本機(jī)型是綜合送料厚料平縫機(jī)（單針）的版，采用大型立式旋梭（粗線專用旋梭）勾線，滑桿挑線。上下軸用滾針軸承支承，同步齒形帶傳動，柱塞式油泵潤滑系統(tǒng)。采用針桿擺動興壓腳、送布牙同步送料方式。整機(jī)在綜合性能上傳動輕滑，噪聲小，耐用度高，并設(shè)有保護(hù)旋梭超負(fù)荷的離合裝置，確保了縫制品質(zhì)量和旋梭的安全。本產(chǎn)品在4400基礎(chǔ)上改進(jìn)，加大操作空間（520mmx150mm),車線最粗車至20股線，針距達(dá)到到12mm/針。特別適用于汽車座墊、安全帶、安全氣囊等縫制，還可適用于帳蓬、降落傘、涼席、船帆等大型器具的縫制。

This model is the latest product of compound feed lockstitcher, which is designed with large vertical rotating hook (Specially for thick thread) for thread loop catching and sliding bar for thread up-taking. The application of the needle bearings for arm shaft and hook shaft, cog belt driving, plunger oil pump for automatic lubrication. Compound feeding by needle bar, presser foot and feed dog provides this series with such splendid features as smooth running, quietworking and long service life. It is also equipped with a safety clutch to prevent the hook from damage by over-duty operation. This machine is derived from 4400, which increased the working space (520mm*150mm), it will sew 20 plies twisted thread at maximum, the stitch length gets to 12mm/needle. So it is especially availablein stitching car seats, safety belts,safety air bags, tents, parachutes, mat, sails, etc.