Sash stays, particularly friction casement stays, work by using friction to hold a window open at a desired angle.
Based on the provided reference, streamlined sash holds (a type of sash stay) function without traditional knobs or locking mechanisms. Instead, the flat rod simply slides into a sleeve, creating friction that holds the window open at any point between zero and ninety degrees.
Understanding the Friction Mechanism
This type of sash stay relies on a simple, yet effective, principle: controlled friction.
Here's a breakdown:
- Components: The stay typically consists of a flat rod and a corresponding sleeve or channel. These are usually made of metal or durable plastic.
- Operation: As the window is opened or closed, the flat rod moves within the sleeve.
- Holding Power: The internal design of the sleeve and the surface properties of the rod are engineered to create a specific amount of resistance – friction – when the rod slides. This friction is carefully calibrated.
- Positioning: When the window is stopped at a particular angle, the friction between the rod and the sleeve is strong enough to counteract the weight of the window and external forces like wind, effectively holding the window firmly in that position.
- Adjustment: To move the window, a user applies a slight force, which overcomes the static friction, allowing the rod to slide again until a new position is chosen.
Types of Sash Stays
While the reference specifically details friction stays, it's worth noting that other sash stay types exist, such as:
- Notched Stays: These have a rod with specific notches that lock into a catch, offering fixed open positions.
- Locking Stays: Some have a locking mechanism that can be tightened or loosened to secure the window position.
However, the mechanism described in the reference – the sliding flat rod creating friction within a sleeve – is characteristic of modern, streamlined friction casement stays, offering smooth operation and flexible positioning.
Practical Benefits of Friction Stays
- Infinite Positioning: Unlike notched stays, friction stays allow the window to be held open at any angle within their range (commonly 0 to 90 degrees), offering precise control over ventilation.
- Sleek Design: As mentioned in the reference, many are streamlined with no external knobs, providing a clean look.
- Ease of Use: Simply push or pull the window to adjust the opening; no separate locking action is required.
In summary, friction sash stays utilize the controlled resistance created by a sliding rod within a sleeve to secure a window's position without the need for manual locking points or knobs, offering smooth adjustment and infinite positioning.
