US961206A - Bed-and-cylinder printing-press. - Google Patents

Description

A. 1H. BROWBR. BBD AND `GYLIINTDR PRINTING PRESS.

APPLICATION FILED JULY 20, 1906.

Patented June 14,1910.

5 SHEETS-SHEET 1.

ANDREW Ev GRAHAM ce. wnomumouawnzaswAsmNGTDN. no.

A'. T. H.. BROWER. BBD AND CYLINDER PRINTING PRESS.

APPLICATION FILED JULMU, 190s.

961,206. 'PatenteaJune14,191o.

5 SHEETS*SHEET 2.

Mmm xsA mun/m :cA wumumacmmma wAsumuTuN, s a

A. T. H. BROWER.

BED AND CYLINDER PRINTING PRESS.

l APPLICATION FILED JULY 20, 1906.

961,206. Patented June 14,1910.

5 SHEETS-SHEET 3.

A. 'I'. H. BROWER.

BED AND CYLINDER PRINTING PRESS.

APPLICATION FILED JULY zo, 1906.

Patented June 14, 1910.

5 SHEETS-SHEET 4.

ANDREW B sp1/mm Cn., PwomunnanAPHERs, WASHINGTON. n.1:

A. T. H. BROWBR.

BED AND CYLINDER PRINTING PRESS.

APPLICATION FILED .IULY 20, 1906.

Patented June 14, 1910.

5 SHEETS-SHEET 5.

lthe construction shown in Fig. 7.

ABRAHAM T. I-I. BROWER, OF CHICAGO, ILLINOIS.

BED-AND-CYLINDER PRINTING-PRESS.

Specification of Letters Patent.

Application filed .Tuly 20, 1906.

Patented June 14:, 1910. serial No. 326,964.

T all whom t may concern:

Be it known that I, ABRAHAM T. H. BRowER, a citizen of the United States, residing at Chica o, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Bed-and- Cylinder Printing-Presses, of which I do declare the following to be a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

One main object of my present invention is to provide an improved means for increasing the speed of bed-and-cylinder presses and this object I accomplish by giving to the bed a return impetus immediately after its trunnions have passed the center of the cam shoes whereby the reversal of the bed is effected.

The invent-ion has for its further object to provide features of improvement that shall materially contribute to the speed and accuracy of the press.

lit-h these several objects in view the invention consists in the features of novelty hereinafter described and illustrated in the accompanying drawings and particularly pointed out in the appended claims.

Figure 1 is a view in side elevation of a bed-and-cylinder press embodying my invention. Fig. 2 is a plan view (parts being shown in section) illust-rating the mechanism beneath the bed of the press. Fig. 3 is a view in vertical cross section on line 3 3 of Fig. 1. Fig. l is a detail view in vertical sec-tion on line fle-4l of F ig'. 3, illustrating more particularly one of the cam shoes, or reversing shoes of the press. Fig. 5 is a view in vertical longitudinal section on line 5 5 of Fig. 3. Fig. 6 is a view in vertical longitudinal section on line 6-6 of Fig. 3. Fig. 7 is a view similar to Fig. 6 but illustrating a modification of the invention. Fig. 8 is an enlarged detail view showing one of the cam-wheels illustrated in Fig. 7. Fig. 9 is an enlarged detail view of section through the three-way valve employed in Fig. 10 is a view similar to Fig. 7 but illustrating a further modication of the invention.

A designates the main frame of the machine whereby the bed B and the cylinder C are sustained. The bed B is mounted to reciprocate over the ways a of the main frame A and the cylinder C is carried by shaft c that is journaled inuprights at the sides of the main frame and is provided at one end with a gear wheel that meshes with the gear wheel 16 keyed to one of the sections 17 of the bed rack pinion shaft. The other section 18 of the bed rack pinion shaft extends from the opposite side of the machine to a point adjacent its center and the sections 17 and 18 are suitably journaled in bearings on the main frame. The section 17 of the bed rack pinion shaft has Xed to it adjacent its inner end a beveled gear wheel 19 and similarly a beveled gear wheel 20 is fixed adjacent the inner end of the bed rack pinion shaft section 18, and these beveled gear wheels 19 and 20 are connected together by a beveled gear wheel 21 that is journaled in a suitable bearing 22 of the main frame. To the eXtreme inner ends of the sections 17 and 18 of the bed rack pinion shaft are keyed respectively the bed rack pinions 23 and 24 that are arranged in close proximity and will travel in opposite directions.

Upon the under side of the bed B the bed rack 25 is mounted in a manner permitting it to be shifted at right angles to the path of movement of the bed, in order thatthe bed rack 25 may be brought into position to engage either of the bed rack pinions 23 or 24. As shown the bed rack 25 is formed with dovetailed channels 2o adjacent its ends (see Fig. 5) that engage corresponding I dovetailed ribs 27 upon the under side of the bed B, and the ribs 27 thus support the rack 25 while allowing it to be shifted transversely of the bed.

By reference more particularly to Figs. 1, 2 and 3 of the drawings it will be seen that when revolution is imparted to one of the sections of the bed rack pinion shaft the bed rack pinions 23 and 24 will revolve in opposite directions and the bed B will be driven either forward or backward accordingly as it is in engagement with one or the other of these pinions. The pinion 23 serves to impart the forward or printing movement,

to the bed B while the pinion 24 imparts to the bed B the backward or idle movement.

Inasmuch as the cylinder shaft o is directly geared to the gear wheel 16 of the bed rack pinion shaft section 17, the danger of lost motion or of inaccuracy of movement between the bed and cylinder is materially less than in the constructions in which the bed rack pinion shaft is not thus directly geared to the shaft of the cylinder. Moreover, inasmuch as the bed rack 25 is located above the pinions 23 and 24 and as close as possible to the bed B a more direct and positive application of power is transmitted from the bed rack pinion shaft to the bed than is possible with constructions in which the bed rack is suspended at a distance beneath the bed. The bed rack pinion 24 which imparts the return or idle movement to the bed is driven from the section 17 of the bed rack pinion shaft through the intermediate beveled gearing shown but the presence of such intermediate gearing is not believed to be detrimental for effecting the return movement of the bed since during such movement the same accurate coincidence between the bed and cylinder is not required as upon the forward or printing movement of the bed.

In order to effect a transverse shift of the bed rack 25 to cause it to engage with one or the other of the bed rack pinions 23 and 24, the mechanism next to be described is preferably employed. By reference more particularly to Figs. 3 and 5 of the drawings, it will be seen that through the lower portions of the bars 28 that extend from the bed rack 25 are formed slots through which passes a shifter bar 30 (see Figs. 2, 3 and 5) the slotted ends of which bar are pivotally connected as at 31 to crank arms 32; each of these crank arms being carried by its corresponding shaft 33 that is journaled in a bracket 34 at the corresponding end of the main frame. The lower end of each of the short vertical shafts 33 has keyed thereto a beveled pinion 35 that meshes with the beveled gear 36 mounted upon the shaft 37 that is journaled in suitable bars 38 at the end of the main frame. Each of the shafts 37 has keyed thereto at one end a crank arm 40 and the slotted lower ends of the crank arms 40 are united by a connecting bar 41 (see Fig. 5) that extends from end to end of the machine. The bar 41 is slotted adjacent its center and through this portion of the bar 41 pass several shafts to be presently described. From the side of the bar 41 projects astud 42 that enters a cam shaped groove 50 that is formed in the side of the gear wheel 51, this gear wheel being mounted upon the shaft 52 (see Figs. 3 and 5) journaled in bearings of the main frame. Revolution is imparted to the gear wheel 51 by pinion 54 that is mounted upon the shaft 55. The shaft 55 has keyed thereto a gear wheel 56 that meshes with a pinion 57 upon the section 18 of the bed rack pinion shaft. Hence, it will be seen that as the bed rack pinion shaft sections have revolution im parted thereto, revolution will be transmitted from the shaft section 18 and its pinion 57 to the gear wheel 56, the shaft 55 and the gear wheel 51, and as the gear wheel 51 is thus revolved, the cam groove 50 in the side of this gear wheel will cause the shifter rod 41 to travel back and forth as will be clearly seen by reference to Fig. 5 of the drawings. As the rod 41 is thus shifted, it will in turn rock the crank arms 40 and the shaft 37 thereby causing the beveled gear wheels 35 and 36 to rock the short vertical shafts 33 and cause the cranks 32 at the upper ends of said shafts to move transversely the shifter bar 30. As the shifter bar 30 is thus moved (see Fig. 3) it will produce a corresponding transverse movement of the bed rack 25 thereby causing this rack to leave the path of one of the bed rack pinions 24, for example, and pass into position to engage the other bed rack pinion 23 or vice versa. It will be understood, of course, that this shifting of the bed rack 25 will be effected when the bed completes its movements and after the rack 25 is free from engagement with the pinions.

As shown, there are four gear wheels corresponding to the gear wheel 56 above described, two of these gear wheels receiving revolution from the section 18 of the bed rack pinion shaft and the other two of such gear wheels receiving revolution from the section 17 of the bed rack pinion shaft. The construction and arrangement of these gear wheels will be understood by reference more particularly to Figs. 2, 3, 5 and 6 of the drawings. Thus, by reference to Fig. 6, it will be seen that with the pinion 57 on the section 18 of the bed rack pinion shaft meshes the gear wheel 56 and the corresponding gear wheel 60 and by reference to Figs. 2 and 3 it will be seen that gear wheels 61 and 62 mesh with the pinion 63 that is mounted upon the section 17 of the bed rack pinion shaft. The gear wheels 61 and 62 are the same in construction as the gear wheels 56 and 60 shown in Fig. 6 of the drawings, and like these gear wheels are provided each with a cam groove 64 upon its inner face. The gear wheel 60 is mounted upon a shaft 66, and the gear wheels 61 and 62 are mounted respectively upon the shafts 67 and 68, these several shafts being journaled in ,bearings of the main frame. Beneath the gear wheels 56 and 60 extend the shafts 70 and 71 that carry respectively the rock arms 72 and 73, and similarly beneath the gear wheels 61 and 62 extend the shafts 74 and 75 that carry respectively the rock arms 76 and 77. Each of the rock arms 72, 73, 76 and 77 has a stud 78 projecting from its side and entering the cam shapedgroove 64 of the adjacent gear wheel 56, 60, 61 or 62. The upper end of each of the rock arms 72, 7 3, 76 and 77 is pivotally connected the inner end of a rod 8O and the outer end of this rod is pivoted as at 81 to a lever 82 that is mounted upon a shaft 83 at the end of the main frame. To the upper end of each of the levers 82 is pivoted as at 84 the outer end of the stem 85 of a piston 86 that closes the end of a dash-pot 87 located at the top of the main frame of the machine.Y As shown, there are four of these dash-pots 87 and each is equipped with a piston 86 and parts connected thereto as shown more particularly' in Figs. 2 and 6 of the drawings. The open inner end of each of the dash-pots 87 is adapted to receive a plunger 90, the stem 91 of which is fixed to a block or bar 92 depending from the under side of the bed B. In order to equalize the compression within the dash-pots 87 at each end of the main frame, when plural dash-pots are used, they may be connected together as by a pipe 94v or hollow rods may be employed for the plungers 90, t-hese hollow rods being connected together by a suitable pipe or channel so that when the plungers enter the dashpots there will be a. free passage of air from one dash-pot to the other thus equalizing the resistance in the dash-pots. Vhen the dashpots are connected by pipe 94 such pipe will enter them at a point slightly in advance of the pistons 86.

My purpose in providing the dash-pots 87 with movable pistons S6 and in providing suitable means such, for example, as the cam-wheels 56, 60, &c. for imparting movement to the pistons S6 is togive to the bed of the press a return impetus immediately after the bed reversing mechanism (to be presently described) has checked the momentum of the bed and the parts are in such position that the reverse movement of the bed may be effected. The gear wheels 56, 60, 61 and 62 have their movement so timed with respect to the travel of the bed and the cam groove 6l of each of these gear wheels is so shaped that when the bed B reaches the end of its travel in either direction and its momentum has been checked by the reversing mechanism (to be presently described) and by the dash-pots already described, the cams 64 of the gear wheels 56, 60, 61 and 62 will impart an inward movement to thel pistons S6 and will cause these pistons to exert a corresponding thrust upon the plungers 90 that are attached to the underside of the bed B, thereby giving a quick initial movement to the bed which will not only materially increase its speed but will also save the teeth of the bed rack and the bed rack pinions from the excessive strain incident to an engagement of the bed rack and its pinions when the latter are driven at a very high speed. The volume of air compressed within the dash-pots between the plungers 90 and the pistons 86 will be found a most effective medium through which to transmit the inward thrust of the pistons 86 to the bed.

While any of the usual means may be employed for checking and reversing the bed B at the ends of its movement, I prefer to employ the novel construction of reversing mechanism next described. My improved reversing shoe is shown as comprising` wheels 100 and 101 that are mounted upon the sections 17 and 18 of the bed rack pinion shaft. Each of these wheels 100 and 101 is formed with a cam groove 102 extending across its face and into each of these cam grooves 102 projects a stud or trunnion 103 that is carried by an arm 104- depending from the underside of the bed B. The ends of the cam grooves 102 are formed Haring so as to facilitate the entrance of the studs 103 into these grooves. The first half of the grooves or cam ways are so shaped that they serve to slow down the bed while carrying it on so that the rack shall leave the rack pinion, after which the rack will be laterally shifted. The second half of the cam grooves or ways is a reverse of the first half so that when the bed movement has been checked it will be reversed with 'a movement that gradually increases until it approximately equals the maximum speed atvwhich it is intended to travel and at which time it will be delivered to the bed rack pinion.

As shown motion is imparted to the gear wheel 16 on the outer end of the bed rack pinion shaft, from a pinion 110 that is fixed to a short drive shaft 111 that has its inner end journaled in the side of the main frame A and in a standard 112 that rises at one side of the main frame; and upon the drive shaft 111 are mounted the fast and loose pulleys 113 and 1111 adapted to receive a driving belt (not shown).

From the construction of parts as thus far described, it will be seen that when revolution is imparted to the drive shaft 111, motion will be transmitted therefrom by the pinion 110 and gear wheel 16 to the bed rack pinion shaft section 17 and from the gear wheel 16 to the gear 15 and cylinder C. During the forward or printing movement of the bed B its rack 25 will be in engagement with the gear 23 at the inner end of the section 17 of the bed rack pinion shaft and hence it will be seen that the bed rack pinion shaft and the cylinder' shaft c will be united `by one pair of gear wheels so that during the forward or printing movement of the bed the gearing between the cylinder and bed is reduced to a minimum and the danger of lost motion between these parts is rendered much less than would be the case if intermediate gearing were employed between the gear wheels upon the cylinder shaft and the bed rack pinion shaft. So also it will be seen that inasmuch as the bed rack 25 is mounted beneath the bed B the power would be most eectively and directly applied to the bed from the bed rack pinion shaft.

1t will be understood, of course, that during the forward or printing movement of the bed its rack 25 will be in engagement with the gear wheel 23.011 the inner end of the bed rack pinion shaft section 17 but as the bed B approaches the end of its t-ravel in a forward direction its studs or trunnions 103 (see Fig. 4) will pass into the cam grooves 102 of the reversing shoes or wheels 100 101 and the movement of the bed in forward direction will thus be arrested and immediately thereafter the reversing shoes or wheels 100 101 will occupy such position as to aid in starting the bed B upon its return or idle movement.

rIhe cam- wheels 56, 60, 61 and 62 will occupy such positions with respect to the sections 17 and 1S of the bed rack pinion shaft and consequently with respect to the reversing shoes or wheels 100 101 that as soon as the studs or trunnions 103 have crossed the centers of the reversing shoes or wheels 100 101 the cam ways or grooves 64 in the wheels 56, 60, 61 and 62 will cause the studs 7S to rock the arms 72 and through the medium of the rods SO to rock the arms 82 thereby causing the pistons 86 to move inward and further compress the air in the dash-pots 87 so as to exert a quick initial pressure upon the plungers 90 and give a reversing impetus or initial movement to the bed B.

It will be understood, of course, that the cam grooves 64 of the wheels 56 and 61 at one side of the center of the press (see Fig. 6) are arranged in a position reverse to that of the cam grooves 64 in the wheels 60 and 62, as the wheels 56 and 61 perform their function of imparting an initial impetus to the bed when the bed is in the position shown in Fig. 6, while the wheels 60 and 62 perform a similar function when the bed is at the opposite end of its travel. By thus giving to the bed immediately after it has been arrested by the reversing` shoes a quick initial movement, the bed rack 25 as it engages the pinions 23 or 24 will have such momentum that the strain upon the teeth of the bed rack 25 and the pinions will be very greatly reduced and, consequently, the pinions 23 and 24 may be run at a correspondingly higher speed. Hence, without danger of severe strain or breakage of parts, the speed of the press may be materially increased.

By reference to Fig. 5 of the drawings it will be seen that as the bed B reaches the end of its travel in either direction, the bed rack 25 will pass from engagement with the pinions 23 and 24 and at such time the bed rack 25 will be shifted transversely of the bed through the medium of the rock arms 32. the shifter bar 30, the gear wheels and 36, the rock arms 40 and the rod 41, the stud 42 of the rod 41 serving to impart to the rod 41 the movement which this stud receives from the cam groove 50 of the wheel 51. The wheel 51 will be so positioned with respect to the bed rack pinion shaft that the cam groove 50 of this wheel 51 will shift the rod 41 at the time that the bed B reaches approximately the end of its travel in either direction and after the bed rack 25 has passed from engagement with the teeth of the driving pinions 23 and 24.

So far as I am aware my present invention presents the first instance of a bed-andcylinder press in which provision has been made for imparting a quick initial return impetus to the bed otherwise than by the usual reversing shoes. In carrying out this broad feature of my invention, mechanism of Various kinds may be employed. Thus, for example, in Figs. 7 9 of the drawings I have shown means whereby the initial return impetus given to the bed may be effected by compressed air. In these views of the drawings there are shown two compressed air tanks 115, one located at each end of the machine, although obviously a single storage tank may be used. The tanks 115 are connected by suitable pipes 116 with the outer ends of the dash-pots 87 and in each of the pipes 116 there is arranged suitable valve mechanism for controlling the admission of compressed air to the dash-pots. As shown each pipe 116 has interposed therein a threeway valve casing 120 having an escape port 121 and having a compressed air delivery port 122 and a port 123 whereby the valve casing is connected to the dash-pot. The three-way valve 124 within the casing 120 has its ports arranged as shown in Fig. 9 of the drawings and to this valve 124 is connected a rock arm 125 to which is attached a rod 126 that is pivoted to the end of a rock arm 127 mounted upon a shaft 128 suitably supported in the main frame. From each of the rock arms 127 projects a stud 129 that enters a cam groove 130 in a wheel that is geared to the bed rack pinion shaft. In Fig. 7 of the drawings I have shown two Cain-wheels 131 and 132 the peripheral teeth of which engage with a pinion on the bed rack pinion shaft and the wheel 132 is formed with a cam groove 130 like that of the wheel 131 and performing a like function. The cam groove 130 is of such shape that while the bed B is traveling in the direction of the arrow (Fig. 7), the stud 129 will be within the circular portion of the cam groove 130; and at such time the threeway valve 124 will occupy the position shown in Fig. 9 so as to allow a restricted escape of air from the dash-pot 87 as the plunger 90 passes into the dash-pot. As the bed B reaches the limit of its movement, the irregular portion of the cam groove 130 acts upon the stud 129 thereby causing the threeway valve 124 to be shifted in such manner that the escape of air from the dash-pot through the port 121 is cut off and communication is established through the valve between the ports 122 and 123 thus admit ting compressed air from the tank or reservoir 115 to the outer end of dash-pot 87. When compressed air is thus admitted to the outer end of the dash-pot, it will exert its pressure upon the plunger 90 at such time within the dash-pot and will serve to impart a quick initial impetus to the bed. The shape of the cam grooves 130 will be such, as indicated in Figs. 7 and 8 of the drawing, that the three-way valve 124 will be shifted so as to admit compressed air to the dash-pot S7 in propel` amount and so as to restore the three-way valve to the position shown in Fig. 9 of the drawings before the plunger 90 leaves the dash-pot and while the stud 129 is moving in the circular portion of the cam grooves 130 the three-way valve will be maintained in the position shown in Fig. 9 of the drawing.

In Fig. 10 oi' the drawing, I have illustrated another modified form of mechanism for imparting an initial thrust or impetus to the bed B immediately after the reversing shoes have arrested the motion of the bed and have moved to such extent as to enable the bed to be started upon its reverse travel. In this form of the invention there depends from each end of the bed B one or more brackets 140 that carry at their free ends studs 141, each of these studs being arranged in position to engage a vertical rock arin 142 that is pivotally mounted as at 143 upon a bracket 144 extending from the end of the main frame A. To each of the rock arms 142 is connected a rod 145 that passes through an opening in the end of the main frame and carries a coil spring 146 that is held upon the rod 145 by means of suitable nuts 147, the spring 146 tending to draw the rock arm 142 inward toward the main frame as shown at the left-hand side of Fig. 10 of the drawing. To each of the rock arms 142 is connected a slotted outer end of a rod 148, the slot at the outer end of this rod sitting over a stud 149 of the rock arm and the inner end of the rod 14S is pivotally connected to the upper end of the rock arm 150 that is mounted upon a shaft 151 suitably sustained by the main frame. From the side of each of the rock arms 150 projects a stud 152 that enters a cam groove 153 formed in a gear wheel adjacent thereto. By reference to Fig. 10, it will be seen that there are two gear wheels 154 and 155 each provided with cam grooves 153. Each of these gear wheels meshes with a pinion mounted upon the bed rack pinion shaft.

From the foregoing description, it will be seen that when bed B reaches the end of its travel as indicated in Fig. 10 of the drawing, the stud 141 beneath the outer end of the bed will engage the cam-shaped upper end of the rock arm 142 thereby moving this rock arm outward and compressing the coil spring 146. As the rock arm 142 is thus moved outward its stud 149 will approach the end of the slot of the rod 148 and at such time the stud 152 of the rock arm 150. will enter the irregular or noncircular portion of the cam groove 153 of the wheel 154. As the wheel 154 is revolved in the direction of the arrow (F ig. 10) it will cause the rock arm 150 to move inward thereby causing the rod 148 to draw inward the rock arm 142, and this inward movement of the rock arm 142 will force its upper end to exert an initial thrust upon the stud 141 depending beneath the end of the bed B and thus give the bed a quick impetus which will cause the bed rack to initially engage the bed rack pinion at a much higher speed than would be possible if the action of the ordinary reversing shoes were relied upon to effect the initial reverse movement of the bed.

So far as I am aware, the present invention presents the irst instance of a bed movement in which the ordinary checking and reversing shoes are supplemented by mechanism comprising a member carried by the bed, a member supported by the main frame and means for imparting a thrust to the member' carried by the bed immediately after the reversing shoes have arrested the movement of the bed and left the members in position for the reverse travel. The modied form of the invention illustrated in Figs. 7 and 10 of the drawings show how, without departing from the spirit of the invention, it may be embodied in various forms.

I do not wish to be understood as claiming in this application features shown herein but claimed in my application, Serial No. 437,674.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The combination with a reciprocating bed and with devices for checking and reversing the movement of said bed, of mechanism for giving to the bed an initial return impetus, comprising a member carried by the bed, a member carried upon the main frame and means for impart-ing to the member carried by the main frame a positive thrust in excess of the recoil of the checking mechanism immediately after the movement of the bed has been arrested.

2. The combination with the reciprocating bed and mechanism for operating and reversing said bed, of a dash-pot mechanism for checking the movement of said bed comprising cooperating members mounted on the bed and on the machine frame, and means'for operating said frame member to maintain the maximum pressure attained in said dash-pot mechanism and for thrusting said frame member inwardly at the end of the movement vof the bed, whereby a positive impetus in excess of the recoil of said dash-pot mechanism is imparted to the bed to start the saine on its return movement, substantially as described.

3. The combination with a reciprocating bed and with reversing shoes and studs, of mechanism for checking the movement of the bed and means for giving to said checking mechanism immediately after the movement of the bed has been arrested, an inward thrust in excess of the recoil of the checking mechanism, in order to impart an initial return impetus to the bed.

4. The combination with the reciprocating bed and mechanism for operating the same and reversing the movement thereof, of a dash-pot mechanism for checking the movement of said bed comprising coperating members mounted on the bed and on the machine frame, and means for holding said frame member stationary during the checking operation of said dash-pot mechanism and for thrusting said frame member inwardly immediately after the movement of the bed has been arrested to impart a positive impetus in excess of the recoil of the dash-pot mechanism to the bed to start the same upon its return movement, substantially as described.

5. The combination with the reciprocating bed and mechanism for operating the same and for reversing the movement thereof, of dash-pot mechanism for checking the movement of the bed comprising` a member fixed to said bed and a coperating member movably mounted on the machine frame, and mechanism for positively reciprocating said frame member in opposite directions arranged to hold the same stationary during the checking operation of said dash-pot mechanism and to thrust the same inwardly immediately after the movement of the bed has been arrested, whereby a positive impetus in excess of the recoil of the dash-pot mechanism is imparted to the bed to start the same upon its return movement, substantially as described.

6. The combination with a reciprocating bed and with a main frame, of dash-pot mechanism for checking the movement of said bed comprising cylinders mounted at opposite ends of said main frame, plungers carried by the bed and adapted to enter said cylinders, pistons mounted within the outer ends of said cylinders and means for imparting a positive thrust to each of said pistons immediately after the movement of the bed has been arrested, in order to give an initial return impetus to the bed.

7. In a bed-and-cylinder printing press the combination with a reciprocating bed, of mechanism for imparting a quick initial return movement to the bed at the ends of its travel in each direction, said mechanism comprising parts projecting beneath the opposite ends of the bed, members arranged at the opposite ends of the main frame to engage said projecting parts and means for imparting to each of said members a positive thrust in excess of the recoil of the checking mechanism immediately after the movement of the bed has been arrested.

8. In a bed-and-cylinder printing press the combination with the bed and with the main frame, of dash-pot mechanism comprising cylinders mounted at the opposite ends of the main frame, plungers connected to the opposite end portions of the bed and adapted to enter the inner ends of said cylinders, pistons movably mounted within the outer ends of said cylinders and cam-wheels and connections therefrom to the pistons for imparting to said pistons, inward movement immediately after the bed has reached the end of its travel.

ABRAHAM T. H. BRGVER.

Vitnesses:

Gmo. P. FISHER, Jr., LILLIAN PRENTIGE.

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