US1535224A - Sheet grippers - Google Patents

Description

April'zs, 1925.- l 1,535,224

C. W. HARROLD SHEET GRIPPERS Filed Oct. '7. 1921 Patent-ed Apr. 28, 1925.

UNITED STATES PATENT oFFicE.

CHARLES W. HARROLD, OF CLEVELAND, OHIO, ASSIGNOR T THE HARRIS AUTOMATIC PRESS COMPANY, 0F CLEVELAND, OHIO, A CORPORATION lOF OHIO.

sumar enrrrnns.

Application filed October 7, 1921. Serial No. 506,169.

To all whom t may concern.'

Be it known that I, CHARLES a citizen of the United States, residing in the city ofCleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Sheet Grippers, of which the following is a specification, reference being made to the accompanying drawings forming a part thereof.

My invention relates to improvements in the gripping devices usuallyl employed 1n printing presses for transferring sheets of and it is extremely difficult, or practically impossible, to adjust and clamp the separate grippers on the bar with sufficient accuracy so that each gripper in the set will bear with like pressure lon the sheet. The common experience has been that two or three grippers may do the work in holding the sheet,

- while others are unable to do any practical holding of the sheet due to the inequalities of the adjustment and clamping of such grippers on the gripper bar. This results in requent pulling out of the sheet from the grippers, necessitating stopping the press and spoiling the disengaged sheet.

A further feature of novelt vision of a spring mechanism y which the individual grippers need be set on the gripper `bar with only approximate accuracy, yet all the individual grippers will perform an equally distributed service in holding the sheet with suiiicient firmness along the entire leading edge, thereby decreasing in a marked degree the likelihood of the sheet pulling loose or tearing while carried by the cylinder.

In the accompanying drawings, Figure 1 shows an end view of a press cylinder carrying my improved spring-gripper mechanism as one embodiment of my invention;

Figure 2 is a fragmentary plan view;

Figure 3 is an enlarged det-ail side view W. HARROLD,y

is the proof the spring i er lin' er the end of the finger being bigdkgrri) olf; g

Figure 4 is a plan view thereof;

Figure 5 is enlarged end view of the griaper looking from the right in Fig. 3; an

Figure 6 is a sectional plan view, the section belng taken on the line 6--6 of Fig. 3 lookin in the direction of the arrow.

Similar numerals refer to similar throughout the several figures.

Referring to the drawings, more particularly Figs. 1 and 2, the cylinder 7 of the press is mounted on the shaft 8 which is journalled in the usual manner in the frame 9 by means not shown. The gripper bar 10 is journalled in both ends of the cylinder 7 so as to oscillate therein to open and close the grippers carried by such bar. On one end of 'the gripper bar 10 is the arm 11 (shown in Figs. 1 and 2) carrying the camroller l2 which rides in the fixed cam 13 secured to the frame 9. On the opposite end of the gripper bar l0 (see Fig. 1) isthe arm 14 carrying the rod l5 on which is arranged the large coil spring 16 held under pressure by the block 17 secured to the end ofthe cylinder 7 by which mechanism the grippers '18 are forced downwardly on the surface 'of the cylinder 7 to hold the sheet. Since these parts are common forms of printing machinery .construction and are well-known in the art, they need not be more fully described.

Secured to the gripper bar 10 are a series of spaced-apart split collars 19 rigidly alixed thereto by thc screw bolts 20, as shown in Fig. 5. Each collar 19 has the integrally formed projection 23 extending transversely therefrom; adjoining each split collar 19and loosely mounted on the gripper bar 19 is the gripper bracket 24 to carry the gripper finger 18, the bracket having the upper jaw 25 and the lower jaw 26 within which is contained the projecting lug 23 of the collar 19 as shown in Figs. 5 and 6. The projecting lug 23 has a socket 27 formed in its top surface through which socket and the jaws 25 and 26 passes the bolt 28 secured by the pin 29 to hold the bracket 24 in alineinent with the collar 19. Coiled about the bolt 28 is the compression spring 30 the lower end bearing in the socket 27 while the upper end bears against the upperjaw 25 of the gripper bracket 24. The projecting partsv Macnee lug 23 maintains the gripper bracket 24, loosely mounted on the bar 10, in close proximity to the split collar 19 clamped to the bar 10 by the screw bolt 2O with the gripper 18 normally slightly depressed through the expansion of the spring 30.

The operation of my improved sheet-gripper is substantially as follows: When the gripper barllO is oscillated by the cam 13 so asd to close the gripper fingers 18 on the sheet, the coiled sprlng 16 serves to compress all of the gripper fingers 18 on the cylinder 7, as shown in Fig. 1, while the individual coiled springs 30"'on each gripper yieldingly equalize the pressure among the individual gripper fingers 18 so that if one gripper bears with too great a pressure the coil spring 30 is compressed to slightly raise such ripper to aline with the others on the b cylin er 7 to the end that each individual gripper 18 yieldingly holds the sheet with like firmness on the cylinder 7 through the varying compression of the separate springs 30 relieving any excess pressure on any particular gripper 18 from the large coil spring 16, while affording suiiicient pressure should the pressure of the spring 16 fail to act.

A further advantage 1n using the closed cam 13 is that the cylinder 7 may be rotated at a very high speed without rebounding or jarring the parts, so that. where closed cams are used for positively opening and closing the grippers, grippers rigidly fixed to the gripper bar 10 could not be usedwith safety, but where each of the gripper fingers is yieldingly held in spring tension, as hereinbefore shown and described, the positive stroke to the gripper bar and lingers through the cam 13 would not Lend to tear or loosen the sheet from such fingers, all of which would bear with equal firmness on the cylinder 7 in maintaining the sheet thereon under an evenly distributed pressure.

While the construction herein shown and described embodies the invention in its pre erred form, it will be understood that changes and variations may be made in the various parts without departing from the principles and scope of the invention.

l claim as my invention:

1. ln a sheet-gripper mechanism, a sheet support, an oscillatable gripper-bar, a plurality of grippers rotatably mounted on said bar to close on said support, means, carried exteriorly by, and laterally adjustable, on said bar for variably and adjustably limiting the rotative movement of each of said grippers, means for opening and closing said grippers in unison includin yieldingly compressing said grippers collectively on the said support, and resilient means between each gripper and said first mentioned means for holding thegripper in individual yielding contact with said support while closed, said resilient means norrneans forl mally forcin `each gripper to its limit on said gripperar.

2. In a sheet-gripper mechanism, a sheet support, an oscillatable gripper-bar, a plurality of grippers rotatably mounted on said bar to close on said support, means, carried exteriorly by, and laterally adjustable, on said bar for variably and adjustably limiting the rotative movement of each of said grippers, means for opening and closing sald grippers in unison including means for yieldingly compressing said grippers collectively on the said support, and separate resilient means carried'between said first mentioned means and each gripperto equalize the pressure of each nger when closed on the sheet, said resilient means normally forcing each gripper to its limit on said gripper- 3. ln a sheet-gripper mechanism, a sheet support, an oscillatable ripper-bar, a plurality of grippers rotatablly mounted on said bar to close on said support, projecting lugs, Carried exteriorly by, and laterally adjustable, on said bar for variably and adjustably limiting the rotative movement of each of said grippers, means for opening and closing said grippers in unison including means for yieldingly compressing said grippers collectively on the said support, and a coil spring between each gripper and each projecting lug arranged in the same plane transversely as said grip-per movement to equalize the pressure of each gripper when closed on the sheet, said spring normally forcing each gripper to its limit on said gripper-bar.

4f. A sheet-gripper comprising a relatively fixed sheet support, an oscillatable ygripperbar, a gripper finger to close against said support having a pair of jaws loosely mountlil@ ed on the gripper-bar, a collar adjustablyv secured to said gripper-bar adjacent the gripper-.finger having a projecting lug extending laterally between the gripper jaws,

and a compression spring arranged between sald projecting lug and upper jaw to exert pressure on the gripper-finger directly in the same transverse plane as said finger closes against said sheet support. f

5. A--sheet-gripper comprising arelatively fixed sheet support, an oscillatable gripperbar, a gripper linger to close against "said support having a pair of jaws loosely mounted on the'gripper-bar, a collar adjustably secured to said gripper-bar adjacent the gripper-finger having a projecting lug extending laterally between the gripper jaws, a bolt passing through said jaws and projecting lug, and a compression spring coiled 4about the bolt between said projecting lug and upper jaw to exert pressure on the gripper-finger directly* in the same transverse plane as said linger closes against said sheet support.

6. A. sheet-gripper comprising a relatively 4fixed sheet support, an oscillatable gripperjecting lug, and removably secured thereto,

ar, a gripper linger to close against said and a compression spring coiled about the 10 y support havlng a pair of jaws loosel mountbolt between said projectlng lug and upper ed on the grlpper-bar, a collar a justably jaw to exert pressure on the gripper-Enger i secured to said 'gripper-bar adjacent the directly in the same transverse plane as said gripper-finger having a projecting lug exlinger closes against said sheet support. tending laterally between the gripper ]aws,

a lbolt passing through said jaws and pro- CHARLES W. HARROLD.

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