Design Construction and Performance Analysis …
29
Fig. 5 The stitched sample
with other unwanted technical difficulties this modification can increase a notable
efficiency in seam production.
In the graph above, the relation between both of the operations has been shown.
The X-axis showed the total shift time and the Y-axis showed the effective time
of operation in the graph. It has been seen that for the bobbin less operation, the
lockstitch sewing machine can run efficiently almost all the shifting time, neglecting
any intended break. But with the conventional operation, it took around 80 min in
8 h just to change the bobbin case. So there has been a distinguishing result between
these two operations.
The designed machine overcomes the time consumption problem promisingly
for its direct thread path from an outer package. Besides, other problems like in
conventional lockstitch sewing machines when a bobbin runs out in the middle of a
continuous seam overlapping occur to continue the production. Sometime entanglement occurs which is also become eliminated by this constructed lockstitch sewing
machine. The performance analysis also shows some better characteristics with a
little flaw. The motion derived from the machine pulley now turned into a half rotation through rack and pinion but for using the same specification for gears like
diameter, teeth no. between identical parts, the ultimate motion remains equivalent.
However, for the bottom thread path, the cylindrical pipe and the modified hook
ensures the optimum tension for regulating proper stitch. Furthermore, maintenance
is quite easier for keeping the expected efficiency. Stitch class: 301 is produced here
using a needle and bottom thread but without using any bobbin. The strength of the
stitch compared to conventional lockstitch sewing machine no detectable difference
appeared. Even, by using high strength heavy fabrics can be sewed spontaneously
(Fig. 6).
The costing is quite reasonable for this modification. The aforementioned details
express that the difference between a conventional lock stitch sewing machine and
the modified one is a small number of shafts, gears and some actions such as grinding,
29
Fig. 5 The stitched sample
with other unwanted technical difficulties this modification can increase a notable
efficiency in seam production.
In the graph above, the relation between both of the operations has been shown.
The X-axis showed the total shift time and the Y-axis showed the effective time
of operation in the graph. It has been seen that for the bobbin less operation, the
lockstitch sewing machine can run efficiently almost all the shifting time, neglecting
any intended break. But with the conventional operation, it took around 80 min in
8 h just to change the bobbin case. So there has been a distinguishing result between
these two operations.
The designed machine overcomes the time consumption problem promisingly
for its direct thread path from an outer package. Besides, other problems like in
conventional lockstitch sewing machines when a bobbin runs out in the middle of a
continuous seam overlapping occur to continue the production. Sometime entanglement occurs which is also become eliminated by this constructed lockstitch sewing
machine. The performance analysis also shows some better characteristics with a
little flaw. The motion derived from the machine pulley now turned into a half rotation through rack and pinion but for using the same specification for gears like
diameter, teeth no. between identical parts, the ultimate motion remains equivalent.
However, for the bottom thread path, the cylindrical pipe and the modified hook
ensures the optimum tension for regulating proper stitch. Furthermore, maintenance
is quite easier for keeping the expected efficiency. Stitch class: 301 is produced here
using a needle and bottom thread but without using any bobbin. The strength of the
stitch compared to conventional lockstitch sewing machine no detectable difference
appeared. Even, by using high strength heavy fabrics can be sewed spontaneously
(Fig. 6).
The costing is quite reasonable for this modification. The aforementioned details
express that the difference between a conventional lock stitch sewing machine and
the modified one is a small number of shafts, gears and some actions such as grinding,