Cord locking mechanism

A locking mechanism for the control cords of a window blind extends partially into the headrail of a window blind, and a cord separation member on the portion of the mechanism within the headrail has discrete openings through which the cords pass and are separated as they enter the mechanism. A guide pin is positioned transversely across the upper end of the mechanism with one end of the guide pin being disposed nearer the separation member and lower than the other end, so that the cords passing over the pin may be rotated to a selected side of this portion of the mechanism. A cord gripping means is mounted below the guide pin, and includes a fixed gripping member disposed centrally within the second portion of the mechanism, and a movable gripping member is mounted within this second portion of the mechanism for gripping the cords therebetween. The separation member, guide pin and movable gripping member are all positionable alternatively for either left hand or right hand operation of the locking mechanism. A clip having downwardly depending legs and outwardly extending end portions wider than the opening in the headrail is inserted downwardly through the top of the headrail behind the front panel of the headrail to lock the locking mechanism in place within the opening in the headrail.

BACKGROUND OF THE INVENTION 
This invention relates to a cord locking mechanism for the control cords of 
a window blind or the like, and particularly to a cord locking mechanism 
which will firmly and simultaneously grip a number of control cords, and 
which can be quickly mounted and selectively operated in either a right 
hand or left hand position. 
Quite frequently, window blinds, such as pleated window shades, are 
operated by a number of cords which extend down the blind or shade at 
intervals and control the raising and lowering of the shade. The locking 
mechanism, which is mounted to one side or the other on the headrail of 
the blind or shade, locks the cords in place and thus permits the blind or 
shade to be locked into a selected raised position, and the mechanism must 
be capable of handling several cords. The problem has been that with a 
multitude of cords, the cords invariably become twisted and bunched, 
making it difficult for the locking mechanism to grip all of the cords 
firmly and simultaneously. 
In addition, a cord locking mechanism may be used on either side of the 
window blind, so that the control cords may be located at either side, and 
it is preferable that each individual locking mechanism be capable of 
either left hand or right hand operation so that the inventory of locking 
mechanisms can be minimized. Moreover, the locking mechanism must be 
capable of being mounted quickly and easily in position on the headrail of 
the shade or blind. 
With the present invention, the locking mechanism separates the cords and 
maintains them in a separated condition so that they may be individually 
and uniformly gripped within the locking mechanism, and twisting and 
bunching of the cords will be minimized. The cords are thus firmly and 
simultaneously gripped. The locking mechanism constructed in accordance 
with the invention is adapted for either left hand or right hand 
operation, with a simple reorientation of several parts of the mechanism, 
and it may be quickly and easily mounted in position on the headrail of 
the blind or shade. 
SUMMARY OF THE INVENTION 
In accordance with this invention, a cord locking mechanism is provided for 
a plurality of cords of a window blind or the like, into which the window 
cords extend in a substantially horizontal direction and from which the 
cords extend in a substantially vertical direction. The mechanism includes 
a cord separation means, for separating the cords substantially 
horizontally as they enter the mechanism. A guide means is positioned 
inwardly from the cord separating means, and the cords extend over this 
guide means substantially horizontally and from the guide means 
substantially vertically. Cord gripping means is positioned below the 
guide means, and includes a pair of gripping members for receiving the 
cords between them. At least one of the gripping members is movable 
selectively either toward the other gripping member to grip the cords and 
prevent vertical upward movement of the cords, or away from the other 
gripping member to release the cords and permit vertical upward movement 
of the cords therebetween. 
The locking mechanism preferably has an inner body portion and an outer 
body portion. The inner body portion is adapted to be inserted into the 
headrail of the blind, and houses the cord separation means, and the outer 
body portion is adapted to abut the headrail of the blind and house the 
guide means and the cord gripping means. 
It is preferred that a substantially U-shaped resilient clip, having 
downwardly pending legs and outwardly extending end portions, be providing 
for insertion behind the front panel of the headrail through the top of 
the headrail in order to lock the mechanism in place with the outer body 
portion abutting the outside of the headrail, and the end portions of the 
clip abutting the inside of the headrail. 
It is preferred that the cord separation means consist of a separation 
member having a plurality of discrete openings for accommodating and 
separating the cords, and that there be means for removably attaching this 
cord separation member to the inner body portion of the mechanism in one 
of two alternate oblique positions, so that the cords may enter the 
separation member alternatively from either side of the inner body 
portion. It is also preferred that the guide means consist of a guide pin 
and a means for mounting the guide pin transversely across the upper end 
of the outer body portion, alternatively in one of two positions, with one 
guide pin end disposed nearer the inner body portion and lower than the 
other guide pin end, so that the cords passing over the guide pin may be 
rotated to a selected side of the outer body portion. 
It is further preferred that one of the gripping members of the cord 
gripping means be mounted in fixed position centrally within the outer 
body portion, and that the second gripping member be mounted alternatively 
on one side or the other of the first gripping member for movement toward 
and away from the first gripping member to respectively grip and release 
the cords, and permit selective left hand or right hand operation of the 
locking mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The cord locking mechanism 10 of this invention is illustrated in FIGS. 1 
and 2 mounted on the headrail 12 of a pleated window shade 14 having a 
bottom rail 16. The window shade, including the headrail 12 and the bottom 
rail 16, is of standard construction with a plurality of cords 17 
extending through the headrail 12, and then downwardly to engage the 
bottom rail 16 so that the bottom rail may be raised and lowered as 
desired in the usual and well-known manner. The locking mechanism 10 is 
adapted for right hand and left hand operation, that is, for mounting on 
either the left hand side or the right hand side of the headrail 12. The 
mechanism is mounted within an opening 12a on the front face of the 
headrail 12. In FIG. 1, the mechanism 10 is shown mounted on the right 
hand side of the headrail, and in FIG. 2, the mechanism is shown mounted 
on the left hand side of the headrail. 
The locking mechanism 10 is best illustrated in FIG. 3, and includes a body 
consisting of a horizontal first or inner body portion 18 and a vertically 
extending second or outer body portion 20. In the preferred embodiment, 
these two body portions 18 and 20 are integrally formed and molded of a 
plastic material, although they could be formed separately and molded of 
any other type of material. 
The inner body portion 18 has a flat bottom 22 and a pair of parallel 
siderails 24 and 26. The upper portions of the siderails 24 and 26 extend 
inwardly toward each other for a slight distance, and thus overhang the 
bottom 22 of the inner body portion to provide grooves adjacent the bottom 
22 of this inner body portion. 
A cord separator 28 has an integral flat base 30 which is substantially 
square and has four downwardly sloping sides, 30a, 30b, 30c and 30d. The 
upper portion of the cord separator 28 is a rectangular block having a 
plurality of round holes 32 therein, and it extends diagonally across the 
square base 30. The holes 32 are staggered as best seen in FIGS. 3-5 where 
7 holes are shown. This arrangement results in total separation of the 
cords and accommodates nearly twice as many cords as could be accommodated 
by other separation means, such as for example pins. The downwardly 
sloping sides 30a-d of the separator base fit within parallel grooves 
formed by the siderails 24 and 26 of the inner body portion 18, and since 
the separator base 30 is square, the separator 28 may be orientated with 
its appertured upper portion disposed either diagonally in the orientation 
of FIGS. 3 and 6 or diagonally in the orientation of FIG. 9, depending 
upon whether the sloping sides 30c and 30d are in engagement with the 
rails 24 and 26 as shown in FIGS. 3 and 5, or whether the sloping sides 
30a and 30b are in engagement with these rails as shown in FIG. 9. The 
cord separator 28 and its base 30 may be removed by sliding the base to 
the right as viewed in FIGS. 2 and 4, and it may be reinserted in either 
the right hand or the left hand orientation. It will be noted that the two 
alternative positions of the separator 28 are substantially perpendicular 
to each other. The cord separator 28 separates the cords as they enter 
into the cord locking mechanism 10 from the headrail 12 of the window 
shade, as best shown in FIGS. 6-9. 
The outer body portion 20 of the cord locking mechanism is hollow, having 
side walls 20a and 20b, a rear wall 20c and a front wall 20d. Across the 
top of this outer body portion there is positioned a single guide pin 34 
the orientation of which is unique and serves to hold the cords in their 
separated condition while directing them within the hollow outer body 
portion 20. In order to mount this guide pin in its desired position of 
adjustment, there are provided on the left hand side of the outer body 
portion a pair of slots 36a and 36b, and on the right hand side, there are 
corresponding slots 38a and 38b. The innermost slots, 36b and 38b, are 
longer (deeper) than the outermost slots 36a and 38a, and the guide pin 34 
in the right hand orientation of the mechanism as viewed in FIGS. 3 and 4, 
is disposed with one end in slot 36a and the other in slot 38b. In this 
orientation the right hand end of the pin 34 will be disposed nearer the 
inner body portion 10 than the left hand end, and the right hand end of 
the pin will also be disposed lower than the left hand end because the 
slot 38b is longer than the slot 36a. 
This inwardly and downwardly angled orientation of one end of the pin from 
the other end guides the cords 17 to one side or the other of the interior 
of the outer body portion 20, as may be seen from a comparison of FIGS. 6 
and 9. In the left hand orientation as shown in FIG. 9, the pin 34 extends 
between the slot 38a and the slot 36b, with the end of the pin in slot 36b 
being disposed inwardly nearer the inner body portion 18 and lower than 
the end of the pin which is disposed in slot 38a. Thus the cords 17 will 
be directed to the left hand side of the interior of the outer body 
portion 20 in this orientation of the guide pin 34. 
Disposed within the hollow outer body 20, below the guide pin 34, is a 
fixed gripping member 40 in the form of a pin which extends through a 
through-hole 42 in the rear side of the outer body portion 20 (see FIG. 
5). The opposite end of the fixed gripping member pin 40 extends into a 
blind hole 44 in front wall 20d of the outer body portion. The pin 40 thus 
is mounted in fixed position centrally in the interior of the hollow outer 
body portion 20 below the guide pin 34, and it extends axially, i.e. 
between the front face 20d and the rear face 20c of the outer body 
portion. 
Carved in the interior of the front wall 20d of the outer body portion 20 
are a pair of vertical channels 46 and 47, which are connected at the top 
by a carved-out horizontal connecting portion 48. A similar pair of 
channels 49 and 50 are carved in the interior of the rear wall 20c of the 
outer body portion and these channels are connected at the top by a 
carved-out horizontal connecting portion 51. The slots 46, 47, 49 and 50 
provide a mounting for a movable gripping member 52 in the form of a 
roller having a knurled surface. This movable gripping member or roller 52 
has outwardly extending axle ends 54 and 55 which fit within the opposing 
channels in the front and rear walls 20d and 20c of the outer body portion 
20. In FIGS. 1 and 3-8, this roller 52 is mounted with the axle ends 54 
and 55 in the channels 47 and 50 respectively. The axle ends and channels 
are of such size that the movable gripping member knurled roller 52 may 
move upwardly in the channels freely and may rotate freely. The channels 
are preferably so located and the roller 52 of such size that the roller 
will not freely move past the fixed pin 40 but it may be pushed past this 
pin by a small force. After the roller 52 has been forced upwardly past 
the fixed pin 40 the axle ends 54 and 55 will reach the carved-out 
portions 48 and 51 in the front and rear walls of the outer body portion. 
These carved-out horizontal connecting portions are in effect horizontal 
channels through which the axle ends 54 and 55 of the roller move beneath 
the guide pin 34. The roller may be moved within these horizontal channels 
laterally over the fixed pin 40 and beneath the guide pin 34, without 
removing the guide pin, until the axles 54 and 55 reach the vertical 
channels 46 and 49, at which time the movable gripping member roller may 
move downwardly and be forced past the fixed gripping member pin 40 on the 
left side to the bottom of the slots 46 and 49, and to the position 
illustrated in FIGS. 2 and 9. 
This capability of moving the roller 52 from one set of vertical channels 
to the other within the body portion 20, without removing the guide pin 34 
is important. The roller will stay in proper orientation during this 
movement and cannot drop out of the body 20 because the angularly disposed 
guide pin 34 will prevent it. Of course once the roller 52 has been 
repositioned the guide pin 34 may then be removed and repositioned as has 
been described. 
It is preferred that the knurled roller 52 be coated with a high lubricity, 
environmentally and chemically resistant coating. One such coating which 
has been found particularly useful an aerospace coating called Everlube 
6150 manufactured by EM Corporation of West Lafayette, Ind. This is an 
aluminum pigmented coating, qualified to Boeing Material Specification BMS 
10-85E, Type I, Class A and Class B and designed to meet National 
Aerospace Standard NAS 4006. This prevents binding of the roller 52 
against the inner walls 20c and 20d. This coating is controlled 
dimensionally to aerospace tolerance controls (+/-0.0002 inches) to 
prevent build-up, but allows sufficient coating and lubricity to provide 
for continuous, dependable operation and movement of the roller. 
As may be best seen in the perspective view FIGS. 1 and 2, and in the top 
plan views of FIGS. 6 and 9, the outer body portion 20 of the cord locking 
mechanism is wider than the inner body portion 18. The inner body portion 
is of a width and height which will permit it to pass through the opening 
12a in the front face of the headrail 12. This may be seen in FIGS. 6 and 
7. The opening 12a extends upwardly into the top of the headrail 12, which 
is shown in FIG. 7 and in FIGS. 1 and 2. A pair of vertical channels 56 
and 57 are formed on opposite sides of the inner body portion 18, spaced 
just inwardly from the junction of that body portion with the outer body 
portion 20. A substantially U-shaped metal clip 58 has downwardly 
depending legs 59 and 60, the ends 59a and 60a of which are flared 
outwardly. 
When the inner body portion 18 is inserted into the opening 12a of the 
headrail 12, the shoulders formed by the sidewalls 20a and 20b of the 
outer body portion will abut the front face of the headrail 12 outside of 
the opening 12a, and clip 58 may be inserted downwardly through the 
opening which extends into the top of the headrail. The downwardly 
depending legs 59 and 60 of the clip will be guided by the vertical 
channels 56 and 57 respectively, and the outwardly flared end portions 59a 
and 60a, which must be squeezed inwardly in order to pass into the opening 
12a in the top of the headrail, resume their normal flared-out position 
behind the front face of the headrail 12, as best shown in FIG. 6. Thus, 
the clip 58 will lock the cordlock mechanism 10 in position within the 
opening 12a of the headrail 12, with the shoulders formed by the sidewalls 
20a and 20b of the outer body portion 20 engaging the outside surface of 
the headrail front wall and the outwardly-flared end portions 59a and 60a 
of the clip 58 engaging the inside surface of the headrail front wall. 
The cord locking mechanism 10 is adapted to be operated in either the left 
hand or the right hand position, that is, either to the right or the left 
side of the headrail 12. In FIG. 1, the right side operation is shown, and 
in FIG. 2, the left hand operation is shown. In order to prepare the 
cordlock for the right hand operation, the knurled roller forming the 
movable gripping member 52 is inserted into the outer body portion 20 
through the top, with the axle ends 54 and 55 in the vertical channels 47 
and 50 respectively. Pressure is applied to the knurled roller to move it 
downwardly past the fixed gripping member pin 40 to the bottom of the 
slots 47 and 50. 
Next, the diagonal guide pin 34 is inserted, one end being disposed in slot 
36a of the sidewall 20a, and the other end resting in slot 38b of the 
sidewall 20b of the outer body portion. Since the slot 38b is closer to 
the inner body portion 18 than the slot 36a, the pin 34 will be diagonally 
oriented as shown in FIG. 6, and since the slot 38b is longer than the 
slot 36a, the bottom of the pin which is nearest the inner body portion 18 
will also be lower than the opposite end of the pin 34. The cord separator 
28 is then assembled in the inner body portion 18 in the right hand 
position as shown in FIGS. 1 and 6. The cord separator 28 is diagonally 
angled so that the cords 17 may enter it from the left. This means that 
the sides 30d and 30c of the separator base 30 are inserted in the grooves 
formed by the side rails 24 and 26 as shown in FIGS. 5 and 6. The cords 17 
are then inserted through the apertures 32 in the cord separator 28. They 
are pulled over the guide pin 34, and then inserted downwardly between the 
fixed gripping pin member 40 and the movable gripping member knurled 
roller 52 as shown in FIGS. 6 and 7. The cords 17 exit from the cord 
locking mechanism 10 in a vertical direction. 
To lock the cords in position, they may be pulled vertically downwardly and 
then allowed to move upwardly. Since in this vertical position the cords 
will engage the knurled surface of the movable gripping member roller 52, 
the roller will be drawn upwardly in the slots 47 and 50 as the cords are 
allowed to move upwardly until the cords 17 are pinched between the fixed 
gripping member pin 40 and the movable gripping member knurled roller 52 
to lock the cords in position as shown in FIGS. 6-8. To release the cords, 
the cords are angled to the left in FIG. 1 and pulled downwardly. This 
will release the movable gripping member 52, and it will drop to the 
bottom of the channels 47 and 50. The cords may then move upwardly through 
the cord locking mechanism and into the headrail 12. 
In rigging the locking mechanism 10 for left hand operation, the movable 
gripping member 52 is inserted on the left hand side of the cord mechanism 
outer body portion 20, as shown in FIGS. 2 and 9, with the end axle ends 
54 and 55 extending into the channels 46 and 49 on the left hand side of 
the outer body member interior. The guide pin 34 is inserted across the 
top of the outer body portion diagonally opposite to that of the right 
hand rigging, with the left hand end of the pin being in slot 36b and the 
right hand end being in slot 38a. Since slot 36b is longer than slot 38a, 
the left hand end of the pin will be lower and will be angled toward the 
inner body portion 18 of the mechanism, as illustrated in FIG. 9. 
The cord separator 28 is then assembled in the inner body portion 18 in the 
left hand position as shown in FIG. 9, with the downwardly sloping sides 
30a and 30b of the separator base 30 disposed within the grooves formed 
under the upwardly and inwardly extending side rails 24 and 26. The cords 
are then threaded through the apertures 32 from the right hand side and 
are passed over the guide pin 34 as illustrated in FIG. 9, and then 
downwardly between the fixed gripping member pin 40 and the movable 
gripping member roller 52. The operation of the locking mechanism 10 in 
the left hand position is identical with that of the right hand operation 
except that the movable gripping member roller 52 is released from 
gripping engagement with the cords by pulling the cords downwardly and to 
the right. 
It may be seen that the cords are separated uniquely by the apertured cord 
separator 28, each of the cords 17 extending through a separate one of the 
apertures 32 in the cord separator. The guide pin 34 is oriented similarly 
to that of the cord separator. That is, in the right hand rigging the 
right end of the pin 34 will be disposed inwardly from the left end and 
the right end of the separator 28 will also be disposed inwardly from the 
left end (See FIG. 6). In the left hand rigging, the left end of the pin 
34 will be disposed inwardly from the right end and the left end of the 
separator will be disposed inwardly of the right end. Since the end of the 
guide pin 34 nearest the inner body portion 18 and the separator 28 is 
lower than the opposite end of the pin, the cords which have been 
separated by the separator 28 will be guided or rotated to the right side 
of the interior of the outer body portion 20 of the mechanism, and then 
downwardly between the fixed gripping member pin 40 and the movable 
gripping member knurled roller 52. As they extend from the separator 28, 
over the guide pin 34 and between the gripping members 40 and 52, the 
cords will remain separated and they will be prevented from bunching and 
overlapping one another, thereby assuring that there will be a firm grip 
on all of the cords, and that they will be gripped evenly and uniformly 
between the movable gripping member knurled roller 52 and the fixed 
gripping member pin 40. 
The foregoing description has been given by way of example, and numerous 
modifications may be made in the specific structure illustrated without 
departing from the spirit and scope of the invention as hereinafter 
claimed.