1. Field of the Invention
The present invention relates to a connecting construction for a sidestay of heald frame and a transverse beam of a weaving machine, and more particularly to a connecting construction of the above type in which the sidestay integrally forms a projecting portion for connecting to be inserted into a concave engagement space defined in an end face of the transverse beam with the projecting portion including means for pressingly securing a peripheral wall of the concave engagement space in a longitudinal direction of the sidestay.
2. Description of the Prior Art
A conventional connecting construction of the above-described type employs the securing means having a construction as shown in FIG. 4. That is, a projecting portion 7' of the sidestay 1 has a forked shape and opposing inner faces 7C and 7D of two legs 7a, 7b of this projecting portion 7' are inclined to become gradually adjacent to each other towards the sidestay 1. Between the legs 7a and 7b, there is provided a wedge-shaped securing member 9' slidable with respect to the opposing inner faces 7C, 7D. The legs 7a and 7b are deformed at roots thereof with a movement of the securing member 9' towards the sidestay 1, and outer faces 7E, 7F of the legs 7a, 7b are secured by means of a bolt 11' to peripheral wall faces 6A, 6B opposing to each other in the longitudinal direction of the sidestay of the concave engagement space 6 defined in the transverse beam 2 (e.g. a Japanese utility model application published under SHOWA 51-13578).
However, in the case of the above-described conventional construction, for pressingly bolt-securing the legs to the peripheral wall faces with the movement of the securing member towards the sidestay, the legs per se need to be deformed. Therefore, there tends to occur irregularities in the amount of deformation of the legs due to inevitable manufacturing errors e.g. in a distance in the sidestay longitudinal direction between the two legs and in an inclination angle of the opposing inner faces. These irregularities result in errors in an attaching postion of the transverse beam in the sidestay longitudinal direction, and moreover there occur such inconveniences to be described hereinafter.
As shown in FIG. 2, in the heald frame, it has been necessary to set with a high precision a distance `D` between a pair of upper and lower heald rods 4 extending in between the right and left sidestays 1, 1 with a tolerance of 1.0 to 1.5 mm in the case of a high speed weaving machine. Since positions of the heald rods 4 in the sidestay longitudinal direction are regulated by middle hook hangers 5 for supporting intermediate portions of the heald rods 4 to a transverse beams 2, the distance `D` varies depending on the attaching positions of the transverse beams 2 in the sidestay longitudinal direction. As the result, if there are irregularities in the attaching positions of the beams 2 in the sideway longitudinal direction as is the case with the conventional construction, it is impossible to set the distance `D` with a high precision.
Furthermore, in the heald frame, with vertical movements attendant with a rotation of the weaving machine, there occurs an inertia force which tends to bend the transverse beam 2 into an arch repeatedly, as shown in FIGS. 3(a) and 3(b), providing a bending moment to a connecting portion between the sidestay and the transverse beam. This bending moment is especially large in the case of a high speed or super high speed weaving machine. Therefore, with the conventional construction, since the legs are secured with deformation, contact pressure between the outer faces of the legs and the peripheral wall faces varies from one plane to another, certain portions of the outer faces and the peripheral wall faces are more subjected to stress than the rest portions of the same each time the bending moment acts thereon, and consequently, due to the deformation of the outer faces and the peripheral wall faces, there tends to occur looseness or damage in the connecting portion between the sidestay and the transverse beam.