US2736259A

US2736259A - sather

Info

Publication number: US2736259A
Authority: US
Publication date: 1956-02-28
Anticipated expiration: 1973-02-28

Description

Feb. 28. 1956 o. H. SATHER 2,736,259

PREMAKE READY PLATE CYLINDER Filed Feb. 5, 1952 6 Sheets-Sheet 1 IN V EN TOR.

B ,a zg gg Feb. 28, 1956 sATHER 2,736,259

PREMAKE READY PLATE CYLINDER Filed Feb. 5, 1952 6 Sheets-Sheet 2 Feb. 28, 1956 o. H. SATHER 2,736,259

PREMAKE READY PLATE CYLINDER Filed Feb. 5, 1952 s Sheets-Sheet 5 INVENTOR. CYLU/fi 5afkef, BY

, L ILTII LL ill: K

Feb. 28, 1956 o. H. SATHER 3 PREMAKE READY PLATE CYLINDER Filed Feb. 5, 1952 e Sheets-Sheet 6 IN V EN TOR.

United States Patent '0 PREMAKE READY PLATE CYLINDER Oliver H. Sather, Chicago, Ill. 7 Application February 5, 1952, Serial No. 269,946

15 Claims. (Cl. 101378) The invention relates to the art of printing and has reference more particularly to a novel and improved pre-make ready plate' cylinder.

For attaching printing plates to the peripheral surface of rotary printing cylinders it has been customary to perforate the surface of the cylinder with a plurality of small openings or grooves, and fastening means have been employed having location in said openings or grooves for releasably locking printing plates in registered position on the cylinder. It is also old and well known in the art to equip rotary printing cylinders with leading and trailing edge clamping means operative to clamp stereotype printing plates to said rotary cylinders. The present invention aims to improve apparatus of this nature and accordingly provides a pre-make ready plate cylinder incorporating "novel and improved clamping means for releasably attaching to the cylinder either a plate carrying jacket or a plate carrying shell. It may also be possible to use the improved clamping means of the invention for releasably attaching a stereotype plate to rotary printing cylinders.

In order to provide a pre-make ready plate cylinder in accordance with the inventionthe cylinderjacket or cylinder shell is perforated on its exterior surface by aplurality of relatively small openings, preferably'disposed in spaced substantially checkerboard arrangement. The printing plates, carrying the matter to be printed, are secured in accurate register to the peripheral surface of the jacket or shell by the use of conventional plate hooks and the jacket or shell, which is nowready for printing, is then clamped to the cylinder'in registered position thereon by novel clamping means as herein disclosed and described. As a result of the above procedure anumber of special advantages are secured. In the first place, the printing plates can be attached in register to the shell in the composing room. Accordingly, the entire operation, which is known as make-ready, can be performed away from the press and while the press is producing and running off another job of printing. It is also possible to check the arrangement and disposition of the printing plates'on the shell by a proofing operation in the composing room before the plate carrying shell is applied to the press. Another advantage resides in the fact that the operation of clamping the plate carrying shell to the cylinder can be effected with speed'and accuracy" so that the period of idleness for the printing press is imthermore reduced. Y

Therefore another object of the invention resides in the provision of improved clamping meansadapted for incorporation within a rotary printing cylinder for locking a plate carrying shell to the cylinder, and which clamping means will include two clamping devices, each having location within the cylinder on the respective sides thereof.

Another object of the invention resides in the provision of improved clamping means adapted 'for incorporation within a rotary printing cylinder as herein described, and wherein the actuating means for each clamping device will project exteriorly of the cylinder, being located at and being accessible to the operator at the conventional gap of the cylinder.

Another object of the invention is to provide improved clamping means as described which will incorporate registering means in the form of a fixed registering bar carried by the cylinder and whereby said fixed registering bar serves to always locate a plate carrying shell on the cylinder. in the same position for accurate registra tion.

A further object is to provide efficient and accurate clamping means for incorporation within a printing cyl inder whereby a plate carrying shell can be r'eleasably locked in registered position on the cylinder and which said clamping means will engage both the leading and trailing edge of the shell to thereby apply circumferential tension holding the shell to the cylinder.

A more specific object is to provide a novel and improved clamping means of the character described which will incorporate registering bars with which the leading and trailing edge of the shell will contact, and wherein the registering bar for the trailing edge will be located in the cylinder gap and will have openings through which extend the actuating means for the clamping devices.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation as will be more fully described and particularly pointed out in the specification, drawings and claims appended hereto. i in the drawings which illustrate an embodiment of the invention, and wherein like reference characters are used to designate like parts- Figure l is a perspective view of a plate carrying shell constructed in accordance with the invention, the same being illustrated with several printing plates releasably secured thereto;

Figure 2 is an enlarged fragmentary plan view of a section of the shell illustrating the arrangement of the openings;

Figure 3 is a sectional view taken along line 3-3 of Figure 2;

Figure 4 is a transverse sectional view of a pre-make ready printing cylinder illustrating a preferred form of clamping means for the plate carrying shell;

Figure 5 is a transverse sectional view similar to Figure 4 but showing certain clamping members in released position;

Figure 6 is an elevational view of the gap side of the pre-make ready printing cylinder of Figures 4 and 5, illustrating the location and arrangement of the clamping means and the actuating means at this side of the cylinder;

Figure 7 is a transverse sectional view of a pre-make ready printing cylinder illustrating a modified form of clamping means for the plate carrying shell;

Figure 8 is a fragmentary transverse sectional view illustrating the modified clamping means of Figure 7 but showing only the clamping structure for engaging the plate carrying shell at the gap side of the cylinder; and

Figure 9 is a transverse sectional view of a pre-make ready printing cylinder illustrating a further modification of shell and clamping means coming within the invention;

Figure 10 is a front elevational view of the clamping member 97 keyed to shaft 76 so as to rotate for clamping and releasing its plate carrying shell;

Figure 11 is an elevational view of one of the spring tensioning devices on shaft 76; and

Figure 12 is an end view with parts being shown in section of a modified form of the invention wherein the cylinder is provided with a single plate carrying shell.

In the drawings, the base portion of the printing cylinder is illustrated as having at least one and'may have as many as four plate carrying shells attached thereto by clamping members at the leading edge and at the trailing edge of each shell. Such a plate carrying shell may take the form as shown in Figure 1, wherein the shell identified by numeral is semi-circular in transverse section, having the

longitudinal grooves

11 and 12 formed on the interior surface at the leading and trailing edges, respectively, for coaction with clamping members, the construction and operation of which will be presently described. The printing plates such as 13 and 14 are releasably secured to the exterior surface of the shell by plate hooks 15 which are located in openings 16. Said openings are arranged in honeycomb formation on the exterior surface of the shell Figure 2 in order that the plates may be secured thereto in the desired adjusted positions. The bottom of each opening 16 is reduced in diameter by section 17 Figure 3, which thereby forms the shoulder 18 with which the plate hooks engage and by which said means are locked in the openings.

Figure 4 illustrates a printing cylinder having top and bottom plate carrying shells clamped thereto by improved clamping means coming within the invention. The base portion of the cylinder is identified by numeral 22, and is provided with a number of cored openings 23 and 24 for reducing the weight of the cylinder, and which openings extend longitudinally of the same. At diametrically opposite sides of the base portion the same is provided with longitudinal grooves or recesses for accommodating the clamping members which serve to clamp the shells to the base portion in a manner to lock them in registered position on the cylinder. The groove 25 of keystone shape, having the undercut edges 26, extends from end to end for the length of the cylinder and said groove receives the registering bar 27 of equal length and which is secured centrally of the groove by the securing screws 28. The top and bottom surfaces of the registering bar have a slight taper in an outward direction. A taper of about one degree is preferred. The

clamping members

30 and 31 contact with and ride on the said tapering surfaces, identified by numeral 29. For clamping purposes each member is provided with a nose 32 adapted to enter and coact with its particular groove 11 in the leading edge of a plate carrying shell. Each clamping member has a tapering formation in cross section since the outer surface of each member is formed to engage its respective undercut surface 26.

Actuating screws comprise the means for actuating the clamping members to effect radial movement thereof into and out of clamping relation with the grooves 11 in the shell. Clamping member 30 is actuated by screw 33 which extends through passages in the base portion provided therefor and projects into the longitudinal groove 35 similar to groove 25 but being rectangular in shape and being located at the gap side of the printing cylinder. The actuating

screws

33 and 34 are threaded at their left hand end as at 36 for threaded engagement with their respectlve clamping member. At their opposite end each actuating screw is provided with a head portion 37 having location in recess 38 provided therefor and the terminal end of each screw is squared as at 40 for receiving a tool or the like by which the actuating screw is turned by the operator. The bottom of groove 35 receives the thrust plate 41 which is suitably fastened in place by the securing screws 42. The thrust plate acts as a cover for recesses 38 and as a stop for the heads 37. When the actuating screws are rotated to produce outward movement of the clamping

members

30 and 31 to effect a loclrin g'of the plate carrying shell, the thrust resulting from this operation is absorbed by plate 41, being imparted thereto by the heads 37. When the clamping members are moved in an opposite direction, that is, inwardly of the printing cylinder for the purpose of releasing the plate carrying shells, the heads 37 move into contact with the bottom of the recesses 38 and the thrust of this operation is thus transmitted to the cylinder.

The

p g ars

43 and 44 are prov ded f r ping the opposite edge of the plate carrying shells at the gap side of the printing cylinder. The bars extend for approximately the length of the clamping members, ha ing location within the longitudinal groove 35 and being retained in the groove by retaining plates 45. Said plates are located at spaced intervals for the length of the clamping bar and each bar is provided with an opening such as 46 through which the extending end of the retaining plate 45 projects. The securing screws 42, which fasten the thrust plate 41 to the base portion of the cylinder, can be employed for additionally bolting the retaining plates 45 which lie flat against the outer surface of the thrust plate, all as clearly shown in Figure 6. When the clamping bars 43 and 44 are not in use they are still retained within the longitudinal groove 35, being allowed to drop down to the bottom of the groove, which has the efiect of removing the tapered clamping end 47 of each bar below the surface of the base portion and therefore out of coaction with a groove, such as 12, in the plate carrying shell. For accommodating the clamping bars when in operative clamping relation with the plate carrying shell, the thrust plate 41 is notched as at 4-8 on respective sides thereof, as will be clear from an inspection of Figure 5. When the clamping bars are located in their respective notches the tapered nose 47 thereof will be located within a groove such as 12 in the plate carrying shell on the cylinder.

Numerals 5t) and 51 indicate the actuating screws for the clamping bars, the same having threaded relation with a bar and being adapted to engage a side wall of the longitudinal groove 35. The head of each actuating

screw

50 and 51 is squared as at 52 for receiving a tool or the like by which the actuating screw is turned and when the same is turned in a certain direction its actuating bar is caused to coact with the groove 12 of the shell, applying circumferential tension thereto, thus locking the shell to the cylinder, provided, of course, that the opposite end of the shell is held by a clamping

member

30 or 31.

The manner of clamping a plate carrying shell to the cylinder is illustrated in Figure 5, wherein the shell 21 is shown in clamped position, whereas, shell 20 has just been placed on the cylinder and is not as yet clamped thereto. For such purpose the operator employs a suitable tool engaging the squared end 40 of the actuating screw 33, to rotate the screw and cause outward movement of the clamping member 30 in a substantially radial direction to locate nose 32 of the member within groove 11. The next operation results in the proper positioning of the clamping bar 43 in its recess 48 on the thrust plate 41. The actuating screw 50 is then rotated in the proper direction to force the clamping bar 43 in a downward direction whereby to apply the necessary circumferential tension to the shell 20 to securely lock the same in registered position on the printing cylinder. The one degree taper on the top and bottom surfaces 32 of the registering bar 27 is such as to facilitate the sliding movement of the clamping

members

30 and 31 on the registering bar and location of their nose portions 32 into the grooves 11 of the plate carrying shells. The surfaces 32 are accurately machined and the registering bar is accurately positioned centrally within the longitudinal groove 25 so as to provide a registering means for accurately positioning the plate carrying shells on the cylinder. The effect of the tapering surfaces 26, in combination with the surfaces 32 is to limit outward movement of the clamping members. Said members move outwardly and stop just short of their nose portions 32 contacting the base of grooves 11 in the shells. However, each shell will be accurately positioned since the clamping edge 53 of each nose portion will be forced into a close sliding fit with the outer edge of groove .11. 7

It will be observed that the clamping members and clamping bars are all actuated from the gap side of the cylinder. ,Accordingly, from this side of the cylinder the and 21.

the cylinder.

the gap side of the cylinder.

'70, 71 and 72 secure the blockswithin their respective r operator can actuate screws ,33 and 34 forthe clamping members and can also actuate screws andi51.for' the clamping bars. As a result the clamping of a shell to the cylinder can be effected with great speed and accuracy and even less time is required to release the members and bars in orderto remove the clamping shell from the cylinder. As shown in Figure 6, a total of four plate carrying shells may be releasably. locked to a cylinder such as 22, havingendmembers v54 and 55.

Plate carrying shells

20 and 21 are locked to the cylinder by structure such as described,rthe shells being located at the right hand end of the cylinder in end contact with member 54. Depending on the length of the cylinder, it may be possible to apply thereto apair of similar plate carrying shells20a and 21a, the same being located at the left hand end of the cylinder and in contact with shells Clamping means as described will also be employed for locking shells 20a and 21a to the cylinder. End member 55 is provided with a plurality of adjusting screws such as 56 and which screws extend in a longitudinal direction through the end member so as to con tact the plate carrying shells 20a and 21a. By tightening the screws 56 end play can be taken up at this end of the cylinder. As illustrated in Figure 6 it will be seen that each plate carrying shell is held by two clamping members and by two clamping bars, with each clamping member and bar having at least two actuating screws in .threaded relation therewith.

In Figures 7, 8 and 9 a modified form of clamping means is disclosed, the same being characterized by registering bars with which the shells are adapted to directly contact for locating the shells in registered position on The base portion of the cylinder, indicated by numeral 60, is provided with a plurality of longitudinally extending cored openings 61 and 62 for reducing the weight of the cylinder. On diametrically opposite sides the cylinder is provided with longitudinal grooves of substantially similar shape, although inverted with respect to each other, as clearly evident from an inspection of Figure 7. The longitudinal groove on the left hand side of the cylinder is indicated by numeral 63, whereas, the longitudinal groove on the right hand side is indicated by numeral 64. Journalling blocks are located in each groove,

numerals

65 and 66 indicating the blocks located in groove 63,

similar blocks

67 and 68 being located in groove 64 since the clamping structure of this modification is the same at both sides of the cylinder, with the actuating screws therefor being operable from only Securing screws such as longitudinal grooves. For purposes of the invention each .block 65 and 67 has secured thereto a registering bar.

For example, block 65 has theregistering bar 73 suitably secured thereto by screws 74, as best shown in Figure 9, and in a similar mmner the registering bar 75 is secured to the block 67. It will be understood that registering bar 73 is located at the gap side of the cylinder, whereas, bar 75 is located on the side opposite the gap.

Referring more particularly to block 65, it will be understood that a plurality of these blocks are disposed in end to end relation for the length of the groove 63, see Figure 9. Said blocks journal an actuating shaft 76 for the clamping members 77. ,A number of such clamping members are secured to shaft 76 in spaced relation along the length of the shaft, the members being keyed to the shaft as at 78 and each member having a nose portion 80 adapted for location within a groove such as 81, providedon the interior surface adjacent one edge of the plate carrying shell v82. Each block 65 approximately centrally of its length is suitably recessed for receiving a spring tensioning device for the shaft 76, the same including an arm 83 securely fixed to a flattened portion of shaft 76 by the screw 84, see Figure 11. The arm extends inwardly of said recess and is adapted to overlie the coil spring 85 in opening 86 in jaw member 7 l s m e 9 sh tflfi an sxts d sw said recess. The action of the coil spring, with respect to the jaw member and 'arm, is to tension shaft 76 and take up any play in the parts as'a result of manufacture or such as may develop by wear. g i i At spaced locations, alternating with the springtensioning device, the clamping members are keyed, as described, to the actuating shaft 76. One member for each shaft 76 is provid ed witha pair ofl'bifuirjc'ated arms 88 within which islocated the, block 89, the samebeing suitably pivoted to the arms by trunnionssuch as '90. Each block has threaded connection with art actuating screw 91 which extends to the gap side of the cylinder where the same is provided with head 92 suitably socketed for receiving a tool or the like, thus permitting the operator to rotate the actuating screw for effecting actuation of the clamping member 77. The head! is located within a recess provided therefor in the registering bar 73, the bottom of the recess being provided by the block 65. Thus, the block 65 or bar73func tions to absorb 'the thrust of the actuating screw 91 when the same is rotated either to clamp the plate carrying shell orrelease a plate carrying shell. A tool receiving opening. i s formed in the registering bar 73 in alignment with the socketed opening 92' in actuating screw 91 :inorder to allow for insertion of a tool into said socketed opening.

Similar structure is provided, as shown by Figure 7, including a movable clamping member, actuating shaft and screw for the plate carrying, shell 9 4. Said shell at one end thereof, on its interior surface, is provided with the groove 95 for receiving thenose 96 of the movable clamping member 97. Said clamping member 197 is similar in all respects to clamping member 77, the same being keyed at 78 to an actuating shaft76 suitably journalled by the blocks 67, located in the groove at this side of the cylinder. Spring tensioning devices are provided therefor, see Figure 11, including the arm 83 suitably secured to shaft 76 by screw 84 and which arm is tensioned as described by coil spring 85, having location in the jaw member 87. One clamping member 97 for each shaft 76 has bifurcated arms 98, Figure 10, within which is jlocated the block 100. Said block has threadedrelation with the actuating'screw 01 which extends transversely of the cylinder to registering bar,73. ,Actuating screw 101 is provided with a head 102 having location within a recess formed in the registering bar 73. Here also the bottom of the recess is provided by the block 65. The head is socketed'at 102 for receiving a tool and'the opening 104 in the registering bar is aligned with the socketed opening in order to allow the insertion of the tooltherein so that the operator may rotate actuating screw ml to in turn actuate clamping member 97.

The cylinder 66 is provided with stationary clamping members located on approximately diametrically opposite sides of the cylinder and which stationary clamping members are suitably supported by the

blocks

66 and 68,respectively. Referring firstof all to block 66, it will be seen that said block is held in its longitudinalgroove by its securing screw 72. Certain blocks are spaced longitudinally of the groove asillustrated inFigure 9, and a stationary clamping member 105 is disposed between certain spaced blocks, being supported therefrom by the supporting shaft 106, suitably journalled by said spaced blocks. Each stationary clampingmember 105 is provided with a nose portion 105a adapted to enter a groove 1115b provided on the interior surface of plate carrying shell 94 and which is located at the edge opposite groove 95. The stationary clamping member 105 maybe suitably keyed or otherwise fastened to shaft 106 by pin 99. The member 105 is backed by the coil spring 103 located in recess 109. The action of the'coil spring issimilar' to the spring tensioning devices p'reviously'described" in that it takes up play in the'partsf Actually, the clamping member 105 has movement of less than one-sixteenth'of an inch. The blocks'68'are disposed in a similar manner in their' respective' grooves on the opposite side of the cylinder and certain spaced blocks journal the supporting shaft 110'which in turn supports the stationary gripping member 111. Each gripping member 111 is provided with a nose 112 adapted to enter a groove such as 113 formed along this edge on the interior surface of the plate carrying cylinder 82. Each member 111 may be secured to its supporting shaft 110 by being keyed or pinned as at 114. Here also the cylinder is recessed at 115 for receiving the coil spring 116 which backs the stationary gripping ing member 97 is actuated into retracted position by rotation ofthe actuating screw 101. The semi-circular shell is then fitted to the cylinder with the groove 198 being located on nose portion 107 of the gripping member 165. Actuating screw 101 is then rotated in an opposite direction to effect a clamping of the shell on the cylinder by locating nose 96 of the movable clamping member 97 into the groove 95. For this purpose a suitable tool is inserted through opening 104 into the socketed end of head 102, and the actuating screw 101 is conveniently rotated by the operator. der it will be observed that the edge adjacent groove 95 is in firm contact with the registering bar 75. In a similar manner the top shell 82 can be clamped to the cylinder which necessitates actuation of the actuating screw 91.

When said shell is in place it will be seen that its longitudinal edge adjacent groove 81 will be in contact with the registering bar 73.

The modification disclosed in Figure 12 employs a single shell for covering the peripheral surface of the cylinder with the exception of the gap opening in the cylinder. In this modification the gap opening extends for approximately ninety degrees and it is possible by using said gap opening to apply a single plate carrying shell to the cylinder, the shell being removable in a manner substantially the reverse to that of its application.

The cylinder, generally indicated by numeral 124}, is provided with the gap opening 121, extending for approximately ninety degrees so that the operative surface of the cylinder comprises the remaining two hundred and seventy degrees. The plate carrying shell 122 is adapted to cover the operative surface of the cylinder and accordingly extends from one side of the gap opening around the cylinder to the other side of the gap opening. At each longitudinal edge of the shell the same is provided with a groove such as 123 and 124, respectively. of the gap opening the body portion of the cylinder is recessed for receiving clamping bars by means of which the shell is securely clamped to the cylinder. The recess 125 extends longitudinally of the cylinder for the length of the same and this recess receives the wear plate 126 suitably bolted to the cylinder by the threaded bolts 127. The wear plate 126 provides the shoulder 128 adapted to locate the clamping bar 130 so that its terminal end is located in groove 123 of the shell. In order to remove the clamping bar 130 from clamping relation with the shell the bar is released from contact with shoulder 12.8 and the same is allowed to drop to the base of recess 125 in a direction inwardly of the cylinder. For this purpose the slot 129 is provided in the clamping bar 130. The said slot receives the actuating screw 131 by means of which the clamping bar is fixedly secured to the wear plate 126 and thus to the cylinder. One or more actuating screws may be provided for the clamping bar 130, the same being suitably spaced longitudinally of the bar and each being located in a transversely elongated slot 129 With the shell in clamped position on the cylin- On each side which permits operative and inoperative positioning of the clamping bar. Along the opposite side of the gap opening in the cylinder wall a recess 132 is provided similar to recess 125'. However, the clamping bar 133 has location in recess 132, the same having the slot 134 formed therein through which is adapted to extend the retaining plate 135. The clamping bar 133 is rendered operative for clamping a shell to the cylinder by means of the actuating screws 136 having threaded relation with said clamping bar.

To render the clamping bars 130 and 133 operative they are located in the corner slots provided therefor, which sufliciently elevates the clamping bars so that their opposite end is projected into its respective groove, either 123 or 124, in the plate carrying shell. The clamping bar 130 may be considered as the stationary bar with 133 comprising the movable clamping bar. Circumferential tension is applied to the plate carrying shell by actuation of the screws 136 having threaded relation with clamping bar 133. These screws can be turned until the shell is tightened and firmly clamped to the cylinder. It will be observed that the actuating screws terminate in a gap opening of the cylinder and that both groups of actuating screws therefore are operable from this side of the cylinder.

in removing the single plate carrying shell 122 from the cylinder it is, of course, first necessary to release clamping bars 126 and 133. In released position the bars are located in the bottom of their respective recesses. The shell is now rotated relative to the cylinder to position one longitudinal edge in the gap opening of the cylinder, and said rotation is continued until the gap opening permits withdrawal of the shell in a lateral direction from the cylinder. In returning the plate carrying shell to the cylinder 120 the same procedure is repeated with the steps, however, being reversed.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

l. A printing cylinder assembly comprising a cylinder and separable shells therefor adapted to cover the peripheral surface of the cylinder except for the conventional opening at the gap side of the cylinder, each shell being semi-circular in cross-section, and clamping means engaging each shell adjacent the longitudinal edges respectively, said clamping means including a movable clamping member mounted for movement by the cylinder, an actuating screw having threaded relation with the clamping member for effecting movement thereof, and a second clamping member for each shell also having an actuating screw in threaded relation therewith, the actuating screws for both clamping members terminating at the gap side of the cylinder and being operable from this side of the cylinder, the second mentioned clamping member being loosely secured to the cylinder and each of said clamping members being capable of movement relative to the cylinder to a limited extent.

2. A printing cylinder assembly comprising a cylinder and at least two semi-circular plate carrying shells for said cylinder for covering the peripheral surface of the same except for the conventional gap opening at one side of the cylinder, a pair of clamping members for each shell for clamping the shell to the cylinder, one of said clamping members being mounted by the cylinder for movement approximately radially of the cylinder, the other clamping member comprising a clamping bar loosely secured to the cylinder at the gap side thereof and being capable of movement relative to the cylinder to a limited extent, an actuating screw having threaded relation with the first mentioned clamping member for effecting radial movement thereof, and a second actuating screw having greases threaded relation with the clamping bar, both said'actuating screws terminating in the gap opening-and being operable from this side of the cylinder.

3. A printing cylinder assembly comprising a cylinder and at least two semi-circular plate carrying shells for said cylinder for covering the peripheral surface of the same except for the conventional gap opening at one side of the cylinder, a pair of clamping members for each shell for clamping the shell to the cylinder, a registering bar fixed to. the cylinder and extending longitudinally of the same, one of said clamping members being mounted by said registering bar for transverse movement into and out of clamping position, the other clamping member comprising a clamping bar loosely secured to the cylinder at the gap side thereof and being capable of movement relative to the cylinder to a limited extent, an actuating screw having threaded relation with the first mentioned clamping member for effecting transverse movement thereof, and a second actuating screw having threaded relation with the clamping bar, both said actuating screws terminating in the gap opening and being operable from this side of the cylinder.

4. A pre-make ready plate cylinder, the combination of a cylinder portion and a plate carrying shell therefor, said cylinder portion having a pair of longitudinal grooves diametrically spaced on opposite sides of the cylinder, one groove forming the gap opening for the cylinder, the other groove having side walls which are undercut inwardly of the cylinder, a registering bar fixed to the cylinder and located centrally in the base of the last mentioned groove, clamping means for clamping the shell to the cylinder including a movable clamping member disposed on each side of the registering bar in contact therewith, each clamping member having a tapering outer surface complementary to the slope of its adjacent wall of said groove, whereby outward movement of each clamping member is limited, other clamping members disposed in the groove at the gap side of the cylinder, each said last mentioned clamping member including a longitudinal clamping bar, retaining means for each clamping bar, and actuating means individual to each clamping member and to each clamping bar.

A pre-make ready plate cylinder as defined by claim 4, wherein the actuating means consists of an actuating screw for each clamping member and for each clamping bar having threaded relation therewith, and wherein said actuating screws terminate in the gap opening and are operable from this side of the cylinder.

6. A pre-make ready plate cylinder, the combination of a cylinder portion and a plate carrying shell therefor, said cylinder portion having a pair of longitudinal grooves diametrically spaced on opposite sides of the cylinder, one groove forming the gap opening for the cylinder, the other groove having side walls which are undercut inwardly of the cylinder, a registering bar fixed to the cylinder and located centrally in the base of the last mentioned groove, clamping means for clamping the shell to the cylinder including a movable clamping member disposed on each side of the registering bar in contact therewith, each clamping member having a tapering outer surface complementary to the slope of its adjacent wall of said groove, whereby outer movement of each clamping member is limited as a result of contact of the tapering outer surface of the member with its respective wall of the groove, and actuating means individual to each clamping member for effecting movement of the same into and out of clamping relation with said shell, said actuating means extending transversely of the cylinder and terminating in the gap opening of the cylinder.

7. A pro-make ready plate cylinder as defined by claim 6, wherein the side walls of the registering bar, having contact with the clamping members respectively, are tapered in a direction outwardly of the cylinder portion to facilitate coaction of the clamping members with a shell 10 on the cylinder to effect a clamping of' the shell or a re-' lease or the shell. 7

8. A pre-make ready plate cylinder, the combination of a cylinder portion adapted to have one or more plate carrying shells clamped thereto, said cylinder portion having a pair of longitudinal grooves diametrically spaced on opposite sides of the cylinder, one groove forming the gap opening for the cylinder, the other groove having a bottom wall substantially normal to a radius intersecting the bottom wall centrally of its length and having inwardly undercut side walls, a registering bar fixed to the cylinder and located centrally of the bottom wall of said last mentioned groove, and clamping means carried by the cylinder portion including a movable clamping member disposed on each side of the registering bar in contact therewith, each clamping member having a tapering outer surface complementary to the slope of its adjacent undercut wall of said groove, whereby outer movement of each clamping member is limited as a result of contact of the tapering outer surface of the member with its respective side wall of the groove.

9. In a rotary printing press, a plate cylinder having at least one longitudinal groove in its peripheral surface, a clamping member disposed in said groove and adapted to have movement transversely of the cylinder to be projected from or to be retracted within the groove, said clamping member in cross-section having an outward taper and said groove in crosssection becoming wider inwardly of the cylinder and providing sloping surfaces complementary to those of the clamping member, whereby said groove serves to limit the forward projecting movement of the clamping member, and actuating means for said clamping member, said actuating means extending transversely of the cylinder to the side thereof diametrically opposite the groove and being operable from this side of the cylinder.

10. In a rotary printing press, a plate cylinder having at least one longitudinal groove in its peripheral surface, said groove in cross-section being keystone in shape and having a bottom wall substantially normal to a radius intersecting the bottom wall centrally of its length and having sloping undercut side walls, a registering bar fixed to the cylinder and located centrally of the bottom wall of said last mentioned groove, and clamping means carried by the cylinder including a movable clamping member disposed on each side of the registering bar and adapted to contact the bar, each clamping member having movement transversely of the cylinder to be projected from or to be retracted Within the groove, each clamping member in cross-section tapering in an outward direction and having a sloping outer surface complementary to the slope of its adjacent undercut wall of said groove, whereby movement of each clamping member in an outward direction is limited as a result of contact of the sloping surface of the member with its respective wall of the groove, and actuating means for said clamping members respectively, each said actuating means extending trans versely of the cylinder to the side thereof diametrically opposite the groove and being operable from this side of the cylinder.

11. A rotary printing press as defined by claim 10, additionally including clamping bars located on the side of the cylinder opposite the groove, wherein the cylinder on this side is provided with a second groove extending longitudinally and within which are located the clamping bars, retaining means for the clamping bars which permit limited relative movement of the bars with respect to the cylinder, and actuating screws for the bars respectively having threaded relation therewith.

12. A printing cylinder assembly comprising a cylinder ing plates to the shell, clamping means for releasably securing the plate carrying shell to the cylinder, said clamping means including clamping devices within the cylinder on respective sides thereof for engaging the trailing edge of the shell at the gap side of the cylinder and the leading edge of the shell at the side of the cylinder opposite the gap, actuating means for certain of said clamping devices, said actuating means extending transversely within the cylinder, and said actuating means terminating at the gap side of the cylinder and being accessible to the operator through the gap at this side of the cylinder.

13. A printing cylinder assembly comprising a cylinder and separable shells therefor adapted to cover the peripheral surface of the cylinder except for the conventional opening at the gap side of the cylinder, each shell being adapted to support one or more printing plates releasably securely thereto, and each shell having a longitudinal groove located adjacent each edge on the interior surface thereof, clamping means for releasably securing each plate carrying shell to the cylinder including clamping devices within the cylinder on respective sides thereof for engaging the trailing edge of the shell at the gap side of the cylinder and the leading edge of the shell at the side of the cylinder opposite the gap, and actuating screws for certain clamping devices for moving the same into and out of coaction with a groove in its particular shell, each actuating screw having threaded relation with its clamping device and extending transversely within the cylinder to project exteriorly of the cylinder at the gap side of the same.

14-. A pre-make ready plate cylinder comprising the combination of a cylinder portion and a semi-circular plate-carrying shell therefor, said shell having a groove along each longitudinal edge on the inside surface of the shell, said cylinder having clamping members adapted to coact with the grooves for clamping the shell to the cylinder, certain clamping members being movable and other clamping members being stationary, said cylinder portion having diametrically spaced recesses extending longitudinally on opposite sides of the cylinder for accommodating the clamping members respectively, supporting means disposed in one recess and extending longitudinally for the length thereof, a shaft journalled for rotation in said supporting means, said movable clamping members being keyed to the shaft and being disposed at intervals along the length of the shaft, at least one actuating screw having threaded relation with a movable clamping member for actuating the same upon rotation of the screw, whereby said shaft is rotated to thus actuate the other clamping members keyed to the shaft, said actuating screw extending transversely within the cylinder and being journalled thereby, and said actuating screw terminating on that side of the cylinder having said other recess and relatively adjacent said other recess, and other supporting means having location in the other recess and being disposed longitudinally of the cylinder, the said stationary clamping members being supported by the said other supporting means.

15. A pre-make ready plate cylinder, comprising the combination of a cylinder portion and plate carrying shells therefor, said cylinder portion having a pair of longitudinal recesses formed therein at the gap side of the cylinder and at the side diametrically opposite the gap, respectively, supporting means disposed in one recess of each pair, each said supporting means extending longitudinally of its recess and providing a registering bar, a shaft journalled in each of said supporting means, at least one clamping member keyed to each shaft and thus being movable upon rotation of the shaft, a stationary clamping member disposed in the other recess of each pair and being fixedly secured to the cylinder, said plate carrying shells each having a groove along its longitudinal edges and with which the clamping members at respective sides of the cylinder are adapted to engage for clamping the shells to the cylinder portion with the leading edge of each shell in contact with its respective registering bar, and an actuating screw for rotating each shaft to thus actuate the movable clamping members keyed to the shafts, said actuating screws extending transversely within the cylinder and being journalled thereby, and said actuating screws terminating at the gap side of the cylinder and having their terminal ends in associated relation with the registering bar at this side of the cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 433,232 Brooks July 29, 1890 852,786 Hodgman May 7, 1907 2,047,357 Crafts July 14, 1936 2,050,950 Huck Aug. 11, 1936 2,496,200 Crafts Jan. 31, 1950