Patent GB-190910775-A (GB)
Title: Improvements in Escapement Mechanism for Typewriting Machines.
Inventor: RONCHETTI JOSEPH ALBERT
IPC: B41J19/18
Filed: 1909-05-06
Granted: 1910-04-28
Abstract: 10,775. Ronchetti, J. A. May 9, 1908, [Convention date]. Letter spacing mechanism. - An escapement comprises fast and loose dogs 5, 6, Figs. 1 and 2, which are mounted on a rocker 4 and engage an escapement wheel 24, the loose dog 6 being loosely mounted and guided by means which arrest the dog gradually and silently in the spacing movement. The dog 6 is formed with cam-surfaces 19, 20 which engage rollers 15, 16 mounted on posts 13, 14 secured to the rocker 4. A cap-plate 22 secured to the post 14 is connected to the dog 6 by a spring 23 the tension of which may be varied by adjusting the position of the cap-plate. Normally the loose dog 6 engages the wheel 24, as shown in Figs. 1 and 2, and when the rocker is vibrated the fast dog 5 is caused to engage the wheel, and the dog 6 is raised clear and is thereupon moved inwardly and laterally by the spring 23 into the position shown in Fig. 8. When the rocker is again depressed the dog 6 is engaged by the oncoming tooth of the wheel 24, and is moved back into the position shown in Fig. 1, the wheel 24 thus making a one tooth movement forward, the cam-surfaces 19, 20 being so formed as to arrest the dog 6 when it is in alinement with the dog 5. The dog 6 is arrested gradually in its spacing movements by the cam-surfaces 19, 20 and the operation of the escapement is thereby rendered noiseless. When the wheel 24 is rotated in the reverse direction for back-spacing, the loose dog swings clear of the oncoming teeth. The fast dog 5 is adjustably secured to the rocker 4 by means of a pivot screw 7 and a clamp screw 11, Fig. 4, passing through an eccentric bushing 10, which is mounted in an aperture in the dog 5 and is formed with an hexagonal head 12. The rocker 4 is journaled on studs 3 and is formed with an arm 25 having a pivotal connexion 26 with an arm 30 which is connected to an arm 32 on a universal rockshaft 33. The connexion 26 is a frictional yielding connexion so that if necessary the universal bar may continue its stroke after the rocker 4 has been arrested. The connexion consists of a flanged roller 27 which is carried by a stud 26 and is straddled by the forked end 28 of the arm 30 and by the forked end 36 of an adjustable spring 35 which is secured to the arm 30. The spring 35 engages one flange of the roller and forces the arm 30 against the other flange. The vibratory movements of the rocker 4 are arrested by means of a spring arm 41 secured to the rocker and formed with a fork which plays between adjustable stops 40, 38. The stop 38 is threaded into the frame and may be locked in adjusted position by a nut 42, and the stop 40 is threaded into the stop 38 and may be adjusted with regard to the stop 38 and locked by a nut 43. In a modification, the loose dog engages the roller 16 by a flat instead of a cam-surface, and the spring arm 41 is replaced by a rigid arm which plays between stop-screws. In a further modification, shown in Fig. 19, the rocker 4 is formed with a cam-surface 51 which engages a roller 52 journaled in ears on the loose dog 6, and a roller 16 on the rocker engages a cam-surface 54 formed on the dog. The dog is provided with a spring 55 which is secured to a cap-plate 17. The fast dog 5 is adjustably secured to the rocker by a screw 60, which passes through a slot in the dog and is clamped by a screw 58.