illustrated in the drawing has two presser feet 23 associated with each cam system of the machine each pair of presser feet is carried on a blade 24 extending downwardly between the knocking over bits of the machine the blade 24 and the presser feet 23 may be mounted for example in the manner described in british patent specification no 1 588 970 which refers back to the presser foot mounting described in british patent specification no 1 288 043 in the presser foot mounting of british patent specification no 1 588 970 the blade here the blade 24 carrying two presser feet is slidably mounted on a downwardly directed supporting arm and the blade and thus the presser feet are resiliently urged downward on the supporting arm that is in the direction downwardly between the needle beds in the present drawing preferably the downward load applied to the presser foot is as set out in the following table table______________________________________ maximum load on presser footmachine gauge gm ______________________________________ e12 300 e10e8 600e7e6 1 100e5______________________________________ for the purpose of the table the gauge is defined as the number of needles contained in one inch 25 4 mm of needle bed each presser foot 23 in the present machine has a trapezoidal cross section the upper and lower surfaces of the presser foot being parallel to one another and the side edges 25 of the presser foot being inclined downwardly and inwardly each at an angle.