PFlow Industries, Inc.
Since 1977, PFlow has been solely devoted to the design and manufacturer of vertical reciprocating conveyors (VRC’s) material handling equipment, systems, and specials. As the VRC pioneer, PFlow has led the industry from the start.
414-352-9000
6720 N. Teutonia Avenue Milwaukee, WI, 53209 USA

414.352.9000

6720 North Teutonia Avenue
Milwaukee, WI 53209
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Our VRC & Lift Patents

Since PFlow began with Bob Pfleger’s creation of the inclined vertical conveyor in 1977 – we have been leading the vertical reciprocating conveyor industry by continually improving our lift products. These lift advancements serve not only to increase productivity across the world, but also to keep worker’s safe. You can view just some of our revolutionary lift patents below, then, check out our various material lift products to see them in action!

Vertical Conveyor
US 5205379 A

Google Patent Link

PFlow Lift Patent - Vertical Conveyor - US 5205379 A

Inventors: Robert H Pfleger

Abstract: A vertical conveyor for lifting materials between different vertical levels. The conveyor comprises a pair of spaced upright supports or beams and a carriage to support a load or cargo is guided for vertical movement on the beams. A hydraulic cylinder unit is associated with each beam and the ram or piston rod of each cylinder unit carries a first sheave, while a second sheave is located at the upper end of each beam. A link chain formed of a plurality of interconnected loops is trained over each first and second sheave, and one end of each chain is dead-ended on the respective beam, while the opposite end of the chain is connected to the carriage. Retraction of the piston rod will move the carriage upwardly to a second vertical level. The axes of the first sheaves are located at 90° with respect to the axes of the second sheaves, so that the cylinder can be mounted tight against the beams to minimize the bending moment. A horizontal shaft connects the second sheaves and synchronizes movement of the two chains.

System for chain chordal action suppression
Quantum Drive
US20160368737A1

Google Patent Link

PFlow Lift - Quantum Drive - Patent Chain Chordal Suppression - US20160368737A1

Inventors: Mark R Webster

Abstract: A vertical lift conveyor for lifting materials between different vertical levels. The vertical lift conveyor includes a pair of spaced uprights and a carriage that moves vertically along the spaced uprights. The vertical lift conveyor includes a drive assembly including a drive motor coupled to a drive shaft. Each end of the drive shaft includes a first sprocket and a second sprocket that each engages one of a pair of lift chains. The first and second sprockets each include a plurality of teeth (N). The first and second sprockets are offset from each other 180/N°. The offset between the first and sprockets creates sinusoidal velocity profiles for the two chains that are out of phase with each other. A connection block is used to connect the pair of lift chains to each side of the carriage combines the lift chain velocities into a linear vertical velocity for the carriage.

Shopping cart conveyor with gated access
US 7453358 B2

Google Patent Link

PFlow Lift Patent Shopping Cart Conveyor US 7453358 B2Inventors: Mark R Webster

Abstract: A shopping cart conveyor that inhibits the loading of a non-compliant shopping cart onto the conveyor. In one aspect, the invention provides a conveyor comprising a track operable to guide the shopping cart between a first location and a second location, a gate assembly including a door movable between a closed position inhibiting entry to the track and an open position allowing entry to the track, a lock for securing the door in the closed position, and a sensor (e.g., an ultrasonic sensor, an optical sensor, a radar sensor, an infrared sensor, an RFID reader, a magnetic sensor, and a mechanical sensor) positioned to detect the presence of a shopping cart. In another aspect, the conveyor is configured to move the gate from the closed position to the open position when the sensor detects the presence of a shopping cart. Preferably this is done using a drive mechanism coupled to the gate.

Vertical conveyor with hydraulic drive
US 20080078624 A1

Google Patent Link

PFlow Lift Patent Vertical Conveyor with Hydraulic Drive US 20080078624 A1Inventors: Mark R Webster

Abstract: A vertical conveyor that includes a frame, a carriage, and a drive mechanism. The frame includes a vertical support member, and the carriage is coupled to the frame to carry a load. The carriage is mounted for movement along the vertical support member. The drive mechanism includes a first actuator and a second actuator. The first actuator includes a cylinder and a rod that extends from the cylinder to raise the carriage. The second actuator includes a cylinder and a rod each having lengths greater than lengths of the cylinder and rod of the first actuator. The rod of the second actuator extends from the cylinder of the second actuator to raise the carriage and the cylinder of the first actuator.

Vertical lift with synchronizer
US 20100111653 A1

Google Patent Link

PFlow Lift Patent Vertical lift with synchronizer US 20100111653 A1Inventors: Mark R Webster

Abstract: A vertical lift including a support, a carriage that is mounted for vertical movement relative to the support, a drive system including an actuator that is coupled directly to the carriage, and a synchronizer that is coupled between the carriage and the support

Multi-level vehicle lift
US 8075237 B2

Google Patent Link

PFlow Lift Patent Multi-level vehicle lift US 8075237 B2Inventors: Mark R Webster, Gene M Barth

Abstract: A multi-level vehicle lift comprising a first platform mounted for movement between a lowered position and a raised position. A second platform is positioned below the first platform and is coupled to the first platform by a lift member such that movement of the first platform above a first raised position causes movement of the second platform. A third platform is positioned below the second platform and coupled to the first platform by a lift member such that movement of the first platform above a second raised position causes movement of the third platform A pit may be positioned below the platforms, and the lower-most platform is in the pit when the first platform is in the lowered position. Preferably, the pit is recessed into a ground surface, and an upper surface of the first platform is substantially flush with the ground surface when in the lowered position.