GB2120687A

GB2120687A - Improved automatic flat bed knitting machine

Info

Publication number: GB2120687A
Application number: GB08313175A
Authority: GB
Inventors: Benito Stoppazzini
Original assignee: LANZARINI PIETRO; ROSSI MARISA
Current assignee: LANZARINI PIETRO; ROSSI MARISA
Priority date: 1982-05-21
Filing date: 1983-05-13
Publication date: 1983-12-07
Also published as: DE3317479C2; DE3317479A1; ES272369Y; GB8313175D0; IT8203433A0; FR2527238A1; ES272369U; FR2527238B1; GB2120687B; IT1192894B

Abstract

In this machine, each slit 3 in the needle bed has inserted in it a jack 5 provided with a first butt 6, a second butt 7 and a third butt 8. The selection of each jack 5 takes place in two stages: the first defined by selection means 11, integral with the carriage, lifting the jack by its second butt 7 to position R1; and the second defined by a fixed cam 12a, integral with the carriage 1, intercepting the third butt 8, with consequent further lifting of the jack to position R2. Once the selection has taken place, the first butt 6 is intercepted by a group 50 of fixed cams 13, 14, 15 integral with the carriage 1. Subsequently an additional fixed cam, integral with the carriage 1, operates on the third butt 8 in order to return the jack 5 to the non operative position R. <IMAGE>

Description

SPECIFICATION Improved automatic straight bar knitting machine As is known, the needle beds of an automatic straight bar knitting machine have in them equidistant slits, perpendicular to the direction in which the carriage moves.

In each slit, starting at the top and working downwards, there is, in the order stated, a needle, a middle metal strap and a lower metal strap, this destined to carry the needle into operation (obviously with the synchronous driving action of the middle metal strap).

The lower metal strap is provided with a first and a second butt, the latter being destined, in cooperation with corresponding selection means provided in the carriage, to select the metal strap: the said selection is defined by the metal strap undergoing a predetermined upward movement sufficient to position the first butt in the path of one or more fixed cams, integral with the carriage, which by intercepting the said first butt carry definitely upwards the lower metal strap (and consequently the middle metal strap) and the relevant needle, causing the latter to be placed in operation.

In each carriage, and for every one of the needle beds, provision is made for one or more sets of selection means, in which the individual elements in each set are aligned perpendicularly to the direction in which the carriage moves.

Each of the selection means, operated for example by an electromagnet, is movable between a non-operative and an operative position, the latter necessitating the second butt of the corresponding metal strap being intercepted.

It is obvious that it is advisable to increase the number of selection means per set, since with the same set it is possible, with each working stroke of the carriage, to select an identical number of metal straps.

The foregoing requires the use of selection means that occupy a limited amount of space height-wise (that is to say in the direction perpendicular to that in which the carriage moves), so that it be possible to insert the means in between a pair of second butts belonging to two consecutive metal straps in such a way that the said means intercept the corresponding butt at the one pertaining to the following (or preceding) metal strap.

What has just been stated leads perforce to limiting the upward movement of the second metal strap (when selected) and this calls for very close tolerances in the positioning, one with respect to the other, of the metal straps, the selection means and the fixed cams.

In the event of the selection means delaying in or imperfectly intercepting the corresponding butt, the upward movement of the metal strap is below the predetermined value, and this results either in the non-interception of the first butt on the part of the fixed cams (the less disastrous of the suppositions) and thus the needle in question is not carried into operation, or else in the breakage of the said first butt against the side of the said cams.

The object of the invention is to make available an improved automatic knitting machine so constructed as to simplify the stages necessary for the carrying into operation of the needles, with everything being done in an extremely functional way and in a short amount of time, with a considerable positive effect on the operating speed of the machine.

The foregoing is achieved with the machine according to the invention, in which provision is made in the carriage, in respect of each needle bed, for at least one set of selection means, aligned perpendicularly to the direction in which the carriage itself moves, each of which movable between a non-operative and an operative position, the said needle bed having in it equidistant slits, perpendicular to the said movement direction of the carriage, in the top part of each of which is freely inserted a corresponding needle; the said improved machine being characterized by the fact that it comprises: a metal strap for each needle freely inserted in the slit provided for the latter, in a position below the needle butt, and provided with three butts, namely a first, a second and a third butt, starting at the bottom and working upwards, that project with respect to the front face of the needle bed, the second of which being destined to be intercepted, at the bottom, by the corresponding selection means when these are in the operative position, with an upward movement, in consequence of the said interception, of the metal strap from the nonoperative position to a first intermediate position; a first fixed cam integral with the carriage and positioned overhead of the said selection means, downstream thereof with respect to the direction in which the carriage moves, destined to intercept the lower part of the third butt solely when the metal strap is in the first intermediate position, with the upward movement, consequential to this particular interception, of the said metal strap from the first intermediate position to a second intermediate position; a number of fixed cams integral with the carriage and positioned downstream of the said first fixed cam with respect to the said working direction, destined to intercept in succession the first butt solely when the metal strap is in the said second intermediate position, with the movement of the said metal strap, consequential to the said interception, first of all upwards with the needle concerned carried into operation and then downwards into a third intermediate position situated between the said second and first intermediate positions; and a second fixed cam, integral with the carriage and positioned overhead of the said selection means, downstream of the said number of fixed cams with respect to the above mentioned working direction, destined to intercept the upper part of the third butt solely when the metal strap is in the third intermediate position, with the downward movement, consequential to this final interception, of the said metal strap from the third intermediate position to the non-operative position.

From the foregoing it is obvious that the selection of the metal strap takes place in two stages. The first stage is defined by the selection means intercepting the second butt: the metal strap is carried into the first intermediate position.

The second stage, following on immediately after the first, is defined by the first cam intercepting the lower part of the third butt: the metal strap is carried into the second intermediate position.

The stage in which the needle is carried into operation is defined by the fixed cam of the said set intercepting the lower part of the first butt.

The elementary metal strap cycle is completed with the cams of the said set intercepting the upper part of the first butt and, finally, with the second fixed cam intercepting the upper part of the third butt.

The characteristics of the invention that have not emerged from the foregoing text are emphasized in the description given hereunder, referred to the accompanying tables of drawings, in which: Fig. 1 shows, in a lateral view, one of the metal straps; Fig. 2 shows, in a front diagrammatic view, one part of the carriage; Fig. 3 shows, in sectional form, a view along the line I-I in Fig. 2; Fig. 4 shows, in sectional form, a view along the line Il-Il in Fig. 2; Figs. 5 and 6 show, diagrammatically, the initial and final interception position of one of the selection means against the second butt of the corresponding metal strap; Fig. 7 shows, diagrammatically, the most significant positions adopted by a selection strap.

With reference to the said figures, at 1 has been shown diagrammatically a carriage of an automatic straight bar knitting machine sliding above a needle bed (not illustrated since of a known type), the latter having in its slits 3 (two of which have been shown in dashes) perpendicular to the movement direction of the carriage (directions T1 and T2). In the top of each slit is freely inserted a metal strap 4 (shown partially in dashes) and the upper part of this is provided with a needle of a known type (not illustrated).

Underneath the butt 4a of the metal strap 4 in the said slit is freely inserted a metal strap 5 provided, starting at the bottom and working upwards, with three butts, namely a first butt 6, a second butt 7 and a third butt 8.

In the support structure of the carriage 1 a number of bushes 9 are provided (in the case under examination there are eight bushes per set); the axes of the bushes in each set are situated in a plane perpendicular to the directions T1 and T2.

Corresponding rods 10 provided with selection means 11, each provided with two inclined surfaces 11 a and 11 b, respectively, symmetrical with respect to the aforementioned plane, are freely inserted in the said bushes.

The said rod is rendered movable (by means of a device protected with a co-pending patent application on the part of the same Applicant) from a non-operative position I to an operative position 0, more about which will be said later on.

Above the selection means 11 of each set, provision is made for a fixed cam 12, integral with the carriage, constituted by two surfaces 1 2a and 1 2b, respectively, symmetrical with respect to the said plane of symmetry of the means 11. Again above each set of selection means 11 a second cam 1 6 is provided, constituted by two surfaces 1 spa and 1 6b, respectively, symmetrical with respect to the said plane and positioned bilaterally in comparison to the surfaces 1 2a and 1 2b. It should be stressed that the final part of the surface 1 spa is positioned at the same height as the initial part of the surface 1 2a.

It should also be stressed that with respect to the direction T1, the initial part of the surface 1 2a is located downstream with respect to the surfaces 1 1 a.

Between one set of selection means 11 and the one that follows on or precedes, is placed a group 50 of fixed cams, which in the case under consideration has three cams 13, 14 and 1 5. The last two are symmetrical with respect to a plane equidistant from the planes of symmetry of two consecutive sets of selection means 11.

Each selection means 11 is destined to intercept, when placed in the operative position 0, the second butt 7 of the corresponding metal strap 5. In this particular instance, the metal strap in question is considered to be one whose butt 7 is intercepted by the second selection means 11 from the bottom.

In actual fact the metal strap 5 is fixed, while in the carriage traverses in the T1 and T2 direction; since there is a question of relative motion between the metal strap and the carriage, in Fig. 7 it has been supposed that the carriage is fixed and that the metal strap 5 traverses in the T2 direction and that this is equivalent to considering the metal strap 5 fixed and the carriage traversing in the T1 direction.

In the event of the selection means 11 remaining in the non-operative position I (Fig. 3), the metal strap 5 stays in the out of action position R and the butt 6 passes across a longitudinal groove 20.

Vice versa with the selection means 11 in the operative position 0, the interception occurs of the surface 1 a against the lower part of the butt 7. This causes a first upward movement of the metal strap 5 which goes into position R1 (the first intermediate position). With the metal strap at R, the interception takes place (because of the carriage traversing in the T, direction) of the surface 1 2a against the lower part of the butt 8: this brings about a second upward movement of the metal strap 5 which goes into position R2 (the second intermediate position).

With the metal strap at R2 the interception takes place (because of the carriage traversing in the T direction) of the surface 1 3a of the cam 13 against the lower part of the butt 6. This causes a further final upward movement of the metal strap from the R2 to the R3 position and the carrying into operation of the relevant needle (with which the metal strap 4 is provided).

The displacement of the carriage in direction T, causes, in the order stated, the interception of the surfaces 1 4a and 1 5a of the cams 14 and 15 against the upper part of the butt 6. This has the effect of lowering the metal strap from the R3to the R4 position, the latter being midway between positions R, and R.

With the metal strap 5 at R4, the interception occurs of the surface 1 6a of the cam 16 belonging to the next set of selection means 11, against the upper part of the butt 8. This causes the metal strap 5 to be lowered further from the R, to the R position. In this way an elementary cycle for the metal strap 5 ends and the said strap can, at this juncture be selected anew by the means 11 that follow on.

When the carriage traverses in the direction T2 the same considerations apply. In this case, the intervening surfaces are 1 b, 1 2b, 1 sub, 1 4b, 1 3b and 16b.

To conclude, the improved machine in question utilizes one single metal strap 5 in place of the two metal straps employed in conventional solutions, with the selection of each metal strap being achieved through the operation of the selection means 11 on the butt 7 and, subsequently, through the cam 12 operating on the self same butt. This latter point is particularly advantageous since, even in the event of the selection means 11 being late in operating on the butt 7 or of the latter being even slightly displaced from position R, the cam 12 intervenes to carry the metal strap 5 into position 112.

It is understood that the foregoing description has been given purely as an unlimited example and thus that all variants of a constructional nature can be taken as falling within the framework of protection afforded to the invention as described above and claimed hereinafter.

Claims

1. Improved straight bar knitting machine, in which provision is made in the carriage, in respect of each needle bed, for at least one set of selection means, aligned perpendicularly to the direction in which the carriage itself moves, each of which movable between a non-operative and an operative position, the said needle bed having in it equidistant slits, perpendicular to the said movement direction of the carriage, in the top part of each of which is freely inserted a corresponding needle; the said improved machine being characterized by the fact that it comprises: a metal strap 5 for each needle freely inserted in the slit 3 provided for the latter, in a position below the needle butt, and provided with three butts 6, 7 and 8, namely a first, a second and a third butt, starting at the bottom and working upwards, that project with respect to the front face of the needle bed, the second of which being destined to be intercepted, at the bottom, by the corresponding selection means 11 when these are in the operative position 0, with an upward movement, in consequence of the said interception, of the metal strap 5 from the nonoperative position R to a first intermediate position R,;; a first fixed cam 12 integral with the carriage 1 and positioned overhead of the said selection means 11, downstream thereof with respect to the direction T1-T2 in which the carriage 1 moves, destined to intercept the lower part of the third butt 8 solely when the metal strap 5 is in the first intermediate position R1, with the upward movement, consequential to this particular interception, of the said metal strap 5 from the first intermediate position R, to a second intermediate position R2;; a group 50 of fixed cams 13, 14, 1 5 integral with the carriage 1 and positioned downstream of the said first fixed cam 12 with respect to the said working direction T,- T2, destined to intercept in succession the first butt 6 solely when the metal strap 5 is in the said second intermediate position R2, with the movement of the said metal strap 5, consequential to the said interception, first of all upwards with the needle concerned carried into operation and then downwards into a third intermediate position R4 situated between the said second and first intermediate positions R2 R,; and a second fixed cam 16, integral with the carriage 1 and positioned overhead of the said selection means 11, downstream of the said group 50 of fixed cams 13, 14, 1 5 with respect to the above mentioned working direction T1-T2, destined to intercept the upper part of the third butt 8 solely when the metal strap 5 is in the third intermediate position R4, with the downward movement, consequential to this final interception, of the said metal strap 5 from the third intermediate position R4to the nonoperative position R.

2. Machine according to Claim 1, wherein the final part of the second fixed cam 16 is at the same height as the initial part of the first fixed cam 12.

3. Machine according to Claim 1 , wherein the travel of the said carriage 1 in both directions T1-T2 is working travel, and the profile of the said selection means 11 is symmetrical with respect to a plane perpendicular to the movement direction of the carriage, and wherein the profiles 1 2a-1 2b and 1 6a-1 6b of the said first and second fixed cam 12 and 16, as well as the profiles of the cams 13, 14, 1 5 of the said group of cams 50 are symmetrical with respect to the said plane.

4. Improved straight bar knitting machine, substantially as hereinbefore described with reference to the accompanying drawings.