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US 4,286,675 AGranted
Narrow profile power handle for line trimmer and the like
AssigneeBeaird-Poulan Division of Emerson Electric Co.
InventorLloyd H. Tuggle
Life of this patent
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AssigneeBeaird-Poulan Division of Emerson Electric Co.
InventorLloyd H. Tuggle
Estimating the term…
A narrow profile power handle uniquely adapted for use as a flexible line trimmer having improved handling and safety features is disclosed. The power handle is also equipped with a quick connect and disconnect coupling and is useful for driving attachments to produce hand held rotary implements and tools such as brush cutters, edgers, cultivators, drills, etc., hand held reciprocating implements and tools such as hedge clippers, saws, etc., as well as portable water pumps, air compressors, generators, etc. The crankshaft of a two-stroke internal combustion engine is disposed along the longitudinal axis of a narrow profile housing which includes a rear handle having a hand grip portion disposed above and projecting rearwardly parallel to the axis of the housing. The cylinder extends upwardly from the crankcase, the carburetor is disposed below the crankcase, the flywheel, ignition system and starter to the rear, and the gas tank is disposed below the rear handle. The muffler is disposed along the forward face of the housing for discharging products of combustion forwardly of the housing and away from the operator, thereby permitting the assembly to be rotated for various trimming operations without exposing the operator to the risk of burn injury. A recoil starter handle, a choke control, throttle control and ignition kill switch are conveniently clustered around and near the hand grip portion of the rear handle which allows the operator to observe and exercise positive control over both the power handle and the cutter head while starting and operating the engine. The power handle includes a quick disconnect coupling for attaching the portable power unit to drive various attachments. As a result of this arrangement, the power handle is generally symmetrical about the longitudinal vertical plane and is of minimum width. The drive shaft of the line trimmer assembly is aligned with the crankshaft of the engine and a forward handle is disposed above the drive shaft ahead of the engine housing. As a result, the center of gravity of the overall line trimmer assembly is below and between the forward and rearward handles, thereby providing improved balance and maneuverability.
A portable power tool comprising a rotary head coupled to one end of an elongated tubular drive shaft assembly and an internal combustion engine coupled to the opposite end of the drive shaft assembly, an elongated housing enclosing the internal combustion engine, the housing including a rear handle having a hand grip portion disposed above and projecting rearwardly along the top of the housing, a muffler communicating with the exhaust port from the internal combustion engine and disposed along the forward face of the housing for discharging products of combustion forwardly of the housing, and a forward handle attached to the tubular drive shaft assembly having a hand grip portion disposed substantially above the discharge path of the products of combustion.
A narrow profile power handle assembly comprising an elongated housing including a control handle disposed above and projecting rearwardly parallel to the longitudinal axis of the housing, and a internal combustion engine enclosed within the housing having a cylinder with an axis, a piston reciprocably disposed in the cylinder for movement alternately through compression and power strokes, a crankcase, a crankshaft coupled to the piston and projecting through the crankcase along the longitudinal axis of the housing wherein the crankshaft, cylinder and control handle are substantially symmetrically disposed relative to the plane defined by the intersection of the longitudinal axis of the housing and the longitudinal axis of the cylinder.
The system for coupling the drive shaft of a prime mover disposed in a drive unit housing to an implement having a power input shaft journaled in an implement housing which comprises:
An implement for attachment to a portable power unit having an internal combustion engine driving a drive socket and a power unit housing having a tubular boss disposed coaxially with the drive socket, the tubular boss having a cylindrical interior bore and an exterior threaded section and detent means on the end thereof, the implement including an implement housing including means for threadedly engaging the exterior threads on the boss to secure the implement housing to the power unit housing, and a drive shaft journaled in the implement housing for engagement by the drive socket.
A portable power unit for driving implements comprising
A muffler for an internal combustion engine comprising an external shell having opposed first wall and second wall and a plurality of restrictive exhaust jets formed around the peripheral wall therebetween, a first tubular member forming a central exhaust inlet passageway extending through the first wall to a point adjacent the second wall, the tubular means terminating a short distance from the second wall to provide a peripheral passageway between the tubular means and the second wall having a cross sectional area less than the cross sectional area of the tubular means to thereby form a venturi effect and a reduced pressure to cool and disburse the exhaust gases, and a perforated second tubular member disposed around the first tubular member for diffusing the exhaust gases before the exhaust gases reach the exhaust jets.
A portable power tool comprising
An implement for attachment to a portable power unit having an internal combustion engine driving a drive socket and a power unit housing having a tubular boss disposed coaxially with the drive socket, the tubular boss having a cylindrical interior bore and means for securing a tubular implement housing therein, the implement including an implement housing for insertion in the tubular boss to secure the implement housing to the power unit housing, and a drive shaft journaled in the implement housing and positioned for engagement within the drive socket.
Dependencies are inferred from the claim text.