US1275002A

US1275002A - Gripper-motion.

Info

Publication number: US1275002A
Application number: US20863917A
Authority: US
Inventors: Michael A Droitcour
Original assignee: Individual
Current assignee: Individual
Priority date: 1917-12-24
Filing date: 1917-12-24
Publication date: 1918-08-06
Anticipated expiration: 1935-08-06

Description

M. A. DROITCOUR.

GRIPPER MOTION.

APPLICATION FILED DEC.24, |917.

1 ,275,002 Patented Aug. 6, 1918.

MICHAEL A. DROITCOUR, 0F DELPI-IOS, OHIO.

GRIPPER-MOTION.

To all whom t may concern:

Be it known that I, MICHAEL A. DROIT- tCOUR, a citizen of the United States, residing at Delphes, in the county of Van Wert and State of Ohio, have invented certain new and useful Improvements in Gripper- Motions; and I hereby declare 'that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form part of this specification. n

This invention is an improvement in gripper mechanisms such as are used on the impression cylinders and transfer reels of printing presses and in other mechanisms wherein cylinders or reels provided with grippers are used to handle sheets of paper and the like, or to transfer such sheets from one point to another.

The object of the present invention is to simplify and improve the means for operating the grippers; to cause the grippers to securely hold the sheets when closed thereon; to remain in inoperative position when opened; to lessen the shock and strain upon the tumbler and tumbler-pins in opening and closing the grippers; and to provide an eiiicient gripper mechanism which will be capable of operating easily and reliably at high speeds. p

I will explain one preferred embodiment of the invention as illustrated in the accompanying drawings and summarize in the claims the essential features and combinations of partsfor which protection is desired. l

In said drawings:

Figure l is a partial end elevation of a cylinder provided with my novel gripper operating mechanism and showing the grippers closed in full lines. 1

Fig. Q is a top plan view of Fig. l showing the gripper actuating devices.

Fig. 3 is a View similar to Fig. showingthe grippers opened.

The cylinder l may be the impression cylinder of a printing press, or a transfer cylinder or reel for handling sheets. A rock shaft 2 carrying the gripper fingers is mounted in said cylinder in the usual manner, and has a slotted tumbler 2a on its outer end, which in the construction indi- 1 but cated is adapted to be alternately engaged by tumbler-pins 3 and 3b, whichmay be mounted adjacent the end of the cylinder and operated in the usual manner by suitable means, not shown, so that each will be pro- Specication of Letters Patent.

jected at the proper time into position to engage the tumbler and operate the same in the usual manner and then retracted out of the way. Attached to the gripper shaft@ are gripper fingers 2b which arev adapted to engage the end of the sheet when the grippers are closed (as in Fig. l) and to release the .sheet when the grippers are'opened, as in Fig. 3.

Mounted on the shaft 2 adjacent the tumbler 2a is a cam disk L which is preferably substantially circular, and is provided with a major peripheral recess 4a which is Vengaged by the controlling device when the grippers are closed (see Fig. l) and with a minor peripheral recess 4b which is also engaged by the controlling device when the grippers are opened (see Fig. 3).

These A"recesses la and t" are adapted to be engaged by the controlling device, which is preferably a roller 5 mounted on a pin 5a, supported in the bifurcated head 6*l of a rod 6, which rod passes through an eye 6b attached to the cylinder head. An expansion spring Gc is preferably strung on the rod between the head 6'?t and the lug 6b kso as to normally project; the roller toward the cam. The movementof the roller toward the axis of the Cani however is controlled by a link 7 shown as having a bifurcated end 7a embracing` the head 6a and pivotally connected with the pin 5a; and the other end of the link 7 is pivoted on al stud 7 b attached to the cylinder head within the gripper pocket inthe cylinder.l

The link 7 controls and limits the inward movement of the cam rollerv 5 toward the shaft 2, and the spring 6c normally tends-to Vproject this roller past cam 4; and it will be observed that when the roller 5 is engaged with the recess 4a the line of movementof the cam roller 5 under the action of the spring 6 is practically perpendicular to a radial line drawn from the axis of the shaft 2 or cam 4 as indicated by the dotted lines X*X in Fig. 1. Consequently the spring pressure is not'directed inward toward the axis of the cam 4 but against one end of the recess ta; and `when roller 5 is in recess 4a,

practically the `full pressureof the spring is exerted on cam 4 to directly close the fingers 2b and hold them forcibly butl yieldin gly in Contact with the edge of the pocket, so that they will `yieldingly but securely grip the edge of a sheet of paper S, which hasbeen placed in position to' be engaged by Patented Aug. 6, 1918. Application filed December 24, 1917. Serial No..208,639.

the grippers, when they close in the well understood manner.

At the time in the revolution of the cylinder when it is desired to open the grippers the pin 3b is moved into position to engage tumbler 2, see Fig. e, said pin Sb'being so located as to enter the mouth of the slot in the tumbler and as the cylinder rotates cause the tumbler to turn the gripper shaft 2 approximately 120 degrees to the position indicated in Fig. 3; in which position the cam roller 5 engages the minor notch 4b in cam 4 and will hold the grippers securely Open;

T he recess 4b in cam 4 is preferably smaller and more shallow than recess 4, and when the roller 5 engages recess 4b, see Fig. 3, the point` of contact of the roller against the cam member 4 is almost directly below the cam shaft 2 and the link 7 then controls the movement of the roller so that the spring has little or no tendency to rotate the gripper cam, as it does when the parts are in the position shown in Fig. 1, but the Vroller will hold the cam 4 and retain the grippers in open position.

A stop S may be provided to pre-vent eX- cessive movement of the grippers 2l* .in either direction.

Then the tumbler first' engages the pin the initial movement of the tumbler moves the roller back as indicated in dotted lines in Fig. 1 against the tension of the spring 6 until the cam roller rides upon the circular portion 4C of the periphery of the cam 4, whereupon the pressure of thespring on or against the cam is practically neutralized and the cam roller then has an easy uniform rolling Contact with the cylindric portion 4c of the cam 4; therefore, except on the initial starting movement of the cam there is only a rolling pressure between the cam roller and the cam, which makes it very easy for the tumbler and pin to shift the gripper shaft and takes strain off of the tumbler pin and tumbler. gripper shaft practically the only duty performed by the pin and the tumbler after the cam roller disengages the recess in the cam, is that of continuing the turning movement of the shaft 2 until the cam roller engages the other recess in the cam.

With this invention the usual auxiliary crank arm on the gripper shaft and double motion spring connections engaging said arm to hold the grippers in open or closed position, are dispensed with; the only opposition to movement of the tumbler offered by the spring is that which is required to disengage the roller 5 from the recess (4u or 4b) with which it may be in engagement at the moment of starting the tumbler. When the tumbler is engaged by a pin in ln turning the 1,275, ooe

starting to swing the grippers open or closed the tumbler has a long leverage which enables it to easily overcome the spring, and renders its action easy and gentle, and permits of high speed. The ease of movement is due to the peculiar mounting of the cam roller; and when the roller is engaged with recess 4 the pressure of the spring is eX- erted in the first instance to directly and positively hold the fingers closed, and the fingers can readily and securely hold sheets of different thickness.

What I claim is:

1. A gripper mechanism comprising a gripper carrying shaft and devices for rocking same; a cam-member on said shaft havmg a parti-circular portion and recesses at separated points of said portion, a controlling member adapted to engage said recesses when the shaft is rocked, spring actuated means carrying said member, and means to limit the movement of said member toward the rock shaft whereby when the grippers are closed the action of the spring is effectively directed against the cam member substantially at right angles to a radial line emanating from the gripper shaft.

2. In combination a cylinder, a rock shaft therein carrying grippers, a tumbler' on the end of said shaft, and devices engaging said tumbler to shift the same; with a cam on said shaft having spaced recesses in its periphery, a cam roller beside said cam of the cam and to enter the recesses therein; a movable spring projected member to which the cam roller is connected, and a link pivotally connected with said member and to an adjacent pivot on the cylinder; all so arranged that when the grippers are closed the spring forces the cam to positively but yieldingly hold fthe grippers in closed position.

3. lin combination, a gripper carrying shaft, a tumbler thereon, and tumbler' engaging devices; with a cam on said shaft having a parti-circular portion and spaced recesses in its periphery, a cam roller adapted to engage said cam and to enter the recesses therein; a spring-projected rod carrying said cam roller, and a link pivotally connected with said cam roller and with a fixed point adjacent the cam to limit the inward movement of said cam roller; whereby when the grippers are closed the pressure of the spring is effectively directed against the cam at substantially right angles to a radial line projected from the axis of the gripper shaft.

1n testimony that 1 claim the foregoing as my own, 1 aHiX my signature.

MlCHAEL A. DROHCOUR,

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of atents. Washington, D.. C.

4adapted to yieldably engage the periphery