GILMAN DOVETAIL SLIDES HELP PUT COMFORT, PRECISION IN CONTACT
LENS MANUFACTURING
Grafton,
WI, (April 29, 1999)
A small piece of plastic, a polymer actually, resting on the
cornea helps millions of people see better, comfortably. Contacts
are a precision crafted lens which improve vision and allow the
eye to breathe normally. But how is this precision crafted contact
lens manufactured?
This is where DAC Vision (Carpinteria, CA), a world-leading manufacturer
of lathes used to make contact and intraocular lenses, comes into
the picture. In order to provide the level of accuracy needed
to help contact lens wearers see, DAC Vision manufactures two,
three and four axis CNC lathes including the Series III/4XC.
The 4XC is a four-axis, ultra precision, diamond turning lathe.
This lathe uses a left hand diamond tool #1 to remove the majority
of the material which is blocked or held directly by the collet,
and to form the contour, while the final cut is done with tool
#2. The 4XC is fitted with the Contact Lens Software Package offering
edge radius input producing reliable and repeatable radii on spherical
and aspherical design, the machining time is typically less than
60 seconds per side. Since the ultimate goal is contact lens comfort
(which depends on shape, lift and thickness of the lens edge)
and precision, the 4XC is vital to the comfort of contact lens
wearers. According to Jim Drain, DAC Vision's Vice President,
Managing Director-Santa Barbara, "Performance is not just nice
surfaces - our customers' eye care professionals must be able
to improve their patient's vision."
Since 1980, DAC vision has trusted SKF Precision Technologies
DC6, DC8, and DC10 (6", 8" & 10" widths) cast iron
dovetail slides in its lathes to ensure absolute accuracy,
stability, and ultra-smooth vibration-free motion. These
are fitted with lead screws, bearings, plates and accordion
way covers. Drain says, "In our applications it is critical
that mechanical resonance and electrical noises do not
find their way to the lens surface. SKF Precision Technologies
cast iron dovetail slides really do the job." SKF Precision
Technologies slides are used as a positioning stage by
adding brushless motors, rotary and linear encoders and
cabling to the computer numerical control. This combination
allows the slide to have 0.1 micron resolution from the
linear encoder to ensure absolute positioning, and 0.050
micron resolution from the rotary encoder to synthesize
the tachometer and provide the best possible resolution
during the cut cycle.
SKF Precision Technologies, a unit of SKF USA Inc., is an ISO 9001 registered
global supplier of high-precision machine components, including
slides, spindles, customized modular components and index tables.
SKF is one of the world's largest bearing manufacturers with over
70 factories worldwide.
