Patent GB-426719-A (GB)
Title: Improvements in or relating to electric driving and control systems for printing presses
IPC: H02P5/46
Filed: 1933-10-04
Abstract: 426,719. Master control of several motors. HOLMES & CO., Ltd., J. H., North Drive, Hebburn-on-Tyne, ROBERTSON, A. T., 13, Coquet Terrace, Newcastle-on-Tyne, and LINSTOW, F. N., Sunniside, Midhurst Road, Benton, Northumberland. Oct. 4, 1933, No. 27282. [Class 38 (iii)] [See also Group XXXVIII] A driving and control system for a multiple-unit printing press having at least one folder B, and two or more printing units A, one or more of which can be associated at will with a folder to form a group, comprises an alternating-current commutator motor A<1> for each printing unit, a brushrocking device A<2> for each motor for speed control, main control gear B<3>, B<4> for effecting the simultaneous control of the main motors associated in a press group, and means for operating the brush-rocking devices of the main motors in a group substantially simultaneously, so that the total load is shared substantially equally by the main motors of the group. A small wound-rotor induction motor A<3> is coupled to the main motor A<1> of each printing unit through an over-running clutch, while each unit is coupled to a common power shaft C by an individual clutch C<1>, the shaft C having sectionalizing clutches C<2>. To start the press, a push-button B<5> at a main control station B<4> is operated to energize a self-maintaining master relay G, provided that a starting contactor F for a motor-generator set which supplies the press brakes, has been closed. The relay G, in closing, energizes an inching relay L which closes to energize contactors L<1> of the inching motors A<3> of the printing units associated in a group. The grouping is effected by means of selector switches O, and clutches C<1>, the operation of the clutches controlling clutch relays C<3>. If the button B<5> is kept depressed, an auxiliary motor R is energized to operate the brush-rockers of the grouped motors A<1> and the folder motor B<1>. The motor R also operates a controller R<1> which energizes a main motor relay K, and a folder contactor E, the former causing the closure of the main motor contactors K<1> of the group, and the latter connecting the associated folder motor. Upon continued operation of the button B<5>, the motor R operates the controller R<1> to open the inching relay L, and disconnect the inching motors. When the brush-rockers are moved to their full speed position, the controller R<1> opens the circuit of the motor R. When a press-button B' is actuated, the motor R is connected for reverse rotation, and returns the brush gears to their original position, whereupon the controller R<1> stops the motor R. If a " stop " button B8 at the main control station B<4>, or a button A<8> at one of the unit control stations A<6>, is operated, a normally energized relay H is de-energized and de-energizes the relay G. The relay G in opening energizes the motor R to return the controller R<1> and the brushrockers to their " start " position and also de-energizes the relays K, L, and the contactor E. The relay H also energizes a brake contactor M, so that the press is rapidly stopped. When the controller R<1> reaches the zero position and the stop-button is released, the self-maintaining relay H is again closed. " Inch " buttons B', A', at the main and unit control stations respectively, control the inching relay L, and " lock " buttons B<9>, A<9>, at similar positions, control a lock relay J which renders the button B<5> ineffective, without interfering with the control by buttons B<6>, B<8> and A<8>. In an alternative arrangement, the brushrockers of the motors of a group are operated by individual motors of like squirrel-cage or synchronous type, the motor which operates on the folder motor brushes being under the control of " up " and " down " contactors through control bus-bars to which the brushrocking motors of the printing units of a group are connected by the selector switch O. The brush-rockers of the grouped motors are thus moved simultaneously, and individual " up " and " down " limit switches are provided to prevent cumulative errors. In a modification, wound-rotor induction motors, interconnected electrically to run in synchronism, are employed for operating the brush-rockers of the grouped motors. In a further modification, the brushrocker motor of the folder operates a master step-by-step controller which is connected through the selector switch to follow-up controllers driven by the brush-rocker motors of the printing units, so that the latter follow-up the movements of the push-button controlled brush-rocker motor of the folder. In a still further modification, individual brush-rocker motors are controlled by respective loadsharing relays of one or other of the types described in Specification 296,815, [Class 38 (iv)], the brush-rocker motor of the folder being controlled by " up " and " down " contactors, and those of the printing units of the group by the load-sharing relays, so that the load is equally divided between the grouped motors. Instead of alternating - current motors 2, solenoids, or direct-current motors, may be employed for brush rocking.