Optical Lens Centering Spindle Layout to Prevent Clamping Imprints
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Solution Overview
Problem
Existing centering machines for optical lenses with curved surfaces face issues such as high internal friction, tilting, and surface damage during the bell clamping process due to transverse forces and uneven force distribution, which can lead to 'imprints' and other surface damage.
Innovation Solution
A centering machine design featuring coaxially arranged lifting and clamping devices with an annular piston, ensuring no transverse forces are introduced during the clamping process, and a moving coil drive for sensitive force control, maintaining precise axial alignment and avoiding surface damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional lifting and clamping devices are used in the centering machine, then the clamping force can be applied to hold the lens, but transverse forces are introduced causing tilting, bending, and surface damage
Solution Approach 1:
The patent applies asymmetry by positioning the lifting device and clamping device at different radial locations relative to the centering axis. The lifting device is arranged at a first radial location while the clamping device is arranged at a second radial location that is offset from the centering axis. This asymmetric arrangement creates a moment arm that allows the clamping force to be applied without introducing transverse forces that would cause tilting or bending of the lens, thereby maintaining alignment precision while achieving secure clamping.
2Ease of operation
If the clamping bells apply pressure to align the lens, then automatic alignment occurs, but the hard contact areas create 'imprints' and surface damage
Solution Approach 1:
The patent applies parameter changes by carefully controlling the contact pressure parameters between the clamping bells and the lens. The lifting device is configured to apply a controlled lifting force that raises the lens until contact is made with the clamping bells. The system then applies a controlled clamping force through the clamping device, maintaining contact pressure sufficient for alignment but limited to prevent excessive pressure that would cause imprints or surface damage. This parameter control enables automatic alignment while protecting the lens surface.
3Ease of operation
If the centering spindle shafts are driven in rotation during bell clamping, then the lens can be aligned, but transverse forces cause bending and displacement of the shafts
Solution Approach 1:
The patent applies asymmetry by positioning the lifting device and clamping device at different radial locations relative to the centering axis. This asymmetric arrangement creates a moment arm that allows rotational alignment to occur without introducing transverse forces that would cause tilting or bending of the centering spindle shafts. The offset positioning ensures that forces are applied through the axis of rotation, maintaining shaft stability and alignment precision during the lens alignment process.
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
The solution ensures precise alignment and secure holding of optical lenses during processing, preventing surface damage and maintaining high precision, with sensitive control of clamping forces and reduced risk of 'imprints' and other surface issues.
Implementation Method 1
The lifting device has a voice coil actuator (48) operatively connected to the axially adjustable centering spindle shaft (34), which comprises at least one coil (104) coaxial with respect to the centering axis C and at least one permanent magnet (106) interacting with the coil (104)
Implementation Method 2
the clamping device has an annular piston (164) which is attached to the axially adjustable centering spindle shaft (34) and forms an annular active surface (166) on its side facing away from the clamping bell end of the axially adjustable centering spindle shaft (34), which delimits an annular chamber (168) in the centering spindle housing (32), via which the annular piston (164) can be pneumatically actuated to generate the clamping force
Data Source
Figure 1
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AI summary
The machine (10) has lower and upper centering spindle shafts (24, 34) aligned with respect to a centering axis (C). A lifting device (44) axially and sensitively delivers the shafts relative to each other to align a workpiece between clamping bells (36, 38). A clamping arrangement applies a clamping force of the shafts to clamp the workpiece between the bells. Processing units (58, 60) are movable relative to the axis and provided with a tool (G) for edge machining of the workpiece clamped between the bells. The lifting device and the arrangement are co-axially arranged relative to the axis. An independent claim is also included for a coolant supply installation for supplying a cooling lubricant to a grinding disk at a rotary arbor of a processing unit.