Sew-off means for automatic sewing machines

Claim 2

In an automatic sewing unit of the type comprising an elongated table, a sewing machine mounted on said table and having a post, an arm and a head with a reciprocating needle assembly and a guide means in contact with the material being sewn for advancing the material in a sewing direction along said table and guiding said material with respect to said reciprocating needle assembly to produce a seam of predetermined straight or curved contour, a sew-off means comprising a foot, means to bring said foot into engagement with said material, means to remove said guide means from contact with said material and means to shift said foot and said material transversely of said sewing direction at a predetermined angularity thereto whereby to produce the desired sew-off stitches in said material at the end of said seam.

Claim 3

The structure claimed in claim 1 including a lever pivotally mounted at the top of said sewing machine head and extending substantially transversely thereof, a fluid actuated cylinder mounted substantially vertically on one side of said sewing machine head, said head cylinder having a substantially vertically oriented piston rod, link means connecting said piston rod to one end of said lever, a push rod being pivotally and swingably mounted at its upper end to the other end of said lever, said push rod depending downwardly along the side of said head opposite said side to which said head cylinder is mounted, said foot being connected to the lOwer end of said push rod by a universal joint, said lever being pivotable by said head cylinder about said pivotal mounting at the top of said head between a first position wherein said foot is located adjacent said needle of said needle assembly and spaced upwardly from said material and a second position wherein said foot is located adjacent said needle of said needle assembly and in contact with said material.

Claim 4

The structure claimed in claim 1 wherein said means to shift said foot and said material transversely of said sewing direction comprises a fluid actuated cylinder affixed at its rearward end to said sewing machine post and having a piston and piston rod, means operatively connecting said piston rod to said foot.

Claim 5

The structure claimed in claim 1 including adjustment means for determining the angularity of said sewing direction of said shifting of said foot.

Claim 6

The structure claimed in claim 1 including a guide for said foot to maintain the proper orientation thereof with respect to said sew-off angularity to said sewing direction and to prevent said foot from being dragged into said needle.

Claim 7

The structure claimed in claim 2 wherein said head cylinder is an air actuated cylinder and means to introduce air into said head cylinder at the end of said seam.

Claim 8

The structure claimed in claim 2 including means operatively connecting said lever to said guide means, said lever being further pivotable by said cylinder after said foot is in contact with said material about said upper end of said push rod to a third position wherein said guide means is raised out of contact with said material.

Claim 9

The structure claimed in claim 2 wherein said guide means comprises an elongated guide rail and said sewing machine is of the type having a cam block operatively engaged with said guide rail and mounted on a pressure bar passing upwardly through said sewing machine head and extending thereabove, said lever being pivotally attached to a block at the top of said sewing machine head, said block having a vertical perforation therethrough, the upper end of said pressure bar extending into said perforation and being slidable therein, said upper end of said pressure bar being notched, said block having a dog pivotally affixed thereto, said dog being pivotable between a position in engagement with said notch in said pressure bar to determine the lowermost position of said pressure bar and a position out of engagement with said notch to permit the free vertical upward movement of said pressure bar with respect to said block, said lever pivoting about said attachment to said block when pivoted from said first position to said second position, said lever being further pivotable by said head piston after said foot is in contact with said material about said upper end of said push rod to a third position wherein said block, said pressure bar engaged by said dog, said cam block and said guide rail engaged by said cam block are raised upwardly removing said guide means from contact with said material.

Claim 10

The structure claimed in claim 3 wherein cylinder affixed to said post is an air actuated cylinder, said post cylinder containing hydraulic fluid ahead of said piston and a reservoir therefor for uniform movement of said piston rod upon actuation of said post cylinder, and means to introduce air into said post cylinder at the end of said seam.

Claim 11

The structure in claim 7 wherein said means to shift said foot and said material transversely of said sewing direction comprises a fluid actuated cylinder affixed at its rear end to said sewing machine post and having a piston and piston rod, said post cylinder piston rod being operatively connected to said push rod.

Claim 12

The structure claimed in claim 8 wherein said means to shift said foot and said material transversely of said sewing direction comprises a fluid actuated cylinder affixed at its rear end to said sewing machine post and having a piston and piston rod, said post cylinder piston rod being operatively connecteD to said push rod.

Claim 13

The structure claimed in claim 10 including adjustment means for determining the angularity to said sewing direction of said shifting of said foot.

Claim 14

The structure claimed in claim 10 including bracket means affixed to said head, a shaft supported by means on said bracket and axially shiftable within said means, one end of said shaft operatively connected to said piston rod of said post cylinder, the other end of said shaft operatively connected to said push rod.

Claim 15

The structure claimed in claim 13 wherein said bracket is adjustably mounted on said head, said bracket and said shaft thereon being locatable at the angularity to said sewing direction desired for said sew-off stitches whereby to shift said foot and to form said sew-off stitches at said desired angularity.

Claim 16

The structure claimed in claim 14 including a guide for said foot to maintain the proper orientation thereof with respect to said sew-off angularity to said sewing direction and to prevent said foot from being dragged into said needle.