US2467881A

US2467881A - Ribbon guiding means for typewriters

Info

Publication number: US2467881A
Application number: US624162A
Authority: US
Inventors: Brumhill Claude Wellington
Original assignee: Imperial Typewriter Co Ltd
Current assignee: Imperial Typewriter Co Ltd
Priority date: 1945-06-07
Filing date: 1945-10-24
Publication date: 1949-04-19
Anticipated expiration: 1966-04-19
Also published as: GB596685A; FR927674A

Description

April 19, 1949. v c. w. BRUMHILL 2,467,881

RIBBON GUIDING MEANS FOR TYPEWRITERS Filed 001'). 24, 1945 12 Sheets-Sheet 1 April 19, 1949.

c. w. BRUMHILL RIBBON GUIDING MEANS FOR TYPEWRITEBS 12 Sheets-Sheet 2 Filed Oct. 24, 1945 [NVENTOE April 19, 1949. c. w. BRUMHILL RIBBON GUIDING MEANS FOR TYPEWRITERS 12 Sheets-Sheet 3 Filed Oct. 24, 1945 April 19, 1949. c. w. BRUMHILL 2,467,881

RIBBON GUIDING MEANS FOR TYPEWRITERS Filed Oct. 24, 1945 l2 Sheets-Sheet 4 /NVENTOR a, (awn April 194.9. c. w. BRUMHILL 2,467,881

RIBBON GUIDING MEANS FOR TYPEWRII ITERS Filed Oct. 24, 1945 I 12 Sheets-Sheet 5 IN VE/VZ'OR April 1949- c. w. BRUMHILL 2,467,881.

RIBBON GUIDING MEANS FOR TYPEWRITERS 12 Sheets-Sheet 6 Filed Oct. 24 1945 Q Q] 1' V April 19, 1949. c. w. BRUMHILL RIBBON GUIDING MEANS FOR TYPE WRITERS 12 Shets-Sheet 7 Filed Oct, 24, 1945 un v [NI/mm? 51mm April 1949.- I v C.W.BRUMHILL 2,467,381

RIBBON GUIDING MEANS FOR 'IYPEWRI'IERS Filed Oct. 24 1945 12 Sheets- Sheet a Ffiao 0 3/ ;L CZ- PEL 4 4 2 43 c g w r e c. w. BRUMHlLL RIBBON GUIDING MEANS FOR TYPEWRITERS April 19, 1949.

Filed Oct. 24, 1945 12 Sheets-Sheet 9 M j" (M April 19, 1949- c. w. BRUMHILL 2,467,881

RIBBON GUIDING MEANS FOR TYPEWRITERS lNvENmR April 19, 1949. c. w. BRUMHILL 2,467,831

RIBBON GUIDING MEANS FOR TYPEWRITERS Filed Oct. 24, 1945 v 12 Sheets-Sheet 11 April 19, 1949. c. w. BRUMHILL RIBBON GUIDI'NG MEANS FOR TYPEWRITERS l2 Sheets-Sheet 12 Filed Oct. 24, 1945 K nwewme W01, Z

Patented Apr. 19, 1949 RIBBON GUIDING MEANS FOR TYPEWRITERS Claude Wellington 'Brumhill, Leicester, England, assigncr to The Imperial Typewriter Company, Limited, Leicester, England Application October 24, 1945, Serial No. 624,162

In Great Britain June 7, 1945 7 Claims.

This invention is concerned with typewriting machines, and especially with machines of the kind (commonly known as hectograph machines) wherein type impressions are obtained on the back of a master sheet, of paper or the like, by a ribbon positioned at a typing station behind said sheet of paper between it and a support surface or roller, such machines having a carriage including said support surface or roller which traverses in one direction as typing proceeds and is also movable idly in the reverse direction. The aforesaid master sheet is subsequently used for the production of a multiplicity of copies by a hectograph duplicating process.

An important object of the invention is an improved arrangement of ribbon guiding means in machines of this kind, but the invention is also more widely applicable to typewriting and like machines wherein a ribbon is traversed with the carriage in letterspacing and the like, but remains stationary at the typing station during the reverse movement of the carriage, and a further object of the invention is a construction whereby the overall dimensions of the machine are maintained within reasonable proportions and an advantageous ribbon path and smooth feed results. Another object is the arrangement of ribbon-guiding means which permits carriages of different widths, and therefore having different lengths of traverse, to be interchangeably applied to one and the same machine base without the ribbon guides or spools overhanging from the ends of the machine.

According to this invention, a typewriting or like machine, especially a machine of the kind specified, has a carriage which traverses in typing or letterspacing towards one end of the machine and idly in the reverse direction towards the other end of the machine, a take-up device having a stationary location for taking up used ribbon discharged from the carriage, and ribbon guiding means for traversing a length of the ribbon with the carriage during the typing or letterspacing traverse of the latter so as to present successive areas of the ribbon at the typing station and to discharge used ribbon during such traverse to the take-up device, which means includes two ribbon guides for a final straight lap of the ribbon one of which guides has a stationary location towards said one end of the machine and the second is mounted on the carria e beyond the centre line towards the other end of the machine, the length of which lapwhen the carriage occupies its extreme position at said other end of the machine is at least equal to the length of traverse. Preferably, the machine has a similar arrangement for the ribbon supply. that is to say, there is a ribbon supply device having a stationary location, and two ribbon guides for an initial straight lap of the ribbon one of which guides has a stationary location towards said other end of the machine and the second is mounted on the carriage beyond the centre line towards the first said end of the machine, the length of which lap when the carriage occupies its extreme position at the first said end is at least equal to the length of the traverse.

The foregoing and other features of the in-. vention set out in the appended claims are incorporated in the construction 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 of the carriage; Figure 5 is a section on a larger scale looking in the direction of arrows J-J 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 G-G in Fig. 6 showing details of the take up device;

Figure 8 is a section through said device on the said line GG; Figure 9 is a sectional view on the line 0-0, Fig. 8; Figure 10 is a View in the direction of arrow H in Fig. 6; Figure 11 is a plan view in the direction of arrows VV 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 of the ribbon clamp, shown in Fig. 10; Figure 15 is a diagram of the ribbon path.

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 B and rack release lever 21 for carriage rack I28, paper feed rollers 9 for feeding a master sheet ID of paper or the like round the platen, means for feeding the normal typewriter ribbon l l in front of the master sheet Ill at the typing station TS so as to be struck by the type heads I2 and means for feeding I-Iectograph paper ribbon I3 along the face of the platen at 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 [4 (forming the subject of co-pending U. S. patent application Serial No. 624,159) fixed to a. stationary support [6 curving forwards and downwards over the platen.-

The ribbon I3 is drawn from a supply spool 28 carried by a rotatable supply device 29 and the used ribbon is Wound up on a take-up spool 30 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, respectively, as viewed from the front) and are carried by a stationary frame 32 applied to the machine. From the supply spool 28 the ribbon l3 passes over the stationary roller 33 (i. e. occupying a stationary location) on the right hand end of machine whence it goes to a roller 34- on the left hand end of the carriage, then to a roller 35 on the right hand end thereof, from the latter it runs forward under a horizontal guide roll 36 on the front of the carriage, over an inclined guide 31, along the front of the platen 6 through the guide l4 over an inclined guide 38 and under a horizontal guide 39 at the left hand end of the carriage and rearwarols to guide roller 48 also carried on the left hand end of the carriage. From the roller 4|lit runs along the back of the carriage to roller 4| on the right hand end thereof and thence as a final lap to a stationary roller 42; at the left hand end of the machine, whence it runs down to the take-up p ol: 30.

It will be seen that as the carriage traverses to, the left in typing or letter spacing the final lap between rollers 4| and 42 is decreased so that the ribbon I3 is surrendered to the take-up device 3| whilst the initial lap between

rollers

33 and 34. is increased so that the ribbon is drawn off the supply'spool 2,8; as a result the ribbon I3 at the front of. the platen travels with the carriage and successive areas, thereof are presented at the typing station TS.

It will further be noticed that the length of the traverse of the carriage 4 is substantially equal to the length of the platen 6, since all points in the length; of this platen must be brought to the typing: station TS. Therefore, as during typing traverseof the carriage, ribbon has to be surrendered to the take-up device 3| from the final lap which extends fromvthe roller 4| on the right hand end. of the carriage to the stationary roller 42 at: the left hand end of the body I, the length of this lap when the carriage is; at the right hand extremity of its traverse must be at least equal to the length of the traverse. Conversely, since it it desired that during the idle traverse of the carriage to the right the ribbon |3 should remain stationary at the typing station TS, so that in effect the carriage. moves through a loop of the ribbon extending from the supply device to the take up device, theinitial lap of'the ribbon which runs from the stationary roller 33 on the right hand end of the body I to the roller 34 at the left hand end of the carriage must, when the, carriage is in its extreme left hand position, be of a length at least equal to the traverse of the carriage. The arrangement of rollers shown permits this requirement to be met without having the rollers or supply or take-up spools protruding unduly beyond the ends of the body and also permits carriages of differing widths to be applied to one and the samebase. Considering, the final lap, theimportant feature is that while the stationary roller 42 is located at the left hand end of the body the other roller 4| is carried atthe'other side of the centre line of the carriage, indeed at the right hand end of the latter. Similarly, an importantfeature in so far as the initial lap is concerned is thatwhereas the stationary roller 33 is mounted at the right hand end of the body, the other roller 34 is mounted on the carriage beyond the centre line thereof, and indeed at the left hand end of it. It will therefore be seen that this roller disposition gives a compact arrangement in which the two laps are of adequate length. Furthermore, the longer the carriage, the longer do these two laps become without it being necessary to move the

rollers

33 and 42.

The rotary take-up device 3| consists of a spring drum 43 (Fig. 8) which is wound up during the reverse traverse of the carriage by means of a cord 44 (Fig. 6.) anchored to the carriage at 45. One side of this drum 43 carries a ratchet wheel 46 which drives an adjacent disc 41 by means of a spring loaded pawl 48 carried by the latter, the drive being in the clockwise direction in Fig. 6. Disc 41 drives a larger disc 49 through the medium of a yielding driving device comprising spring Washer 50 which in effect provides a slipping clutch, and the spool 30 in which the used ribbon is wound up as at 52 has a releasable drive engagement 53 with disc 49 and is detachably mounted on the spindle 54 of the take-up device 3| by means of a nut 55. The large disc 49 is provided, with a toothed periphery and whenever the carriage rack bar I28 is lifted a spring loaded pawl 56, Fig. 6, engages this disc to hold the take-up spool 30 stationary; that is to say, whenever the rack, release lever 21 or the tabulator key is depressed the take-up spool is prevented from revolving. Whenever the take-up spool 30 is thus checked, the slip action of the friction washer. 50 allowsthe spring drum 43 to wind up its 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 I3 is discharged from the carriage ity is wound up on the take-up spool30 and as the diameter of the wound package 52 increases slip takes place at the frictional spring washer 5|) so that an approximately even wind-up is obtained. The disc is also provided with a. check. pawl preventing its reverse rotation.

The mechanism, by which the pawl 56 is depressed into engagement with the disc 49 when the rack: bar I28 is raised is shown in Figures 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 and the other end,overlyinglever-59 which normally holds the pawl 56 out of engagement under the influence of a spring 30.

The rotary supply device 29 and its spool 28 (Fig. 6) are substantiallythesame as the takeupdevice; 3| and its spool 30 (except in that the supply.- device 29.- does, not incorporate a spring drum 43;)- and therefore no further illustration of the; supply device: and its spool is needed. It.

may be mentioned, however, that the supply spool 2-8 is connectedto a toothed disc 62, which is the equivalent of disc 49, through a resilient coupling; comprising a. spring. loaded lever 63 carried by the disc 62,,and1 frictional resistance is applied to the disc. 62 through. a. spring washer similar to, 5.0, this, resistance being sufiicient to keepthe; ribbon I3 in contact with the guide rollers and to prevent any spinning of theloaded spool.- The disc 62 is, checked by. a spring loaded pawl 54'connectedby link 55,110 the lever 5950 that. when the1 rackbar |28 is raised both the spoolstare. locked,againstrotation. As' a result.

when the carriage 4 is moved in either direction without letter spacing taking place the area of ribbon presented at the typing station TS remains substantially stationary.

In the typing traverse of the carriage the ribbon I3 is wound off the supply spool 28 so that the diameter of the roll decreases and is wound on to the spool 30 of take-up device 3| so that the diameter of the roll 52 increases. Therefore the effort required to pull the ribbon I3 off the supply increases while the effort required to accumulate the used ribbon increases, so that the washer 50 of the take-up device must be set at a maximum frictional value. Unless precautions were taken, this variation in effort would be liable to cause an uncertain pitch of travel of the ribbon at the typing station and there would be the danger that the typing impressions would overlap, leading to poor duplicates of the master sheet.

In order to overcome this, the ribbon l3 passes through a ribbon clamp 66 located on the carriage between the supply and the guide M, which clamps the ribbon to the carriage during letter spacing or typing traverse but releases it when the carriage is traversed in either direction by hand, and when the tabulator key 3 or the rack release lever 21 is depressed. This clamp 66 is best shown in Fig. 14 and consists of a fixed part 66a. and a movable part 66b biased to the open position by spring 13 (Fi 6) but urged together through the medium of the lever 61 pivoted at 68 and a spring 69 to grip the ribbon in its traverse between guide rolls 34 and 35. In order to release the clamp when the rack bar I28 is raised there is a lever 1'0 (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 14 extending along the back of the carriage, from the lower end of the threearmed lever 'Il through a stationary block 15 which is out with a pocket having a ramp or inclined face '16 housing a friction member constltuted by a ball 11. 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 (but with a force insuflicient to lock said rod to the block 15) so that the rod 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 14 on the ball 11 tends to carry the latter away from the inclined face 16 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 I3 is gripped comparatively near the supply spool before it proceeds along the front of the platen 6 and through the stationary guide I4. 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 areso 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.

1 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 difliculty there is provided a let-down mechanism 80, Fig. 6, by which the spring tension of the carriage can be reduced to a predetermined amount when using the carriage with the aforesaid ribbon mechanism thereon.

- When the usual typewriter carriage is used,

ample the carriage 4 is traversed and the ribbon 13-, is wound up by power means.

Furthermore, the machine shown may be employed for ordinary typing by removing rib bon I3 and guide I4.

The-clamping means for clamping the ribbon disclosed in the drawing and specification of the present application are claimed in the claims of my copending U. S. patent application Serial No. 624,161 ofeven date.

.21 claim:

-1. A typewriting or like machine, having a carriage which traverses in typing or letter-spacing towards one end of the machine and idly in the reverse direction towards the other end of the machine, a take-up device having a stationary location for taking up used ribbon discharged from the carriage, and ribbon guiding means for traversing a length of the ribbon with the carriage during the typing or letter-spacing traverse of the latter so as to present successive areas of the ribbon at the typing station and to discharge used ribbon during such traverse to the take-up device, which means includes two ribbon guides for a final straight lap of the ribbon one of which guides has a stationary location towards one end of the machine and the second is mounted on the carriage beyond the centre line thereof towards the other end of the machine, the length of which lap when the carriage occupies its extreme position at said other end of the machine is atleast equal. to the length of traverse.

2. A machine according to claim 1, having a. ribbon supply device having a stationary location, and two ribbon guides for an, initial straight lap of the ribbon, one of which guides has a stationary location towards said other endof the machine and the second ismounted on the car'- riage beyond the centre line towards the first said end of the machine, the length of: which lap; when the carriage occupies its extreme position at the first said end is at least equal to the length of traverse.

3. A machine according to claim 1,. having thesecond final-lap guide at the other end of the carriage.

4. A machine according to claim 1, having a ribbon supply device having a stationary loca tion, and two ribbon guides for an initial straightlap of the ribbon, one of which guides has a stationary location towards said other end of the machine and the second of which guides is mounted on that end of the carriage which is towards the first said end of the machine, the length of which lap' when the carriage occupies its extreme position at the first said end is at least equal to the length of traverse.

5. A typewriting or like machine, having a carriage which traverses in typing or letter-spacing towards one end of the machine and idly in the reverse direction towards the other end of the machine, a take-up device having a stationary location for taking up used ribbon discharged from the carriage, ribbon guiding means for traversing a length of the ribbon with the carriage during the typing or letter-spacing traverse of the latter so as to present successive areas of the ribbon at the typing station and to discharge used ribbon during such traverse to the t'ake-up device, which means includes two ribbon guidesfor a. final straight lap of the ribbon one of which guides has a stationary location towards one end of the machine and the second is mounted on the carriage beyond. the center line thereof towards the other end of the machine, the length of which lap when the carriage occupies its extreme position atsaid other end of the machine is at least equal. to the length of traverse and a clamp for clamping the ribbon to the carriage during the typing traverse: but for releasing it during the reverse; traverse.

6. A typewriting, or like machine, having a carriage which traverses intyping or letter-sp'ac-- ing towards one end of the machine and; idly in the reverse direction towards the other end of the machine, a take-up device having. a stationary location for taking up used ribbon discharged from the carriage, guiding means for traversing a length of the ribbon with the carriage during.

the typing or letter-spacing traverse of the latter soas to present successive areas of the ribbon at the typing station and to discharge used ribbon during such traverse to the take-up device, which means includes two ribbon guides for a final straight lap of the ribbon one of which guides has a stationary location towards one end of the machine and the second is mounted on the carriage beyond the center line thereof towards the other end of the machine, the length of which lap when the carriage occupies its extreme position at said other end of the machine is at least equal to the length of traverse, a clamp, locatedat the ribbon-supply side of the typing station,

, for clamping the ribbon to the carriage during the typing traverse but for releasing it during the reverse traverse, and means for rendering the take-up device ineffective during the reversetraverse.

7. In a typewriting or like machine having a carriage which traverses in typing towards oneend of the machine and idly in the reverse direction towards the other end of the machine, the combination of a ribbon-supply device having a stationary location; a take-up device having a stationary location for taking up used ribbon discharged from the carriage; ribbon-guiding means for traversing a length of the ribbon with the carriage during the typing or letter-spacing traverse of the latter so as to present successive areas of the ribbon at a typing station and to discharge used ribbon during such traverse to the take-up device, which means includes two ribbon guides for an initial straight lap of the ribbon, one of which guides has a stationary location towards said other end of the machine and the second is mounted on the carriage beyond the center line towards said one end of the machine, and two ribbon guides for a final straight lap of the ribbon one of which guides has a stationary location towards said one end of the machine and the second is mounted on the carriage beyond the center line thereof towards said other end of the machine; an operator's control for efiecting an idle traverse of the carriage in the typing-traverse direction and means operable by said control for rendering the take-up device inoperative.

CLAUDE WELLINGTON BRUMHILL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 657,422 Van Beck Jan. 24, 1928 2,217,180 Noonan Oct. 8, 1940 2,240,578 Rumibutis May 6, 1941 2,278,009 Handley Mar. 31, 1942