US2089900A - Printing press - Google Patents

Description

Au 10, 1937. K L 2,089,900

PRINTING PRESS Filed May 23, 1.936

Patented Aug. 10, 1937 EJNH'EED STATES PATENT QFFICE 6 Claims.

This invention relates to mechanical movements and more particularly to reciprocating bed motions for printing presses or machines of similar construction and operation.

The present invention is similar to that described in my prior Patent No. 1,777,092, granted September 30, 1930, and has the same general objects and purposes. These include the provision of driving gearing for a bed and cylinder press or analogous device which is of simple design and construction, compact, readily accessible, easily assembled and replaced, and in which lost motion and backlash are reduced to a minimum. In this embodiment, as in the case of the one disclosed in my prior patent, the weight of the moving parts is evenly distributed on the supporting frame and the over-all Width of the driving gearing beneath and laterally of the bed is materially reduced.

A more particular object of the present invention, however, is the further simplification of the reciprocating bed driving mechanism by which several of the mechanical elements may be eliminated, and greater economy of construction and operation and a further reduction in the weight of the press may be attained.

The present invention in its preferred embodiment contemplates the provision, in the bed reversing mechanism, of a novel swinging crosshead, driven through a pin and slot connection by one of the initial driving pinions of the press, and. connected in turn to the oscillating member which is provided with the segmental gear or arcuate rack which meshes with the terminal bed racks to effect the reversal of the bed at the ends of its strokes.

A further feature of especial importance in the present case resides in the fact that the swinging cross-head or yoke is slung from its supporting pivots by depending links, whereby it occupies a relatively low position within the press frame thus maintaining the center of gravity of the press at as low a point as possible.

Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawing in which one embodiment of my invention is illustrated by way of example.

In the drawing:

Figure 1 is a somewhat diagrammatic view in side elevation of a mechanical movement embodying the principles of my invention as applied to a press of the bed and cylinder type; this view being partly in cross section and similar to Figure 2 of the drawing of my Patent No. 1,777,092;

Figure 2 is a fragmentary vertical sectional view taken on line 2-2 of Figure 1; and

Figure 3 is a similar view taken substantially on line 33 of Figure l. V

For the purpose of illustration, the present invention is shown in the drawing in connection with a printing press of the two revolution type having the usual impression cylinder l and re ciprocating type bed I2, although it is understood that the invention may be embodied in printing presses or reciprocating bed machines of various other types. The press may be provided with the usual feed board l3 and delivery mechanism 14 together with gripper and sheet stripping mechanism of any suitable character.

The frame of the press is not illustrated in the drawing, but it will be understood that it comprises side frame members and bracing and connecting elements of any appropriate construction, for example, such as is illustrated in somewhat fragmentary form in my above mentioned patent. The impression cylinder if! is suitably journalled in the press frame and the proper anti-friction supports for the reciprocating bed l2 are also provided as in the conventional press of this type.

The gearing for reciprocating the bed, which forms the chief feature of the present invention, is preferably driven from a suitable source of power associated with the shaft I which carries the pinion I6. That portion of the train of gearing which is driven by the pinion l5 and serves to reciprocate the bed l2 during the inter mediate portions of its strokes is the same as that illustrated and described in my Patent 1,777,092 and will be but briefly set forth herein. The pinion l0 meshes with the gear ll which is preferably disposed centrally of the press between the side frames, and which is keyed to the shaft 23 which rotates in a bearing 24 formed in a frame member, and carries on an outer end the gear 20. This gear 20 meshes with the annular externally toothed portion 22 of a disc-like driving element 2| preferably carried exteriorly of the supporting frame of the press. The element 2! is keyed or otherwise secured to the transversely extending rotatable shaft 25 which is suitably journalled in the side frame members.

The element 2i is provided with a pair of segmental internally toothed portions 21 and 28 which are disposed within the externally toothed portion 22 and spaced axially of the shaft 25 for movement in adjacent planes perpendicular to the shaft. These toothed portions may be separately formed and bolted to the interior of the member 2! for convenience in manufacture, assembly and replacement, although it is obvious that the teeth may be formed directly in the member 25 if so desired. A gear 30 mounted upon and suitably secured to the shaft 32 is dispose-d so as to engage and mesh with the internal toothed portion 21, and a gear 33 secured to the shaft 34 and spaced axially of the gear 30 is adapted to mesh with the internally toothed portion 28. As will be apparent from the drawing, the relative circumferential positions of the toothed portions 2? and 28 and of the gears 30 and 33 are such that the gears 30 and 33 are alternately and consecutively engaged by the segmental toothed portions to drive the gears alternately in opposite directions. The length of the toothed portions 2'! and 28 is such that there is a distinct hiatus in the driving action between the periods of driving the respective gears, and.

this interval permits the reversing mechanism for retarding, stopping and accelerating the bed to come into play. The action of this mechanism will presently be described.

Shafts 32 and 34 are extended transversely of the bed and are provided, preferably adjacent the intermediate portion thereof, with a pair of intermeshing gears 37 and 38 which are respectively keyed or otherwise secured to these shafts. It will be seen that by reason of this connection between the shafts, the gear 31 will be driven alternately in opposite directions by the successive action of the segmental toothed portions 2? and 28 carried by the member 2|. A rack 48 is secured to the underside of the bed I! so as to extend longitudinally thereof and is so disposed as to be constantly in mesh with the gear 3'5. It will thus be seen that the rotation of the member Ed is such as to drive the bed directly through the shaft 32 during the execution of the printing stroke and to execute the return stroke through the shaft 34 and the intermediate gear 33, this arrangement serving to reduce backlash and lost motion to a minimum and eliminate slurs in the impression.

The impression cylinder ill is driven by the gear to which it is connected by suitable: mechanism (not shown) which may provide for the periodic elevation of the cylinder from printing contact with the bed during certain portions of the cycle of the press. The gear 45 may mesh directly with the toothed portion 22 of the member 2!.

As already pointed out, it is necessary to provide a reversing mechanism for the bed, operative at the ends of each stroke to retard the movement of the bed, bring it to a stop, and serve to accelerate it in the opposite direction. This portion of the mechanism embodies one of the principal features of the present invention and is clearly illustrated in Figures 1 and 2 of the drawing.

A pair of toothed racks 50 and 5| are secured to the underside of the bed near each end thereof and are preferably removable therefrom and adjustable lengthwise thereof. These racks are adapted for engagement at each end of the bed stroke with a lever member 52' which is provided with a segmental toothed portion 54 which is adapted to mesh with the racks 50 and 5| during the end portions of the cycles of movement of the bed. The member 52 is essentially a lever of the first class, being fulcrumed on a shaft 55 and provided with a generally upwardly extending 75 bifurcated portion 56, 51 to which the segmental toothed portion 54 is fixed, and a downwardly extending link or arm which is adapted to be oscillated by the suspended swinging cross-head member which is preferably substantially lozenge-shaped being provided with the triangular horizontally extending arms 66 and 6'2. The arm 61 is pivotally connected as at 68 with the lower end of the swinging lever arm 66, and the cross-head arm 86 is pivotally connected at 69 with the pendulum-like link iii which depends from the supporting shaft 12. a

The swinging cross-head or yoke member 65 is centrally provided with a transverse groove 13 within which a cylindrical block or roller l4 carried by a crank pin is adapted to move. The crank pin 15 is carried by the gear member l! which, as previously described, is driven by the pinion [5 comprising the initial member of the driving train of the press.

The operation of the device will be readily apparent from the foregoing description and from the drawing. The major intermediate portion of each stroke of the bed is effected through the train of gears l6, ll, Zil, 22 and from thence through either of the trains 2?, 3t, 5? and 46 or 28, 33, 38, 37 and it, to drive the bed uniformly in opposite directions.

The reversal of the bed at the ends of each stroke is effected through the gear ll which performs the functions of a crank rotating about the shaft 23 as a center and serving to oscillate the yoke or cross head 55 through the pin and slot connection T3'l5. The yoke or cross head 65 is suspended at each end by means of the link it! and the arm 68 of the lever 52 so that through the influence of the crank-gear Hit performs a substantially harmonic oscillation. This movement is transmitted through the arm Gil of the lever member 52 to the opposite end of this lever which carries the segment 5%. At the end of each stroke of the bed the segment 55 engages one or the other of the terminal racks 55' and M and at these points takes control of the movement of the bed serving to effectively slow it down, bring it to a stop and accelerate it in its opposite direction until it again comes under the influence of the gear 31 which meshes with the bed rack (iii.

The line 86 represents the approximate base line of the press. and it will be understood that the suspension of the swinging cross-head 65 from the parallel linkage 68, ill disposes this oscillating member at a relatively low point with respect to the press, thus keeping the center of gravity as low as possible.

It will be recognized that by the present invention the operative mechanism described is rendered simpler and more economical in both its operationand construction, requiring fewer parts and consequently involving less liability of deterioration due to wear and the resulting introduction of lost motion or backlash in the bed and cylinder drives. Thus a very simple and economical press is provided in which slurring of the printing impression is substantially obviated.

It will be understood that various changesand modifications may be made in the exemplary embodiment disclosed herein without departing from the scope of the invention as defined in the following claims. 7

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a reciprocating bed motion for printing presses or the like, the combination with a bed,

of means for reciprocating said bed through the intermediate portions of the strokes thereof in either direction, and means for reversing the direction of movement of the bed at the ends of the strokes, said last mentioned means comprising a toothed rack carried by the bed, a lever having a segmental toothed portion on one arm thereof adapted to mesh with said rack, and mechanism associated with the other arm for imparting substantially harmonic reciprocation thereto, said mechanism including a bodily swinging yoke pivotally connected with said other arm, and means for swinging said yoke.

2. In a reciprocating bed motion for printing presses or the like, the combination with a bed, of means for reciprocating said bed through the intermediate portions of the strokes thereof in either direction, and means for reversing the direction of movement of the bed at the ends of the strokes, said last mentioned means comprising toothed racks carried by the bed, a substantially vertically extending lever of the first class having a segmental toothed portion on the upper arm thereof adapted to alternately mesh with said racks, and mechanism associated with the lower arm for imparting substantially harmonic reciprocation thereto, said mechanism including a yoke pivotally connected with said lower arm of said lever and mounted for bodily swinging movement, and a continuously rotating crank having a slidable driving connection with said swinging yoke.

3. In a reciprocating bed motion, the combination with a bed, of means for reciprocating said bed through the central portion of the stroke thereof in either direction, and means for reversing the direction of movement of the bed at both ends of the stroke thereof, said last mentioned means comprising rack teeth carried by said bed at each end thereof, a member provided with a segmental toothed portion adapted to I mesh with said rack teeth, a continuously rotatbed in alternately opposite directions through the major portion of the stroke thereof, a rotatable element provided with an annular toothed portion, means driven by said rotatable element for actuating said gearing, mechanism for reversing the direction of movement of the bed at the ends of the stroke, said mechanism including a suspended bodily swinging cross-head, a pinion meshing with said annular toothed portion of said rotatable element, and a crank pin carried by said pinion and having a slidable connection with said swinging yoke for actuating the latter.

5. In a reciprocating bed motion, the combination with a bed, of means for reciprocating said bed through the central portion of the stroke thereof in either direction, and means for reversing the direction of movement of the bed at both ends of the strokes thereof, said last mentioned means comprising rack teeth carried by said bed at each end thereof, a member provided with a toothed portion adapted to mesh with said rack teeth, a continuously rotating crank, a cross head yoke suspended at its ends respectively by parallel links for swinging oscillatory movement transversely of the axis of said crank, one of said links being operatively connected with said member, and a pin and slot slidable connection between said crank and said cross-head.

6. In a reciprocating bed motion for printing presses or the like, the combination with a bed, of means for reciprocating said bed through the intermediate portions of the strokes thereof in either direction, and means for reversing the direction of movement of the bed at the ends of the strokes, said last mentioned means comprising a toothed rack carried by the bed, a substantially vertically extending lever of the first class having a segmental toothed portion on the upper arm thereof adapted to mesh with said rack, a cross-head yoke directly pivotally connected at one of its ends with the lower arm of said lever, a link pivotally connected with the other end of said yoke, said link being suspended from a pivotal connection with a stationary part of the press and being equal in length to the lower arm of said lever and at all times parallel thereto, and a continuously rotating crank having a pin and slot driving connection with said yoke.

WILLIAM M. KELLY.

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