Moving Bridge CMM Leg Recess for Full X-Axis Measurement
Solution Overview
Problem
Moving bridge type coordinate measuring machines face limitations in measuring parts with wide widths due to interference issues between the quill and the primary leg, restricting the usable X-axis measuring range and requiring costly extensions to access the full planar surface without increasing the machine's footprint.
Innovation Solution
A recess or 'pocket' is formed in the primary leg of the moving bridge assembly to accommodate the quill, allowing it to translate further without interference, enabling measurement of parts covering the full planar surface area without significant cost or footprint expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the primary leg has a wide width and long length for stability, then the stability of the moving bridge assembly is improved, but the usable X-axis measuring range is reduced due to quill interference
Solution Approach 1:
The primary leg is designed with non-uniform cross-section: the upper portion (where the quill operates) has a reduced width creating clearance, while the base portion maintains a wide width for stability. This local variation in dimensional quality allows the leg to simultaneously provide stability through its base while accommodating the quill's full X-axis travel range without interference.
2Adaptability or versatility
If the cross slide and quill are positioned near the primary leg end, then measurement coverage is improved, but interference between the quill and primary leg occurs
Solution Approach 1:
The primary leg's cross-sectional width is reduced in the upper region where the quill passes, creating a local clearance zone. This allows the quill to reach the extreme ends of the cross member for maximum measurement coverage without colliding with the primary leg, while the base of the leg maintains its full width for structural stability.
3Area of stationary object
If table extension is added to allow quill access to complete planar surface, then measurement area is improved, but cost and footprint are significantly increased
Solution Approach 1:
Instead of extending the table or base to increase the measurement area (adding external elements), the invention inverts the approach by modifying the primary leg itself - reducing its upper width to create clearance. This allows the existing table area to be fully utilized without any extensions, avoiding increased cost and footprint while achieving complete surface access.
Data Source
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AI summary
A recess or pocket is formed in at least one leg of a moving bridge assembly of a coordinate measuring machine, and in a particular embodiment in a primary leg of a moving bridge assembly, to permit a quill to move farther in the X direction to an end of a planar base surface of the coordinate measuring machine adjacent the leg without interfering with the leg. The recess formed in the leg of the moving bridge assembly permits coordinate measurements of a part whose width covers the full area of the planar surface of the base, without necessarily adding significant cost or increasing the footprint of the measurement system.