US1118406A - Feed mechanism for type-writers. - Google Patents

Description

H. ETHERIDGE. FEED MECHANISM FOR TYPE WRITERS. APPLICATION FILED MAY 23, 1914.

1,1 1 8,406. Patented Nov. 24, 1914.

2 SHBIITBSHEET 1.

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H. ETHERIDGE. FEED MECHANISM FOR TYPE WRITERS.

APPLICATION IILED MAY 23, 1914.

Patented Nov. 24, 1914.

2 SHEETS-SHBET 2.

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HERBERT ETHERIDGE, 0F WIMBLEDON PARK, ENGLAND, ASSIGNOR TO THE BABI'LOCR TYPEWBITER COMPANY LIMITED, OF LONDON, ENGLAND.

FEED MECHANISM FOR TYPE-WRITERS.

Specification of Letters Patent.

Patented Nov. 24, 1914.

Application filed May 23, 1914. Serial No. 840,475.

To all whom it may concern:

Be it known that I, HERBERT Ernaaroen, a subject of the King of England, residing at Wimbledon Park, in the county of Surrey, England, have invented certain new and useful Improvements in Feed Mechanism for Type-Writers, of which the following is a specification.

This invention relates to the feed mechanism for the platen carriages of typewriters and has for its object to provide an improved form of such mechanism.

he present invention consists in the combination in a typewriter escapement mecha nism of an escape-wheel, a pivoted pawl and ratchet,- one of which members moves with the escape-wheel, and the' other with the feed pinion for the carriage, and means for swinging the pawl about its plvots to disengage it from the ratchet at will to free the escape-wheel, said means being so disposed as not to interfere with the p votal movement of the pawl when permitting backward movement of the carriage. i

The escapement wheel may be carrledon a spindle having a pinion thereon whleh meshes with the platen-carriage rack of the typewriter, the escapement wheel being free to rotate on the spindle and opcratively con nected with the spindle by the ratchet and pawl, a back-spacing pinion being also mounted on the spindle and provided with a key-operated pawl for actuating the backspacing pinion.

The ratchet and pawl connection between the spindle and the escapement wheel malty tie comprise a ratchet wheel mounted on escapement wheel, project laterally from the wheel parallel with the axis of the spindle, a U-shaped pawl-member pivoted transversely on the spindle and having a segmental series of teeth at the base of the U to engage the ratchet wheel on one side of the pivot and means engaging the free ends of the U on the other side of the pivot for operating the pawl.

The pawl may be actuated by a plate surrounding the escapement wheel spindle and. adapted by movement axially of the spindle to engage the free arms of the pawl to operate it; this plate may be operated independently by the tabulator key or keys and by the carriage release lever.

In the accompanying drawings Figui-e whereof the ratchet teeth- 1 is a view of the escapement mechanism from the rear of the machine; Fig. 2 is a plan in section on the line 2-2 of Fig. 1. and Fig. 3 is a perspective view of a detail:

Like reference letters indicate like parts throughout the drawings.

The spindle A is mounted in bearings A, A n the frame of the machine and carries at its upper end a pinion B meshing with the rack on the platen carriage. An escapement wheel C is carried on a sleeve C loose on the spindle A and on the upper side of the wheel C is a crown ratchet wheel C whose teeth C" extend in a direction parallel with the axis of the spindle A. A pawl member D is mounted on a pivot D transversely disposed on the spindle A. The pawlmember D is of U-shape and it is pivoted about the middle of the length of each arm of the U. The bottom of the U is provided with a series of teeth D shaped to conform to the ratchet teeth C on the wheel C and a spring D mounted on the pivot pin D is arranged to hold the teeth D, C normally in engagement.

The lower end of the spindle A has mounted fast on it a back-spacing pinion E and a pawl E is provided to operate this pinion and feed it back in steps of one tooth each. This pawl is operated by the link and lever connections E E, E, Fig. 2, from a key conveniently situated on the front of the machine. It will be understood that the pawl E is arranged to feed the pinion E in the reverse direction to that in which itnormally travels under the control of the letter-spacing mechanism.

The means for releasing the pawl-member D from engagement with the ratchet wheel 0 comprises a plate F surrounding the spindle and carried on two arms F suitably guided in the framework of the machine. lhe plate is normally held up out of engagement with the pawl-member by the spring F Above the ends of the arms F there is disposed on the platen carriage a. rod G which is capable of being depressed by the carriage-release lever G. A springcontrolled detent C enga es the escapement wheel C and prevents it rom being turned backward.

The tabulator keys, of which there are provided a number corresponding with the number of tabulator stops on the platen carriage, are each connected to levers H which are arranged to bear on the upper side of the plate l and depress it when a tabulator key is depressed.

It will be appreciated that the hereinbefore described construction of pawl-member D and its operating plate F is such that although the pawl-member is carried around with the spindle it can be engaged and operated in any position in its rotation by the plate F; also that the provision of a segmental series of teeth D on the pawl 1nstead of only a single tooth diminishes the wear and increases the reliability of. the mechanism.

The operation of the mechanism is as follows :The platen carriage is fed along in the ordinary manner by a spring under the control of the escapement wheel C. The rack on the platen carriage engages with the pinion B on the spindle, thereby causing it to rotate and carry with it the pawl-member D which normally engages the ratchet teeth C and' 'carries the escapement-wheel around with it. The movement oif the escapement-wheel is'controlled by dogs K operated by the key-levers or space-bar. When it is required to return the platen carriage to begin another line, it is pushed back and the teeth D of the pawl rideover the teeth U of the ratchet wheel, so that this return motion is permitted and the escapeinentwheel C remains stationary. .lf it is required to set the platen carriage back by one or two spaces the back-spacing key is depressed and the pawl'll is thereby brought into engagement with the pinion E causing it to turn the spindle back by the required amount. The pinion D is fast on thespindle and by its engagement with the platen carriage rack it moves the platen carriage back the required amount. During this movement the teeth D of the pawl again ride over the teeth C of the ratchet wheel C The spring-controlled detent C prevents backward rotation of the escapement-wheel C. This is provided because the friction of the pawl riding backward over the ratchet-teeth. may be suflicient to carry the escapement-wheel back until its teeth engage with the other side of the dog which is holding it. JVhen this occurs the pawl teeth D would not engage in the correct position with the ratchet-teeth C and the platen carriage, which has been moved back, will move forward again to take up this movement of the escapement wheel.

When the tabulator mechanism is operated the teeth ID on the pawl are lifted out of engagement with the teeth G and the carriage is free to travel under the actionof its 'driving spring until'the tabulator stops come into engagement. During this movement the spindle rotates freely, as the pawl is held out of engagement, owing to the plate F engaging the arms D all'times during their rotation. A similar action occurs when the carriage-realease lever G is operated. The pawl is held out of engagement and the carriage is free to travel through any required distance.

It will be understood that throughout this specification where the term typewriter is used any typing mechanism, such for example as is sometimesemp'loyed in an adding machine, is intended to be included.

What I claim as my invention and desire to secure by Letters Patent is 1. In a typewriter-escapement-mechanism the combination of, a spindle, a carriagefeed-pinion thereon, an escapement-Wheel thereon, one of the elements on the spindle being fast with the spindle, a ratchet-andpawl operatively connecting the pinion and the wheel, and means for swinging the pawl about its pivotal axis to disengage it from the ratchet at will, said means not interfering with the free pivotal movement of the pawl when riding over the ratchet, substantially as set forth.

2. In a typewriter-escapement-mechanism the combination of a spindle, a carriage- :teed-pinion fast thereon; an escapementwheel loose thereon and having in" addition to the escape teeth a set of ratchet teeth, a pawl carried around with said spindle and pivotally mounted. thereon to cooperate I with said ratchet-teeth in such manner as to operatively engage it with the spindle, means engaging said pawl and movable to swing it pivotally out from engagement with 'the ratchet-teeth, said means not interfering with. the free pivotal movement of the pawl when riding over the ratchet, substantially as set forth.

3. In a typewriter-escapementmechanisin the combination of a spindle, a carriagefeed-pinion fast thereon, an escapement wheel loose thereon, and having inaddition to the escape-teeth a series of ratchet-teeth projecting parallel with the axis of said spindle, a U-shaped pawl-member pivoted transversely on said spindle and having on one side of the pivot a segmental series of teeth at the base of the U to engage the ratchet-teeth and means engaging the free ends of the U-shaped pawl on the other side of the pivot and movable to disengage it from the ratchet-teeth at will, said means not interfering with the free pivotal movement of the pawl when riding over the ratchet, substantially as set forth.

4. Tn atypewriter-escapement-mechanisrn the combination of a spindle, a carriagefeed-pinion fast thereon, an escapementwheel loose thereon, having in addition to the escape-teeth a series of ratchet-teeth, a pawl rotating with said spindle and pivoted thereon, cotiperatingwith said ratchet-teeth, a plate surrounding said spindle and movable axially thereof to engage the free end its v of the pawl and swing it out of engagement with said ratchet, substantially as set forth.

5. In a typewriter the combination of a spindle, a carriage-feed-pinion thereon, an escapement-Wheel thereon, a ratchet-andpawl operatively connecting the wheel and pinion, means for swinging the pawl about its pivotal axis to disengage it from the ratchet, a carriage-release lever operatively 10 connected to said means, and tabnlator-keys also operatively connected to said. means, substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HERBERT ETHERIDGE.

Witnesses:

HARRY B. BRIDGE,

A. J. Cowmc.

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