US3661277A

US3661277A - Positioning means for material cutter

Info

Publication number: US3661277A
Application number: US1506A
Authority: US
Inventors: Dorse James Young
Original assignee: Harris Intertype Corp
Current assignee: Harris Graphics Corp
Priority date: 1970-01-08
Filing date: 1970-01-08
Publication date: 1972-05-09
Anticipated expiration: 1989-05-09
Also published as: DE2100366A1

Abstract

A material cutting device having a backgauge which may be manually positioned by means of a hand wheel accessible to the operator also includes a position indicating tape upon which visible indicia representing the backgauge position are printed or engraved. The visible indicia may be referred against an index mark located adjacent a circular scale mounted to rotate with the hand wheel. The close proximity of the circular scale, the index mark, and the visible indicia on the control tape facilitates the positioning of the backgauge by the operator.

Description

United States Patent [151 3,66 1 ,277

Young May 9, 1972 s41 POSITIONING MEANS FOR MATERIAL FOREIGN PATENTS OR APPLICATIONS CUTTER [72] Inventor: Dorse James Young, Centerville, Ohio [73] Assignee: Harris-lnteI-type Corporation, Cleveland,

Ohio 1 [22] Filed: Jan. 8, 1970 [21] Appl. No.: 1,506

[52] U.S.Cl ..2l4/I.6,116/115.5

[51 Int. Cl ..B23q 7/00 [58] Field ofSearch ..214/1.5-1.7;

[56] References Cited UNITED STATES PATENTS 2,071,402 2/1937 Hazelton ..83/522 X 2,213,068 8/1940 Eickman 2,673,611 3/1954 Seybold 3,527,128 9/1970 Thumin ..214/1.6X

521,684 2/1956 Canada ..116/ll5.5

714,183 10/1941 Germany ..83/522 932,344 7/1963 Great Britain ..83/522 618,634 3/1961 Italy ..83/522 Primary Examiner-Gerald M. Forienza Assistant E.vaminer-Frank E. Werner Attorney-Marechal, Biebel, French & Bugg ABSTRACT 3 Claims, 5 Drawing Figures PATENTEDMAY 9 I972 3.661.277

sum 1 0F 2 FIG 1 RELATED APPLICATION Reference is hereby made to application Ser. No. l,407, filed Jan. 8, I970 assigned to the same assignee as the present invention.

BACKGROUND OF THE INVENTION In material cutting devices, such as shown in US. Pat. No. 3,176,556, the position of a backgauge which moves a pile of material beneath a clamp and knife for cutting is indicated by a continuous, flexible metal indicator tape connected to move with the backgauge. Typically, the indicator tape is carried above a table supporting the material while the hand wheel by which the operator positions the backgauge manually is connected directly to a lead screw rotatably supported beneath the table. The indicator tape is usually first referred to by the operator to position the backgauge to a first order of accuracy. The operator must then shift his eyes from the indicator tape located above the table to a circular scale, usually located below the table and mounted on the hand wheel, for the final positioning of the backgauge to a second order of accuracy.

Since the machine operator must refer to widely spaced locations in order to position the backgauge manually, and thus the material on the table, the operator must be careful and take time so as not to position the backgauge inaccurately.

SUMMARY OF THE INVENTION This invention relates to a novel arrangement of an indicator tape and circular scale for positioning a backgauge of a material cutter whereby the machine operator may refer to only one location to ascertain quickly the position of the backgauge.

A hand wheel is connected to a lead screw supported for rotation beneath the table for positioning the backgauge. In the preferred embodiment, the flexible indicator tape is part of a control mechanism located at the forward part and underneath the table and moved in response to the rotation of the lead screw. The indicator tape is a magnetic tape upon which control marks may be recorded and thereafter used to position the backgauge automatically. The indicator tape is provided with visible indicia which is divided into units of length, and fractions thereof, and may be observed through an opening in the housing of the control mechanism. By comparing the indicator tape to an index mark on the housing, the backgauge position may be ascertained to a first order of accuracy.

A circular scale mounted to rotate adjacent the opening in the control mechanism housing also carries on it visible indicia which may be referenced to the index mark on the housing to indicate the position of the backgauge to a second order of accuracy. The circular scale is correlated to the movement of the backgauge so that one revolution of the scale is equivalent to one unit of length as defined on the indicator tape.

Due to the close proximity of the visible indicia on both the circular scale and the tape, the operator need only refer to a single location to ascertain accurately the position of the backgauge.

Accordingly, it is an object of this invention to provide an improved material cutting device in which an indicator tape having visible indicia placed thereon is mounted adjacent a circular scale which rotates with a lead screw moving a backgauge, the visible indicia on both the tape and the scale being observable by a machine operator at essentially one location; and to provide an improved material cutting apparatus wherein a continuous magnetic control record which may be used to position a backgauge automatically also carries thereon visible indicia which, as observed by the machine operator, is located adjacent a circular scale connected to rotate with the lead screw driving a backgauge.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a material cutting device which includes the position indicating apparatus of this invention;

FIG. 2 is a front elevational view showing a flexible indicator tape in connection with the lead screw which moves the backgauge;

FIG. 3 is a plan view showing in part the relationship between the flexible indicator tape and the circular scale connected to rotate with the lead screw;

FIG. 4 is a side view, particularly in cross section, showing the relationship between the flexible indicator tape and the circular scale; and

FIG. 5 is an enlarged view taken on the view line 5-5 in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the position indicating apparatus of this invention is preferably used on a material cutting apparatus, shown generally in FIG. 1, which includes a table 10 upon which a stack of material 11, such as paper, may be placed to be cut by a knife 12. A clamp 13 holds the material during cutting while backgauge 15 positions the material beneath the knife. The backgauge is moved by a lead screw 17 rotatably supported beneath the table. A slot 18 is formed in the table 10 and receives an extension of the backgauge 15 which cooperates with the lead screw 17 to move the backgauge. A hand wheel 20 is attached to one end of the lead screw and permits the machine operator to position the backgauge manually. The backgauge is also supplied with power from a drive means 21 for positioning the backgauge automatically under the direction of position control means, shown generally at 25.

The position control means 25 is contained in a housing 27 and includes a flexible continuous tape 30 which is reeved over a sprocket wheel 31 and a roller 32. The sprocket wheel 28 has formed thereon a plurality of pins 33 which engage sprocket holes 34 in the tape 30 to provide accurate and positive control over the movement and position of the tape.

The sprocket wheel 31 is connected to rotate under the control of the lead screw 17 through a chain 35 drivingly connected to the lead screw by a sprocket wheel 36 and to the sprocket wheel 31 through

gears

37 and 38 and sprocket 39.

The sprocket wheel 31 is carried in a carriage 41 which is slidably mounted within the housing 27. A spring 42 connected between the carriage 41 and the housing 27 urges the carriage 41 to the left, as viewed in FIG. 3, and therefore places the chain 35 in tension.

The roller 32, which supports the right end of the tape 30, is also mounted in a carriage 43, and this carriage is biased to the right, as viewed in FIG. 3, by a spring 44. The spring constant of spring 44 is less than that of spring 42 so as not to lessen substantially the tension on the chain 35 while at the same time permitting the tape 30 to be supported between the sprocket wheel 31 and the roller 32 without slack.

In the preferred embodiment, the gear ratios between the

sprockets

36 and 39, and the

gears

37 and 38 are so selected that the tape 30 moves through the same linear distance as the backgauge 15. The tape 30 carries on it visible indicia to which the operator may refer to ascertain the position of the backgauge 15. The visible indicia is in units of length, typically inches, and fractions thereof, i.e., A-inch divisions, thus allowing the operator to ascertain the position of the backgauge to a first order of accuracy.

The visible indicia may be viewed through an opening 50 formed in the housing 27. This opening is preferably provided with a window 51 which includes an index mark 52 against which the visible indicia may be referenced.

The hand wheel 20, as shown in FIGS. 4 and 5, has mounted thereto a circular scale 55 which is also provided with visible indicia, preferably by engraving. The circular scale 55 rotates adjacent the window 51, and the marks thereon may be observed by reference to the index mark 52.

The pitch of the lead screw 17 may be selected so that for one complete revolution of the lead screw, the backgauge will move one unit of length (ie 1 inch). Thus the circular scale 55 is divided into small fractions of that unit of length and provides means for ascertaining the position of the backgauge within one of those units of length to a second order of accuracy.

Both the visible indicia on the circular scale 55 and on the tape 30 are observable by reference to a single location 60 to ascertain the position of the backgauge 15, the indicia on the tape 30 indicating the position of the backgauge to a first order of accuracy and the indicia on the circular scale indicating the position to a second order of accuracy.

In the preferred embodiment, the tape 30 is a magnetic tape upon which magnetic control marks may be placed which may be sensed by magnetic recording and/or playback heads 65 which form part of the automatic control mechanism. The backgauge 15 is usually positioned manually by the operator who rotates the hand wheel 20 and refers to the visible indicia on the tape 30 and the circular scale 55 in order to position the backgauge accurately. Electronic circuitry is provided to record that position on the magnetic tape 30 so that in subsequent operations of the material cutting device, the backgauge will be made to stop again in that position.

The tape 30, while designated to be continuous, is actually a length of magnetic recording tape which has been spliced at one location. The length of the tape used in the preferred embodiment is such that the splice will never come into view through the window 51 and will not traverse the magnetic playback and/or recording heads 65. This is done by making the tape longer than the distance through which the backgauge 15 travels by an amount at least equal to the distance between the position of the recording heads 65 and the window 51.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. Apparatus for indicating the position of a movable member by reference to two position indicating means observable at a single location, said apparatus comprising means for moving said member;

first means for indicating the position of said member to a first order of accuracy, said first means including a flexible magnetic tape connected to move in response to the movement of said member and having visible indicia placed thereon, said tape having control marks recorded thereon;

sensing means responsive to said control marks for automatically positioning said member in preselected locations; and

second means mechanically connected to said member for indicating the position of said member to a second order of accuracy, said second means including a circular scale having visible indicia thereon, said scale mounted to rotate adjacent said tape in response to the movement of said member;

the indicia on said first and second means being observable at a single location to ascertain the position of said member to both said first and second orders of accuracy.

2. The apparatus of claim 1 further including an index mark to which both the visible indicia on said tape and said scale may be referenced.

3. The apparatus of claim 1 wherein said flexible magnetic tape moves in one to one relation with the movement of said member, said visible indicia on said tape being divided into units of length, said scale being so related to the movement of said member that one revolution of said scale is equivalent to one ofsaid units oflength.

Claims

1. Apparatus for indicating the position of a movable member by reference to two position indicating means observable at a single location, said apparatus comprising means for moving said member; first means for indicating the position of said member to a first order of accuracy, said first means including a flexible magnetic tape connected to move in response to the movement of said member and having visible indicia placed thereon, said tape having control marks recorded thereon; sensing means responsive to said control marks for automatically positioning said member in preselected locations; and second Means mechanically connected to said member for indicating the position of said member to a second order of accuracy, said second means including a circular scale having visible indicia thereon, said scale mounted to rotate adjacent said tape in response to the movement of said member; the indicia on said first and second means being observable at a single location to ascertain the position of said member to both said first and second orders of accuracy.

3. The apparatus of claim 1 wherein said flexible magnetic tape moves in one to one relation with the movement of said member, said visible indicia on said tape being divided into units of length, said scale being so related to the movement of said member that one revolution of said scale is equivalent to one of said units of length.