US473244A - Blackboard-compasses - Google Patents
Blackboard-compasses Download PDFInfo
- Publication number
- US473244A US473244A US473244DA US473244A US 473244 A US473244 A US 473244A US 473244D A US473244D A US 473244DA US 473244 A US473244 A US 473244A
- Authority
- US
- United States
- Prior art keywords
- compasses
- leg
- blackboard
- tip
- drafting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229920001971 elastomer Polymers 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 210000001847 Jaw Anatomy 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- 239000002023 wood Substances 0.000 description 4
- 239000000899 Gutta-Percha Substances 0.000 description 2
- 229920000588 Gutta-percha Polymers 0.000 description 2
- 240000000342 Palaquium gutta Species 0.000 description 2
- 239000010985 leather Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000006011 modification reaction Methods 0.000 description 2
- 230000002393 scratching Effects 0.000 description 2
- 238000006748 scratching Methods 0.000 description 2
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
- B43L—ARTICLES FOR WRITING OR DRAWING UPON; WRITING OR DRAWING AIDS; ACCESSORIES FOR WRITING OR DRAWING
- B43L9/00—Circular curve-drawing or like instruments
- B43L9/02—Compasses
Definitions
- My invention consists of an improved pair of d rafting-co1npasses more particularlyadapted for use in connection with blackboards in 1o schools and elsewhere.v Y
- Figure l is a side view of my improved Compasses, shown as being used upon a blackboard B or other drawing-surface.
- Fig. 2 is a sectional View
- FIG. 3 is a sectional view of the crayon-holding jaws of the other leg of the Compasses.
- Fig. 4 is a side View, partly @o in section, of a modification; and Fig. is an end view ot' the centering point or tip.
- the two legs A and D may Conveniently be made of wood z5 or other suitable light material and pivoted together by any suitable means at :n
- the leg A has at its outer end the crayon-holdingjaws a a of any suitable construction, or it may be made in any suitable way to carry the desired markingmeans.
- I have shown tapering spring-jaws a a, made by cutting cross-slots Vwith a central longitudinal hole in the wood of the compass-leg, as shown.
- a ring a' threaded on its inner face, may be used, as shown in Fig. 3. I do not, however, restrict myself to any special construction of vthis part of the drafting-Compasses, as it forms no special feature ot' my present invention.
- incr- which will retain the position of the com- 6o pass-leg on the blackboard without scratching or making indentations;
- This tip may be made of different shapes; but Iprefer that shown in Fig. 2 or that shown in Figs. 4 and y 5. In the latter case the tip is made more round than in the one shown in Fig. 2, and is provided with raised cross-ribs r to increase the lateral rigidity and steadiness of the tip.
Description
`(Model.)
H. P. SMITH. BLAGKBOARD GOMPASSES.
Patented Apr. 19, 1892.
W/ TNE SSE S 4 UNITED STATES p PATENT OFFICE.
HEMAN P. SMITH, OF BROOKLYN, NEIV YORK, ASSIGNOR T BENJAMIN I-l. TOQUET, OF WESTPORT, CONNECTICUT.
BLACKBOARD-COMPASSES.
SPECIFICATION forming part of Letters Patent No. 473,244, dated April 19, 1892.
Application led December 2, 1891. Serial No. 413,774. (Model.)
T o all whom t may concern.-
Beit known that I, HEMAN P. SMITH,a citizen of the United States, and a resident of Brooklyn, Kings county, New York, have invented an Improvement in Drafting-Compasses, of
which the following is a specification.
My invention consists of an improved pair of d rafting-co1npasses more particularlyadapted for use in connection with blackboards in 1o schools and elsewhere.v Y
In the accompanying drawings, Figure l is a side view of my improved Compasses, shown as being used upon a blackboard B or other drawing-surface. Fig. 2 is a sectional View,
r 5 drawn to a larger scale, of my improved swiveling or centering end for the supporting-leg VNVof the Compasses. .Fig 3 is a sectional view of the crayon-holding jaws of the other leg of the Compasses. Fig. 4 is a side View, partly @o in section, of a modification; and Fig. is an end view ot' the centering point or tip. When my invention is applied to the manufacture of blackboard-Compasses, the two legs A and D may Conveniently be made of wood z5 or other suitable light material and pivoted together by any suitable means at :n The leg A has at its outer end the crayon-holdingjaws a a of any suitable construction, or it may be made in any suitable way to carry the desired markingmeans. I have shown tapering spring-jaws a a, made by cutting cross-slots Vwith a central longitudinal hole in the wood of the compass-leg, as shown. To compress vthe jaws upon the crayon, a ring a', threaded on its inner face, may be used, as shown in Fig. 3. I do not, however, restrict myself to any special construction of vthis part of the drafting-Compasses, as it forms no special feature ot' my present invention.
4o My invention has special reference to theconstruction of the other leg D of the Compasses, the object being to construct the Compasses so that they maybe used Without making holes in the board and yet without being liableto slip thereon. reduced outer end CZ of the leg D a tube or socket E, which can turn on the leg, or the latter Canturn in the socket. To keep the two together, a headed screw s may be passed through the diaphragm e of the tube into the 5o end of the leg. A point or tip R of rubber or equivalent'material is fitted into the outer end of this tube E, and this forms the center point to bear upon the board B, Fig. 1, and about which the Compasses are turned to draw 5 5 circles and curves of various kinds. The equivalent material which may be used in place of rubber for the tip is any materialsuch as gutta percha, leather, vulcanized liber,
incr-which will retain the position of the com- 6o pass-leg on the blackboard without scratching or making indentations; This tip may be made of different shapes; but Iprefer that shown in Fig. 2 or that shown in Figs. 4 and y 5. In the latter case the tip is made more round than in the one shown in Fig. 2, and is provided with raised cross-ribs r to increase the lateral rigidity and steadiness of the tip.
Although I have described my invention more particularly as applied to blackboard- 7o compasses, it may be used on drafting-compasses for other purposes.
I claim as my invention- A pair of drafting-Compasses having on one leg a tube in which the leg may .turn and which carriesa rubber orequivalent centeringpoint, substantially as described.
In testimony whereof I have signed my name to this specification in the presence o two subscribing witnesses.
HEMAN P. SMITH.
.Vitnesses: l
[JOHN REVELL,
HUBERT HowsoN.
For this purpose I tit freely to the 45v
Publications (1)
Publication Number | Publication Date |
---|---|
US473244A true US473244A (en) | 1892-04-19 |
Family
ID=2542103
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US473244D Expired - Lifetime US473244A (en) | Blackboard-compasses |
Country Status (1)
Country | Link |
---|---|
US (1) | US473244A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5546663A (en) * | 1992-12-03 | 1996-08-20 | Helix Limited | Compass having a squat tip |
-
0
- US US473244D patent/US473244A/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5546663A (en) * | 1992-12-03 | 1996-08-20 | Helix Limited | Compass having a squat tip |
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