Electrically driven potter's wheel

Claim 2

An electrically driven potter's wheel comprising: a rotary molding table having a drive shaft, a generally cup-shaped member being generally downwardly open and having a resilient ring along an inner surface of its lower edge, said member being rotatably mounted and fixed to said shaft, an electric motor, a conical roller directly coupled to said electric motor and arranged to frictionally engage said ring to drive said table, and speed-changing means for moving said conical roller in a generally vertical direction relative to said ring to vary the effective contact radius of said roller.

Claim 3

An electrically driven potter's wheel comprising: a casing, a molding table rotatably mounted to said casing and having a drive shaft, a generally cup-shaped member being generally downwardly open and having a resilient ring along an inner surface of its lower edge, said member being rotatably mounted on said casing and fixed to said shaft, drive means comprising: an electric motor, a conical roller directly coupled to said electric motor and arranged to frictionally engage said ring to drive said table, a speed changing shaft rotatable by a user of the potter's wheel, and an arm extending from said speed changing shaft and connected pivotably to said electric motor to displace the latter generally vertically relative to said ring when said speed changing shaft is rotated, a spring operably disposed between said electric motor and said casing for generating contact pressure between said ring and said conical roller, and a seat provided on the side wall of said casing to bear against all of the force of said spring in a state wherein said drive means is sufficiently lowered to enable said molding table can be turned freely in independently of said drive means, said force acting on said seat being decreased in the course of raising of said drive means from maximum to zero by the frictional engagement between said conical roller and said ring which occurs gradually increasing contact pressure from zero to maximum.

Claim 4

An electrically driven potter's wheel comprising: a casing, a molding table rotatably mounted to said casing and having a drive shaft, a generally cup-shaped member being generally downwardly open and having a resilient ring along an inner surface of its lower edge, said member being rotatably mounted on said casing and fixed to said shaft, drive means comprising: an electric motor, a conical roller directly coupled to said electric motor and arranged to frictionally engage said ring to drive said table, a speed changing shaft rotatable by a user of the potter's wheel, and an arm extending from said speed changing shaft and connected pivotably to said electric motor to displace the latter generally vertically relative to said ring when said speed changing shaft is rotated, a spring operably disposed between said electric motor and said casing for generating contact pressure between said ring and said conical roller, and a seat provided on the side wall of said casing to bear against all of the force of said spring in a state wherein said drive means is sufficiently lowered to enable said molding table can be turned freely in independently of said drive means, said force acting on said seat being decreased in the course of raising of said drive means from maximum to zero by the frictional engagement between said conical roller and said ring which occurs gradually increasing contact pressure from zero to maximum.