Motor operated tap changer employing contact drum switches

Claim 2

A position selector control device for tap changing apparatus comprising first and second rotary drum switches each having a rotary contact assembly and a plurality of fixed contacts, said rotary contact assemblies being connected to a motor which moves the tapping contacts so that one said rotary contact assembly rotates in a direction which increases the number of fixed contacts it touches while the other said rotary contact assembly rotates in a direction which decreases the number of fixed contacts it touches, and said fixed contacts of said first rotary drum switch being electrically connected to said fixed contacts of said second rotary drum switch at respective positions to form a plurality of fixed contact pairs, said rotary contact assemblies always being relatively positioned so that only one of said fixed contact pairs is not touched by either of said rotary contact assemblies.

Claim 3

The position selector control device for tap changing apparatus of claim 1 including a selector switch having a plurality of contact sets each being electrically connected to said fixed contact pairs of said rotary drum switches through patch panel means, said patch panel means allowing a quick change of the electrical connection of said selector switch contact sets from one of said fixed contact pairs to another of said fixed contact pairs.

Claim 4

A position selector control device for tap changing apparatus comprising a selector switch, first and second rotary drum switches, first and second motor relays, said selector switch having a plurality of contact sets which are electrically connected to said rotary drum switches, said first and second motor relays being electrically connected to said first and second rotary drum switches, means energizing said first motor relay to cause a motor to move the tapping contacts in one direction and means energizing said second motor relay to cause said motor to move the tapping contacts in the opposite direction, said rotary drum switches each having a rotary contact assembly which is connected to said motor so that closing a set of contacts of said selector switch causes one of said motor relays to energize until one of said rotary contact assemblies rotates to a position which deenergizes said motor relay.

Claim 5

A position selector control device for tap changing apparatus comprising a selector switch, first and second rotary drum switches, first and second motor relays, said selector switch having a plurality of contact sets which are electrically connected to said rotary drum switches, said first and second motor relays being electrically connected to said first and second rotary drum switches, means energizing said first motor relay to cause a motor to move the tapping contacts in one direction and means energizing said second motor relay to cause said motor to move the tapping contacts in the opposite direction, said rotary drum switches each having a rotary contact assembly which is connected to said motor so that closing a set of contacts of said selector switch causes one of said motor relays to energize until one of said rotary contact assemblies rotates to a position which deenergizes said motor relay.

Claim 6

Tap changing apparatus comprising a transformer having a tapped winding, a movable tapping contact for connecting an external circuit to said tapped winding, drive means including a motor for moving said tapping contacts, a selector switch having a plurality of contact sets, first and second rotary drum switches each having a rotary contact assembly and a plurality of fixed contacts, said rotary contact assemblies being connected to said motor so that when said motor is operating one said rotary contact assembly rotates in a direction which increases the number of fixed contacts it touches while the other said rotary contact assembly rotates in a direction which decreases the number of fixed contacts it touches, said fixed contacts of said first rotary drum switch being electrically connected to said fixed contacts of said second rotary drum switch at respective positions to form a plurality of fixed contact pairs, said rotary contact assemblies always being relatively positioned so that only one of said fixed contact pairs is not touched by either of said rotary contact assemblies, said contact sets of said selector switch each being electricallY connected to said fixed contact pairs of said rotary drum switches through patch panel means, said patch panel means allowing a quick change of the electrical connection of said selector switch contact sets from one of said fixed contact pairs to another of said fixed contact pairs.

Claim 7

Tap changing apparatus comprising a transformer having a tapped winding, a movable tapping contact for connecting an external circuit to said tapped winding, drive means including a motor for moving said tapping contacts, a selector switch having a plurality of contact sets, first and second rotary drum switches each having a rotary contact assembly and a plurality of fixed contacts, said rotary contact assemblies being connected to said motor so that when said motor is operating one said rotary contact assembly rotates in a direction which increases the number of fixed contacts it touches while the other said rotary contact assembly rotates in a direction which decreases the number of fixed contacts it touches, said fixed contacts of said first rotary drum switch being electrically connected to said fixed contacts of said second rotary drum switch at respective positions to form a plurality of fixed contact pairs, said rotary contact assemblies always being relatively positioned so that only one of said fixed contact pairs is not touched by either of said rotary contact assemblies, said contact sets of said selector switch each being electricallY connected to said fixed contact pairs of said rotary drum switches through patch panel means, said patch panel means allowing a quick change of the electrical connection of said selector switch contact sets from one of said fixed contact pairs to another of said fixed contact pairs.