US3093906A

US3093906A - Drawing board for steel rule dies

Info

Publication number: US3093906A
Application number: US19329A
Authority: US
Inventors: Frank J Cohara
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-04-01
Filing date: 1960-04-01
Publication date: 1963-06-18
Anticipated expiration: 1980-06-18

Description

June 18, 1963 F. J- COHARA 3,093,906

DRAWING BOARD FOR STEEL RULE DIES Filed April 1, 1960 44 f am V NVENTOR. 344M arm. BY.

ATT'Y,

United States This invention relates to the making and manufacture of steel rule dies and is more particularly concerned with a drawing board of special design particularly adaptable for use by the draftsrnan in the preparation of steel rule dies.

Otherwise stated, the invention contemplates the provision of a drawing board adaptable for use in the manufacture of steel rule dies and having means whereby the workpiece may be easily and securely held in position for accurate and precise work thereon.

More specifically stated, it is a principal object and accomplishment of the invention to provide means whereby the workpiece may be removed from the drawing board for other work thereon and then be capable of being replaced in its previous position on the drawing board in precisely the same former position for further work.

It is an important object and accomplishment of the invention to provide a steel rule die drawing board which is simple to operateand rugged and reliable in use.

Another important object and accomplishment of the invention is to provide a steel rule die drawing board having adjustable means providing versatility in use and whereby said drawing board may conveniently and quickly accommodate various sized workpieces.

An ancillary object and accomplishment of the invention is to provide a new and novel drawing board for use in the manufacture of steel rule dies and consideration being given to the design and selection of materials in the manufacture thereof to prevent warping and distortion of the base of the drawing board as well as the marginal working edges so that extremely accurate and precise work may be continuously performed on any workpiece placed on the drafting board.

The invention seeks, as a final object and accomplishmeat, to provide a steel rule die drawing board of the character indicated and which is particularly characterized by a design arrangement to more advantageously and satisfactorily perform the functions required of it and adapted to provide a compact unit which will successfully combine the factors of structural simplicity and durability, and yetbe economical to manufacture.

Additional objects, features and advantages of the invention disclosed herein will be apparent to persons skilled in the art after the construction and operation are understood from the within description.

It is preferred to accomplish the various objects of this invention and to practice the same in substantially the manner as hereinafter more fully described, and as more particularly pointed out in the appended claims.

Embodiments of the invention are illustrated in the accompanying drawing forming a part hereof and wherein:

FIG. 1 is a perspective view of the steel rule die drawing board illustrating a workpiece disposed thereon and a T-square in its normal operating position at one edge of said drawing board;

FIG. 2 is a top view of an adjustable pressure controlled workpiece holding device with portions thereof shown in section to more clearly illustrate the construc tion; and

FIG: 3 is a sectional view of a portion of the drawing board for steel rule dies, this view being taken substantially on the plane of the line 3-3 on FIG. 1.

The drawing is to be understood to be more or less of a schematic character for the purpose of illustrating atent and disclosing a typical or preferred form of the improvements contemplated herein and in the drawings like reference characters identify the same parts in the several views. 7

Referring to the drawings, particularly to FIG. 1, the drawing board for steel rule dies contemplated by the present invention is designated in its entirety by the numeral 20 and comprises a base 21 of a substantially rectangular shape and preferably made of canvas impregnated Bakelite, marginal straight edges respectively indicated at 22 and 23 formed of brass and attached to the base 21 at two marginal edges as shown in FIG. 1 but having a Masonite filler 24 disposed between the base 21 and the

straight edges

22 and 23, said base 21 having a plurality of through apertures 25 adapted to adjustably and releasably receive securing

pins

26 and 27 respectively forming a part of pressure controlled locking devices indicated in their entireties by the

numerals

30 and 31 and which are adaptable for locating and maintaining a workpiece A in its proper position with respect to the drawing board 20, and a straight edge T- squa-re indicated in its entirety by the numeral 33.

Attention is now invited to FIGS. 1 and 3 wherein it can be seen that the base 21 is provided with equally spaced through apertures as at 25 and each aperture at the top regions thereof is provided with a countersunk opening 36 in order to act as a guide and more easily receive stud portions of the securing

pins

26 and 27. It is very important in a drawing board of the type contemplated herein that there be a minimum of wanping because of the extreme accuracy required when working on the workpiece A and in order to facilitate the drawing of absolute parallel lines and lines at right angles to same. It has been found preferable to form the base of canvas impregnated Bakelite because this material is not generally affected by temperature, moisture, humidity, etc., and will maintain its shape under normal circumstances in use and may be cut to precise dimensions for use in a drawing board as contemplated by this invention. As may best be seenin FIGS. 1 and 3, two marginal edges are provided withthe

straight edges

22 and 23 preferably formed of brass and secured to the base 21 as shown. Each of the

straight edges

22 and 23 are provided with a plurality of apertures 40 each having screw thread portions disposed therein adapted to receive screw thread portions *41 of a brass stud 42 and any projections that may appear are filed smooth as at 43 so that the top surface of the

straight edges

22 and 23 are smooth and free from obstructions. The lower end projections 44 of the stud 42 are adapted for receipt into an aperture 45 in the base 21, said aperture 45 at the lower regions thereof being provided with an enlarged opening 46 adapted to accommodate the lock washer 47 and nut 48 as shown.

In FIG. 3 it can be seen that the Masonite filler 24 is disposed between the respective straight edges 2-2 and 23 and the base 21, and said Masonite filler 24 is provided with a suitable aperture as at 50 to accommodate portions of the screw thread stud 41.

It is important to note that the

apertures

45 and 50 are slightly larger than the diameter of the screw thread stud 41 in order to provide adjustment of the marginal

straight edges

22 and 23 with respect to the base 21.

Particular attention i directed to the recess 54 which is provided in order to assure accuracy of the marginal

straight edges

22 and 23 and so that no portions of the workpiece A would be in contact with the Masonite filler 24 when disposed on the drawing board. Otherwise stated, the surface 55 of the brass marginal straight edges 22' and 23 are relied upon to maintain the workpiece 1.9 in its proper location on the drawing board 21. The relatively small recess 54 may also be used to accommodate any small particles of Waste materials coming from; erasures, etc., while working on the workpiece A.

Particular attention is invited to FIG. 1 wherein the pressure controlled

locking devices

30 and 31 are shown in one of many relative locations on the base 21 and in FIG. 2 there is shown a detail plan view of one of the pressure controlled locking devices. Because each of these pressure controlled locking devices is of identical construction it is only necessary to describe one and the locking device as indicated by the numeral 31 will be described herein.

In FIG. 2 the pressure controlled locking device 31 comprises abody portion 60 having curved end regions 61 and a flat side 62 in opposed relation to the curved end portions 61. The body 60 is provided with a

recessed studs

65 and 66 of the pressure controlled

locking devices

30 and 31 so that the workpiece A is held securely in the drawing board 20. It can be seen that various sized workpieces may be employed and appropriate adjustrnents can be made as hereinbefore described in order to accommodate these ditterent sized workpieces.

If the draftsman requires removal of the workpiece A from the drawing board 20 for other Work thereon or for any other purpose, it is only necessary for him to exert appropriate manual pressure upon the workpiece A sutlicient to overcome the pressures exerted upon the two edges of the workpiece A by the pressure responsive studs '65 and 66 and thereafter conveniently remove same channel 63 having a plurality of through apertures 64 vdisposed therein and adaptable to accommodate the securing pin 27. Five through apertures as at 64 are shown in order to provide a measure of adjustment in the use of the pressure controlled locking devices to securely but adjustably hold the workpiece A in its relafrom the drawing board 20. Replacement of the workpiece A in its original position on the drawing board 20 can be accomplished by placing the workpiece A so that the appropriate edges will be in contact with the pressure

responsive studs

65 and 66 of both pressure controlled locking devices and 31 and by exerting appropriate manual pressure the workpiece A can be moved into' position so that the other two edges will snap into contact with the marginal

straight edges

22 and 23 there? by permitting the draftsman to replace the workpiece A on the drawing board 20 in substantially its original position thereon.

From the foregoing disclosure it may be observed that I have provided an improved drawing board for use in the manufacture of steel rule dies and which efliciently ture 69in the body 60 of the pressure controlled locking device 31. "In order to facilitate longitudinal movement of the stud v65 within the aperture 69 there is provided a Bakelite sleeve bearing 70: which is suitably fixedly secured in the position as shown by cementing or any other similar process. means urging the stud 65 to its projecting position as shown in FIG. 2 there is provided a spring 7-1, one end 72 of which is adapted for engagement with the innermost regions of the aperture 69' and the other end 73 of which is arranged for engagement with enlarged head portions 68 of the stud 65.

In reviewing the relative disposition .of the pressure controlledlocking devices ,30 and 31 in FIG. 1 it can In order to provide a pressure be seen that the outer end portions of the studs 65 and 66are in engagement with the side portions of the workpiece A and by proper selection of an aperture 25 in the base 21 and an aperture 64 in the pressure controlled locking device '31 the securing pin 27 may be passed therethrough so as to provide locking pressure in the

studs

65 and 66 to maintain the workpiece A in its relative position with respect to the base 21. Thus, it can be seen that the pressure controlled locking device 31 will provide such locking presure to adjacent side edges of the workpiece A while the pressure controlled locking device 30 will provide a similar degree of pressure to another adjacent side of the workpiece A, thereby to maintain the other two sides of the workpiece A in proper engagement with the respective marginal

straight edges

22 and 23 all as shown in FIG. 1. a

The pressure controlled

locking device

30 and 31 are 7 preferably made of Bakelite but any suitable plasticmaterial may also be used if desired. The T-square 33 may be of conventional design and need not be further described herein.

In operation the user will select a workpiece as at A and dispose it on the base 21 of the drawing board 20 as shown in FIG. 1 and then by judicious selection of the appropriate apertures 25 in the base 21 and aperture 64 in the pressure controlled

locking devices

30 and 31 and thereafter insert respectively the securing

pins

26 and 27 so that appropriate pressure is applied to the two edges of the workpiece A by the pressure responsive fulfills the objects thereof as hereinbefore stated and which provides numerous advantages which may be summarized as follows: a

(l) Structurally simple, eflicient and durable;

(2) Economical to manufacture and readily adaptable to mass production manufacturing principles; and

(3) The provision of a drawing board for steel rule dies and having means whereby the workpiece may be not only easily and securely held in position for accurate and precise work thereon but also permitting the same workpiece to be readily removed for other work thereon and be conveniently and quickly replaced precisely in its p former position for further work.

While I have illustrated preferred embodiments of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but wish to avail myself of all changes within the scope of the appended claims.

I-claim:

1. A drawing board for steel rule dies comprising two straight edges disposedat right angles to each other and adjustably mounted on a perforated base adapted to accommodate a four-sided workpiece so that two sides of said workpiece are in contact with said straight edges, securing means respectively manually operable to mount the straightedges to said perforated base in adjustable position with respect to said perforated base, said base having a plurality of equally spaced apertures, pressure responsive locking means for holding a work piece'in position on said drawing board, said pressure responsive locking means being movable and adjustably secured to said base, a stud pin forming a part of said pressure responsive locking means and operable for manually movably and adjustably securing said pressure responsive means to said base and having portions thereof adapted to be received into one of said equally spaced apertures in said base, said pressure responsive locking 'means comprising a body having curved end regions and a flat side in opposed relation to the curved end regions, said body having a recessed channel having a plurality of through apertures disposed therein and adaptable to accommodate said stud pin, a pair of studs disposed in spaced relationship and with portions thereof projecting from the flat side of said body and axially movable in relation to said body responsive to manual l l l pressure, separate spring means disposed within said body and in engagement with a respective stud to provide a resilient force urging 51 id studs axially outwardly of said body so that end portions thereof are in engagement with a side of said workpiece to exert resilient pressure thereon to maintain an opposed side of said workpiece in contact with an adjacent straight edge, and each of said studs having means respectively cooperating with portions of said body to limit the axial outward movement of said studs with respect to said body.

2. In a drawing board for steel rule dies including a base adapted to accommodate a workpiece and provided with a plurality of equally spaced apertures and having straight edges adjustably mounted on at least two marginal sides thereof at right angles to each other; pressure responsive locking means for holding a workpiece in position on said drawing board, said pressure responsive locking means being manually movable and adjustably secured to said base by a stud pin forming a part of said pressure responsive locking means and said stud pin having portions thereof adapted to be received in one of said equally spaced apertures in said base, said pressure responsive locking means comprising a body having curved end regions and a flat side in opposed relation to the curved end regions, said body having a recessed channel having a plurality of through apertures disposed therein and adaptable to accommodate said stud pin, a pair of studs disposed in spaced relationship and with portions thereof projecting from the fiat side of said body and axially movable in relation to said body responsive to manual pressure, separate spring means disposed within said body and in engagement with a respective stud'to provide a resilient force urging said studs axially outwardly of said body so that end portions thereof are in engagement with a side of said workpiece to exert resilient pressure thereon to maintain an opposed side of said work-piece in contact with an adjacent straight edge, and each of said studs having means respectively cooperating with portions of said body to limit the axial outward movement of said studs with respect to said body.

3. In a drawing board for steel rule dies, the combination with a base of substantially rectangular shape and adapted to accommodate a workpiece, said base having a plurality of equally spaced apertures, of marginal straight edges adjustably mounted on at least two marginal sides of said base in a manner to provide at least two straight edges at right angles to each other, and pressure responsive locking means manually movable and adjustably secured to said base by a stud pin forming a part of said pressure responsive locking means and said stud pin having portions thereof adapted to be received into one of said equally spaced apertures in said base, said pressure responsive locking means comprising a body having curved end portions and a flat side in opposed relation to the curved end portions, said body having a recessed channel having a plurality of through apertures disposed therein and adaptable to accommodate said stud pin, a pair of studs disposed in spaced relationship and with portions thereof projecting from the flat side of said body and axially movable in relation to said body responsive to manual pressure, separate spring means disposed within said body and in engagement with a respective stud to provide a resilient force urging said studs axially outwardly of said body so that end portions thereof are in engagement with a side of said workpiece to exert resilient pressure thereon to maintain an opposed side of said workpiece in contact with an adjacent straight edge, and each of said studs having means respectively cooperating with portions of said body to limit the axial outward movement of said studs with respect to said body.

4. A drawing board for steel rule dies comprising, a base of substantially rectangular shape and adapted to accommodate a workpiece, said base having a plurality of equally spaced apertures, straight edges adjustably mounted on at least two marginal sides of said. base and providing two straight edges at right angles to each other, a first pressure responsive locking device for holding a workpiece in position on said drawing board, a stud pin forming part of said first pressure responsive locking device and having portions adapted to be received into one of said equally spaced apertures in said base, said first pressure responsive locking device being manually movable and adjustably secured to said base and having pressure responsive means adapted for engagement with a side of said workpiece to exert resilient pressure thereon to maintain an opposed side of said workpiece in contact with an adjacent straight edge, said first pressure responsive locking device comprising a body having curved end regions and a flat side in opposed relation to the curved end regions, said body having a recessed channel having a plurality of through apertures disposed therein and adaptable to accommodate said stud pin, a pair of studs disposed in spaced relationship and with portions thereof projecting from the fiat side of said body and axially movable in relation to said body responsive to manual pressure, separate spring means disposed within said body and in engagement with a respective stud to provide a resilient force urging said studs axially outwardly of said body so that end portions thereof are in engagement with a side of said workpiece to exert resilient pressure thereon to maintain an opposed side of said workpiece in contact with an adjacent straight edge, and each of said studs having means respectively cooperating with portions of said body to limit: the axial outward movement of said studs with respect to said body, and a second pressure responsive locking device of identical construction to said first pressure responsive locking device but arranged so that the axially movable studs forming a part thereof are in engagement with another side of said workpiece to exert resilient pressure thereon to maintain another opposed side of said workpiece in contact with the other adjacent straight edge.

References Cited in the file of this patent UNITED STATES PATENTS 165,888 Stevenson July 20, 1875 724,116 Maley Mar. 31, 1903 744,559 Kendrick Nov. 17, 1903 1,499,989 Lehmann July 1, 1924 1,807,895 Cheshire June 2, 1931 2,002,348 Louviaux May 21, 1935 2,097,209 Cooper et al Oct, 26, 1937 2,470,437 Hoert-h May 17, 1949 FOREIGN PATENTS 898,673 France July 10, 1944

Claims

1. A DRAWING BOARD FOR STEEL RULE DIES COMPRISING TWO STRAIGHT EDGES DISPOSED AT RIGHT ANGLES TO EACH OTHER AND ADJUSTABLY MOUNTED ON A PERFORATED BASE ADAPTED TO ACCOMMODATE A FOUR-SIDED WORKPIECE SO THAT TWO SIDES OF SAID WORK-P;IECE ARE IN CONTACT WITH SAID STRAIGHT EDGES, SECURING MEANS RESPECTIVELY MANUALLY OPERABLE TO MOUNT THE STRAIGHT EDGES TO SAID PERFORATED BASE IN ADJUSTABLE POSITION WITH RESPECT TO SAID PERFORATED BASE, SAID BASE HAVING A PLURALITY OF EQUALLY SPACED APERTURES, PRESSURE RESPONSIVE LOCKING MEANS FOR HOLDING A WORKPIECE IN POSITION ON SAID DRAWING BOARD, SAID PRESSURE RESPONSIVE LOCKING MEANS BEING MOVABLE AND ADJUSTABLY SECURED TO SAID BASE, A STUD PIN FORMING A PART OF SAID PRESSURE RESPONSIVE LOCKING MEANS AND OPERABLE FOR MANUALLY MOVABLY AND ADJUSTABLY SECURING SAID PRESSURE RESPSONSIVE MEANS TO SAID BASE AND HAVING PORTIONS THEREOF ADAPTED TO BE RECEIVED INTO ONE OF SAID EQUALLY SPACED APERTURES IN SAID BASE, SAID PRESSURE RESPONSIVE LOCKING MEANS COMPRISING A BODY HAVING CURVED END REGIONS AND A FLAT SIDE IN OPPOSED RELATION TO THE CURVED END REGIONS, SAID BODY HAVING A RECESSED CHANNEL HAVING A PLURALITY OF THROUGH APERTURES DISPOSED THEREIN AND ADAPTABLE TO ACCOMMODATE ASAID STUD PIN, A PAIR OF STUDS DISPOSED IN SPACED RELATIONSHIP AND WITH PORTIONS THEREOF PROJECTING FROM THE FLAT SIDE OF SAID BODY AND AXIALLY MOVABLE IN RELATION TO SAID BODY RESPONSIVE TO MANUAL PRESSURE, SEPARATE SPRING MEANS DISPOSED WITHIN SAID BOLDY AND IN ENGAGEMENT WITH A RESPECTIVE STUD TO PROVIDE A RESILIENT FORCE URGING SAID STUDS AXIALLY OUTWARDLY OF SAID BODY SO THAT END PORTIONS THEREOF ARE IN ENGAGEMENT WITH A SIDE OF SAID WORKPIECE TO EXERT RESILIENT PRESSURE THEREON TO MAINTAIN AN OPPOSED SIDE OF SAID WORKPIECE IN CONTACT WITH AN ADJACENT STRAIGHT EDGE, AND EACH OF SAID STUDS HAVING MEANS RESPECTIVELY COOPERATING WITH PORTIONS OF SAID BODY TO LIMIT THE AXIAL OUTWARD MOVEMENT OF SAID STUDS WITH RESPECT TO SAID BODY.