Zero-lag electrical switching element for motors

Claim 2

In a speed-responsive electrical switching device for motors having a starting circuit and a running circuit, the combination of a yieldably mounted first electrical contact for one of said circuits, a yieldably mounted second electrical contact for the other of said circuits, a switch arm movably disposed therebetween for circuit-making engagement with one or the other of said contacts, and means for initially maintaining said switch arm in circuit-making engagement with said first contact until completion of movement of said switch arm into circuit-making engagement with said second contact, whereby both of said circuits are energized until the switchover from one to the other is completed.

Claim 3

A combination as defined in claim 1, including means for causing circuit-opening disengagement of said switch arm and said first contact after movement of said switch arm into circuit-making engagement with said second contact.

Claim 4

A combination as defined in claim 1, including speed-responsive means operatively engaging said switch arm for effecting actuation thereof.

Claim 5

A combination as defined in claim 1, wherein said contacts are yieldably biased for movement toward each other, said switch arm is movable between said contacts in opposition to the bias of the contact to be engaged by said switch arm, said first contact yieldably following the movement of said switch arm to provide said means for maintaining said circuit, and an abutment disposed in the path of following movement of said first contact to arrest said following movement thereof after said switch arm has engaged said second contact.

Claim 6

A combination as defined in claim 4, wherein said switch arm is resiliently biased for circuit-making engagement with said second contact, and including speed-responsive means for maintaining said switch arm disengaged from said second contact And engaged with said first contact in opposition to the bias of said switch arm.

Claim 7

A combination as defined in claim 2, wherein said contacts are yieldably biased in opposition to each other.

Claim 8

A combination as defined in claim 6, wherein said first electrical contact establishes said starting circuit and said second electrical contact establishes said running circuit.

Claim 9

In an electrical switching mechanism for effecting uninterrupted transfer from a first electrical circuit to a second electrical circuit, a single-pole double-throw switch, said switch having a first contact for making said first electrical circuit, said switch having a second contact for making said second electrical circuit, said contacts being resiliently mounted in opposition to each other whereby one of said contacts is caused to follow said pole and maintain circuit-making engagement with said pole during its transfer movement to engagement with the other of said contacts, and means for arresting said following movement of said first contact to open said first circuit after said second circuit has been closed.

Claim 10

In an electrical switching mechanism for effecting uninterrupted transfer from a first electrical circuit to a second electrical circuit, a single-pole double-throw switch, said switch having a first contact for making said first electrical circuit, said switch having a second contact for making said second electrical circuit, said contacts being resiliently mounted in opposition to each other whereby one of said contacts is caused to follow said pole and maintain circuit-making engagement with said pole during its transfer movement to engagement with the other of said contacts, and means for arresting said following movement of said first contact to open said first circuit after said second circuit has been closed.

Claim 11

A single-pole double-throw switch as defined in claim 8, including means for arresting said following movement of said second contact to open said second circuit after said first circuit has been closed.

Claim 12

A single-pole double-throw switch as defined in claim 8, wherein said pole is normally maintained in engagement with said first contact, and including condition-sensing means operatively associated with said pole for actuating circuit-transfer movement thereof into engagement with said second contact.