The Singer Model 27 and later model 127 were a series of lockstitch sewing machines produced by the Singer Manufacturing Company from the 1880s to the 1960s.
(The 27 and the 127 were full-size versions of the Singer 28 and later model 128 which were three-quarter size).
Of Vibrating Shuttles These are shuttles of the long description, moving in a segment of a circle. The most novel machine of this kind is the vibrating shuttle machine just produced by the Singer Manufacturing Company.
In this case the shuttle itself consists of a steel tube, into the open end of which the wound reel is dropped, and is free to revolve quite loosely.
Variation of tension is thus obviated in a very simple manner.
The chief point of interest in the machine is undoubtedly the means employed in transferring the motion from the main shaft to the underneath parts, an arrangement as ingenious and effective as any device ever introduced into stitching mechanism. Robert Whitehall [sic], and consists of a vertical rocking shaft situated in the arm of the machine[.] Motion is imparted to it by means of an elbow formed upon the main shaft acting upon two arms, called wipers, projecting from the rocking shaft, the angle formed by the arms exactly coinciding with that of the elbow in its revolution.
It was popular in its time, and some of them remain. He then designed the sewing machine which would shortly become Singer's answer to the White machine.
The Whitehill design became the third Singer machine with a high arm, and quickly eclipsed the other two—neither of which Bolton liked anyway.
A round leather "treadle belt" passes up from the treadle, up through the cabinet, over the handwheel by following the belt groove, back down through the cabinet again, and then back to the treadle.
The belt is joined end-to-end with a clip to make a loop, and can be shortened and reclipped (using special "treadle belt pliers") as needed to keep proper tension.
Such a weight strains the meaning of the term 'portable', even when fitted with only a hand crank and minimal wood case.
(Today's laptop computers typically weigh 3 to 5 pounds (1.4 to 2.3 kg).) This quickly led Singer to produce a 3/4ths size version intended for portability, exactly as the White Sewing Machine Company was doing with its new 3/4ths size 'Peerless' machine.