US 4,841,929 AGranted

Portable rotary power tool

AssigneeWhite Consolidated Industries, Inc.

InventorsLloyd H. Tuggle, Jeffery G. Sadler

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Abstract

A gasoline engine driven flexible line trimmer is provided with a modularly constructed power head section which significantly facilitates the original manufacturing assembly, and subsequent service disassembly, of the power head. In a clutch drive embodiment thereof, the power head has four readily separable modules--an engine module comprising a main engine shroud to which the engine is internally secured; a fan housing module; a starter module comprising a starter housing and a recoil starter mechanism retained therein; and a coupling module comprising a clutch housing carrying therein structure for operatively interconnecting the engine's clutch to the flexible drive shaft disposed within the trimmer shaft. In a direct drive version thereof, the power head has two separable modules--the engine module and a combined fan housing, starter and coupling module defined by a single housing within which the starter and coupling structure is carried. Pull rope installation in the starter mechanism is facilitated and made safer by pulley locking and retaining structure incorporated in the starter module, and improved air filter element sealing is provided by virtue of a specially designed air filter housing and choke plate assembly associated with the carburetor. Shaft vibration transmitted to the trimmer user through the supporting shoulder strap structure is significantly reduced by a specially designed resilient strap connector assembly securable to the trimmer shaft.

Claims26

Dependent claims

An internal combustion engine driven power tool comprising working means drivable to perform a predetermined work function;

power transmitting means for receiving rotational power from a source thereof and responsively transmitting the received power to said working means to drive the same;
and a power head assembly including:
a shroud member having an open front end, an engine support wall section spaced rearwardly from said open front end, a fuel-air mixture passage extending through said support wall section from an exterior surface thereof to an interior surface thereof, a reed valve operatively secured to said inner surface of said support wall section over said fuel-air mixture passage, and a chamber extending rearwardly of said support wall section, said chamber communicating with the interior of said shroud member and having a rear end opening;
an internal combustion engine for generating rotational power, said engine being partially enveloped by said shroud member and having a crankcase with an open rear end portion interiorly secured to said support wall section over said reed valve so that said support wall section defines a rear closure wall of said crankcase, the balance of said engine being supported from said crankcase, said engine further having a cylinder connected to a side portion of said crankcase within said shroud member, a muffler secured to said cylinder and positioned within said chamber, and a carburetor externally secured to said support wall section and operatively positioned over said fuel-air mixture passage;
housing means removably connectable to said shroud member over said open front end thereof;
coupling means, positioned within said housing means, for rotationally coupling said engine to said power transmitting means;
and
manually operable starter means, internally carried by a portion of said housing means for removal therewith from said shroud member, for starting said engine.

5 more elements

An internal combustion engine driven power tool comprising working means drivable to perform a predetermined work function;

power transmitting means for receiving rotational power from a source thereof and responsively transmitting the received power to said working means to drive the same;
and modular power head means for supplying rotational power to said power transmitting means, said modular power head means including:
an engine module comprising a shroud member having an open front end, and an internal combustion engine secured to and supported by a wall section of said member, said engine having crankcase and cylinder portions disposed within said shroud member and removable through said open front end thereof, a crankshaft having a front longitudinal portion projecting forwardly from said open front end of said shroud member and having an outer end portion, and a flywheel coaxially carried on and rotationally locked to said front longitudinal portion of said crankshaft;
a housing section removably connected to said open front end of said shroud member and enclosing said flywheel and said front longitudinal portion of said crankshaft;
coupling means, positioned within said housing section, for rotationally coupling said engine to said power transmitting means;
and
manually operable starter means, carried by said housing section for removal therewith from said shroud member, for starting said engine.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/253,303Filed 30 Sep 1988 · continuation
Priority: 17 Dec 1987
Granted: 27 Jun 1989
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

F02B 63/02
Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices: for…
F01B 1/12
Reciprocating-piston machines or engines characterised by number or relative disposition of cylinders or by being built-up from separate…:…
F02B 1/04
With positive ignition: with fuel-air mixture admission into cylinder
F02B 2075/025
Having less than six strokes per cycle: two