US1930068A

US1930068A - Ribbon reversing mechanism for typewriting machines

Info

Publication number: US1930068A
Application number: US436969A
Authority: US
Inventors: Frank H Trego
Original assignee: COXHEAD RALPH C CORP
Current assignee: COXHEAD RALPH C CORP; RALPH C COXHEAD Corp
Priority date: 1930-03-19
Filing date: 1930-03-19
Publication date: 1933-10-10
Anticipated expiration: 1950-10-10

Description

Oct. 10, 1933. H T E 1,930,068

RIBBON REVERSING MECHANISM FOR TYPEWRITING MACHINES Filed March 19. 1950 4 Sheets-Sheet l INVENTOR flan/r 72640.

BY QM ATTORNEY F. H. TREGO Oct. 10, 1933.

RIBBON REVERSING MECHANISM FOR TYPEWRITING MACHINES Filed March 19, 1930 4 Sheets-Sheet 2 R w 0 Q n W A M fl m Y B RIBBON REVERSING MECHANISM FOR TYPEWRITING MACHINES Filed March 19, 1930 4 Sheets-Sheet 3 INVENTOR F/zm/r h. Treqo.

A TTORNE Y F. H. TREGO Oct. 10, 1933.

RIBBQN REVERSING MECHANISM FOR TYPEWRITING MACHINES Filed March 19, 1930 4 Sheets-Sheet 4 INVENTOR fid/M Vega BY A TTORNEY Patented Oct. 10, 1933 1,930,068 V I RIBBON REvERs'ING FOR. TYPEWRITING MACHINES Frank H. Trege, New Y rl l Y as signonby' mesne assignments, to Ralph C. Goxlie'ad Gore poration, New York, N. Y.,

Delaware a" corporation of Application March 19, 1930. Serial N 0. 436,969

2 Claims. (01; isi'i i's) This invention relates to improvements in typewriting machines and more particularly to ribbon reversing mechanism therefor.

An object of the invention is to provide efficient ribbon reversing means which is simple inconstruction and which may be manufactured economically.

The ribbon spools are supported, one on each of two shafts, either of which shafts may be connected to a transverse drive shaft operable, through intermediate means, by the key levers, to feed the ribbon.

The ribbon reversing means includes two toothed wheels secured to the drive shaft, which are normally ineffective, each one having associated therewith a pawl to effect a shifting of the drive shaft and thus reverse the feed of the rib"- bon.

The pawls are normally out of engagement with the toothed wheels. As the end of the ribbon is approached on one spool, an element'on the ribbon engages a ribbon guide arm to actuate a shaft having an actuating arm connected thereto; said actuating arm engaging one of the pawls to swing it into engagement with the associated toothed wheel. Upon subsequent rotation of the drive shaft the latter is shifted axially through the co-operation of the pawl with its toothed wheel, thus disconnecting one of the spool shafts and connecting the other with the drive shaft.

A feature of the invention relates to a novel element which is bent up from a single piece of wire to constitute the pawl actuating shaft and the ribbon guide arm. The pawl actuating arm is adjustably secured to said element so that it may be properly located thereon relatively to the pawl actuated thereby.

Other features and advantages will hereinafter appear.

In the drawings,

Fig. 1 is a sectional side elevation of part of the machine showing the invention applied thereto;

Fig. 2 is a fragmentary top plan view of the machine;

Fig. 3 is a sectional front view taken on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary top plan view taken on the line 44 of Fig. 3, showing the ribbon reversing means inactive;

Fig. 5 shows the ribbon reversing pawl, at the left-hand side of the machine, thrown into engagement with its co-operating element by means actuated by the ribbon; and

Fig. 6 is a view similar to Fig. 4 showing the drive shaft shifted to disconnect the spool shaft at the right and connect the one at the left to thus reverse the feed of the ribbon.

Similar reference characters represent similar parts throughout the several views.

The invention is illustrated in connection with a Var'ityper writing machine which includes a main frame lfl'having a cross bar 11 provided with fulcrum's 12 about which key levers 13 may be actuated. When a character key 14 is depressed the key lever operates the printing instrumentalities including a type shuttle 15 and a'hammer 16 (Fig. 2) by means, not shown. The

rear end 17 of each key lever engages a universal bar 18 to swing a frame 19, by which it is carried, about pivots 20 'to actuate suitable escapement mechanism not shown to feed the carriage, in-

eluding feed rollers R and R. by which a worksheet is fed up between the type shuttle and the hammer 16.

Ribbon spools

21 and 21 are suitably connected to the upper ends of

vertical shafts

22 and 22 said shafts being'guided at their upper ends by a plate. 23 secured to the machine frame 10, the' lower ends of said shafts being guided in a plate 24 of the main frame.

A transverse shaft 25, to drive the

shafts

22 and 22 is supported in

bearings

26 and 26 extending downwardly from the plate 24; said shaft being rotated slightly at each actuation of a key lever by a spring pressed pawl 27 pivotally. supported by a stud 28 on the universal bar frame 19. said pawl engaging a ratchet 29 secured to the drive shaft The rotation of the drive shaft is transmitted through pin-ions 30 and to

gears

31 and 31* secured to the lower ends of the spool shafts22 and 22 to rotate the latter. The

pinions

30 and 30 are spaced sufliciently apart so that only'one of them engages with its co-operative gear at a time.

The ribbon spools2l and 21 have

cores

32 and 32 to which the opposite ends of a ribbon 33 are attached so that the ribbon may be wound on either spoolwhile it is being delivered from the other. As illustrated in Figs. 3 and 4 the drive shaft 25 is connected with the spool shaft 22*. Consequently the ribbon is being wound on the spool 21 by the shaft 22 which is being 1y rests upon it at one end. The other end of the detent is loosely supported by a shouldered screw 34 threaded into a key lever guide bar 34 To prevent the free end of the detent 34 from moving laterally out of engagement with the ratchet 29, said detent is located in a slot 34 formed in the bar 34 To manually reverse the feed of the ribbon the drive shaft may be shifted laterally, by a finger piece thereon (Fig. 4), to disconnect the

gears

30 and 31 and connect the

gears

30 and 31 so that subsequent rotation of the shaft '25 drives the spool shaft 22 in the direction of the arrow (Fig. 3) to wind the ribbon on the spool 21. A spring-pressed ball detent 36, located in a hole 37 of the bearing post 26, engages in grooves 38 and 39 on the shaft 25 to hold the latter in either of its axial positions to maintain engagement of the

pinions

30 and 30 with their

gears

31 and 31 respectively, according to the axial position of said shaft.

The ribbon 33 is conducted from the spool 21 to a guide 40 (Fig. 2) of an arm 41 integral with a vertical shaft 42. It passes from the guide 40 to a ribbon vibrator 43 which is actuated, at each printing operation, by the key levers through means not shown. From the vibrator 43 the ribbon passes to a guide 40 of an arm 41 on a vertical shaft 42 and then to the spool 21 "The

shafts

42 and 42 are supported at their upper ends in brackets 44 and 44 respectively, and are guided at their lower ends in the plate 24 of the main frame. They are actuable by

heads

45 and 45 on opposite ends of the ribbon 38 to initiate the automatic reverse of the ribbon, the ribbon reversing operation being completed through means operated by the drive shaft 25 in a manner hereinafter described.

The automatic ribbon reversing mechanism includes two

toothed wheels

46 and 46 on the rive shaft 25, and pawls 47 and 4'7 to co-operate therewith; said pawlsbeing normally ineffective as shown in Fig. 4. When the end ofg-the ribbon on the spool 21 is reached the head 45 thereon actuates the arm 41 to the position in. Fig. 5, thus rotating the vertical shaft 42 against the action of a return spring 48, which spring normally holds an engaging portion 49, of the arm 41, against a stop 50 on the bracket 44. An arm 51, secured to the lower end of the shaft 42, engages an ear 52 of the element or pawl 47 to swing the latter about a pivot 54 on the main frame, and cause a tooth 55 of said pawl to engage the toothed face of the crown wheel 46 as indicated in Fig. 5. Subsequent rotation of the drive shaft 25, which is effected by the key levers as previously described, swings the pawl 4"] further about its pivot 54, from the position in Fig. 5, to move said drive shaft rightwardly to connect the pinion 30 with the gear 31 and disconnect the pinion 30 from the gear 31 as in Fig. 6, the detent 36 being effective to complete the axial shifting of the drive shaft to" snap the wheel 46 out of engagement with the pawl 47 (Fig. 8) whereupon the pawl is immediately returned toward normal by the return spring 48 connected to the shaft 42. When the ribbon starts to wind on the spool 21 thehead 45 moves away from the guide 40, thus permitting the spring 48 to complete the" return of the pawl 47. Y

The various parts of the ribbon reversing means at the right-hand side of the machine, which are similar to those at the left-hand side, bear the same reference characters with the superscript a, and it will be understood that their operation effects an axial movement of the drive shaft 25 leftwardly (Fig. 3) to connect the ribbon spool 21 and disconnect the spool 21.

The pawl actuating

arms

51 and 51 are threaded into

sleeves

56 and 56 respectively, the latter being secured to the

shafts

42 and 42 by screws 5'? and 57 It will be understood that with this arrangement the

arms

51 and 51 may be adjusted horizontally to the

ears

52 and 52 of the pawls 47 and 47 It will be understood that the ribbon guide 40, arm 41 and shaft 42 are made up of a single piece of wire bent to form the various parts.

Thus there is provided simple ribbon reversing mechanism which can be manufactured economically, and which is highly efiicient in its operation.

Having thus described the invention it should be understood that alterations and changes may be made without departing from the spirit of the invention as defined in the appended claims.

I claim:-

1. In a typewriting machine, the combination of a ribbon, two ribbon spools, two shafts one for each spool, to which said spools are connected, a transverse driving shaft connectable to either of the spool-supporting shafts, key-' levers, means operable by said key-levers to rotate said driving shaft, a crown toothed wheel on said shaft, a horizontally disposed pivoted pawl to swing perpendicularly into engagement with the toothed face of said wheel, a vertical car on said pawl,.means including a horizontally dis-- posed arm extending into said ear, said means being operable by said ribbon to swing said pawl into engagement with said wheel so that subsequent rotation of the drive shaft effects a longitudinal movement thereof through the cooperation of the pawl with said wheel to disconnect the drive shaft from one of said spool shafts and connect it-with the other spool shaft, and a return spring for said pawl.

' 2. .In a typewriting machine, the combination of a drive shaft, means to rotate the latter, two driven shafts, a ribbon passing from one of the driven shafts to the other, gears on all of the shafts whereby the drive shaft may rotate the driven shafts one at a time, crown ratchets extending in opposite directions on the drive shaft, two normally ineffective pawls, one for each ratchet to co-operatetherewith to effect an axial movement of the drive shaft so as to connect it with one of the driven shafts and disconnect it from the other shaft, fixed pivots for said pawls, upwardly extending pawl operating shafts, each of the last named shafts having an arm at its upper end to rotate it by the ribbon, and an arm at its lower end connected to one of the pawls to swing the latter into engagement with the associated ratchet so that the ratchet by subsequent rotation of the drive shaft rotates the pawl to shift the drive shaft axially to change its connection with the driven shafts, and .a spring connected to each pawl operating shaft to restore it and the connected pawl to normal.

FRANK H. TREGO.