US2419369A - Ribbon feed mechanism for manifolding machines - Google Patents

Description

April 22, 1947- R. w. RITZERT 2,419,369-

RIBBON FEED MECHANISM FOR MANIFOLDING MACHINES Filed April 28, 1943 2 Sheets-Sheet l 9 I4 .F' w

- s g Y a 3 "-14 3/ INVENTOR 4 a ROBERT w. RITZERT ATTORNEYS April 22, 1947. w, rrz 2,419,369

RIBBON FEED MECHANISM FOR MANIFOLDING MACHINES Filed April 28, 1943 2 Sheets-Sheet 2 INVEIQTOR ROBERT. w. RITZERII BY W MM ATTORNEYS Patented Apr. 22, 1947 RIBBON FEED MECHANISM FOR MANIFOLDING MACHINES Robert W. Ritzert, Dayton, Ohio, assignor to The Egry Register 00., Dayton, Ohio, a corporation of Ohio Application April 28, 1943, Serial No. 484,813

1 The present invention relates to manifolding machines, and in particular to such machines which are adapted to make multiple copies of typed or printed material by means of copying ribbons or carbons, particularly those machines used in connection with typing, adding and tabulating machines and the like.

' In a typical prior art machine over which the present machine represents an improvement, the manifolding attachment is constituted of a framework carrying rollers over which the required number of paper sheets are fed upwardly from the typing or printing platen of the main machine and the finished copies are received in their basket or carrier at the rear of the machine. The multiple typing or printing effect is provided by a plurality of carbon ribbons or webs which are interleaved between the paper sheets at the position of the platen. These ribbons are caused'to move across the paper, i. e., normal to the movement of the paper, during the spacing line interval by means of a pin wheel drive. Thus the carbon ribbons are moved from one side of the paper to the other side in steps corresponding to the line spacing operations of the main typing machine, the separate movements of the ribbons ranging between one-quarter and one-half inch. I However, when the last line has been typed o printed on the paper, an automatic ejection mechanism is brought into play-to move the entire group of paper rapidly upwardly over a considerable distance such that the succeeding sheet of the multiple group of paper lengths is placed in position for the next typing or print ing operation. During this ejection spacing feeding operation of the paper webs, the pin wheel which feeds the carbon ribbons across the paper is rotated a plurality of times in order to effect a plurality of steps of movement of the copying ribbons. movement. of the carbon ribbons during the paper ejection operation serves to overcome any tendency for the carbon ribbon to stick to the paper during the time that the paper is moved rapidly across the ribbon. However, a manifolding machine of this type is designed to accommodate paper webs or sheets which are fed to the machine from a folded condition which obviously leaves creases or folds'extending across the paper at positions which represent the upper and lower limits of the length of each paper web. It has been found that notwithstanding the tendency for the pin wheel mechanism to pre- This quick and sustained- 2 Claims. (Cl. 197153) vent sticking or adhesion of the carbon ribbon to the paper during the normal line spacing op; eration, this provision is not entirely satisfac tory during'the paper eject operation due to the fact that the carbon ribbons are tightly interleaved between the paper webs at the typing position and during this eject operation the folds of the paper must necessarily cross the carbon ribbons, causing these folds to carry the carbon ribbons with them as the paper is moved upwardly into the receiving basket.

In View of the fact that the paper webs move very quickly during this eject operation andover a considerable distance sufiicient in order to po-' sition the next group of sheets as determined by the distance between the folds into the typing position, there is a tendency for the carbon ribbon to break. This tendency is enhanced in case the ribbon is of the paper rather than the cloth type but in any event thi bowing-up effect on the ribbon represents a disadvantage in th eflicient operation of the machine.

A number of different structures have been provided to reduce the tendency of the ribbons to break and these structures, for the most part, involve the feature of moving the ribbon during the eject operation to a position where there is considerable spacing between the paper webs and therefore away from the typing position where clamping effects are present. The presentinvention provides still another method and apparatus for preventing the breakage of the ribbons.

The latter are usually made of paper having a width slightly greater than the height of the type or other impression. These paper strips are fed from a plurality of spools, as many as there are ribbons, and the ribbons are interleaved with the paper web-s. The ribbons are pulled across the webs by means of a pin wheel about which they are wound in stack form.

It has been found that when the paper is of excellent quality its strength is sufiicient to guard against breakage except during the eject operation when the paper webs move across the carbon ribbons during the eject operation and the creases or folds in the paper tend to dig into the ribbons and thus carry them upwardly with the fast moving paper.

However, should the grade of the paper become inferior or if there are any dimensional weaknesses in the cross section of the paper, one or more lengths of the ribbon may break. Severe changes in atmospheric condition,-such as hum d ty, m ght, enhanc .th enc Under such conditions the ribbon would break even during the line spacing operation where difiiculty on this score would not normally be present if the paper were of proper grade. The ribbons would most certainly break during the eject operation unless special apparatus is provided by which the ribbons are moved to a regionin. which thereis considerable looseness between the. ribbons. and the paper webs.

Ribbons of this general character are auto--- matic in operation in that when they have. been initially set up to print or type and tabulateaccording to a certain form, and after the ribbons have been interleaved with. the: paper webs, the ribbons proceed to type or printwithout further supervision or assistance from the operator. One operator may have under his care a large number or battery of these machines and should one or more of the ribbons of any one of the machine's break, it may be some time before this fact becomes knowntothe operator. so; that in, themeantime much of the work is spoiled due. to lack: of; the; necessary carbon copies. This matter of-car bon ribbon breakage is'therefore a very important item.

The primary object of the invention is" to'increase; the usable life of the ribbons or carbon coated strips which are employed in a multiple typing: or printing machine.

Another object is to provide apparatus of a simple and inexpensive character to minimize and preferably to prevent'the breakage. of" ribbons which: are: usually interleaved between the paper webs; in: a'muljtiplei typing or printing machine;

Still another object. is to provide improved-am paratus that: will immediately detect thebreakage of. one or" more lengths: of the ribbon and. will automatically signal the; operator or will. stop the entire machine.

Theforegoingobjects" are obtainedin brief" by employing a double width ribbo-nin place of the single width and causing. the ribbon to: be'posia ti'oned' with: respect to: the typing position such that'the type arms strike only one half the width of theribbon and then is later re-fed. through the machine in such aposition that. the type arms strike'the other half of the ribbon. Thus, both halves of theribbon are employed for typing or printing purposes with consequent no waste-"in carbon surface and yet the ribbon will be considerably stronger than those used heretofore due to the double cross-sectional area. Thebrea'kage in the ribbon is detected in accordance with another feature of my invention by means of a tensi'oni-ng determining device, or rather a device which indicates complete lack of tension as when the ribbon breaks.

The invention will be better understood when reference is made to the following description and the accompanying drawings in which:

Figure 1 represents a perspective view taken partly: from the front and side-cf a typical form of typing; adding and tabulating machine improved in accordance with the present invention.

Figure 2 is an enlarged fragmentary view'showingin elevation the various parts of the im provement and the manner in which these parts operate. This view illustrates that part of the machine which centers around the improved ribbon' feeding and guiding mechanism.

Figure .3 is a longitudinal sectional view of the ribbon feeding and receiving spools, including the actuating mechanism. Thi section is taken approximately along the line 3-3 in Figure 1.

Figure e is an enlarged vertical sectional view taken through the multiple spool compartment and the ribbon breakage detecting apparatus. This View is taken along line 4-4 in Figure 1.

Figure 5 shows in the upper and lower views respectively the first typing level of the ribbon and t'hesecond typing level; 1

Figure 6 is a fragmentary detail view of the actuating mechanism and th winding and unwinding ribbon spools and showing the manner in. which the. rotation of'the spools can be respectively reversed.

Figure 7shows still another way in which the carbon. ribbon of considerable width is caused to be typed thruout its entire area.

Referring more particularly to Figure 1 reference numeral l-designates the main portion of th machine which may be power driven by meansof a motor 2 and which may comprise any or the ordinary types of printing, typing, tabulating, and'listing machines. Thereyis; a oom binecl: clutch and gear. box 3 interposed betweenthe motor 2 and the actuating element which drives the platen 4 of the machine. In orderto accommodate the typing Orprinting on multiple lengths of paper, a manifolding attachment gen-- erally indicated at 5 isemployed. This attach-- ment may be secured to the main typing-machine in any suitable manner and in general comprises a pair of oppositely disposed side frames 6. withupwardly extending brackets 1,. the latter carrying a shaft 8 on which is mounted one or'more. rollers 9. There is also a series of rollers pro-. vided just above the typing position; on which the manifolded paper II) rests,- the latter then passing upwardly around the roller or rollers: 9. to the rear of the attachment. The paper is usually fed into the machine from a stack form inwhich the paper lengths are reverselyfolded and the paper is held in a flattened condition against. theroller 9 in any suitable manner; during the typing operation, after which the paper reverts to its folded state beyond the rollers 9 and; is receivedby a basket in stacked; condiiton. As shown a number of vertically disposed bars ll, may'beprovided to maintain the, flat state of the. paper, these bars being; secured to a horizontal, bar l2 at the top and carrying at the bottom a horizontally disposed guide bar l3, which. bears, againstthepaper.

In order. to feed the paper upwardly during; the line spacing movement and:then:. later durin the eject movement, i. e., when the paperis; moved quickly and over considerable distance. represented by the vertical space, between, the last; typed line of; one form and the first typed line-of the next form, one or more sprocket chains andsprocket wheels (not, shown) are employed. These wheels are mounted on the same shafts asthe rollers, and the chains carry projections which fit into openings; l4; provided on. the. center line of the. paper. The. movement of the. paper 119* wardly is controlled. automatically by suitable gearing which derives-its power from the. motor 2 through the control box 3, the operationv being such-that the paper remains in a stationary-pm sition throughout thetypingof one line and then is automatically moved upwardly a short distance (the space between lines) ready 'for the 'next line to be typed. At the conclusion of thetyping of the last line the paper move quicklyu-pwardly to such a position as to bring the first line to be typed on the next form op osite the typing position.

In order-to type or print simultaneously-a numher of paper webs, a plurality of carbon ribbons I5 is employed, these ribbons interleaving the webs and caused to move from the right to the left by mechanism which will be described presently. There may also be provided an extra ribbon for the so called original or first copy, this ribbon being carried on spool supports i6 which are independent of the supports which carry and guide the carbon paper strips interleaved with the paper webs.

Figures 3 and 4 illustrate ribbon feeding and receiving apparatus which may be employed to advantage in the improved machine. As shown there are four spools (assuming that there are five copies, including the original copy of the paper manifolds to be made) all contained within a cylindrical metal casing ll. The spools are mounted on a shaft I8 and are separated from one another by spacers I9. The innermost spool is separated from the inner side of the casing I! by a heavy washer 20. The shaft l8 forms an extension of the main shaft 2| which is provided with a shoulder 22 against which the inner side of the casing I1 abuts. The outer end of the shaft portion l8 may be threaded and provided with anut 23 which serves to hold the spools on the shaft.

It will be understood that, as shown at Figure 1, there are two casings ll, one at each side of the machine and each containing four spools which serve alternately to supply or receive ribbon from the typing position. Each casing I1 is provided at its lower side with slits 24, as many as there are ribbon spools and directly adjacent each slit there is an idler roller 25 secured to the inner surface of the casing, the function of the roller being to guide the ribbon to and from its respective slit. The upper surface of the casin I! may serve as a support for the side frames 6 to which the brackets i may be secured. The casings are supported from the remainder of the side frame structure indicated at 26 of the machine in any suitable and well known manner, for example, by means of a riveted flanged element 21.

As shown in Figures 2 and 4, the ribbons l5, after leaving the slits 24 of one of the casings l1 passes over a guiding structure, a so-called turn plate generally indicated at 28, then passing along the length of the platen at the typing position after which the ribbons are caused to extend vertically upward over a second turn plate at the opposite side of the machine. The ribbons then enter the slits 24 of the oppositely positioned spool casing 11. As shown in Figure 4 the turn plates 23 comprise an L-shaped member, one leg 29 of which is adapted to bear against the side frame member 26 and the other leg 30 extends in a direction parallel to the axis of the platen. Leg 30 comprises a large rectangular sheet of metal which extends a considerable distance downwardly from the leg 29 and is provided at its lower end with three or more notches indicated at 3| which have diagonal edges.

The arrangement is such that the ribbons i5 move in a vertical direction along the leg or plate 30, the ribbons being. separated by the notches 3| and the diagonal edges of which serve to give the ribbons a 90 turn. The turn plate 28 is located directly below the spool casing I! so that combination of the spools and the diagonal edges provided at the bottom of the turn plates serves rigidly to hold the ribbons in an exact vertical position. After leaving one of the turn plates the ribbon lengths in effect stack themselves on one another but these lengths are separated by the thickness of each paper web as the ribbons interleave the multiple sheets of paper. After leaving the opposite side of the paper the ribbons are caused to pass around the diagonal edges of a second turn plate 28' which again causes the direction of the ribbons to change and the ribbons are brought into register with the slits 24 of the oppositely positioned spool casing.

It was customary prior to this invention to apply a continuous tension on the ribbons by means of a pin wheel and to feed the ribbons from only one set of spools usually located at the right hand side of the machine, the pin wheel being positioned at the left. The pin wheel was given a rotation through suitable mechanism during the line spacing operation of the machine and was caused to rotate a number of times during the eject operation and at the same time maintaining the ribbon taut and in a stationary position during the typing operation. However, it has been found that under these conditions, and particularly when employing a poorer grade of carbon ribbons, there is a greater tendency for the ribbon to break during any one of the operations of the machine, especially during the eject operation when the paper moves at a fast rate and over a considerable distance in a direction transverse to the direction of the ribbon.

Breakage of the ribbon is a serious problem more especially in manifold typing or printing machines in which a number of copies of the printed or typed paper are required.

It will be understood that the friction between the paper ribbon and the paper webs is severe at the typing position due to the tendency of the interleaved elements to pack closely against one another. This packing condition is enhanced when the creases or folds of the manifolded paper which separate the forms from one another pass across the individual ribbons. The horizontal portions of the ribbons are held rigidly in position by the supply spools at one end and the pin wheel at the other end so that there is very little or no opportunity for the ribbons to give in a transverse direction in order to accommodate, at least in part, the vertical longitudinal movement of the paper webs. The carbon ribbons of standard make and which were available on the market prior to the present emergency were usually strong enough to resist any tendency to break, at least during the line spacing operation. Other provisions were usually provided for reducing the breakage tendency during the eject operation of the machine. However, the ribbons which are available on the present market are found to be of inferior quality, having less tensionai strength than the earlier forms of ribbon and on occasion the cross-sectional area of each ribbon may vary due to inferior workmanship and other attendant circumstances.

In accordance with my invention, I completely avoid any breakage of the ribbons by providing a ribbon at least twice the width of a normal rib bon and therefore having twice the cross-sec tional area with the resulting increased opposition to breakage. In order to render the use of the double width ribbon economically feasible, we have provided means by which the ribbon is theoretically divided into upper and lower por; tions, each having the same width as the ordi nary ribbon and each of these portions are alternately' employed in the typing operation.

In carrying out the principles of this invenae aaae tion we provide; means-by which the turn plates 28 can be moved upwardly at any desired time in orderto bring the lower portion of each ribbon into the typing position. For this purpose each transversely extending leg of the turn plate andwhich may comprise a flat sheet of metal is provided with a pair of vertically disposed slots 32 which cooperate with outwardly extending bolts 33 secured to the side frames 2%. Wing nuts 34 are threaded on the bolts 33, the arrangement being such that the plate 29 of each turn plate 28 can be moved by an operator in a vertical position as guided by the slots 32 and thus move-the median line of the ribbon pack [5 upwardly. The effect obtained is illustratively indicated in Figure 5, the upper view of which shows the type impressions 35 at the upper edges of the ribbon while the lower view shows the type impressions near the lower edge of the rib-- bon when the plates 29 at each side of the machine are raised through an appropriate distance. It will be understood that the removal of one typing level to the other takes place after the complete length of the ribbon has moved once across and between the manifolded forms.

The ribbon may be moved in opposite directions by any suitable mechanism of which one type willnow be described.

Ribbon feeding mechanism Referring more-particularly to Figures 2, 3 and 6, the; shaft 2! is provided at its middle position with a, pair of spaced bevel gears 36, 31 which are keyed or pinned to the shaft. Directly under one of, these gears and extending in a vertical direction is a shaft 38 which is pivoted as indicated at 39'to the end section of a power driven shaft 40 provided with a universal joint indi cated at M. The shaft portion 38 is provided with a pair of spaced collars 42 which are positioned. on opposite sides of a yoke 43 to which a pull rod 4'4 is pivotally secured. The rod terminates in a button 45 and is provided with a pair of' spaced arcuate notches 48 which cooperate with a curved spring arm 47 which serves as a stop. Thev rod 44 extends through an opening provided in a panel plate 43 to which is secured a horizontally disposed plate member 49 having a slot 5!] which serves to regulate the horizontal or swinging movement of the shaft portion 38. Now assume that the shaft 40 is driven through suitable mechanism or gearing by the motor 2 and that the button 45 is in its fully pulled-out position. The rotary effort of the shaft 40 is transmitted to the bevel gear'35 through a bevel gear 5| which is secured to the shaft portion 52. Thus the shaft 2! (Figure 3) of the ribbon spool mechanism is caused to rotate and let us say in such a direction that the ribbon is caused to be wound on the left hand set of spools and to leave the right hand set of spools as seen in Figure 3. The. effect issuch that. the ribbon is maintained in: a. taut condition, serving the same function as. the pinwheel in the. earlier form of machine disclosed hereinbefore. Nowassume that the shaftil is caused to rotate the proper number of turns only during the-line spacing operation and during the eject operation so that the ribbon is caused to remain stationary in its interleaved condition during the time that it takes to type each single line. The ribbon will continue to move during the stated. periods and remain stationary during the. other. periods until the ribbon has been entirely unwound from the'right hand series of spools andis. now wound completely on 8 the, left hand series of spools. The. button. 45 is now moved to. the right sothatthe spring arm 4'! will contact. with. the left hand notch 4.6 causingthe bevel gear 51 to swing about its pivot 39 and to mesh with the bevel gear 31..

Under these conditions, whenthe. shaft, M1 is caused to rotate, this rotary effort is communicated to the spool shaft 2.! in-the reverse direction from its previous direction. In. other words the ribbon is now caused to be unwound from the. lefthand assembly of spools and to be wound onthe right hand assembly. The shaft 4d is given. a continuous rotation in order that theright hand series of spools will become; loaded. with ribbon and therefore in the same condition as they were before'the spools were unwound during the provious typing operation, leaving just enough ribbon onthe left hand series of spools soas to main-- tain a tautcondition of the ribbon. The continu-- ous rotation of the shaft 4|) is stopped. in anysuitable manner and the plates 29 at both sides of the machinev are elevated by unloosening the wing nuts 34 and then tightening the same.

The shaft 40 is now given its usual intermittent movement, i-. e., a relatively short movement during the line spacing operation and a much longer movement during the eject operation, leaving the ribbon in a stationary condition while the succeeding lines are being typed or printed. The effect of moving th plate 29 upwardly is to bring the lower half portion of the double width ribbon under the type or printing bars as indicated in the lower view' of Figure 5 so that in effect fresh surfaces of carbon ribbons are presented to the type bars. After the entire lengths. of th ribbons have been exhausted at the end of the second typing operation, rather the sec.- ond traverse of the ribbons across the paper webs, fresh ribbon is provided by loading the right hand series of spools and threading the ribbon in the usual manner between the sheets of paper and finally catching th left hand end of the ribbons in the left hand spools.

From the foregoing it is evident that while I have provided a so-called double width ribbon in order to take advantage of the greater resistance to breakage due to the larger cross-sectional area of the ribbon, the latter is actually used twice, once at the upper half portion and later at the lower half portion, thus rendering the use of the double width ribbon completely feasible and economical. It has been found that even when employing the poorest grade of carbon paper for the. ribbon material the enchanced cross-sectional area brought about by the use of a double width ribbon entirely precludes breakage of the ribbon except under the most unusual circumstances such as if the ribbon were accidentally snagged.

Ribbon-breakage detecting device In Figure 4 I showapparatus by which the;

, the front leg 30 of the turn plate 23 is provided with asemi-circular indent indicated at 52 which extends transversely ofthe plate and has a length comparable to the combined, width of the ribbons. There is a rectangular casing 53 projecting outwardly from the front portion 30 of theturn plate, the top and bottom sidesv of the casing being positioned on opposite sides ofthe indent 52-. The casing is provided at the upper and lower: sides with: a plurality of. slits to re ceivethe separatelengths of theribbom l 5. There.

is a, flexible member or spring 54 which is riveted to the outermost sid of the casing as indicated at 55, this spring having a flattened portion 56 which is adapted to bear against the ribbons as they move through the casing. The contact pressure can be adjusted by means of thumb screw 51 which bears against the spring. The casing 53 is provided with an opening at a position directly opposite the indent 52, this opening being adapted slidably to receive a rod 58 carrying a knob 59 at its inner end which is urged against the ribbon by means of a pressure spring 60. The rod 58 is provided with a flexible strip 6| which carries a contact 62. This contact cooperates with a second contact 63 secured to the casing 53 and which is electrically charged through a wire 64. The latter may be connected to a relay 64a positioned in the energizing circuit of the motor 2 or the wire may be connected directly to an indicating device such as a lamp 64b shown in Fig. 4. It willbe understood that there are as many knobs 59 and rods 58 as there are ribbons to be protected.

The switch mechanism may be contained in a protective casing 65 secured to the main casing 53 in any suitable manner. The operation of the ribbon breakage detecting mechanism is readily apparent from the drawings. Should any one of the lengths of ribbon break the knob 59 which bears against that ribbon is permitted to move inwardly into the indent 52 and in so doing, contact is established between the contacts or terminals 62 and 63. This contact may energize an electromagnet or relay (not shown) which is so connected to the armature circuit of the motor 2 as to cause the motor to stop, thus bringing all of the mechanism to a halt. If desired, the closing of the switch at the contacts may additionally or alternately energize a signal light warning the operator who ma not be in immediate attendance, of the breakage of at least one of the ribbons. It is apparent that the apparatus as described responds to a change in the tautness of the ribbon so that contact is established at the switch when any condition arises by which 4 the ribbon, at any portion between the winding and unwinding spool becomes loose.

\Another way in which the ribbon may be typed thruout its entire width has been illustrated in Figure 7. One or the other of the turn plates 28 (Fig. 2) may be elevated to cause the ribbons to move lengthwise of the platen in a diagonal direction. In Figure 7 the right hand turn plate is assumed to be lifted. It will be noted that the typed characters tend to move from the upper left hand corner of the ribbons to the lower right hand comer. Inasmuch as the ribbons move from right to left during the time spacing operation as explained hereinbefore, every portion of each ribbon is used for impression purposes notwithstanding its considerable width. The same results would be obtained if the ribbons were given a slant with respect to the platen in the opposite direction by elevating the left hand turn plate 28.

Thus, in accordance with my invention I have disclosed not only apparatus by which the tensional strength of the ribbon may be greatly enhanced without affecting its economy of use but in addition a highly efi'icient and a simple mechanism by which the operator is warned of the breakage of the ribbon or any other unusual condition concerning the ribbon and if desired the motor may automatically be brought to a stop. The operator would re-thread a new ribbon without any loss in the typing or printing output of the machine.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. A power driven typing machine comprising a platen adapted to receive a sheet of paper, a carbon ribbon supply roll and a carbon ribbon receiving roll located on opposite sides of the platen but out of line therewith, means for guiding the carbon ribbon from the supply roll, along the platen to the receiving roll, said guiding means comprising a. pair of turn plates located at opposite ends of the platen, means for exercising a drag on the carbon ribbons, said means including supports secured to said turn plates, a plurality of flexible members carried by said supports and each bearin against a separate ribbon to provide frictional contact, and means also secured to said turn plates subsequent to said flexible member automatically responsive to breakage in a ribbon as it moves from one of said rolls to the other roll across the paper in order to indicate when said breakage occurs, said flexible member and means last named being located side by side and being adapted to move in parallel directions toward each carbon ribbon and on the same side thereof.

2. A power driven typing machine comprising a platen adapted to receive a sheet of paper, a carbon ribbon supply roll and a carbon ribbon receiving roll located on opposite sides of the platen but out of line therewith, means for guiding the carbon ribbon from the supply roll, along the platen to the receiving roll, said guiding means comprising a pair of turn plates located at opposite ends of the platen, means for exercising a drag on the carbon ribbons, said means including supports secured to said turn plates, a flexible member carried by said supports and bearing against the ribbon to provide frictional contact, and means also secured to said turn plates for contacting said ribbon immediately subsequent to said flexible member and responsive to breakage of said ribbon as it moves from one of said rolls to the other roll across the paper whereby said breakage may be indicated, said flexible member and mean last named being located side by side and being adapted to move in parallel directions toward each carbon ribbon and on the same side thereof.

ROBERT W. RITZERT.

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

UNITED STATES PATENTS German 1935

Images