Patent GB-552805-A (GB)
Title: Improvements in or relating to apparatus for automatically maintaining register in multi-unit rotary web press
IPC: B41F13/02
Filed: 1941-02-03
Abstract: 552,805. Automatic control systems. STEVENS, A. H (News Syndicate Co., Inc.). Feb. 3, 1941, No. 1428. [Class 38 (iv)] [Also in Group XVI ] Feeding webs:-In order to maintain register of the impressions in a multicolour intaglio or other printing press, notwithstanding differences in diameter of the printing cylinders, the impression cylinders are used as the web feeding means and are provided with automatically operating speed controlling devices whereby the speed of the web is maintained substantially constant notwithstanding slight differences in the diameters of the impression cylinders. In one form, Figs. 2 and 4, the web A passes to each printing unit over a control roller B4 and from that unit over a second control roller B3. The unit comprises a printing cylinder 2 and an impression cylinder 3 which forms the web feeding roller and is driven from a gear on the cylinder 2 through a differential gear 20 controlled by the movements of the rollers B<SP>3</SP>, B<SP>4</SP>. These rollers are carried by a frame B fixed to a pivot shaft 14 having an arm 15 connected by a link 34 and crank 33 to a shaft 32 mounted on the machine frame. If the speed of the web entering a unit is different from that of the web as it leaves the unit, the frame B is rocked in one direction or the other causing a corresponding rocking of the shaft 32 to apply one or the other of two brake shoes 23, 24 to rotating parts of the differential and thus increase or decrease the speed of the roller 3 to restore the equality of the speeds of the entering and leaving web. The brake shoes are actuated from the shaft 32 by oppositely acting toggles each comprising a screwed rod 35 threaded transversely through the shaft 32 and a rod having rounded ends seated in recesses in the end of the rod 35 and in the brake shoe. Springs normally urge the shoes away from the covering parts of the differential. In another form, the movements of the frame B are caused to close one or other of two electric switches to operate a reversible electric motor which adjusts a variable speed gear of the belt and expanding pulley type, this speed gear driving the planet carrier of the differential gear driving the impression roller of the unit. In this form, Fig. 9, a gear F<SP>1</SP> on the shaft of the printing cylinder 2 drives, through a gear F<SP>2</SP>, the input gear C<SP>1</SP> of the differential gear, the output gear of which drives the impression roller 3 through gear F<SP>3</SP>, bevel gears F<SP>4</SP>, F<SP>6</SP>, shaft F<SP>8</SP>, bevel gears F<SP>7</SP>, F<SP>9</SP>, gear F<SP>10</SP>, on the shaft of gear F<SP>9</SP>, gear F<SP>12</SP> freely mounted on the backing-up roll 4 of the impression roller, and gear F<SP>13</SP> on the impression roller shaft. The gear C<SP>1</SP> carries the gear C2 through sun wheels secured to these gears and planet gears C8 the carrier of which has secured thereto a gear C<SP>11</SP> engaged by the output gear D<SP>2</SP> of a variable speed gear such as described in Specification 441,889. [Group XXIV], and comprising a belt D5 connecting expanding conical pulleys D<SP>6</SP>, D<SP>7</SP> adjusted by a right and left-hand screw D<SP>10</SP>. The input gear D4 of the variable speed gear is driven directly by the gear C<SP>1</SP>. The adjustment of the screw D<SP>10</SP> thus varies the speed of the planet wheel carrier and hence the speed of the impression and feed roller 3. The screw D<SP>10</SP> is connected by chain gear M<SP>8</SP> to a shaft M5, Fig. 15, driven from the reversible electric motor M by gearing M<SP>2</SP>, M<SP>3</SP> and a gear M<SP>4</SP> on the shaft M5. Pressed by a spring into contact with one side of the gear M<SP>4</SP> is a brake disc M<SP>10</SP> having an arm M<SP>13</SP> connected to balanced springs M<SP>18</SP>, M<SP>19</SP> tending to restore the arm to the normal position shown after displacement in either direction by the friction of the gear M<SP>4</SP>. In this normal position, a second arm M14 on the disc M<SP>10</SP> lies midway between a pair of stops M<SP>15</SP> M<SP>16</SP>. The arm M<SP>14</SP> is connected to an arm M<SP>22</SP> on a shaft M<SP>21</SP> carrying a pair of cam projections M<SP>25</SP>, in the gap between which has normally a roller on the arm M<SP>26</SP> of a normally closed switch M<SP>20</SP> in series with each of the switches actuated by the web-operated frame. When this frame is rocked, the motor M is driven in one direction or the other intermittently to adjust the screw D<SP>10</SP>. The initial movement of the motor driven gear M4 turns the disc M<SP>10</SP> so that one or the other of the cams M<SP>25</SP> opens the switch M<SP>20</SP>. Current is thereby cut off from the motor M the momentum of which is immediately thereafter arrested by the engagement of the arm M<SP>14</SP> with the stop M<SP>15</SP> or M<SP>16</SP>. The disc M<SP>10</SP> is then returned to normal position by one of the springs M<SP>18</SP>, M<SP>19</SP> and the switch M<SP>20</SP> is again closed. If the small adjustment of the screw M<SP>10</SP> has been insufficient to restore the speed of the web to normal, the switch controlled by the web actuated frame is still open, and one or more further actuations of the motor M takes place until such restoration of the speed is effected. In a further form, the speed adjusting devices are applied to the drive of the back-up roller which drives the impression roller frictionally.