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Publication numberUS2972402 A
Publication typeGrant
Publication dateFeb 21, 1961
Filing dateJul 2, 1959
Priority dateJul 2, 1959
Publication numberUS 2972402 A, US 2972402A, US-A-2972402, US2972402 A, US2972402A
InventorsBernard Howard
Original AssigneeTeleprinter Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Ribbon feed mechanism
US 2972402 A
Abstract  available in
Images(4)
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Claims  available in
Description  (OCR text may contain errors)

Feb. 21, 1961 Filed July 2, 1959 B. HOWAR D RIBBON FEED MECHANISM 4 Sheets-Sheet 1 CAPACIWE E a ,m

INVENTOR 552M 20 How/m0 BY ATTORNEYS Feb. 21, 1961 B, HOWARD 2,972,402

RIBBON FEED MECHANISM Filed July 2, 1959 4 Sheets-Sheet 2 INVENTOR 652M42 Igor/M0 BY fiin w Mi ATTORNEY Feb. 21, 1961 v Q B. HOWARD 2,972,402

RIBBON FEED MECHANISM Filed July 2, 1959 4 Sheets-Sheet 3 INVENTOR 552M420 //0WA 20 Tiqfi.

BY M

Feb. 21, 1961 B. HOWARD RIBBON FEED MECHANISM 4 Sheets-Sheet 4 Filed July 2, 1959 INVENTOR HOW/IEO BY M v ATTORNEY:

RIBBON FEED MECHANISM Bernard Howard, Ramsey, N.J., assignor to Teleprinter Corporation, Paramus, N..l'., a corporation of New Jersey Filed July 2, 1959, Ser. No. 824,641

19 Claims. (Cl. 197-165) This invention relates to devices such as typewriters and telegraph printers using an inked ribbon.

Conventional ribbon feed mechanism employs ratchet wheels and pawls actuated in response to the printing operation, and includes reversing mechanism to make one ratchet pawl or the other effective. In practice, this mechanism has proved to be unreliable compared to the main mechanism of the printing machine, and has caused a disproportionately great amount of breakdown and maintenance.

One primary object of the present invention is to gener ally improve ribbon feed mechanisms. A more particular object is to provide such a mechanism which is inexpensive, reliable, and self-contained in that it employs its own motor. Despite the use of a motor, the remaining mechanism is so inexpensive and simple that the overall cost is reduced and reliability is increased. A further object is to provide mechanism which will use a standard typewriter spool.

To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the ribbon feed mechanism and the elements thereof and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings, in which:

Fig. 1 is a partially sectioned elevation of mechanism embodying features of the invention;

Fig. 1A shows a fragment of Fig. -1 drawn to enlarged scale;

Fig. 2 is a section taken approximately in the plane of line 2-2 of Fig. 1;

Fig. 3 is a schematic plan view showing how the invention may be applied to a typewriter;

Fig. 4 is a wiring diagram explanatory of the con nections to the reversible motor;

Fig. 5 is a section similar to a portion of Fig. 1 but showing a modification which reduces the axial separation of the spools;

Fig. 6 is a fragmentary elevation which supplements Fig. 5 by showing the stop pawl;

Fig. 7 is a fragmentary section taken in the plane of line 77 of Fig. 6;

Fig. 8 is a front elevation of a modified form of the invention using spools which may be of equal diameter and both of which may be standard;

Fig. 9 is a section taken approximately in the plane of the-line 9-9 of Fig. 8; and

Fig. 10 shows the friction clutch portion of Fig. 9 drawn to enlarged scale.

Referring to the drawing, and more particularly to Figs. 1 and 2, the ribbon feed mechanism comprises a first ribbon spool 12 and a reversible electric motor 14. This motor is a very slow-speed motor or so-called clocktype motor the final shaft of which turns only a few revolutions per minute. The motor drives 'the spool through appropriate means which in this case is simply a shaft 16 fitted with a conventional spool lock 18 to hold Patented Feb. 21, 1961 ICE the spool 12 on the shaft, and also fitted with a driving pin 20 which engages the spool to drive the same. The spool 12 is preferably a standard typewriter spool.

The mechanism further comprises a second ribbon spool 22 which is driven through frictional slip drive means generally designated F, the said means being disposed between the first spool 12 and the second spool 22. This drive means includes a wheel 24 and a friction disc 26 between the wheel 24 and the spool 22. The arrangement is such that the friction drive means F attempts to drive the spool 22 at a linear ribbon speed which is higher than that of the first spool 12, when the first spool is acting as a supply spool and the second spool 22 is acting as a take-up spool.

The wheel 24 is associated with a means 30 to prevent rotation of the wheel in opposite direction, and because of this the friction drive means F becomes a friction brake means holding back the second spool 22 when it acts as a supply spool while the first spool 12 acts as a take-up spool, i.e., when the direction of rotation of motor 14 has been reversed.

In the present case, the wheel 24 is. a ratchet wheel, and the means 30 is a pawl engaging the ratchet wheel, as is best shown in Fig. 2.

In the form of the invention here shown, the second spool 22 has a diameter larger than that of the first spool 12'. Indeed, the minimum diameter of spool 22 with no ribbon thereon is preferably equal to and may be larger than the maximum diameter of spool 12 with a full ribbon wound thereon. 'Moreover, in this form of the invention the spools are coaxial, as shown. The .friction drive mechanism F tends to rotate both spools at the same rotative speed. It is the difference in diameter of the spools that provides the desired higher linear ribbon speed (meaning theattempted speed) referred to above.

In Fig. 1,'the ribbon leaves the top of spool 12 as shown at 32', and passes over ribbon guides 34 and 36 (Fig. 2), and thence back to the bottom of spool 22, as shown at 38 (Fig. 1). In the particlular printer here shown the type is formed on an eight-sided type cylinder 40 (Fig. 2), and the printing operation is caused by a hammer 42 which strikes the ink ribbon at 44 against the paper .46 which in the present case is a narrow tape moving inhorizontal direction while the ribbon is moving in vertical direction. Oneadvantage of the present ribbon feed mechanism with its independent motor drive is its great flexibility, it being adapted to installation in all kinds of printers with little or no modification of the feed mechanism, because the ribbon guides which bring the ribbon'to the paper, and the electrical connections, are the only external connections other than physical mounting of the motor mechanism somewhere in or on the printer.

Fig. 3 schematically represents an ordinary typewriter viewed in plan. The paper roll or carriage is suggested at 50, while the keyboard is located at 52. The ribbon 54 is wound on smaller and larger coaxial spools 56 and 58; A ribbon guide is provided at 60, instead of a spool as in an ordinary typewriter. At the printing point 62 the ribbon passes through a conventional ribbon support which raises and lowers the ribbon each time a character is printed. It will be evident that the mechanism 56, 58 may correspond to that described above, the main dilference being that the spool axis is vertical instead of horizontal.

Reverting now to Fig. l, a reversing switch for the motor 14 is shown at 64. It is preferably of the over-thecenter or toggle type, so that it remains closed in one direction or the other. It may be actuated by a rocker arm or lever 66 pivoted at 68 and providing ribbon slots at its ends. In the present case, one end carries a pair of closely adjacent collateral pins or posts 70 which form one ribbon slot, and the other end carries a similar pair of pins 72 which form theother ribbon slot. The arrangement will be understood from inspection of Fig. 2 which shows a lever 66 which oscillates or rocks on a centerpivot 68. Pins 70 are mounted at one end of lever 66, and pins 72 at its other end. The part 32 of the ribbon passes between the pins 72, and the part 33 passes between the pins 70.

As is usual, the pins or ribbon slots are dimensioned to freely pass the ribbon, but not to pass an eyelet or like means conventionally secured near each end of the ribbon in order to cause reversal of the ribbon feed. In Fig. 2 the part 32 of the ribbon is moving to the left, and when the end of the ribbon has been nearly reached an eyelet on the ribbon engages the pins 72 and carries the tiltable rock arm with it. This causes a bifurcation 74 to move downward and thus to trip the reversing switch from one position to its opposite position, where it remains until the opposite end of the ribbon with its eyelet reaches the ribbon slot 70, which then is in its right-hand position and is moved by the eyelet to the lefthand position shown.

The motor here used is a series RSM synchronous reversible motor made by Hurst Tool and Mfg. Co., Inc., of Princeton, Ind. It includes reduction gearing such that its output shaft, marked 89 in Fig. 1, turns at only six rpm. The motor is a single-phase motor, but a capacitor is used to displace the phase in two parts of the field. The arrangement is indicated in Fig. 4, in' which the field is represented by coils 82 and 84. The capacitor is shown at 86, and the reversing switch 64 is a single pole, double-throw switch. When connected to the upper contact, the coil 84 leads and the coil 82 lags in phase; and conversely, when switch 64 is closed to its lower contact the coil 82 leads and the coil 84 lags in phase. Thus, the field rotates in one direction or the other and causes corresponding rotation of the rotor.

Reverting to Fig. 1, and considering the mechanism in greater detail, shaft 16 has a socket 911 which is secured to motor shaft 80 by means of a set screw 92. Shaft 16 carries a driving chuck 94 with its pin 20, and these are secured to the shaft by means of a set screw 96. Ratchet wheel 24 (Figs. 1 and 1A) is smooth on both faces and is freely rotatable on the sleeve or hub portion of chuck 94. The friction disc 26 is an annulus or ring partly received in one face of spool 22, and bearing directly against one side of ratchet wheel 24. The desired frictional engagement preferably is maintainedby means of a spring disc or washer 98 disposed between chuck 94 and ratchet wheel 24. It will be evident that this urges the ratchet wheel axially into engagement with the friction disc 26.

The standard ribbon spool 12 is positively driven in one direction or the other by the motor. When starting a new ribbon, the large spool 22 acts as a take-up spool. Its attempted one-to-one drive is too fast because of its larger diameter, and instead it slips and takes up the ribbon only as fast as it is fed from the supply spool 12. When all of the ribbon has been transferred from spool 12 to spool 22, the direction of feed is reversed, whereupon the spool 12 winds the ribbon under motor drive. The spool 22 then would unwind the ribbon much too fast if it were driven as before by the spool 12, but instead the friction drive F is automatically converted from a friction drive to a friction brake by the action of the stop pawl 30, which holds the ratchet. Wheel 24 stationary. The friction disc 26 then becomes a brake disc which tends to hold the spool 22 back, so that it releases ribbon only to the extent that the ribbon is pulled from it by the motor drive of spool 12.

A slightly modified construction is shown in Figs. 5, 6, and 7 of the drawings. This is substantially the same as the mechanism shown in Fig. 1, except that axial displacement between the two spools has been reduced by housing the friction drive parts F within the large spool.

In Fig. 5 the spool 112, motor 114, shaft 116, spool lock 118, and drive pin 12! all correspond to the parts shown in Fig. 1, except that shaft 116 is somewhat shorter. The spool 122 is hollowed or recessed at 123 to receive the ratchet wheel 124 and friction disc 126. The spring washer is shown at 127 and exerts axial pressure between the chuck 128 and the ratchet wheel 124.

The upper end of the stop pawl 130 has been broken away in Fig. 5, but is better shown in Fig. 6. It has an offset or inwardly directed tooth 132 which engages the ratchet wheel 124. These parts are also shown in Fig. 7.

In theory a ratchet wheel could be used alone as a friction drive means. The friction disc helps provide the desired friction but is not essential. The spring washer helps maintain a desired uniform friction, and compensates for wear of the parts, particularly the friction disc.

As so far described, the spools tend to turn at the same speed, but differ in diameter. In Figs. 8, 9, and 10 I show another form of the invention in which the spools are of the same diameter but tend to turn at different speeds. Referring to Fig. 9, the first ribbon spool 142 is driven by a reversible electric motor 144, which may be the same as that previously described. The spool 142 is carried on a shaft 146 having spool lock 148 and a driving pin 150. These parts are secured to motor shaft 152 by means of a socket 154 with a set screw 156.

The second ribbon spool is shown at 158 and may have the same diameter as spool 142. They preferably are both standard typewriter spools. Spool 158 is mounted on a shaft 160 having a spool lock 162. Shaft 161 is not a drive shaft, and it may be stationary with its other end riveted at 164.

As before, there is a frictional slip drive means between spool 142 and spool 158, and this attemptsto drive spool 158 at a higher speed. For this purpose the drive means includes step-up gearing. In the present case, shaft 146 carries a gear 166 meshing with an idler 168 which meshes with a gear 170. The latter is smaller in diameter than gear 166, and is driven at higher speed. The difierence in diameter is made enough to compensate for the difference between the diameter of an empty ribbon spool and a filled ribbon spool.

As before, the friction drive means includes a ratchet wheel 172. A disc 174 is disposed between the ratchet wheel and the spool 158, and disc 174 has a drive pin 175. There is also a spring washer 176 (Fig. 10) between gear and ratchet wheel 172, thus urging all of the parts into frictional engagement. The stop pawl which prevents reverse rotation of the ratchet wheel.172 is shown at 178 (Figs. 8 and 9).

In Fig. 8 the spool 142 is acting as a supply spool, and the spool 158 is acting as a take-up spool. The motor is driving spool 142 in counterclockwise direction. The ribbon passes round a ribbon guide 130 and then through a ribbon slot 182 and thence around a ribbon guide 184 to a printing point which may be at the region 186. The ribbon continues around a ribbon guide 188 and through a ribbon slot 190 and thence around ribbon guide 192 to the take-up spool 158. Although the latter is empty and of small diametenthere is no slack because it is turned at a higher rotative speed by reason of the step-up gear ratio mentioned above.

The smooth round pins forming the ribbon slots are carried at the ends of a tiltable rock arm 194 pivoted at 196. The reversing switch 198 is a single pole doublethrow switch which is moved over the center to one side or the other by a bifurcation200 in arm 202, carrying the tiltable lever 194-.

It will be evident that when the end of the ribbon is approached, an eyelet on the ribbon will reach the ribbon slot 182 and tilt the upper end of arm 194 from its right-hand to its left-hand position, thereby moving the lower end from left-hand to right-hand position, and reversing the switch and consequently the motor. Spool 142 becomes a take-up spool which pulls ribbon grad ually from spool 158 which then acts as a supply spool. At this time, the stop pawl 1-78 automatically takes efiect and the friction drive is converted to a friction brake which serves to hold back the supply spool 158.

It will be understood that while the'spools have been shown coaxial in Fig. l, and displaced from one another in Fig. 8, this is not essential; and spools which are of different diameter and tend to turn at the same speed may be mounted on displaced axes; and, conversely, spools which are equal in. diameter but which are turned at different speeds may be mounted in coaxial relation.

It is believed that the construction and operation of my improved ribbon feed mechanism, as well as the advantages thereof, will be apparent from the foregoing detailed description. The mechanism is self-contained and is adapted to be used on widely different kinds of printing mechanisms, with little or no modification. Despite the cost of the motor, the necessary mechanism is so inexpensive, and the manufacturing tolerances are so great, that the total cost is less than that of conventional ribbon feeds. The present ribbon feed is reliable, and eliminates a cause of frequent service complaints when using conventional ribbon feeds. The mechanism may be used with standard and non-standard ribbons and spools.

It will be understood that while I have shown and described my invention in several preferred forms, changes may be made in the structures shown, without departing from the scope of the invention as sought to be defined in the following claims.

In the claims the term ribbon is not intended to include other forms of tape.

I claim:

1. A ribbon feed mechanism comprising a first ribbon spool, a reversible motor, means causing said motor to drive said spool at slow speed, a second ribbon spool, rotatable friction slip drive means between the first spool and the second spool arranged to attempt to drive the second spool in one direction at a linear ribbon speed higher than that of the first spool when the first spool is acting as a supply spool and the second spool is acting as a take-up spool, and means cooperating with said friction drive means to prevent rotation in the opposite direction, whereby said friction drive means becomes a friction brake means holding back the second spool when it acts as a supply spool while the first spool acts as a take-up spool.

2. A ribbon feed mechanism comprising a first ribbon spool, a reversible electric motor, means causing said motor to drive said spool positively at slow speed, a second ribbon spool, friction slip drive means including a ratchet wheel between the first spool and the second spool arranged to attempt to drive the second spool in one direction at a linear ribbon speed higher than that of the first spool when the first spool is acting as a supply spool and the second spool is acting as a take-up spool, and a stop pawl engaging said ratchet wheel to prevent rotation in the opposite direction, whereby the friction drive means becomes a friction brake means holding back the second spool when it acts as a supply spool while the first spool acts as a take-up spool.

3. A ribbon feed mechanism as defined in claim 1 in which the second spool has a diameter larger than that of the first spool, in order to provide the desired higher linear ribbon speed.

4. A ribbon feed mechanism as defined in claim 2 in which the second spool has a diameter larger than that of the first spool, in order to provide the desired higher linear ribbon speed.

5. A ribbon feed mechanism as defined in claim 1 in whichv the second spool has a diameter larger than that of the first spool, the minimum diameter of the second spool with no ribbon thereon being at least as large as the maximum diameter of the first spool with a full ribbon thereon.

6. A ribbon feed mechanism as defined in claim 2 in which the second spool has a diameter larger than that of the first spool, the minimum diameterof the second spool with no ribbon thereon being at least as large as the maximum diameter of the first spool with a full ribbon thereon.

7. A ribbon feed mechanism as defined in claim 1 in which the first and second spools and the friction drive means are disposed coaxially, and in which the first spool is a standard typewriter ribbon spool.

8. A ribbon feed mechanism as defined in claim 2 in which the first and second spools and the friction drive means are disposed coaxially, and in which the first spool is a standard typewriter ribbon spool.

9. A ribbon feed mechanism as defined in claim 1 in which the second spool has a diameter larger than that of the first spool, the minimum diameter of the second spool with no ribbon thereon being at least as large as the maximum diameter of the first spool with a full ribbon thereon, and in which the first and second spools and the friction drive means are disposed coaxially, and in which the first spool is a standard typewriter ribbon spool.

10. A ribbon feed mechanism as defined in claim 2 in which the second spool has a diameter larger than that of the first spool, the minimum diameter of the second spool with no ribbon thereon being at least as large as the maximum diameter of the first spool with a full ribbon thereon, and in which the first and second spools and the friction drive means are disposed coaxially, and in which the first spool is a standard typewriter ribbon spool.

11. A ribbon feed mechanism as defined in claim 1 in which the drive means between the first and second spools includes step-up gearing for attempting to drive the second spool at a higher rotative speed than the first spool.

12. A ribbon feed mechanism as defined in claim 2 in which the drive means between the first and second spools includes step-up gearing for attempting to drive the second spool at a higher rotative speed than the first spool.

13. A ribbon feed mechanism as defined in claim 1 in which the first and second spools have the same di ameter when empty, and in which the drive means between the first and second spools includes step-up gearing for attempting to drive the second spool at a higher rotative speed than the first spool.

14. A ribbon feed mechanism as defined in claim 2 in which the first and second spools have the same diameter when empty, and in which the drive means between the first and second spools includes step-up gearing for attempting to drive the second spool at a higher rotative speed than the first spool.

15. A ribbon feed mechanism as defined in claim 1 in which the first and second spools are both standard typewriter ribbon spools having the same diameter, and in which the drive means between the first and second spools includes step-up gearing for attempting to drive the second spool at a higher rotative speed than the first spool.

16. A ribbon feed mechanism as defined in claim 2 in which the first and second spools are both standard typewriter ribbon spools having the same diameter, and in which the drive means between the first and second spools includes step-up gearing for attempting to drive the second spool at a higher rotative speed than the first spool.

17. A ribbon feed mechanism as defined in claim 1 inwhich the motor is an electric motor, and further comprising a reversing switch for said motor, and a switch actuator including a tiltable rock arm which is pivoted in the middle and which has a ribbon slot in each end, one of said ribbon slots receiving the ribbon adjacent one spool and the other ribbon slot receiving the ribbon 7 adjacent the other spool, said slots being dimensioned to freely pass the ribbon but not ,the conventional eyelet or like means conventionally secured near each end of the ribbon to cause reversal of the ribbon feed.

18. A ribbon feed mechanism as defined in claim 2 and further comprising a reversing switch for said motor, and a switch actuator including a tiltable rock arm which is pivoted in the middle and which has a ribbon slot in each end, one of said ribbon slots receiving the ribbon adjacent one spool and the other ribbon slot receiving the ribbon adjacent the other spool, said slots being dimensioned to freely pass the ribbon but not the eyelet or'like means conventionally secured near each end of the ribbon to cause reversal of the ribbon feed.

19. A ribbon or tape feed mechanism comprising a first spool, a second spool coaxial with the firstspool, and means whereby the first spool attempts to drive the second spool at a linear speed higher than the first spool, with the first spool acting as a supply spool and the second spool acting as a take-up spool, said means including a frictional slip drive means between the first spool and the second spool.

References Cited in the file of this patent UNITED STATES PATENTS 1,628,164 Lippert May 10, 1927 2,609,077 Schroder Sept. 2, 1952 2,889,909 Rehurek June 9, 1959

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1628164 *Jan 31, 1924May 10, 1927Remington Arms Co IncAutomatic ribbon-reversing mechanism for cash registers
US2609077 *Oct 22, 1949Sep 2, 1952Underwood CorpRibbon feed for typewriting machines
US2889909 *Dec 30, 1957Jun 9, 1959IbmRibbon feed mechanism
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3409114 *Apr 26, 1966Nov 5, 1968Maruzen Sewing MachineRibbon feeding mechanism
US3444979 *Jun 2, 1966May 20, 1969Olivetti & Co SpaRibbon feeding device for a variable spacing typewriter
US3643779 *Dec 14, 1970Feb 22, 1972Scm CorpRibbon mechanism for cartridge supported ribbons
US3902585 *May 7, 1973Sep 2, 1975Data Products CorpElectric switch actuated printer ribbon reversing mechanism
US3910399 *Jul 19, 1973Oct 7, 1975Suwa Seikosha KkReversible ink ribbon feed device having unitary bulk sensors
US3954167 *Oct 17, 1974May 4, 1976Extel CorporationHigh speed printer
US4467976 *Oct 4, 1982Aug 28, 1984International Business Machines CorporationRibbon cartridge comprising a stuffer box intermediate a supply reel and take-up reel
US4676678 *Feb 14, 1985Jun 30, 1987Kabushiki Kaisha ToshibaRibbon cassette cartridge having a lid and a locator slot
US4687358 *May 14, 1985Aug 18, 1987Kabushiki Kaisha ToshibaTransfer material holding cassette including core rotation inhibiting means
US4747715 *Jan 8, 1987May 31, 1988Creative AssociatesIn a printer
US6048118 *Aug 7, 1998Apr 11, 2000Axiohm Transaction Solutions, Inc.Compact ribbon cassette with integral friction plate
US6135657 *Apr 5, 1999Oct 24, 2000Axiohm Transaction Solutions, Inc.Ribbon cassette with coaxial spools on common shaft with partition for preventing contamination
EP0105136A2 *Aug 9, 1983Apr 11, 1984International Business Machines CorporationInking ribbon cartridge and printing apparatus for use therewith
Classifications
U.S. Classification400/219.1, 400/234, 400/225, 400/236
International ClassificationB41J33/14, B41J33/12, B41J33/00, B41J33/518
Cooperative ClassificationB41J33/12, B41J33/518
European ClassificationB41J33/518, B41J33/12