US2975704A - Rotary duplicating machines - Google Patents

Description

March 21, 1961 Filed April 30, 1956 L. H. SMITH ROTARY DUPLICATING MACHINES 3 Sheets-Sheet 1 March 21, 1961 H. SMITH 2,975,704

ROTARY DUPLICATING MACHINES Filed April 30, 1956 3 Sheets-Sheet 2 March 21, 1961 L. H. SMITH 2,975,704

ROTARY DUPLICATING MACHINES Filed April 150, 1956 3 Sheets-Sheet 3 2,975,704 ROTARY DUPLICATING MACHINES LeslieHarrold Smith, GideaPark, England, assignor' to l Roneo Limited, London, England Filed Apr, 30, 1956, Se. No. 581,754

filaims priority, application Great Britain May 2, 1955 6 Claims. (Cl.'101-116) This invention relates topower operated rotary duplieating-machines of the kind having a printing drum which supportsa stencil sheet andcontains a supply of ink which passes via perforations which extend partly but not wholly around'the surface of the drum and through the stencil sheet during the printing process.

Itis desirablewith all previously proposed duplicating machines'of the kind referred to,to be sure to leave the printing drum in a predetermined position when not in use to prevent the leakageofink from the supply in the which will foul the machine. For this-purposeit is knowntoprovidea mark on'the'drurn which has to be registered with a mark on thefrarne of the machine or bepositioned at the topto avoid the disadvantage above referred to;

Th'object of the present invention is to provide a du-. plicating machine of the kind referred to in which irrespective of the speed at which the machine is operated the drum comes to rest automatically in the preferred position when the machine is stopped, the preferred position being when the imperforate portion of the drum surface is 'in the lowest position thus preventing, when the machine is not in use, leakage of ink from the supply inthe drum'which will foul the machine.

The invention consists in a duplicating machine of the kind referred tohalving a variable speed gear in which upon operating a lever, knob or the like to stop the machine or in which after a preselected number of copies has been duplicated or when only a few sheets of paper remain on the feed board, the variable speed gear automatically engages the lowest operating speed before the power is switched olf.

' The invention further consists in a duplicating machine as set forth in the preceding'paragraph in which an electric switch for the control of the power is switched off by the action of a lever mechanism operated by a cam associated with the printing drum.

The inventionstill further consists in a duplicating machine as set forth above having means for manually regulating the'speed at which the printing drum rotates which is connected to an operating knob by way of an adjusting screw and nut, a connecting link, a lever and a loose link which is urged .to move longitudinally in the direction to lower the speed ratio by spring means before the switching oh but is prevented from so doing by a catch which maybe tripped either manually or mechanically after a preselected number of copies have been duplicated or when only 'a few sheets of paper remain on the feed board.

The machine still further consists in a duplicating machine of the type referred to in which the last copy completelyfpa'sses through the machine while variable speed gear mean's automatically engages, the lowest operating speed before the power is switched off.

The accompanying drawings show, by way of example only, one embodiment of the invention in which:

Figure 1 is a perspective view of one form of start and stop mechanism,

2,975,704 Patented Mar. I 21, 1961 Figure 2 is a side elevation, and

Figure-3 is a plan view of the samemechanisrn.

The machine duplicating speed may be selected, with the machine running or stationary, by rotating knob 26 which rotates adjusting screw 18-by a like amount causing nut 27 to move longitudinally along screw 18. Lever 4, which is connected by link 28 to nut 27 and which is pivoted on stud 44 which is therefore moved to a known position by rotating knob 26. The position of lever 4 determines the position in which lever 6 is held while the machine is operating and to which lever 6 is set by the manual operation of. lever 17. The machine is switched on by manually operating lever 17 attached to one arm of a U-shaped lever 6 pivoted on stud 40 by bell crank 29 and by link 30, thereby bringing a stud 31 projecting from lever 6 up to lever- 4 where it isheld in position by the arrangement of catch 5 onto stud 31. Lever 6 is connected to a slide 8 on which is pivoted catch 16 which, when the machine is not operating, is located to the right of roller 20, and which when moved from right to left by the action of slide 8 displaces roller 20 attached to one arm of U-shaped lever 21 pivoted on spindle 45. Screw 22 is also associated with pivoted lever 21, therefore, when catch 16 displaces lever 21 by roller 20, screw 22 depresses switch button '7 thereby switching on the machine.

Slide 8 is also connected through bell crank 9, pull rod 15, link 32 to the pivoted lever 33 which is connected by brackets 34 and 35 to operating arms 12 and 36 respectively pivoted on pins 357 and '38. Operating arms 12 and 36, being pivoted 011 pins 37 and 38 close at one end while opening at the other end, and vice versa, thereby regulating the transmission ratio'between the expansible input pulley 39 and the expansible driven pulley 14. The expansible form of the pulleys 14 and 39 enables the effective diameters at the point of engagement with belt 13 to be varied as required, thereby regulating the transmission ratio. 1 The input expansible half pulleys 39 are free to move longitudinally on spline shaft 41, which in this instance is driven via a gearbox by an electric motor, and the driven expansible half pulleys 14 are free to move longitudinally along spline shaft 42 which may be connected by a train of gears, or by a chain, or by a combination of both as in this instance, to a gear associated with the printing drum 1. As slide & moves forward, hook lever 11, the bottom end of which is free to move by action of spring 43 in a similar direction, hooks itself when depressed by cam 2 through bell crank 3, under a fixed catch plate 19. Lever 11 moves up and down with each revolution of earn 2 by the action of the cam through hell crank 3 and by the action of the spring 4?! but the latter also holds the hooked end of the lever 11 in contact with the catch plate while the machine is operating.

The machine is switched oif by tripping catch 5, either by the manual operation of lever 48, which being associated with angle plate 46 by bell crank 49 and link 47 causes angle plate 46 to trip catch 5 by the upward movement oflever 48, or when catch 5 is tripped mechanically after a pro-selected number of copies have been duplicated or when only a few sheets of paper remain on the feed board, by a mechanism not illustrated which, in this instance, displaces bell crank 49 thereby, through link 47, causing angle bracket 46 to move upwardsand trip catch 5.' When catch 5 is tripped, releasing lever 6, slide 8 attached to the lever 6 endeavors to return under spring tension, but, its return speed is controlled, through bell crank 9, pull rod 15, links 32 and 33, brackets 34 and 35 and arms '12 and 36 operating on theexpansible half pulleys 14 and 39, which return by virtue of the machine load transmitted through V-belt 13 assisted by spring 44 to their positions from which the machine is driven at its approximate slow speed. The complete return to the switch otr'position of slide 8 is prevented by plate 23 attached to slide 8 contacting hook lever 11 where it is held until such time as lever 11 is depressed to its lowest position by cam 2 through bell crank 3, in which position, the hooked end of lever 11 is free to disengage from catch plate 19. When hook lever 11 is at its low position and released from plate 19, slide 8 completes its return, and plate 23 attached to slide 8 displaces hook lever 11 and so positions the latter that at the top of its stroke, a plate 50 on lever 11 is located in line with lever 10 which is then rotated to the switch off position by the downward stroke of lever 11. Lever 10 is fixed to spindle 25 as is also lever 24, therefore when lever 10 is rotated by the action of lever 11, lever 24 is rotated a like amount and depresses the switch button in line with lever 24.

When catch is tripped either manually or mechanically in the manner described above, the movement of hell crank 49 also disengages the sheet feeding mechanism. Since the printing drum rotates one or more revolutions while the drum speed is being reduced after catch 5 has been tripped and before lever ill completes the switching off, the last copy completely passes through the machine before the latter stops.

The complete return to the switch 0 position of slide 8 is impeded by hook lever 11 until such time as the latter is released from its hooking position by cam 2 through hell crank 3. When hook lever 11 is at its low position and released, slide 8 completes its return, still under spring tension, displacing lever 11 and so positioning the latter that at the top of its stroke it is in line with the lever 16 which is then rotated to the switch olf position by the downward stroke of lever 11.

By the method described above:

(1) The speed of rotation of the printing drum 1 decreases to the slowest operating speed before the machine stops.

(2) The last copy to be duplicated completely passes through the machine before the latter stops.

(3) The printing drum 1 stops at an approximate predetermined position when the machine is switched off, irrespective of the original duplicating speed.

It is to be understood that the above description is by way of example only and details for carrying the invention into efifect may be varied without departing from the scope of the invention.

I claim:

1. In a rotary duplicating machine of the type having a frame, a printing drum, a variable speed gear operatively connected to the drum, electric switch means controlling the power supply to the drum, and means operatively associated with the variable speed gear operative to adjust said gear to the lowest-operating speed prior to actuation of the electric switch means to cut-off the power supply, such latter means including a slide mounted within the frame for longitudinal reciprocable movement, lever means pivoted to the frame and connected to the slide whereby pivotal movement of the lever means displaces the slide in one direction, spring means connected to the slide urging the slide in the opposite direction, catch means on the frame, operating means connected to the lever means to displace the slide in said one direction with the catch means engaging the lever means to hold the same in such position, a switch actuating means mounted for rotary movement in the path of travel of the slide, trip means on the slide operative on the movement of the slide in said one direction to rotate the switch actuating means to actuate the electric switch means to supply power to the drum, latch means displaceable substantially perpendicularly and in the direction of movement of the slide disposed in the frame with at least a portion thereof being in the" path of movement of the slide, cam means rotatable with the drum and operatively connected to the latch means to displace the latch means perpendicularly operative on movement of the slide in said one direction to move the latch means in a direction whereby the latch means engages the slide, movement imparting means connected to the variable speed gear, means pivotally connecting the movement imparting means to the slide and including a lost-motion connection, a further trip means operatively associated with said switch actuating means and located in proximity to said latch means, and further means operable to disengage said catch means from said lever means whereby the spring means urges the slide in the opposite direction whereupon said movement imparting means and its connections to the variable speed gear and the slide adjust the gear to the lowest operating speed and thereafter the latch means is displaced by the cam means to actuate the further trip means to rotate the switch actuating means to actuate the electric switch means to cut-off the power supply.

2. Power operated duplicating machines comprising a perforated printing drum for supporting a stencil and serving as storage means for a supply of ink, an electric motor for driving the machine, a variable speed gear between the motor and the drum for varying the speed at which the drum rotates and with said motor rotating the drum continuously during printing, a switch for switching the motor on and off, manually operable speed set means, link and lever means between the speed set means and the variable speed gear, resilient means urging the link andlever means in the direction to change the gear into the condition giving the lowest speed of rotation of the drum, projection means upon the link and lever means which engages and operates the on and off switch to switch oif the motor in the condition of the gear giving the lowest speed of rotation of the drum, and catch means upon the link and lever means which holds the latter in the position corresponding to the speed of operation to which the machine is set for operating which may be tripped either manually or automatically after a pre-selected number of copies have been duplicated or when only a few sheets of paper remain in the machine.

3. Duplicating machine as claimed in claim 2 in which the variable speed gear comprises two pairs of interlocking half pulleys joined by a V-belt, the degree of interlocking determining the speed ratio of the gear.

4. Duplicating machine as claimed in claim 2 in which the relationship between the printing drum and the trip mechanism is such that the last copy to be duplicated completely passes through the machine before the latter sto s.

i Duplicating machine as claimed in claim in which the said relationship is determined by the position of a cam associated with the printing drum. I e

6. Duplicating machine as claimed in claim 2 in which the drum is imperforate below the level of the ink when in the position in which the drum comes to rest.

References Cited in the file of this patent UNITED STATES PATENTS 1,461,876 Hagelstein July 17, 1923 1,972,978 Carroll Sept. 11, 1934 1,991,686 Lister Feb. 19, 1935 2,069,729 Storck Feb. 2, 1937 2,094,181 Morrison Sept. 28, 1937 2,168,486 Marchev Aug. 8, 1939 2,243,283 Morrison May 27, 1941 2,519,894 Dohl Aug. 22, 1950 2,690,120 Burroughs Sept. 18, 1954 Retz J an. 29, 1957

Images