Development apparatus

Claim 2

In a magnetic apparatus for developing a latent electrostatic image on a photoconductive surface including an elongated housing being adapted to hold a quantity of magnetic developer material therein and having an opening positioned adjacent to the photoconductive surface, means to produce a continuous flow of developer material through said housing, a hollow applicator roll positioned in the opening in said housing so that the applicator roll is partially immersed in the developer material supported in said housing, magnetic means supported within said applicator roll and being capable of producing a main flux field directed substantially towards the photoconductive surface, and means to rotate said applicator roll through the developer material and the main flux field to form a brush of developer material in the main flux field capable of contacting the photoconductive surface, the improvement comprising: means to reposition said magnet within said applicator roll to displace the flux field relative to photoconductive surface whereby the brush of magnetic material is moved out of developing contact with the photoconductive surface, and means movable from a first position during developing contact to a second position to collapse the magnetic brush when said magnetic brush is moved out of developing contact with the photoconductive surface.

Claim 3

Apparatus for developing a latent electrostatic image on a photoconductive surface including: an elongated housing being adapted to hold a quantity of magnetic developer material therein and having an opening positioned adjacent to the photoconductive surface, means to produce a continuous flow of developer material through said housing, a hollow applicator roll positioned in the opening in said housing so that the applicator roll is partially immersed in the developer material supported in said housing, magnetic means supported within said applicator roll and being capable of producing a main flux field directed substantially towards the photoconductive surface, means to rotate said applicator roll through the developer material and the main flux field to form a brush of developer material in the main flux field capable of contacting the photoconductive surface, means to reposition said magnet within said applicator roll whereby the brush of magnetic material is moved out of developing contact with the photoconductive surface, means to collapse the magnetic brush when said magnetic brush is moved out of developing contact with the photoconductive surface, wherein said means to collapse said brush comprises a blade pivotally supported on end in said housing and being operatively connected to said means to rotate said magnet by a movable linkage whereby said blade raised out of brush interference when the magnet is in developing position, and the blade is moved into contact with said brush to break down the brush fibers when the magnet is in the nondeveloping position.

Claim 4

Apparatus for developing a latent electrostatic image on a photoconductive surface including: an elongated housing being adapted to hold a quantity of magnetic developer material therein and having an opening positioned adjacent to the photoconductive surface, means to produce a continuous flow of developer material through said housing, a hollow applicator roll positioned in the opening in said housing so that the applicator roll is partially immersed in the developer material supported in said housing, magnetic means supported within said applicator roll and being capable of producing a main flux field directed substantially towards the photoconductive surface, means to rotate said applicator roll through the developer material and the main flux field to form a brush of developer material in the main flux field capable of contacting the photoconductive surface, means to reposition said magnet within said applicator roll whereby the brush of magnetic material is moved out of developing contact with the photoconductive surface, means to collapse the magnetic brush when said magnetic brush is moved out of developing contact with the photoconductive surface, wherein said means to collapse said brush comprises a blade pivotally supported on end in said housing and being operatively connected to said means to rotate said magnet by a movable linkage whereby said blade raised out of brush interference when the magnet is in developing position, and the blade is moved into contact with said brush to break down the brush fibers when the magnet is in the nondeveloping position.

Claim 5

The apparatus of claim 2 having further means operatively connected with said brush repositioning means to prevent further rotation of said applicator roll when said magnetic brush is moved out of contact with the photoconductive surface.

Claim 6

Apparatus to develop a latent electrostatic image on a record receiving member including: a housing having an opening therein adjacent to the photoconductive member, said housing being adapted to support a quantity of magnetic developer material therein, a hollow nonmagnetic cylindrical applicator roll rotatably mounted in said opening and being partially immersed in said develoPer material, an elongated magnet positioned within said applicator roll being capable of producing a main magnetic flux field substantially directed towards the photoconductive surface, said magnet being independently supported for rotation within said applicator roll, drive means to rotate said applicator roll sequentially through the developer material and the main flux field whereby a magnetic brush of developer material is continually formed said brush being of a length capable of contacting the photoconductive surface, means to rotate said magnet within said applicator roll from a developing position wherein the magnetic brush is in contact with the record receiving member to a second nondeveloping position wherein said brush is out of contact with said receiving member, clutching means associated with said applicator drive means and being operatively connected to said last mentioned means to prevent further rotation of said applicator roll when the brush is moved to a second position, means to collapse said brush when said magnet is in the second nondeveloping position.

Claim 7

Apparatus to develop a latent electrostatic image on a record receiving member including: a housing having an opening therein adjacent to the photoconductive member, said housing being adapted to support a quantity of magnetic developer material therein, a hollow nonmagnetic cylindrical applicator roll rotatably mounted in said opening and being partially immersed in said develoPer material, an elongated magnet positioned within said applicator roll being capable of producing a main magnetic flux field substantially directed towards the photoconductive surface, said magnet being independently supported for rotation within said applicator roll, drive means to rotate said applicator roll sequentially through the developer material and the main flux field whereby a magnetic brush of developer material is continually formed said brush being of a length capable of contacting the photoconductive surface, means to rotate said magnet within said applicator roll from a developing position wherein the magnetic brush is in contact with the record receiving member to a second nondeveloping position wherein said brush is out of contact with said receiving member, clutching means associated with said applicator drive means and being operatively connected to said last mentioned means to prevent further rotation of said applicator roll when the brush is moved to a second position, means to collapse said brush when said magnet is in the second nondeveloping position.

Claim 8

The apparatus of claim 4 wherein said means to collapse said brush comprises a blade pivotably supported on end in said housing and being operatively connected to said means to rotate said magnet by a movable linkage whereby said blade raised out of brush interference when the magnet is in a developing position, and the blade is moved into contact with said brush to break down the brush fibers when the magnet is in the nondeveloping position.