US893246A - Mechanical movement. - Google Patents

Description

PATENTED JULY 14, 1908.

N 0 T S N H nu .J T R MECHANICAL MOVEMENT. APPLIOATION FILED JULY 27, 1905. RENEWED NOV-21. 1907.

2 BHBETSSHEET 1.

In Me. W500 1 311754 715 (021. 5 flttaeree 5 I 'wTl/esses No. 893,246. PATENTED JULY 14, 1908.

R. T. JOHNSTON.

MECHANICAL MOVEMENT. APPLIOATION'IILED JULY 27,1905. RENEWED NOV.21. 1907. Y

' mums-$113M z.

UNITED STATES PATENT OFFICE. ROBERT T. JOHNSTON, OF TAUNTON, MASSACHUSETTS, ASSIGNOR TO THE CAMPBELL PRINT- ING PRESS & MANUFACTURING COMPANY, OF TAUNTON, MASSACHUSETTS.

MECHANICAL MOVEMENT.

Patented July 14, 1908.

Renewed November 21, 1907. Serial No. 403,189.

for reciprocating the beds of printing presses,

which consists of a main driving mechanism and a reversing mechanism.

The particular object of the invention is to improve the main driving mechanism which gives the bed its constant speed backward and forward movements. The main driving mechanism commonly employed for this purpose consists of two racks attached to the,

bed and a gear disposed between said racks which gear is either moved up and down or slid axially to engage alternately with said racks. j Y

When a rising and falling -movement is imparted to the driving gear, a structure is provided which is objectionable for the reason that the gear cannot be rigidly supported and which is apt to have lost motion; while when the gear is slid axially it must drive one rack at considerable distance from its support. I overcome these objections by setting the racks a distance a art a little greater than the diameter'of the rivin gear and in providing two intermediates w ich are slid laterally-to engage the racks alternately.

The gear disposed between the racks is made wide-faced so that each intermediate is in mesh whether it is operating or not. The intermediates can he slid on rigid studs or bearings and as each intermediate only comes into operation when it is in the plane of the racks, the parts will be rigidly supported when in operation.

The best form now known to me for practicing the invention is shown in the accom panying two sheets of drawings in which,

Figure 1 is a side elevation partly in section illustrating my invention, and Fig; 2 is a cross-sectional elevation thereof.

Referring-to the drawings and in detail, A designates the reciprocating bed or member which is mounted in the usual way so as to reciprocate on the frame of the machine.

B designates the impression cylinder and 10 designates a ower shaft to which power may be applied om any suitable source by 'drive the impression cylinder by meshing with a large gear 15 secured thereon. The

relation between the gears 13 and 15 is such that the driving shaft 14 makes three revolutions for each two revolutions of the impression cylinder the mechanism being illustrated as applied to the ordinary two-revolution impression cylinder printing machine having a three-revolution driving shaft or movement.

Secured to the bed are upper and lower racks 16 and 17. The inner end of the shaft 14 is journaled in a strong bracket 18. On the end of the shaft 14 is arranged a large Wide-faced gear 19 which is dis osed between the racks 16 and 17, the rac (s 16 and 17 being set so as to just clear said gear.

Loosely fitted on said stud 20 is an intermediate gear 21 which is hereinafter termed the upper intermediate. This gear is set to mesh with the gear 19 and the upper surface of the same comes above the upper surface of the gear 19 in position to engage the upper rack 16. Also secured in the bracket 18 is a stud 22. Arranged on the same similarly to the upper intermediate 21 is a lower intermediate 23 which is set in position to engage the lower rack 17 A lever 24 is pivoted on a stud 25 j ournaled in an arm projecting from the bracket 18. This lever has hooks 26 which engage the sides of the upper intermediate 21 and hooks 2727 which engage the sides of the lower intermediate 23. By this arrangement, when one intermediate is moved into the plane of the racks 16 and 17, the other intermediate will be moved out of position laterally to clear its rack.

28 designates a cam shaft. This cam shaft is driven bya pinion 29 secured on the driving shaft 14 which meshes with a gear 30 secured on the cam shaft 28; the reduction between the pinion 29 and the gear 30 being three to one so that the cam shaft 28 will make one revolution for each complete operation of the machine. Secured on the cam shaft 28 is a cam 31. A lever 32 is mounted on a stud 33 and carries a roller 34 which en-- gages the groove of the cam 31. The lever 32 is connected by a link 35 to the lower end of the rocking lever 24.

-stud 20 is rigidly secured in said bracket 18.

The gear 19 is made of the usual size; that is, if the improvement is applied to a threerevolution movement as shown, the circumference of said gear represents the length of the constant speed forward and backward movements. A wrist-pin 36 may be set on said gear and may operate the usual yoke 37 from which the reversing movement is obtained, the details of which reversing movement are not described herein as they may be of any improved type and form no part of the present invention.

In operation, the upper intermediate 21 engages the u per rack 16 for the return movement of t e bed and the lower intermediate 23 engages the lower rack 17 for the forward or printing movement of the bed. The intermediates are shifted during the reversing movement. This shift, takes place when no part of the work is being performed by the main driving mechanism and can be easily accomplished without wear. By this arrangement, thegear 19 is rigidly supported and each intermediate when it comes into operation, is working close up to the bearing of its supporting stud. By this arrangement astrong, simple, accurately working main driving mechanism is provided.

The details and arrangements herein described may be greatly varied by a skilled mechanic without departing from the scope of my invention as expressed in the claims.

Having thus fully described my invention, What I claim and desire to secure by Letters- Patent of the United States is 1. In a mechanical movement, a main driving mechanism comprising upper and lower racks, a gear arranged between the same of less diameter than the dlstance between the racks, two intermediates, and

means for bringing the intermediates alternately into operation.

2. In a mechanical movement, a main driving mechanism comprising upper and lower racks, a gear arranged between the same of less diameter than the distance between the racks, two intermediates, and means for sliding the same axially to cooperate with said racks.

3. In a mechanical movement, a main driving mechanism comprising upper and lower racks arranged in the same plane, a gear having a face wider than said racks and of less diameter than the distance between the racks, two intermediates continuously meshing with said gear, and means for sliding the intermediates axially in opposition.

4. In a mechanical movement, a main driving mechanism comprising upper and lower racks, a wide-faced gear arranged between the same of less diameter than the distance between the racks, studs secured to the frame, intermediates journaled on said. studs, and means for bringing the intermediates into operation alternately.

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

. ROBERT T. JOHNSTON. Witnesses:

CHARLES EVERETT MOORE, RosA C. ONEIL.

Images