The invention relates to a device used by professionals within the optical and ophthalmic industry to heat dyes to a specific temperature to color plastic lenses.
Within the optical lenses manufacturing industry, it has been a widespread practice to color lenses after manufacture in accordance with the customer's preference. Numerous devices have been used for this purpose, the most common being a type that utilizes a double tank system. The first tank is heated electrically, and a heat transfer medium indirectly heats a tank of dye. The dyes used in this process are prone to crystallization and sediment formation. The double tank system helps with this tendency. Optical dyes are most effective at a narrow temperature range (200-205° F.).
An examination of the various kinds of equipment available to the optical/ophthalmic industry reveals that instruments of the type under discussion are available. Wertheim and Talcott discuss devices which do not employ heat transfer fluids. However, these other systems are without the unique features of the present device.
Accordingly, several objects and advantages of the present device are:
The device consists of three basic parts.
1. Tanks that contain the dye.
2. A heating system that heats the dyes from the side of the tanks.
3. A stirring system that keeps the dye in constant agitation.
Operation
The tanks are filled with the dye solution and the device is heated up to the correct operating temperature. The thermostat controls the heating process and maintains an accurate temperature in the heat transfer medium to within several degrees. When the device reaches the optimal temperature for the lenses and the dye, the lenses are lowered into the dye solution. Coloring of the lens typically takes place within a few seconds.
Accordingly, the reader will see that the device will allow an improved method of coloring optical lenses. The method of heating has been designed to heat the dyes from the side of the tank. This unique design eliminates the problems caused by the dye materials. When these materials settle to the bottom of the tank, heating from below can lead to burning and crystallization of the dyes.
In addition, the constant agitation of the dye helps prevent sediment formation that leads to burning and crystallization of the dyes. The agitation also maintains a high concentration level of the dye around the lens, which increases the diffusion rate of the dye. The agitation reduces the violence of boiling, so that higher temperatures (close to boiling) may be used safely. This also increases the diffusion rate of the dye. The thermostat controls the temperature of the heat transfer medium, which may be set at any temperature from 23° C. to 130° C. The combination of side heating, agitation, and thermostatic temperature control result in an improved system for coloring plastic lenses.
Number | Name | Date | Kind |
---|---|---|---|
111476 | Ronning | Jan 1871 | A |
2236837 | Rimmel | Apr 1941 | A |
2551651 | Vandewater | May 1951 | A |
3892945 | Lerner | Jul 1975 | A |
4256697 | Baldwin | Mar 1981 | A |
5052337 | Talcott et al. | Oct 1991 | A |
5549543 | Kim | Aug 1996 | A |
6216360 | Wertheim | Apr 2001 | B1 |
6417498 | Shields et al. | Jul 2002 | B1 |
Number | Date | Country |
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06175082 | Jun 1994 | JP |