Patent GB-773838-A (GB)
Title: Improvements in or relating to control system for typographical line casting machines
IPC: B41B27/10
Filed: 1955-07-08
Abstract: 773,838. Type-bar-making machines. DOW JONES & CO., Inc. July 8, 1955 [July 15, 1954], No. 19819/55. Class 100(3) Driving mechanism; assembling matrices. Apparatus for controlling the operation of a typographical line-casting machine by analysing perforations in a control tape comprises a constantly rotating shaft, electrical connections therefrom for controlling the type feed and analysing means, electrically operated means responsive to the analysing means for controlling the release of matrices and operation of the elevator, connections from said shaft for raising and lowering the elevator, and means responsive to the operation of the elevator for disabling the tape feed and analysing means when the elevator is not in its lowermost position. The apparatus is of the general construction described in Specification 735,206, and differs therefrom only as set out hereunder. The shaft 304, Fig. 1c, is continuously rotated and drives the shaft 334, Figs. 1d and 5, through a slip clutch so as to rotate it whenever such rotation is not positively prevented. The elevator is raised and lowered by means of a disc 333 mounted on the shaft 334 separately, from the stop members 332, 335, through arms 431, 433 both adjustable in length, and a sector 437 engaged by means of a notch 437a with a spring-urged plunger 438 carried by the elevator-operating handle 436. For manual operation, the plunger is pressed in to disconnect the sector. When the shaft 334 is freed for rotation by withdrawal of the pawl 331 from engagement with the arm 332 on the first energization of the solenoid 330, the shaft rotates only a small amount, which has hardly any effect on the elevator and is then stopped by a second detent comprising a stop 332a engaging a shoulder 429 on a member 421 pivoted at 422 to an arm 423 pivoted at 424. A ratchet wheel 416 is mounted on a threaded extension 414 of the shaft 304, and normally rotates with the shaft. The ratchet is held against a collar screwed on the end of the extension and secured thereto, and a coil spring attached at one end to the collar and at the other end to the ratchet causes said normal rotation. When the stop 332a engages the shoulder 429 the member 421 is forced upwards against the action of a spring 425 until a tooth 420 comes into the path of the ratchet teeth, and stops the ratchet wheel from rotating. Owing to the threading of the extension 414, the ratchet wheel now moves axially away from the collar until a projection on the ratchet wheel comes into the path of a projection on the extension whereupon the ratchet wheel is driven positively, thereby pivoting the member 421 to release the stop 332a. The spring 425 then lowers the member 421 to release the ratchet wheel which is restored by the coil spring, and the shaft 334 rotates until stopped by the arm 335. The collar can be adjusted on the extension so as to alter the time taken before the ratchet wheel is driven positively, whereby the mechanism acts as an adjustable time delay for the elevator. In order that the tape feed and analysing devices cannot be actuated while the elevator is not in its lowermost position, circuits through contacts 301, 302, Fig. 1c and contacts 293, 294 are completed through contacts 501, 502 and 506, 507 respectively of a relay 503, which is energized through contacts 360, 362, Fig. 1d only when the shaft 334 is in its normal position held by the arm 332. Relay 503 can only be energized when shaft 304 is in that half of its revolution when contacts 508, 509 are closed, at which time the sensing circuits have adequate time to perform their functions. During the other half-revolution, the relay 503 is kept energized by means of a circut from D.C. + by line 527, contacts 526, 525, line 524, contacts 523, 522, line 521, relay 503, line 520, contacts 519, 518, line 517 contacts 516, 515, line 514, and line 504 to D.C.-. If shaft 334 begins to rotate, relay 503 is de-energized, because contacts 360, 362 are opened. Owing to the position of arms 332, 335, the lobe 347 of cam 348 is in position 180 degrees. The lobe 378 of cam 379 controlling the rotary solenoid for straightening the matrices is shorter than in Specification 735,206 so as to energize the solenoid only while the shaft 334 is held by the second time-delay detent. Specification 356,197 also is referred to.