US2893730A - Clutch for printing machine - Google Patents

Description

July 7, 1959 L. YMIASKOFF CLUTCH FOR PRINTING MACHINE Filed Oct. 29, 1957 0 54 "Z? 27 N IIMII w I l I l6 INVENTOR.

i 90.4 1 (EM ATTORNE Y United States Patent 6 CLUTCH FOR PRINTING MACHINE 'Leonard Miaskoif, Brooklyn, 'N.Y., assignor to Davidson Corporation, a corporation .of New York Application October 29, 1957, Serial No. 693,206

1 Claim. (Cl. 271-26) This invention relates to short run duplicators and more particularly to cam shaft clutch means which permit termination of suction feeder movement, in any desired position of the suction feeder, in accordance with a predetermined clutch setting.

In short .run duplication work, it is desirable to replace one printing plate secured on the printing cylinder with another plate, without disturbing the machine .operation, thus cutting non-productive machine time to a minimum. Such replacement of printing plates may be effected by the use of a proper plate gripper, which will suitably secure the leading edge of a pn'nting plate fed thereto, in much the same way that a paper gripper will secure a sheet to .be printed.

Consequently, it is desirable to provide a conveniently disposed auxiliary feed station for .use in presenting new plates to the feed rollers of the duplicator. Since the printing plates are often manually fed to these rollers, .the auxiliary feed station must be positioned above the paper feeding station. Due to this positioning of the feed stations, the suction feet which feed paper to the feed rollers, obstruct the path between the auxiliary feed station and the feedrollers, during a good portion of each machine cycle.

Previously, when the desired number of copies had been printed from the plate on the printingcylinder, and a new plate was to be secured on the cylinder, the machine was stopped completely in .order to arrest the movement of the suction feet, to prevent the feet from interfering with feeding of the new plate. Usually, however, the suction feet came to rest in .a position which blocked passage of the plate, necessitating hand rotation of the 'machine until the suction feet moved to a position in which there was no such interference.

The present invention alleviates this problem by proiding the .cam shaft, which controls suction foot mo- .tion, with a clutch, which. not only permits termination of suction foot movement without stopping the machine, but which makes immaterial the instant .at which the operator employs the clutch, insofar as determining the position in which the suction feet will come to rest. The present clutch may be set to disengage only when the suction feet are disposed in a position which will not hinder plate feeding.

Features and advantages of the invention may be gained from the foregoing and the descriptionof a preferred embodiment thereof which follows:

In the drawings:

Figure 1 is a front elevational view of the clutch ac tuating mechanism of the present invention;

Figure 2 is a plan yiew .of the clutch and clutch actuating mechanism;

Figure 3 is a cross-sectional front elevational view of the present clutch taken on line 33 of Figure 2;

Figure 4 is a cross-sectional view taken on line 4-4 of Figure "1;

Figure 5 is a side elevational view of the actuating plate of the present clutch; and

2,893,730 Patented July 7., .1959

Figure 6 is a side elevational view of the .notched plate used in conjunction with the clutch of thisinvention.

Referring to the drawings, particularly Figures .-1 and 2, the side frame 10 of a short run duplicator isprovided with an aperture through which a stud 11 is disposed. The stud 11 has a threaded bushing 12 slidably mounted on one end, inward of side frame 10. The bushing 12 is braced by a supporting bracket 18, and fixed in position by locking nut 19. Stud 11 is furnished with .an actuating :plate 13 on its other end, outward of the side frame, secured on the stud by locking nuts 14. Adjacent the frameward end of bushing 12, .a collar .15 is loosely mounted on stud 11, i.e., the .collar is both rotatable and slidable on the stud. A clutch handle 16, threaded radially into .collar 15, has a knob 17 secured to its free end. A cam member 20 is rigidly mounted on stud 11 intermediate collar 15 and side frame 10. A compression spring 21, surrounding a collar portion of cam member 20, is disposed between the side frame 1.0 and the face of cam member 2.9 which is parallel to .the side frame. Spring 21 urges translation .toward the right on the part of cam member 20, and hence stud 11. This motion is resisted, however, .by the abutment of cam surface 22 of .cam member 20 against clutch handle 16, the collar 15 .of which bears against bushing 12. When clutch handle 16 is pivoted in the direction indicated by the arrow in Figure 4 to the face .29 of cam member 20, which .is the neutral position of the clutch handle, stud 11 will be allowed to slide to the right through collar 15 and bushing 12 in accordance with a predetermined timing to be hereinafter described.

low pressure tube 23, mounted adjacent its ends in the side frames of the duplicaton'is connected to a suction pump (not shown). .A suction tube 24, tapped off low pressure tube 23, provides the reduced pressurerequired at the suction foot 25.. Although, in the interest of clarity only one suction foot is shown in the drawings, there may be several spaced across the width of the machine. Each suction foot would have its own suction tube 214, however, all the suction tubes would employ the same low pressure tube 23. The suction pump on-off switch 28 is mounted on the outward side of side frame 10.

A camshaft 26 is rotatably mounted in the side frames of the duplicator. One .end of the cam shaft 26 passes through an aperture in side frame 10, .see Figures 2 and 3. A sprocket wheel 27, rotatably mounted adjacent the end of cam shaft 26, is rotated by means of a chain drive 39 from the printing cylinder shaft (not shown). The chain drive is so designed the cam shaft 26 and the main printing cylinder rotate in a one-to-one ratio, when the clutch of this invention is in its running position. When cam shaft '26 so rotates, cams 31 provide suction foot 25 with the motion necessary .to transfer .a blank sheet from a supply stack to the feed rollers, of the duplicator, which subsequently automatically feed the sheet to the paper gripper of the printing cylinder.

Referring to Figures 2 and 3, a driving clutch member 32 is rotatably mounted on a bushing 33, which is fixedly mounted on cam shaft 26. The clutch member 32 is so mounted to prevent sprocket wheel 27 from sliding to the right along cam shaft '26 when the clutch member slides to the right, as will hereinafter be mentioned. Clutch member .32 is provided with an eccentric hole 34 in one end, which accommodates a short stud 35. A compression spring 36, disposed between the inner end of stud 35 and the floor .of hole 34, tends to urge stud 35 outwardly. A small pin '37 threaded into stud .35, and projecting radially therefrom, passes through an enlarged aperture 40 in the periphery of clutch member 32, serving to limit the outward movement of stud 35 and urged by spring 36. Pin 37 is so extend beyond the end surface of clutch member 32.

However, due to the over size of aperture 40, the outer .end of stud 35 may be made flush with the end of the clutch member. When stud 35 is in its normal position, shown in Figure 3, it engages an eccentric depression 41 disposed in the inner face of sprocket wheel 27. Therefore, in this position, when sprocket wheel 27 rofates, driving clutch member 32 rotates.

Atv its other end, clutch member 32 is provided with two peripheral fingers 42 and 43 projecting axially therefrom, disposed 180 apart. Fingers 42 and 43 are disposed in two radial slots in driven clutch member 44, which fixed on cam shaft 26. Therefore, in the running position of the clutch, shown in Figures 2 and 3, when sprocket wheel 27 is rotated, i.e., when the machine is running, the cam shaft 26 will be rotated.

A notched plate 45 is fastened to the outward side of side frame by bolting means 46. This is the same bolting means which fastens supporting bracket 18 to the inward side of side frame 10. Figure 6 shows a face view of plate 45 indicating the position of the notch 47, and certain apertures necessary to allow cam shaft 26 and stud 11 to pass through the plate. Cam shaft 26 passes through aperture 50, stud 11 passes through aperture 51, and apertures 52 accommodate the bolt means. It is evident in Figures 3 and 6 that the depth of notch 47 is something less than the thickness of plate 45. Notch 47 is appended by a sloping arcuate slot 53 which slopes between the outer face of plate 45 and the lower surface of notch 47. This is a safety precaution to prevent damage to the clutch in the event that, at the same time, stud 35 is disposed in depression 41, finger 42 is disposed in notch 47, and the machine is running. If this should happen, which it rarely does, finger 42 will merely strike incline 53 and ride up to the face of plate 45.

Driving clutch member 32 is provided with an annular groove 54, intermediate its ends. This groove is engaged by the semi-circular cut-out portion of actuating plate 13, which may be seen clearly in Figure 5. The narrow end of actuating plate 13 holds the suction pump switch 28 closed when the clutch handle 16 is in running position, Figure 2. When clutch handle 16 is pivoted to its neutral position, i.e., when the clutch handle contacts face 29 of cam member 20, spring 21 urges cam member 20 toward the right, handle urging stud 11 toward the right. Actuating plate 13 will therefore slide cam member 20 slightly toward the right, bringing the end of long finger 42 into contact with the face of notched plate 45. The clutch and hence the cam shaft are of course, still rotating at this time. The end of long finger 42 slides in an arcuate path on the face of plate 45 until the finger reaches a position directly in line with notch 47. When this occurs, the finger is driven into the notch by actuating plate 13, which provides a sufficient motion of cam member 20 and actuating plate 13 toward the right to extract stud 35 from depression 41 in sprocket wheel 27, and to open suction pump switch 28.

In operation, the invention performs in the following manner. Assume that the duplicator is reproducing copies of a printing plate of master sheet presently secured on the printing cylinder, and another printing plate is ready for use. When one less than the desired number of sheets have been printed from the plate on the cylinder, and the final sheet has been presented to the feed rollers, the clutch handle 16 is thrown into neutral position. The exact moment that this is done is unimportant since no significant reaction will occur until the predetermined point in the cycle at which finger 42 and notch 47 become co-linear. When this occurs, the above described movements of cam member 20 and actuating plate 13 takenplace terminating the rotation of cam shaft 26 and shutting off the suction at suction feet 25. The motion imparted to the suction feet by cams 31 is, therefore, terminated at such a time that the suction feet remain disposed in a desirable position, insofar as permitting -a new printing plate to be presented to the feed rollers for subsequent feeding to the plate gripper of the printing cylinder, is concerned. Before the new plate is presented to the feed rollers, of course, the printing plate presently held in the plate gripper is ejected therefrom.

When the new printing plate has been secured on the printing cylinder, clutch handle 16 is pivoted into running position, i.e., that position shown in the drawings. In following the surface 22 of cam member 20, clutch handle 16 slides stud 11 back toward the left placing the actuating plate and clutch member 32 into the position shown in the drawings. Stud 35 will probably not engage depression 41 immediately since sprocket wheel 27 is rotating. However, when stud 35 contacts the inner face of the sprocket wheel, the entire stud will be forced into hole 34 compressing spring 36. As sprocket wheel 27 continues to rotate, depression 41 will be brought into direct line with stud 35, at which time the stud will snap into depression 41. The rotative motion of sprocket wheel 27 is thereby transmitted through the clutch to earn shaft 26. Since the suction pump was turned on the moment actuating plate 13 moved toward the left, feeding of blank sheets begins concurrent with the commencement of cam shaft 26 rotation.

It is not intended to set forth all the variations that may be made, but it is contemplated that many of the features of the invention disclosed may be carried out in other ways and that many widely different embodiments of the invention can be made Without departure from the spirit and scope of the invention. It is therefore intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

In a printing press having a suction feeder wherein a suction foot is reciprocated from a sheet grasping position to a sheet feed position, and means for actuating said suction foot including a rotatable shaft having means associated therewith for reciprocating said suction foot a clutch adapted to be disengaged at a single predetermined point only in the printing cycle, said clutch comprising, a rotating driving member, a coupling member slideably mounted for engagement and disengagement with said driving member, a second coupling member fixedly secured to said aforementioned shaft, 2. plate fixedly mounted with respect to said afore-mentioned shaft and being provided with a detent in a fixed predetermined position, a log member, spring means for urging said coupling member out of engagement with said driving means and said lug member toward said plate whereby as the coupling members continue to rotate and said lug becomes aligned with the detent in said plate said spring will be permitted to slide said coupling to introduce said lug into the detent and to disengage the driving connection between said driving member and said coupling member so that said shaft and the suction foot reciprocated thereby are brought to a halt in a predetermined position, and manually actuated means for sliding said coupling member against the force of said spring to permit engagement of said coupling member and said driving member.

References Cited in the file of this patent i UNITED STATES PATENTS 1,669,006 Johnston May 8, 1928 2,162,071 Eason June 13, 1939 2,668,707 Spiess Feb. 9, 1954 2,725,229 Battey Nov. 29, 1955

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