US1601494A - Ribbon-feeding mechanism - Google Patents

Description

Se t; 28, 1926.

. A. B. ELY

RIBBON FEEDING MECHANISM Filed April 9. 1923 2 Sheets-Sheet 1 IN VEN TOR .A 10125015.

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M in ATTORNEYS Sept. 23', 1926. A. B. ELY

RIB BON FEEDING MECHANISI Filed April 9'. 1923 2 Sheets-Sheet 2 INVENTOR Ala/150,15. E9

' ATTORNEY$ Patented Sept, 28, 1926.

UNITED- STATES earns PATENT OFFICE.

ALONZO B. ELY, OF GROTON, NEW YORK, ASSIGNOR TO CORONA TYPEWRI'IER COM- PANY, INQ, OF GRO'ION, -I\TEW YORK, A CORPORATION OF NEW YORK.

RIBBON-FEEDING MECHANISM;

Application filed April 9,

This invention relates to improvements in ribbon feeding mechanism for typewriting machines. recording calculators, and the like, and has for its principal object to provide a simple and inexpensive mechanism for rotating the ribbon spools which is substantially noiseless in operation and positivein its feeding action. Other objects are to provide a pawl and ratchet feed mechanism w adjnstable to compensate for inaccuracies in manufacture of the parts. in which backlash is eliminated, and in which the parts are so constructed and arranged that the ribbon will be positively fed a predetermined extent at each operation of the feed mechanism notwithstanding inaccurate formation or assembly of the parts of said pawl and ratchet mechanism, such as ecrentr icratchet wheels and bent or improper-. 1y aimed shafts for the ratchet wheels.

The improvements have been illustrated in connection with a' Corona typewriting machine equipped with an automatic ribbon feeding and reversing mechanism constructed as shown in the application of Otto .Petermann filed October 21, 1922, Serial No. 596,062, but, while one object of the present invention is to provide a highly efficient and substantially noiseless ribbon feeding mechanism for said Corona machine, it will be obvious that the improvements are not limited in'their application to said machine.

In the accompanying drawings,

Figure 1 is a vertical longitudinal sectional view of a Corona typewriting machine provided with the improved feed mechanism i Fig. 2 a detail view showing one of the feed pawls near the end of the rearward moven'ieut of'the rocking frame;

a plan view of the mechanism for rotating the right-hand spool;

Fig. 4 a perspective view of one of the feed pawls; Y

5 a front elevation of the parts shown in Fig. 3; and

Fig. 6 a side elevation of the parts shown in Fig. 3.

Referring to the parts by numerals, l designatesthe main or base frame part of the Corona machine; 2 designates the vertically shift-able posts slidably held in guide brackets 3 at opposite sides of the frame 1;

r f a designates the forwardly extending arms 1923. Serial No. 630,788.

'6 designates the folding arm s pivotally held by screws 37 at their forward ends to the forward ends of barset and carrying the bed 7 for the platen carriage 8 at their rear ends. Arms 6 are foldable' forwardly to place bed 7, carriage 8 and platen 9 in inverted position over the keyboard. Posts 2 are connected at their lower ends by a rod 10 shiftable vertically by a pair of shift key levers (not shown) to elevate posts 2, arms 4 and 6, and the parts thereon to two clifferent case-shift positions.

The printing key levers 11 are pivoted on fulcrum rods 12 in the frame 1 and are connected by links 13 to type bars 1 1 mounted on pivot wire 15 in a segment 16 secured to the rear wall of the main frame. Each key lever has a finger 17 underlying the transverse member of a universal bar 18 which is substantially U-shape in plan view and has-its side arms pivoted on the rear fulcrunirod 12. The space bar 19 is supported on spacing levers 19 pivoted on a rod 20 in the frame 1 and engaging under the universal bar at their rear ends. The key levers, spacing levers and universal bar are restored'to normal position after operation by return springs 21 connecting the same with a bracket 22 in frame 1.

'A. pair of upstanding levers 23, connected at their upper ends by a cross-bar 2 1, are pivoted intermediate their ends on screws 25 threaded in brackets 3. Said levers are rocked fore and aft of the machine by links 26'connecting the lower ends thereof with the universal bar 18, and said levers are provided with lugs 27 engaging in slots 28 in the side arms 29 of an upstanding sheet metal universal rocking frame. This frame is of substantially inverted U-shape, the side arms 29 being connected at their upper ends by an integral, flat cross-bar 30 and being pivoted at their lower ends on red 10. The frame swings fore and aft of the machine when levers 23 are rocked and moves vertically with rod 10 during case shifting. The cross-bar 30 is provided with means for actuating the ribbon vibrating mechanism of the Corona machine (not shown) and also carries a tappet 31 for actuating the escape ment dog-rocker of said machine (not shown).

The inked ribbon 38 is connected at its ends 45 rigidly held to brackets l3.

in the usual manner to a pair of ribbon spools "i1, only one of these spools being shown as the spools at both sides of the machine and the rotating means therefor are constructed in the same manner. On each folding frame arm 6 a sheet metal bracket 43 is rigidly secured by screws 44.. Spools 41 are held to rotate with sleeves 63 rotatably and slidably mounted on posts Worm gears 6% fixed on the lower ends of sleeves 63 mesh with worms 52 fir-(ed on shafts 51 each journalled in ears 48 and a9 on one of the brackets 43. Ratchet wheels 53, stamped from sheet metal stock, are fixed on the inner ends of the worm shafts 51 to rotate with the shafts. An arm 54- extends forwardly from ear l8, said arm lying in a vertical plane and formed at its forward end with a laterally bent lug 56 disposed in a horizontal plane forward of and in a plane higher than the adjacent worm shaft 51. Ratchets 53 are spaced a substantial distance inside of the ears 48. The cross-bar 30 of the universal rocking frame is formed at its ends with ears 35 lying in a vertical plane Xtending fore and aft of the machine, said ears being located inside of and to the rear of the ratchet wheels 53. The crossbar is also formed at its ends with outwardly extending stop lingers 30 located under the ratchet wheels. Trip devices controlled by the ribbon govern the operation of suitable feed-reversing mechanism which moves one worm gear 64: into mesh with its associated worm 52 and simultaneously moves the other worm gear 64. out of mesh with its associated worm 52. The foregoing parts are all constructed as shown and described in said application of Otto Petermann above referred to, and the improvements will be now described.

A one-piece, sheet metal feed-pawl is pivotally held against the outer face of each ear 35 on the rocking frame by means of a shouldered pivot screw 91 which extends through an aperture 92 in the main body portion of the pawl intermediate the ends of the pawl. The main body part 90 of the pawl is flat and lies in a vertical plane eat-ending parallel with and inside of the inner face of the adjacent ratchet wheel 53. Part 90 of the pawl is formed with a horizontal slot 93 extending rearward from the forward end of the pawl, and stop finger 3O on the rocking frame extends through this slot which is substantially wider than the thickness ofthe stop finger. The up )er part of the slotted forward portion of the pawl body is formed with an integral, laterally bent lug 94f which extends upwardly above the upper edge of. the pawl body and is beveled along its upper edge to form a 9. adapted s ssees e e h neonesa ratchet 53 below the axis of said ratchet. Lug 94 is preferably made two or three times as wide as the thickness of the ratchet wheel so its broad nose part 95 will cooperate with the ratchet notwithstanding inaccuracies in manufacture of the parts. Said lug is also slotted horizontally for about half its width at 96 whereby nose part 95 may be permanently bent up and down. Lug 9a is permanently bendable fore and aft of the machine. It will be thus seen that the nose part of the pawl may be adjusted at various angles as may be required by imperfect manufacture or assembly of the several parts of the pawl and ratchet feed mechanism. 1

The rear portion ofthe pawl body '90 is offset upwardly relatively to the forward portion so that substantially all of the ma terial of which said rear portion is formed is located above the horizontal plane of the pivotal. axis of the pawl. This rear or tail piece of the aawl is rolled or folded laterally upon itself as shown at- 97 to form acompart weighted tail portion for the pawl. It will be noted that the weighted tail piece is located entirely at the rear of the pivotal axis of the pawl and entirely, or substantially entirely, in a plane above the horizontal plane of the pivotal axis of the pawl. t will be obvious, therefore, that on the back stroke of the pawl, when a printing key or the space bar is depressed, the nose 95 will ride very lightly and substantially without noise over the teeth of ratchet 53 owing to the arrangement of the weighted tail of the pawl, while on the forward stroke of the pawl the weighted tail will insure immediate and continued engagement of nose 95 between the. teeth of the ratchet as the rocking frame 293O begins its return or forward movement. Positive feeding of the ribbon the desired extent at each key operation is thus insured even during very rapid operation of the machine.

To prevent back-lash of the ratchet wheels 53 during the backward stroke of the feed pawls 90, a noiseless detent or brake device 98 is provided for each spool rotating means. These detents comprise flat springsseoured by screws 99 at their forward ends on top of lugs 56 on arms 54 of brackets d3, said springs being bent downward at 100 near the rear edge of lugs 56 andpressing firmly down under tension on the worm shafts 5.1 between ratchet wheels 53 and ears L8. Springs 98 thus serve to frictionally hold shafts 51 and ratchets 53against reverse rotation and accomplish this result in a silent manner.

Fingers 30.- l'imit the rocking of. the feed pawls in both directions and prevent weights 9? from moving to a point where they will n t automatically more. the noses. at the palWIs into Operative engagement with the cii ratchet wheels when the machine is placed in an upright position and unfolded, as will be obvious from an inspection of Figs. 1 and 2,

hat I claim is'f w 1. In a ribbon feeding mechanism, the combination of a drive shaft, a ribbon spool driven from said shaft, a ratchet wheel on said shaft, a broad flat resilient detent member frictionally engaging said shaft adjacent one end of said member, means rigidly supporting said member at its other end, a vibrating pawl carrier, means for vibrating said carrier, and a one-piece sheet metal pawl pivotally held to said carrier having a nose engaging the ratchet Wheel and a tail portion folded upon itself to form a counterweight.

2 In a ribbon feeding mechanism, the combination of a drive shaft, a ribbon spool driven from said shaft, a ratchet wheel on said shaft, a broad flat resilient detent member frictionally engaging said shaft adja cent one end of said member, means rigidly supporting said member at its other end, a vibrating pawl carrier, means for vibrating said carrier, and a one-piece sheet metal pawl pivotally held to said carrier having a nose engaging the ratchet wheel and a tail portion folded upon itself to, form a counterweight, said tail portion being located substantially entirely at that side of the plane of movement of the pivotal axis of the pawl nearest the ratchet wheel.

3. In a ribbon feeding mechanism, the combination of a drive shaft, a ribbon spool driven from said shaft, a ratchet Wheel on said shaft, a broad fiat resilient detent member frictionally engaging said shaft adjacent one end of said member, means rigidly supporting said member at its other end, a vibrating pawl carrier, means for vibrating said carrier, and a one-piece sheet metal pawl pivotally held to said carrier having a nose engaging the ratchet wheel and a tail portion folded upon itself to form a counterweight, said tail portion being located substantially entirely at that side of the plane of movement of the pivotal axis of the pawl nearest the ratchet wheel and said nose being substantially wider than the thickness of the ratchet wheel.

4. In a ribbon feed mechanism, the combination of a rotatably mounted spool-driving ratchet wheel, means supporting said ratchet wheel to rotate about a horizontal axis, a sheet metal feed pawl having a nose co-operating with the teeth of the ratchet wheel, means supporting the pawl for pivotal movement about an axis parallel with the axis of the ratchet wheel, and key actuated means for moving the pivotal support of the pawl back and forth transversely of the axes of the pawl and ratchet wheel, the body ortion of the pawl being disposed vertically edgewise and having the major portion of its mass located above and at the opposite side of the axis of the pawl from that at which the nose of the pawl is located.

5. In a ribbin feed mechanism, the combination of a horizontally disposed spool driving shaft, a ratchet wheel fixed on said shaft, a pivoted feed pawl having an up turned nose at on side of its pivotal axis for engaging the ratchet wheel, means movable transversely of the spool-driving shaft for pivotally supporting the pawl on an axis parallel with and below the spool-driving shaft, and a counterweight carried by said pawl at the opposite side of its pivotal axis from the nose of the pawl, said counterweight being located substantially entirely above the plane of movement of the pivotal axis of the pawl.

6. In a ribbon feed mechanism, the combination of a horizontally disposed spooldriving shaft, a ratchet wheel fixed on said shaft, a pivoted feed pawl having an upturned nose at one side of its pivotal axis for engaging the ratchet wheel, means movable transversely of the spool-driving shaft for pivotally supporting the pawl on an'axis parallel with and below the spool-driving shaft, a counterweight carried by said pawl at the opposite side of its pivotal axis from the nose of the pawl, said counterweight being located substantially entirely above the plane of movement of the pivotal axis of the pawl, and a spring detent frictionally engaging the spool-driving shaft under tension.

7. In a ribbon feed mechanism, the combination of a horizontally disposed spooldriving shaft, a ratchet wheel fixed on said shaft, a pivoted feed pawl having an up turned nose at one side of its pivotal axis for engaging the ratchet wheel, means movable transversely of the spool-driving shaft for pivotally supporting the pawl on an axis parallel with and below the spooldriving shaft, a counterweight carried by said pawl at the opposite side of its pivotal axis from the nose of the pawl, said counterweight being located substantially entirely above the plane of movement of the pivotal axis of the pawl, and means for restraining swinging movements of the pawl about its pivot in both directions substantially beyond that necessary for engagement and disengage ment of the pawl nose with the teeth of the ratchet wheel.

8. A silent ribbon feed mechanism, comprising a spool driving ratchet wheel, means supporting said wheel to rotate about a horizontal axis, a feed pawl having a nose and a counterweighted tail portion, a vibratory pawl carrier, means plvotally supporting said pawl on the carrier at a point intermediate said nose and tail portion of the pawl to turn about a horizontal axis, and

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j nose of the pawl back and forth between i toothed spaces of the ratchet wheel located below the liori zontal plane of the sis of retation of said wheel.

9. A silent ribbon feed mechanism, comprising a spool driving ratchet wheel, means supporting'said wheel to rotate about a horizontal axis; a feed pawl having a nose and a; counterweighted tail portion, a vibratory pawl carrier, means pivotally supporting said pawl on the carrier at a point intermediate said nose and tail portion of the pawl to turn about a horizontal axis, means for vibrating the carrier to shift the nose of the pawl back and forth between tooth spaces of the ratchet wheel located below the horizontal plane of the axis of rotation of said wheel, and a friction brake means for resisting back-lash of the ratchet wheel.

10. In a typewriting maol ine having a ribbon spool and a universal bar, the combi nation of a spool. driving ratchet wheel, a shaft supporting said wheel to rotate about a horizontal axis extending transversely of the machine, a pawl carrier, means supporting said carrier to swing about an axis extending transversely of the machine at a lower level than the wheel sh aft, a feed pawl having an'ose and a counterweighted tail portion, means pivotally supporting said pawl at a point between said nose and tail portion thereof on the pawl carrier above the pivotal axis of the carrier, and means for rocking said carrier from the universal bar to vibrate the nose of the pawl between tooth spaces of said wheel located below the horizontal plane of the axis of the wheel.

11. In a typewriting machine, a silent ribbon. feedingmeans comprising a universal bar, a rocking member operable by the universal bar and supported to vibrate about a horizontal axis, a horizontally disposed rib bon spool drive shaft, a ratchet wheel fixed on said shaft, a pawl pivoted'on said rocker member to swing about a horizontal axis, said pawl having a nose at one side of its pivot extending under the ratchet wheel and a weighted tail portion at the opposite side of its pivot located substantially entirely above the horizontal plane of the pivotal axis of the pawl, and a friction detent en gaging said drive shaft.

12. In a typewriting machine, the combination with a ribbon spool and a horizontal ly disposed shaft connected to drive said spool, of a ratchet wheel fixed on said shaft, a hey-operated member movable transversely of the shaft, and a sheet metal pawl pivotally held to said member and extending transversely of the shaftnnder the ratchet wheel, said pawl having a laterally bent nose portion at one end beveled along its upper edge for engagement with the teeth of the ratchet wheel, said nose portion being substantially wider than the thickness of the ratchet wheel and provided with a slot ex tending; horizontally from one side edge thereof.

13. In a typewriting machine, the combi nation with a ribbon spool and a horizontally disposed shaft connected to drive said spool, of a ratchet wheel fixed on said shaft, a key-operated member movable transverse ly of the shaft, and a sheet metal pawl pivotally held to said member and extending transversely of the shaft under the ratchet wheel, said pawl having a laterally bent nose portion at one end beveled along; its upper edge for engagement with the teeth of the ratchet wheel, said nose portion being substantially wider than the thickness of the ratchet wheel and provi led with a slot extending horizontally from one side edge thereof,,and said pawl having an integral tail portion folded upon itself with the major portion thereof located above the horizontal plane of the pivot of the pawl.

14:. In a typewriting machine, the combination with a ribbon spool and a horizontally disposed shaft connected to drive said spool, of a ratchet wheel fixed on said shaft, alrey-operated member movable transverse ly of the shaft, a pawl extending transversely of the shaft under the ratchet wheel and formed at one end with an upturned nose engaging the ratchet wheel, means pivotally holding the pawl intermediate its ends to said key-operated member to swing up and down, a weight carried by the other end of the pawl having its major portion located above the horizontal plane of the pawl pivot, said pawl being provided with a slot at one side of its pivot, and afixed stop carried by the key-operated member engaged in said slot for limiting the swinging movements of the pawl about its pivot.

In testimony whereof I hereunto aflix my signature.

ALONZO B. ELY,

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