US2479669A - Ribbon feeding mechanism for typewriters - Google Patents

Description

Aug. 23, 1-949. 0. w. BRUMHILL 2,479,669

RIBBON FEEDING MECHANISM FOR TYPEWRI TERS Filed Oct. 24, 1945 I 11 Sheets-Sheet 1 & Im/IVI/EIVTOR 7, AGE/VT Aug. 23,1949. c. w. BRUMHILL RIBBON FEEDING MECHANISM FOR TYPEWRITERS ll Sheets-Sheet 2 Filed Oct. 24, 1945 Aug.'23, 1949. c. w. BRUMHILL RIBBON FEEDING MECHANISM FOR HYPEWRI'IERS 11 Sheets-Sheet 5 Filed 001;. v 24, 1945 Aug. 23, 1949. c. IBRUMIQILL 2,479,669

RIBBON FEEDING. MECHANISM FOR TYPEWRITERS' Filed Oct. 24, 1945 ll Sheets-Sheet 4 Aug. 23, 1949. c. w. BRUIMHILL 2,479,669

RIBBON FEEDING MECHANISM FOR TYPEWRITERS Filed Oct. 24, 1945 n Sheets-Sheet 5 PM U m l/VVf/VTZOR BY 3 WM Aavr Aug. 23, 1949. c. w. BRUMHILL 2,479,669

RIBBON FEEDING MECHANISM FOR TYPEWRITERS Filed Oct. 24, 1945 I ll Sheets-Sheet 6 c. w. BRUMHILL RIBBON FEEDING MECHANISM FOR TYPEWRITERS Aug. 23, 1949.

Filed Oct. 24, 1945 ll Sheets-Sheet 7 FIG] Awmw

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Aug. 23, .1949. c. w. BRUMHILL RIBBON FEEDING MECHANISM FOR TYPEWRITERS Filed Oct. 24, 1945 I lunnnnuuunn" un"-..

'11 Sheets-Sheet s Aug. 23, 1949. c. w. BRUMHILL 2,479,669

I RIBBON FEEDING MECHANISM FOR TYPEWRITERS Filed 001;. 24, 1945 11 Sheets-Sheet 9;

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C. W. BRUMHILL RIBBON FEEDING MECHANISM FOR TYPEWRITERS Aug. 23, 1949.

11 Sheets-Sheet 10 Filed Oct. 24, 1945 FIG. 3:

Aug-23,1949. c. w. BRUMHILL 2,479,669

RIBBON FEEDING MECHANISM FOR TYPEWRITERS Filed Oct. 24, 1945 ll Sheets-Sheet 11 Patented Aug. 23, 1949 RIBBON FEEDING MECHANISM Fort TYPEWRITERS Claude Wellington Brumhill, Leicester, England, assignor to The Imperial Typewriter Company Limited, Leicester, England Application October 24, 1945, Serial No. 624,161 In Great Britain June 7, 1945 4 Claims.

This invention concerns typewriting and like machines and is primarily but not exclusively concerned with machines of the kind (commonly known as hectograph machines) wherein type impressions are produced in reverse on the back of a master sheet, of paper or the like, by feeding the ribbon at the typing station at the back of the said sheet between it and a support surface, such as a platen, and having a carriage including said support surface which traverses as typing proceeds and is also movable idly in the reverse direction. This master sheet is subsequently employed for the production of a multiplicity of copies by a hectograph duplicating process. An object of the invention is to provide means whereby a substantially even take-up of the used ribbon is achieved.

As viewed from one aspect, the invention provides a typewriting or like machine, especially a machine of the kind specified, having ribbon guiding and feeding means for traversing the length of ribbon with the carriage during the typing or letter spacing traverse of the latter to present successive areas of the ribbon at the typing station but for holding a length of the ribbon stationary at the typin station during the reverse traverse of the carriage, including a rotary take-up device having a stationary location and means for driving it during the typing traverse of the carriage to accumulate the used ribbon discharged from the typing station during the said traverse and drawn past the station from the ribbon supply, and a ribbon clamp for clamping the ribbon to the carriage during the typing traverse but for releasing it during the reverse traverse.

As viewed from another aspect the invention also provides a typewriting or like machine, especially a machine of the kind specified, having ribbon guiding and feeding means for traversing a length of the ribbon with the carriage during the typing or letter spacing traverse of the latter so as to prevent successive areas of the ribbon at the typing station but for holding a length of the ribbon stationary at said station during the reverse traverse of the carriage, including a rotary take-up device at a stationary location for winding-up during said typing traverse the used ribbon drawn past the said station from a supply; a yielding drive for the take-up device, a clamp on the carriage for gripping the ribbon at the supplyside of-the typing station during the typing traverse of the carriage, and means for releasing the clamp during the reverse traverse of the carriage. Preferably there is an operator's 2 I a control such for example as a rack release or a tabulating key for effecting an idle traverse of the carriage in the typing-traverse direction, and means operable by said control for releasing the clamp and for rendering the take-up device inoperative. It is further preferred that the machine shall have a rotary ribbon-supply device at a stationary location and there may be means operable by the said control for preventing rotation of said supply device.

An important subsidiary feature of the invention resides in clamp operating mechanism comprising a member traversing with the carriage but movable in relation to it to operate the clamp, and a friction device engagin said member to produce said relative movement during carriage traverse in one direction.

The foregoing and other features of the invention set out in the appended claims are incorporated in the machine which will now be described as an example with reference to the accompanying drawings in which- Figure 1 is a plan of the machine;

Figure 2 is a side elevation of it;

Figure 3 is a rear elevation;

Figure 4 is a front elevation showing part the carriage;

Figure 5 is a section on a larger scale looking in the direction of arrows JJ in Fig. 4;

Figure 6 is a rear view showing certain details of the supply and take-up device;

Figure 7 is an exploded part section on the line GG in Fig. 6 showing details of the take-up device;

Figure 8 is a section through said device on a larger scale taken on line G-G in Fig. 6;

Figure 9 is a sectional view on the line O--O in Fig. 8;

Figure 10 is a view in the direction of arrow H in Fig. 6;

Figure 11 is a view in the V-V in Fig. 6;

Figure 12 is a perspective view of the friction device aforesaid;

Figure 13 shows further details thereof;

Figure 14 is an enlarged plan view ofthe ribbon clamp, looking in the direction of arrow I in Fig. 10.

The invention is shown as applied to a typewriter having a body I with a keyboard 2, incorporating a tabulating key 3, and a carriage 4 traversing on guides 5 which carriage incorporates a platen 6 with a line space lever 8 and rack release lever 21 for carriage rack I28, paper direction of arrows feed rollers 9 for feeding a master sheet In of paper or the like round the platen, means for feeding the normal typewriter ribbon H in front of the master sheet H! at the typing station TS so as to be struck by the type heads 12 and means for feeding hectograph paper ribbon .13 along the face of the platen rat the back .of the master sheet with its treated face forward. This ribbon i3 is positioned at the typing station by means of a guide it (forming the subject .of oil-pending U. S. patent application No. 624',159,"now Patent No. 2,467,880, dated April 19, 1949) fiXed'to a stationary support l6 curving forwards and downwards over the platen.

The ribbon i3 is drawn from a supply spool 28 carried by a rotatable supply device 2.9 and the used ribbon is wound up on a take-up spool ".35: carried by a rotatable take-up device 3!. These two devices occupy stationary locations :at the back of the machine (at the right and left hand .ends thereof, irespectively, .asviewed from the and are carried iby ;a stationary --fra-m e 32 applied to the machine. From the suppl spool 57:8 thekribhn :ls? passes over the stationary roller 33, i. -ie. .occupyiing a stationary location) on the righthandiendof machine whence it goes to a moller d d \on the lett .Ehand end of the carriage, than 17053, roller 35am the right hand :end thereof, ENE-$213.6 letter it runs tor-wards under :a horizontal guide roll 36 on the front-of the carriage,

overan inclined :g-u-ide -3*'l ,s-along the front of thenplaten through the guide M, over an innlinedi 'uide 8 and tinder 1a horizontal guide 39 at the left hand :end, of the carriage and rear- .yvards to :guide :roller til also carried on the left hand .end of the haulage. From the roller til it runs along the back of the -;carriage to roller M on the right hand end thereof and thence-as atlnalslapttozstationar-y roller 42 at the-left hand end .of the machine, whence it runs down tothe take up spool efl.

t wi l e seen thatzas the-carriage traverses to the left in typing hr letter spacing the final lap between rollers 4 and 4,2 is decreased .so that the ribbon I3 is surrenderedto the take-updcvice 3,1 whilst the-initial lap between ro-llers 3.3 and 36 is increased so that the ribbon is drawn -01T the supplyrspool 2.8; .as'a. result the ribbon 3 .at the front of theip-laten travels with'the :carriage and successive -.areas thereof arepresented at the typing station TS. I I

. .The rotary take-up device 3-! consists of a spring drnmfig Ei;g. -8-) which is wound up during the reverse traverse of the carriage by means of a cord M {Fig *6 anchored to the carriage at #5. One side of thisdrum =43 acarries a ratchet wheel 66. which'drivesaILadJ-acent disc 41 by ineans'of a spring loaded pawl 48 carried by the latter, the drive being in the clock-wise direction in Fig. 6. Disc 4'! drives a larger disc 49 through the rnedium of a ,-yield-ing .driving adeviee comprising spring washer 50 which in effect provides -axslipl ingielutch, and the spool :in which the used ribbon is wound up as at 52 has aireleasabledrive engagement 53 with disc =49 and is detachably mountedaon spindle -54 of the take-up .device 31 {means of a :nut55. The large disc 159 :is provided with a toothed periphery and whenever thecarriage rack bar 23 is Jifteda spring loaded pawl .56, Fig. 16., moves -under its spring loading-to engage this-disc to hold the-ta-ke-up spool stationary; that is tosay, whenever the-rackre+ lease-levertil orithe tabulator keyis depressed the take-up spool is prevented from revolving. Whenei/er'the take-up spool-:30 -is thus "checked the slip action of the friction washer allows 4 the spring drum 43 to wind up it's connecting cord 44. The take-up spool is therefore only free to rotate, and that in a clockwise direction as viewed from the rear, when the carriage 4 is travelling under the action .of letter spacing. Thus, as the ribbon lid is discharged from the carriag it is wound up on the take-up spool 30 .and as the diameter of the wound package 52 increases lip takes place at the frictional spring washer 50 so that an approximately even wind up is obtained. The disc 49 is also provided with .amheckpazwl fiipreventing its reverse rotation.

The mechanism by which the pawl 56 is per- .mitted to engage the disc 59 when the rack bar 28 is raised is shown in Figs. 6 and 13. It consists :of a lever 51 (pivoted between its ends at 58 to the stationary frame 32) having one end overlying the rack bar I28 and the other end overlying lever 59 which normally holds the pawl 56 out o-fwengasementnmderthe influence-of aspring The notary supply .device 29 .and its spool 28 .(Fig. .6) aresubstantially the same as the take-up device it! and its-spool '30 excep in that :the s pply device '25 does notincorporate -a springd-rum i3) and therefore .no further illustration .of .the supply device .and its spooliis needed. It may be mentioned, however, that the supply spool 28 is connected .to .a toothed .discifiz. which is the equivalent of .disc '59, .throug'ha resilient-coupling comprisinga spring loaded lever .63 carried by the .disc .62, and ilictional resistance is .applied .to the -.disc 62 .jih'rough a spring washer similar to 'EiLfthis resistance'heing sufficient to kee the ribbon J3 in contact with the. ,guiderollers and to prevent any spinning of the loaded spool. The disc 62 i checked by a pring loaded pawl'fill .connectedbyilink 65 .to theilever 5.9 so that when the rack 'bar 28 is raised both the spools are locked against rotation. As airesult when the carriage i is moved inleither direction withoutletterrspacing taking place the area of ribbon .presentedat the typing station TS remains substantially .stationary,

Tn the'typing traverse ,oif the carriage'the ribbon "i3 is wound off 'the supply spool .28 .so .that the diameter oftherdll decreases and is wound on to the spool "30 oftake-up device 3] so that the diameter of the roll 52 increases. Therefore the effort reqinred'to'pull the ribbon .13 off the supply "increases while-the effort required from th pring'gdrumto accumulate the used ribbon increases, so that the washerlill .of the take-up device must be set. at a maximum frictional value.

Unless precautions were taken, this variation in efiertwould beJiable to cause anuncertain pitch of travet rtheiribbonatthe typing station and there would "be "the danger that the typing =impress'ions would overlap, leading to poor duplicates 'iof'the master. sheet.

'In order to overcome this. .the .ribho'n .113 .passes t ough a r bbon clamp lidlocatedion thecarriage between .the' supply and the guide M, which clamps the ribbon "to the carriage during letter spacing ortvping traverse but releases it when the carriage is traversed "in either direction .by and when themabulatonkeyfi or the rack release lever .21 .is depressed. This .clamp 5 is best showniniFig. .Mend. consists .-of .a fixedlpart 66a and a movable part :fifib -.biased =-to the open position-bvspring l3 .(Fignfi) but urged -together through-themediumhit/he lever 62-1 pivoted at-68 and'a spring ;.69-ito grip the-ribbon in itsttra-verse between guide nollsdkandfifi. order-tozrelease the clamp when the rack bar 28 is raised there is a lever (Fig. 10) having one end overlying said bar and the other end overlying an arm of a T- shaped lever H (Figs. 6 and 10) which has a further arm connected by link 12 to lever 61 to move the latter in the clamp-releasing direction.

The clamp 66 is also opened when the carriage is traversed in the reverse direction by pushing or pulling any part of it without depressing the rack release lever 21. For this purpose, the frictional device shown in Fig. 12 is employed. This comprises a rod 74 extending along the back of the carriage from the lower end of the threearmed lever 1| through a stationary block 15 which is cut with a pocket having a ramp or inclined face 16 housing a friction member constituted by a ball 17. This ball is pressed towards the right hand end (as viewed from the front) of the machine by plunger 18 and spring 19, so that it exerts a frictional grip on the rod 14. When the carriage is traversed to the right by pushing or pulling on any part of it, the ball grips the rod 14 lightly (but with a force insufficient to lock said rod to the block 75) so that the rod 14 lags slightly behind the carriage and rocks the lever H to release the clamp 66. Conversely when the carriage is moved in the typing direction, the drag of the rod M on the ball 11 tends to carry the latter away from the inclined face 76 so that the rod 14 travels comparatively freely. That is to say, whether the carriage be moved in the reverse direction either by the line space lever 8, or by pushing or pulling on any part, the clamp 66 remains open. As a result, the ribbon remains stationary at the typing station because it is held by the two locked spools 28 and 30, and the carriage virtually moves through a loop of the ribbon. When the carriage is moving in the letter-spacing direction, the ribbon I3 is clamped to it so that it cannot creep endwise and is moved in the exact letter-spacing pitch of the carriage past the typing station TS. The clamp 66 is so positioned that the ribbon it is gripped comparatively near the supply spool before it proceeds along the front of the platen 6 and through the stationary guide l4. Therefore the tension on the ribbon is reduced to a minimum.

It may be pointed out that nip rollers are not employed in the ribbon transport system. Nip rollers are commonly spring urged together to grip the hectograph ribbon, and they tend to destroy the treated surface of it. This is specially undesirable when more than one direct impression is required to be made on the ribbon. It is further pointed out that the guide rollers are so arranged that the untreated surface of the ribbon makes contact with them, which again is advantageous. Their length is somewhat greater than the width of the ribbon, and they are so disposed that the ribbon will arrange itself approximately in the middle of each roller. This avoids undue scraping of the edges of the ribbon and prevents the accumulation of hectograph dust which is very objectionable.

The ribbon mechanism described and illustrated is designed to suit a carriage which can be detached from the typewriter base I. The spring drive of the take-up device 3| when added to the existing spring motor of the typewriter carriage would impose too great a resistance to the manual movement of the carriage in the non-typing direction. To avoid this difficulty there is provided a let-down mechanism 80, Fig. 6, by which the spring tension of the carriage motor can be reduced to a pre-determined amount when using the carriage with the aforesaid ribbon mechanism thereon.

. When the usual typewriter carriage is used, this device permits of an easy re-adjustment of the carriage motor to its original tension. It comprises an escapement wheel 81 with a Geneva stop mechanism 82, a manually-operable escapement pawl 83, and a winding-up .key 84. The Geneva stop mechanism limits the extent to which the motor may be let down.

Although the invention has been described as applied to a manual typewriter, it is applicable to a motor-operated machine in which for example the carriage 4 is traversed and the ribbon I3 is wound up by power means.

Furthermore, the machine shown may be employed for ordinary typing by removing ribbon l3 and guide M.

The ribbon guiding means disclosed in the drawing and specification of the present application is claimed in my copending U. S. patent application Serial No. 624,162, of even date, now Patent No. 2,467,881, dated April 19, 1949.

I claim:

1. A typewriting or like machine, having ribbon feeding means for traversing a length of ribbon with the carriage during the typing or letterspacing traverse of the latter to present successive areas of the ribbon at the typing station but for holding a length of the ribbon stationary at the typing station during the reverse traverse of the carriage, including a rotary take-up device having a stationary location and means for driving it during the typing traverse of the carriage to draw off the used ribbon discharged from the typing station during said typing traverse and drawn past the typing station from a ribbon supply, a ribbon clamp for clamping the ribbon to the carriage during the typing traverse and mechanism operable by movement of the carriage in the reverse direction to open said clamp.

2. A machine according to claim 1, having clamp-operating mechanism comprising a member traversing with the carriage but movable in relation to it to operate the clamp, and a friction device engaging said member to produce said relative movement during carriage traverse in one direction.

3. A machine according to claim 1, having clamp operating mechanism comprising a member traversing with the carriage but movable in relation to it to operate the clamp, and a friction device engaging said member to produce said relative movement during carriage traverse in one direction, which friction device comprises a friction member for gripping the traversing member, and a stationary ramp for causing the friction member to grip upon traverse of said traversing member in one direction but for freeing said friction member upon traverse in the other direction.

4. In a typewriting machine having a carriage capable of traversing in one direction in typing or letter spacing and idly in the reverse direction which carriage is equipped with rack release means for permitting the carriage to be moved in the typing direction and with line space means for effecting movement of the carriage in the reverse direction, said carriage being also capable of being moved manually in said reverse direction without operation of the rack release means or the line space means; ribbon feeding means for traversing a length of ribbon with the carriage during the typing or letter spacing traverse thereof to present successive areas of the ribbon at the typing station but for holding a length of the rilibonrstationaiy at ihetyping' station :iurin'g'the reverse traverse of the carriage lrrespective of whether said reverse traverse .is efiectecl manually aor :by operation of the line'espace means, including a rotary Ataike-up .device having a stationmy location, means for drivingrit during the typtraverse of the carriage for receiving used ribbon discharged irom--thetyping station during typmg traverse and drawn past the typing station from a ribbon supply, a 'i'ibbonnlamp for clamping fine ribbon to the carriage during the typing traverse which clamp com-prises iawo'memhers relatively movable inwards one another to grip the ribbon or to release it,*m'echanism operable by the rack release means for ripening said clamp, mechanism operable by the line space means for opening said clamp, and mechanism I18 =1operab1e upon manual reverse traverse of the carriage without operation of the rack release or line space means, to open said clamp.

CLAUDE WELLINGTON BRUMHILL.

,R EFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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