The present invention relates to a kit for modifying a control mechanism of a window blind, and in particular to an easily retrofitable kit for adapting a conventional, cord-operated, window blind for use with a drive motor of a conventional blind remote control unit.
Vertical blinds have become increasingly popular over the past several years. Such blinds typically include a head rail containing tracks extending the length thereof for slidably supporting a plurality of vane carriers, a plurality of vanes suspended from the carriers, a pivot rod extending through the carriers permitting sliding or traversing of the vanes between open and closed positions at one or both ends of the headrail, and a gearing system between the pivot rod and each carrier, whereby rotation of pivot rod causes a corresponding, simultaneous pivoting of the vanes.
The carriers and vanes are usually moved between the open and closed positions using a loop of cord suspended from a control housing at one end of the head rail. The cord is connected to the carrier at the other end of the blind, so that pulling on one side of the cord loop moves the vanes in one direction, and pulling on the other side of the loop moves the vanes in the opposite direction. During opening or closing of the blind, the carriers slide along the stationary pivot rod.
It is common to provide vertical blinds with either manual or powered mechanisms for pivoting the vanes. In the case of a manual system, a pulley within the control housing is coupled to the pivot rod, usually via a gear set within the control housing. In some cases, the pulley is directly coupled to the pivot rod by means of a direct coupler. A control chain is looped onto the pulley and is suspended below the control housing so that the pivot rod can be rotated in either direction by pulling on an appropriate side of the chain. The gear set between the pulley and the pivot rod controls the rotation speed of the pivot rod, relative to the pulley, to ensure that the vanes can be pivoted between fully open and fully closed positions without requiring the user to apply excessive forces to the chain.
Alternatively, a powered mechanism can be used to rotate the pivot rod. In this case, a motorized drive unit, which may be remotely controlled, has an output shaft directly coupled to the pivot rod. Typically, the drive unit will include an internal gear set, which will cause the output shaft to rotate at a speed which will pivot the vanes from fully opened to fully closed positions in a reasonable amount of time, while allowing the motor itself to turn at a suitable speed selected for efficiency, and performance.
An owner of a manually controlled blind may wish to convert the blind to utilize a remotely controlled drive unit. This raises several difficulties. For example, the conventional manual mechanism is designed to rotate the pivot rod via a built-in gear set, and the input speed of that gear set is unlikely to be compatible with the output shaft speed of the conventional motorized drive unit. Thus installing a conventional motorized unit requires either replacement or extensive modification of the manual control system. Either of these alternatives is generally too complex to be satisfactorily performed by the owner of the blind. This problem severely limits the market for remote control systems, because they cannot be sold to owners of pre-existing manual blinds as a "do-it-yourself" retrofit.