US676970A - Mechanical movement. - Google Patents

Description

No. 676,970. Patented lune 25, I90|l. E. W. SWINDELLS.

MECHANICAL MOVEMENT. (Applica-tion filed Aug. 11, 1000.) \No Modal.) U 2 Sheets-Sheet l.

\ v-l lllllllllllllllllmllllllllhIlllllllllllIllllllllllllllllllllIlllllllllllllumlllllllll llllllllllU -lmlm we Norms versus co. mmuuwo.. WASmNGwN. nA c.

No. 676,970. Patented :une 25, 190|.

E. W. SWINDELLS. M

MECHANICAL MOVEMENT. (Application med Aug. 11, 1900.

(no Model.) 2 sheets-sneek 2.

I UNITED STaTns 1 TAW-ENT FFIIQE@ MECHANICAL MOVEMENT.

SPECIFICATION forming part 0f Letters Patent No. 676,970, dated June 25, 1901.

Application iiled August 11,1900. Serial No. 26,665. (No model.)

.To all whom t r11/ay concern.-

Be :tknown that I, EUGENE W. SwINDELLs, a citizen of the United States of America, and a resident of the city of St. Louis, in the State of Missouri, have invented a new and useful Mechanical Movement, of which the following is a specication.

My invention relates to printing-presses, and has for its object to improve the movement of the type-bed. It consists in the mechanical movement hereinafter described and in the application thereof to a printing-press, as hereinafter described.

In the accompanying drawings, which form part of this specification, and wherein like symbols refer to like parts wherever they occur, Figure I is a side view of my device detached, showing the 'positions of the parts at the forward limit of movement. Fig. II is a like view showing the parts in an intermediate position. Fig. III is a horizontal sectional view of the device on the line III III of Fig. I. Fig. IV is a transverse section thereof on the line IV IV of Fig. I, except that the main driving-gear is shown inelevation; and Fig. V is a side elevation showing my movement applied to a printing-press.

My movement is designed to transmit motion to the type-bed of a printing-press in such a manner that during the printing operation its speed is exactly the same as the peripheral motion of the impression-cylinder, and each forward and backward motion of the type-bed will start up and slow down gradually.

The main driving-gear lis mounted in the framework 2 of the printing-press and meshes with a gear-wheel 3 on the impression-cylinder. The main driving-gear is preferably twice the diameter of the cylinder-gear, and the pitch-line of the cylinder-gear preferably coincides with the periphery of the cylinder. The driving-gear has iiXed thereon and concentrically therewith a segmental gear 4, whose pitch-line is an arc of about one hundred and twenty degrees of a circle of onehalf the diameter of the gear-wheel to which it is fixed. The peripheral motion of the toothed segment is thus one-half of the peripheral motion of the impression-cylinder. It is preferable to have the untoothed edge of this segmental gear in the form of an are of a circle of the same diameter as the toothed segment.

The bed 5 of the printing-press is mounted in any suitable manner to reciprocate on the frame 2 below the impression-cylinder. This bed 5 has a rack 6, which meshes with a gearwheel 7, mounted on a shaft 8, which is journaled in the frame. This shaft 8 also Vcarries a gear 9 of one-half the diameter of the other gear 7. This smaller gear 9 is driven by a rack lO, which is fixed to a cross-head 11, which slides in ways provided therefor on the frame. The motion of this bed is therefore double the motion of the cross-head.

The cross-head ll is a hollow frame whose inner edges are straight at the sides and concave curves at the ends. The straight sides are the same length as the toothed segment and are toothed to constitute racks l2; but the curved ends I3 are preferably made smooth in the form of circular arcs of greater radius than the radius of the segment. The width of the frame between the pitch-lines of the side racks is the same as the diameter of the pitch-circle of the segmental gear, and this gear revolves between them in the same plane therewith, so that it engages one rack and then the other alternately.

It is obvious that during the engagement of the rack and gear the rate of motion of the cross-head to which the rack belongs will be one-half of that of the impression-cylinder, and consequently the rate of motion of the bed will be the saine as that of the impression-cylinder so long as the' pitch-line of the teeth of the segmental gear is tangent to the pitch-line of the teeth of a side rack. In the construction j nst described this condition continues through one hundred and twenty degrees, or one-third of a revolution of the segmental gear. When the last tooth ofthe gear becomes disengaged, the momentum of the bed carries the curved end of the cross-head `against the untoothed edge of the gear, and

the motion of the cross-head is thus gradually retarded until the dead-center is reached,

at which point the direction of motion is reversed, and the motion gradually increases until the teeth of the gear mesh with the teeth of the second rack. At this point the rate of motion of said cross-head becomes one-half of that of the impression-cylinder and continues at this rate through'one-third of a revolution of the segmental gear, when the operation of gradually slowing down and reversing is again repeated. The motion of the bed of the press is therefore the same as that of the impression-cylinder and their register secured during the printing stroke or movement of said bed. To avoid the effects of momentum or backlash, the following device is provided: A plate 14 is fixed to the cross-head and carries ,opposite the central part of the opening therein a thimble or cylindrical collar 15, mounted on a stud. The segmental gear has fixed to it a cam 16, Whose edge is so designed that Athroughout the operation of reversal the edge of the cam is so close to the thimble as to be practically in contact therewith. By this arrangement it is impossible for the momentum of the bed to produce the effects of backlash. It is obvious that the positions of the thimble and the cam may be reversed with the same result.

This device is capable of considerable modiication without departing from my invention.

Thus the segmental gear may be shorter or longer than one hundred and twenty degrees, in which case the cross-head is modified accordingly. So bevel-gearing may be used insteadof spur-gearin g, in which case the crosshead may be fiatWise instead of sidewise, and it may be placed under the bed and between the side frames of the machine. The sizes of the gears may he varied without affecting theefficiency of the movement. So the action of the smooth edge of the segmental gear `against the curved ends of the cross-head is a cam or wiper action, and the shape of the curves may be varied. So, too, the effect of backlash is overcome by the thimble and cam arrangement even without the cooperation of the curved ends of the cross-head. Other modifications may be made, and I do not wish to limit myself to the construction shown.

The principal advantages of my device are that it reduces the number of connections between the im pression-cylinder and the bed to a minimum. It obviates the necessity for the driving-shaft between the cylinder and the bed usually found in cylinder-presses, and thus insures a minimum of lost motion in the connections between the cylinder and the bed land a consequent greater accuracy in register.

What I claim is- 1. A mechanical movement comprising a segmental gear having its back edge curved and an open cross-head arranged to reciprov cate in a frame, the inner sides of said crosshead being formed into racks adapted to mesh with said gear and the inner ends thereof being curved on the inside with'a larger radius than that part of the back edge of the gear, substantially as and for the purpose set forth.

2. A mechanical movement comprising a segmental gear, and an open cross-head arranged to reciprocate in a fra-me, the inner sides of said cross-head being formed into racks to mesh with said gear, and a thimble and a cam arranged to cooperate to prevent backlash, the thimble being mounted on either the segmental gear or on the crosshead, and the cam being correspondingly mounted on either the cross-head or the segmental gear, substantially as and for the purpose set forth.

3. A mechanical movement comprising a segmental gear having its back edge cur-ved and an open cross-head arranged to reciprocate in a frame, the inner sides of said crosshead being formed into racks adapted to mesh with said gear and the inner ends thereof being curved on the inside with a larger' radius than that of the back edge of the gear, and a thim'ble and a cam arranged to cooperate to prevent backlash, the thimble being mounted on either the segmental gear or on the cross-head, andthe cam being correspondingly mounted on the cross-head or the segmental gear, substantiall y as and for the purpose set forth.

4. In a cylindrical printing-press, a bed movement comprising a segmental gear operatively connected to the driving-shaft and having its back edge formed into a cam,and an open cross-head arranged to reciprocate in the frame,- the inner side of said crossLhead being formed into racks adapted to mesh with said-segmental gear and the ends thereof being curved on the inside Withla larger radius than that of the back edge of the segmental gear, said cross-head having a rack fixed thereto, which meshes with a gear-wheel operatively connected with the type-bed, substantially as and for the purposes specified.

5. In a cylindrical press, a bed movement comprising a segmental gear operatively connected to the driving-shaft and an open crosshead arranged to reciprocate in the frame and having its inner sides formed into racks adapted to mesh with said segmental gear, and a thimble and a cam arranged to coperate to prevent backlash, the thimble being mounted on either the segmental gear or on the cross-head and the cam being correspondingly mounted on either the cross-head or the segmental gear, said cross-head having a rack fixed thereto which meshes with the gearwheel operatively connected with the typebed, substantially as and for the purpose set forth.

6. In a cylindrical printing-press, a gearwheel on the main driving-shaft, an impression-cylinder geared thereto and a reciprocating type-bed having a rack thereon, a segmental gear fixed concentrically on the driving-gear, an open cross-head having its sides Wheel ou said shaft meshing with the rack on formed into racks adapted to eoperabe with said bed, substantially as and for the purpose xo said segmental gear and having its ends set forth. formed into cam-surfaces adapted to coper- 5 ate with the back edge of the segmental gear, EUGENE V SWINDELLS a rack xed to the cross-head and coperat- Witnesses: ing with a gear-Wheel on a shaft journaled in VHENRY A. KERSTING, the frame of the press and a second gear- JAMES A. CARR;

Images