Improved device for selecting the shift of the rocker arm of the reed operating mechanism of a terry loom

Abstract: A device for selecting the shift of the rocker arm of the reed operating mechanism in a terry loom, in which the two push rods hinged to said rocker arm are also hinged respectively to two terry height adjustment levers each of which comprises a shoulder tooth for cooperation with a corresponding coupling pin slidable within a guide in the control lever and urged into the active position against the action of a spring by a corresponding selection lever carrying an armature for a corresponding fixed electromagnet, said lever cooperating with a ledge on the control lever by means of a spring tending to withdraw said armature from said electromagnet.

Description: This invention relates to a device for selecting the shift of the rocker arm of the reed operating mechanism of a terry loom which by not using an electromagnet for moving the pins which couple the control lever to one of the two push rods of said rocker arm and allowing the device to be sealed and hence lubricated in an oil bath, and by using only one operating cam both for operating the lever systems and for said pin movement, results in the achievement of higher operating speeds as required by modern terry looms, a longer life of the device and considerable energy saving, with consequent cost reduction. It is already known from our preceding U.S. Patent No. 4,406,308 of September 27, 1983, to vary the beating position of the reed of a terry loom from a "closed" or normal position to an "open" or retracted position for terry formation by moving the rocker arm of the reed operating mechanism from its standard position against the action of a return spring, by means of a push rod which is hinged to the shank of said rocker arm and is itself driven by a control lever which is coupled to said push rod and, by means of a spring, is elastically maintained in contact with the contour of an operating cam driven by the loom drive shaft. To achieve two different terry heights without stopping the loom, two push rods are generally used hinged to different points of said rocker arm shank, the selection of which of said two push rods is to shift said rocker arm being determined by two electromagnets rigid with said control lever, these being each arranged to magnetically move a pin coupled to the corresponding push rod. This known device for selecting the rocker arm shift has a series of drawbacks due substantially to the vibration and wear to which the electromagnets used for moving the coupling pins are subjected; again the time required by said electromagnets for moving the coupling pins limits their efficiency in modern high-speed terry looms. The electromagnets also utilize considerable energy in that as they have to produce a considerable movement of the pins, a large magnetic field is required with a consequent large power consumption, even if said pins are made with small dimensions to limit their inertia. Finally, the presence of these electromagnets within the region of operation of the coupling pins makes it impossible to seal this region and hence lubricate the pins in an oil bath, as would be required to increase the reliability of the mechanism and to reduce the wear of said pins to a minimum. The object of the present invention is to obviate the aforesaid drawbacks by providing a device for selecting the shift of the rocker arm of the reed operating mechanism of a terry loom, which allows high operating speed, results in very low wear and hence a long life and a considerable energy saving, and in addition allows effective lubrication in an oil bath. This is substantially attained by moving the slidable coupling pins from an active position to a passive position or vice versa not by electromagnets but by selection levers, one end of which cooperates via a spring with a ledge on the control lever, and the other end of which carries an armature arranged to cooperate with a respective electromagnet the only purpose of which is to retain it, the approach of the armature to the magnet being determined by said cooperation between said ledge on the control lever and said end of the selection lever; in this manner not only is a very low feed power required by the electromagnets with consequent considerable energy saving, but there is absolutely no limitation on operating speed. Said slidable coupling pins are hence housed in suitable grooves in said control lever and opposed by a spring tending to urge them into a passive or retracted position within said groove whereas when in their active or inserted position within said groove they cooperate with a shoulder tooth present at one end of terry height adjustment levers which are idly pivoted on the same axis of rotation as said control lever and have connected to their other end in different positions the ends of said push rods for said rocker arm, to which the push rods are hinged at their other ends. It is apparent that in this manner the vibrations can no longer act on the electromagnets, which are now supported by a fixed element, and that the device can be easily closed hermetically and hence lubricated by an oil bath. Thus the device for selecting the shift of the rocker arm of the reed operating mechanism in a terry loom, comprising two push rods for shifting said rocker arm from a standard position defined by a return spring to an operating position in which said reed is brought into a retracted or open position to form the terry, said push rods being driven respectively by a control lever which by means of a spring is elastically maintained in contact with the contour of an operating cam driven by the loom drive shaft, and is made to cooperate with one or other of said push rods, is characterised according to the present invention in that said two push rods, hinged to said rocker arm, are also hinged at their other end to mutually different points on an arm of two terry height adjustment levers respectively, which are idly pivoted on the same axis of rotation as said control lever and each have on their other arm a shoulder tooth arranged to cooperate with a corresponding coupling pin slidable within a guide provided in said control lever, in which the pin is retained by a spring in the passive or retracted position, said pin also cooperating with one end of a selection lever the other end of which carries the armature of an electromagnet fixedly mounted in the casing of the device, said selection lever also cooperating with a ledge on said control lever by the action of a spring which tends to withdraw said armature from said electromagnet. The invention is further described hereinafter with reference to the accompanying drawings which illustrate a preferred embodiment thereof by way of non-limiting example in that technical or constructional modifications can be made thereto but without leaving the scope of the invention. In said drawings: Figure 1 is a front sectional view of a device for selecting the shift of the rocker arm of the reed operating mechanism of a terry loom, in accordance with the invention; Figure 2 is a sectional view from above of the device of Figure 1, to a different scale. In the figures the reference numeral 1 indicates the rocker arm of the reed operating mechanism 2 of a terry loom which, being completely known, is represented simply by portions of the two mutually pivoted arms 3 and 4 respectively, the common joint 5 of which is inserted into and guided within the circular-arc slot 6 of said rocker arm 1. One end of two push rods 11 and 12 is hinged by the through pin 10 to the rocker arm 1, which is pivoted at 7 and is held by a return spring 8 against a shoulder 9 to assume the standard position corresponding to the reed in the normal beating position, their other end being hinged to a bock 13 and 14 respectively. Said blocks 13 and 14 are fixed respectively, by screws 15, to mutually different points on an arm of two terry height adjustment levers 16 and 17 respectively, on the other arm of which there is provided a shoulder tooth 18 and 19 respectively. These latter levers 16 and 17 are inserted into the sealed casing 20 of the device and are mounted idly on the shaft 21 which rotates the control lever 22 which is maintained by a spring 23 with its roller 24 elastically in contact with the contour of the operating cam 25 fixed on the shaft 26 driven in the direction of the arrow 27 by the loom drive shaft, and comprises on its arm 22' two guides, 28 and 29 respectively, for two slidable coupling pins 30 and 31 arranged to cooperate respectively with said shoulder teeth 18 and 19 of said levers 16 and 17. Said pins 30 and 31 tend to assume a passive or retracted position, ie beyond the influence of the respective teeth 18 and 19, each by the action of a spring 32 acting between an appendix 33 projecting from said control lever 22 and inserted in a slot 34 in said pins, and the rear wall of said slot. The coupling pins 30 and 31 also cooperate with the end, 35' and 36' respectively, of two selection levers 35 and 36 pivoted on the same axis 44, their other end, 35'' and 36'' respectively, carrying the armature, 37 and 38 respectively, of two electromagnets 39 and 40 fixed in the casing 20 of the device and energized by an electronic control unit not shown on the figures, to which they are connected by the conductors 41. Finally, the selection levers 35 and 36 comprise appendices, 42 and 43 respectively, which are maintained in contact with corresponding ledges 45 and 46 on said control lever 22 by the action of springs, 47 and 48 respectively, which act between said ends 35'' and 36'' of the selection levers 35 and 36 and a fixed support 49 in the sense of withdrawing said armatures 37 and 38 from the respective electromagnets 39 and 40. The method of operation of such a device is apparent. While the contour of the operating cam 25 presents a protuberance in front of the roller 24 of the control lever 22, this latter is obliged to rotate clockwise about the shaft 21, with corresponding rotation of the coupling pins 30 and 31. At this point two cases can arise: either the electromagnet 39 is energized and retains against itself the armature 37 of the selection lever 35, which therefore remains in the position shown in Figure 1 and therefore continues to retain the coupling pin 30 in the active or inserted position against the action of the spring 32, so that said pin cooperates with the shoulder tooth 18 of the terry height adjustment lever 16 to oblige this latter lever to rotate clockwise about said shaft 21 and cause the rocker arm 1 to rotate anticlockwise about the axis 7 against the action of its return spring 8 and hence position the loom reed in its open or retracted position to form the terry; or the electromagnet 39 is not energized so that when the control lever 22 rotates to lower its ledge 45, the selection lever 35 is now obliged by its spring 47 to rotate anticlockwise about the axis 44, so enabling the spring 32 of the coupling pin 30 to move said pin into its passive or retracted position so that, as there is no longer cooperation with said tooth 18, the lever 16 does not rotate with the result that the rocker arm 1, by the effect of the return spring 8, remains in the position of Figure 1 corresponding to the reed in its closed or normal position. It is apparent that the continuous cooperation between the ledge 45 of the control lever 22 and the appendix 42 of the selection lever 35 always moves this latter lever into the position shown in Figure 1 each time the control lever 22 is compelled to rotate anticlockwise.

Claims: A device for selecting the shift of the rocker arm (1) of the reed operating mechanism (2) in a terry loom, comprising two push rods (11, 12) for shifting said rocker arm (1) from a standard position defined by a return spring (8) to an operating position in which said reed is brought into a retracted or open position to form the terry, said push rods 11, 12 being driven respectively by a control lever (22) which by means of a spring (23) is elastically maintained in contact with the contour of an operating cam (25) driven by the loom drive shaft, and is made to cooperate with one or other of said push rods, characterised in that said two push rods (11, 12), hinged to said rocker arm (1), are also hinged at their other end to mutually different points on an arm of two terry height adjustment levers (16, 17) respectively, which are idly pivoted on the same axis (21) of rotation as said control lever (22) and each has on its other arm a shoulder tooth (18, 19) arranged to cooperate with a corresponding coupling pin (30, 31) slidable within a guide (28, 29) provided in said control lever (22), which the pin (30, 31) is retained by a spring (32) in the passive or retracted position, said pin (30, 31) also cooperates with one end of a selection lever (35, 36) the other end of which carries the armature (37, 38) of an electromagnet (39, 40) fixedly mounted in the casing (20) of the device, said selection lever (35, 36) also cooperates with a ledge (45, 46) on said control lever (22) by the action of a spring 47, 48 which tends to withdraw said armature (37, 38) from said electromagnet (39, 40).

Inventors: CORAIN LUCIANO, CORAIN, LUCIANO
Applicants: NUOVO PIGNONE SPA, NUOVOPIGNONE INDUSTRIE MECCANICHE E FONDERIA S.P.A.
Application year: 1992
Main classification: D03D39
IPC codes: D03D39, D03D49