Abstract:
A press for stitching book block sections employs a transport system for transporting book sections to a stitching station. Carriages are mounted to an endless conveyor. A saddle is pivotally mounted to each of the carriages. The book sections are received on the saddle and transported to the stitching station in a continuous fashion. The pivotal swing of the saddles is controlled by rollers engaging cam paths as the conveyor is circulated.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to stitching presses which are employed to threadably stitch sections to form book blocks. More particularly, the present invention relates to automated machines which include a station for stitching book block sections and an automatic conveyor system for transporting the book block sections to the stitching station. 
     In stitch press systems to which the invention relates, book block sections are transported in semi-continuous fashion and selectively positioned in the operating area of a sewing or stitching head. A feeding apparatus comprises a conveyor system to accurately position the book sections and to feed the book sections to the sewing head in a rapid high-output fashion. In conventional systems, the sewing needles and hook needles of the sewing head are frequently subjected to bending stresses due to the interface with the high speed feeding apparatus. The bending stresses frequently result in premature wear of the needles and in the enlargement of the holes punched by the needles. The book block spline may thus tend to rise. The resulting book binding may be both susceptable to structural damage and aesthetically unpleasing. 
     SUMMARY OF THE INVENTION 
     Briefly stated, the invention in a preferred form is a press for stitching book block sections. The press comprises a stitching station and a conveyor system for receiving book block sections at a feed station and transporting the sections to the stitching station. The conveyor comprises an endless conveyor chain defining a conveyor path which changes general direction in the vicinity of the feeding station and the stitching station. Carriages are coupled to the conveyor at generally spaced fixed locations thereof. A saddle is pivotally connected to each of the carriages for receiving book sections and transporting the book sections. 
     The carriages are guided in radial and axial positions along portions of the conveyor path by means of rollers which traverse various associated cam paths. In addition, the pivotal swing of the saddles relative to the carriages is controlled by follower rollers which traverse associated paths. As the conveyor continuously moves along the conveyor path, the saddles swing to a first pivotal position at the feed station to acquire a book section and continue to the stitching station where the saddle momentarily dwells and assumes a second pivotal position. The saddle swings of the second pivotal position for release from the book section and subsequently returns to the feed station. 
     The saddles have a pair of receiving surfaces disposed at fixed relative acute angles. One of the receiving surfaces will be caused to have a generally vertical orientation at the stitching station and this surface swings to a non-vertical angle after the saddle leaves the stitching station. The receiving surface also pivoted in a counter-clockwise direction in the feed zone as the conveyor moves in a clockwise direction. The saddle is disposed in both radial and axial offset relationships to the carriage. A pair of follower rollers is mounted opposite the carriage to guide the pivotal swing at the stitching station. 
     An object of the invention is to provide a new and improved stitching press for interconnecting sections of a book block. 
     Another object of the invention is to provide a new and improved stitching press which enhances the accuracy of positioning a book block section at a stitching head to thereby improve the quality of the stitching. 
     A further object of the invention is to provide a new and improved stitching press having an improved transport system for producing high quality bindery stitching in a reliable, high speed and efficient process. 
     Others objects and advantages of the invention will become apparent from the drawings and the specification. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view, partly in schematic, of a book block stitching press including a transport system in accordance with the present invention; 
     FIG. 2 is a fragmentary side view of the transport system and stitching press of FIG. 1, partly in schematic form, and viewed in the direction X of FIG. 3; and 
     FIG. 3 is a schematic front elevational view, of an upper portion of the transport system of FIG. 1. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the drawings, wherein like numerals represent like parts throughout the figures, a stitching press is employed for threadably stitching book sections 1 to form book blocks. The stitching press has a transport system which receives book block sections 1 (at the left of FIG. 1) and transports the sections to the vicinity of a stitching head 9 wherein the book block sections 1 are interconnected by stitches. The stitched block sections stand upright in back-to-back relationship on delivery table 30 after the stitching operation. The stitching head 9 is generally of conventional form and function. 
     The transport system for the stitching press comprises an endless chain 6 which is continuously circulated around four sprockets 2-5 by means of a drive (not illustrated). The drive chain 6 circulates generally in the direction of the FIG. 1 arrow. The four sprockets 2-5 are relatively positioned so that lines connecting the rotational axes of the sprockets describe a four-sided polygon. The sprockets are driven by a variable speed drive. The transport path defined by the chain 6 may be described as a conveyor path which changes direction in the vicinity of the sprockets and in particular sprockets 2 and 3. One direction change at sprocket 3 occurs in the vicinity of the stitching head 9 whereby the conveyor path rises toward the stitching head and then traverses away from the stitching head in an obliquely inward orientation, i.e., the change of direction of the conveyor path is greater than 90° at the stitching station. As will be described below, the conveyor path configuration produces a comparatively long dwell phase time interval at the stitching station as a result of the longer path distance over which a direction change is produced in the vicinity of the stitching head. 
     A plurality of individual carriages 7 are connected to the chain 6 and are equidistantly spaced along the chain. A stitching saddle 8 is rotatably coupled to each carriage 7. The sewing saddles 8 are laterally offset with respect to the plane of movement of the carriages 7 as will be detailed below. 
     With reference to FIG. 3, each of the carriages 7 has pairs of vertical guide rollers 10 and 11 mounted at opposing ends of a pair of axles 13. Another pair of vertical guide rollers 12 is mounted on the axles 13 between rollers 10 and 11. The individual carriages 7 are positively guided in a first direction, i.e., in the radial direction of the sockets, by means of the guide rollers 10 which traverse a face cam 14, guide rollers 12 which traverse an interiorly intermediately located cam path 15, and guide rollers 10 which traverse a side-located cam path 16. 
     The carriages 7 also each have an additional pair of guide rollers 17 on one side of the carriage and an opposing pair of guide rollers 18 on the other side of the carriage. The rotational axes of rollers 17 and 18 are orthogonal to the rotational axes of rollers 10-12. The guide rollers 18 traverse a side track 19. The guide rollers 17 traverse a side track 20 which is adjacent and generally perpendicular to the cam path 16. The guide rollers 17 and 18 essentially function to provide a guidance for the carriage 7 in the axial direction of the sprockets. 
     During the circulatory movement of the sprocket chain 6 via articulated-action traction links 21, the carriages 7 and their associated saddles 8 are positively guided in both the axial direction and the radial direction. The upper edge 8b of each stitching saddle is offset in relation to the sprocket chain 6 by a distance which corresponds to the radius of the sprockets 2 and 3, as shown in FIG. 1. Accordingly, the saddles 8 encounter a dwell phase at the feed zone in the region of sprocket 2 and at the stitching station in the operating region of the stitching head 9 while the sprocket chain continues to operate. The stitching head 9 functions to interlink the series of book block sections 1 at the stitching station which also constitutes a region of a change of direction of the conveyor path. Also, in the feed zone, the book block sections 1 are sequentially pushed onto the individual sewing saddles 8 from a feed saddle 22 at a second region wherein the conveyor sprocket chain changes direction in the vicinity of the sprocket 2. Thus, the saddle experiences a dwell time interval at both the feed zone position and the stitching station position of the transport system. 
     With additional reference to FIG. 3, each saddle 8 is rotatably suspended from a carriage 7 by means of a pivot-bearing pin 23. The pivot pin 23 is supported in an extension arm 7a of the carriage. The free end of the pivot-bearing pin 23 axially projects from the extension arm 7a and carries a diametrally disposed control lever 24. The control lever 24 is mounted in rotatably fixed relationship to the pivot pin 23. Two follower rollers 25 and 26 are mounted on the control lever 24 at opposed ends thereof. The rollers 24 and 25 are mounted for axis or rotation about axes which are oriented to the parallel pivot pin 23. Roller 26 travels on a face cam 27. Follower roller 25 comes into functional engagement with cam path segments 28 (FIG. 1) and 29 (FIGS. 1 and 2) respectively associated with sprockets 2 and 3. During the circulatory movement of the sprocket chain 6, the follower roller 25 successively engages the cam path segments 28 and 29 to essentially overcome a dead center position of the stitching saddle 8 as the direction of motion of the saddle changes. 
     The pivotal position of the saddle 8 is controlled by the follower roller 26 which is associated with the control lever 24. Follower roller 26 traverses the face cam 27 so that the saddle 8 describes a swinging movement counter to the clockwise running direction of the transport conveyor. At the stitching station, the leading supporting surface 8a of the sewing saddle is initially swung into a perpendicular position for performing the stitching operation while continuing to bear against the preceding book block section 1 which has just been stitched and is standing vertically on the delivery table 30. The sewing saddle is then swung backwards i.e., in a counter-clockwise direction, and guided out of the stitching station in a downward direction. The latter motion path causes the book section to release from the saddle 8. The empty saddle then returns to the feed zone. 
     The saddle 8 also describes a controlled swinging movement in the feed zone of the transport. An inward movement of the saddle 8 is produced by a curved section 27a of cam 27 (FIG. 1) which forces the supporting surface 8a to an inclined position with the sewing saddle 8 simultaneously swinging into the book block section from below. This swinging movement guarantees that the book block section is reliably transferred from the feed saddle 22 to the saddle 8 regardless of the format size of the book block. In addition, the high cycle rate of the transport system is maintained. 
     With reference to FIGS. 2 and 3, the stitching saddles 8 are guided in the vicinity of the stitching head 9 in order to perform the stitching operation, and in the vicinity of the feed saddle 22 in order to acquire the book block sections for transport to the stitching head. High quality stitching and functional reliability of the transport system is achieved by the guidance system for the transport system. Two spaced follower rollers 31 and 32 are mounted on the free end of the saddle 8 (FIG. 3). The follower rollers 31 and 32 traverse respective control paths 33 and 34 (FIG. 2) in the feed zone and traverses respective control paths 35 and 36 (FIG. 2) in the operating area of the stitching head 9. The courses described by the paths 33, 34, 35 and 36 correspond to the paths followed on the drive side. Each of the control paths 33-36 is enlarged to provide a widened entry section in order to ensure that the control rollers 31 and 32 enter the control paths in a reliable fashion. 
     A second control roller 37 is provided on the bearing axle of the lower control roller 32 in order to obtain the desirable dwell phase in the operating area of the stitching head 9 or at the stitching station. The second roller 37 is guided onto a control path 38 and, together with control roller 31, is maintained in position for a short period of time at the change of direction of the control path 36. 
     It will be appreciated that the movements of the saddles are positively guided and controlled in an efficient manner which ensures both a high degree of operational reliability and a high output feed/transport for the stitch press. Consequently, the book blocks may be formed in a rapid process which also ensures a high degree of binding quality for the book sections. 
     While a preferred embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.