Child Safety Device for Looped Cords

1. Field of the Invention

This invention relates generally to looped lift cords of the type used in window coverings such as pleated shades, venetian blinds and Roman shades, and more particularly, the invention relates to safety devices used with such lift cords.

2. Description of the Prior Art

Pleated shades, Roman shades and venetian blinds typically have window covering material or blind slats extending between a headrail and bottom rail and two or more lift cords connected to the bottom rail. Within the headrail is some type of cord locking device. Typically, two or more lift cords are connected at one end to the bottom rail and extend up through the window covering material or blind slats into the headrail. The lift cords then pass through a cord locking device and out of the headrail such that an opposite end of the lift cords is accessible to an operator. These window shades and blinds are typically raised by the operator pulling on the accessible portion of the lift cords and are lowered by releasing the lift cords. Because all lift cords must move in unison, the lift cords are typically tied together or otherwise looped as can be seen in FIG. 1. The lift cords often extend downward from the headrail to within a few feet of floor level.

A second type of lift mechanism for window coverings has a spool within the headrail to which the lift cords are attached. The window covering is raised and lowered by winding and unwinding the lift cords around the spool. A continuous looped cord is provided around one end of the spool. The spool is rotated by pulling on one of the two sides of the loop depending upon whether clockwise or counter-clockwise rotation is desired. Although this lift mechanism operates differently from the first described mechanism, a window covering containing this second type of mechanism would also look very similar to the window covering shown in FIG. 1. This type of lift mechanism is disclosed in my U.S. Pat. No. 5,184,660.

Looped lift cords extending from a window treatment such as is shown in FIG. 1 present an attractive danger to infants or children who may play with the lift cords. There have been several instances in which children and infants have become entangled in such cords and accidentally hanged.

In the past, attempts to reduce the danger associated with these lift cords have focused on moving the lift cords out of the accessible range of infants such as by tying or clipping the cords to shorten them or otherwise moving the lift cords away from floor level and away from the infant's reach. Moving the cords out of the way after use is troublesome, and the operator must remember to move the cords after each use. Other attempts have focused on a detachable connection of the ends of the lift cords such as is disclosed in U.S. Pat. No. 4,909,298 to Langhart et al. Detachable lift cords require a certain level of force to detach. Moreover, recent tests of the commercially available embodiment of the Langhart patent have shown that this product failed to detach in simulated entanglements. Moreover, a detachable tassel cannot be used with the spool type lift mechanism which requires continuous rotation of the looped cord around the spool.

Thus, there is a need in the industry for a safety device to reduce the danger associated with looped lift cords which is reliable and which does not require any separate actions by the operator. Such a device must operate efficiently, yet be aesthetically pleasing. It must be inexpensive and easy to install, particularly on window coverings which are hanging in a window.

The cords used for the first type of lift mechanism are typically made of woven cotton polyester materials. For the spool type lift mechanism the looped cord may be woven or may be a bead chain. There is a need for a safety device which can be used with both woven cords and bead chains.

I provide a safety device for reducing the dangers associated with looped lift cords of a window covering assembly. The device is easily fitted over the cord before, during or after installation of the window covering on a window.

The safety device generally has a main body containing a channel through which the looped cord travels, an anvil is present at the base of the channel. Above the anvil is a blade which is spring biased in the up position. Preferably, the blade is attached to a movable plunger. Alternatively, the blade can be positioned near the plunger. Should a child become entangled within the loop of the cord, that action would force the plunger to move the blade against the anvil thereby cutting that portion of the cord within the cord channel. In this way the loop is broken and the child is free.

The safety device preferably has a cover which fits over the cord channel to retain the looped cord therein. The cover is designed such that after the cord is placed in the channel and the cover is closed, the cover cannot be readily removed.

I prefer to use a V-shaped blade. This shape provides more efficient cutting action. Additionally, it is less likely that a person could cut himself with such a blade when installing the safety device. After the safety device is installed the blade is fully enclosed and poses no danger .

FIG. 1 is a prior art window shade assembly affixed to a window showing a looped lift cord.

FIG. 2 is a perspective view of a present preferred safety device attached to a looped lift cord on a pleated shade which has been lowered to a closed position.

FIG. 3 is a view similar to FIG. 2 in which the window shade has been raised to an open position.

FIG. 4 is an exploded perspective view of the first preferred safety device in FIGS. 2 and 3 with the cover removed.

FIG. 5 is a cross-sectional view of the first preferred safety device shown in FIGS. 2 and 3 with the plunger in an up position taken along the lines V--V.

FIG. 6 is a sectional view similar to FIG. 4 with the plunger in a depressed position.

FIG. 7 is a cross-sectional view taken along the line VII--VII of FIG. 2.

FIG. 8 is a cross-sectional view of a second present preferred embodiment of my safety device with the plunger in an up position.

FIG. 9 is a sectional view showing the embodiment of FIG. 8 with the plunger in a depressed position.

FIG. 10 is a sectional view taken along the line X--X of FIG. 8.

FIG. 11 is a cross-sectional view of a third present preferred embodiment of my safety device with the plunger in an up position.

FIG. 12 is a sectional view showing the embodiment of FIG. 11 with the plunger in a depressed position.

FIG. 13 is a is side view of the embodiment of FIGS. 11 and 12.

FIG. 14 is a sectional view showing a fourth present preferred embodiment of my safety device.

FIG. 15 is a top plan view of an alternative blade which can be used in the safety device.

The present invention can be used with any type of window covering which uses looped lift cords including pleated shades, roman shades and venetian blinds. Although the present preferred embodiments are shown and described in use with pleated shades, the invention is not so limited.

An example of a window covering having a cord which forms a loop is shown in FIG. 1. This window treatment product 2 could be a pleated shade, roman shade or venetian blind. When the window covering is in an open position, the cord 4 typically extends below the window sill 6 and can be easily reached by young children.

In FIGS. 2 and 3 a pleated shade 10 is shown in an open and closed position. The pleated shade typically has a top rail 14, bottom rail 16 and pleated material 12 therebetween. A lift cord 18 extends through the pleated material into the headrail. The lift cord may continue through the cord lock 20 forming a looped cord 28 and run back through the headrail and an opposite side (not shown) of the window covering to the bottom rail. Alternatively, the lift cord 18 may be attached to a spool (not shown) in the headrail about which the cord 18 is wrapped. A first present preferred embodiment of my safety device 30 is attached to the looped cord 28. The inside of the safety device 30 is shown in FIGS. 4 thru 7. Referring now to these figures, the safety device 30 generally is comprised of a main body 32 having an anvil 42 and adjacent cord channel 40 through which the looped cord 28 passes. If desired, weights 33 (shown in chain line in FIG. 5) may be placed within the main body 32. Positioned above the anvil is a plunger 34 having a blade 44 attached thereto. Bosses 54 are positioned on the plunger 34. These bosses are sized to fit within cavity 55 and permit the plunger to move the blade 44 into the cord channel 40. This arrangement prevents plunger 34 from being pulled from the body 32 after the cover 46 has been attached. At least one spring 36 is provided between the plunger 34 and the main body 32 to bias the plunger away from the cord channel 40. When a force acts upon the plunger 34 in the direction of the anvil 42, the plunger 34 will move to the position shown in FIG. 6. During that movement the blade 44 passes through the cord channel 40, and cuts the looped cord 28 passing therethrough into two portions 28a and 28b. Since the severed portions 28a and 28b of the cord can freely pass through the cord channel 40, the safety device 30 will fall from the severed cord and the loop will be broken. A child or animal that had been caught in the loop is freed as the severed portions 28a and 28b of the cord separate. At that point the owner of the shade will be required to replace the looped lift cord but accidental hanging or other tragedy has been averted.

As can be seen in FIG. 7 I prefer to provide a cover 46 which fits over the main body 32 and much of the plunger 34. The cover has a stake 47 which fits within a hole 48 in the main body 32. The stake 47 secures the cover 46 against the body 32 as shown by the dotted line in FIG. 4. Preferably, the stake 47 and hole 48 are sized and configured to prevent removal of the cover 46. Alternatively, one could use a screw in place of stake 47. Consequently, after the safety device has been placed on the looped cord 28 there is no access to the blade. I also prefer to provide a cord channel 41 within cover 46. This could be sized to carry a second cord or to complement cord channel 40 in receipt of a single cord. Alternatively, one could configure cord channel 40 to carry two or more cords.

The child safety device preferably would be sold with the cover separate from the main body. The installer or owner of the window covering would lay the cord in the cord channel 40 then snap the cover 46 over the body 32.

I prefer to use a V-shaped blade as shown most clearly in FIGS. 4 and 7. This shape has two opposed cutting edges 50 and 52. One could also use a single blade preferably angled as shown in the embodiment of FIG. 10. However, the V-shaped blade is less likely to cut the finger of the person placing the cord in the channel. Moreover, one third to one half less force must be applied to cut a cord with the V-blade than is required to cut the cord with a straight blade.

As can be seen from the second embodiment shown in FIGS. 8, 9 and 10, the safety device could be disk shaped. This embodiment 60 is comprised of a body 62 and attached cover 61. Within the body 61 are cord channel 63 and anvil 65, plunger 64, spring 66 and blade 68. The cord channel 63 is U-shaped and follows the exterior contours of the main body 62. In this embodiment a single angled blade 68 is used.

From FIG. 10 it should be apparent that the blade 68 could be pivotably or otherwise moveably attached to the main body 62 and not attached to the plunger. Such an embodiment is shown in FIG. 14. Although the blades 44 and 68 shown in the first two embodiments are V-shaped or diagonally oriented relative to the cord channel, other blade shapes and orientations could be used. For example, in FIG. 15 a suitable blade 90 having a curved cutting edge 92 is shown.

Although the first two present preferred embodiments are shown with a woven cord, the safety device could also be used on a beaded chain as shown in FIGS. 11 thru 13. Beaded chain 80 is comprised of a series of plastic beads 86 along a plastic or woven cord 84. The third preferred embodiment shown in FIGS. 11 thru 13 is similar to the other embodiments. There is a main body 74 having a cord channel 75 with slotted anvil 69. Cover 73 is attached to the main body after the beaded cord 80 has been placed in the cord channel 75. A plunger 76 having an attached blade 77 is fitted within the main body 74. I prefer to provide a pin 72 with an enlarged head 82 and slot 71 with a recess 81 to keep the plunger 76 held within the body. The enlarged head prevents removal of the plunger 76 from the body 74. Springs 78 are provided to bias the plunger 76 in an up position. Within the body 74 indexing means 79 are provided adjacent the blade slot 89 to index the beaded chain 80 that passes through the cord channel 75 so that a bead 86 is not adjacent the blade channel 89 whenever the safety device is freely hanging on the beaded chain. Therefore, when the plunger 76 is activated the blade 77 can easily cut the cord portion 84 rather than strike a bead 86.

In the fourth present preferred embodiment shown in FIG. 14, the blade 93 is located within blade cavity 91 and pivotably attached to the body 94 at pivot pin 95. When the plunger 96 is depressed the head 97 of the plunger will push the blade 93 causing it to pivot about pin 95 and cut the cord 98 within cord channel 99.

The present safety device is preferably made of molded plastic such as polycarbonate. The body and plunger are plastic and the spring is a plastic web. If desired, metal filings or other material could be added to the plastic during molding to increase the weight of the device.

While certain present preferred embodiments have been shown and described, it is distinctly understood that the invention is not limited thereto but may be otherwise embodied within the scope of the following claims.