Take-down device for knitting machines

Abstract: The claimed take-off device to be used on circular knitting machines for manufacturing hosiery or like knitwear, comprises two co-axial discs (6, 7) arranged adjacent each other so as to form a passage for a knitwork. One (6) of said discs is provided with a helical surface (61) for engaging the knitwork which is forced to said surface by the second disc. One of said discs is rotatable while the other is stationary. On the disc (7) that does not have the helical surface there are provided, on its thrust surface, radial grooves (71) for guiding the knitwork in the wale direction.

Description: The invention relates to a take-off device in a circular knitting machine for manufacturing hosiery or like knitwear, according to the first part of claim 1. From the GB-A-432 233 - as nearest prior art - it is known such a take-off device in a knitting machine for drawing the knitwork away from the needles of a needle cylinder. Said take-off device comprises two disc members arranged coaxially to the axis of the needle cylinder and provided with contact surfaces for engaging and forcing the knitwork therebetween from said needle cylinder radially inwardly to a central opening provided in the lower disc member. The upper disc member is rotatably mounted with its central portion on a vertical adjustable rod and is driven in a timed relation with the needle cylinder. The lower disc member having a tubular elongation inside the needle cylinder is held stationary during the circular knitting. The contact surfaces of one or both disc members are provided with spiral grooves or ribs, so that the knitwork is intended to pass immediately upon leaving the needles. By reason of the relative rotation of the knitwork and the disc members, the spiral formation of the grooves or ribs tends to pull the knitwork inwards to the central opening of the lower disc member. When both of the disc members are provided with spiral grooves and ribs, the rib of one disc member projects into the grooving of the other, with the result, that the knitwork is caused to follow a tortuous path between the opposed disc members, so that the knitwork is frictionally engaged by the spiral ribs and by reason of the relative rotation of the knitwork and the coacting disc members the knitwork is gradually drawn away from the needles. In the DE-AS-1 030 961 is described a circular knitting machine, in which inside of a rotatably driven needle cylinder is arranged a shifting tube and an inner sleeve which rotates together with the needle cylinder and with the knitwork. The upper end portion of this inner sleeve has a funnel-like form and an upper contact ring surface. The inside of the funnel-like portion is provided with length notches or grooves for obtaining an uniformly wrinkling of the knitwork without deflections from the radial direction. Further it is disclosed in the - not prepublished - EP-A-0 385 154 a mechanical take-off device in a double cylinder knitting machine comprising two take-off members for gripping and drawing off the knitwork therebetween from the needle cylinders. One of said take-off members rotates with the needle cylinder and has a substantially smooth contact faces. The other take-off member is stationary against rotations and provided with a screw-like contact surface having spiral ribs thereon. By reason of the relative rotation of the knitwork together with the pressed first take-off member against the other take-off member the knitwork will be forced in the exact radial direction towards the central opening of the take-off member. If by the manufacturing of ribbed fabrics, particularly in 4:2, 5:2 divisions in the known double-cylinder machines more adjacent lower needles will be used, a helix causes the knitwork wales to cease their vertical orientation and to twist also helically. This drawback makes then troubles in the subsequent manipulation and finishing. The object of the present invention is to eliminate this disadvantage and provide a take-off device, which ensures that the knitwork leaves the machine with straight wales, i.e. not helically twisted, so that it can be easily manipulated in subsequent finishing steps. This object will be solved by the features of claim 1. An advantage of the invention consists in that various structural embodiments to correspond either to great-diameter, or small-diameter needle cylinders are preferably available. Advantageously each of the radial grooves has two edges, one of which is slowly sloping in the direction opposite the needle cylinder rotation while the other is substantially perpendicular to the disc surface, so that the knitwork is being gradually forced into the groove whereupon the perpendicular edge warrants the straight knitwork course in the wale direction. Further, the number of radial grooves can correspond to the number of needles, so that each of the knitwork wales is guided in the radial direction. Preferred embodiments of the invention will hereinafter be described with reference to accompanying schematic drawings in which Fig. 1 is an axial sectional view of needle cylinders together with the take-off device; Fig. 2 is a bottom view of the disc provided with radial grooves; Fig. 3 is a side view of the disc shown in Fig. 2; Fig. 4 is a detail view of one radial groove of the disc; As it is known, a double-cylinder circular knitting machine for manufacturing hosiery comprises an upper and a lower needle cylinder 1 and 2, respectively, in which double-head needles (not shown) together with sinkers for controlling them are mounted. The needles are controlled by knock-over sinkers 3 and by pressing sinkers 4 to form a knitwork which is then withdrawn by a mechanical take-off device consisting of the following elements. To a stationary take-off tube 5 in the lower needle cylinder 2 there is secured a lower take-off disc 6 having the form of a funnel and being provided on its upper front portion with a surface 61 having spiral ribs thereon. With said disc 6 is associated an upper take-off disc 7 which has the form of a ring and is fixedly attached to vertical rods 8. The vertical rods 8 together with vertical rods 9 carry a ring 10 of the pressing sinkers 4. The rods 8 are mounted for reciprocation in a bearing member 11 fixedly connected to the upper needle cylinder 1. In the lower front surface of the upper take-off disc 7, which means on its conical front portion facing the surface 61 of the lower take-off disc 6, there are provided radial grooves 71 which can be better seen in Figs. 2 and 3. Said radial grooves 71 are preferably shaped so that they have two edges 710 and 711 (Fig. 4). The edge 710 is substantially perpendicular to the disc front surface while the second edge 711 is inclined and is sloping slowly in the directions opposite of rotation of the needle cylinders 1 and 2. The rods 8 and 9 are separately actuated by a control drum of the machine via well-known gearing (not shown). The take-off device operates as follows: During the welt knitting the take-off device is at standstill. The upper take-off disc 7 is lifted while the knitwork is being formed and, owing to an inserted elastic thread, displaced toward the middle. After the welt has been finished, the upper take-off disc 7 is brought by a command from the control drum into contact with the knitwork, so that the knitwork is forced onto the spiral ribs of the conical surface 61 and due to the rotation of disc 6 it is being "screwed" into said surface 61, stretched and withdrawn from the needles. Simultaneously, the knitwork is being pressed into the radial grooves 71 of the upper take-off disc 7 by which it is guided in the direction of wales being formed, and prevented from being twisted in accordance with the helix. The knitwork is being safely rolled on the edge 711 into the radial groove 71 while being retained by the edge 710, After the knitting has been finished, the upper take-off disc 7 is lifted again by a command from the control drum whereupon the knitwork is knocked-over. Within the scope of the present invention it is made possible to provide the radial grooves in the lower take-off disc, and the spiral ribs on the upper take-off disc. Similarly the upper disc may be made rotatable while the lower one is kept stationary.

Claims: Take-off device in a circular knitting machine for manufacturing hosiery or like knitwear, comprising two disc members (6, 7) provided with a central opening and arranged coaxially to the axis of the needle cylinders (1, 2) of said knitting machine for forcing and leading the knitwork therebetween from said needle cylinders radially inwardly to one of said central openings, one (7) of said disc members (6, 7) being axially shiftable against the other member (6), one (6) of said disc members (6, 7) being rotatably against the other stationary member (7) and being provided on its surface facing the other member (7) with a surface (61) having spiral ribs thereon, whereas the contact surface of the other stationary member (7) is directed in parallel to the surface (61), characterized in that the contact surface of the other circular member (7) is shaped with radial grooves (71) to guide the knitwork in the wale direction. Take-off device according to Claim 1, characterized in that each of said radial grooves (71) has two edges (710, 711) of which one of said edges (711) is sloping slowly in the direction opposite to the rotation of the opposite disc member (6) while the other edge (710) is substantially perpendicular to the surface of the disc member (7). Take-off device according to Claim 1 or 2, characterized in that the number of the radial grooves (71) corresponds to the number of the needles in the needle cylinder.

Inventors: CHROMY MIROSLAV, FUCIK MILAN, POHORILSKY JIRI, CHROMY, MIROSLAV, FUCIK, MILAN, POHORILSKY, JIRI
Applicants: UNIPLET AS, UNIPLET A.S.
Application year: 1991
Main classification: D04B15
IPC codes: D04B15