This invention relates to an actuator assembly for a picker head in shuttleless looms for making wire cloth, particularly wire cloth for use in the manufacture of strainers, window screens, etc.
As is known,in wire cloth looms, a picker head, provided with a wire engaging latch and being reciprocated in timed relationship with the loom sley, is arranged to pass the weft wire through the shed formed by warp wires laid on mutually parallel planes, thereby weaving the wire cloth.
To that end, the picker head is passed, over an initial portion of its stroke distance, through the shed up to one side thereof, whereat it will pick up the weft wire by means of its openable end bill; thereafter, the picker head is returned rapidly through the shed to take the weft wire in between the warp wires and thus weave, at each back and forth stroke, a portion of the cloth.
In such loom types, the picker head movement is implemented by means of complex camming mechanisms which receive their motion from the loom main drive via additional driving and timing members.
This contributes, of course, to the complexity of the loom as a whole. while with such prior looms, the wire insertion is not entirely satisfactory on account of frequent breakages caused in the wire by the vibration and irregular motion of the picker head. IT-A-1 126 425 discloses a picker element and related drive which have been effective to greatly reduce the occurrence of breakages in the weftwire, so as to result, with fairly high efficiency, in the production of a wire cloth having satisfactory characteristics.
However, actual tests conducted on production looms so constructed, and further extensive studies by the Applicant, have shown that the mechanism proposed in IT-A-1 126 425, while being generally satisfactory, was not entirely faultless, among its deficiencies being that it could not provide a very high rate of operation for the cited picker element.
A further disadvantage shown by said mechanism was that adjustment for operative transition from one cloth type to a different, especially heavier grade, one involved a significant degree of complexity.
DE-C-844275 dating back to the year 1952 discloses a mechanism for actuating a shuttle in a ribbon loom wherein the actuating mechanism comprises a cross the axis of rotation of which is arranged to run over a circular path and the cross is driven by a planetary gearing in which the shaft of the planet gear coincides with the crankshaft.
Apart from the fact that this prior disclosure is concerned exclusively with low speed shuttle looms, it does not provide a solution for the problem of a perfect timing of the actuating mechanism with the loom sley.
Thus the task of this invention is to provide an improved actuator assembly and/or mechanism for a picker head in shuttleless looms for making wire cloth, which can move the picker head at a very high speed and in perfectly timed relationship with the position of the loom sley at each operative phase of the picker head.
Within that task it is an object of the invention to provide an assembly as indicated, which can actuate the picker head during the return or weft wire drawing stroke thereof such that the weft wire is held under constantly applied tension, thus preventing it from becoming entangled and producing a cloth having optimum characteristics.
It is another object of this invention to provide an assembly as indicated, which can be readily adjusted for adaptation in an optimum fashion to the production of the various types of wire cloth presently on demand by the market.
Still another object of the invention is to provide an assembly as indicated, which is construction-wise simple and reliable, and in particular which may be easily fitted on existing looms without involving substantial alteration of the latter.
It is a further object of this invention to provide an actuator assembly as indicated, which is compatible, in particular, with currently available commercial picker actuating carriage assemblies.
Yet another object of the invention is to provide an actuator assembly as indicated, which can be easily manufactured from materials and on equipment commonly available on the market.
The above task and objects are achieved by an actuator assembly for a picker head in shuttleless looms as defined in claim 1.
Further features and advantages of the actuator assembly for a picker head in shuttleless looms for making wire cloth. according to this invention, will be more readily understood from the following detailed description of a preferred embodiment thereof, with reference to the accompanying illustrative drawings. where:
Making now specifc reference to the drawing views, and in particular to Figures 1 and 2, the actuator assembly for a picker head according to this invention will be next described in detail, although a detailed discussion of the loom incorporating it is omitted herein inasmuch as reference can be had for its description to the aforementioned prior Italian patent application by this same Applicant.
More specifically, the actuator assembly for a picker head, according to the invention, is generally designated with the reference numeral 1.
Said assembly, as shown best in Figure 2, comprises a gear case SC affixed to an abutment shoulder SP (Figure 1) on the loom, which gear case has a substantially cylindrical shape and contains rigid therewith a first spur gear 2 (Figure 2) journalled to one end of the loom crankshaft (not shown) and made relatively rotatable therewith, and a second spur gear 3 arranged to mesh with the first spur gear 2. The first and second gears 2 and 3 are provided in a 1:1 drive ratio and are supported on a plate-like gear carrier or holder element 4 of substantially rectangular shape, which supports the gear 3 rotatably at its upper end, and the gear 2 is relatively rotatable with respect to its lower end. To that aim, formed in the plate-like carrier 4, respectively at the upper and lower ends thereof, are two throughgoing round holes, indicated at 5 and 6, respectively, which are arranged to accommodate conventional means of securing the carrier 4 onto the loom crankshaft and the spur gears 3 and 2, respectively. However, such conventional means will not be described in detail herein.
It may suffice to say that the crankshaft (not shown) and cited gears 2 and 3 are associated with the plate-like element 4, and the gear 3 is in mesh engagement with the gear 2, thereby, on rotating the loom crankshaft, the plate-like element 4 and gear 3 are rotated, the gear 3 describing an epicycloid around the gear 2 with which it meshes.
On the opposite side of the plate-like element 4 with respect to that side which carries the gear 3, a disk assembly, generally indicated at 7, is supported which, in one embodiment, may comprise an outer bearing race 8 and a center disk element 9, between the disk element 9 and bearing race 8 there being arranged, in a manner known perse, plural bearing balls 10. The center disk element 9 has a slot or throughgoing aperture 11 formed therein which is sized and configured to receive one end of a first connecting rod element 13, as explained more detailedly hereinafter.
It may be seen that between the disk assembly 7 and plate-like gear carrier element 4 there intervenes a cover C, provided to close the gear case as shown more clearly in Figure 7.
In particular, the cover C is made pivotally rigid with the disk assembly 7 and gear carrier plate 4, so that in operation said cover C will also turn. Again with reference to Figure 2, the elongate slot 11, which may have an enlarged end to facilitate coupling to the connecting rod 13, is arranged to accommodate, fixedly but adjustably, one end of said first connecting rod element 13, the other end of which is engaged articulatedly with a set of rods, generally designated with the reference numeral 16, formed essentially by six rods which are interconnected to define a substantially triangular arrangement lying on an essentially vertical plane, with the actuator assembly in a fully assembled condition. More specifically, the rod set 16 comprise two rods 17 and 18 which have a substantially yoke-like configuration and define the base of said triangular configuration, two additional rods 20 and 21 defining one side of said triangular configuration, and two rods 22 and 23 defining the other side of the triangular configuration. The yoke-like shape of the rods 20 and 21 causes them to meet each other at a substantially common end, e.g. their welded end indicated at 19, having a through connection hole 19'. As may be seen, the common end 19 of the rod pair 20 and 21 projects farther than the two base rods 17 and 18, which have their common end located more to the rear than said end 19, the common end of the rods 17 and 18 being for example welded at said rearward location.
On the other hand, the rods 22 and 23 are substantially straight and parallel ones, and have coupling holes, not referenced herein, formed at each end, their respective lower ends also projecting from the aforementioned two base rods 17 and 18 defining the aforementioned triangular configuration.
In particular, the two base rods 17 and 18 in the triangular configuration set, or bow divider-like set, are formed at their diverging ends with two slots or elongate longitudinal apertures, indicated at 24 and 25, respectively, for engaging adjustably therewith the pair of substantially parallel rods 22 and 23.
For said adjustable coupling, there is provided a throughgoing peg element, orthreaded bolt, 26 which couples the two rods 22 and 23 together at their lower end portions, said peg being passed, as may be seen, through the slots 24 and 25. The peg 26, which comprises as mentioned a releasable bolt, will enable, as is apparent, adjustment of the positions of the rods 23 and 24 in the slots 24 and 25, and such rods to be locked in the adjusted positions.
Thus, the actuator assembly of this invention provides at least two adjustment points already, namely the aforementioned coupling of the first connecting rod 13 within the slot 11 and the coupling just described of the two rods 22 and 23 within the slots 24 and 25 of the rods 17 and 18. Said dual adjustment affords the faculty of synchronizing in an optimum fashion the motion transmitted by the actuator assembly of this invention with the motion of the other main loom members, and in particular the sley.
The triangular rod arrangement described hereinabove is articulated at one side, respectively at the lower ends of the rods 22 and 23, to an adjustment carriage assembly, generally indicated at 30, shown more detailedly on an enlarged scale in Figure 6.
In particular, the lower ends of the rods 22 and 23 are made rigid, e.g. through a pin 32, with a pivot connection 33, which pivot connection 33 is made rigid with a plate-like element 34 of substantially C-like configuration, which plate-like element 34 is adapted for sliding movement in a longitudinal slot 35 formed in the lower body 36 of the carriage. For producing said sliding movement of the plate 34, and hence of the pivot connection 33 attached thereto, a handwheel element, indicated at 37, is provided, the handwheel 37 being coupled to the sliding plate 34 through any suitable means, such as a worm and gear means, not shown.
It may be appreciated that the adjusting carriage assembly 30 is substantially rigid with the abutment SP of the loom, a plate-like element 40 being also made rigid, via a support41, with the abutment of the loom, the element 40 being provided to function as a stop for the sliding motion of the plate 34 associated with the adjusting carriage assembly 30.
Again in connection with the cited adjusting assembly 30, it should be noted that it is quite easy to adjust the positions of the two rods 22 and 23 in the cited triangular arrangement by simply threading out substantially no more than three bolts, namely the bolt or pin 26 joining the two rods 22 and 23, and the two bolts 41 and 42 which locate the sliding positions of the sliding plate 34 in the longitudinal slots 35 of the carriage body 36. This easily carried out adjustment, required to suit the motion supplied by the inventive assembly to the type of cloth being weaved, constitutes a peculiar aspect of the invention not to be found with the complex camming devices of the prior art, which were on the contrary quite difficult to adjust, the adjustment thus achieved being less fine than that to be obtained with the carriage assembly of the inventive actuator assembly.
At the end portion 19 of the two rods 20 and 21, and through the hole 19', the cited triangular rod arrangement, or bow divider-like arrangement, are articulated, by conventional means, such as a pin 50, to a twin connecting rod element 51 which has its opposite end connected, through an additional pin element 52, for example to a picker head actuating carriage 54. The carriage 54 is a part of an actuating assembly 55, which is available commercially and requires no further detailed discussion herein.
It is considered that the foregoing description is adequate for understanding the operation of the actuator assembly according to the invention.
Making reference to Figures 3 to 5, which illustrate different operative steps in the actuation of the picker head, the operation of the actuator assembly according to the invention will be next described. The main motion is in particular derived from the loom main shaft as drive by the motor M (Figure 1), through a drive belt 56 and flywheel-pulley 57. Assuming that the flywheel-pulley 57 turns in a clockwise direction, as indicated by the arrowA in Figure 1, the rotary motion is transmitted from the main shaft to the crankshaft mentioned hereinabove, which in turn drives the gearsystem of the actuator mechanism according to the invention, thereby the rotation of the outward gear 3 and elements connected thereto, in particular to the plate 4, cover C, and disk assembly 7, will occur in a counterclockwise direction, as shown by the arrow B. Consequently to the rotation of the crankshaft, the gear 3 will describe an epicycloidal path around the gear 2, wherein the disk assembly 7 turns togeth- erwith the cover C. The rotary motion imparted to the disk assembly 7 will cause the first connecting rod element 13 to drive in a push-pull mode the triangular rod arrangement which, being pivoted at 33, reciprocates the picker head actuating carriage. In particular, Figure 3 shows the main connecting rod 13 in the fully backward position, which in accordance with the invention is a picker rest position. Of course, the dimensions of the connecting rod 3 and rod mechanism as a whole should be selected to determine a desired rest interval for the picker head after drawing the weft wire through the shed. In Figure 4, the connecting rod 13, under the drive from the gears 2 and 3, plate 4, and disk assembly 7, begins its outward travel, which corresponds to a working stroke during which the picker head (not shown) starts through the shed in its movement across it for picking up the weft wire from the left-hand extremity of the shed.
In particular, the weft wire is engaged with the connecting rod in its fully extended position and the carriage 54 at the bottom travel limit of its back-and- forth stroke distance. Said fully extended position of the connecting rod 13 is shown schematically in Figure 5. Thus, in the condition corresponding substantially to that shown in Figure 5, the picker head is engaged with the weft wire. As the crankshaft is rotated further, the connecting rod element 3 starts its backward movement, thereby the picker head will be caused to move backward through the shed with the wire (not shown) engaged therewith, dimensions being selected such that the picker head is at a standstill over an angle of substantially 120-130°. This standstill phase of the picker head constitutes an advantageous aspect of the invention, because during that phase, the weft wire may be cut in ideal conditions to yield an optimum cloth in a nearly finished condition.
It should be noted in this respect that the cited standstill interval of the picker head does not jeopardize, as actual tests have shown, the cloth production rate, which is higher than the rates currently achieved with conventional looms of the same general type.
It should be further pointed out that the inventive actuator assembly enables, by virtue of its peculiar construction, the picker head to hold the weft wire at all times under tension, which is effective to prevent the wire from becoming entangled and further improve the quality of the resulting wire cloth.
Also to be enhanced is the cited dual adjustment ability of the inventive actuator assembly, which adjustment is easy to make as well as being extremely accurate. Thus, ease of adjustment brings about a corresponding ready adaptability of the whole machine to produce a desired cloth type, especially as regards the cloth grade.
It may be appreciated from the foregoing that the invention fully achieves its objects.
While but one, presently preferred embodiment of the invention has been described by way of example, the skilled one in the art will readily recognize that many modifications and variations may be introduced therein without departing from the true scope of the inventive idea. As an example, the specific dimensions of the main component parts of the actuator assembly according to the invention may be selected contingent on individual application requirements.