US2511654A - Ball-bearing clamp to hold straightedge on a drafting board - Google Patents

Description

June 13, 1950 2,511,654

D. D. SPOOR BALL BEARING CLAMP TO HOLD STRAIGHT EDGES 0N DRAFTING BOARDS Filed Dec. 13, 1946 v f4 fg 9 f6 Inventor Un/ E l?. POOR ara/away Patented June 13,. 1950 BALL-BEARING CLAMP 'ro HOLD STRAIGHTEDGE oN A DRAFTING BOARD Dale D. Spoor, Kalamazoo, Mich.

Application December 13, 1946, Serial No. 716,020

2 claims. 1

The present invention relates to improvements lin ways and means expressly constructed and adapted to accommodate and shiftably mount a straight edge on a drafting table, drawing board or the like, it being the primary object of the invention to structurally, functionally and otherwise improve upon known types of clamps in this field of invention.

Another object of the invention has to do with novel straight edge clamps and means for mechanically and slidably mounting the same on a drawing board, this in a manner to adjustably situate the straight edge in proper operative relation to the drawing surface of said board whether the latter be in a horizontal, vertical or intermediate drafting position.

A further object of the invention resides in the provision of a structural adaptation which lends itself particularly applicable and commercially satisfactory and efficiently adaptable to requirements of the trade and the user under virtually all conditions and circumstances.

A still further object of the invention, generally speaking, is to improve upon and reduce the number of elements and parts which enter into the complete combination, thereby not only increasing resultfulness and the efliciency of the structure as a whole, but also rendering same less costly to manufacture, and to otherwise simplify factors of assembling, sale and reliable usage.

In addition to the above and considered from a structural and functional point of view, an added object of the invention is to provide simple grooved bars, these beingattached securely to transverse end portions of the drawing board, the same serving as tracks, and further providing effective devices to accommodate special slide brackets, the brackets functioning as carriages on which the end portions of the straight edge are detachably and adjustably mounted. y

Other objects, features .and advantages will become more readily apparent from the various views of the accompanying sheet of drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout same:

Figure 1 is a fragmentary view illustrating a corner portion of a drafting or drawing board, parts being in section and elevation, said view showing one of the clamps and complemental features thereof.

Figure 2 is an end elevation with portions broken away and shown in section and other parts removed, of Figure 1, observing the latter in a direction from right to left.

Figure 3 is a top plan view of the structure shown in Figure 1.

Figure 4 is a reduced view showing a drafting table, this provided with the invention herein under advisement.

Figure 5 is a fragmentary end elevation of the structure seen in Figure 1 with certain parts removed.

Figure 6 is a perspective of a clip forming a part of the track means.

Reference being had first to the complete illustration in Figure 4, we observe an ordinary type of drafting table, same including a stand or base A and a tiltable top, such as will hereinafter be referred to either as a drafting or drawing board B. The straight edge is denoted by the numeral 8 and is of a length greater than the length of the board B, the end portions thereof being provided with centralized attaching and adjusting slots 9. Both ends of the straight edge are slotted and adjustably and slidably mounted on the drawing board. In this connection, andinasmuch as the structure at each end of the board is the same, a description of the structure at one one end will suffice for both.

In carrying out the specific principles of the invention a bar I0, substantially rectangular in cross sectionaliform, and of a length corresponding to the width of a drawing board is provided. As shown in Figure l said bar I0- is secured, by screws or equivalent fastening means Il, to the coacting end portion of the board. It is preferably positioned so that the bottom surface thereof is substantially iiush with the corresponding bottom surface of said board. The top and bottom surfaces of said bar have shallow longitudinal grooves I2 and I3 respectively and these serve as track ways. Thus, the grooved bar functions as a simple track and lends itself admirably Well adapted to a simple and expedient Slide bracket I4. Said bracket It comprises a channel-shaped portion I5 which functions as a shoe and which is mounted upon and shiftable along said track. The particular manner in which the shoe is saddled upon the track is brought out in Figures 1 and 2 and in reference to Figure 1 it will be seen that the upper and lower flanges of said shoe are provided with holes I6 and I1 properly seated to accommodate anti-friction balls I8 and I9. The web portion of the shoe is provided with appropriate set-screw 20 which serves, whenever necessary or desired, to bind and fasten the shoe in a predetermined as well as an established position. In this connection it is well to point out that by making the parts under precision dimensions, sucient retentive action may be attained between the shoe and track to cause the shoe to remain relatively stationary when placed in a set position and without necessarily having to tighten the set-screw 20. The upper portion of the bracket or shoe is of general L-shaped form as at 2l and the horizontal or upper limb of this is provided with an upstanding screw-threaded stud 22. The inner end portion of the stud is formed with a substantially rectangular block-like guide and assembling element 23 which serves to snugly accommodate the coacting slot 9.

The numeral 24 designates a washer surrounding the stud, 25 a coiled spring, and 26 a knurled nut on the stud which serves to properly tension and regulate the spring. It is thus thatthe slotted end of the straight edge is detachably and adjustably assembled.

Reference being had now to Figure 2, the nu- Ameral ,2l designates .a cleat/or clip.=which is .-secured by a fastening 28 to oneend .ofthe Abar yin a manner tofclosethe adjacent lopen endsof -the trackway grooves. Theopposite ends Vof .said grooves are closed in at the time of manufacture.

l -It :will be evident thateby slidably bracketing ,the-eend :portions of va straight edge .to the .transverse ends of a drawing board and saddlingJ-the brackets over simple gtrack bars, -a structural adaptation is thus provided 4whereby thevstraight vedge is `constantly Yon the board .and .is AeverV in readiness V`for useV .when needed and for placement at an out-of--the-way position when A,not needed. The use of. ball bearing brackets, and :tracking supporting-.means provides what Yis believed to .bean exclusive and ideal Ameansaccoinplishing the ends desired.

.low the top .of said board, a.- one-.piece longitudinally shiftableadaptor Vbracketincludinga chan.- nel-.shaped .portion .constituting ashes, said shoe partially encasing, -.tting.ovenand boingslidable .back .and forth on said bar, saidshoeembodyng top and .bottom Vflanges provided with freely rollable ball hearings, `the topand bottom surfaces of .said bar ,beingprovided .with `open-,ended channels vproviding trackways for `said ,ball bearings,

Ythe latter Vbeingseated in said tramways. Ysaid brackets including an YI -shaped upstanding por- `tion having its Vh orizoiital limb parallel to and ,above the `top flange of theshoe and located on a plane substantially ush with the top surface of said board and equipped with an upstanding screw-threaded stud carrying a nut to accommodate, if desired, a member which may be slidably mounted for shiftable movement on said board, and end cleats removably mounted on the opposite end portions of said bar and closing the open ends of the respective channels.

2. An anti-friction slide structure of the class shown and described comprising a board having a flat top susceptible of use, as desired, as a drafting board, a bar detachably screwed to one marginal .edge portion of said board, said bar being substantially rectangular in cross section, the top and bottom surfaces of said bar having openended channels providing trackways for freely rollable ball bearings, the bottom surface of said bar being flush with the bottom of the board and the top of said bar being on a plane below the top surface v,of ,saidv .board,a ,onepiece .longitudinally shiftableadaptor .bracket includinga channelshaped .portion vhaving top and bottom anges A.and .a bightconnecting said flanges, saidchannel-shaped portion, L Jartially encasing and vfitting Overandbeing slidable baokandforth on said bar .and `oonstifailtins .an antifriction slide, .anti-friction balls mounted for free rotation 4in the top ,andv bottom .danses and situated .mand rollable back .and .forth .in .Said trackways, said bracket .including aninverted .lfshaped portion 'having yhorizontal and vertical llirrhibstlae horizontal limb beingin .spaced .parallelism above .the top danse .of Saidboe- .and being 'in aplane .substantially flush with ythe .dat top of .Said board-and orovided with an upstanding screw-.threaded stud, an assembling and retaining nut carried by said stud, a Set screw carried by .Said bight and .re-

4leasably engageable with a coacting. surface of said bar, vand a pair ,of end cleats removably Amounted on vthe oppositeend portions of said bar and having their respective end portions lined up with y,and closing the .end portions .of said channels DALE D. SPOOR.

' REFERENCES CITED T .he following references lare vof record in .the le .of .tbispatentt UNITED STATES PATENTS Number Name Date 429,586 Sajous June 3, 1890 1,045,523 Cossey Nov. 26, 1912 1,183,977 Hoee May 23, 1916 1,4&3,998 Meltzer Feb. 6, 1923 1,5 84-,839 Cameron May 18, 1926 115095379 Morris Dec. 7, 1926 2,370,861 Jakeway Mar. 6, 1945 YVllOREIGrN PATENTS Number Country Date A531,850 YGermany Aug. 31,1931

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