Abstract An apparatus for removing the molding flash from normally soft or resilient molded parts, such as rubber, which utilizes a nonsymmetrical tumbling barrel for tumbling and mixing the parts to be deflashed. Low temperature fluid is fed into the barrel to cause freezing or embrittlement of the molded parts to a predetermined extent and temperature-responsive speed control is used for rotation of the tumbling barrel to achieve uniform results and improved efficiency in the cost and effectiveness of the deflashing operation. The temperature sensing probe is isolated from the parts being tumbled, but is so located as to more accurately reflect the temperature of the parts, rather than the temperature of the atmosphere in the barrel. The electric motor utilized to drive the tumbling barrel is disposed in the path of exhaust flow of the cryogenic gas so as to be cooled thereby to reduce the heat factor and consequently the power requirements.
In a control system for a cryogenic deflashing apparatus having a power-driven rotatable tumbling barrel, the combination of a drive control circuit for initiating rotation of said barrel at a creep speed, temperature-sensing means disposed in said barrel, means for cooling the interior of said barrel to a selected low temperature, and means responsive to the attainment of said selected temperature for establishing a high speed drive control circuit to cause rotation of said barrel at a speed substantially greater than said creep speed.
Claim 2
Dependent Claim
84 words
In a control system for a cryogenic deflashing apparatus having a power-driven rotatable tumbling barrel, the combination of a drive control circuit for initiating rotation of said barrel at a creep speed, temperature-sensing means disposed in said barrel, means for cooling the interior of said barrel to a selected low temperature, and means responsive to the attainment of said selected temperature for establishing a high speed drive control circuit to cause rotation of said barrel at a speed substantially greater than said creep speed.
Claim 3
Dependent Claim
21 words
A combination as defined in claim 1, wherein said high speed is at least twice as great as said creep speed.
Claim 4
Dependent Claim
26 words
A combination as defined in claim 1, including valve means responsive to the attainment of said selected temperature for arresting the operation of said cooling means.