STITCHING HEAD

Abstract: A stitching head (10) includes a crank (12) rotatable about a longitudinal axis through an oscillatory displacement in each of the opposite drive and return directions of a cycle. The crank has a plurality of crank pins (66, 68, 70) displaced radially from the longitudinal axis of the crank. A pivotally mounted staple supporter (14) receives and supports an elongated piece of wire. A reciprocably mounted staple former (16) cooperates with the staple supporter to form the piece of wire into a staple. A reciprocably mounted staple driver (18) cooperates with the staple supporter and former to drive the staple into a product. A plurality of links (60, 62, 64) couple the crank pins with the staple supporter, former and driver. The links cause independent but coordinated movement of the supporter, former and driver to form and drive the staple into the product. The crank pins are disposed at a plurality of separate locations on the crank radially displaced at different distances from the longitudinal axis of the crank.

Description: Background of the Invention Field of the Invention The present invention relates to stitching, or stapling, collated signatures. Particularly, the present invention relates to a stitching head used for stapling collated signatures together. Description of the Prior Art Machines which form staples from wire and drive the staples into collated signatures are known. These known machines are typically used for binding books, pamphlets, magazines and the like. Two signature collating machines which include a stitching head are disclosed in U.S. Patents Nos. 4,196,835 and 4,236,706. The stitching heads are disposed above the path of a saddle conveyor which moves collated signatures. Each stitching head moves along a portion of the path in synchronization with the collated signatures. A clincher is disposed below the moving collated signatures. The stitching heads bend a short piece of wire to form a staple and drive the staple through the collated signatures as the signatures move. The clincher folds the ends of the staple to finish the stitching operation. The stitching head of U.S. Patent No. 4,196,835 includes a drive shaft which carries cams. Upon rotation of the drive shaft, the cams operate the stitching mechanism and clincher through linkage assemblies. The signature collating machines of the aforementioned patents perform satisfactorily and accomplish high speed binding. However, as with any system, there is a continuing need to make certain improvements. Summary of the invention The present invention is an improved stitching head. The stitching head comprises a crank rotatable about an axis (A) through a predetermined oscillatory displacement. A staple supporter is provided for receiving and supporting an elongated piece of wire. Further, there are provided a staple former cooperable with the staple supporter for forming the piece of wire into a staple and a staple driver cooperable with the staple supporter and the staple former for guiding and driving the staple into a product. According to the invention, a first link couples the crank with the staple supporter, a second link couples the crank with the staple former, a third link couples the crank with the staple driver, each of said staple supporter, said staple former and said staple driver being directly driven by the crank relative to each other in response to crank rotation to form the piece of wire into the staple and drive the staple into the product. The document EP-0 013 165 A1, however, discloses a stiching head having a crank, a staple supporter, a staple former and a staple driver. The staple supporter is rotatable about an axis and biased into a supporting position by a spring. The supporter is pushed by the driver out of the path of travel of the staple after the staple is formed. The staple supporter is not coupled to the crank by a link to directly drive the supporter relative to the former and the driver. The staple supporter is driven by the staple driver. Furthermore, the former and the driver are both coupled to the crank by a single link. The former and the driver are not coupled to the crank by separate links. One link couples both former and the driver to the crank. In a preferred embodiment of the invention, the first link pulls the staple supporter out of the path of movement of the staple driver as the staple driver moves toward the staple supporter. The three links pivotally couple a plurality of separate locations on the crank which are radially displaced from the rotational axis (A) thereof with respective locations of the staple supporter, former and driver for causing the staple supporter, former and driver to move relative to each other to form the piece of wire into the staple and drive the staple into the product. Brief Description of the Drawings Further features of the present invention will become apparent to those skilled in the art to which the present invention relates from a reading of the following specification made with reference to the accompanying drawings, in which: Fig. 1 is a side elevational view of the stitching head embodying the present invention; Fig. 2 is a rear elevational view of the stitching head, as seen along line 2-2 of Fig. 1; Fig. 3 is a front elevational view of the stitching head as seen along line 3-3 of Fig. 1; Fig. 4 is a cross-sectional view of the stitching head taken approximately along the line 4-4 of Fig. 1; Figs. 5-9 are side elevational views of the stitching head having selected parts in different relative positions; and Figs. 10 and 11 are elevational views illustrating a wire piece before and after being formed into a staple. Detailed Description of the Invention Referring to Figs. 1 to 4, a single input, multiple output stitching head 10 embodying the present invention is illustrated. The stitching head 10 can be incorporated as part of a stitching assembly in a signature collating apparatus similar to the ones of the aforementioned U.S. Patents Nos. 4,196,835 and 4,236,706 to Schlough, which are incorporated herein by reference. The stitching head 10 includes a crank 12, a staple supporter 14, a staple former 16 and a staple driver 18. A frame 20 includes frame sides 24 spaced apart by blocks 22. A shaft 26 is supported for rotation about axis A by the frame sides 24 in bearings 28. The crank 12 is fixed to the shaft 26. The shaft 26 and the crank 12 are rotatably moved by a suitable drive source (not shown) connected to the shaft. The crank 12 moves through an oscillatory displacement, such as sixty degrees, in opposite drive and return directions of a complete cycle. The crank 12 includes surfaces 12a and 12b which engage a stop 29, supported by the frame 20, to prevent crank oscillation beyond a desired amount. The staple supporter 14 of the stitching head 10 is pivotally mounted between the spaced frame sides 24 by a pin 30. The supporter 14 has a cradle portion 32 shaped as an upwardly open shallow vee defined on an end portion 34. The cradle portion 32 is adapted for receiving and supporting an elongated piece of wire W (Fig. 10). The width of the cradle portion 32 is less than the length of the piece of wire W. The cradle portion 32 supports the wire W along a middle portion M (Figs. 10 and 11). Opposite end portions E extending beyond the opposite sides of the cradle portion 32. The staple supporter 14 pivots relative to the frame 20 between a supporting position (Figs. 1 and 5-7) and a retracted, nonsupporting position (Fig. 9). The staple former 16 (Fig. 1) of the stitching head 10 includes a pair of spaced apart elongated forming members 36 (Fig. 4). The forming members 36 are reciprocably mounted along the interior of one of the frame sides 24 and spaced apart to receive the outer end 34 of the staple supporter 14 therebetween. The forming members 36 are reciprocably movable relative to the frame 20 and relative to the staple supporter 14 between raised and lowered positions along and past the opposite sides of the end portion 34 of the staple supporter. The staple former 16, in cooperation with the staple supporter 14, forms the piece of wire W into a staple S (Fig. 11). The forming members 36 have lower ends 38 with inverted downwardly open shallow vee configurations aligned above and laterally outward of the vee shaped cradle portion 32 of the staple supporter 14. The forming members 36 have respective opposing longitudinally extending grooves 40 (Figs. 4 to 8) at their interior opposite facing sides. The grooves 40 are vertically alinged with the apices of the vee configurations of the lower ends 38 of the forming members 36 and the cradle portion 32 of the staple supporter 14. As the forming members 36 move from the raised toward the lowered position, the lower ends 38 engage opposite end portions E of the piece of wire W to bend the end portions E of the wire approximately ninety degrees relative to the middle portion M. The staple S is formed with the middle portion M disposed in the cradle portion 32 of the staple supporter 14. The bent end portions E are disposed between the staple supporter 14 and the forming members 36 within the longitudinal grooves 40. The stitching head 10 further includes a knife blade 42 (Fig. 3) mounted along the exterior of one of the frame sides 24. The blade 42 is coupled to one of the forming members 36 for reciprocable movement in a vertical direction to sever the piece of wire W from a continuous supply of wire (not shown). The blade 42 moves to sever the wire W prior to the start of forming the wire W into a staple S. The blade 42 is moved past a hardened hollow sleeve 44 through which the wire W is fed from the continuous supply. The sleeve 44 is adjustably connected by fastener 46 to one of the frame sides 24 adjacent the mounting base 22 of the frame 20 to align with the cradle portion 32. The sleeve 44 is adjustable to set the length of wire W being fed and to determine the position of the severed piece of wire W in the head 10. The staple driver 18 (Fig. 4) of the stitching head 10 is reciprocably mounted between the forming members 36 for vertical movement. The staple driver 18 includes a main body 48 having a tapered lower end 50 defining a transverse vertical slot 51 and a flat plate 52 mounted in the slot in alignment above the piece of wire W. Opposite lateral edges 54 of the plate 52 extend laterally outward of the sides of the main body 48 and slidably fit within the grooves 40 in the forming members 36. A bottom edge 56 of the plate 52 is displaced a small distance above the lower end 50 of the main body 48 so as to define a linearly-extending recess 58 for receiving the middle portion M of the staple S. The staple driver 18 is reciprocably movable between the spaced forming members 36 of the staple former 16. When the staple driver 18 moves downwardly, the bottom edge 56 of the plate 52 engages the middle portion M of the staple S disposed in the cradle portion 32. The bent end portions E of the staple S remain within the grooves 40 of the forming members 36. The staple driver 18 drives the staple toward and into a series of collated signatures C disposed directly below the head 10 (Figs. 5 to 9). Thus, the staple driver 18 cooperates with the staple supporter 14 and staple former 16 in guiding and driving the staple into a product. The stitching head 10 includes a plurality of links 60, 62 and 64 for transmitting the motion of the crank 12 to the respective staple supporter 14, former 16 and driver 18. The crank 12 has a plurality of crank pins 66, 68 and 70 journalled at separate locations radially displaced at different distances from the rotational axis A. A first link 60 pivotally interconnects a first crank pin 66 on the crank 12 and a pivot pin 72 on an opposite end of the staple supporter 14. A pair of links 62 pivotally interconnect respective axially aligned second crank pin 68 on the drive crank 12 and pivot pins 74 journalled on the forming members 36. A third link 64 pivotally interconnects a third crank pin 70 on the drive crank 12 and a pivot pin 76 on the upper end of the main body 48 of the staple driver 18. The links 60, 62, 64 couple the crank pins 66, 68, 70 with the staple supporter 14, former 16 and driver 18 for independent but coordinated movement to form, guide and drive the staple S into the product. The links 60, 62, 64 define a four-bar linkages separately coupling the staple supporter 14, former 16 and driver 18 with the input drive crank 12. Another link 78 connects the knife blade 42 to one of the second links 62 so that the blade 42 moves with the one forming member 36 to sever the wire W. The lower severing edge 80 of the blade 42 engages the wire W before the lower end 38 of the respective forming member 36 engage the wire. Referring now to Figs. 5 through 9, the stitching head 10 is shown at successive fifteen degree increments of the sixty degree drive half of an oscillatory cycle of the crank 12. The staple supporter 14, former 16 and driver 18 move concurrently as the crank 12 rotates. The staple supporter 14 and former 16 complete respective movements first. This is due to the relative lengths of the respective radii and phasing of the crank pins 66, 68, 70 relativec to the rotational axis A of the drive crank 12. The radius R(1) between the rotational axis A of the drive crank 12 and the first crank pin 66 journalled to the first link 60 is shortest. The radius R(3) between the axis A and the third crank pin 70 journalled to the third link 64 is longest. The radius R(2) is between radii R(1) and R(3) in length. Thus, in sixty degrees of rotation of the crank 12, the length of the arc traversed by the first crank pin 66 is shortest. The third crank pin 70 traverses the longest arc. The second crank pins 68 traverse an arc between those of the first and third crank pins 66, 70, respectively. In Fig. 5, beginning at the zero degree position of the crank 12 along the drive cycle, the staple supporter 14 is in a supporting position. The cradle portion 32 of the staple supporter 14 supports the wire W. The staple former 16 is at the raised position. The staple driver 18 is in the raised position above the wire W and the cradle portion 32 of the staple supporter 14. A series of collated signatures C are disposed below the stitching head 10. The collated signatures move along a path with the stitching head 10 in a direction parallel to the wire W. In Fig. 6, at fifteen degrees of rotation of the crank 12, links 62 force the two forming members 36 of the staple former 16 to descend along the opposite sides of the outer end 34 of the staple supporter 14. The blade 42 severs the wire W from the supply. The first link 60 passes through a dead-center condition, where the link 60 is parallel to the raduis R(1), to force the staple supporter 14 to pivot about pin 30 a small amount. The forming members 36 bend the end portions E of the wire W ninety degrees downwardly relative to the middle portion M supported on the cradle portion 32. The link 64 starts to move the staple driver 18 downwardly toward the cradle portion 32 of the staple supporter 14. Fig. 7 illustrates the crank 12 at thirty degrees of rotation. The two forming members 36 are still forced downwardly by links 62. The staple supporter 14 pivots clockwise as the link 60 passes dead-center and begins upward movement. The middle portion M of the staple S remains stationary as the inclined surface 82 of the cradle portion 32 slides past the staple on a constant arc about the pivot pin 30. The bent opposite end portions E remain within the grooves 40 between the forming members 36. Link 64 forces the staple driver 18 to continue to descend toward the staple S. In Fig. 8, at the forty-five degrees of rotation of the crank 12, the links 62 pass through the dead-center condition and the two forming members 36 remain substantially stationary in an overlying relation to the collated signatures C. The forming members 36 compress the fold of the signatures C to facilitate penetration by the tips of the staple S. The middle portion M of the staple S is supported on the right inclined end surface 84 of the staple surpporter 14. The link 60 forces the staple supporter 14 to move toward the retracted position at an accelerating rate. Link 64 forces the staple driver 18 to drive the tips of the bent end portions E of the staple S through the signatures C. The remainder of the bent end portions E of the staple S are still guided within the grooves 40 and against the sides of the end surface 84 to prevent buckling as the signatures C are penetrated by the tips. In Fig. 9, at sixty degrees of rotation of the crank 12, the link 60 pulls the staple supporter 14 to fully retract out of the path of the driver 18. Link 64 forces the staple driver 18 to completely drive the end portions E of the staple S through the signatures C. The drive source then reverses the crank 12 through a sixty-degree return displacement to complete one oscillatory cycle. The components of the stitching head 10 are returned to the initial positions as illustrated in Fig. 5. A dwell in the movement occurs at the zero degree position of Fig. 5 to allow time for the wire W to be fed into the cradle portion 32 of the staple supporter 14 for the next stitching cycle. In summary, the links 60, 62, 64 coordinate the respective movements of the staple supporter 14, former 16 and driver 18 to form a staple S and pull the staple supporter 14 out of the path of movement of the staple driver 18. As the staple supporter 14 is pulled out of the path of movement of the staple driver 18, it continues to cooperate with the staple former 16 to guide the staple S. From the above description of a preferred embodiment of my invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be included herein and covered by the appended claims.

Claims: A stitching head (10) comprising: a crank (12) rotatable about an axis (A) through a predetermined oscillatory displacement; a staple supporter (14) for receiving and supporting an elongated piece of wire (W); a staple former (16) cooperable with said staple supporter (14) for forming the piece of wire (W) into a staple (S); and a staple driver (18) cooperable with said staple supporter (14) and said staple former (16) for guiding and driving the staple (S) into a product (C); characterized in that a first link (60) couples said crank (12) with said staple supporter (14), a second link (62) couples said crank (12) with said staple former (16), a third link (64) couples said crank (12) with said staple driver (18), each of said staple supporter (14), said staple former (16) and said staple driver (18) being directly driven by said crank (12) relative to each other in response to crank (12) rotation to form the piece of wire (W) into the staple (S) and drive the staple (S) into the product (C). The stitching head (10) as recited in claim 1, wherein said first link (60) pulls said staple supporter (14) out of the path of movement of said staple driver (18) as the staple driver (18) moves toward said staple supporter (14). The stitching head (10) as recited in claim 1, wherein said links (60, 62, 64) pivotally couple a plurality of separate locations (66, 68, 70) on said crank (12) being radially displaced from said rotational axis (A) thereof with respective locations (72, 74, 76) of said staple supporter (14), former (16) and driver (18) for causing said staple supporter (14), former (16) and driver (18) to move relative to each other to form the piece of wire (W) into the staple (S) and drive the staple (S) into the product (C). The stitching head (10) as recited in claim 3, wherein said plurality of links (60, 62, 64) define a four-bar linkage separately coupling said staple supporter (14), former (16) and driver (18) with said crank (12). The stitching head (10) as recited in claim 1, wherein said crank (12) is rotatable in a drive half of one cycle through an oscillatory displacement of 60°. The stitching head (10) as recited in claim 3, wherein said plurality of separate locations (66, 68, 70) on said crank (12) are radially displaced from said rotational axis (A) thereof at different distances. The stitching head (10) as recited in claim 3, wherein said staple former (16) includes a pair of spaced forming members (36) and a pair of said links (62) pivotally couples one of said locations (68) on said crank (12) with said respective forming members (36).

Inventors: SCHLOUGH, JAMES R.
Applicants: AM INTERNATIONAL INCORPORATED
Application year: 1987
Main classification: B42B4
IPC codes: B27F7