This article first appeared in Practical Engineering 1940 Vol1 No5. The information contained within is accurate as of 1940. The article describes new developments in Engineering at the time.
A New Cable-Covering Machine
An interesting new machine for covering V.I.R., aerial, telephone, flexible and other cable has recently been produced by B. and F. Carter and Co., Ltd., of Bolton. It has an approximate rate of production of 720ft. per hour at 14 stitches per inch, using 40's single ends, cotton yarn when braiding 3/029's vulcanised India rubber cable.
The heads are arranged coaxially, one immediately above the other. The core passes through one head and then immediately through the other. The inner envelope is knitted by the upper head which rotates in a clockwise direction, whilst the outer envelope is knitted by the lower head, which rotates in an anti-clockwise direction. The cams and creel holders are stationary. Owing to the special design of the knitting heads, the tension on the yarn being knitted can be varied as the machine is running, to such a degree that the sheath or cover is made very tight on the core. This is an important feature, as this sheath or cover should not slip back on the conductor or core when being threaded through the conduits.
To form a knitted sheath, the wales or stitches are spirally disposed round the conducting wire or core instead of being straight, this provides an improved form of flexible cord-like body with knitted tubular envelopes, of such construction that neither bending of the body causes rupture of the envelope, nor twisting of the body causes damage to the envelope, either before or after compounding.
The machine is a self-contained unit driven by an electric motor and operated by push-button controls from front and back. Fitted with electrical automatic controls, so that if an end breaks, yarn, supply, conductor or core runs out, or through loose stitching, the machine stops almost instantaneously without any over-running, there being no apparent visible evidence to show a piecing-up. The pay-out and take-up stands are arranged for maximum size of drums or reels of 24in. diameter by 12in. between flanges, these stands are arranged with easy lifting and lowering device and fitted with traverse motion for traversing the cable, variable for length of traverse and lay of wind.