US524160A - Compasses - Google Patents

Description

of which the following is a specification;

`UNITED STATns PATENT OFFICE.

MILTON BRADLEY, OF SPRINGFIELD, MASSACHUSETTS.`

COMPASSES.V

SPECIFICATION forming part of Letters Patent No. 524,160, dated August 7, 1894.

. Application filed April 11, 1894.

To alwhom tm/ty concern.-

Be it known that I, MILTON BRADLEY, a

siding at Springfield, in the county o'f Hampden and State of Massachusetts, haveinvented new and useful Improvements in Compasses,

This invention relates to compasses for the j e use of draftsmen and students, the object be- .e IS

ing to improve the construction of such instruments in respect to the leg-joint thereof, to means on one of the-legs for holding and Operating a pencil and to means for `uniting a steel point to the other leg, all as hereinafter fully set forth.

In the drawings forming part of this speciication, Figure l isa perspective view of a pair of Compasses Vembodying my improvements, a pencil being there shown connected to one of the legs thereof. Fig. 2 illustrates,

. vin perspective views, the handle and the jointpin and `nut of the instrument, and the spanner for turning said nut. Figs. 3 and 4 are perspective views of the'upper ends of the two legs ofthe compasses, illustrating the joint formation of each leg. Fig. 5`is a longitudinal section of the lower end of the peni cil-carrying leg. Fig. `6 is a side view of the e lower end of said last named leg, showing the V3,0

front side of the pencil tube broken away at Yits lower extremity. Fig. 7 is an end view of l the pencil-tube and a cross sectional view of the leg'thereto connected. Figs. 8 and 9 are y sectional views about on line 9 9, Fig. 1, of 35 the point-bearing leg, illustrating the` manner of securing the point rigidly in the leg.

In the drawings, 2 indicates the point-bearing leg, and Sthe pencil-bearing leg of the instrument. The 4joint-parts of said legs are constructed as follows: 0n the upperl end of one leg, 2, for instance, is a circular, platelike formation, a, havingthe kcentral bolthole, b, and the concentric vupstanding ring, c, on the inner side of said plate, located about-'midway between the border and the center of the latter. On the upper end of the opposite leg of the instrument, 3, is a similar circular plate, cl, having` also a central bolt-hole, e, corresponding to said hole, b, of the leg, 2, and having a concentric circular groove, f, in its inner face of such width, diameter, and depth, as adapts it to receive sition.

Serial No. 507,087. `(No model.)

. therein the said projecting ring, c, of the leg, 'i

ring and said groove are brought into j uxtapo- The said ring, c, and groove, f, are formed with most-carefully adjusted tools, to the end that the ring shall f it perfectly into the groove, thus bringing the said inner surfaces of the plates, a and d, so that they bear one against the other, and, together with the said interengagement of the ring, c and the groove,

f, constitute such a wide bearing for the joint parts of the compass legs that great durability of the joint is secured, and there y,is no tendency to looseness and consequent inadvertent displacement `of the `legs when adjusted to certain relative positions of spread', and whilebeing used.

. The handle, K, of the instrumen-t consists. y

of a metallic tube, 4., to which` are secured two metal disks, 5, each havinga laterally extending arm, 6, on its border which enters and is secured to the inner surfaceof 4the' tube, K, by solderingor other vsuitable means. The said disks are perforated to correspond with said bolt-holes, b and e, of the joint parts i -of the compasses As shown in Fig. 1, the head (or united joint parts) of `the instrument is claspedbetween said disks, 5,and a joint-bolt, 7,'.Whose diameter is less than that of said bolt-holes,

8. Said bolt, 7,'is made to fit loosely in said bolt-holes so that it may act together with Y said nut, simply to prevent any separation of" the surfaces of said joint-parts onwhich are the said interlocking ring, c, and groove, f;

and so that said bolt shall not exercise any 1 function of an ordinary j oint-pivot, and thereby prove an obstacle to the proper free coac-A tion of said grooves of the joint.

and ring-bearing parts g The legs, 2 and 3,'of the compass'es areprefj,

erably made of brass, or similar easy-working metal, and to provide a suitable hard and t durable point on the free end of one of "the legs,`which shall serve the usual and well known purpose, a pointed steel rod, 9, is rig- Ico idly ixed in said leg in the following manner: Said leg, from its lower end upwardly, has a groove, 10, formed therein of suitable length,'and in said Vgroove said rod, 9, is

placed, and the borders, x, of said groove are then pressed, or swaged,over, and rigidly upon said rod, thereby permanently fixing it to said leg, as shown in Fig. 1.

To provide means for holding a pencil, 71,

`'on one leg of the compasses, and means for accurately advancing said pencil in the dij rection of its length, as its point is Worn, or

Vthe surface of the pencil. Said dog is pro-l cut away by sharpening it, a split metallic tube, l2, is soldered, or otherwise suitably xed, to said leg, as shown, which slightly expands when the pencil is put into it, and o n said tube, preferably at the lower end thereof,

is xed, or bent therefrom, a dog, 13, havingl an edge thereon suitable for engaging with A short split tube, J, is fixed on said leg, 3, a j

little above said tube, 12, to aid in holding the pencil which passes th rough it more steady While it is turned to feed it forward and back. The said dog, 13, holds the pencil positively against slipping in the tube, 12, and the angularly arranged dog ou the latter provides for very finely graduating the movement of the pencil. In practice it is found that said screw-feed movement of the pencil through the tube results in marking the latter with spiral convolutions, as shown in Fig. 1.

What I claim as my invention is- 1. A uniting joint for compass legs, consistving of a circular plate on one leg having therein a circular groove concentric With a central bolt-hole through said plate, combined with a like` plate on the opposite leg of the compass having thereon an upstanding ring concentric with the central bolt-hole through said plate and fitting closely Within said groove, a handle having two-perforated disks thereon between which said joint-plates are received, and a joint-bolt passing through said joint-plates and disks and holding the parts through which it passes in juxtaposition, substantially as set forth.

2. A uniting joint for compass legs consisting of a circular plate, d, having the central bolthole, e, and the concentric groove, f, therein, combined with the circular plate, d, of the opposite leg having the central bolthole, b, and the upstanding concentric ring, c, thereon for engagement within said groove, a handle, and a bolt holding said joint-parts in juxtaposition, and said handle thereon, substantially as set forth.

3. Means for holding and operating a pencil on a compass-leg consisting of a split tube rigidly fixed thereto to receive a pencil, having a pencil-engaging dog thereon projecting inwardly and standing at an incline relative to the axial line of said tube, substantially as set forth. v

4. Means for holding and operating a pencil on a compass-legconsisting of a split tube rigidly fixed thereto to receive a pencil, having a pencil-engaging dog thereon projecting inwardly and standing at an incline relative to the axial line of said tube, combined with 'a second split pencil-guiding tube fixed on 5. A uniting joint for compass legs consisttion, and said handle thereon, substantially as set forth.

MILTON BRADLEY.

lVitnesses:

I-I. A. CHAPIN, K. I. CLEMoNs.

Images