US2921661A - Paper guiding device - Google Patents

Description

Jan. 19, 1960 M. v. scoz-zA AvA 2,921,561

PAPER GUIDINGJ DEVICE Filed Dec. 22, 1958 PAPER GUIDING DEVICE Milton V. Scozzafava, Arcadia, Califl, assignor to Clar;

Corporation, San Gabriel, Calif., a corporation of Cahfornia Application December 22, 1958, Serial No. 782,086

4 Claims. (Cl. 197-133) This invention relates to improvements in business machines and has particular reference to means for threading a paper tape or the like into proper position to be printed.

Business machines incorporating printing mechanism for printing on a strip or sheet of paper generally comprise a rotatable platen around which the paper is fed to a printing station where the printing is elfected. After passing the printing station, the paper passes under a guide bar or the like which holds the paper close to the platen and which may also form a tear-01f bar to permit printed portions of the paper to be torn off.

Such guide or tear-off bar must be located far enough past the printing station so as to not interfere with the operation of the printing mechanism and yet must be placed relatively close to the surface of the platen in order to hold the paper against or at least near the surface of the platen to obtain a clear print on the paper. This placement of the guide bar presents a problem in threading the paper since the leading edge of the latter tends to pass at least substantially tangentially off of the platen surface and thus it tends to pass over instead of under the guide bar.

Attempts to overcome the above problem have led to a movable guide bar construction which may be moved outwardly away from the platen surface during threading of the paper which is later moved into close proximity therewith. Although such arrangements are generally satisfactory, they not only require additional mechanism, but also require additional manipulation in order to properly thread the paper.

It therefore becomes a principal object of the present invention to facilitate threading of paper in a business machine of the above type.

Another object is to eliminate the need for providing a movable guide and/or tear-off bar for a machine of the above type.

Another object is to cause a paper strip fed over the surface of a rotatable platen to lie close to the platen surface of its own accord.

Another object is to facilitate threading of two strips of paper in superposition through a machine of the above type. v

The nianiier at which the z'aibove and other objects of the invention are accomplished will be readily understood on reference to the following specification when read 'in ccinjunctieh with "the accompanying drawings,

wherein:

Fig. 1 is a sectional View through the platen and paper guide means of an adding machine embodying a preferred form of the present invention.

Fig. 2 is a plan view taken substantially along the line 22 of Fig. l, with the platen removed.

Fig. 3 is a sectional view taken substantially along the line 3-3 of Fig. 1.

Fig. 4 is a fragmentary sectional view taken along the line 4-4 of Fig. 2.

atent O Patented Jan. 19, 1960 Fig. 5 is a sectional view through the present invention.

Referring, in particular, to Figs..1 to 4, a rotatable platen 11 is provided which may be incorporated, for example, in a machine of the type disclosed in the U.S. patent to Busch et al. No. 2,744,682. Reference may be had to this patent for an understanding of other portions of the machine not disclosed herein. In such machines the platen may be rotated by hand during threading operations.

Printing mechanism is provided to print data on a pair of superimposed paper strips 12 and 13 at aprinting point P on the surface of the platen. The printing mechanism comprises a series of type wheels, one of which is shown at 14, having type characters 15 therearound. The wheels are rotatable into different positions to present different type characters to be printed at the printing station and the wheels are carried by arms 16 which are swung toward the platen during a printing operation of the machine whereby to carry the wheels into printing contact.

In order to obtain duplicate impressions on the two paper strips, a single ribbon 17 is provided, the latter being guided over a rotatable guide roller 18 and extend ing in parallel strands 20 and '21 along the length of the platen. The ends of the printing ribbon are fed to and from suitable take-up and supply rolls (not shown) and may be arranged and driven in a manner similar to that disclosed in the U.S. patent to Gearheart et al. No. 2,744,605.

The outer paper strip 13 is fed over a pressure roller 22 and through a chute formed by spaced guide elements 23 and 24, upwardly between the two strands of the printing ribbon and then under a tear-off bar 25 which extends beyond the length of the platen and is suitably attached to side frames 126 and 27 having bearings therein which support the platen. The inner paper strip 12 is fed between the platen 11 and guide element 24 and thence upwardly between the inner printing ribbon strand 21 and the platen "and under the outer strip 13.

The lower guide element 23 is pivoted on a cross rod 26 and extends downwardly and forwardly where it curves upwardly rather sharply, terminating 'just below the printing station P.

The pressure roller 22 extends through an opening in the guide element 23 and is rotatablys'upported by trunnion bearings formed in cars 127 struckout of the body of the guide element. The roller also extends through an opening 28 in the guide element 24 and is urged upwardly to press both paper stiips in contact with each other against the undersurface of the platen by a tension spring '30 attached to the guide element 23.

The guide element 24 is attached to a cross 'bar .31 and extends substantially parallel with the element .23 to form the guide chute. A curved guide plate 32 is attached to the guide element 24, forming aguide for the upper strip 12, and terminates in spaced relation with the upperedgeof theelement 24 to form a trough 33 for guiding the lower edge of the ribbonstrand .20. Tabs 34 and 35 extend upwardly from the plate 32 :and guide element 24, respectively, on'opposite ends of \the platen to assist in :guiding ithez-iibbon istrandltl.

In threading new paper strips into position, the outer strip 13 is threaded first. For this purpose, the guide element 23 is preferably first lowered slightly by pressing downwardly on a bar 36 which overlies a foot 37 on the guide element. The leading edge of the strip 13 is then inserted between the pressure roller 22 and the platen. Thereafter, the element 23 is released to the action of spring 30 and the platen 11 advanced clockwise, feeding the strip around the relatively sharp arcuate portion 38 of the guideway, which, it will be noted, is of a modified form of much smaller radius that the radius of the platen. Due to this relatively sharp curvature and the fact that the strip is thus forced through an acute angle of approximately'6O degrees, the'leading edge as well as the rest of the strip, as it passes through the chute, tends to curl toward the platen and as it emerges from between the two ribbon strands 20 and 21, it moves along in close proximity with the surface of the platen until it passes under the tear-01f bar 25. It has been found that by forming the arcuate portion 38 at ,4; inch radius, the paper will curl sufficiently and will yet readily pass through such curved portion without blocking. However, this dimension may be varied materially without losing the curling effect on the paper.

It will be noted that the leading edge of the strip 51 will leading edge of the paper strip, it will extend in a straight line when viewed from the top and thus lie close to the platen throughout its width. 7

It will be further noted that because of the tendency for the paper to follow the periphery of the platen, the bar 25 is not needed to maintain the paper directly adjacent the platen surface and therefore its only function is to facilitate tearing off of the paper.

The strip 12 is threaded after the strip 13 has been fully entered. The strip 12 is inserted between the platen and the portion of strip 13 directly over the pressure roller 22. Thereafter, as the platen 11 is rotated, the strip 12 will follow the inner contour of the curved guide plate 32 and will pass between the surface of the platen and the inner ribbon strand 20.

Fig. illustrates a modified form of the invention in which provision is made to guide a single paper strip only past the printing point P. In this modification, a paper guiding arrangement similar to that disclosed and claimed in the US. patent to Bennett et al. No. 2,819,783 is utilized to guide the paper onto the surface of the platen 11. That is, a paper trough 40 is pivoted on a stationary cross rod 41 and is urged clockwise by a tension spring 42 to yieldably press a pressure roller 43 rotatably carried thereby against the under periphery of the platen.

A second pressure roller 44 is provided having trunnion bearing journals 45 which are capable of both rolling and rotating in contact with tongue sections 46 extending rearwardly from the trough 40. Spring means (not shown) are preferably connected to the roller 44, urging the same forwardly, i.e. to the left in Fig. 5.

The forward end of the trough is curved upwardly at 47 along a relatively sharp radius and terminates adjacent the ribbon 17, which, in this case, comprises a single strand. A paper guiding member 48 extends across the width of the trough 40 and is attached in spaced relation thereto by suitable means (not shown) to form a guideway 50 for a paper strip 51.

It will be noted that the leading edge of the strip will commence curling toward the periphery of the platen 11 as it leaves the guideway so as to definitely pass between the ribbon 17 and the platen. As the leading edge continues during a threading operation, it will continue to move adjacent the platen and thus pass under the guide bar 25. Also, due to its curling tendency the strip will tend to lie directly adjacent the periphery of the platen at the printing point.

Although I have described my invention in detail and have therefore used specific terms and language herein,

it is to be understood that the present specification is illustrative rather than restrictive and that changes and modifications may be made without departing from the spirit or scope of the invention as set forth in the claims appended hereto.

Having thus described the invention, what I desire to secure by United States Letters Patent is:

1. In a business machine having a platen, a printing mechanism for printing data at a printing station on a paper strip extending over said platen, and a tear-off bar adjacent the surface of said platen and to one side of said printing station, said platen presenting a convex curved surface to said paper strip, comprising means forming a curved guide-way on the side of said printing station opposite said tear-off bar for guiding said strip adjacent the surface of said platen at said printing station, said guide-way having a curvature such as to cause the leading edge of said strip to curl toward the surface of said platen and under said tear-01f bar, and said guideway being positioned to cause said leading edge to follow said platen surface toward said printing station.

2. In a business machine having a rotatable cylindrical platen and printing mechanism for printing data at a printing station on a paper strip extending over said platen, comprising means forming an arcuate guide-way on' one side of said printing station for guiding said strip adjacent the surface of said platen at sm'd printing station, said guide-way having a radius materially smaller than the radius of said palten whereby to cause the leading edge of said strip to curl toward the periphery of said platen, and said guideway being positioned to cause said leading edge to follow the surface of said platen toward said printing station.

3. In a business machine having a rotatable cylindrical platen, printing mechanism for printing data at a printing station on a paper strip extending over said platen, and a pressure roller for frictionally engaging said strip with said platen at a point removed from said printing station, comprising means forming a curved guide-way for guiding said strip intermediate said pressure roller and said printing station, said guide-way having a curvature such as to curl the leading edge of said strip toward the peripheral surface of said platen, and said guideway being positioned to cause said leading edge to follow said surface of said platen toward said printing station.

4. In a business machine having a rotatable cylindrical platen, printing mechanism for printing data at a printing station on a paper strip extending over said platen, and a pressure roller for frictionally engaging said strip with said platen at a point removed from said printing station, comprising means forming an arcuate guide chute for guiding said strip intermediate said pressure roller and said printing station, said guide chute having a radius materially smaller than the radius of said platen and of such dimension as to cause the leading edge of said strip to curl toward the peripheral surface of said platen, and said guide chute being positioned to cause said leading edge to follow said surface of said platen toward said printing station.

References Cited in the file of this patent UNITED STATES PATENTS

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