US3675573A

US3675573A - Blanket bar and adapter bar assembly for printing blanket

Info

Publication number: US3675573A
Application number: US68728A
Authority: US
Inventors: Ronald W Hawks
Original assignee: Roberts and Porter Inc
Current assignee: MIDLAND COLOR Co
Priority date: 1970-09-01
Filing date: 1970-09-01
Publication date: 1972-07-11
Anticipated expiration: 1989-07-11

Abstract

An assembly for attaching a printing blanket on a press cylinder of an offset printing press. An adapter bar and blanket bar are provided with cooperating features which provide interlocking engagement for quick and easy mounting by way of a quick release locking means.

Description

O United States Patent n51 3,675,573 Hawks [451 July 1 l, 1972 s41 BLANKET BAR AND ADAPTER BAR 1.578.736 3/1926 John...............................v..101/415.l ASSEMBLY FOR PRINTING BLANKET 2,694,976 11/1954 Huck..... |0l/41$.l 1,215,344 2/1917 C1ark..... ..l0l/415.l lnvenlofl "mks, Des 2,046,122 6/1936 non/41s.! x Asslgnee: Rubens Porter Inc. Primary Examiner-Clyde l. Coughenour [22] Filed: Sept. 1, 1970 Attorney-Molinare. Allegretti. Newitt 8: Witcofi" [2|] Appl. No.2 68,728 57 BS An assembly for attaching a printing blanket on a press (52] US. Cl .1..l0l/4l5.l, 101/378 cylinder ofan offset printing press. [51] Int. Cl. r v ..B4ll'27/l2 An ada pter bar and blanket bar are provided wlth cooperatmg [581 Field 4 features which provide interlocking engagement for quick and easy mounting by way of a quick release locking means. [56] References Cited 3 Claims, 5 Drlwlng figures UNITED STATES PATENTS l,39|,ll7 9/l921 Huebner ..10l/415.1

BLANKET BAR AND ADAPTER BAR ASSEMBLY FOR PRINTING BLANKET BACKGROUND OF THE INVENTION This invention relates to an assembly of an adapter bar and a blanket bar for securely attaching a rubber printing blanket to a press cylinder of an offset printing press.

Printing blankets used on offset printing presses comprise an elongated sheet of material having a heavy cotton backing and the upper face thereof being coated with rubber or synthetic material to provide a surface which is utilized to pick up the ink image from an ofi'set plate or other image carrier for transfer onto a sheet of paper or other material to be printed. The leading and trailing edges of the blanket are each provided with what are known as blanket bars, with portions engaging opposite surfaces of the end portion of the blanket. The press cylinder is provided with a suitable recess or opening in its periphery into which the ends of the blanket with the blanket bars attached are inserted and firmly attached. Mounted within the recess of the press cylinder are suitable adapter bars into which the blanket bars, at the opposite ends of the blanket, are firmly secured. The adapter bars are usually associated with suitable mountings for adjustment of the adapter bars, to take up slack in the blanket and insure a firm fit of the blanket against the surface of the press cylinder. Heretofore, blanket bars were formed of elongated strips of metal or other rigid material firmly attached to the opposite surfaces of the blanket, adjacent the ends thereof. Usually such strips are secured in place by bolts, screws or rivets, and/or by the use of various types of adhesive, or any other suitable means of attachments. The matter of attaching such strips to the ends of the blanket are time consuming and result in numerous disadvantages.

More recently a new type of blanket bar has been devised, and which is of generally V shape in cross-section, comprising a pair of elongated leg portions, interconnected at corresponding edges, for embracing the entire end portion of the blanket. Such recent types of blanket bars are usually provided with a plurality of ridges or sets of prongs, extending longitudinally of the bars, on the inner surface of the legs thereof, and which serve to bit into the blanket when the bar embraces and is compressed around the end portion of the blanket, for firmly gripping and securing the blanket bar to the end of the blanket. The ridges or prongs on the inner surface of one of the legs are offset with respect to the ridges or prongs on the inner surface of the other leg to provide a firm interlocking grip on the blanket. Such types of blanket bars are formed as extrusions of aluminum or other suitable metal and are capable of being quickly and easily attached to the blanket. Blanket bars of this general category are disclosed in Kirkpatrick US. Pat. No. 3,296,673,dated Jan. 10, I967.

More particularly, the present invention is directed to a novel assembly of an adapter bar and blanket bar, provided with cooperating features which provide interlocking engagement of the bars and which pennits quick and easy mounting of a blanket bar in an adapter bar for securing the blanket in proper relation to the outer surface of the press cylinder.

Another object is to provide a novel assembly of an adapter bar and a blanket bar which permits quick and easy mounting or demounting of the blanket bar with respect to the adapter bar, together with fastening means for quickly and easily locking the blanket bar in operative position in the adapter bar or for permitting quick and easy removal of the blanket bar from the adapter bar to provide quick and easy placement of the blanket in proper operative relation to the surface of the press cylinder or removal therefrom.

A further object of this invention is to provide means for visually indicating whether the blanket bar is in locked or unlocked position with respect to the adapter bar when the two bars are assembled.

Other objects and advantages of this invention will be apparent from the following description, taken in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged, fragnentary, perspective view of an amembly of an adapter bar and blanket bar, with a printing blanket secured to the blanket bar and embodying the present invention.

FIG. 2 is a sectional view, taken at line 2-2 on FIG. 1, showing the adapter bar and blanket bar, with the blanket attached to the latter, positioned in cooperating relation, with the fastening means shown in an unlocked position.

FIG. 3 is a sectional view similar to FIG. 2 but showing the fastening means in operative position for positively and securely locking the blanket bar in the adapter bar.

FIG. 4 is a fragmentary, longitudinal view, part in section. through the adapter bar, taken at line 4-4 on FIG. 2. with the blanket bar omitted.

FIG. 5 is a fragmentary perspective view of the blanket bar in its initial position, preparatory to receiving the end of a blanket.

DESCRIPTION OF THE PREFERRED EMBODIMENT As may be seen in the drawing, the assembly comprises an adapter bar A and a blanket bar B mounted in the adapted bar and with one end of the printing blanket, indicated generally at C, secured to the blanket bar. The adapter bar as shown is of a design which is especially adapted for use with certain well-known offset printing presses. The adapter bar may be of different configuration and dimensions for use in other different types of presses. It is to be understood that the adapter bars and blanket bars usually are of a length corresponding to the width of the printing blanket with which it is to be used. Widths and lengths of printing blankets for different models of presses varies substantially, and usually are in the range of 22 inches to inches wide.

The adapter bar A has a body or base 10 formed with an elongated channel 12, extending from end to end of the body. The channel has a flat bottom wall 14, with the forward edge defined by an upstanding abutment l6, and its rear edge defined by an upstanding wall 18 which continues into a forwardly extending lip portion 20. The inner surface of the lip portion is spaced from the bottom wall [4 which together with the wall 18 defines a generally U-shaped portion 22 of the channel. The inner surface of the abutment 16 is shaped to provide a V-shaped tongue or ridge 24, preferably extending the full length of the adapter bar, with the opposite surfaces of the tongue defining an angle in the general range of 45.

The outer shoulder of the body 10 of the adapter bar A, is fonned with appropriate slots or openings 25, for receiving fastening elements for securing the adapter bar to its mounting in the reces of the press cylinder.

Mounted in the U-shaped portion 22 of the channel, against the inner surface of wall 18, are a plurality of longitudinally spaced apart, compressible, resilient pads 26, formed of sponge rubber or other synthetic material. The surface of the pads, ad'acent said wall 18, are provided with a suitable coating of adhesive for securing them in position in the channel. The pads may be of small size, in the range of l inch long and may be spaced suitable distances apart, such about I 2 inch.

The blanket bar 8 may be formed of various material and various shapes and as shown in the drawing the bar is formed as an extrusion of aluminum or other suitable material and initially is of generally V-shaped formation, including a pair of inter-connected spaced apart

legs

30 and 32, with the spacing of the legs at the juncture being suficient to accommodate the hickness of the end of the printing blanket C. The inner surfaces of the

legs

30 and 32 are provided with a multiplicity of longitudinally extending ridges 34, of generally V-shaped cross section, with the ridges on one of the legs being staggered or offset with respect to the ridges on the other leg so that when the blanket C is placed into the blanket bar and the legs are compressed together, the two sets of ridges serve to firmly grip and bite into the blanket material, as seen in FIG. 2 of the drawing, for positively gripping and attaching the blanket bar 8 to the blanket C. Preferably, although not absolutely necessary, the inner surfaces of the

legs

30 and 32 are coated with a suitable adhesive to insure a permanent gripor bond with the blanket. The outer free edge of the lower leg 32 of the blanket bar B is formed with a longitudinally extending V-shaped groove 36, with opposite main surfaces of the groove positioned at an angle of approximately 45 to each other.

When the blanket bar B, with the blanket C secured thereto, is being mounted in the adapter bar A, the closed end of the blanket bar is inserted into the U-shaped channel portion 22, in contact with the resilient pads 26, to compress them sufficiently so that the forward end of the lower leg 32 of the blan' ket bar clears the tongue 24 of the abutment l6 and permits seating of the blanket bar B against the flat bottom surface 14 of the channel 12 of the adapter bar. The resiliency of the pads 26 serves to urge the blanket bar 8 in a forwardly, or outwardly direction so that the V-shaped groove 36 is moved and guided into cooperative engagement with the V-shaped tongue 24 of the abutment 16, for locking the forward edge of the assembly together. In this position, the upper surface of the leg 30 of the blanket bar, adjacent the closed end thereof, is disposed in relatively close relation to the inner surface of the lip of the adapter bar.

Suitable fastening means is provided for quickly and easily releasably securing the blanket bar B, with the printing blanket C attached thereto, in the adapter bar A. This means comprises two or more fasteners, preferably Allen Head type screws 40, mounted in threaded openings formed in the lip portion 20, the wall 18 and the base 10 of the adapter bar, as seen in FIGS. 2 and 4. Each of the fastening screws is formed with a longitudinally extending notch 42, of a length at least equal to the distance between the under surface of the lip 20, and the flat bottom surface 14 of the channel. The depth of the notch is such that in one position of adjustment, as hereinafter described, the fiat bottom surface of the notch is approximately flush with the inner surface of wall [8 of the adapter bar A. The head of each of the screws is cut to provide a flat index surface 46, which is circumferentially aligned with the fiat bottom surface of the notch 42 in the screw, as clearly seen in FIG. 2.

in order that the blanket bar B with the printing blanket attached may be initially positioned in cooperative relation in the channel 14 of the adapter bar A, as seen in FIG. 2, the screws 40 must be positioned so that their notches 42 and the flat index surfaces 46 on the heads face in the direction of the blanket bar. To securely lock the blanket bar B in the adapter bar A, the screws 40 are rotated 180, to the position seen in FIG, 3 of the drawings, so that the threads of the screws 40 bite into the outer surface of the closed end portion of the blanket bar B and forcibly urge the blanket bar forwardly for full inter-engagement of its V-shaped groove 36 with respect to the'V-shaped tongue 24 on the abutment 16 of the adapter bar, Such positive movement simultaneously forces the blanket bar in a downward direction and wedges the lower surface of the V-shaped groove 36 against the under surface of the shaped tongue 24 on the abutment, to positively lock the blanket bar in fixed relation to the adapter bar. It will also be apparent that the tongue and groove features on the abutment shoulder 16 of the adapter bar and the outer free end of the lower leg 32 of the blanket bar also initially serve to guide and seat the blanket bar in a proper cooperating relation to the adapter it will be noted from FIG. 3, when the screws have been rotated to securely lock the blanket bar in the adapter bar, the flat index surfaces 46 of the screws 40 are aligned with the top edge of the outer surface of the upright wall 18 of the adapter bar to visually indicate that the bars are in locked position. Likewise when the screws are in the position seen in FIG. 2, the index surfaces indicate an unlocked relation of the assembly of the bars.

It is apparent that the adapter bar, when mounted in the recess of the press cylinder, permits the blanket bar with the blanket attached, to be quickly and easily detachably secured in coo rative relation by merely rotating the fastenin screws 40, 1E8". Thus, substantial time is saved in attac ing or detaching the printing blanket in operative relation to the surface of the press cylinder.

What is claimed is:

1. in an assembly for attaching a printing blanket on a press cylinder of an offset printing press, comprising an elongated adapter bar formed for attachment within a recessed portion of a press cylinder and provided with a base having a channel extending from end to end and having a bottom wall with its forward edge defined by an upstanding abutment shoulder and its rearward edge defined by an upstanding wall which continues into a forwardly extending lip portion with its under surface spaced from the bottom wall to form a U-shaped portion of the channel, an elongated blanket bar having portions secured to opposite sides of a free end portion of a printing blanket and adapted to be detachably mounted in the adapter bar to position the blanket on the press cylinder, the inner surface of said abutment shoulder on the adapter bar being engageable by the inner edge of the underside portion of the blanket bar, the improvement comprising means carried on the adapter bar for coacting with the outer edge of said blanket bar for wedging the inner end of the underside side portion of the blanket bar against said abutment shoulder and positively locking the blanket bar to the adapter bar, said means comprising a threaded type headed fastener threaded through said lip of the adapter bar and adapted to extend, in one position of adjustment, across said U-shaped portion of the channel of the adapter bar into wedging engagement with the outer edge of the blanket bar, said fastener having a portion of its shank cut away for a length at least equal to the space between the underside of the lip and the bottom wall of the channel, providing a flat face, which in another position of adjustment of the fastener disposed substantially flush with the inner surface of the closed end of said U-shaped portion of the channel.

2. The construction defined in claim I, wherein the head of the fastener being provided with an index feature adapted to be selectively registered with a feature on the upper surface of said lip portion of the adapter bar to visually indicate the position or location of said flat face of the cut away portion of the screw.

3. The construction defined in claim 1, wherein the threaded fastener is threaded through the lip and into the base of the adapter bar.

l i i i

Claims

2. The construction defined in claim 1, wherein the head of the fastener being provided with an index feature adapted to be selectively registered with a feature on the upper surface of said lip portion of the adapter bar to visually indicate the position or location of said flat face of the cut away portion of the screw.