Sewing machine and motor speed regulating system therefor

Claim 2

An electric motor module for a sewing machine having frame, a drive shaft journaled in said frame, stitch-forming instrumentalities operably connected to said drive shaft, and a separate and remotely located motor speed controller, said electric motor module comprisiing a split motor housing consisting essentially of an end support base and a cover detachably connected to said end support base, a motor assembly removably carried by said end support base, a motor control module mounted on said end support base including electrical circuit components adapted to regulate the flow of current to said motor within any of at least two predetermined motor speed ranges in cooperation with said remotely located speed controller, switch means mounted on said end support base cooperable with said circuit components and with said motor speed controller for selecting one of said predetermined speed ranges, and socket means formed in said end support base and adapted to connect the motor with a source of electric power and to operably connect said circuit componets, switch means and motor speed controller.

Claim 3

An electric motor module for a sewing machine according to claim 1, wherein the said end support base is provided with a cover receiving seat which receives and orients the cover properly with the said end support base.

Claim 4

An electric motor module for a sewing machine according to claim 2, wherein the said cover is provided with an integral partitiion disposed to provide an electric motor receiving compartment and a motor control module receiving compartment.

Claim 5

In a sewing machine comprising a frame, a drive shaft journaled in said frame adapted to transmit reciprocatory movement to stitch sewing instrumentalities, a split motor housing carried by said frame, a motor mounted in said housing and adapted to impart rotary motion to said drive shaft, and a solid state controlled rectifier speed regulating system for said motor carried by said housing, the improvement whIch comprises the combination of a split motor housing consisting essentially of an end support base and a cover detachably connected thereto, a remotely located motor speed controller, said motor being removably carried by said end support base, a motor control module mounted on said end support base including electrical circuit components adapted to regulate the flow of current to said motor within any of at least two predetermined motor speed ranges in cooperation with said remotely located speed controller, switch means mounted on said end support base cooperable with said circuit components and motor speed controller for selecting one of said predetermined speed ranges, and socket means integrally formed in said end support base adapted to connect the motor with a source of electric power and to operably connect said circuit components, switch means and motor speed controller.

Claim 6

In a sewing machine comprising a frame, a drive shaft journaled in said frame adapted to transmit reciprocatory movement to stitch sewing instrumentalities, a split motor housing carried by said frame, a motor mounted in said housing and adapted to impart rotary motion to said drive shaft, and a solid state controlled rectifier speed regulating system for said motor carried by said housing, the improvement whIch comprises the combination of a split motor housing consisting essentially of an end support base and a cover detachably connected thereto, a remotely located motor speed controller, said motor being removably carried by said end support base, a motor control module mounted on said end support base including electrical circuit components adapted to regulate the flow of current to said motor within any of at least two predetermined motor speed ranges in cooperation with said remotely located speed controller, switch means mounted on said end support base cooperable with said circuit components and motor speed controller for selecting one of said predetermined speed ranges, and socket means integrally formed in said end support base adapted to connect the motor with a source of electric power and to operably connect said circuit components, switch means and motor speed controller.

Claim 7

A sewing machine according to claim 4, wherein said motor control module comprises a plurality of discrete electrical components, mounted on a printed circuit board.

Claim 8

A sewing machine according to claim 4, wherein said motor control module comprises an integrated circuit chip.

Claim 9

A sewing machine according to claim 5, wherein said motor control module is mounted on a metal bracket in heat sink relation therewith, said bracket being secured to said end support base in close proximity to said socket means.

Claim 10

A sewing machine according to claim 6, wherein said motor control module is mounted on a metal bracket in heat sink relation therewith, said bracket being secured to said end support base in close proximity to said socket means.

Claim 11

A sewing machine according to claim 6, wherein said motor control module includes at least one discrete electrical component.

Claim 12

A sewing machine according to claim 9, wherein said motor control module is mounted on a metal bracket in heat sink relation therewith, said bracket being secured to said end support base in close proximity to said socket means.

Claim 13

A sewing machine according to claim 5, wherein said switch means is positioned on the exterior of said end support base, said switch means being operably connected to manually operable selector means carried by said sewing machine frame whereby said switch means may be selectively regulated to disconnect the power supply to said motor and to establish quantitive limits for the flow of current to said motor to thus establish any of said predetermined motor speed ranges.

Claim 14

A sewing machine according to claim 6, wherein said switch means is positioned on the exterior of said end support base, said switch means being operably connected to manually operable selector mns carried by said motor and to establish quantitive limits for the flow of current to said motor to thus establish any of said predetermined motor speed ranges.

Claim 15

A sewing machine according to claim 9, wherein said switch means is positioned on the exterior of said end support base, said switch means being operably connected to manually operable selector means carried by said sewing machine frame whereby said switch means may be selectively regulated to disconnect the power supply to said motor and to establish quantitive limits for the flow of current to said motor to thus establish any of said predetermined motor speed ranges.

Claim 16

A sewing machine according to claim 4, wherein said motor control module comprises: (a) an SCR having anode, cathode, and gate electrodes, said anode electrode being adapted to be connected to a source of AC voltage and said cathode electrode being coupled to one end of the armature winding of said motor; (b) a diode having cathode and anode electrodes, said cathode electrode being connected to the gate electrode of said SCR and said anode electrode being connected to the cathode electrode of said SCR; (c) a capacitor, said capacitor being connected from the gate electrode to the cathode electrode of said SCR; (d) a first resistor coupled from the gate electrode of said SCR tO the other end of said armature winding; and (e) a second resistor coupled from the gate electrode of said SCR to said motor speed controller.

Claim 17

A sewing machine according to claim 14, wherein said motor speed controller is provided with a potentiometer having two end terminals and a variable arm terminal, one of said end terminals being coupled to the anode electrode of said SCR, the other end terminal being coupled to said other end of said armature winding, a normally open switch being also provided and having two terminals, said first switch terminal being connected to said variable arm terminal of said potentiometer and said second switch terminal being coupled to said gate electrode of said SCR, via said second resistor, whereby, an operator closing said normally open switch couples a firing voltage from the variable arm of said potentiometer to the gate electrode of said SCR.