Slidably mounted building products, such as sliding windows, single hung and double hung windows and sliding doors, are well known in the new construction and remodeling industry. These products are typically operated by a user exerting a sliding-type force on the movable sash in order to open or close the same. As will be appreciated, the amount of force that needs to be exerted can at times be substantial, and thus physically handicapped persons or those persons with inadequate strength may not be able to operate them.
Furthermore, with the advent of so-called "smart homes" it is desired to be able to control electronically or by computer the opening and closing of windows and doors, without the need for a person to be present to open and close the same. Currently existing windows and doors with sliding sashes would be extremely difficult to convert to automatic operation.
In the first half of the 20th century, several patents were issued which disclosed crank type window operating apparatus for slidably mounted windows. For example, Lovell U.S. Pat. No. 1,152,425 shows a double hung window which can be moved up and down by use of a hand crank. The hand crank turns a bevel gear connected to a left-hand rod and a right-hand rod, the rods turning another bevel gear which in turn rotates a longitudinally disposed screw mounted in each of the vertical window frame members. A movable nut is threadably mounted on each screw and is also secured to the window sash. Rotation of the screws causes vertical movement of the movable nuts, which in turn lowers or lifts the window sash in the window frame. See also U.S. Pat. Nos. 1,571,819; 1,966,815; 2,545,449; 2,913,920; and 3,022,065.
Although this prior art has been known for many years, there are today virtually no commercially available slidably mounted doors and windows which are operated by hand crank or motor driven mechanisms. There is, therefore, a need for a modern operating mechanism for slidably mounted building products that is inexpensive as well as easy to use. The mechanism must be useful for windows and doors having wood, metal or polymeric frames and must be reliable and easy to install in both new and existing homes.