Allen Engineering Corporation

Hugh L Adams

J Dewayne Allen

Timmy D Guinn

Michael W McKean

Ralph C Luebke

High performance, multiple rotor riding trowels for finishing concrete comprise hydraulic circuitry enabling complete joystick control to the operator. The rigid trowel frame mounts separate spaced-apart, downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface. The rotor assembly blades finish the surface while supporting the trowel. The rotor assemblies are tilted with double acting, hydraulic cylinders to effectuate steering and control. Double acting hydraulic cylinders also control blade pitch. Separate gimbaled, hydraulic motors revolve each rotor assembly. A joystick system enables operator hand control with minimal physical exertion. The joystick system activates electrical circuitry that fires solenoid control valves to energize various hydraulic cylinders that tilt the rotors and alter blade pitch. The hydraulic steering control circuit driven by a motor driven pump pressures a flow divider circuit to control the solenoid tilt control valves. A bypass-valve in line before the flow divider enables an operator to customize the trowel steering speed. A motor drive control circuit responsive to a hydraulic pump controls each hydraulic drive motor, and provides for speed control and heat dissipation.

Hydraulically driven, multiple rotor riding trowel

A high performance, hydraulically-propelled, multiple rotor riding trowel for finishing concrete is controlled with hydraulic circuitry enabling steering wheel and foot pedal control. The rigid trowel frame preferably mounts three separate spaced-apart, downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface. The rear rotor assemblies are tilted with double acting, hydraulic cylinders to effectuate steering and control in response to foot pedals. Double acting hydraulic cylinders also control blade pitch. Separate gimbaled, hydraulic motors revolve each rotor assembly. A steering wheel controlling a front, hydraulic steering control valve controls the front tilting cylinder to facilitates steering with minimal physical exertion.

A self-propelled paver that distributes, consolidates, places and finishes polymer concrete to rapidly resurface roadbeds. A mobile, wheeled chassis mounts an adjustable hopper that receives premixed polymer from a mixer truck that precedes the paver. A finishing assembly secured to the chassis has a distribution assembly for applying concrete transversely across the surface, and a trailing finishing screed that surfaces and densifies the concrete. An active, hydraulic suspension dynamically orients the chassis and the finishing assembly with the roadbed. Individual height adjusting cylinders can be extended or contracted by an automatic grade control that logically senses grade through an external string line. The distribution system comprises an open bottom exposing the surface to be paved, and an open top adapted to receive concrete from a trough extending from the hopper. A bidirectional auger is rotatably disposed within a distribution box for moving concrete upon the surface. The finishing screed comprises a rigid strike off that initially contacts uncompacted concrete laid by the distribution system. An intermediate pan extending between the strike off and a trailing bull float mounts a plurality of vibrators that facilitate concrete densification. The vertically displaceable hopper can be adjusted to an appropriate operative orientation relative to the mixing truck. When tested in place with a nuclear densitometer, resultant concrete density will meet or exceed standards established for all modern paving jobs. Ride quality as measured by a profilograph according to known procedures will meet all established standards.

Polymer concrete paving machine

Riding trowel for concrete finishing

A riding trowel used for concrete finishing includes a dolly wheel lifting system. The lifting system elevates the trowel out of contact with the concrete surface when transporting, adjusting, or maintenancing the trowel. The trowel comprises a rigid metallic frame normally offset from the concrete surface to be finished by a pair of downwardly projecting, bladed rotors. A pair of primary steering control levers is linked to the rotors beneath the frame for trowel operation. Each rotor assembly comprises a rotatable blade assembly depending downwardly into contact with the concrete surface. The wheel system comprises a cooperating pair of spaced apart, dolly wheel assemblies which are removably fitted to the front and back of the frame, so that the trowel may be pushed around for loading and unloading purposes in directions generally coincident with its longitudinal axis. Each dolly wheel assembly comprises an upright, extensible stanchion supported upon a rigid cross piece extending between a pair of spaced apart wheels. The stanchion mounts a pair of rigid, spaced apart rods that are adapted to be mated to suitable mandrels formed in the frame front and rear, about the trowel center of gravity. The stanchion comprises upper and lower tubular members that are telescoped together and which may be axially displaced or retracted by an internal screw jack to raise or lower the trowel. When the trowel is raised above the concrete surface, the blades are safely exposed for servicing.

A compact, lightweight riding trowel for finishing concrete of enhanced maneuverability. A rigid frame is supported above the concrete by a pair of downwardly projecting synchronized rotors, each of which revolves multiple blades frictionally contacting the surface. Lights attached to frame corners provide illumination. The operator manually steers with a pair of primary control levers which tilt the rotors to generate steering forces. The pitch of each rotor blade is controlled manually or electrically, and a cable-driven clutch fork system is activated to vary pitch between minimum and maximum. Each of the tiltable rotor assemblies is driven by gear boxes coupled to the motor through a flexible disk drive shaft. Each gear box is mounted to the frame underside by a pivot steering box. Parallel lever arms extending beneath the frame in a direction generally perpendicular to the biaxial plane defined by the rotors are deflected by the primary control levers. Each activates elongated torque rods coupled to the gearboxes and tilts the rotors in a plane parallel with the biaxial plane. The torque rods are generally aligned, and for leverage they are braced by a gusset and offset from that axis of rotation defined within the pivot boxes which enables one of the rotors to tilt in an arc perpendicular to the biaxial plane. One lever arm controls a torque shaft interconnected with a tertiary linkage system which tilts one rotor in a plane perpendicular to the biaxial plane, and which achieves a mechanical advantage.

Growing community of inventors

Bassett, AR, United States of America

Hugh L Adams