GB2231064A - Knitting machine - Google Patents

Description

1 KNITTIN9 MACHINE 07 (S _91 The Present invention relates to knitting

machines provided with loop cutting mechanisms for cutting loops of yarn during knitting so as to give the knitted fabric a Pile finish. Knitting machines of this type comprise two needle beds. One well-known construction is the circular knitting machine in which the first needle bed is in the form of an upright cylinder, and the second needle bed is in the form of a circular plate or cover (known as the "dial") located just above the cylinder but with a small gtp between thorn. A second well-known construction is the flat bed knitting machine, in which both needle beds are flat and lie at an angle to one another with a small gap between the edges of the two needle beds.

In knitting machines of the type described one particular arrangement of loop cutting mechanism has been in use for many years. This known loop cutting arrangement is illustrated in Figure 1, which shows a perspective view of a small part of a circular knitting machine. The loop cutting arrangment comprises an array of fixed needles 101 mounted on the dial 102, and an array of movable hooks 103 mounted on cylinder 104. Yarn is threaded through the fixed needles 101. The yarn which is to be cut, and is hereinafter referred to as the "pile yarn", is also 1 threaded around the movable hooks 103, and is indicated by reference numeral 200, whereas the yarn which is not intended to be cut, hereinafter referred to as the "backing yarn", is not threaded around the movable hooks 103, and for simplicity has been omitted from the drawings. In operation, a movable hook 103 pulls the pile yarn 200 downwards the desired distance so as to give the required height of pile, the presser wheel 105 tensions the loop to a predetermined tension which is set by adjustment of the position of the presser wheel before knitting commences, and a cutting blade 106 mounted on each movable hook 103 is then operated to cut the loop. The movement of the books and blades 102, 106 Is governed by came which are not shown.

The known loop cutting mechanism illustrated in Figure 1 suffers from a number of disadvantages, which relate to the presence of the presser wheel 105. One disadvantage is that when the position of the pressure wheel 105 is adjusted it may be incorrectly set so as-to abrade against a needle bed. A second disadvantage is that the dimensions of the pressure wheel 105 make it necessary to leave a certain distance between the dial 102 and the cylinder 104 which increases the required travel distance of the hooks and blades 103, 106 and thus lowers the efficiency of the knitting machine and makes the knitting operation more difficult.

2 - 1.1 The present invention provides a knitting machine including a 100P Cutting mechanism for providing a pile finish comprising an array of fixed needles on one needle bed, and a complementary array of reciprocable hooks and knives on the other needle bed, characterized in that the complementary array comprises on each trick of the needle bed a pairs of reciprocable hooks for determining the size of a loop and for tensioning the loop, and a reciprocable knife between the pair of reciprocable hooks for cutting the tensioned loop, and a drive mechanism for causing reciprocal movement of the pairs of hooks and subsequent reciprocal movement of the knives.

The principal advantage of the invention is that the Pressure wheel is eliminated, thereby eliminating the possibility of damage to a needle bed, and giving greater efficiency and flexibility in operation of the knitting machine.

The invention will now be described more particularly by way of example with reference to the accompanying drawings in which:- Figure 1, as Previously mentioned, is a perspective view of the prior art loop cutting mechanism;

Figure 2 is a Perspective view of one construction of loop cutting mechanism according to the invention, incorporated in the two needle beds of a knitting machine; and Figure 3 illustrates the individual components of the 100P cutting mechanism according to Figure 2.

Referring now to Figures 2 and 3, the loop cutting mechanism comprises needles 1 an a first needle bed 2, pairs of hooks 3a and 3b on a second needle bed 4 disposed at an angle to the first, and a cutting knife 5 between the hooks 3a and 3b of each pair, each trick of the second needle bed 4 including one pair of hooks 3a and 3b and one knife 5. The pair of hooks 3a and 3b and the cutting knife 5 are each operated by cams which abut against cam followers 6, 7 in the same manner as in the prior artloop cutting mechanism.

5241C(54-57) eLMME is 6067C(6) A knitting machine Including a loop cutting mechanism for providing a pile finish comprising an array of fixed needles (1) on one needle bed (2), and a complementary array of reciprocable hooks (3a,3b) and knives (5) on the other needle bed (4), in which the complementary array comprises on each trick of the needle bed (4) a pair of reciprocable hooks (3a,3b) for determining the size of a loop and for tensioning the loop, and a reciprocable knife (5) between the pair of reciprocable hooks (3a,3b) for cutting the tensioned loop, and a drive mechanism for causing reciprocal movement of the pairs of hooks (3a, 2b) and subsequent reciprocal movement of the knives (5).

2. A knitting machine Including a loop cutting mechanism substantially as herein described with ref-erence to and as shown in Fig. 2 and 3 of the accompanying drawings.

A Published 1990asThe Patent Office, State House. 6671 High HolbOrn. Lc)ndonWC1R4TP-FL-tlier copies maybe obtained from The Patent Office. Sales Brineli, St mary Cray, Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray. Kent. Con. 1,87