Window coverings serve multiple functions. For example, window coverings may be used to shield or filter light, provide privacy, enhance security, and/or function as a decorative piece for a particular space or room. Common window coverings include blinds and roller shades.
Both blinds and roller shades typically use a bracket assembly located at the top or above the window to support the blinds or roller shade. To control the extent that a blind or shade is open, conventional systems often rely on simple mechanical controls, such as a ratchet and pawl mechanism or a clutch and chain system, to move the blind or shade up and down, and to position the shade at intermediate locations along a predetermined extent of travel.
As roller shade designs evolved, motor powered shades were desired. Motorization of the roller shade was accomplished, in one example, by replacing the simple, mechanical control system with an electric motor that is directly coupled to the shade tube. The motor may be located inside or outside the shade tube, is fixed to the roller shade support and is connected to a simple switch, or, in more sophisticated applications, to a radio frequency (RF) or infrared (IR) transceiver, that controls the activation of the motor and the rotation of the shade tube.
Many known motorized roller shades provide power, such as 120 VAC, 220/230 VAC 50/60 Hz, etc., to the motor and control electronics from the facility in which the motorized roller shade is installed. Recently-developed battery-powered roller shades provide installation flexibility by removing the requirement to connect the motor and control electronics to facility power. The batteries for these roller shades can be mounted within, above, or adjacent to the shade mounting bracket, headrail or fascia.
Often it is desirable to couple a group of blinds or shades move in unison. There are several conventional ways to mechanically link blinds or shades together so that the blinds or shades move in unison, particularly when actuated by motorized control. For example, flex cable systems may be used to transmit the rotational force between multiple shades and blinds. However, these conventional systems often induce substantial parasitic drag and require excessive power to operate. For battery powered blinds and shades, the need for excessive power to overcome the difficulties of conventional systems can quickly drain the power source, resulting in the frequent loss of automated control and the accompanying need to constantly replace the batteries to restore operation. Accordingly, it is desirable to provide a method and apparatus for linking a group of blinds or roll shades to reduce parasitic power loss when in a motorized configuration while maintaining aesthetic appeal and convenience of use.