US678476A - Bed-motion for bed-and-cylinder printing-machines. - Google Patents

Description

No. 678,476. Patented luly I6, |90I. L. C. CRDWELL. BED MDTIDN FDR BED AND CYLINDER PRINTING MACHINES.

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' Patented lllly I6, I90I. L. C. CRUWELL. BED IIDTION FDR BED AND CYLINDER PRINTING MACHINES.

(Application led Apr. 28, 189B.)

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UNITED STATES "PATENT EEICE.

LUTHER C. CROWELL, OE NEW YORK, N. Y., ASSICNOR, RY .DIRECT AND MESNE ASSIGNMENTS, To ROBERT HOE AND CHARLES w. CARPENTER, OE SAME PLACE, (COPARTNERS UNDER THE FIRM-NAME OE R. HOE

AND COMPANY.)

BED-MOTION FOR BED-AND-GYLINDER PRiNTlNG-MACHINES.

Application filed April 2 8, l 8 9 8.

To aZZtl/wm, it may concern,.-

Be it known that I, LUTHER C. CROWELL, a citizen of the United States, residing at New York,county of Kings,a'nd State of New York, have invented certain new and useful Improvements in Bed-Motions for Bed-and-Cyl'- inder Printing-Machines, fully described and represented in the following specification and the accompanying'drawings, forming a part of the same.

This invention relates to certain improvements in bed-motions for bed-and-cylinder printing-machines. The reciprocation of the heavy beds which are used in this class of machines presents very considerable difficulties, since the beds must be driven at high speeds to enable the machines to have the desired capacity of production. ,The speed of these machines is, on the other hand, limited by reason of the fact that the bed must be slowed down and reversed at each end of its stroke, and this must be done in such a Way as to avoid excessive shock and strain,which would produce great wear and tear upon the Working parts. Furthermore, in bed-and-cylinder machines itis of particular importance in order to secure registry and a'good impression that the cylinder and bed move in exact synchronism during the time, the printing is effected, and in that class of bed-and-cylinder machines in which a constantly-revolving cylinder is used in connection With the reciprocating bed, the cylinder being driven vin synchronism with the bed during the printing stroke and the bed being caused to return independently of the cylinder during the non-printing stroke, it is usual to insure the synchronous movement of the cylinder and bed bya rack-and-pinion connection during that part of the printing stroke in which the printing is done, the cylinder being held out of engagement with the -bed and independently driven during the return or nonprinting stroke., It has been found in this class of machines that crank "mechanism is better adapted for driving the bed than many other devices which have been tried; but such mechanisms have the disadvantage, however, that the movement given thereby is not at SPECIFICATION forming-part of letters Patent No. 678,476, ated July 1c, 190i.

Serial No. 679,088. (No model.)

any time constant. It is considered desirable in the highest class of printing to have the movement of the printing-couple during the printing operation constant and steady, on' the ground that better results are produced by such a movement than by a movement which first constantlyincreases and then constantly decreases. Such a constant and steady movement cannot of course be attained by the use of the ordinary crank mechanism.

Another disadvantage of the crank-movement in its present form as applied to machines employing a constantly-revolving cylinder is the loss of ltime incident to the return ofthe bed. It ofcourse requires as much time to return the bed during its non-printing stroke by the ordinary crank-movement as it does to cause it to effect its printingstroke, and since the cylinder is out of print ing contact with the bed during the entire return of the bed all the time consumed in this operation is Wasted.

The object of this invention is to produce a crank-movement which shall avoid the disadvantages hereinabove stated and which when used in bed-and-cylinder printing-machines ofthe type referred to shall give the bed a constant and even` movement during thetime when the printing is done, thereby producing a machine vadapted for the nest kinds of printing and at the same time shall operate to produce a quick return of the bed, thereby enabling the machine to be run at much higher speeds than heretofore.

With this object in view myinvention consists in a certain construction and in certain parts, improvements, and combinations thereof, which will be described in the following specification, and the novel features of which will be particularly pointed out in the claims hereunto appended. Y

In the accompanying drawings, which constitute a part of this specification, and in which like reference characters indicate the same parts, Figure 1 represents a side view of a bed-and-cylinder printing-machine of the two-revolution type embodying the improved crank-movement for operating the bed. Fig. 2 is a similar View showing the parts in the relation which they occupy when the printing is about to begin. Fig. 3 is a similar view showing in full lines the position occupied by the parts at the end of the printing operation and in dotted lines the position of the parts at the end of the printing stroke of the bed. Fig. t is a similar View showing the parts in the position they occupy after the bed has been reversed and is on its return stroke. Fig. 5 is an end view.

In the embodiment of myinvention shown in the drawings the frame of the machine is indicated by A. Rising from this frame are standards B, in which are mounted the sliding boxes C. The impression-cylinder D is mounted in the sliding boxes C, the movement of the boxes being effected through the medium of a raising and lowering mechanism of ordinary type consisting of the rods I0, the toggle 11, connecting-rod 12, and rocking lever 13, carrying a bowl which engages a cam-groove in the face of a cam-disk J. The reciprocation of the bed is produced by the ordinary railroad-gear F, meshing with the usual racks on the bed and frame. The bed is provided with a rack 14, which engages with a rack 15 on the cylinder when the cylinder is in its lowermost position.

Mount-ed in suitable bearings in the frame is a stationary shaft or rod G, upon which is loosely mounted a crank-arm H. Also mounted in suitable bearings in the frame is a shaft I, upon which is mounted the large crankwheel E. It will be observed that the shaft G and the shaft I are so positioned with relation to each other that the centers of revolution of the large crank-wheel E and the looselymounted crank-arm H lie in different vertical planes and also in dierent horizontal planes. In other words, these two centers of revolution are offset from each other in two directions. The large crank-wheel E has mounted thereon a crank-stud K, and to this crankstud is connected a link L, the other end of which is connected to the loosely-mounted crank H, preferably at the point at which the crank is connected to the connecting-rod M, which joins the crank and the railroad-gear F. The crank-wheel E is provided with gearteeth E and is driven by a pinion E, the beltpulley of which is shown in dotted lines in the several figures.

Journaled in suitable bearings in the bed is a shaft O, which has at one end a pinion P, which engages the teeth of the crank-wheel E, and at its other end another pinion 20. This pinion 2O meshes with an intermediate 21, which in turn meshes with a pinion 22, which is constantly in mesh with a gear 23, which preferably forms a part of a clutch mechanism by which the impression-cylinder is connected to and driven by the train of gearing before described during the time when it is not driven by the bed. This clutch mechanism is or may be similar to that disclosed in Patent No. 622,125, dated March 28, 1899, granted to me. inasmuch as said clutch est/8,4%

mechanism forms no part of the present invention, a description of it is not necessary; but reference is made to said patent for a full disclosure of the construction.

Referring to Fig. 1, in which the looselymounted crank-arm H is at the dead-center and the bed is consequently at the point of reverse, it will be understood that the crankwheel E, which of course is constantly rotating, will, through the medium of the link connection L, draw the loosely-mounted crankarm H around in a circular path, and the crank-arm H Will, through the connectingrod M, cause al movement of the railroad-gear, and consequently of the bed. During the first part of the movement of this crank-arm it will be noticed that the arcs traveled by the crank-stud K and the end of the looselymounted crank-arm H are substantially, though not exactly, parallel, and this parallelism continues practically until the parts reach the positions indicated in Fig. 2. During this time, therefore, it will be seen that the bed has a movement substantially corresponding to that which would be given to it by the ordinary crank-movement-that is, a constantly-increasing movement.

Considering the parts in the position shown in Fig. 2, at about which time the printing operation is to begin, it will be noticed that the crank-stud K has passed the vertical line and the arc in whichit travels is constantly drawing nearer to the arc which the end of the crank-arm H is describing in its movement. The angle between the link L, which connects the crank-stud K and the looselymounted crank-arm H, and the crank-arm is therefore at thistime constantly decreasing, or, in other words, the crank-stud K is in its forward travel constantly approaching the center of rotation of the crank-arm H. The crank-arm H is not, therefore, receiving a movement equivalent to that which would be given it if its center were coincident with that around which the crank-stud K is revolving, but receives a movement which is the resultant of the two movements which the stud has with relation to the center of rotation of the crank-arm. The effect of this will be to cause the crank-arm II to have a practically constant movement. It may be here remarked that theoretically the movement will not be q an exactly constant movement, but from a practical standpoint it is so nearly so that it may be considered for mechanical purposes as absolutely constant. It is at this time that the printing-cylinder is moving in unison with the bed and the printing is being done. This constant movement of the crank-arm H continues until the parts have substantially reached the position indicated in Fig. 3, at which time the printing operation has been completed. The cylinder' will now be raised by the raising and lowering devices and the bed will pass toits point of reverse. The positions of the various parts with relation to each other at the point of reverse are indicated in dotted lines in Fig. 3. If now the dotted-line position of the crank-stud K in Fig. 3 be compared with the full-line position of this stud in Fig. 1, it Will be noticed that this stud has traveled in carrying the looselylnounted crank through a half-revolution,and consequently in giving the bed its reciprocation in one direction, considerably more than half the circumference. As the movement of the crank-diskabout its own center is constant, it will be seen that the time which the crank-disk will occupy in traveling from the dotted-line position shown in Fig. 3 to the full-line position shown in Fig. l, in which time and by which movement it will complete the second half-revolution of the crank-arm H, and consequently effect the return of the bed, will be considerably less than the time it occupies in giving the crank-arm H its iirst half-revolution, since the distance to be'traveled in giving the crank-arm H its rst halfrevolution is greater than the distance to be traveled to give it its second half-revolution. The result is, therefore, that the bed is given a quick return.

It will be noticed that the center of rotation of the crank-wheel E'not only lies in a horizontal plane which is non-coincidentwith the horizontal plane passing through the center of rotation of the crank H, but also lies in a vertical plane which is nearer the center of the bed than the vertical plane passing through the center of rotation of the loosely-mounted crank. The center of the crankwheel E is thus positioned to give the bed its constant speed at the proper time-that is to say, when the cylinder comes in contacttherewith to effect the printing operation. Vhile this crankmovement is shown as applied to a bed-and-cylinder printing-machine, it is to be understood that its use is by no means limited to reciprocating the beds of such machines, but that it is of general application and may be used Wherever it is desired to give a bed during a portion of its reciprocation a practically constant movement and to give it a quick return.

What is claimed isl. Inabed-movement,thecombination with a bed having a rack, of a railroad-gear in mesh with the rack and operating to drive thebed, a loosely-mounted crank, a connecting-rod directly connected to the axle of the gear and to the loosely-mounted crank, a second crank having its center offset from the first crank, means for driving the second crank, and connections between the two cranks, substantially as described.

2. In a bed-movement,the combination with the bed, of a loosely-mounted crank and connections therefrom to the bed, a second crank having its center located outside the vertical and horizontal planes which pass through the center of rotation of the loosely-mounted crank, means for driving the second crank, and connections between the two cranks, substantially as described.

3. In abed-movement,the combination with a bed having a rack, of a railroad-gear in mesh with the rack and operating to drive the bed, a loosely-mounted crank, a connecting-rod directly connected tothe axle of the gear and to the loosely-mounted crank, a second crank having its center located outside the vertical and horizontal planes which pass through the center of rotation of the loosely-mounted crank, means for driving the second crank, and connections between the two cranks, substantially as described.

4. In a bedmovement,the combination with the bed, of a loosely-mounted crank, and connections therefrom to the bed, a second crank having its center lying in a vertical plane which is nearer the center of the bed than the vertical plane passing through the center of rotation of the loosely-mounted crank, and in a horizontal plane which is non-coincident with the horizontal plane passing through the center of the loosely-mounted crank, means for driving the second crank, and connections between the two cranks, substantially as described.

5. In a bedmovement,the combination with a bed having a rack, of a railroad-gear in mesh with the rack and operating to drive the bed, a loosely-mounted crank, a connecting-rod directly connected to the axle of the gear and to the loosely-mounted crank, a second crank havingV its center lying in a vertical plane which is nearer the center of the bed than the vertical plane passing through the center of rotation of the loosely-mounted crank, and in a horizontal plane which is non-coincident with the horizontal plane passing through the center of the 1oosely-mounted crank, means for driving the second crank, and connections between the two cranks, substantially as described.

6. In a bed-movement-,the combination with a loosely-mounted crank, of a connecting-rod between it and the bed, a second crank having its center of rotation lying in vertical and horizontal planes which are non-coincident with those passing through the center of rota-V tion of the loosely-mounted crank, a link connection between the two cranks, and means for driving the second crank, substantially as described.

7. In a bed-movement, the combination with a bed havingarack, of arailroad-gear in mesh with the rack and operating to drive the bed,- a loosely-mounted crank, a connecting-rod directly connected to the axle of the gear and to the loosely-mounted crank, a second crank having its center of rotation lying in vertical and horizontal planes which are non-coincident with those passing through the center of rotation of the loosely-mounted crank, a

link connection between the two cranks, and means for driving the second crank, substantially as described.

8. In a bedmovement,the combination with the shaft I having a crank-wheel E thereon, of the shaft Gr having a loosely mounted crank H thereon, the centers of the two shafts IOS) being oifset from each other in two directions,

a crank-stud K on the crank-wheel E, a link L connecting the loosely-mounted crank and the crank-stud, a connecting-rod M connected 5 to the link L and the loosely-mounted crank,

a bed having a rack, a railroad-gear to the axle of which the link L is directly connected, and suitable driving mechanism for the crank-wheel E, substantially as described.

1o 9. In abedmovement,the combination with the shaft I having a crank-wheel E thereon,

of the shaft G having a looselymounted crank H thereon, the centers of the two shafts being oiset from each other in two directions,

I5 a crank-stud K on the crank-wheel E, a link L connecting the loosely-mounted crank and the crank-stud, a connecting-rod M connected to the link L and the loosely-mounted crank, a railroad-gear operated by the connectingrod M to reciprocate the bed, and suitable 2o driving mechanism for the crank-wheel E, substantially as described.

In testimony whereot` I have hereunto set my hand in the presence of two subscribing witnesses. I

LUTHER C. CROWELL.

Witnesses:

T. F. KEHOE, JAMES Q. RICE.

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