Precision Advancing Device For Sheet Material

Abstract

A precision device for advancing sheet material comprises a guide through which the sheet material is adapted to advance, a leaf spring, one end of which is affixed to the guide and the other end of which projects through an opening in the guide toward the sheet material, and a solenoid actuated core, which projects into contact with a medial portion of the leaf spring in such a way as to depress the forward end of the leaf spring into frictional engagement with the sheet material and to advance the sheet material a predetermined increment for each actuation of the solenoid. Since each stroke of the spring is predetermined by stops on the guide, each actuation of the solenoid constitutes a digital input by which the sheet material is advanced by a single increment.

Description

BACKGROUND AND SUMMARY

The present invention relates to a precision device for advancing sheet material particularly for use in high-speed printing devices and the like and, more particularly, to apparatus in which an elongated sheet or strip of paper may be advanced increment by increment predeterminately under the control of a precision-actuating mechanism. A variety of prior devices, usually involving feed rollers or the like, have been proposed for feeding such an elongated sheet or strip of paper into a high-speed printing device. However, precision control of incremental rotation of such rollers has been difficult because of their relatively large inertial mass.

The primary object of the present invention is to provide an extremely low mass precision feed mechanism in the form of a guide having a smooth face over which an elongated sheet or strip of paper is adapted to be advanced, a leaf spring finger, the rearward end of which is fixed and the forward end of which frictionally engages the paper in the guide in order to move it forward when the medial portion of the spring is depressed, and a solenoid-actuated prod which actuates the finger once each cycle. Accordingly, the forward speed of the paper is determined by the repetition frequency of the solenoid prod. Since each cycle of the finger causes a forward movement of the sheet by a precise increment, the repetition frequency of the solenoid prod causes forward movement of the paper at a precise speed.

Other objects of the present invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the devices, together with their components and interrelationships, which are exemplified in the present disclosure, the scope of which will be indicated in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and object of the present invention, reference is made to the following detailed description, taken in connection with the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a paper advancing device embodying the present invention, the device being shown in the deactuated condition;

FIG. 2 is a cross-sectional view of the paper advancing device of FIG. 1, the device being shown in the actuated condition, with the paper having been moved forward by a single increment;

FIG. 3 is a cross-sectional view of FIG. 1, taken substantially along the line 3--3 of FIG. 1;

FIG. 4 is a top plan view of the paper advancing device of FIG. 1; and

FIG. 5 is a schematic view of a paper feed system in accordance with the present invention.

DETAILED DESCRIPTION

The paper advance device of FIG. 1, 2 and 3 is shown as including a guide 10 through which a paper strip 12 is adapted to advance forward under the control of a stepping finger 14. Paper 12 in guide 10 may be of any convenient width, it merely being necessary that there be a small clearance between the edges of paper 12 and the inner edges of the guide. In conventional fashion, paper 12 is composed of a felted mass of cellulosic fibers, with suitable fillers and binders to produce a self-supporting sheet. The fibrous construction of paper 12 is a characteristic feature which permits it to be engaged on one side while on the other side retaining the necessary characteristics for sliding movement in contact with the guide.

Guide 10 is shown as having a lower channel member 16 that provides a medial channel surface 18, a pair of channel sides 20, 22 which are perpendicular to channel surface 18 and a pair of upwardly extending flange portions 24, 26 which generally are parallel to central portion 18. Connected to flanges 24, 26 is an upper channel member 28, the edges of which are connected to the flanges by suitable fasteners 30, 32. Channel members 16, 28 are composed of a noncorroding metal such as stainless steel, the inner surfaces of which are highly polished in order to minimize the friction between paper sheet 12 and the surfaces of the guide which it contacts.

Stepping finger 14 is in the form of a shaped leaf spring, having a rearward straight extension 34, which is spot-welded to channel element 28 as at 36, an outwardly bowed medial portion 38 and a contact finger portion 40. In the preferred embodiment of the present invention, contact finger 40 is substantially perpendicular to the longitudinal axis of stepping finger 40 and substantially extends the width of stepping finger 40. It will be readily appreciated that, in an alternative embodiment, contact finger 40 is formed with a recess in the center portion thereof. Normally, the configuration of leaf spring 14 is such that the innermost point 42 of contact finger portion 40 is slightly spaced from the upper face of paper sheet 12 such that forward contact portion 40 is abutted against the rearward edge 44 of a slot 46 into which finger portion 40 projects. In contact with the medial portion 38 of spring 14 is a prod 48 which is connected to the core of a solenoid 50. Ordinarily prod 48 is biased into its uppermost position by a suitable spring (not shown). The configuration of leaf spring 14 is as shown and described in connection with FIG. 1. When solenoid 50 is energized through suitable leads 52, prod 48 is projected forwardly into the position shown in FIG. 2. Under these conditions, prod 48 engages medial portions 38 of leaf spring 14 in such a way as to flex the leaf spring inwardly, thereby causing contact finger portion 40 first to engage and to slightly depress the surface of paper sheet 12 and then to forwardly advance paper sheet 12 within the channel until the forward edge of contact finger portion 40 abuts against the forward end 54 of slot 46. It thus will be observed that the motion of contact portion 40 which is in contact with paper sheet 12 is precisely regulated by the distance between rearward edge 44 and forward edge 54 of slot 46. Also the frequency of actuation and deactuation of solenoid 50 determines the number of increments of paper sheet 12 advanced within a unit time and, therefore, the speed of advancement of the paper sheet.

The operation of the device of FIGS. 1, 2, and 3 is illustrated in FIG. 4, which shows a precision ticket printing system. This device includes a channel member 10 and leaf spring contact member 14 for advancing a paper sheet 12, all in accordance with the operation explained in connection with FIGS. 1, 2, and 3. Sheet 12 is provided from a supply roll 56, which is mounted for rotation about a suitable axis 58. From channel 10, precise increments of sheet 12 are projected into a printer 60, which is capable of printing and cutting the forward extremity of the paper sheet in such a way as to produce a ticket, the visual material on which is sufficiently precise to enable the use of the ticket in a punched card handling device or the like. Solenoid 50 is shown as being controlled by a manually adjustable speed selector 62 which determines the output frequency of pulses from a pulser 64. Each pulse produced by pulser 64 is amplified in a driver 66 which produces a pulse of sufficient strength and duration to cause actuation of prod 48.

The present invention thus provides a compact and substantially zero mass paper advance mechanism for precision use in connection with computer interface equipment or the like. Since certain changes may be made in the foregoing disclosure without departing from the scope of the present invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing be interpreted in an illustrative and not a limiting sense.

Claims

What is claimed is:

1. A precision paper sheet advance device comprising channel means providing a surface against which an advancing paper sheet is adapted to slide, said channel means formed with an elongated slot opposed ends of which define forward and rearward stops, resilient means having first and second ends, said first end mounted to said channel means, said second end operating as a contact finger that is constrained for forward movement between said rearward stop and said forward stop in contact with said paper sheet and for rearward movement from said forward stop to said rearward stop out of contact with said paper sheet, and actuating means for causing said forward movement of said finger contact means at a selected frequency.

2. A precision paper sheet advance device comprising channel means providing a surface against which an advancing paper sheet is adapted to slide, said channel means formed with an elongated slot opposed ends of which define forward and rearward stops, resilient means having first and second ends, said first end mounted to said channel means, said second end operating as a contact finger that is constrained for forward movement between said rearward stop and said forward stop in contact with said paper sheet and for rearward movement from said forward stop to said rearward stop out of contact from said paper sheet, drive means for causing forward movement of said finger contact means at a selected frequency, supply means for said paper sheet means at the input extremity of said guide means, print means for impressing information on the forward increment of said paper sheet, solenoid means for actuating said drive means, pulse means for actuating said solenoid means and speed selection means for determining the frequency of said pulse means.

3. The advance device of claim 2 wherein said actuating means is a solenoid.

4. The advance device of claim 2 wherein said channel means is composed of metal.

5. The advance device of claim 2 wherein said channel means is composed of stainless steel.

6. A precision paper sheet advance device comprising channel means providing a surface against which an advancing paper sheet is adapted to slide, said channel means formed with an elongated slot opposed ends of which define forward and rearward stops, a leaf spring having rearward, medial, and forward portions, said rearward portion affixed to said guide, said medial portion bowed outwardly from said guide, said forward portion defining a contact finger that is constrained for forward movement between said rearward stop and said forward stop in contact with said paper sheet and for rearward movement from said forward stop to said rearward stop out of contact with said paper sheet, and actuating means for causing forward movement of said finger contact means at a selected frequency.

7. A precision paper sheet advance device comprising channel means providing a surface against which an advancing paper sheet is adapted to slide, a leaf spring providing a rearward portion affixed to said guide, a medial portion bowed outwardly from said guide and a contact finger that is constrained for movement between a rearward stop and a forward stop in contact with said paper sheet and for movement from said forward stop to said rearward stop out of contact with said paper sheet, and a solenoid for causing forward movement of said finger contact means at a selected frequency.

8. The advance device of claim 6 wherein said channel means is composed of metal.

9. The advance device of claim 6 wherein said channel means is composed of stainless steel.

10. A precision paper sheet advance device comprising channel means providing a surface against which an advancing paper sheet is adapted to slide, a leaf spring providing a rearward portion affixed to said guide, a medial portion bowed outwardly from said guide and a contact finger that is constrained for movement between a rearward stop and a forward stop in contact with said paper sheet and for movement from said forward stop to said rearward stop out of contact from said paper sheet, drive means for causing forward movement of said finger contact means at a selected frequency, supply means for said paper sheet means at the input extremity of said guide means, print means for impressing information on the forward increment of said paper sheet, solenoid means for actuating said drive means, pulse means for actuating said solenoid means and speed selection means for determining the frequency of said pulse means.