The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 28, 1999
Filed:
Apr. 18, 1997
Stuart V Holsten, O'Fallon, MO (US);
Joseph T Gierer, Glen Carbon, IL (US);
Karmen D Cox, St. Peters, MO (US);
James I Metzger, Jr, Ballwin, MO (US);
Emerson Electric Co., St. Louis, MO (US);
Abstract
A switch and speed control assembly for use in a wet/dry utility vacuum or blower is disclosed. The switch and speed control assembly provides a single rotary control actuator for turning the vacuum or blower on and off, for infinitely varying the speed of the motor, and for providing a momentary boost control. The switch and speed control assembly includes a thumb wheel fitted to the shaft of a voltage varying potentiometer, a snap action switch in operable relation to the exterior edge of the thumb wheel, and a compression spring contained beneath the thumb wheel. As the thumb wheel is rotated in an increasing 'on' direction, the contacts of the snap action switch are closed, allowing electric current to flow to the motor of the wet/dry utility vacuum or blower. The voltage levels in the motor, and correspondingly the speed of the motor, are controlled by varying the potentiometer voltage through rotation applied to the thumb wheel. During boost operating conditions, the thumb wheel engages the compression spring such that when the force engaging the momentary boost condition abates, the thumb wheel returns to a normal operating condition. Additional features incorporated in the switch and speed control assembly include: mechanical stops for both the 'Off' and 'High On' modes; a static guard to protect the electrical components and the user from static discharges; fastener free mounting within wet/dry utility vacuum or blower housings; a configuration designed to prevent mechanical loads present on the thumb wheel from being transferred to the potentiometer shaft and other electrical components, such as the switch; and internal wire routing designed to minimize inductive influences between the wires.