US2543664A - Drafting assembly or kit - Google Patents

Description

E. H. MAY

DRAFTING ASSEMBLY OR KIT Feb. 27, 1951 Filed Feb. 9, 1948 JNVENTOR.

M N ilxllllllllllll|\l| llllllllllll l1 Ulnar \wm NM MN k mm 0 vNi Ev QM w llll nfi W M M w m T T A Patented Feb. 27, 1951 DRAFTING ASSEMBLY OR KIT Ellwood H. May, Rockford, Ill., assignor to EngineeringManufacturing 00., Sheboygan, Wis., a corporation of Wisconsin Application February 9, 1948, Serial No. 7,150

This invention relates to a drafting assembly or kit comprising a drafting board and an associated T square mounted thereon. An object of the invention is to provide an assembly of the above character with novel means for retaining the draf ting board and the T square in an assembled relation so as to prevent accidental loss of the T square while at the same time permitting theT square to slide relative to the board as required by a user. f b r Another objectof the inventionis the provision in an assembly of the above character having novel clamping means acting between the head of the T square andtheboard f or frictionally securing the T square in a desired adjusted position on the board. I I

Another object of the invention is to provide an b rof h sh re. ch r t w ich. i simple in construction-and which is relatively inexpensive to manufacture. H

Another object of the invention isto provide a drafting board and T square assembly; of the above character which can be made in relatively small sizes for students and the like so that it is readily portable, which is always ready for use, and in which the board and T square are, held together as a unit so thatgit can be carriecl be tween classrooms or the like and theuser does not have to worry about the traight edge becoming displaced fromthe board. y

Other objects and advantagesoi the invention will become apparent from thefollowingdetailed description taken in connection with the accompanying drawings, in which V,

Figure 1 is a bottom .plan view ofa drafting board and T square assembly embodying the in.- vention, and d g A Fig. 2 is a side elevationalview of the above assembly. I

Referring now to the drawings. the invention is shown embodied ina portable drafting board and T square assembly or unit. In general, the latter comprises a drafting board Ii! with a- T square ll having'astraig h't edge blade I 2, extend:- ing across a fro'ntl3 of the boardill and movable relative to the board as required by the user, At one end the blade l2.is attached to ahead I4 slidably engaging aside edge 1 6 of the board and arranged to frictionally engage the board .to maintain theblade l2 in' any desired position on' the front of the board..- l). d f 1 j As shown inFig'ure, 1' the, drafting board H] is: rectangular in shape and comprises spaced sub stantially"straighil ip'arallel "side-edges" I and I II 3 Claims. (01. 33-80) I board may be formed from any suitable material.

For purposes of illustration the board is shown in this instance as being formed from wood. The front [3 of the board is preferably formed with a smooth surface for the reception of drawing paper or the like.

Provision is made for securing the T square II in an assembled relation with the board ID in a manner which prevents accidental removal of the Tsquare from theboard yet permits free movement of the blade l2 between the top edge 18 and the bottom edge [9 of the board. For this purpose suitable clips 20 and 2| associated with opposite ends of the T square ll and engageable with aback [5- (see Fig. 2) of the board H] are utilized. As shown in Fig. 2 the clip 20, connected to the end of the straight edge I2 away from the head I4, comprises a- U-shaped member having spaced legs 22 and 23 connected together by a bridging member 24. The leg 22 is rigidly secured to the side of the blade away from engagement with the paper receiving surface l3 as by a rivet 26 and the leg 23 is shaped to be received, in a rabbet 21, the purpose of which will presently appear, formed along the side edge I! of the board and opening on tothe side edge H and back [5 respectively. Th bridging portion 24 spaces the portions 22 and 23 apart a distance corresponding to the combined thickness of the blade I2 and the thickness of ,the board in at its side edge l7. Preferably the legs 22 and23 are spaced so that there is a small clearance between the clip 20 and the edge of the board.

The clip 2i as contemplated in this embodiment of the invention is formed by a plate 25 secured .to the side of the head [4 away from the blade l2 and shaped to be received in a rabbet 23, formed along the side edge 16 of the board In and opening on tothe side edge I6 and back [5 respectively. The thickness of the head It is substantially equal to the thickness of the board measured along the side edge l6 so that the plate 25 flush with the back of the head is readily receivable in the rabbet.

An important feature of this drafting board and T square assembly is the provision wherein the T square may be readily clamped in any desired position so that the blade I2 on the front l3 of the board 10 can be located as required with respect to the drawingpaper. In this embodiment of the invention this is effected by a movable clamp 29 mounted on the head M of the T square l liand shaped to beengageable with a shoulder 3|. spaced from the side edge 15 of theboard against which the head 14 abuts and a spring-32 3 disposed between the movable clamp 29 and the head I4 urging the head into engagement with the side edge I6 and the clamp into engagement with the shoulder 3I. The movable clamp 29 as shown in Figures 1 and 2 is formed in part by the plate 25 which is mounted on the head M for relative movement and an upstanding flange 32 integral with the plate 25 and shaped to abut the shoulder 3|. As best shown in Fig. 2 the shoulder 3| is formed by one Side of a groove 33 formed inwardly from the side edge I6 on the back I of the board I I] and intersecting the rabbet 28. To permit relative movement of the clamp 29 with respect to the head I4, the plate 25 is formed with spaced elongated slots 34' through which screws 36 extend for loosely retaining the plate 25 in position on the head I4. Washers 31 may. be disposed between the head I4 and the platev 25 to minimize friction between the respective parts.

While the spring 32 may take many different shapes and many suitable means may be employed for mounting the spring, as shown herein, the spring 32 comprises a U-shaped member disposed between the plate 25 and the head I4 to effect a clamping action of the flange 32 against the shoulder 3I and the head I4 against the side edge I6. Thus, one end 38 of the spring is anchored under a tab 39 formed from the plate 25 and the other and M of the spring is received in an opening42 in a post 43 rigid with the head I4. The post 43 projects through an elongated slot 44 formed in the plate 25 and disposed between the spaced slots 34-.

As shown in this embodiment of the invention, the back I5 of the board In is formed with rabbets 2! and 28 adjacent the side edges I6 and I respectively. This construction permits a central portion 46 of the board In as seen in- Fig. 2 to rest on the fiat surface and the lower portions of the clips and 2 I are raised sufiiciently from the flat surface to permit free movement of the T square II on the board I0.

Means for limiting the movement of the T square II relative to the top edge I8 and bottom edge I9 of the board I0 is provided for preventing the accidental removal of the T square II from. the: board I0. As shown in Figure-1' stops in the form of pins 41 are positioned at each end of the rabbets 21 and 28 respectively. Thus, when. the blade I2 is moved to the top edge I8 of theboard the clips 20 and 2I engage the respective pins 41 and prevent removal of the T square I I from the drafting board II]. In a similar manner the stops 41 at the bottom edge I9 of the. board also prevent removal of the blade I2 when the latter is moved to the bottom of the drafting board.

I claim:

1. In a portable drafting board and T square assembly, the combination of: a drafting board having first and second side edges in spaced substantially parallel relation, the opposed faces of the board being plane and forming a front working surface and a plane back, said board having a rabbet of substantial depth along the first side edge opening on to the back and first side edge of the board, said rabbet including a cut of greater depth than the balance of the rabbet located to form a shoulder spaced inwardly from and parallel to the first side edge of the board, a T square comprising a head portion of substantially lesser thickness than the board having an edge shaped to abut against the first side edge of said board, and a straight edge extending across and in contact with the front surface of the board having one end rigidly attached to said head and the opposite end extending to the second side edge of the board, a plate attached to the back of the head comprising a first portion shaped to extend into said rabbet from the first edge of the board and a second portion in side by side relation with the back of said head and having an elongated slot, means engageable; with said second portion and extending through said slot for retaining said plate in an assembled relation with said head, a flange integral with said plate and; engageable with said shoulder, and a compression spring acting between said plate and said head: for releasably urging the edge of the head into Clamping engagement with the first edge of the board and said flange into clamping engagement with; the shoulder, said plate, said means, Said flange and said spring being shaped and positioned wholly between planes defined by the front and back surfaces of said board.

2. In a portable drafting board and T square assembly, the combination of, a drafting board having first and second side edges in spaced substantially parallel relation, the opposed faces of the board being plane and forming a front working surface and a plane back, said board being provided with rabbets of substantial depth along the first and second side edges'opening on to the back and side edges of the board, said rabbet along the first side edge including a cut of greater depth than the balance of the rabbet located to form a shoulder spaced inwardly from and parallel to the first side edge of the board, a T' square comprising a head portion of substantially lesser thickness than the board having an edge shaped to abut against the first side edge of said board, and a straight edge extending across the front surface of the board having one end rigidly attached to said head and the opposite end extending to the second side edge of the board, a clip comprising spaced legs, means for securing one of said legs rigidly to said opposite end of said straight edge against the front side thereof; the other legs extending intothe rabbet along the second side edge from the edge of the board forwardly of the plane defined by the back of the board, a plate attached to the back of the head with respect thereto, said plate having a portion shaped to extend into said first rabbet from the first edge of the board and a second portion in side by side closely spaced relation with the backof said head, said second portion having aplurality of spaced slots, spaced headed members extending through two of said slots for supporting said plate on said head for movement with respect thereto, a post rigid with said head and extending through a slot disposed between said headed members, a flange integral with said plate engageable with said shoulder, and a compression spring disposed between said post and said plate for-releasably urging the head into engagement with the first edge of the board and said flange into engagement with the shoulder, said plate, saidheaded members, said post, said flange and said spring being shaped and positioned wholly between planes defined by the front and back. surfaces of saidboard.

3. In a portable drafting board and T square assembly, the combination of, a drafting board having first and second side edges in spaced substantially parallel relation, the opposed faces of the board being plane and forming a front working surface and a plane back, said board being provided with rabbets, of substantial depth along the first and second side edges opening on to the back and side edges of the board, said rabbet along the first side edge including a cut of greater depth than the balance of the rabbet located to form a shoulder spaced inwardly from and parallel to the first side edge of the board, a T square comprising a head portion of substantially lesser thickness than the board having an edge shaped to abut against the first side edge of said board, and a straight edge extending across the front surface of the board having one end rigidly attached to said head and the opposite end eX- tending to the second side edge of the board, a clip comprising spaced legs, means for securing one of said legs rigidly to said opposite end of said straight edge against the front side thereof, the other legs extending into the rabbet along the second side edge from the edge of the board forwardly of the plane defined by theback of the board, a plate attached to the back of the head with respect thereto, said plate having a portion shaped to extend into said first rabbet from the first edge of the board and a second portion in side by side closely spaced relation with the back of said head, said second portion having a plurality of spaced slots, spaced headed members extending through two of said slots for supporting said plate on said head for move ment with respect thereto, a post rigid with said head and extending through a slot disposed between said headed members, a flange integral with said plate engageable with said shoulder,

stops disposed in said rabbets adjacent each.

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

UNITED STATES PATENTS Number Name Date 571,252 Walkinshaw Nov. 10, 1896 611,697 Lundy Oct. 4, 1898 1,020,253 Blair Mar. 12, 1912 1,389,904 Rudolph Sept. 6, 1921 2,332,967 Fatkin Oct. 26, 1943 FOREIGN PATENTS Number Country Date 213,098 Germany Sept. 8, 1909 274,947 Germany June 3, 1914

Images