Patent GB-332918-A (GB)
Abstract: 332,918. Wheeler, W. H., and Ogden, J. W. March 8, 1929, [Convention date]. Franking-machines; tripping-arrangements.- A postal franking-machine comprises a rotary printing drum and a positively driven impression roller and automatic means for arresting the advance of an envelope after an impression has been printed thereon and again advancing the envelope to receive another impression adjacent the first one. As shown, the machine comprises a base unit A, Fig. 2, containing envelope-moistening mechanism 200 (not described) and an impression roller 111, and a portable unit B, which contains a printing-roller and registering- mechanism, and may be detached and carried to the post-office forresetting. The unit A is provided with studs 100<a> and a screw 100<b> for securing the unit B and with a key adapted to enter a hole in the bottom of the unit B to release locking-mechanism (not described), which prevents the operation of the printing-mechanism when the units are separated. The unit B comprises a casing 1 in two parts connected by a bolt 19 passing through the cover part and secured to the lower part by a sealed screw 19<a>. The printing-roller 16, Fig. 8, carries a franking-die 17<b> and a postmarking-die 18, and is provided at each side with knurled feed discs 16<a> cut away at 16d opposite to the dies, the whole roller being cut away to leave a clear space for the introduction of the letters. The roller 16 is enclosed by a housing 2, Fig. 2, extending from the casing 1 and provided with a front plate 2a secured .by screws and by a bolt, the nuts of which are within the casing 1. Inking-devices (not described) are enclosed within the housing 2, and they may be removed through a side door 2<c> or reinked through a top door 2d. The printing-roller 16 is fixed on a shaft 6, Fig. 3, rotated by spiral gears from a shaft 5 driven by a hand-crank 21. The end of a rod 22<a> normally lies in the path of the crank 21, and, before the crank can be rotated, a thumblever 22, Figs. 2 and 3, fixed on the rod 22a must be turned, whereupon a pin 22d on the rod engages a cam slot 22<t> in a fixed plate 22<e> and the rod is withdrawn. The thumb-lever is released when the crank has passed, and the rod is projected by a spring 22
 and stops the crank after one revolution. The impression roller 111 is mounted in a frame 112, Figs. 7 and 8, depressible about a pivot 100<d> against spring action. Fingers 13, 13a arranged one at each side of the printing- roller 16 are adapted to be rocked about a shaft 15 to depress the envelope and the frame 112. The fingers are carried by a frame 13<b> on which is a lug 13<c> engaged by a screw 14<c> in a frame 14b on an arm 14, which is fixed to the shaft 15, and is rocked by a cam 9b in the normal operation of the machine when a single stamp followed by the postmark is to be printed, the fingers holding down the envelope until the franking-die is about to print. When more than one stamp is to be printed, the shaft is moved outwardly by means of a knob 15<a> to bring the arm 14 under the influence of a second cam 9<a>, which depresses the fingers 13, 13<a> to detain the letter and trip the impression roller immediately after the stamp has been printed and until the franking-die comes round again. When the last stamp followed by the postmark is to be printed, the knob 15<a> moves in again to replace the lever 14 over the cam 9<b>. The impression roller 111 is positively rotated, and, as it lies slightly below the frame 112, it does not tend to feed forward an envelope pinched between the finger 13 and the frame 112. The finger 13a is arranged at a higher level than the finger 13 and holds the envelope clear of the die. The Specification as open to inspection under Sect. 91 (3) (a) describes (1) mechanism relating to the adjustment of the machine to print stamps of different values; and (2) means for preventing fraudulent impressions being obtained by pressing an envelope against the inked die while in printing position. (1) This forms the subject-matter of Specification 332,931. (2) A guard 34, Fig. 5 (Cancelled) is pivoted at 34<a> to the roller 16, normally lies below the level of the periphery of the roller, and is adapted to be projected just before the die commences to print. In the position of rest, the guard is withdrawn, and is held in that position by a cam 35 having a notch 35<a> engaging a pin 34b on the guard. A roller 35<c> on the end of an arm 35<d> bears against a fixed cam If, and when, owing to the rotation of the roller 16, the roller 35<c> leaves the high part of the cam 1f, the cam 35 is rotated, and releases the pin 34b, whereupon a spring 34
 tends to project the guard. When so projected, a pawl 36 swings round and locks behind a shoulder 34f on the guard and prevents reverse movement thereof. The other end of the pawl is held by a notch in the cam 35, and these parts remain in this position until, on further rotation of the roller 16, the cam 35 is swung back and removes the pawl 36, and, by engaging the pin 34<b>, withdraws the guard. The guard is only projected by its spring if the frame 112 is lowered which would necessarily be done if an attempt were made to insert an envelope and press it against the die : otherwise the frame 112 or an envelope fed in the ordinary way supports the guard. This subjectmatter does not appear in the Specification as accepted.