Helical wire shearing and twisting mechanism for spring mattress units

Claim 2

A helical shearing and twisting mechanism for a spring assembly machine adapted to rotate and thread a helical wire proper about mating portions of coil springs in row formation, thereby to join the rows of coil springs to one another to form a spring mattress having marginal portions delineated by edgewise coil springs, said shearing and twisting mechanism comprising: a mounting member secured to the spring assembly machine adjacent the edgewise mating coil springs which delineate a marginal portion of the spring mattress; a shearing head journalled in the mounting member for rotary motion in forward and reverse directions relative to the mounting member; the said shearing head including an outer end surface having an open slot formed therein, said slot including a shearing edge; said shearing head normally residing in a receiving position with said slot disposed at an angle corresponding to the lead of the helical wire and arranged to receive And confine an endwise portion of the helical wire projecting beyond the edgewise coil springs with a portion thereof projecting beyond the slot; a reciprocating, normally extended, shearing knife slideably carried by the mounting member and having a shearing edge coacting with the shearing edge of the slot for shearing the end portion of the helical wire proper which projects beyond the slot; means for rotating the shearing head in a direction to shear the helical wire between the edge of the shearing knife and shearing edge of the slot of the shearing head; and means interconnecting the shearing knife and shearing head for shifting the outer end of the knife clear of the slot of the shearing head after the end portion of the helical wire proper is sheared; said shearing head arranged to continue said rotary motion after the shearing knife is shifted clear of the slot, thereby to twist the sheared portion of the helical toward the helical proper in a direction to form a loop which encircles at least one of the said mating portions of the edgewise coil springs, thereby to lock the helical wire to the edgewise coil springs.

Claim 3

A shearing and twisting mechanism as set forth in claim 1 in which the shearing head includes a camming surface located inwardly from the outer end surface of the shearing head, said camming surface rotatable with the shearing head and arranged to engage the helical wire proper adjacent the sheared end thereof to force the same outwardly of the slot of the shearing head as the loop is formed by the slot during continued rotary motion of the shearing head.

Claim 4

A shearing and twisting mechanism as set forth in claim 1 in which the slot of the shearing head has a depth extending inwardly from the outer end surface of the shearing head for a distance equal to at least one-half the diameter of the helical wire whereby the portion of the helical wire, which is confined in the slot after shearing, is twisted toward the helical wire proper to form the said loop.

Claim 5

A shearing and twisting mechanism as set forth in claim 1 in which the shearing head has a flat outer end surface disposed at right angles to the axis of rotary motion of the shearing head and in which the means interconnecting the shearing knife and shearing head provides a dwell period during which the shearing knife is shifted to a stationary position while said coacting shearing edges act upon the helical wire to shear the same and thereafter to shift the shearing knife to a position clear of the slot to provide clearance for forcing the helical wire from the slot as the said loop is formed by the slot during continued rotation of the shearing head.

Claim 6

A shearing and twisting mechanism as set forth in claim 1 in which the shearing head has a flat outer end surface disposed at right angles to the axis of rotary motion of the shearing head and in which the means interconnecting the shearing knife and shearing head provides a dwell period during which the shearing knife is shifted to a stationary position while said coacting shearing edges act upon the helical wire to shear the same and thereafter to shift the shearing knife to a position clear of the slot to provide clearance for forcing the helical wire from the slot as the said loop is formed by the slot during continued rotation of the shearing head, the shearing head including an outwardly inclined camming surface rotatable with the head and arranged to engage the helical wire proper adjacent the sheared end thereof to force the same outwardly from the slot of the head as the said loop is formed.

Claim 7

A shearing and twisting mechanism as set forth in claim 1 in which the shearing head has a flat outer end surface disposed at right angles to the axis of rotary motion of the shearing head and in which the shearing knife includes a portion spaced from the said outer end surface, said portion including a shear finger contacting the flat outer end surface and having a shearing edge coacting with the sheaRing edge of the slot, the means interconnecting the shearing knife and shearing head providing a dwell period during which the shear finger resides in an extended stationary position overlying said slot of the shearing head during rotary motion of the head while said coacting shearing edges act upon the helical wire to shear the same, the interconnecting means thereafter shifting the shear finger to a retracted position relative to the slot to provide clearance for forcing the helical wire from the slot as the said loop is formed by the slot during continued rotation of the shearing head.

Claim 8

A shearing and twisting mechanism as set forth in claim 1 in which the shearing head has a flat outer end surface disposed at right angles to the axis of rotary motion of the shearing head and in which the shearing knife includes a portion spaced from the said outer end surface, said portion including a shear finger contacting the flat outer end surface and having a shearing edge coacting with the shearing edge of the slot, the means interconnecting the shearing knife and shearing head providing a dwell period during which the shear finger resides in an extended stationary position overlying said slot of the shearing head during rotary motion of the head while said coacting shearing edges act upon the helical wire to shear the same, the interconnecting means thereafter shifting the shear finger to a retracted position relative to the slot to provide clearance for forcing the helical wire from the slot as the said loop is formed by the slot during continued rotation of the shearing head, the shearing head including an outwardly inclined camming surface rotatable with the head and arranged to engage the helical wire proper adjacent the sheared end thereof to force the same outwardly from the slot of the head as the said loop is formed.

Claim 9

A shearing and twisting mechanism as set forth in claim 1 in which the shearing head includes a cam lobe rotatable there with and in which the means interconnecting the shearing knife and shearing head includes a shiftable yoke element associated with the cam lobe, said yoke element connected to the shearing knife for shifting the same, said cam lobe and yoke element providing a dwell period, whereby the knife remains in a stationary position while the end portion of the helical is sheared, the yoke element and cam lobe thereafter shifting the knife to a position clear of the slot of the shearing head during continued rotation of the shearing head.

Claim 10

A shearing and twisting mechanism as set forth in claim 1 in which the slot of the shearing head includes a recess formed at one side portion of the slot, said recess delineating the shearing edge which coacts with the shearing edge of the knife, whereby the sheared end portion of the helical is bent from the loop in a direction to cause the said sheared end to face the mating portion of the edgewise coil spring which is encircled by the loop.

Claim 11

A helical shearing and twisting mechanism for a spring assembly machine having guide means and being adapted to rotate and thread the convolutions of a helical wire proper about mating portions of coil springs in row formation, thereby to join the coil springs together to form a spring mattress having marginal portions delineated by edgewise coil springs, said wire shearing and twisting mechanism comprising: a mounting member secured upon an end portion of the assembly machine adjacent the edgewise mating coil springs which delineate a marginal portion of the spring mattress, the mating portions of said edgewise coil springs being confined in said guide means; a shearing head journalled in the mounting member for rocking motion in forward and reverse direction; said shearing head having a flat outer surface disposed at right angles to the axis of rotation of the head; said flat outer surface including an open slot formed therein, the shearing head normally residing in a receiving position with the slot disposed at an angle corresponDing to the lead of the helical wire, whereby the helical wire is threaded relative to the said guide means, the mating portions of the edgewise coil springs, and said slot; said slot thereby adapted to confine a partial convolution of the helical wire proper, with the remainder rising above the flat outer surface of the head; said slot having a shearing edge exposed at the flat outer surface of the shearing head; a shearing knife having an end portion overlying the flat outer surface of the shearing head and mounted for reciprocation relative thereto; the end portion of the knife which overhangs the end portion having a cross slot formed therein; said cross slot of the shearing knife thereby providing clearance for the convolution of the helical confined in the slot of the shearing head and rising above the flat outer surface thereof; the slot of the shearing knife delineating shear finger having an end in contact with the flat outer surface of the head at a point disposed between the cross slot and guide means and providing a shearing edge coacting with the shearing edge of the slot to sever the convolution of helical wire confined in said slot upon rotary movement of the shearing head; means for rotating the shearing head in a direction to shear the end of said convolution between the coacting shearing edges of the head and shearing finger; means interconnecting the head and shearing knife for shifting the knife toward a retracted position after the end portion of the helical is sheared, whereby the shear finger of the knife resides in a position displaced rearwardly of the slot of the shearing head; said means arranged to continue the rotation of the head after retracting said knife, whereby the partial convolution confined in said slot is twisted during said continued rotation in the same direction to form a closed loop; said shearing and forming head being located in a position relative to the guide means to cause the said loop to encircle a portion of the edgewise coil spring at the marginal portion of the spring mattress, thereby to lock the helical against endwise displacement.

Claim 12

A helical shearing and twisting mechanism for a spring assembly machine having guide means and being adapted to rotate and thread the convolutions of a helical wire proper about mating portions of coil springs in row formation, thereby to join the coil springs together to form a spring mattress having marginal portions delineated by edgewise coil springs, said wire shearing and twisting mechanism comprising: a mounting member secured upon an end portion of the assembly machine adjacent the edgewise mating coil springs which delineate a marginal portion of the spring mattress, the mating portions of said edgewise coil springs being confined in said guide means; a shearing head journalled in the mounting member for rocking motion in forward and reverse direction; said shearing head having a flat outer surface disposed at right angles to the axis of rotation of the head; said flat outer surface including an open slot formed therein, the shearing head normally residing in a receiving position with the slot disposed at an angle corresponDing to the lead of the helical wire, whereby the helical wire is threaded relative to the said guide means, the mating portions of the edgewise coil springs, and said slot; said slot thereby adapted to confine a partial convolution of the helical wire proper, with the remainder rising above the flat outer surface of the head; said slot having a shearing edge exposed at the flat outer surface of the shearing head; a shearing knife having an end portion overlying the flat outer surface of the shearing head and mounted for reciprocation relative thereto; the end portion of the knife which overhangs the end portion having a cross slot formed therein; said cross slot of the shearing knife thereby providing clearance for the convolution of the helical confined in the slot of the shearing head and rising above the flat outer surface thereof; the slot of the shearing knife delineating shear finger having an end in contact with the flat outer surface of the head at a point disposed between the cross slot and guide means and providing a shearing edge coacting with the shearing edge of the slot to sever the convolution of helical wire confined in said slot upon rotary movement of the shearing head; means for rotating the shearing head in a direction to shear the end of said convolution between the coacting shearing edges of the head and shearing finger; means interconnecting the head and shearing knife for shifting the knife toward a retracted position after the end portion of the helical is sheared, whereby the shear finger of the knife resides in a position displaced rearwardly of the slot of the shearing head; said means arranged to continue the rotation of the head after retracting said knife, whereby the partial convolution confined in said slot is twisted during said continued rotation in the same direction to form a closed loop; said shearing and forming head being located in a position relative to the guide means to cause the said loop to encircle a portion of the edgewise coil spring at the marginal portion of the spring mattress, thereby to lock the helical against endwise displacement.

Claim 13

A shearing and twisting mechanism as set forth in claim 10 in which the guide means comprise a pair of spaced positioning jaws secured to the mounting member, said jaws delineating a throat for confining mating portions of the edgewise coil springs and providing a passageway for guiding the helical wire about said mating portions, said shearing and twisting head being journalled at a point adjacent the jaws, whereby the helical wire is threaded relative to the said throat, the mating portions of the edgewise coil springs, and the slot of the shearing head.

Claim 14

A shearing and twisting mechanism as set forth in claim 10 in which the guide means comprise a pair of spaced positioning jaws secured to the mounting member, said jaws delineating a throat having teeth forming a sinuous passageway for confining mating portions of the edgewise coil springs and for guiding the helical wire about said mating portions, said shearing and twisting head being journalled at a point adjacent the jaws, whereby the helical wire is threaded relative to the sinuous passageway delineated by said throat, the mating portions of the edgewise coil springs, and the slot of the shearing head.

Claim 15

A shearing and twisting mechanism as set forth in claim 10 in which the shearing head includes a cam lobe rotatable therewith and in which the means interconnecting the shearing knife and shearing head includes a shiftable yoke element associated with the cam lobe, said yoke element connected to the shearing knife for shifting the same, said cam lobe and yoke element providing a dwell period, whereby the knife remains in a stationary position with the end portion thereof overlying the flat outer surface of the head, while the end portion of the helical is sheared, the yoke element and cam lobe thereafter shifting the knife to a position clear of the slot of the shearing head during continued rotation of the shearing head.

Claim 16

A shearing and twisting mechanism as set forth in claim 10 in which the shearing head includes a cam lobe rotatable therewith and in which the means interconnecting the shearing knife and shearing head includes a shiftable yoke element associated with the cam lobe, said yoke element connected to the shearing knife for shifting the same, said cam lobe and yoke element providing a dwell period, whereby the knife remains in a stationary position with the end portion thereof overlying the flat outer surface of the head, while the end portion of the helical is sheared, the yoke element and cam lobe thereafter shifting the knife to a position clear of the slot of the shearing head during continued rotation of the shearing head, the shearing head including an outwardly inclined camming surface rotatable with the head and arranged to cam the helical wire upwardly toward a mating portion of the edgewise coil spring after the knife is shifted to said position clear of the slot.

Claim 17

A shearing and twisting mechanism as set forth in claim 10 in which the mounting member includes a slideway, the shearing knife being shiftably confined in the slideway for reciprocation, the shearing head including a cam lobe rotatable with the head, a yoke element associated with the cam lobe and connected to the shearing knife for reciprocation of the shearing knife, said cam lobe and yoke element providing a dwell period, whereby the knife remains in a stationary position with the end portion thereof overlying the flat outer surface of the head while the end portion of the helical is sheared, the yoke element and cam lobe shifting the knife to a position clear of the slot during continued rotation of the shearing head.

Claim 18

A shearing and twisting mechanism as set forth in claim 10 in which the mounting member includes a slideway, a knife actuating slide member shiftably confined in the slideway for reciprocation, the shearing head including a cam lobe rotatable with the head, the slide member including a yoke element associated with the cam lobe for shifting the slide member in response to rotation of the shearing head and cam lobe, said shearing knife being confined in said slideway and connected to the slide for reciprocation with the slide, said cam lobe and yoke element providing a dwell period, whereby the knife remains in a stationary position with the end portion thereof overlying the flat outer surface of the head while the end portion of the helical is sheared, the yoke element and cam lobe shifting the slide and knife to a position clear of the slot during continued rotation of the shearing head.