US1949132A

US1949132A - Printing press

Info

Publication number: US1949132A
Application number: US568603A
Authority: US
Inventors: Smith Walter Harold
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-10-13
Filing date: 1931-10-13
Publication date: 1934-02-27
Anticipated expiration: 1951-02-27

Description

w. H. SMITH PRINTING PRESS Feb. 27, 1934.

Filed 03%,..13 1931 www retain FRENTING PRESS Waiter lflarold Smith, Toronto, Qntario, Cana-da Application October i3, 1931. Serial No. 568,603

(Cl. lill- 4151) 3 Claims.

My invention relates to improvements in printing presses, more particularly to the style of press known as a lithographed offset press, which Smploys wo or more cylinders, employing a thin metallic or celluloid strip for the printing plate and a rubber blanket covering the offset cylinder to receive the print which in turn contacts With the sheet to be printed being held against the offset cylinder by a third cylinder (not shown) which gives the desired impressional contact.

The object of this invention is to provide a cylinder Whose circumference is exactly equal to the exact length of sheet to be printed and to provide means for holding the printing plate and the rubber blanket securely with a minimum amount of opening for the holding or clamping means to secure the maxunurn of actual print- 'lng surface in a srnall ina/chine. This becomes diicult as the diameter is too Small to allow of any internal clamping devices.

A further object is to allow a number oi narrow plates to be held on the cylinder at the saine time and a single means for securing all the plates simultaneously and enabling the quick disengagement of the clamping means for the removal ci the printing plates, and it consists essentially of the arrangement and construction of parts as hereinafter incre particularly explained.

Fig. 1 is a perspective view of a fragmentary portion of a press showing the plate cylinder and impression cylinder and my device applied thereto, the cylinder being intermediately broken away of its length.

Fig. 2 is a longitudinal sectional View through the plate cylinder and adjacent portions, the plate cylinder being broken away intermediately of its length.

Fig. 3 is an enlarged sectional View through the plate cylinder.

Fig. 4 is a similar view to Fig. 3 through the impression Cylinder.

Fig. 5 is a sectional view oi a fragmentary portion or" the plate cylinder showing the parts in the initial attaching position.

Fig. 6 is a perspective detail of one of the wedging bars.

Fig. '7 is a fragmentary portion of the irnpression cylinder pad.

Fig. 8 is a sectional View through the bar 18.

ln the drawing lire characters of reference indicate corresponding parts in each figure.

1 and 2 indicate the side bearing standards of the machine in which the plate cylinder shaft 3 and impression cylinder shaft 4 are journalled in the usual manner and provided With intermeshing gears 5 and 6. 7 and 8 are respectively the plate cylinder and impression cylinder formed integral with or secured to their respective shafts 3 and a. The cylinders 7 and 8 are @if provided with longitudinal grooves 7X and 8X. 9 represents the printing plate forming one printing element Which is thin sheet metal and is Wrapped around the cylinder 7, the ends 9X and being bent at right angles to the pad of the f plate and inserted in each side oi the groove "IX as will hereinafter appear.

10 is the impression cylinder pad forming the other printing element which is of sheet rubber and is Wrapped around the cylinder 8 so as to contact peripherally With the exterior surface of the plate 9, the ends of the pad being inserted in the groove 8X and secured therein by means which I will hereinafter describe.

l1 and 12 are collars turnably mounted upon the shaft 3 at each end of the cylinder 7 each provided, in its inner face or the face opposing the end of the cylinder, with an eccentric groove 11X having an opening 11 formed in the eX- terior wall oi the groove for a purpose which will hereinafter appear. 1S and 14 are similar collars turnably mounted upon the shaft 4 at each end of the impression cylinder 8.

The collars 11, 12, 13 and 14 are preferably provided with an exterior knurled portion 15 so as to enable of the collar being manually gripped for the purpose of turning and if desired such portion may be provided With a series of holes for the insertion of a pin Wrench for aiding in turning the collars to their operative position.

The impression cylinder pad is provided adjacent one edge, with a series of orices 10X through Which, when such edge is inserted in the groove SX, extend short pins 16X equal in length to the thickness of the pad 10. By this means one end of the pad is attached in position, the free portion of the pad being Wrapped around the cylinder 8 and the other or free end then inserted in the groove 8X, a portion of the pad 17 being on one side of the groove and a portion 1'1X on the opposite side.

It will be noted that the bar 18 is provided, near its inner edge, with short spicular projections 18 and near its opposite edge with longer spicular projections 18, just long enough to ex- 10.5 tend through the pad and so as not to prevent the pad entering the groove 8X. When the bar is drawn edgewise into the groove, by means which I will hereinafter describe, the short pins 18X iirst engage the pad drawing it into the il.

groove to the bottom thereof, the projections 18 then engaging the pad and passes through the same so as to have a tight hold thereon to draw the pad into position tightly around the cylinder 8.

When the pad 10 is attached one end 9 of the plate 9 is inserted in the groove 7X, the cylinder '7 is then revolved with the plate in contact with the pad l0 thereby bending and wrapping such plate tightly around the cylinder 7 until the opposite end is in position for insertion into the groove.

In order to initially hold the portion 9X in the groove during this operation a bar 20 is inserted in the groove so as to bear against the portion 9X, being forced thereagainst by means of a leaf spring 21 which is secured, at its outer end, in a recess 22 formed in the bar as clearly indicated in Fig. 5, the free end of the spring 21 bearing against the opposite wall of the groove. When the opposite end 9o of the plate is inserted within the groove a wedging bai1 23 is then forced into the groove between the plate portion 9 and the opposing face of the bar 20 thereby compressing the spring 21 into the recess 22 to allow the bar to assume the position shown in Figs. 1 and 3. As the bar is forced into this position, by means which I will hereinafter describe, sharp teeth or projections 23X formed by indenting the surface of the metal bar is indicated at 23o thereby forming a projection with a transverse cutting edge which, when the bar is forced into position within the groove, cuts into the metal forming the portion 9o of the plate and draws such portion tightly into the groove and the plate into tight contact with the exterior surf ace of the cylinder 7.

I will now describe the means by which the bars 18 and 23 are forced into their securing position. As this means is identical I will only describe it in connection with the bar 23.

The bars 23 and 18 are provided at each end with the pin projections 24 and 25 which, when the bar is initially placed in the groove 7X or 8X, pass through the entering notches or opening 11 formed in the wall of the eccentric groove 11X so as to enter such groove at each end of the cylinder 'l and 8.

The collars 15 and 16 or 13 and 14 are then turned, the eccentricity of the groove in each case forcing the pins 24 and 25 inward carrying the bars radially into position within the grooves '7X and 8X as above described. By this means it will be seen that both the plate and pad are secured to a cylinder of very small diameter with the opposing ends of the plate or pad in very close proximity to each other so that practically none of the usual surface is Wasted thereby permitting of the use of a very small cylinder for the printing of small items such as letter heads enabling the interchange of a plate from job to job at a comparatively small cost. 'Ihe plate and pad are, of course, detached by turning the collars 15 and 16 or 13 and 14 in opposite directions to that above'described so that the bars 23 and 18 are forced in the opposite or outward direction to free the ends of the plate or pad.

What I claim as my invention is:

1. In a press cylinder having a narrow deep longitudinal groove therein, the combination with a printing element having inturned end edges one of which fits against one wall of said groove, a bar equal in width to the distance between both inserted inturned element ends one side face of which slidably bears against one inserted element end during the bars insertion and engaging mea-ns between the other side face of the bar and the other inturned element end adapted as the bar is inserted to draw the uninserted element end to the inserted position, and means for forcing the bar edgewise into the groove.

2. In a press cylinder having a narrow deep longitudinal groove therein, the combination with a printing element having inturned end edges one of which is anchored to one wall of said groove, a bar equal in width to the distance between both inserted inturned element ends, one side face of which slidably bears against one inserted element end during the bars insertion, and teeth formed on the other side face adapted to engage and tear into the other inturned edge portion of the element as it is drawn thereby into the groove as the tension on the element approaches the stretching point of the element.

3. In a press cylinder having a narrow deep longitudinal groove having parallel walls, of a printing element having inturned end edge portions, one of said inturned ends fitting against one wall of the groove, a bar equal in Width to the distance' between both inserted inturned element ends one side face of which slidably bears against one inserted element end during the bars insertion, and teeth formed on the other side face of the bar equal in depth to the thickness of the element so that the cutting edges of the teeth reach the other side wall of the groove and adapted when engaged to tear into the other inturned edge portion of the element as it is drawn thereby into the groove and as the tension of the element aproaches the stretching point of the element.

WALTER HAROLD SMITH.