Brake for gravity roller conveyors

Claim 2

In a conveyor having a plurality of spaced individually rotatable rollers defining a pass line tangent to the upper surfaces of said rollers and at a declining angle to the horizontal for transporting objects in the declining direction of conveyor movement by gravitational forces, a brake comprising in combination a flexible band disposed adjacent the periphery of certain of said rollers apart from the pass line, band positioning means for supporting the band adjacent said certain rollers, said certain rollers being rotatable in their normal forward direction by the passage of an object over said rollers, and trigger means positioned to be actuated by the presence of a conveyed object at a predetermined position on said pass line downstream of said certain rollers for automatically tensioning said band to apply a frictional braking force to said certain rollers.

Claim 3

Apparatus as defined in claim 1 in which said tensioning means includes a trigger lever and actuating means protruding above the pass line into the path of conveyed objects, said lever being swingable in a downward direction upon being encountered by a conveyed object to create a tension force in said band.

Claim 4

Apparatus as defined in claim 1 in which said tensioning means includes a trigger roller substantially tangent to the pass line and having a friction-producing surface, and linkage means for translating rotation of said trigger roller into tensioning movement of said band.

Claim 5

Apparatus as defined in claim 1 in which said tensioning means includes an electric eye positioned adjacent said pass line downstream of said certain roller, and power tensioning means responsive to the detection of a conveyed object by said electric eye for applying a tensioning force to said band.

Claim 6

In a conveyor comprising a sides of spaced individually rotatable rollers defining a pass line extending along the length of said conveyor and at a declining angle to the horizontal over which objects are transported in the declining direction under gravitational forces, said rollers being rotatable in their normal forward direction by the passage of one article over said rollers, a brake including an elongated flexible band disposed adjacent the underside of certain of said rollers, flexible band supports disposed on opposite sides of each of said certain rollers to be braked and having an upper extremity below said pass line and above the lower extremity of said certain rollers, said flexible band being disposed between said supports and said certain rollers to be braked and positioned against the underside of rollers securing the said certain rollers at a predetermined angle of wrap at the periphery of each of said certain rollers, trigger means, said band being secured at one end to said trigger means, said trigger means being positioned to be actuated by the presence of a conveyed object at a predetermined position on said pass line downstream of said certain rollers for automatically tensioning said flexible band to apply a frictional braking force to said certain rollers, and anchor means located downstream of said certain rollers securing the opposite end of said band against movement relative to said rollers whereby said anchor means resists tension forces induced in said band by said trigger means, and whereby during the time said tensioning means is actuated to tension said flexible band further forward rotational movement of said certain roller causes additional tensioning of said flexible band and a self-energizing additional braking force to said certain rollers.

Claim 7

In a conveyor comprising a sides of spaced individually rotatable rollers defining a pass line extending along the length of said conveyor and at a declining angle to the horizontal over which objects are transported in the declining direction under gravitational forces, said rollers being rotatable in their normal forward direction by the passage of one article over said rollers, a brake including an elongated flexible band disposed adjacent the underside of certain of said rollers, flexible band supports disposed on opposite sides of each of said certain rollers to be braked and having an upper extremity below said pass line and above the lower extremity of said certain rollers, said flexible band being disposed between said supports and said certain rollers to be braked and positioned against the underside of rollers securing the said certain rollers at a predetermined angle of wrap at the periphery of each of said certain rollers, trigger means, said band being secured at one end to said trigger means, said trigger means being positioned to be actuated by the presence of a conveyed object at a predetermined position on said pass line downstream of said certain rollers for automatically tensioning said flexible band to apply a frictional braking force to said certain rollers, and anchor means located downstream of said certain rollers securing the opposite end of said band against movement relative to said rollers whereby said anchor means resists tension forces induced in said band by said trigger means, and whereby during the time said tensioning means is actuated to tension said flexible band further forward rotational movement of said certain roller causes additional tensioning of said flexible band and a self-energizing additional braking force to said certain rollers.