US2714852A

US2714852A - Device for securing and tensioning a flexible transfer blanket on a cylinder

Info

Publication number: US2714852A
Application number: US97295A
Authority: US
Inventors: Laszlo M Stempel
Original assignee: ALBERT CHARLES NOLTE; LASZLO M STEMPEL
Current assignee: ALBERT CHARLES NOLTE; LASZLO M STEMPEL
Priority date: 1949-06-04
Filing date: 1949-06-04
Publication date: 1955-08-09
Anticipated expiration: 1972-08-09

Description

Aug. 9, 1955 M. STEMPEL FOR SECURING AND TENSIONING A DEVICE FLEXIBLE TRANSFER BLANKET ON A CYLINDER Filed June 4, 1949 NQI INVENTOR LASZLO M. STEMPEL ATTORNEY United States atent DEVICE FOR SECURING AND TENSIONING A FLEXIBLE TRANSFER BLANKET ON A CYL- INDER Laszlo M. Stempel, New York, N. Y., assignor to Laszlo M. Stempel, New York, N. Y., and Albert Charles Nolte, Plandome, N. Y., joint trustees Application June 4, 1949, Serial No. 97,295

4 Claims. (Cl. 101-415.1)

The present invention relates to transfer cylinders for applying a printed or lithographed impression to a web of paper or other material.

More particularly, the invention relates to means for securing and tensioning a flexible transfer blanket which is wrapped around the periphery of the cylinder.

Arrangements for the tensioning of the flexible transfer blankets are known in the art, and these generally teach the fastening of one end of the blanket within a slot in the cylinder. The free end is then drawn into the cylinder slot adjacent to the end which is already secured therein. Such tensioning arrangements have the effect of tightening the transfer blanket about the circumference of the cylinder by means of tension applied to only one end of the blanket. Because of frictional forces between the inner surface of the blanket and the periphery of the transfer cylinder, there is a tendency towards eccentricity resulting from non-uniformity of the circumferential tension forces in the flexible transfer blanket. Accordingly, it is an object of the invention to provide a transfer blanket fastening arrangement in which the tension is applied substantially equally to both ends of the transfer blanket.

A further object of the invention is to provide a recess in the transfer cylinder adapted to receive the tensioning devices for both ends of the transfer blanket, and which will render a minimum portion of the cylinder circumference unusable for printing purposes.

Still another object of the invention is to provide fastening and tensioning members adapted to fit Within a recess in the cylinder, and which will effectively close the recess when the blanket is tensioned about the circumference of the cylinder.

Other and further objects will become apparent upon reading the following specification, together with the accompanying drawing which forms a part thereof.

The present invention is in the nature of an improvement upon the invention disclosed and claimed in my copending application, Serial No. 33,636, filed June 17, 1948, for Transfer Printing Mechanisms.

In the drawing:

Fig. 1 is a transverse sectional view showing a cylinder,

a blanket, and associated parts embodying features of the invention, the section being taken along the line 11 of Fig. 4 looking in the direction of the arrows, and the blanket being shown as partially applied;

Fig. 2 is a view similar to Fig. 1, but showing both blanket clamps lodged in the cylinder recess and the collars turned to a retaining position;

Fig. 3 is a view similar to Fig. 2, but showing the collars turned still further to retain the blanket clamps in positions such that the blanket will be held taut; and

Fig. 4 is a view in sectional elevation, partly broken away, of the transfer cylinder of Figs. 1 to 3, the section shown at the left-hand portion of Fig. 4 being taken along the line 4-4 of Fig. 3, looking in the direction of the arrows.

Referring to Fig. 1, a transfer cylinder 11 is provided with a longitudinal slot 12 adapted to receive a pair of 1 bar 14 and a cooperative clamping bar 28.

bar members 13 and 14. Slot 12 is so shaped that bar member 14 may first be inserted within the slot and pushed to one side, as shown in Fig. l, and the bar member 13 may then be inserted.

Collars

15 and 15 are provided with

eccentric recesses

16 and 16, and with apertures 1'7 letting into the recesses. The purpose of the collars will be explained a little farther on. Each of the collars and 15 is shown made in two sections secured together by bolts 18, which serve to assemble each collar with capacity for free rotation upon a neck portion 19 of cylinder 11.

The cylinder 11 is shown with extended shaft portions journalled in suitable bearings 21, the bearings being supported by side walls 22 of the printing press or other machine. Suitable provision is made for driving the transfer cylinder, and for bringing it into engagement with the printing plate and with the web of material to be printed. These facilities are well-known in the art, and may take any desired form.

A transfer blanket 25 is provided at opposite ends with sets of holes, spaced to conform to the spacing of rivets or screws 26 and 27. The rivets 26 clamp one end of the blanket to the bar 13, while the rivets 27 are applied through the opposite end of the blanket and through the The bars 14 and 28 are located at opposite sides of the blanket, and are drawn together by the rivets to clamp the blanket between them.

in operation, the bar member 14 is first inserted within the slot 12 as in Fig. 1. The bar member 14 extends beneath an overhanging shoulder in the recess and is thereby guarded temporarily against accidental dislodgement. The bar member 13 is then inserted. The condition at the beginning of the insertion of the bar 13 is also illustrated in Fig. 1.

" posite end portions of the blanket above the bars 13 and 23, and fills the remaining width of the slot 12.

The bar 29 is provided at its opposite ends with extensions 31 which are caused to enter the

eccentric recesses

16 and 16 through the apertures 17 slightly before the bar 29 reaches the position illustrated in Fig. 2. After these end portions have been passed through the opening 17, the

eccentric collars

15 and 15 are rotated substantially equally to draw the ends of the bar member 29 radially inward within the slot 12 towards the center of the cylinder.

Since, at this time, the bar member 29 engages both the bars 13 and 23, both ends of the transfer blanket are forced equally into the slot and towards the center of the cylinder by the bar member 29. The blanket 25 is thus drawn snugly around the periphery of the cylinder 11 with a tension which is substantially equally applied at both ends of the blanket. Unevenness in tension along the bar members 13 and 28 may be equalized by separate rotation of one of the

eccentric collars

15 or 15.

In the final position of the parts, as illustrated in Fig. 3, the bar member 29 is drawn completely within the slot 12, so as not to protrude beyond the periphery of the cylinder and the blanket.

The bar 29 is formed with an external groove 30 so that a cold chisel or other driving tool placed against it will have no tendency to slide off.

When it is desired to remove a blanket from a cylinder, the

collars

15 and 15 are first turned to align the openings 17 with the slot 12. The inner faces of the end portions of the bar 29 are formed with cut-outs or recesses 32, which overlie recessed portions 33 of the cylinder 11. A screw driver or other prying tool may be inserted in the notches and used as a lever for starting the bar 29 outward. The bar 29 can then be freely withdrawn and a new blanket can be substituted in an obvious manner.

I have described what I believe to be the best embodiment of my invention. I do not wish, however, to be confined to the embodiment shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. In a transfer press, the combination with a transfer cylinder having a longitudinal recess therein, and a relatively narrow aperture communicating with the recess through the periphery of the cylinder, of a of bar members shaped to pass individually through the aperture, and to lie side by side and in engagement with each other within the recess, a flexible blanket wrapped around the periphery of the cylinder and secured at its 1 opposite ends to the respective bar members, a third bar member broad enough to substantially fill the aperture space between the blanket ends adapted to be inserted through the aperture and into simultaneous engagement with the outer faces of the other two bar members in the recess, and individually adjustable tightening means disposed adjacent the respective ends of the longitudinal recess and each adapted through the third bar to urge the adjacent ends of the first and second bars radially inward toward the cylinder in substantially equal degree.

2. In a transfer press, the combination with a transfer cylinder having a longitudinal recess therein of uniform cross-section, said cross-section being shaped to provide a relatively narrow entrance portion through the periphery of the cylinder and an enlarged internal portion, a pair of bar members shaped to pass individually through the aperture and to lie side by side and in engagement with each other within the enlarged portion of the recess, a flexible transfer blanket wrapped around the periphery of the cylinder and secured at its opposite ends to the respective bar members, and a pair of rotatable collars each mounted adjacent one end of the cylinder and in coaxial relation thereto, and each having a cylindirical opening therein eccentric with respect to the cylinder, 2. third bar member broad enough to substantially fill the aperture space between the blanket ends adapted to be inserted into the recess between the blanket ends and into simultaneous engagement with the outer faces of the two bar members, said third bar member having protruding ends insertable into the cylindrical openings of the respective collars, each collar being arranged upon rotation thereof relative to the cylinder to act through the third bar member to urge the associated ends of the other bar members substantially radially inward toward the center of the cylinder in substantially equal degree.

3. In a transfer press, in combination, a transfer cylinder having a longitudinal recess formed therein, and a relatively narrow aperture communicating with the recess through the periphery of the cylinder, of a pair of bar members shaped to pass individually through the aperture and to lie simultaneously in the recess in engagement with one another, a flexible blanket wrapped around the periphery of the cylinder and secured at its opposite ends to the respective bar members, a third bar member insertable in the aperture in position to overlie the first two bar members and broad enough substantially to fill the aperture space between the blanket ends, said third bar member when forced inward being adapted to urge both of the two first-mentioned bar members inward toward the center of the cylinder simultaneously and at substantially the same rate.

4. In a transfer press, the combination, a transfer cylinder having a longitudinal recess formed therein, a relatively narrow aperture communicating with said recess through the periphery of the cylinder, a pair of bar members shaped to pass individually through the aperture and to lie simultaneously in the recess in engagement with one another, a flexible blanket wrapped around the periphery of the cylinder and secured at its opposite ends to the respective bar members, a third bar member insertible in the aperture in a position to engage said pair of bar members and broad enough so that its width and that of the two blanket sections substantially fill the aperture space, said third bar member when forced inward being adapted to urge both of the two first mentioned bar members inward toward the center of the cylinder simultaneously and at substantially the same rate.

References Cited in the file of this patent UNITED STATES PATENTS 2,279,204 Neilson Apr. 7, 1942 2,388,193 Stempel Oct. 30, 1945