STITCHING HEAD MONOBLOCK DRIVE UNIT

The invention refers to a stitching head monoblock drive unit, driven by a splined shaft, and resulting in transmitting motion to two arms, so that the latter eventually ensure the perpen dicular movement of two end pieces (conrods), where one of them cuts and - at the same time - forms the stitching wire into a set shape, while the other provides the final stapling, the result being stitching two work pieces together; the latter are often made from wood or compressed paperboard and are assembled into frames or packaging crates of various types. The invention is used and applied in automatic or semi- automatic stitching machines, where rapid head movement is necessary, at the same time ensuring stable operation, reliability and easy maintenance. The drive ratio between the two arms is a key measure, so as to ensure a high stitching machine operating speed.

Until recently, stitching wood or similar pieces using such machines was performed using mechanisms with similar movement characteristics, yet performing at lower motion speed; most importantly, they employed significantly more complex and noisy devices, such com plexity resulting in more cumbersome maintenance.

The issues resulting from using such mechanisms related mainly to the maintenance requirements as well as the size of the mechanism, and, to a lesser degree, their production outcome. The present invention serves to achieve higher speeds and at the same time, it elim inates maintenance and cleaning issues and minimizes size; this way, groups can converge more closely and stitching of smaller packages is possible.

Application of the present invention drastically increases movement speed and operation and product output rates; in addition, it simplifies maintenance by reducing downtime.

An advantage of this invention is that its construction is relatively simple, compared to the current state-of-the-art of such designs. Another advantage is the high operating speed of its stitching head. Simple maintenance and reduced operating noise.

The invention is illustrated in the following figures. Figure 1/4 depicts the mechanism in 3-D perspective section view and side view without end-pieces (pistons); figure 2/4 is a side view of the mechanism with integrated stitching head; figure 3/4 depicts the individual constituent parts of the stitching head, and figure 4/4 is a kinematic depiction of the parts comprising the mechanism, in an order where the mechanism is operating as a whole, for installation on the respective machine.

In particular, axle (1) uses the splined hub to drive part (2) through its eccentrically circular hole. Part (2) rotates, thus transmitting motion to part (3) located around it; the latter, in turn propels and sends part (4), located above, in elliptical orbit. In addition to being pushed by part (3), the movement of part (4) is determined by the presence of pins (5) & (6). Part (4) is indirectly coupled to the arms (7) & (8). These in turn are coupled to stitching head end- pieces, (18) & (17) respectively, resulting in their perpendicular movement. The movement of the arm (7) is transmitted through pins (16) & (5) and through part (11), while pins (6) & (14) and parts (12) & (13) drive arm (8).

The manufacturer refers to part (13) as the “balancer” due to its symmetric shape and its reciprocal motion. This “balancer” is coupled to arm (8) through a pin (14). Part (25) serves to feed wire which is cut and formed in the appropriate shape with the aid of parts (23), (24) & (29). Parts (23) & (24) are screwed on the piston (20). The latter is driven by the end-piece (17) through parts (21) & (22). Part (29), thanks to part (31) is forced downwards, due to the force exerted on its edge; it tends to rotate this edge around the pin (30). In this way, part (29) retains the wire and allows it to be shaped. The above mentioned "balancer" features a double linkage which allows it an idle time and results in delayed movement of arm (8), forcing work pieces to a momentary standstill; at the same time, part (28), driven through the piston (27), the end-piece (18) and the arm (7), staples the shaped wire. In order to make the stitch, the motion of part (28) propels part (29) upwards; thus the wire is released and can be stitched.

Further parts, in addition to those described above, are the pin (26) coupling part (27) to the end-piece (18), the stitching head base (9) and cap (10), the pin (16) for the linkage of the arm (7) and the part (32) to enhance the mechanical strength of part (31). All the above are attached on a pair of plates (19) constituting the base frame of the whole mechanism.