US2619903A

US2619903A - Gripper bar mechanism

Info

Publication number: US2619903A
Application number: US737236A
Authority: US
Inventors: Alexander J Albrecht
Original assignee: R Hoe and Co Inc
Current assignee: R Hoe and Co Inc
Priority date: 1947-03-26
Filing date: 1947-03-26
Publication date: 1952-12-02
Anticipated expiration: 1969-12-02

Description

2, 1952 A. J. ALBRECHT 2,

GRIPPER BAR MECHANISM Filed March 26, 1947 AJaxqnder J AJbrE/abz INVENTOR Patented Dec. 2, 1952 UNITED STATES PATENT OFFICE GRIPPER BAR MEOHAN ISM Alexander J. Albrecht, West New York, N. J., as-

signor to R. Hoe & 00., Inc., New York, N. Y., a corporation of New York Application March 26, 1947, Serial No. 737,236

6 Claims.

This invention relates to printing machines and more particularly to sheet fed machines of the flexible conveyor type.

A sheet fed printing machine of the flexible conveyor type, and to which the present improvements may be applied, is fully described in Huck Patent 2,231,914.. As there disclosed, the successive sheets are carried through the printing uni-ts by gripper bars having a number of gripper elements or jaws which open and close to receive a sheet at the registering unit anddischarge a sheet at the delivery, but which remain closed during the passage of the sheetthrough the'successive printing units.

One object of the present invention is to provide an improved gripper bar and mechanism for opening and closing the gripper elements thereof. v

A further object ofthe invention is to provide an improved device for holding a sheet adjacent its corners. Y

. With these and still 'other objects which will appear in the following full description in mind, the invention consists in the combinations and arrangements of parts and details of construction which will now first be fully described in connection with the accompanying drawing. and then be more particularly pointed out in the appended claims.

In the drawing: I

Figure 1 is a crosssection througha gripper barand parts of a registering cylinder;

Figure 2 is a plan view of one. end of the gripper bar of Fi ure 1;' V

Figure 3 is a plan view on a reduced scale of one end of the gripper bar and registering cylinder;

Figure 4 is a detail view showing an attachment employed for holding down a sheet corner; and

Figure '5 is a section on the line 55 of Figure 4.

The invention relates to the gripper bar and the mechanism employed for opening and closing the jaws thereof. The other press elements and their operation and cooperation with th gripper bar are well known in themselves, being fully described in the Huck patent above referredto and, accordingly, are not shown herein.

Figure 1 shows a portion of a registering cylin.--

der l having a recess 2 in which the gripper bar 3 is received. As will be well understood by those skilled. in the art, the gripper bar will be seated in the recess 2 at a proper point in the rotation of the registering cylinder and. the mechanism within and associated with the cylinder will operate to open and close the jaws of the gripper for receiving and grasping a registered sheet. Heretofore, and as shown in the Huck patent, the gripper bars have comprised a plurality-of elements extending longitudinally of the registering cylinder and to which a relative movement is imparted for the purpose of controlling the action of gripper jaws associated therewith. Such elements have taken the form of telescoped tubes, one jaw of each gripper being carried by an outer tube, and the other by the inner tube, so that relative movement of these tubes causes the jaws to open and close. Such a construction is rela-. tively heavy, complicated and bulky and theaction of the registering cylinder upon ths ripper bar may have a tendency to unseat the gripper 'bar.

The gripper bar of the present invention com-1 prises a single longitudinally extending element in the form of a tube 4 which carriesa number of gripper elements 5 spaced along its lengthat suitable intervals. Each gripper element 5 comprises a frame 6 which is fastened to the tube 4 as by means of thescrews 1 and upon which is form-ed an inneror; lower jaw 80f a pair; of gripper jaws. The outer or upper jaw 9 cooperating therewith. is carried by a lever 10 which is slotted as indicated to fit around the frame 6 and pivotally mounted thereon by a shaft H. the lever l0 counterclockwise about shaft ll separates or opens the jaws 8 and 9, while swinging it clockwise into the position of the figure causes the jaws to close for grasping a sheet. The lever in is operated by a poppet bar I 2, one end of which is connected to the inner or lower end of the lever It by a link l3, having forks at each end which. are pivotally connected to the rod l2 and lever l0. and [5 for accommodating the poppet rod [-2 and associated elements. The aperture l4 receives a thrust member I6 which surrounds the rod [2 and within which the rod [2 slides, while the aperture. i5 is threaded and receives a corre spondingly threaded thrust member l-T, also hav- Swinging The tube 4 has opposed apertures Mling a central aperture through which the rod I2 slides. A washer I8 is fastened to the rod I2 and inner and outer springs I9 and are interposed between the washer I8 and thrust membe IS. The spring pressure holds the thrust member I6 in the position shown, in which a, peripheral fiange thereon seats in a counterbore in the inner surface of the tube 4, as indicated, tending to force the washer I8 against the fixed thrust member IT. A sheet of paper between the jaws 8 and 9 will be held firmly thereby due to the action of the springs I9 and 20 and washer I8 will be slightly spaced from the thrust member I! under such conditions. As will be apparent, a definite gripper pressure is thus obtained by each gripper 5, and this pressure will not be influenced by the action of any of the other grippers 5.

The gripper bar is located in a definite position in the registering cylinder by rollers ZI rotatably mounted on a plate 22 fastened to the registering cylinder and cooperating with bearer rings 23 toward the ends of the gripper bar. At each end of the gripper bar there is fastened an end frame assembly 24 carrying a roller 25 which cooperates with an upper cam track, the surface of which is indicated by the phantom line 26, for holding the gripper bar firmly down against the rollers 2 I. The end frame assemblies 24 carry also rollers 2'! and 28 for positioning the gripper bar in cylinder I, in the manner shown in the Huck patent. A flexible conveyor in the form of a sprocket chain 29 at each end of the gripper bar serves to carry the bar to and from the various units in the usual way.

The various grippers 5 are operated by a series of fingers 36 carried by a shaft 3|, which is journaled in the registering cylinder I and one end of which carries an arm 32 and cam follower roller 33, indicated in phantom in Figure l, the roller 33 following a stationary cam 34 afiixed to the frame and a portion of which is also indicated in Figure l. The solid line position of the fingers 38 in the drawing of Figure l is an intermediate position in which the fingers are just engaging the poppet rods I2 for opening the jaws 8 and 9. A box cam 3 is designed to move the fingers 39 into a more outward position indicated by the phantom line 3% for providing space for the insertion and removal of the gripper bar and into a more inward position, indicated by the phantom outline 38 for pressing the poppet rods I2 to open the gripper jaws. The operation of the cam and the control of the times of opening and closing of the gripper bar jaws may be the same as in the Huck patent referred to.

With the sheets of certain sizes it may happen that a sheet, when in laterally registered position, will extend sufficiently far beyond the last gripper element of the series which engages its forward end so as to create a possibility of the free corner of the sheet turning upwards and becoming bent so as to spoil the appearance of the sheet and interfere with the printing action. For holding down such a free corner, there is provided an attachment in the form of an offset finger mounted on an extending end 35 of the shaft I I associated with the gripper in question. The finger 35 is held on shaft II by screw 3? and is coupled to the movable jaw 9 by means of a pin 38 so as to move therewith. The finger 35 will not grip the sheet but will hold its corner down on the cylinder.

It will be understood that while a shaft 3 I with its gripper operating fingers 3e and cam roller 33 is herein shown only in connection with a registering cylinder, such as the cylinder 13 of Patent 2,231,914, it is also used on a discharge cylinder that passes the sheets to a delivery such as the transfer chain 29 of the machine shown in the patent. In that machine, each of the gripper bars, of which there are nineteen in a four-unit machine, is provided with gripper operating mechanism, whereas with the improved gripper bar herein disclosed, gripper operating mechanism is required only on the registering cylinder and on the discharge cylinder.

What is claimed is:

1. In a sheet fed printing press of the type having a plurality of gripper bars carried through the press by conveyor chains, and in combination, a gripper bar comprising a tubular supporting member having a plurality of aligned transverse bores spaced along its length, a fixed gripper jaw and movable gripper jaw adjacent each said bore, and an operating rod slidably mounted in each bore, connected at one end to the adjacent movable jaw and spring pressed to hold the same in sheet gripping position against the fixed jaw, the opposite ends of the said operating rods extend ing outwardly from the said tubular supporting member for pressing said rods inwardly against the action of the springs to open the gripper jaws, and a registering cylinder having means for receiving and holding the gripper bar through a predetermined angle of rotation of the cylinder, and a member mounted in the registering cylinder and movable with respect to it for'pressing the said rods of the gripper bar, when so held, inwardly to open the gripperjaws.

2. In a sheet fed printing machine, and in combination, a plurality of grippers for receiving and holding the leading edge of a sheet and comprising lower jaws and cooperating upper jaws movable with respect thereto for gripping and releasing a sheet, and means'operable with said grippers and located beyond the grippers for holding down the corner of a sheet, the mechanism being constructed and arranged to provide a space under the corner of the sheet when held down by the last said means.

3. In a sheet fed printing machine, a gripper bar comprising a supporting member and a plurality of grippers spaced therealong, and means also carried by said gripper bar, located beyond said grippers and operable with said grippers for holding down the corner of a sheet upon a registering cylinder, the gripper bar being constructed and arranged so as to leave a space under the corners of the sheet when so held down by the last said means.

4. In a sheet fed printing machine, a gripper bar comprising a supporting member and a plurality of grippers spaced therealong, each gripper comprising a fixed jaw and a movable jaw and means also carried by said gripper bar beyond the grippers and movable with a movable gripper jaw for holding down the corner of a sheet upon a registering cylinder, the gripper bar being constructed and arranged so as to leave a space under the corner of a sheet when so held down by the last said means.

5. In a sheet fed printing machine, a gripper bar comprising a supporting member and a plurality of separately operable grippers spaced therealong, and means also carried by said gripper bar beyond said grippers and operable with said grippers for holding down the corner of a sheet upon a registering cylinder th grippers being constructed and arranged so as to 5 leave a space under a corner of a sheet when so held down by the last said means.

6. In a sheet fed printing machine, a gripper bar comprising a supporting member and a plurality of separately operable grippers spaced therealong, each gripper comprising a fixed inner jaw and movable outer jaw, and means also carried by said gripper bar beyond the grippers and operable with the movable jaw of one of said grippers for holding down the corner of a sheet upon a registering cylinder, the gripper bar being constructed and arranged so as to leave a space under the corner of a sheet when so held down by the last said means.

ALEXANDER J. ALBRECHT.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 137,347 Cottrell Apr. 1, 1873 747,213 Pancoast Dec. 15, 1903 1,050,842 Main Jan. 21, 1913 1,275,002 Droitcour Aug. 6, 1918 1,495,257 Dudley May 27, 1924 1,508,951 Baker Sept. 16, 1924 1,675,592 Blaine July 3, 1928 2,007,886 Stussi July 9, 1935 2,231,914 Huck Feb. 18, 1941 2,392,392 Kaddeland Jan. 8, 1946 2,411,123 Wood Nov. 12, 1946