Sash Window Latch Segmentation for Structural Integrity
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Solution Overview
Problem
Conventional latch devices for vertically sliding, inwardly tiltable sash windows require large indentations at the intersecting portions of the frame elements, which weaken the sash and compromise its strength, hermeticity, and watertightness, especially under external wind pressure.
Innovation Solution
A sash window assembly design that eliminates the need for large indentations by using latch devices with a fastening member that projects and retracts vertically, operated by an internal mechanism, and mounted through passage holes in the frame elements, allowing the sash to tilt inward without compromising structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional latch devices are mounted by forming large indentations at the intersecting portions of frame elements, then the latch device can be securely fastened to the sash, but the strength of the sash is reduced and the indentation deforms under wind pressure
Solution Approach 1:
The latch device is divided into separate components: a case mounted in a recess, a fastening member that projects from the case, and an operating member. This segmentation allows the case to be securely mounted in a smaller recess rather than requiring a large indentation, while the fastening member provides the necessary fastening function.
Solution Approach 2:
The mounting approach transitions from requiring a large two-dimensional indentation across the intersecting portion to using a smaller recess in one frame element combined with a projecting fastening member that extends into the other frame element, effectively utilizing the depth dimension.
2Ease of manufacture
If large indentations are formed at the intersecting portions for latch device mounting, then the latch device can be installed, but hermeticity and watertightness are compromised
Solution Approach 1:
The latch device is segmented into a case mounted in a recess and a fastening member that projects separately, allowing the case to be installed in a smaller, more localized recess that does not compromise the overall hermeticity and watertightness of the sash structure.
3Reliability
If the case is fastened with screws in the conventional latch device, then the latch device is securely mounted, but extensive reinforcements are required to prevent strength reduction
Solution Approach 1:
The latch device is segmented into a case that is mounted in a recess using a smaller number of fasteners, and a fastening member that provides additional securing function. This segmentation reduces the need for extensive reinforcements compared to mounting the entire latch device in a large indentation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances the strength and operational reliability of the sash window assembly by preventing deformation under wind pressure and maintaining hermeticity and watertightness without the need for extensive reinforcements.
Implementation Method 1
a spring that urges the engaging member in the projecting direction
Data Source
AI summary
A sash window assembly includes: a window frame having upper, lower, and left and right vertical frame members; and at least one sash guided by the vertical frame members and supported to be openable and closable by being slid vertically. The sash has: latch devices provided respectively at left and right ends in an upper end portion of the sash; an upper frame element having first passage holes formed in a top surface thereof and through which respective operating members of the respective latch devices are exposed toward an indoor space; a lower frame element; left and right vertical frame elements, each having a second passage hole formed in a depth-direction surface of the vertical frame element and through which a fastening section of the latch device is passed; and a face material provided inside the upper, lower, and left and right vertical frame elements.