Coil and coil head formation dies for coils with non-conventional terminal convolutions

Information

  • Patent Grant
  • 6640836
  • Patent Number
    6,640,836
  • Date Filed
    Tuesday, November 28, 2000
    24 years ago
  • Date Issued
    Tuesday, November 4, 2003
    21 years ago
Abstract
Machinery for automated manufacture of formed wire structures such as innerspring assemblies for mattresses and seating and flexible support structures includes one or more coil formation devices configured to produce generally helical spring coils having a terminal convolution which extends beyond an end of the coil; a conveyor system having a plurality of flights slidably mounted upon a continuous track and connected to a chain and driven by an index driver; a coil transfer machine which removes a row of coils from the conveyor and inserts the coils into an innerspring assembler; and an innerspring assembler. A coil forming block on a coiler machine has a cavity in which a terminal convolution of the coil is formed, and from which the coil is cut by a cutter which extends into the cavity. Coil head formation dies at coil head forming stations of the coil forming machine also have a cavity for receiving a terminal convolution of a coil, and flanges which surround the cavity and provide a punch set for punches which form a coil head proximate to the terminal convolution in the die.
Description




FIELD OF THE INVENTION




The present invention pertains generally to formed wire structures and, more particularly, to machinery for automated manufacture and assembly of wire form structures such as coils and springs, and innerspring assemblies having an array of interconnected wire springs or coils.




BACKGROUND OF THE INVENTION




Innerspring assemblies, for mattresses, furniture, seating and other resilient structures, were first assembled by hand by arranging coils or springs in a matrix and interconnecting them with lacing or tying wires. The coils are connected at various points along the axial length, according to the innerspring design. Machines which automatically form coils have been mated with various conveyances which deliver coils to an assembly point. For example, U.S. Pat. Nos. 3,386,561 and 4,413,659 describe apparatus which feeds springs from an automated spring former to a spring core assembly machine. The spring or coil former component is configured to produce a particular coil design. Coils are produced from steel wire stock which is fed through a die and bent or coiled at designed radiuses by cam-controlled forming guides. Following the helical formation of the coil in this manner, the heads or end turns of the coils may be secondarily formed by punch dies. Most coil designs terminate at each end with one or more turns in a single plane. This simplifies automated handling of the coils, such as conveyance to an assembler and passage through the assembler. Coil forming machinery of the prior art is not configured or easily adapted to produce coils of alternate configurations, such as coils which do not terminate in a single plane.




The timed conveyance of coils from the former to the assembler is always problematic. Automated production is interrupted if even a single coil is misaligned in the conveyor. The conveyor drive mechanism must be perfectly timed with operation of the coil former and a transfer machine which picks up an entire row of coils from a conveyor and loads it into the innerspring assembler.




The spring core assembly component of the prior art machines is typically set up to accommodate one particular type of spring or coil. The coils are held within the machine with the base or top of the coil fit over dies or held by clamping jaws, and tied or laced together by a helical wire or fastening rings. This approach is limited to use with coils of particular configurations which fit over the dies and within the helical lacing and knuckling shoes. Such machines are not adaptable to use with different coil designs, particularly coils with a terminal convolution which extends beyond a base or end of the coil. Also, these types of machines are prone to malfunction due to the fact that two sets of clamping jaws, having multiple small parts and linkages moving at a rapid pace, are required for the top and bottom of each coil.




SUMMARY OF INVENTION




The present invention overcomes these and other disadvantages of the prior art by providing novel machinery for complete automated manufacture of formed wire innerspring assemblies from wire stock. In accordance with one particular aspect of the invention, there is provided: a coil formation device for forming coils having a generally helical coil body, a non-helical coil head, and a terminal convolution generally smaller than the coil body, the coil formation device having a wire feed mechanism which feeds wire stock into a coil forming block, the coil forming block having a cavity within which a terminal convolution of the coil is formed, a coil radius forming wheel against which wire stock bears to form a generally helical shape to the coil body, a helical guide pin in contact with the wire stock and operative to move relative to the forming block to form a generally helical shape to the coil body, a wire cutting tool configured to cut the wire stock within the cavity of the coil forming block, a geneva for transferring a coil from the coil forming block to a coil head forming station, the coil head forming station having a coil head formation die, the coil head formation die having a cavity configured to receive a terminal convolution of the coil, and a flange proximate to the cavity about which an end turn of the coil body is positioned by the geneva, and at least one punch operative to strike the end turn of the coil body against the flange of the coil head formation die to form a coil head between the coil body and the terminal convolution.




In accordance with another particular aspect of the invention, there is provided: a coil head formation die for use with a coil forming machine for forming a coil head in an end turn of a body of a coil having a terminal convolution contiguous with a body of the coil, the coil head formed by operation of one or more punches of the coil forming machine operative to strike a portion of the end turn of the coil against the die while the end turn of the coil and the terminal convolution of the coil are engaged with the coil head formation die, the coil head formation die having a cavity configured to receive a terminal convolution of the coil, and a portion configured to oppose a punch which strikes the end turn of the coil to form a coil head.




And in another aspect of the invention, there is provided: an automated innerspring assembly system for producing innerspring assemblies having a plurality of wire form coils interconnected in an array, the automated innerspring assembly system having at least one coil formation device operative to form wire stock into individual coils configured for assembly in an innerspring assembly, and operative to deliver individual coils to a coil conveyor, a coil conveyor associated with the coil formation device and operative to receive coils from the coil formation device and convey coils to a coil transfer machine, a coil transfer machine operative to remove coils from the coil conveyor and present coils to an innerspring assembler, an innerspring assembler operative to receive and engage a plurality of coils arranged in a row, to position a received row of coils parallel and closely adjacent to a previously received row of coils, to fixedly compress two adjacent rows of coils in a fixed position and interconnect the adjacent rows of coils with fastening means, and to advance interconnected rows of coils out of the assembler and receive and engage a subsequent row of coils, and repeat the process until an entire innerspring assembly is formed.











These and other aspects of the invention are herein described in particularized detail with reference to the accompanying Figures.




BRIEF DESCRIPTION OF THE FIGURES




In the accompanying Figures:





FIG. 1

is a plan view of the machinery for automated manufacture of formed wire innerspring assemblies of the present invention;





FIG. 2

is an elevational view of a coil former machine of the present invention;





FIG. 3A

is a perspective view of a conveyance device of the present invention;





FIG. 3B

is a perspective view of the conveyance device of

FIG. 3A

;





FIG. 3C

is a cross-sectional side view of the conveyance device of

FIG. 3A

;





FIG. 3D

is a sectional view of the conveyance device of

FIG. 3D

;





FIG. 3E

is a sectional view of the conveyance device of

FIG. 3C

;





FIG. 4A

is a side elevation of a coil transfer machine used in connection with the machinery for automated manufacture of formed wire innerspring assemblies of the present invention;





FIG. 4B

is a side elevation of the coil transfer machine of

FIG. 4A

;





FIG. 5

is a perspective view of an innerspring assembly machine of the present invention;





FIG. 6A

is an elevation of the innerspring assembly machine of

FIG. 5

;





FIG. 6B

is a perspective view of a knuckler die attachable to the innerspring assembler;





FIGS. 7A-7I

are schematic diagrams of coils, coil-receiving dies, and die support pieces as arranged and moved within the innerspring assembly machine of

FIG. 5

;





FIGS. 8A and 8B

are cross-sectional and top views of a coil head formation die of the present invention, engaged with a wire coil;





FIGS. 9A and 9B

are end views of the innerspring assembly machine of

FIG. 5

;





FIG. 10A

is an end view of the innerspring assembly machine of

FIG. 5

;





FIG. 10B

is an isolated perspective view of an indexing subassembly of the innerspring assembly machine of

FIG. 5

;





FIG. 11

is an isolated elevational view of a clamp subassembly of the innerspring assembly machine of

FIG. 5

;





FIG. 12

is a partial plan view of an innerspring assembly producible by the machinery of the present invention;





FIG. 13

is a partial elevational view of the innerspring assembly of

FIG. 12

;





FIG. 14A

is a profile view of a coil of the innerspring assembly of

FIG. 12

;





FIG. 14B

is an end view of a coil of the innerspring assembly of

FIG. 12

;





FIGS. 15A-15D

are cross-sectional views of a belt-type coil conveyance system of the present invention;





FIG. 16

is a top view of a chain winder version of a coil conveyance system of the present invention;





FIGS. 17A-17G

are elevational views of an alternate coil connecting mechanism of the present invention;





FIGS. 18A-18G

are elevational views of an alternate coil connecting mechanism of the present invention;





FIGS. 19A-19F

are elevational views of an alternate coil connecting mechanism of the present invention;





FIG. 20

is a partial frontal view of a coil formation station of a coil forming machine of the present invention;





FIG. 21

is a perspective view of a coil formation station of a coil forming machine of the present invention;





FIGS. 22 and 23

are perspective views of a coil head formation die of the present invention, and





FIGS. 24 and 25

are plan and elevation views of a coil head formation die of the present invention.











DETAILED DESCRIPTION OF PREFERRED AND ALTERNATE EMBODIMENTS




The described machinery and methods can be employed to produce innerspring assemblies


1


, including mattress or furniture or seating innerspring assemblies, in a general form as depicted in

FIGS. 12 and 13

. The innerspring assembly


1


includes a plurality of springs or coils


2


in an array such as an orthogonal array, with axes of the coils generally parallel and ends


3


of the coils generally co-planar, defining resilient support surfaces of the innerspring assembly


1


. The coils


2


are “laced” or wirebound together in the array by, for example, generally helical lacing wires


4


which run between rows of the coils and which wrap or lace around tangential or overlapping segments of adjacent coils as shown in FIG.


13


. Other means of coil fastening can be employed within the scope of the invention.




The coils formed by the coil formation components of the machinery may be of any configuration or shape formable from steel wire stock. Typically, innerspring coils have an elongated coil body with a generally helical configuration, terminating at the ends with one or more turns of the wire in a plane which forms a load-bearing head. Other coil forms and innerspring assemblies not expressly shown are nonetheless producible by the described machinery and are within the scope of the invention.




The following machinery and method descriptions are made with reference to a particular mattress innerspring with a particular type of coil


2


shown in isolation in

FIGS. 14A and 14B

. An example of this type of coil is described and claimed in U.S. Pat. No. 5,013,088. The coil


2


has a generally helical elongate coil body


21


which terminates at each end with a head


22


. Each head


22


includes a first offset


23


, second offset


24


, and third offset


25


A generally helical terminal convolution


26


extends from the third offset


25


axially beyond the head. A force responsive gradient arm


27


may be formed in a segment of the helical body


21


leading or transitioning to the coil head


22


.




As shown in

FIG. 14B

, the first offset


23


may include a crown


28


which positions the offset a slightly greater distance laterally from the longitudinal axis of the coil. The second and third offsets


24


and


25


are also outwardly offset from the longitudinal axis of the coil. As shown in

FIG. 13

, the first and third offsets


23


and


25


of each coil overlap the offsets of adjacent coils and are laced together by the helical lacing wires


4


, and the terminal convolutions


26


extend beyond (above and below) the points of laced attachment of the coil head offsets.





FIG. 1

illustrates the main components of the automated innerspring manufacturing system


100


of the invention. Coil wire stock


110


is fed from a spool


200


to one or more coil former machines


201


,


202


which produce coils such as shown in

FIGS. 14A

,


14


B or any other types of generally helical coils or other distinct wire form structures. The coils


2


are loaded into one or more coil conveyors


301


,


302


which convey coils to a coil transfer machine


400


. The coil transfer machine


400


loads a plurality of coils into an innerspring assembly machine


500


which automatically assembles coils into the described innerspring array by attachment with, for example, a helical wire formed from lacing wire stock


510


spool-fed to the assembler through a helical wire former and feeder


511


, also referred to as a coil interconnection device.




Each of the main components of the system


100


are now described individually, followed by a description of the system operation and the resulting wire form structure innerspring assembly. Although described with specific reference to the automated formation and assembly of a particular innerspring, it will be appreciated that the various components of the invention can be employed to produce any type of wire form structure.




Coil Formation




The coil formers


201


,


202


may be, for example, a known wire formation machine or coiler, such as a Spuhl LFK coiler manufactured by Spuhl AG of St. Gallen, Switzerland. As shown schematically in

FIG. 2

, the coil formers


201


,


202


feed wire stock


110


through a series of rollers and wire-formers to bend the wire into the designed coil formation. The radius of curvature in the helical segments of the coils is determined by the shapes of cams (not shown) in rolling contact with a cam follower arm


204


. The coil wire stock


110


is fed to the coiler by feed rollers


206


into a forming block or die


208


. As the wire is advanced through a guide hole or exit point


2081


in the die


208


, it contacts a coil radius forming wheel


210


, attached to an end of the cam follower arm


204


. The forming wheel


210


is moved relative to the forming block


208


, toward and away from the line of feed of the wire stock


110


, by travel distances defined by rotating cams which the arm


204


follows. In this manner, the radius of curvature of the helix of the coil is formed as the wire emerges from the forming block against the forming wheel.




A helix is formed in the wire stock after it passes the forming wheel


210


by a helix guide pin


214


which moves in a generally linear path, generally perpendicular to the wire stock guide hole


2081


in the forming block


208


, in order to advance the wire in a helical path away from the forming wheel


210


. Once a sufficient amount of wire has been fed through the forming block


208


, past the forming wheel


210


and the helix guide pin


214


, to form a complete coil, a cutting tool


212


is advanced against the forming block


208


to sever the coil from the wire stock. The severed coil is then advanced by a geneva


220


to subsequent formation and processing stations as further described below.




As shown in

FIG. 14B

, the coil


2


has several different radii of curvature in the helical coil body. In particular, the radius or total diameter of the terminal convolution


26


is significantly less than that of the main coil body


21


. Furthermore, the wire terminates and must be severed at the very end of the terminal convolution


26


. This particular coil structure presents a problem with respect to the forming block


208


which must be specifically configured to accommodate the terminal convolution


26


, allow the larger diameter coil body to advance over the forming block, and allow the cutting tool


212


to cut the wire at the very end of the terminal convolution.




As shown in

FIG. 2

, and in

FIGS. 20 and 21

, the forming block


208


of the invention includes a cavity


218


dimensioned to receive a terminal convolution of the coil. The cutting tool


212


is located proximate to the cavity


218


in the forming block


208


to sever the wire at the terminal convolution within cavity


218


. The internal walls of cavity


218


are generally arcuate along an interior surface


2181


against which the wire


110


bears as it is radially formed by the forming wheel


210


. The surface of the cavity


218


against which the wire stock


110


bears is tapered in a helical configuration. The taper in the cavity


218


is congruent with a helix angle formed in the wire stock


110


by the helical guide pin


214


. The helical guide pin


214


is operative to engage wire stock


110


formed within the cavity. A helical-form groove is preferably made in surface


2181


to further guide the helix formation of the terminal convolutions and coil body. The helix guide pin


214


is cam-controlled to move out away from the forming block and cavity


218


, to thereby form the differing helical portions of the terminal convolutions


26


and the coil body


21


. The termination of the coil wire at the last terminal convolution


26


to form within cavity


218


requires the cutting tool


212


to project into cavity


218


to cut the wire against an opposing cutting blade


2121


mounted within and/or projecting from cavity


218


, as shown in FIG.


20


.




Referring again to

FIG. 2

, a geneva


220


with, for example, six geneva arms


222


, is rotationally mounted proximate to the front of the coiler. Each geneva arm


222


supports a gripper


224


operative to grip a coil as it is cut from the continuous wire feed at the forming block


208


. The geneva rotationally indexes to advance each coil from the coiler guide block to a first coil head forming station


230


. Pneumatically operated punch tools


232


are mounted in a radial arrangement about the first coil head forming station


230


to form the coil offsets


23


-


25


, the force responsive gradient arm


27


, or any other contours or bends in the coil head or helical turn at one end of the coil body, by striking the wire against a die. The geneva then advances the coil to a second coil head forming station


240


oriented at an opposite end of the coil which similarly forms a coil head by punch tools


232


and corresponding dies.




For making the type of coil


2


described with reference to

FIGS. 12-14

, a special coil head formation die


2000


is utilized at each coil head forming station


230


,


240


. As shown in isolation in

FIGS. 22-25

, the coil head formation die


2000


has interlocking halves


2001


,


2002


which when mated form a joint die body


2003


having a back wall


2004


and contoured side sections


2005


and


2006


. The projection of the side sections


2005


and


2006


from the back wall


2004


forms a cavity


2010


within the die body


2003


. Cavity


2010


is configured to receive the terminal convolution


26


of the coil. Extending outward from the side sections


2005


,


2006


are flanges


2007


and


2008


. The side walls


2009


of flanges


2007


,


2008


are configured according to the shape of the coil head


22


to be formed, so that as the first turn of the coil body


21


is positioned about the perimeter of flanges


2007


,


2008


(with the terminal convolution


26


positioned within the die cavity


2010


), the punch tools


232


at the coil head forming stations


230


,


240


strike the wire against the side walls


2009


of flanges


2007


,


2008


to form the coil head


22


in the configuration of the external periphery of the flanges


2007


,


2008


, e.g. with offset segments


23


,


24


,


25


shown in FIG.


14


B. The combination of the die cavity


2010


and the coil head forming flanges


2007


,


2008


enables production of a wide variety of coil designs, including any coil design having different diameters at the terminal ends (i.e., terminal convolutions smaller than the coil body) and any coil head design contiguous with the terminal convolutions which can be formed in a punch process. The die


2000


is mounted to a mounting plate on the coiler at the coil head forming stations by fasteners such as bolts which extend through fastener holes


2011


in the back wall


2004


. By this arrangement, different coil head formation dies


2000


can be selectively installed with a coil forming machine for custom manufacture of different coil designs. By use of different coil formation and coil head formation dies, the design variations may include either the terminal convolution or the coil head.




As a coil


2


is advanced by the geneva arm


222


from the coil forming block


208


to the first coil head forming station


230


, the terminal convolution


26


is positioned within cavity


2010


. The larger radius turn


21




t


of the helical coil body


21


proximate to the terminal convolution


26


is positioned over or around flanges


2007


,


2008


as shown in FIG.


22


. The punch dies


232


are positioned to strike the wire of turn


21




t


against the side walls


2009


of flanges


2007


,


2008


to form the described offsets or contours or bends of the coil head


22


according to the relative locations of the side walls


2009


of flanges


2007


,


2008


. As shown in

FIG. 22

, the wire of turn


21




t


is in contact with the outermost portions of the side walls


2009


and closely proximate to the intersection of the side walls


2009


with the perpendicular surfaces of the side sections


2005


,


2006


.




The geneva engages the coil end with the die


2000


, inserting the terminal convolution


26


into the die cavity


2010


through the opening


2078


formed by flanges


2007


,


2008


, and positioning the end turn of the coil body about the side walls


2009


of flanges


2007


,


2008


by passing the terminal convolution of the coil over a compression plate


2015


(shown in

FIG. 2

) positioned proximate to the head forming station. The end of the coil, including the terminal convolution


26


, is axially compressed to a point past the outermost edge of flanges


2007


,


2008


, so that as the compressed coil is carried past the shield, it expands so that the terminal convolution


26


pops into the die cavity


2010


, and the first turn


21




t


of the coil body is engaged about the flanges


2007


,


2008


, snug against the side walls


2009


of flanges


2007


,


2008


. The side walls


2009


of flanges


2007


,


2008


are tapered to facilitate both coil entry into the die


2000


and exit once the coil head is formed.




The geneva then advances the coil to a tempering station


250


where an electrical current is passed through the coil to temper the steel wire. The next advancement of the geneva inserts the coil into a conveyer,


301


or


302


, which carries the coils to a coil transfer machine as further described below. As shown in

FIG. 1

, one or more coil formation machines may be used simultaneously to supply coils in the innerspring assembly system.




Coil Conveyance




As shown in

FIG. 1

, coils


2


are conveyed in single file fashion from each of the coil formation machines


201


,


202


by respective similarly constructed coil conveyors


301


,


302


to a coil transfer machine


400


. Although described as coil conveyors in the context of an innerspring manufacturing system, it will be appreciated that the conveyance systems of the invention are readily adaptable and applicable to any type of system or installation wherein conveyance of any type of object or objects is required. As further shown in

FIGS. 3A-3E

, conveyer


301


includes a box beam


303


which extends from the geneva


220


to a coil transfer machine


400


. Each beam


303


includes upper and lower tracks


304


formed by opposed rails


306


, mounted upon side walls


307


. A plurality of flights


308


are slidably mounted between rails


306


. Each flight


308


has a clip


310


configured to engage a portion of a coil, such as two or more turns of the helical body of a coil, as it is loaded by the geneva


220


to the conveyor. As further shown in

FIGS. 3C and 3E

, each flight


308


has a body


309


with opposed parallel flanges


311


which overlap and slide between rails


306


. A bracket


312


depends from the body


309


of each flight. Each bracket is attached to a pair of adjacent pins


313


of links


314


of a main chain


315


, with additional link


314


between each of the flights. The main chain


315


extends the length of the beam


302


and is mounted on sprockets


316


at each end of each beam. The flights


308


are thus evenly spaced along the main chain


315


.




To translate the flights


308


in an evenly spaced progression along track


304


, an indexer


320


is mounted within the box beam


303


. The index


320


includes two parallel indexer chains


321


which straddle the main chain


315


and ride on co-axial pairs of sprockets


322


. The sprockets


322


are mounted upon shafts


324


. The chains


321


carry attachments


323


at an equidistant spacing, equal to the spacing of the flights


308


when the main chain


315


is taut. Once the main chain is no longer driven by the indexer, the main chain goes slack and the flights begin to stack against one another, as shown at the right side of

FIGS. 3A and 3B

. Now the pitch between flights is no longer determined by the distance between attachments on the main chain, but by the length of the flight bodies


309


which abut. This allows the conveyor to be loaded at one pitch, and unloaded at a different pitch.




The conveyor is further provided with a brake mechanism. As shown in

FIG. 3D

, a brake mechanism includes a linear actuator


331


with a head


332


driven by an air cylinder


330


or equivalent means to apply a lateral force to a flight positioned next to the actuator, thus pinching the flight against the interior side of the track


304


. By controlling the air pressure in the air cylinder


330


, the degree and timing of the resulting braking action of flights along the conveyor can be selectively controlled.




Alternatively, as shown in

FIG. 3E

, a fixed rate spring


334


may be incorporated into the horizontal flange of a track


304


where it is passed by each flight and applies a constant braking force to each of the flights. The size or rate of the spring can be selected depending upon the amount of drag desired at the brake point along the conveyor track.




Associated with each coil conveyor is a coil straightener, shown generally at


340


in

FIGS. 3A and 3B

. The coil straightener


340


operates to uniformly orient each coil within a flight clip


310


for proper interface with coil transfer machinery described below. Each straightener


340


includes a pneumatic cylinder


342


mounted adjacent beam


303


. An end effector


344


is mounted upon a distal end of a rod


346


extending from the cylinder


342


. The pneumatic cylinder is operative to impart both linear and rotary motion to the rod


346


and end effector


344


. In operation, as a coil is located in front of the straightener


340


during passage of a flight, the end effector


344


translates out linearly to engage the presented end of the coil and simultaneously or subsequently rotates the coil within the flight clip to a uniform, predetermined position. The helical form of the coil body engaged in the flight clip allows the coil to be easily turned or “screwed” in the clip


310


by the straightener. Each coil in the conveyors is thereby uniformly positioned within the flight clips downstream of the straightener.




The described coil conveyance can also be accomplished by certain alternative mechanisms which are also a part of the invention. As shown in

FIGS. 15A-15D

, an alternate device for conveying coils from a coil former to a coil transfer station is a belt system, indicated generally at


350


, which includes a pocketed flap belt


352


and an opposing belt


354


. Coils


2


are positioned by a geneva to extend axially between the belts


352


and


354


, as shown in FIG.


15


A. The flap belt


352


has a primary belt


353


and a flap


355


attached to the primary belt


353


along a bottom edge. As shown in

FIG. 15B

, a fixed opening wedge


356


spreads the flap


355


away from the primary belt


353


to facilitate insertion of the coil head into the pocket formed by the flap and primary belt. An automated insertion tool may be used to urge the coil heads into the pocket. As shown in

FIG. 15C

, a straightening arm


358


is configured to engage a portion of the coil head, and driven to uniformly orient the coils within the pocket. Once inserted into the pocket and correctly oriented, the coils are held in position relative to the belts by a compressing bar


360


against which the exterior surface of flap


355


bears. The compressing bar


360


is movable at the region where the coils are removed from the belt by a coil transfer machine, to release the pressure on the flap to allow removal of the coils from the pocket. As further shown, the primary belt


353


and opposing belt


354


are each attached to a timing belt


362


, a flexible plastic backing


364


, and a backing plate


366


which may be steel or other rigid material. This construction gives the belt the neccesary rigidity to securely hold the coils between them, and sufficient flexibility to be mounted upon and driven by pulleys, and to make turns in the conveyance path.





FIG. 16

illustrates pairs of spring winders


360


which can be employed as alternate coil conveyance mechanisms in connection with the system of the invention. Each spring winder


360


includes a primary chain


361


and secondary chain


362


driven by sprockets


364


to advance at a common speed from a respective coil former to a coil transfer station or assembler as further described below. Coil engaging balls


366


, dimensioned to fit securely within the terminal convolutions of the coils, are mounted at equal spacings along the length of each chain. The chains are timed to align the balls


366


in opposition for engagement of a coil presented by the geneva. Each chain may be selectively controlled to change the relative angle of the coils as they approach the coil transfer stage, as shown at the right side of FIG.


16


. Magnets may be used in addition to or in place of balls


366


to hold the coils between the sets of chains.




Coil Transfer




As shown in

FIGS. 1 and 4A

and


4


B, each conveyor


301


,


302


positions a row of coils in alignment with a coil transfer machine


400


. The coil transfer machine includes a frame


402


mounted on rollers


404


on tracks


406


to linearly translate toward and away from conveyors


301


,


302


and the innerspring assembler


500


. A linear array of arms


410


with grippers


412


grip an entire row of coils from the flights


304


of one of the conveyors and transfer the row of coils into the innerspring assembler. The number of operative arms


410


on the coil transfer machine is equal to a number of coils in a row of an innerspring to be produced by the assembler. By operation of a drive linkage schematically shown at


416


, in combination with linear translation of the machine upon tracks


406


. The coil transfer machine lifts an entire row of coils from one of the conveyors (at position A) and inserts them into an innerspring assembly machine


500


. Such a machine is described in U.S. Pat. No. 4,413,659, the disclosure of which is incorporated herein by reference. The innerspring assembler


500


engages the row of coils presented by the transferor as described below. The coil transfer machine


400


then picks up another row of coils from the other parallel conveyor (


301


or


302


) and inserts them into the innerspring assembly machine for engagement and attachment to the previously inserted row of coils. After the coils are removed from both of the conveyors, the conveyors advance to supply additional coils for transfer by the coil transfer machine into the innerspring assembler.




Innerspring Assembler




The primary functions of the innerspring assembler


500


are to:




(1) grip and position at least two adjacent parallel rows of coils in a parallel arrangement;




(2) connect the parallel rows of coils together by attachment of fastening means, such as a helical lacing wire to adjacent coils; and




(3) advance the attached rows of coils to allow introduction of an additional row of coils to be attached to the previously attached rows of coils, and repeat the process until a sufficient number of coils have been attached to form a complete innerspring assembly.




As shown in

FIGS. 5

,


6


,


9


-


10


, the innerspring assembler


500


is mounted upon a stand


502


of a height appropriate to interface with the coil transfer machine


400


. The innerspring assembler


500


includes two upper and lower parallel rows of coil-receiving dies,


504


A and


504


B which receive and hold the terminal ends of each of the coils, with the axes of the coils in a vertical position, to enable insertion or lacing of fastening means such as a helical wire between the coils, and to advance attached rows of coils out of the innerspring assembler. The dies


504


are attached side-by-side upon parallel upper and lower carrier bars


506


A,


506


B which are vertically and horizontally (laterally) translatable within the assembler. The innerspring assembler operates to move the carrier bars


506


with the attached dies


504


to clamp down on two adjacent rows of coils, fasten or lace the coils together to form an innerspring assembly, and advance attached rows of coils out of the assembler to receive and attach a subsequent row of coils. More specifically, the innerspring assembler operates in the following basic sequence, described with reference to FIGS.


7


A-


7


I:




1) a first upper and lower pair of carrier bars


506


A (with the attached dies


504


A) are vertically retracted to allow for introduction of a row of coils from the coil transfer machine (FIG.


7


A);




2) the first upper and lower pair of carrier bars


506


A are vertically converged upon a newly inserted row of coils (FIG.


7


C);




3) adjacent rows of coils clamped between the upper and lower dies


504


are attached by fastening or lacing through aligned openings in the adjacent dies (FIG.


7


D);




4) the second upper and lower pair of carrier bars


506


B are vertically retracted to release a preceding row of coils from the dies (FIG.


7


E),




5) the upper and lower carrier bars


506


A are laterally translated to the position previously occupied by upper and lower carrier bars


506


B, to advance the attached rows of coils out of the assembler (FIG.


7


I), and




6) carrier bars


506


B are laterally translated opposite the direction of translation of carrier bars


506


A, to swap positions with carrier bars


506


A to position the dies to receive the next row of coils to be inserted (FIG.


7


I).




In

FIG. 7A

coils are presented to the innerspring assembler by the coil transfer machine in the indicated direction. Upper and lower rows of dies


504


A, mounted upon upper and lower carrier bars


506


A, are vertically retracted to allow the entire uncompressed length of the coils to be inserted between the dies. A previously inserted row of coils is compressed between upper and lower dies


504


B, mounted upon upper and lower carrier bars


506


B positioned laterally adjacent to carrier bars


506


A (FIG.


7


B). The upper and lower dies


504


A are converged upon the terminal ends of the newly presented coils to compress the coils to an extent equal to the preceding coils in dies


504


B (FIG.


7


C). The horizontally adjacent carrier bars


506


A and


506


B are held tightly together by back-up bars


550


(schematically represented in FIG.


7


D), actuated by a clamping mechanism described below. With the dies clamped together, the adjacent rows of coils compressed between the upper and lower adjacent dies


504


A and


504


B are fastened together by insertion of a helical lacing wire


4


through aligned cavities


505


in the outer abutting side walls of the dies, and through which a portion of each coil in a die passes (FIG.


7


E). The lacing wire


4


is crimped at several points to secure it in place upon the coils. When the attachment of two adjacent rows of coils within the dies is complete, clamps


550


are released (

FIG. 7F

) and the upper and lower dies


504


B are vertically retracted (FIG.


7


G). The upper and lower dies


504


A and


504


B are then laterally translated or indexed in the opposite directions indicated (in

FIG. 7I

) or swapped , to laterally exchange positions, whereby one row of attached coils are advanced out of the innerspring assembler, and the empty dies


504


B are positioned for engagement with a newly introduced row of coils. The described cycle is then repeated with a sufficient number of rows of coils interconnected to form an innerspring assembly which emerges from the assembler onto a support table


501


, as shown in

FIGS. 1 and 5

.




As shown in

FIGS. 8A and 8B

, the coil-engaging dies


504


are generally rectangular shaped blocks having tapered upward extending flanges


507


contoured to guide the head


22


of the coil


2


about the exterior of the die to rest upon a top surface


509


of side walls


511


of the die. As shown in

FIG. 8A

, two of the offsets of the coil head


22


extend beyond the side walls


511


of the die, next to an opening


505


through which the helical lacing wire


4


is guided to interconnect adjacent coils. A cavity


513


is formed in the interior of the die, within walls


511


, in which a tapered guide pin


515


is mounted. The guide pin


515


extends upward through the opening to cavity


513


, and is dimensioned to be inserted into the terminal convolution


28


of the coil which fits within cavity


513


. The dies


504


of the present invention are thus able to accommodate coils having a terminal convolution which extends beyond a coil head, and to interconnect coils at points other than at the terminal ends of the coils.




The mechanics by which the innerspring assembler translates the carrier bars


506


with the attached dies


504


in the described vertical and lateral paths are now described with continuing reference to

FIGS. 7A-7I

, and additional reference to

FIGS. 9A and 9B

,


10


and


11


. The carrier bars


506


(with attached dies


504


) are not permanently attached to any other parts of the assembler. The carrier bars


506


are thus free to be translated vertically and laterally by elevator and indexer mechanisms in the innerspring assembler. Dependent upon position, the carrier bars


506


and dies


504


are supported either by fixed supports or retractable supports. As shown in

FIGS. 9A and 9B

, the lowermost carrier bar


506


A rests on a clamp assembly piece supported by a lower elevator bar


632


B. The uppermost carrier bar


506


A is supported by pneumatically actuated pins


512


which are extended directly into bores in a side wall of the bar, or through bar tabs attached to the top of the carrier bar and aligned with the pins


512


. Actuators


514


, such as for example pneumatic cylinders, are controlled to extend and retract pins


512


relative to the carrier bars. The pins


512


on the coil entry side of the innerspring assembler are also referred to as the lag supports. The pins


512


on the opposite or exit side of the assembler (from which the assembled innerspring emerges) are alternatively referred to as the lead supports. On the exit side of the assembler (right side of

FIGS. 9A and 9B

, left side of FIG.


10


A), the upper carrier bar


506


B (in a position lower than upper carrier bar


506


A) is supported by fixed supports


510


, and the lower carrier bar


506


B is supported by lead support pins


512


.




As shown in

FIG. 10A

, a chain driven elevator assembly, indicated generally at


600


, is used to vertically retract and converge the upper and lower carrier bars


506


A and


506


B through the sequence described with reference to

FIGS. 7A-I

. The elevator assembly


600


includes upper and lower sprockets


610


, mounted upon axles


615


, and upper and lower chains


620


engaged with sprockets


610


. The opposing ends of the chains are connected by rods


625


. Upper and lower chain blocks


630


A and


630


B extend perpendicularly from and between the rods


625


, toward the center of the assembler. Lower axle


615


is connected to a drive motor (not shown) operative to rotate the associated sprocket


610


through a limited number of degrees sufficient to vertically translate the chain blocks


630


A and


630


B in opposite directions, to coverage or diverge, upon rotation of the sprockets. When the sprockets


610


are driven in a clockwise direction as shown in

FIG. 10A

, chain block


630


A moves down, and chain block


630


B moves up, and vice versa.




The chain blocks


630


A and


630


B are connected to corresponding upper and lower elevator bars


632


A and


632


B which run parallel to and substantially the entire length of the carrier bars. The upper and lower elevator bars


632


A and


632


B vertically converge and retract upon the described partial rotation of sprockets


610


. The upper lead and lag support pins


512


and associated actuators


514


are mounted on the upper elevator bar


632


A to move vertically up or down with the elevator assembly.




The two parallel sets of upper and lower carrier bars,


506


A and


506


B, are laterally exchanged (as in

FIG. 7I

) by an indexer assembly indicated generally at


700


in FIG.


10


A. The indexer assembly includes, at each end of the assembler, upper and lower pairs of gear racks


702


, with a pinion


703


mounted for rotation between each the racks. One of each of the pairs of racks


702


is connected to a vertical push bar


706


, and the other corresponding rack is journalled for lateral translation. The right and left vertical push bars


706


are each connected to a pivot arm


708


which pivots on an index slide bar


710


which extends from a one end of the assembler frame to the other, between the pairs of indexer gear racks. A drive rod


712


is linked to vertical push bar


706


at the intersection of the push bar with the pivot arm. The drive rod


712


is linearly actuated by a cylinder


714


, such as a hydraulic or pneumatic cylinder. Driving the rod


712


out from cylinder


714


moves the vertical push bar


706


and the attached racks


702


. The translation of the racks


702


attached to the vertical push bar


706


causes rotation of the pinions


703


which induces translation in the opposite direction of the opposing rack


702


of the rack pairs.




As further shown in

FIG. 10B

, for each pair of racks


702


, one of the racks


702


carries or is secured to a linearly actuatable pawl


716


, dimensioned to fit within an axial bore at the end of a carrier bar


506


(not shown). The corresponding opposing rack


702


carries or is attached to a guide


718


having an opening with a flat surface


719


dimensioned to receive the width of a carrier bar


506


, flanked by opposed upstanding tapered flanges


721


. As shown in

FIG. 10A

, on the lower half of the assembler, the lower rack


702


of the opposed rack pairs carries a guide


718


in which a lower carrier bar


506


B (not shown) is positioned. The opposed corresponding rack


702


carries pawl


716


engaged in an axial bore in lower carrier bar


506


A (not shown). An opposite arrangement is provided with respect to the upper pairs of racks


702


. With the carrier bars


506


thus in contact with the indexer assembly, linear actuation of the drive rods


712


causes the carrier bars


506


A and


506


B to horizontally translate in opposite directions and exchange vertical plane positions (i.e. to swap), to accomplish the process step previously described with reference to the FIG.


7


I.




The innerspring assembler of the invention further includes a clamping mechanism operative to laterally compress together the adjacent pairs of dies


504


A and


504


B (or carrier bars


506


) when they are horizontally aligned (as described with reference to FIG.


7


D), so that the coils in the dies are securely held together as they are fastened together by, for example, a helical lacing wire. As shown in

FIG. 5

(and schematically depicted in FIGS.


7


A-


7


I), the innerspring assembler includes upper and lower back-up bars


550


which are horizontally aligned with the corresponding carrier bars


506


during the described inter-coil lacing operation. Each back-up bar


550


is intersected by or otherwise operatively connected to arms


562


,


564


of a clamp assembly shown in FIG.


11


. The clamp assembly


560


includes a fixed clamp arm


562


, and a moving clamp arm


564


, connected by linkage


566


. A shaft


570


extending from a linear actuator


568


, such as an air or hydraulic cylinder, is connected at a lower region to linkage


566


. Extension of shaft


570


from actuator


568


causes the distal end


565


of the moving clamp arm


564


to laterally translate away from the adjacent carrier bar


506


to an unclamped position. Conversely, retraction of the shaft


570


into the actuator


568


causes the distal end


565


of the moving clamp arm


564


to move toward the adjacent carrier bar


506


, clamping it against the horizontally adjacent carrier bar


506


, and against the adjacent carrier bar


506


which backs up against the fixed clamp bar


562


. The clamp assemblies


560


on the upper half of the assembler are mounted upon the assembler frame and does not move with the carrier bars and dies. The clamp assemblies


560


on the lower half of the assembler are mounted on the elevator bar


632


B to move with the carrier bars. Thus by operation of actuator


568


the clamp assemblies either hold adjacent rows of dies/carrier bars tightly together, or release them to allow the described vertical and horizontal movements.




One or more of the dies


504


may be alternately configured to crimp and/or cut each of the helical lacing wires once it is fully engaged with two adjacent rows of coils. For example, as shown in

FIG. 6B

, a knuckler die


504


K is attachable to a carrier bar at a selected location where the helical lacing wire is to be crimped or “knuckled” to secure it in place about the coils. The knuckler die


504


K has a knuckle tool


524


mounted upon a slidable strike plate


525


which biased by springs


526


so that the tip


527


of the knuckle tool


524


extends beyond an edge of the die. In the assembler, a linear actuator (not shown) such as a pneumatically driven push rod, is operative to strike the strike plate


525


to advance the knuckle tool


524


in the path of the strike plate to bring the tool into contact with the lacing wire. Where upper and lower knucler dies


504


K are installed on the upper and lower carrier bars of the assembler, the linear actuator is provided with a fitting which contacts both the upper and lower strike plates of the knuckler dies simultaneously.




The invention further includes certain alternative means of lacing together rows of coils within the innerspring assembly machine. For example, as shown in

FIGS. 17A-17G

, lacer tooling


801


includes a guide ramp


802


upon which the terminal end of coils


2


are advanced into position by a finger


804


which positions the coil ends within partable tooling


806


. As shown in

FIG. 17C

, the downward travel of the finger


804


positions segments of the adjacent coils heads within complementary tools


806


which then clamp to form a lacing channel for insertion of a helical lacing wire. Once laced together, the tools


806


part and the connected coils are advanced to allow for introduction of a subsequent row of coils.

FIG. 17B

illustrates a starting position, with the coil heads of a new row of coils at left and a preceding row of coils engaged by the finger


804


. In

FIG. 17C

, the finger is actuated downward to draw the coil head segments in between the parted tools


806


. In

FIG. 17D

, the finger


804


then returns upward as the coil heads are laced together within the tools


806


which are placed tightly together about overlapping segments of the adjacent coil heads. In

FIG. 17E

, the tools


806


open to release the now connected coils which recoil upward to contact finger


804


(as in FIG.


17


F), and the connected coils are indexed or advanced to the right in

FIG. 17G

to allow for introduction of a subsequent row of coils.





FIGS. 18A-18G

illustrate still another alternative means and mechanism for lacing or otherwise connecting adjacent rows of coils. The coils are similarly advanced up a guide ramp


802


so that overlapping segments of adjacent coil heads are positioned directly over extendable tools


812


. As shown in

FIG. 18B

, the tools


812


are laterally spread and, in

FIG. 18C

, extend vertically to straddle the overlapping coil segments, and clamp together thereabout as in

FIG. 18D

to securely hold the coils as they are laced together. The tools


812


then part and retract, as in

FIGS. 18E and 18F

, and the connected coils are indexed or advanced to the right in FIG.


18


G and the process repeated.





FIGS. 19A-19F

illustrate still another mechanism or means for lacing or interconnecting adjacent coils. Within the innerspring assembler are provided a series of upper and lower walking beam assemblies, indicated generally at


900


. Each assembly


900


includes an arm


902


which supports dual coil-engaging tooling


904


, mounted to articulate via an actuator arm


906


. The tooling


904


includes cone or dome shaped fittings


905


configured for insertion into the open axial ends of the terminal ends of the coils. This correctly positions a pair of coils between the upper and lower assemblies for engagement of lacing tools


908


with segments of the coil heads (as shown in FIG.


19


C). Once the lacing or attachment is completed, the assemblies


900


are actuated to laterally advance the attached coils to the right as shown in FIG.


19


D. The assemblies


900


then retract vertically off the ends of the coils, and then retract laterally (for example to the left in

FIG. 19F

to receive the next row of coils.




The coil formers, conveyors, coil transfer machine and innerspring assembler are run simultaneously and in synch as controlled by a statistical process control system, such as an Allen-Bradley SLC-504 programmed to coordinate the delivery of coils by the genevas to the conveyors, the speed and start/stop operation of the conveyors the interface of the arms of the coil transfer machine with coils on the conveyors, and the timed presentation of rows of coils to the innerspring assembler. and operation of the innerspring assembler.




Although the invention has been described with reference to certain preferred and alternate embodiments, it is understood that numerous modifications and variations to the different component could be made by those skilled in the art which are within the scope of the invention and equivalents.



Claims
  • 1. A coil formation device for forming coils having a generally helical coil body, a non-helical coil head, and a terminal convolution generally smaller than the coil body, the coil formation device comprising:a wire feed mechanism which feeds wire stock into a coil forming block, the coil forming block having a cavity within which a terminal convolution of the coil is formed, a coil radius forming wheel against which wire stock bears to form a generally helical shape to the coil body, a helical guide pin in contact with the wire stock and operative to move relative to the forming block to form a generally helical shape to the coil body, a wire cutting tool configured to cut the wire stock within the cavity of the coil forming block, a geneva for transferring a coil from the coil forming block to a coil head forming station, the coil head forming station having a coil head formation die, the coil head formation die having a cavity configured to receive a terminal convolution of the coil, and a flange proximate to the cavity about which an end turn of the coil body is positioned by the geneva, and at least one punch operative to strike the end turn of the coil body against the flange of the coil head formation die to form a coil head between the coil body and the terminal convolution.
  • 2. The coil formation device of claim 1 wherein the wire feed mechanism feeds wire stock into an upper portion of the cavity in the coil forming block, and an interior of the coil forming block cavity has a helical guide surface.
  • 3. The coil formation device of claim 1 wherein the helical guide pin is operative to extend into alignment with the cavity of the coil forming block.
  • 4. The coil formation device of claim 1 wherein the wire cutting tool includes a movable cutting blade mounted outside of the coil forming block, and a stationary blade mounted in the coil forming block, the movable cutting blade operative to move relative to the stationary blade to cut the wire stock within the cavity of the coil forming block.
  • 5. The coil formation device of claim 1 wherein the wire cutting tool is configured to cut the wire stock at the end of a terminal convolution of the coil at a point inside a diameter of the body of the coil which is greater than a diameter of the terminal convolution.
  • 6. The coil formation device of claim 1 wherein the geneva is operative to engage the coil body and to remove the terminal convolution of the coil from the cavity in the coil forming block and insert the terminal convolution into the cavity of the coil head formation die at the coil head forming station.
  • 7. The coil formation device of claim 1 wherein the coil head formation die has an opening through which the terminal convolution of the coil enters the cavity of the coil head formation die.
  • 8. The coil formation device of claim 1 wherein the coil head formation die is a two part assembly.
  • 9. The coil formation device of claim 1 wherein the coil head formation die includes flanges configured to fit within an end turn of a coil body proximate to a terminal convolution of the coil in the cavity of the coil head formation die.
  • 10. The coil formation device of claim 1 wherein the coil head formation die has at least one flange with a side wall configured for operation with punch, whereby a segment of wire of a coil engaged with the coil head formation die is formed by the punch against the wire and the side wall of the flange.
  • 11. The coil formation device of claim 10 wherein the at least one flange of the coil head formation die is proximate to the cavity, and the terminal convolution of a coil engaged with the coil head formation die is connected to the end turn of the coil body by a segment of wire which traverses the flange.
  • 12. The coil formation device of claim 1 wherein the coil head formation die is configured so that an end turn of the coil body of a coil engaged with the die is located near an intersection of the flange and a surface of the die.
  • 13. A coil formation die for use with a coil former machine, the coil former machine having a wire feed mechanism for feeding wire stock from which coils are formed, a coil forming wheel against which wire stock is fed to form the wire into a coiled configuration, a helical guide pin operative to move the wire relative to the coil forming wheel to form a helix in the coiled wire, and a cutting device for cutting a formed coil from the wire stock,the coil formation die being attached to the coil former machine at a wire stock feed point and proximate to the coil forming wheel, the helical guide pin, and the cutting device, the coil formation die having a body with a wire stock feed hole through which wire stock is passed, and a cavity proximate to the wire stock feed point whereby at least a portion of the wire stock can be formed by the coil forming wheel in the cavity.
  • 14. The coil formation die of claim 13 wherein a surface of the cavity against which the wire stock bears is tapered in a helical configuration.
  • 15. The coil formation die of claim 14 wherein the taper in the cavity is congruent with a helix angle formed in the wire stock by the helical guide pin.
  • 16. The coil formation die of claim 11 wherein a stationary blade of the cutting device is mounted within the cavity.
  • 17. The coil formation die of claim 11 wherein a movable blade of the cutting device is operative to extend into the cavity.
  • 18. The coil formation die of claim 11 wherein the helical guide pin is operative to engage wire stock formed within the cavity.
  • 19. The coil formation die of claim 11 wherein the coil forming wheel is generally aligned with the cavity.
  • 20. The coil formation die of claim 11 wherein the helical guide pin contacts only a body portion of the coil and does not contact the wire stock in the cavity.
  • 21. The coil formation die of claim 11 wherein the wire stock feed point is near a top area of the cavity.
  • 22. The coil formation die of claim 11 in the general configuration of a block attachable to a coil forming machine, and the cavity formed at one end of the block.
  • 23. The coil formation die of claim 11 in combination with a coil forming machine for forming helical coils with at least one terminal convolution smaller than a body of the coil, wherein the coil formation die is selected according to a size or configuration of the cavity of the die to form the terminal convolution of the coil.
  • 24. A coil head formation die for use with a coil forming machine for forming a coil head in an end turn of a body of a coil having a terminal convolution contiguous with a body of the coil, the coil head formed by operation of one or more punches of the coil forming machine operative to strike a portion of the end turn of the coil against the die while the end turn of the coil and the terminal convolution of the coil are engaged with the coil head formation die, the coil head formation die having a cavity configured to receive a terminal convolution of the coil, and a portion configured to oppose a punch which strikes the end turn of the coil to form a coil head.
  • 25. The coil head formation die of claim 24 comprising a body having a back wall and side walls which extend from the back wall to form the cavity, and at least one flange which extends from a side wall, the flange configured to oppose a punch operative to strike an end turn of a coil proximate to the flange.
  • 26. The coil head formation die of claim 24 having a back wall and side walls which define a cavity, and an opening in the side walls through which a terminal convolution of a coil can enter the cavity.
  • 27. The coil head formation die of claim 24 combination with a coil forming machine having a back wall and side wall which define a cavity, an opening to the cavity generally opposite the back wall, and a compression plate attached to the coil formation machine proximate to the coil head formation die, the compression plate positioned to at least partially compress a coil prior to engagement of a portion of the coil with the cavity in the coil head formation die.
  • 28. The coil head formation die of claim 24 in combination with a coil having a terminal convolution positioned within the cavity of the die, wherein the terminal convolution is at least partially compressed within the cavity.
  • 29. The coil head formation die of claim 25 having at least one flange proximate to the cavity.
  • 30. The coil head formation die of claim 27 wherein a body of the die is in two parts.
  • 31. The coil head formation die of claim 25 in combination with a coil forming machine having a coil formation station, and at least one coil head formation station, and a geneva for carrying coils between the stations, wherein the cavity of the coil head formation die at the coil head formation station has an opening oriented in a direction of travel of a coil carried by the geneva.
  • 32. A coil formation die for forming a generally helical wire coil with helix of different diameter at different sections of the coil, the coil formation die comprising a die body having a guide wire stock guide through which wire stock is fed to a wire stock exit point to contact a coil forming wheel of a coil forming machine, a cavity in the die body proximate to the wire stock exit point, the cavity having an arcuate configuration against which a portion of the wire stock is formed by the coil forming wheel, and the cavity being positioned relative to a wire cutting device of the coil forming machine so that a formed coil can be cut from the wire stock within the cavity.
  • 33. A coil head formation die for use with a coil forming machine having a coil head formation station at which a coil is positioned for formation of a coil head by operation of one or more punches on a turn of the coil, the coil head formation die having a die body attachable to the coil head formation station, the die body having a back wall and side sections which extend from the back wall, the back wall and side sections defining a cavity for receiving a portion of a coil, and a punch striking structure for positioning a portion of the coil to be struck by a punch to form a coil head.
  • 34. A coil head formation die for forming a coil head in a turn of a generally helical coil having a terminal convolution with a diameter different than a diameter of a body of the coil, the coil head formation die having a die body with a rear wall and side walls which define a cavity for receiving a terminal convolution of a coil, a portion of the die body positionable adjacent to a turn of a coil engaged with the die and against which a punch can operate to form one or more bends in the turn of the coil proximate to the terminal convolution.
  • 35. A coil formation die for use with a coil forming machine for forming a generally helical wire spring coil of varying diameter, the coil formation die having die body and a wire stock guide in the die body through which wire stock is fed to a wire stock exit point past which the wire stock contacts a coil forming wheel of the coil forming machine to coil the wire stock at varying diameters, a cavity in the die body proximate to the wire stock exit point, the cavity having a generally arcuate surface against which at least a portion of the wire is formed by the coil forming wheel.
Parent Case Info

This application is a continuation-in-part of application Ser. No. 09/151,872 filed Sep. 11, 1998 now U.S. Pat. No. 6,155,310.

US Referenced Citations (2)
Number Name Date Kind
3541827 Hansen Nov 1970 A
5444905 St. Clair Aug 1995 A
Continuation in Parts (1)
Number Date Country
Parent 09/151872 Sep 1998 US
Child 09/723668 US