Abstract: A starter module configured to limit an engine speed of an engine for a walk behind trowel at time of startup. The walk behind trowel includes a rotor driven by the engine, a throttle to command an operating state of the walk behind trowel, and a clutch operable to selectively couple an output of the engine to the rotor. The starter module includes a sensor operable to provide a signal representative of an operating state of the trowel upon engine start-up. The starter module further includes a controller configured to receive the signal representative of the operating state of the walk behind trowel, and to prevent the clutch from engaging the engine output to drive the rotor if the detected operating state is outside of a designated range for idling operation of the engine.

Abstract: A method is provided of making and using a walk behind rotary trowel that is “dynamically balanced” so as to minimize the forces/torque that the operator must endure to control and guide the trowel. Characteristics that are accounted for by this method include, but are not limited to, friction, engine torque, machine center of gravity, and guide handle position. As a result, dynamic balancing and consequent force/torque reduction were found to result when the machine's center of gravity was shifted substantially relative to a typical machine's center of gravity. Dynamic balancing can be achieved most practically by reversing the orientation of the engine relative to the guide handle assembly when compared to traditional walk behind rotary trowels and shifting the engine as far as practical to the right. This shifting has been found to reduce the operational forces and torque the operator must endure by at least 50% when compared to traditional machines.

Abstract: A guide handle of a handle assembly for an industrial machine such as a walk behind trowel has the open-ended handlebar characteristics of a so-called “bicycle” style guide handle and the belly bar and gripping versatility characteristics of a “whale tail” style guide handle. The belly bar spans the gap between the two handgrip portions, and both portions are mounted on a center post of the handle assembly at the bottom leg of a generally U-shaped mounting portion. The mounting portion can be welded or otherwise affixed to a post of the handle assembly at any desired angle, thereby permitting the orientation of the guide handle to be optimized for a given guide handle height.

Abstract: A lightweight, easy to assemble, and compact exciter assembly for a compaction device such as a drum assembly of a vibratory trench roller or the like includes a fixed weight and one or more free swinging weights mounted on an exciter shaft, without using any mounting hardware, so as to hold the free swinging weights axially in position while permitting them to swing between first and second angular positions on the exciter shaft. Preferably, the fixed weight is mounted on a central portion of the exciter shaft, and two free swinging weights are mounted adjacent the ends of the fixed weight so as to be restrained from substantial sliding movement along the exciter shaft solely by the fixed weight and other operative components of the exciter assembly such as bearings and/or gears or other torque transfer elements.

Abstract: A portable vibratory screed machine is provided with a vibration restraint operable to reduce undesirable vibration of the engine and to extend the life of the engine. The portable vibratory screed machine includes a machine frame having a reference structure. The machine further includes an engine mounted on the reference structure via a mount that surrounds a drive shaft that is driven by the engine's output. A vibratory assembly remotely located from the engine is powered by the engine to vibrate a screed plate. The vibration restraint directly couples the engine housing to the reference structure at a location that is spaced apart from the mount.

Abstract: A walk behind rotary trowel is configured to be “dynamically balanced” so as to minimize the forces/torque that the operator must endure to control and guide the trowel. Characteristics that are accounted for by this design include, but are not limited to, friction, engine torque, machine center of gravity, and guide handle position. As a result, dynamic balancing and consequent force/torque reduction were found to result when the machine's center of gravity was shifted substantially relative to a typical machine's center of gravity. Dynamic balancing can be achieved most practically by reversing the orientation of the engine relative to the guide handle assembly when compared to traditional walk behind rotary trowels and shifting the engine as far as practical to the right. This shifting has been found to reduce the operational forces and torque the operator must endure by at least 50% when compared to traditional machines.

Abstract: A brake of a concrete finishing trowel responds automatically to the cessation of drive torque delivery to the rotor to actively brake the trowel's drive train, hence inhibiting or preventing frame rotation. The brake preferably takes advantages of inherent characteristics of an inclined gear, such as a worm of a gearbox, to permit an internal component of the gearbox to shift automatically upon the cessation of drive torque therethrough from a brake released position to a brake engaged position. In the case of a worm gear-based gearbox, the worm is configured such that reaction forces that are normally generated by the delivery of drive torque therethrough shift the worm to release the brake during normal trowel operation. These forces are eliminated in the absence of drive torque transfer, permitting the worm to shift to a brake engaged position.

Abstract: A diaphragm carburetor-based fuel supply system is equipped with an air purge system that vents trapped air from the fuel supply system. The air purge system preferably includes a vent tube having an outlet opening into the upper portion of the system's fuel tank and an inlet located as close as practical to the diaphragm chamber of the carburetor, preferably within an internal passage of the carburetor or at least in a fitting or fuel supply tube portion located closely adjacent the fuel inlet of the carburetor. The resulting system requires only a few pull strokes to start a freshly fueled engine, as opposed to about 15 strokes in a system lacking such an air purge system. It also permits the use of a choke that is incapable of fully closing, thereby negating the need for a “false hit” during cold engine start.

Abstract: A control module for a walk behind trowel configured to detect and to prevent an uncontrolled or undesirable motion of the trowel. The trowel includes an engine configured to drive rotation of a rotor. The control module includes a gyroscope and a controller. The gyroscope is configured to provide an electrical signal representative of an angular rate of motion of a reference structure on the walk behind trowel. The controller is configured to receive the electrical signal from the gyroscope and to determine when a change in the angular rate of motion of the trowel exceeds a threshold value, and in response, to prevent the engine from driving the rotor to rotate.

Abstract: A diaphragm carburetor-based fuel supply system is equipped with an air purge system that vents trapped air from the fuel supply system. The air purge system preferably includes a vent tube having an outlet opening into the upper portion of the system's fuel tank and an inlet located as close as practical to the diaphragm chamber of the carburetor, preferably within an internal passage of the carburetor or at least in a fitting or fuel supply tube portion located closely adjacent the fuel inlet of the carburetor. The resulting system requires only a few pull strokes to start a freshly fueled engine, as opposed to about 15 strokes in a system lacking such an air purge system. It also permits the use of a choke that is incapable of fully closing, thereby negating the need for a “false hit” during cold engine start.

Abstract: A method of servicing construction equipment comprising forming an association of construction equipment manufacturers and providing a service agent of the association. The service agent refers a service need to a service dealer. The service agent is not an agent of the service dealer to whom the service need is referred.

Abstract: A method of assembling an exciter assembly for a compaction machine includes mounting a torque transfer element and a bearing on an exciter shaft. A fixed eccentric weight is mounted on the exciter shaft. First and second free swinging eccentric weights are mounted on the exciter shaft adjacent respective ends of the fixed eccentric weight so as to be rotatable a limited amount relative to the exciter shaft. The first and second free swinging eccentric weights are restrained from substantial axial movement along the exciter shaft solely by being sandwiched the first and second free swinging eccentric weights between the respective ends of the fixed eccentric weight and operative components of the exciter assembly. All of the mounting steps are performed without the use of any mounting hardware.

Abstract: A power buggy is configured to be safe, stable, easy to control, and comfortable. Frequently-used controls, such as a dump control, a kill switch, and a directional control, are located at or very near handgrips of an operator's handle so as to permit the operator to control the vehicle without releasing either of the handgrips. The power buggy comprises a plurality of wheels and a movable chassis which is supported on the wheels and which has front and rear end portions. A dumpable article support is supported on the front end portion of the chassis. The power buggy also includes an axial piston hydrostatic pump assembly that has an axial piston pump which supplies power to the wheels and a second pump which charges a hydraulic system of the power buggy.

Abstract: A centrifugal pump includes a volute and an impeller that are disposed in a pump chamber accessible through an access opening in the front wall of the pump's casing. The access opening is normally closed by a cover attachable to a front wall of the casing. The volute is attached to the cover by fasteners accessible from the outside of the cover so as to permit the cover and volute to be removed either as a unit or individually. The volute therefore is more easily accessed and removed than conventional pump volutes. In order to maximize self-priming and suction lift capability, the volute includes a discharge duct that converts substantially circular flow at the inlet of the discharge duct to substantially tangential flow at the outlet of the discharge duct, thereby maximizing the separation of air from the discharged liquid stream and minimizing the amount of entrained air in that portion of the discharged liquid stream that is recirculated to a recirculation inlet of the self-priming pump.

Abstract: A truss screed includes a shaft guard that covers the screed's exciter shaft to protect it from concrete and debris and that protects the surroundings from the rotating exciter shaft. The shaft guard includes a plurality of tubing sections that surround the shaft and that are supported on joints disposed between the guard sections. In a first preferred embodiment of the shaft guard, each joint includes a resilient spring ring, a support cup that receives the spring ring and an end of an associated tubular section, and a bearing that engages the support cup and that supports the joint and a portion of the exciter shaft on the screed's frame. In a second preferred embodiment, each joint includes a support cup that supports an end of the associated tubular section, a bearing, and a U-shaped bracket that couples the support cup to the bearing. The bearing and/or the bracket have elongated slots therethrough for accommodating misalignment of joint components.

Abstract: An air-cooled gearbox assembly for a concrete finishing trowel or the like is configured to maximize its cooling efficiency so as to negate the need to oversize the gearbox of the assembly. The assembly includes an air cooler including vertical fins on the gearbox and a blower. A shroud on the blower interacts with the fins on the gearbox to channel air vertically onto and over the upper and lower surfaces of the gearbox. The shroud also seals against the side edges of the gearbox to prevent the air from short-circuiting airflow passages formed between the fins. The airflow patterns resulting from this arrangement maximize convective heat transfer, thus maximizing cooling efficiency. The gearbox's thermal capacity is therefore considerably enhanced. As a result (all other things being equal), a much lighter gearbox can be used in a given application than otherwise would be required. Weight savings of more than 40% can be expected.

Abstract: A reciprocating impact tool such as a rammer or a breaker is provided with a lubricating oil supply system that supplies lubricating oil to a fuel supply line of the tool's two-cycle engine, thereby eliminating the need to premix the fuel and oil. The oil is supplied at a rate that varies with the speed of the reciprocating member of the tool, thereby assuring that the fuel and oil are mixed in the proper proportions. The oil pump delivers oil to the fuel supply line well-upstream of the engine's carburetor or other fuel supply device, thereby taking advantage of movement and vibration of the reciprocating member to assure that the delivered oil is thoroughly mixed with the fuel in the fuel line before the mixture is inducted into the engine's combustion chamber, leading to complete atomization of the oil and resultant benefits, including improved lubrication and complete combustion of the oil.