The carriage (picture 25) is made up of two metal plates linked by a stiff bridge (P); the plates work individually and simultaneously on the front and the rear needle-beds.
The plates include cam locks (F) bearing the drive and control systems of the needles, i.e. the cams.
When the carriage moves right- or leftwards, the thread guides (B),(C),(D),(E) are locked individually by the corresponding pistons (A) on the upper part of the bridge, that are manually driven.
Brushes are also mounted on the carriage to ensure a smooth needle latch opening and grant a correct feeding of the yarn.
The Cam-locks
The cam-locks (picture 26) are a cam system which gives the necessary working information to the individual needles; they include a fixed part, working as support, and movable cams, which can be divided into raising cams and lowering or knock-over cams (2). The raising cam includes:
The fixed or movable cams form a symmetrical channel where the needle butt slides; the needle moves downward and upward in the groove to form the stitch.
The different parts of the cams are chamfered; their profiles are curvilinear to make the needle move smoothly.
The angle of inclination of the cams ranges between 40° and 50°; these values grant an optimum running of the needle and avoid high pressures between metal parts during the motion and excessive tensions on the yarn during the downward stroke of the needle.
The raising cam, both tucking or looping, can be :
A. Closed or sunk cam
CARRIAGE STROKE
BUTT NEEDLE
BUTT NEEDLE
CARRIAGE STROKE
B. Half-way cam
CARRIAGE 4-
STROKE
BUTT NEEDLE
BUTT NEEDLE
CARRIAGE 4-
STROKE
C. Open cam
CARRIAGE STROKE
BUTT NEEDLE
BUTT NEEDLE
CARRIAGE STROKE
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