US2001759A - Typewriting machine - Google Patents

Description

y 1935- H. A. AVERY 2,001,759

TYPEWRITING MACHINE Filed Aug. 18, 1935 2 Sheets-Sheet 1 \II [E Q N Q a IIIIIIIII INVENTOR HENRY ALLEN AVERY 8Y9 1 I M ATTO RN EYS H. A. AVERY TYPEWRITING MACHINE May 21, 1935.

Filed Aug. 18, 1955 2 Sheets-Sheet 2 INVENTOR HENRY ALLEN AVERY ATTORNEYS Patented May 21, 1935 UNITED "STATES TYPEW RIT ING MACHINE Henry Allen Avery,*Groton, N. Y., assignor to L. C. :Smith & Corona Typewriters Inc., Syracuse, N. Y., a corporation of New York Application August 13, 1933, Serial No. 685,693

3 Claims.

invention relates to improvements in typewriting machines and more particularly to typewriting machines in which the' type barsare given a shifting movement for case changing.

a .Theinvention has for its principal objects to provide .a simple, eflicient and compact typewriting machine in which the case shifting movement is imparted to the type .bars; to provide simple andefllcient means for supporting, guiding and imparting case Ishift movement to the typebars of a typewriting machine; and to provide a simple and compact case shift mechanism for a small and low portable typewriting machine of the 'kind a shiftable type bar segment supporting the type bars to strike upon the upper front quarteroftheplatenl other ends whichwill To the foregoing and hereinafter appear, the invention consists in the features of construction, arrangements of parts, and combinations of devices set forth in thefoldescription and particularly pointed out ln ethe appended claims. In .the accompanying. drawings illustrating the preferred .embodiment ofthe invention:

Fig. 1 is avertical central longitudinal sectional viewof the improved typewriting machine;

Fig. 2 is a view similar to Fig. 1 but showing the type bar segment and type bars shifted into posi tion for typing upper case characters; and

3 is a, fragmentary. front view of the machine as viewed perpendicularly to the plane of the type bar segment,.the parts of the case shift mechanism being in normal lower case position asinFig.1. f

The stationary main frame of the machine is formed of sheet metal and comprises side plates I0, a front end plate 1|, a rear end plate l2, a rearwardly tilted cross plate I3 held to and extending between the side plates in the rear half of theframe, and a platen carriage supporting jbed plate |4. Bed. plate |4has upwardly. and rearwardly extending raceway flanges 5, is tilted rearwardly and downwardly to lie in a plane perpendicular to that in which lies the cross plate I3, preferably hasits forward edge lying substantially in the plane of plate I3, isseated on lugs I which extend inward from the top edges of the side plates, and is also seated on lugs I! which extend rearwardly from thetop edgeof the cross plate |3. Screws |8.hold the bed plate to lugs Ii, andscrews l9 hold the bed plate to lugs IT.

The platen is journalled in the end members of the rearwardly and downwardlygtilted platen carriage 2|,and the baseof the carriage has forwardly and downwardly extending ;ra1ceway flanges 22 between which and the raceway flanges l5 on the bed plate ball bearings 23 are confined.

The type actionvmay be varied as to construc tion, that shown being of the kind disclosed in my co-pendin'g application Serial No. 586,319, filed January 13, 1932,.and need beonly briefly described. The type bars 24 are pivoted on the pivot wire 25 in the slotted type bar segment 26 which lies parallel to the cross plate, the pivot Wire lying in a plane tangent to the platen at the upper front portion of the platen as is usual in three-quarter or semi-front strike typewtiting machines. Draw links 21 extend upwardly and forwardly from the heelsof the type bars tothe upper ends of upstanding levers '28 which are 'piv: oted' on an arcuate pivot wire 29 in the hori zontally arranged slotted segment 30. Segment 3|! curves rearward from themiddle to the sides of the machine and is held at its ends to the side plates of the frame. Levers 28are actuated by the type'keys 3| connectedby stems 32 to toggle devices 33. Each toggle device is pivotally anchoredto two pivot wires 34 and 3 held in a support 36 attached to the side members of the framefand the toggle devices are also pivotally anchored at 3l to the levers 28. A return spring 38 for each type action is anchored at its ends to the toggle device and upstanding lever of the type action. The key carrying stems are normally engaged under a stop device extending across the frame and held to the sides of the frame.

' The type bar segment 25 has three bosses 40 extending rearward therefrom at its middle and 35 end portions to the front face of a shiftable sup-. porting plate or shift frame member 4| to which the segment is held by screws 42 which are threaded into said bosses. Plate 4| lies parallel to frame plate l3 closely in front of said plate l3. At each of the two upper corners thereof plate 4| is provided with a forwardly bent lug 43 having a closed slot 44 extending parallel to the plane of plate 4| to form a short raceway member or flange on plate 4|. Each lug 43 abutsthe outer edges of a pairof superposed bracing lugs 45 and 45 formed on plate 4| and lying 'flatwise in planes extending forward and upward perpendicular to the plate. Small plates 41,..held fiatwise to the front face of plate l3 outside of raceway members 43 by screws 48, each have a short forwardly bent lug 49 provided with a closed slot 5|] extending parallel to the plane of plates l3 and 41 to form fixed raceway members opposed to the raceway members 43 of the shiftframe. In each of the races thus formed adjacent the two sides of the machine there is confined a single ball bearing 5|. Each raceway member 49 abuts the inner ends of two superposed bracing lugs 52 and 53 extending forward and upward flatwise from.

plate 41.

A pair of forwardly and upwardly extending sheet metal arms 54, fastened at 55 to lugs 45, have an arcuate type bar rest 56 secured at its ends at 51 to the forward ends of said arms, said restengaging under the type bars to support the arcuate system of type bars in an upwardly and forwardly inclined position for action to the platen by the type keys.

The main plate member 4| of the shift frame has a lug 58 extending fiatwise rearwardly and downwardly from the lower edge of said plate midway the ends of the plate and lying in a plane perpendicular to the plate. The cross plate l3 of the main frame is cut out at 59 to afford clearance for upand down movement of lug 58 with plate 4|. Threaded up through'the rear part of lug 58 is an adjustable shift stop screw 60 normally engaged under a rearwardly-and .downwardlyf in clined and slightly springy shift stop lug 6| onla stop carryingplate 52 held by screws 63 to plate l3. PlatelBZ has a lug 64 extending fiatwise forward and upward through the cut out 59 in plate l3, and a slightly springy sheet metal bar 65,1ies fiatwise against the'b'ottom face of lug 64 and is held at one end to said lugby screws .19 and'fill, one of which may have a lock nut thereon as shown. Near its free end bar 65has threaded,v upwardmtherethrough an adjustable shift'stop screw 66 which passes loosely through a suitable clearance aperture in lug 64 and has its upper end spaced below, but lying in the path of movement ofthe forward end oflug 58 on the shift frame plate to arrest downward movement of the shiftframe and the bar segment I At its two lower corners the-main plate member 4| of the shift frame is provided with forwardly and downwardlyextending lugs S'Hying flatwise in vertical fore and aft planes. A rockshaft 68' extends across the main frame and is journalled at its'. ends in, the, side plates |-0 of the main frame. This rock shaft extends above segment 30 and under the type, bars 24 and draw links 21 intermediate 'the ends of the type bars, and has a downwardly bowed middle section to afford clearance for the draw links for the type bars in the middle section of the type segment. Rearwardly anddownwardly extending rock arms 10 on the higher end sections of the bowed rock shaft, adjacent the outer ends of the .middle downwardly bowed section of the shaft, are connected bytransversely extending horizontal piv ots 69 to the forward ends of, lugs filand serve as lower supports and guides for the shift frame.

A plane parallel'to the planes of the type bar pivot wire, segment 25, and plates 4| and I3, passes through the'axes of the ball bearings 5| and pivots 69in both the upper and lower case positions of the shift frame, the pivots 69 moving, in shifting from lower case to upper case position, between points equal distances above and below a plane which is perpendicular to the above mentionedplanes and passes through the axis of the rock shaft, thus. providing for printing of bothlower andupper case types on their feet. In

passing from one case'position to the other the shift frame rocks slightly upon the ball bearings 5| and pivots69. The draw links 2'! swing about their pivotalconnectionsiwithilevers 28 during case changing movements, their rear ends moving between points equal distances above and below planes intersecting said connections and perpendicular to the plane of plate l3.

Bellcranks H are fixed on rock shaft 68 adjacent the ends of the shaft, each bellcrank having a forwardly extending arm and an upwardly extending arm. Springs 12 are attached at their forward ends to brackets 72 held to side plates ID of the frame, said springs being attached at their rear ends to the upper ends of the upwardly ex- "tending arms of bellcranks H to normally hold the shift frame and type basket shifted upward into lower case printing position, the lower case types being nearest the type bar pivots in the machine. shown and as is common in typewriting machines.

Bellcranks H are rocked against the pull of springs 12, to shift the shift frame downward to the upper case printing position shown in Fig. 2, by meansof either one of two shift key levers" located adjacent opposite sides of the main frame. Each shift key lever I4 extends fore 'and'aftiof the machine and is fulcrumed between itsendson a horizontally and transversely extending pivot15' carried by the main frame. The forwardly extending arm ofeach shift key lever carries a shift key 16. A short slot 11 extends forward fromthe rear end of each shift key lever, providing a forked lever end embracing a horizontally andtransf- Versely extending stud 18 carried by the forwardly extending arm of the adjacent bellcrank H. Springs 12 also serve to return, the shift eyle'f vers to. normal position. s

A segmentshift mechanismis' thus provided which operates easily, rapidly. and quietly; and which is also of simple, light and compact construction. v I

WhatIclaimis: 1

1. A typewriting machine havinga main frame, a type basket supporting shift frame,'means on said frames forming two up and down extending ball racesspaced apart transversely'of' the ma chine, a single bearing ball in each. ball race for supporting the shift frame for sliding and piv otal movement, a rock shaft journaled on the main frame and extending transversely of the machine, a pair of parallelrearwardly extending rock armson said shaft, horizontal transversely extending pivots connecting the rear ends of said rock arms to the shift frame at a level below the ball races, cooperating stop means onthe main and shift frames for. limitingup and down movements of the shift frame, a bellcrank fixed on said rock shaft having a forwardly extendingarm and an upwardly extending. arm, aspring'connected'to said upwardly. extending arm of the bellcrank and to the main frame'for rocking the shaft in one direction, a key lever fulcrumed on the main frame having a rearwardly extending arm provided with a longitudinal'slotjand also having'a forwardly extending arm, a. shift key carried by ,the forwardly extending arm of the key lever, and a horizontal transversely extending stud carried by the forwardly extendin'g'arm of the bellcrank and engaged in the slot in the rearporting the type bars to normally extend upward- 7 ly and forwardly from their pivots, key operated draw links for actuating the type bars and normally extending upwardly and forwardly from the type bar heels, means on the main frame and shift frame forming a pair of transversely spaced ball races extending in an upwardly and rearwardly inclined plane, a single bearing ball in each race, said balls supporting the shift frame for sliding and pivotal movement, a shift key operated rock shaft extending transversely of the main frame and having horizontal end portions journalled in the frame and a downwardly bowed middle portion affording clearance for the actuating draw links for the central type bars, a pair of parallel rock arms fixed on said end portions of said shaft and extending downwardly and rearwardly therefrom and pivotally connected at their rear ends to the shift frame at a level below the ball races, and cooperating stop means on the main and shift frames for arresting shifting movement of the shift frame in lower and upper case printing positions in both of which the type bar pivots are located in the same upwardly and rearwardly inclined plane tangent to the platen at a printing point on the'upper front quarter of the platen.

3. In a typewriting machine, the combination of a main frame, a type basket supporting shift frame, means on said frames forming two opposed ball races spaced apart transversely of the machine, a single bearing ball in each ball race for supporting the shift frame for sliding and pivotal movement, a rock shaft journalled on the main frame and extending transversely of the machine, a pair of parallel rock arms fixedly held to said shaft and spaced apart transversely of the machine, horizontally aligned pivots extending transversely of the machine and pivotally connecting the rock arms to the shift frame at points spaced from the ball races lengthwise of the races, cooperating stop means on the main and shift frames for limiting case shift movements of the shift frame, a bellcrank fixedly held to the rock shaft, a spring connected to the main frame and one arm of the bellcrank to rock the shaft in one direction, and a shift key lever fulcrumed on the frame and having a key carrying arm and an arm having a pin and slot connection with the other arm of the bellcrank to rock the shaft in opposition to said spring.

HENRY ALLEN AVERY.

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