(1) Field of the Invention
The present invention relates generally to a locking window and, more particularly, to a window latch for such a window.
(2) Description of the Prior Art
Up to the end of World War II, most windows were constructed of wood. However, following the War, aluminum windows were initially constructed for low-end housing. Over time, the clear superiority of metal windows led to their use in many different types of housing. Similarly, vinyl windows were introduced in low-end housing in the beginning of the last decade. The use of vinyl windows has grown much more quickly than metal windows. In fact, the majority of windows are now constructed using vinyl.
During this time, locking windows have generally used metal latches similar to those that were initially used on wooden windows. Now, although vinyl windows are the predominant construction, there has still been a hesitancy to use plastic hardware. However, metal is much heavier than its corresponding plastic counterpart. Also, plastic retains its appearance when mishandled or otherwise misused that would causes unacceptable chips to form on painted metal hardware. Also, in today's global economy, window hardware may be made in another country. Accordingly, advantages of substantial weight savings to create lower shipping costs have become even more important.
However, making a locking window having a plastic latch is more than a mere substitution of materials. Because plastic is generally more flexible than metal, attempts at constructing a window latch have failed since there's not a sufficient amount of support to prevent bowing. The significance of bowing relates primarily due to the requirement that a latch be able to maintain a static load of about 160 pounds. When a conventional latch design is formed from plastics, the bowing of the latch is so substantial that the static load will actually slide off the latch arm. Because of this problem, such plastic window latches having conventional designs have not been able to pass the static load test.
Also, the labor cost for attaching a latch to a window affects the overall cost of a locking window. One factor affecting this cost is the number of fasteners required for attaching a latch to a window. Another factor is the alignment of the window latch on the window. However, reducing the number of fasteners introduces undesirable and unacceptable play of the latch during opening and closing while at the same time making alignment more difficult. The increased difficultly of alignment rather than decreasing cost, increases cost since properly aligning the latch during attachment involves more time.
Thus, there remains a need for a new and improved locking window having a window latch which may be completely formed from chip resistant plastics while, at the same time, still provides sufficient firmness due to its arrangement to resist normal wear and tear during assembly and use.