GB2112690A - Cut and clench device, and method - Google Patents

Abstract

A device for cutting a helically wound wire (40) and forming a loop at the cut end, comprises a guiding-positioning member (96) for restraining relative movement of the helical for cutting and forming a loop on the end of the helical, and shearing-clenching member (88) movable relative to the guiding-positioning member between a rest position and cutting and clenching positions. When moved from the rest position (Fig. 7a) to the cutting position (Fig. 7b), a first shearing surface 140 on the shearing-clenching member and a mating second shearing surface 129 on a cutting channel 128 of the guiding-positioning member cooperate to shear the helical. As the shearing-clenching member continues in a single motion between the cutting and clenching positions, an abutment surface 138 on the shearing-clenching member engages one of the sheared ends of the helical and cooperates with an edge 170 on a retaining channel 126 of the member 96 to form a residual loop (Figs. 7c, 7d). The device and method are particularly suited for the automated cutting and finishing of helicals in the manufacture of bedspring assemblies. <IMAGE>

Description

SPECIFICATION Cut and clench device, system and method BACKGROUND OF THE INVENTION The present invention relates to a device, a system, and a method of automatically cutting a helical and of clenching the cut end to form a loop. The invention is especially useful in bedspring manufacturing.

In the manufacture of helicals of relatively small diameter, it is convenient to form a continuous helical and then cut it into individual helicals of desired lengths. Commonly, a continuous strand of wire is fed from a wire reel by rollers and guided into a helicalforming pin. As the wire passes through the pin it is formed into a continuous helical.

When the continuous helical is cut in a conventional manner into individual helicals, sharp ends are formed. These sharp ends can cause problems in some uses of the helicals.

For example, such helicals are used to lace together adjacent rows of coil springs to form a resilient bedspring assembly. The helicals are cut to a uniform length but the rows of the coil springs are not always the same length. Accordingly, the sharp ends of the helicals protrude from some of the rows and can puncture the overlying padding material and fabric covering. Additionally, the helicals are free to rotate and their ends sometimes rotate out of engagement with the end coil springs. This rotation is commonly called "spin-out" or "helical spin-out" and may result in penetration by the sharp ends of the overlying padding material and in puncturing of a fabric covering. The sharpness of the ends of the helicals aggravates the penetration and puncturing problems.Finally, during manufacture, the protruding ends of the helicals make the handling of the bedspring assemblies more difficult. Moreover, there is a potential danger that a helical spin-out may even result in separation of coil springs laced together by the end portions of the helicals.

In the past, several approaches have been tried to eliminate the above-mentioned problems. Patent No. 3,653,082, discloses that the helicals, lacing together adjacent rows of coils springs, may be compressed around the overlapping portions of the pairs of coil springs along the perimeter of the bedspring assembly. U.S. Patent Nos. 4,109,330 and 4,1 55,1 30 disclose, respectively, that welding and capping of the helicals may be used to restrain helical spin-out. Despite the fact that each of the above solutions greatly advanced the art and reduced the magnitude of problems associated with free ends of helicals, some aspects of the problems remain unsolved. The above solutions have also increased the manufacturing costs of bedspring assemblies.There is therefore a long felt and still unsatisfied need for an inexpensive solution which would entirely eliminate the problems associated with free ends of helicals used in bedspring assemblies.

It is, therefore, one object of the present invention to provide a device and a method for economically and effectively eliminating problems associated with protruding helicals, sharp ends of helicals and spin-outs of helicals.

Another object of the present invention is to automatically and efficiently, trim the end portions of helicals protruding from the coil springs of bed assemblies, hide the sharp ends of the helicals and loop the ends of the helicals to prevent spin-outs.

It is still another object of the present invention to provide a device and process of automatically cutting a continuous helical into segments having tight loops formed at one or both ends thereof.

It is a further object of the present invention to provide a device and process for economically forming a tight loop at the ends of the helicals of a bedspring assembly to prevent spin-outs and hide sharp ends of the helicals.

It is yet another object of the present invention to provide a device and process for automatically trimming the helicals of a bedspring assembly adjacent the end coil springs of adjacent rows to eliminate excessive protrusion of the end sections of the helicals.

Other objects of this invention will become apparent to those skilled in the art upon studying this disclosure.

SUMMARY OF THE INVENTION The present invention is directed to a device, a system, and a method for eliminating problems caused by protruding end sections, sharp ends, and spin-outs of helicals.

The device of the present invention includes guiding-positioning means, shearing-clenching means, and moving means. The guiding-positioning means receives a helical and guides the helical as it passes therethrough. It also continuously provides a first shearing surface in front of and a clenching surface behind a convolution of the helical. The shearingclenching means includes a second shearing surface and an abutment surface. At a predetermined time, the moving means causes the guiding-positioning means and the shearingclenching means to move with respect to each other such that the first shearing surface and the second shearing surface move toward each other to cut the helical. The cut end of the helical is then pushed by the abutment surface toward the clenching surface so as to form a loop.

The device of the present invention can be used to form a system useful in the manufacturing of bedspring assemblies. The system includes a first device of the present invention which cuts the helical and clenches the cut end of the helical. A second device of the present invention cuts and clenches the leading section of the helical after the helical is laced to hold together pairs of adjacent rows of a bedspring assembly. The second device is positioned to trim enough of the leading end section of the helical so as to substantially eliminate the protrusion of the helical. As a result of clenching, the end sections of the helicals cannot spin out and the sharp ends are hidden.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a helical forming machine and a lacing machine, both equipped with the cut and clench system constructed in accordance with the present invention, as seen from a position in front of and to the left of the forming machine and the lacing machine.

Figure 2 is an enlarged partial perspective view of the helical forming machine of Fig. 1 including devices of the cut and clench system.

Figure 3 is a plan view of a device of the cut and clench system of the present invention and portions of the helical forming machine, taken along the line 3-3 of Fig. 2.

Figure 4 is a sectional view of a device of the cut and clench system of the present invention taken along the line 4-4 of Fig. 3.

Figure 5 is an isometric view of the guidingpositioning member and the shearing-clenching member of the cut and clench device of Fig. 3 with the shearing-clenching member in the rest position.

Figure 6 is a sectional view of the guidingpositioning member of the cut and clench device of the present invention taken along line 6-6 of Fig. 5.

Figure 7a is a plan view of portions of the cut and clench device of Fig. 3 with parts broken away and the shearing-clenching member in the rest position.

Figure 7b is a plan view of portions of the cut and clench device of Fig. 3 with the shearing-clenching member in the cutting position.

Figure 7c is a plan view of portions of the cut and clench device of Fig. 3 with the shearing-clenching member between the cutting and clenching positions.

Figure 7d is a plan view of portions of the cut and clench device of Fig. 3 with the shearing-clenching member in the clenching position.

Figure 7e is a plan view of portions of the cut and clench device of Fig. 3 with the shearing-clenching member withdrawn to the rest position.

Figure 8 is a sectional view of portions of the cut and clench device of the present invention taken along the line 8-8 of Fig. 7b.

Figure 9 is a sectional view of portions of the cut and clench device of the present invention taken along the line 9-9 of Fig. 7c.

Figure 10 is an end view of a helical which has been cut and clenched in accordance with the present invention.

Figure 11 is a perspective view of portions of the lacing machine of Fig. 1, including devices of the cut and clench system of the present invention, as seen from a position behind and to the left of the lacing machine.

Figure 12 is plan view of a section of a bedspring assembly including a helical which has been cut and clenched in accordance with the present invention.

Figure 13 is a plan view of a section of a bedspring assembly including a helical which has been cut and clenched at one end in accordance with the present invention and, in addition, compressed against the coil springs.

DETAILED DESCRIPTION OF THE PRESENT INVENTION General Description The present invention solves problems that have plagued bedspring assembly manufacturers for years. Namely, the present invention eliminates the problems caused by sharp ends, protruding end sections and spin-outs of helicals.

The device of the present invention includes a stationary guiding-positioning member, a shearing-clenching member, a guide for permitting the shearing-clenching member to slide with respect to the guiding-positioning member, and a mechanism for sliding the shearing-clenching member. The guiding-positioning member has a retaining channel for receiving a portion of a convolution of a helical as the helical passes therethrough. The retaining channel prevents sliding of the helical traversing the guiding-positioning member.

The shearing-clenching member is movable relative to the guiding-positioning member to rest, cutting, and clenching positions. When the shearing-clenching member is in the rest position, it allows uninterrupted passage of the helical through the guiding-positioning member. At predetermined times the mechanism moves the shearing-clenching member toward the channel. As the shearing-clenching member approaches the cutting position, a first shearing edge on the guiding-positioning member is approached by a mating second shearing surface on the shearing-clenching member. As the shearing-clenching member reaches the cutting position the first and second shearing surfaces cooperate to cut the helical. The shearing-clenching member is then moved past the cutting position toward the clenching position. An abutment surface on the shearing-clenching member engages the cut end of the helical and pushes it toward the other end of the helical. As the shearing-clenching member reaches the clenching position, the end partial convolution of the helical is formed into a loop and the sharp end is positioned inward of the end of the helical.

The guiding-positioning member can include a second channel parallel to the retaining channel and spaced therefrom to receive the convolution of the helical adjacent the convolution in the retaining channel. This second channel can conveniently include the first shearing surface. The shearing-clenching member is moved in the approximate direction of the helix so as to effect cutting and clenching of the helical by a single movement. The abutment surface can include an inwardly curved area which serves to restrain lateral movement of the cut end of the helical and thereby facilitate turning the wire back into the restrained convolution to form a loop.

Description Of The Preferred Embodiment The present invention will now be further described in connection with the preferred embodiment depicted in the drawings. Referring now to Fig. 1, the cut and clench devices constructed in accordance with the present invention are designated generally by numerals 10, 12, 14, and 16.

The cut and clench devices 10 and 12 are mounted on a helical forming machine 18. As shown in Fig. 2, the helical forming machine 18 receives wires 20 and 22 from wire reels (not shown). The wires 20 and 22 are passed through wire guides 24 and 26, respectively.

Two pairs of feed rollers 28, 30 and 32, 34 move the wires 20 and 22 through respective helical forming pins 35 housed within cylindrical dies 36 and 38 respectively. As wires 20 and 22 are forced through the respective forming pins 35, they are formed into helicals 40 and 42, respectively. The helicals 40 and 42 are received by horizontal storage tubes 44 and 46, respectively. The feed rollers 28, 30 and 32, 34 are lubricated by pools of lubricant 48 and 50 as they are rotated in the directions shown by power means housed within the base 52 of the helical forming machine 18. Compression springs 54 and 56 are mounted for adjustable biasing of the feed rollers 28, 30 and 32, 34 against the wires 20 and 22.

Referring now to Fig. 1, a lacing machine, designated generally by numeral 58, is positioned adjacent the helical forming machine 18 so as to receive the helicals 40 and 42 from the storage tubes 44 and 46. The lacing machine 58 also receives a series of coil springs, not shown, either manually or automatically from a magazine feeder. The coil springs are positioned into a row by means of vertically spaced rows of jaws 60 and 62 which clamp the uppermost and lowermost convolutions of the coil springs. This first row of coil springs is then indexed automatically rearward and clamped in a second position to permit a second row of coil springs to be positioned in front of and adjacent the first row of coil springs.Having thus positioned two adjacent rows of coil springs, the lacing machine 58 automatically threads pre-cut lengths of the helicals 40 and 42 through the coil springs to lace coil springs of the adjacent rows into pairs and to form a resilient network between adjacent coil springs within a common row.

Referring now to Fig. 2, The cut and clench device 10 is mounted on the helical forming machine 18 by means of a vertical bracket 64 and a horizontal bracket 66 so as to receive the helical 40 from the cylindrical die 36. A mounting plate 68 is fixed to the horizontal bracket 66 so as to position the cut and clench device 10 at an angle corresponding to the helix of the helical 40. In response to actuation of a fluid cylinder 70, mounted upon the mounting plate 68, the cut and clench device 10 cuts off a preselected length from the helical 40. The cut and clench device 10 also forms a loop on the cut end of the cut-off helical segment, leaving the other end of the helical 40 without a loop.

The cut and clench device 12 is constructed, mounted and operated in the same manner as the device 1 0. It cuts off a preselected length from the helical 42 and forms a loop on the cut end of the cut-off helical segment. The helical 42 is formed below the helical 40. A horizontal bracket 72 and a mounting plate 74 are used to mount the cut and clench device 12, which includes a fluid cylinder 76 similar to the fluid cylinder 70. In addition, a transfer tube 78 is installed between the cylindrical die 38 and the storage tube 46 to maintain proper alignment of the helical 42 due to the greater distance between the cylindrical die 38 and the storage tube 46 relative to the distance between the cylindrical die 36 and the storage tube 44.

Referring now to Fig. 3, a yoke 80 is mounted on the end of a piston rod 82 of the fluid cylinder 70. The yoke 80 includes a transverse pin 84 which is received by a mating actuating channel 86 ground in the upper surface of a shearing-clenching member 88 so as to move the shearing-clenching member 88 in response to fluid pressure within the fluid cylinder 70. The shearingclenching member 88 is ground from a length of square tool stock and rides with a sliding fit within a square passage 89, as shown in Fig.

4, for alignment of the shearing-clenching member 88 with the helix of the helical 40.

As shown in Fig. 3, a fence member 90 is secured to the mounting plate 68 by cap screws 92 and 94 so as to restrain lateral movement of the helical 40.

The square passage 89 for the shearingclenching member 88 is formed by several members, as shown in Fig. 4. A guidingpositioning member 96, also formed from a length of square tool stock, forms the bottom of the passage 89, and a machined block 98 and a horizontal guide plate 100 form the sides of the passage 89. A generally triangular top plate 102 is secured to the machined block 98 by three flat head machine screws 104, 106 and 108. The horizontal guide plate 100 is held in place by the screw 108 and by abutment with the fence member 90 so as to prevent vertical displacement of the helical 40.

The machined block 98 is generally square in plan view, as shown in Fig. 3. One corner thereof is machined off leaving an angular surface 110 so as to provide clearance for the yoke 80. Another corner 112 is partially machined away to facilitate access to set screws 114 and 116 which secure the guiding-positioning member 96 to the machined block 98. A channel 118 is machined diagonally across the machined block 98 to provide a seat for the guiding-positioning member 96 and to provide the sides of the square passage 89 for the shearing-clenching member 88. The rearward portion 120 of the machined block 98 abuts the fence member 90 and is machined to form a platform 122 for the guided passage of the helical 40.A socket head machine screw 121 is threaded through the triangular top plate 102 and against the shearing-clenching member 88 so as to eliminate excessive vertical movement of the shearing-clenching member 88 and the guidingpositioning member 96. The machine screw 121 is locked in proper adjustment by a lock nut 123 which is tightened against the triangular top plate 102.

As shown in Fig. 5, the guiding-positioning member 96 is a length of square tool stock which has been ground to a particular wedgeshaped point and grooved with parallel channels. The chamfered end surface 124 is parallel to the helical 40 and abuts the fence member 90. A retaining channel 126 and a cutting channel 128 are ground in the upper surface of the guiding-positioning member 96 at an angle corresponding to the pitch of the helix of the helical 40 so as to receive adjacent convolutions thereof. The cutting chan#nel 128 includes a first shearing surface 129 which is described below. A clearance notch 130 and a beveled end surface 132 are ground to allow clearance for additional convolutions of the helical 40.

The shearing-clenching member 88, also shown in Fig. 5, includes a chisel-like end of a particular configuration. The square tool stock of the shearing-clenching member 88 is tapered downward in the region generally designated by numeral 133 and inward along the side surface 134 nearest the lacing machine 58 and terminates with a flat end surface 136 which is angled steeply backward. An inwardly curved relief 138, centered within the lower portion of the flat end surface 136, forms a centered vertical second shearing surface 140 and centering portions 142 and 144 extending along the sides thereof. The side surface 146 of the shearing-clenching member 88 nearest the helical forming machine 18 is recessed along a vertical shoulder 148 to form a vertical relief portion 150 to provide clearance for a portion of the helical 40.

Referring now to Figs. 3 and 4, the helical 40 is maintained in vertical position by the platform 122 of the machined block 98 and the horizontal guide plate 100. Horizontal alignment is provided by the fence member 90 and a vertical guide surface 152 which remains when the platform 122 is machined.

It will thus be seen that the fence member 90, the machined block 98, the horizontal guide plate 100, and the triangular top plate 102 form two rectangular passages which intersect at the retaining and cutting channels 126 and 128, one of the passages being a guide means for the helical 40 and the other locating the guiding-positioning member 96 and providing guide means for the shearingclenching member 88. Due to the rotation imparted by the helical forming pin 35, the helical 40 is rotated against the guiding-positioning member 96 and is threaded through the cutting and retaining channels 128 and 126.

The operation of the cut and clench device 10 is shown sequentially in Figs. 7a-7e. Fig.

7a shows the shearing-clenching member 88 in its rest position, the shearing-clenching member 88 being retracted from contact with the helical 40. White the shearing-clenching member 88 is in the rest position, the rotating helical 40 is guided from right to left between the triangular top plate 102 and the fence member 90 and is threaded through the cutting channel 128 and the retaining channel 126 until a pre-selected length has entered the storage tube 44.

Upon actuation of the fluid cylinder 70, the shearing-clenching member 88 is moved long itudinally through the square passage 89 from the rest position indicated in Fig. 7a to the cutting position indicated in Fig. 7b. In this cutting position, the shearing-clenching member 88 engages the helical 40 at the vertical second shearing surface 140. The inwardly curved relief 138 and the centering portions 142 and 144 of the shearing-clenching member 88 ensure that the wire of the helical 40 is centered upon the second shearing surface 140, as shown in Fig. 6. A restrained convolution 154 and a convolution 156 to be cut are only slightly deflected in Fig. 7b relative to their positions shown in Fig. 7a. The vertical relief portion 150 of the shearing-clenching member 88 allows the shearing-clenching member 88 to clear the adjacent convolution 158.

As shown in Figs. 6, 8, and 9, the retaining channel 126 and the cutting channel 128 of the guiding-positioning member 96 have a depth approximately one-half the diameter of the helical 40 and have a width slightly greater than the diameter of the wires 20 and 22. Upon further engagement of the helical 40 by the shearing-clenching member 88, the wire of the helical 40 is deflected against the first shearing surface 129 consisting of one of the side walls of the cutting channel 128 of the guiding-positioning member 96. The first and second shearing surfaces 129 and 140 cooperate to initiate shearing of the wire of the helical 40 along a horizontal top surface 162 of the guiding-positioning member 96 along a diameter of the helical 40.Upon further movement of the shearing-clenching member 88, the shearing of the helical 40 is completed, forming a first cut end 164 upon the measured length cut from the helical 40 and a second cut end 166 upon the remaining portion of the helical 40.

As shown in Fig. 7c, the retained convolution 154 of the helical 40 is laterally restrained by engagement with the fence member 90 as well as with the retaining channel 126. As the shearing-clenching member 88 is advanced beyond the position shown in Fig.

7c to the clenching position shown in Fig. 7d, the one-half convolution 168 between the first shearing surface 129 and a clenching surface 170 of the retaining channel 126 is bent back upon itself in a direction corresponding to the helix of the helical 40 into the restrained convolution 154. The inwardly curved relief 138 of the shearing-clenching member 88 acts as an abutment surface and ensures that the cut end 164 is maintained in lateral alignment with the helix of the helical 40. In the fully clenched position, the side portion of the one-half convolution 168 is pushed beyond the helix to allow for resiliency of the wire and ensure that a permanent deformation is achieved.

Immediately after clenching, the shearingclenching member 88 is retracted by the piston rod 82, either by fluid power or spring means, to the rest position shown in Fig. 7e.

The finished configuration of the one-half convolution 168 is a tight loop in the helix of the helical 40, as shown in Fig. 10. The second cut end 166 is left without a loop. The actuation and retraction of the shearingclenching member 88 is accomplished quickly because the second cut end 166 is held stationary against the lower surface of the shearing-clenching member 88 during a substantial part of the cycle. The helical 40 is constantly produced from the helical forming pin 35 and immediately threads through the retaining channel 126 and cutting channel 128 upon release of the second cut end 166.

Although the present invention may take different forms specially suited to various applications, the preferred embodiment described herein utilizes a guiding-positioning member 96 having a horizontal top surface 162 and a cooperating shearing-clenching member 88 slidable upon the horizontal top surface 162. Further, the first and second shearing surfaces 129 and 140, the abutment surface (inwardly curved relief 138), and the clenching surface 170 are substantially vertical surfaces having edges adjoining the horizontal top surface 162. In that configuration, the depth of the cutting channel 128 in the guiding-positioning member 96 can be used to predetermine the size and shape of the loop formed at the end of the helical.For example, if the depth of the cutting channel 128 is onehalf the diameter of the helical 40, as described above, then the edges of the first and second shearing surfaces 129, 140 and of the abutment surface (inwardly curved relief 138), and the clenching surface 170 establish cutting and clenching vectors directed along a diameter of the helical 40. By deepening the cutting channel 128, the cutting and clenching vectors may be directed above the diameter of the helical so as to form a residual loop which will be smaller. By reducing the depth of the cutting channel 128, the cutting and clenching vectors may be directed lower so as to form a residual loop which will be larger.

In addition to the cut and clench devices 10 and 12, just described, the system includes other cut and clench devices, designated by numerals 14 and 16, mounted on the lacing machine 58, as shown in Fig. 11. Due to the narrow configuration of the shearing-clenching member 88 and the guiding-positioning member 96 and the angulation of the machined block 98, the piston rod 82, and the fluid cylinder 70, the cut and clench device of the present invention is idealy suited for this installation. The cut and clench devices 14 and 16 can be mounted immediately next to perimeter coil springs 172 and 173 to permit trimming and looping of a helical such that only a short portion of the helical protrudes beyond the region 174 where the perimeter coil spring 172 and the paired perimeter coil spring 173 overlap, as shown in Fig. 12.

Note that the orientation of the cut and clench device 14 and 16 is reversed left to right relative to the cut and clench devices 10 and 12 so as to provide a loop on the helical rather than on the scrap which is trimmed therefrom.

To provide clearance for the structure of the lacing machine 58, the cut and clench device 14 is installed upside down relative to the cut and clench devices 10, 12 and 16 so as to engage the upper helical 176 adjacent the upper convolutions 178 and 179 of the perimeter coils springs 172 and 173, as shown in Fig. 11. This orientation has no adverse effect upon the operation of the cut and clench device 14, however. The cut and clench device 16 is mounted so as to engage the lower helical 180 adjacent the lower convolution 182 of the perimeter coil spring 172. For clarity, the elements of the cut and clench devices 14 and 16, which correspond to elements shown in earlier figures depicting the cut and clench devices 10 and 12, are indicated with corresponding prime numerals.

The cut and clench system of the present invention is engaged automatically during the normal operation of the machinery for manufacturing the bedspring assembly. Two measured lengths of helicals are cut from the helicals 40 and 42 by the cut and clench devices 10 and 12, leaving a first loop on one end, and are stored within the storage tubes 44 and 46 located between the helical forming machine 18 and the lacing machine 58.

When two paired rows of vertical coils springs are positioned within the lacing machine 58, the ends of the measured lengths of helical without the loops are laced through the paired vertical coils springs to form the upper and lower helicals 176 and 180. The helicals are threaded through the coil springs until the first loops are proximate the perimeter coil springs nearest the helical forming machine.

The ends of the helicals without the loops are then trimmed and looped by the cut and clench devices 14 and 16 as described above.

The storage tubes 44 and 46 are then automatically reloaded with measured lengths of helical while other coil springs are being fed and positioned by the lacing machine 58.

Although not required for the practice of the present invention, applicant prefers to utilize the cut and clench device described herein in conjunction with compressing of the helicals 176 and 180 against the perimeter-coil springs 172 and 173. As shown in Fig. 13 the compressing or crushing occurs in the region 174 where the paired coil springs 172 and 173 overlap and wherein the convolutions 178 and 179 of the coil springs 1 72 and 173 are already flattened or offset in alignment with the axis of the helical 176.

The compressing as shown can be done automatically and economically to stabilize the transverse helicals and to further ensure against helical spin-out.

Applicant has found that this preferred embodiment is particularly well suited for use with the Woodfield Automatic Indexing Assembler model FS7 and the helical forming attachment also manufactured by Woodfield Engineering Co., Ltd., 54 Batep Road, Rossendale, BB47PA Lancashire, England. The preferred fluid cylinder is Martonaire model M/5460MART manufactured by Martonaire Ltd., St. Margarets Road, Twickenham, England, also available from Woodfield Engineering Co. and used in conjunction with MAC valve No. 225B211C available from MAC Valves, Inc., 30569 Beck Road, Wixom, Michigan 48096. Applicant has found that standard 3/8ths inch tool stock is suitable material for grinding the guiding-positioning member 96 and the shearing-clenching member 88 when used with a helical 40 having an outside diameter of approximately 5/16thus of an inch.

It will be seen from the foregoing description of the preferred embodiment that the present invention provides a versatile device and method for cutting a helical automatically into individual helicals having uniform loops formed in one or both ends thereof. The invention disclosed herein improves the uniformity of products and reduces the manufacturing cost thereof. The device and method of the invention are particularly efficient because they can be used to cut a helical while the helical is being formed, only momentarily holding a small portion of the helical stationary. Due to the shape, compact size, and ease of installation possible with the device of the present invention, the advantages of the present invention can be realized in a wide variety of applications. In the manufacture of bedspring assemblies as described above, the use of the present invention eliminates excessive protrustion of the helicals. Further, the loops thus formed hide the sharp ends of the helicals and prevent helical spin-out, thereby preventing penetration and puncturing of the overlying padding and fabric covering.

While the preferred embodiment has been described in considerable detail, the present invention is not to be limited to such detail.

Claims (24)

1. A device for cutting and clenching a helical to form a looped end, comprising: (a) guiding-positioning means for receiving the helical and guiding the helical as it passes therethrough, said guiding-positioning means having a first shearing surface and a clenching surface; (b) shearing-clenching means having a second shearing surface and an abutment surface; and (c) moving means for moving the first and second shearing surfaces toward each other to cut the helical and for moving the clenching surface and abutment surface toward each other to form a loop in the cut end of the helical.

2. A device as recited in claim 1 wherein the guiding-positioning means comprises a guiding-positioning member having a retaining channel for receiving the helical to guide the helical as it passes therethrough, and wherein the retaining channel includes the clenching surface.

3. A device as recited in claim 2 wherein the first shearing surface is spaced from the clenching surface such that the first shearing surface is continuously in front of a convolution of the helical and the clenching surface is continuously behind said convolution as the helical passes through the guiding-positioning member.

4. A device as recited in claim 3 wherein the guiding-positioning member includes a second channel parallel to the retaining channel for receiving the helical, the second channel including the first shearing surface.

5. A device as recited in claim 4 wherein the first channel and the second channel have a depth substantially equal to one-half of the diameter the helical and wherein the abutment surface is slidable by the moving means across the guiding-positioning member so as to push a cut end of the helical toward the axis of the helical.

6. A device as recited in claim 2 wherein the shearing-clenching means comprises a shearing-clenching member which is movable by the moving means relative to the guidingpositioning member sequentially between rest, cutting, and clenching positions, the rest position allowing uninterrupted passage of the helical through the guiding-positioning member.

7. A device as recited in claim 6 wherein the shearing-clenching member is elongated and includes an inwardly curved end surface which serves as both the second shearing surface and the abutment surface.

8. A device as recited in claim 6 wherein the abutment surface is engageable with one cut end of the helical to push the cut end toward the clenching surface so as to bend the cut end back into the convolution received by the retaining channel as the shearingclenching member is moved from the cutting position to the clenching position by the moving means.

9. A device as recited in claim 6 wherein the shearing-clenching member is elongated and is slidable lengthwise over the guidingpositioning member in a direction corresponding generally to the helix of the helical.

10. A device as recited in claim 6 wherein the moving means comprises a fluid cylinder, linkage means between the fluid cylinder and the shearing-clenching member for moving the shearing-clenching member relative to the guiding-positioning member in response to fluid pressure, and guide means for maintaining alignment of the shearing-clenching member relative to the guiding-positioning member.

11. A system for forming a looped helical within a bedspring assembly, comprising: (a) helical forming means for forming a wire into a helical; (b) first cut and clench means, operable to receive the helical from the helical forming means, for cutting and clenching a first end of the helical so as to form a first looped end; (c) lacing means, operable to receive the helical from the first cut and clench means, for lacing the helical through the bedspring assembly such that the second end leads and the first looped end trails; and (d) second cut and clench means operable to receive the second end of the helical, after lacing by the lacing means, for cutting and clenching the second end of the helical so as to form a second looped end.

12. A system as recited in claim 11 wherein the lacing machine is operable to position the first looped end so as to substantially eliminate protrusion of the first end from the bedspring assembly, and wherein the second cut and clench means is operable to trim excess length from the helical so as to substantially eliminate protrusion of the second looped end of the helical from the bedspring assembly.

13. A system as recited in claim 11 wherein the first cut and clench means and the second cut and clench means are devices comprising: (a) guiding-positioning means for receiving the helical and guiding the helical as it passes therethrough, said guiding-positioning means having a first shearing surface and a clenching surface; (b) shearing-clenching means having a second shearing surface and an abutment surface; and (c) moving means for moving the first and second shearing surfaces toward each other to cut the helical and for moving the clenching surface and abutment surface toward each other to form a loop in the cut end of the helical.

14. A system as recited in claim 11 wherein the lacing means includes a storage tube for receiving the helical from the first cut and clench means and for storing the helical prior to lacing the helical into the bedspring assembly.

15. A system as recited in claim 11 wherein the first cut and clench means and the second cut and clench means include timing means and power means so as to be automatically actuated in synchronization with the helical forming means and the lacing means.

16. A method of cutting and clenching a helical to form a looped end, comprising: (a) passing the helical through a guidingpositioning member having a first shearing surface and a clenching surface; (b) moving a shearing-clenching member relative to the guiding-positioning member from a rest position to a cutting position such that the first shearing surface cooperates with a second shearing surface on the shearingclenching member to cut the helical; (c) moving the shearing-clenching member relative to the guiding-positioning member from the cutting position to a clenching position such that the clenching surface of the guiding-positioning member cooperates with an abutment surface of the shearing-clenching member to bend the cut end of the helical to form a loop in the end of the helical.

17. A method as recited in claim 16 wherein the moving of the shearing-clenching member relative to the guiding-positioning member from the rest position through the cutting position to the clenching position is by a single continuous motion and is in a direction corresponding substantially to the helix of the helical.

18. A method as recited in claim 17 wherein the helical is continuously passed through the guiding-positioning member while the shearing-clenching member is in the rest position and wherein the shearing-clenching member is immediately withdrawn from the clenching position to the rest position such that cutting and clenching of the helical is effected with only a momentary interruption of passing of the helical.

19. A method for forming a looped helical within a bedspring assembly comprising, in sequence: (a) forming a wire into a helical; (b) cutting and forming a loop on a first end of the helical; (c) lacing the helical through the bedspring assembly, beginning with the second end such that the looped first end is laced last; and (d) cutting and forming a loop on the second end of the helical.

20. A method as recited in claim 19 which further comprises storing the helical in a storage tube after forming of the loop on the first end but before lacing of the helical into the bedspring assembly.

21. A device for cutting and clenching a helically wound wire to form a looped end substantially as herein described with reference to Figs. 3 to 9 of the accompanying drawings.

22. A system for forming a looped helically wound wire within a bedspring assembly substantially as herein described with reference to the accompanying drawings.

23. A method of cutting and clenching a helically wound wire to form a looped end substantially as herein described with reference to Figs. 3 to 9 of the accompanying drawings.

24. A method of forming a looped helically wound wire within a bedspring assembly substantially as herein described with reference to the accompanying drawings.