EP1236821A1

EP1236821A1 - Needle selection device in hosiery knitting machines or the like, particulary for medium- and large- diameter circular machines

Info

Publication number: EP1236821A1
Application number: EP02003290A
Authority: EP
Inventors: Tiberio Lonati
Original assignee: Vignoni Srl
Current assignee: Vignoni Srl
Priority date: 2001-02-28
Filing date: 2002-02-22
Publication date: 2002-09-04
Also published as: ITMI20010409A1

Abstract

A needle selection device comprising a supporting frame (2) that can face a needle holder (50, 60) of a hosiery knitting machine or the like and slidingly supports a plurality of stacked selection sliders (9a, 9b) provided with a front end that can face the needle holder. The selection sliders can move on command with respect to the frame along a sliding direction in order to pass from an inactive position, in which they are spaced with their front end (11a, 11b) from the needle holder (50, 60) so that they do not interfere with selection elements that interact with the needles of the machine, to an active position, in which they are closer, with their front end, to the needle holder in order to interfere with the selection elements. Means (25) for individually locking the selection sliders (9a, 9b) in the active position are provided. The selection sliders can be moved individually on command from the inactive position to the active position, independently of the position of the other selection sliders. The locking means can be deactivated individually on command for the passage of the corresponding selection slider from the active position to the inactive position.

Description

The present invention relates to a needle selection device in hosiery knitting machines or the like particularly for medium- and large-diameter circular machines.
It is known that in hosiery knitting machines or the like, in order to produce various knitted patterns the needles are selected so that in each instance some needles knit at a feed or drop of the machine and other needles are excluded from knitting at that feed or drop.
Needle selection is performed usually by resorting to a selection element, termed selector or sub-needle, which is accommodated in the same slot of the needle holder in which the needle is arranged. The selection element is provided with a heel that can engage or not cams that face the needle holder in order to actuate or not the needle located in the same slot of the needle holder.
In many cases, the selection element can oscillate on the plane of arrangement of the needle located in the same slot of the needle holder in order to pass from an active position, in which its heel is extracted from the corresponding slot of the needle holder in order to engage the cams that actuate it, to an inactive position, in which its heel is embedded in the corresponding slot of the needle holder so as to not engage said cams.
The oscillation of the selection element in order to pass from the active position to the inactive position is achieved by way of selection devices, which face the needle holder directly upstream of the various feeds or drops of the machine in the direction of the motion of the needle holder with respect to the cams.
In large-diameter circular knitting machines, these selection devices are generally constituted by blocks which support a plurality of plates or teeth, which are fixed to the block and are directed, with one of their ends, toward the needle holder. Said plates or teeth interact with the selection elements as a consequence of the relative motion between the needle holder and the selection device.
In these devices, when action on a specific selection element is not required, the corresponding plate or tooth is eliminated.
For this reason, at each change of knitting that requires a different needle selection it is necessary to replace the selection device with another one in which the plates or teeth are arranged differently, or disassemble and reassemble the device, arranging the plates or teeth in a different manner. This operation entails stopping the machine and is quite labor-intensive and onerous.
In order to solve these problems, a selection device has been proposed which is disclosed in Italian patent application no. BS96A-000096; it is substantially constituted by a supporting frame that can be arranged so as to face the needle holder of the machine and which supports a plurality of stacked selection sliders, which face, with their front end, the needle holder. Each selection slider can slide on command with respect to the frame toward the needle holder in order to pass from an inactive position, in which it is spaced with its front end from the needle holder in order to avoid interfering with selection elements that interact with the needles, to an active position, in which it is close, with its front end, to the needle holder in order to interfere with the selection elements, and vice versa. The passage of the selection slider from the inactive position to the active position is contrasted elastically by a spring, and there are means for locking the selection slider in the active position.
A control plate is mounted on the rear side of the block, faces the rear end of the selection sliders, and is provided with slots aligned with the rear ends of the selection sliders. The control plate can move toward the rear face of the frame, from which the rear ends of the selection sliders protrude, when said sliders are in the inactive position, and it is possible to locate on the control plate a selection card that is adapted to block the slots that are aligned with the selection sliders that in accordance with the needle selection to be performed must be moved into the active position, leaving free instead the slots that are aligned with the selection sliders that must remain in the inactive position.
In this manner, by moving the control plate toward the rear side of the frame, the selection sliders aligned with the slots blocked by the selection card are pushed into the active position, while the other selection sliders, by passing through the slots that are not blocked by the selection card, remain in the inactive position.
The means for locking the selection sliders are provided so that they are deactivated at the beginning of the sliding of the control plate toward the rear side of the frame and so that they are activated at the end of said sliding.
With this device, if one wishes to change the needle selection set by the selection card it is necessary to replace the selection card.
In any case, it is not possible to act on the selection sliders in order to modify the needle selection imposed by the selection card, and the device cannot be used without a selection card.
This fact is an operational limitation, since it entails the need to provide as many selection cards as there are needle selections to perform, and if one wishes to alter a provided selection even as regards the position of just one selection slider it is necessary to provide a new selection card.
The aim of the present invention is to solve the above described problem, providing a needle selection device in hosiery knitting machines or the like, particularly for medium- and large-diameter circular machines, whose operating flexibility is increased with respect to conventional devices.
Within this aim, an object of the invention is to provide a device that can use a selection card but allows to modify the needle selection without necessarily changing the selection card, thus allowing to perform unlimited needle selections with a limited number of selection cards.
Another object of the invention is to provide a device that can be used even without a selection card.
Another object of the invention is to provide a selection device that offers high assurances of safety and reliability in operation.
This aim and these and other objects that will become better apparent hereinafter are achieved by a needle selection device in hosiery knitting machines or the like, particularly for medium- and large-diameter circular machines, which comprises a supporting frame that can face a needle holder of a hosiery knitting machine or the like and slidingly supports a plurality of stacked selection sliders in which a front end can face said needle holder, said selection sliders being movable on command with respect to said frame along a sliding direction in order to pass from an inactive position, in which they are spaced with their front end from said needle holder so that they do not interfere with selection elements that interact with the needles of the machine, to an active position, in which they are closer, with their front end, to said needle holder with respect to said inactive position in order to interfere with said selection elements, means being provided for individually locking said selection sliders in said active position, characterized in that said selection sliders can be moved individually on command from said inactive position to said active position, independently of the position of the other selection sliders, and in that said locking means can be deactivated individually on command for the passage of the corresponding selection slider from said active position to said inactive position.
Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the device according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
Figure 1 is a partially sectional side elevation view of the selection device according to the invention;
Figure 2 is an enlarged-scale sectional view of Figure 1, taken along the line II-II, which illustrates an operating condition of the device according to the invention;
Figure 3 is an enlarged-scale sectional view of Figure 1, taken similarly to Figure 2, illustrating another operating condition of the device according to the invention;
Figures 4 to 6 are schematic perspective views of elements of the selection device according to the invention, illustrating a particular system for actuating the selection sliders;
Figure 7 is an enlarged-scale view of a detail of Figure 6;
Figure 8 is a schematic axial sectional view of a circular knitting machine with cylinder and dial, equipped with selection devices according to the invention.
With reference to the figures, the device according to the invention, generally designated by the reference numeral 1, comprises a supporting frame 2, which is substantially constituted by two mutually facing shoulders 3 and 4 which are connected one another by transverse plates 5, 6 and 7.
Sliding and guiding passages 8a, 8b for selection sliders 9a and 9b are formed in the transverse plates 5, 6 and 7; said sliders are supported by the frame 2 so that they can slide along a sliding direction indicated by the arrow 10.
The number of the selection sliders 9a and 9b can vary according to the requirements of needle selection. In particular, in the illustrated embodiment, there are two sets of stacked selection sliders, respectively a first set of selection sliders 9a and a second set of selection sliders 9b, which are arranged side by side.
The frame 2 is designed to face, in a hosiery knitting machine or the like, particularly in a large-diameter circular knitting machine, the needle holder, which can be constituted by the bar of a rectilinear knitting machine or, as shown, by the needle cylinder 50 or by the dial 60 of a circular machine.
The selection sliders 9a and 9b have a front end 11a and 11b to be directed toward the needle holder 50, 60 which is designed to engage the selection elements, such as sub-needles or selectors, usually provided in these machines.
Said front end 11a and 11b of the selection sliders 9a and 9b can be shaped appropriately, for example so as to form an inclined plane, in order to act on the selection elements in a manner similar to the one disclosed in BS96A-000096.
The frame 2 is placed on the machine so that the sliding direction 10 of the selection sliders 9a and 9b is substantially perpendicular to the side of the needle holder 50, 60 that faces the frame 2.
The selection sliders 9a and 9b can move individually on command with respect to the frame 2 along the sliding direction 10, in order to pass from an inactive position, in which they are spaced, with their front end 11a and 11b, from the needle holder 50, 60 so as to not interfere with the selection elements 61 that interact with the needles 62 of the machine, to an active position, in which they are closer, with their front end 11a and 11b, to the needle holder 50, 60 with respect to the inactive position, so as to interfere with said selection elements 61, as will become better apparent hereinafter.
The device comprises means 25 for individually locking the selection sliders 9a and 9b in the active position.
According to the invention, the selection sliders 9a and 9b can move individually on command from the inactive position to the active position independently of the position of the other selection sliders. Furthermore, the locking means 25 can be deactivated individually on command for the passage of the corresponding selection slider 9a and 9b from the active position to the inactive position.
More particularly, the selection sliders 9a and 9b have a rear end 12a and 12b which, when the selection sliders 9a and 9b are in the inactive position, protrudes from the rear side, i.e., from the transverse plate 7a and 7b of the frame 2, which lies opposite the front side to be directed toward the needle holder 50, 60.
An actuation element 13 conveniently faces the rear side of the frame 2; in the illustrated embodiment, said actuation element is hood-shaped and slidingly supported, by means of a pair of lateral wings 14a and 14b, by the shoulders 3 and 4 of the frame 2. Said actuation element 13 has slots 15a and 15b, which are aligned with the selection sliders 9a and 9b and can be crossed by the portion of the selection sliders 9a and 9b that protrudes rearward from the transverse plate 7. The actuation element 13 can slide with respect to the frame 2, along the sliding direction 10, in order to pass from a deactivation position, in which it is spaced from the rear side of the frame 2, to an activation position, in which it is closer to the rear side of the frame 2. A selection card 17 can be inserted in a seat 16 provided for this purpose inside the actuation element 13; said selection card is provided, according to the selection requirements, so as to block part of the slots 15a and 15b so that the movement of the actuation element 13 from the deactivation position to the activation position, when a selection card 17 is inserted therein, causes the passage of the selection sliders 9a and 9b, aligned with the slots 15a and 15b blocked by the selection card 17, from the inactive position to the active position.
Conveniently, between the frame 2 and each selection slider 9a and 9b elastic means are provided, constituted for example by springs 18a and 18b, which contrast elastically the passage of each selection slider from the inactive position to the active position. Substantially, the springs 18a and 18b, in the absence of other forces that act on the selection sliders 9a and 9b, keep the selection sliders 9a and 9b in the inactive position. Proximate to the front end 11a and 11b of each selection slider 9a and 9b there is a shoulder 19a and 19b that is designed to engage, when the selection sliders 9a and 9b are in the inactive position, against the front side of the transverse plate 5, so as to stop the sliding of the selection sliders 9a and 9b caused by the action of the springs 18a and 18b.
Each selection slider 9a and 9b has, on one of its sides, a stop tooth 19a and 19b, which has a front side 20a and 20b, shaped so as to define an inclined plane with respect to the sliding direction 10, and a rear side 21a and 21b, which is substantially perpendicular to the sliding direction 10.
The locking means 25 comprise, for each selection slider 9a and 9b, a pawl 26a and 26b, which is supported by the frame 2 and can engage with its head 27a and 27b said retention tooth 19a and 19b.
The head 27a and 27b of the pawl 26a and 26b has a front side 28a and 28b, which is substantially perpendicular to the sliding direction 10, and a rear side 29a and 29b, which is shaped like an inclined plane with respect to said sliding direction 10. Each pawl 26a and 26b is pivoted, with an intermediate portion, to a shaft 30a and 30b which is fixed, at its axial ends, to the shoulders 3 and 4 of the frame 2 and is orientated so that its axis is substantially perpendicular to the plane of arrangement of the various selection sliders 9a and 9b and substantially perpendicular to the sliding direction 10.
Each pawl 26a and 26b can rotate about the corresponding shaft 30a and 30b in order to pass from an engagement position, in which it engages by means of the front side 28a and 28b of its head 27a and 27b the rear side 21a and 21b of the tooth 19a and 19b, so as to lock the corresponding selection slider 9a and 9b in the active position in contrast with the action of said spring 18a and 18b, to a disengagement position, in which it disengages from the tooth 19a and 19b of the corresponding selection slider 9a and 9b. Each pawl 26a and 26b can rotate about the corresponding shaft 30a and 30b in contrast with the action of second elastic means, which are constituted for example by a coiled spring 31a and 31b that is interposed between the pawl 26a and 26b and the shaft 30a and 30b. The spring 31a and 31b pushes constantly the head 27a and 27b of the pawl 26a and 26b against the side of the corresponding selection slider 9a and 9b that bears the tooth 19a and 19b.
Thanks to the inclined-plane shape of the front side of the tooth 19a and 19b and of the rear side of the head 27a and 27b of the pawl 26a and 26b, it is possible to transfer each selection slider 9a and 9b from the inactive position to the active position simply by pushing the selection slider along the sliding direction 10. In this case, such particular shape of the tooth 19a and 19b and of the head 27a and 27b of the pawl 26a and 26b in fact allows the tooth to move beyond the head of the pawl, causing a rotation of the pawl about the respective shaft 30a and 30b in contrast with the action of the spring 31a and 31b which immediately thereafter causes the engagement of the head 27a and 27b of the pawl against the rear side 21a and 21b of the tooth.
It should be noted that the actuation element 13, in passing from the deactivation position to the activation position and vice versa, advantageously interferes with the end of the pawls 26a and 26b that lies opposite the head 27a and 27b, so as to cause the disengagement of the pawls 26a and 26b from the selection sliders 9a and 9b, which as a consequence of this fact move automatically into the inactive position.
More particularly, the sides of the actuation element 13 that face the pawls 26a and 26b have an inclined- plane portion 35a and 35b that can engage the end 33a and 33b of the pawls 26a and 26b that lies opposite the head 27a and 27b. Furthermore, the actuation element 13 has, on said sides, openings 36a and 36b that allow the pawls 26a and 26b to return into the engagement position after the actuation element 13 has been moved into the activation position. The openings 36a and 36b furthermore allow to act on the end 33a and 33b of the pawls in order to cause manually the individual passage of the pawls 26a and 26b from the engagement position to the disengagement position.
Advantageously, the device also comprises an additional slider 40, which is stacked with the selection sliders of at least one set and can slide with respect to the frame 2 along the sliding direction 10. The additional slider 40 supports, on its front end 41 that is designed to be directed toward the needle holder 50, 60, a cam 42, which can move, as a consequence of the sliding of the additional slider 40, from an inactive position, in which it is spaced from the needle holder 50, 60, so as to not interfere with the needles 62 or with the selection elements 61 that cooperate with the needles 62 of the machine, to an active position, in which it is closer to the needle holder 50, 60, in order to interfere with the needles 62 or with the selection elements 61.
Locking means are provided also for the additional slider 40, in order to lock it in the active position; said locking means can be deactivated on command in order to cause the passage of the additional slider 40 from the active position to the inactive position.
Substantially, the additional slider 40 can be provided like the selection sliders 9a and 9b and can be stacked, according to requirements, within a group of selection sliders 9a and 9b.
The locking means of the additional slider 40 are constituted by a pawl, which is provided similarly to the pawls 26a and 26b and is pivoted about one of the shafts 30a and 30b. The operation of the additional slider 40, in passing from the inactive position to the active position and vice versa, is practically identical to the operation of the selection sliders 9a and 9b.
In particular, the additional slider 40 also has a rear end 43, arranged opposite the front end, that protrudes from the rear side of the frame 2; said rear end 43 can be contacted by the selection card 17 or manually in order to transfer the additional slider 40 from the inactive position to the active position. Furthermore, when the additional slider 40 is in the active position, it is possible to act manually on the corresponding pawl in order to disengage said pawl from the additional slider 40, causing, by way of a spring similar to the spring 18a or 18b, the passage of the additional slider 40 from the active position to the inactive position.
Conveniently, means 44 are provided for controlling the actuation of the additional slider 40. Said control means 44 allow the additional slider 40 to pass from the inactive position to the active position only when the selection sliders 9a that belong to the same group in which the additional slider 40 is inserted are in the active position.
The control means 44, as shown in particular in Figures 4 to 7, are conveniently constituted by a bolt or bar 45, which is supported by the transverse plate 7 so that it can slide along a direction that is perpendicular to the extension of the stack of selection sliders 9a that contains the additional slider 40.
The bolt 45 engages, with one of its portions, a slot 46a that is provided for this purpose in the side of the selection sliders 9a and of the additional slider 40 that is directed away from the side that bears the tooth 19a. On this portion of the bolt 45 there are transverse millings 47, which and are spaced so as to match the spacing between the selection sliders 9a, and there is a specifically provided milling 48 for the additional slider 40, which however is staggered with respect to the spacing between the additional slider 40 and the selection sliders 9a. Only when all the selection sliders 9a are in the active position, as shown in Figure 4, are their slots 46a mutually aligned, allowing the sliding of the bolt 45 in order to place the slot 48 at the additional slider 40. This sliding thus allows to move the additional slider 40 from the inactive position to the active position, as shown in Figure 5, but no longer allows the passage of the selection sliders 9a from the active position to the inactive position until the additional slider 40 is returned to the inactive position and the bolt 45 has been moved again in order to align its slots 47 with the selection sliders 9a.
It should be noted that if even just one of the selection sliders 9a is in the inactive position, the bolt 45 cannot be moved and therefore, since the slot 48 is staggered with respect to the additional slider 44, said additional slider cannot move into its active position (Figures 6 and 7). The sliding of the bolt 45 in order to pass from one position to the other can be contrasted elastically by means of a spring 49.
Figure 8 illustrates the use of two devices according to the invention in a circular knitting machine provided with a cylinder 50 and a dial 60.
In said machine there are needles 62 that include a selection element 61. Said selection element 61 has, on its side directed toward the outside of the needle holder 50, 60, a selection tab 63, which is designed to be contacted by the selection sliders 9a and 9b, and an actuation heel 64. The selection element 61 can oscillate, within the slot 50a, 60a of the needle holder 50, 60 in which it is accommodated, in order to pass from a first position, in which it is extracted, with the selection tab 63 and the actuation heel 64, from the corresponding slot 50a, 60a of the needle holder 50, 60 so as to engage, by way of the actuation heel 64, cams that move the selection element 61 and accordingly the needle 62 associated therewith, thus actuating the needle 62, to a second position, in which both the selection tab 63 and the actuation heel 64 are embedded in the slot 50a, 60a of the needle holder 50, 60 so as to prevent the engagement of the selection element 61 with said cams and thus exclude from knitting the needle 62 connected thereto, at a given feed or drop of the machine.
The operation of the device according to the invention is as follows.
In inactive conditions, all the selection sliders 9a and 9b are in the inactive position, as shown in particular in Figure 2.
If one wishes to perform a selection by using selection cards, a selection card 17 is placed within the actuation element 13 and said actuation element is moved from the deactivation position to the activation position. In moving from the deactivation position to the activation position, the actuation element 13 moves into the inactive position any selection sliders 9a and 9b that are in the active position and then moves the selection sliders 9a and 9b that are aligned with the holes 15a and 15b blocked by the selection card 17 from the inactive position to the active position, as shown in Figure 3. The selection sliders 9a and 9b moved into the active position interfere with the selection tabs 63 of the selection elements 61 arranged in the needle holder 50, 60 and move said selection elements 61 from the first position to the second position. The needles 62 connected to said selection elements 61 are not actuated at the feed or drop at which the selection device according to the invention is arranged.
If it is necessary to modify the selection set by the selection card 17 so as to move into the active position one or more selection sliders 9a and 9b that according to the selection card 17 should be in the inactive position, it is possible to act manually on that or those selection sliders in order to push them from the inactive position to the active position. This operation is possible because the tooth 19a and 19b can move beyond the head 27a and 27b of the corresponding pawl 26a and 26b, although the actuation element 13 is in the activation position, since the actuation element 13 does not prevent the passage of the pawls 26a and 26b from the engagement position to the disengagement position.
The device according to the invention can be actuated entirely manually. In this case, with the actuation element 13 in the activation position or in the deactivation position, one acts manually on the rear end 12a and 12b of the selection sliders 9a and 9b that according to the needle selection to be performed must be moved from the inactive position to the active position. In order to move instead the selection sliders from the active position to the inactive position, one acts manually on the end 33a and 33b of the corresponding pawl 26a and 26b, so as to cause its disengagement from the tooth 19a and 19b of the corresponding selection slider 9a and 9b.
If one wishes to use the cam 42, after moving into the active position all the selection sliders 9a located in the same set in which the additional slider 40 is arranged, the bolt 45 is moved so as to release the additional slider 40, which can thus be moved from the inactive position to the active position, as shown in Figures 4 and 5.
It has been found in practice that the device according to the invention fully achieves the intended aim and objects, since by allowing actuation both manually and by means of a selection card, and by allowing to modify manually the selection preset by means of a selection card, it allows various possibilities of selection of the needles in a machine without requiring a large number of selection cards.
The device thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements.
In practice, the materials used, as well as the dimensions, may be any according to requirements and to the state of the art.
The disclosures in Italian Patent Application No. MI2001A000409 from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

A needle selection device in hosiery knitting machines or the like, particularly for medium- and large-diameter circular machines, comprising a supporting frame that can face a needle holder of a hosiery knitting machine or the like and slidingly supports a plurality of stacked selection sliders in which a front end can face said needle holder, said selection sliders being movable on command with respect to said frame along a sliding direction in order to pass from an inactive position, in which they are spaced with their front end from said needle holder so that they do not interfere with selection elements that interact with the needles of the machine, to an active position, in which they are closer, with their front end, to said needle holder with respect to said inactive position in order to interfere with said selection elements, means being provided for individually locking said selection sliders in said active position, characterized in that said selection sliders can be moved individually on command from said inactive position to said active position, independently of the position of the other selection sliders, and in that said locking means can be deactivated individually on command for the passage of the corresponding selection slider from said active position to said inactive position.
The device according to claim 1, characterized in that said selection sliders have a rear end, arranged opposite the end to be directed toward said needle holder, which protrudes, when the corresponding selection slider is in said inactive position, from the rear side of said frame that lies opposite the side to be directed toward said needle holder; an actuation element being provided which faces said rear side of the frame and can move on command from a deactivation position, in which it is spaced from said rear side of the frame, to an activation position, in which it is closer to said rear side of the frame; said actuation element having slots at said selection sliders which can be crossed by said rear ends of the selection sliders so as to not interfere with said selection sliders in passing from said deactivation position to said activation position; a selection card being insertable in said actuation element and being suitable to block part of said slots for the movement of the selection sliders, in alignment with the blocked slots, from the inactive position to the active position when said actuation element moves from said deactivation position to said activation position.
The device according to claims 1 and 2, characterized in that it comprises first elastic means which contrast elastically the passage of each selection slider from said inactive position to said active position.
The device according to one or more of the preceding claims, characterized in that said selection sliders have, on one of their sides, a retention tooth with a front side that is shaped so as to form an inclined plane and with a rear side that is substantially perpendicular to said sliding direction; said locking means comprising, for each one of said selection sliders, a pawl which is supported by said frame and can engage said retention tooth with its head, which has a front side that is substantially perpendicular to said sliding direction and a rear side that is shaped so as to form an inclined plane with respect to said sliding direction; said pawl being movable on command from an engagement condition, in which it engages, with the front side of its head, the rear side of said tooth of the corresponding selection slider in order to lock it in said active position in contrast with said first elastic means, to a disengagement position, in which it disengages from the tooth of the corresponding selection slider; said pawl being movable from the engagement position to the disengagement position also by virtue of the passage of the corresponding selection slider from said inactive position to said active position as a consequence of the sliding of the front side of said tooth against the rear side of the head of the pawl.
The device according to one or more of the preceding claims, characterized in that it comprises second elastic means which contrast elastically the movement of said pawl from said engagement position to said disengagement position.
The device according to one or more of the preceding claims, characterized in that said pawl is pivoted, with an intermediate portion, to said frame about an axis that is substantially perpendicular to said sliding direction and to the plane of arrangement of the corresponding selection slider.
The device according to one or more of the preceding claims, characterized in that said actuation element, in passing from said deactivation position to said activation position and vice versa, engages said pawl in order to move it from said engagement position to said disengagement position.
The device according to one or more of the preceding claims, characterized in that said pawl, both when said actuation element is in said activation position and when it is in said deactivation position, can be maneuvered manually from the outside of said frame in order to move it from said engagement position to said disengagement position.
The device according to one or more of the preceding claims, characterized in that the rear end of each selection slider, in said inactive position, can be maneuvered manually from the outside of said frame in order to move the selection slider from said inactive position to said active position.
The device according to one or more of the preceding claims, characterized in that it comprises an additional slider which is stacked with said selection sliders and can slide with respect to said frame along said sliding direction; said additional slider having a cam on its front end meant to be directed toward said needle holder; said additional slider being movable on command along said sliding direction, in order to pass from an inactive position, in which said cam is spaced from said needle holder in order to avoid interfering with the needles or with elements connected thereto, to an active position, in which said can is closer to said needle holder with respect to said inactive position, in order to interfere with the needles of the machine or with elements connected thereto, and vice versa; means being provided for locking said additional slider in said active position, said locking means being deactivatable on command in order to move said additional slider from said active position to said inactive position.
The device according to one or more of the preceding claims, characterized in that said additional slider has a rear end, arranged opposite said front end, which protrudes from the side of said frame that lies opposite the side to be directed toward said needle holder, said rear end being contactable by said selection card or manually in order to move said additional slider from said inactive position to said active position.
The device according to one or more of the preceding claims, characterized in that said additional slider is provided substantially like said selection sliders and the means for locking said additional slider are provided substantially like the means for locking said selection sliders.
The device according to one or more of the preceding claims, characterized in that it comprises means for controlling the actuation of said additional slider; said control means allowing said additional slider to pass from said inactive position to said active position only when said selection sliders are in said active position.
The device according to one or more of the preceding claims, characterized in that it comprises two stacks of selection sliders arranged side by side along the direction of motion of said needle holder with respect to said frame.