US3312164A

US3312164A - Printing devices

Info

Publication number: US3312164A
Application number: US525074A
Authority: US
Inventors: John P Sebring
Original assignee: Moore Business Forms Inc
Current assignee: Moore Business Forms Inc
Priority date: 1966-02-04
Filing date: 1966-02-04
Publication date: 1967-04-04
Anticipated expiration: 1984-04-04
Also published as: GR34391B; SE343700B; BE693632A; CH445914A; NO120860B; ES336989A1; FR1511764A; GB1164903A; DE1561264A1

Description

April 4, 1967 J. P. sEBRlNG PRINTING DEVICESl Filed Feb. 4. 196e M W j m INVENTOR. n Jfa 2.7156575@ LL/f 41g 6%@ Waff/493 United States Patent fice 3,312,164 Patented Apr. 4, 1967 3,312,164 PRINTING DEVICES John P. Sebring, Lewiston, NY., assigner to Moore Business Forms, Inc., Niagara Falls, NIY., a corporation of Delaware Filed Feb. 4, 1966, Ser. No. 525,074 8 Claims. (Cl. lill- 93) This invention relates to printing devices and more particularly to such devices wherein the impression on the sheet is made by causing a hammer to strike the reverse side of the paper or other medium and force the immediate area of the front surface thereof against a type face.

This particular printing device probably finds its most important use in computer machines, where a print-out is made on a continuous multiple part form. In many of these machines the imprinting is made against a type chain carrying a complete font of type. Such a chain is moved to and fro selectively so that the proper character is placed into printing position, and then the impression is made by the print hammer striking through the multiple part form from the rear surface thereof.

However, it has been found, particularly in the case of the last few carbon impressions in a multiple form, that a shadow or halo appears around the impressed figure or number. This phenomenon is caused by the action ofthe hammer which appears to mold at least the rearward layers of the multiple form around the edges of the hammer, due to the partial embedment of the hammer element in the multiple relatively soft or yielding form pack. Us ually the halo or shadow appears only on the last few elements of the multiple form but obviously this constitutes a disadvantage and drawback in this kind of printing.

It is therefore a principal object of the present invention to provide means for use in printing apparatus of the class described for eliminating such undesirable shadow or halo impressions.

The present invention results from the discovery that such defects can be eliminated by the interposition of a particular kind of shield between the print hammer and the back of the form. This shield is of laminar form and is made of multiple layers of thin plastic material and the invention contemplates the provision broadly of a range of layers of the material and thicknesses within which the desired result becomes appreciable, and also the provision of optimum laminar and thickness qualifications for the maximum results.

More specifically, the invention contemplates .the provision of a laminar shield or pack comprised of multiple layers of Mylar plastic. Mylar is a trademark distinguish ing a polyester film material manufactured by'E. I. du Pont de Nemours & Co., the material being polyethylene terephthalate, which is a polymer formed by the condensation reaction of ethylene glycol and terephthalic acid. This material will be further defined by its known properties in the present specification.

The invention thus embraces an impact printing machine of the kind described employing this novel and improved shield, and also includes the multiple layer shield as an article of manufacture.

Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which one embodiment of the invention is illustrated by way of example.

In the drawings:

FIGURES 1 and 2 are diagrammatic views,l not drawn to scale, showing respectively prior art arrangements with the parts in position prior to and during impact bythe hammer;

FIGURES 3 and 4 are views similar to FIGURES l and 2 respectively and illustrative of the two corresponding stages with the use of the novel shield forming an essential element of the present invention;

FIGURE 5 is a fragmentary view suggesting one way of securing the novel shield to the nose frame of a printing apparatus and in front of the hammers;

FIGURE 6 is an enlarged fragmentary view showing the preferred structure of the plastic shield;

FIGURE 7 is a fragmentary View illustrating as Well as possible, considering the limitations of drawing, the undesirable halos or shadows which prevail in the impact printing machines now in use; and

FIGURE 8 is a similar View illustrating the freedom from shadow or halo on a record sheet nearest the hammer in a device following the principles of the present invention.

In the generic and quite diagrammatic showings in FIGURES l and 2, the prior art developments along this line of printing are exemplied. At 10 in these figures there is indicated a type element representative of numerous prior art constructions, whether carried upon a rotatable cylinder or arranged in the form of a chain. The character comprising letters, numbers, or punctuation marks is of course embossed or otherwise delineated upon the face of the type member 10 as at 12.

Similarly illustrated in diagrammatic fashion is a ribbon which can be moved step-by-step across the face 12 of the type 1() by suitable actuation of the

reels

16 and 17 upon which the ribbon is wound.

A projectable hammer member 20 of which there may be any desired number selectively actuated, is mounted for delivering an impact against the rear surface of the sheet or manifold pack which passes between the hammer and the type and ribbon set-up. Such a manifold pack is illustrated, for example, at in these figures of drawing and will be seen to comprise in the illustrated example, four record sheets a and three interposed carbon or transfer sheets b.

Thus as used in the claims, the term sheet.of record material or the like shall mean a single layer vora multi-layer pack. i Now in the normal operation of currently used-devices of this character, as illustrated in FIGURES 1 and 2, the hammer 20 in delivering its blow strikes the rear surface of the pack 25 and forces it against the portion of the ribbon 15 which overlies the type face 12 of the type element 10. As shown in possibly somewhat exaggerated form due to the necessary enlargement of the thickness of the pack for illustrative purposes, the face 21 of the hammer compresses the sheets a and b and embeds itself slightly within the rear surface of the pack r causing the rearmost sheets to wraparound the margins of the hammer face 21 and thus cause the carbon or transfer coating to frame the character impression with a rough irregularly imprinted shadow or halo. This undesirable framing of the character is suggested in FIGURE 7 of the drawings and it occurs definitely on the rearmost record sheet a and frequently on several of the rearward sheets.

As mentioned in the presentation of the objects of the present invention, applicant has provided a buffer strip which is interposed between the face 21 of the hammer 20 and the rearmost record sheet a of the pack 25. This guard strip or shield is diagrammatically illustrated at 30 in FIGURESG and 4 of the drawings. The idle position of the various parts is suggested in FIGURE 3 Iand the positions shown in FIGURE 4 are diagrammatically illustrative of the effect upon impact of the hammer upon the rear face of the guard or shield 30 which lies'against the manifold pack 25. I i

The impact of the hammer is absorbed by the shield strip 30 and seems to broaden out the force of impact of the hammer so that the rearward portions of the multiple form do not mold themselves around the Ihammer face, but the hammer Astill transmits enough pressure to make summarizing these results, the following delineations appear. The described improvement begins to make itself appreciable in the case of each material, with two layers of tilm each of a thickness of 0.0035 inch-total thickness 0.007 inch; two layers of film each of a thickness of D a good impression, such as suggested in FIGURE S of .005 inch-total thickness 0.010 inch, and six layers of the drawings. film each of a thickness of .0015 inch--total thickness Experimentation has shown that this novel and beneii- 0.090 inch. It can be said then that with respect to all cial effect is limited to some extent by the thickness of laminar thicknesses any total of over 0.011 inch or -a total the individual sheets comprising the guard strip, the 10 of below 0.007 inch, gives poor results. Also, it has been number f sheets employed, and the plastic material of determined that individual Single Sheets 0f more than which the sheets are made. 0.005 inc-h of thickness are not usable.

Before going into these somewhat critical data, it would Finally, the optimum results superior to any other combe well to show an example of one install-ation of the binations have been found to be the use of seven laminaguard sheet in relation to the hammers. In FIGURE 6 15 tions of nlm of 0.0015 inch of thickness, giving a total of the drawings a typical pack or laminar shield is illusthickness of 0.0105 inch. trated in somewhat diagrammatic exaggerated form. The Thus it may be stated that the effective total thickness pack comprises outer sheets A and B and inner sheets C lies Within the approximate range of 0.007 inch to 0.0105 which are embraced between the outer sheets. In order inch. to provide a convenient envelope for holding the lamina- 20 It is understood that thepresent invention is applicable tions together, the end sheets A and B are somewhat to a wide variety of impact hammer printing devices wider than the intermediate sheets C and the protruding and that the machines illustrated and described diagramedges D may be secured together adhesively or otherwise, matically herein are for generic illustration only. Also, for example, by means of a strip of double-face `adhesive various changes and modifications may be made in the tape suggested at D. 25 embodiments disclosed without departing from the scope -In FIGURE there is illustrated one form of hammer of the invention as determined by the subjoined claims. enclosure, sometimes referred to as a nose cone. This Having thus described the invention, what is claimed casing iS indicated nl 50 'and cOmPriSeS a freni face 51, as new and desired to be secured by Letters Patent is:

a p panel 52, end Wall 53, and attaching flange 54. 1. Printing apparatus comprising a type member hav- Along the width of the enclosure 50 is provided an elon- 30 ing a surface formed to present a type character, means gated Slot 50 ihrOllgh Which a multiplicity 0f hammers for supporting a sheet of record material with its surface are adapted to be projected. to be printed presented in front of said type surface,

The laminar Shield 0r buffer Pack 30 may he Secured hammer means for delivering a blow to the rear surface acrOSS the face 51 0f the frame 50 21S indicated in FIC of said record material to force the front face against URE 5, the ilange Portion D'Of the Peck being Secured 35 said type surface to imprint a character thereon, laminar O the member in any Suitable fashion 3S Suggested means supported in front of said hammer and between at 55- the hammer and the rear surface of said record sheet to It has been determined by eXPcrimenmliOn that thc sustain the direct force of the hammer blow and eliminate desired result is attained by the use of multiple sheets the production of a halo or Shadow image bordering the 0f Polyester PlaSic material made from Polyethylene 40 character reproduced on the record sheet, said laminar terephihnlaie, Ithe Polymer formed hy the condensation means comprising multiple layers of thin plastic sheeting, reaction of ethylene glycol and terephthalic acid. Thls Said plastic sheeting being a polyester mm made from material 1s manufactured 'by E. I. du Pont de Nemours& polyethylene terephthalate, the Polymer formed by the C0' under. the trademark Mylar' Ideritfyllg properiles condensation reaction of ethylene glycol and terephthalic of theD preferred fom off 1l/Iylar fir use 1n thils applicatilon 45 acid may e enumerate as o ows: u timate tensi e strengt 40,000 p.s.i.; stress to produce 5% elongation-21,000 to 1.12 hThe hapalrlatui 'asfsetlforth m dun? 1 in Whlch the 25,000 p.s.i.; ultimate elongation-50%; tensile moduim ast e o owing Urt 1er Properties ltlmate tnslle lusf 800,000 plsj.; impact Strength 6'0 kgrcmjmil; strength-40,000 psi.; stress to produce 5 ,a elongationdensity-1.37 grams/Cc.; coeicient of friction (kinetic) 50 21,090 to 25,000 PS-19 ultimate mignon-50%? tensile (film-to-ilm) 0.38; melting point, 250 to 265 C. modulus-800,000 p.s.1.; density-1.377; and coeticient With regard to the thickness `of the individual lamina- 0f friction (kinetic) (lm0lm)-038- tions and the number of laminations employed, it is inter- 3- The apparatus aS Sei forth in Claim 1 in Which the esting to note the following results of experiments: laminar means comprises a pack of from two to seven Number oi Laminations Total No Change Slight Considerable Maximum Thickness Improvement Improvement Results Lamlnation thickness,

5 layers of film of from 0.0015 inch to 0.005 inch of thickness of each layer.

4. The apparatus as set forth in claim 1 in which the laminar means has a total thickness of from about 0.0070 inch to about 0.0105 inch.

5. The apparatus as set forth in claim 1 in which the total thickness of the laminar means is approximately 0.0105 inch.

6. The apparatus as set forth in claim 1 in which the laminar vmeans comprises seven layers of film each layer about 0.0015 inch thick.

7. Printing apparatus comprising a type member having a surface formed to present a type character, means for supporting a sheet of record material with its surface to be printed presented in front of said type surface, hammer means for delivering a blow to the rear surface of said record material to force the front face against said type surface to imprint a character thereon, laminar means supported in front of said hammer and between the hammer and the rear surface of said record sheet to sustain the direct force of the hammer blow and eliminate the production of a halo or shadow image bordering the character reproduced on the record sheet, said laminar means comprising multiple layers of thin plastic sheeting, said laminar means comprising at least three layers, the inner and outer layers being somewhat Wider than the intervening layers and the extended portions of said inner and outer layers being secured together thus providing yan envelope for said intervening layers.

8. As an article of manufacture for use in an impact printing device wherein hammers are employed to strike the rear face of record sheeting to force the forward face thereof against xed type for effecting an impression', a buffer strip for insertion between said hammers and the record sheeting, said buffer strip comprising from about three to about seven layers of polyester lm made from polyethylene terephthalate, the polymer formed by the condensation reaction of ethylene glycol and terephthalic acid, the innermost and outermost layers being somewhat wider than the intervening layers and the extended portions of said inner and outer layers being secured together thus forming -an envelope for containing said intervening layers.

References Cited by the Examiner UNITED STATES PATENTS 168,373 10/1875 Chipman 161--99 1,939,306 12/1933 Leslie 161--99 2,584,092 1/1952 Keller et al. lOl-38 3,090,297 5/1963 Wilkins et al. 101--93 3,143,063 8/1964 Stark 101--93 ROBERT E. PULFREY, Primary Examiner.

W. F. MCCARTHY, Assistant Examiner.

Claims

1. PRINTING APPARATUS COMPRISING ATYPE MEMBER HAVING A SURFACE FORMED TO PRESENT A TYPE CHARACTER, MEANS FOR SUPPORTING A SHEET OF RECORD MATERIAL WITH ITS SURFACE TO BE PRINTED PRESENTED IN FRONT OF SAID TYPE SURFACE, HAMMER MEANS FOR DELIVERING A BLOW TO THE REAR SURFACE OF SAID RECORD MATERIAL TO FORCE THE FRONT FACE AGAINST SAID TYPE SURFACE TO IMPRINT A CHARACTER THEREON, LAMINAR MEANS SUPPORTED IN FRONT OF SAID HAMMER AND BETWEEN THE HAMMER AND THE REAR SURFACE OF SAID RECORD SHEET TO SUSTAIN THE DIRECT FORCE OF THE HAMMER BLOW AND ELIMINATE THE PRODUCTION OF A HALO OR SHADOW IMAGE BORDERING THE CHARACTER REPRODUCED ON THE RECORD SHEET, SAID LAMINAR