Page:United States patent 766474.pdf/12

 by referring to Figs. ,, and , from which it will be seen that the armature 7, of the electromagnet 5 is secured to a vertical spindle 45, journaled in suitable bearings and also having in fixed relation there with a duplex shifting lever 46 for shifting the coupling members 9 and 10 simultaneously, so as to bring them alternately into engagement with the central coupling member S. Near its upper end the spindle 45 has secured thereto an escapement 47 for permitting the feed-wheels 22 and 23 to turn alternately, the wheel 23 being held fast by the escapement and the wheel 22 being permitted to rotate when the electromagnet 5 is energized and the coupling member 10 clutches to the central member S. The return movements of the coupling-lever 46 and the escapement 47 are of course controlled by a suitable retracting-spring 48, secured to the post 49. In this construction the gear-wheel 23 forms part of a carrier supporting a plurality of components or groups of components selectible in accordance with the electrical signal components of the code characters received by the instrument. It also constitutes one element of the group-selecting means here in before mentioned.

Referring particularly to, inclusive, it will be seen that the gear-wheel 23 has secured thereto a segment 50, supporting all of the character-selecting components before referred to, and that these components are divided into six groups, each group with the exception of one containing two components and the components of each group being mounted in different angular positions about the shaft 21. These components are preferably long and short stops or pins representative of the desired feed-values—such, for example, as those which I have hereinbefore stated may be assigned to them—the stops of the first group being designated, respectively, by 51 and 52, those of the second group by 53 and 54, those of the third group by 55 and 56, those of the fourth group by 57 and 58, those of the fifth group by 59 and 60, and that of the sixth group by 61. The component carrier and all of the parts associated directly therewith are normally mounted to have intermittent rotary movements about the shaft 21 and axially-reciprocatory movements lengthwise of the shaft. These reciprocatory and rotary movements of the carrier 50 determine the selection of the groups according as the carrier is advanced step by step from one position to another along said shaft and also represent the movement of the selected component in each group mounted on the carrier. In order that the pinion 39 and the carrier 23 may remain rotatively connected regardless of the group selected, one of these elements, preferably the pinion, has a tooth-face long enough to control the six stages of the controlling movement of the means for selecting the groups and the components thereof. One of the dogs 47&prime; and 47&Prime; of the escapement 47 also has a face long enough to co&ouml;perate with the spur-gear 23 in all of its group selecting positions. The subdivisions or steps and the traveling movements of the group-selector are determined in this case by a selector proper. (Clearly illustrated in detail in Figs., , and .) In the form shown this selector is a sleeve 65, mounted to reciprocate along the shaft 21 and held against rotation by the walls of the guide-slot 66, cooperative with a suitable guide. At diametrically opposite points in the periphery of the sleeve toothed racks, preferably two in number and designated by 67 and 68, are shown, each of these racks containing seven rack-teeth or one more than the groups of components to be selected. At one end thereof the sleeve 65 has the socket 69 of a coupling box and four coupling-pins 70 projecting in this construction inwardly into a groove 71 in the complementary member 72 of the coupling-box. This connection therefore compels the component-carrier and its components to travel lengthwise of the shaft 21, while at the same time permitting said carrier and components to have intermittent feed or rotary movements relative to the sleeve 65. The step-by-step movement of the sleeve 65 may be effected by means of an electromagnetically-operated pawl 3, which in this case is operated by an electromagnet 74 and is preferably controlled by a local circuit, which is made when the main circuit to the telegraph instrument is broken. The pawl 73 is of the by-pass or safety type and is normally pressed toward the teeth of the rack 67 by a light spring 74 on a pivoted armature 75. This pawl has a tail-piece 73&prime;, which coacts with a stop, such as the stop-pin 73&Prime;, to shift the pawl out of engagement with the teeth of the rack after each step movement of the rack. When the electromagnet 74 is energized, the spring 74 instantly presses the pawl into engagement with the adjacent tooth of the rack and the continued movement of the armature 75 causes the pawl to move the rack one step in opposition to the force of the spring 65. The breaking of the local circuit through the electromagnet 74 results in the return of the pivoted armature 75 by the spring 76. A releasing-pawl is shown at 77 for the purpose of permitting the sleeve 65 to return to its normal or zero position after the reception of a group of electrical signals representing a code character. This pawl is pivoted in a suitable manner and is operated by an electromagnet 78, which is controlled by the time constant of a break in the circuit to the receiving instrument longer than the breaks between the signal components of the respective code characters. The spring 78&prime; normally holds the pawl 77 in engagement with the teeth of the rack 68 to prevent return movement of the sleeve.