Liquidizer speed control

Claim 2

In a speed control for a fractional horsepower universal motor having field coils electrically connectable at one end to one side of the armature, two serially connected oppositely poled diodes, terminally connected between a source of alternating current and said armature and having a common connection between them, first switch means connected between said common connection and the other end of the field coils, second switch means directly connectable said other end of the field coils and said source, and means for alternately opening and first closing said first and second switch means.

Claim 3

The combination defined in claim 1 including means controlling said switch means to open said switch means concurrently.

Claim 4

The combination defined in claim 1 in which said field coils are of different impedances and including a switch to connect the coils in series, and manually controlled means for opening said switch and switch means concurrently.

Claim 5

In a speed control for a universal motor powered by alternating current the combination of a plurality of field coils of different impedances electrically connectable at one end to the armature, permutation switching means including a plurality of switches for interconnecting the coils in selected relationships to vary their composite effective impedance for the motor field and including at least two pushbuttons each separately coacting with said switches to provide said relationships, two serially connected oppositely poled rectifier means connected between said one end and a source of alternating current and having a common connection between them first switch means connected between said common connection and the other end of the field coils, second switch means directly connectable between said other end of the field coils and said source of alternating current, control means for said switch is movable in one direction by one of said pushbuttons to close said second switch means and open said first switch means to supply full alternating current to said field and released to move in another direction by the other of the two pushbuttons to open said second switch means and close said first switch means to supply rectified current to said field to provide two different speeds at said same relationship.

Claim 6

In a speed control for a universal motor powered by alternating current the combination of a plurality of field coils of different impedances electrically connectable at one end to the armature, permutation switching means including a plurality of switches for interconnecting the coils in selected relationships to vary their composite effective impedance for the motor field and including at least two pushbuttons each separately coacting with said switches to provide said relationships, two serially connected oppositely poled rectifier means connected between said one end and a source of alternating current and having a common connection between them first switch means connected between said common connection and the other end of the field coils, second switch means directly connectable between said other end of the field coils and said source of alternating current, control means for said switch is movable in one direction by one of said pushbuttons to close said second switch means and open said first switch means to supply full alternating current to said field and released to move in another direction by the other of the two pushbuttons to open said second switch means and close said first switch means to supply rectified current to said field to provide two different speeds at said same relationship.

Claim 7

The combination called for in claim 4 including a third pushbutton for opening said switch means concurrently to deenergize the motor.

Claim 8

The combination called for in claim 5 in which said control means comprises a slider member having a cam inclined in one direction engaged by one of said pushbuttons and a cam inclined in the opposIte direction engaged by the other pushbutton.

Claim 9

The combination called for in claim 6 which includes latch means for said switch control means activated by movement thereof by one of the pushbuttons and released by actuation of the other pushbutton.

Claim 10

The combination called for in claim 7 in which said latch means comprises a shoulder between a high and low dwell at the station for said switch which shoulder is engaged by the switch when the switch is closed, and means carried by said switching means to move said switch to the level of the high dwell when said other of the two pushbuttons is actuated.

Claim 11

The combination called for in claim 4 in which said control means comprises a slider having a cam inclined in one direction engaged by said one of said pushbuttons, and resilient means urging said slider in the opposite direction upon release of the latch means.

Claim 12

The combination called for in claim 4 in which said control means comprises a slider member for each one of said switch means having a cam inclined in one direction engaged by one of said pushbuttons and alternately opening and closing said switch means with respect to each other.

Claim 13

The combination called for in claim 10 which includes latch means for each of said two switch control means being activated by movement thereof by one of the pushbuttons and released by actuation of the other pushbutton.

Claim 14

The combination called for in claim 11 in which said latch means for each slider comprises a shoulder between a high and low dwell at the station for said switch which shoulder is engaged by the switch when the switch is closed, and means carried by said switching means to move said switch to the level of the high dwell when said other of the two pushbuttons is actuated.

Claim 15

The combination called for in claim 10 in which each slider includes a cam inclined in one direction engaged by said one of said pushbuttons, and resilient means urging each slider in its opposite direction upon release of the latch means to open each respective switch means, and a third pushbutton and slider for releasing the other sliders to the action of said resilient means for opening said switch means concurrently.

Claim 16

The combination called for in claim 10 in which said latching means for each slider member comprises a shoulder between a high and a low dwell at the station for said switch means which shoulder is engaged by the switch when the switch is closed, resilient means urging said slider in the direction opening said switch means, and means carried by said switching means to move said switch from engagement with said shoulder to the level of the high dwell when said other of the two pushbuttons is actuated for movement by said resilient means of the high dwell under the switch to hold the switch open.

Claim 17

In a speed control for a fractional horsepower universal motor having a plurality of cowound field coils of different impedances on the stator, electrically connectable at one end, one side of the armature, two serially connected oppositely poled diodes terminally connected between a source of alternating current and said armature and having a common connection between them, first switch means having a normally closed conductor connected between said common connection and the other end of the field coils, switch means having a normally closed conductor directly interconnecting said other end of the field coils and said source, switch control means for opening said conductors including a pair of switch control sliders independently movable between alternate positions and having notches along their top edge defining two stations with inclines related to provide three permutations of the sliders, pushbutton means engaging said slider inclines at each station, said sliders having recesses along their bottom edges one at each switch station, one of said sliders having cams in two recesses to close the first switch conductor while opening the secOnd switch conductor with movement in one direction and opening the first switch conductor while closing said second switch conductor with movement in the other direction, the other one of said sliders having in two recesses cams coordinated with the movement of said first slider to close the switch closed by the one slider in alternate position and to open both switches in a third relative positioning of the two sliders.

Claim 18

In a speed control for a fractional horsepower universal motor having a plurality of cowound field coils of different impedances on the stator, electrically connectable at one end, one side of the armature, two serially connected oppositely poled diodes terminally connected between a source of alternating current and said armature and having a common connection between them, first switch means having a normally closed conductor connected between said common connection and the other end of the field coils, switch means having a normally closed conductor directly interconnecting said other end of the field coils and said source, switch control means for opening said conductors including a pair of switch control sliders independently movable between alternate positions and having notches along their top edge defining two stations with inclines related to provide three permutations of the sliders, pushbutton means engaging said slider inclines at each station, said sliders having recesses along their bottom edges one at each switch station, one of said sliders having cams in two recesses to close the first switch conductor while opening the secOnd switch conductor with movement in one direction and opening the first switch conductor while closing said second switch conductor with movement in the other direction, the other one of said sliders having in two recesses cams coordinated with the movement of said first slider to close the switch closed by the one slider in alternate position and to open both switches in a third relative positioning of the two sliders.

Claim 19

In a speed control for a fractional horsepower universal motor a field including a plurality of field coils of different impedances, a speed control switch device for said coils including a first switch means for connecting said coils in series, second switch means for connecting said coils in parallel, control means for opening said second means and closing said first means, semiconductor circuit means bridging said field coils including oppositely poled serially connected semiconductors, means connecting one pole of one semiconductor to a source of power and a switch between said pole and one end of said field coils, and switch means connecting the other pole of said one semiconductor to said one end of said field coils.

Claim 20

In a speed control for a fractional horsepower universal motor a field including a plurality of field coils of different impedances, a speed control switch device for said coils including a first switch means for connecting said coils in series, second switch means for connecting said coils in parallel, control means for opening said second means and closing said first means, semiconductor circuit means bridging said field coils including oppositely poled serially connected semiconductors, means connecting one pole of one semiconductor to a source of power and a switch between said pole and one end of said field coils, and switch means connecting the other pole of said one semiconductor to said one end of said field coils.