Double ratchet conveyor drive mechanism

Claim 2

A ratchet drive mechanism comprising a drive shaft, a first ratchet mounted on said shaft and secured thereto for rotation therewith and having teeth extending in a first direction, a second ratchet mounted on said shaft and secured thereto for rotation therewith and having teeth extending in the direction opposite to said first direction, at least one ratchet drive pawl, support means for mounting said at least one ratchet drive pawl and adapted for rotation about the elongated axis of said shaft, means for resiliently urging said at least one ratchet drive pawl into engagement with the teeth of said first ratchet during the forward rotation of said support means about the said elongated axis to rotate said first and second ratchets and said shaft during the forward rotation of said support means, reciprocating means for driving said support means forward and then backward in oscillatory rotative motion about said elongated axis, a pivotably mounted brake arm adapted to be rotated into contact with a tooth of said second ratchet during the forward rotation of said support means, a striker arm resiliently mounted on said support means and adapted to engage said brake arm and pivot said brake arm into contact with a tooth of said second ratchet during the final portion of the forward rotation of said support means.

Claim 3

Apparatus in accordance with claim 1 wherein said resiliently mounted striker arm is adapted to apply pressure to a tooth of said second ratchet to cause the driven tooth of said first ratchet to move back into contact with said ratchet drive pawl before the commencement of the backward motion of said support means in the event that said first and second ratchets and said drive shaft continued to rotate after the end of the forward motion of said support means.

Claim 4

Apparatus in accordance with claim 1 wherein two ratchet drive pawls are mounted on said support means on opposite sides of said shaft.

Claim 5

Apparatus in accordance with claim 3 wherein said support means comprises an annular housing for said lower ratchet.

Claim 6

Apparatus in accordance with claim 1 wherein said striker arm is movably mounted in a bracket on said support means, with a compression spring positioned about said striker arm between the striker head and said bracket so that said spring is compressed when said brake arm engages a tooth of said second ratchet, to thereby cushion the deceleration of said shaft at the end of the forward rotation of said support means.

Claim 7

Apparatus in accordance with claim 1 wherein said striker arm is movably mounted in a bracket on said support means, with a compression spring positioned about said striker arm between the striker head and said bracket so that said spring is compressed when said brake arm engages a tooth of said second ratchet, to thereby cushion the deceleration of said shaft at the end of the forward rotation of said support means, said spring being adapted to apply pressure to a tooth of said second ratchet to cause the driven tooth of said first ratchet to move back into contact with said ratchet drive pawl before the commencement of the backward motion of said support means in the event that said first and second ratchets and said drive shaft continued to rotate after the end of the forward motion of said support means.

Claim 8

Apparatus in accordance with claim 6 wherein two ratchet drive pawls are mounted on said support means on opposite sides of said shaft.

Claim 9

A ratchet drive mechanism comprising a drive shaft, a first ratchet mounted on said shaft and secured thereto for rotation therewith and having teeth extending in a first direction, a second ratchet mounted on said shaft and secured thereto for rotation therewith and having teeth extending in the direction opposite to said first direction, at least one ratchet drive pawl, support means for mounting said at least one ratchet drive pawl and adapted for rotation about the elongated axis of said shaft, means for resiliently urging said at least one ratchet drive pawl into engagement with the teeth of said first ratchet during the forward rotation of said support means about the said elongated axis to rotate said first and second ratchets and said shaft during the forward rotation of said support means, reciprocating means for driving said support means forward and then backward in oscillatory rotative motion about said elongated axis, a pivotably mounted brake arm adapted to be rotated into contact with a tooth of said second ratchet during the forward rotation of said support means, a striker arm resiliently mounted on said support means and adapted to engage said brake arm and pivot said brake arm into contact with a tooth of said second ratchet during the final portion of the forward rotation of said support means, an endless conveyor, an annular drive plate for driving said conveyor, said drive plate being positioned about said shaft for rotative movement free of the movement of said shaft, a clutch plate mounted on said shaft and secured thereto for rotation therewith, one of said drive plate and said clutch plate being provided with depressions in the surface thereof facing the other of said drive plate and said clutch plate, said other of said drive plate and said clutch plate being provided with pins for engaging said depressions, and means for resiliently mounting said pins so that a jamming of said conveyor will cause said pins to disengage from said depressions, thereby permitting said shaft to be indexed without rotating said drive plate.

Claim 10

A ratchet drive mechanism comprising a drive shaft, a first ratchet mounted on said shaft and secured thereto for rotation therewith and having teeth extending in a first direction, a second ratchet mounted on said shaft and secured thereto for rotation therewith and having teeth extending in the direction opposite to said first direction, at least one ratchet drive pawl, support means for mounting said at least one ratchet drive pawl and adapted for rotation about the elongated axis of said shaft, means for resiliently urging said at least one ratchet drive pawl into engagement with the teeth of said first ratchet during the forward rotation of said support means about the said elongated axis to rotate said first and second ratchets and said shaft during the forward rotation of said support means, reciprocating means for driving said support means forward and then backward in oscillatory rotative motion about said elongated axis, a pivotably mounted brake arm adapted to be rotated into contact with a tooth of said second ratchet during the forward rotation of said support means, a striker arm resiliently mounted on said support means and adapted to engage said brake arm and pivot said brake arm into contact with a tooth of said second ratchet during the final portion of the forward rotation of said support means, an endless conveyor, an annular drive plate for driving said conveyor, said drive plate being positioned about said shaft for rotative movement free of the movement of said shaft, a clutch plate mounted on said shaft and secured thereto for rotation therewith, one of said drive plate and said clutch plate being provided with depressions in the surface thereof facing the other of said drive plate and said clutch plate, said other of said drive plate and said clutch plate being provided with pins for engaging said depressions, and means for resiliently mounting said pins so that a jamming of said conveyor will cause said pins to disengage from said depressions, thereby permitting said shaft to be indexed without rotating said drive plate.

Claim 11

Apparatus in accordance with claim 8 wherein said resiliently mounted striker arm is adapted to apply pressure to a tooth of said second ratchet to cause the driven tooth of said first ratchet to move back into contact with said ratchet drive pawl before the commencement of the backward motion of said support means in the event that said first and second ratchets and said drive shaft continued to rotate after the end of the forward motion of said support means.

Claim 12

Apparatus in accordance with claim 8 wherein two ratchet drive pawls are mounted on said support means on opposite sides of said shaft.

Claim 13

Apparatus in accordance with claim 10 wherein said support means comprises an annular housing for said lower ratchet.

Claim 14

Apparatus in accordance with claim 8 wherein said striker arm is movably mounted in a bracket on said support means, with a compression spring positioned about said striker arm between the striker head and said bracket so that said spring is compressed when said brake arm engages a tooth of said second ratchet, to thereby cushion the deceleration of said shaft at the end of the forward rotation of said support means.

Claim 15

Apparatus in accordance with claim 8 wherein said depressions are uniformly spaced at intervals corresponding to the degree of rotation of said shaft for each forward movement of said support means so that said pins will reengage said depressions only when said drive plate is in proper relationship with said drive shaft.

Claim 16

Apparatus in accordance with claim 8 wherein said striker arm is movably mounted in a bracket on said support means, with a compression spring positioned about said striker arm between the striker head and said bracket so that said spring is compressed when said brake arm engages a tooth of said second ratchet, to thereby cushion the deceleration of said shaft at the end of the forward rotation of said support means, said spring being adapted to apply pressure to a tooth of said second ratchet to cause the driven tooth of said first ratchet to move back into contact with said ratchet drive pawl before the commencement of the backward motion of said support means in the event that said first and second ratchets and said drive shaft continued to rotate after the end of the forward motion of said support means.

Claim 17

Apparatus in accordance with claim 14 wherein two ratchet drive Pawls are mounted on said support means on opposite sides of said shaft.