portion 11 as a result of the diameter of the balls 4, and because of the comparatively high stiffness of the cord 3.

When the blind is to be wound up onto the spindle a downwardly directed force is applied onto the run of the ball cord closest to the wall whereby the balls 4 of the ball cord will slip along the slip plane 12 shown in Figure 4 outwardly towards the lower part of the broader portion 10 thus permitting the ball cord to be withdrawn to rotate the spindle. Hence, the slip plane 12 acts as a guide for the balls of the ball cord during the wind-up of the blind.

From the foregoing it will be appreciated that this invention relates especially to a ball cord lock intended to be used for roller blinds and comprising a cord pulley having an axially extending stub axle for receiving and retaining one end of a roller blind spindle, an endless loop of a ball cord arranged around the cord pulley and in engagement therewith and which can be used to wind up and unwind the roller blind attached to said spindle, a lock housing formed by two complementary housing halves which housing constitutes a journal for and encloses the cord pulley, a bracket which is connected to the lock housing and which is intended to be mounted at a window, and a constricted cord locking portion formed in the lock housing for catching and retaining one of the runs of the ball cord loop whereby the rotation of the cord pulley in one direction (and accordingly unwinding of the blind when in the wound-up condition is prevented) and wherein the constricted cord locking portion is arranged immediately adjacent the periphery of the cord pulley under one of the runs of the freely suspended ball cord, the open end of the constricted cord locking portion is directed towards the outer of the runs of the ball cord as shown in Figure 3, and the depth of the constricted cord locking portion increases in the vertical direction from the open part towards the closed part of the portion, the edge surfaces of the cord locking portion located closest to the cord pulley constituting a slip plane for the balls of the ball cord.

WHAT WE CLAIM IS: - 1. A cord lock for use with a roller blind, said lock comprising a cord pulley mounted for rotation in a vertical plane within a housing, and endless loop of cord arranged around said pulley, a run of cord depending from each side of the pulley and extending beyond the housing, said cord having a plurality of balls secured thereon at spaced intervals, the cord or balls or both being adapted to engage the pulley, one run of cord passing through an opening in the housing, which opening has a broad portion through which the run of cord together with the attached balls may pass freely and a constricted portion through which only the cord and not the balls may pass, the portions of the housing defining the constricted portion having an upper surface which when viewed in a vertical section inclines downwardly towards said broad portion, the arrangement of the lock being such that when a run of the cord lies within the constricted portion of the opening the run of cord is retained, to prevent the run of cord being wound onto the pulley, by engagement of one of the balls with the part of the housing defining the constricted

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The ball cord 3 is shown by continuous lines in the locked position and by broken lines in the position which it adopts when a pulling force is applied to the run of the ball cord closest to the wall. From Figure 4 it is clear that the broader portion 10 extends around a substantial part of the lower peripheral portion of the cord pulley 1. The cord locking portion 11 which is seen from the side, extends from the broader portion 10 to a plane which extends vertically downwardly from the righthand edge of the pulley. The portions of the housing 5 that define the locking portion 11 are substantially triangular in side elevation as can be seen in Figure 4, the lowest side being curved to follow the perimeter of the housing 5 and the longest side facing, and inclining downwardly towards, the broader portion 10. As a result of this shape of the cord locking portion 11 there is formed a slip plane 12 along the longest side of the triangle for the balls 4 of the ball cord. The operation of the illustrated and described ball cord lock is as follows: the cord pulley 1 is subjected to a counterclockwise directed torque in Figures 1 or 4, for example from a completely or partially wound-up blind supported on the spindle. The run of the ball cord located closest to the wall will, in this situation, be located within the cord locking portion 11 and one of said balls will be retained against the lower peripheral surface of the lock housing as a result of the applied torque. If it is desired to unwind or lower the blind further the ball cord 3 is moved out of the cord locking portion 11 by grasping the portion of the ball cord closest to the wall, and moving that portion forwardly away from the wall so that said portion is inclined at an angle to the vertical so that the ball cord passes through the broader portion 10 onto the pulley 1. Whilst the ball cord is retained at said angle, the cord is permitted to move round the pulley until the blind has reached a desired position whereafter the ball cord is released. The ball cord is then caught by the cord locking portion 11 as a result of the diameter of the balls 4, and because of the comparatively high stiffness of the cord 3. When the blind is to be wound up onto the spindle a downwardly directed force is applied onto the run of the ball cord closest to the wall whereby the balls 4 of the ball cord will slip along the slip plane 12 shown in Figure 4 outwardly towards the lower part of the broader portion 10 thus permitting the ball cord to be withdrawn to rotate the spindle. Hence, the slip plane 12 acts as a guide for the balls of the ball cord during the wind-up of the blind. From the foregoing it will be appreciated that this invention relates especially to a ball cord lock intended to be used for roller blinds and comprising a cord pulley having an axially extending stub axle for receiving and retaining one end of a roller blind spindle, an endless loop of a ball cord arranged around the cord pulley and in engagement therewith and which can be used to wind up and unwind the roller blind attached to said spindle, a lock housing formed by two complementary housing halves which housing constitutes a journal for and encloses the cord pulley, a bracket which is connected to the lock housing and which is intended to be mounted at a window, and a constricted cord locking portion formed in the lock housing for catching and retaining one of the runs of the ball cord loop whereby the rotation of the cord pulley in one direction (and accordingly unwinding of the blind when in the wound-up condition is prevented) and wherein the constricted cord locking portion is arranged immediately adjacent the periphery of the cord pulley under one of the runs of the freely suspended ball cord, the open end of the constricted cord locking portion is directed towards the outer of the runs of the ball cord as shown in Figure 3, and the depth of the constricted cord locking portion increases in the vertical direction from the open part towards the closed part of the portion, the edge surfaces of the cord locking portion located closest to the cord pulley constituting a slip plane for the balls of the ball cord. WHAT WE CLAIM IS: -

1. A cord lock for use with a roller blind, said lock comprising a cord pulley mounted for rotation in a vertical plane within a housing, and endless loop of cord arranged around said pulley, a run of cord depending from each side of the pulley and extending beyond the housing, said cord having a plurality of balls secured thereon at spaced intervals, the cord or balls or both being adapted to engage the pulley, one run of cord passing through an opening in the housing, which opening has a broad portion through which the run of cord together with the attached balls may pass freely and a constricted portion through which only the cord and not the balls may pass, the portions of the housing defining the constricted portion having an upper surface which when viewed in a vertical section inclines downwardly towards said broad portion, the arrangement of the lock being such that when a run of the cord lies within the constricted portion of the opening the run of cord is retained, to prevent the run of cord being wound onto the pulley, by engagement of one of the balls with the part of the housing defining the constricted

portion of the opening, the arrangement of the lock also being such that when the run of the cord lying within the constricted portion is pulled away from the pulley to cause rotation of the pulley a ball on the cord engages and slides along said inclined surface thus causing the cord to move from the constricted portion to the broad portion to permit free movement of the cord.

2. A cord lock according to Claim 1, wherein said narrower portion is im- mediately adjacent the cord pulley.

3. A cord lock according to Claim 1 or 2, wherein the pulley has an axially extending stub axle adapted to engage one end of a roller blind spindle.

4. A cord lock according to any one of the preceding claims wherein the housing is formed of two substantially identical housing halves.

5. A cord lock according to any one of the preceding claims wherein the housing is mounted on a bracket having means thereon to engage and retain a decoration or embellishment on said housing.

6. A cord lock according to any one of the preceding claims being provided with mounting means for' mounting the cord lock on a wall or the like in such a-way that' the run of the cord remote from the wall passes through the broad portion of the opening and the run of the cord closest to the wall normally passes through the narrower portion of the opening.

7. A cord lock- substantially as wherein described with reference to, and as shown in, the accompanying drawings.

8. A roller blind provided with a cord lock in accordance with any one of the preceding claims.