Patent GB-191208255-A (GB)
Title: Improvements in or relating to the Escapement Mechanism of Typewriters.
Inventor: SPIRO CHARLES
IPC: B41J19/18
Filed: 1912-04-04
Granted: 1913-04-04
Abstract: 8255. Spiro, C. April 4. Letter-spacing mechanism.-Relates to escapement-mechanism in which the dogs are carried integrally by a rocker. (1) The dogs C, C<1> are formed on a rocker consisting of a plate C<2>, which is pivoted by readily-detachable means such as a single screw C<3> on a plate D arranged in an accessible position under the platencarriage. The rocker is operated from the universal bar by a member E, which merely abuts on a lug C<7> on the rocker, the arrangement permitting the rocker to be readily detached by unfastening the screw C<3>. The rocker bears on a roller D<7> journaled on the plate D. The dog C is normally held in engagement with the escapement-wheel A by a spring C<4>, which holds an arm C<5> of the rocker against a stop C<6> on the plate D. The dog C.' is a half-tooth space above the level of the dog C, so that as the rocker moves forward and backward the on-coming tooth of the escapement-wheel falls on the dog C<1> and then on the tooth C, the feed being effected in two steps. The dog C<1> is bevelled to facilitate disengagement from the escapement-wheel. (2) In arrangements wherein the universal bar F', Fig. 5, is pivoted to arms F<3> projecting from a rock-shaft F and can be shifted to or from the rock-shaft for the purpose of adjusting the throw of an inkribbon vibrator K, the following means are provided for maintaining a constant throw of the rocker C<2>. The member E is pivoted at E<1> to the rock-shaft and is formed with a tail E<2> for engagement by a finger L on the bail, the acting-face E' of the tail being spaced from the finger and being sloped so that the lostmotion is the same in either position of the bail. Accenting - arrangements.-The finger L is pivoted at L<1> to the bail and can be swung clear of the tail E<2> by an accenting-key M, which is provided with a roller M<1> adapted to engage a cam-lever L<2> pivoted on the bail and connected to the finger by a link L<11>. Carriage-releasing arrangements.-The plate D is pivoted on a screw D<1>, Fig. 1, and can be moved by the usual release-lever G or the tabulating-key H<4> to swing the dogs clear of the escapement-wheel. For this purpose the yoke G<1> of the lever G is formed with a cam G<2> engaging the edge of the plate D, the yoke being operated either directly by a lever G or by the tabulating-key H<4>, which is arranged to operate a lever H formed with a finger H<1> engaging a finger G<3> on the yoke. The plate D is formed with a finger D<3>, which is normally held against a stop D<5> by a spring D<2>. Line-locking devices.-The usual locking- fingers J<4>, J<5> of the 'Bar-lock ' machine are modified by being formed on a lever J<1> which is pivoted on a screw J on the plate D and is slotted at J<2> to engage the screw D<1>, the lever being normally held in the position shown by the dog-returning spring C<4>. At line-end, a stop on the platen-carriage engages the finger J<4> and turns the finger J<5> into engagement with a finger J<6> on the rock-shaft F, thereby preventing operation of the keys.