Conveying chain pair for gripper carriages on sheet-fed machines, particularly offset printing presses
United States Patent 1191 Preuss Apr. 22, 1975 CONVEYING CHAIN PAIR FOR GRlPPER 2.150.610 3/1939 Raffetto l98/l8l CARRIAGES ON SHEET FED MACHINES, 3.094.206 6/1963 Stewart et al.. 198/181 X PARTICULARLY OFFSET PRINTING 3.389.662 6/1968 Jacoby 198/129 X PRESSES Primary Evuminer-Evon C. Blunk [75] In entor: ed c Preuss, prendlingen. Assistant Examiner-Douglas D. Watts Germany Arlornqn Agent, or Firm-Wolfe, Hubbard. Leydig, [73] Assignee: Roland Offsetmaschinenfabrik Volt &amp; am&#34;  
  Faber &amp; Schleicher AG [22] Filed: Sept. 17, 1973 [57] ABSTRACT A conveyor chain in the form of a roller chain guided [21] PP N03 3971790 between spaced longitudinal guide members presenting flat land surfaces lying in a vertical plane at the [30] Foreign Application priority Data fdge the chain. Certain ones of the pins 031L116 rol- 2 I 224 er c am, 1n a repet1t1ve pattern, are exten e outscpt Gummy 6061 wardly of the land surfaces. Mounted upon the pins [52] U S Cl 74/250 0 74/251 198/1419 are a series of flatly overlapping cover plates which [51] III t Cl IIIIIIIIIIII Fl6g 13/02 ride against the land surfaces and seal the guideway [58] Fie&#39;ld R 250 R against entry of contaminants or escape of lubricant. 74/250 C &#39;i&#34;&#39; 77R ln the preferred embodiment the cover plates are of oval construction with the rounded end portions thereof having cooperating circular recesses to permit flat seating as well as relative articulation of the cover [56] g g zg g gii plates when the chain is directed along a curved path. 1.665.100 4/l928 Klauckc 74 245 R 7 Claims 3 Drawing Figures r I 3 ll [[J 3 I. O .i  
  I 2 I I5 PATENTEDAPRZZISTS sumzqgg m F u I. a u  
  CONVEYING CHAIN PAIR FOR GRIPPER CARRIAGES ON SHEET-FED MACHINES; PARTICULARLY OFFSET PRINTING PRESSES In a conveyor chain construction for a sheet fed printing press. conveyor chains are provided as a laterally spaced pair with gripper mechanisms carried bridgingly between them. The chains are guided in trackways which must be lubricated. Because the abrasive dust. paper particles and the powder used to prevent offsetting the printed impressions from one sheet to another. the surfaces quickly become coated with a gummy accumulation which is difficult to remove and which tends to destroy the effect of the lubricant and thus shorten the life of the chains and trackways. More over. the lubricant from the chains often is thrown upon the sheets being transported requiring that the soiled sheets be discarded.  
  It is. accordingly. an object of the present invention to provide a conveyor chain construction which has novel sealing means for operation in a contaminated environment such as that to be found about conveying and delivery mechanism of a printing press. It is a general object to provide a conveyor chain construction in which the chain and its guideways are sealed against entry of foreign matter and sealed against escape of lubricant so that the moving parts are protected against the effect of abrasive materials and the lubricant is kept clean and fully effective. It is a related object to provide a conveyor chain construction which is both simple and effective but which reduces maintenance to a minimum. avoiding necessity for frequent cleaning or lubrication and permitting operation at high speed and efficiency over a long period of time. It is. moreover. an object of the invention. when the device is used in a printing press, to prevent the sheets which are being transported from being spotted and soiled by escaping lubricant.  
  It is a further object of the present invention to provide a conveyor chain of the roller type which is guided in a track or guideway and in which the guideway is en closed by cover plates which are secured to the side of the chain in overlapping. flatly interfitted relation. with each plate in the series being circularly recessed for permitting articulated movement of adjacent plates as the chain is guided in a curved path.  
  It is finally an object of the present invention to provide a sealing arrangement for a conveyor chain which is simple and inexpensive. which may be added at minimum cost to existing designs of conveyors and which may be employed as a conversion feature in conveyors already in the field.  
  Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings in which:  
  FIG. I is a plan view of a section of conveyor chain looking along line 1-1 in FIG. 2, with portions in partial section.  
  FIG. 2 is an elevational view looking along line 22 in FIG. 1.  
  FIG. 3 is a vertical section taken along line 3-3 of FIG. 1.  
  While the invention has been described in connection with a preferred embodiment. it will be understood that I do not intend to be limited to the particular embodiment shown but intend, on the contrary, to cover thevarious alternative and equivalent constructions included within the spirit and scope of the appended claims.  
  Turning now to the drawings there is shown a length of conveyor chain of the type usually referred to as roller chain made up of parallel rows of flat links 11, 12 in overlapping relation. pinned together by pins 13, certain of the pins, 14. being extended laterally away from the chain for a purpose which will shortly appear. lnterposed between the rows of links are rollers or spacers 15. The rollers may have an internally telescoped hardened liner as indicated in cross section at 16.  
  It will be understood that two such conveyor chains 10 are mounted horizontally in parallel relation for the purpose of supporting spaced gripper carriages as indicated at 18 (FIGS. 1 and 3). It will be understood. however. that the gripper carriages do not per se form a part of the present invention so that there is no need to describe the gripper carriage construction. and reference. for this purpose. may be had to the prior art and published literature.  
  For the purpose of guiding the chain I0 along a path of movement. a guide assembly 20 is provided which. as shown in FIG. 3, is preferably in the form of a channel 21 of inverted U-shaped construction secured along one of its walls. by means not shown. to supporting frame structure 22. The member 21 has a downwardly presented edge 23. Supported in opposed. edgewise position is a cooperating guide member 24 having an upwardly facing edge 25. The edges are spaced parallel to one another to form a track or guideway, and are of such width as to mate with. and support. the rollers 15 of the conveyor chain. It will be understood that while the track defined by the edges 23, 25 may have a long. straight run portion. the chain 10 is endless and the track is accordingly curved or looped at its ends (not shown).  
  In accordance with the present invention. land surfaces are provided straddling the chain and lying in a vertical plane which extends along the lateral edge of the chain. Carried on the pins of the chain. and along one side of the chain. are overlapping coverplates which ride flatly against the land surfaces and which are cooperatingly recessed in the region of overlap to provide a continuous sealing surface and to permit relative movement. or articulation. as the chain departs from a straight line path. Referring to the drawings. a typical cover plate is shown at 30, formed of a flat layer of metal or plastic. of oval contour. and having pin openings 31, 32 centered within its rounded ends 33. 34. In order to nest together the overlapping portions of adjacent cover plates. the cover plate has a shallow recess 35 of circular profile at one end and a similar shallow circular recess 36 at the opposite end, the two recesses being oppositely faced. The plate presents a flat inwardly facing surface 37.  
  Turning attention to the adjacent cover plate 40, which may be of the same or different length. it will be seen that this plate has spaced openings 41, 42 for mounting purposes with rounded ends 43, 44 formed with shallow circular recesses 45, 46 and having a flat inwardly facing surface 47.  
  For the purpose of sealingly engaging the inwardly facing surfaces 37, 47 on the plates. flat land surfaces 51, 52 are provided extending along the edge of the chain in straddling relation. Such surfaces are formed on members 53. 54 which may be secured by welding or the like to the respective guide members 21. 24. The land surfaces 51. 52 are alined with one another in the same plane. a plane which is slightly offset from the chain body as shown in FIG. 3. Because the recessing of the adjacent cover plates. the cover plates cooperate to provide a continuous sealing engagement with the land surfaces. Means are preferably provided for causing the cover plates to bear resiliently against the land surfaces; for example. a coil spring 55 may be used (FIG. 1) seating against a bushing 56 which is tele scoped into the alined plate openings.  
  Since the conveyor chain is endless. turn-arounds must be provided. and for this purpose the track surfaces 23. 25 which bear against the chain rollers may be mutually curved so that the chain links and cover plates undergo articulating movement. Because of the fact that the ends of the cover plates and the cooperating recesses in which such ends are fitted are ofcircular profile. a substantially continuous seal is provided. yet the adjacent plates are free to swing with respect to one another. At least one of the openings 31., 32 or 41. 42 in each of the cover plates is made oversized so as to accommodate the relative shifting of the plate mounting centers which occurs as the chain&#39;is drawn around a curve.  
  As a result of the continuous -face engagement between the cover plates and the land surfaces which they engage. the guideways surrounding the chain. along its right-hand side as viewed in FIGS. 1 and 3, is sealed against entry offoreign matter and against loss oflubricant normally provided at the track surfaces. ln the case of a conveyor chain for transporting of gripper carriages in a sheet fed printing press installation. the air is constantly contaminated with paper. dust and abrasive particles as well as the anti-offset powder which is applied to the freshly printed surfaces of the sheet such substances forming a gummy accumulation which is difficult to remove and which so affects lubrication that the chains and guideway wear prematurely. It will be apparent that with use of present design seal. contaminants are kept out and lubricant is kept in. with no possibility of soiling the transported sheets.  
  The discussion has been directed to the seal which exists at the inner or right-hand edge of the chain 10. lt will be understood that the left-hand edge of the chain may be protected by the simple expedient of bridging the opening at the lower edge of the inverted channel. While the invention has been found to be particularly well suited to use in conveyors for sheet fed presses. it will be understood that the invention is not limited thereto and may be employed wherever it is desired to shield and protect a conveyor chain of the roller type.  
 What I claim is:  
  1. In a conveyor chain construction for use in a contaminated environment. the combination comprising a roller chain having parallel rows of flat links and having 5 pins for pinning the links in overlapping relation with rollers interposed between them. the rollers being of lesser dimension so as to define a longitudinally extending groove on each side of the chain. parallel guide members enclosing the chain and extending longitudinally of the chain on both sides thereof, the guide members presenting edges registering with the grooves and engaging the rollers to provide a lubricated guideway for the chain, the guide members having flat closely spaced land surfaces straddling the chain and lying in a plane close to the chain which extends perpendicularly to the roller axes along one side of the chain. certain of the pins in a regularly recurring pattern being extended axially beyond the land surfaces. and a series of covering plates secured to the extended pins. each covering plate having a pair of holes engaged by an adjacent pair of pins. the covering plates being in longitudinally overlapping relation and sufficiently wide as to bear upon both of the land surfaces so as to seal the chain and lubricated guideway against entry of foreign matter and against escape of the lubricant.  
  2. The combination as claimed in claim 1 in which the mutually overlapping portions of the covering plates are cooperatingly recessed so that the covering plates provide substantially continuous and uninterrupted contact with the land surfaces.  
  3. The combination as claimed in claim 2 in which the recessed portions are of mating circular profile to permit articulation of the covering plates as the chain departs from a straight path.  
  4. The combination as claimed in claim 1 in which the covering plates are of oval profile and sufficiently long so as to span a multiple of the pin-to-pin distance on the chain.  
 gripper structure is secured to the extended pins in a 5. The combination as claimed in claim 1 in which