US2549403A - T-square and drawing board - Google Patents

Description

April 7, 1951 s. H. WEINBERG, JR 2,549,403

T-SQUARE AND DRAWING BOAR D Filed Oct. 17, 1947 INVENTOR SIDNEY H. WEINBERG,JR.

ATTORNEY Patented Apr. 17, 1951 T-SQUARE AND DRAWING BOARD Sidney H. Weinberg, J r., Baldwin, N. Y., assignor to Bassons Picture Framing 00., Inc., a corporation of New York Application October 17, 1947, Serial No. 780,463

I 4 Claims. (01. 3380) This invention relates to an improved drafting board and T-square construction, and has for one of its objects the provision of an inexpensive, easily manufactured and simplified T-square which is self-aligning and maintains a constant angle with respect to one of the, lateral edges'of the drawing board'for all positions on the board, regardless of irregularities in the opposed lateral edge. I r

Another object of the invention is to provide a rugged and light-weight T-square construction which enables substantially frictionless movement over a drawing board and whose height above the board is adjustable.

A feature of the invention lies in .the use of a carriage on the under side of the T-square and located opposite the T-head, which is provided with a pair of anti-friction rollers of the ball bearing type rigidly mounted in a cross-member permitting a pivotal or swivel-like movement with respect to the straight edge portion of the T- square.

Other objects and features of the invention will become readily apparent from a reading of the following description which is accompanied by a drawing, wherein:

Fig. 1 is a perspective view of the combination T-square and drawing board of the invention:

Fig. 2 is a cross-section of Fig. 1 along the line 2-2; V

Fig. 3 is a bottom view of the T-square;

Fig. 4 is an end view of the T-square taken along the line 4-4 of Fig. 3; and

Fig. 5 is a modification of the carriage support of the T-square which enables adjustment of the height of the straight edge portion relative to the rollers or wheels. 1

In the drawing, wherein like parts are represented by like reference numerals throughout the various figures, there is shown a drawing board In and a T-square 20. The drawing board I0 is provided with a flat rail or track II in theform of a metal strip fastened to one lateral edge, and

another rail or track I 2, in the form of a rod pOsi- I tioned below the top surface of the board In and secured to the opposite lateral edge. The rails or tracks can be fastened to the drawing board in any suitable manner, as for example by meansof screws I3 whose heads are shown countersunk in track ll. 7

The T-square 20 comprises a straight edge or ruler portion 2| which extends. over the top of the drawing board, a head 22 at 'oneend supporting on its under side a pair of grooved wheels 23, 23, and an adjustable andswivable carriage 22 by means of'screws 25. A metallic washer- 26" is positioned between the head 22 and each wheel at the other end including another pair of grooved wheels 24, 24. These wheels are preferably similar in dimensions and of the ball bearing type so as to be substantially frictionless in movement.

The wheels 23, 23 are fastened tethe .T-head 23, as shown.

The wheels 24, 24 are fastened to a crossbar 30 by means of screws 27. The cross bar 30, in turn, is secured at its center to a pin or bolt 3| which projects upward through a slot 32 in the straight edgeportion 2|. The pin 3| serves to support'or suspend the cross-bar 30 and wheels 24, 24 from the straight edge. A metallic washer 33 or Waldes clip prevents the pin or bolt 3| from falling through the slot 32 and is movable with the carriage as an integral unit. The end of the T-square opposite the head 22 is provided with a downward extension 35 having a hole or aperture 36 through which one end of a bolt or pin 3! extends- The opposite end of the pin 3'! .is fastened, as by riveting or by threaded engagement, to the center of the cross bar 30;. A spring 38 surrounds the pin 31 and acts between the downward extension 35 and the cross bar.3ll to exertpressure in such direction as .to force the carriage comprising wheels 24, 24 and crossbar '30 against the rail or track I2. The cross bar {'30 which supportsthe wheels 24, 24, is integrally united with the pin 31 so that any pivotal move-' ment of the cross bar 30 will be transmitted as'a pivotal .movement to the win v31.

a swiveling or, pivoting movement of the pinw3l. In the operation of the invention, theT-square responds to the slightest touch of the fingersjfor movement over the drafting board. The ball bearing wheels 23 and 24 are frictionless and glide over the tracks I] and I2. The angle between the straight edge of the T-squareand the track H is maintained constant throughout the entire length of thetrack II regardless of i1',-,

It should be I noted that hole 36 is sufiiciently large to permit 3 away from the T-head will compress the spring 38 and move the wheels 24 and cross bar 30 toward the downward extension 35, thus releasing the carriage from rail l2 and enabling the T- square to be lifted from the drawing board.

Fig. 5 shows an arrangement for enabling adjustment of the height of the straight edge portion of the T-square above the face or top surface of the drafting board. For this purpose, each of the grooved wheels 23 and 24 on both carriages is supplied with a fastening screw 25 which threadedly engages its supporting member 22 or 30. The end of the rotatable screw 25 furthest removed from the wheel is provided with a knurled edge for finger adjustment. A pair of lock-nuts 49 on opposite sides of the supporting member 22 or threadedly engage the screw 25 for locking the screw in any desired adjustment. It should be understood that the two wheels on each carriage are always similarly positioned relative to the straight edge for all adjustments of the screw 25', although there may be slight differences in adjustments of the wheels of one carriage relative to the wheels of the other carriage. The raising of the T-square I Over its entire length permits it to ride free 7 of the paper on the board, thus preventing possible smudging of pencil lines on the paper.

In one embodiment of the invention constructed and successfully used, the T-head 22, straight edge portion 2! and crossbar 30 were made of aluminum, resulting in an extremely light weight and rugged T-square which moved with a minimum of friction over the face of the drawing board.

It will be understood of course that various modifications may be made in the details of the invention without departing from the spirit and scope of the appended claims, and that the drawing is given by way of illustration and not .by way of limitation. As an example, the shape and form of the tracks and the grooves in the wheels may be changed, and equivalent constructions may be used for the height adjusting mechanism of Fig. 5.

I claim:

1. In combination, a drawing board having metal tracks on oppositely disposed lateral edges, a T-square having a head supporting roller for association with one of saidtracks, and a straight edge portion supporting a carriage for association with the other of said tracks, said last carriage being on the under side of said straight edge and comprising a pair of spaced wheels and a cross member connected between and supporting said wheels, a pin fastened to the center of said cross member and projecting upward through a longitudinally running slot in said straight edge portion, a downward projection integral with said'straight edge portion located near said carriage, another pin arranged at right angles to said first pin and extending along the longitudinal axis of the straight edge portion of said T-square, said other pin being fastened to the center of said cross member and projecting through a hole in said downward projection, said hole being appreciably larger than said last pin to enable free pivotal movement of said carriage in said hole, and a tension spring surrounding said last pin and acting between said downward projection and said cross member for exerting pressure against said carriage in a direction toward said drawing board.

2. In combination, a drawing board having metal tracks on oppositely disposed lateral edges,

a T-square having a head supporting rollers for association with one of said tracks, and a straight edge portion supporting a carriage for association with the other of said tracks, said last carriage being on the under side of said straight edge and comprising a pair of spaced wheels and a cross member connected between and supporting said wheels, a pin fastened to the center of said cross member and projecting upward through a longitudinally running slot in said straight edge portion, a downward projection integral with said straight edge portion located near said carriage, another pin arranged at right angles to said first pin and extending along th longitudinal axis of the straight edge portion of said T-square, said other pin being fastened to the center of said cross member and projecting through a hole in said downward projection, said hole being appreciably larger than said last pin to enable free pivotal movement of said carriage in said hole, a tension spring surrounding said last pin and acting between said downward projection and said cross member for exerting pressure against said carriage in a direction toward said drawing board, and means for adjusting the spacing of the wheels of said carriages relative to said straight edge portion, whereby. said portion can be raised above said drawing board.

3. A T-square supporting a carriage near the end thereof removed from the T-head and on the under side of the straight edge portion, said carriage comprising a pair of spaced wheels and a cross bar fastened to said wheels, also on the under side of the straight edge portion, a pin fastened to the center of said cross bar and projecting upward through a longitudinal slot in said straight edge portion, a downward projection integral with said straight edge portion farther removed from said T-head than said wheels, another pin arranged at right angles to said first pin and extending along the longitudinal axis of the straight edge portion of said T-square, said other pin being fastened to the center of said crossmember and projecting through a hole in said downward projection, said hole being appreciably larger than said last pin to enable free pivotal movement of said carriage, and a tension spring surrounding said last pin and acting between said downward projection and said cross member for exerting pressure against said carriage in a direction toward said drawing board.

4. A carriage supported on a T-square and comprising a plurality of spaced Wheels and a cross bar connected between and supporting said whee1s,a pin fastened to the top of said cross bar at the center thereof and projecting upward through a longitudinal slot in said T-square, a Washer holding said pin in position in said slot, whereby said carriage i supported by said pin, a downward projection integral with said T-square, another pin arranged at right angles to said first pin and extending along the longitudinal axis of the straight edg portion of said Tsquare, said other pin being fastened to the side of said cross bar at the center thereof and projecting through a hole in said downward projection, said hole being appreciably larger than saidlast pin to enable pivotal movement of said carriage, and a tension spring surrounding said last pin and acting between said downward projection and said cross member for exerting pressure against said carriage in a direction toward said drawing board;

SIDNEY H. WEINBERG, JR.

'(References onfollowing page) REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 429,586 Sajous June 3, 1890 975,956 Iwanami Nov. 15, 1910 Carlson Apr. 9, 1918 Number Number

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