Metal working – Method of mechanical manufacture – Spring making
Reexamination Certificate
2000-03-14
2002-04-23
Echols, P. W. (Department: 3726)
Metal working
Method of mechanical manufacture
Spring making
C029S227000, C029S243560, C029S712000
Reexamination Certificate
active
06374495
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to an apparatus and method for assembly of mattress spring assemblies, and more particularly, to an apparatus and method for automatically applying clips to borderwires extending about mattress innersprings.
BACKGROUND OF THE INVENTION
Mattress spring assembly clipping machines are known that automatically apply clips onto borderwires and mattress innersprings that are preassembled via helical wires to form a matrix of innersprings and by clipping the corner innersprings to the borderwires. These known machines use a driven pusher assembly that advances the preclipped mattress spring assemblies along the frame in a ha generally vertical orientation supported by way of an inclined wall. Clip applicator tools are provided at a lower cutout along the wall at a clipping station so that as the spring assembly is advanced between the tools, they are timed to be fired to apply the clips by clinching them about the borderwires and the ends of the innersprings adjacent thereto.
While these vertical-type of automatic clipping machines have proven to be much faster than manual application of the clips as by a worker who holds an applicator tool and positions it for manual firing to apply the clip, a significant limitation on their cycle times is the need to have the borderwires and innersprings in proper orientation relative to each other for clipping to occur successfully. It is generally true that in the preclipped spring assemblies, a good percentage of the inner or coil springs will have their end coils or turns disposed outward beyond the borderwires. However, for clipping to be successful, the end turns of the coil springs need to be disposed inwardly of the borderwires, and accordingly, the automatic clipping machines generally utilize a positioning mechanism to orient the borderwires and end coils in the appropriate clipping orientation. This problem of properly positioning the borderwires and innersprings in their proper clipping orientation can be exacerbated by the wide variety of different sizes and types of mattress spring assemblies that the machine needs to be able to handle. In other words, the machine should be able to clip spring assemblies for twin, full, queen and king size mattresses while also being able to deal with spring assemblies of the same size that have different types, sizes, and numbers of springs used therewith.
In many prior machines, the positioning mechanism utilizes some sort of side pusher device at the clipping station that is activated to push the end turns of the coil springs toward each other and past the borderwires. One significant limitation with these prior positioning mechanisms is that they have to be retracted each time the spring assembly is indexed to the next innerspring for its clipping to avoid interfering with the travel of the spring assembly. As is apparent, this cycle of actuating and retracting the positioning device slows down the entire cycle time for the machine undesirably lowering the production rates that can be obtained therewith.
Another prior machine disclosed in PCT publication WO 97/44275 has spreader pins that are operable to pull the borderwires away from each other and from the end turns of the coil springs. The spreader pins are not retracted after each clip is applied and thus do not cause the problems of the previously-described positioning mechanisms that have to be retracted with each coil that is clipped. However, the pulling action of the spreader pins on the borderwires creates several undesirable problems. First, unlike the coil springs which are specifically designed to be axially compressed, the borderwires are not intended to be pulled apart from each other as contemplated with the '275 machine. Accordingly, pulling the borderwires apart takes much more force than pushing on the coil springs. Further, where the machine is clipping high density mattress spring assemblies, e.g. 600 coil springs for a full size spring assembly, aligning and fitting the spreader pins between adjacent barrels of the closely spaced coil springs can be highly problematic. Should the spreader pins get caught in a coil spring, the machine will have to be stopped to untangle the spring assembly from the spreader pin(s) with the clipping process then restarted with this downtime slowing down production. In addition, where the coil springs are of the “open-coil” variety where their end coils have a cut end so that they are not closed to form a complete circular end coil, it is more likely that the end coil can wrap itself around the borderwire as the mattress assembly is put together via preclipping and moved to the automatic clipping machine. In this instance, pulling the borderwires with the spreader pins can destroy the coil spring having its cut end wrapped about the wire. Another problem is that the operation of the spreader pins too close to the preclipped corner innersprings may weaken or pull the clips off these preclipped corners. In practice it has been found that the machine has to start and stop clipping three or four coils spaced from the preclipped corners to avoid pulling the preclipped end turns apart from the borderwires.
Accordingly, there is a need for a high-speed automatic clip applying machine for mattress spring assemblies. More particularly, there is a need for a high-speed machine that positions the borderwires and coil innersprings in a proper clipping orientation and allows an entire side or end of the spring assembly to be automatically clipped in a highly accurate manner.
SUMMARY OF THE INVENTION
In accordance with the present invention, an apparatus and method are provided for applying clips to mattress spring assemblies in a highly accurate and fast manner via operating or positioning members that properly position the innerspring coils relative to the borderwires for clipping thereof, viz. with the end turns of the innerspring coils disposed inwardly relative to adjacent borderwires in a predetermined clipping orientation. Improperly positioned innersprings have their end coils shifted past the borderwires as an incident of being advanced downstream to be clipped by the apparatus and method herein. In this manner, the positioning members are operable to use the progression of the spring assemblies as they are driven downstream in the automatic clipping machine to properly position the innerspring coils relative to the borderwires for being clipped thereto. More particularly, there is at least one positioning member disposed upstream from the clip applicator tool such as in a positioning station that acts to cause the end turns of the mattress innerspring coils as the innersprings move into engagement therewith, to progressively shift into the predetermined clipping orientation that is necessary for proper clipping of the end turns to the borderwires. The positioning member does not have to be cycled between operative and inoperative positions for each clip that is applied thus speeding the overall clipping process for the spring assembly.
In the preferred form, the at least one positioning member includes a lift member that is affixed to the lower support of the clipping machine so that bottoms of portions of the innerspring coils intermediate the end turns thereof ride thereover. As the innerspring intermediate portions engage the lift member and continue their downstream travel, they progressively rise up a ramp surface of the lift member which causes the end turns to be lifted over the borderwires. The at least positioning member further includes cam members that engage the lifted end coils and progressively push them in the transverse direction with continuing downstream travel of the spring assembly. Thus, the lift member raises the end coils to clear the borderwires while at the same time the cam members push the end coils past the borderwires so that they are shifted from an outward disposition relative to the borderwires to the preferred inward disposition relative thereto. It has also been found that the lifting action of the lift member adva
Chandler Joseph
Lackler Paul
Echols P. W.
Fitch Even Tabin & Flannery
Stanley Fastening Systems
LandOfFree
Apparatus and method for securing borderwires to mattress... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for securing borderwires to mattress..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for securing borderwires to mattress... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2821428