Magnetic holding means - standby

Claim 2

Means for controlling magnetization of a magnet in conjunction with a main source of electricity, comprising, first circuit means connecting the main source with the magnet, a standby source of electricity, second circuit means connecting the standby source with the magnet, relay circuit means incorporated in the first circuit means, relay means including a control member in the relay circuit means and contacts in the first and second circuit means, the relay means and relay circuit means being operative, in response to energization of the main source, for holding the first circuit means closed, and the second circuit means open, and in response to de-energization of the main source, for holding the first circuit means open and the second circuit means closed, means for charging the standby source by the main source, and, the means for charging the standby source including means operative independently of the charge condition of the standby source for periodically connecting the standby source with the main source for charging the standby source.

Claim 3

Means for controlling magnetization of a magnet in conjunction with a main source of electricity, comprising, first circuit means connecting the main source with the magnet, a standby source of electricity, second circuit means connecting the standby source with the magnet, relay circuit means incorporated in the first circuit means, relay means including a control member in the relay circuit means and contacts in the first and second circuit means, the relay means and relay circuit means being operative, in response to energization of the main source, for holding the first circuit means closed, and the second circuit means open, and in response to de-energization of the main source, for holding the first circuit means open and the second circuit means closed, the standby source being operative for energizing the magnet when the first circuit means is open and the second circuit means is closed, and visual indicator means to show when the magnet is being energized by the standby source.

Claim 4

Means for controlling magnetization of a magnet in conjunction with a main source of electricity, comprising, first circuit means connecting the main source with the magnet, a standby source of electricity, second circuit means connecting the standby source with the magnet, relay circuit means incorporated in the first circuit means, relay means including a control member in the relay circuit means and contacts in the first and second circuit means, the relay means and relay circuit means being operative, in response to energization of the main source, for holding the first circuit means closed, and the second circuit means open, and in response to de-energization of the main source, for holding the first circuit means open and the second circuit means closed, the standby source being operative for energizing the magnet when the first circuit means is open and the second circuit means is closed, and visual indicator means to show when the magnet is being energized by the standby source.

Claim 5

Means for controlling magnetization of a magnet in conjunction with a main source of electricity, comprising, first circuit means connecting the main source with the magnet, a standby source of electricity, second circuit means connecting the standby source with the magnet, relay circuit means incorporated in the first circuit means, relay means including a control member in the relay circuit means and contacts in the first and second circuit means, the relay means and relay circuit means being operative, in response to energization of the main source, for holding the first circuit means closed, and the second circuit means open, and in response to de-energization of the main source, for holding the first circuit means open and the second circuit means closed, a test circuit which includes the standby source, the test circuit including means operative, when the standby source is periodically put in circuit, and responsive to the charge condition of the standby source, for connecting the standby source with the main source when the voltage level of the standby source is below a predetermined value, the test circuit including means for adjusting the point of effective operation of the circuit for adjusting the point of low voltage value of the standby source for connecting the standby source with the main source.

Claim 6

Means for controlling magnetization of a magnet in conjunction with a main source of electricity, comprising, first circuit means connecting the main source with the magnet, a standby source of electricity, second circuit means connecting the standby source with the magnet, relay circuit means incorporated in the first circuit means, relay means including a control member in the relay circuit means and contacts in the first and second circuit means, the relay means and relay circuit means being operative, in response to energization of the main source, for holding the first circuit means closed, and the second circuit means open, and in response to de-energization of the main source, for holding the first circuit means open and the second circuit means closed, a test circuit which includes the standby source, the test circuit including means operative, when the standby source is periodically put in circuit, and responsive to the charge condition of the standby source, for connecting the standby source with the main source when the voltage level of the standby source is below a predetermined value, the test circuit including means for adjusting the point of effective operation of the circuit for adjusting the point of low voltage value of the standby source for connecting the standby source with the main source.

Claim 7

Controlling means according to claim 3 wherein the adjusting means includes reverse wound relay means for accurately defining the voltage point of the battery at which the battery is connected with the main source.

Claim 8

Controlling means according to claim 2 and including a test circuit for putting the battery in circuit therein, the test circuit including a low battery voltage sensing relay and operative for connecting the test circuit in circuit with the main source in response to the voltage of the battery lowering to a predetermined value.

Claim 9

Controlling means according to claim 5 wherein the test circuit includes reverse wound relay means and adjustable resistor means for adjustably setting the relay means for sensing the battery at a predetermined voltage value.

Claim 10

Means for controlling the magnetism of a magnet in conjunction with a main source of AC, comprising, a power circuit deriving AC from the main source and including a first transformer circuit which includes a rectifier and latch relay means and a release relay means controlled thereby, the power circuit including a second transformer circuit which includes rectifier means and the magnet to be controlled, and providing DC to the magnet, a standby source, relay means in the second transformer circuit for controlling the connection of the standby source with the magnet, means responsive to the latch relay means for controlling the connection of the magnet with the main AC source, and means responsive to the voltage condition of the magnet for releasing the latch relay means.

Claim 11

Means for controlling the magnetism of a magnet in conjunction with a main source of AC, comprising, a power circuit deriving AC from the main source and including a first transformer circuit which includes a rectifier and latch relay means and a release relay means controlled thereby, the power circuit including a second transformer circuit which includes rectifier means and the magnet to be controlled, and providing DC to the magnet, a standby source, relay means in the second transformer circuit for controlling the connection of the standby source with the magnet, means responsive to the latch relay means for controlling the connection of the magnet with the main AC source, and means responsive to the voltage condition of the magnet for releasing the latch relay means.

Claim 12

Controlling means according to claim 3 and including reversing switch means in the second transformer circuit for reversing current to the magnet, and the latch relay release means is operative for controlling the direction of current to the magnet.

Claim 13

Controlling means according to claim 8, and including a current relay in series with the magnet and operative for controlling the latch relay release means, and thereby the reversing switch means, in response to the condition of the magnetism of the magnet.

Claim 14

Controlling according to claim 9 wherein the current relay means is operative for directing current to the magnet in magnetizing direction upon the value of the magnetism lowering to a predetermined minimum and for directing it in demagnetizing direction upon the value of the magnetism rising to a predetermined maximum.

Claim 15

Means for controlling the magnetism of a magnet in conjunction with an AC main source of electricity, comprising, first circuit means connecting the main source with the magnet, a standby source of electricity, second circuit means connecting the standby source with the magnet, rectifier means interposed between the main source and the magnet for converting the AC to DC and imposing it on the magnet, transformer means deriving power from the AC source, a test circuit including the standby source, second recifier means between the transformer means and the standby source for delivering DC to the standby source, SCR means between the second rectifier means and the standby means, and zener control means in the test circuit for controlling the circuit means between the second rectifier means and the standby means.

Claim 16

Means for controlling the magnetism of a magnet in conjunction with an AC main source of electricity, comprising, first circuit means connecting the main source with the magnet, a standby source of electricity, second circuit means connecting the standby source with the magnet, rectifier means interposed between the main source and the magnet for converting the AC to DC and imposing it on the magnet, transformer means deriving power from the AC source, a test circuit including the standby source, second recifier means between the transformer means and the standby source for delivering DC to the standby source, SCR means between the second rectifier means and the standby means, and zener control means in the test circuit for controlling the circuit means between the second rectifier means and the standby means.

Claim 17

Controlling means according to claim 11 wherein the zener circuit means includes reverse wound relays, and zener rectifiers for controlling the reverse wound relays.

Claim 18

Controlling means according to claim 7 and including manual switch means for controlling the latch relay means and operative on actuation thereof for controlling voltage value in the second transformer circuit and thereby the voltage value imposed on the magnet.

Claim 19

ControlliNg means according to claim 13 and including release relay means, and also including a current relay in series with the magnet, and circuit means responsive to the release relay for reversing the voltage imposed on the magnet, and therethrough operative for demagnetizing the magnet, and the circuit including means controlled by the current relay for de-energizing the release relay means pursuant to the release relay means being energized, whereupon a load held by the magnet is released therefrom upon the voltage value of the magnet diminishing to a predetermined point.

Claim 20

Controlling means according to claim 14 and including voltage relay means controlled by the voltage value of the magnet, and means controlled by the voltage relay means for testing charge conditions of the standby source.

Claim 21

Controlling means according to claim 15 and including sensing means having a component for sensing the condition of charge of the standby source, and the low voltage value of the standby source.

Claim 22

Controlling means according to claim 13 and including manual switch means for controlling the release relay means, the release relay means being normally de-energized and being energized by the manual release button, and also being released pursuant to the voltage value of the magnet being diminished substantially to zero.