US2595842A - Machine for making mechanical drawings - Google Patents

Description

M y 6, 1952 A. A. GOERZ 2,595,842

MACHINE FOR MAKING MECHANICAL DRAWINGS Filed Oct. 1. 1946 -9- illlllllllli yf mmnu l6 G/NVENTOR A 7' TORNE 7" Patented May 6, 1952 UNITED STATES PATENT OFFICE MACHINE FOR MAKING MECHANICAL DRAWINGS 8 Claims. 1

This invention relates to a machine for making mechanical drawings.

Stated more specifically, the invention pertains to a detached or portable drafting machine which, when placed on a drafting board will make drawings and measure drawings without the use upon the board of fixed attachments or extraneous guides.

Accordingly it is an object of the invention to provide a self-contained, detached drafting machine which has incorporated into its structure improved means for accurately determining its movements across a drafting board in various directions having predetermined angular relations.

Among other objects are: to provide improved means for adjustably mounting straightedges; to provide an improved combination of brake and brake release means for roller means movable across the surface of the board; to provide manually operable means for adjusting the surface or rolling contacts of pairs of wheels in relation to the surface of the drafting board; to provide improved handle means for the accurate movement of the machine across the board; to provide an improved adjustable combination of straightedge and protractor; to provide for the machine an improved central bridge member; to provide an improved combination of primary and secondary straightedges; and to provide improved means for adjustably connecting various parts of the machine with each other.

Other objects, advantages and features of invention will hereinafter appear.

Referring to the accompanying drawing, which illustrates a preferred embodiment of the invention,

Fig. 1 is a plan view of the machine, parts being broken away to contract the view.

Fig. 2 is a cross-section on line 22 of Fig. 1.

Fig. 3 is a horizontal sectional detail on line 3-3 of Fig. 2.

Fig. 4 is a fragmental plan of the slide member shown in Fig. 3 having through it a key-hole shaped slot.

Fig. 5 is a fragmental part sectional view on line '55 of Fig. 1.

Referring in detail to the drawing, in the central portion of Fig. 2 is shown an elongated bridge 5 which forms part of a supporting frame and which consists of a rigid metal (or metal sub stitute) horizontal plate having from end to end along one of its long edges a downwardly directed leg-forming flange 6 from the midlength part of which projects outwardly a foot 1, saidfoot con-- sisting of a horizontally outbent ear integral with said flange 6. Adjacent to its opposite edge the bridge 5 has secured to its under side a primary straight edge 8 attached by a pair of tapered tongue-amd-groove joints 9 interlocking in a well known manner. The outer edge portion of this member 8 has a conventional bevel 10, its extreme edge however, being vertical at H. Along the inner side of said bevel extends an upwardly opening groov I2.

Said groove [2 forms a guide for the downwardly directed flange M of a coupling plate l5 whereby a secondary straightedge I6 is attached to the primary straightedge 8 in a slidably adjustable manner, the frictional engagement of said flange [4 with the outer wall of said groove I2 maintaining said secondary straightedge I6 in adjusted positions. The coupling member l5 overlies the flat top of the inner marginal portion of said secondary straightedge and is secured to it by a tongue-and-groove joint ll, like the joints 9 already described. Said straightedge l6 has a vertical inner surface I 8 which slidably abuts the aforesaid vertical edge or surface II of the primary straightedge 8.

A goosenec'k member 22 has a shank 23 attached to an end portion of the secondary straightedge It by means of another tapered demountable slip joint 24. .Said gooseneck member carries a sliding foot 25. Said gooseneck provides an extended clear passage for penciling along the secondary straightedge l6. Said gooseneck carries a third straightedge 26 disposed at a right angle to the straightedge l t, the gooseneck member having a head 21 joined to the third straightedge by means of another conventional demountable joint 28.

At the opposite side of the device the already mentioned foot I is utilized to attach a semicircular protractor plate 30 by means of a pin 3! carrying a milled nut 32, thus mounting the protractor for swingable adjustment.

At each side of said protractor the foot 1 carries at its lower edge an outwardly directed car 33, each of said ears having an index mark 34 leading to its inner edge to cooperate with the indicating markings 3-5 along the margin of the protractor.

In order to provide for moving the device back and forth across the surface of a drafting table in a direction extending at a right angle to the primary straightedge 8, a vertically adjustable wheel or roller shaft 40 is mounted below the bridge 5, a roller 4t having a milled or friction tread being fixedly fastened to each end of said shaft. Near each end of th bridge depends therefrom a bearing member 42 for the end portions of said shaft. Said bridge 5 and its supporting frame tilts upon the shaft 46, as shown in Fig. 2. Over the midlength portion of said shaft the bridge member carries a vertical pin 43 furnished at its lower end with a flattened head 44 through which is a vertically elongated aperture 45 within the width of which the shaft 40 has a free working fit and a Slight vertical play.

Upon the bridge member 5 is mounted a small housing 46 having an apertured top in which is loosely fitted a small cap or closure nut 41 which is adjustably screwed onto the aforesaid pin 43 so that said housing 46 and related shaft adjusting means is disposed at a point about the midlength part of the shaft. Around said pin is loosely coiled a compression spring 48 the upper end of which bears against a washer 49. Said spring, therefore, acts against abutment means carried by said pin. Said pin has around it a groove 50 which cooperates with a keyhole slot 5| in a slidably adjustable plate '52 having at one end an upturned operating flange 53. The housing 46 is shown having inwardly directed foot flanges 54 which receive the upwardly directed attaching screws 55. The slide 52 fits workably between said foot flanges and overlies. an aperture in the bridge as large as the widest part of the keyhole slot. Said slide serves releasably to lock the pin 43 in a depressed position. If it is desired to lower the roller 4| from the full line to the dotted line position of Fig. 2 the cap 41 will be screwed outwardly a little farther on the threaded portion of the pin 43. Also to lock said roller in a still farther depressed position the cap 41 can be depressed sufliciently to bring the pins groove 50 into register with the circular part of the keyhole slot 5| of the slide 52 and then the slide can be manually shifted to bring the narrow part of its slot into engagement with the grooved part of the pin, which is connected with the midlength part of the shaft 40.

The foot flange of the bridge 5 carries not only the protractor 30 but also carries a metal strap 60 fixed to said protractor and shaped as a broad inverted U. In the lower part of each end of this strap is a bearing aperture for a shaft 6| to each end portion of which is fixed a milled wheel 62 to track on the drafting board or its covering, one of these wheels extending through an aperture 63 provided for it in the protractor. Adjacent to the latter wheel the protractor has secured to its lower face a somewhat compressible chafing member 64.

The strap 60 carries at its inner end a laterally expanded foot 65, thus providing at each side an ear to receive a screw 66 to attach the strap to the protractor. The protractor pivot pin 3| has at its lower end a countersunk clamping kerfcarrying head 68, and has a milled nut 32 screwed onto its upper end portion. Between its ears the aforesaid foot 65 has a recess 10 providing a clearance for th aforesaid foot 1, so that the member 60 may be detached after removing the screws 66. The machine may be used either with or without having attached to it the strap 60 and shaft and wheels which it carries.

From Fig. 2 it will be seen that, in regard to the drafting table top surface 1|, the left portion of the machine (carrying the protractor 30) is in engagement with said surface H, but the right hand portion of the machine (carrying the primary and secondary straightedges) clears the surface II of the board. The position of the machine shown in this view results from the operator pressing downwardly upon the shaft-carrying member 60. When the machine is thus tilted the wheels 62 engage the drafting board and enable the operator to move the machine across the board at a right angle to shaft 6|. When, however, the operator presses down down upon the protractor the brake member 64 contacts the board H and holds the protractor stationary allowing the various straightedges to be adjusted as desired and used advantageously in drafting. When the machine is tilted in the opposite dimotion the foot member 25 of the gooseneck member contacts the drafting table and also the rollers 4| track upon the board accurately guiding the movement of the machine along a straight line extending at a right angle to the shaft upon which said rollers are mounted, provided that, at such time the cap 41 and pin 43 are held depressed by the plate 52. The brake afiorded by the head 44 is at times usable to prevent the machine from rolling off from the drafting board. The relieving of the pressure of the rollers 4| upon the drafting board is to provide additional clearance for swiveling or swinging the machine around the protractor. Even when the rollers are in their raised position they may not entirely clear the board, if the board has a yielding covering thereover, so that it is still desirable to use the brake.

When the straightedges l6 and 26 are connected to each other by the gooseneck member as shown in Fig. 6, they should be spaced apart as shown at 12, the proper distance to receive between them the point portion of the draft-sman's pencil.

The secondary straightedge 6 has a. handle l9 attached by screws 20, to slidably operate the flange l4 in the groove l2, and also to lift the straightedge l6 clear of the table surface II independently of the straightedge 8 as shown in broken lines in Fig. 2. Owing to the fact that the end portions of the secondary straight edge "5 are shown extending considerably beyond each end of its coupling member I5, it is evident that said secondary straightedge may be so adjusted as to project beyond the ends of the primary straightedge. When the operator brings the handle I9 down toward the housing 46 (for example to the broken line portion of Fig. 2), there results an equalizing of pressure upon the rollers 4| and a midpositioning of secondary straight edge l6 and of the third straightedge 26 to effect a symmetrical drag about th vertical center line of the machine: thereby causing a tendency for the machine to maintain a true line course of travel. In order to pick up the machine the operator has to bring said housing and handle together. Owing to the guides 42 for the end portions of the shaft 40 having through them vertically elongated apertures through which said shaft passes, said shaft can be lifted, thus bringing its rollers 4| out of contact with the surface of the drafting board, through the action of spring 48, or said shaft can be manually depressed by the already described means to contact said rollers with the board. Said rollers 4|, when in the depressed position, form a fulcrum over which the machine is tiltable so that it occupies one position (shown in Fig. 2) when the pair of rollers 62 contact the board and the other position when said rollers 62 are lifted from the board, the primary straightedge 8 engaging the surface of the drafting board in the latter position of the machine. The protractor 30 may be held fixedly stationary on the surface of the drafting board while the portion of the machine pivoted to it is angularly adjusted about the pivot 31.

I claim:

1. In a drafting machine, a bridge member, a pair of axially alined wheels for drafting board travel, an axle member common to said wheels, mounting means for said axle member including bearing means through which said axle passes and an upwardly projecting pin which passes loosely through said bridge member, a spring carried by said bridge member, means carried by said pin against which said spring abuts to raise said pin and thus lift said axle member normally to maintain said wheels out of contact with said board, means manually to depress said pin to bring said wheels into an operative contact with the board against the opposition of said spring, means to releasably lock said wheels in such contact, a straightedge secured to one side portion of said bridge, and a protractor pivotally attached to its opposite side portion, said protractor comprising a plate engageable in a flatwise manner with the surface of a drafting board and having angle indicating graduations, said bridg member having foot portions in a cooperative relation to said graduations.

2. In a drafting machine, a frame, at least two horizontal straightedges carried by said frame, one of them extending at a right angle to the other, two pairs of axially alined drafting board-engaging wheels carried by said frame, the axis of one of said pairs of whls extending at a right angle to that of the other pair, and means for adjusting at least one of said pairs of wheels to and from operative engagement with the surface of the drafting board.

3. In a drafting machine, a frame, at least two horizontal straightedges carried by said frame, one of them extending at a'right angle to the other, two pairs of axially alined drafting board-engaging wheels carried by said frame. a common shaft to which the wheels of each pair are fixed, and means to vertically adjust at least one of said shafts to adjust therewith the pair of wheels carried by it to and from an operative engagement with the surface of the drafting board, said shaft adjusting means being mounted upon the frame at a point above the midlength part of the shaft with which it is connected.

4. The subject matter of claim 3, and said frame including a bearing member for each end portion of said vertically adjustable shaft, each of said bearing members having through it a vertically elongated slot within the width of which the shaft has a working fit to allow vertical adjustment of the shaft.

5. In a drafting machine, a frame, at least two horizontal straightedges carried by said frame, one of them extending at a predetermined angle to the other, two pairs of axially alined drafting board wheels carried by said frame, the axis of one of said pairs of wheels extending at an angle in relation to that of the other pair, a shaft for each of said pairs of wheels, one wheel being fixedly secured to each end portion of said shafts, bearing means carried by the frame for each end portion of the shafts and allowing a slight vertical movement of such end portions of one of said shafts, a pin connected with the midlength portion of said one shaft and upstanding therefrom, a spring mounted upon the frame tendin to raise said pin, said pin being manually depressible against the opposition of said spring to depress said one shaft with which the pin is connected and thereby cause the wheels carried by said one shaft to engage th surface of the drafting board, and manually operable means carried by the frame releasably to lock said one shaft in its depressed position.

6. In a drafting machine, a frame, two horizontally extending shafts carried by said frame, drafting board wheels fixedly secured axially to end portions of said shafts, said shafts extending at substantially a right angle to each other, said frame being tiltable between two positions in relation to a horizontal drafting board surface when supported thereon, one pair of said wheels operatively engaging said surface in one of said positions and being disengaged therefrom in the other of said positions and the other pair forming a fulcrum for said tilting, pencil guiding means including a straightedge carried by said frame, a horizontal foot carried by said frame, a

. protractor pivoted to said foot to swing horizontally, an antislip foot carried by said protractor, said frame being tiltably supportable as aforesaid to bring said antislip foot into and out of engagement with aforesaid supporting surface, and indicating means carried by the protractor and an adjacent part of the frame to enable the operator to make predetermined angular adjustments of said straightedge in relation to the protractor carried by said frame.

'7. In a drafting machine, a frame, a first and second horizontally extending shaft carried by said frame and extending at substantially a right angle to each other, said second shaft being horizontally spaced away from said first shaft, drafting board wheels fixedly secured axially to the end portions of said shafts, said frame being tiltabl upon said first shaft between two positions in relation to a horizontal drafting board surface when supported thereon, the pair of said wheels on said second shaft operatively engaging said surface in one of said positions and being disengaged therefrom in the other of said positions, and pencil guiding means consisting of a plurality of straightedges carried by said frame and angularly related to each other.

8. The subject matter of claim '7, and means manually to adjust into and out of an operative contact with the surface of the drafting board the pair of wheels which cooperates with the aforesaid pair of wheels which at times are disengaged from the surface of the drafting board.

ARTHUR A. GOERZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,012,340 DuPont Dec. 19, 1911 1,269,324 Shaver June 11, 1918 1,690,645 Lloyd Nov. 6, 1928 1,746,830 Harmon Feb. 11, 1930 FOREIGN PATENTS Number Country Date 58,057 Sweden Dec. 30, 1924

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