Sewing machine threading device

A pneumatic threading device of a sewing machine having a stitch forming apparatus including a needle of the sewing machine and a loop capturing apparatus forming stitches by entangling a needle thread being threaded to a needle eye of said needle by cooperating with said needle and threading to the needle eye of said needle pneumatically, comprising:

• a hermetic lip being hermetically touchable to a peripheral band-ring-shaped region of said needle surrounding a thread exit of the needle eye of said needle and having a corresponding peripheral band-ring-shaped pad surrounding a suction port hole sucking from the thread exit of the needle eye of said needle,
• a needle thread suction conduit pipe being connected to said suction port hole of said hermetic lip,
• a position switching mechanism moving said hermetic lip to a threading position so that said suction port hole is aligned to the thread exit of the needle eye of said needle and is touched to said needle at the time of the needle threading and moving to a standby position by retreating said hermetic lip from said needle at the time of the stitch forming, and
• a pump that said needle thread suction conduit pipe is connected to a suction port and performing the needle threading to the needle eye of said needle by sucking one end of the needle thread being inserted to a thread entrance of the needle eye of said needle to said suction port via said suction port hole from the thread exit of the needle eye of said needle through said needle thread suction conduit pipe at the time of the needle threading, wherein:
• a separator having a thread stopping wall that said needle thread being carried by the suction from said needle thread suction conduit pipe collides and a space preventing that flow velocity of air colliding against said thread stopping wall is lower than flow velocity being carried by the suction toward said pump and said needle thread being stopped by the collision against said thread stopping wall is sucked toward said pump is provided between said needle thread suction conduit pipe and said pump.

A pneumatic threading device of a sewing machine having a stitch forming apparatus including a needle of the sewing machine and a loop capturing apparatus forming stitches by entangling a needle thread being threaded to a needle eye of said needle by cooperating with said needle and threading to the needle eye of said needle pneumatically, comprising:

• a hermetic lip being hermetically touchable to a peripheral band-ring-shaped region of said needle surrounding a thread exit of the needle eye of said needle and having a corresponding peripheral band-ring-shaped pad surrounding a suction port hole sucking from the thread exit of the needle eye of said needle,
• a needle thread suction conduit pipe being connected to said suction port hole of said hermetic lip,
• a position switching mechanism moving said hermetic lip to a threading position so that said suction port hole is aligned to the thread exit of the needle eye of said needle and is touched to said needle at the time of the needle threading and moving to a standby position by retreating said hermetic lip from said needle at the time of the stitch forming, and
• a pump that said needle thread suction conduit pipe is connected to a suction port and performing the needle threading to the needle eye of said needle by sucking one end of the needle thread being inserted to a thread entrance of the needle eye of said needle to said suction port via said suction port hole from the thread exit of the needle eye of said needle through said needle thread suction conduit pipe at the time of the needle threading, wherein:
• said position switching mechanism has an operation part forming a preparatory position becoming a preparatory state of said needle threading by primary manual operation and holding said preparatory position and a needle threading positioning part being moved with said operation part and forming a needle threading position becoming a needle threading state of said needle threading from said preparatory position with predetermined needle threading timing depending on secondary manual operation.

A pneumatic threading device of a sewing machine having a stitch forming apparatus including a needle of the sewing machine and a loop capturing apparatus forming stitches by entangling a needle thread being threaded to a needle eye of said needle by cooperating with said needle and threading to the needle eye of said needle pneumatically, comprising:

• a hermetic lip being hermetically touchable to a peripheral band-ring-shaped region of said needle surrounding a thread exit of the needle eye of said needle and having a corresponding peripheral band-ring-shaped pad surrounding a suction port hole sucking from the thread exit of the needle eye of said needle,
• a needle thread suction conduit pipe being connected to said suction port hole of said hermetic lip,
• a position switching mechanism moving said hermetic lip to a threading position so that said suction port hole is aligned to the thread exit of the needle eye of said needle and is touched to said needle at the time of the needle threading and moving to a standby position by retreating said hermetic lip from said needle at the time of the stitch forming, and
• a pump that said needle thread suction conduit pipe is connected to a suction port and performing the needle threading to the needle eye of said needle by sucking one end of the needle thread being inserted to a thread entrance of the needle eye of said needle to said suction port via said suction port hole from the thread exit of the needle eye of said needle through said needle thread suction conduit pipe at the time of the needle threading, wherein:
• the stitch forming apparatus forming the stitches by entangling the needle thread and the looper thread being threaded respectively to the needle eye of said needle and the looper hole of said looper by cooperating with the looper as said loop capturing apparatus is provided, and
• a looper thread introduction entrance that an exhaust port of said pump is connected,
• a looper thread guide conduit pipe being connected to said looper thread introduction entrance and carrying one end of said looper thread being inserted to said looper thread introduction entrance by compressed air from said exhaust port,
• a looper thread connecting conduit pipe being fitted into said looper thread guide conduit pipe in the nested state and touching the looper hole entrance of said looper at the time of the looper threading, and
• a conduit pipe connecting mechanism making said looper thread connecting conduit pipe touch the looper hole entrance of said looper and performing the looper threading to the looper hole of said looper through said looper thread connecting conduit pipe via said looper thread guide conduit pipe from said looper thread introduction entrance about one end of the looper thread being inserted to said looper thread introduction entrance at the time of the looper threading and separating said looper thread connecting conduit pipe from the looper hole entrance of said looper at the time of the stitch forming are provided.

A pneumatic threading device of a sewing machine having a stitch forming apparatus including a needle of the sewing machine and a loop capturing apparatus forming stitches by entangling a needle thread being threaded to a needle eye of said needle by cooperating with said needle and threading to the needle eye of said needle pneumatically, comprising:

• a hermetic lip being hermetically touchable to a peripheral band-ring-shaped region of said needle surrounding a thread exit of the needle eye of said needle and having a corresponding peripheral band-ring-shaped pad surrounding a suction port hole sucking from the thread exit of the needle eye of said needle,
• a needle thread suction conduit pipe being connected to said suction port hole of said hermetic lip,
• a position switching mechanism moving said hermetic lip to a threading position so that said suction port hole is aligned to the thread exit of the needle eye of said needle and is touched to said needle at the time of the needle threading and moving to a standby position by retreating said hermetic lip from said needle at the time of the stitch forming, and
• a pump that said needle thread suction conduit pipe is connected to a suction port and performing the needle threading to the needle eye of said needle by sucking one end of the needle thread being inserted to a thread entrance of the needle eye of said needle to said suction port via said suction port hole from the thread exit of the needle eye of said needle through said needle thread suction conduit pipe at the time of the needle threading, wherein:
• said conduit pipe connecting mechanism has an operation part being attached to a sewing machine bed, and forming a preparatory position becoming preparatory state of said looper threading by the primary manual operation and holding said preparatory position and
• a looper threading positioning part forming a looper threading position becoming looper threading state of said looper threading with predetermined looper threading timing depending on the secondary manual operation from said preparatory position.

A pneumatic threading device of a sewing machine having a stitch forming apparatus including a needle of the sewing machine and a loop capturing apparatus forming locked stitches by entangling a needle thread being threaded to a needle eye of said needle by cooperating with said needle and threading to the needle eye of said needle pneumatically, comprising:

• a hermetic lip being hermetically touchable to a convex semicircular edge part of said needle including a thread exit of the needle eye of said needle and having a corresponding concave semicircular edge part including a suction port hole sucking from the needle eye of said needle,
• a needle thread suction conduit pipe being connected to said suction port hole of said hermetic lip,
• a position switching mechanism making said hermetic lip touch said needle so that said suction port hole is aligned to the thread exit of the needle eye of said needle at the time of the needle threading and moving to a standby position by retreating said hermetic lip from said needle at the time of the stitch forming,
• a pump that said needle thread suction conduit pipe is connected to a suction port and performing the needle threading to the needle eye of said needle by sucking one end of the needle thread being inserted to a thread entrance of the needle eye of said needle to said suction port via said suction port hole from the thread exit of the needle eye of said needle through said needle thread suction conduit pipe at the time of the needle threading,
• a stitch forming apparatus forming chain stitches by entangling the needle thread and the looper thread being threaded respectively to the needle eye of said needle and the looper hole of said looper by cooperating with the looper as said loop capturing apparatus,
• a looper thread introduction entrance that an exhaust port of said pump is connected,
• a looper thread guide conduit pipe being connected to said looper thread introduction entrance and carrying one end of said looper thread being inserted to said looper thread introduction entrance by compressed air from said exhaust port,
• a looper thread connecting conduit pipe being fitted into said looper thread guide conduit pipe in the nested state and touching the looper hole entrance of said looper at the time of the looper threading, and
• a conduit pipe connecting mechanism making said looper thread connecting conduit pipe touch the looper hole entrance of said looper and performing the looper threading to the looper hole of said looper through said looper thread connecting conduit pipe via said looper thread guide conduit pipe from said looper thread introduction entrance about one end of the looper thread being inserted to said looper thread introduction entrance at the time of the looper threading and separating said looper thread connecting conduit pipe from the looper hole entrance of said looper at the time of the stitch forming.