Abstract: A reciprocating piston engine, in particular a single-cylinder Diesel engine (2), has an air filter (1) in the suction pipe (3). To service the same, a pressure gauge (13) is arranged downstream of the filter cartridge (7), in the direction of flow. A check valve is provided at the measurement site or in the measurement pipe (12) between the measurement site and the pressure gauge (13).

Abstract: A generator is provided inside the casings of a power unit which is fitted to the rear end of a crank shaft. The generator has a stator provided to a generator cover detachably fitted to cover a rear opening of the casing. A harness extends from the stator and is led outside through a grommet provided between the joining faces of the casing and the generator cover. A space is formed behind the generator cover to insert a tool such as an impact wrench with the power unit left mounted on the vehicle body. It is possible to detach and maintain the generator only by detaching the generator cover while leaving the power unit mounted on the vehicle body.

Abstract: An air cleaner apparatus for an internal combustion engine having a filter element with a generally planar face disposed in a direction parallel to the flow of air, the apparatus includes a central portion and an air guide disposed adjacent the central portion. The central portion communicates with the air guide through the filter element. The central portion has at least one air inlet in operative communication with the engine for permitting the flow of air from the air guide through the filter element and into the engine. The air guide includes an air scoop and an air exhaust, each disposed in a plane generally perpendicular to the direction of the flow of air relative to the housing. The air scoop and the air exhaust are disposed at opposite ends of the filter element such that a portion of the flow of air entering the air guide through the air scoop enters the central portion through the face of the filter element. The remainder of the flow of air exits the air guide through the air exhaust.

Abstract: An improved centrifugal air cleaning system including a fan, a fan volute defined, in part, by a curved outer wall and a base wall, and a deflector wall projecting from the base wall intermediate the fan and the outer wall. An air inlet port is formed in the base wall and is located between the deflector wall and the outer wall. The deflector wall includes a first wall portion and a second wall portion. The first wall portion has a curvature generally matching a curvature of the fan while the second wall portion diverges from the fan toward the outer wall. The first wall portion prevents radially projected particles from reaching the air inlet port while the second wall portion cooperates with the outer wall to define a restricted flow path downstream of the air inlet port that creates a relatively high pressure condition at the inlet port and injects substantially particle-free air into the carburetor.

Abstract: An air path is provided in the main body of a chain saw so as to connect an air inlet port provided on the main body and a carburetor chamber of the internal combustion engine and also connected to a cooling fan chamber. For use under normal conditions, combustion air is taken from the air inlet port into the carburetor chamber. In case of a rainy or snowy day, the air inlet port is closed and combustion air is taken from the cooling chamber into the carburetor chamber, air control means is provided between the air path and the cooling fan chamber. This air control means generates stagnation of air flow in the cooling chamber in order to supply air into the carburetor chamber and prevent dust and the like from being taken into the air path.

Abstract: An air cleaner apparatus for an internal combustion engine having a filter element with a generally planar face disposed in a direction parallel to the flow of air, the apparatus includes a central portion and an air guide disposed adjacent the central portion. The central portion communicates with the air guide through the filter element. The central portion has at least one air inlet in operative communication with the engine for permitting the flow of air from the air guide through the filter element and into the engine. The air guide includes an air scoop and an air exhaust, each disposed in a plane generally perpendicular to the direction of the flow of air relative to the housing. The air scoop and the air exhaust are disposed at opposite ends of the filter element such that a portion of the flow of air entering the air guide through the air scoop enters the central portion through the face of the filter element. The remainder of the flow of air exits the air guide through the air exhaust.

Abstract: An engine assembly for powering a watercraft that has a front cover which contains a number of electrical components for the engine including the flywheel magneto of the engine, a CDI ignition system for firing the spark plugs and additional components. This permits ease of servicing and reduces the number and length of the interconnecting electrical conduits.

Abstract: A hand-held tool such as a chain saw has a housing and a combustion engine enclosed in the housing. The working tool is driven by the combustion engine. An air filter box has a filter element for dividing the filter box into a dirt room and a clean room. The air filter box is closed off by a lid. A suction channel connects the clean room to the combustion engine. An air inlet channel for guiding dirt-laden air into the dirt room of the air filter box is provided. The air inlet channel extends substantially straight and upwardly. A suction tube is connected to the suction channel and projects into the clean room for extending the suction channel. The air inlet channel is located in the lid and extends substantially transverse to the suction tube.

Abstract: A seal and fastener isolator system for a thermoplastic valve cover that has the seal made of a silicone rubber and is integrally formed with the fastener isolator so as to allow the entire assembly to be manufactured in one molding operation.

Abstract: A sealing assembly for use with an internal combustion engine includes a gasket of elastomeric material inserted within a groove formed in the surface of an engine part. The gasket has an anchoring portion which fits within the groove and a sealing portion extending outside of said groove. The bottom, side and top walls of the groove form a retaining portion which is at least 5% larger than the anchoring portion of the gasket at the time of assembly. The anchoring portion may expand and fill the retaining portion of the groove upon exposure to the engine fluids. At least one top wall of the retaining portion of the groove opposes a shoulder of the anchoring portion of the gasket at an interior angle of not more than about ninety degrees.

Abstract: An air filter for an internal combustion engine has a housing with an interior chamber. The housing has housing walls at least one of which is in the form of a filter element. One of the housing walls has a suction opening for connecting the air filter to a suction channel of the combustion engine, wherein combustion air flows through the filter element into the interior chamber and from the interior chamber through the suction opening into the combustion engine. Air flow resistance elements are arranged in the interior chamber upstream of the suction opening. The air flow resistance elements are arranged in a first and a second row. The first and second rows are spaced apart from one another in the direction of flow of the combustion air. The air flow resistance elements of the first row of the second row are spaced laterally from one another to form gaps therebetween. The air flow resistance elements of the first row are positioned so as to be substantially aligned with the gaps of the second row.

Abstract: The present invention provides an air cleaner assembly including an air cleaner housing includes an air inlet connected with an air duct through which atmospheric air is introduced and an air outlet connected with an intake hose for supplying the air to a combustion chamber, a filter element disposed in the air cleaner housing to filter out impurities within the air, a slot formed on the air cleaner housing to slidably mount the filter element in the air cleaner housing, and a guide rib for securely mounting the filter element which is inserted into the slot.

Abstract: A dirt and debris screen for liquid cooled internal combustion engines comprises a disc or shallow formed cup of perforated mesh attached to the fan hub or fan shaft just upstream of the radiator and fan. Rotating at fan speed dirt and debris collected by the disc is centrifugally ejected from the edge of the disc and thereby prevented from entering the air passages through the radiator. The centrifugal ejection also makes the disc substantially self-cleaning.

Abstract: A cover (10) is for use on a multi-cylinder overhead camshaft engine (20) having a pair of projecting members (112, 120). The cover (10) has a plurality of walls (300-308) for intercepting oil sprayed from the camshaft (80) of the engine. A pair of tubular projections (328, 330) connected with one wall (300) of the cover are engageable in a press fit relationship with the projecting members to support the cover in a position adjacent to the camshaft. A plurality of ribs (310-324) are disposed generally above the camshaft and extend parallel to the camshaft for catching and collecting oil sprayed from the camshaft and for dripping the oil down onto the camshaft. A W-shaped rib (326) on the inside of the cover collects oil flowing along the inside of the cover. The oil drips down from points (476, 486) of the W-shaped rib to lubricate selected portions (180, 206) of the engine. A multi-cylinder cover assembly (42, 60) encloses a plurality of the covers (10).

Abstract: A two-stroke internal combustion engine for a motor saw includes a crankcase (12), a fan housing (19) having an impeller (20), and a carburetor chamber (17) having a carburetor (16). An intake passage (15) connects the carburetor to the crankcase and the carburetor chamber is connected via an inlet passage (21) to the fan housing at the outlet side of the impeller for centrifugal purification of combustion air. The carburetor chamber (17) has an opening (22) connected to atmosphere or to a lowpressure zone of the fan housing (19).

Abstract: The combination apparatus, preseparator, vacuum regulator and check valve silences and filters air flow and separates air-contaminant mixtures. The combination apparatus comprises an annular housing having an outer wall and a channel defining a central axis. The channel has a primary gas inlet coupled to an air filter, a primary gas outlet coupled to an engine induction system, and a channel wall therebetween. A secondary inlet port passes through the outer wall and a secondary inlet port defines an opening in the channel. A baffle is axially disposed within the housing defining a first and second flow passageway. Second baffles are disposed within the first and second passageways to effect serpentine flow through each flow passageway and filter material is disposed within each flow passageway. A preseparator is coupled between the secondary inlet and an engine breather and has an annular housing with preseperator baffles disposed therein for effecting serpentine flow therethrough.

Abstract: A pressure side integrated air filter assembly for a turbocharged engine includes an air filter carrier which is designed and arranged to receive an air filter element and which is adapted to mount to the intake manifold of the turbocharged engine. The air filter carrier which receives an air filtering element is disposed within the intake manifold and the intake manifold cover serves as the air filter cover. A peripheral flange on the air filter carrier is used to support the air filter assembly by being clamped between the intake manifold cover and the intake manifold. This peripheral flange substitutes for the intake manifold gasket. The air filter carrier and the air filter element each have a trapezoidal shape in cross section as a way to conserve space within the intake manifold.

Abstract: A method and apparatus for increasing the internal height of a casing of an air cleaner for an engine in order to accommodate a larger air filter. A larger air filter is accommodated by increasing the distance between the upper and lower members of the casing by increasing the thickness of the air filter's peripheral flange or by adding a spacer element between the upper and lower members.

Abstract: Most existing noise reduction enclosures used with engines and engine driven equipment have failed to meet the reduced noise emission requirements of today and of the future. A few of the present enclosures meet the reduced noise emission requirements of today and of the future but are extremely expensive to purchase and are large bulky structures. The subject enclosure (10) is reasonably priced and provides an enclosure which is effective in reducing the noise emitted therefrom. The enclosure (10) includes a housing (32) having a generally rectangular configuration and being divided into an engine portion (56) defining an engine compartment (57) and a duct portion (54). The outlet ducts (88) having a length greater than the inlet ducts (84). To further enhance the noise reduction of the enclosure (10) a plurality of dynastic hardware is attached to the housing (32).

Abstract: For regenerating an exhaust gas particulate collecting filter, there is provided an exhaust gas particulate purifying process in which damage to the filter caused by a thermal action can be prevented and further electric power can be saved when an electric current supply to an electric heater attached to the filter is controlled. In the filter container (4), an electric heater (21) is provided on an end surface of the filter on an upstream side with respect to a regenerating gas flow, or provided at a position close to the end surface. Also, a temperature sensor (22) for measuring a temperature of the filter is provided inside the filter or at a position close to an end surface of the filter opposite to the aforementioned end surface.

Abstract: The invention concerns an arrangement relating to a cutting machine, a circular saw machine, a chain saw machine or the like, which is powered by an internal combustion engine. The machine comprises a working unit and a power unit, the power unit comprising at least a pre-filter and a main filter for intake air, and a motor cylinder. The pre-filter and the main filter are provided in a closed pre-filter chamber and in a closed main filter chamber, respectively, the pre-filter chamber forming a top portion of the power unit extending substantially over the entire length and substantially over the entire width of the power unit. The main filter chamber is located under the pre-filter chamber. A closed hood space is provided between the upper side of the pre-filter body and the inside of the roof of a filter cover, and a passage extends from the closed hood space at the side of or through the pre-filter chamber and the pre-filter body, down to the main filter chamber located under the pre-filter chamber.

Abstract: An engine generator set apparatus including an internal combustion engine including a drive shaft driving an electrical generator, the engine and the generator being disposed along a longitudinal axis. A housing substantially enclosing the engine and generator, the housing including air inlets and air outlets. A fan drawing outside ambient air through the air inlets in the housing and along an inlet air pathway, the generator being axially disposed intermediate of the fan and the engine.

Abstract: Disclosed herein is an outboard motor comprising a cylinder block having a horizontally extending lower mounting surface and a rearwardly located vertically extending cylinder head mounting surface, a cylinder head fixed to the cylinder head mounting surface, extending rearwardly from the cylinder block, and including a bottom wall portion having therein a rocker arm support shaft aperture and a camshaft aperture, a camshaft supported vertically and horizontally in the cylinder head about an axis located rearwardly of the cylinder head mounting surface, a rocker arm support shaft supported vertically and horizontally in the cylinder head about an axis located rearwardly of the cylinder head mounting surface, and a lower unit including a driveshaft housing supporting a propeller fixed to the cylinder block lower mounting surface and including an upper rearward profile located forwardly of the camshaft aperture and the rocker arm support shaft aperture and extending so as to enable, when the housing is fixed to

Abstract: A generator engine set includes a brush partition for separating a space defined between an air blower housing and an enclosure into two areas so that an air flow from one area to the other area is substantially prohibited. The brush partition includes a flexible bristle portion and a rigid spline portion. The spline portion is retained in a receiving member on an outer surface of the air blower housing by a clip. The bristle portion extends toward the enclosure and engages an inner surface of the enclosure. Accordingly, a warmed air flow is prohibited from recirculating back into cooling air inlets.

Abstract: An automotive drip pad assembly having an elongated drip pan with an oil absorbent pad attached to its top surface. The drip pan has a front wall, a rear wall, and laterally spaced side walls that form an open top container. Cylindrical bosses on the walls of the drip pan have vertical bore holes that receive the inner ends of four tie wires that are attached thereto. The outer ends of the tie wires are attached to fixed structural members on the under side of the vehicle. The drip pan can be positioned beneath the vehicle anywhere oil or oil related products leak.

Abstract: An air filter for an internal combustion engine which has a filter insert is arranged in a housing having a clean air outlet and an unfiltered air inlet provided with a screen. An auxiliary unfiltered air inlet is also provided which is closed by a flap under normal operating conditions but which opens under the influence of a negative pressure generated in the filter housing if the screen becomes clogged because of snow or ice entrained in the air stream, so that air can enter the filter through the auxiliary air inlet.

Abstract: A filter system for filtering the air intake of an internal combustion engine including a housing having a bottom half and a cover half, at least two filter inserts each consisting of pleated filter paper or filter batting, and a circumferential gasket. The two filter inserts are connected by a junction strip which simultaneously seals the raw air chamber from the clean air chamber between the two filter inserts.

Abstract: The invention relates to a cutting machine, circular saw machine or the like powered by an internal combustion engine. The machine comprises a cutting unit or corresponding unit having a rotational tool, and a power unit, which comprises an air-cooled motor cylinder in a motor room limited by a casing which at least partly consists of a cylinder cover; and an impeller rotatable about the crank shaft with impeller wings, which during rotation propels a cooling air flow outwards toward the periphery of a fan housing and further to the motor room under and inside the cylinder cover. At least a first filter chamber with a filter for intake air for the internal combustion engine is provided over the cylinder cover, and a nozzle tube for the intake air extends from an intake port close to the periphery of the impeller up through the motor room terminating in the at least first filter chamber over the cylinder cover.

Abstract: This invention is directed to multi polymer structures for internal combustion engines, as well as structures for other vehicle drive train parts. For example, a valve rocker cover for an internal combustion engine in accordance with this invention is a composite of at least two different molded thermoplastic resins, which structure comprises a valve cover body molded of a polybutylene terephthalate resin and a sealing flange molded of a polyetherimide resin, with both parts in a bonding relationship. The valve rocker cover can also have attached to the underside a sealent so as to provide a seal between the valve cover and engine block when so assembled. The method of producing a composite in accordance with this invention is either insert molding or coinjection molding.

Abstract: An air cooled internal combustion engine for a hand-held power tool has a flywheel fan that is rotated within a fan housing. The bottom of the fan housing, which is perpendicular to the axis of rotation of the fan, includes an opening for an air duct. Ramps axe formed around the leading edges of the duct opening, either on a plate (metal or plastic) attached to the housing or integrally with the bottom wall, for deflecting solid particles entrained in the air away from the outlet. A relatively particle-free stream of pressurized air stream is diverted into the duct and delivered to an air intake box containing an air filter and carburetor.

Abstract: A filter cover for an air cleaner assembly of an internal combustion engine. The filtering cover is composed substantially of filtering material which filters air as the air is drawn through the filtering cover and into the air cleaner assembly. The filtering cover greatly increases the air filtering surface area of an air cleaner assembly resulting in improved performance and operation of the engine.

Abstract: A cooling air blower for a combustion engine for a two-stroke engine of a hand-held working tool has a cooling air channel for supplying cooling air to a combustion engine and a blower fan for conveying air into the cooling air channel. A combustion air channel branches off the cooling air channel for guiding combustion air to an intake member of the combustion engine. The combustion air channel has a section extending adjacent to the cooling air channel. The combustion air channel has furthermore an air intake socket within that section, the air intake socket being narrower than the cooling air channel and extending transverse, when viewed in a plan view, to a main air flow direction of the cooling air channel into the cooling air channel. The air intake socket is positioned at a slant relative to the main air flow direction and has an inlet opening located on a side of the intake socket facing away from the blower fan.

Abstract: A portable work producing apparatus, such as a chain saw, has an engine cooled by air from a blower driven by the engine. The engine's carburetor is pressurized with clean air from the blower. The blower includes a centrifugal impeller mounted within a fan housing having a set of blades for creating a vacuum to draw air into the housing. The impeller has a second set of relatively low-profile blades underneath the impeller for creating a vacuum under the impeller that draws air in through holes defined through the hub of the impeller. The air drawn through the holes is supplied to the carburetor. A circular screen extends from the axis of the impeller over the holes. Small particles entrained in the air stream entering the housing tend to be carried by the predominant portion of the stream into the housing. The screen is positioned and of a size that the trajectories of more massive particles entering the housing that are not blown into the housing bounce off the screen.

Abstract: A number of embodiments of crankcase ventilating systems for gas powered internal combustion engines employed in heat pumps. The crankcase ventilating system includes an oil vapor separator for separating and condensing oil from the crankcase ventilating gases and returning water vapor and the crankcase ventilating gases to the engine induction system for further combustion and purification. A number of various arrangements for controlling the temperature of the oil vapor separator are disclosed and an embodiment is disclosed that employs a pair of oil vapor separators acting in series.

Abstract: An intake assembly of the present invention delivers air to a carburetor of an internal combustion engine. The assembly includes a housing mountable on the carburetor and which encloses an air filter. A first port is formed within a wall of the housing to permit fluid communication between the housing and the carburetor. The first port is positioned between the air filter and the carburetor. A second port is formed in a wall of the housing to permit air to enter the housing. The second port is positioned relative to the air filter on a side opposite from the first port. A valve assembly is pivotably mounted within the second port such that the valve assembly is positionable to control an air flow through the second port. Means are provided for controlling the pivoting of the valve assembly.

Abstract: Most existing noise reduction enclosures used with engines and engine driven equipment have failed to meet the reduced noise emission requirements of today and of the future. A few of the present enclosures meet the reduced noise emission requirements of today and of the future but are extremely expensive to purchase and are large bulky structures. The subject enclosure (10) is reasonably priced and provides an enclosure which is effective in reducing the noise emitted therefrom. The enclosure (10) includes a housing (32) having a generally rectangular configuration and being divided into an engine portion (56) defining an engine compartment (57) and a duct portion (54). The outlet ducts (88) having a length greater than the inlet ducts (84). To further enhance the noise reduction of the enclosure (10) a plurality of dynastic hardware is attached to the housing (32).

Abstract: An engine air intake screen assembly having a rotating screen is provided. A blade is positioned directly under the screen to scrape accumulated debris off the inside surface of the rotating screen, and to also chop debris flowing through the screen. The screen covers an opening in a blower housing and rotates when the engine is running. In one form, a set screw allows the clearance distance between the blade and the inside surface of the rotating screen to be adjusted.

Abstract: A cooling structure for a motor section of a working vehicle with an engine having a vertical output shaft and mounted in an engine hood having an ambient air intake opening defined in an upper surface thereof, and a fan disposed above the engine to draw in cooling air. The cooling air is guided by an air guide cover to flow to a cylinder head and a carburetor attached to a side wall of the cylinder head. The motor section further includes a muffler disposed adjacent and below the carburetor. A muffler cover is disposed between the carburetor and muffler. Part of the air having cooled the carburetor is used to cool an upper surface of the muffler cover. The remaining part of the air having cooled the carburetor is directed under the muffler cover for use in cooling the muffler.

Abstract: A mounting arrangement is provided for mounting the air cleaner for an internal combustion engine in a vehicle. The air cleaner generally includes a casing having air inlet and outlet openings and an open side, a pot-shaped housing containing a filter element and having an open side selectively attachable to the open side of the casing. The mounting arrangement provides two substantially parallel and horizontal rods upon which the air cleaner can be placed. The air cleaner can be held to the rods by a variety of techniques, including hooks and guide rings. The mounting structure allows the housing to be detached and slid away from the casing for cleaning or replacement of the filter element, then be accurately realigned with the casing so that an accurate seal can be engaged.

Abstract: The invention is directed to a cooling-air blower for an internal combustion engine including a two-stroke engine of a portable handheld work apparatus. Cooling air is guided by a cooling-air channel to an internal combustion engine and a combustion-air channel conducts air to the intake pipe of the engine. A portion of the cooling-air flow is tapped at the pressure end of the blower. A segment of the combustion-air channel is disposed next to the cooling-air channel. A profile hollow body having a streamlined configuration extends from this segment of the combustion-air channel into the cooling-air channel. The profile hollow body is aligned at its location in the cooling-air channel with the flow direction of the cooling-air flow and has a rear end facing away from this flow. An inlet opening is provided in this rear end of the hollow body for receiving a portion of the cooling-air flow which is then passed to the combustion-air channel through the hollow body.

Abstract: This invention relates to ventilation of the engine bay and engine in an automotive vehicle and utilizes a hot air channel to conduct hot air emitted by the heat-exchanger and a cold air by-pass channel for supplying unheated fresh air directly to the engine.

Abstract: A portable, hand-held blower/vacuum unit has a housing structure defined by an upper engine shroud removably connected to the top wall of a lower impeller housing. Disposed within the shroud is a small internal combustion engine having a vertical crankshaft which extends downwardly through a depending well section formed on the top wall of the impeller housing, the lower shaft end being drivingly connected to a centrifugal fan impeller positioned within the impeller housing and operative to force a flow of ambient air therethrough. The engine is resiliently and floatingly mounted within the shroud by a resilient support system which prevents rigid contact between the engine and the shroud or the impeller housing to thereby substantially reduce engine vibration transmitted to the housing structure, and permit deflection of the engine relative to the housing structure to lessen the possibility of engine damage caused by impeller impact from ingested objects.

Abstract: A front cover has at a front surface central portion thereof an integral mounting seat for installation of a mounting bracket and at a rear surface central portion thereof an integral boss adapted to extend between the mounting seat and a front end of a cylinder head and cylinder block assembly. The boss is fastened together with the mounting bracket to the front end of the cylinder head and cylinder block assembly. A resilient sealing member is interposed between the peripheral end of the front cover and the front end of the cylinder head and cylinder block assembly such that the front cover is supported rigidly at the boss together with the mounting bracket and resiliently at the peripheral end upon the front end of the cylinder head and cylinder block assembly.

Abstract: In a motor saw comprising an engine portion and a handle portion, the engine portion comprises a carburetor (17) located in a separate carburetor chamber (13) and connected to the cylinder (10) of the engine by means of a flexible inlet tube (18) passing through a partition wall (15) between the carburetor and the cylinder. For reducing vibrations transmitted to the carburetor, a supporting means is provided between the carburetor and the handle portion. The supporting means comprises a link (22) which is articulately connected to the carburetor as well as to the handle portion.

Abstract: A liquid-cooled internal combustion engine having a piston-controlled exhaust, particularly a two-stroke cycle internal combustion engine, is provided with a generator or a magneto-generator unit and with a lubricating oil pump. The cylinder head is provided with a cap, which defines a space for cooling liquid and extends over the cylinder approximately as far as to the exhaust port and at its end that is adjacent to the crankshaft has a sealing surface. In order to minimize the transmission of solid-borne sound and the radiation of sound, the cap and the cover for the oil pump are secured by means of collar screws, which have been tightened against a stop, and a washer provided with a vulcanization-bonded rubber layer is disposed between the head of each of said screws and the cap or the cover.

Abstract: A heat shield for shielding the solenoid of an engine starter from heat generated by an internal combustion engine. The shield is formed of metal and has a first pair of deflectable spring arms for securing the heat shield to a solenoid of an engine starter. The arms have arcuate portions that are adapted to engage the case of the solenoid and the arms are deflected apart when the shield is assembled to the solenoid. The arms then spring back toward each other to tightly grip the solenoid. The heat shield has another pair of deflectable arms the end portions of which are adapted to engage fasteners that secure the shield to the drive housing of an engine starter. The heat shield has a deflectable spring finger that is adapted to engage the solenoid to prevent vibration of the heat shield.

Abstract: The invention is directed to a portable handheld work apparatus including a motor-driven chain saw, cutoff machine and the like. The work apparatus includes a housing and an internal combustion engine mounted in the housing for driving a work tool. The housing defines a space from which said engine draws combustion air and a fan wheel is disposed in the housing for generating a cooling-air flow which leaves the fan wheel in a direction tangential to the periphery of the fan wheel for cooling the engine. The housing has a U-shaped channel for conducting the cooling-air flow. The U-shaped channel is disposed so as to face toward the fan wheel with the base wall thereof being disposed at a predetermined spacing from the periphery of the fan wheel. The U-shaped channel has a pass-through formed in the base wall at a pregiven spacing downstream from the fan wheel for passing a portion of the cooling-air flow to the space as combustion air for the engine.

Abstract: A gasket assembly and method of making same from at least two gasket structures provides a sufficiently leak-proof seal without the use of a fluid sealing or caulking medium. The first gasket has a contact area on a major surface which includes an array of peaks and valleys which is periodic in two dimensions. The second gasket has an end surface with a contact area which includes an array of valleys and peaks which is periodic in two dimensions. When the peaks and valleys on the contact area of the major surface of the first gasket are engaged with the valleys and peaks on the end surface of the second gasket, the peaks and valleys allow for shift along the x-axis, y-axis and z-axis, accommodating any misalignment of the gaskets within a predetermined stack-up error and thereby providing proper engagement to yield a substantially leak-proof seal.

Abstract: A portable, hand-held blower unit is powered by a small internal combustion engine having movable choke and throttle control elements linked to a single adjustment knob. Rotation of the knob between full throttle and full choke positions thereof simultaneously adjusts the engine's throttle and choke settings and maintains predetermined engine start and run positional relationships therebetween. The engine carburetor has mounted thereon a specially designed air intake box which substantially reduces engine air intake noise. In the normal operating position of the unit the engine drive shaft is generally vertically oriented, with the carburetor being secured to the top of the engine and the underside of the air intake box. The lower end of the drive shaft is coaxially secured to the unit's blower fan impeller which is spaced upwardly apart from a pull rope starter pulley rotatably carried by the fan impeller housing.

Abstract: An arrangement for mounting an electronic control unit on an internal combustion engine which protects the unit from structural and thermal damage.