Abstract: A rotatable pneumatic feeding head having a vacuum shoe with apertures for picking up an envelope from an envelope stack by negative air pressure. The feeding head has an outer cylinder with holes communicating with the apertures, and an inner cylinder with cutout regions operatively connected to a vacuum pump. The inner cylinder and the outer cylinder are rotated independently of each other such that when they are aligned, a negative pressure is created at the apertures through the cutout regions and the holes. When the inner cylinder and the outer cylinder are out of alignment, the negative pressure is cut off from the apertures. The vacuum shoe is removable so that it can be repaired or replaced when it is damaged or worn.

Abstract: A flat article hopper having a plurality of bottom rods to form a supporting surface for supporting a stack of flat articles and a paddle to push the flat articles towards a flat article feeder at the downstream end. A scrub wheel is rotatably mounted on a fixed, rotation axis on the paddle and is in contact with one of the bottom rods. The rotation axis of the scrub wheel is oriented at an angle relative to the rotation axis of the contacting rod, so that when the contacting rod rotates, it causes the scrub wheel to rotate, thereby producing a force on the paddle urging the paddle to move towards the downstream end. Preferably, the flat article hopper has a side rod on one side of the envelope stack, and the supporting surface is tilted from the horizontal surface, so that the flat articles are moved towards the side rod by gravity in order to register against the side rod. Preferably, the side rod also rotates in order to reduce the friction between the flat article stack and the side rod.

Abstract: A rotatable pneumatic feeding head having a vacuum shoe with apertures for picking up an envelope from an envelope stack by negative air pressure. The feeding head has an outer cylinder with holes communicating with the apertures, and an inner cylinder with cutout regions operatively connected to a vacuum pump. The inner cylinder and the outer cylinder are rotated independently of each other such that when they are aligned, a negative pressure is created at the apertures through the cutout regions and the holes. When the inner cylinder and the outer cylinder are out of alignment, the negative pressure is cut off from the apertures. The vacuum shoe is removable so that it can be repaired or replaced when it is damaged or worn.

Abstract: A method and apparatus for feeding envelopes in an envelope insertion machine, wherein a rotatable pneumatic feeding head is used to pick up an envelope from an envelope stack by a negative air pressure. The pneumatic feeding head is also used to move the envelope to a pair of take away rollers so that the envelope picked up by the feeding head can be moved further away from the envelope stack. It is preferred that the feeding head includes an outer cylinder having a row of vacuum ports and an inner cylinder having a plurality of apertures for air passage operatively connected to a vacuum pump. The inner cylinder is independently rotatable relative to the outer cylinder so that the negative air pressure is provided to the vacuum ports when the apertures of the inner cylinder are aligned with the vacuum ports, and the negative air pressure is turned off from the vacuum parts when the apertures and the vacuum ports are out of alignment.

Abstract: An envelope hopper having a plurality of bottom rods to form a supporting surface for supporting a stack of envelopes and a paddle to push the envelopes towards an envelope feeder at the downstream end. A scrub wheel is rotatably mounted on a fixed, rotation axis on the paddle and is in contact with one of the bottom rods. The rotation axis of the scrub wheel is oriented at an angle relative to the rotation axis of the contacting rod, so that when the contacting rod rotates, it causes the scrub wheel to rotate, thereby producing a force on the paddle urging the paddle to move towards the downstream end. Preferably, the envelope hopper has a side rod on one side of the envelope stack, and the supporting surface is tilted from the horizontal surface, so that the envelopes are moved towards the side rod by gravity in order to register against the side rod. Preferably, the side rod also rotates in order to reduce the friction between the envelope stack and the side rod.