Anti-theft electric meter

Claim 2

In a watthour meter including a metering movement adapted to rotate in response to the flow of energy in a pair of line conductors connected to terminals from the meter, reverse connection of the conductors with the terminals causing reverse rotation of the metering movement, forward rotation of the movement occurring on upright mounting of the meter, and reverse rotation occurring on inverse mounting of the meter, the improvement comprising a gravity responsive stop element adapted to be spaced from the metering movement when the meter is connected forwardly with the line conductors, and adapted to contact the metering movement when the meter is reversibly connected with the line conductors for preventing reverse rotation of the metering movement.

Claim 3

A watthour meter as claimed in claim 1 wherein the stop element is an arm pivotally mounted for movement between the spaced position and contact position.

Claim 4

A watthour meter having a metering movement rotatable in response to the flow of electrical energy in a pair of line conductors, said meter comprising: means for mounting said meter and electrically connecting said meter with the line conductors; a winding responsive to the electrical current in the line conductors; the mounting means permitting upright mounting of the meter and forward electrical connection with the conductors, or inverted mounting of the meter and reverse electrical connection with the conductors whereby the winding acts to cause forward or reverse rotation of the metering movement, and a gravity responsive contact element mounted to contact the metering movement when the meter is inverted whereby reverse rotation of the movement is prevented.

Claim 5

A watthour meter having a metering movement rotatable in response to the flow of electrical energy in a pair of line conductors, said meter comprising: means for mounting said meter and electrically connecting said meter with the line conductors; a winding responsive to the electrical current in the line conductors; the mounting means permitting upright mounting of the meter and forward electrical connection with the conductors, or inverted mounting of the meter and reverse electrical connection with the conductors whereby the winding acts to cause forward or reverse rotation of the metering movement, and a gravity responsive contact element mounted to contact the metering movement when the meter is inverted whereby reverse rotation of the movement is prevented.

Claim 6

A watthour meter as claimed in claim 3 wherein the gravity responsive contact element is retained in a position remote from the rotatable metering movement when the meter is upright.

Claim 7

A watthour meter as claimed in claim 4 wherein the contact element frictionally engages the movement.

Claim 8

A watthour meter as claimed in claim 5 wherein the contact element is a pivotally mounted arm.

Claim 9

A watthour meter as claimed in claim 6 wherein the arm includes an end having a broadened surface for contacting the movement, a shoe of frictional material being located on the end.

Claim 10

A watthour meter as claimed in either claim 5, 6 or 7 including a latching means for locking the stop element in a position remote from its position assumed with the meter initially upright, and a sight hole in a face to the meter through which said stop element is visible.

Claim 11

A watthour meter as claimed in either claim 5, 6 or 7 wherein the movement provides a roughened surface to enhance the preventive effect of the contact element when in contact with the movement.

Claim 12

A watthour meter as claimed in claim 3, wherein the meter includes a face plate for displaying meter readings, and the element is mounted on the face plate.