Improved device for supporting the thread guide of an automatic flat knitting machine

Abstract: The device is fitted to a flat knitting machine that comprises a carriage 90 moving above two needle beds 70, and featuring anchor plates 50. The device comprises slides 100 mounted upon a bar 2, located above the needle beds, with thread guides 60 fixed to these slides. Each slide 100 features a track P3 in which two facing ledges 101a, 101b are formed that can be struck by an anchor plate, consequently causing the slide to be drawn along. Two rockers 40, that pivot upon each slide, comprise two arms 41,42, first and second, which work in conjunction with a ledge 101a,101b, and a side 101c of the slide. If the second arm 42 is kept alongside the side 101c, the anchor plate 50 is prevented from striking against the ledge 101a, 101b, and when the same second arm 42 is moved away from the side 101c, the anchor plate 50 is enabled to strike against the ledge 101a, 101b.

Description: The present invention concerns the technical sector covering knitting machines of the type comprising two needle beds, located symmetrically to one another, above which a carriage moves , during its movement causing the needles in the needle beds to be selected following a preset programme, also feeding out the thread coming from the various different bobbins to the set of needles. The knitting machine features bars for this latter operation which are located above the needle beds, parallel to one another and to the said needle beds, and slides, which are able to move along these bars, and feature the same number of thread guides, with functions known to experts in the sector. The above-mentioned carriage features vertically movable anchor plates that are able to strike the selected slides and move them along together with the carriage itself. The stroke of the slides is limited by stops which can be locked in position on the same bars, these stops being shaped so as to enable the above-mentioned anchor plates to gradually disengage from them, and to stop the related slide in both the carriage's directions of movement. A first known form of producing the above-mentioned components is illustrated in Figures 1a and 1b in the enclosed drawings, in which two characteristic situations of the slides, respectively moving and stopped, are shown. In these figures 1 indicates a slide, one face of which features a groove, that couples in complementary fashion with the said bar, while a thread guide of known type, not illustrated, is locked to the opposite face of the slide 1, extending towards the needle beds below (not illustrated). The upper edge 1a of the slide 1 forms a track P, whose profile is symmetrical in relation to the direction of movement of the carriage (not illustrated) of a knitting machine. Anchor plates 50 work in conjunction with the abovementioned carriage, these anchor plates taking up a raised or lowered vertical position (delimited using known means) which respectively cause the same anchor plate 50 to strike or not strike the track P of the slide 1 below it. It should be emphasised that the above-mentioned known means delimiting the lowered position of the anchor plate 50 permit the latter a measure of "elastic excursion" in the direction of the raised position, enabling it to follow the profile of the aforementioned track P until reaching the related ledge 1b, formed in the same track P for each of the two directions of movement S, M of the carriage; the said slide 1 thus being drawn along together with the aforementioned carriage (Fig. 1a). The distance moved by the slide 1 is limited, in each direction of movement S, M, by a stop 3, comprising a bracket 4 upon which a cam 5 is mounted. In the example described, the stop 3 delimiting the end of stroke position in direction of movement S is considered. The bracket 4 is removably mounted on the aforementioned bar 2 in the desired position in which the slide 1 stops when striking against the same bracket 4. The cam 5, which operates beside the above-mentioned track P, is shaped in such a way as to enable the anchor plate 50 to gradually disengage from the aforementioned ledge 1b during the last stretch of the stroke of slide 1, by means of a first ramp 5a which lifts the anchor plate 50 itself, also enabling it to move over the above-mentioned bracket 4 (Fig. 1b). The same cam 5 features a second ramp 5b, which enables the same anchor plate 50 to move over the bracket 4 during its stroke in the opposite direction immediately before engaging with the slide 1. As can easily be deduced, it is possible for a slide 1 to be located in the section between two consecutive stops 3 in the known solution described above. As a consequence the range of operating processes possible in the knitting machines incorporating the above-mentioned components is necessarily limited; in other words the above solution is acceptable for carriages fitted with only one operating unit. A second known form of producing the above components is shown in the enclosed tables of drawings, in Figures 2a, 2b, 2c, which enables two slides to be fitted in each of the said sections between two consecutive stops; this is required on carriages featuring two identical operating units that are mounted beside one another. In order to effect this the components must not only comprise the slides described below, but also a further anchor plate, working in conjunction with each bar, in addition to those already present in the example above. Figure 2a illustrates the disengagement of the first anchor plate 50a from the corresponding first slide 10 at the end of the latter's stroke; Figure 2b illustrates the second slide 11, drawn along by the second anchor plate 50b, before it is stopped; Figure 2c illustrates the disengagement of the of the second anchor plate from the second slide at the end of the latter's movement behind the first slide. With reference to the said figures, 2 indicates a bar, identical to the previous one, to which a stop 3, similar to the one described above, is fixed. The stop 3 delimits the end of stroke position on one side of two slides 10, 11, first and second respectively, for one direction of movement M of the carriage mounting two anchor plates 50a, 50b, with the said first anchor plate 50a operating with the aforesaid first slide 10, and with the second anchor plate 50b operating with the second slide 11. The aforementioned slides 10 and 11 differ from one another, and from the above-mentioned slide 1, only where their upper ribs 10a and 11a, forming the same number of tracks P1 and P2, are concerned. The upper ribs 10a, 11a, whose profiles are symmetrical to one another in relation to the direction of the movement of the aforesaid carriage, feature ledges 10b and 11b which serve the same function as ledges 1b described above. The aforementioned tracks also feature two projections 10c and 11c which protrude from the related slides 10 and 11 and face one another. The said projection 10c is aligned with the cam 5 of stop 3, while the projection 11c is aligned with the upper ribs 10a, 11a. In this way it is possible for the said projections 10c, 11c to cross over, and for the above slides 10, 11 to move beside one another. In Figure 2a the first slide 10 is illustrated in its end of stroke position, which is to say stopped up against the stop 3, with the related anchor plate 50a disengaged from the corresponding ledge 10b. In Figure 2b, the second slide 11 is illustrated drawn along by the related anchor plate 50b, the latter being engaged with the corresponding ledge 11b, just before the aforementioned projections 10c, 11c cross over. In Figure 2c, the second slide 11 is illustrated at the end of its stroke behind the first slide 10, with the related anchor plate 50b disengaged from the ledge 11b as a result of the fact that the above-mentioned projections have crossed over. In the same way the same anchor plate 50b will be disengaged during a subsequent stage, not illustrated, by the first slide 10 as well as by the stop 3. A first disadvantage of this second form of producing the components consists in the fact that it is impossible to increase the number of slides in each section between two consecutive stops beyond two, in contrast to more sophisticated machines whose carriages feature three or more independent operating units. A second disadvantage results from the fact that the slides 10, 11, as well as the stops 3, differ from one another, thus leading to both higher production costs and higher warehouse costs. A further solution to provide for a number of slides between two consecutive stops is described in DE-A-2 207 165 which comprises the features included in the preamble of independent claim 1. The rockers illustrated in an embodiment of this invention however do not work in conjunction with the ledges of the related stop in order to disengage the anchor plate of a carriage from the related ledge of the slide. In contrast to the present invention, they are actuated by a cam on the stop to engage a shoulder on the anchor plate shortly before release of the slide from said anchor plate to further draw the slide and lock it on the stop. The object of the present invention is to propose a universal thread guide support device that is able to fulfil its related function in both directions of movement of the carriage, and to be fitted in any number whatsoever in the sections between two stop brackets removably mounted on the same bar. The above objects are obtained proceeding in accordance with that proposed in Claim 1. The technical advantages conferred by the technical solution described in the Claims particularly regard the possibility of fitting a large number of slides in the section between two stops, consequently optimising one's use of the carriage's corresponding operating units. The slides are perfectly identical, which simplifies both their production and use; this enables stops of the same kind to be used, it being sufficient for these to be simple brackets. In addition to this, the special design of the slides, having related rockers, ensures the optimum operation of all the components described, particularly due to the lack of any jamming, possible in known types of slides using fixed elements. The characteristics of the present invention are emphasised hereinafter with specific reference to the enclosed table of drawings, in which: Figure 3 is an illustration in perspective of the slide which is the subject of the present invention; Figures 4a, 4b, 4c, 4d, 4e, 4f are diagrammatic side views of the most important operating stages of a series of slides mounted so that it couples with a bar. With reference to the said figures, 2 indicates a bar, located above the needle beds 70 of a knitting machine, upon which a slide 100, the object of the present invention, is mounted in such a way that it couples with and is able to slide along the bar 2. This is made possible by the fact that one face of the body 101 of the slide 100 features a horizontal groove that couples in complementary fashion with the bar 2, in a similar way to the slides of known type described above. The opposite face of the same body 101 features a vertical groove which is designed to receive the upper portion 60a of a thread guide 60, of known type, that extends towards the needle beds 70 below. The upper rib 101a of the slide 100 forms a track P3, whose profile is symmetrical in relation to the direction of movement of the carriage 90 (directions S, M) of a knitting machine. The above-mentioned track P3 features two ledges 101b, each of which serve for one direction of movement of the carriage 90; the latter features anchor plates 50 which, when in their lowered position, strike against the aforesaid ledges 101b in order to draw along the slide 100; the stroke through which this latter moves being delimited, in each of the aforementioned directions of movement, by a stop 3 comprising a bracket 4 which is removably mounted on the bar 2. Two rockers 40, each of which operates in conjunction with one of the above-mentioned ledges 101b, are mounted in a symmetrical position so that they pivot near the upper rib 101a on the aforesaid body 101. Each rocker 40 comprises two arms 41, 42, first and second respectively, the first arm 41 of which extends beside the above-mentioned track P3, beyond the corresponding ledge 101a towards the centre of the aforementioned body 101, and the second arm 42 of which extends downwards by the side 101c of the same body 101. The end of the first arm 41 is tapered, forming a first ramp 41a for rising above the aforementioned ledge 101b. A boot 43 in shock-absorbing elastic material is fitted to the free end of the second arm 42. The rocker 40 features a second ramp 44 between the above-mentioned arms 41, 42, designed to be gradually borne upon by the aforementioned anchor plate, acting on the above-mentioned track P3. The second ramp 44 slants in the opposite direction to the aforementioned first ramp 41a (Fig. 3). Each rocker 40 is able to turn through a predetermined angle around the axis of the above-mentioned pivot from a first position T to a second position R, and vice versa. In the said first position T, the first arm 41 is aligned with the aforesaid track P3, and the second arm 42 is situated alongside side 101c of the body 101. In the aforementioned second position R, the first arm 41 is lowered whilst the second arm 42 is moved away from the aforesaid side 101c. The above-mentioned rotation can alternatively be free, prevented or actively effected following the modes described below. Figure 4a illustrates, by way of example, four slides 100a, 100b, 100c, 100d, first, second, third and fourth respectively, that are situated up against one another, with the said fourth slide 100d in its turn being stopped up against one of the above-mentioned stops 3 present on the bar 2. Figure 4a also illustrates a first anchor plate 50a, in the lowered position, moving in direction M, close to the aforesaid stop 3. Figure 4b shows the above-mentioned first anchor plate 50a, which, having moved beyond the aforementioned fourth, third and second slides, has reached the first slide 100a, and, positioned on the related ledge 101b of the track P3 of the same slide 100a, draws the latter along in direction M. During the stage described above, the aforementioned anchor plate 50a is able to follow the profiles of each track P3, without striking against any of the ledges 101b of the aforementioned fourth, third and second slides, in that the rockers 40 of each of the latter, being in contact with one another, or in contact with the stop 3, are prevented from rotating and held in position T. The presence of the first ramps 41a and second ramps 44, and the fact that the movement of the aforementioned anchor plate 50a permits it a certain amount of vertical "elastic excursion", as stated above, cause the first slide 100a to be struck and drawn along as described above, the rocker 40 of the latter, for ledge 101b regarding operation when the carriage 90 is moving in direction M, being able to freely rotate from the first position T to the second position R as a result of the pressure exerted by the same anchor plate 50a upon the first arm 41, which, moving downwards, enables the anchor plate 50a itself to strike the above-mentioned ledge 101b. Other anchor plates 50b, 50c, second and third respectively, are shown in the same Figure 4b, designed to draw along the corresponding second and third slides 100b, 100c as shown in the following Figure 4c. Figure 4d shows the same first slide 100a drawn along by the corresponding first anchor plate 50a, in the last section of its stroke towards the stop 3, with the latter being struck by the boot 43 fixed to the second arm 42 of the above-mentioned rocker 40 in position R. As a consequence of the aforesaid second arm 42 striking the stop 3, the same rocker 40 is made to rotate from the aforementioned second position R to the first position T. As a consequence of this, the first arm 41 lifts and disengages the above-mentioned anchor plate 50a from the related ledge 101b (Fig. 4e). The following Figure 4f shows an intermediate stage where the second anchor plate 50b is disengaged from the corresponding slide 100b, close to the latter's stopping up against the above-mentioned first slide 100a in the same way as described above. The above sequence of stages is effected once again, if programmed, during the carriage's stroke in direction S, opposite to direction M, with the related anchor plates striking the slides in the reverse order, from the fourth slide 100d onwards.

Claims: Improved device for supporting the thread guide of an automatic flat knitting machine, the latter comprising at least one bar (2), located parallel to and above the needle beds (70) of the same machine, a carriage (90), able to move in a horizontal plane, and fitted with anchor plates (50), being able to move in a vertical plane, the said anchor plates being able to strike against slides (100), mounted so that they couple with the said bar, and draw them along in both directions of movement (S), (M) of the same carriage (90), drawing them along a section of the said bar (2) delimited by two consecutive stops (3) fixed to the same bar (2), each of the aforementioned slides (100) comprising a body (101) featuring: a horizontal groove in one face of the body itself and coupling in complementary fashion with the aforesaid bar (2); a vertical groove on the opposite face of the same body (101), designed to receive the upper portion (60a) of a thread guide (60) that extends towards the aforementioned needle beds (70) below it; a track (P3) formed by the upper rib (101a) of the same body (101), the said track (P3) featuring a ledge (101b) for each direction of movement (S), (M) of the aforementioned carriage (90), these ledges (101b) being designed to be struck by the corresponding above-mentioned anchor plate (50), in the lowered position, for the above-mentioned slide (100) to be drawn along, and further comprising for each said slide (100) two rockers (40), mounted so that they pivot on the above-mentioned body (101), in a symmetrical position in relation to a plane perpendicular to the bar (2), the said device being characterised in that each of the said rockers (40) is working in conjunction with one of the said ledges (101b) and comprises two arms (41), (42), first and second respectively, with the first arm (41) extending beside the aforementioned track (P3), beyond the corresponding ledge (101b) towards the centre of the above-mentioned body (101), and with the second arm (42) extending downwards by the side (101c) of the same body (101), with the same rocker (40) able to rotate through a predetermined angle around the axis of the said pivot, from a first position (T) in which the first arm (41) is aligned with the aforementioned track (P3), to lift and disengage the anchor plate (50) from the related ledge (101b), and the second arm (42) is situated alongside the side (101c), to a second position (R) in which the first arm (41) is lowered and the second arm (42) moved away from the side (101c), and viceversa; it being possible for the above-mentioned rotation to be alternatively free, actively effected or prevented, the said rotation being free, from the aforementioned first position (T) to the second position (R), and effected in synchrony with the striking of the above-mentioned anchor plate (50) first against the aforesaid first arm (41) and then against the aforementioned ledge (101b), the said rotation being actively effected, from the said second position (R) to the first position (T), as a result of the aforementioned second arm (42) striking against one of the above-mentioned stops (3) or against the second arm of a further identical slide (100), this said rotation finally being prevented in the aforementioned position (T) as a result of the slide (100) itself being in a stopped position with its second arm (42) stopped up against one of the said stops (3) or against the second arm of another slide (100). Device as in claim 1, characterised in that the above-mentioned rocker (40) features two ramps (41a), (44), first and second respectively, the said first ramp (41a) being formed in the end of the aforementioned first arm (41) for enabling movement over the above-mentioned ledge (101b); and the said second ramp (44) being formed between the said first and second arms (41), (42), and sloping in the opposite direction to the said first ramp (41a), in order to lead smoothly on to the above-mentioned track (P3). Device as in claim 1, characterised in that the end of the aforesaid second arm (42) features a boot (43) in a shock-absorbing elastic material.

Inventors: STOPPAZZINI BENITO, STOPPAZZINI, BENITO
Applicants: EMM SRL, EMM S.R.L.
Application year: 1989
Main classification: D04B15
IPC codes: D04B15