Ignition systems for portable power tools

An ignition system for a portable power tool having a carburetor and an ignition circuit comprising:

• a housing for holding an air filter, the housing having a port in communication with a port in the carburetor for the passage of air from the housing to the carburetor;
• means on the housing by which the housing may be secured to the portable power tool, and a mounting element on the housing for the mounting thereon of an ignition switch for the portable power tool;
• a choke lever connected to an air valve for controlling the flow of air to the carburetor, the choke lever being reciprocally movable between a first position in which air flow to the carburetor of the portable power tool is not substantially restricted and a second position in which air flow to the carburetor is substantially restricted, the choke lever including a depending abutment;
• an ignition switch positioned on the mounting element so as to be movable between a run position in which the power tool may be operated and a stop position in which the power tool may not be operated, the ignition switch including a depending abutment located in the line of reciprocal movement of the depending abutment of the choke lever when the ignition switch is in the stop position so that reciprocal movement of the choke lever from the first position to the second position causes the depending abutment on the choke lever to engage the depending abutment on the ignition switch and move the ignition switch from the stop position to the run position;
• and
• a leaf spring engaging the ignition switch at a first site of engagement on the ignition switch when the ignition switch is in the stop position and engaging the ignition switch at a second site of engagement on the ignition switch when the ignition switch is in the run position, the leaf spring being biased for alternatively applying a force to the ignition switch at the first and second sites of engagement in a direction toward the mounting element and away from the choke lever.

An ignition system for a portable power tool having a carburetor and an ignition circuit comprising:

• a housing for holding an air filter, the housing including a housing base and a housing cover for the housing base, the housing base including;
• a housing base floor including ports through which air may flow to the carburetor and means by which the housing base may be attached to the carburetor;
• a housing base perimeter wall integral with the housing base floor and extending, generally, perpendicularly from the perimeter of the housing base floor in the direction of the housing cover, the housing base perimeter wall having an inside surface and an outside surface, the inside surface of the housing base perimeter wall and the housing base floor defining a housing base interior, and the housing base perimeter wall including an anterior section, a posterior section, a first lateral section joining one terminus of the anterior section to one terminus of the posterior section and a second lateral section joining the other terminus of the anterior section to the other terminus of the posterior section such that when the housing is installed in the portable power tool the anterior section is nearest the front of the power tool, the posterior section is nearest the rear of the power tool and the first and second lateral sections are disposed toward opposite sides of the power tool;
• an augmentation integral with the first lateral section of the housing base perimeter wall, the augmentation extending, substantially perpendicularly from the housing base floor in a direction away from the housing cover;
• a pair of opposed support legs for securing the housing base to the chassis of the portable power tool, a first of the opposed support legs being integral with the augmentation and the second of the opposed support legs being integral with the second lateral section of the housing base wall;
• a mounting element integral with the outside surface of the first lateral section of the housing base perimeter wall for the mounting thereon of an ignition switch for the portable power tool;
• a choke lever connected to an air valve for controlling the flow of air to the carburetor, the choke lever being reciprocally movable between a first position in which air flow to the carburetor of the portable power tool is not substantially restricted and a second position in which air flow to the carburetor is substantially restricted, the choke lever including a depending abutment;
• an ignition switch positioned on the mounting element so as to be movable between a run position in which the power tool may be operated and a stop position in which the power tool may not be operated, the ignition switch including a depending abutment located in the line of reciprocal movement of the depending abutment of the choke lever when the ignition switch is in the stop position so that reciprocal movement of the choke lever from the first position to the second position causes the depending abutment on the choke lever to engage the depending abutment on the ignition switch and move the ignition switch from the stop position to the run position;
• and
• a leaf spring engaging the ignition switch at a first site of engagement on the ignition switch when the ignition switch is in the stop position and engaging the ignition switch at a second site of engagement on the ignition switch when the ignition switch is in the run position, the leaf spring being biased for alternatively applying a force to the ignition switch at the first and second sites of engagement in a direction toward the mounting element and away from the choke lever.