# US 4,392,033 A · Centrifugal switching system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,392,033 A - Document ID: US4392033A - Status: Granted - Kind: A - Application number: 06/251,430 - Filed: 1981-04-06 - Granted: 1983-07-05 - Earliest claimed: 1981-04-06 - Assignees: Illinois Tool Works Inc. - Inventors: Francis C. Peterson - Web page: https://patentgrep.com/patent/US4392033A ## CPC - H01H 35/10: Centrifugal switches (level of mercury displaced by centrifugal action H01H29/26) - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) ## Abstract A switch actuating device designed to control the speed of rotation of shafts, particularly electric motor shafts. A plastic hub section is designed to be positioned about the shaft, and a plurality of relatively independent, flexing leg, weight members, radially disposed from the hub and integrally connected to the hub by a thin web section, create the actuating members for acting on a switch which directly controls the rotation of the shaft. The web section is dome-like in configuration so that the top regions of the legs are at an axial plane below the uppermost region of the hub and is so designed to permit the legs to force the web upwardly snappingly into contact with the independent switch member. ## Claims ### Claim 1 In an actuator responsive to centrifugal forces for actuating a switching system in a motor assembly, an actuator member fixedly mounted on an armature shaft within the motor assembly, said actuator member comprising a hub section of a predetermined thickness and axial extent, a generally dome-like, circumferentially disposed, and substantially continuous web section extending radially outwardly from and axially in one direction relative to said hub section, said dome-like web section including a generally convex surface with a plurality of circumferentially spaced weight leg sections emanating from the outer periphery thereof, each of said weight leg sections extending axially relative to said axial extent of said hub in said one direction for a predetermined axial extent, and wherein the dome-like web includes a plurality of radially extending slots inwardly directed from the outer periphery of said actuator member, circumferentially extending means on said actuator member proximate said outer periphery for actuating a prepositioned switch mounted within said switching system, whereby as said armature shaft reaches a predetermined rotational speed said weight leg sections move radially outwardly causing said dome-like web to snap from a first position to a second position wherein said circumferentially extending means actuates said prepositioned switch when said dome-like web is in said second position. ### Claim 2 (depends on 1) An actuator member for the system described in claim 1, wherein each weight leg section has a predetermined thickness at its upper extremity, a portion of said thickness being freely extending and unconnected with the dome-like web and the adjacent legs and an inner portion of the thickness being integrally connected to the outer perimeter of the dome-like web. ### Claim 3 (depends on 1) An actuator member for the system described in claim 1, wherein each weight leg section has a differing thickness from their uppermost extremity to their lowermost extremity and the diameter at the lowermost extremity being less than the diameter at the uppermost region when said actuator is unbiased. ### Claim 4 (depends on 1) An actuator member for the system described in claim 1, wherein said circumferentially extending means includes a continuous raised rib of limited height and thickness formed on the actuator from the uppermost surface of the dome-like web and spaced inwardly from the outer perimeter of the actuator but generally directly above the innermost perimeter of the weight leg sections. ### Claim 5 (depends on 1) An actuator member for the system described in claim 1, wherein the radial extent of the slots is less than the radial extent of the uppermost extremity of the weight leg sections, each weight leg section tapering in thickness from its uppermost extremity to its lowermost extremity with the outer perimeter defined by the lowermost extremities of the weight leg sections being less than the outer perimeter defined by the uppermost extremities of the weight leg sections. ### Claim 6 (depends on 1) An actuator member for the system described in claim 1 wherein the hub and weight leg sections are injection molded to a dome-like web of spring metal. ### Claim 7 (depends on 1) An actuator member for the system described in claim 1, wherein the predetermined axial extent of the hub section is less than the predetermined axial extent of the weight leg sections. ### Claim 8 (depends on 1) An actuator member for the system described in claim 1, wherein the outermost peripheral regions of the weight leg sections are cantilever extending from the outermost perimeter of the dome-like web section, the uppermost outer surface of each said weight leg section in the composite being generally conical extending outwardly and downwardly from the outer periphery of the dome-like web. ### Claim 9 (depends on 1) An actuator member for the system described in claim 1, wherein the dome-like web section is of a predetermined radial extent greater than the thickness of the hub. ### Claim 10 (depends on 1) An actuator member for the system described in claim 1, wherein the weight leg sections, hub and dome-like web are formed as a one-piece molded thermoplastic device. ### Claim 11 (depends on 1) An actuator member for the system described in claim 1, wherein the weight leg sections are thermoplastic molded integrally to the outermost perimeter region of a dome-like web of thin spring metal, the uppermost region of the leg sections defining a predetermined radial extent inwardly from the outermost perimeter of said actuator member. ### Claim 12 (depends on 6) An actuator member for the system, described in claim 6, wherein the dome-like web includes a plurality of circumferentially spaced, radially extending slots equal in number to the number of legs, a similar number of apertures having non-circular inner peripheries each located intermediate adjacent slots and adapted to lock the injection molded leg sections to the outer periphery with a thin layer of plastic on the upper surface of the outer periphery of the dome-like web, the majority of the weight of each weight leg section extending from the lower surface of the dome-like web. ### Claim 13 (depends on 6) An actuator member for the system described in claim 6, wherein the dome-like web includes a centrally located aperture including radially extending slots serving to fixedly retain the hub when said hub is molded to the inner periphery of the dome-like web.