Tablet-coating apparatus

Claim 2

A tablet-coating apparatus comprising in combination: a rotary tumbling drum having a horizontal axis of rotation, said drum having a flat foraminous peripheral surface substantially concentric with said axis and imperforate side wall portions contiguous to said peripheral surface, means for rotating said drum at a speed to effect tumbling of a charge of tablets in a bed of substantially uniform depth in a given sector in the lower leading quadrant of said drum with the lowermost layer of said tablets in contact with a given area of said drum''s foraminous peripheral surface, said drum having an interior space above said bed or tumbling tablets through which a coating material is downwardly applied on said tumbling tablets, an exhaust inlet flexibly biased against the exterior of said drum''s flat peripheral surface at said given sector and over an area less than and centrally located relative to said bed of tumbling tablets, said exhaust inlet being mounted on pivoted lever means removably supporting said exhaust inlet and swingable away from said drum to accommodate removal of said inlet from the exterior of said drum''s flat peripheral surface, the area of said foraminous peripheral surface other than said sector providing an area greatly exceeding the area of said exhaust inlet, pressure differential means effecting a continuous velocity flow of a large quantity of air from said foraminous peripheral area other than said sector downwardly through said tumbling bed to said exhaust inlet for driving said coating material downwardly into the tumbling bed of tablets, drying the thus coated tablets and forcing the particles and dust from fragmented tablets at said given sector through the foraminous periphery of the drum and into the exhaust inlet.

Claim 3

A tablet-coating apparatus comprising in combination: a rotary tumbling drum having a horizontal axis of rotation, said drum having a flat foramInous peripheral surface substantially concentric with said axis and imperforate outwardly tapered side wall portions contiguous to said peripheral surface, means for rotating said drum at a speed to effect tumbling both circumferentially and axially of a charge of tablets in a bed of substantially uniform depth in a given sector in the lower leading quadrant of said drum with the lowermost layer of said tablets in contact with a given area of said drum''s foraminous peripheral surface, said drum having an interior space above said bed of tumbling tablets through which a coating material is downwardly applied on said tumbling tablets, an exhaust inlet flexibly biased in rolling engagement against the exterior of said drum''s flat peripheral surface at said given sector and over an area less than and centrally located both circumferentially and axially relative to said bed of tumbling tablets, said exhaust inlet being mounted on pivoted lever means removably supporting said exhaust inlet and swingable away from said drum to accommodate removal of said inlet from the exterior of said drum''s flat peripheral surface, the area of said foraminous peripheral surface other than said exhaust inlet, pressure differential means effecting a continuous velocity flow of a large quantity of air from said foraminous peripheral area other than said sector downwardly through said tumbling bed to said exhaust inlet for driving said coating material downwardly into the tumbling bed of tablets drying the thus coated tablets and forcing the particles and dust from fragmented tablets at said given sector through the foraminous periphery of the drum and into the exhaust inlet.

Claim 4

A tablet-coating apparatus comprising in combination: a rotary tumbling drum having a horizontal axis of rotation, said drum having a flat foramInous peripheral surface substantially concentric with said axis and imperforate outwardly tapered side wall portions contiguous to said peripheral surface, means for rotating said drum at a speed to effect tumbling both circumferentially and axially of a charge of tablets in a bed of substantially uniform depth in a given sector in the lower leading quadrant of said drum with the lowermost layer of said tablets in contact with a given area of said drum''s foraminous peripheral surface, said drum having an interior space above said bed of tumbling tablets through which a coating material is downwardly applied on said tumbling tablets, an exhaust inlet flexibly biased in rolling engagement against the exterior of said drum''s flat peripheral surface at said given sector and over an area less than and centrally located both circumferentially and axially relative to said bed of tumbling tablets, said exhaust inlet being mounted on pivoted lever means removably supporting said exhaust inlet and swingable away from said drum to accommodate removal of said inlet from the exterior of said drum''s flat peripheral surface, the area of said foraminous peripheral surface other than said exhaust inlet, pressure differential means effecting a continuous velocity flow of a large quantity of air from said foraminous peripheral area other than said sector downwardly through said tumbling bed to said exhaust inlet for driving said coating material downwardly into the tumbling bed of tablets drying the thus coated tablets and forcing the particles and dust from fragmented tablets at said given sector through the foraminous periphery of the drum and into the exhaust inlet.

Claim 5

A tablet-coating apparatus as defined in claim 1 in which a cleansing reservoir encompasses the lower peripheral surface of said drum proximate said sector.