Marathon Electric Mfg. Corp.

Marathon Electric Manufacturing Corportion

Duane R Nolte

Michael A Logsdon

Gary L Schurter

Gary L Shurter

David L Konkol

A centrifugal actuator for operating a motor start winding switch includes a base fixed to the shaft as a bearing shoulder and a hub slidably mounted to the base by a groove mating projection and grooves. The hub has a flange which actuates the switch. The hub and base include stops which limit the hub travel. Diametrically opposite hinge units on the base receive offset pivot arms including a pivot rod held in the unit by weight connected coil springs. The weights are L-shaped having heavy plate and offset levers having a hinge or pivot plate therebetween. The pivot plate is offset from the plane of the levers and includes an opening forming the pivot rod having a coined pivot edge. The base hinge units have hook members within which the rod pivots. The outer tab of the hook enters the pivot plate opening in the run position to lock the weight in place. The base is secured to the shaft with an end surface to function as a shoulder for a bearing. The base is mounted with loaded portions to prevent base creeping or deflection. The base and hub are weight balanced for vertical motors. The pivot rod is located to place the pivot point of the weight at substantially the center of the mass of the weight, giving due consideration to the hub.

Centrifugal actuator for controlling a switch unit particularly a start winding switch unit for an electric motor

A centrifugal switch assembly for a single phase induction motor connecting a start winding and/or start capacitors in circuit. A centrifugal actuator positions a contact unit on a cantilevered spring arm relative to an aligned fixed contact unit. Each contact unit is identically constructed with a cylindrical steel base and an outer contact button which defines a radial lip. A silicone rubber boot in the form of a tubular member having similar thick end hubs connected by a thin-wall convolution between the hubs to establish a flexible enclosure. The hubs are telescoped respectively over the contact bases with the same interference fit to totally enclose the contact units. The lips of the contact buttons lock the boot to the contact units. The boot length is greater than the spacing of the open contact units and the convolution is continuously deflected to create a closing force. A pressure relief pin hole is formed in a crease at the connection of the convolution and the hub secured to the final contact unit to allow air flow from the enclosed contacts and uninterrupted closure of the switch assembly.

Enclosed electrical contact assembly for dynamoelectric machines

A centrifugal switch assembly for a single phase induction motor connects a start winding and/or start capacitors in circuit. A centrifugal actuator positions a contact unit on a cantilevered spring arm relative to an aligned fixed contact unit. Each contact unit is identically constructed with a cylindrical steel base and an outer contact button which defines a radial lip. A silicone rubber boot in the form of a tubular member having similar thick end hubs connected by a thin-wall convolution between the hubs to establish a flexible enclosure. The hubs are telescoped respectively over the contact bases with the same interference fit to totally enclose the contact units. The lips of the contact buttons lock the boot to the contact units. The boot length is greater than the spacing of the open contact units and the convolution is continuously deflected to create a closing force. A pressure relief pin hole is formed in a crease at the connection of the convolution and the hub secured to the fixed contact unit to allow air flow from the enclosed contacts and uninterrupted closure of the switch assembly.

A standard induction motor includes an outer bearing including first and second end brackets joined to the opposite end of a tubular main frame by through bolts. Each of the end brackets is a cup-shaped member with a circular outer wall and a flat outer radial wall. The first end bracket has four spaced air inlet openings in the circular wall with axial cross bars forming elongated air passageways. A separate rodent guard unit is secured to each ventilation opening and includes an outer plate abutting the exterior of the circular wall and having integral clip members engaging edges of the ventilation opening. Each plate has circumferentially elongated openings extending across the cross bars to form small rodent excluding passageways. The second end bracket has a L-shaped ventilation opening in the circular wall and the radial wall. An L-shaped rodent guard has axially spaced wires overlying the air outlet opening in the circular wall and radially spaced wires overlying the ventilation opening in the radial wall. The wires are connected to each other by circumferentially spaced L-shaped support wires. Two of the radial wires abut the radial wall to opposite ends of through bolt openings and are secured in place by the through bolts and spanning a washer.

Ventilating apparatus for dynamoelectric machine with animal restricted

A centrifugal switch assembly for a single phase induction motor connects a start winding in circuit to start the motor. A centrifugal actuator positions a movable contact on the end of a cantilevered spring arm relative to an aligned fixed switch carried by an insulating flat plate secured within the motor. A silicone rubber boot in the form of a tubular member has a first heavy end telescoped over the movable contact with a resilient gripping of the side of the contact. The opposite end of the boot is a heavy end which is freely telescoped over the opposite contact into engagement with the flat plate to totally enclose the contacts, but may also be attached to the contact with a resilient grip. The boot has an intermediate convolution between the two ends. The convolution is formed as a very thin wall to establish a highly flexible but supporting wall member. The boot length is greater than the spacing of the open contacts and the convolution is continuously deflected to create a compressive support of the boot between the flat plate and the movable contact. The contacts open to de-energize the circuit during the starting of the motor. The boot may have more than one convolution between the mounting the fixed contact ends. The boot is formed from a special silicone rubber and is specially processed and stored in a sealed enclosure prior to assembly.

Growing community of inventors

Wausau, WI, United States of America

Duane R Nolte