EP0359915B1 - Drawing system for a spinning machine, in particular for a drawing frame - Google Patents

Description

The invention relates to a drafting system for a spinning machine, in particular for a draw frame, with lower rollers arranged stationary in punches and with upper rollers assigned to the lower rollers, which are held with pressure arms attached to the punches and which can be moved away from the lower rollers by pivoting the pressure arms away.

In a known drafting arrangement of the type mentioned at the outset (EP-B 0 062 185), relatively narrow tolerances with regard to the pivoting bearing of the pressure arms and with respect to the individual holders of the top rollers have to be observed so that the set positions between top rollers and bottom rollers and in particular parallelism between the rollers the roller pairs is guaranteed. High rigidity with respect to the pressure arms must also be provided.

The invention has for its object to simplify a drafting system of the type mentioned and still ensure with sufficient certainty an exact alignment of the rollers to each other.

This object is achieved in that the punches are provided with guides in which, in the closed state, at least one of the top rollers is guided and aligned with the bottom rollers.

Since the upper rollers are aligned with the guides of the punches with respect to the lower rollers in this embodiment, the rigidity and the manufacturing accuracy of the pressure arms themselves no longer play a decisive role in order to nevertheless ensure an exact alignment of the rollers with one another.

In a further embodiment of the invention it is provided that the top rollers are held by means of elastically flexible holding means. This ensures that there are no overdeterminations and that only the guides of the punches determine the position of the top rollers. Due to the elastically flexible holding means, differences in the infeed movement can be easily compensated for.

In a further embodiment of the invention, it is provided that the axle bodies of the top rollers are each provided with two parallel guide surfaces, to which corresponding guides approximately aligned radially to the associated bottom roller are assigned. In this way, a clearly defined orientation is obtained.

In a further embodiment of the invention it is provided that the guides for at least one of the top rollers are part of holding devices which are adjustably attached to the punches in the circumferential direction of the associated bottom roller. This means that the top rollers, which are adjustable in the circumferential direction of the bottom rollers, can be precisely aligned with the bottom rollers. The top rollers must of course be kept adjustable.

• Fig. 1 zeigt eine Ansicht einer ersten Ausführungsform eines schematisch dargestellten Streckwerkes,
• Fig. 2 eine Ansicht einer weiteren Ausführungsform eines Streckwerkes,
• Fig. 3 eine Einzelheit der Fig. 2 als teilweise geschnittene Ansicht im Bereich einer Stanze und eines Druckarmes und
• Fig. 4 eine Ansicht in Richtung des Pfeiles IV auf den Druckarm mit einer Halterung für einen Achskörper einer Oberwalze.

Further features and advantages of the invention result from the following description of the embodiments shown in the drawing and the subclaims.

• 1 shows a view of a first embodiment of a schematically illustrated drafting arrangement,
• 2 is a view of a further embodiment of a drafting system,
• Fig. 3 shows a detail of Fig. 2 as a partially sectioned view in the area of a punch and a pressure arm and
• Fig. 4 is a view in the direction of arrow IV on the pressure arm with a holder for an axle body of an upper roller.

The drafting system, which is shown only very schematically in FIG. 1, has three lower rollers (11, 12, 13) which are stationary in punches (10) and are driven in a manner not shown in detail. Upper rollers (15, 16, 17, 18) are assigned to these lower rollers (11, 12, 13), the roller pairs (13, 18) and (12, 17) being a pre-drafting field and the roller pairs (12, 16) and (11, 15) form a main default area. The top rollers (15, 16, 17, 18) are held on both sides by pressure arms (14) which are mounted on the punches (10) so as to be pivotable about a pivot axis (23) parallel to the bottom rollers (11, 12, 13). The operating position of the pressure arms (14) shown can be locked in a manner not shown. By opening the pressure arms (14), the upper rollers (15, 16, 17, 18) are pivoted away from the lower rollers (11, 12, 13) so that the drafting system is opened generously.

The upper rollers (15, 16, 17, 18) have axle bodies (21) which are delimited by two lateral, parallel surfaces. With these axle bodies (21) they engage in guides (19) which are oriented essentially radially to the associated lower rollers (11, 12, 13). When the pressure arms (14) are closed, the axle bodies (21) enter the corresponding guides (19). As will be explained later, the axle bodies (21) are held elastically transversely to the guide surfaces, so that they can be easily inserted into the guides (19) when the pressure arms are closed.

The guides (19) for the upper rollers (15, 17) are attached directly in the punches (10). These top rollers (15, 17) are held in the pressure arms (14) with an unchangeable position. In order to adjust the stretching field lengths, the upper rollers (16, 18), on the other hand, are arranged so as to be adjustable in the circumferential direction of the associated lower rollers (12, 13). For example, a slot guide (50) is shown for the upper roller (16), in which a holder (51) of the upper roller (16) is adjustably guided. When the pressure arms (14) are in the closed position, this slot guide (51) runs concentrically with the associated lower roller (12). A corresponding adjustment possibility can be provided for the pressure roller (18). The guides (19) for the upper rollers (16, 18) are part of holding devices (22) which are mounted and rotatable in the punches concentrically with the lower rollers (12, 13). The guides (19) of these holding devices (22) therefore maintain their respective alignment with the lower roller (12, 13) with each adjustment.

As can be seen from Fig. 1, the top rollers (15, 17) are provided with loading devices in the form of hydraulic or pneumatic pressure elements (30). The upper rollers (16, 18) can be equipped in a corresponding manner with loading devices. However, it is also possible to attach different types of load devices to these, as will be explained later in the present application.

Of course, it is not necessary for all the upper rollers (15, 16, 17, 18) to be guided in the guides of the punches (10). In particular, this will not be necessary in many cases for the top roller (18), which delimits the pre-drafting zone in the infeed direction. In the embodiment according to FIG. 2 it is therefore provided that this top roller (18) is fixed by means of holding elements (28) which can be adjusted in guides (29) of the pressure arms (14) and which also carry the pressure elements (27) for the top roller (18) .

In the embodiment according to FIG. 2, a preferably motorized adjustment drive (24) is provided for the holding device (22). This consists of a shaft (52) which is preferably adjustable by motor and optionally also manually, which drives a crank (53) to which a push crank (54) is articulated, which in turn is connected to the holding device (22). The shaft (52) expediently extends across the entire drafting system and connects the holding devices (22) arranged on both sides so that they run synchronously.

The holding device of FIG. 2, which is shown on a larger scale in FIG. 3, also carries a loading device (25) which can be connected to the upper roller (16) in the operating position. The holding device (22) consists of a plate-shaped base body which is provided with a cylindrical extension (31) in which the lower roller (12) is supported with bearings (32). The cylindrical extension (31) is in turn rotatably arranged in the punch (10). On the opposite side, the base body of the holding device (22) is provided with an attachment (41) which has an essentially rectangular or square cross section and to which a hydraulic or pneumatic pressure element (35) is attached, the piston (36) of which is in the radial direction the lower roller (12) and also to the upper roller (16) can be extended away from the latter. The piston (36) is supported with a piston rod on a cross strut (33) of a bracket which is formed from two tabs (34) and a locking bolt (37). The locking bolt (37) is assigned a hook-shaped end (38) of the axle body (21) of the top roller (16), into which it can be hung. A link guide (40) is provided on the side flanks of the extension (41), which has a section running radially to the lower roller (12) and an inclined portion in which guide pins (39) of the tabs (34) engage. In the retracted position of the piston (36), the bracket is thus pivoted outward so that the locking bolt (37) assumes the position (37 ') in FIG. 3 and thus from the end of the axle body (21) of the upper roller (16). free is.

The axle body (21) of the top roller is guided in the guide (19) of the plate-shaped base body of the holding device (22) which protrudes beyond the punches (10). It is held on the pressure arms (14) by means of holders (20) which are shown in detail in FIG. 4. These holders (20) consist of a bracket (55) which receives the axle body (21) between them and which is received via a rubber-elastic element (56) by a bracket (57) which is connected to the support guide with a bolt (61) (50) is performed. On the bracket (57) engages a guide rod (58) which is guided with a sliding guide (59) on a further rod (60) so that when adjusting the slot guide always a radial alignment of the axle body (21) to the Guide (19) of the punch (10) or the holding device (22) is obtained.

In a modification of the embodiment shown, it can also be provided that the holders (20) for the axle body (21) of the top roller are not attached to the pressure arm (14) but to the holding device (22) via a swivel arm. In this case, when the holding device (22) is adjusted, the upper roller (16) is also adjusted at the same time. The pressure arms then only serve to transfer the top roller with its swivel bracket into the operating position.

Claims (10)

1. Drawing system for a spinning machine, in particular for a drawing frame, with bottom rolls arranged stationarily in roller stands, and with top rolls cooperating with the said bottom rolls, which top rolls are supported on pressure arms mounted on the roller stands and can be moved away from the bottom rolls by a pivotal movement of the pressure arms, characterized in that the roller stands (10) are provided with guides in which, in the closed condition, at least one of the top rolls (15, 16, 17, 18) is guided and aligned with the bottom rolls (11, 12, 13).

2. Drawing system according to claim 1, characterized in that the top rolls (15, 16, 17, 18) are held by elastically yielding holding means (20).

3. Drawing system according to claim 1 or 3, characterized in that each of the shaft bodies (21) of the top rolls (15, 16, 17, 18) are provided with two parallel guiding surfaces (22) coacting with corresponding guides (19) that are aligned approximately radially with the respective bottom roll (11, 12, 13).

4. Drawing system according to any of claims 1 to 3, characterized in that the guides (19) for at least one of the top rolls (15, 16, 17, 18) are part of holding means (22) arranged on the roller stands (10) adjustably in the circumferential direction of the respective roll (12, 13).

5. Drawing system according to any of claims 1 to 4, characterized in that the top roll (16, 18) that coacts with adjustable guides (19) of the roller stands (10) is adjustably mounted on the pressure arms (14) and can be locked in the respective adjusted position.

6. Drawing system according to any of claims 1 to 5, characterized in that the holding means (22) are mounted on the roller stands (10) pivotably and concentrically to the respective bottom roll (12, 13).

7. Drawing system according to claim 6, characterized in that the adjustable holding means (22) are provided with a setting drive (24).

8. Drawing system according to any of claims 1 to 7, characterized in that the bottom rolls (12, 13) are supported in the holding means (22) that are mounted on the roller stands pivotably and concentrically to the respective bottom roll (12, 13).

9. Drawing system according to any of claims 1 to 8, characterized in that the holding means (22) are provided with loading means (25) for the respective top roll (16) which loading means can be brought into engagement with the top roll (16) in the closed condition of the pressure arms (14).

10. Drawing system according to any of claims 1 to 9, characterized in that the top roll (16), which coacts with adjustable guides (19) of the roller stands (10), is held on the holding means (22) by pivoting elements and can be transferred to its operative position by means of the pressure arms (14).

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