Improved joint for connecting uprights and cross members of heald frames for weaving looms

Abstract: In improved joints for connecting uprights and cross members of heald frames for looms, in which the cross members are applied to shaped plates projecting from the uprights by means of a U-shaped frame (6), an arm (8) of said U-shaped frame is pivoted on the remaining part (7) of the frame and is allowed to oscillate only so as to move away from the other arm.

Description: The present invention concerns a joint for connecting the uprights and the cross members of heald frames for weaving looms, and its object is to guarantee easy removel, while using the loom, of the lateral uprights of said frames so as to insert the stitches, both manually and with automatic selvedge thread drafting machines. It is already known, in the technique of textile machines, to join the uprights and the cross members of heald frames, by making use of shaped plates projecting from the uprights, close to the ends thereof with which cooperate the outwardly opening U-shaped ends of the cross members, which latter are then fixed to said plates, with possibility of easy removal, by different means. It is also known - for example from EP-A-0 189 216 - to form the ends of the cross members with outwardly opening U-shaped brackets, applied to said members by riveting, and to make one of the arms of said brackets elastic and then apply a fastening screw thereon. More precisely, said brackets are formed of a die-cast square plate, to which there is applied by riveting a square spring ending with a fold designed to mate with a depression of the upright plate and to be engaged by a fastening screw. This arrangement has been improved by the Applicant's Italian Utility Model No.211907, wherein the U-shaped bracket applied to the end of the cross members of heald frames is formed in one piece with the elastic arm. In both these cases, the change of configuration of the U-shaped bracket applied to the cross member - required for its engagement with the shaped plate of the upright - is obtained by elastic deformation of one of the spring-shaped arms of said bracket. It has now been found that better results - to obtain a stouter engagement and facilitate production - can be achieved by modifying the above configuration through a change of shape of said bracket, suitably formed in two mutually connected parts. The present invention provide's this improved solution and concerns, more exactly, a joint for connecting uprights and cross members of heald frames for looms, of the type in which the cross members are applied to shaped plates projecting from the uprights members by means of a U-shaped bracket, characterized in that, a first arm of said U-shaped bracket is pivoted on the remaining part of the bracket which part forms a second arm and in that, said first arm can rotate between a first position where the free ends of the two arms are parallel and a second position where the free end of the arm is further away from the second arm than in the first position. In practice, said first arm is a square arm mounted by way of a cylindrical hinge onto a square plate forming said remaining part of the bracket, and said cylindrical hinge is formed on the external part of said square plate, more or less at the centre of the base of the U-shaped bracket. Preferably, elastic means can be provided in said U-shaped bracket to oppose the rotation of said first arm in respect of the other arm. Said elastic means suitably comprise a rubber pad interposed between the portion of the first arm close to the hinge and an extension of the square plate external to said arm. The invention is now described in further detail, by mere way of example, with reference to the accompanying drawing, in which: Fig. 1 is a view of the U-shaped bracket forming the joint according to the invention; Fig. 2 is a view of the frame of figure 1, showing also the elastic means opposing the rotation of the pivoted arm; and Fig. 3 is a view of the joint according to the invention, formed with the bracket of figure 2. With reference to figure 3 of the drawing, the upright 1 of a heald frame (not shown in full) comprises, near its upper end, a shaped plate 2 projecting towards the inside of the heald frame. Said plate - made, like the upright, of light metallic material, as aluminium or a suitable alloy - is formed at the top wit!, a bulge 3, on the upper part of which there is a round space for housing a barrel-shaped insert 4 of hard material, as steel or like. The cross member 5 of the heald frame carries in turn, riveted onto its end, a U-shaped bracket 6 meant to be connected to the plate 2, as shown in figure 3 of the drawing. According to the invention, the U-shaped bracket 6 is formed (fig. 1) in two parts - obtained by die-casting - which comprise a stout stiff square plate 7 and a square arm 8, more slender than the plate 7 but equally stiff, an end of which is pivoted by means of a cylindrical hinge joint 9 onto the external part of the square plate 7, more or less at the centre of the base of the U-shaped bracket 6. The other end of the arm 8 has a thickening 10, shaped so as to house the bulge 3 of the plate 2 - as shown in figure 3 - when the U-shaped bracket 6 engages with said plate to form the joint of the invention. The cylindrical hinge 9 is obtained by forming a seat 11 on the square plate 7 and a transversal cylindrical body 12 into the arm 8. In the bracket illustrated in figure 1, said arm 8 can freely rotate in 9 so as to move away from the opposite arm of the square plate 7, while it cannot rotate towards said arm beyond the position of parallelism shown in figures 2 and 3, as its central square portion meets with the suitably shaped end of the square plate 7. In the bracket shown in figure 2, the rotation of the arm 8 away from the other arm is instead opposed by elastic means, consisting of a rubber pad 13 interposed between the portion of said arm 8 close to the hinge 9 and an extension 14 of the square plate 7, formed externally to the hinge 9 and to the arm 8 as a prolongation of the element delimiting the seat 11. The construction in two stiff and stout pieces, formed by die-casting, guarantees a very practical and efficient structure of the bracket, the mounting of which in correspondence of the hinge 9 is very easily obtained. Also easy and convenient is the mounting of the joint, which is obtained by positioning the bracket 6 of the cross members onto the plate 2 of the uprights and causing the thickening 10 of the arm 8 to go over the bulge 3 of said plate 2. The joint is then locked by using, in a manner known per se, a fastening screw 15 which forces the thickening 10 of the arm 8 onto the plate 2. If using the bracket of figure 1, mounting and removal of the joint are obtained by mere rotation the arm 8, in the most convenient way but with the need to apply at once the screw 15 during assembly; whereas, in the case of the frame of figure 2, mounting and removal require to force the rotation of the arm 8 against the opposition of the pad 13, but with the advantage, during assembly, of a tripping connection between the two elements of the joint, the final locking of which, by means of the screw 15, can thus be more conveniently obtained later on.

Claims: Joint for connecting uprights and cross members of heald frames for looms, of the type in which the cross members (5) are applied to shaped plates (2) projecting from the uprights members (1) by means of a U-shaped bracket (6), characterized in that, a first arm (8) of said U-shaped bracket (6) is pivoted on the remaining part of the bracket, which part forms a second arm (7), and in that, said first arm (8) can rotate between a first position, where the free ends of the two arms (7,8) are parallel, and a second position, where the free end of the arm (8) is further away from the second arm (7) than in the first position. Joint as in claim 1), wherein said first arm (8) is a square arm mounted by way of a cylindrical hinge (9) onto a square plate (7) forming said remaining part of the bracket (6). Joint as in claim 2), wherein said cylindrical hinge (9) is formed on the external part of said square plate (7), more or less at the centre of the base of the U-shaped bracket (6). Joint as in claim 1), wherein said U-shaped bracket (6) comprises elastic means (13) opposing the rotation of said first arm in respect of the other arm (7). Joint as in claims 1) to 4), wherein said elastic means consist of a rubber pad (13) interposed between the portion of the first arm (8) close to the hinge (9) and an extension (14) of the square plate (7) external to said arm (8).

Inventors: FAVINI LUIGI, PEZZOLI LUIGI, FAVINI, LUIGI, PEZZOLI, LUIGI
Applicants: OMV OFF MECC VILMINORE, VILMINORE OFFICINE MECCANICHE S.P.A.
Application year: 1989
Main classification: D03C9
IPC codes: D03C9